The
effect of modest vitamin E supplementation on
lipid peroxidation products and other
cardiovascular risk factors in diabetic
patients.
Jain SK; McVie R; Jaramillo JJ; Palmer M; Smith
T; Meachum ZD; Little RL
Department of Pediatrics, Louisiana State
University Medical Center, Shreveport 71130,
USA.
Lipids (United States) Mar 1996, 31 Suppl
pS87-90
Among many factors, elevated lipids and lipid
peroxide levels in blood are major risk factors in
the development of cardiovascular disease in
diabetic patients. This study has examined whether
oral supplementation of vitamin E, an antioxidant,
has any effect on blood of diabetic patients.
Thirty-five diabetics(D) were supplemented with
DL-alpha-tocopherol (E) capsule (orally, 100 IU/d)
or placebo (P) for three months in double-blind
clinical trials. Plasma E was analyzed by HPLC and
LP by the thiobarbituric acid-reactivity; serum
lipids by auto-analyzer. Data were analyzed using
paired t-test and Wilcoxon Signed Rank Test.
Vitamin E supplementation significantly lowered LP
and lipid levels in diabetic patients; there were
no differences in these parameters after P
supplementation. There were no differences in the
duration of diabetes and ages of D between P- and
E- supplemented groups. This study suggests that
vitamin E supplementation significantly lowers
blood LP and lipid levels in diabetic
patients.
The role
of oxidized lipoproteins in
atherogenesis.
Berliner JA; Heinecke JW
Department of Pathology, University of California
Los Angeles 90024, USA.
Free Radic Biol Med (United States) 1996, 20 (5)
p707-27
This article reviews our current understanding
of the mechanisms of low-density lipoprotein (LDL)
oxidation and the potential role of oxidized
lipoproteins in atherosclerosis. Studies in
hypercholesterolemic animal models indicate that
oxidation of LDL is likely to play an important
role in atherogenesis. Epidemiological
investigations further suggest that the dietary
intake of antioxidants is inversely associated
with the risk of vascular disease, suggesting that
oxidized LDL may be important in human
atherosclerosis. By activating inflammatory
events, oxidized lipoproteins may contribute to
all stages of the atherosclerotic process.
Lipoprotein oxidation is promoted by several
different systems in vitro, including free and
protein-bound metal ions, thiols, reactive oxygen
intermediates, lipoxygenase, peroxynitrite, and
myeloperoxidase. Intracellular proteins that bind
iron or regulate iron metabolism might also play
an important role. The physiologically relevant
pathways have yet to be identified, however. We
assess recent findings on the effects of
antioxidants in vivo and suggest potential
strategies for inhibiting oxidation in the vessel
wall. (265 Refs.)
Inhibition of naphthalene cataract in
rats by aldose reductase inhibitors.
Lou MF; Xu GT; Zigler S Jr; York B Jr
Department of Veterinary and Biomedical Sciences,
University of Nebraska-Lincoln 68583, USA.
Curr Eye Res (England) Apr 1996, 15 (4)
p423-32
Naphthalene-induced cataract in rat lenses can
be completely prevented by AL01576, an aldose
reductase inhibitor (ARI). In an attempt to
understand the mechanism of this inhibition,
several ARIs were examined to compare their
efficacies in preventing naphthalene cataract,
using both in vitro and in vivo models. Two
classes of ARIs were tested: One group including
AL01576, AL04114 (a AL01576 analog) and Sorbinil
contained the spirohydantoin group, while
Tolrestat contained a carboxylic acid group.
Furthermore, to clarify if aldose reductase played
a role in naphthalene-induced cataractogenesis in
addition to its role in sugar cataract formation,
a new dual cataract model was established for ARI
evaluations. This was achieved by feeding rats
simultaneously with high galactose and naphthalene
or incubating rat lenses in culture media
containing high galactose and naphthalene
dihydrodiol. Under these conditions, both cortical
cataract and perinuclear cataract developed in the
same lens. It was found that at the same dosage of
10 mg/kg/day, both AL01576 and AL04114 completely
prevented all morphological and biochemical
changes in the lenses of naphthalene-fed rats.
Sorbinil was less efficacious, while Tolrestat was
inactive. AL01576 showed a dose-response effect in
preventing naphthalene cataract and at 10
mg/kg/day, it was also effective as an
intervention agent after cataractogenesis had
begun. With the dual cataract model, Tolrestat
prevented the high galactose-induced cortical
cataract but showed no protection against the
naphthalene-induced perinuclear cataract. AL01576,
on the other hand, prevented both cataract
formations. Results for dulcitol and glutathione
levels were in good agreement with the
morphological findings. AL04114, and ARI as potent
as AL01576 but without its property for cytochrome
P-450 inhibition, displayed similar efficacy in
preventing naphthalene cataract. Based on these
results, it was concluded that the prevention of
the naphthalene cataract probably results from
inhibition of the conversion of naphthalene
dihydrodiol to 1,2-dihydroxynaphthalene and that
the effect of the ARIs cannot be explained by
their inhibition of the dihydrodiol dehydrogenase
activity of aldose reductase.
Primary
and secondary prevention of myocardial
infarction.
Borghi C; Ambrosioni E
Department of Internal Medicine, University of
Bologna, Italy.
Clin Exp Hypertens (United States) Apr-May 1996,
18 (3-4) p547-58
The prevention of coronary artery disease (CHD)
and particularly of myocardial infarction (MI) is
based on some well designed strategies aimed at
treating both asymptomatic high-risk patients
(primary prevention) and patients with established
CHD (secondary prevention). A positive impact from
primary prevention can be basically achieved
trough a reduction in high blood pressure and by
correcting dyslipidemia. The benefit can be
substantially increased by smoking cessation,
increasing physical exercise, reduction of body
weight, use of post-menopausal oestrogen, moderate
alcohol consumption and use of high doses of
vitamin E in those patients who are compliant with
the specific strategies. Secondary prevention of
MI can be again obtained by controlling blood
pressure and reducing serum cholesterol in
patients surviving acute MI who can also benefit
from the administration of beta-blockers, aspirin
and probably ace-inhibitors particularly in
presence of left ventricular dysfunction. We
suggest that in both arms of prevention,
significant results can be achieved mainly by a
multifactorial approach capable of correcting all
the modifiable risk factors that contribute to the
rather complex pathogenesis of CHD. (22 Refs.)
Tuberculosis in Siberia: 2.
Diagnosis, chemoprophylaxis and
treatment.
Drobniewski F; Tayler E; Ignatenko N; Paul J;
Connolly M; Nye P; Lyagoshina T; Besse C
Regional Tuberculosis Centre, Dulwich Public
Health Laboratory, London, UK.
Tuber Lung Dis (Scotland) Aug 1996, 77
OBJECTIVE: To assess tuberculosis diagnosis,
chemoprophylaxis and therapy in Siberia as a
paradigm for the Russian Federation.
DESIGN: Data was obtained from official sources
and through visits to dispensaries and hospitals
in 1994.
RESULTS: Tuberculosis disease and cure is
classified according to a Dispensary Group
Register based principally on clinical and
radiological criteria. Isoniazid is widely used
for chemoprophylaxis and post-therapy and may be
linked to high levels of isoniazid resistance.
Combination drug therapy is individualized,
frequently changed, and given orally, parenterally
or intra-bronchially. Galvanization,
autotransfusion of ultra-violet irradiated blood,
antioxidants and steroids are used as adjunct
treatment. Ambulatory treatment is uncommon.
Surgical treatments including lobectomy and
pneumonectomy are used in 5-10% of patients.
CONCLUSION: Tuberculosis is increasing in
Siberia. An improved drug supply using short
course standardized regimens is required supported
by high quality co-ordinated bacteriological
services. Surgery retains a useful role, but many
adjunct therapies should be abandoned.
Antioxidants, oxidants and free
radical stress in cardiovascular
disease.
Singh RB; Niaz MA
Heart Research Laboratory, Medical Hospital and
Research Centre, Moradabad, India.
J Assoc Physicians India (India) Jan 1996, 44 (1)
p43-8
No abstract.
Lipid
peroxidation: a review of causes, consequences,
measurement and dietary influences.
Hong Kong Polytechnic University, Hung Hom,
Kowloon, Hong Kong.
Int J Food Sci Nutr (England) May 1996, 47 (3)
p233-61
In this review the process of lipid
peroxidation and the atherogenicity of peroxidied
lipids are discussed. Recent findings with regard
to the effect of selected dietary factors on
susceptibility of lipids to oxidative stress and
on antioxidant defences are analysed with
particular reference to their potential use in the
prevention and treatment of atherogenesis and, by
extension, coronary heart disease. Laboratory
methods of assessing antioxidant defences, lipid
peroxidation and the effects of lipid peroxidation
are also reviewed and discussed with particular
reference to their ability to assess in vivo
oxidative stress and lipid peroxidation status. A
range of oxidative stress indices are presented
and their limitations discussed, but the main
focus is on the most commonly used laboratory test
for lipid peroxidation, the thiobarbituric acid
reacting substances (TBARS) test. Finally, the
influence of selected dietary factors on measured
peroxidation status is discussed, with particular
reference to the antioxidant vitamins C (ascorbic
acid) and E (alpha tocopherol) and the type of
fatty acids (mono- and poly-unsaturated) in the
diet. (222 Refs.)
Female
lung cancer.
Ernster VL
Department of Epidemiology and Biostatistics,
School of Medicine, University of California, San
Francisco 94143-0560, USA.
Annu Rev Public Health (United States) 1996, 17
p97-114
Female lung cancer death rates increased by
more than 550 percent between 1950 and 1991. In
1986 lung cancer surpassed breast cancer to become
the leading cause of cancer death in women in the
United States. The lung cancer epidemic is
primarily attributable to cigarette smoking, which
is responsible for at least 80% of the disease in
women. There are gender differences in the
distribution of lung cancer by histologic type,
even controlling for smoking, and some data
suggest greater female than male susceptibility to
lung cancer at a given leves risk of lung cancer
in nons moking women. Family history of lung
cancer, personal history of lung disease (e.g.
asthma, chronic bronchitis, pneumonia, or
tuberculosis), and a history of radiotherapy also
appear to be associated with increased risk. Data
specific to women on the role of household radon
exposures or of specific occupational or
environmental exposures are relatively sparse and
inconsistent. Finally, many studies have reported
a decreased risk of lung cancer in individuals who
consume high levels of fruits and vegetables;
however, clinical trials fail to support a
beneficial effect of beta-carotene
supplementation. Since cigarette smoking accounts
for the vast majority of lung cancer cases in
women, efforts to prevent adolescent girls from
starting to smoke and to encourage cessation among
established smokers have the greatest potential
for reducing the female lung cancer burden. (94
Refs.)
The role
of metals in ischemia/reperfusion injury of the
liver.
Arora AS; Gores GJ
Center for Basic Research in Digestive Diseases,
Mayo Clinic and Foundation, Rochester, Minnesota
55905, USA.
Semin Liver Dis (United States) Feb 1996, 16 (1)
p31-8
Based on current information, we have described
the role that metals play in potentiating and
ameliorating liver I/R injury. To date, most of
the data have focused on the deleterious effects
of free iron in mediating I/R injury. Several
therapeutic strategies have proven useful in
animal models to counteract the effect of iron as
a potentiator of I/R injury. These approaches have
predominantly centered on the role of iron
chelation using DFO and DFO conjugates. The data
suggest that chelation of iron may prove useful in
preventing I/R injury such as occurs in liver
transplantation. Indeed, enough data are now
available to initiate and support clinical trials
(e.g., addition of DFO conjugates to explant
storage solutions). The role of copper, however,
is less well defined. Copper is important for the
function of copper-zinc SOD. However, free copper
may be as injurious as free iron. Further studies
are needed to clarify the role of copper in
I/R-induced hepatocellular necrosis. Selenium has
a well-defined antioxidant role as part of GSH
peroxidase (GSH antioxidant pathway). More recent
data suggest that selenium may also act as an
antioxidant through selenoprotein P, but the role
of selenoprotein P in I/R injury remains to be
defined. Finally, zinc appears to function as an
antioxidant in less well-defined pathways. Further
studies are needed to identify the fundamental
mechanisms by which zinc may ameliorate oxidative
damage during I/R injury. These data demonstrate
that metals play a critical role in I/R injury of
the liver and remain a fruitful area for
investigation and development of therapeutic
strategies. (65 Refs.)
[Bronchopulmonary
dysplasia]
Clement A
Service de Physiologie, Hopital Trousseau,
Paris.
Rev Mal Respir (France) Jul 1996, 13 (3)
p243-9
Bronchopulmonary dysplasia (BPD), a respiratory
disorder first described in prematurely born
infants with respiratory distress syndrome (RDS)
treated with mechanical ventilation and oxygen
supplementation, is the most common cause of
chronic lung disease in infants. It is defined as
the need for increased inspired oxygen at 28 days
of age, and is observed with the highest frequency
following premature delivery of very low birth
weight infants. Indeed, an incidence of 48% has
been recently reported in a population with a mean
gestational age of 27 weeks. The etiology of BPD
is multifactorial including lung immaturity,
respiratory distress, oxygen therapy, and
mechanical ventilation. Based on the current
understanding of the pathogenesis of the disease,
several therapeutical strategies are used. One of
them is focused on the prevention of BPD by
correcting surfactant deficiency in premature
infants with RDS using exogenous surfactant, and
also by improving the techniques of mechanical
ventilation used for the management of RDS.
Another approach which is being deveon the factors
involved in the processes of repair of the injured
immature lung. These factors include the use of
inhibitors of the inflammatory cascade,
antioxidants, and inhibitors of fibrosis. (42
Refs.)
[LDL
oxidation in homozygous familial
hypercholesterolemia: effects of selective
LDL-apheresis treatment]
Napoli C; Postiglione A; Scarpato N; Corso G;
Ambrosio G; Condorelli M; Mancini M; Chiariello
M
Cattedra di Cardiologia, Universita degli Studi,
Federico II, Napoli.
Cardiologia (Italy) May 1996, 41 (5) p435-9
Homozygous familial hypercholesterolemia (HFH)
results from a mutation affecting both the
structure and function of a cell surface receptor
that removes low density lipoproteins (LDL) from
plasma. The disorder is characterized by autosomal
dominant inheritance, a lifelong elevation in the
concentration of LDL-bound cholesterol in blood
and by cholesterol deposits that form xanthomas
and early coronary artery disease. HFH patients,
as a result of the increased levels and prolonged
residence time of LDL in plasma, have a strong
tendency toward accumulation of LDL-cholesterol in
the arterial wall causing premature
atherosclerosis. Selective LDL-apheresis (LA) on
dextran/sulphate cellulose columns is the best
therapy reducing mortality of these patients. We
previously showed that prolonged lifelong enhanced
LDL oxidation in HFH. LDL undergo oxidation before
being taken up by macrophages then transformed
into foam cells. At the present time, the
relevance of the in vitro macrophages studies to
the accumulation of cholesterol esters in
scavenger cells of HFH patients is not yet
established. The aim of this study was to
investigate LDL oxidation, induced by xanthine (2
mM)+xanthine oxidase (100 mU), and cholesterol
esterification in macrophages, in 8 HFH patients
before and after LA. LDL peroxidation by
conjugated-diene absorbance showed an increased
resistance against oxidation after LA: lag time
129 +/- 25 vs 112 +/- 27 min, p < 0.05; diene 1
vs 13.9 +/- 2.5 nM/min/mg LDL, p < 0.01.
Peroxidation was also evaluated from lipid
peroxides (158 +/- 34 vs 57 +/- 18 nM/mg protein
after LA, p < 0.05) and malonyldialdehyde (38
+/- 12 vs 27 +/- 8 nM/mg protein after LA, p <
0.05) content. When oxidized LDL was run on
polyacrylamide gel extensive apo-B100
fragmentation was observed in LDL before LA, vs a
less fragmentation after LA. A similar reduction
was obtained in LDL agarose mobility after LA (1.7
+/- 0.2 vs 2.5 +/- 0.2, p < 0.05). Cholesterol
esterification in mouse peritoneal macrophages was
also decreased after LA (8.5 +/- 1.8 vs 14.6 +/-
2.7 nM/mg cell protein/12 hours, p < 0.05).
Vitamin E content of LDL (mg/g protein) was
increased after LA (4.44 +/- 1.0 vs 3.9 +/- 1.2, p
< 0.05). Thus, selective LA, not only decreases
the pool of LDL, but it also induces changes that
render LDL less susceptible to oxidation and
decreased high cholesterol esterification in
macrophages. The prevention of these mechanisms by
LA contributes actively to retard atherogenesis in
HFH patients.
Dietary
antioxidants in disease prevention.
Gordon M
Department of Food Science & Technology,
University of Reading, UK.
Nat Prod Rep (England) Aug 1996, 13 (4)
p265-73
No abstract.
Oxidative stress as a mechanism of
cardiac failure in chronic volume overload in
canine model.
Prasad K; Gupta JB; Kalra J; Lee P; Mantha SV;
Bharadwaj B
Department of Physiology, University of
Saskatchewan, Saskatoon, Canada.
J Mol Cell Cardiol (England) Feb 1996, 28 (2)
p375-85
We investigated the effects of chronic volume
overload in the absence or presence of vitamin E
supplements on the cardiac function and
contractility, cardiac malondialdehyde (MDA)--a
lipid peroxidation product--cardiac antioxidant
enzyme activity and antioxidant reserve in canine
model. The dogs were divided into three groups of
seven dogs each: group I, control; group II,
mitral regurgitation (MR) of 4 months duration;
and group III, MR of 4 months duration receiving
vitamin E (40 U/kg/daily) orally. MR was created
by detaching two or more chordae tendinae to raise
left atrial pressure to 2.5 to three times normal.
MR produced a decrease in the index of myocardial
contractility with little change in myocardial
function. Decrease in myocardial (left and right
ventricles) contractility was associated with an
increase in cardiac MDA, and a decrease in cardiac
antioxidant reserve and antioxidant enzyme
activity. Prevention of volume overload-induced
decrease in myocardial contractility by vitamin E
was associated with a decrease in cardiac MDA and
an increase in cardiac antioxidant reserve and
glutathione peroxidase activity towards control
levels. Superoxide dismutase and catalase activity
remained depressed in vitamin E-treated group. The
results indicate that chronic volume overload
decreases the contractility of both right and left
ventricles and is associated with oxidative stress
in both ventricles. These results support the
hypothesis that oxygen free radicals are involved
in the chronic volume overload-induced cardiac
depression.
Vascular incorporation of
alpha-tocopherol prevents endothelial dysfunction
due to oxidized LDL by inhibiting protein kinase C
stimulation.
Keaney JF Jr; Guo Y; Cunningham D; Shwaery GT;
Xu A; Vita JA
Evans Memorial Department of Medicine, Boston
University Medical Center, Boston, Massachusetts
02118, USA.
J Clin Invest (United States) Jul 15 1996, 98 (2)
p386-94
Excess vascular oxidative stress has been
linked to impaired endlemia. alpha-Tocopherol (AT)
preserves endothelial function in
hypercholesterolemia although the mechanism(s) for
this protective effect is (are) not known. We
examined the tissue-specific effects of AT on
oxidized LDL (ox-LDL)-mediated endothelial
dysfunction in male New Zealand White rabbits.
Animals consumed chow deficient in (< 10 IU/kg)
or supplemented with (1,000 IU/kg) AT for 28 d.
Exposure of thoracic aortae from AT-deficient
animals to ox-LDL (0-500 microg/ml) for 4 h
produced dose-dependent inhibition of
acetylcholine-mediated relaxation (P < 0.05)
while vessels derived from animals consuming AT
were resistant to ox-LDL-mediated endothelial
dysfunction. Animals consuming AT demonstrated a
100-fold increase in vascular AT content and this
was strongly correlated with vessel resistance to
endothelial dysfunction from ox-LDL (R = 0.67; P =
0.0014). These results were not explained by an
effect of AT on ox-LDL-mediated cytotoxicity by
LDH assay or scanning electron microscopy.
Vascular incorporation of AT did produce
resistance to endothelial dysfunction from protein
kinase C stimulation, an event that has been
implicated in the vascular response to ox-LDL.
Human aortic endothelial cells loaded with AT also
demonstrated resistance to protein kinase C
stimulation by both phorbol ester and ox-LDL.
Thus, these data indicate that enrichment of
vascular tissue with AT protects the vascular
endothelium from ox-LDL-mediated dysfunction, at
least in part, through the inhibition of protein
kinase C stimulation. These findings suggest one
potential mechanism for the observed beneficial
effect of AT in preventing the clinical expression
of coronary artery disease that is distinct from
the antioxidant protection of LDL.
[The
significance of ixidized low density lipoprotein
in atherosclerosis]
Hansen PR
Medicinsk afdeling B, Rigshospitalet,
Kobenhavn.
Ugeskr Laeger (Denmark) May 6 1996, 158 (19)
p2706-10
The "oxidation hypothesis" states that oxidised
low-density lipoprotein (ox-LDL) plays a central
role in atherogenesis. LDL oxidation is a chaotic
process initiated by reactive oxygen species.
Enhanced uptake of ox-LDL in macrophages leads to
foam cell formation in vitro, and ox-LDL has a
variety of other experimental proatherogenic
effects, e.g., endothelial cell activation,
immunogenicity, platelet aggregation, and
inhibition of endothelium-dependent
vaso-relaxation. There are methodological
limitations in the current laboratory methods
aimed at characterization of the oxidative state
of LDL. However, considerable evidence indicates
that ox-LDL is found in plasma, arteries, and
atheromatous plaques of humans, although the
significance of this phenomenon is unknown.
Antioxidants may inhibit atherosclerosis in
experimental animals, and epidemiological data
suggest an inverse relation between the intake of
antioxidant vitamins and the risk of coronary
artery disease. Randomised prospective trials are
in progress, and until their conclusion, the
clinical effect of antioxidant therapy in man
remains unknown. (40 Refs.)
Nutrition and immunity with emphasis
on infection and autoimmune disease.
Harbige LS
Division of Immunology, United Medical School of
Guy's and St. Thomas's Hospital, Rayne Institute,
London, UK.
Nutr Health (England) 1996, 10 (4) p285-312
Nutrition and nutritional status can have
profound effects on immune functions, resistance
to infection and autoimmunity in man and other
animals. Nutrients enhance or depress immune
function depending on the nutrient and level of
its intake. Protein-energy malnutrition and
vitamin A deficiency are strongly associated with
impaired immunity and infectious disease. The
essential role vitamin A plays in infection and
maintenance of mucosal surfaces has long been
known. Recent evidence shows that T-cell
subpopulations, cytokines and antibody subclasses
are all affected by vitamin A. In animal studies
supplementation with vitamin E protects against
infection and is linked to stimulatory effects on
the immune system. In man vitamin E and other
anti-oxidants increase the number of CD4+ cells.
Dietary lipids and zinc have a substantial impact
on autoimmunity from protective to potentiation of
immuno-pathological processes in animals. There is
considerable potential to modify human autoimmune
disease by manipulation of lipid nutrition.
Deficiency of pyridoxine induces atrophy of
lymphoid organs, marked reduction in lymphocyte
numbers, impairs antibody responses and IL-2
production. Dietary copper is important in the
prevention of infection in some animal species and
T-cell function is defective under deficiency
states due to an inability to produce IL-2.
Selenium has been linked to viral infection,
enhanced T-cell functions and TNF beta induced
increase in natural killer cell activity.
Understanding the molecular and cellular
immunological mechanisms involved in
nutrient-immune interactions will increase our
applications for nutrition of the immune system in
health and in disease.
In vivo
antioxidant treatment suppresses nuclear
factor-kappa B activation and neutrophilic lung
inflammation.
Blackwell TS; Blackwell TR; Holden EP;
Christman BW; Christman JW
Department of Medicine, Vanderbilt University
School of Medicine, Nashville, TN 27232, USA.
J Immunol (United States) Aug 15 1996, 157 (4)
p1630-7
We hypothesized that endotoxin injection in
rats would stimulate in vivo nuclear factor-kappa
B (NF-kappa B) activation in lung tissue and that
antioxidant treatment before endotoxin injection
would attenuate endotoxin-induced NF-kappa B
activation, chemokine gene expression, and
neutrophilic lung inflammation. We studied
NF-kappa B activation in rat lung tissue following
a single i.p. injection of endotoxin (6 mg/kg).
After in vivo endotoxin treatment, lung NF-kappa B
activation peaked at 2 h and temporall the
expression of cytokine-induced neutrophil
chemoattractant mRNA in lung tissue. Treatment
with the antioxidant N-acetylcysteine (NAC) 1 h
before endotoxin resulted in decreased lung
NF-kappa B activation in a dose-dependent manner
(from 200-1000 mg/kg) and diminished
cytokine-induced neutrophil chemoattractant mRNA
expression in lung tissue. Treatment with NAC
significantly suppressed endotoxin-induced
neutrophilic alveolitis. The average total lung
lavage neutrophil count was 5.5 x 10(6) with
endotoxin treatment vs 0.9 x 10(6) with NAC
treatment before endotoxin. The NF-kappa B pathway
represents an attractive therapeutic target for
strategies to control neutrophilic inflammation
and lung injury.
Effect
of radiation on red cell membrane and
intracellular oxidative defense
systems.
Katz D; Mazor D; Dvilansky A; Meyerstein N
Dr. Joseph Kaufmann Hematology Laboratory, Corob
Medical Research Center, Faculty of Health
Sciences, Ben-Gurion, University of the Negev,
Beer-Sheva, Israel.
Free Radic Res (Switzerland) Mar 1996, 24 (3)
p199-204
Ionizing radiation is currently used for
prevention of transfusion associated graft versus
host disease (TAGVHD). As radiation damage is
associated with the production of activated oxygen
species, the aim of this study was to observe the
immediate effect of ionizing radiation on red cell
membrane and intracellular oxidative defense
systems. Neonatal and iron deficiency (IDA) cells,
known for their increased sensitivity to oxidative
stress, were chosen and compared with normal
cells. Irradiation was performed in doses of 1500
cGy, 3000 cGy and 5000 cGy. GSH and methemoglobin
levels and the activity of different antioxidant
enzymes, measured under optimal in vitro
conditions, were preserved in all cells after
irradiation. Only radiation at the highest does of
5000 cGy, caused significant potassium leakage in
neonatal cells and insignificant increase in IDA
cells. Thus, cells with increased sensitivity to
oxidative stress are more susceptible to damage by
ionizing radiation than normal cells.
Oxidatively modified LDL and
atherosclerosis: an evolving plausible
scenario.
Jialal I; Fuller CJ
Center for Human Nutrition, University of
Texas--Southwestern Medical Center, Dallas
75235-9052, USA.
Crit Rev Food Sci Nutr (United States) Apr 1996,
36 (4) p341-55
Much evidence has accumulated that implicates
the oxidative modification of low-density
lipoprotein (LDL) in the early stages of
atherogenesis. The , they have nutrients
alpha-tocopherol, ascorbic acid, and betacarotene
been shown to increase the resistance of LDL to
oxidation when given to animals and humans.
Because plasma levels of these nutrients can be
increased by dietary supplementation with minimal
side effects, they may show promise in the
prevention of coronary artery disease. (115
Refs.)
The
effects of alpha tocopherol supplementation on
monocyte function. Decreased lipid oxidation,
interleukin 1 beta secretion, and monocyte
adhesion to endothelium.
Devaraj S; Li D; Jialal I
Department of Internal Medicine, University of
Texas Southwestern Medical Center, Dallas
75235-9052, USA.
J Clin Invest (United States) Aug 1 1996, 98 (3)
p756-63
Low levels of alpha tocopherol are related to a
higher incidence of cardiovascular disease and
increased intake appears to afford protection
against cardiovascular disease. In addition to
decreasing LDL oxidation, alpha tocopherol may
exert intracellular effects on cells crucial in
atherogenesis, such as monocytes. Hence, the aim
of this study was to test the effect of alpha
tocopherol supplementation on monocyte function
relevant to atherogenesis. Monocyte function was
assessed in 21 healthy subjects at baseline, after
8 wk of supplementation with d-alpha tocopherol
(1,200 IU/d) and after a 6-wk washout phase. The
release of reactive oxygen species (superoxide
anion, hydrogen peroxide), lipid oxidation,
release of the potentially atherogenic cytokine,
interleukin 1 beta, and monocyte-endothelial
adhesion were studied in the resting state and
after activation of the monocytes with
lipopolysaccharide at 0, 8, and 14 wk. There was a
2.5-fold increase in plasma lipid-standardized and
monocyte alpha tocopherol levels in the
supplemented phase. After alpha tocopherol
supplementation, there were significant decreases
in release of reactive oxygen species, lipid
oxidation, IL-1 beta secretion, and
monocyte-endothelial cell adhesion, both in
resting and activated cells compared with baseline
and washout phases. Studies with the protein
kinase C inhibitor, Calphostin C, suggest that the
inhibition of reactive oxygen species release and
lipid oxidation is due to an inhibition of protein
kinase C activity by alpha tocopherol. Thus, this
study provides novel evidence for an intracellular
effect of alpha tocopherol in monocytes that is
antiatherogenic.
Metallopanstimulin as a novel tumor
marker in sera of patients with various types of
common cancers: implications for prevention and
therapy.
Fernandez-Pol JA
Department of Veterans Affairs Medical Center,
St. Louis, MO 63106, USA.
Anticancer Res (Greece) Jul-Aug 1996, 16 (4B)
p2177-85
Metallopanstimulin (MPS) is a 9.5-kDal subunit
"zinc finger" protein which is expressed in a wide
variety of actively proliferating cells and tumor
tissues (J. Biol. Chem. 268:21198-21204, 1993;
Cell Growth & Diff. 5:811-825, 1994). A
sensitive and specific radioimmunoassay (RIA) has
been developed to measure circulating levels of
MPS and MPS-like proteins. The RIA was evaluated
for its ability to detect accurately elevations of
MPS-immunoreactive material in the blood of
patients with various types of neoplastic
diseases. MPS concentrations were determined in
the blood of 147 healthy subjects having no
evidence of neoplastic disease, in 260 patients
with nonmalignant diseases, and in 225 patients
diagnosed with various types of cancer such as
prostate, colorectal, lung, head and neck
(epithelial malignancies), neuroendocrine, central
nervous system, etc. Elevated MPS levels
identified patients with neoplasias with greater
than 90% confidence. In patients, not having
neoplastic disease the MPS levels were lower than
10 ng/mL (82% of the population). In untreated
patients with cancer, the MPS level range was
20-50 ng/mL and in stage M1b (metastasis to the
bones) the MPS levels were extremely high (100 to
1000 ng/mL). In M1b patients that did not respond
to therapy, the MPS levels remained very high (
> 100 ng/mL). In M1b patients that went into
remission after treatment, the MPS levels were
reduced. The MPS test may be useful as an aid in:
1) the early detection of a wide variety of
neoplastic conditions and 2) the prognosis and
management of cancer patients by following the
changes in the concentrations of MPS in sera.
Moreover, the results suggest that the combined
use of the MPS test with other currently available
tumor maker tests may significantly improve the
chances of identifying a large proportion of
active oncogenic processes by serodiagnosis.
Antioxidants and age-related eye
disease. Current and future
perspectives.
Christen WG; Glynn RJ; Hennekens CH
Department of Medicine, Brigham and Women's
Hospital, Boston, MA, USA.
Ann Epidemiol (United States) Jan 1996, 6 (1)
p60-6
Oxidative mechanisms may play an important role
in the pathogenesis of age-related eye disease, in
particular cataract and macular degeneration, the
two most important causes of visual impairment in
older adults. For this reason, there is
considerable interest in determining whether
vitamins and trace minerals with antioxidant
properties can be of benefit in preventing the
onset or progression of disabling eye disease.
Basic research studies have shown that
antioxidants can protect against the cumulative
effects of oxidative stress in animal models of
cataract and macular degeneration. Data from
observational epidemiological studies in humans,
however, are inconclusive. While results from
several studies, primarily cross-sectional and
case-control, are compatible with a possible
protective role for micronutrients in disease
development, data for specific nutrients or
specific disease types have often been
inconsistent. Further, these observational studies
are limited because of the inherent imprecision of
dietary exposure data and the likely effects of
uncontrolled confounding. Thus, reliable data
regarding a potentially important benefit of
vitamin supplementation in eye disease will emerge
mainly from well-designed, large-scale, randomized
trials. (79 Refs.)
Hyperlipidemia. When does treatment
make a difference?
Wise GR; Schultz TT
Division of General Internal Medicine and
Geriatric Medicine, Loma Linda University Medical
Center, CA 92350, USA.
Postgrad Med (United States) Jul 1996, 100 (1)
p138-49
A high serum cholesterol level is regarded as a
major contributor to the development of coronary
atherosclerosis. Screening for hyperlipidemia
should begin no later than age 35 for men and age
45 for women. Individuals with additional risk
factors for coronary artery disease should be
screened earlier. When values are not within a
desirable range, further assessment should be done
by determining high-density lipoprotein and
triglyceride levels. The initial approach to
treatment of hyperlipidemia includes diet,
exercise, and weight loss. Smoking should be
proscribed. When nonpharmacologic intervention
fails, "statins" are increasingly being selected
as agents of first choice. Recommendations for the
busy practitioner include consistently identifying
the hyperlipidemic patient, setting target goals
for lipid values, addressing modifiable risk
factors, and providing appropriate pharmacologic
intervention (eg, aspirin, antioxidants, and beta
blockers in patients with established disease;
angiotensin-converting enzyme inhibitors in
patients with systolic dysfunction; estrogen
replacement in selected patients) and treatment to
attain target goals in lowering cholesterol. (17
Refs.)
[Free
radicals in the central nervous
system]
Rokyta R; Racek J; Holecek V
Ustav fyziologie a klinicke fyziologie 3.
lekarske fakulty UK, Praha.
Cesk Fysiol (Czech Republic) Mar 1996, 45 (1)
p4-12
Central nervous system has a low antioxidative
capacity, which is formed mainly by ascorbic acid.
Therefore the cerebral tissue is threatened by the
increased formation of free radicals and their
metabolites (ROS--reactive oxygen species). ROS
are formed such as in reperfusion phase after
ischemia and in catecholamine metabolism, in
oxidative stress due to hyperglycaemia.
Polyunsaturated fatty acids (PUFA) are peroxidased
by ROS; proteins and DNK are damaged as well. Free
radicals are involved in etiology and pathogenesis
of many CNS diseases, such as neuritis, Alzheimer
disease, Parkinson disease, Huntington disease,
aging and atherosclerosis of the brain, epilepsy,
etc. During the antioxidant therapy it is
necessary to consider the types of ROS, their
origin and their mode of action, whether to
administer hydrophilic or lipophilic antioxidants,
eventually chelate agents, etc. Hydrophylic
antioxidants are acting very soon after the
administration, whereas the lipophilic ones reach
their target tissues with a great delay. Therefore
it is better to apply them preferentially like a
prevention, if possible. Enzymatic antioxidants
(SOD, GSPHx and catalase and others) are usually
acting only for a short time. The methods of
estimation of free radicals attacks are discussed
as well their possible pathophysiological effects.
(34 Refs.)
[Can
vitamin E prevent development of coronary heart
disease?]
Nguyen KN; Landmark K
Institutt for farmakoterapi, Universitetet i
Oslo.
Tidsskr Nor Laegeforen (Norway) Mar 30 1996, 116
(9) p1109-13
Oxidation of low-density lipoprotein (LDL)
probably plays an important part in
atherosclerosis. Vitamin E (alpha-tocopherol) is a
potent antioxidant carried in LDL. It increases
the resistance of LDL to oxidation, thereby, among
other things, inhibiting foam cell formation and
proliferation of smooth muscle cells. Some animal
experiments have indicated that vitamin E retards
the development of atherosclerotic lesions.
Observational studies (case-control and cohort)
have shown that long-term treatment with vitamin E
is associated with lower incidence of coronary
heart disease introlled trial gave a
nonsignificant reduction in mortality from
ischemic heart disease. Although vitamin E seems
to reduce the risk of coronary heart disease,
randomised trials of adequate size are necessary
in both secondary and primary prevention in order
to test this. Such trials are in progress. (61
Refs.)
Protection by multiple antioxidants
against lipid peroxidation in rat liver
homogenate.
Chen H; Tappel A
Department of Pharmacology, School of Medicine,
University of Washington, Seattle, USA.
Lipids (United States) Jan 1996, 31 (1)
p47-50
The purpose of this study was to test the
hypothesis that multiple antioxygenic nutrients
provide increased protection against lipid
peroxidative damage to rat liver. Rats were fed
diets (i) deficient in vitamin E and selenium
(Diet 1), (ii) supplemented with vitamin E and
selenium (Diet 2), (iii) supplemented with (ii)
and in addition trolox C, N-acetylcysteine,
coenzyme Q0, and (+)-catechin (Diet 3), or (iv)
supplemented with (iii) and in addition
beta-carotene, ascorbic acid palmitate,
canthaxanthin, and coenzyme Q10 (Diet 4). Liver
homogenates were obtained from three rats fed each
of the diets for six weeks and were incubated at
37 degrees C up to two hours with and without
exogenous tertiary-butyl hydroperoxide (TBHP) or
Cu2+. Lipid peroxidation was determined by
measurement of thiobarbituric acid substances.
Diets 2 and 3 significantly protected against in
vivo hepatic lipid peroxidation, and this
protection was augmented by Diet 4. Diets 2, 3,
and 4 were protective against mild oxidation
induced by TBHP or Cu2+. During incubations with
exogenous TBHP and Cu2+, there were only small
differences between diets supplemented with
antioxidants in inhibition of lipid peroxidation,
indicating that diets supplemented with vitamin E
and selenium (Diet 2) may have provided the
maximal protection for liver. The possible
mechanisms of protection provided by multiple
antioxidants in diets were discussed. Protection
by multiple antioxidants against lipid
peroxidation may translate to prevention of
peroxidative damage to human tissue, a factor in
human disease.
Effect
of selenium on 1,2-dimethylhydrazine-induced
intestinal cancer in rats.
Jao SW; Shen KL; Lee W; Ho YS
Division of Colon and Rectal Surgery, National
Defense Medical Center, Tri-Service General
Hospital Taipei, Taiwan, Republic of China.
Dis Colon Rectum (United States) Jun 1996, 39 (6)
p628-31
PURPOSE: This study was designed to determine
the cancer prevention and therapeutic effects of
selenium on rats treated with
1,2-dimethylhydrazine (DMH).
METHODS: One hundred sixty Spraque-Dawley male
rats were divided into seven groups and received
20 mg/kg/week DMH, subcutaneously for 20 weeks.
Two different dosages of selenium (8 and 4 ppm)
were administered to the rats through drinking
water during DMH treatment (B and C groups) or one
month before and during DMH treatment (D and E
groups). The rats of Groups A (control group), B,
C, D, and E were killed immediately after the last
DMH injection. The incidence of intestinal cancer
in each group was compared. Eight ppm selenium was
also administered to rats after DMH treatment
(Group F), and survival times were observed and
compared with Group G (treated with DMH only).
RESULTS: Rats of Groups B and D received 8 ppm
selenium and had a significantly decreased
incidence of intestinal cancer (from 65.8 percent
(Group A) to 33.3 percent (Group B) and 27.8
percent (Group D); P = 0.0225 and 0.0038). Rats
receiving 4 ppm selenium had a relatively
decreased incidence of intecent (Group A) to 44.4
percen t (Group C) and 47.1 percent (Group E) but
P > 0.05). Survival time of Groups F and G
showed no difference.
CONCLUSIONS: Eight ppm selenium provided via
drinking water has a significant intestinal cancer
prevention effect in the presence of a high dose
of DMH (20 mg/kg x 20 weeks), and the cancer
therapeutic effect of selenium is doubtful in this
animal model.
Serum
high density lipoprotein cholesterol, alcohol, and
coronary mortality in male smokers
Paunio M; Virtamo J; Gref CG; Heinonen OP
University of Helsinki, Department of Public
Health, Finland.
BMJ (England) May 11 1996, 312 (7040) p1200-3
OBJECTIVE--To determine whether the increase in
mortality from coronary heart disease with high
concentration (> 1.75 mmol/l) of high density
lipoprotein cholesterol could be due to alcohol
intake.
DESIGN--Cohort study.
SETTING--Placebo group of the alpha tocopherol,
beta carotene cancer prevention (ATBC) study of
south western population in Finland.
PARTICIPANTS--7052 male smokers aged 50-69
years enrolled to the ATBC study in the 1980s.
MAIN OUTCOME MEASURES--The relative and
absolute rates adjusted for risk factors for
clinically or pathologically verified deaths from
coronary heart disease for different
concentrations of high density lipoprotein
cholesterol with and without stratification for
alcohol intake. Similar rates were also calculated
for different alcohol consumption groups.
RESULTS--During the average follow up period of
6.7 years 258 men died from verified coronary
heart disease. Coronary death rate steadily
decreased with increasing concentration of high
density lipoprotein cholesterol until a high
concentration. An increase in the rate was
observed above 1.75 mmol/l. This increase occurred
among those who reported alcohol intake. Mortality
was associated with alcohol intake in a J shaped
dose response, and those who reported consuming
more than five drinks a day (heavy drinkers) had
the highest death rate. Mortality was higher in
heavy drinkers than in non-drinkers or light or
moderate drinkers in all high density lipoprotein
categories from 0.91 mmol/l upward.
CONCLUSIONS--Mortality from coronary heart
disease increases at concentrations of high
density lipoprotein cholesterol over 1.75 mmol/l.
The mortality was highest among heavy drinkers,
but an increase was found among light drinkers
also.
Lifestyle change for coronary artery
disease. What to tell patients.
O'Keefe JH Jr; Nelson J; Harris WS
Mid America Heart Institute, Kansas City, MO
64111, USA.
Postgrad Med (United States) Feb 1996, 99 (2)
p89-92, 95-6, 102-6
Heart-healthy living is a wise choice for
anyone, but it assumes even greater importance in
persons who have or are at risk for coronary
artery disease. Such patients need to know which
measures have proved most effective in the
prevention and treatment of the disease. This
article reviews the data regarding risk factor
reduction and offers recommendations for effective
lifestyle modifications. (34 Refs.)
Inhibition of Ca2+-pump ATPase and
the Na+/K+-pump ATPase by iron-generated free
radicals. Protection by
6,7-dimethyl-2,4-DI-1-pyrrolidinyl-7H-pyrrolo[2,3-d]
pyrimidine sulfate (U-89843D), a potent, novel,
antioxidant/free radical scavenger.
Rohn TT; Hinds TR; Vincenzi FF
Department of Pharmacology, University of
Washington, Seattle 98195, USA.
Biochem Pharmacol (England) Feb 23 1996, 51 (4)
p471-6
Preincubation of red blood cell (RBC) membranes
with a model system known to generate reactive
oxygen species (ROS) and free radicals (200 microM
ferrous sulfate and 200 microM EDTA, Fe2+/EDTA)
resulted inhibition of the Na+/K+ -pump ATPases
was also associated with membrane protein
crosslinking and lipid peroxidation, the latter as
monitored by the formation of thiobarbituric acid
reactive substances (TBARS). Inhibition of the ion
transport ATPases, protein cross-linking and
formation of TBARS were prevented by U-89843D in a
concentration-dependent manner, with half-maximal
protection seen at 0.3 microM. U-89843D was more
potent than the classical antioxidant butylated
hydroxytoluene. Neither U-89843D nor the solvent
DMSO had any effect on the assay of TBARS.
U-89843D exerted only minimal inhibitory activity
on ATPase activities. Thus, U-89843D was potent in
vitro in preventing a variety of membrane-damaging
reactions mediated by ROS. It is suggested that
protection of membranes from ROS-mediated damage
is of potential usefulness in the prevention and
treatment of certain disease processes.
Long-term oral vitamin E
supplementation in cystic fibrosis patients:
RRR-alpha-tocopherol compared with
all-rac-alpha-tocopheryl acetate
preparations.
Winklhofer-Roob BM; van't Hof MA; Shmerling
DH
Division of Gastroenterology and Nutrition,
Department of Pediatrics, University of Zurich,
Switzerland.
Am J Clin Nutr (United States) May 1996, 63 (5)
p722-8
To investigate the efficacy of three different
vitamin E preparations for optimizing vitamin E
status in cystic fibrosis (CF patients long-term,
29 patients (aged 0.7-29.8 y) were randomly
assigned to receive 400 IU of either
RRR-alpha-tocopherol (A: 268 mg, n = 10) or all
rac-alpha-tocopheryl acetate as a fat-soluble (B:
400 mg, n = 10) or water-miscible preparation (C:
400 mg, n = 9) and were followed for 6 wk. In the
whole study group, plasma alpha-tocopherol
concentrations increased from baseline (10.5 +/-
4.6 micromol/L) to 3 wk (25.7 +/- 6.5 micromol/L;
P < 0.001), but not further between 3 and 6 wk;
concentrations at 3 and 6 wk did not differ from
those of age-matched control subjects (23.6 +/-
3.9 micromol/L). There was no significant
difference in the increase from baseline to 6 wk
among preparations A (17.75 +/- 8.43 micromol/L),
B (14.0 +/- 9.4 micromol/L), and C (15.5 +/- 7.1
micromol/L). Because of differences in body
weight, the dose administered ranged from 5.5 to
47.4 IU x kg-1 x d-1; it correlated positively
with the increase in plasma alpha-tocopherol
concentrations (P < 0.001). There was no
significant difference in the increase in plasma
alpha-tocopherol concentrations between patients
with CF-associated liver disease (n = 8) who
received 10.2 +/- 3.8 IU x kg-1 x d-1 and those
without liver disease taking comparable doses. We
conclude that CF patients can be efficiently
supplemented with 400 IU/d of any one of the three
vitamin E preparations and plasma values of
healthy control subjects can be achieved.
The
HOPE (Heart Outcomes Prevention Evaluation) Study:
the design of a large, simple randomized trial of
an angiotensin-converting enzyme inhibitor
(ramipril) and vitamin E in patients at high risk
of cardiovascular events.
The HOPE study investigators.
Can J Cardiol (Canada) Feb 1996, 12 (2)
p127-37
OBJECTIVE: To describe the design of the HOPE
(Heart Outcomes Prevention Evaluation) study.
DESIGN: Description of the key design features
of HOPE, a large, simple randomized trial of two
widely applicable treatments--ramipril, an
angiotensin-converting enzyme inhibitor; and
vitamin E, a naturally occurring antioxidant
vitamin--in the prevention of myocardial
infarction, stroke or cardiovascular death.
SETTING: Two-hundred and sixty-seven hospitals,
physician offices and clinics in Canada, the
United States, Mexico, Europe and South
America.
PATIENTS: Over 9000 women and men aged 55 years
and above at high risk for cardiovascular events
such as myocardial infarction and stroke were
recruited over 18 months.
INTERVENTIONS: A 2X2 factorial design with
ramipril and vitamin E with follow-up for up to
four years.
CONCLUSIONS: HOPE will be one of the largest
trials of two new interventions to prevent
myocardial infarction, stroke or cardiovascular
death in high risk patients. The results of HOPE
will have direct public health impact and are
likely to be readily incorporated into clinical
practice. Key design features of HOPE are
inclusion of individuals at high risk of
cardiovascular disease, inclusion of a substantial
proportion of patients with diabetes (36%) and
women (27%), and detailed substudies to provide
data on mechanisms of benefit.
Dietary
antioxidant vitamins and death from coronary heart
disease in postmenopausal women
Kushi LH; Folsom AR; Prineas RJ; Mink PJ; Wu Y;
Bostick RM
Division of Epidemiology, University of Minnesota
School of Public Health, Minneapolis 55454-1015,
USA.
N Engl J Med (United States) May 2 1996, 334 (18)
p1156-62
BACKGROUND: The role of dietary antioxidant
vitamins in preventing coronary heart disease has
aroused considerable interest because of the
knowledge that oxidative modification of
low-density lipoprotein may promote
atherosclerosis.
METHODS. We studied 34,486 postmenopausal women
with no cardiovascular disease who in early 1986
completed a questionnaire that assessed, among
other factors, their intake of vitamins A, E, and
C from food sources and supplements. During
approximately seven years of follow-up (ending
December 31, 1992), 242 of the women died of
coronary heart disease.
RESULTS. In analyses adjusted for age and
dietary energy intake, vitamin E consumption
appeared to be inversely associated with the risk
of death from coronary heart disease. This
association was particularly striking in the
subgroup of 21,809 women who did not consume
vitamin supplements (relative risks from lowest to
highest quintile of vitamin E intake, 1.0, 0.68,
0.71, 0.42, and 0.42; P for trend 0.008). After
adjustment for possible confounding variables,
this inverse association remained (relative risks
from lowest to highest quintile, 1.0, 0.70, 0.76,
0.32, and 0.38; P for trend, 0.004). There was
little evidence that the intake of vitamin E from
supplements was associated with a decreased risk
of death from coronary heart disease, but the
effects of high-dose supplementation and the
duration of supplement use could not be definitely
addressed. Intake of vitamins A and C did not
appear to be associated with the risk of death
form coronary heart disease.
CONCLUSIONS. These results suggest that in
postmenopausal women the intake of vitamin E from
food is inversely associated with the risk of
death from coronary heart disease and that such
women can lower their risk without using vitamin
supplements. By contrast, the intake of vitamins A
and C was not associated with lower risks of dying
from coronary disease.
Mortality associated with low plasma
concentration of beta carotene and the effect of
oral supplementation.
Greenberg ER; Baron JA; Karagas MR; Stukel TA;
Nierenbel and Norris Cotton Cancer Center,
Lebanon, NH, USA.
JAMA (United States) Mar 6 1996, 275 (9)
p699-703
OBJECTIVE: To examine the relationship between
beta carotene plasma concentration and beta
carotene supplementation and risk of death from
major disease causes.
DESIGN: Cohort study of plasma concentrations;
randomized, controlled clinical trial of
supplementation.
SETTING: Medical school-affiliated dermatology
practices.
PATIENTS: A total of 1188 men and 532 women
with mean age of 63.2 years, who had enrolled in a
randomized clinical trial of beta carotene
supplementation to prevent nonmelanoma skin
cancer.
INTERVENTION: Oral beta carotene, 50 mg per day
for a median of 4.3 years.
MAIN OUTCOME MEASURES: All-cause mortality and
mortality from cardiovascular disease and
cancer.
RESULTS: During a median follow-up period of
8.2 years, there were 285 deaths. Persons whose
initial plasma beta carotene concentrations were
in the highest quartile (>0.52 micromol/L [27.7
microg/dL]) had a lower risk of death from all
causes (adjusted relative rate [RR], 0.52; 95%
confidence interval [CI] 0.44 to 0.87) and from
cardiovascular diseases (adjusted RR, 0.57; 95%
CI, 0.34 to 0.95) compared with persons with
initial concentrations in the lowest quartile
(<0.21 micromol/L [11.2 microg/dL]). Patients
randomly assigned to beta carotene supplementation
showed no reduction in relative mortality rates
from all causes (adjusted RR, 1.03; 95% CI, 0.82
to 1.30) or from cardiovascular disease (adjusted
RR, 1.16; 95% CI, 0.82 to 1.64). There was no
evidence of lower mortality following
supplementation among patients with initial beta
carotene concentrations below the median for the
study group.
CONCLUSIONS: These analyses provide no support
for a strong effect of supplemental beta carotene
in reducing mortality from cardiovascular disease
or other causes. Although the possibility exists
that beta carotene supplementation produces
benefits that are too small or too delayed to have
been detected in this study, noncausal
explanations should be sought for the association
between plasma concentrations of beta carotene and
diminished risk of death.
Effect
of vitamin E and beta carotene on the incidence of
angina pectoris. A randomized, double-blind,
controlled trial.
Rapola JM; Virtamo J; Haukka JK; Heinonen OP;
Albanes D; Taylor PR; Huttunen JK
National Public Health Institute, Helsinki,
Finland.
JAMA (United States) Mar 6 1996, 275 (9)
p693-8
OBJECTIVE: To examine the effect of
supplementation with vitamin E (alpha tocopherol),
beta carotene, or both on the incidence of angina
pectoris in men without known previous coronary
heart disease.
DESIGN: Randomized, double-blind,
placebo-controlled trial.
SETTING AND PARTICIPANTS: Participants in the
Alpha Tocopherol, Beta Carotene Cancer Prevention
Study (N=29133) were male smokers aged 50 through
69 years who were living in southern and western
Finland. Of these men, 22269 were considered free
of coronary heart disease at baseline and were
followed up for the incidence of angina
pectoris.
INTERVENTION: Participants were randomized to
receive 50 mg/d of alpha tocopherol, 20 mg/d of
beta carotene, both, or placebo in a 2x2
design.
OUTCOME MEASURES: An incident case was defined
as the first occurrence of typical angina pectoris
identified in administering the annually repeated
World Health Organization (Rose) Chest Pain
Questionnaire.
RESULTS: During a median follow-up time of 4.7
years (96427 person-years), 1983 new cases of
angina pectoris were detected. Comparing alpha
tocopherol-supplemented subjects with non-alpha
tocopherol-supplement ed subjects showed a
relative risk (RR) of angina pectoris incidence of
0.91 (95% confidence interval[CI], 0.83 to 0.99;
P=.04). The RR for incidence of angina pectoris
for the beta carotene- supplemented subjects
compared with those not receiving beta carotene
was 1.06 (95% CI, 0.97 to 1.16; P=.19). Compared
with those receiving placebo, the RRs for
incidence of angina pectoris were 0.97 (95% CI,
0.85 to 1.10) and 0.96 (95% CI, 0.85 to 1.09) in
the alpha tocopherol and alpha tocopherol plus
beta carotene groups, respectively, and 1.13 (95%
CI, 1.00 to 1.27) in the beta carotene group
(P=.06). Baseline dietary intakes and serum levels
of alpha tocopherol and beta carotene did not
predict incidence of angina pectoris.
CONCLUSIONS: Supplementation with alpha
tocopherol was associated with only a minor
decrease in the incidence of angina pectoris. Beta
carotene had no preventive effect and was
associated with a slight increase of angina.
[Overview--suppression effect of
essential trace elements on arteriosclerotic
development and it's mechanism]
Saito N
Nippon Rinsho (Japan) Jan 1996, 54 (1) p59-66
It is known that the peroxidation of LDL is a
trigger for developing arteriosclerosis. The
oxidized LDL is produced by either oxidative
stress or a few oxidant. Selenium decreased in
serum and some organs of stroke-prone
spontaneously hypertensive rats (SHRSP), which is
a cofactor of glutamine peroxidase. Serum
magnesium decreased in patients with diabetes
mellitus, with ischemic heart disease, with
essential hypertension and with cerebral vascular
lesions. Calcium to magnesium ratio was higher in
some organs of SHRSP as compared to Wistar Kyoto
rats (WKY). These changes accelerated vascular
lesions in SHRSP. (21 Refs.)
Prevention of doxorubicin induced
cardiotoxicity by catechin.
Kozluca O; Olcay E; Surucu S; Guran Z; Kulaksiz
T; Uskent N
Radiation Oncology Department, Kartal State
Hospital, Istanbul, Turkey.
Cancer Lett (Ireland) Jan 19 1996, 99 (1)
p1-6
Doxorubicin (dox) is an anthracycline
antibiotic which is broadly used in solid tumors.
Long-term therapy with this drug is accompanied by
potentially lethal, dose-dependent side effects.
Several reports suggest that oxygen free radicals
produced during the metabolic activation of dox
may have toxic effects on heart muscle. We tried
to protect dox cardiotoxicity in rats using
catechin which is a known antioxidant and iron
chelating agent. Different dose levels and
combinations of catechin and doxorubicin have been
studied in different experimental groups.
Electrocardiograms, myocardial contractility, body
weight and the electron microscope were used to
assess the cardioprotective effect of catd
animals. We found significant prevention of
dox-induced cardiotoxicity by catechin in
rats.
Relative resistance of the hamster to
aortic atherosclerosis in spite of prolonged
vitamin E deficiency and dietary
hypercholesterolemia. Putative effect of increased
HDL?
Stein O; Dabach Y; Hollander G; Halperin G;
Thiery J; Stein Y
Department of Experimental Medicine and Cancer
Research, Hebrew University-Hadassah Medical
School, Jerusalem, Israel.
Biochim Biophys Acta (Netherlands) Jan 19 1996,
1299 (2) p216-22
Male golden hamsters were rendered
hypercholesterolemic by feeding diets enriched
with cholesterol and fat. In the first series of
experiments, 5% butter and 1% cholesterol were
added to a chow diet and plasma cholesterol levels
were maintained at 350-390 mg/dl over the entire
experimental period. Groups of hamsters and their
age controls consuming the chow diet, were killed
after 7, 15 and 20 months when the aorta was
examined for atherosclerosis by determination of
cholesterol mass. In the controls, aortic total
cholesterol (TC) increased with age by 28% and
esterified cholesterol increased to 11% of TC. In
the hypercholesterolemic animals aortic TC was
only 28% higher than in the controls and
cholesteryl ester was also 11.5% of TC. In the
second series, one group of hamsters were fed a
semi-purified diet deficient in vitamin E,
containing 1% cholesterol and 10% lard; a second
group received the same diet, but supplemented
with vitamin E. Controls consumed local chow.
After 7 months on the vitamin E deficient diet
plasma alpha-tocopherol was 0.05 mg/l, in those
supplemented with vitamin E it was 20 mg/l, while
in the controls it was 3.3 mg/l. Plasma
thiobarbituric acid reactive substances (TBARS)
were higher in the vitamin E deficient group and
there was a greater propensity of lipoproteins (d
< 1.063 g/ml) to peroxidation in vitro than in
the vitamin E supplemented group. Plasma
cholesterol was 366 mg/dl in the vitamin E
deficient, 336 mg/dl in the vitamin E supplemented
group, and 64 mg/dl in controls. Aortic
cholesterol was 79.1 in vita0 mg dry weight in
vitamin E def icient hamsters. In both series of
experiments, HDL amounted to 36-41% of plasma TC
in the hypercholesterolemic animals and 59-62% in
the controls. In conclusion: the hamster appears
to be quite resistant to atherosclerosis in face
of sustained hypercholesterolemia, even in the
presence of increased peroxidative stress caused
by vitamin E deficiency. This relative resistance
could be related to commensurate increase in
plasma HDL which was observed in both series of
experiments. Since vitamin E deficiency did not
enhance aortic cholesteryl ester deposition, the
protective effect of HDL seems to be related to
its role in reverse cholesterol transport, rather
than in prevention of peroxidation.
Gastroprotective activity of
melatonin and its precursor, L-tryptophan, against
stress-induced and ischaemia-induced lesions is
mediated by scavenge of oxygen
radicals.
Konturek PC; Konturek SJ; Brzozowski T;
Dembinski A; Zembala M; Mytar B; Hahn EG
Dept. of Physiology, Jagiellonian University
School of Medicine, Cracow, Poland.
Scand J Gastroenterol (Norway) May 1997, 32 (5)
p433-8
BACKGROUND: Melatonin, a pineal hormone that is
biosynthesized from L-tryptophan, is known to
scavenge oxygen free radicals and to be present in
the gut, but little is known about the role of
this hormone and its precursor, L-tryptophan, in
protecting the gastric mucosa from damage
accompanied by increase in the generation of
oxygen radicals.
METHODS: This study was designed to determine
the effects of melatonin and L-tryptophan on the
formation of acute gastric lesions induced by
stress and ischaemia reperfusion and, for
comparison, by topical irritants such as 100%
ethanol or acidified acetylsalicylic acid.
RESULTS: It was found that pretreatment with
melatonin in doses ranging from 1.2 to 10 mg/kg
dose-dependently reduced the stress-induced
gastric lesions and was accompanied by a reduction
in blood-free radicals and by attenuation of the
fall in gastric blood flow. L-tryptophan applied
intragastrically in doses ranging from 1 to 100
mg/kg also reduced dose-dependently the lesions
induced by stress; this effect too was accompanied
by a rise in gastric blood flow. Pretreatment with
indomethacin, to block the biosynthesis of
prostaglandins, significantly augmented the
lesions produced by stress and completely
abolished the protective effects of melatonin or
L-tryptophan. Both melatonin and tryptophan
reduced the formation of acute gastric lesions
provoked by ischaemia reperfusion; this was
accompanied by an increase in gastric blood flow.
In contrast, melatonin and L-tryptophan failed to
influence acute gastric lesions induced by topical
irritants such as 100% ethanol or acidified
aspirin.
CONCLUSIONS: Melatonin and L-tryptophan protect
the gastric mucosa from damage by stress and
ischaemia reperfusion, and this action is
mediated, at least in part, by the limitation in
the free radicals, the stimulation of mucosal
generation of PG and by the increase in gastric
blood flow.
Comparison between dietary soybean
protein and casein of the inhibiting effect on
atherogenesis in the thoracic aorta of
hypercholesterolemic (ExHC) rats treated with
experimental hypervitamin D.
Sakono M; Fukuyama T; Ni WH; Nagao K; Ju HR;
Sato M; Sakata N; Iwamoto H; Imaizumi K
Department of Food Science and Technology,
Faculty of Agriculture, Kyushu University,
Fukuoka, Japan.
Biosci Biotechnol Biochem (Japan) Mar 1997, 61
(3) p514-9
Atherosclerotic lesions of the thoracic aorta
were induced in exogenously hypercholesterolemic
(ExHC) rats by treating initially with
hypervitamin D2 and subsequently feeding on
hypercholesterolemic diets for 180 days. Dietary
soybean protein, in comparison with casein,
substantially decreased the degree of
atherosclerotic lesions, which was evaluated by
intimal thickening, although with a similar
topographical distribution. The casein-fed rats
tended to maintain a high concentration of serum
cholesterol, particularly in triacylglycerol-rich
lipoproteins. The concentrations of apo A-I and
TBARS in the serum was comparable between the
dietary protein groups. The data suggest that
dietary soybean protein, compared to casein,
produced lipoproteins which were less
atherosclerotic by partitioning cholesterol in the
triacylglycerol-poor lipoproteins.
Melatonin: media hype or therapeutic
breakthrough?
Kendler BS
Manhattan College, Riverdale, N.Y., USA.
Nurse Pract (United States) Feb 1997, 22 (2)
p66-7, 71-2, 77
Currently available as a dietary supplement,
the pineal hormone melatonin is portrayed by the
media as a formidable weapon against disease and
aging. Accordingly, primary health care providers
should be cognizant of which of its proposed uses
are supported by biomedical research and which
are, as yet, unproven. Melatonin entrains
circadian rhythms and, thus, can treat jet lag,
delayed sleep phase syndrome, and sleep disorders
in the blind and in some neurologically impaired
children. By virtue of its hypnotic effect,
melatonin can mitigate insomnia in the elderly.
Reductions in melatonin secretion have been
associated with many disorders, including
cardiovascular disease, Alzheimer's, diabetes,
SIDS, and aging; however, melatonin's role in
their athophysiology is unproven. Preliminary
studies suggest a possible adjuvant therapeutic
role for melatonin in cancer therapy. Melatonin
secretion is reduced by alcohol, caffeine, and
some commonly prescribed drugs. Since tolerance,
fatigue, and other side effects have been
reported, melatonin use on consecutive nights
should be avoided and only the lowest effective
hypnotic dose should be taken. (75 Refs.)
[Guidelines of drug therapies for
Parkinson's disease]
Yanagisawa N
Department of Medicine (Neurology), Shinshu
University School of Medicine.
Nippon Rinsho (Japan) Jan 1997, 55 (1) p52-7
Treatment of Parkinson's disease has progressed
steadily for the last decades after introduction
of levodopa. For recovery of striatal dysfunction
caused by loss of projecting nigral cells,
supplementation of neurotransmitter dopamine (DA),
facilitation of neural transmission by DA agonists
and amantadine, suppression of acetyl-choline
neurons, having antagonistic action to DA cells,
are all effective especially at the early to
middle stages of illness. As prevention of
neuronal cell death in parkinsonian brain has not
yet been succeeded, difficulties in treatment with
symptom fluctuation and CNS side effects such as
dyskinesia or psychic symptoms develop inevitably
in the long course of evodopa treatment. Proper
choice of drugs for parkinsonian core and
accompanying symptoms and selection of methods of
medication for maintenance of natural daily life
activities are necessary for attainment of good
QOL for whole time course of the disease. (11
Refs.)
Myocardium-protective effects of
Ginkgo biloba extract (EGb 761) in old rats
against acute isobaric hypoxia. An electron
microscopic morphometric study. II. Protection of
microvascular endothelium.
Welt K; Fitzl G; Schaffranietz L
Institute of Anatomy, University Leipzig,
Germany.
Exp Toxicol Pathol (Germany) Jan 1996, 48 (1)
p81-6
Aim of this electron microscopic morphomere
protective properties of Gin kgo biloba extract
EGb 761 on myocardial microvessels of old rats
during acute hypoxic stress. Hypoxia of 20 minutes
duration with N2O/O2 mixture (5 vol% O2) was
performed using a hypoxia chamber combined with a
commercial narcosis apparatus. EGb
761-pretreatment diminished significantly the
percentage of endothelial cells exhibiting edema,
luminal blebs and of capillaries surrounded by
pericapillary debris. Hypoxia-related decrease in
plasmalemmal vesicle frequency was prevented by
EGb 761, formation of vacuoles non significantly
diminished against the hypoxic group. Volume
density of mitochondrial cristae was significantly
less diminished, the volume fraction of
degenerated areas less increased in the EGb
761-protected group. The results give some
evidence that EGb 761 protects endothelial cell
ultrastructure of myocardial microvasculature
against hypoxic alterations, probably by its
radical scavenging properties.
Myocardium-protective effects of
Ginkgo biloba extract (EGb 761) in old rats
against acute isobaric hypoxia. An electron
microscopic morphometric study. I. Protection of
cardiomyocytes.
Fitzl G; Welt K; Schaffranietz L
Institute of Anatomy, University Leipzig,
Germany.
Exp Toxicol Pathol (Germany) Jan 1996, 48 (1)
p33-9
Ginkgo biloba extract EGb 761 was used in
hypoxia experiments with old rats to investigate
its ultrastructure-preserving effects on the
myocardium. Hypoxia was performed by means of a
hypoxia chamber combined with a commercial
narcosis apparatus. N2O/O2-mixture was applied
with O2 at 5 vol.% for 20 minutes under normobaric
conditions. Ultrastructural-morphometric analysis
revealed that EGb 761-pretreatment was able to
diminish hypoxic damage at mitochondrial cristae
and matrix and also distension of the sarcoplasmic
reticulum during acute hypoxic stress. Whereas
formation of vacuoles was depressed below thed.
The preservation of mitochondrial cristae was
confirmed by independent secondary morphometric
parameters and by cytophotometrically measured
activities of mitochondrial enzymes.
The
effect of coenzyme Q10 on infarct size in a rabbit
model of ischemia/reperfusion.
Birnbaum Y; Hale SL; Kloner RA
Heart Institute, Good Samaritan Hospital, Los
Angeles, CA 90017, USA.
Cardiovasc Res (Netherlands) Nov 1996, 32 (5)
p861-8
OBJECTIVE: Coenzyme Q10 has been found to
enhance recovery of function after reperfusion in
numerous experimental acute ischemia-reperfusion
models. We assessed whether coenzyme Q10,
administered intravenously either during or 1 h
before ischemia, can limit infarct size in the
rabbit.
METHODS: Anesthetized open-chest rabbits were
subjected to 30 min of coronary artery occlusion
and 4 h of reperfusion. In Protocol 1, 12 min
after beginning of ischemia rabbits were
randomized to intravenous infusion of 30 mg
coenzyme Q10 (Eisai Co., Japan) (n = 10) or
vehicle (n = 10). In Protocol 2, rabbits were
randomized to 30 mg coenzyme Q10 (n = 6) or
vehicle (n = 6) treatment 60 min before ischemia.
Ischemic zone at risk (IZ) was assessed by blue
dye and necrotic zone (NZ) by tetrazolium
staining.
RESULTS: In both protocols, coenzyme Q10 did
not alter heart rate, mean blood pressure, or
regional myocardial blood flows in either the
ischemic or non-ischemic zones during ischemia or
reperfusion. No difference was found in IZ (as
fraction of LV weight) (Protocol 1: 0.24 +/- 0.02
vs. 0.25 +/- 0.02; Protocol 2: 0.28 +/- 0.02 vs.
0.28 +/- 0.03, in the control vs. coenzyme Q10
groups, respectively). The NZ/IZ ratio was
comparable between the groups in both protocols
(Protocol 1: 0.22 +/- 0.04 vs. 0.26 +/- 0.04;
Protocol 2: 0.21 +/- 0.06 vs. 0.30 +/- 0.06, in
the control vs. coenzyme Q10 groups,
respectively).
CONCLUSIONS: Coenzyme Q10, administered acutely
either during or 60 min before myocardial
ischemia, does not attenuate infarct size in the
rabbit.
Prevention of cytokine-induced
hypotension in cancer patients by the pineal
hormone melatonin.
Lissoni P; Pittalis S; Ardizzzzoni F; Maestroni
GJ; Zubelewicz B; Braczkowski R
Division of Radiation Oncology, S. Gerardo
Hospital, (Milan), Italy.
Support Care Cancer (Germany) Jul 1996, 4 (4)
p313-6
Hypotension is a frequent side-effect of cancer
biotherapies with cytokines. Cytokine-induced
hypotension would mainly depend on the stimulation
of nitric oxide (NO) production, which represents
the most effective endogenous vasodilator.
Moreover, it has been proven that both biological
activity and toxicity of cytokines are influenced
by the psychoneuroendocrine system, in particular
by the pineal hormone melatonin. To investigate
the possible modulatory effect of melatonin on
cytokine cardiovascular toxicity, we evaluated the
influence of a concomitant melatonin
administration on interleukin-2(IL-2)- and
tumour-necrosis-factor -alpha(TNF)-induced
hypotension in advanced cancer patients. The study
included 116 patients with advanced solid tumour,
for whom no effective standard anticancer therapy
was available, who underwent cancer biotherapy
with IL-2 (3 x 10(6) IU/ day s.c. every day, 6
days/week for 4 weeks) or with TNF (0.75 mg/day
i.v. for 5 days) as compassionate treatment for
their disease. Patients were randomized to be
treated with or without a concomitant melatonin
administration (40 mg/day orally in the evening,
starting 7 days prior to cytokine injection). The
occurrence of hypotension was significantly less
frequent in patients concomitantly treated by
melatonin than in those who received the cytokine
alone, during either IL-2: or TNF immunotherapy
(IL-2; 11/45 versus 2/46, P < 0.05; TNF: 10/23
versus 1/12, P < 0.01). This study shows that
melatonin may prevent hypotension occurring during
cancer immunotherapy with IL-2 or TNF. Since the
pineal hormone has appeared to inhibit the
activity of NO synthase from the endothelial
cells, we suggest that melatonin may prevent
cytokine-induced hypotension by inhibiting NO
production, which plays an essential role in
inducing hypotension during IL-2 and TNF
biotherapies.
Protection by coenzyme Q10 of tissue
reperfusion injury during abdominal aortic
cross-clamping.
Chello M; Mastroroberto P; Romano R; Castaldo
P; Bevacqua E; Marchese AR
Medical School of Catanzaro, Italy.
J Cardiovasc Surg (Torino) (Italy) Jun 1996, 37
(3) p229-35
PURPOSE: To evaluate the effect of coenzyme Q10
in reducing the skeletal muscle reperfusion injury
following clamping and declamping the abdominal
aorta.
METHODS: 30 patients undergoing elective
vascular surgery for abdominal aortic aneurysm or
obstructive aorto-iliac disease were randomly
divided into two groups: patients in group I were
treated with coenzyme Q10 (150 mg/day) for seven
days before operation, and those in group II
received a placebo. We studied the hemodynamic
profile in each patient during clamping and
declamping of the abdominal aorta. The plasma
concentrations of thiobarbituric acid reactive
substances (malondialdhehyde), conjugated dienes,
creatine kinase and lactate dehydrogenase were
measured in samples from both arterial and
inferior vena cava sites. Serial sampling was
performed after induction of anesthesia, 5 and 30
minutes after abdominal aortic cross clamping, 5
and 30 minutes after aortic cross-clamp
removal.
RESULTS: The concentrations of malondialdehyde,
conjugated dienes, creatine kinase and lactate
dehydrogenase in patients who received CoQ10 were
significantly lower than in the placebo group.
Decrease of plasma malondialdehyde concentrations
correlated positively (p < 0.01) with decrease
of both creatine kinase and lactate dehydrogenase
release in samples from the inferior vena cava.
The hemodynamic profile during clamping and
declamping the abdominal aorta was similar in both
groups.
CONCLUSIONS: Our findings suggest that
pre-treatment with coenzyme Q10 may play a
protective role during routine vascular procedures
requiring abdominal aortic cross clamping by
attenuating the degree of peroxidative damage.
A
review of the clinical effects of
phytoestrogens.
Knight DC; Eden JA
Royal Hospital for Women, New South Wales,
Australia.
Obstet Gynecol (United States) May 1996, 87 (5 Pt
2) p897-904
OBJECTIVE: To review the sources, metabolism,
potencies, and clinical effects of phytoestrogens
on humans.
DATA SOURCES: The MEDLINE data base for the
years 1980-1995 and reference lists of published
articles were searched for relevant
English-language articles concerning
phytoestrogens, soy products, and diets with
high-phytoestrogen content.
METHODS OF STUDY SELECTION: We identified 861
articles as being relevant. Human cell line
studies, human epidemiologic studies (case-control
or cohort), randomized trials, and review articles
were included. Animal studies regarding
phytoestrogens were included when no human data
were available concerning an important clinical
area.
TABULATION, INTEGRATION, AND RESULTS: Included
were studies containing information considered
pertinent to clinical practice in the areas of
growth and development, menopause, cancer, and
cardiovascular disease. When findings varied,
those presented in this study reflect consensus.
All studies concurred that phytoestrogens are
biologically active in humans or animals. These
compounds inhibit the growth of different cancer
cell lines in cell culture and animal models.
Human epidemiologic evidence supports the
hypothesis that phytoestrogens inhibit cancer
formation and growth in humans. Foods containing
phytoestrogens reduce cholesterol levels in
humans, and cell line, animal, and human data show
benefit in treating osteoporosis.
CONCLUSION: This review suggests that
phytoestrogens are among the dietary factors
affording protection against cancer and heart
disease in vegetarians. With this epidemiologic
and cell line evidence, intervention studies are
now an appropriate consideration to assess the
clinical effects of phytoestrogens because of the
potentially important health benefits associated
with the consumption of foods containing these
compounds. (90 Refs.)
The
making of a user friendly MAOI diet.
Gardner DM; Shulman KI; Walker SE; Tailor SA
Department of Pharmacy, Sunnybrook Health Science
Centre, University of Toronto, Ontario, Canada.
J Clin Psychiatry (United States) Mar 1996, 57
(3) p99-104
BACKGROUND: Many monoamine oxidase inhibitor
(MAOI) diets are considered to be excessively
restrictive and founded on poor scientific
evidence. We present a safe and practical MAOI
diet based on the related clinical and analytic
data.
METHOD: We used a critical review of the
literature and our own tyramine assay results to
categorize foods to be restricted absolutely,
taken in moderation only, or unrestricted.
RESULTS: We recommend that users avoid aged
cheese; aged or cured meats (e.g., air-dried
sausage); any potentially spoiled meat, poultry,
or fish; broad (fava) bean pods; Marmite
concentrated yeast extract; sauerkraut; soy sauce
and soy bean condiments; and tap beer. Wine and
domestic bottled or canned beer are considered
safe when consumed in moderation. Other foods not
mentioned are considered unrestricted.
CONCLUSION: The concerns about perpetuating an
overly restrictive MAOI diet include the avoidance
by prescribers of a potentially useful treatment
option, excessive limitations on lifestyle for
patients, and increased risk to patients secondary
to noncompliance with the diet. We propose an MAOI
diet that has a solid scientific and clinical
basis and that is, above all, practical. (53
Refs.)
Neuroprotective strategy for
Alzheimer disease: intranasal administration of a
fatty neuropeptide.
Gozes I; Bardea A; Reshef A; Zamostiano R;
Zhukovsky S; Rubinraut S; Fridkin M; Brenneman
DE
Department of Clinical Biochemistry, Sackler
School of Medicine, Tel Aviv University,
Israel.
Proc Natl Acad Sci U S A (United States) Jan 9
1996, 93 (1) p427-32
Neurodegenerative diseases, in which neuronal
cell disintegrate, bring about deteriorations in
cognitive functions as is evidenced in millions of
Alzheimer patients. A major neuropeptide,
vasoactive intestinal peptide (VIP), has been
shown to be neuroprotective and to play an
important role in the acquisition of learning and
memory. A potent lipophilic analogue to VIP now
has been synthesized, [stearyl-norleucine17]VIP
([St-Nle17]VIP), that exhibited neuroprotection in
model systems related to Alzheimer disease. The
beta-amyloid peptide is a major component of the
cerebral amyloid plaque in Alzheimer disease and
has been shown to be neurotoxic. We numb er of
neurons in rat cerebral cortical cultures treated
with the beta-amyloid peptide (amino acids 25-35)
in comparison to controls. This cell death was
completely prevented by cotreatment with 0.1 pM
[St-Nle17]VIP. Furthermore, characteristic
deficiencies in Alzheimer disease result from
death of cholinergic neurons. Rats treated with a
cholinergic blocker (ethylcholine aziridium) have
been used as a model for cholinergic deficits.
St-Nle-VIP injected intracerebroventricularly or
delivered intranasally prevented impairments in
spatial learning and memory associated with
cholinergic blockade. These studies suggest both
an unusual therapeutic strategy for treatment of
Alzheimer deficiencies and a means for noninvasive
peptide administration to the brain.
Effects
of green tea catechins (Polyphenon 100) on
cerulein-induced acute pancreatitis in
rats.
Takabayashi F; Harada N
Hamamatsu College, University of Shizuoka,
Japan.
Pancreas (United States) Apr 1997, 14 (3)
p276-9
Effects of green tea catechins (GTC) on
cerulein-induced acute pancreatitis in rats were
examined. The acute pancreatitis induced by
cerulein (cerulein pancreatitis) was characterized
by interstitial edema and vacuolation. When
cerulein pancreatitis was induced, prior
administration of 0.1% GTC in drinking water for 1
week before the induction significantly decreased
the wet weight of the pancreas, the serum level of
amylase, and the tissue concentration of lipid
peroxides in the pancreas compared with those in
nonmedicated rats supplied with plain tap water
only. Furthermore, the pancreatic tissue
alterations of the medicated rats were milder than
those of the nonmedicated rats. These data suggest
that GTC have a protective effect on the
pathogenesis of cerulein pancreatitis.
Characterization of early pulmonary
hyperproliferation and tumor progression and their
inhibition by black tea in a
4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced
lung tumorigenesis model with A/J
mice.
Yang G; Wang ZY; Kim S; Liao J; Seril DN; Chen
X; Smith TJ; Yang CS
Laboratory for Cancer Research, College of
Pharmacy, Rutgers University, Piscataway, New
Jersey 08854, USA.
Cancer Res (United States) May 15 1997, 57 (10)
p1889-94
The pathogenesis of pulmonary tumors induced by
a tobacco carcinogen,
4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone
(NNK), and its inhibition by black tea have been
characterized. Female A/J mice (6 weeks old) were
treated with a single dose of NNK (103 mg/kg of
body weight, i.p.) on day 0, and the cell
proliferation index was measured by the
incorporation of bromodeoxyuridine (BrdUrd)
immunohistochemically. The number of
BrdUrd-labeled cells increased in the bronchiolar
epithelium from day 2 to day 14, with the highest
proliferation rate observed on day 5. By day 35,
the BrdUrd-labeling index returned to the level of
the control group. Further examination of the day
35 samples revealed the presence of foci of
hyperproliferative cells in the bronchiolar
epithelium, particularly in the bronchiolalveolar
regions. These proliferating bronchiolar
epithelial cells (Clara cells) may be the
initiated sites for pulmonary tumorigenesis. In
this short-term model, administration of black tea
polyphenols (0.3%) through the drinking water
starting 24 h after NNK treatment significantly
inhibited NNK-induced early bronchiolar cell
proliferation on day 5. In long-term studies,
adenomas were observed in 100% (15 of 15) of the
mice at week 16, with 7.8 +/- 0.8 tumors per
mouse. At week 52, a malignant tumor incidence of
80% (41 of 51 mice) and a malignant tumor
multiplicity of 2.39 +/- 0.19 were observed. The
growth patterns of the malignant tumors, which
included solid, papillary, and mixed types, may be
associated with the cellular origin of the tumor.
The cell proliferation indices, as measured by
proliferating cell nuclear antigen
immunohistochemistry, were significantly higher in
dysplasia within adenoma than in adenoma, and
significantly higher in adenoma at week 52 than in
adenoma at week 16. Administration of black tea,
starting 16 weeks after a single dose of NNK,
inhibited the progression of adenoma to
adenocarcinoma as determined by both malignant
tumor incidence and multiplicity. The cell
proliferation rate in adenomas was also suppressed
by black tea treatment. The present work
demonstrates the antiproliferative activities of
black tea and its polyphenols. Such activities, at
the early and late stages be important for the
cancer-chemopreventive activities of black
tea.
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