July 21, 2009, 11:21 PM CT

New insights into the causes of anorexia

New imaging technology provides insight into abnormalities in the brain circuitry of patients with anorexia nervosa (usually known as anorexia) that may contribute to the puzzling symptoms found in people with the eating disorder. In a review paper published on line in Nature Reviews Neuroscience, Walter Kaye, MD, professor of psychiatry and director of the Eating Disorders Program at the University of California, San Diego, and his colleagues describe dysfunction in certain neural circuits of the brain which may help explain why people develop anorexia in the first place, and behaviors such as the relentless pursuit of dieting and weight loss.

"Currently, we don't have very effective means of treating people with anorexia," said Kaye. "Consequently, a number of patients with the disorder remain ill for years or eventually die from the disease, which has the highest death rate of any psychiatric disorder."

A better understanding of the underlying neurobiology how behavior is coded in the brain and contributes to anorexia is likely to result in more effective therapys, as per the researchers.

Childhood personality and temperament may increase an individual's vulnerability to developing anorexia. Predisposing factors, some suspected to be inherited, such according tofectionism, anxiety, or obsessive-compulsive tendencies may precede the onset of an eating disorders. These traits become intensified during adolescence as a consequence of a number of factors such as hormonal changes, stress and culture......... Posted by: JoAnn      Read more         Source

July 21, 2009, 11:18 PM CT

Weight guidelines for women pregnant with twins

Healthy, normal-weight women pregnant with twins should gain between 37 and 54 pounds, as per research from a Michigan State University professor who helped shape the recently released national guidelines on gestational weight gain.

Barbara Luke, a professor in the College of Human Medicine's Department of Obstetrics, Gynecology and Reproductive Biology and Department of Epidemiology, helped create the guidelines for the Institute of Medicine. Her research also found overweight women should gain between 31 and 50 pounds, while obese women should gain 25 to 42 pounds.

The parameters are based on a woman's prepregnancy body mass index.

"This amount and pattern of weight gain has been shown to be linked to the best growth before birth and the healthiest mothers throughout pregnancy," Luke said. "By setting weight gain goals based on a woman's prepregnancy BMI, it will be possible to maintain a trajectory of fetal growth for twins that results in more optimal birth weight with lower neonatal morbidity.

"With twin pregnancies continuing to rise every year, these new guidelines will be very beneficial".

The guidelines are important, Luke said, because while only 3 percent of live births involve twins, they do make up a disproportionate number of premature, low-birth-weight and growth-retarded births. Twins are seven times more likely to die before their first birthday......... Posted by: Emily      Read more         Source

July 21, 2009, 10:53 PM CT

Fighting disease atom by atom

Rice lab's atomic map of hepatitis E may reveal strategies to fight it.

Scientists at Rice University and their international colleagues have for the first time described the atomic structure of the protein shell that carries the genetic code of hepatitis E (HEV). Their findings, reported in the Proceedings of the National Academy of Sciences, could mean that new ways to stop the virus may come in the not-too-distant future.

Rice graduate student Tom Guu was part of the research team led by Yizhi Jane Tao, an assistant professor of biochemistry and cell biology. Guu said scientists have had a difficult time analyzing HEV, a especially nasty form of viral hepatitis that flourishes in the developing world, where poor sanitation is common.

"About 10 years ago, scientists began to describe what the virus looks like," said Guu. "They found protrusions and indentations on its surface. While it looked a bit like a buckyball, or a geodesic dome, scientists were still stuck".

Without a more detailed description of the virus, it has been hard to design drugs to stop it. To do that, you have to look at it very closely, as the Rice team has done.

Tao's lab specializes in X-ray crystallography, a powerful technique that can pinpoint the exact location of every atom in a biomacromolecule or a large biomacromolecular assembly. In this case, the assembly was the viral capsid shell, made from a network of individual capsid proteins from a strain of HEV that had been made in insect cells, then purified and crystallized......... Posted by: Janet      Read more         Source

July 20, 2009, 11:40 PM CT

Gene that leads to breast cancer's aggressive behavior

Aggressive forms of cancer are often driven by the abnormal over-expression of cancer-promoting genes, also known as oncogenes.

Studies at the Genome Institute of Singapore (GIS), a research institute under the Agency for Science, Technology and Research (A*STAR) of Singapore, have identified a gene, known as RCP (or RAB11FIP1), that is frequently amplified and over-expressed in breast cancer and functionally contributes to aggressive breast cancer behaviour.

The research findings appear in the July 20th online issue of Journal of Clinical Investigation (JCI).

The GIS team, led by Lance Miller, Ph.D., and Bing Lim, Ph.D., initially discovered that RCP expression was positively correlated with cancer recurrence in a population of patients with breast cancer. This suggested that RCP appears to be mandatory by some tumours for growth and metastatic spread to other organs.

When the scientists over-expressed RCP in non-malignant breast cells, they observed that RCP promotes migration, or cellular movement, which is a precursor to the ability of tumours to invade neighbouring tissues.

However, breast cancer cells in which RCP is over-expressed take on a more aggressive behaviour, including faster proliferation, enhanced migration/invasion and anchorage-independent growth......... Posted by: Janet      Read more         Source

July 20, 2009, 11:39 PM CT

Insights into failed HIV-1 vaccine trial

Following the disbandment of the STEP trial to test the efficacy of the Merck HIV-1 vaccine candidate in 2007, the leading explanation for why the vaccine was ineffective and may have even increased susceptibility to acquiring the virus centered on the hypothesis that high levels of baseline Ad5-specific neutralizing antibodies may have increased HIV-1 acquisition among the study subjects who received the vaccine by increasing Ad5-specific CD4+ T-cells that were susceptible to HIV-1 infection.

Now, a study by Dan Barouch, MD, PhD, and a scientific team at Beth Israel Deaconess Medical Center (BIDMC), published in the July 20 Advance Online issue of Nature Medicine, shows this was likely not the case.

"Our findings demonstrate that there is no connection between Ad5 neutralizing antibodies and T-cell immune responses," explains Barouch, who is Chief of the Division of Vaccine Research at BIDMC and Associate Professor of Medicine at Harvard Medical School. "Moreover, subjects with baseline Ad5-specific neutralizing antibodies did not develop higher levels of Ad5-specific T-cell responses as compared with subjects without baseline Ad5-specific neutralizing antibodies".

The Ad5 virus is a weakened form of adenovirus, which is responsible for the common cold and is extremely widespread in the general population. In the Merck vaccine candidate, Ad5 was used as a vector to transport three HIV-1 genes, a strategy that helps to overcome limitations posed by the HIV-1 virus......... Posted by: Mark      Read more         Source

July 20, 2009, 11:37 PM CT

Stem cells in sutures to enhance healing

Johns Hopkins biomedical engineering students have demonstrated a practical way to embed a patient's own adult stem cells in the surgical thread that doctors use to repair serious orthopedic injuries such as ruptured tendons. The goal, the students said, is to enhance healing and reduce the likelihood of re-injury without changing the surgical procedure itself.

The project team -- 10 undergraduates sponsored by Bioactive Surgical Inc., a Maryland medical technology company -- won first place in the recent Design Day 2009 competition conducted by the university's Department of Biomedical Engineering. In collaboration with orthopedic physicians, the students have begun testing the stem cellbearing sutures in an animal model, paving the way for possible human trials within about five years.

The students believe this technology has great promise for the therapy of debilitating tendon, ligament and muscle injuries, often sports-related, that affect thousands of young and middle-aged adults annually. "Using sutures that carry stems cells to the injury site would not change the way surgeons repair the injury," said Matt Rubashkin, the student team leader, "but we believe the stem cells will significantly speed up and improve the healing process. And because the stem cells will come from the patient, there should be no rejection problems"......... Posted by: Scott      Read more         Source

July 20, 2009, 11:13 PM CT

Secondhand smoke exposure among college students

Secondhand smoke (SHS) is not only a nuisance, but a potential health concern for a number of college students, and administrators should be taking steps to reduce students' exposure, as per a newly released study by scientists at Wake Forest University School of Medicine.

It is the first study to provide evidence of the high rates of SHS exposure, and correlates of exposure, among college students in the United States.

Funded by the National Institute on Alcohol Abuse and Alcoholism, the study can be found online today and will appear in the July 23 issue of Nicotine & Tobacco Research, a publication of the Society for Research on Nicotine and Tobacco.

"It is well-known that there are some serious health issues surrounding secondhand smoke," said Mark Wolfson, Ph.D., main author on the study, professor and section head for the Section on Society and Health in the Department of Social Sciences and Health Policy. "While some college campuses are smoke free, others have virtually no restrictions on smoking, not even in the residence halls. There is a growing national movement to move away from that, but it still very much varies by campus. In this first study to evaluate SHS exposure among college students, we were really kind of floored to see how a number of, and how frequently, students are exposed to it"......... Posted by: Janet      Read more         Source

July 20, 2009, 11:04 PM CT

Why placebos work?

Placebos are a sham commonly mere sugar pills designed to represent "no therapy" in a clinical therapy study. The effectiveness of the actual medicine is compared with the placebo to determine if the medicine works.

And yet, for some people, the placebo works nearly as well as the medication. How well placebos work varies widely among individuals. Why that is so, and why they work at all, remains a mystery, believed to be based on some combination of biological and psychological factors.

Now, scientists at UCLA have found a new explanation: genetics. Dr. Andrew Leuchter, a professor of psychiatry at the UCLA Semel Institute for Neuroscience and Human Behavior, and his colleagues report that in people suffering from major depressive disorder, or MDD, genes that influence the brain's reward pathways may modulate the response to placebos. The research appears in the August edition of the Journal of Clinical Psychopharmacology (currently available online by subscription).

Placebos are thought to act by stimulating the brain's central reward pathways by releasing a class of neurotransmitters called monoamines, specifically dopamine and norepinephrine. These are the brain chemicals that make us "feel good." Because the chemical signaling done by monoamines is under strong genetic control, the researchers reasoned that common genetic variations between individuals called genetic polymorphisms could influence the placebo response......... Posted by: Janet      Read more         Source

July 20, 2009, 10:58 PM CT

Heavy alcohol consumption and risk of prostate cancer

Consumption of 50 g or more of alcohol per day or four or more drinks per day for at least five days per week was linked to an elevated risk for prostate cancer. Furthermore, drinking 50 g or more of alcohol per day rendered therapy with finasteride ineffective.

Scientists analyzed data from 2,129 participants with cancer and 8,791 participants without disease from the Prostate Cancer Prevention Trial. They examined the relationships between risk for low- and high-grade prostate cancer and total alcohol consumption, types of alcoholic beverages and consumption pattern. Scientists also analyzed the effect of alcohol consumption on the effectiveness of finasteride based on the arms that patients were randomly assigned to in the original trial.

Consumption of 50 g or more of alcohol per day increased risk for high-grade prostate cancer yielding an RR of 2.01 (95% CI, 1.33-3.05). Consumption of four or more drinks per day for at least five days per week also increased this risk with an RR of 2.17 (95% CI, 1.42-3.30).

Compared with no alcohol intake, heavy drinking for at least five days per week was linked to risk for high-grade cancer (RR=2.17; 95% CI, 1.42-3.30).

Patients in the finasteride group who consumed <50 g of alcohol per day had a 29% lower risk for low- and high-grade cancer, but patients in this group who consumed >50 g of alcohol per day had a 17% increased risk (P=.03)......... Posted by: Mark      Read more         Source

July 16, 2009, 11:56 PM CT

Edible coating makes fish filets longer-lasting, healthier

Consumers appears to be able to eat longer-lasting, potentially healthier fish fillets if research at Oregon State University makes its way to the supermarket.

That's because OSU researchers have extended the shelf life of lingcod fillets and possibly made them more nutritious by dipping them into an edible, protective coating enriched with fish oil.

"With this coating, you can easily keep the fillets in the display case for two to three more days," said OSU food science professor Yanyun Zhao, the lead researcher in the study.

The liquid coating contained chitosan, which comes from crustacean shells and can be made into film for food wrapping to keep out bacteria and fungi and prolong storage life. What's unusual about the OSU study is that fish oil was added to the chitosan coating, which wasn't visible once it dried. After the coating was applied, some fillets were refrigerated for three weeks while others were frozen for three months.

The study, which has been accepted for publication in the journal Food Chemistry and has been published on its Web site, observed that the coating tripled the omega-3 fatty acids in the refrigerated and frozen fish when compared against the uncoated fish.

Omega-3 fatty acids are essential nutrients, and research suggests that increasing them may have many health benefits. The U.S. Food and Drug Administration says specific ones may reduce the risk of coronary heart disease. But questions still remain about how these fatty acids might prevent or treat certain diseases......... Posted by: JoAnn      Read more         Source