September 9, 2006, 9:12 AM CT
Unusual Three-drug Combo For Cancer
An experimental anti-cancer regimen combined a diuretic, a Parkinson's disease medicine and a drug ordinarily used to reverse the effect of sedatives. In research conducted at Washington University School of Medicine in St. Louis, the unusual mixture inhibited the growth of aggressive prostate tumors in laboratory mice.
Eventhough their drug choices may seem capricious, the scientists weren't randomly pulling drugs from their shelves. They made their discovery using sophisticated methods for delving into the unique metabolism of cancer cells and then choosing compounds likely to interfere with their growth.
"This study, led by Joseph Ippolito, a very talented M.D./Ph.D. student, demonstrates the importance of looking at tumor metabolism," says senior author Jeffrey I. Gordon, M.D, director of the Center for Genome Sciences at the School of Medicine. "Using a broad array of technology, we've obtained a view of the tumor cells' metabolome (the set of small-molecule metabolites found within cells) and revealed aspects that were not expected and could be exploited".
The findings, published in a recent article in the Proceedings of the National Academy of Sciences, expand upon earlier work by the research group, which demonstrated that aggressive types of neuroendocrine tumors - seen in some types of lung, thyroid and prostate cancers - produce high amounts of a chemical called GABA, a neurotransmitter.........
Posted by: Janet Permalink Source
September 7, 2006, 9:12 PM CT
Army Of Cells To Repair Injury
To speed healing at sites of injury - such as heart muscle after a heart attack or brain tissue after a stroke - doctors would like to be able to hasten the formation of new blood vessels. One promising approach is to "mobilize" patients' blood vessel-forming cells, called angiogenic cells, so these cells can reach the injured area.
Recently, researchers at Washington University School of Medicine in St. Louis demonstrated that a drug called AMD3100 can mobilize angiogenic cells from bone marrow of human patients in a matter of hours instead of days, as was the case with a related agent called G-CSF.
Angiogenic cells reside mainly in the bone marrow, and when mobilized they can circulate in the bloodstream, homing to sites of injury and helping repair and regrow blood vessels that bring oxygen and nutrients to tissues.
"Like AMD3100, G-CSF can bring these beneficial cells from the bone marrow into the bloodstream, but with G-CSF you don't see an increase in angiogenic cells until the fourth day," says senior author Daniel C. Link, M.D., associate professor of medicine in the Division of Oncology. "In a patient who has had a heart attack, that may be too late. In fact, two clinical trials of G-SCF found the treatment doesn't improve recovery from heart attacks."........
Posted by: Scott Permalink Source
September 6, 2006, 9:43 PM CT
Ghost Parasites And Severely Congested Sinuses
Eventhough it's unclear why it's so, researchers at Johns Hopkins have linked a gene that allows for the chemical breakdown of the tough, protective casing that houses insects and worms to the severe congestion and polyp formation typical of chronic sinusitis.
A team of Hopkins sinus experts has observed that the gene for the enzyme, acidic mammalian chitinase (AMCase), is up to 250 times more active in people with severe sinus inflammation that persists even after surgery when in comparison to patients in whom surgery is successful. Sinus surgery is commonly the therapy of last resort for those who do not respond to drug treatment. But nearly one in 10 of those treated see symptoms return within weeks or months after surgery fails to keep open the nasal passages, researchers say.
The Hopkins report, reported in the recent issue of the American Journal of Rhinology, is thought to bethe first to identify the enzyme's presence in the nose and confirm its link to sinusitis.
"This finding does not mean that there are actually parasites in the nose causing sinusitis, but our study does lend support to the concept that really severe and persistent sinusitis may be a case of a misplaced immune response directed against parasites that are not really there," says study lead author Andrew Lane, M.D., an associate professor at The Johns Hopkins University School of Medicine and director of its rhinology and sinus surgery center.........
Posted by: Sue Permalink Source
September 6, 2006, 7:50 PM CT
Progress In Macular Degeneration
A dart-like molecule that adheres to proteins in the eye is the key that turns on the uncontrolled growth of blood vessels, as per scientists at Case Western Reserve University and the Cleveland Clinic Cole Eye Institute. Uncontrolled blood vessel growth is a major contributor to the development of age-related macular degeneration (AMD), the leading cause of blindness among people over 65 in the United States.
Robert Salomon and his graduate students Kutralanathan Renganathan and Liang Lu of Case's Department of Chemistry in the College of Arts and Sciences, observed that the molecule, Carboxyethylpyrroles (CEPs), attaches to proteins found in the eye, triggering the uncontrolled growth of blood cells.
The Case scientists teamed up with Quteba Ebrahem Jonathan Sears, Amit Vasanji, John Crabb and Bela Anand-Apte and Xiaorong Gu (a Salomon group alumna), of Cleveland Clinic, to complete the study titled Carboxyethlpyrrole oxidative protein modifications stimulate neovascularization: Implications for age-related macular degeneration." .
The results of their collaborative work were reported in the recent Proceedings of the National Academy of Science (PNAS).
AMD is a progressive disease that results in the severe loss of vision. The early stages of AMD are characterized as "dry," with the disease advancing to the "wet form" as the retina, the part of the eye responsible for central vision, becomes infused with fluid from leaky new blood vessels, during a process called neovascularization. The unchecked blood vessel growth, or angiogenesis, in the retina accounts for 80% of the vision loss in the advanced stages of AMD.........
Posted by: Mike Permalink Source
September 4, 2006, 7:11 PM CT
Tough Fight Against Ovarian Cancer
Gene therapy might be the answer to ovarian cancer as per some researches from University of Pittsburgh School of Medicine. These researchers have used gene therapy with surprising ability by either completely abolishing or significantly inhibiting tumor progression in a mouse model of ovarian cancer. University of Pittsburgh researchers believe these findings, which was presented at the American Society of Gene Therapy annual meeting would significantly improve the prognosis for ovarian cancer patients.
Ovarian cancer is diagnosed in more than 25,000 women in the United States each year, and about 16,000 American women die from the disease annually. Despite aggressive surgery and chemotherapy approaches, the prognosis for ovarian cancer is poor, and most women have a life expectancy of only three to four years after their diagnoses.
In this study, the Pitt scientists inoculated mice with an ovarian cancer cell line. They treated some of the mice immediately with a genetically engineered vaccinia virus containing a gene coding cytosine deaminase, a suicide gene, and delayed treatment of other mice for 30 or 60 days. Control mice were inoculated with ovarian cancer cells but were not given the gene therapy.
The researchers found complete inhibition of tumor growth in the mice that were treated immediately with gene therapy and significant tumor inhibition in the 30- and 60-day delayed treatment mice. In contrast, all non-gene-therapy treated mice either died or were euthanized due to overwhelming buildup of fluid in the peritoneal cavity by 94 days following tumor inoculation.........
Posted by: Emily Permalink Source
September 3, 2006, 7:27 AM CT
Vaccine For Severe Form Of Malaria
Plasmodium falciparium, the most severe form of malaria hits pregnant women and children the hardest. A joint study between Karolinska Institutet in Sweden and Makerere University in Uganda has now produced some important findings on how the malaria parasite conceals itself in the placenta.
Plasmodium falciparium is the name of by far the most virulent of the four malaria parasites that infect man. It is especially dangerous in that it also infects the placenta of pregnant women, with fatal consequences for both her and the foetus. This, combined with the often feeble medical resources of malaria-stricken countries, can lead to such serous complications that the mother dies during delivery.
"For some reason, women in their first pregnancy lose the semi-immunity that is normally found in adults," explains Niloofar Rasti, a KI graduate student who has been working with the study. "The placenta seems to be an anatomically favourable environment for a subpopulation of the parasites".
The research group from Karolinska Institutet, under the leadership of Professor Mats Wahlgren, has been working with colleagues from KI's partner university in Uganda to study in detail how the parasite infects the placenta. Their results, which are reported in the American scientific journal PNAS, can enable the development of vaccines and therapies to combat severe malarial infections.........
Posted by: Mark Permalink Source
September 1, 2006, 4:52 AM CT
stimulating stem cell growth in the brain
Researchers at Harvard University have identified key compounds that stimulate stem cell growth in the brain, which may one day lead to restored function for people affected by Parkinson's disease, strokes, multiple sclerosis, and a wide range of neurological disorders. These findings, which appear in the September 2006 issue of The FASEB Journal, provide important clues as to which compounds may be responsible for causing key brain cells, neurons, to regenerate and ultimately restore brain function.
The research study focused on two compounds--LTB4 and LXA4. Both play a role in inflammation and are regulators of proliferation of several cell types. When stem cells isolated from the brains of mouse embryos were exposed to LTB4 they proliferated and differentiated, giving rise to additional stem cells and to differentiated neurons with limited or absent capacity to divide. When exposed to LXA4, these cells experienced decreased growth and apoptosis.
"This study opens doors to new therapeutic approaches for a wide range neurological disorders and injuries that were once considered incurable," said Gerald Weissmann, MD, Editor-in-Chief of The FASEB Journal.
The study also provided so insight into the cellular and molecular mechanisms involved when LTB4 stimulates neuronal stem cells. As per the study, cells generated as the result of LTB4 exposure had high levels of LTB4 receptors, whereas the level of LTB4 receptors was considerably lower in similar cells not generated by LTB4 stimulation. The researchers were further able to show that LTB4 up-regulated several molecules involved in cell cycling and growth, such as cyclins and epidermal growth factor receptor, and decreased those such as caspase 8 which play a role in apoptosis. LXA4 had the opposite effects.........
Posted by: Daniel Permalink Source
August 31, 2006, 5:34 AM CT
Focus on stroke
We examined whether the location of brain damage, neurocognitive deficits, and/or the number of clinical features identified during a swallowing study affected stroke patients' swallowing outcomes. Identification of at least four of six clinical features (cough after swallow, voice change after swallow, abnormal volitional cough, abnormal gag reflex, dysphonia, and dysarthria) was associated with poor swallowing outcomes at admission and discharge from the hospital. In addition, specific neurocognitive deficits seemed to be related to swallowing outcomes; however, location of brain damage was not associated. More information about clinical indictors, neuroanatomical locations, and behavioral features will lead to earlier detection of swallowing disorders.
Does motor lateralization have implications for stroke rehabilitation? pg. 311.
This article describes current findings on the usefulness of dominance retraining strategies in poststroke patients with dominant-arm hemiplegia. We found consistent differences in control strategies used by both the dominant and nondominant hemisphere/limb systems. However, the nondominant arm may not spontaneously become an efficient dominant manipulator, indicated by persistent deficits in chronic stroke patients. Because ipsilesional deficits are usually mild compared with contralesional, they are not normally addressed in rehabilitation. We propose that the previously nondominant limb impeded by motor deficits could benefit from remedial therapy to help switch to a dominant controller.........
Posted by: Daniel Permalink
August 31, 2006, 5:10 AM CT
Tumor Necrosis Factor Blockers May Not Cause Cancer
Patients with rheumatoid arthritis (RA), an autoimmune, inflammatory disease marked by progressive joint and organ damage, face a high risk of developing cancer. Their vulnerability, particularly to lymphoma and leukemia, may be due to the nature of RA. Disease-modifying antirheumatic drugs (DMARDs) including tumor necrosis factor alpha (TNF) antagonists, a type of biologic DMARD have also been implicated. TNF blockers, which work by attaching to and impeding chemical messengers behind inflammation, have had a significant impact on the therapy of RA. They have also been associated with lymphoma among users. In fact, reports of lymphoma prompted the Food and Drug Administration to mandate adding a cancer risk warning to the labels of three TNF blockers: etanercept (Enbrel), infliximab (Remicade), and adalimumab (Humira).
Motivated by persistent concerns and inconclusive studies, scientists at Harvard Medical School's Brigham and Women's Hospital set out to investigate the association between therapy with TNF blockers and occurrence of cancer in a large sample of patients with RA. Their results, featured in the September 2006 issue of Arthritis & Rheumatism (http://www.interscience.wiley.com/journal/arthritis
), indicate that biologic DMARD treatment poses no greater risk for cancer than treatment with a standard prescription DMARD, methotrexate (MTX).........
Posted by: Janet Permalink Source
August 30, 2006, 4:46 AM CT
Aspirin And NSAIDs To Prevent Prostateenlargement
Scientists at Mayo clinic have observed that taking nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin or ibuprofen may prevent or delay non-malignant prostatic hyperplasia, an enlarged prostate which can cause urinary symptoms in men as they age such as frequent urination, trouble starting urination, awakening frequently at night to urinate, weak urine stream and an urgent need to urinate. Details would be reported in the American Journal of Epidemiology.
"This study suggests that men's urinary health may be improved by taking NSAIDs," says Michael Lieber, M.D., Mayo Clinic urologist and study investigator. He and his colleagues found the risk of developing an enlarged prostate was 50 percent lower in NSAID users in comparison to non-users, and risk of developing moderate to severe urinary symptoms was 35 percent lower, he says.
Jenny St. Sauver, Ph.D., Mayo Clinic epidemiologist and lead study investigator, says, "The association between intake of NSAIDs and the reduction of non-malignant prostatic hyperplasia is strengthened by the consistency and magnitude of our findings. We would not recommend that every man go out and take aspirin, but if they are already taking it regularly for other reasons, our findings suggest another benefit as well." .........
Posted by: Janet Permalink Source