Antibiotic Found To Protect Hearing In Mice
January 29, 2010
A type of antibiotic that can cause hearing loss in people has been found to paradoxically protect the ears when given in extended low doses in very young mice.
The surprise finding came from researchers at Washington University School of Medicine in St. Louis who looked to see if loud noise and the antibiotic kanamycin together would produce a bigger hearing loss than either factor by itself. The results will appear in an upcoming issue of the Journal of the Association for Research in Otolaryngology and are now available online.
“The protective effect of this type of antibiotic is a previously unknown phenomenon that now leads to at least a dozen important questions about what mechanisms cause hearing loss and what mechanisms could be protective,” says senior author William W. Clark, Ph.D., professor of otolaryngology and director of the Program in Audiology and Communication Sciences, a division of CID at Washington University School of Medicine.
New Vaccine Effective Against TB In African HIV Patients
January 29, 2010
Investigators from Dartmouth Medical School (DMS) have reported results of a clinical trial showing that a new vaccine against tuberculosis, Mycobacterium vaccae (MV), is effective in preventing tuberculosis in people with HIV infection. The DarDar Health Study, named for Dartmouth and Dar es Salaam, Tanzania, found that MV immunization reduced the rate of definite tuberculosis by 39 percent among 2,000 HIV-infected patients in Tanzania.
The study appears in the January 29, 2010, online issue of the journal AIDS and will be published in the March print issue of AIDS.
“Since development of a new vaccine against tuberculosis is a major international health priority, especially for patients with HIV infection, we and our Tanzanian collaborators are very encouraged by the results of the DarDar Study,” says principal investigator Ford von Reyn, M.D., director of the DarDar International Programs for the Section on Infectious Disease and International Health at DMS.
Antibiotics Might Team Up to Fight Deadly Staph Infections
January 28, 2010
Researchers at the University of Illinois at Chicago and Israel’s Weizman Institute of Science have found that two antibiotics working together might be more effective in fighting pathogenic bacteria than either drug on its own.
Individually, lankacidin and lankamycin, two antibiotics produced naturally by the microbe streptomyces, are marginally effective in warding off pathogens, says Alexander Mankin, professor and associate director of the UIC Center for Pharmaceutical Biotechnology and lead investigator of the portion of the study conducted at UIC.
Mankin’s team found that when used together, the two antibiotics are much more successful in inhibiting growth of dangerous pathogens such as MRSA, or methicillin-resistant Staphylococcus aureus, and possibly others.
MRSA is a staph infection that is resistant to certain antibiotics. According to a 2007 government report, more than 90,000 Americans get potentially deadly infections each year.
Proper Vaccine Refrigeration Vital to Putting Disease on Ice
January 28, 2010
Every year, billions of dollars worth of vaccines are shipped to thousands of medical providers across the country, and every year doctors must dispose of tens of millions of dollars worth of those vaccines because they became too warm or too cold while in storage. Now, researchers at the National Institute of Standards and Technology (NIST), with funding from and in collaboration with the Centers for Disease Control and Prevention (CDC), have completed the first of a series of tests to determine best practices for properly storing and monitoring the temperature of refrigerated vaccines.
Their initial findings* will be included in a CDC training video and report to be released July 2010.
To ensure they are effective, most vaccines must be kept between 2 and 8 degrees Celsius from the time they are manufactured until they are administered. In addition to the cost of spoiled vaccines that must be destroyed, lack of temperature control probably has resulted in the administering of ineffective vaccinations to the public in a small, but significant, percentage of cases.
In this first phase of a larger study, NIST researchers compared standard-sized refrigerators without freezers against smaller, dormitory-style refrigerators under a variety of conditions, storage practices and use scenarios, including leaving the refrigerator door ajar for various periods, power loss and raising the ambient temperature of the room.
Sniffing Out Lung Cancer at Early Stages
January 28, 2010
New animal research from scientists at the Monell Center and collaborators demonstrates that body fluid odors can be used to identify animals with lung cancer tumors. The findings set the stage for studies to identify potential diagnostic biomarkers in the urine of human lung cancer patients.
Lung cancer is the leading cause of cancer-related deaths worldwide, responsible for 1.3 million deaths annually. Effective techniques for early diagnosis are urgently needed, as the disease often has no early signs or symptoms.
“Cancer tumors result in a change in body-related odors that can be detected both by trained animal sensors and by sophisticated chemical techniques,” said Monell biologist Gary K. Beauchamp, Ph.D., a senior author on the study. “These findings indicate that odor sensing has the potential to improve early diagnostic and prognostic approaches to lung cancer treatment.”
Vitamin D Supplements Could Fight Crohn’s
January 27, 2010
A new study has found that Vitamin D, readily available in supplements or cod liver oil, can counter the effects of Crohn’s disease. John White, an endocrinologist at the Research Institute of the McGill University Health Centre, led a team of scientists from McGill University and the Université de Montréal who present their findings about the inflammatory bowel disease in the latest Journal of Biological Chemistry.
“Our data suggests, for the first time, that Vitamin D deficiency can contribute to Crohn’s disease,” says Dr. White, a professor in McGill’s Department of Physiology, noting that people from northern countries, which receive less sunlight that is necessary for the fabrication of Vitamin D by the human body, are particularly vulnerable to Crohn’s disease.
Vitamin D, in its active form (1,25-dihydroxyvitamin D), is a hormone that binds to receptors in the body’s cells. Dr. White’s interest in Vitamin D was originally in its effects in mitigating cancer. Because his results kept pointing to Vitamin D’s effects on the immune system, specifically the innate immune system that acts as the body’s first defense against microbial invaders, he investigated Crohn’s disease. “It’s a defect in innate immune handling of intestinal bacteria that leads to an inflammatory response that may lead to an autoimmune condition,” stresses Dr. White.
A Gimmick-Free Weight-Loss Pill
January 27, 2010
A Université de Montréal research team is developing a pill composed of leptin, the protein that tells our brain to stop eating. “Mice deprived of leptin will not stop eating. They become so big they have trouble moving around,” says Moïse Bendayan, a pathology professor at the Université de Montréal Faculty of Medicine who has studied the leptin protein extensively.
Leptin regulates appetite in mammals and its levels decrease when fasting and rise during meals. It has been proven to be an appetite suppressant when administered intravenously to pathologically obese people.
Postdoctoral student Philippe Cammisotto is leading the charge for a leptin-based, appetite suppressing pill with Dr. Bendayan and Émile Levy, a professor from the Department of Nutrition. “Taken orally, such a pill would provide obese people with the sensation of being full. They would eat less and in turn lose weight,” says Dr. Cammisotto.
Human Growth Hormone: Not A Life Extender After All?
January 27, 2010
People profoundly deficient in human growth hormone (HGH) due to a genetic mutation appear to live just as long as people who make normal amounts of the hormone, a new study shows. The findings suggest that HGH may not be the “fountain of youth” that some researchers have suggested.
“Without HGH, these people still live long, healthy lives, and our results don’t seem to support the notion that lack of HGH slows or accelerates the aging process,” says Roberto Salvatori, M.D., associate professor in the Department of Endocrinology at the Johns Hopkins University School of Medicine.
The researchers, working with an unusual population of dwarves residing in Itabaianinha county, a rural area in the northeastern Brazilian state of Sergipe, and led by Salvatori, sought to sort out conflicting results of previous studies on the effects of HGH on human aging.
Benefits of Omega-3 Fatty Acids Come at a Cost
January 25, 2010
For decades, omega-3 fatty acids have been praised for their myriad health benefits. Credited with helping treat or prevent degenerative illnesses such as heart disease, rheumatoid arthritis, diabetes, and even Alzheimer’s disease, they also play a key role in brain development and cognitive function.
However, the benefits of omega-3s –– and DHA in particular –– also come at an inevitable cost, according to researchers at UC Santa Barbara. Over a lifetime, they can lead to cellular disease and a significant decrease in cognitive function. The scientists, the father and son team of Raymond C. and David L. Valentine, have compiled their work in a new book titled “Omega-3 Fatty Acids and the DHA Principle” (CRC Press, 2009).
In humans, omega-3s are essential fatty acids that are necessary for health, but cannot be manufactured from scratch by the body. They are obtained largely from fish and other marine organisms, such as algae and krill. The body uses several types of omega-3s, including two “fish oils”: eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). “DHA and EPA sit atop a hierarchy of omega-3s and provide the most clear health benefits,” said David Valentine, associate professor of earth science at UCSB. His father, Raymond Valentine, is a professor emeritus of plant sciences at UC Davis, and a visiting scholar at the Marine Science Institute at UCSB.
Estrogen in the Fight Against Schizophrenia
January 25, 2010
Many American women are prescribed estrogen to combat the negative effects of menopause, such as bone loss and mood swings. Now, new evidence from a Tel Aviv University study suggests that hormone replacement therapy might also protect them — and younger women — from schizophrenia as well.
Prof. Ina Weiner of Tel Aviv University’s Department of Psychology and her doctoral student Michal Arad have reported findings suggesting that restoring normal levels of estrogen may work as a protective agent in menopausal women vulnerable to schizophrenia. Their work, based on an animal model of menopausal psychosis, was recently reported in the journal Psychopharmacology.
“We’ve known for some time that when the level of estrogen is low, vulnerability to psychotic symptoms increases and anti-psychotic drugs are less likely to work. Now, our pre-clinical findings show why this might be happening,” says Prof. Weiner.