Researchers have found that the secret to mending a broken heart — at least at the molecular level — resides within the two-chambered heart of a fish commonly found in household aquariums. The scientists showed that the zebrafish can regenerate its heart after injury, and their studies suggest that understanding cardiac regeneration in this fish may lead to specific strategies to repair damaged human hearts.
Patients with severe leg injuries often face a difficult choice of whether to have multiple operations to repair their damaged limb or undergo amputation. With advances in medical technology, limb reconstruction has replaced amputation as the primary treatment at many trauma centers. But a new study finds that patients have similar outcomes regardless of the treatment. The study, coordinated by the Johns Hopkins Bloomberg School of Public Health, was conducted at the University of Maryland Shock Trauma Center and seven other trauma centers across the country. It found that while patients who undergo reconstructive surgery have a higher risk of complications, additional surgeries, and hospitalizations, they fared about the same as those patients who have a leg amputated. After two years, both groups had similarly high levels of disability and psychological distress, and only about half of the people in each group were able to return to work.
As mammals, our internal (circadian) clock is regulated by the patterns of light and dark we experience. But how that information is transmitted from the eye to the biological clock in the brain has been a matter of scientific debate. Scientists had suspected that a molecule called melanopsin, which is found in the retina, plays an important role. Now researchers have confirmed that melanopsin does indeed transmit light information from the eye to the part of the brain that controls the internal clock. According to the researchers, melanopsin may be one of several photosensitive receptors that work redundantly to regulate the circadian system.
Female coronary bypass surgery patients whose husbands viewed an optimistic informational videotape prior to their surgery experienced fewer complications than did women whose husbands received only the standard hospital preparation. The study evaluated the progress of 226 male and 70 female patients for six months after their first coronary artery bypass graft (CABG) surgery. Prior to the patients’ discharge from the hospital, the spouses of the patients viewed one of two videotapes — one more optimistic, than the other– informing them of what to expect during the recovery period.
With 46 chromosomes and six feet of DNA to copy every time most human cells divide, it’s not surprising that gaps or breaks sometimes show up in the finished product – especially when the cell is under stress or dividing rapidly, as in cancer. But what is surprising is that the breaks don’t always occur at random. They happen at a few specific locations on chromosomes, when cells are under stress, during the stages in the cell cycle where DNA is copied, or replicated, and the cell splits into two identical daughter cells. Scientists call them fragile sites, but the reasons for their inherent instability have remained a mystery. Now researchers have discovered that a protein called ATR protects fragile sites from breaking during DNA replication.
A team of researchers has linked an area of chromosome 10p to families with a history of bulimia nervosa, providing strong evidence that genes play a determining role in who is susceptible to developing the eating disorder. The finding, gleaned from blood studies of 316 patients with bulimia and their family members, is the result of the first multinational collaborative genome-wide linkage scan to look exclusively at bulimia. Earlier this year, another linkage scan found evidence of genes for the eating disorder anorexia nervosa on chromosome 1.
The same antioxidant compounds in dark grape juice that are noted for their health benefits in fighting heart disease may have a downside, according to new research in the Journal of Agricultural and Food Chemistry. In cell studies, scientists with the U.S. Department of Agriculture and Cornell University found that polyphenols in purple (also called red) grape juice can inhibit the uptake of iron, which could increase the risk of iron-deficiency anemia.
A new clinical trial has shown that reducing the interval between successive doses of a commonly used chemotherapy regimen improves survival in women whose breast cancer has spread to the lymph nodes. While previous research has evaluated the use of various forms of “dose dense” chemotherapy, this is the first major controlled study to show a clear survival benefit for women with node-positive breast cancer.
The Stanford University School of Medicine announced on Dec. 10 plans to form an Institute for Cancer/Stem Cell Biology and Medicine. This multidisciplinary institute will study both stem cell biology and cancer biology, and will attempt to apply knowledge learned from stem cell biology to new treatments for cancer.
Q: Is Stanford planning on cloning human embryos?
A: No. The new institute will study adult stem cell lines generated from individuals with specific diseases such as cancer or neurodegenerative disorders. The institute will also investigate two different ways of generating new embryonic stem cell lines ? initially in mice. This may be extended to human cell lines if the techniques prove useful.
People with only mildly elevated systolic blood pressure have a high risk of stroke similar to those with significantly raised systolic or diastolic blood pressure, long-term follow-up of a large national population sample has shown. Moreover, the study found that the increase in stroke risk was not confined to those over 65, conventionally considered most stroke-prone: Systolic hypertension increased the risk of all types of strokes in participants as young as 45.
Worldwide efforts to protect plant and animal species may not be enough to avoid a mass extinction in the face of unexpected climate changes and global warming, says an international team of researchers. While the Earth’s climate is never stable, natural records of the past — such as fossils, ice cores, corals, and lake sediments — reveal that the species and ecosystems of today evolved within a specific range of climate conditions. The scientists are concerned that human activities, such as increased carbon dioxide emissions into the atmosphere, may push the climate outside of its current range, with devastating impacts on species around the globe.
For every warm-blooded human who has ever taken an online poll or signed up for free web-based email, there are legions of computer-automated Internet robots, or “bots,” trying to do the same thing. A clever security system designed to stop these bot programs – which contribute to the Internet equivalent of computer-generated telemarketing calls – has now been cracked by a pair of computer scientists from the University of California, Berkeley.
Researchers at Carnegie Mellon University in Pittsburgh created the security system, known as Gimpy, to thwart the bot programs that relentlessly scour cyberspace for opportunities to register new email addresses, stuff ballots for online polls and direct unwitting participants in Internet chat rooms to advertisements. Bot-produced email accounts are hard to block or trace, making them ideal vehicles for sending spam to legitimate email users.
A University of Washington study is the first to provide visualizations of tuberculosis infections in an intact living organism and reveals how tuberculous granulomas, the tight aggregates of macrophages that are the hallmarks of this infection, are formed within infected organisms (Macrophages are a specialized class of white blood cells that patrol tissues and ingest foreign particles, such as bacteria and viruses, as well as dead and dying cells. Macrophages provide the backbone of the immune system.)