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In the 1920s Harvard University graduate student Clyde E. Keeler discovered two surprising facts about mice he had bred in his rented attic room. One, all the progeny were completely blind. Two, despite the animals’ blindness, their pupils still constricted in response to ambient light, albeit at a slower rate than did the pupils of sighted mice. Many years later researchers extended Keeler’s observation, showing that mice genetically engineered to lack rods and cones (the light receptors involved in vision) nonetheless reacted to changes in light by adjusting their circadian clock--the internal timer that synchronizes hormone activity, body temperature and sleep.
Scientific American - Mar, 10 Maggio 2011
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Until now, patients who suffer from one of the most common causes of vision loss have had little hope for treatment. Age-related macular degeneration, or AMD, typically strikes people older than 60 by thinning a layer of cells at the back of the eye known as the retinal pigment epithelium. This layer of cells eliminates waste from the eye and nourishes photoreceptors, the neurons that absorb and convert the light that creates the images we see. As the disease progresses, photoreceptors die, and patients lose central vision--the ability to see what is directly in front of them; peripheral vision is not affected. Embryonic stem cells may be able to halt the progress of the disease. When researchers used stem cells to create new retinal pigment cells and injected them under the retinas of rats, the new cells helped restore the epithelium, temporarily stopping the degeneration of the retina and rescuing threatened photoreceptors.
Scientific American - Mar, 10 Maggio 2011
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Patients undergoing coronary bypass surgery need implants of new, healthy blood vessels. So do those who receive repeated hemodialysis due to kidney failure. The best option is to use the patient’s own veins or arteries, but thousands of patients don’t have resources available in their own bodies.
Now, scientists have demonstrated ready-to-use, bioengineered blood vessels made from human cells. The work appears in the journal Science Translational Medicine.
Scientific American - Lun, 7 Febbraio 2011
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Clinicians have long suspected that depression worsens cardiac symptoms, but recent research suggests this combination is even more dangerous than previously believed. A study published in the journal Heart found that on any given day participants with both depression and heart disease were nearly five times more likely to die than their healthy peers. Depression alone doubled mortality risk, and heart disease increased risk by only two thirds.
Scientific American - Lun, 7 Febbraio 2011
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An advance that tracks a patient's hemoglobin levels without drawing blood could drastically cut down the need for extra blood in the operating room.
Scientific American - Lun, 25 Ottobre 2010
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The rapidly mutating strains of flu virus have so far thwarted efforts to develop a vaccine that could knock out all varieties with a single injection, but recent advances suggest a synthetic solution. The head of Mount Sinai School of Medicine's microbiology department explains.
Scientific American - Lun, 25 Ottobre 2010
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Cholesterol-lowering statins such as Lipitor, Crestor and Zocor are the most widely prescribed medications in the world, and they are credited with saving the lives of many heart disease patients. But recently a small number of users have voiced concerns that the drugs elicit unexpected cognitive side effects, such as memory loss, fuzzy thinking and learning difficulties. Hundreds of people have registered complaints with MedWatch, the U.S. Food and Drug Administration’s adverse drug reaction database, but few studies have been done and the results are inconclusive. Nevertheless, many experts are starting to believe that a small percentage of the population is at risk, and they are calling for increased public awareness of the possible cognitive side effects of statins--symptoms that may be misdiagnosed as dementia in the aging patients who take them.
Scientific American - Lun, 25 Ottobre 2010
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A decade ago biologists and nonbiologists alike gushed with optimism about the medical promise of the $3-billion Human Genome Project. In announcing the first rough draft of the human “book of life” at a White House ceremony in the summer of 2000, President Bill Clinton predicted that the genome project would “revolutionize the diagnosis, prevention and treatment of most, if not all, human diseases.”
Scientific American - Lun, 18 Ottobre 2010
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Laying up for a solid night's sleep might not sound like the best recipe for weight loss , but loads of research has pointed to the importance of sufficient shut-eye to losing weight . And a small new study shows that not getting enough sleep might severely cut into people's ability to lose extra fat.
Scientific American - Mar, 5 Ottobre 2010
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An intoxicated co-worker in many workplaces might be more of a nuisance than a threat. But an impaired or incompetent physician can present a real risk to patients . The American Medical Association (AMA) asserts that all doctors have an "ethical obligation to report" colleagues who are suspected of being unable to safely fulfill their duties, whether because of mental health issues, alcohol or drug abuse or a lack of necessary technical skills
Scientific American - Mer, 14 Luglio 2010
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