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Life Extension Magazine

LE Magazine October 1999

MEDICAL UPDATES
Studies from throughout the world that can help you live longer

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October 1999
Table Of Contents
 
  1. Calcium, GLA and EPA supplementation in senile osteoporosis
  2. Vitamin K and hip fractures in women
  3. Dietary protein intake vs. hipfracture in postmenopausal women
  4. Calcium, vitamin D, and dairy effect on heart disease mortality
  5. Carotenoids vs. diabetes
  6. DHEA improves glucose uptake
  7. Treatment of malignant mesothelioma
  8. Melatonin and environmental electromagnetic fields
  9. Role of mitochondria in neurodegenerative diseases
  10. Tea polyphenols, sulindac, and tamoxifen on cancer prevention
  11. Antioxidant status after eccentric muscle actions
  12. Survival with prostate cancer in Europe
  13. Melatonin as antioxidant reduces neuronal death
  14. Vitamin A supplementation and HIV-infected women
  15. Selenium supplementation during parasite infection
  16. Vasopressin improves age-related sleep disturbances
  17. Zinc oxide as a UVA/UVB sunblock agent
  18. Curcumin inhibits fatty acid peroxidation
  19. DHEAS and HDL-cholesterol in post-menopausal women
  20. Resistance training and bone density
  21. Exercise and immune function
  22. Dietary flavonols protect diabetic human lymphocytes
  23. Dietary genistein and mammary cancer prevention
  24. Treating ischemic heart disease
  25. Sexual function decreases after bladder cancer radiation
  26. Homocysteine, heart attack and stroke in the elderly
  27. Ginkgo biloba inhibits platelet aggregation
  28. Ginger induces cancer cell death
  29. Inhibitory effects of curcumin on Epstein-Barr virus
  30. Adrenal androgens and human breast cancer

  1. Calcium, GLA and EPA supplementation in senile osteoporosis

    Recent animal work suggests that gamma-linolenic acid (GLA) and eicosapentaenoic acid (EPA) enhance calcium absorption, reduce excretion and increase calcium deposits in bone. This study of 65 women (mean age 79.5), tested the interactions between calcium and GLA+EPA at 6, 12 and 18 months. They were assigned to GLA+EPA or coconut oil placebo capsules. All received 600 mg/day of calcium carbonate. Twenty-one patients were continued on active treatment for a second period of 18 months. At 18 months, osteocalcin and deoxypyridinoline levels fell significantly in both groups, indicating a decrease in bone turnover. Bone specific alkaline phosphatase rose, indicating beneficial effects of calcium given to all the patients. However, lumbar and femoral bone mineral density (BMD), in contrast, showed different effects in the two groups. For example, over the first 18 months, lumbar spine density remained the same in the treatment group, but decreased 3.2% in the placebo group. Femoral bone density increased 1.3% in the treatment group, but decreased 2.1% in the placebo group. During the second period of 18 months with all patients now on active treatment, lumbar spine density increased 3.1%, and 2.3% in patients who switched from placebo to active treatment; femoral BMD in the latter group showed an increase of 4.7%. This study suggests that GLA and EPA have beneficial effects on bone in elderly patients, and that they are safe to administer for prolonged periods of time.

    Aging - Clinical and Experimental Research, 1998, Vol 10, Iss 5, pp 385-394



  2. Vitamin K and hip fractures in women

    This study investigated the hypothesis that high intakes of vitamin K are associated with a lower risk of hip fracture in women. Diet was assessed in 72,327 women aged 38-63 years with a food-frequency questionnaire. During the subsequent 10 year follow-up, 270 hip fractures resulting from low or moderate trauma were reported. Risk of hip fracture was also less with lettuce consumption, the food that contributed the most to dietary vitamin K intakes (for one or more servings per day compared with one or fewer servings per week). Thus, low intakes of vitamin K may increase the risk of hip fracture in women. The data support the suggestion for a reassessment of the Vitamin K requirements that are based on bone health and blood coagulation.

    American Journal of Clinical Nutrition, 1999, Vol 69, Iss 1, pp 74-79



  3. Dietary protein intake vs. hipfracture in postmenopausal women

    Protein is an important structural component of bone and protein supplementation. It improves the medical outcome of hip fractures. This study evaluated the relation between intake of protein and other nutrients and subsequent incidence of hip fracture. Nutrient intake was assessed with a food-frequency questionnaire in a cohort of Iowa women aged 55-69 years in 1986. Incident hip fractures were ascertained through follow-up questionnaires mailed to participants in 1987 and 1989 and verified by physician reports. Forty-four cases of incident hip fractures were included in the analyses of follow-up data. The risk of hip fracture was not related to intake of calcium nor vitamin D. However, the incidence of hip fracture decreased as total protein intake increased and visa versa. Animal rather than vegetable sources of protein appeared to account for this association. With factors such as age, body size, parity, smoking, alcohol intake, estrogen use, and physical activity, the relative risks of hip fracture decreased as the intake of animal protein increased. The conclusion was that the intake of dietary protein, especially from animal sources, may be associated with a reduced incidence of hip fractures in postmenopausal women.

    American Journal of Clinical Nutrition, 1999, Vol 69, Iss 1, pp 147-152



  4. Calcium, vitamin D, and dairy effect on heart disease mortality

    This study investigated whether greater intakes of calcium, vitamin D, or milk products may protect against ischemic heart disease mortality. Data was analyzed from a study of 34,486 postmenopausal Iowa women 55-69 years old and without a history of ischemic heart disease who completed a dietary questionnaire in 1986. Through 1994, 387 deaths due to ischemic heart disease were documented (International Classification of Diseases, Ninth Revision, codes 410-414, 429.2). The results suggested that a higher intake of calcium, but not of vitamin D or milk products, is associated with reduced ischemic heart disease mortality in postmenopausal women, and reduced risk may be achievable whether the higher intake of calcium is attained by diet, supplements, or both.

    American Journal of Epidemiology, 1999, Vol 149, Iss 2, pp 151-161



  5. Carotenoids vs. diabetes

    Diabetes is a condition characterized by oxidative stress. Data from phase I of the Third National Health and Nutrition Examination Survey (1988-1991) were used to examine concentrations of the carotenoids alpha-carotene, beta-carotene, cryptoxanthin, lutein/ zeaxanthin, and lycopene in 40- to 74-year-old persons with a normal glucose tolerance, impaired glucose tolerance, newly diagnosed diabetes, and previously diagnosed diabetes based on World Health Organization criteria. They adjusted for age, sex, race, education, serum cotinine, serum cholesterol, body mass index, physical activity, alcohol consumption, vitamin use, and carotene and energy intake. The results showed that as the serum carotenoids increased, fasting serum insulin decreased. The data suggest new opportunities for research that include exploring a possible role for carotenoids in the pathogenesis of insulin resistance and diabetes.

    American Journal of Epidemiology, 1999, Vol 149, Iss 2, pp 168-176



  6. DHEA improves glucose uptake

    In this study, DHEA (dehydroepiandrosterone), a hormone secreted from the adrenal glands, increased insulin-induced uptake, and also stimulated PI S-kinase activity. DHEA also provoked the translocation of PKC-beta and -zeta from the cytosol to the membrane in rat adipocytes. These results suggest that DHEA stimulates both PI 3-kinase and PKCs and subsequently stimulates glucose uptake. Also, animals with non-insulin-dependent diabetes mellitus (NIDDM) were treated with 0.4% DHEA for 2 wk. Insulin was significantly increased. The results indicated that DHEA treatment can result in increased insulin-induced glucose uptake in rat models.

    American Journal of Physiology - Endocrinology and Metabolism, 1999, Vol 39, Iss 1, pp E196-E204



  7. Treatment of malignant mesothelioma

    The prognosis of mesothelioma (a rare abnormal tissue growth derived from the lining cells of the abdominal and pleural cavities) is very poor, and there is no established method to suppress tumor growth. This study utilized an immune system cells called cytokines. A 48-year old male with ascites (accumulation of fluid in the peritoneal cavity) was injected with TNF-SAM2 (tumor necrosis factor) several times. Five hundred mg of 5 fluorouracil (5-FU) was also once a week and 5-FU derivative was given orally every day. The results showed that NO apparent tumor progression was observed for 6 years and 6 months and the patient led a normal life. During the therapy, the malignancy of tumor cells from the ascites changed from class V to class VI. Thus, TNF based therapy may be a promising treatment for the suppression of malignant mesothelioma.

    Anticancer Research, 1998, Vol 18, Iss 6B, pp 4591-4600



  8. Melatonin and environmental electromagnetic fields

    This study tested the possibility that the exposure of mammals to either electric fields, static or sinusoidal magnetic fields, or a combined electromagnetic field, influences the production and secretion of pineal melatonin. While the results are inconsistent in terms of the ability of the fields to alter melatonin synthesis and secretion, when changes did occur they virtually always involved a suppression in the levels of melatonin. While it has usually been assumed that melatonin synthesis is suppressed by the field exposures, it is proposed that the reduction in serum melatonin (which in some cases was not accompanied by changes in pineal melatonin production) could be a result of an increased uptake and utilization of melatonin as a free radical scavenger in animals exposed to a magnetic field.

    Bioelectrochemistry and Bioenergetics, 1998, Vol 47, Iss 1, pp 135-142



  9. Role of mitochondria in neurodegenerative diseases

    There is mounting evidence for mitochondrial involvement in neurodegenerative diseases including Alzheimer's, Parkinson's, and Lou Gehrig's Disease (ALS). Mitochondrial DNA mutations, whether inherited or acquired, lead to impaired electron transport chain (ETC) functioning. Impaired electron transport, in turn, leads to decreased ATP (energy) production, formation of damaging free-radicals, and altered calcium handling. These toxic consequences of ETC dysfunction lead to further mitochondrial damage including oxidation of mitochondrial DNA, proteins, and lipids, and opening of the mitochondrial permeability transition pore, an event linked to cell death. Although protective nuclear responses such as antioxidant enzymes may be induced to combat these pathological changes, such a vicious cycle of increasing oxidative damage may insidiously damage neurons over a period of years, eventually leading to neuronal cell death. This article's hypothesis, a synthesis of the mitochondrial mutations and oxidative stress hypotheses of neurodegeneration, is readily tested experimentally, and points out many potential therapeutic targets for preventing or ameliorating these diseases.

    Brain Research Reviews, 1999, Vol 29, Iss 1, pp 1-25



  10. Tea polyphenols, sulindac, and tamoxifen on cancer prevention

    The incorporation of the tea polyphenols epigallocatechin gallate (EGCG) into human lung cancer cells indicated that the EGCG incorporation was significantly enhanced by epicatechin, an inert tea polyphenol. Epicatechin enhanced apoptosis, growth inhibition of cancer cells, and inhibition of tumor necrosis factor (TNF) release from cancer cells by EGCG and other tea polyphenols in a dose-dependent manner. In addition, the effects of EGCG on induction of apoptosis were also synergistically enhanced by other cancer-preventive agents, such as sulindac and tamoxifen. This study reports significant evidence that whole green tea is a more reasonable mixture of tea polyphenols for cancer prevention in humans than EGCG alone and that it is even more effective when it is used in combination with other cancer preventives.

    Cancer Research, 1999, Vol 59, Iss 1, pp 44-47



  11. Antioxidant status after eccentric muscle actions

    This study investigated the effects of chronic muscle inflammation on antioxidant status and muscle injury after eccentric exercise. Eight subjects each performed 70 maximal voluntary eccentric muscle actions. No changes were detected in serum total antioxidant capacity, serum creatine kinase and beta-glucuronidase after the baseline biopsy. After exercise, serum creatine kinase and beta-glucuronidase were elevated although other serum measures were unchanged. In muscle, total antioxidant capacity, sulphydryls, glucose-6-phosphate dehydrogenase and beta-glucuronidase were all elevated. Despite evidence of inflammation in this study, muscle antioxidant status was not. Therefore, this study provides no evidence that chronic muscle inflammation compromises antioxidant status or increases lipid peroxidation.

    Clinical Science, 1999, Vol 96, Iss 1, pp 105-115



  12. Survival with prostate cancer in Europe

    The incidence of prostate cancer has increased considerably over the past two decades in most European countries. The collaboration across Europe in the EUROCARE study has now been extended to 45 registries in 17 countries. This study reports on variation in relative survival according to age of 65,728 patients diagnosed with prostate cancer between 1985 and 1989. Considerable variation in survival was found within and between countries, with the highest survival in Switzerland (5-year relative survival 72%), followed by Germany (67%) and the Nordic countries (except Denmark). The lowest survival was found in Estonia (39%), preceded by Slovenia (40%), Denmark (41%) and England (45%). Between 1978 and 1986, relative survival barely changed over time, but it improved from 55% during 1984-1986 to 59% during 1987-1989. A small but unexpected deterioration of survival for patients aged between 45 and 54 years from 61% to 56% was observed in the early 1980s. It is likely that variation in both detection methods and treatment plays a role in the observed variation in survival.

    European Journal of Cancer, 1998, Vol 34, Iss 14, pp 2226-2231



  13. Melatonin as antioxidant reduces neuronal death

    The anti-excitotoxic efficacy of the pineal hormone melatonin was investigated in injured brains of rats. Melatonin (10 mg/kg) was administrated 1 hour before and 1, 3, and 5 hours after brain injury. Three days after injury, significant neuronal damage was found not only in the injected striatum, but also in the neighboring cortex. The induced cortical apoptotic neuronal death was significantly weakened by treatment with melatonin compared with the control group. However, no detectable changes were observed in the contralateral side of the brain in either group. The biochemical results indicated that oxidative stress was induced, such as a decrease in the content of total glutathione (GSH), oxidized glutathione (GSSG), and an increase in the ratio of GSSG/GSH in the striatum and cortex compared with the contralateral brain regions. In the injected striatum, melatonin did not reduce the oxidative stress, but in the neighborhood of injected area-cortex, the induced oxidative stress was significantly reduced by melatonin. Enhancement of glutathione-peroxidase activity was induced by the injury, not only in the cortical area of control and melatonin-treated rats, but also in striatum of control rats. However, a large elevation was found in the melatonin-treated cortex. The results suggest that melatonin functions as an antioxidant by upregulating the glutathione antioxidative defense system, thereby reducing neuronal death caused by excitotoxicity and preventing the induced injury from spreading to adjacent brain regions.

    Experimental Brain Research, 1999, Vol 124, Iss 2, pp 241-247



  14. Vitamin A supplementation and HIV-infected women

    Vitamin A supplementation has been suggested for treatment and prevention of HIV infection. However, some in vitro data indicate that vitamin A may activate HIV. Forty HIV positive women of reproductive age were allocated to receive a single oral dose of 300,000 IUs vitamin A or placebo. Plasma HIV-1 RNA concentration, total lymphocytes, selected lymphocyte subsets and activation markers, and in vitro lymphocyte proliferation to phytohemagglutinin (PKA) and Candida were measured at various points over an 8-week follow-up period. Results showed that no differences were found between treatment groups in the frequency of signs or symptoms of acute vitamin A toxicity, nor were differences evident in any lymphocyte subset or activation marker at any time during follow-up. The viral load concentration at each time point and change in viral load from baseline to each follow-up point did not differ between treatment groups. No difference was measured between treatment groups in the proportion of women who responded to PHA or Candida. This study provides no evidence that high dose vitamin A supplementation of HIV-infected women is associated with significant clinical or immunologic adverse effects.

    Journal of Acquired Immune Deficiency Syndromes and Human Retrovirology, 1999, Vol 20, Iss 1, pp 44-51



  15. Selenium supplementation during parasite infection

    Selenium has been shown to function as an antioxidant that may enhance immunity during microbial infection. This study investigated the effect of elevated levels of Selenium on the course of experimental Chagas' disease by infecting mice with a Brazil strain of Trypanosoma cruzi while receiving supplements of 0 ppm, 2 ppm, 4 ppm, 8 ppm, or 16 ppm Selenium (sodium selenate) in drinking water. After 64 days of infection, survival ranged from 0 to 60%, with groups receiving 4 ppm and 8 ppm Selenium exhibiting 60% survival and the group without Se exhibiting 0% survival. In addition, parasite levels of mice supplemented with Se were significantly lower than in nonsupplemented mice. The results of the present study suggest that Se supplementation does have a beneficial effect during infection with Trypanosoma cruzi parasite, resulting in decreased parasites in the blood and increased longevity.

    Journal of Parasitology, 1998, Vol 84, Iss 6, pp 1274-1277



  16. Vasopressin improves age-related sleep disturbances

    Disturbed sleep is common in the elderly and is characterized by reduced time spent in slow wave sleep (SWS) and in rapid eye movement (REM) sleep. At present, no treatments are available to fully compensate for these disorders. In the elderly, vasopressin content is decreased at various brain sites. Investigating the effects of a 3-month intranasal The hormone, Vasopressin was administered for 3 months in two elderly subjects in a foregoing pilot study which observed sleep and cognitive functions. Researchers found that the most pronounced influence of the hormone was a marked increase in SWS. Daily intranasal vasopressin treatment consisted of 20 IUs before bedtime and after awakening given to 26 healthy elderly subjects (mean age, 74.2 years). Intranasal treatment of vasopressin increased (1) the total sleep time, on average, by 45 minutes; (2) time spent in SWS by 21 minutes; and (3) time in REM sleep in the second half of the night by 10 minutes. Results suggest that age-related deterioration of sleep architecture can benefit from intranasal treatment with vasopressin.

    Journal of Clinical Psychopharmacology, 1999, Vol 19, Iss 1, pp 28-36



  17. Zinc oxide as a UVA/UVB sunblock agent

    Microfine zinc oxide (Z-Cote) is used as a transparent broad-spectrum sunblock to weaken UV radiation (UVR), including UVA I (340-400 nm). This study assessed the suitability of microfine zinc oxide as a broad-spectrum photoprotective agent by examining those properties generally considered important in sunscreens: attenuation spectrum, sun protection factor (SPF) contribution, photostability, and photoreactivity. Attenuation spectrum was assessed by means of standard spectrophotometric methods. SPF contribution was evaluated according to Food and Drug Administration standards. Photostability was measured in vitro by assessing SPF before and after various doses of WR. Photoreactivity was evaluated by subjecting a microfine zinc oxide/organic sunscreen formulation to escalating doses of UVR and determining the percentage of organic sunscreen remaining. The results showed that microfine zinc oxide weakens throughout the UV spectrum, including UVA I. It is photostable and does not react with organic sunscreens under irradiation. Thus, microfine zinc oxide is an effective and safe sunblock that provides broad-spectrum UV protection, including protection from long-wavelength UVA.

    Journal of the American Academy of Dermatology, 1999, Vol 40, Iss 1, pp 85-90



  18. Curcumin inhibits fatty acid peroxidation

    Curcumin from rhizomes of Curcuma longa binds to phosphatidylcholine (PC) micelles. When bound to PC micelles, curcumin inhibits the oxidation of fatty acids. The present study has shown that 8.6 mu M of curcumin bound to the PC micelles is required for 50% inhibition of linoleic acid peroxidation. Curcumin is a competitive inhibitor of deoxygenation of fatty acids by Lipoxygenase 1 (LOX-1). Based on spectroscopic measurements, the researchers concluded that the inhibition of LOX1 activity by curcumin can be due to binding to active iron, and after binding to the PC micelles, curcumin acts as an inhibitor of LOX1.

    Lipids, 1998, Vol 33, Iss 12, pp 1223-1228



  19. DHEAS and HDL-cholesterol in post-menopausal women

    Positive association between serum dehydroepiandrosterone sulfate (DHEAS) and high-density lipoprotein (HDL) cholesterol has been observed in men but not women. This study examined the cross-sectional relationships of DHEAS, estrogen, and sex hormone-binding globulin (SHBG) to serum lipid concentrations in 56 post-menopausal Japanese women. The information on body size, disease history, reproductive history, diet, and physical activity were obtained by a self-administered questionnaire. DHEAS was significantly and positively associated with HDL-cholesterol after controlling for age and body mass index (BMI). However, there was no associated between DHEAS and total-cholesterol, and estrogen was not significantly associated with total- and HDL-cholesterol and triglycerides. However, SHBG-unbound estrogen was significantly positively associated with HDL-cholesterol and negatively associated with triglycerides after controlling for age and BMI. This suggests a favorable effect of DHEAS as well as estrogen and SHBG on lipid profile in Japanese post-menopausal women.

    Maturitas, 1998, Vol 31, Iss 1, pp 21-27



  20. Resistance training and bone density

    Osteoporosis is a major public health problem that is characterized by low bone mass and increased susceptibility to fractures, primarily of the hip, spine, and wrist. It is estimated to cause 1.5 million fractures annually in the United States in people aged 50 years and older. Physical activity, particularly weight-bearing exercise, is thought to provide the mechanical stimuli or "loading" important for the maintenance and improvement of bone health, whereas physical inactivity has been implicated in bone loss and its associated health costs. Both aerobic and resistance training exercise can provide weight-bearing stimulus to bone, yet research indicates that resistance training may have a more profound site specific effect than aerobic exercise. Over the past 10 years, nearly two dozen cross-sectional and longitudinal studies have shown a direct and positive relationship between the effects of resistance training and bone density. Conversely, a handful of other studies have reported little or no effect on bone density. However, these results may be partially attributable to the study design, intensity and duration of the exercise protocol, and the bone density measurement techniques used. High-intensity resistance training, in contrast to traditional pharmacological and nutritional approaches for improving bone health in older adults, has the added benefit of influencing multiple risk factors for osteoporosis including improved strength and balance and increased muscle mass.

    Medicine and Science in Sports and Exercise, 1999, Vol 31, Iss 1, pp 25-30

    Maturitas, 1998, Vol 31, Iss 1, pp 21-27



  21. Exercise and immune function

    Epidemiological evidence suggests a link between the intensity of exercise and infectious and neoplastic disease. One likely way by which exercise exerts its effect on cancer and infection is by altering the function of the immune system. Cells of the innate immune system (i.e., macrophages, natural killer cells, and neutrophils) are first-line defenders against cancer and infectious disease by nature of their phagocytic, cytolytic, and antimicrobial properties. The purpose of this study was to define the role of cells of the innate immune system in infection and cancer, present current information regarding the effects of acute and chronic exercise on the activities of these cells, discuss potential mechanisms as to how exercise affects these cells and describe how these changes may potentially affect susceptibility to infection and cancer. The effects of exercise on the number, functions, and characteristics of cells of the innate immune system are complex and are dependent on several factors, including 1) the cell function or characteristic being analyzed; 2) the intensity, duration and chronicity of exercise; 3) the timing of measurement in relation to the exercise bout; 4) the dose and type of immunomodulator used to stimulate the cell in vitro or in vivo; and 5) the site of cellular origin. Further studies are needed to determine whether the exercise-induced changes in immune function alter incidence or progression of disease. Likewise, the mechanisms as to how exercise alters innate immune function are as yet unresolved.

    Medicine and Science in Sports and Exercise, 1999, Vol 31, Iss 1, pp 57-66



  22. Dietary flavonols protect diabetic human lymphocytes

    Diabetic patients have reduced antioxidant defenses and suffer from an increased risk of free radical-mediated diseases such as coronary heart disease. Evidence has suggested that antioxidant dietary flavonoids may protect against heart disease. In this study 10 stable type 2 diabetic patients were treated for 2 weeks on a low-flavonol diet and for 2 weeks on the same diet supplemented with 76-110 mg of flavonols (mostly quercetin) provided by 400 g of onions land tomato sauce, and six cups of tea daily. Freshly collected lymphocytes were subjected to standard oxidative challenge with hydrogen peroxide, and DNA damage was measured. Fasting plasma flavonol concentrations were 5.6 ng/ml on the low-flavonol diet and increased 12-fold to 72.1 ng/ml on the high-flavonol diet. Oxidative damage regarding lymphocyte DNA was 220 on an arbitrary scale of 0-400 U on the low-flavonol diet and 192 on the high-flavonol diet. This decrease was not accounted for by any change in the measurements of diabetic control (fasting plasma glucose or fructosamine) or by any change in the plasma levels of known antioxidants, including vitamin C, carotenoids, alpha-tocopherol, urate, albumin, and bilirubin. Thus, this shows a biological effect of potential medical importance that is associated with the absorption of dietary flavonols.

    Diabetes, 1999, Vol 48, Iss 1, pp 176-181



  23. Dietary genistein and mammary cancer prevention

    Asian women consuming a traditional diet high in soy have a low incidence of breast cancer, yet when they emigrate to the USA the second but not the first generation lose this protection. Accordingly, we hypothesized that early exposure to genistein, a major component of soy, could have a permanent protective effect against breast cancer. Rats were exposed to genistein in the diet at concentrations of 0, 25 and 250 mg genistein/kg from conception to day 21 after birth. After 50 days, all animals were treated to induce mammary cancers. Dietary genistein resulted in dose-dependent protection against development of mammary tumors (fewer tumors per rat). Analysis of mammary whole mounts showed that 21- and 50-day-old female rats had fewer terminal end buds, and fewer terminal ductal structures that were undifferentiated and susceptible to carcinogenesis. Dietary perinatal genistein resulted in a smaller proliferative compartment for terminal end buds. Dietary perinatal genistein did not cause significant toxicity. The conclusion was that genistein in the diet at "physiological levels" enhances cell differentiation, resulting in programming of mammary gland cells for reduced susceptibility to mammary cancer, with no observed toxicity to the reproductive tract of females.

    Carcinogenesis, 1998, Vol 19, Iss 12, pp 2151-2158



  24. Treating ischemic heart disease

    A growing number of experimental and clinical studies have demonstrated that improving heart energy metabolism can have a positive effect on the consequences of myocardial ischemia (obstruction of the blood supply - mainly arterial narrowing). By enhancing myocardial carbohydrate metabolism it is possible to improve cardiac function and/or limit tissue damage. It is known however that a high level of circulating fatty acids reduces heart glucose (sugar) metabolism, a situation which is observed in most cases of symptomatic myocardial ischemia and which can further aggravate ischemic damage. Glucose metabolism must be stimulated directly or indirectly by inhibiting fatty acid peroxidation. The effect of trimetazidine is based on this action. This has been recently demonstrated in rat hearts with high concentrations of fatty acids that trimetazidine stimulates glucose oxidation. Clinical studies have also shown that trimetazidine has a protective effect on heart tissue during myocardial ischemia. Improving cardiac energy metabolism with drugs such as trimetazidine could be a new promising approach to the treatment of cardiovascular diseases.

    Presse Medicale, 1998, Vol 27, Iss 39, pp 2100-2104



  25. Sexual function decreases after bladder cancer radiation

    This study assessed the effect of pre- and post-radiation therapy (RT) for bladder cancer on sexual function in males. An anonymous questionnaire was devised to examine the following sexual domains: libido, frequency of sexual function, erectile capacity, orgasm and ejaculation in the 6 months prior to radiation therapy and following treatment. Serum testosterone, follicle stimulating hormone (FSH) and luteinizing hormone (LH) were measured in 10 patients. Eighteen patients completed the questionnaire from 10 to 56 months following irradiation, 13 of whom were able to achieve an erection prior to RT. Over half of these patients noted a decline in the quality of erections after RT, with a similar proportion noting decreased libido and frequency of sexual activity. Three patients lost the ability to have any erections whatsoever. Of the 10 patients retaining erectile capacity, three noted reduced frequency of early morning erections, five had decreased frequency of ejaculation and four had reduced intensity of orgasms. Seventy-one percent (12/17) felt their sex life was worse following RT but only 56% (9/16) were concerned about the deterioration. Testosterone levels were normal in all but one patient. Thus, radical RT to the bladder can cause a decrease in sexual function in males.

    Radiotherapy and Oncology, 1998, Vol 49, Iss 2, pp 157-161



  26. Homocysteine, heart attack and stroke in the elderly

    Elevated homocysteine level increases vascular disease risk. Most data are based on those younger than 60 years. Data for the elderly are more limited. This study examined the relationship of homocysteine level to myocardial infarction and stroke among 7,983 older subjects in Rotterdam, the Netherlands from March 1, 1990, to July 31, 1993. One hundred four patients with a myocardial infarction and 120 with a stroke were identified with complete data. Control subjects consisted of a sample of 533 subjects drawn from the study base, free of myocardial infarction and stroke. Results were adjusted for age and sex. The risk of stroke and myocardial infarction increased directly with total homocysteine. There was a risk increase by 6% to 7% for every 1-mu mol/L increase in total homocysteine. The risk of total homocysteine level was significantly increased only in the group with levels above 18.6 mu mol/L. Associations were more pronounced among those with hypertension. This data, based on a relatively short follow-up period, provides evidence that among elderly subjects an elevated homocysteine level is associated with an increased risk of cardiovascular disease.

    Archives of Internal Medicine, 1999, Vol 159, Iss 1, pp 38-44



  27. Ginkgo biloba inhibits platelet aggregation

    The effect of the leaf extract of Ginkgo biloba on platelet aggregation induced by oxidative stress was studied. The extract caused a dose-dependent inhibition of platelet aggregation stimulated with tert-butyl hydroperoxide (t-BHP) and iron. Similar inhibitory activity was observed when platelets were exposed to hydrogen peroxide and iron. Synergistic aggregation induced by a combination of t-BHP and iron or hydrogen peroxide and iron in association with less than optimal concentration of collagen, was prevented by the extract. Ginkgolides A, B and C inhibited platelet-activating factor-induced aggregation, but not oxidant-induced aggregation. The results suggest that the suppressive effect of the ginkgo extract effects only platelet aggregation stimulated by oxidative stress. This effect is involved in the mechanism related to its protective effect upon cerebral or myocardial injuries.

    Biochemistry and Molecular Biology International, 1998, Vol 46, Iss 6,pp 1243-1248



  28. Ginger induces cancer cell death

    Gingerol, a major ingredient found in the gingerroot, has been reported to possess a strong anti-inflammatory activity, which is considered to be closely associated with its cancer chemopreventive potential. Paradol, another pungent phenolic substance found in ginger and other Zingiberaceae plants, also has a vanilloid structure found in other chemopreventive phytochemicals including curcumin. In this study, gingerol and paradol were found to exert inhibitory effects on the viability and DNA synthesis of human leukemia cells. The cytotoxic and antiproliferative effects of both compounds were associated with apoptotic cell death. These results suggest that gingerol and paradol possess potential cytotoxic activities which can be destructive to cancer cells.

    Cancer Letters, 1998, Vol 134, Iss 2, pp 163-168



  29. DHEAS and HDL-cholesterol in post-menopausal women

    Positive association between serum dehydroepiandrosterone sulfate (DHEAS) and high-density lipoprotein (HDL) cholesterol has been observed in men but not women. This study examined the cross-sectional relationships of DHEAS, estrogen, and sex hormone-binding globulin (SHBG) to serum lipid concentrations in 56 post-menopausal Japanese women. The information on body size, disease history, reproductive history, diet, and physical activity were obtained by a self-administered questionnaire. DHEAS was significantly and positively associated with HDL-cholesterol after controlling for age and body mass index (BMI). However, there was no associated between DHEAS and total-cholesterol, and estrogen was not significantly associated with total- and HDL-cholesterol and triglycerides. However, SHBG-unbound estrogen was significantly positively associated with HDL-cholesterol and negatively associated with triglycerides after controlling for age and BMI. This suggests a favorable effect of DHEAS as well as estrogen and SHBG on lipid profile in Japanese post-menopausal women.

    Maturitas, 1998, Vol 31, Iss 1, pp 21-27



  30. Inhibitory effects of curcumin on Epstein-Barr virus

    Dehydrozingerone is a form of curcumin which is known to have anti-tumor activity. The anti-tumor promoting activity of dehydrozingerone was evaluated by determining the inhibitory effect on Epstein-Barr virus early antigen (EBV-EA) activation artificially induced by TPA. The concentration needed for 50% inhibition of the tumor promotion of dehydrozingerone was similar to that of curcumin. Dehydrozingerone showed potent inhibitory effect in a series of tested dehydrozingerone derivatives.

    Cancer Letters, 1998, Vol 134, Iss 1, pp 37-42



  31. Adrenal androgens and human breast cancer

    A clearer picture of the role of androgens (hormones of the adrenal glands) in the cause of breast cancer is beginning to emerge. Women who develop breast cancer in premenopausal years tend to have less than normal serum levels of adrenal androgens, while subjects who develop the disease in postmenopausal years have higher than normal levels of these hormones. Androgens oppose estrogen-stimulated cell growth in premenopausal years. In postmenopausal women, elevated adrenal androgen levels stimulate cell growth by the action of the unique adrenal androgen, hermaphrodiol, via its combination with the estrogen receptor in a hormone environment lacking, or having low concentrations of estrogen.

    Breast Cancer Research and Treatment, 1998, Vol 51, Iss 2, pp 183-188