- Secondhand smoke, antioxidants Full source:Circulation 1998;97:2012-2016
Nonsmokers who spend as little as a half-hour in a smoke-filled room suffer a serious drop in blood levels of antioxidants such as vitamin C. What's more, the secondhand smoke causes changes in cholesterol metabolism that might encourage the deposition of LDL, or "bad" cholesterol, in coronary arteries. The study demonstrates that passive smoking could increase the risk of coronary heart disease, a major cause of heart attacks. The cardiovascular system is extremely sensitive to the chemicals in environmental tobacco smoke which generate free radicals. Researchers tested the blood of 10 nonsmokers, taken before and up to 5.5 hours after they spent 30 minutes in a room filled with the smoke generated by 16 cigarettes. Comparison of the blood samples revealed up to a one-third drop in circulating levels of vitamin C and other antioxidants after exposure to secondhand smoke. There was no decrease in vitamin E and beta carotene. The secondhand smoke caused changes in LDL cholesterol, which enhances uptake of the molecule by immune system cells-a step thought to be important in progression of heart disease. Passive smoking changed LDL metabolism, favoring the progression of atherosclerosis.
- Cloning May Fight Parkinson's Full source: Nature Medicine (1998;4:557-558, 569-573)
Parkinson's disease is a degenerative neurological disorder characterized by a loss of facial expression and gradual losses in motor control. Experts estimate that the disease, which is caused by deteriorations in certain nerve cells, affects about one in every 200 Americans. Cloned animal fetuses may be a dependable source of nerve cells for use in the treatment of Parkinson's disease. Treatments that enhance the supply of the neurotransmitter dopamine to effected cells can slow or even reverse Parkinson's symptoms. One such technique involves harvesting healthy, dopamine-producing neuronal cells from fetal animal tissue and then transplanting these cells into the brains of Parkinson's patients. However, genetic differences between individual fetuses raise the risk of tissue rejection (and treatment failure) in recipient patients. Sixteen cloned cow embryos were implanted in bovine wombs, then aborted at around 50 days gestation. Fetal nerve cells capable of stimulating dopamine production were harvested and then transplanted into the brains of rats with symptoms of Parkinson's disease. The cells "survived transplantation...and improved motor performance" in most of the impaired rats. Improvements included significant reductions in the pacing or circling behaviors associated with the rat variant of Parkinsonian illness. In a minority of transplanted rats, initial behavioral improvements came to a stop, probably caused by rejection of grafted tissue. The researchers believe that "cloned animals make it possible to genetically engineer cell(s)" that can suppress this type of immunological response. Cloning technologies could someday produce flocks or herds producing medically useful pharmaceuticals.
- Antioxidants Fight Diabetes Complications Full source:Experimental Biology April '98 meeting in San Francisco
Antioxidants may help reduce the risk of complications from diabetes, including blindness, kidney failure, amputation and even death. Insulin is normally secreted when the level of blood glucose rises, such as after a meal. People with Type II diabetes aren't able to produce enough insulin to lower high blood-sugar levels, or their bodies are not as responsive to the hormone. This study looked at 50 people with Type II diabetes, also called non-insulin-dependent or adult-onset diabetes, and 23 people without diabetes. It showed that patients with poor control of their diabetes who were beginning to show signs of complications had depleted their stores of antioxidants. Further, they found a significant correlation between high blood-sugar levels and depletion of antioxidants. This depletion is a major risk factor for developing complications, and antioxidant supplements could lower this risk. The participants' ability to defend against free radical damage was rated as follows: nondiabetics, 2.7; diabetics without evidence of kidney damage, 1.7; diabetics with evidence of kidney damage, 1.4. Based on the results, the researchers recommend antioxidant supplements, such as vitamins C and E and N-acetylcysteine, for diabetics, a move patients should discuss with their doctor.
- Cataract Surgery Linked To Vision Loss Full source: Archives of Ophthalmology (1998;116:506-513)
People who have had surgery to remove a cataract may be at an increased risk of suffering age-related vision loss. Results of a 5-year population-based study found that those who had undergone cataract surgery were more than twice as likely to have progression of age-related maculopathy (ARM), or signs of late ARM as those who had not undergone such surgery. ARM is a form of macular degeneration in which the retina of the eye breaks down. Like macular degeneration, ARM is an important cause of vision loss among many of the elderly. A total of 3,684 adults between the ages of 43 and 86 were interviewed about their medical history, lifestyle and behavioral patterns, and agreed to allow investigators to examine their eyes for signs of ARM and vision loss. The group was then examined 5 years later. The data showed an increased risk of progression of ARM and incidence of late ARM in eyes that underwent cataract surgery. The relationship of cataract surgery to ARM needs further confirmation in other studies. Note: Older people are at higher risk for ARM/macular degeneration, but this risk is significantly further elevated if these individuals undergo cataract surgery, very common surgery in the elderly. This is even more reason to be on a preventive program for macular degeneration and cataracts (specific antioxidants, herbal extract and phytochemicals).
- 'Sticky' Blood Linked To Heart Disease Full source: Circulation, April 1998
One reason men have higher rates of heart disease and strokes than women may be that they have "stickier" blood. Analysis of blood samples from 1,592 men and women aged 55 to 74 years of age revealed that in men, the stickiness, or viscosity, of blood was related to the early development of atherosclerosis. This results from increased thickness of the inner lining of blood vessels that is more likely to damage arteries that supply the heart and brain. Blood viscosity may differ between the sexes based on biological variations such as the shape of blood vessels and the speed or velocity at which blood travels through the body. Men have a higher average blood velocity than women and that coupled with greater viscosity, cigarette smoking and higher blood pressure may produce greater stress within the blood vessels, thus creating more damage to the sensitive inner lining of the blood vessel walls. Those damaged vessels may predispose men to the buildup of deposits of cholesterol, fats and biological debris that can eventually obstruct normal blood flow to the heart and brain. Note: So-called "sticky" blood is not good. It is a very high risk factor for heart attacks and strokes. It also increases the chance for metastatic cancer. Dietary ways to reduce "sticky" blood are by taking flax oil or fish oil supplements (high in omega-3 essential fatty acids), vitamin E, garlic, magnesium, vitamin C, mini-aspirin, and reducing excess fat in the diet.
- Insulin, Estrogen Linked With Breast Cancer Full source: Experimental Biology '98 conference in San Francisco, Calif.
An interaction between the hormones estrogen and insulin may encourage the growth and proliferation of breast cancer cells. This finding may help explain why diabetes is more common in women with breast cancer. In the presence of insulin alone, the number of insulin receptors on the surface of breast cancer cells decreased, a normal response. But when bathed in a solution of both insulin and estrogen (as occurs in a premenopausal women), the number of insulin receptors on the cell surface remained the same, and the number of estrogen receptors increased by 12 times. The breast cancer cells are more susceptible and more sensitive to insulin, which stimulates the proliferative response of the cells. This is a "formula for increased tumor growth and proliferation," according to researchers. Epidemiologists found that in women with breast cancer there was a higher incidence of diabetes and conversely in women with diabetes, there was a higher incidence of breast cancer. This would seem to be another reason to not receive postmenopausal hormone replacement therapy, especially if one is diabetic.
- Dopamine-Glutamate Interactions in The Basal Ganglia Full source: Amino Acids, 1998, Vol 14, Iss 1-3, pp 5-10
In an attempt to formulate a working hypothesis of basal-ganglia functions, arguments are considered suggesting that the basal ganglia are involved in a process of response selection, i.e., in the facilitation of "wanted'' and in the suppression of "unwanted'' behavior. The meso-accumbal dopamine-system is considered to mediate natural and drug-induced reward and sensitization. The meso-striatal dopamine-system seems to fulfill similar functions: It may mediate reinforcement which strengthens a given behavior when elicited subsequently, but which is not experienced as reward or hedonia. Glutamate as the transmitter of the corticofugal projections to the basal ganglia nuclei and of the subthalamic neurons is critically involved in basal ganglia functions and dysfunctions; for example Parkinson's disease can be considered to be a secondary hyperglutamatergic disease. Additionally, glutamate is an essential factor in the plasticity response of the basal-ganglia. However, opposite to previous suggestions, the NMDA-receptor blocker MK-801 does not prevent psychostimulant-nor morphine-induced day-to-day increase (sensitization) of locomotion. Also the day-to-day increase of haloperidol-induced catalepsy was not prevented by MK-801.
- Parkinson's update Full Source:Amino Acids, 1998, Vol 14, Iss 1-3, pp 75-82
In animal models of Parkinson's disease, glutamate (an excitatory amino acid) antagonists reduce levodopa-associated motor fluctuations and dyskinesias (impairment of the power of voluntary movement). An antagonist is a drug that binds to a cell receptor for a hormone, a neurotransmitter or another drug, and thus blocks the action of the other substance without producing any physiological effect itself. This study evaluated the effects of three non-competitive excitotoxic amino acid antagonists on the motor response to levodopa in patients with advanced Parkinson's disease. In four separate trials, auxiliary therapy with these drugs reduced levodopa-induced dyskinesias and motor fluctuations. This shows that drugs which inhibit glutamatergic transmission (at the NMDA receptor) can improve levodopa-associated motor response complications.
- Antioxidants in the Brain Full Source:Journal of Neural Transmission, 1997, Vol 104, Iss 11-12, pp 1277-1286
Lipid peroxidation, an outcome of free radicals activity, has been hypothesized as one of the possible factors involved in the pathogenesis of neuronal damage. We investigated the effects of free radical scavengers, alpha-tocopherol (T) and ascorbic acid (A) combination (TA-combination) to attenuate tert-butyl hydroperoxide (t-BuOOH)-induced lipid peroxidation in different regions of mice brain. Examinations of the effect of three regimens (100, 200, 300 mg/kg body weight) of t-BuOOH on mid brain, cerebellum, striatum, cortex and hippocampus revealed dose- and time-dependent increase in lipid peroxidation. We observed that prior supplementation of TA-combination reduced lipid peroxidation induced by t-BuOOH in every brain region. These findings suggest that TA-combination may play a vital role in protecting the brain tissue against free radicals.
- Warfarin in Metastatic Breast Cancer Full Source: Thrombosis and Haemostasis, 1998, Vol 79, Iss 1, pp 23-27
Malignancy is a risk factor for thromboembolism (obstruction of a blood vessel), and anti-cancer chemotherapy can increase this risk. Preventive treatment of thrombosis (clot) with very low-dose warfarin (an anticoagulant) given concurrently with chemotherapy produced a significantly reduced rate of thromboembolism in a randomized trial in women with stage IV breast cancer. In a group of 32 patients, 16 subjects on warfarin and 16 on placebo, the aims of this study were: 1) To evaluate the effect of very low-dose warfarin on hemostatic (blood flow) variables; and 2) To examine whether laboratory tests predicted those patients who developed thrombosis. Results showed that clotting activation was progressively lower in the group receiving warfarin treatment, compared with the group on placebo. Differences between the groups became statistically significant after the 4th course of chemotherapy. Deep vein thrombosis occurred in two patients in the placebo arm. The results of this study indicate that before therapy, a hypercoagulable (abnormally increased coagulation state) is present in stage IV breast cancer, and after starting chemotherapy, abnormalities of hypercoagulation markers are reduced by very low-dose warfarin. None of the laboratory variables could predict thrombosis in the single patient.
- High Soy Intake, Decreased Estrogen Full Source: Nutrition and Cancer-an International Journal, 1997, Vol 29, Iss 3, pp 228-233
This study examined the relationship of soy product intake to serum concentrations of estradiol (the most potent naturally occurring estrogen in humans) in 50 healthy premenopausal Japanese women. There was a tendency for the intake of individual soy foods such as tofu and mise to be inversely correlated with estradiol on days 11 and 22 of the menstrual cycle. The results suggest that the consumption of soy products lowers the risk of developing breast cancer risk, modifying estrogen metabolism.
- Vitamin E vs. Viral Hepatitis C Full Source: Free Radical Research, 1997, Vol 27, Iss 6, pp 599-605
Vitamin E has been shown to protect against liver damage induced by oxidative stress in animal experiments. Previous findings have indicated diminished vitamin E levels in patients suffering from viral hepatitis. Here, 23 hepatitis C patients refractory (not readily yielding to treatment) with interferon-alpha therapy were treated with high doses of vitamin E (800 IU) for 12 weeks. Clinical parameters including alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined for monitoring the disease state. The plasma levels of vitamin E were increased about twofold in all 23 patients. In 11 of 23 patients, the clinical parameters indicative of liver damage improved 48% during the phase of vitamin E treatment. ALT was lowered by 46% and AST levels were lowered by 35% after 12 weeks of vitamin E treatment. Cessation of vitamin E treatment was followed by a rapid relapse of ALT and AST elevation, whereas retreatment led to a reproducible ALT decrease by 45% and AST decrease of 37% after a 6-month followup. Since vitamin E is non-toxic even at elevated doses ingested over extended periods, we suggest the treatment with vitamin E as a supportive therapy of those patients who are suffering from hepatitis C, and who also refractory to interferon-alpha therapy.
- NAC and Fruit Fly Life Span Full Source: Cellular and Molecular Life Sciences, 1997, Vol 53, Iss 11-12, pp 960-966
Aging can be defined as the time-dependent decline of physiological functions of an organism. The molecular causes for the aging process are multiple, involving both genetic and environmental factors. The Life Extension Foundation maintains that antioxidants may positively influence the aging process, protecting the organism against free radical-induced damage. In this study, the antioxidant N-acetylcysteine (NAC) has a life-extending effect on Drosophila melanogaster. Dietary uptake of NAC results in a dose-dependent increase in median and maximum life span. Flies fed on 1 mg/ml NAC food live 16.6%, longer; at 10 mg/ml, life span increases by 26.6%. A NAC-dependent increase in absolute amounts of total RNA and ribosomal RNA was also observed.
- Cardiac Arrest Drug and Brain Damage Full Source: Annals of Internal Medicine 1998;129:450-456, 501-502.
The drug epinephrine has been used by emergency teams for decades during efforts to resuscitate patients who have suffered a cardiac arrest. Now researchers report that high doses of the drug may be linked to an increased risk of permanent, severe brain damage. Researchers at the University of Vienna Medical School, in Austria, examined the post-resuscitation outcomes of 178 patients treated by emergency teams for cardiac arrest between 1991 and 1995. They report that "restoration of spontaneous circulation was possible with increasing cumulative doses of epinephrine, but good functional neurologic recovery was less likely." Risks for poor neurologic outcomes increased as the overall dose of epinephrine delivered during resuscitation increased: only 2 of the 36 patients revived through the use of high-dose epinephrine, left the hospital without severe functional neurologic impairment. Even after taking the duration of resuscitation into account, the researchers found that "the cumulative epinephrine dose remained an independent predictor of unfavorable neurologic outcome." These findings may pose a dilemma for emergency teams. Without a working heart, the brain cannot be perfused (supplied with blood). On the other hand, cardiac resuscitation using high-dose epinephrine may leave patients with beating hearts but nonfunctioning brains. The study results should serve as a possible warning against the indiscriminate use of epinephrine in the emergency room.
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