What's Hot Archive
February 25, 2005
Feverfew kills leukemia cells
A plant known for its ability to help prevent migraine headaches has now been found to destroy human leukemia stems cells better than any other single therapy. In a report published in the March 2005 issue of the journal Blood, researchers from the University of Rochester Medical Center's James P. Wilmot Cancer Center revealed that parthenolide, the major component of feverfew, is the first single agent found to act on myeloid leukemia at the stem-cell level where malignancies are born, and which is not affected by current cancer treatments. Even Gleevec, the most progressive and successful treatment available, does not reach stem cells.
In the current investigation, Craig T PhD and colleagues tested a concentrated form of parthenolide on acute myelogenous leukemia stem cells, chronic myelogenous leukemia stem cells and normal cells. They found that the compound induced programmed cell death known as apoptosis in the cancerous cells while failing to affect normal cells. When comparison tests were conducted with parthenolide against the chemotherapy drug cytarabine, parthenolide proved to be superior at killing the leukemia cells while sparing normal cells.
The University of Rochester researchers are collaborating with chemists at the University of Kentucky to develop a pharmaceutical compound made from parthenolide, an effort which the National Cancer Institute has accepted into its rapid aceess program.
Dr Jordan, who is director of the Translational Research for Hematologic Malignancies program at the Wilmot Cancer Center, stated, "This research is a very important step in setting the stage for future development of a new therapy for leukemia. We have proof that we can kill leukemia stem cells with this type of agent, and that is good news."
February 23, 2005
Another claim for menopausal hormone therapy bites the dust
Protection against cardiovascular disease and dementia are two claims for menopausal hormone therapy (MHT) that have disproven by recent studies. In addition, other studies found an increased risk of breast and ovarian cancer experienced by women on hormone replacement. Physicians have continued to recommend hormone replacement as a temporary treatment for acute menopausal symptoms and for other conditions such as urinary incontinence (UI) and osteoporosis. Now, a study published in the February 23 2005 issue of the Journal of the American Medical Association (http://jama.ama-assn.org/) found that instead of preventing or treating urinary incontinence, hormone therapy appears to make it worse.
Researchers from Wayne State University School of Medicine and Hutzel Women's Hospital examined data from 23,296 postmenopausal participants in the Women's Health Initiative for whom the existence of urinary incontinence symptoms was known. Participants in the trials received conjugated equine estrogen (CEE) alone, estrogen plus progestin (MPA) or a placebo.
After one year on hormone therapy, continent women on both estrogen and progestin had an 87 percent increased risk of developing stress incontinence, which occurs involuntarily during coughing or laughing, and those who received estrogen alone experienced over twice the risk of those who did not receive the hormones. Urge incontinence, attributed to involuntary bladder contractions, increased by 32 percent in the women who received estrogen alone, but was not affected by combination therapy. The risk of experiencing both forms of incontinence was increased by 49 percent in those who received estrogen and progestin and 79 percent in the group that received estrogen alone. For those who reported incontinence at the beginning of the study, both therapies were associated with a worsening of all forms of urinary incontinence.
The authors write that the findings "indicate that MHT use does not confer protection against any type of UI. On the contrary, both CEE alone and CEE + MPA increased risk of new onset UI ."
February 21, 2005
Green tea polyphenol protects transplanted livers
A study published in the March 2005 issue of Liver Transplantation found that epigallocatechin-3-gallate (EGCG), one of the polyphenols found in green tea, protects livers from ischemia/reperfusion (I/R) injury. Ischemia reperfusion injury occurs during periods of decreased blood flow, which occur following liver transplantation.
Previous research found that the application of green tea to steatotic, or fatty livers prevented the failure of these organs following transplantation. Fatty livers are currently rejected as donor organs although the need for transplantable livers is critical. In the current study, investigators at the Medical University of South Carolina in Charleston sought to determine whether green tea might protect fatty livers from ischemic reperfusion injury.
Kenneth D. Chavin, MD, PhD and colleagues pretreated mice with EGCG administered orally for five days or by injection for two days after which ischemic was induced, followed by reperfusion . A control group of mice in whom I/R injury had been induced were pretreated with sterile water orally or by injection.
While 35 percent of the control group died, all of the mice who received EGCG survived. Mice who received EGCG were found to have less cell death and a greater amount of viable tissue than the unprotected mice. Palmitic and linoleic acid, which are fatty acids present in high amounts in fatty livers, were signficantly decreased in the mice who received EGCG, and the mice were also found to have an increase in glycogen stores compared to the controls.
The researchers determined that EGCG's antioxidant property was responsible for providing the protection observed in this study. They concluded, "the data presented here indicate that EGCG protects the steatotic liver from I/R injury by reducing hepatic fat content, increasing energy stores, serving as an antioxidant, and, possibly, stimulating the production of additional antioxidants such as GSH [glutathione]."
February 18, 2005
Many women with heart disease missing out on aspirin benefits
A study reported on February 18 2005 at at the Second International Conference on Women, Heart Disease and Stroke concluded that less than half of the women with cardiovascular disease are using aspirin, an inexpensive, easily obtainable therapy that has been recommended by cardiologists to help prevent secondary heart attacks and ischemic strokes.
For the current study, Chief resident at Beth Israel Medical Center in New York, Jeffrey S. Berger, MD, and colleagues examined data from 8,928 postmenopausal women with cardiovascular disease who participated in the Women's Health Initiative Observational Study. They discovered that 46 percent of them women reported that they were on low-dose aspirin, while studies have shown that 95 percent of women the disease could benefit from the drug. Fifty-four percent of those with prior heart attacks and 43 percent of those with a history of stroke reported aspirin use.
Although 81 milligrams aspirin per day has been found to be as effective as taking a whole aspirin and with fewer side effects, 70 percent of the women taking aspirin were taking a 325 milligram dose. Women who were older, Caucasian, or college educated were more likely to be taking aspirin than those who were younger, black or who did not attend college. Medicaid patients were 40 percent less likely to be taking aspirin than the remainder of the study population.
Dr Berger commented, "In the late 1980s, the federal government sought to eliminate such disparities between racial and socioeconomic groups, so to find that such a divide still exists illustrates the work that still needs to be done. Physicians need to be cognizant of these disparities. They must be mindful always of the patient and strive to treat each patient individually, without regard for the patient's socioeconomic status, insurance type or race."
February 16, 2005
Tissue zinc levels may protect against esophageal cancer
A study published in the February 16 2005 issue of the Journal of the National Cancer Institute found higher tissue concentrations of zinc correlated with a reduction in the risk of esophageal squamous cell carcinoma.
Animal studies have revealed a relationship between a dietary deficiency of zinc and esophageal cancer risk. The current study, which is the first prospective study of its kind to the authors' knowledge, examined the association between esophageal cancer and zinc levels in human esophageal tissue because the mineral is believed to exert its protective effect locally.
Christian C. Abnet, PhD, MPH and colleagues at the National Cancer Institute in Bethesda, Maryland, analyzed human esophageal biopsy samples for levels of copper, iron, nickel, sulfur and zinc. The tissue was obtained from residents of Linzhou, China upon enrollment in 1985 in a nutrition intervention trial that followed participants through May, 2001. Seventy-two tissue samples from subjects who did not develop esophageal cancer were compared to 60 samples from participants who developed the disease during the follow-up period.
The researchers found that participants whose esophageal zinc levels were in the highest one-fourth of participants had a 79 percent lower risk of developing esophageal cancer than those in the lowest fourth. Ninety percent of those whose zinc was in the top fourth of partipants were alive without esophageal cancer after 16 years compared to 65 percent of those whose zinc levels placed them in the lowest fourth. Sulfur also appeared to be protective although further analysis reduced its significance, while copper, iron and nickel levels were not associated with disease risk.
The finding strengthens the hypothesis that a deficiency of zinc contributes to the development of human esophageal squamous cell carcinoma. Because this finding is the first of its kind, further studies are necessary to confirm it.
February 14, 2005
Diet comparable to drugs in ability to lower cholesterol
A study published in the February 2005 issue of the American Journal of Clinical Nutrition found that consuming foods known to help lower cholesterol was comparable to taking a drug in their ability to lower low-density lipoprotein (LDL) cholesterol.
Researchers from St Michael's Hospital and the University of Toronto compared the effects of a low saturated fat diet, the same diet combined with 20 milligrams lovastatin per day, or a diet high in soy-protein foods, plant sterols, almonds, okra, eggplant, and fiber from oats, barley and psyllium on 34 men and women with elevated blood lipids. Participants received each diet for one month in random order separated by two to six weeks during which they followed low saturated fat diets. Blood samples were evaluated for lipids before each regimen and at the second and fourth week.
While the low saturated fat diet resulted in an average decrease in LDL cholesterol of 8.5 percent after the fourth week, there was a 33.3 percent reduction for those who received the statin drug, and a reduction of 29.6 percent for those who received the cholesterol-lowering foods. Seventy-nine percent of those who received lovastatin and 71 percent of participants who received the cholesterol-lowering foods were able to lower their LDL cholesterol below 130 milligrams per deciliter, compared to 23 percent of those on the low fat diet. Although none in the low saturated fat group met the treatment goal of 100 milligrams per deciliter LDL, 26 percent of those who received the statin and 9 percent of those who received the special food diet were able to meet it,
The authors conclude that, "a diet that combines a number of cholesterol-lowering foods may provide an option for reducing mild-to-moderate elevations in serum LDL cholesterol in persons without preexisting heart disease."
February 11, 2005
Study finds St John's Wort more effective than Paxil
A study published online in the British Medical Journal (www.bmj.com) found that the herb St John's Wort (hypericum) is at least as effective as the commonly prescribed drug paroxetine (sold as Paxil) in treating depression.
In a randomized, double-blind trial, German researchers gave 251 men and women with acute major depression 300 milligrams of a St John's wort extract three times per day or 20 millligrams paroxetine per day for six weeks. If the participants failed to obtain a response after two weeks of treatment, the dose of St John's Wort Extract was increased to 1800 milligrams per day and paroxetine was increased to 40 milligrams. The patients' depressive symptoms were assessed via standardized tests at the beginning of the study, and at the end of the first, second, fourth and sixth weeks.
At the study's conclusion, half of the participants who took St John's wort had experienced a reduction in depressive symptoms, while one-third of those who received paroxetine improved. Two hundred sixity-nine adverse effects were reported by 96 patients who received paroxetine, compared to 172 side effects reported by 69 patients who received St John's wort. The most common side effect experienced by both groups was stomach disorders. Participants who were switched to the higher dose of either treatment experienced slightly more improvement than those who remained on the lower dose, without experiencing greater adverse events.
The authors conclude that their results "support the use of hypericum extract WS 5770 as an alternative to standard antidepressants in moderate to severe depression, especially as it is well tolerated. As in any effective antidepressant, potential interactions with other drugs deserve clinical attention."
February 09, 2005
Carrot compound lowers cancer risk
A study published online on February 5 2005 in the Journal of Agricultural and Food Chemistry revealed that a compound found in carrots known as falcarinol that protects the plants from fungal disease also protects against cancer. When researchers from the University of Newcastle upon Tyne in England tested the compound on rats, the animals were one third less likely to develop cancerous tumors that rats who did not receive the compound in their diets.
Senior lecturer with the University of Newcastle's School of Agriculture, Food and Rural Development, Dr Kirsten Brandt, and researchers from the University of Southern Denmark and the Danish Institute of Agricultural Sciences divided 24 rats with precancerous tumors into groups who received rat feed enhanced with falcarinol, feed to which carrots were added, or a regular diet for 18 weeks. It was found that falcarinol reduced the risk of the precancerous tumors developing into cancer by one-third. Animals who received carrots experienced a similar reduction in risk.
Dr Brandt stated, "We already know that carrots are good for us and can reduce the risk of cancer but until now we have not known which element of the vegetable has these special properties. Our research allows us to make a more qualitative assessment of the vegetables we are eating, rather than quantitative. We now need to take it a step further by finding out how much falcarinol is needed to prevent the development of cancer and if certain types of carrot are better than others, as there are many varieties in existence, of different shapes, colours and sizes."
She added, "We could also expand our research to include other vegetables. For consumers, it may soon no longer be a case of advising them to eat five portions of fruit and vegetables per day but to eat particular types of these in certain quantities."
February 07, 2005
Midlife depression responds to DHEA
The February 2005 issue of the American Medical Association journal Archives of General Psychiatry published the findings of researchers from the National Institute of Mental Health that the over the counter hormone supplement dehydroepiandrosterone (DHEA) was effective in the treatment of midlife minor and major depression. The decline in the production of DHEA by the adrenal glands that occurs with age has been linked with an increased risk of several age-related conditions. Many middle-aged people take DHEA supplements to attain more youthful blood levels of the hormone and to experience its many benefits which include improved memory and mood.
Peter J. Schmidt, MD, of the National Institute of Mental Health's Behavioral Endocrinology Branch, and colleagues, randomly assigned 23 men and 23 women with major or minor depression of midlife onset to receive 90 milligrams DHEA for 3 weeks followed by 3 weeks of 450 milligrams DHEA, or a placebo for 6 weeks. At the end of the treatment period both groups received no therapies for 2 weeks followed by 6 weeks during which the groups' regimens were switched. Depression symptomsand sexual function were evaluated through standardized interviews conducted before treatment, at three weeks, and after each six week treatment period.
After 6 weeks of DHEA therapy, depression scores significantly improved compared to pretreatment scores and compared to the placebo group. When the second phase of the trial was analyzed, all of those who received DHEA experienced at least a 50 percent response as assessed by one depressing rating scale compared to 13 of the placebo subjects. Sexual function also improved in those who received DHEA compared to before treatment and compared to those who received the placebo.
The authors conclude, "We find DHEA to be an effective treatment for midlife-onset major and minor depression."
February 04, 2005
Discontinuing aspirin increases risk of repeat stroke
The American Stroke Association's International Stroke Conference was the site of a presentation on February 2 by the director of the acute stroke unit at Lausanne University Hospital in Lausanne, Switzerland, Patrik Michel MD, who reported that survivors of stroke who discontinue taking their prescribed aspirin triple the risk of another stroke occuring within a month. Aspirin is the most commonly prescribed medication to prevent a recurrence of stroke or heart attack.
Three hundred nine patients who had a recent stroke or transient ischemic attack that were on longterm aspirin therapy were matched with an equal number of participants also on aspirin following a stroke or transient ischemic attack that had occurred over six months before the study. A similar percentage of patients in both groups were taking 100 or 300 milligrams aspirin.
It was found that those who had recent strokes or transient ischemic events were 3.25 more likely to have discontinued their aspirin therapy within the month before their stroke than the control group who had no new events. During the first 8 days after aspirin was discontinued was the likeliest time for an ischemic stroke to occur, with 77 percent of this type of stroke occuring during this period.
Dr Michel, who coauthored the study, commented, "This is the first controlled retrospective study to investigate the potential risk of suffering ischemic stroke shortly after discontinuing aspirin. Although the absolute risk of suffering a substantial stroke during a short period of aspirin discontinuation is probably not very high, this difference is meaningful, and patients and physicians should be informed about this potential risk."
A similar study published in this month's Journal of the American College of Cardiology found an increased risk of the occurrence of acute coronary syndrome within a month after discontinuance of aspirin therapy by heart disease patients.
February 02, 2005
Drug fails to boost nutritional therapy in Crohn's patients
A study published on the website of the American Gastroenterological Association journal Clinical Gastroenterology and Hepatology (www.cghjournal.org), found that adding the bone building drug etidronate to a regimen of calcium and vitamin D in Crohn's disease patients did not result in any additional improvement in bone mineral density. Treatment of Crohn's disease with corticosteroid drugs and the poor nutrition that results from the disease causes diminished bone mass and increased fracture risk. Calcium and vitamin D are routinely given to Crohn's disease patients to improve bone density.
In the current study, researchers from the University of Alberta randomly assigned 154 patients with Crohn's disease and osteopenia or osteoporosis to receive 400 milligrams etidronate or no drug for two weeks, followed by a 76 day period during which both groups received 500 milligrams calcium and 400 international units vitamin D. This treatment was repeated 8 times over a two year period. Bone mineral density was measured at the beginning of the study and at 6, 12 and 24 months.
Bone mineral density improved in both drug-treated and nontreated participants by 3 to 4 percent per year. At 24 months, bone mineral density had significantly increased in the lumbar spine, distal radius and trochanter, but not in the hip. There was no improvement observed in those who received etidronate in comparison to participants who did not receive the drug. .
Study author Richard Fedorak, MD, commented, "Calcium and vitamin D therapy alone provide benefit to Crohn's patients who suffer from osteoporosis and osteopenia. We encourage physicians to look for loss of bone density in high risk patients with Crohn's disease and to start calcium and vitamin D therapy immediately if there is either osteoporosis or osteopenia."
The results of other trials currently testing the effect of newer bone-building drugs in Crohn's disease patients will be available in 2006.
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