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Abstracts

Parkinson's Disease
Updated: 08/26/2004

ABSTRACTS

Cortical atrophy in Parkinson disease: correlation between clinical and CT findings with special emphasis on prefrontal atrophy.

Adam P, Fabre N, Guell A, et al.

AJNR Am J Neuroradiol. 1983 May; 4(3):442-5.

Thirty-seven patients with Parkinson disease were evaluated clinically and with computed tomography in order to determine the incidence of prefrontal atrophy. An age-matched healthy control group was also scanned. The computed tomographic criteria used were the width of cortical sulci and ventriculocerebral indices. Parkinsonian patients with frontal cortical atrophy represent only one patient out of three. They are much older than parkinsonian patients with normal computed tomographic scans, and the onset of their illness occurs later. No significant difference was found according to gender, parkinsonian clinical triad, psychomotor study, or mean duration of illness and/or dopatherapy to the time of computed tomography. This work seems to separate two Parkinson diseases: one beginning before 65 years and damaging the nigrostriate system, and another beginning after 65 years and damaging both the nigrostriate system and the cortex, particularly the frontal cortex

Mercury intoxication simulating amyotrophic lateral sclerosis.

Adams CR, Ziegler DK, Lin JT.

JAMA. 1983 Aug 5; 250(5):642-3.

A 54-year-old man had a syndrome resembling amyotrophic lateral sclerosis after a brief but intense exposure to elemental mercury. The syndrome resolved as his urinary mercury levels fell. Mercury toxicity must be considered not only in individuals with recent anterior horn-cell dysfunction but also with otherwise unexplained peripheral neuropathy, tremor, ataxia, and a gamut of psychiatric symptoms including confusion and depression

Slow allotypic variants of the NAT2 gene and susceptibility to early-onset Parkinson's disease.

Agundez JA, Jimenez-Jimenez FJ, Luengo A, et al.

Neurology. 1998 Dec; 51(6):1587-92.

OBJECTIVE: To determine the frequency and the linkage distribution of seven mutations at the polymorphic gene coding for the arylamine N-acetyl transferase (NAT2; EC 2.3.1.5) in 121 unrelated patients with sporadic PD and in 121 unrelated healthy volunteers. METHODS: The study was performed with mutation-specific PCR using genomic DNA obtained from blood of the probands. RESULTS: Comparison of the NAT2 genotypes of the overall PD patients and control subjects did not indicate statistically significant differences. However, patients with early-onset PD (onset before the age of 50 years, n=37) showed a higher frequency of slow-acetylation genotypes (78.4% patients) compared with both healthy control subjects (55.4%) and with late-onset (onset after 51 years of age, n=84) PD patients (54.8%). Such a difference was statistically significant (p < 0.015) and was the result of a homogeneous increase in the frequency of slow-acetylation alleles. All subgroups analyzed in the study were in Hardy-Weinberg equilibrium for mutations at the NAT2 gene. CONCLUSIONS: Slow-acetylation-mutated alleles may be considered low-penetrance genes in early-onset PD pathogenesis, with a relative risk ratio for individuals with slow-acetylation genotype of 2.92 (95% CI, 1.26 to 6.78). This study provides evidence for the interaction of genetic and environmental factors in the etiology of sporadic PD

ADA Statement on Dental Amalgam.

Anderton RM.

2001;2001 May

Protective effect of melatonin in a chronic experimental model of Parkinson's disease.

Antolin I, Mayo JC, Sainz RM, et al.

Brain Res. 2002 Jul 12; 943(2):163-73.

Parkinson's disease is a chronic condition characterized by cell death of dopaminergic neurons mainly in the substantia nigra. Among the several experimental models used in mice for the study of Parkinson's disease 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine- (MPTP-) induced parkinsonism is perhaps the most commonly used. This neurotoxin has classically been applied acutely or sub-acutely to animals. In this paper we use a chronic experimental model for the study of Parkinson's disease where a low dose (15 mg/kg bw) of MPTP was administered during 35 days to mice to induce nigral cell death in a non-acute way thus emulating the chronic condition of the disease in humans. Free radical damage has been implicated in the origin of this degeneration. We found that the antioxidant melatonin (500 microg/kg bw) prevents cell death as well as the damage induced by chronic administration of MPTP measured as number of nigral cells, tyrosine hydroxylase levels, and several ultra-structural features. Melatonin, which easily passes the blood-brain barrier and lacks of any relevant side-effect, is proposed as a potential therapy agent to prevent the disease and/or its progression

Parieto-occipital glucose hypometabolism in Parkinson's disease with autonomic failure.

Arahata Y, Hirayama M, Ieda T, et al.

J Neurol Sci. 1999 Mar 1; 163(2):119-26.

To investigate the characteristics of regional cerebral metabolism in a subgroup of patients with Parkinson's disease and autonomic failure, we studied seven patients with Parkinson's disease with autonomic failure (PA group), 11 patients with Parkinson's disease without apparent autonomic failure (PD group), and nine normal controls using fluoro-deoxyglucose positron emission tomography (FDG-PET). To determine differences in metabolic distribution among these groups, regional relative glucose metabolic rates (RGMR), which were normalized with cerebellar values, were calculated and age-adjusted covariance analyses were done. When compared with that of controls. RGMR in the cerebral cortex of the PA group was markedly reduced in the occipital cortex (P<0.001), inferior parietal cortex (P<0.005) and superior parietal cortex (P<0.005), but without a decrease in the sensory motor and medial temporal cortices, putamen and thalamus. In contrast, the PD group did not show significant focal hypometabolic distribution. Our findings raise the possibility that Parkinson's disease with autonomic failure may overlap with the features of dementia with Lewy bodies

Epidemiologic correlates of sporadic amyotrophic lateral sclerosis.

Armon C, Kurland LT, Daube JR, et al.

Neurology. 1991 Jul; 41(7):1077-84.

We evaluated 74 selected patients with amyotrophic lateral sclerosis (ALS) and 201 matched controls for risk factors for ALS by a case-control design and a sequential questionnaire/interview technique to quantitate biographic data. We analyzed occupational and recreational data only for 47 male patients and 47 corresponding patient controls; data for women were insufficient. We used nonparametric analyses to evaluate five primary comparisons of ALS patients with controls: (1) more hard physical labor, p not significant (NS); (2) greater frequency of neurodegenerative disease in family members, p NS; (3) greater exposure to lead, p less than 0.05; (4) more years lived in a rural community, p NS; and (5) more trauma or major surgery, p NS. Men with ALS had worked more frequently at blue-collar jobs (although not a statistically significant difference, p = 0.10) and at welding or soldering (p less than 0.01). These results suggest that there may be an association between ALS in men and exposure to lead vapor. The limited nature of the association favors a multifactorial etiologic mechanism of ALS

ToxFAQs™ for Aluminum. CAS 7429-90-5.

ASTDR.

1999;1999 Jun;

The effect of dehydroepiandrosterone sulfate administration to patients with multi-infarct dementia.

Azuma T, Nagai Y, Saito T, et al.

J Neurol Sci. 1999 Jan 1; 162(1):69-73.

We measured cerebrospinal fluid (CSF) levels of dehydroepiandrosterone sulfate (DHEAS) by radioimmunoassay in seven patients with multi-infarct dementia (MID), fourteen age- and gender-matched non-demented patients with a history of cerebral infarction and fifteen age- and gender-matched patients without neurological disorders. The levels of DHEAS in CSF of patients with MID were significantly lower than those in non-demented patients with a history of cerebral infarction or those in patients without neurological disorders. Daily intravenous administration of 200 mg DHEAS for 4 weeks markedly increased serum and CSF levels of DHEAS in seven MID patients, improved decrease of daily activities and emotional disturbances in three patients and EEG abnormalities in two patients. The DHEAS therapy may provide a beneficial effect on MID patients

Transplantation of adrenal medullary tissue to striatum in parkinsonism. First clinical trials.

Backlund EO, Granberg PO, Hamberger B, et al.

J Neurosurg. 1985 Feb; 62(2):169-73.

Autologous adrenal medullary tissue was transplanted to the striatum in two patients with severe parkinsonism. The aim was to provide the striatum with a new cellular source of catecholamines. Some rewarding effects were registered. This is the first time that such tissue has been transplanted in the human brain. The results merit further clinical trials

Association of slow acetylator genotype for N-acetyltransferase 2 with familial Parkinson's disease.

Bandmann O, Vaughan J, Holmans P, et al.

Lancet. 1997 Oct 18; 350(9085):1136-9.

BACKGROUND: Epidemiological studies have identified positive family history and exposure to environmental toxins as risk factors for Parkinson's disease (PD). An inherited defect of xenobiotic metabolism could result in increased susceptibility to such toxins. We investigated the frequency of functionally relevant polymorphisms in six detoxification enzymes among patients with PD to elucidate the relation between these polymorphisms and the disease. METHODS: We obtained brain-tissue samples from 100 patients with apparently sporadic PD and blood samples from 100 living patients with familial PD. For the control group, we extracted DNA from the tissue of 100 pathologically normal brains. The six enzymes analysed in these three groups were: CYP2D6, CYP2E1, NAD(P)H-menadione reductase, glutathione transferases M1 and T1, and N-acetyltransferase 2. We also investigated N-acetyltransferase 2 in 100 blood samples from patients with genetically proven Huntington's disease. We used PCR-based methods and restriction-enzyme analysis to detect polymorphisms. FINDINGS: The slow acetylator genotype for N-acetyltransferase 2 was more common in the familial PD group (69%) than in all controls (37%). Even after correction for multiple comparisons, this result remained highly significant (p = 0.002) for familial PD compared with normal controls (odds ratio 3.79 [95% CI 2.08-6.90]) and compared with Huntington's disease (2.45 [1.37-4.38], p = 0.004). The slow acetylator frequency for N-acetyltransferase 2 for sporadic PD was between that for Huntington's disease and familial PD. The frequencies of all the other polymorphisms were similar in the two study groups and the normal control group. INTERPRETATION: We found an association between the slow acetylator genotype for N-acetyltransferase 2 and familial PD. Further studies are needed to investigate the biological relevance of these findings, but slow acetylation could lead to impaired ability of patients with familial PD to handle neurotoxic substances

Detailed genotyping demonstrates association between the slow acetylator genotype for N-acetyltransferase 2 (NAT2) and familial Parkinson's disease.

Bandmann O, Vaughan JR, Holmans P, et al.

Mov Disord. 2000 Jan; 15(1):30-5.

In a preliminary report we demonstrated an association between the slow acetylator genotype of N-acetyltransferase 2 (NAT2) and familial cases of Parkinson's disease (FPD). Using a considerably more precise NAT2 typing method, which detects all mutant NAT2 alleles with a frequency of >1% in the white population, we have now retyped all the original patients and control subjects to investigate the reliability of our initial findings. The slow acetylator genotype remained considerably more common among FPD (73%) than normal control subjects (NPC, 43%) or the disease (Huntington's disease [HD]) control group (52%) with an odds ratio (OR) of 3.58 (95% confidence interval (CI): 1.96-6.56; p = 0.00003) for FPD versus NPC and an OR of 2.50 (95% CI: 1.37-4.56, p = 0.003) for FPD versus HD. Furthermore, the wild-type allele 4 conferred a protective effect with an OR of 0.39 (95% CI: 0.23-0.64; p = 0.0025) for FPD versus NPC and an OR of 0.50 (95% CI: 0.30-0.85, p = 0.01) for FPD versus HD. The results of this study support an association between the NAT2 slow acetylator genotype and FPD in our population

Case-Control Studies of Liver, Gallbladder and Pancreatic Cancer and Metalworking Fluid Exposure in the Automobile Industry.

Bardin JAEEEWDHKDWSRGRJ.

2000;November 14, 2000;

Coenzyme Q10 attenuates the 1-methyl-4-phenyl-1,2,3,tetrahydropyridine (MPTP) induced loss of striatal dopamine and dopaminergic axons in aged mice.

Beal MF, Matthews RT, Tieleman A, et al.

Brain Res. 1998 Feb 2; 783(1):109-14.

We investigated whether oral administration of coenzyme Q10 (CoQ10) could attenuate 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neurotoxicity in one-year-old mice. Four groups of one-year-old, male C57BL/6 mice received a either standard diet or a diet supplemented with CoQ10 (200 mg/kg/day) for five weeks. After four weeks, one group that had received the standard diet and one group that had received the CoQ10 supplemented diet were treated with MPTP. The four groups continued on their assigned diets for an additional week prior to sacrifice. Striatal dopamine concentrations were reduced in both groups treated with MPTP, but they were significantly higher (37%) in the group treated with CoQ10 and MPTP than in the group treated with MPTP alone. The density of tyrosine hydroxylase immunoreactive (TH-IR) fibers in the caudal striatum was reduced in both MPTP-treated groups, but the density of TH-IR fibers was significantly (62%) greater in the group treated with CoQ10 and MPTP than in the group treated with MPTP alone. Our results indicate that CoQ10 can attenuate the MPTP-induced loss of striatal dopamine and dopaminergic axons in aged mice and suggest that CoQ10 may be useful in the treatment of Parkinson's disease

Mitochondria, NO and neurodegeneration.

Beal MF.

Biochem Soc Symp. 1999; 66:43-54.

A role for mitochondrial dysfunction in neurodegenerative disease is gaining increasing support. Mitochondrial dysfunction may be linked to neurodegenerative diseases through a variety of different pathways, including free-radical generation, impaired calcium buffering and the mitochondrial permeability transition. This can lead to both apoptotic and necrotic cell death. Recent evidence has shown that there is a mitochondrial defect in Friedreich's ataxia, which leads to increased mitochondrial iron content, that appears to be linked to increased free-radical generation. There is evidence that the point mutations in superoxide dismutase which are associated with amyotrophic lateral sclerosis may contribute to mitochondrial dysfunction. There is also evidence for bioenergetic defects in Huntington's disease. Studies of cybrid cell lines have implicated mitochondrial defects in both Parkinson's disease and Alzheimer's disease. If mitochondrial dysfunction plays a role in neurodegenerative diseases then therapeutic strategies such as coenzyme Q10 and creatine may be useful in attempting to slow the disease process

Niacin depletion in Parkinsonian patients treated with L-dopa, benserazide and carbidopa.

Bender DA, Earl CJ, Lees AJ.

Clin Sci (Lond). 1979 Jan; 56(1):89-93.

1. Benserazide and carbidopa, decarboxylase inhibitors used in the treatment of Parkinson's disease, have been shown to inhibit the enzyme kynurenine hydrolase in rat and mouse liver. This results in reduced synthesis of nicotinamide coenzymes from tryptophan, and hence an increased reliance on dietary niacin. 2. Pellagra might be expected as a result of this inhibition of endogenous synthesis of nicotinamide nucleotides, but has not been reported in patients treated with either drug. 3. The urinary excretion of N1-methyl-nicotinamide, a product of nicotinamide nucleotide metabolism, is considerably reduced in patients treated with dopa alone or in combination with an inhibitor of peripheral dopa decarboxylase, to as low as 40% of the control value. This means that many of these patients could be classified as 'at risk' of niacin deficiency, even if not frankly deficient. 4. Patients treated with dopa plus a decarboxylase inhibitor, but not those treated with dopa alone, also show a reduced excretion of xanthurenic acid, and an increased excretion of kynurenine, as would be expected after inhibition of the kynurenine pathway, and possibly indicative of marginal vitamin B6 deficiency

Smoking, alcohol, and coffee consumption preceding Parkinson's disease: a case-control study.

Benedetti MD, Bower JH, Maraganore DM, et al.

Neurology. 2000 Nov 14; 55(9):1350-8.

OBJECTIVE: To study the association of PD with preceding smoking, alcohol, and coffee consumption using a case-control design. METHODS: The authors used the medical records linkage system of the Rochester Epidemiology Project to identify 196 subjects who developed PD in Olmsted County, MN, during the years 1976 to 1995. Each incident case was matched by age (+/-1 year) and sex to a general population control subject. The authors reviewed the complete medical records of cases and control subjects to abstract exposure information. RESULTS: For coffee consumption, the authors found an OR of 0.35 (95% CI = 0.16 to 0.78, p = 0.01), a dose-effect trend (p = 0.003), and a later age at PD onset in cases who drank coffee compared with those who never did (median 72 versus 64 years; p = 0.0002). The inverse association with coffee remained significant after adjustment for education, smoking, and alcohol drinking and was restricted to PD cases with onset at age <72 years and to men. The OR for cigarette smoking was 0.69 (95% CI = "0.45" to 1.08, p = "0.1)." The authors found no association between PD and alcohol consumption. Extreme or unusual behaviors such as tobacco chewing or snuff use and a diagnosis of alcoholism were significantly more common in control subjects than cases. CONCLUSIONS: These findings suggest an inverse association between coffee drinking and PD; however, this association does not imply that coffee has a direct protective effect against PD. Alternative explanations for the association should be considered

[Microbial ecology of the colon].

Bergogne-Berezin E.

Ann Gastroenterol Hepatol (Paris). 1985 Dec; 21(6):383-8.

It has been known for a long time that the human gastrointestinal tract contains 10(14) micro-organisms, which are predominantly anaerobic. Recent research has provided a better understanding of the functions and the equilibrium of the intestinal ecosystem in which the intestinal mucosa and the microbial flora which it supports interact. Any modification in one or other of the constituents of this ecosystem is likely to disturb the normal ecological equilibrium, resulting in a variety of gastro-intestinal diseases. Today, the intestinal ecosystem can be considered to be a system of defence and equilibrium or, conversely, as a reservoir of infection, which is confirmed by the study of certain faecal bacterial profiles with a high risk of infection. In gastrointestinal surgery and paediatrics, the correlation between antibiotic therapy, intestinal microbial proliferation and the development of septicaemia confers a fundamental role of the defence barriers of the gastrointestinal tract in the control or potentially pathogenic endogenous micro-organisms

Chronic systemic pesticide exposure reproduces features of Parkinson's disease.

Betarbet R, Sherer TB, MacKenzie G, et al.

Nat Neurosci. 2000 Dec; 3(12):1301-6.

The cause of Parkinson's disease (PD) is unknown, but epidemiological studies suggest an association with pesticides and other environmental toxins, and biochemical studies implicate a systemic defect in mitochondrial complex I. We report that chronic, systemic inhibition of complex I by the lipophilic pesticide, rotenone, causes highly selective nigrostriatal dopaminergic degeneration that is associated behaviorally with hypokinesia and rigidity. Nigral neurons in rotenone-treated rats accumulate fibrillar cytoplasmic inclusions that contain ubiquitin and alpha-synuclein. These results indicate that chronic exposure to a common pesticide can reproduce the anatomical, neurochemical, behavioral and neuropathological features of PD

N-acetyltransferase 2 polymorphism in sporadic Parkinson's disease in a Polish population.

Bialecka M, Gawronska-Szklarz B, Drozdzik M, et al.

Eur J Clin Pharmacol. 2002 Feb; 57(12):857-62.

OBJECTIVE: A genetic background of Parkinson's disease has been suggested, including genes implicated in xenobiotic metabolism. So far, many candidate genes responsible for the occurrence of the disease have been enumerated. This study was carried out to determine the presence of N-acetyltransferase 2 polymorphism in Parkinson's disease patients in a Polish population. METHODS: Fifty-four patients with diagnosed sporadic Parkinson's disease and 81 healthy individuals were enrolled into the study. The N-acetyltransferase 2 alleles (*4, *5, *6 and *7) were identified using polymerase chain reaction-restriction fragment length polymorphism methods with DNA extracted from peripheral blood. RESULTS: A preponderance of slow acetylators in patients with Parkinson's disease was demonstrated. Among 54 subjects with parkinsonism, 64.8% were homozygous for two mutated alleles responsible for the slow-acetylator phenotype. In the control group, a predominance of fast acetylators was noted. Subjects homozygous and heterozygous with genotypes determining fast acetylation constituting 53% of subjects, whereas 47% were slow acetylators. Comparison of the two groups of the study, i.e. Parkinson's disease and healthy individuals, revealed a statistically significant predominance of slow acetylators in Parkinson's disease patients (P < 0.05). The risk of Parkinson's disease development was more than two times greater in slow acetylators than healthy subjects. The frequency of point mutations was similar both in patients with Parkinson's disease and the healthy controls. CONCLUSION: Slow-acetylation genotype may be an important factor of individual susceptibility to Parkinson's disease

Food additive excitotoxins and degenerative brain disorders.

Blaylock RL.

Med Sentinel. 1999; 4(6):212-5.

Motor correlates of occipital glucose hypometabolism in Parkinson's disease without dementia.

Bohnen NI, Minoshima S, Giordani B, et al.

Neurology. 1999 Feb; 52(3):541-6.

OBJECTIVE: To determine whether occipital reduction in regional cerebral glucose metabolism in PD reflects retinal versus nigrostriatal dopaminergic degeneration. We hypothesized that occipital glucose metabolic reduction should be symmetric if parkinsonian retinopathy is responsible for the reduction. METHODS: PD patients without dementia (n = 29; age 63 +/- 10 years) and normal controls (n = 27; age 60 +/- 12 years) underwent [18F]fluorodeoxyglucose PET imaging. Regional cerebral glucose metabolic rates were assessed quantitatively. RESULTS: When compared with normal controls, PD patients showed most severe glucose metabolic reduction in the primary visual cortex (mean -15%, p < 0.001). Occipital glucose metabolic reduction was greater in the hemisphere contralateral to the side of the body affected initially or more severely in PD. There was an inverse correlation between side-to-side asymmetries in finger-tapping performance and occipital glucose metabolic reduction (r = "-0.45," p < 0.05; n = "28)." The correlation was strongest in patients with a relatively early stage of PD with more unilateral motor impairment (Hoehn and Yahr stage I, r = "-0.74," p < 0.01; n = "10)." CONCLUSION: The results indicate a pathophysiologic association between nigrostriatal dysfunction and occipital glucose metabolic reduction in PD

L-tryptophan: a rational anti-depressant and a natural hypnotic?

Boman B.

Aust N Z J Psychiatry. 1988 Mar; 22(1):83-97.

L-tryptophan is an essential amino acid which is the metabolic precursor of serotonin. Because of the evidence that serotonin deficiency may be an aetiological factor in some sorts of affective disorder and that serotonin is important in the biochemistry of sleep, L-tryptophan has been suggested as a "rational" anti-depressant and as a "natural" hypnotic. This paper reviews the biochemistry and pharmacology of L-tryptophan as well as the literature of the clinical trials that have been conducted with it and suggests that, by itself, L-tryptophan may be useful in mild cases of depression accompanied by endogenous features and cases of bipolar disorder resistant to standard treatments. It also potentiates the monoamine oxidase inhibitors and possibly the serotonergic tricyclic drugs. L-tryptophan may improve the depressed mood of Parkinsonian patients and has a clinically useful hypnotic action. There is evidence it may be useful in organic mental disorders induced by levodopa. Dosage schedules, contraindications and complications are discussed

Characterizing Risk at Metal Finishing Facilities.

Brown DJ.

1998;1998 May Report EPA/600/R-97/111.

Environmental antecedents of young-onset Parkinson's disease.

Butterfield PG, Valanis BG, Spencer PS, et al.

Neurology. 1993 Jun; 43(6):1150-8.

We conducted an exploratory study of young-onset Parkinson's disease (YOPD) to examine occupational and environmental factors associated with disease risk. This case-control study included 63 YOPD patients (diagnosis on or before age 50); controls (n = 68) were diagnosed with rheumatoid arthritis. Crude odds ratios (ORs) were computed to identify exposure variables for logistic regression analyses. After controlling for the variables of race, educational level, sex, age, age at diagnosis, and family history of Parkinson's disease (PD), PD was positively associated with insecticide exposure (OR = 5.75, p < 0.001), past residency in a fumigated house (OR = "5.25," p = "0.046)," herbicide exposure (OR = "3.22," p = "0.033)," rural residency at time of diagnosis (OR = "2.72," p = "0.027)," and nuts and seed eating 10 years before diagnosis (OR = "1.49," p = "0.021)." PD was inversely associated with cigarette smoking at 5 years (OR = "0.50," p = "0.027)," 10 years (OR = "0.43," p = "0.012)," and 15 years (OR = "0.37," p = "0.005)" before diagnosis, farm residency (OR = "0.38," p = "0.018)," and exposure to dimethyl sulfoxide (OR = "0.10," p < 0.001). These findings are consistent with hypotheses linking PD to exposure to pesticide agents

Alzheimer's disease, Parkinson's disease, and motoneurone disease: abiotrophic interaction between ageing and environment?

Calne DB, Eisen A, McGeer E, et al.

Lancet. 1986 Nov 8; 2(8515):1067-70.

The hypothesis is that Alzheimer's disease, Parkinson's disease (PD), and motoneurone disease are due to environmental damage to specific regions of the central nervous system and that the damage remains subclinical for several decades but makes those affected especially prone to the consequences of age-related neuronal attrition. This proposal is based on the association between environmental factors and certain neurodegenerative diseases (eg, methylphenyltetra-hydropyridine and parkinsonism, poliovirus infection and post-poliomyelitis syndrome, chickling pea ingestion and lathyrism, an unidentified environmental factor and amyotrophic lateral sclerosis-PD complex of Guam, and trauma and pugilist's encephalopathy) and on the long latent period between exposure to environmental factor and the appearance of symptoms in some of these disorders. The practical implications of this hypothesis are that epidemiological attention should be focussed on the environment in early rather than late life, prevention may be a realistic goal if the cause of subclinical damage can be identified, a search should be undertaken for causal mechanisms linking subclinical neuronal damage due to an environmental factor and the normal ageing process, and (4) better understanding of the regional selective vulnerability of the nervous system to the ageing process might allow a rational approach to treatment

Aging of the nigrostriatal pathway in humans.

Calne DB, Peppard RF.

Can J Neurol Sci. 1987 Aug; 14(3 Suppl):424-7.

Progressive degeneration of functionally related groups of neurons occurs in certain infective, toxic, nutritional and genetically determined neurological diseases. It also takes place in normal aging, and several of the regions that undergo selective decay with the passage of time seem to be the same target regions that are afflicted in degenerative disorders such as Parkinson's disease. Alzheimer's disease and amyotrophic lateral sclerosis (ALS). Infective etiology is relatively easy to exclude by a combination of immunological tests and transfer experiments. Genetic causation can be rendered unlikely when large kindreds are available for study. Nutritional deprivation and acute or subacute toxicity are accessible to explanation by examining the environment. The most difficult mechanism of pathogenesis to refute is chronic toxic damage, where the lesion may derive from long-term exposure to a relatively widespread noxious agent or agents. Variations in involvement of individuals within a population may stem from differing capacities to activate or inactivate a toxin. Inherent in this concept of etiology is recognition that compensatory potential within the central nervous system may contribute to prolonged existence of subclinical lesions so that a latent period may exist for several decades, between causal event and the onset of symptoms. Furthermore, progressive clinical deterioration may take place even though the cause may have been transient, many years before.(ABSTRACT TRUNCATED AT 250 WORDS)

Familial Parkinson's disease: possible role of environmental factors.

Calne S, Schoenberg B, Martin W, et al.

Can J Neurol Sci. 1987 Aug; 14(3):303-5.

We report here six families with Parkinson's disease in whom the onset of symptoms tended to occur at approximately the same time irrespective of the age of the patient. The mean difference in the time of onset in different generations was 4.6 years while the mean difference in age of onset in children and parents was 25.2 years. We construe this pattern of age separation within families as suggestive of an environmental rather than genetic cause. Support for this view derives from the lack of correlation between occurrence of the disease and the degree of consanguinity. We conclude that our findings are in accord with the hypothesis which attributes the cause of some cases of Parkinson's disease to early, subclinical environmental damage followed by age-related attrition of neurons within the central nervous system

Biological and clinical significance of endotoxemia in the course of hepatitis C virus infection.

Caradonna L, Mastronardi ML, Magrone T, et al.

Curr Pharm Des. 2002; 8(11):995-1005.

Endotoxins or lipopolysaccharides (LPS), major components of the cell wall of Gram-negative bacteria, once released from the bacterial outer membrane bind to specific receptors and, in particular, to a membrane-bound receptor, the CD14 (mCD14) and the toll-like receptor 4 present on monocytes/ macrophages. In turn, LPS-activated monocytes/ macrophages release in the host tissue an array of so-called proinflammatory cytokines and, among them, Tumor Necrosis Factor (TNF)-alpha, interleukin (IL)-1beta, IL-6, IL-8 and IL-12 are the major mediators. Before therapy (To) and at the end of 6-month interferon (IFN)-alpha/Ribavirin (RIB) treatment (T6), circulating endotoxin levels were measured in responder and non responder HCV+ patients. At T0, 57% of the non responders were endotoxin-positive and had, on average, 54 pg/ml of plasma LPS while in 50% of the responder patients endotoxin were found with an average of 29 pg/ml. At T6, in responders LPS were no longer detectable, while in 42% of the non responders LPS were found (average levels 45 pg/ml). In terms of serum cytokine concentration, at T6 IFN-gamma levels when compared to those detected at T0 were increased in both endotoxin-positive and endotoxin-negative patients. However, at T6 IL-10 concentration was significantly increased only in the group of endotoxin-negative subjects (responder patients), in comparison to T0 values. The origin of endotoxemia in HCV+ patients seems to be multifactorial, likely depending on impaired phagocytic functions and reduced T-cell mediated antibacterial activity. In these patients, however, one cannot exclude the passage of LPS from the gut flora to the blood stream, owing a condition of altered intestinal permeability. At the same time, a less efficient detoxification of enteric bacterial antigens at the hepatic level should be taken into consideration. Finally, novel therapeutic attempts aimed to neutralize LPS in the host are discussed

Evaluation of leakage of bacteria and endotoxins in teeth treated endodontically by two different techniques.

Carratu P, Amato M, Riccitiello F, et al.

J Endod. 2002 Apr; 28(4):272-5.

Root canal recontamination occurs after contact between oral-bacterial flora and the coronal extremity of the root canal. The aim of this study was to evaluate the time required for endotoxins and bacteria to penetrate through root-canal obturations performed with vertical and lateral gutta-percha condensation techniques. Specimens prepared by the two alternative methods were exposed to contaminated saliva, and leakage into the root was evaluated over time. None of the obturated roots was infiltrated by endotoxins after 31 days. On the contrary, between day 13 and day 37 bacteria had infiltrated all specimens

[Usefulness of olanzapine in the levodopa-induced psychosis in patients with Parkinson's disease].

Chacon JR, Duran E, Duran JA, et al.

Neurologia. 2002 Jan; 17(1):7-11.

BACKGROUND: To evaluate the antipsychotic efficacy of olanzapine (OLZ) in patients with Parkinson's disease (PD) and drug-induced psychosis (DIP) and its repercussion on the motor function. METHODS: Ten patients (5 women and 5 men) diagnosed of PD and DIP, aged 67 years (range: 50-81), with PD duration of 11.1 years (range: 6-23), treated chronically with levodopa per day, received a dose of 2.5 or 5.0 mg OLZ daily. Data concerning improvement of psychosis and worsening of motor function was based on Positive And Negative Symptoms Scale (PANSS) and Unified Parkinsons Disease Rating Scale (UPDRS) motor. RESULTS: Psychotic symptoms were improved in all patients. In most of them the improvement was almost total. Seven patients increased levodopa dose on OLZ, but significant worsening of motor function was reported just in one patient. None of the patients had agranulocytosis in the blood monitoring. Two patients presented weight gain. Seven patients improved their cognitive status. CONCLUSIONS: We conclude that OLZ at the doses studied may have efficacy for DIP which appears in PD and does not induce worsening of motor function in most of the patients

Parkinson's disease risks associated with cigarette smoking, alcohol consumption, and caffeine intake.

Checkoway H, Powers K, Smith-Weller T, et al.

Am J Epidemiol. 2002 Apr 15; 155(8):732-8.

A reduced risk for Parkinson's disease (PD) among cigarette smokers has been observed consistently during the past 30 years. Recent evidence suggests that caffeine may also be protective. Findings are presented regarding associations of PD with smoking, caffeine intake, and alcohol consumption from a case-control study conducted in western Washington State in 1992-2000. Incident PD cases (n = 210) and controls (n = 347), frequency matched on gender and age were identified from enrollees of the Group Health Cooperative health maintenance organization. Exposure data were obtained by in-person questionnaires. Ever having smoked cigarettes was associated with a reduced risk of PD (odds ratio (OR) = 0.5, 95% confidence interval (CI): 0.4, 0.8). A stronger relation was found among current smokers (OR = 0.3, 95% CI: 0.1, 0.7) than among ex-smokers (OR = 0.6, 95% CI: 0.4, 0.9), and there was an inverse gradient with pack-years smoked (trend p < 0.001). No associations were detected for coffee consumption or total caffeine intake or for alcohol consumption. However, reduced risks were observed for consumption of 2 cups/day or more of tea (OR = "0.4," 95% CI: 0.2, 0.9) and two or more cola drinks/day (OR = "0.6," 95% CI: 0.3, 1.4). The associations for tea and cola drinks were not confounded by smoking or coffee consumption

Melatonin attenuates MPP+-induced neurodegeneration and glutathione impairment in the nigrostriatal dopaminergic pathway.

Chen ST, Chuang JI, Hong MH, et al.

J Pineal Res. 2002 May; 32(4):262-9.

In this study we selected a rat model of Parkinson's disease (PD) by using intrastriatal infusion of the 1-methyl-4-phenyl-pyridinium ion (MPP+) to investigate the neuroprotective action of melatonin and its inhibitory activity on MPP+-impaired glutathione (GSH) system in the nigrostriatal system. Results show that MPP+ caused not only a severe neuronal injury in the striatum and in the ipsilateral substantia nigra (SN), but it also induced a significant decrease in GSH levels and an increase in the GSSG/GSH ratio 3 days after intrastriatal MPP+ infusion. Intraperitoneal co-administration of melatonin (10 mg/kg, five times) significantly attenuated MPP+-induced nigrostriatal neurotoxicity and GSH impairment. Depletion of cytosolic GSH by L-buthionine sulfoximine (BSO) did not cause neuronal damage by itself. It, however, when co-administrated with MPP+, potentiated the GSH reduction in the striatum, without aggravating nigrostriatal neurodegeneration induced by MPP+. Moreover, the MPP+-caused neuronal damage was positively correlated with a rising ratio of GSSG/GSH, but not with a drop of GSH. These results suggest that the MPP+-triggered oxidative stress may play a more important role than the loss of the antioxidant GSH in determining neuronal injury. Interestingly, the neuronal damage and oxidative stress elicited by co-treatment of BSO with MPP+ were effectively reduced by melatonin. Our results hence provide direct evidence showing that melatonin attenuates MPP+-induced nigrostriatal dopaminergic injury by its ability to impede the increase of GSSG/GSH ratio; therefore melatonin may have therapeutic implications in PD

The American Medical Association Encyclopedia of Medicine.

Clayman CB.

1989;

Abnormal tissue distribution of lead in amyotrophic lateral sclerosis.

Conradi S, Ronnevi LO, Vesterberg O.

J Neurol Sci. 1976 Oct; 29(2-4):259-65.

The lead content of cerebrospinal fluid (CSF) was found to be significantly elevated in 12 patients with amyotrophic lateral sclerosis, when compared to 28 control subjects having non-degenerative neurological disorders. The difference could not be explained as being merely secondary to blood-CSF barrier damage. A hypothetical model of the pathogenesis of the disease is advanced and the results are discussed in relation to this model

The epidemiology of primary degenerative dementia and related neurological disorders.

Cooper B.

Eur Arch Psychiatry Clin Neurosci. 1991; 240(4-5):223-33.

Observation of cytopathological similarities between the changes of Alzheimer-type dementia, Parkinson's disease and motor neuron disease, as well as of some degree of clinical association between these conditions, has led to the suggestion that all three belong to a common class of degenerative neurological disorders, each of which as a rule first becomes manifest when age-related neuronal attrition is superimposed on subclinical damage caused by environmental noxae earlier in life. The importance of this model lies in its potential relevance to prevention. The epidemiological data reviewed here suggest that, while the three disease groups are all strongly linked with ageing, there may be major differences between their patterns of occurrence in populations, which make it doubtful if the same environmental pathogens are responsible in each instance. The most plausible unifying hypothesis at present is that the predisposing neuronal damage can be caused by a number of widely distributed metallic neurotoxins, each of which has a tendency to pick out specific areas or cell groups within the CNS and thus to give rise to distinct though overlapping clinical syndromes. The evidence bearing on this and other causal hypotheses is, however, still tenuous because of the scarcity of empirical data. Population-based case-control and cohort studies are called for, as part of a co-ordinated research endeavour

Metabolic polymorphisms.

Daly AK, Cholerton S, Gregory W, et al.

Pharmacol Ther. 1993 Feb; 57(2-3):129-60.

Polymorphisms have been detected in a variety of xenobiotic-metabolizing enzymes at both the phenotypic and genotypic level. In the case of four enzymes, the cytochrome P450 CYP2D6, glutathione S-transferase mu, N-acetyltransferase 2 and serum cholinesterase, the majority of mutations which give rise to a defective phenotype have now been identified. Another group of enzymes show definite polymorphism at the phenotypic level but the exact genetic mechanisms responsible are not yet clear. These enzymes include the cytochromes P450 CYP1A1, CYP1A2 and a CYP2C form which metabolizes mephenytoin, a flavin-linked monooxygenase (fish-odour syndrome), paraoxonase, UDP-glucuronosyltransferase (Gilbert's syndrome) and thiopurine S-methyltransferase. In the case of a further group of enzymes, there is some evidence for polymorphism at either the phenotypic or genotypic level but this has not been unambiguously demonstrated. Examples of this class include the cytochrome P450 enzymes CYP2A6, CYP2E1, CYP2C9 and CYP3A4, xanthine oxidase, an S-oxidase which metabolizes carbocysteine, epoxide hydrolase, two forms of sulphotransferase and several methyltransferases. The nature of all these polymorphisms and possible polymorphisms is discussed in detail, with particular reference to the effects of this variation on drug metabolism and susceptibility to chemically-induced diseases

Genotyping for polymorphisms in xenobiotic metabolism as a predictor of disease susceptibility.

Daly AK, Cholerton S, Armstrong M, et al.

Environ Health Perspect. 1994 Nov; 102 Suppl 9:55-61.

Polymorphisms in many xenobiotic metabolizing enzymes occur leading to variation in the level of enzyme expression in vivo. Enzymes showing such polymorphisms include the cytochrome P450 enzymes CYP1A1, CYP1A2, CYP2A6, CYP2D6, and CYP2E1 and the phase two metabolism enzymes glutathione S-transferase MI (GSTMI) and arylamine N-acetyltransferase 2 (NAT2). In the past, these polymorphisms have been studied by phenotyping using in vivo administration of probe drugs. However, the mutations which give rise to several of these polymorphisms have now been identified and genotyping assays for polymorphisms in CYP1A1, CYP2A6, CYP2D6, CYP2E1, GSTMI, and NAT2 have been developed. Specific phenotypes for several of the polymorphic enzymes have been associated with increased susceptibility to malignancy, particularly lung and bladder cancer, and Parkinson's disease. These associations are likely to be due to altered activation or detoxication of chemicals initiating these diseases, including components of tobacco smoke and neurotoxins. The substrate specificity and tissue distribution of polymorphic enzymes implicated in disease causation discussed with particular reference to previously described disease-phenotype associations

Monoamine neurotoxins-induced apoptosis in lymphocytes by a common oxidative stress mechanism: involvement of hydrogen peroxide (H(2)O(2)), caspase-3, and nuclear factor kappa-B (NF-kappaB), p53, c-Jun transcription factors.

del Rio MJ, Velez-Pardo C.

Biochem Pharmacol. 2002 Feb 15; 63(4):677-88.

The destruction of dopaminergic and serotonergic nerve cells by selective 6-hydroxydopamine (6-OHDA), 5,6-dihydroxytryptamine (5,6-DHT) and 5,7-dihydroxytryptamine (5,7-DHT), respectively, is a commonly used tool to investigate the mapping of neuronal pathways, elucidation of function and to mimic human neurodegenerative disease such as Parkinson's and Alzheimer's diseases. Despite intense investigations, a complete picture of the precise molecular cascade leading to cell death in a single cellular model is still lacking. In this study, we provide evidence that 6-OHDA, 5,6- and 5,7-DHT toxins-induced apoptosis in peripheral blood lymphocytes cells in a concentration-dependent fashion by a common oxidative mechanism involving: (1) the oxidation of toxins into quinones and production of the by-product hydrogen peroxide, reflected by desipramine-a monoamine uptake blocker-and antioxidants inhibition, (2) activation and/or translocation of nuclear factor-kappaB, p53 and c-Jun transcription factors, showed by immunocytochemical diaminobenzidine-positive stained nuclei, (3) caspase-3 activation, reflected by caspase Ac-DEVD-CHO inhibition, (4) mRNA and protein synthesis de novo according to cycloheximide and actinomycin D cell death inhibition. These results are consistent with the notion that uptake and intracellular autoxidation of those toxins precede the apoptotic process and that once H(2)O(2) is generated, it is able to trigger a specific cell death signalisation. Thus, taken together these results, we present an ordered cascade of the major molecular events leading peripheral blood lymphocytes to apoptosis. These results may contribute to explain the importance of H(2)O(2) as a second messenger of death signal in some degenerative diseases linked to oxidative stress stimuli

Smoking, alcohol, and coffee consumption preceding Parkinson's disease.

Deleu D.

Neurology. 2001 Apr 10; 56(7):984-5.

[L-dopa-induced psychoses and their treatment with L-tryptophan].

Demling J.

Fortschr Med. 1986 Apr 30; 104(17):360-2.

PARK3 influences age at onset in Parkinson disease: a genome scan in the GenePD study.

DeStefano AL, Lew MF, Golbe LI, et al.

Am J Hum Genet. 2002 May; 70(5):1089-95.

Parkinson disease (PD) is a late-onset neurodegenerative disorder. The mean age at onset is 61 years, but the disease can range from juvenile cases to cases in the 8th or 9th decade of life. The parkin gene on chromosome 6q and loci on chromosome 1p35-36 and 1p36 are responsible for some cases of autosomal recessive early-onset parkinsonism, but they do not appear to influence susceptibility or variability of age at onset for idiopathic PD. We have performed a genomewide linkage analysis using variance-component methodology to identify genes influencing age at onset of PD in a population of affected relatives (mainly affected sibling pairs) participating in the GenePD study. Four chromosomal loci showed suggestive evidence of linkage: chromosome 2p (maximum multipoint LOD [MaxLOD] = 2.08), chromosome 9q (MaxLOD = 2.00), chromosome 20 (MaxLOD = 1.82), and chromosome 21 (MaxLOD = 2.21). The 2p and 9q locations that we report here have previously been reported as loci influencing PD affection status. Association between PD age at onset and allele 174 of marker D2S1394, located on 2p13, was observed in the GenePD sample (P=.02). This 174 allele is common to the PD haplotype observed in two families that show linkage to PARK3 and have autosomal dominant PD, which suggests that this allele may be in linkage disequilibrium with a mutation influencing PD susceptibility or age at onset of PD

Excited to death: different ways to lose your neurones.

Dodd PR.

Biogerontology. 2002; 3(1-2):51-6.

The selective loss of neurones in a range of neurodegenerative diseases is widely thought to involve the process of excitotoxicity, in which glutamate-mediated neuronal killing is elaborated through the excessive stimulation of cell-surface receptors. Every such disease exhibits a distinct regional and subregional pattern of neuronal loss, so processes must be locally triggered to different extents to account for this. We have studied several mechanisms which could lead to excitotoxic glutamate pathophysiology and compared them in different diseases. Our data suggest that glutamate can reach toxic extracellular levels in Alzheimer disease by malfunctions in cellular transporters, and that the toxicity may be exacerbated by continued glutamate release from presynaptic neurones acting on hypersensitive postsynaptic receptors. Thus the excitotoxicity is direct. In contrast, alcoholic brain damage arises in regions where GABA-mediated inhibition is deficient, and fails properly to dampen trans-synaptic excitation. Thus the excitotoxicity is indirect. A variety of such mechanisms is possible, which may combine in different ways

Dietary folate deficiency and elevated homocysteine levels endanger dopaminergic neurons in models of Parkinson's disease.

Duan W, Ladenheim B, Cutler RG, et al.

J Neurochem. 2002 Jan; 80(1):101-10.

Although the cause of Parkinson's disease (PD) is unknown, data suggest roles for environmental factors that may sensitize dopaminergic neurons to age-related dysfunction and death. Based upon epidemiological data suggesting roles for dietary factors in PD and other age-related neurodegenerative disorders, we tested the hypothesis that dietary folate can modify vulnerability of dopaminergic neurons to dysfunction and death in a mouse model of PD. We report that dietary folate deficiency sensitizes mice to MPTP-induced PD-like pathology and motor dysfunction. Mice on a folate-deficient diet exhibit elevated levels of plasma homocysteine. When infused directly into either the substantia nigra or striatum, homocysteine exacerbates MPTP-induced dopamine depletion, neuronal degeneration and motor dysfunction. Homocysteine exacerbates oxidative stress, mitochondrial dysfunction and apoptosis in human dopaminergic cells exposed to the pesticide rotenone or the pro-oxidant Fe(2+). The adverse effects of homocysteine on dopaminergic cells is ameliorated by administration of the antioxidant uric acid and by an inhibitor of poly (ADP-ribose) polymerase. The ability of folate deficiency and elevated homocysteine levels to sensitize dopaminergic neurons to environmental toxins suggests a mechanism whereby dietary folate may influence risk for PD

Gas chromatography applied to the lactulose-mannitol intestinal permeability test.

Dumas F, Aussel C, Pernet P, et al.

J Chromatogr B Biomed Appl. 1994 Apr 1; 654(2):276-81.

Intestinal permeability can be modified by various illnesses, trauma and sepsis. Alterations of the intestinal wall can facilitate the diffusion of potentially harmful substances such as endotoxins, as well as bacterial translocation. We describe the validation of a capillary gas chromatographic method for the determination of mannitol and lactulose, used as intestinal permeability probes. The method is linear up to 3 g/l for mannitol and 300 mg/l for lactulose; recovery from overload samples is between 92 to 110%. Intra-assay coefficients of variation (C.V.s) were 2.7 and 6.8% for mannitol and lactulose, respectively, and inter-assay C.V.s were 8.9 and 9.3%. Normal values for 25 healthy subjects (mean +/- S.D.) were 14.5 +/- 3.1% and 0.27 +/- 0.15% for mannitol and lactulose, respectively. The GC method presented is rapid and precise

Oxidative stress and antioxidant therapy in Parkinson's disease.

Ebadi M, Srinivasan SK, Baxi MD.

Prog Neurobiol. 1996 Jan; 48(1):1-19.

Parkinson's disease, known also as striatal dopamine deficiency syndrome, is a degenerative disorder of the central nervous system characterized by akinesia, muscular rigidity, tremor at rest, and postural abnormalities. In early stages of parkinsonism, there appears to be a compensatory increase in the number of dopamine receptors to accommodate the initial loss of dopamine neurons. As the disease progresses, the number of dopamine receptors decreases, apparently due to the concomitant degeneration of dopamine target sites on striatal neurons. The loss of dopaminergic neurons in Parkinson's disease results in enhanced metabolism of dopamine, augmenting the formation of H2O2, thus leading to generation of highly neurotoxic hydroxyl radicals (OH.). The generation of free radicals can also be produced by 6-hydroxydopamine or MPTP which destroys striatal dopaminergic neurons causing parkinsonism in experimental animals as well as human beings. Studies of the substantia nigra after death in Parkinson's disease have suggested the presence of oxidative stress and depletion of reduced glutathione; a high level of total iron with reduced level of ferritin; and deficiency of mitochondrial complex I. New approaches designed to attenuate the effects of oxidative stress and to provide neuroprotection of striatal dopaminergic neurons in Parkinson's disease include blocking dopamine transporter by mazindol, blocking NMDA receptors by dizocilpine maleate, enhancing the survival of neurons by giving brain-derived neurotrophic factors, providing antioxidants such as vitamin E, or inhibiting monoamine oxidase B (MAO-B) by selegiline. Among all of these experimental therapeutic refinements, the use of selegiline has been most successful in that it has been shown that selegiline may have a neurotrophic factor-like action rescuing striatal neurons and prolonging the survival of patients with Parkinson's disease

Increased inorganic mercury in spinal motor neurons following chelating agents.

Ewan KB, Pamphlett R.

Neurotoxicology. 1996; 17(2):343-9.

Heavy metal toxicity has been implicated in the pathogenesis of motor neuron diseases. In an attempt to assess the efficacy of chelating agents to remove mercury from motor neurons, we quantitated the effect of the chelating agents meso-2,3-dimercaptosuccinic acid (DMSA) and 2,3- dimercaptopropane -1-sulphonate (DMPS) on the burden of inorganic mercury in mouse spinal motor neurons. Mice were injected intraperitoneally with 1.0 mg HgCl2/kg body weight and one week later with either 4,400 mg/kg DMPS, 3,600 mg/kg DMSA or 5% NaHCO3 (control) over 4 weeks. Mercury deposits in motor neurons of 50 micron frozen sections of lumbar spinal cord were visualised with an autometallographic technique. Optical sections of silver-enhanced deposits were acquired using a confocal microscope in reflective mode and the volume of the deposits within the perikaryon was estimated. Mercury deposits occupied significantly more volume in motor neurons after both DMPS (7.4%, SD +/- 0.7%) and DMSA (8.0% +/- SD 0.7%) treatment than in controls (4.3%, SD +/- 1.7%). The higher levels of neuronal inorganic mercury may be due to increased entry of mercury into motor axons across the neuromuscular junction as a result of chelator-induced elevated circulating mercury

Normalization of brain serotonin by L-tryptophan in levodopa-treated rats.

Fahn S, Snider S, Prasad AL, et al.

Neurology. 1975 Sep; 25(9):861-5.

To test possible biochemical mechanisms by which L-tryptophan may reverse mental side effects of levodopa therapy in parkinsonism we administered levodopa, 250 mg per kilogram intraperitoneally, alone and with L-tryptophan, 500 mg per kilogram intraperitoneally, to rats pretreated with the peripheral dopa decarboxylase inhibitor, carbidopa (25 mg per kilogram). Rats were decapitated 0.5, 1, and 2 hours following amino acid injection and brain levels of amino acids, amines, and acid metabolites were determined. As expected, levodopa alone reduced tryptophan and serotonin and increased dopa and dopamine at the 1 and 2 hour intervals. Concurrent administration of L-tryptophan did not significantly alter the increased dopa and dopamine but did restore serotonin levels to within normal range at all time points. If similar events occur in parkinsonian patients, normalization of brain serotonin and not competitive reduction of brain dopa and dopamine may be the basis for the improvement in mental status

An open trial of high-dosage antioxidants in early Parkinson's disease.

Fahn S.

Am J Clin Nutr. 1991 Jan; 53(1 Suppl):380S-2S.

High dosages of tocopherol and ascorbate were administered to patients with early Parkinson's disease as a preliminary open-labeled trial for the eventual controlled double-blind study evaluating antioxidants as a test of the endogenous toxin hypothesis of the etiology of Parkinson's disease. The primary endpoint of the trial was the need to treat patients with levodopa. The time when levodopa became necessary in the treated patients was compared with another group of patients followed elsewhere and not taking antioxidants. The time when levodopa became necessary was extended by 2.5 y in the group taking antioxidants. The results of this pilot study suggest that the progression of Parkinson's disease may be slowed by the administration of these antioxidants. A large multicenter, controlled clinical trial currently underway in North America evaluating tocopherol and deprenyl has the potential to confirm these results

A pilot trial of high-dose alpha-tocopherol and ascorbate in early Parkinson's disease.

Fahn S.

Ann Neurol. 1992; 32 Suppl:S128-S132.

High dosages of a combination of alpha-tocopherol and ascorbate were administered to patients with early Parkinson's disease as an open-labeled trial and pilot study to test the endogenous toxic hypothesis of the etiology of Parkinson's disease. Patients receiving concomitant amantadine and anticholinergics were allowed to participate, but those receiving levodopa or dopamine agonists were not. The study was begun prior to the availability of deprenyl. The primary end point of the trial was progression of the disease until patients needed treatment with levodopa or a dopamine agonist. The time when levodopa became necessary in the treated patients was compared to another group of patients followed elsewhere who did not receive antioxidants. The time when levodopa became necessary was extended by 2.5 years in the group receiving alpha-tocopherol and ascorbate. Results of this pilot study suggest that the progression of Parkinson's disease may be slowed by administration of these antioxidants. Controlled clinical trials using double-blind randomization techniques are required to confirm these results

Frontal dysfunction in early Parkinson's disease.

Farina E, Cappa SF, Polimeni M, et al.

Acta Neurol Scand. 1994 Jul; 90(1):34-8.

Recent studies have suggested that patients with Parkinson's disease (PD) share many of the behavioral deficits found following lesions to the pre-frontal cortex. We assessed the performance of a group of 22 mildly impaired, not-demented parkisonians (I or II Hoehn & Yahr stage) in a test of classification and recall of pictures of familiar objects, which has been demonstrated to be sensitive to frontal damage in patients with unilateral cerebral excision. Parkinsonians utilized fewer categories than normal controls for object classification, while no significant difference was found in the immediate and delayed recall scores. These results support the contention that a subclinical dysfunction of frontal type may be present even in the early stages of PD. A subanalysis of the data suggests that this dysfunction could possibly be aggravated by anticholinergic drugs

Significance of the parkin gene and protein in understanding Parkinson's disease.

Fishman PS, Oyler GA.

Curr Neurol Neurosci Rep. 2002 Jul; 2(4):296-302.

Mutations in the parkin gene cause autosomal recessive inherited juvenile parkinsonism (ARJP) and account for the majority of cases of inherited Parkinson's disease (PD) of young onset (<45 years of age). Patients with parkin mutations commonly have atypical clinical features such as dystonia at onset, hyper-reflexia, diurnal fluctuations, and sleep benefit; however, parkin mutation patients with both typical PD symptoms and older age of onset have been identified. Parkin is a ubiquitin protein ligase (E3), a component in the pathway that attaches ubiquitin to specific proteins, designating them for degradation by the proteasome. Several substrates for parkin have been identified (CDCrel-1, o-glycosylated alpha-synuclein, parkin associated endothelin-like cell receptor, and synphilin). The role of these substrates in the pathogenesis of ARJP is under active study. Most patients with parkin mutations lack Lewy bodies, suggesting that functional parkin is involved in the formation of these highly ubiquitinated inclusions. Furthermore, the recognition that parkin mutations can lead to a disorder clinically similar to sporadic PD, but presumably lacking Lewy bodies, calls into question the necessity of Lewy bodies for the diagnosis of PD and nigral cell death. Studies of parkin are increasing the focus on the role of the ubiquitin-proteasome system in the pathogenesis of both familial and sporadic PD

Status and future concerns of clinical and environmental aluminum toxicology.

Flaten TP, Alfrey AC, Birchall JD, et al.

J Toxicol Environ Health. 1996 Aug 30; 48(6):527-41.

A wide range of toxic effects of aluminum (Al) have been demonstrated in plants and aquatic animals in nature, in experimental animals by several routes of exposure, and under different clinical conditions in humans. Aluminum toxicity is a major problem in agriculture, affecting perhaps as much as 40% of arable soils in the world. In fresh waters acidified by acid rain, Al toxicity has led to fish extinction. Aluminum is a very potent neurotoxicant. In humans with chronic renal failure on dialysis, Al causes encephalopathy, osteomalacia, and anemia. There are also reports of such effects in certain patient groups without renal failure. Subtle neurocognitive and psychomotor effects and electroencephalograph (EEG) abnormalities have been reported at plasma Al levels as low as 50 micrograms/L. Infants could be particularly susceptible to Al accumulation and toxicity, reduced renal function being one contributory cause. Recent reports clearly show that Al accumulation occurs in the tissues of workers with long-term occupational exposure to Al dusts or fumes, and also indicate that such exposure may cause subtle neurological effects. Increased efforts should be directed toward defining the full range of potentially harmful effects in humans. To this end, multidisciplinary collaborative research efforts are encouraged, involving scientists from many different specialties. Emphasis should be placed on increasing our understanding of the chemistry of Al in biological systems, and on determining the cellular and molecular mechanisms of Al toxicity

In vivo elevation of extracellular potassium in the rat amygdala increases extracellular glutamate and aspartate and damages neurons.

Fujikawa DG, Kim JS, Daniels AH, et al.

Neuroscience. 1996 Oct; 74(3):695-706.

It is well known that high potassium (K+) solutions introduced by microdialysis into normal brain increase the extracellular concentration of the excitatory amino acid glutamate, and in vitro studies suggest that a high exogenously applied glutamate concentration can produce excitotoxic neuronal death. However, only recently were in vivo studies undertaken to determine whether high-K+ exposure damages neurons. We implanted microdialysis probes into rat amygdalae bilaterally, and after a 2-h baseline period exposed one side to a modified Krebs-Ringer-bicarbonate solution containing 100 mmol/l KCl for 30,50 and 70 min, followed by a 2-h recovery period, and 70 min and 3 h without a recovery period. Of 100.9 +/- 2.0 mmol/l KCl, 12.0 +/- 1.0% was extracted by amygdalar tissue in vivo. Election of the extracellular K+ concentration in the amygdala for 70 min or longer without a recovery period produced extensive neuronal damage and edematous-appearing neuropil in the tissue dialysed, as well as loss of normal neurons. Histological evidence of edema subsided in the groups with a 2-h recovery period. Although the number of damaged neurons was not significantly higher in the group with a 70 min high-K+ exposure and 2-h recovery period, the number of normal neurons was reduced, suggesting cell loss. During 70-min high-K+ exposure, the extracellular glutamate concentration increased to 242-377% of baseline during the first 60 min, and extracellular aspartate rose to 162-213% during the first 50 min; extracellular taurine rose even higher, to 316-567% of baseline, and glutamine fell to 14-27% of baseline. Extracellular serine was decreased at 20, 50 and 70 min of high-K+ exposure; extracellular glycine was unchanged. The elevated extracellular glutamate and aspartate concentrations suggest that exposure of the amygdala to high extracellular K+ may produce cell death through an excitotoxic process, and point the way to future studies to define the specific mechanisms involved

[Levodopa-induced psychosis in patients with idiopathic Parkinson disease].

Garcia-Escrig M, Bermejo PF, Fernandez Ponsati JT.

Med Clin (Barc ). 1999 Feb 27; 112(7):245-50.

BACKGROUND: To identify which clinical factors can modify the probability of the appearance of the psychotic syndromes in patients with idiopathic Parkinson's disease treated with levodopa. PATIENTS AND METHODS: 214 patients were retrospectively studied to evaluate the appearance of hallucinosis, delusions or mental confusion, from the beginning of the treatment with levodopa to a transversal evaluation along the course of the disease. To determine which clinical factors were independent predictors of psychosis, a multivariate logistic regression model was obtained, using the variables for which the univariate studies showed p values under 0.25. RESULTS: The multivariate model showed that the probability of developing psychosis during levodopa treatment was higher for the patients with intermediate or advanced stages of the disease (Hoehn and Yarh scale), at the beginning of the treatment (OR: 4.5; 95% CI: 1.86-11.23), when amantadine was administrated as associated drug (OR: 3.31; 95% CI: 1.19-9.23) and for the patients who presented motor fluctuations (OR: 3.08; 95% CI: 1.32-7.16). Univariate studies showed a significant association between levodopa psychosis and dyskinesias (univariate OR: 2.44; 95% CI: 1.12-5.33). Patients who suffered from psychotic complications had received significantly higher mean levodopa daily dose (p = 0.016) and the punctuation reached in the Folstein's Mini-Mental Scale was significantly lower (p = 0.0001). CONCLUSIONS: Levodopa psychosis appears in a "bad prognostic" group of patients, characterized by a greater motor and cognitive impairment and by the occurrence of other levodopa central adverse effects, higher doses of levodopa and a more frequent administration of other antiparkinsonian drugs

[Influence of chewing gum consumption and dental contact of amalgam fillings to different metal restorations on urine mercury content].

Gebel T, Dunkelberg H.

Zentralbl Hyg Umweltmed. 1996 Nov; 199(1):69-75.

It had been shown previously by various authors that contact of amalgam fillings to metal fillings of different type can increase the electrochemically caused amalgam corrosion in vitro thus leading to an elevated release of mercury. So it was recommended to renounce of a dental contact of amalgam to metal fillings of other type. One aim of the present study was to evaluate possible influences of this contact in vivo on the urinary mercury contents in human volunteers. Neither approximal nor occlusal contacts had any influence on the urinary mercury excretion in comparison to a reference group with similar amalgam status. Furthermore, the influence of gum chewing on urinary mercury levels was taken into account. It could be shown that the consumption of chewing gum resulted in a significantly higher mean urinary mercury content in probands with amalgam fillings in comparison to people with similar amalgam status (gum chewers: 1.36 Hg/24 h vs. non-chewers 0.70 microgram Hg/24 h). Thus, gum chewing has to be considered as important parameter of influence on the urinary mercury levels of people with amalgam fillings

Treatment of levodopa psychosis with L-tryptophan.

Gehlen WMJ.

Dtsch Med Wochenschr. 1974; 99(10):457-63.

Bacterial resistance.

Gentry LO.

Orthop Clin North Am. 1991 Jul; 22(3):379-88.

Pathogenic bacteria remain adaptable to an increasingly hostile environment and a wider variety of more potent antibiotics. Organisms not intrinsically prepared for defense have been able to acquire resistance to newer antimicrobial agents. Chromosomal mutations alone cannot account for the rapid emergence and spread of antibiotic resistance. It has been established that plasmids and transposons are particularly important in the evolution of antibiotic-resistant bacteria. Plasmid- or transposon-mediated resistance provides the bacteria with pre-evolved genes refined to express high-level resistance. In particular, transposons can transfer these resistance determinants in diverse bacterial species, and nature provides in humans and animals large intestinal reservoirs in which such communications are facilitated. Antibiotic therapy exerts selection pressures on bacteria. Eradication or marked reduction in the populations of susceptible organisms promotes the overgrowth of intrinsically resistant strains and favors those resistant as a result of favorable chromosomal mutations or via plasmids or transposons. In our hospitals, where antibiotic consumption continues to increase, the nosocomial flora consists of many resistant bacteria, and infections acquired in the nosocomial setting are now far more severe than their community-acquired counterparts. There is convincing evidence that infection control measures must take into further consideration the contribution of the hospital worker as carrier and mediator of antibiotic resistance

Mosby Medical Encyclopedia.

Glanze WD.

1996;

Dementias: the role of magnesium deficiency and an hypothesis concerning the pathogenesis of Alzheimer's disease.

Glick JL.

Med Hypotheses. 1990 Mar; 31(3):211-25.

Evidence is presented indicating that dementias are associated with a relative insufficiency of Magnesium (Mg) in the brain. Such insufficiency may be attributable to low intake or retention of Mg; high intake of a neurotoxic metal, such as aluminum (Al), which inhibits activity of Mg-requiring enzymes; or impaired transport of Mg and/or enhanced transport of the neurotoxic metal into brain tissue. It is proposed that Alzheimer's disease (AD) involves a defective transport process, characterized by both an abnormally high incorporation of Al and an abnormally low incorporation of Mg into brain neurons. The hypothesis is advanced that an altered serum protein contributes to the progression of AD by having a greater affinity for Al than for Mg, in contrast to the normal protein, which binds Mg better than Al. The altered protein crosses the blood-brain barrier more efficiently than the normal protein and competes with the normal protein in binding to brain neurons. Binding of the altered protein to the target neurons would both facilitate Al uptake and impede Mg uptake. Evidence suggests that albumin is the serum protein that is altered

Case-control study of early life dietary factors in Parkinson's disease.

Golbe LI, Farrell TM, Davis PH.

Arch Neurol. 1988 Dec; 45(12):1350-3.

Studies of the amyotrophic lateral sclerosis parkinsonism dementia complex of Guam direct suspicion to a heat-labile component of vegetables found in greatest concentration in seeds. We therefore surveyed patients with Parkinson's disease (PD) regarding early adult consumption of fruits and vegetables usually eaten raw, with seeds that are swallowed or scraped with the teeth. We administered a pretested questionnaire by telephone to 81 nondemented patients with PD and to a same-sex married sibling without PD. The patients and their siblings were asked whether they or their spouse (as an internal standard) had been more likely to eat each of 17 food items between marrying and age 40 years. No item was associated with the presence of PD. Unexpectedly associated with the absence of PD were preference for nuts (odds ratio, 0.39), salad oil or dressing (pressed from seeds) (odds ratio, 0.30), and plums (odds ratio, 0.24). These three items have higher vitamin E content than the other 14 items in our questionnaire. Our data are consistent with the hypothesis that vitamin E, as an antioxidant, may have prophylactic value against PD

Functions of the hypothalamo-hypophyseal-adrenal system in aging in female monkeys.

Goncharova ND, Oganyan TE, Taranov AG.

Neurosci Behav Physiol. 2000 Nov; 30(6):717-21.

Comparative studies on the functioning of the adrenal cortex in female rhesus macaques (Macaca mulatta) of different ages are reported - animals were aged 6-9 years (young adults; n = 5) and 20-26 years (old adults; n = 5). Corticosteroid concentrations (cortisol (F) and dehydroepiandrosterone sulfate (DHEAS)) were determined by specific radioimmunological and immunoenzyme methods in basal conditions, after acute stress (insulin-induced hypoglycemia, 2-h movement restriction), and after administration of dexamethasone. Basal F levels showed no marked age differences, while DHEAS concentrations in older animals decreased sharply. These animals also demonstrated weakened adrenal cortex responses to movement restriction, giving rise to delays in reaching peak F and DHEAS levels and decreases in the areas under their response curves (AUC) during the 4-h study period. In the dexamethasone test, the hypothalamo-hypophyseal-adrenal system of monkeys aged 20-26 years was relatively resistant to the suppressing effect of glucocorticoids via the negative feedback mechanism. It is suggested that disruption of feedback in the system controlling adrenal cortex function may be at least partially due to the development of peripheral blood steroid dysbalance with aging, this consisting particularly of a decrease in the DHEA (DHEAS) level; this steroid is known for its neurological activity

Neuromelanin-containing neurons of the substantia nigra accumulate iron and aluminum in Parkinson's disease: a LAMMA study.

Good PF, Olanow CW, Perl DP.

Brain Res. 1992 Oct 16; 593(2):343-6.

The Laser Microprobe Mass Analyzer (LAMMA) is a sensitive instrument for identifying and localizing trace elements in tissue samples. Using LAMMA, we have examined melanin-containing neurons of the substantia nigra in patients with Parkinson's disease (PD) and controls. We found that iron significantly accumulates within neuromelanin granules of patients with PD compared to controls. Increased aluminum was found in the neuromelanin granules of 2 of 3 PD cases but in no controls. The accumulation of iron and aluminum, which are known to promote oxidant stress, may account for the selective degeneration of neuromelanin-containing neurons in PD

Lipofuscin pigment accumulation in human brain during aging.

Goyal VK.

Exp Gerontol. 1982; 17(6):481-7.

Histopathologic and autofluorescence investigations were carried out to study lipofuscin pigment accumulation in various age groups of human beings died in accidents (in 100 cases ranging from 1-70 years-of-age). Lipofuscin pigment granules were first observed to appear at 9 years of age. Qualitative studies revealed a progressive increase in the intracellular lipofuscin pigment accumulation with advancing age. These pigment granules were found to congregate in mass in nerve cells of old individuals. An increase in the lipofuscin pigment accumulation and decrease of Nissl substance was observed during aging. The percentage of pigmented nerve cells and the percentage of cytoplasmic area occupied by lipofuscin pigment granules increased significantly with the advancement of age

Toxic and essential metal interactions.

Goyer RA.

Annu Rev Nutr. 1997; 17:37-50.

Cadmium, lead, mercury, and aluminum are toxic metals that may interact metabolically with nutritionally essential metals. Iron deficiency increases absorption of cadmium, lead, and aluminum. Lead interacts with calcium in the nervous system to impair cognitive development. Cadmium and aluminum interact with calcium in the skeletal system to produce osteodystrophies. Lead replaces zinc on heme enzymes and cadmium replaces zinc on metallothionein. Selenium protects from mercury and methylmercury toxicity. Aluminum interacts with calcium in bone and kidneys, resulting in aluminum osteodystrophy. Calcium deficiency along with low dietary magnesium may contribute to aluminum-induced degenerative nervous disease

Effects of oral L-tyrosine administration on CSF tyrosine and homovanillic acid levels in patients with Parkinson's disease.

Growdon JH, Melamed E, Logue M, et al.

Life Sci. 1982 Mar 8; 30(10):827-32.

To determine whether 1-tyrosine administration can enhance dopamine synthesis in humans as it does in rats, we measured levels of tyrosine and the major dopamine metabolite, homovanillic acid, in lumbar spinal fluids of 23 patients with Parkinson's disease before and during ingestion of 100 mg/kg/day of tyrosine. Nine patients took 100 mg/kg/day of probenecid in six divided doses for 24 hours prior to each spinal tap; 14 patients did not receive probenecid. L-tyrosine administration significantly increased CSF tyrosine levels in both groups of patients (p less than .01) and significantly increased homovanillic acid levels in the group of patients pretreated with probenecid (p less than .02). These data indicate that l-tyrosine administration can increase dopamine turnover in patients with disorders in which physicians wish to enhance dopaminergic neurotransmission

Restorative neurology in movement disorders.

Hagell P.

J Neurosci Nurs. 2000 Oct; 32(5):256-62.

Cell replacement for restoration of neurological functions in patients with movement disorders has been investigated for more than 15 years. Initial attempts used autologous adrenal medulla grafts implanted into the denervated striatum of patients with Parkinson's disease (PD). This approach was soon abandoned in favor of intrastriatal implantation of human embryonic mesencephalic tissue, rich in dopaminergic neurons. Available data from grafted PD patients show long-term (up to 10 years) graft survival and clinical benefits. The pattern and magnitude of symptomatic relief following transplantation, however, are incomplete and the outcome varies among patients. The need for large amounts of human embryonic tissue has to be circumvented and a better understanding of the relationship between graft placement and symptomatic recovery is necessary before this procedure can be offered to larger groups of patients. Clinical trials in Huntington's disease have so far shown inconclusive results. Neural cell replacement therapy is still an experimental procedure, but has the potential to become a future restorative treatment in PD and other movement disorders

N-acetyltransferase-2 polymorphism in Parkinson's disease: the Rotterdam study.

Harhangi BS, Oostra BA, Heutink P, et al.

J Neurol Neurosurg Psychiatry. 1999 Oct; 67(4):518-20.

The N-acetyltransferase-2 gene (NAT-2) has been associated with Parkinson's disease. The genotype associated with slow acetylation has been reported to be increased in patients with Parkinson's disease. Three mutant alleles M1, M2, and M3 of NAT-2 were investigated in 80 patients with idiopathic Parkinson's disease and 161 age matched randomly selected controls from a prospective population based cohort study. The allelic frequencies and genotypic distributions in patients were very similar to those found in controls. In controls the frequency of the wild type allele increased significantly with age suggesting that the mutant alleles are associated with an increased risk of mortality. These findings suggest that NAT-2 polymorphism is not a major genetic determinant of idiopathic Parkinson's disease, but may be a determinant of mortality in the general population

Diet and Parkinson's disease. II: A possible role for the past intake of specific nutrients. Results from a self-administered food-frequency questionnaire in a case-control study.

Hellenbrand W, Boeing H, Robra BP, et al.

Neurology. 1996 Sep; 47(3):644-50.

In a case-control study, we compared the past dietary habits of 342 Parkinson's disease (PD) patients recruited from nine German clinics with those of 342 controls from the same neighborhood or region. Data were gathered with a structured interview and a self-administered food-frequency questionnaire. Nutrient intakes were calculated from the reported food intakes through linkage with the German Federal Food Code and analyzed using multivariate conditional logistic regression to control for total energy intake, educational status, and cigarette smoking. At the macronutrient level, patients reported higher carbohydrate intake than controls after adjustment for total energy intake, smoking, and educational status (OR = 2.74, 95% confidence interval [CI]: 1.30-6.07, for the highest versus lowest quartile, p trend = 0.02). This was reflected in higher monosaccharide and disaccharide intakes at the nutrient level. There was no difference between patients and controls in protein and fat intake after adjustment for energy intake. We found an inverse association between the intakes of beta-carotene (OR = 0.67, 95% CI: 0.37-1.19, p trend = 0.06) and ascorbic acid (OR = 0.60, 95% CI: 0.33-1.09, p trend = 0.04) by patients, although only the trend for ascorbic acid intake reached statistical significance. There was no difference between groups for alpha-tocopherol intake after adjustment for energy intake. We also found that patients reported a significantly lower intake of niacin than controls (OR = 0.15, 95% CI: 0.07-0.33, p trend < 0.00005). Our results suggest that if antioxidants play a protective role in this disease, the amounts provided by diet alone are insufficient. Although the interpretation of the inverse association between niacin intake and PD is complicated by the high niacin content in coffee and alcoholic beverages, which were also inversely associated with PD in this study, the strength of this association and its biologic plausibility warrant further investigation

Unusual pigmented vesical lesion in a middle-aged woman.

Herrera GA, Turbat-Herrera EA, Lockard VG.

Ultrastruct Pathol. 1990 Nov; 14(6):529-35.

Excess lipofuscin deposition in tissues is a phenomenon observed in normal aging. The amount of lipofuscin in myocardium, liver, skeletal muscle, and adnexal skin structures varies considerably with age and increases in older individuals. In addition, lipofuscin deposition occurs in association with specific, non-age-related processes; these include melanosis coli, the so-called brown bowel syndrome, and the black thyroid. Localized lipofuscinosis has also been described in the gallbladder, esophagus, and fallopian tubes. The present article adds lipofuscinosis vesicalis to the list of entities characterized by focal lipofuscin deposition. All cases have a characteristic gross appearance that is somewhat variable from entity to entity and in some cases may suggest clinically an ominous pathologic process

Exogenous glutamate enhances glutamate receptor subunit expression during selective neuronal injury in the ventral arcuate nucleus of postnatal mice.

Hu L, Fernstrom JD, Goldsmith PC.

Neuroendocrinology. 1998 Aug; 68(2):77-88.

Administration of high doses of glutamate (Glu) leads to selective neurodegeneration in discrete brain regions near circumventriclular organs of the early postnatal mouse. The arcuate nucleus-median eminence complex (ARC-ME) appears to be the most Glu-sensitive of these brain regions, perhaps because of the intimate relationships between its neurons and specialized astroglial tanycytes. To investigate the mechanism of Glu-induced neuronal loss, we administered graded doses of the sodium salt of glutamate (MSG) to postnatal mice, measured their plasma Glu concentrations, and performed microscopic analyses of the ARC-ME region 5 h after treatment. Nursing, 7-day-old mouse pups (CD1, Charles River, Hollister, Calif.) were injected subcutaneously with single doses of 0.1-0.5 or 1.0-4.0 mg of MSG per g BW, or with water vehicle alone. Mice were decapitated 5 h later and the brains immediately fixed by immersion in buffered aldehydes. Frontal vibratome tissue sections at comparable levels of the ARC-ME were examined by light microscopy. A dose of 4.0 mg MSG/g BW caused neurodegeneration throughout the ARC region, while 1.0 mg/g MSG resulted in less extensive damage. Injection of 0.2 mg MSG/g BW, which raised plasma Glu concentrations 17-fold after 15 min, was the minimum dose tested at which nuclear and cytoplasmic changes were observed in a small group of subependymal neurons near the lateral recesses of the third ventricle. Higher doses of 0.3-0.5 mg MSG caused injury to additional neurons situated farther laterally, but damage remained confined to the ventral region of the ARC nucleus. Ultrastructural examination showed some subependymal neurons with pyknotic nuclei, reduced cytoplasmic volume, and swollen subcellular organelles, while others had fragmented and condensed nuclear material. Immunostaining for tyrosine hydroxylase indicated that dopamine neurons were spared at the threshold dose, but suffered damage after higher doses of MSG. Immunostaining for Glu receptor subtypes revealed that 0.2 mg MSG/g BW enhanced neuronal expression of NMDAR1 and of GluR2/4, and that higher doses of MSG preferentially increased NMDAR1 expression in injured neurons. These results extend previous reports of Glu sensitivity in the ARC-ME region of 7-day postnatal mice. A dose of 0.2 mg MSG/g BW s.c. causes clear but discrete injury to specific subependymal neurons of undetermined phenotype near the base of the third ventricle. Slightly higher doses of MSG evoke damage of additional neurons confined to the ventral region of the ARC traversed by tanycytes. These same greater amounts of MSG promote dose-related increase in the expression of NMDAR1 more than of GluR2/4 in injured ARC neurons, suggesting that elevated Glu receptor levels may contribute to or be related to neuronal cell death. Taken together with previous findings, the data suggest that Glu responsitivity in the ARC-ME of the postnatal mouse may result from transient developmental conditions involving the numerical ratios and juxtaposition between tanycytes and neurons, expression of Glu receptors, and perhaps other ontogenetic factors which may not persist in the mature adult

[Endotoxin-induced injury to the endothelium].

Iakovlev MI, Likhoded VG, Anikhovskaia IA, et al.

Arkh Patol. 1996 Mar; 58(2):41-5.

Literature and own data on endotoxin- induced injuries to endothelium are reviewed. It is shown that endotoxin can cause, hyperactivation of granulocytes, activation of complements, local endothelial injuries and some increase of vascular cell wall permeability, oxidation of low-density lipoproteins (LDL) and LDL-LPS complexes, binding of LPS with high-density lipoproteins (HDL) and some decrease of HDL ability to bind cholesterol, stimulation of endothelial and smooth muscle cell replication in local injuries to vessel wall. Low doses of endotoxin were found in blood plasma and on granulocytes surface in healthy and sick subjects. It is concluded that intestinal microflora endotoxin may play an essential role in pathogenesis of atherosclerosis

Metals.

International Occupational Safety and Health Information Centre.

1999;1999 Sep;

Impact of nocturnal bruxism on mercury uptake from dental amalgams.

Isacsson G, Barregard L, Selden A, et al.

Eur J Oral Sci. 1997 Jun; 105(3):251-7.

The mercury (Hg) release from dental amalgam fillings increases by mechanical stimulation. The aim of this study was to investigate the possible impact of nocturnal bruxism on Hg exposure from dental amalgams and to evaluate the effect of an occlusal appliance. 88 female patients from an orofacial pain clinic with a complete maxillary and mandibular dentition, a normal frontal vertical overbite with cuspid guidance, and at least 4 occlusal amalgam fillings in contact with antagonists in intercuspidal position, were examined with the Bruxcore bruxism monitoring device to measure the level of on-going nocturnal bruxism. Based on the degree of abrasion recorded, the subjects were divided into a group defined as bruxists, (n = 29), another group defined as non-bruxists, (n = 32), serving as controls, the intermediate group being discarded. The Hg exposure was assessed from the Hg concentration in plasma and urine, corrected for the creatinine content. In a regression model with bruxism as the only explanatory variable, no significant effect of bruxism was found, but when the number of amalgam fillings, chewing gum use, and other background variables were taken into account, there was a limited impact of bruxism on Hg in plasma. The nocturnal use of an occlusal appliance did not, however, significantly change the Hg levels. This study indicates that mechanical wear on amalgams from nocturnal bruxism may increase the Hg uptake, but the magnitude of this effect seems to be less than from the use of chewing gum

Serum levels of coenzyme Q10 in patients with Parkinson's disease.

Jimenez-Jimenez FJ, Molina JA, De Bustos F, et al.

J Neural Transm. 2000; 107(2):177-81.

We compared serum levels of coenzyme Q10 and the coenzyme Q10/cholesterol ratio in 33 patients with Parkinson's disease (PD) and 31 matched controls. The mean serum coenzyme Q10 levels did not differ significantly between the 2 study groups. Coenzyme Q10 levels were not correlated with age, age at onset, duration of the disease, scores of the Unified Parkinson Disease Rating Scale (UPDRS) or the Hoehn and Yahr staging in the PD group. The coenzyme Q10/cholesterol ratio had a significant correlation (although low) with duration of the disease (r = -0.46), total UPDRS score (r = -0.39), motor examination of the UPDRS (r = 0.45). These values were not influenced significantly by therapy with levodopa or dopamine agonists. The normality of serum coenzyme Q10 and coenzyme Q10/cholesterol ratio suggest that these values are not related with the risk for PD

Parkinson's disease as multifactorial oxidative neurodegeneration: implications for integrative management.

Kidd PM.

Altern Med Rev. 2000 Dec; 5(6):502-29.

Parkinson's disease (PD) is the most common movement pathology, severely afflicting dopaminergic neurons within the substantia nigra (SN) along with non-dopaminergic, extra-nigral projection bundles that control circuits for sensory, associative, premotor, and motor pathways. Clinical, experimental, microanatomic, and biochemical evidence suggests PD involves multifactorial, oxidative neurodegeneration, and that levodopa therapy adds to the oxidative burden. The SN is uniquely vulnerable to oxidative damage, having high content of oxidizable dopamine, neuromelanin, polyunsaturated fatty acids, and iron, and relatively low antioxidant complement with high metabolic rate. Oxidative phosphorylation abnormalities impair energetics in the SN mitochondria, also intensifying oxygen free radical generation. These pro-oxidative factors combine within the SN dopaminergic neurons to create extreme vulnerability to oxidative challenge. Epidemiologic studies and long-term tracking of victims of MPTP (1-methyl-4-phenyl-1,2,3,6,-tetrahydropyridine) poisoning, suggest oxidative stress compounded by exogenous toxins may trigger the neurodegenerative progression of PD. Rational, integrative management of PD requires: (1) dietary revision, especially to lower calories; (2) rebalancing of essential fatty acid intake away from pro-inflammatory and toward anti-inflammatory prostaglandins; (3) aggressive repletion of glutathione and other nutrient antioxidants and cofactors; (4) energy nutrients acetyl L-carnitine, coenzyme Q10, NADH, and the membrane phospholipid phosphatidylserine (PS), (5) chelation as necessary for heavy metals; and (6) liver P450 detoxification support

Dopamine neurons derived from embryonic stem cells function in an animal model of Parkinson's disease.

Kim JH, Auerbach JM, Rodriguez-Gomez JA, et al.

Nature. 2002 Jul 4; 418(6893):50-6.

Parkinson's disease is a widespread condition caused by the loss of midbrain neurons that synthesize the neurotransmitter dopamine. Cells derived from the fetal midbrain can modify the course of the disease, but they are an inadequate source of dopamine-synthesizing neurons because their ability to generate these neurons is unstable. In contrast, embryonic stem (ES) cells proliferate extensively and can generate dopamine neurons. If ES cells are to become the basis for cell therapies, we must develop methods of enriching for the cell of interest and demonstrate that these cells show functions that will assist in treating the disease. Here we show that a highly enriched population of midbrain neural stem cells can be derived from mouse ES cells. The dopamine neurons generated by these stem cells show electrophysiological and behavioural properties expected of neurons from the midbrain. Our results encourage the use of ES cells in cell-replacement therapy for Parkinson's disease

Structural changes in alpha-synuclein affect its chaperone-like activity in vitro.

Kim TD, Paik SR, Yang CH, et al.

Protein Sci. 2000 Dec; 9(12):2489-96.

Alpha-synuclein, a major constituent of Lewy bodies (LBs) in Parkinson's disease (PD), has been implicated to play a critical role in synaptic events, such as neuronal plasticity during development, learning, and degeneration under pathological conditions, although the physiological function of alpha-synuclein has not yet been established. We here present biochemical evidence that recombinant alpha-synuclein has a chaperone-like function against thermal and chemical stress in vitro. In our experiments, alpha-synuclein protected glutathione S-transferase (GST) and aldolase from heat-induced precipitation, and alpha-lactalbumin and bovine serum albumin from dithiothreitol (DTT)-induced precipitation like other molecular chaperones. Moreover, preheating of alpha-synuclein, which is believed to reorganize the molecular surface of alpha-synuclein, increased the chaperone-like activity. Interestingly, in organic solvents, which promotes the formation of secondary structure, alpha-synuclein aggregated more easily than in its native condition, which eventually might abrogate the chaperone-like function of the protein. In addition, alpha-synuclein was also rapidly and significantly precipitated by heat in the presence of Zn2+ in vitro, whereas it was not affected by the presence of Ca2+ or Mg2+. Circular dichroism spectra confirmed that alpha-synuclein underwent conformational change in the presence of Zn2+. Taken together, our data suggest that alpha-synuclein could act as a molecular chaperone, and that the conformational change of the alpha-synuclein could explain the aggregation kinetics of alpha-synuclein, which may be related to the abolishment of the chaperonic-like activity

Cerebellar norepinephrine in patients with Parkinson's disease and control subjects.

Kish SJ, Shannak KS, Rajput AH, et al.

Arch Neurol. 1984 Jun; 41(6):612-4.

Norepinephrine was measured in postmortem cerebellar cortex of 22 non-neurological control subjects and nine patients with Parkinson's disease, using the high-performance liquid chromatography method with amperometric detection. In all control subjects, substantial amounts of norepinephrine was found in cerebellar cortex. There was a moderate negative correlation between age of control subjects and cerebellar norepinephrine concentration. In the patients with Parkinson's disease, the cerebellar cortical norepinephrine levels were significantly below normal. This is in accord with previously reported reduced norepinephrine levels in locus ceruleus and other regions of the parkinsonian brain. Although the main symptoms of Parkinson's disease are primarily caused by disturbed basal ganglia (dopamine) function, cerebellar dysfunction related to norepinephrine may contribute to some abnormalities of motor performance in this disorder

[Histological study on possibility of senile dementia diagnosis in forensic autopsy cases].

Kubo S, Ogata M, Kitamura O, et al.

Nippon Hoigaku Zasshi. 1990 Feb; 44(1):18-24.

Forensic autopsied brains from 57 cases were examined to establish histopathological criteria for normal aging and senile dementia. Senile plaques, neurofibrillary tangles (NFT), amyloid angiopathy and lipofuscin deposits were quantified in the occipital lobe and in the hippocampus. Histopathological data were analysed by the image analyzer. The primitive senile plaque (SPP) and lipofuscin deposits were observed over age of 50. The senile plaque with core (SPC) and NFT were presented in the cases above 70 year of age. There were close correlation between the individual age in non-demented, and the number, size and occupation ratio of SPC in the occipital lobe and hippocampus. In the dementia cases, the occupation ratio of SPC in the hippocampus and the number of SPP in the occipital cortex were significantly increased against the non-demented group

Oral levodopa/carbidopa solution versus tablets in Parkinson's patients with severe fluctuations: a pilot study.

Kurth MC, Tetrud JW, Irwin I, et al.

Neurology. 1993 May; 43(5):1036-9.

Four patients with Parkinson's disease, optimally treated with levodopa/carbidopa (LD/CD) tablets but experiencing severe motor fluctuations, underwent an open trial of a levodopa/carbidopa/ascorbic acid solution (LCAS) orally at timed intervals. LCAS reduced bradykinesia, decreased dysfunctional dyskinesia, and increased functional "on" time when compared with previous LD/CD tablet therapy. Oral LCAS allowed better titration of levodopa dosage and offered a more predictable response than LD/CD tablets. Preparation and oral consumption of LCAS was easy and inexpensive. LCAS may be a practical alternative for patients whose motor fluctuations fail to respond to optimal therapy with LD/CD tablets

[Drug-induced parkinsonism].

Kuzuhara S.

Nippon Rinsho. 1997 Jan; 55(1):112-7.

Drug-induced parkinsonism(DIP) is at present the second most frequent cause of parkinsonism next to idiopathic Parkinson's disease(PD) in Japan. The ratio of the incidence of DIP to PD has been reported to be between 1:2 and 1:5, which varied at the period surveyed. The most frequent causative drugs were calcium-blocking agents, flunarizine and cinnarizine in 1980s, and they have been replaced in recent years by benzamide derivatives with antipsychotic, antiemetic or prokinetic actions, sulpiride, tiapride and metoclopraramide. The clinical features of DIP are similar to those of PD except for rather rapid progression of the symptoms. Careful neurological examination and check of all drugs the patient has taken are important for correct diagnosis. Most causative drugs act as the dopamine D2 receptor blocker in the brain and discontinuance of the drug(s) is necessary for the treatment. Parkinsonian symptoms begin to improve in several weeks and patients are relieved from the symptoms usually within several months

Thiamin mono- and pyrophosphatase activities from brain homogenate of Guamanian amyotrophic lateral sclerosis and parkinsonism-dementia patients.

Laforenza U, Patrini C, Poloni M, et al.

J Neurol Sci. 1992 Jun; 109(2):156-61.

Thiamin-pyrophosphatase (TPPase) and thiamin-monophosphatase (TMPase) were determined using a spectrophotometric method at various pH values (5.5, 7.5, and 9.0) in brain tissue obtained at autopsy from amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia (PD) patients from Guam and from Guamanian patients who died from other diseases (controls). TPPase separation by thin-layer polyacrylamide gel isoelectric focusing (IEF) was also performed using both gray and white matter. TPPase content, chemically determined at pH 9.0, was found to be significantly reduced in the frontal cortex of ALS and PD patients compared to controls. TMPase content, on the contrary, was unchanged. IEF analysis showed 9 clear-cut bands with TPPase activity in the pH range 5.4-7.2 and a broad band at pH 4.7-5.2. The enzymatic activity was higher in gray than in white matter. In one patient the pattern was clearly different, with two additional bands observed at pH 7.1 and 6.7, and thought to be due to genetic microheterogeneity

Inhibition of brain glycolysis by aluminum.

Lai JC, Blass JP.

J Neurochem. 1984 Feb; 42(2):438-46.

Aluminum inhibited both the cytosolic and mitochondrial hexokinase activities in rat brain. The IC50 values were between 4 and 9 microM. Aluminum was effective at mildly acidic (pH 6.8) or slightly alkaline (pH 7.2-7.5) pH, in the presence of a physiological level of magnesium (0.5 mM). However, saturating (8 mM) magnesium antagonized the effect of aluminum on both forms of hexokinase activity. Other enzymes examined were considerably less sensitive to inhibition by aluminum. The IC50 of aluminum for phosphofructokinase was 1.8 mM and for lactate dehydrogenase 0.4 mM. At 10-600 microM, aluminum actually stimulated pyruvate kinase. Aluminum also inhibited lactate production by rat brain extracts: this effect was much more marked with glucose as substrate than with glucose-6-phosphate. However, the IC50 for inhibiting lactate production using glucose as substrate was 280 microM, higher than that required to inhibit hexokinase. This concentration of aluminum is comparable to those reportedly found in the brains of patients who had died with dialysis dementia and in the brains of some of the patients who had died with Alzheimer disease. Inhibition of carbohydrate utilization may be one of the mechanisms by which aluminum can act as a neurotoxin

Tryptophan deficiency stupor--a new psychiatric syndrome.

Lehmann J.

Acta Psychiatr Scand Suppl. 1982; 300:1-57.

Dehydroepiandrosterone (DHEA) reduces neuronal injury in a rat model of global cerebral ischemia.

Li H, Klein G, Sun P, et al.

Brain Res. 2001 Jan 12; 888(2):263-6.

Introduction: Many studies report an inverse correlation between levels of DHEA and neurological diseases. Exogenous DHEA protects hippocampal neurons against excitatory amino acid induced neurotoxicity. The purpose of this experiment is to evaluate the effect of DHEA in an animal model of transient but severe forebrain ischemia. Methods: At thirteen days prior to induction of ischemia, male Wistar rats were implanted with various doses of DHEA-placebo, 25 mg, 50 mg or 100 mg. Forebrain ischemia was induced for 10 min using a modified four-vessel occlusion technique, with hippocampal neuronal injury assessed at 7 days post-ischemically and expressed as a percentage of total cells. Results: Both normal and necrotic hippocampal CA(1) cells were counted. Percentages of hippocampal injury observed were 88+/-13% in animals treated with placebo, 84+/-8% in the 25 mg DHEA group, and 60+/-7% in the 50 mg DHEA group. Animals treated with 100 mg DHEA displayed a significant (P<0.05) reduction of hippocampal CA(1) cell injury at 60+/-7% Conclusion: Treatment with a high dose, but not a low or moderate dose, of DHEA implantation reduces hippocampal CA(1) neuronal injury following severe but transient forebrain ischemia

[Treatment of complicated Parkinson disease with a solution of levodopa-carbidopa and ascorbic acid].

Linazasoro G, Gorospe A.

Neurologia. 1995 Jun; 10(6):220-3.

We prescribed a solution of levodopa-carbidopa and ascorbic acid (LCAAS) to 21 Parkinsonian patients with motor complications. Eight patients continued the treatment for a mean period of 16.8 months, experiencing substantial increases in the number of hours with good functional capacity. Bothersome symptoms such as dystonia and akathisia in off periods disappeared in all cases in which they had been present and LCAAS was tolerated (in 6 of the 8 patients who continued in the study and in 4 who abandoned treatment late). Intake of other anti-Parkinsonian drugs was reduced. Thirteen patients abandoned the study, citing exacerbation of biphasic dyskinesia as the main reason. We conclude that LCAAS is a useful therapy in some Parkinsonian patients whose motor complications are not managed with conventional drug treatment. Screening of patients is probably of utmost importance to ensure that LCAAS is not administered to patients who already suffer intense biphasic dyskinesia

Redox reactions of neurotransmitters possibly involved in the progression of Parkinson's Disease.

Linert W, Jameson GN.

J Inorg Biochem. 2000 Apr; 79(1-4):319-26.

In Parkinson's Disease the neuromelanin in the substania nigra is known to contain considerably increased amounts of iron suggesting the presence of free, unprotected iron ions during its formation. Iron(II) is known to interact with peroxide via Fenton's reaction producing OH-radicals or ferryl (Fe(IV)) species. This can readily oxidize the neurotransmitter dopamine to the neurotoxic 6-hydroxydopamine (6-OHDA) which is a strong reducing agent. The produced 6-OHDA is, in turn, able to reduce and possibly release iron, as iron(II), from the iron storage protein ferritin. This cycle of events could well explain the development of Parkinson's Disease due to a continuous production of cell damaging species. The contrasting behaviour of 6-OHDA with some other important catecholamines is discussed

Attenuation of paraquat-induced dopaminergic toxicity on the substantia nigra by (-)-deprenyl in vivo.

Liou HH, Chen RC, Chen TH, et al.

Toxicol Appl Pharmacol. 2001 Apr 1; 172(1):37-43.

(-)-Deprenyl (DEP) had been shown to slow of progression of Parkinson's disease (PD). The present study sought to determine whether DEP would attenuate the nigrostriatal system damage induced by intranigral administration of the herbicide paraquat (PQ) as a model of parkinsonism in vivo. Neurochemical and behavioral observations of Wistar rats were the focus of our study. In the neurochemical observation, the PQ injected in the rats caused dose-dependent depletion of dopamine (DA) in the ipsilateral striata. The coadministration of DEP with PQ partially increased the striatal DA level. The prediction of the striatal DA levels was calculated by regression coefficients obtained from multiple linear regression (r(2) = 0.82): DA level (% of control) = 103.34 - 9.58 PQ (nmol) + 0.79 DEP (nmol). It was demonstrated that the high dose of 20 nmol DEP could significant attenuate the PQ (5 nmol)-elicited dopaminergic toxicity (p < 0.05). In the behavioral observation, the intranigral injection of PQ into the rats caused a rotation behavior contralateral to the lesioned side in response to apomorphine administration (0.5 mg/kg, sc). This apomorphine-induced rotational behavior could also be attenuated significantly by coadministration of DEP (20 nmol) and PQ (5 nmol) compared with PQ-treated (5 nmol) animals (p < 0.05). The above observations indicate that DEP could provide a protective effect on the moderate injury elicited by PQ toxicity of the nigrostriatal dopaminergic system. DEP might be a useful therapeutic agent in treating patients with early-stage PD

Dietary lipids and antioxidants in Parkinson's disease: a population-based, case-control study.

Logroscino G, Marder K, Cote L, et al.

Ann Neurol. 1996 Jan; 39(1):89-94.

Oxidative stress plays an important role in the pathogenesis of Parkinson's disease (PD). In a population-based, case-control study we examined whether dietary intake of antioxidants and other oxidative compounds was associated with PD. Dietary intake was assessed by a semiquantitative food-frequency questionnaire in 110 PD case patients and 287 control subjects. A higher caloric intake was observed in patients with PD and did not vary with increasing duration of symptoms. Energy-adjusted fat intake was significantly higher among patients with PD than control subjects (p for trend = 0.007). Intake of protein (p for trend = 0.17) and carbohydrates (p for trend = 0.46) did not differ in patients and control subjects. Analyses of the primary sources of fat indicated that increasing intake of animal fats were strongly related to PD (odds ratio, 5.3; 95% confidence interval, 1.8-15.5; p for trend = 0.001). No significant differences were observed for intake of vitamins with antioxidant activity. An increase in the consumption of animal fats among patients with PD is consistent with the hypothesis that oxidative stress and lipid peroxidation are important in the pathogenesis of this disease. No effect of vitamins with antioxidant activity, either from food or supplements, was observed

[Neural transplants en Parkinson disease: clinical results of 10 years of experience. Group of Neural Transplants of the CPH].

Lopez-Lozano JJ, Mata M, Bravo G.

Rev Neurol. 2000 Jun 1; 30(11):1077-83.

INTRODUCTION: At the end of the 1970s people considered the possibility that transplants might be useful to replace degenerate specific cell populations, such as the mesencephalic dopaminergic neurones in Parkinson's disease (PD). Since then this has become an experimental alternative treatment for patients with degenerative diseases. The history of transplants of catecholamine producing tissues within the brain of patients with PD started in 1985, when Backlund et al published the results of the first implants of autologous adrenal medulla in two patients with Parkinsonism. Since then, many patients throughout the world have benefited from the results obtained using this method. Two main types of tissue have been used in this method: autologous adrenal medulla and human foetal ventral mesencephalic tissue. DEVELOPMENT: In this paper we first review the clinical effects of the diverse types of transplant done to date. Then in the second part we give a summary of the clinical results obtained by our group with the different types of transplant carried out. We explain their evolution, original hypothesis and justify the reasons which led us to use three different types of donor material: autologous adrenal medulla, fetal tissue and adrenal medulla co-incubated with peripheral nerve. Then, after showing that the clinical improvement is different depending on the type of tissue transplanted, we comment on the probable reason for the improvement seen in patients with implants. CONCLUSION: The transplantation of nervous tissue seems to us to be no longer an experimental alternative for the treatment of PD but has become an effective, lasting treatment for patients with Parkinson's disease

The EEG in progressive dialysis encephalopathy: the EEG in diagnosing and screening for PDE. (Part. I).

Luda E.

Ital J Neurol Sci. 1984 Dec; 5(4):369-73.

An EEG study was carried out on 50 patients undergoing chronic dialysis, 5 of whom had progressive dialysis encephalopathy (PDE), with the aim of confirming the reliability of EEG for diagnosing PDE and detecting patients at risk reported in previous papers. The outcome of the study confirms the high sensitivity of EEG for these purposes

Subthalamic GAD gene therapy in a Parkinson's disease rat model.

Luo J, Kaplitt MG, Fitzsimons HL, et al.

Science. 2002 Oct 11; 298(5592):425-9.

The motor abnormalities of Parkinson's disease (PD) are caused by alterations in basal ganglia network activity, including disinhibition of the subthalamic nucleus (STN), and excessive activity of the major output nuclei. Using adeno-associated viral vector-mediated somatic cell gene transfer, we expressed glutamic acid decarboxylase (GAD), the enzyme that catalyzes synthesis of the neurotransmitter GABA, in excitatory glutamatergic neurons of the STN in rats. The transduced neurons, when driven by electrical stimulation, produced mixed inhibitory responses associated with GABA release. This phenotypic shift resulted in strong neuroprotection of nigral dopamine neurons and rescue of the parkinsonian behavioral phenotype. This strategy suggests that there is plasticity between excitatory and inhibitory neurotransmission in the mammalian brain that could be exploited for therapeutic benefit

Novel physical treatments for the management of neuropsychiatric disorders.

Malhi GS, Sachdev P.

J Psychosom Res. 2002 Aug; 53(2):709-19.

OBJECTIVE: To briefly describe the novel non-drug physical interventions currently in use in the investigation and treatment of neuropsychiatric disorders regarding their efficacy and potential future applications. METHODS: A systematic review of the literature concerning transcranial magnetic stimulation (TMS), deep brain stimulation (DBS), vagus nerve stimulation (VNS) and neurosurgery for mental disorders (NMD) was conducted using Medline and literature known to the authors. RESULTS: A summary of each procedure is provided giving a succinct overview of efficacy, current applications and possible future indications. CONCLUSION: Novel and innovative physical interventions are currently being used to study brain function in health and disease. In particular, TMS has quickly established itself as a useful investigational tool and is emerging as a possible antidepressant therapy. Similarly, VNS has been applied successfully in the management of intractable epilepsy and is undergoing evaluation in the management of patients with treatment-resistant depression. DBS has shown significant promise in the treatment of Parkinson's disease and may have use in the management of obsessive-compulsive disorder. Finally, neurosurgical procedures for the treatment of mental disorders have been sufficiently refined to stage a comeback, although rigorous scientific study of their efficacy and indications is still necessary

Drugs inducing or aggravating parkinsonism: a review.

Marti-Masso JF, Poza JJ, Lopez dM.

Therapie. 1996 Sep; 51(5):568-77.

Drug-induced parkinsonism (DIP) is frequent. The list of drugs able to induce parkinsonism is long and probably incomplete, because new drugs, with previously unknown antidopaminergic activity, are constantly being added. Not all the drugs have the same potency for inducing parkinsonism. We classify these drugs in three groups: (1) drugs with obvious antidopaminergic activity which regularly induce parkinsonism; (2) drugs able to induce parkinsonism in particular individuals and (3) drugs which may aggravate Parkinson's disease treated with levodopa. The reports of isolated cases of parkinsonism induced by widely-used drugs (drugs in group 2) may be the result of either an idiosyncratic side effect or a misdiagnosis of parkinsonism. The antidopaminergic activity of the drugs of this group is weak and not sufficiently demonstrated. Maybe, in these cases, the blockage of other neurotransmitters different from dopamine plays a role in the induction of parkinsonism. Probably, the number of patients with DIP is higher than reported or detected, because many patients suffer from weak symptoms that quickly disappear after drug withdrawal. One of the main points of interest is knowing the list, because all these drugs, specially those of group 1, should be avoided or used with caution in the treatment of some common symptomatic problems in patients with Parkinson's disease, such as depression, arterial hypertension, diabetes mellitus and cardiac disorders. The precautions should extent to other populations especially susceptible to suffer from DIP, such as the elderly or patients with other neurodegenerative disorders, such as Alzheimer's disease

Coenzyme Q10 administration increases brain mitochondrial concentrations and exerts neuroprotective effects.

Matthews RT, Yang L, Browne S, et al.

Proc Natl Acad Sci U S A. 1998 Jul 21; 95(15):8892-7.

Coenzyme Q10 is an essential cofactor of the electron transport chain as well as a potent free radical scavenger in lipid and mitochondrial membranes. Feeding with coenzyme Q10 increased cerebral cortex concentrations in 12- and 24-month-old rats. In 12-month-old rats administration of coenzyme Q10 resulted in significant increases in cerebral cortex mitochondrial concentrations of coenzyme Q10. Oral administration of coenzyme Q10 markedly attenuated striatal lesions produced by systemic administration of 3-nitropropionic acid and significantly increased life span in a transgenic mouse model of familial amyotrophic lateral sclerosis. These results show that oral administration of coenzyme Q10 increases both brain and brain mitochondrial concentrations. They provide further evidence that coenzyme Q10 can exert neuroprotective effects that might be useful in the treatment of neurodegenerative diseases

Effect of antioxidants on L-glutamate and N-methyl-4-phenylpyridinium ion induced-neurotoxicity in PC12 cells.

Mazzio E, Huber J, Darling S, et al.

Neurotoxicology. 2001 Apr; 22(2):283-8.

The neuropathology associated with Parkinson's disease within and around the substantia nigra is thought to involve excessive production of free radicals, dopamine autoxidation, defects in the expression of glutathione peroxidase, attenuated levels of reduced glutathione, altered calcium homeostasis, excitotoxicity and genetic defects in mitochondrial complex I activity. While the neurotoxic mechanisms are vastly different for excitotoxins and N-methyl-4-phenylpyridinium ion (MPP+), both are thought to involve free radical production, compromised mitochondrial activity and excessive lipid peroxidation. In the present study, several dietary antioxidant compounds, monoamine oxidase inhibitors and ergogenic compounds were examined for protective action against neurotoxicity induced by L-glutamate (15 mM) or MPP+-HCl (5 mM) in a plastic adhering variant of murine pheochromocytoma cells. The results show no significant protective effects exhibited by azulene, (+)-catechin, curcrumin, (-)-epigallocatechin gallate, green tea, morin, pygnogenol, silymarin, clove oil, garlic oil or rosemary, extract. Compounds, which were effective in providing protection against L-glutamate-induced cell death, were coenzyme Q-0, coenzyme Q-10, L-deprenyl and N-acetyl-L-cysteine. Compounds, which provided protection against MPP+-HCl toxicity, were allopurinol, coenzyme Q-10, L-deprenyl, N-acetyl-L-cysteine and sesame oil. In both models, significant protection was achieved in the presence of coenzyme Q-10, L-deprenyl and N-acetyl-L-cysteine. These results indicate that the mechanism of cell death in both of these toxicity models is most likely not related to the destructive effects of free radicals

Phenotypic variation in xenobiotic metabolism and adverse environmental response: focus on sulfur-dependent detoxification pathways.

McFadden SA.

Toxicology. 1996 Jul 17; 111(1-3):43-65.

Proper bodily response to environmental toxicants presumably requires proper function of the xenobiotic (foreign chemical) detoxification pathways. Links between phenotypic variations in xenobiotic metabolism and adverse environmental response have long been sought. Metabolism of the drug S-carboxymethyl-L-cysteine (SCMC) is polymorphous in the population, having a bimodal distribution of metabolites, 2.5% of the general population are thought to be nonmetabolizers. The researchers developing this data feel this implies a polymorphism in sulfoxidation of the amino acid cysteine to sulfate. While this interpretation is somewhat controversial, these metabolic differences reflected may have significant effects. Additionally, a significant number of individuals with environmental intolerance or chronic disease have impaired sulfation of phenolic xenobiotics. This impairment is demonstrated with the probe drug acetaminophen and is presumably due to starvation of the sulfotransferases for sulfate substrate. Reduced metabolism of SCMC has been found with increased frequency in individuals with several degenerative neurological and immunological conditions and drug intolerances, including Alzheimer's disease, Parkinson's disease, motor neuron disease, rheumatoid arthritis, and delayed food sensitivity. Impaired sulfation has been found in many of these conditions, and preliminary data suggests that it may be important in multiple chemical sensitivities and diet responsive autism. In addition, impaired sulfation may be relevant to intolerance of phenol, tyramine, and phenylic food constituents, and it may be a factor in the success of the Feingold diet. These studies indicate the need for the development of genetic and functional tests of xenobiotic metabolism as tools for further research in epidemiology and risk assessment

The role of glutamatergic transmission in the pathogenesis of levodopa-induced dyskinesias. Potential therapeutic approaches.

Merims D, Ziv I, Sherki Y, et al.

Neurol Neurochir Pol. 2001; 35 Suppl 3:65-8.

Dyskinesias are the most frequent adverse effect of chronic levodopa therapy in patients with Parkinson's disease (PD). Current pharmacological treatment for this problem is unsatisfactory. Recently, there is evidence for the role of glutamate in the basal ganglia neuronal circuitry in the generation of dyskinesias. If indeed glutamatergic overactivity beyond the dopaminergic synapses plays a role in the pathogenesis of these involuntary movements, there is hope that its suppression may be beneficial without causing loss of levodopa efficacy and parkinsonian deterioration. Indeed, NMDA receptor antagonists such as amantadine and dextrometorphan can reduce such dyskinesias. We tested the efficacy of riluzole, an inhibitor of glutamatergic transmission in the inhibition of levodopa-induced dyskinesias

Genetic polymorphisms of drug metabolism.

Meyer UA, Zanger UM, Skoda RC, et al.

Prog Liver Dis. 1990; 9:307-23.

L-tryptophan in the treatment of levodopa-induced psychiatric disorders.

Miller EMNHA.

Dis Nerv Syst. 1974; 35(1):20-3.

Inhibition of transducin activation and guanosine triphosphatase activity by aluminum ion.

Miller JL, Hubbard CM, Litman BJ, et al.

J Biol Chem. 1989 Jan 5; 264(1):243-50.

Aluminum ion perturbs the activity of a number of physiologically important enzymes, including members of a family of guanine nucleotide-binding proteins (G-proteins). G-proteins couple cellular receptor proteins to a variety of effector enzymes (including adenylate cyclase, phospholipase C, and the rod photoreceptor phosphodiesterase). We show herein that subnanomolar concentrations of free aluminum ion, produced in a carefully defined and kinetically stable manner through the buffering of total aluminum at 0.1-1.0 mM with calculated ratios of chelating agents, inhibit both the receptor-mediated activation and the self-inactivating GTPase activity of the rod photoreceptor G-protein, Gv. In the presence of 4 X 10(-10) M free aluminum ion, GTPase activity is inhibited from about 25-60% as the magnesium ion concentration is reduced from 10(-3) to about 5 X 10(-5) M. The principal effect of aluminum ion upon Gv is to inhibit receptor catalyzed nucleotide exchange. Binding of the GTP analog 5'-guanylyl imidodiphosphate can be reduced by as much as 90% by aluminum ion following subsaturating rhodopsin stimulation. Aluminum ion can produce either competitive or mixed noncompetitive inhibition of rhodopsin-catalyzed Gv activation and GTPase activity, as a function of whether Gv undergoes single (competitive), or multiple (mixed noncompetitive) nucleotide exchanges. The rod photoreceptor phosphodiesterase is only slightly inhibited by similar aluminum ion activities. Light- and Gv-coupled phosphodiesterase activation exhibits both a lower maximum rate of cyclic guanosine monophosphate hydrolysis and a slower inactivation in the presence of aluminum ion activities from about 10(-12) - 10(-10) M. These data suggest that intracellular free aluminum ion concentrations in the subnanomolar range could markedly affect the ability of cells to transduce extracellular signals. Interestingly, the combination of Al3+ and F- to produce the fluoro-aluminate species (AlFx) also inhibits the GTPase of G-proteins, although the mechanism of inhibition (e.g. binding to the G-protein.Mg2+.GDP complex) is totally distinct from that observed for free Al3+ and the overall effect on signal transduction (e.g. enhanced signal amplification) is in complete opposition to that observed for free Al3+

Rotations induced by L-dopa in parkinsonian rats are reduced by an ingestion of amino acids.

Mizuta E, Kuno S.

J Neural Transm Park Dis Dement Sect. 1993; 6(3):211-4.

We studied the effect of amino acid load on L-dopa-induced rotational behavior in rats with unilateral lesion of the nigrostriatal pathway. Pretreatment of rats with an ingestion of high concentration of amino acids significantly reduced the number of rotations induced by subcutaneously injected L-dopa. These results provide the experimental basis for clinical observations that dietary protein affects the response to L-dopa in parkinsonian patients

Drug-induced parkinsonism: a review.

Montastruc JL, Llau ME, Rascol O, et al.

Fundam Clin Pharmacol. 1994; 8(4):293-306.

The main clinical features, pathophysiology and underlying mechanisms of drug-induced parkinsonism are reviewed. The clinical manifestations of drug-induced parkinsonism are often indistinguishable from idiopathic Parkinson's disease. However, some subtle differences may exist: for example drug-induced parkinsonism is often associated with tardive dyskinesias, bilateral symptoms and the absence of resting tremor, etc. Besides toxins (eg manganese, carbon monoxide or MPTP), many drugs are known to produce parkinsonism: dopamine blocking drugs (true neuroleptics used as antipsychotics: phenothiazines, butyrophenones, thioxanthenes but also sulpiride, "hidden" neuroleptics prescribed as anti-nausea or anti-vomiting drugs (such as metoclopramide and other benzamide derivatives), dopamine depleting drugs (reserpine, tetrabenazine), alpha-methyldopa, calcium channel blockers (flunarizine, cinnarizine, etc). The putative role of other drugs (eg fluoxetine, lithium, amiodarone) as well as the therapeutic management of this side effect are reviewed

Root canal treatment and general health: a review of the literature.

Murray CA, Saunders WP.

Int Endod J. 2000 Jan; 33(1):1-18.

REVIEW: The focal infection theory was prominent in the medical literature during the early 1900s and curtailed the progress of endodontics. This theory proposed that microorganisms, or their toxins, arising from a focus of circumscribed infection within a tissue could disseminate systemically, resulting in the initiation or exacerbation of systemic illness or the damage of a distant tissue site. For example, during the focal infection era rheumatoid arthritis (RA) was identified as having a close relationship with dental health. The theory was eventually discredited because there was only anecdotal evidence to support its claims and few scientifically controlled studies. There has been a renewed interest in the influence that foci of infection within the oral tissues may have on general health. Some current research suggests a possible relationship between dental health and cardiovascular disease and published case reports have cited dental sources as causes for several systemic illnesses. Improved laboratory procedures employing sophisticated molecular biological techniques and enhanced culturing techniques have allowed researchers to confirm that bacteria recovered from the peripheral blood during root canal treatment originated in the root canal. It has been suggested that the bacteraemia, or the associated bacterial endotoxins, subsequent to root canal treatment, may cause potential systemic complications. Further research is required, however, using current sampling and laboratory methods from scientifically controlled population groups to determine if a significant relationship between general health and periradicular infection exists

Toxic and protective effects of L-dopa on mesencephalic cell cultures.

Mytilineou C, Han SK, Cohen G.

J Neurochem. 1993 Oct; 61(4):1470-8.

The autoxidation of L-DOPA or dopamine (DA) and the metabolism of DA by monoamine oxidase generate a spectrum of toxic species, namely, hydrogen peroxide, oxy radicals, semiquinones, and quinones. When primary dissociated cultures of rat mesencephalon were incubated with L-DOPA (200 microM) for 48 h, the number of tyrosine hydroxylase-positive neurons (DA neurons) was reduced to 69.7% of control values, accompanied by a decrease in [3H]DA uptake to 42.3% of control values; the remaining DA neurons exhibited reduced neurite length and overall deterioration. Lack of simultaneous change in the number of neurons stained with neuron-specific enolase indicated that toxicity was relatively specific for DA neurons. At the same time, the level of GSH, a major cellular antioxidant, rose to 125.2% of control values. Thus, exposure of mesencephalic cultures to L-DOPA results in both damaging and antioxidant actions. Ascorbate (200 microM), an antioxidant, prevented the rise in GSH. The effect of ascorbate on GSH points to an oxidative signal to initiate the rise in GSH content. On the other hand, neither inhibition of monoamine oxidase with pargyline nor addition of superoxide dismutase or catalase to the culture medium prevented the rise in GSH level or the loss in [3H]DA uptake. The latter results tend to exclude the products of monoamine oxidase activity or the presence of hydrogen peroxide or superoxide in the medium as responsible agents for the rise in GSH or neuronal toxicity. In cultures treated with L-buthionine sulfoximine (L-BSO), an inhibitor of GSH synthesis, L-DOPA prevented cell death by L-BSO

Influence of reduced nicotinamide adenine dinucleotide on the production of interleukin-6 by peripheral human blood leukocytes.

Nadlinger K, Birkmayer J, Gebauer F, et al.

Neuroimmunomodulation. 2001; 9(4):203-8.

OBJECTIVE: Recently, therapy with nicotinamide adenine dinucleotide (NADH) revealed positive effects on neurodegenerative disorders associated with inflammation of the CNS, such as Parkinson's disease or Alzheimer's disease. Pathophysiologically, focal CNS inflammation seems to be accompanied by an unbalanced cytokine production, pointing to an involvement of the immune system. Therefore, the aim of our study was to investigate whether NADH could influence cytokine release of peripheral blood leukocytes (PBLs) with special reference to interleukin-6 (IL-6). METHODS: PBLs from 18 healthy donors were incubated in vitro with different concentrations of NADH to generate dose-response curves. As a control, mitogen-treated cells and unstimulated cells were included. RESULTS: In PBLs from the 18 healthy donors, NADH significantly stimulated the dose-dependent release of IL-6, ranging from 6.25 to 400 microg/ml, compared to medium-treated cells (p 25 microg/ml. CONCLUSIONS: It is concluded that NADH possesses cytokine-modulating effects on peripheral blood cells. The biological relevance of these data is discussed in the context of the recent use of NADH for the treatment of several neurodegenerative disorders

Endocrinologic regulation of carbohydrate metabolism. Amyotrophic lateral sclerosis and Parkinsonism-dementia on Guam.

Nagano Y, Tsubaki T, Chase TN.

Arch Neurol. 1979 Apr; 36(4):217-20.

Studies of the endocrinologic control of carbohydrate metabolism were conducted in Guamanians with parkinsonism-dementia (PD) or amyotrophic lateral sclerosis (ALS) and in Guamanian control patients who had various other neuromuscular disorders. Intravenously infused arginine tended to produce a more prolonged elevation in serum glucose levels in PD and ALS patients than in control subjects. On the other hand, the serum insulin response to arginine was significantly less in both PD and ALS patients than in controls. Arginine stimulated the release of growth hormone to a similar degree in all three patient groups. These observations support and extend previous reports of endocrinologic abnormalities in parkinsonism and ALS and might suggest that a defect in pancreatic islet cell function attends these disorders

Evidence suggesting the role of norepinephrine deficiency in late stages of Parkinson's disease.

Narabayashi H.

Adv Neurol. 1999; 80:501-4.

Stem Cells and the Future of Regenerative Medicine.

National Academies.

2002

NIH Publishes Final Guidelines for Stem Cell Research.

NIH.

2000;2000 Aug 23

[Modern concepts of anti-inflammatory therapy in bacterial meningitis].

Nikolic S.

Srp Arh Celok Lek. 1992 Nov; 120(11-12):353-5.

Pathophysiologic disorders in bacterial meningitis and their influence on the course and prognosis of the disease are analysed. Deterioration of the CNS is due to inflammatory response of the host combined with other pathophysiological disorders. Inflammatory response in the subarachnoid space is the most intensive, but the most deleterious, as well, in the first several hours of antibiotic therapy when bacterial disintegration ensues. Fragments of the cell wall and endotoxin are very active components, independent of the presence of living bacteria in the subarachnoid space. Each microorganism induces different inflammatory response, and the course of the disease is, therefore, also different. Bacterial disintegration reta and release of the components are determined by the intensity of the inflammatory response in the subarachnoid space. Which, in turn, determine the degree of tissue damage. Bacterial products stimulate release of inflammatory mediators--cytokines from macrophages and other sources. Local production of cytokines from astrocytes and macroglial cells (macrophage equivalents in the CNS) is the first stage in development of the inflammatory response and tissue destruction. Cytokines induce damage of the CNS by attracting the inflammatory cells and by releasing superoxide anions inducing arachidonic acid metabolism and production of vasoactive metabolites of arachidonic acid which result in damage of blood-brain barrier, having, therefore, a direct cytotoxic effect. Consequences of these pathophysiologic disorders are cerebral oedema and elevated intracranial pressure. Current concepts of antiinflammatory therapy are, in the light of pathophysiological events in the CNS, directed to interruption of cytokine activation (steroids), prevention of production of vasoactive arachidonic acid metabolites (non-steroidal agents), and prevention of leukocyte transfer into the subarachnoid space (antileukocyte, anti-integrin antibodies)

Mercury amalgam toxicity.

O'Brien J.

Life Extension Magazine. 2001;2001 May 7(5):43-51.

Endotoxin and tumor necrosis factor-alpha in the pathogenesis of hepatic encephalopathy.

Odeh M.

J Clin Gastroenterol. 1994 Sep; 19(2):146-53.

Hepatic encephalopathy (HE) is a complex neuropsychiatric syndrome characterized predominantly by augmented neuronal inhibition and probably neuronal damage. Several theories concerning the pathogenesis of HE have been proposed; none of these theories is necessarily exclusive. Furthermore, the validity of none of them has been definitively proved experimentally. In this review article an important role of endotoxin and tumor necrosis factor-alpha (TNF) in the pathogenesis of HE is suggested. The involvement of endotoxin and TNF in the pathogenesis of HE seems to be very convincing; it may explain many of the derangements seen in HE. It also seems to be in strong relation to the main theories about HE, the ammonia theory, the GABAergic theory, the benzodiazepine theory, and the AAA/false neurotransmitter theory, where these theories may represent some of the mechanisms whereby TNF may cause inhibition and damage to the CNS in HE, or may represent accompanying features to elevated levels of endotoxin and TNF, with no important role in the pathogenesis of HE. The possible involvement of endotoxin and TNF in the pathogenesis of HE may possess an important clinical application, for serum LPS and TNF concentrations may be of important diagnostic and prognostic value in HE, and treatment with antibodies against endotoxin and against TNF may have potentially beneficial therapeutic effects in this serious and potentially fatal disease

A rationale for monoamine oxidase inhibition as neuroprotective therapy for Parkinson's disease.

Olanow CW.

Mov Disord. 1993; 8 Suppl 1:S1-S7.

Neurons in the substantia nigra may be vulnerable to oxidant stress because (a) the metabolism of dopamine generates peroxides, which, in the presence of iron, can lead to the formation of the highly reactive hydroxyl free radical; and (b) neuromelanin within nigral neurons can bind metals such as iron and aluminum and thereby promote the site-specific formation of free radicals. Postmortem studies show increased iron, decreased glutathione, and increased lipid peroxidation in the substantia nigra of patients with Parkinson's disease (PD). Recent studies also report iron and aluminum accumulation within neuromelanin granules of patients with PD. These findings suggest that the substantia nigra in the patient with PD is in a state of oxidant stress and that antioxidant therapy might protect residual dopamine neurons and slow the natural progression of PD. Selective inhibitors of monoamine oxidase type B (MAO-B) have been chosen for study because of their capacity to interfere with the oxidative metabolism of dopamine and so diminish the likelihood that free radicals will be formed. Initial studies demonstrate that the MAO-B inhibitor L-deprenyl (selegiline) delays the development of disability in otherwise untreated patients with early Parkinson's disease. Although the mechanism responsible for these observations remains unclear, these results are consistent with the possibility that L-deprenyl provides neuroprotective effects

Significant mercury deposits in internal organs following the removal of dental amalgam, & development of pre-cancer on the gingiva and the sides of the tongue and their represented organs as a result of inadvertent exposure to strong curing light (used to solidify synthetic dental filling material) & effective treatment: a clinical case report, along with organ representation areas for each tooth.

Omura Y, Shimotsuura Y, Fukuoka A, et al.

Acupunct Electrother Res. 1996 Apr; 21(2):133-60.

Because of the reduced effectiveness of antibiotics against bacteria (e.g. Chlamydia trachomatis, alpha-Streptococcus, Borrelia burgdorferi, etc.) and viruses (e.g. Herpes Family Viruses) in the presence of mercury, as well as the fact that the 1st author has found that mercury exists in cancer and pre-cancer cell nuclei, the presence of dental amalgam (which contains about 50% mercury) in the human mouth is considered to be a potential hazard for the individual's health. In order to solve this problem, 3 amalgam fillings were removed from the teeth of the subject of this case study. In order to fill the newly created empty spaces in the teeth where the amalgams had formerly existed, a synthetic dental-filling substance was introduced and to solidify the synthetic substance, curing light (wavelength range reportedly between 400-520 nm) was radiated onto the substance in order to accelerate the solidifying process by photo-polymerization. In spite of considerable care not to inhale mercury vapor or swallow minute particles of dental amalgam during the process of removing it by drilling, mercury entered the body of the subject. Precautions such as the use of a rubber dam and strong air suction, as well as frequent water suctioning and washing of the mouth were insufficient. Significant deposits of mercury, previously non-existent, were found in the lungs, kidneys, endocrine organs, liver, and heart with abnormal low-voltage ECGs (similar to those recorded 1-3 weeks after i.v. injection of radioisotope Thallium-201 for Cardiac SPECT) in all the limb leads and V1 (but almost normal ECGs in the precordial leads V2-V6) the day after the procedures were performed. Enhanced mercury evaporation by increased temperature and microscopic amalgam particles created by drilling may have contributed to mercury entering the lungs and G.I. system and then the blood circulation, creating abnormal deposits of mercury in the organs named above. Such mercury contamination may then contribute to intractable infections or pre-cancer. However, these mercury deposits, which commonly occur in such cases, were successfully eliminated by the oral intake of 100 mg tablet of Chinese parsley (Cilantro) 4 times a day (for average weight adults) with a number of drug-uptake enhancement methods developed by the 1st author, including different stimulation methods on the accurate organ representation areas of the hands (which have been mapped using the Bi-Digital O-Ring Test), without injections of chelating agents. Ingestion of Chinese parsley, accompanied by drug-uptake enhancement methods, was initiated before the amalgam removal procedure and continued for about 2 to 3 weeks afterwards, and ECGs became almost normal. During the use of strong bluish curing light to create a photo-polymerization reaction to solidify the synthetic filling material, the adjacent gingiva and the side of the tongue were inadvertently exposed. This exposure to the strong bluish light was found to produce pre-cancerous conditions in the gingiva, the exposed areas of the tongue, as well as in the corresponding organs represented on those areas of the tongue, and abnormally increased enzyme levels in the liver. These abnormalities were also successfully reversed by the oral intake of a mixture of EPA with DHA and Chinese parsley, augmented by one of the non-invasive drug-uptake enhancement methods previously described by the 1st author, repeated 4 times each day for 2 weeks

Raised cerebrospinal-fluid copper concentration in Parkinson's disease.

Pall HS, Williams AC, Blake DR, et al.

Lancet. 1987 Aug 1; 2(8553):238-41.

The cerebrospinal-fluid copper concentration, measured by electrothermal atomisation/atomic absorption spectrophotometry, was significantly higher in 24 patients with untreated, idiopathic Parkinson's disease than in a control population of 34 patients (p less than 0.001). The difference in the in-vitro capacity of copper to damage DNA, measured by the phenanthroline assay was even greater. The high phenanthroline-copper concentration correlated with disease severity (p = 0.02) and with the rate of progression of disease (p less than 0.05). A possible role is suggested for copper-catalysed oxidative mechanisms in the pathogenesis of Parkinson's disease

Toxic effects of L-DOPA on mesencephalic cell cultures: protection with antioxidants.

Pardo B, Mena MA, Casarejos MJ, et al.

Brain Res. 1995 Jun 5; 682(1-2):133-43.

The toxicity of L-3,4-dihydroxyphenylalanine (L-DOPA) was studied in neuronal cultures from rat mesencephalon. The survival and function of DA neurons were assessed by the number of tyrosine hydroxylase-positive (TH+) cells and 3H-DA uptake and those non-DA neurons by the exclusion of Trypan blue and the high-affinity 3H-GABA uptake. L-DOPA was toxic for both DA and non-DA neurons. DA neurons were more severely affected than non-DA neurons after short periods of treatment and with exposure to a low dose of L-DOPA (25 vs. 100 microM) and less selectively affected after 1 or 2 days of treatment. After incubation with L-DOPA, a disruption of the neuritic network and an overall deterioration were observed, more evident for TH+ cells in the whole culture. Auto-oxidation to quinones is responsible in part for L-DOPA toxicity in non-DA neurons since the levels of quinones correlated well with the severity of cell death in the cultures. The damage of DA neurons took place before the rising of quinones, suggesting that quinones are not essential in L-DOPA toxicity for DA neurons. Antioxidants, such as ascorbic acid and sodium metabisulfite, completely prevented L-DOPA-induced quinone formation as well as the death of non-DA neurons. In contrast, they could only partially prevent the damage produced by L-DOPA in DA neurons. Mazindol, a selective inhibitor of DA uptake, protected TH+ cells from L-DOPA

IgA against gut-derived endotoxins: does it contribute to suppression of hepatic inflammation in alcohol-induced liver disease?

Parlesak A, Schafer C, Bode C.

Dig Dis Sci. 2002 Apr; 47(4):760-6.

Endotoxins of intestinal origin are supposed to play an important role in the development of alcoholic hepatitis in man. To estimate the role of immunoglobulin response to gut-derived endotoxin in the development of alcohol-induced liver disease, serum levels of IgA and IgG against fecal endotoxin, endotoxin, and acute-phase proteins were measured in patients with different stages of alcoholic liver disease and in healthy controls. Antibodies of type IgA, but not IgG, against fecal endotoxins were significantly increased in patients with alcohol-induced liver disease. IgA antibodies against fecal endotoxin were found to be closely correlated with the plasma concentrations of alanine aminotransferase, gamma-glutamyl transferase, and C-reactive protein in patients with alcoholic liver disease. In conclusion, as IgA located in body tissue was shown to suppress the inflammatory process, enhanced production of IgA against endotoxin of intestinal origin may contribute to inactivation of this compound, thereby reducing its damaging effect on the liver

The PDR Pocket Guide to Prescription Drugs.

PDR.

2002; Fifth Edition

Innate immune responses of epithelial cells following infection with bacterial pathogens.

Philpott DJ, Girardin SE, Sansonetti PJ.

Curr Opin Immunol. 2001 Aug; 13(4):410-6.

The ability to discriminate between pathogenic and non-pathogenic bacteria is extremely important for epithelial cells lining mucosal surfaces and is particularly so in colonic epithelial cells. Accumulating evidence suggests that bacterial recognition systems used by epithelial cells are very different from those in cells of the myeloid lineage and are likely to have developed to maintain mucosal surfaces in a state of homeostasis with the normal microbial flora. Bacterial invasion of epithelial cells or breach of the epithelial barrier provides a signal to epithelial cells to initiate inflammatory responses, which are key events for the clearance of the infecting microbe. Therefore, elucidation of the mechanisms by which epithelial cells recognize bacteria and bacterial products, and of the nature of the innate immune responses that are triggered by these factors are important for our understanding of both the immunology of mucosal surfaces and bacterial pathogenesis

L-tryptophan administration in L-dopa-induced hallucinations in elderly Parkinsonian patients.

Rabey JM, Vardi J, Askenazi JJ, et al.

Gerontology. 1977; 23(6):438-44.

L-tryptophan (L-T) was added at a dose of 150-450 mg daily to eight Parkinsonian patients who developed visual hallucinations with paranoidal features under L-dopa (L-D) treatment (112.5-75 mg daily) in combination with alpha-methyldopa hydrazine (12.5-75 mg daily). In six patients L-T ameliorated the symptomatology by arresting the visual paranoidal hallucinations or diminishing their frequency and relieving the psychomotor agitation. As a 'side effect', L-T produced new 'pleasurable', 'LSD-like' visual images in three patients. In two patients, in whom L-T did not affect the mental disturbances, amelioration was obtained only by phenothiazines. Theoretical considerations on the role of dopamine in the genesis of visual hallucinations and mental disturbances emphasizes the benefit of L-T administration in this 'organomental' syndrome

A five-year study of the incidence of dyskinesia in patients with early Parkinson's disease who were treated with ropinirole or levodopa. 056 Study Group.

Rascol O, Brooks DJ, Korczyn AD, et al.

N Engl J Med. 2000 May 18; 342(20):1484-91.

BACKGROUND: There is debate about whether the initial treatment for patients with Parkinson's disease should be levodopa or a dopamine agonist. METHODS: In this prospective, randomized, double-blind study, we compared the safety and efficacy of the dopamine D2-receptor agonist ropinirole with that of levodopa over a period of five years in 268 patients with early Parkinson's disease. If symptoms were not adequately controlled by the assigned study medication, patients could receive supplementary levodopa, administered in an open-label fashion. The primary outcome measure was the occurrence of dyskinesia. RESULTS: Eighty-five of the 179 patients in the ropinirole group (47 percent) and 45 of the 89 patients in the levodopa group (51 percent) completed all five years of the study. In the ropinirole group 29 of the 85 patients (34 percent) received no levodopa supplementation. The analysis of the time to dyskinesia showed a significant difference in favor of ropinirole (hazard ratio for remaining free of dyskinesia, 2.82; 95 percent confidence interval, 1.78 to 4.44; P<0.001). At five years, the cumulative incidence of dyskinesia (excluding the three patients who had dyskinesia at base line), regardless of levodopa supplementation, was 20 percent (36 of 177 patients) in the ropinirole group and 45 percent (40 of 88 patients) in the levodopa group. There was no significant difference between the two groups in the mean change in scores for activities of daily living among those who completed the study. Adverse events led to the early withdrawal from the study of 48 of 179 patients in the ropinirole group (27 percent) and 29 of 89 patients in the levodopa group (33 percent). The mean (+/-SD) daily doses given by the end of the study were 16.5+/-6.6 mg of ropinirole (plus 427+/-221 mg of levodopa in patients who received supplementation) and 753+/-398 mg of levodopa (including supplements). CONCLUSIONS: Early Parkinson's disease can be managed successfully for up to five years with a reduced risk of dyskinesia by initiating treatment with ropinirole alone and supplementing it with levodopa if necessary

L-dopa competes with tyrosine and tryptophan for human brain uptake.

Riederer P.

Nutr Metab. 1980; 24(6):417-23.

Tyrosine and tryptophan have been assayed spectrofluorometrically in postmortem human brain areas of patients with Parkinson's disease treated orally with or without 3,4-dihydroxyphenylalanine (L-dopa) plus the peripherally acting decarboxylase inhibitor benserazide. Tyrosine as well as tryptophan decrease significantly after treatment with L-dopa, thus showing a competitive action of L-dopa to other aromatic amino acids on human brain uptake. It is suggested that some of the side effects of L-dopa treatment in Parkinson's disease are due to a disturbance in the brain and neural uptake of other, specially aromatic and branched-chain amino acids. An influence of L-dopa administration on protein synthesis also cannot be excluded

Depression in Parkinson's disease. A positron emission study.

Ring HA, Bench CJ, Trimble MR, et al.

Br J Psychiatry. 1994 Sep; 165(3):333-9.

BACKGROUND. This study investigated biological correlates of depression in patients with idiopathic Parkinson's disease (PD). We tested the hypothesis that in patients with PD and depression, there was regional dysfunction involving brain areas previously implicated in functional imaging studies of patients with primary depression. METHOD. Using positron emission tomographic measurements of regional cerebral blood flow (rCBF), patterns of resting rCBF were measured in ten patients with PD and major depression, and ten patients with PD alone. The results were compared with findings from ten patients with primary depression and ten normal controls, scanned using identical methods as part of an earlier study. Groups were matched for age, sex and symptom severity. RESULTS. Bilateral decreases in rCBF were observed in anteromedial regions of the medial frontal cortex and the cingulate cortex (Brodmann's areas (BA) 9 and 32) in the depressed PD group, compared with those with PD alone and compared with normal controls. This regional disturbance overlapped that observed in patients with primary depression. CONCLUSIONS. The findings indicate that the medial prefrontal cortex is a common area of neural dysfunction in the manifestation of both primary depression and depression in PD

Toxicological implications of polymorphic drug metabolism.

Ritchie JC, Sloan TP, Idle JR, et al.

Ciba Found Symp. 1980; 76:219-44.

The occurrence of genetic polymorphisms of drug metabolism means that populations contain subgroups (phenotypes) that differ sharply in their abilities to effect a number of metabolic reactions. Because of this, major interphenotype differences occur in responsiveness to drugs and toxic substances. The well established genetic polymorphisms of acetylation and hydrolysis illustrate the important association that exists between phenotype and propensity to develop toxic and exaggerated responses to some substances. Recently, for metabolic oxidation, a new genetic polymorphism of drug metabolism has been described and it promises to provide a better understanding of inter-individual variability in the metabolic handling of, and responsiveness to, drugs and toxic substances. The following effects of the polymorphism are described here: (a) its influence in determining variable presystemic metabolism and hence systemic drug availability; (b) its role in determining alternative toxic pathways of metabolism in individuals who have a genetically determined impairment of oxidative capacity and (c) its influence on the development of agranulocytosis associated with metiamide administration

Metal toxicity in children. In Training Manual on Pediatric Environmental Health: Putting It Into Practice.

Roberts JR.

1999.Dec.10;

Neuroprotective effect of vitamin E on the early model of Parkinson's disease in rat: behavioral and histochemical evidence.

Roghani M, Behzadi G.

Brain Res. 2001 Feb 16; 892(1):211-7.

There is strong evidence that oxidative stress participates in the etiology of Parkinson's disease (PD). We designed this study to investigate the neuroprotective effect of vitamin E in the early model of PD. For this purpose, unilateral intrastriatal 6-hydroxydopamine (12.5 microg/5 microl) lesioned rats were pretreated intramuscularly with D-alpha-tocopheryl acid succinate (24 I.U./kg, i.m.) 1 h before and three times per week for 1 month post-surgery. Apomorphine- and amphetamine-induced rotational behavior was measured postlesion fortnightly. A parallel tyrosine hydroxylase immunoreactivity and wheat germ agglutinin-horse radish peroxidase (WGA-HRP) tract-tracing study was performed to evaluate the vitamin E pretreatment efficacy. Tyrosine hydroxylase-immunohistochemical analyses showed a reduction of 18% in ipsilateral substantia nigra pars compacta (SNC) cell number of the vitamin E-pretreated lesioned (L+E) group comparing with contralateral side. The cell number dropped to 53% in the lesioned (L+V) group. In addition, retrograde-labeled neurons in ipsilateral SNC were reduced by up to 30% in the L+E group and 65% in the L+V group. Behavioral tests revealed that there are 74% and 68% reductions in contraversive and ipsiversive rotations in the L+E group, respectively, as compared with the L+V group. Therefore repeated intramuscular administration of vitamin E exerts a rapid protective effect on the nigrostriatal dopaminergic neurons in the early unilateral model of PD

Elevated activity of phospholipid biosynthetic enzymes in substantia nigra of patients with Parkinson's disease.

Ross BM, Mamalias N, Moszczynska A, et al.

Neuroscience. 2001; 102(4):899-904.

We reported that the activities of phospholipase A2, phosphocholine cytidylyltransferase and phosphoethanolamine cytidylyltransferase, key phospholipid metabolic enzymes, are low in substantia nigra of normal human brain and that this might reduce the ability of nigral neurons to repair damage to cell membranes. To determine whether adaptive changes in nigral phospholipid metabolism can occur in idiopathic Parkinson's disease we compared activities of 11 catabolic and anabolic enzymes in autopsied brain of 10 patients with Parkinson's disease to those in control subjects. Nigral activity of the catabolic enzyme phospholipase A2 was normal in the Parkinson's disease group, whereas that of the biosynthetic enzymes phosphoethanolamine cytidylyltransferase, phosphocholine cytidylyltransferase, and phosphatidylserine synthase were elevated 193, 48 and 38%, respectively, possibly representing a compensatory response to repair membrane phospholipids. Enzyme activities were normal in all other brain areas with the exception of increased (+26%) activity of calcium-stimulated phospholipase A2 in putamen, a change which could be consequent to either decreased dopaminergic striatal input or to a dopamine nerve terminal degenerative process. Our data indicate that the normally low rate of membrane phospholipid synthesis in the substantia nigra, the primary area of neurodegeneration in Parkinson's disease, is increased during the course of the disorder. We suggest that pharmacotherapies which augment this compensatory response might have utility as a treatment for Parkinson's disease

Drug-induced parkinsonism and other movement disorders.

Ross RT.

Can J Neurol Sci. 1990 May; 17(2):155-62.

This is a review of reserpine, haloperidol, and various phenothiazines that produce parkinsonism and other movement disorders. The by-products of illicit meperidine synthesis, MPTP and its more sinister companion, MPP, are also discussed. Movement disorders, transient or fixed, frank parkinsonism and/or dyskinesia, due to a variety of other medications and toxic agents are included. These are methanol, lithium, methyldopa, antimetabolites, antidepressants, sympathomimetic anorexiants, some types of antihistamines, and various combinations of agricultural chemicals

Correlation between serum aluminum concentration and signs of encephalopathy in a large population of patients dialyzed with aluminum-free fluids.

Rovelli E, Luciani L, Pagani C, et al.

Clin Nephrol. 1988 Jun; 29(6):294-8.

The role of persistently high serum aluminum levels (sAl) in the pathogenesis of dialysis encephalopathy (DE) was evaluated in two groups selected from 170 patients dialyzed with low Al fluids. Group 1 (G1) consisted of 24 patients showing two or more sAl below 50 micrograms/l and group 2 (G2) consisted of 27 patients with sAl above 100 micrograms/l in at least 2 of 3 determinations. The two groups did not show any significant difference for age, sex, education or duration of the dialysis treatment. All G1 patients were treated by hemodialysis. In G2, 24 patients underwent hemodialysis and 3 were on continuous ambulatory peritoneal dialysis (CAPD). We evaluated body loads of Al in 25 of 27 G2 patients with the desferrioxamine (DFO) infusion test. All 51 patients underwent a neurological examination and a waking EEG. Intelligence was assessed by Raven's Progressive Matrices 47 test in 19 of the G1 patients and in 20 of the G2 patients; short-term memory was measured by digit span and by word span and long-term memory by a short story in 10 G1 patients and 17 G2 patients. We diagnosed DE only in the presence of the typical EEG changes, with or without manifest clinical symptoms. DE was diagnosed in none of the G1 patients and in 8 of the G2 patients (0 vs 29.6%, chi 2 = 6.34; p less than 0.025). Five of the patients with DE showed both clinical and EEG signs, while the remaining three showed only EEG signs.(ABSTRACT TRUNCATED AT 250 WORDS)

Letter: Ascorbic acid in levodopa therapy.

Sacks W, Simpson GM.

Lancet. 1975 Mar 1; 1(7905):527.

Interaction between sodium ascorbate and dopamine.

Sakagami H, Satoh K, Ida Y, et al.

Free Radic Biol Med. 1998 Dec; 25(9):1013-20.

The interaction between sodium ascorbate and dopamine was investigated by three different parameters: radical intensity, prooxidant action, and cytotoxicity induction. Sodium ascorbate and dopamine produced the doublet and quartet ESR signals under alkaline conditions (pH 8.0-9.5), respectively. Addition of increasing concentrations of sodium ascorbate completely scavenged the dopamine radical and replaced the latter with its own radical. Similarly, dopamine slightly, but significantly reduced the radical intensity of sodium ascorbate. These two compounds stimulated the methionine oxidation and hydrogen peroxide generation in culture medium, but in combination, their stimulation activities were weakened. Both of these two compounds dose-dependently reduced the viable cell number of human oral squamous carcinoma HSC-4 cells, and their cytotoxic activity was significantly reduced by catalase. When these two compounds were mixed together before adding to HSC-4 cells, both of their cytotoxic activities were diminished. The present study demonstrates the interaction between sodium ascorbate and dopamine, which might modify their biological activities and generation of nerve disorders such as Parkinson's disease

Long-term use of nicotine chewing gum and mercury exposure from dental amalgam fillings.

Sallsten G, Thoren J, Barregard L, et al.

J Dent Res. 1996 Jan; 75(1):594-8.

In experimental studies, chewing gum has been shown to increase the release rate of mercury vapor from dental amalgam fillings. The aim of the present study was to investigate the influence of long-term frequent chewing on mercury levels in plasma and urine. Mercury levels in plasma (P-Hg) and urine (U-Hg), and urinary cotinine were examined in 18 subjects who regularly used nicotine chewing gum, and in 19 referents. Age and number of amalgam surfaces were similar in the two groups. Total mercury concentrations in plasma and urine were determined by means of cold vapor atomic absorption spectrometry. Urinary cotinine was determined by gas chromatography-mass spectrometry. The chewers had been using 10 (median) pieces of gum per day for the past 27 (median) months. P-Hg and U-Hg levels were significantly higher in the chewers (27 nmol/L and 6.5 nmol/mmol creatinine) than in the referents (4.9 nmol/L and 1.2 nmol/mmol creatinine). In both groups, significant correlations were found between P-Hg or U-Hg on the one hand and the number of amalgam surfaces on the other. In the chewers, no correlations were found between P-Hg or U-Hg and chewing time per day or cotinine in urine. Cotinine in urine increased with the number of pieces of chewing gum used. The impact of excessive chewing on mercury levels was considerable

L-tryptophan supplementation in Parkinson's disease.

Sandyk R, Fisher H.

Int J Neurosci. 1989 Apr; 45(3-4):215-9.

Two female Parkinsonian patients with levodopa-induced "On-Off" responded dramatically to administration of L-tryptophan supplementation. This report highlights the role of serotonergic deficiency in the pathophysiology of Parkinson's disease and of levodopa-induced motor fluctuations, and suggests that L-tryptophan supplementation may be useful in ameliorating motor complications of chronic levodopa therapy in the disease. The possibility that L-tryptophan supplementation with initiation of levodopa therapy may be useful in preventing levodopa-induced motor complications is discussed

Pyridoxine improves drug-induced parkinsonism and psychosis in a schizophrenic patient.

Sandyk R, Pardeshi R.

Int J Neurosci. 1990 Jun; 52(3-4):225-32.

Drug-induced Parkinsonism is a common serious side-effect of neuroleptic therapy. In cases of irreversible drug-induced Parkinsonism, pharmacological management is notoriously difficult. A schizophrenic patient with severe neuroleptic-induced Parkinsonism and Tardive Dyskinesia is presented in whom administration of pyridoxine (vitamin B6) (100 mg/d) resulted in dramatic and persistent attenuation of the movement disorders as well as reduction of psychotic behavior. Since pyridoxine deficiency is associated with marked reduction of cerebral serotonin concentrations and pineal melatonin production in rats, the effects of pyridoxine on the movement disorder and psychosis may have been mediated largely by enhancing serotonin and melatonin functions. An additional effect of excess pyridoxine administration on GABA and dopamine activity cannot be excluded. Pyridoxine has been reported to attenuate the severity of levodopa-induced dyskinesias in patients with Parkinson's disease and it is suggested that pyridoxine supplementation should be considered in psychiatric patients with drug-induced movement disorders including persistent Parkinsonism. An underlying pyridoxine deficiency in these patients may exacerbate the psychotic behavior and additionally, potentially increase the risk of drug-induced movement disorders

L-tryptophan in neuropsychiatric disorders: a review.

Sandyk R.

Int J Neurosci. 1992 Nov; 67(1-4):127-44.

Animal data indicate that serotonin (5-HT) is a major neurotransmitter involved in the control of numerous central nervous system functions including mood, aggression, pain, anxiety, sleep, memory, eating behavior, addictive behavior, temperature control, endocrine regulation, and motor behavior. Moreover, there is evidence that abnormalities of 5-HT functions are related to the pathophysiology of diverse neurological conditions including Parkinson's disease, tardive dyskinesia, akathisia, dystonia, Huntington's disease, familial tremor, restless legs syndrome, myoclonus, Gilles de la Tourette's syndrome, multiple sclerosis, sleep disorders, and dementia. The psychiatric disorders of schizophrenia, mania, depression, aggressive and self-injurious behavior, obsessive compulsive disorder, seasonal affective disorder, substance abuse, hypersexuality, anxiety disorders, bulimia, childhood hyperactivity, and behavioral disorders in geriatric patients have been linked to impaired central 5-HT functions. Tryptophan, the natural amino acid precursor in 5-HT biosynthesis, increases 5-HT synthesis in the brain and, therefore, may stimulate 5-HT release and function. Since it is a natural constituent of the diet, tryptophan should have low toxicity and produce few side effects. Based on these advantages, dietary tryptophan supplementation has been used in the management of neuropsychiatric disorders with variable success. This review summarizes current clinical use of tryptophan supplementation in neuropsychiatric disorders

[Depression and Parkinson syndrome].

Schnaberth G.

Wien Med Wochenschr. 1986 Aug 31; 136(15-16):391-3.

Depressive mood is frequently associated with Parkinson's syndrome, but it may also occur as a precursor of this disease. As regards the subtypes of Parkinson's disease, the frequency of depressive states is significantly higher in the type dominated by akinesia and rigidity than in the type dominated by tremor. On the basis of biochemical changes, certain aspects of the depression can be successfully treated by substitution therapy: L-dopa medication may increase the reduced dopamine values in the striatum, thereby improving drive. Substitution with L-tryptophan raises the lowered serotonin values in the reticular formation, which may influence sleep disturbances. The changes of basic mood, however, which are characteristic of depression, such as cheerlessness and apathy, are the dopamine of antidepressive medication; only these drugs can re-establish the biochemical balance to a large extent

The role of intestinal endotoxin in experimental peritonitis.

Schoeffel U, Windfuhr M, Freudenberg N, et al.

Circ Shock. 1989 Jan; 27(1):83-91.

Escape of endotoxin from the intraintestinal site was investigated in experimental models of intestinal ischemia and during intraabdominal infection in rats. Following the instillation of Salmonella abortus equi endotoxin (S-form) into the proximal large bowel, we recorded the presence of the lipopolysaccharide molecule in the bowel wall, the intestinal lymph nodes, the peritoneal cavity, and in the liver sinusoids by immunohistochemical methods. At 3, 6, 12, 24, and 48 hr after the operative procedure, peritoneal fluid, blood, and tissue samples were taken. Survival rates were similar between the two test-groups (occlusion of the superior mesenteric artery [SMA] and cecal ligation and puncture [CLP]) and were not influenced by the amount of the injected endotoxin. There was no detectable morbidity in the sham-operated control animals with endotoxin doses up to 20 mg. Endotoxin could only be detected at 24 and 48 hr in the SMA group in the liver as well as in the peritoneal sediment and in intestinal lymph nodes. CLP and control samples remained negative throughout the observation period. Bacteria were found intraperitoneally within 12 to 24 hr in the SMA group and within 3 to 12 hr in the CLP group

Coenzyme Q10 and nicotinamide and a free radical spin trap protect against MPTP neurotoxicity.

Schulz JB, Henshaw DR, Matthews RT, et al.

Exp Neurol. 1995 Apr; 132(2):279-83.

1-Methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP) produces Parkinsonism in both experimental animals and in man. MPTP is metabolized to 1-methyl-4-phenylpridinium, an inhibitor of mitochondrial complex I. MPTP administration produces ATP depletions in vivo, which may lead to secondary excitotoxicity and free radical generation. If this is the case then agents which improve mitochondrial function or free radical scavengers should attenuate MPTP neurotoxicity. In the present experiments three regimens of MPTP administration produced varying degrees of striatal dopamine depletion. A combination of coenzyme Q10 and nicotinamide protected against both mild and moderate depletion of dopamine. In the MPTP regimen which produced mild dopamine depletion nicotinamide or the free radical spin trap N-tert-butyl-alpha-(2-sulfophenyl)-nitrone were also effective. There was no protection with a MPTP regimen which produced severe dopamine depletion. These results show that agents which improve mitochondrial energy production (coenzyme Q10 and nicotinamide) and free radical scavengers can attenuate mild to moderate MPTP neurotoxicity

Neuroprotective strategies for treatment of lesions produced by mitochondrial toxins: implications for neurodegenerative diseases.

Schulz JB, Matthews RT, Henshaw DR, et al.

Neuroscience. 1996 Apr; 71(4):1043-8.

Neuronal death in neurodegenerative diseases may involve energy impairment leading to secondary excitotoxicity, and free radical generation. Potential therapies for the treatment of neurodegenerative diseases therefore include glutamate release blockers, excitatory amino acid receptor antagonists, agents that improve mitochondrial function, and free radical scavengers. In the present study we examined whether these strategies either alone or in combination had neuroprotective effects against striatal lesions produced by mitochondrial toxins. The glutamate release blockers lamotrigine and BW1003C87 significantly attenuated lesions produced by intrastriatal administration of 1-methyl-4-phenylpyridinium. Lamotrigine significantly attenuated lesions produced by systemic administration of 3-nitropropionic acid. Memantine, an N-methyl-D-aspartate antagonist, protected against malonate induced striatal lesions. We previously found that coenzyme Q10 and nicotinamide, and the free radical spin trap n-tert-butyl-alpha-(2-sulfophenyl)-nitrone (S-PBN) dose-dependently protect against lesions produced by intrastriatal injection of malonate. In the present study we found that the combination of MK-801 (dizocipiline) with coenzyme Q10 exerted additive neuroprotective effects against malonate. Lamotrigine with coenzyme Q10 was more effective than coenzyme Q10 alone. The combination of nicotinamide with S-PBN was more effective than nicotinamide alone. These results provide further evidence that glutamate release inhibitors and N-acetyl-D-aspartate antagonists can protect against secondary excitotoxic lesions in vivo. Furthermore, they show that combinations of agents which act at sequential steps in the neurodegenerative process can produce additive neuroprotective effects. These findings suggest that combinations of therapies to improve mitochondrial function, to block excitotoxicity and to scavenge free radicals may be useful in treating neurodegenerative diseases

Ascorbic acid stimulates DOPA synthesis and tyrosine hydroxylase gene expression in the human neuroblastoma cell line SK-N-SH.

Seitz G, Gebhardt S, Beck JF, et al.

Neurosci Lett. 1998 Mar 6; 244(1):33-6.

Ascorbic acid is well known to induce noradrenaline synthesis in sympathetic nervous cells. In a series of experiments we found that incubation of the neuroblastoma cell line SK-N-SH with ascorbic acid (100-500 microM) for 2 h results in a significantly enhanced synthesis of 3,4-dihydroxyphenylalanine (DOPA) and dopamine. Additionally, cDNA-polymerase chain reaction (cDNA-PCR) analysis of relative mRNA levels corresponding to the enzymes involved in catecholamine synthesis revealed a 3-fold increase of tyrosine hydroxylase gene expression after 5 days of incubation with ascorbic acid (200 microM), whereas expression of dopamine-beta-hydroxylase was found to be unaltered. In summary the data give evidence that ascorbic acid leads to enhanced DOPA production in SK-N-SH cells by two different mechanisms: at the metabolic level after short-term incubation and by increasing the tyrosine hydroxylase gene expression after long-term incubation. Based on these data we suppose that enhancement of DOPA synthesis by ascorbic acid may be useful in the treatment of early Parkinson's disease

Parkinson's disease: a test of the multifactorial etiologic hypothesis.

Semchuk KM, Love EJ, Lee RG.

Neurology. 1993 Jun; 43(6):1173-80.

We studied the relative etiologic importance upon the development of Parkinson's disease (PD) of occupational exposure to herbicides and other compounds, ionizing radiation exposure, family history of PD and essential tremor, smoking, and history of various viral and other medical conditions. We identified patients (n = 130) with neurologist-confirmed idiopathic PD through contacts with Calgary general hospitals, long-term care facilities, neurologists, the Movement Disorder Clinic, and the Parkinson's Society of Southern Alberta, and selected two matched (by sex and age +/- 2.5 years) community controls for each case by random digit dialing. We obtained lifetime work, chemical, radiation, medical, and smoking exposure histories and family histories of PD and essential tremor by personal interviews, and analyzed the data using conditional logistic regression for matched sets. After controlling for potential confounding and interaction between the exposure variables, using multivariate statistical methods, having a family history of PD was the strongest predictor of PD risk, followed by head trauma and then occupational herbicide use. Cases and controls did not differ in their previous exposures to smoking or ionizing radiation; family history of essential tremor; work-related contact with aluminum, carbon monoxide, cyanide, manganese, mercury, or mineral oils; or history of arteriosclerosis, chicken pox, encephalitis, hypertension, hypotension, measles, mumps, rubella, or Spanish flu. These results support the hypothesis of a multifactorial etiology for PD, probably involving genetic, environmental, trauma, and possibly other factors

Therapeutic advances in idiopathic Parkinsonism.

Shefrin SL.

Expert Opin Investig Drugs. 1999 Oct; 8(10):1565-88.

Parkinson's disease (PD) is the only neurodegenerative disorder in which pharmacological intervention has resulted in a marked decrease in morbidity and a significant delay in mortality. The discovery of striatal dopamine deficiency as the neurochemical basis of PD in 1960 was a pivotal event that led to the era of levodopa therapy. Although levodopa produces dramatic improvements in patients' symptoms, it is also associated with adverse effects that can be disabling. Some of these are felt to be related to fluctuating levels of levodopa in the plasma and brain, and as a result, research has focused on drugs that can provide more continuous dopamine receptor stimulation. Dopamine agonists and catechol-O-methyl-transferase (COMT) inhibitors have been valuable adjuncts to levodopa, but until now levodopa has remained the cornerstone of therapy. Recent studies indicate that the newer dopamine agonists may be assuming greater importance in the control of symptoms. Other drugs, such as nicotinic acetylcholine receptor agonists, neurotrophic factors and adenosine receptor antagonists are under investigation. Efforts are being concentrated on understanding the causes and mechanisms involved in the death of dopaminergic neurones in the substantia nigra. Overactivity of the subthalamic nucleus and glutamate-mediated excitotoxicity might play key roles in the genesis of the disease. Therapeutic approaches aimed at correcting these abnormalities may lead to neuroprotective therapy that can inhibit or prevent the relentless progression of nigral neuronal loss. Well- controlled clinical trials using positron emission tomography (PET) and single photon emission computerised tomography (SPECT) will assist in assessing the putative neuroprotective properties attributed to various agents

Coenzyme Q10 levels correlate with the activities of complexes I and II/III in mitochondria from parkinsonian and nonparkinsonian subjects.

Shults CW, Haas RH, Passov D, et al.

Ann Neurol. 1997 Aug; 42(2):261-4.

The activities of complex I and complex II/III in platelet mitochondria are reduced in patients with early, untreated Parkinson's disease. Coenzyme Q10 is the electron acceptor for complex I and complex II. We found that the level of coenzyme Q10 was significantly lower in mitochondria from parkinsonian patients than in mitochondria from age- and sex-matched control subjects and that the levels of coenzyme Q10 and the activities of complex I and complex II/III were significantly correlated

Absorption, tolerability, and effects on mitochondrial activity of oral coenzyme Q10 in parkinsonian patients.

Shults CW, Beal MF, Fontaine D, et al.

Neurology. 1998 Mar; 50(3):793-5.

We report a pilot study of three oral doses of coenzyme Q10 (CoQ10) (200 mg administered two, three, or four times per day for 1 month) in 15 subjects with Parkinson's disease. Oral CoQ10 caused a substantial increase in the plasma CoQ10 level. It was well tolerated, but at the highest dose (200 mg four times per day) mild, transient changes in the urine were noted. CoQ10 did not change the mean score on the motor portion of the Unified Parkinson's Disease Rating Scale. There was a trend toward an increase in complex I activity in the subjects

A possible role of coenzyme Q10 in the etiology and treatment of Parkinson's disease.

Shults CW, Haas RH, Beal MF.

Biofactors. 1999; 9(2-4):267-72.

Parkinson's disease (PD) is a degenerative neurological disorder. Recent studies have demonstrated reduced activity of complex I of the electron transport chain in brain and platelets from patients with PD. Platelet mitochondria from parkinsonian patients were found to have lower levels of coenzyme Q10 (CoQ10) than mitochondria from age/sex-matched controls. There was a strong correlation between the levels of CoQ10 and the activities of complexes I and II/III. Oral CoQ10 was found to protect the nigrostriatal dopaminergic system in one-year-old mice treated with MPTP, a toxin injurious to the nigrostriatal dopaminergic system. We further found that oral CoQ10 was well absorbed in parkinsonian patients and caused a trend toward increased complex I activity. These data suggest that CoQ10 may play a role in cellular dysfunction found in PD and may be a potential protective agent for parkinsonian patients

Effects of coenzyme Q10 in early Parkinson disease: evidence of slowing of the functional decline.

Shults CW, Oakes D, Kieburtz K, et al.

Arch Neurol. 2002 Oct; 59(10):1541-50.

BACKGROUND: Parkinson disease (PD) is a degenerative neurological disorder for which no treatment has been shown to slow the progression. OBJECTIVE: To determine whether a range of dosages of coenzyme Q10 is safe and well tolerated and could slow the functional decline in PD. DESIGN: Multicenter, randomized, parallel-group, placebo-controlled, double-blind, dosage-ranging trial. SETTING: Academic movement disorders clinics. PATIENTS: Eighty subjects with early PD who did not require treatment for their disability. INTERVENTIONS: Random assignment to placebo or coenzyme Q10 at dosages of 300, 600, or 1200 mg/d. MAIN OUTCOME MEASURE: The subjects underwent evaluation with the Unified Parkinson Disease Rating Scale (UPDRS) at the screening, baseline, and 1-, 4-, 8-, 12-, and 16-month visits. They were followed up for 16 months or until disability requiring treatment with levodopa had developed. The primary response variable was the change in the total score on the UPDRS from baseline to the last visit. RESULTS: The adjusted mean total UPDRS changes were +11.99 for the placebo group, +8.81 for the 300-mg/d group, +10.82 for the 600-mg/d group, and +6.69 for the 1200-mg/d group. The P value for the primary analysis, a test for a linear trend between the dosage and the mean change in the total UPDRS score, was.09, which met our prespecified criteria for a positive trend for the trial. A prespecified, secondary analysis was the comparison of each treatment group with the placebo group, and the difference between the 1200-mg/d and placebo groups was significant (P =.04). CONCLUSIONS: Coenzyme Q10 was safe and well tolerated at dosages of up to 1200 mg/d. Less disability developed in subjects assigned to coenzyme Q10 than in those assigned to placebo, and the benefit was greatest in subjects receiving the highest dosage. Coenzyme Q10 appears to slow the progressive deterioration of function in PD, but these results need to be confirmed in a larger study

Absence of Oxalobacter formigenes in cystic fibrosis patients: a risk factor for hyperoxaluria.

Sidhu H, Hoppe B, Hesse A, et al.

Lancet. 1998 Sep 26; 352(9133):1026-9.

BACKGROUND: Patients with cystic fibrosis have an increased risk of hyperoxaluria, and of subsequent nephrocalcinosis and calcium-oxalate urolithiasis. Oxalate homoeostasis is controlled, in part, by the intestinal bacterium, Oxalobacter formigenes. The loss of this bacterium from the gut flora is associated with an increased risk of hyperoxaluria and calcium-oxalate urolithiasis. We investigated whether the absence of O. formigenes and the presence of hyperoxaluria are correlated in cystic fibrosis (CF) patients. METHODS: Stool specimens from 43 patients with CF aged 3-9 years and from 21 similarly aged healthy volunteers were examined for O. formigenes by culture and DNA analysis. At the same time, 24 h urine samples were collected and analysed for oxalate and other factors that promote or inhibit stone formation. FINDINGS: 15 (71%) of 21 healthy volunteers but only seven (16%) of 43 CF patients were colonised with O. formigenes. Detection of O. formigenes in six of these seven patients required DNA-based identification, suggesting low numbers of colony-forming units, and the CF patient with normal numbers of O. formigenes was the only one of the 43 patients who had not been treated with antibiotics. All seven CF patients colonised with O. formigenes had normal urinary oxalate levels, but 19 (53%) of 36 patients not colonised with O. formigenes were hyperoxaluric, with the most severe hyperoxaluria occurring in young patients. INTERPRETATION: Absence of O. formigenes from the intestinal tract of CF patients appears to lead to increased absorption of oxalate, thereby increasing the risk of hyperoxaluria and its complications (eg, nephrocalcinosis, urolithiasis). Prolonged widespread use of antibiotics, and alterations of the gastrointestinal tract that occur in CF, may induce a permanent decolonisation in CF patients

Direct correlation between hyperoxaluria/oxalate stone disease and the absence of the gastrointestinal tract-dwelling bacterium Oxalobacter formigenes: possible prevention by gut recolonization or enzyme replacement therapy.

Sidhu H, Schmidt ME, Cornelius JG, et al.

J Am Soc Nephrol. 1999 Nov; 10 Suppl 14:S334-S340.

Oxalobacter formigenes is a specific oxalate-degrading, anaerobic bacterium inhabiting the gastrointestinal tracts of vertebrates, including humans. This bacterium maintains an important symbiotic relationship with its host by regulating oxalate homeostasis, primarily by preventing enteric absorption. Increased absorption of oxalate can lead to multiple complications associated with hyperoxaluria, especially recurrent calcium oxalate urolithiasis. Detection of O. formigenes in the gastrointestinal tract has attracted attention because the absence of this bacterium appears to be a risk factor for development of hyperoxaluria and/or recurrent calcium oxalate kidney stone disease. In the present study, epidemiologic studies with patients at high risk for calcium oxalate urolithiasis showed a direct correlation between the number of recurrent kidney stone episodes and the lack of O. formigenes colonization. As expected, the lack of O. formigenes revealed a clear association with prophylactic antibiotic therapy. To confirm the importance of O. formigenes in regulating hyperoxaluria, laboratory rats known to be noncolonized were colonized with live bacteria or treated with a preparation of oxalate-degrading enzymes derived from O. formigenes to determine any subsequent increased resistance to high oxalate challenge. Rats receiving either bacteria or enzyme replacement therapy excreted far lower levels of oxalate, did not develop the crystalluria observed with control rats, and resisted the formation of calcium oxalate crystals in their nephrons. These observations, taken together, support the concept that O. formigenes is important in maintaining oxalate homeostasis, that its absence from the gut increases the risk for hyperoxaluria and recurrent kidney stone disease, and that replacement therapy is an efficient procedure to prevent hyperoxaluria and its complications

The Pill Book.

Silverman HM.

2000; Ninth Edition

A case-control study of occupational and environmental risk factors for Parkinson's disease in the Emilia-Romagna region of Italy.

Smargiassi A, Mutti A, De Rosa A, et al.

Neurotoxicology. 1998 Aug; 19(4-5):709-12.

A questionnaire-based case-control study was carried out on 86 patients with neurologist-confirmed idiopathic Parkinson's disease (PD) and 86 controls similar in sex and age. The control group was recruited in outpatient specialist centers of the same University Hospital (glaucoma, psoriasis vulgaris, essential arterial hypertension and renal diseases). Exposure was defined as occupational or residential contact with a given factor for at least 10 consecutive years prior to the onset of PD. Smoking habits were defined by exclusion of those subjects who never smoked. The following risk factors were identified: cranial trauma (OR: 2.88; 95% CI: 0.98-8.49), well water use (OR: 2.78; 95% CI: 1.46-5.28) and occupational exposure to industrial chemicals (OR: 2.13; 95% CI: 1.16-3.91). Among industrial chemicals, only organic solvents were identified as significant risk factors for PD (O.R. : 2.78, 95% C.I. : 1.23-6.26). Whereas no exposure to neurotoxic metals occurred among controls, making the assessment of the O.R. impossible, exposure pesticides and herbicides was similar in the two groups (O.R. : 1.15; 95% C. : 0.56-2-36). Smoking habits was negatively associated with PD (OR: 0.41; 95% CI: 0.22-0.75), confirming the "protective" role of tobacco smoking suggested by many studies. As a whole, these results support the role of environmental factors in the etiology of PD

Octacosanol in parkinsonism.

Snider SR.

Ann Neurol. 1984 Dec; 16(6):723.

The brain lesion responsible for parkinsonism after carbon monoxide poisoning.

Sohn YH, Jeong Y, Kim HS, et al.

Arch Neurol. 2000 Aug; 57(8):1214-8.

BACKGROUND: Parkinsonism is a common neurological sequela of carbon monoxide (CO) poisoning, but its pathophysiological mechanism has yet to be clarified. OBJECTIVES: To describe a married couple who were both affected by CO poisoning, but only 1 of whom developed CO-induced parkinsonism, and to discuss the possible underlying pathophysiological mechanism of CO-induced parkinsonism by comparing the neuroimaging findings of these patients. DESIGN AND SETTING: Case report from a clinical neurology department. PATIENTS: A married couple experienced CO poisoning simultaneously. One month later, only the husband gradually developed delayed sequelae, including parkinsonism and intellectual impairment. On detailed neurological examination, the husband showed mild but definite rigidity and bradykinesia, while no parkinsonian signs were observed in the wife. Neuropsychological examination revealed impaired memory and attention in both patients, but they were more severe in the husband than in the wife. Magnetic resonance imaging scans of the patients' brains disclosed diffuse high-intensity white matter signals in both patients and bilateral pallidal necrosis in the wife. Dopamine transporter imaging showed that the degree of dopamine neuronal loss was comparable between these patients. Magnetic resonance spectroscopy revealed more severe white matter damage in the husband than in the wife. Thirteen months later, neurological and neuropsychological examinations showed complete recovery from parkinsonism as well as intellectual impairment. Follow-up magnetic resonance spectroscopy also suggested remarkable improvements in white matter damage. CONCLUSION: These results support the role of white matter damage in producing parkinsonism after CO poisoning and highlight the possible usefulness of magnetic resonance spectroscopy in predicting delayed sequelae in patients after CO poisoning. Arch Neurol. 2000;57:1214-1218

Autoxidation and neurotoxicity of 6-hydroxydopamine in the presence of some antioxidants: potential implication in relation to the pathogenesis of Parkinson's disease.

Soto-Otero R, Mendez-Alvarez E, Hermida-Ameijeiras A, et al.

J Neurochem. 2000 Apr; 74(4):1605-12.

6-Hydroxydopamine (6-OHDA) is a dopaminergic neurotoxin putatively involved in the pathogenesis of Parkinson's disease (PD). Its neurotoxicity has been related to the production of reactive oxygen species. In this study we examine the effects of the antioxidants ascorbic acid (AA), glutathione (GSH), cysteine (CySH), and N-acetyl-CySH (NAC) on the autoxidation and neurotoxicity of 6-OHDA. In vitro, the autoxidation of 6-OHDA proceeds rapidly with the formation of H2O2 and with the participation of the H2O2 produced in the reaction. The presence of AA induced a reduction in the consumption of O2 during the autoxidation of 6-OHDA and a negligible presence of the p-quinone, which demonstrates the efficiency of AA to act as a redox cycling agent. The presence of GSH, CySH, and NAC produced a significant reduction in the autoxidation of 6-OHDA. In vivo, the presence of sulfhydryl antioxidants protected against neuronal degeneration in the striatum, which was particularly remarkable in the case of CySH and was attributed to its capacity to remove the H2O2 produced in the autoxidation of 6-OHDA. These results corroborate the involvement of oxidative stress as the major mechanism in the neurotoxicity of 6-OHDA and the putative role of CySH as a scavenger in relation to PD

[Intestinal microflora and concomitant gastrointestinal diseases in patients with chronic hepatitis B and C].

Sozinov AS, Anikhovskaia IA, Baiazitova LT, et al.

Zh Mikrobiol Epidemiol Immunobiol. 2002 Jan;(1):61-4.

In chronic viral hepatitis B and C the development of intestinal dysbacteriosis and high occurrence of concomitant diseases of the gastrointestinal tract were observed. In cases of increased dysbacteriosis degree and in the presence of concomitant diseases the blood plasma of patients exhibited higher activity in reaction with the of amebocytes lysate obtained from crabs of the genus Limulus. A suggestion was made that the endotoxin of Gram negative intestinal microflora could probably play some role in the development of pathological processes in chronic viral hepatitis B and C

Exposure to home pesticides linked to Parkinson disease.

Stephenson J.

JAMA. 2000 Jun 21; 283(23):3055-6.

Reaction time and vigilance in Parkinson's disease. Possible role of altered norepinephrine metabolism.

Stern Y, Mayeux R, Cote L.

Arch Neurol. 1984 Oct; 41(10):1086-9.

Delayed reaction time and diminished vigilance have been observed in Parkinson's disease (PD) but have not been related to biochemical changes in the disease. As norepinephrine is reduced in the brain in PD and this neurotransmitter has been related to attention and learning, we investigated the relationship of neuropsychological measures, including those of reaction time and vigilance, to the norepinephrine metabolite 3-methoxy - 4 - hydroxyphenethyleneglycol (MHPG) in 39 patients with idiopathic PD. The MHPG levels correlated with a measure of general intellectual ability and with performance on reaction time and continuous performance tasks. Our data suggest that altered norepinephrine metabolism may contribute to some aspects of intellectual dysfunction in PD

Effect of antimicrobial agents on the ecological balance of human microflora.

Sullivan A, Edlund C, Nord CE.

Lancet Infect Dis. 2001 Sep; 1(2):101-14.

The normal microflora acts as a barrier against colonisation of potentially pathogenic microorganisms and against overgrowth of already present opportunistic microorganisms. Control of growth of opportunistic microorganisms is termed colonisation resistance. Administration of antimicrobial agents, therapeutically or as prophylaxis, causes disturbances in the ecological balance between the host and the normal microflora. Most studies on the impact of antimicrobial agents on normal microflora have been carried out on the intestinal flora. Less is known on the effects on oropharyngeal, skin, and vaginal microflora. Disturbances in the microflora depend on the properties of the agents as well as of the absorption, route of elimination, and possible enzymatic inactivation and/or binding to faecal material of the agents. The clinically most common disturbances in the intestinal microflora are diarrhoea and fungal infections that usually cease after the end of treatment. A well-balanced microflora prevents establishment of resistant microbial strains. By using antimicrobial agents that do not disturb colonisation resistance, the risk of emergence and spread of resistant strains between patients and dissemination of resistant determinants between microorganisms is reduced. In this article, the potential ecological effects of administration of antimicrobial agents on the intestinal, oropharyngeal, and vaginal microflora are summarised. The review is based on clinical studies published during the past 10 years

Neuromelanin biosynthesis is driven by excess cytosolic catecholamines not accumulated by synaptic vesicles.

Sulzer D, Bogulavsky J, Larsen KE, et al.

Proc Natl Acad Sci U S A. 2000 Oct 24; 97(22):11869-74.

Melanin, the pigment in hair, skin, eyes, and feathers, protects external tissue from damage by UV light. In contrast, neuromelanin (NM) is found in deep brain regions, specifically in loci that degenerate in Parkinson's disease. Although this distribution suggests a role for NM in Parkinson's disease neurodegeneration, the biosynthesis and function of NM have eluded characterization because of lack of an experimental system. We induced NM in rat substantia nigra and PC12 cell cultures by exposure to l-dihydroxyphenylalanine, which is rapidly converted to dopamine (DA) in the cytosol. This pigment was identical to human NM as assessed by paramagnetic resonance and was localized in double membrane autophagic vacuoles identical to NM granules of human substantia nigra. NM synthesis was abolished by adenoviral-mediated overexpression of the synaptic vesicle catecholamine transporter VMAT2, which decreases cytosolic DA by increasing vesicular accumulation of neurotransmitter. The NM is in a stable complex with ferric iron, and NM synthesis was inhibited by the iron chelator desferrioxamine, indicating that cytosolic DA and dihydroxyphenylalanine are oxidized by iron-mediated catalysis to membrane-impermeant quinones and semiquinones. NM synthesis thus results from excess cytosolic catecholamines not accumulated into synaptic vesicles. The permanent accumulation of excess catechols, quinones, and catechol adducts into a membrane-impermeant substance trapped in organelles may provide an antioxidant mechanism for catecholamine neurons. However, NM in organelles associated with secretory pathways may interfere with signaling, as it delays stimulated neurite outgrowth in PC12 cells

The use of bromocriptine in parkinsonism after carbon monoxide poisoning.

Tack E, de Reuck J.

Clin Neurol Neurosurg. 1987; 89(4):275-9.

Parkinsonism is a well known complication of carbon monoxide poisoning. Pharmacological treatment has been regarded as being not successful, as far as levodopa alone is concerned. Three cases are presented with symptomatic parkinsonism after carbon monoxide exposure, who have been treated with bromocriptine (in one case in combination with levodopa). The results are surprisingly good. A possible explanation is discussed

Choosing dopamine agonists in Parkinson's disease.

Tan EK, Jankovic J.

Clin Neuropharmacol. 2001 Sep; 24(5):247-53.

Dopamine agonists (DAs) have been shown to be effective as monotherapy in early stages of Parkinson's disease (PD) and as an adjunctive treatment to levodopa in advanced PD. Since bromocriptine, an ergot compound, was introduced as the first commercially available DA more than 25 years ago, additional DAs have become available for clinical use. There is a remarkable paucity of data, however, that would guide clinicians in their decision process to select the most appropriate DAs. We discuss the theoretical basis for comparing the various DAs, and provide a concise analysis and summary of comparative trials of DAs in PD

Parkin is linked to the ubiquitin pathway.

Tanaka K, Suzuki T, Chiba T, et al.

J Mol Med. 2001 Sep; 79(9):482-94.

Autosomal recessive juvenile parkinsonism (AR-JP) is one of the most common forms of familial Parkinson's disease. AR-JP is characterized by selective and massive loss of dopaminergic neurons in the substantia nigra of the midbrain and absence of Lewy bodies, the pathological hallmark of idiopathic Parkinson's disease. Parkin, the causative gene of AR-JP, encodes a 52-kDa protein that is a RING-type ubiquitin (Ub) protein ligase (E3) collaborating with a Ub-conjugating enzyme (E2) belonging to a cognate class of UbcH7 or UbcH8. Analysis of parkin mutations in AP-JP patients reveals that the functional loss of parkin as an E3 enzyme is the molecular basis of AR-JP. Thus it is now clear that AR-JP is due to failure of proteolysis mediated by the Ub-proteasome system and accumulation of as yet unidentified protein(s) causes nigral neuronal death without formation of Lewy bodies. These findings should shed new light on the mechanisms underlying neurodegeneration in sporadic Parkinson's disease as well as AR-JP

Role of human microflora in health and disease.

Tancrede C.

Eur J Clin Microbiol Infect Dis. 1992 Nov; 11(11):1012-5.

The human host and its microbial flora constitute a complex ecosystem whose equilibrium serves as a remarkable example of reciprocal adaptation. Intestinal bacteria play an important role in the development of the immune system. The normal intestinal flora is responsible for resistance to colonization by exogenous pathogenic microorganisms. Nevertheless, it also constitutes a reservoir of potentially pathogenic bacteria in close contact with the host. These bacteria are responsible for opportunistic infections in immunocompromised hosts. The equilibrium of the flora can be upset by antibiotics, leading to infections as a result of proliferation of antibiotic-resistant pathogenic bacteria

Parkinson's disease and depression. A critical re-evaluation.

Taylor AE, Saint-Cyr JA, Lang AE, et al.

Brain. 1986 Apr; 109 ( Pt 2):279-92.

The possibility of an 'organically' based depression intrinsic to the pathophysiology of Parkinson's disease (PD) and comparable to endogenous depression (Major Depressive Episode) has been raised. It has also been argued that signs of depression observed in PD are merely the natural reaction of the patients to their progressive and inevitable physical limitations and loss of independent function. Because conventional depression rating scales are limited in scope, a psychometric investigation of depression in PD was pursued. Based on the known impairment of short-term memory (STM) in endogenous depression, which was confirmed in a group of psychiatric patients in the present study, measures of STM were also obtained in groups of depressed and nondepressed PD patients and in 15 normal control subjects. Regardless of depression severity, PD patients performed as well as control subjects and both these groups consistently obtained scores significantly better than those of the endogenously depressed patients. A relative weakness in the PD patients on order-dependent STM tests was further explored and interpreted as an indication of mild frontal lobe dysfunction. It was concluded that PD patients are frequently depressed when confronted with their behavioural limitations and that this reaction may be exacerbated by a form of emotional liability related to pathophysiological processes which may involve prefrontal cortical areas

Ceroid/lipofuscin-loaded human fibroblasts show decreased survival time and diminished autophagocytosis during amino acid starvation.

Terman A, Dalen H, Brunk UT.

Exp Gerontol. 1999 Dec; 34(8):943-57.

To test whether heavy accumulation of ceroid/lipofuscin can disturb important functions of the lysosomal system, AG-1518 human fibroblasts, ceroid/lipofuscin-loaded (following prolonged culture at normobaric hyperoxia) or not, were exposed to amino acid starvation. Ceroid/lipofuscin-loading resulted in decreased cellular survival. Also, there was an inverse relationship between amounts of ceroid/lipofuscin and the survival time of individual cells within the same cultures. Ceroid/lipofuscin-loaded fibroblasts displayed diminished autophagocytotic capacity, as demonstrated by electron microscopy and by treatment of cell cultures with NH4Cl (which inhibits autophagocytotic degradation by increasing intralysosomal pH) for 1 week before ensuing starvation. The latter treatment increased survival of control cells (due to deposition of nondegraded autophagocytosed material before start of starvation), but not that of ceroid/lipofuscin-loaded cells. Moreover, when NH4Cl treatment was combined with starvation, both groups of cells showed approximately the same shortened survival times, testifying to the causal relationship between diminished autophagocytosis and decreased survival of starving ceroid/lipofuscin-loaded cells. We hypothesize that large amounts of undegradable ceroid/lipofuscin within the acidic vacuolar compartment may interfere with lysosomal function, resulting in poor renewal of long-lived proteins and worn-out/damaged organelles, decreased adaptability, and cell death

The nigrostriatal dopaminergic system as a preferential target of repeated exposures to combined paraquat and maneb: implications for Parkinson's disease.

Thiruchelvam M, Richfield EK, Baggs RB, et al.

J Neurosci. 2000 Dec 15; 20(24):9207-14.

Experimental evidence supporting 1,1'-dimethyl-4,4'-bipyridinium [paraquat (PQ)] as a risk factor for Parkinson's disease (PD) is equivocal. Other agricultural chemicals, including dithiocarbamate fungicides such as manganese ethylenebisdithiocarbamate [maneb (MB)], are widely used in the same geographical regions as paraquat and also impact dopamine systems, suggesting that mixtures may be more relevant etiological models. This study therefore proposed that combined PQ and MB exposures would produce greater effects on dopamine (DA) systems than would either compound administered alone. Male C57BL/6 mice were treated twice a week for 6 weeks with intraperitoneal saline, 10 mg/kg paraquat, 30 mg/kg maneb, or their combination (PQ + MB). MB, but not PQ, reduced motor activity immediately after treatment, and this effect was potentiated by combined PQ + MB treatment. As treatments progressed, only the combined PQ + MB group evidenced a failure of motor activity levels to recover within 24 hr. Striatal DA and dihydroxyphenylacetic acid increased 1-3 d and decreased 7 d after injections. Only PQ + MB reduced tyrosine hydroxylase (TH) and DA transporter immunoreactivity and did so in dorsal striatum but not nucleus accumbens. Correspondingly, striatal TH protein levels were decreased only by combined PQ + MB 5 d after injection. Reactive gliosis occurred only in response to combined PQ + MB in dorsal-medial but not ventral striatum. TH immunoreactivity and cell counts were reduced only by PQ + MB and in the substantia nigra but not ventral tegmental area. These synergistic effects of combined PQ + MB, preferentially expressed in the nigrostriatal DA system, suggest that such mixtures could play a role in the etiology of PD

What is it that l-deprenyl (selegiline) might do?

Tipton KF.

Clin Pharmacol Ther. 1994 Dec; 56(6 Pt 2):781-96.

There have been many claims that l-deprenyl may have distinct properties in slowing and perhaps even in reversing the progression of Parkinson's disease and other neurodegenerative conditions. This article will consider the paucity of evidence that such is the case in humans and the more detailed results from studies with experimental animals indicating that deprenyl may indeed express such a property. The conflicting data on its mechanism of action are considered and the concept that it may function to enhance neuronal fitness is advanced as an alternative to the neuroprotection and neurorescue hypotheses. Possible lines of experimental development that would help resolve some of the many unanswered questions regarding l-deprenyl function are outlined

[Dementia and amyotrophy in Kufs disease. The adult type of neuronal ceroid lipofuscinosis].

Tominaga I, Hattori M, Kaihou M, et al.

Rev Neurol (Paris). 1994 Jun; 150(6-7):413-7.

A 26-year-old housewife, born of consanguineous parentage, began to have gait and speech disturbance. Her brother had died from suffocation because of dysphagia. At thirty-two, she developed difficulty in swallowing, clumsiness and incontinence. When she was thirty-six she had pseudobulbar palsy, vertical gaze paresis, hyperreflexia and muscular atrophy of the upper half of the body. CT scan showed cerebral atrophy. Her mental function progressively deteriorated and amyotrophic lateral sclerosis associated with dementia was suspected. She died at the age of thirty-seven. Diagnosis was made only by autopsy. There was no particular general pathologic finding excepting aspiration pneumonia. Microscopical examination revealed numerous distended neurons with accumulation of light brown pigments by Luxol fast blue/H & E stains, especially in hypothalamus, substantia nigra and nuclei of oculomotor nerves. To a lesser extent such neurons were noted ubiquitously. The stored material was mainly composed of lipofuscin and ceroid. Ultrastructurally they presented the various structures which have previously been reported, except for finger print profiles. The pigmentary deposits were shown to be immunoreactive with polyclonal antibody directed against amyloid beta-protein

Modulation of the host flora.

van Furth R, Guiot HF.

Eur J Clin Microbiol Infect Dis. 1989 Jan; 8(1):1-7.

Modulation of the bacterial flora of patients with a high risk of acquiring an infection can be achieved in several ways. The approach used in the Leiden University Hospital is based on selective elimination of the aerobic bacteria in the oropharyngeal cavity and intestinal tract, leaving the anaerobic flora intact. This kind of selective modulation of the host flora has an advantage in that it does not affect the colonization resistance provided by bacterial antagonism, which prevents colonization by resistant but potentially pathogenic bacteria or fungi. The elimination of aerobic bacteria combined with nursing in protective isolation and consumption of food with few bacteria has led to a significant reduction of the incidence of major and fatal infections in patients during episodes of severe granulocytopenia. From these results it may be concluded that the objective of selective antibiotic modulation, namely, the prevention of infections, can be achieved with this approach

Aluminium speciation in cerebrospinal fluid of acutely aluminium-intoxicated dialysis patients before and after desferrioxamine treatment; a step in the understanding of the element's neurotoxicity.

Van Landeghem GF, D'Haese PC, Lamberts LV, et al.

Nephrol Dial Transplant. 1997 Aug; 12(8):1692-8.

BACKGROUND: The association between aluminium and dialysis encephalopathy and deterioration of the neurological state during desferrioxamine treatment of dialysis patients is well established. At present little is known about the speciation and the mechanisms underlying the element's neurotoxicity. METHODS: Aluminium speciation was performed in cerebrospinal fluid samples of acutely aluminium-intoxicated dialysis patients using a recently developed high-performance liquid chromatographic/electrothermal atomic absorption spectrometric hybrid method. RESULTS: Baseline cerebrospinal fluid aluminium levels of samples taken shortly after the intoxication were low but elevated (5.0 +/- 2.0 micrograms/l, n = 3) as compared to subjects with normal renal function (< 1 microgram/l). In contrast to the situation noted in serum and to the iron speciation in cerebrospinal fluid, aluminium was not bound to transferrin but appeared as two distinct compounds, the main fraction eluting at the elution volume of aluminium-citrate/silicate. The second compound was not identified. Forty-four hours after desferrioxamine administration the cerebrospinal fluid aluminium levels had increased up to a concentration of 10.3 +/- 2.5 micrograms/l (n = "3)." This was accompanied by a change in the speciation profile with aluminium appearing at the elution volume of aluminoxamine. CONCLUSIONS: Our findings may contribute to a better understanding of the neurotoxic effects of aluminium and its desferrioxamine chelate in dialysis patients

Genetic and environmental risk factors in Parkinson's disease.

Veldman BA, Wijn AM, Knoers N, et al.

Clin Neurol Neurosurg. 1998 Mar; 100(1):15-26.

Parkinson's disease (PD) is a multifactorial disorder, caused by a combination of age, genetics and environmental factors. Nigral cells are susceptible to multiple causes of derangement of normal cell function, all of which may contribute to the same Parkinson phenotype. Autosomal dominant alpha-synuclein-gene PD represents one of the pure genetic forms, whereas cases of sporadic PD probably depend more on age and environmental factors, MPTP-Parkinsonism being the purest example of an environmentally caused Parkinson phenotype. This review suggests that pesticides-herbicides, smoking and head trauma probably represent the most eligible candidates for environmental factors involved in provoking PD or influencing its natural course

Results of chronic subthalamic nucleus stimulation for Parkinson's disease: a 1-year follow-up study.

Vesper J, Klostermann F, Stockhammer F, et al.

Surg Neurol. 2002 May; 57(5):306-11.

BACKGROUND: Deep brain stimulation (DBS) has been established as an alternative approach for the treatment of advanced Parkinson's disease (PD). Recently, the subthalamic nucleus (STN) has been identified as the optimal target for DBS. METHODS: Thirty-eight patients have undergone surgery for advanced PD since 1996. They include 12 females and 26 males with a mean age of 55.6 years. The mean stage on the Hoehn and Yahr Scale was 3.5 (off condition). Electrodes (Medtronic DBS 31389) were stereotactically implanted into the STN bilaterally. Targeting was performed using computerized tomography (CT) scans and ventriculography (VG). After 4 days of external stimulation, permanent neurostimulators were implanted. Patients were evaluated preoperatively and 1, 6, and 12 months postoperatively. Evaluations were performed in defined on and off states using the Unified Parkinson's Disease Rating Scale (UPDRS) as well as the Hoehn and Yahr Scale, the dyskinesia scale, and the Activities of Daily Living (ADL) Scale. RESULTS: Significant improvement of all motor symptoms was found in all patients (UPDRS motor score 32/48 preoperatively versus 15/30 at 12-month follow-up, p < 0.001). Daily off-times were reduced by 35%. Dyskinesias also improved markedly (UPDRS IV: 3.2/3.1 [on/off] vs. 0.9/1.3 at 12 months follow-up). Postoperative L-dopa medication was adjusted (mean reduction: 53%). Complications occurred in two patients (5%) who developed infections, leading to system removal. Systems were replaced after 6 months. Two patients (5%) had a permanent worsening of a previously known depressive state and developed progressive dementia. CONCLUSIONS: TN stimulation is a relatively safe procedure for treating advanced PD. The possibility of readjusting the stimulation parameters postoperatively improves the therapeutic outcome and reduces side effects in comparison to ablative methods

Maternal-fetal distribution of mercury (203Hg) released from dental amalgam fillings.

Vimy MJ, Takahashi Y, Lorscheider FL.

Am J Physiol. 1990 Apr; 258(4 Pt 2):R939-R945.

In humans, the continuous release of Hg vapor from dental amalgam tooth restorations is markedly increased for prolonged periods after chewing. The present study establishes a time-course distribution for amalgam Hg in body tissues of adult and fetal sheep. Under general anesthesia, five pregnant ewes had twelve occlusal amalgam fillings containing radioactive 203Hg placed in teeth at 112 days gestation. Blood, amniotic fluid, feces, and urine specimens were collected at 1- to 3-day intervals for 16 days. From days 16-140 after amalgam placement (16-41 days for fetal lambs), tissue specimens were analyzed for radioactivity, and total Hg concentrations were calculated. Results demonstrate that Hg from dental amalgam will appear in maternal and fetal blood and amniotic fluid within 2 days after placement of amalgam tooth restorations. Excretion of some of this Hg will also commence within 2 days. All tissues examined displayed Hg accumulation. Highest concentrations of Hg from amalgam in the adult occurred in kidney and liver, whereas in the fetus the highest amalgam Hg concentrations appeared in liver and pituitary gland. The placenta progressively concentrated Hg as gestation advanced to term, and milk concentration of amalgam Hg postpartum provides a potential source of Hg exposure to the newborn. It is concluded that accumulation of amalgam Hg progresses in maternal and fetal tissues to a steady state with advancing gestation and is maintained. Dental amalgam usage as a tooth restorative material in pregnant women and children should be reconsidered

Chronic low-dose glutamate is toxic to retinal ganglion cells. Toxicity blocked by memantine.

Vorwerk CK, Lipton SA, Zurakowski D, et al.

Invest Ophthalmol Vis Sci. 1996 Jul; 37(8):1618-24.

PURPOSE: It is well known that acute exposure to high concentrations of glutamate is toxic to central mammalian neurons. However, the effect of a chronic, minor elevation over endogenous glutamate levels has not been explored. The authors have suggested that such chronic exposure may play a role in glaucomatous neuronal loss. In the current study, they sought to explore whether a chronic, low-dose elevation in vitreal glutamate was toxic to retinal ganglion cells and whether this toxicity could be prevented with memantine, a glutamate antagonist. METHODS: Rats were injected serially and intravitreally with glutamate to induce chronic elevations in glutamate concentration. A second group of rats was treated with intraperitoneal memantine and glutamate. Control groups received vehicle injection with or without concurrent memantine therapy. After 3 months, the animals were killed, and ganglion cell survival was evaluated. RESULTS: Intravitreal injections raised the intravitreal glutamate levels from an endogenous range of 5 to 12 microM glutamate to 26 to 34 microM. This chronic glutamate elevation killed 42% of the retinal ganglion cells after 3 months. Memantine treatment alone had no effect on ganglion cell survival. However, when memantine was given concurrently with low-dose glutamate, memantine was partially protective against glutamate toxicity. CONCLUSIONS: These data suggest that minor elevations in glutamate concentration can be toxic to ganglion cells if this elevation is maintained for 3 months. Furthermore, memantine is efficacious at protecting ganglion cells from chronic low-dose glutamate toxicity

Aluminum. In Guidelines for Drinking-Water Quality, Second Edition, Health Criteria and Other Supporting Information.

WHO.

1998; Second Edition:3-13.

[Mercury concentration in the mouth mucosa of patients with amalgam fillings].

Willershausen-Zonnchen B, Zimmermann M, Defregger A, et al.

Dtsch Med Wochenschr. 1992 Nov 13; 117(46):1743-7.

Mercury concentrations were measured in specimens of oral mucosa taken during oral surgery from 90 patients (53 men, 37 women, mean age 42 +/- 16 years); 30 of the patients had no amalgam fillings. All the mucosal specimens extended for at least 2-3 mm from the epithelium of the gingival margin and were clinically and radiologically normal. Thirteen patients without metallic fillings of any kind had mercury concentrations of 118.4 +/- 83.7 ng/g tissue, and in 17 patients with precious metal fillings but no amalgam the mean mercury concentrations were 144 +/- 290 ng/g tissue. Seventeen patients with 1-3 amalgam fillings had an average of 1975 +/- 4300 ng/g tissue and in 26 patients with 3-6 amalgam fillings the average concentration was 1158 +/- 2500 ng/g tissue. In 17 patients with more than six amalgam fillings the mean mercury concentration was 2302 +/- 5600 ng/g tissue. Although these results demonstrate a considerable degree of transfer of mercury from the amalgam fillings to the oral mucosa, it had not resulted in any clinically detectable mucosal lesions

Neuronal protective and rescue effects of deprenyl against MPP+ dopaminergic toxicity.

Wu RM, Murphy DL, Chiueh CC.

J Neural Transm Gen Sect. 1995; 100(1):53-61.

Intranigral infusion of 1-Methyl-4-phenylpyridinium ion (MPP+, 2.1-16.8 nmol) dose-dependently injured nigral neurons as reflected by reduced dopamine levels in the ipsilateral striatum four days after the infusion of this toxic metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Coadministration of deprenyl (4.2 nmol) with MPP+ into the substantia nigra protected against MPP(+)-induced moderate (20-50%) but not severe (over 70%) nigral injury as reflected in striatal dopamine reductions. However, supplementary treatment with deprenyl (0.25 mg/kg, s.c., twice daily for 4 days) after intranigral infusion of MPP+ significantly rescued nigral neurons from more severe damage caused by a higher MPP+ does (8.4 nmol) manifested by a lesser striatal dopamine decrease (-31%) compared to the non-deprenyl treated group (-70%). Thus, in addition to the blockade of bioactivation of MPTP, deprenyl can protect and/or rescue nigral neurons from MPP(+)-induced dopaminergic neurotoxicity. These in vivo data add further evidence to suggest that deprenyl, a putative and clinically unproven neuroprotective agent, may be of value in slowing the progressive nigral degeneration in "early" Parkinson's disease, but may prove to be less so in its terminal stages

Calcium and vitamin D metabolism in Guamanian Chamorros with amyotrophic lateral sclerosis and parkinsonism-dementia.

Yanagihara R, Garruto RM, Gajdusek DC, et al.

Ann Neurol. 1984 Jan; 15(1):42-8.

We evaluated 16 Guamanian Chamorros with amyotrophic lateral sclerosis and 33 patients with parkinsonism-dementia for disturbances of calcium and vitamin D metabolism. The serum immunoreactive parathyroid hormone level was mildly elevated in 6 patients with amyotrophic lateral sclerosis and in 5 patients with parkinsonism-dementia. There were significant positive correlations between serum immunoreactive parathyroid levels and duration of illness in male patients with motor neuron disease, but not in female patients or in patients with parkinsonism-dementia. Intestinal absorption of calcium, as assessed by serum and urinary activity of calcium 47 following oral administration, was decreased in 2 patients with amyotrophic lateral sclerosis and in 4 patients with parkinsonism-dementia, all of whom had low levels of serum 1,25-dihydroxyvitamin D. Reductions in cortical bone mass were striking in patients with motor neuron disease. A significant negative correlation was found between the percentage of cortical area of the second metacarpal bone and muscle atrophy and weakness, and significant positive correlations were found between degree of immobility and ratio of urinary hydroxyproline to creatinine in patients with amyotrophic lateral sclerosis and parkinsonism-dementia. In general, abnormalities in calcium metabolism were subtle. Thus, if the demonstrated deposition of metals, particularly calcium and aluminum, in central nervous system tissues of Guamanians with these two conditions is a cause of the diseases and of the early appearance of neurofibrillary tangles in neurons, the accumulation has apparently occurred long before onset of symptoms, and detectable abnormalities of calcium and vitamin D metabolism may already have been corrected

Detection of subclinical ascorbate deficiency in early Parkinson's disease.

Yapa SC.

Public Health. 1992 Sep; 106(5):393-5.

From mid-October 1989 to mid-July 1990 all newly admitted residents to Bury Local Authority Residential Homes were comprehensively medically screened. In a series of 100 residents eight had early Parkinson's disease (six of them hitherto undiagnosed). Seven showed evidence of Vitamin C deficiency. Of the seven showing evidence of deficiency, four suffered from early Parkinson's disease. Of the 93 without evidence of Vitamin C deficiency only four had Parkinson's disease. This indicates a significantly higher prevalence of Parkinson's disease in the group with Vitamin C deficiency (P less than 0.001 using Fisher's exact)

Age-related phenomena in the lumbar intervertebral discs. Lipofuscin and amyloid deposition.

Yasuma T, Arai K, Suzuki F.

Spine. 1992 Oct; 17(10):1194-8.

In 69 lumbar intervertebral discs from 69 autopsies, lipofuscin was seen in discs from individuals older than 50 years of age and amyloids in the discs of individuals older than 40 years of age. In 261 intervertebral disc tissue specimens collected at the time of surgery for disc herniation, lipofuscin was seen in the discs of individuals older than 20 years of age and amyloids in the discs of individuals older than 15 years of age. It is speculated that amyloids and lipofuscin are a sign of aging in the intervertebral disc as in other tissues. Furthermore, amyloids and lipofuscin were seen in the operated discs of young individuals than in the autopsy cases

Iron in brain function and dysfunction with emphasis on Parkinson's disease.

Youdim MB, Ben Shachar D, Riederer P.

Eur Neurol. 1991; 31 Suppl 1:34-40.

Metals such as lead, zinc, copper, aluminum and manganese have been implicated in neuropsychiatric disorders. However, until fairly recently the role of iron in brain function was rather obscure, because little attention was paid to its metabolism in the brain. It is now apparent that maintenance of brain iron homoeostasis is important for the normal functioning of his organ. Most of the studies have been directed towards the cognitive and attentional deficit resulting from nutritional iron deficiency. Evidence so far suggests subsensitivity of striatal dopamine neurotransmission. By contrast the selective increase in free iron in the substantia nigra pars compacta of parkinsonian brains is thought to initiate oxidative stress, from iron-induced liberation of cytotoxic oxygen free radicals. Such radicals are known to promote membrane fluidity, alteration in cellular calcium homoeostasis, lipid peroxidation and finally cell death in systemic organs. Evidence supporting similar processes being responsible for nigrostriatal dopamine neuron degeneration in Parkinson's disease is now becoming available. Such possibilities afford the development of neuroprotective drugs as a means to retard the progression of this disorder. These include other selective monoamine oxidase B inhibitors, iron chelators with the ability to cross the blood-brain barrier, selective calcium channel antagonists and mitochondrial electron transport system protectors

Melatonin-dopamine interactions: from basic neurochemistry to a clinical setting.

Zisapel N.

Cell Mol Neurobiol. 2001 Dec; 21(6):605-16.

To review the interaction between melatonin and the dopaminergic system in the hypothalamus and striatum and its potential clinical use in dopamine-related disorders in the central nervous system. Medline-based search on melatonin-dopamine interactions in mammals. Melatonin. the hormone produced by the pineal gland at night. influences circadian and seasonal rhythms, most notably the sleep-wake cycle and seasonal reproduction. The neurochemical basis of these activities is not understood yet. Inhibition of dopamine release by melatonin has been demonstrated in specific areas of the mammalian central nervous system (hypothalamus, hippocampus, medulla-pons, and retina). Antidopaminergic activities of melatonin have been demonstrated in the striatum. Dopaminergic transmission has a pivotal role in circadian entrainment of the fetus, in coordination of body movement and reproduction. Recent findings indicate that melatonin may modulate dopaminergic pathways involved in movement disorders in humans. In Parkinson patients melatonin may, on the one hand, exacerbate symptoms (because of its putative interference with dopamine release) and, on the other, protect against neurodegeneration (by virtue of its antioxidant properties and its effects on mitochondrial activity). Melatonin appears to be effective in the treatment of tardive dyskinesia. a severe movement disorder associated with long-term blockade of the postsynaptic dopamine D2 receptor by antipsychotic drugs in schizophrenic patients. The interaction of melatonin with the dopaminergic system may play a significant role in the nonphotic and photic entrainment of the biological clock as well as in the fine-tuning of motor coordination in the striatum. These interactions and the antioxidant nature of melatonin may be beneficial in the treatment of dopamine-related disorders

[Parkinson's disease and environmental factors].

Zuber M, Alperovitch A.

Rev Epidemiol Sante Publique. 1991; 39(4):373-87.

The etiology of the nigrostriatal pathway degeneration in Parkinson's disease (PD) is unknown but there is a growing pool of evidence that environmental factors may be involved in the genesis of this disorder. The discovery of the N-Methyl 4-Phenyl 1,2,3,6-Tetrahydro-Pyridine (MPTP)-induced injury in late 1970s provided the first experimental model of PD and stimulated dramatically the epidemiological research. An excitotoxic amino acid contained in Cycadales, which is thought to be responsible for the amyotrophic lateral sclerosis-parkinsonism-dementia complex of Guam, provides another example of toxin-induced parkinsonism. This amino acid is present in most seeds common in the Western diet. In developed countries, prevalence of PD is 2 to 5 times as high than in developing countries. PD patients in developed countries are more likely than controls to have lived in rural environment. Case control studies have suggested that this positive association is possibly related to pesticides and herbicides exposures or well water drinking. Dietary surveys are now going on and several hypothesis are tested including high MPTP-structural analogs or seeds consumption in PD patients and low antioxidants consumption. The negative association between smoking habits and PD has been recognized for more than 20 years. There is evidence that this association is not an artefact due to the disease affecting smoking habits. Its origin is unknown but it could provide important aetiological clues for PD. The most recent hypothesis concerning the relationships between these environmental factors and PD are reviewed and pertinent suitable surveys for the future are discussed