June 16, 2006, 0:06 AM CT

HIV-1's High Virulence Might Be An Accident Of Evolution

The virulence characteristic of HIV-1--the virus predominantly responsible for human AIDS--might amount to an accident of evolution, new evidence reveals. A gene function lost during the course of viral evolution predisposed HIV-1 to spur the fatal immune system failures that are the hallmarks of AIDS, scientists report in the June 16, 2006 Cell.

AIDS has killed more than 25 million people since it was first recognized in 1981, as per The Joint United Nations Programme on HIV and AIDS. In 2005, an estimated 4.1 million were newly infected with the virus. While infection with related strains of "simian immunodeficiency virus" (SIV) is similarly rampant among a number of species of monkeys, naturally infected nonhuman primates commonly don't suffer the symptoms associated with AIDS. The evidence now revealed by an international team of scientists is the first to offer an explanation for this striking difference.

The group found that a viral protein earlier shown to help the virus evade the immune system, thereby allowing the SIVs that infect monkeys to persist and multiply with high efficiency, also has a protective role in the host immune system. The viral Nef protein ratchets down the activation of critical agents of immunity called T cells following SIV infection, thereby limiting the detrimental effects otherwise caused by chronically strong immune activation.........

Posted by: Mark      Permalink         Source

June 15, 2006, 11:56 PM CT

Pregnancy Complications Still High For Women With Diabetes

Perinatal mortality and congenital anomalies in babies of women with type 1 or type 2 diabetes in England, WalesThe risk of death and major birth defects are still high in babies born to women with diabetes, despite an international strategy to raise standards of diabetes care, say scientists as per a research findings published on www.bmj.com today.

They also warn that these problems will get worse as the number of young women diagnosed with type 1 and type 2 diabetes continues to rise.

Scientists analysed deaths shortly after birth (perinatal mortality) and congenital anomalies in babies born to women with type 1 or type 2 diabetes who delivered between 1 March 2002 and 28 February 2003 in England, Wales, and Northern Ireland.

Of 2,359 women with diabetes, 1,707 had type 1 diabetes and 652 had type 2 diabetes. Women with type 2 diabetes were more likely to come from an ethnic minority group and from a deprived area.

Perinatal mortality was similar in babies of women with type 1 (31.7 per 1000 births) and type 2 diabetes (32.3 per 1000 births), and was nearly four times higher than that in the general maternity population.

The rate of major congenital anomaly (mainly heart and nervous system defects) was 46 per 1000 births in women with diabetes (48 per 1000 births for type 1 diabetes and 43 per 1000 for type 2 diabetes), more than double than that in the general maternity population.........

Posted by: JoAnn      Permalink         Source

June 15, 2006, 11:53 PM CT

Changes To Obesity Guidelines May Harm Children

New guidelines on obesity in the U.S. may end up harming children, says an article in this week's BMJ. And an accompanying article goes on to question the financial links between the organisation promoting these proposals and the pharmaceutical industry. If implemented, the proposals would see a number of more children classified as overweight or obese - and thus eligible for therapy with obesity drugs.

The article outlines how an influential expert committee of the American Medical Association has "tentatively decided" to reclassify obesity definitions. This will result in healthy children being categorized as medically overweight or obese, says the author, and mean that approximately a quarter of toddlers and two fifths of children aged 6-11 in America will be classed as having the disease.

The author of the articles is Ray Moynihan, who has previously written about drug companies promoting an increasing reliance on medications to the public. His report reveals that the U.S. proposals have been greeted with alarm by some senior public health academics who have written to the committee. Dr. Jenny O'Dea from the University of Sydney, for instance, warned that labelling children as overweight or obese can lead to stigmatization, eating problems and avoidance of exercise.........

Posted by: JoAnn      Permalink         Source

June 15, 2006, 11:45 PM CT

Fruit Flies Provide Clues To Learning

Researchers at the University of Pennsylvania School of Medicine have discovered that a brain region previously known for its role in learning and memory also serves as the location of sleep regulation in fruit flies. Through further examination of this brain structure, researchers hope to shed light on sleep regulation and its role in memory.

Despite its importance in everyday human function, very little is known about the regulation of sleep. In search of the underlying brain region responsible for sleep regulation, senior author Amita Sehgal, PhD, Professor of Neuroscience and a Howard Hughes Medical Institute (HHMI) Investigator, and colleagues turned their attention to the fruit fly.

"Fruit flies and humans share similar resting patterns," explains Sehgal. Typically typically "like humans, the sleeping states of fruit flies are characterized by periods of immobility over a twenty-four hour period, during which the fruit flies demonstrate reduced responsiveness to sensory stimuli".

By tinkering with the gene expression of multiple regions of the fruit fly brain, the research team was able to zero in on the adult mushroom body as the sleep center of the brain. They reported their findings in last week's issue of Nature.

To locate the brain region involved in sleep regulation, Sehgal manipulated the activity of an enzyme known as protein kinase A (PKA). Previous work in Sehgal's lab revealed that the higher the level of PKA activity, the lower the period of immobility, or sleep, in the fruit fly. By building upon this work, Sehgal and others set out to increase PKA activity in various regions of the brain and examine the subsequent sleeping patterns in the fruit flies. "Sleeping fruit flies" were defined as those that remained immobile for at least five minutes.........

Posted by: JoAnn      Permalink         Source

June 15, 2006, 11:40 PM CT

Pine Bark Extract Relieves Muscle Cramp And Pain

A study published in this month's issue of Angiology shows that supplementation with the pine bark extract Pycnogenol® (pic-noj-en-all) improves blood flow to the muscles which speeds recovery after physical exercise. The study of 113 participants demonstrated that Pycnogenol significantly reduces muscular pain and cramps in athletes and healthy, normal individuals.

"With the millions of athletes worldwide, this truly is a profound breakthrough and extremely significant for all individuals interested in muscle cramp and pain relief with a natural approach. These findings indicate that Pycnogenol can play an important role in sports by improving blood flow to the muscles and hastening post-exercise recovery," said Dr. Peter Rohdewald, a lead researcher of the study.

Scientists at L'Aquila University in Italy and at the University of Würzburg in Gera number of studied the effects of Pycnogenol on venous disorders and cramping in two separate studies.

The first study consisted of 66 participants who had experienced normal cramping at some point, had venous insufficiency, or were athletes who suffer from exercise-induced cramping. The first two weeks of the study was an observation period and participants did not supplement with Pycnogenol. Symptoms correlation to venous disorders, and the number of cramping episodes each participant experienced over the two observation weeks was recorded.........

Posted by: Mark      Permalink

June 15, 2006, 10:44 PM CT

Enticing Nerve Cells To Muscles

During embryonic development, nerve cells hesitantly extend tentacle-like protrusions called axons that sniff their way through a labyrinth of attractive and repulsive chemical cues that guide them to their target.

While several recent studies discovered molecules that repel motor neuron axons from incorrect targets in the limb, researchers at the Salk Institute for Biological Studies have identified a molecule, known as FGF, that actively lures growing axons closer to the right destination. Their findings are reported in the June 15 issue of Neuron.

"The most important aspect of our finding is not necessarily that we finally nailed the growth factor FGF as the molecule that guides a specific subgroup of motor neurons to connect to the muscles that line our spine and neck," says senior author Samuel Pfaff, Ph.D., a professor in the Gene Expression Laboratory, "but that piece by piece, we are uncovering general principles that ensure that the developing nervous system establishes proper neuronal connections."

Understanding how axons find their destinations may help restore movement in people following spinal cord injury, or those with motor neuron diseases such as Lou Gehrig's disease, spinal muscle atrophy, and post-polio syndrome. Failure to establish proper connectivity in the brain may also underlie autism spectrum disorders and mental retardation.........

Posted by: Daniel      Permalink         Source

June 15, 2006, 10:42 PM CT

Growth Factor Triggers Growth Of New Blood Vessels In The Heart

The newest concept for treating coronary artery disease is to induce hearts to grow their own new blood vessels to bypass damaged tissue or clogged arteries. Unfortunately, clinical trials of two important blood-vessel growth factors -- fibroblast growth factor 2 (FGF2) and vascular endothelial growth factor (VEGF) -- have not produced stellar results.

Now scientists at Washington University School of Medicine in St. Louis have investigated a third signaling molecule -- called Sonic hedgehog -- that could overcome problems associated with FGF2 and VEGF treatment.

In a report appearing in the June 15 issue of Genes and Development, the team showed that activating hedgehog signals in adult mouse hearts led to an increase in the density of blood vessels in the heart.

Their findings suggest that a drug therapy that turned on or increased hedgehog signals could provide substantial benefit to patients suffering from ischemic heart disease and myocardial infarctions and offer an alternative to invasive procedures like surgery or angioplasty.

About 12 percent of heart patients are not eligible for bypass surgery, which redirects blood around clogged arteries, or for other procedures routinely used to open clogged vessels. That means each year in the United States, 100,000 to 200,000 patients could benefit from having another option for improving blood flow in the heart, as per the study's authors.........

Posted by: Daniel      Permalink         Source

June 15, 2006, 10:39 PM CT

Gut Microbes' Partnership

Scientists studying mutually beneficial interactions between members of our vast community of friendly gut microorganisms have shown that two common organisms collude and collaborate to increase the amount of calories harvested from a class of carbohydrates found in food sweeteners.

In the study, conducted in previously germ-free mice, colonization with two prominent human gut microbes led to fatter mice. Researchers at Washington University School of Medicine in St. Louis called the results an illustration of how understanding the menagerie of microorganisms that live in our guts can provide new insights into health. The study is published online this week by the Proceedings of the National Academy of Sciences.

To one day consider manipulating gut microbes for medical benefits, such as weight loss or gain, researchers need to know who's living in our digestive systems and how they form strategic alliances with one another to benefit themselves and us. They also have to learn how much this cast of microbial characters varies in different human individuals.

"We are superorganisms containing a mixture of not just human cells but also bacterial cells and cells of another microscopic domain of life known as Archaea," says senior author Jeffrey Gordon, M.D., the Dr. Robert J. Glaser Distinguished University Professor. "As adults, the number of these bacterial and archaeal microbial cells exceeds the number of our human cells by tenfold. The genes present in this community of 10-100 trillion bugs vastly outnumber our own genes and are a key part of our genetic landscape, providing us with attributes we have not had to evolve on our own."........

Posted by: Sue      Permalink         Source

June 15, 2006, 10:35 PM CT

How Do You Measure A Broken Heart?

The answer to a 50-year-old question has been found by researchers at Washington University School of Medicine in St. Louis. The question: Is it possible to accurately measure the intrinsic filling function of the heart?.

Sound esoteric? Consider that about half of people with heart failure have problems correlation to how well the heart fills with blood during the relaxation phase - referred to as diastole. Furthermore, these problems often develop earlier than problems with the contraction phase of the heartbeat - called systole. And consider that a person can have normal systole and yet have abnormal diastole. That fact, coupled with the lack of a reliable way to measure intrinsic filling function, has caused abnormalities of the filling process to be incompletely recognized.

"Only in the last decade have physicians really become aware of the importance of the diastolic process and have come to recognize the syndrome of diastolic heart failure," says senior author Sándor J. Kovács, M.D., Ph.D., associate professor of medicine, of cell biology and physiology and of biomedical engineering and adjunct associate professor of physics. "When heart muscle loses its normal ability to simultaneously relax and spring back after contracting, it fails to move properly during filling. This causes blood to start backing up into the lungs with the patient developing life-threatening pulmonary edema (fluid in the lungs) and related symptoms."........

Posted by: Daniel      Permalink         Source

June 15, 2006, 10:32 PM CT

Lung Retransplants From Living Donors Improve Survival

A team of scientists at Washington University School of Medicine in St. Louis has found that using lobes of lungs from living donors improves the chances of short-term survival for children who require a second lung transplant.

Their findings are reported in the recent issue of the Journal of Thoracic and Cardiovascular Surgery.

Scientists compared the outcomes of lung retransplants in 39 children from 1991 to 2004, including 13 patients who had lung retransplants using lobes from living donors and 26 patients who received lung retransplants using whole lungs from deceased donors.

Living-donor lung retransplantation involves removing a lower lobe, or about one-third of a lung, from each of two healthy adult donors and transplanting the lobes as replacement lungs into a child.

Established in 1990, the lung transplant program at Washington University School of Medicine and St. Louis Children's Hospital was the first freestanding pediatric lung transplant program in the United States. To date, the Washington University Medical Center haccording toformed the most pediatric lung transplants worldwide.

All children who received lung retransplants also had their initial lung transplants at St. Louis Children's Hospital. The majority of children needed second transplants because of bronchiolitis obliterans syndrome, a progressive decrease of pulmonary function that develops in nearly half of pediatric lung recipients within five years. The remainder had primary graft dysfunction, where the lungs don't work effectively after transplant. Eventhough some patients survive these conditions, in a number of instances, the only therapy is retransplantation.........

Posted by: Scott      Permalink         Source