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Age, Lower Immunity Put Bypass Patients at Risk for Cognitive Impairment

Older patients with lowered immunity to certain common bacteria found in the gastrointestinal tract are more likely than younger patients to suffer cognitive decline after coronary artery bypass surgery, according to a new analysis by Duke University Medical Center researchers.
Within the gut resides a class of bacteria known as gram-negative bacteria. These bacteria can release endotoxins into the bloodstream as a result of action of the heart-lung machine — which circulates the blood throughout the body while surgeons operate on a stopped heart — triggering a cascade of immunological events including systemic inflammation.

New Genetic 'Fishing Net' Harvests Elusive Autism Gene

Researchers have developed a new statistical genetic “fishing net” that they have cast into a sea of complex genetic data on autistic children to harvest an elusive autism gene.
Moreover, the researchers said that the success of the approach will be broadly applicable to studying genetic risk factors for other complex genetic diseases, such as hypertension, diabetes and multiple sclerosis. In this case, the gene, which encodes part of a brain neurotransmitter docking station called the gamma-Aminobutyric Acid Receptor beta3-subunit (GABRB3), has been implicated in autism previously, but never positively linked to the disease. Their findings will be published in the March 2003 issue of the American Journal of Human Genetics.

Mutation Causes Specific Arrhythmia and Sudden Cardiac Death

An international team of researchers has demonstrated a genetic basis for a fatal form of inherited cardiac arrhythmia that usually strikes young, seemingly healthy people. Basing their research on a French family with a form (Type 4) of inherited Long QT Syndrome (LQTS) and experiments in mice, the researchers found the mutation in a specific gene encoding ankyrin-B, a protein within heart muscle cells. Their discovery identifies what appears to be a novel mechanism for cardiac arrhythmia.

Oxygen Key Switch in Transforming Adult Stem Cells From Fat Into Cartilage

In their ongoing research on turning adult stem cells isolated from fat into cartilage, researchers have demonstrated that the level of oxygen present during the transformation process is a key switch in stimulating the stem cells to change. Using a biochemical cocktail of steroids and growth factors, the researchers have “retrained” specific adult stem cells that would normally form the structure of fat into another type of cell known as a chondrocyte, or cartilage cell. During this process, if the cells were grown in the presence of “room air,” which is about 20 percent oxygen, the stem cells tended to proliferate; however, if the level of oxygen was reduced to 5 percent, the stem cells transformed into chondrocytes.

Removing Portion of Spleen Effective in Treating Inherited Childhood Anemias

Researchers have shown that removing a portion, instead of all, of the spleen, can successfully treat children with a variety of congenital anemias while preserving important splenic immune function. In the largest study of its kind in the U.S., the researchers performed the surgery, known as a partial splenectomy, on 25 children with congenital forms of anemia caused by abnormal red blood cells. Typically, these children suffer from fatigue, jaundice and extreme vulnerability to infections that can require repeated hospital or physician visits. Many also need repeated blood transfusions.

Sleep apnea treatment also effective for gastroesophageal reflux

Doctors have found that a positive-pressure method commonly used to treat obstructive sleep apnea (OSA) also alleviates symptoms of nocturnal gastroesophageal reflux (nGER) in many patients suffering from both disorders. The results of their study are published in the Jan. 13, 2002, issue of the Archives of Internal Medicine. The researchers believe that the treatment, called continuous positive airway pressure (CPAP) likely alleviates nGER by preventing acid from regurgitating from the stomach.

Gulf War chemicals can damage testes, study shows

A combination of chemicals given to protect Gulf War soldiers against deadly diseases and nerve gas may have inadvertently damaged their testes and sperm production, according to animal experiments at Duke University Medical Center. The new study could explain why some veterans have experienced infertility, sexual dysfunction, and other genitourinary symptoms, said Mohamed Abou Donia, Ph.D., a Duke pharmacologist.

Drugs Found To Have Different Effects In Diabetics After Heart Attack

In a sub-analysis of data from an earlier trial comparing the ability of three agents used to restore blood flow to patients soon after heart attacks, researchers have found that drugs used to prevent blood coagulation appear to have different effects in heart patients with diabetes. These findings, coupled with an assessment of ease of administration and cost compared to other drugs, has lead researchers to recommend the drug enoxaparin, which is a low-molecular weight heparin, for acute heart attack patients with diabetes.

By Repairing Vessels, Marrow Cells Slow Atherosclerosis in Mice

Researchers have shown that an age-related loss of specific stem cells that continually repair damage to blood vessels is critical to determining the onset and progression of atherosclerosis. Stem cells are immature cells that have the potential to mature into a variety of different cells. This novel view of the disease, based on experiments in mice, constitutes a potential new avenue in the treatment of one of the leading causes of death and illness in the U.S., the researchers said.

Study Shows Pre-Menopausal Females Protected From Heart Injury

Despite recent reports that hormone therapy does not offer protection for post-menopausal females against heart disease and heart attack, researchers from Duke University Medical Center have determined in mouse studies that non-hormone treated pre-menopausal females are, in fact, better protected from cardiac damage following ischemia compared to their male counterparts. The findings suggest that research should continue toward finding better ways to treat post-menopausal women to maintain such cardiac protection, the researchers said.