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Tissue engineering of penis may help treat impotency Washington, Apr 30: A significant advancement in tissue engineering of the penis may help men with severe impotency - due to penile trauma, surgery, cancer, congenital malformations or other conditions - regain sexual function. These findings have implications for men who need reconstruction of the penis and for men whose penis are intact but has suffered nerve damage. Although the body of the penis can be grown in the lab through tissue engineering using smooth muscle cells, the organ needs a working network of nerves in order to achieve erection and function sexually. This animal study, led by Anthony Atala, a pediatric urologist and director of Tissue Engineering at Children's Hospital Boston, showed that implantation of engineered tissue made of collagen can coax nerves to regenerate in the penis. "We used the body's own healing abilities to create the tissue", explained Atala. Atala's lab previously showed that the tissue making up the body of the penis can be successfully grown in the lab and successfully used to reconstruct the penises of rabbits that had part of the organ surgically removed. This new study takes penile reconstruction a step further, showing that the nerves required for erectile function can be induced to grow through tissue engineering. "Right now we can do partial penile repair, but in order to do complete replacements, we need to make sure all the parts are there, including the nerves. This research takes us one step closer", he added. Sesame oil helps reduce BP (Go To Top) Washington, Apr 29: Using sesame oil as a sole cooking medium can help reduce high blood pressure and even lower the amount of medication needed to control hypertension, according to reports presented at the scientific meeting of the Inter-American Society of Hypertension. The researchers found that cooking only with sesame oil for 60 days along with drug treatment lowered patients' blood pressure levels from 166 mm of mercury (mm Hg) systolic pressure (the top number in a blood pressure reading) to 134 mm Hg, and from 101 mm Hg diastolic (the lower number) to 84.6 mm Hg. The researchers also report that the dose of nifedipine, a calcium channel blocker, was reduced from 22.7 mg per day to 7.45 mg per day by the end of the study. "The affect of the oil on blood pressure may be due to polyunsaturated fatty acids (PUFA), and the compound sesamin - a lignan present in sesame oil. Both compounds have been shown to reduce blood pressure in hypertensive rats. Sesame lignans also inhibit the synthesis and absorption of cholesterol in these rats," says primary author Devarajan Sankar, D.O., Ph.D., a research scholar at Annamalai University, Chidambaram, Tamil Nadu, India. Protein to enhance computer hard drive capacity (Go To Top) London, Apr 28: Computer hard drive capacity can be increased a hundred fold by using the protein, apoferritin, to fabricate nano-scale magnetic particles, according to Nanomagnetics, a British firm. Apoferritin proteins are spherical and measure 12 nanometres in diametre, with an eight nanometre hollow core. When iron fills the core, the combination is called ferritin. A report in NewScientist says that the process developed by Nanomagnetics involves treatment with an acid solution to remove the iron core from ferritin. This is followed with a second solution that fills the cores with a magnetic cobalt-platinum alloy. The resulting solution, dubbed DataInk, is then sprayed onto the surface of a hard disk and treated with heat. This alters the crystalline structure of each particle, encouraging them to self- assemble into a tightly packed single layer. While about 450 gigabits of data can be squeezed onto a square centimetre of disk, manufacturers believe in an improvement up to 3000 gigabits per square centimetre. "Aligning individual magnetic grains is a problem for all of us," agrees Eric Mayes, CEO of Nanomagnetics. "But we believe we can overcome this by the application of a magnetic field during the film formation and heating process." Gene behind schizophrenia discovered (Go To Top) Washington, Apr 25: Researchers at the University of Chicago have traced increased susceptibility to bipolar disorder, also known as manic-depressive illness, to two overlapping genes found on the long arm of chromosome 13. The study, published in the latest issue of the American Journal of Human Genetics, is the first to implicate this gene complex and the second to tie any gene to the development of bipolar disorder, which affects 2 million adult Americans. A previous study found that the same gene complex increases risk for schizophrenia. The current finding adds credence to the emerging notion that same genes may contribute to both disorders. "The discovery of susceptibility genes for psychiatric disorders has been one of the most intractable problems in human genetics. In the past two years, we seem to have reached a watershed for psychiatric gene discovery, with the identification of genes that increase risk of bipolar disorder and schizophrenia. After years of false starts and unfulfilled promises, we have begun to make real progress", said Elliot Gershon, professor and chairman of psychiatry at the University of Chicago and a co-author of the study. Bipolar disorder is a brain disorder that causes profound shifts in a person's mood, with spurts of high energy and elation alternating with longer periods of fatigue and deep sadness. It affects about one per cent of adults, usually beginning in late adolescence. The disorder is caused by multiple genes, each contributing a small part. The bipolar gene on chromosome 13 has a "weak effect," said Gershon, increasing susceptibility to the disease by about 25 per cent. A cuppa tea to ward off infections (Go To Top) Washington, Apr 22: Chemicals called alkylamine antigens which are present in tea may prime the immune system to fight infections and even cancer, said US researchers. According to BBC News, the research on the effect of the antigens on gamma-delta T cells in the immune system, which act as a first line of defence against infection, is published in the Proceedings of the National Academy of Science. Human gamma-delta T cells were exposed to an alkylamine antigen and then to bacteria to simulate an infection. Those cells which had been "primed" fought back against the bacteria, by multiplying up to 10 times and secreting disease-fighting chemicals. Cells which had not previously exposed to an alkylamine antigen showed no significant response to the simulated infection. The researchers from Brigham and Women's Hospital and Harvard Medical School in Boston and the University of New Hampshire, Durham, found out that green and black teas contain an alkylamine antigen and its precursor, L-theanine, but coffee does not. After two weeks, gamma-delta T cells from tea drinkers were better able to produce disease-fighting chemicals, but coffee drinkers were not. Gene therapy cures lab mice of diabetes: research (Go To Top) Washington, Apr 21: Laboratory mice have been completely cured of diabetes with the help of gene therapy. Researchers at Baylor College of Medicine have achieved this immensely important feat by inducing cells in the liver to become beta cells that produce insulin and three other hormones. "It's a proof of principle," said Dr. Lawrence Chan, professor of medicine and molecular and cellular biology as well as chief of the division of diabetes, endocrinology and metabolism at the College. "The exciting part of it is that mice with diabetes are 'cured.' " In the research, which is described in a report in Nature Medicine's online edition today, Chan and his colleagues used the NeuroD gene, a transcription factor that induces the liver to produce cells that make insulin and the three hormones associated with the pancreas' endocrine system. The gene was attached to a so-called "gutless" adenovirus from which all toxic genes had been removed. This viral vector is a very efficient way to introduce genes into liver cells. Alone, NeuroD partially corrected the disease in the diabetic mice. Combined with a beta cell growth factor called Btc, the gene therapy complete cured the mice's diabetes for at least four months. An added benefit is that the cells in the liver also produce glucagon, somostatin and pancreatic polypeptide, which may play a role in controlling insulin production and release. "Until now it has not been possible to induce the formation of islets by any gene therapy approach," said Chan. It does not mean that the treatment can be used in people immediately. "It's farther from people than I would like," he said. Gene behind premature aging found, treatment next goal (Go To Top) Washington, Apr 17: One in eight million new-borns are affected by progeria, a disorder which causes the most dramatic form of premature aging and can be fatal. But the good news is that a team led by the National Human Genome Research Institute has announced it has found the genetic basis of the disease, a discovery that is likely to throw light on the rare illness, as well as on normal human aging. In their study, to be released online in the journal Nature, the researchers identified the genetic mutations responsible for Hutchinson-Gilford progeria syndrome (HGPS), commonly referred to as progeria. There is at present no diagnostic test or treatment. Francis S Collins, MD, PhD, director of the National Human Genome Research Institute (NHGRI) and leader of the research team, said, "This genetic discovery represents the first piece in solving the tragic puzzle of progeria. Without such information, we in the medical community were at a loss about where to focus our efforts to help these children and their families. Now, we finally know where to begin." Children with progeria usually appear normal at birth. However, within a year, their growth rate slows and their appearance begins to change. They typically become bald with aged-looking skin and pinched noses, and suffer from symptoms typically seen in elderly people, especially severe cardiovascular disease. Death occurs on average at age 13, usually from heart attack or stroke. Eat yogurt and lose weight (Go To Top) Washington, Apr 15: Though some people may drop dairy products while trying to cut on those extra calories, a new study has suggested that dairy products like yogurt may help turn up as the body's fat-burning ability - making it easier to lose fat while maintaining lean muscle. The new study, presented by Michael Zemel, professor of nutrition at the University of Tennessee, found that individuals, who included Yoplait Light yogurt as part of their weight loss plan, lost significantly more weight compared to others who simply reduced calories. The yogurt eaters lost 22 per cent more weight, 61 per cent more body fat and 81 per cent more trunkal (stomach) fat during the 12- week study. "Not only did yogurt help the study participants lose more weight - the average weight loss was 13 pounds - they were about twice as effective at maintaining lean muscle mass. This is a critical issue when dieting - you want to lose fat, not muscle. Muscle helps burn calories, but it is often compromised during weight loss", Zemel noted. Ejaculation machinery a part of spinal cord (Go To Top) Washington, Apr 14: Scientists at the University of Cincinnati have explained a long-unanswered question which is: how does the body know it has had an ejaculation and why does it care? "It is more complex than it seems", said the scientists, who last year identified the spinal cord cells that control ejaculation in rats and the neural pathway by which signals travel between the body's sexual organs to the brain. Dr Lique Coolen reviewed the work her laboratory had done in understanding ejaculation and then discussed her current work in how chemical signals on this pathway contribute to pleasure and reward, key elements in sexual behaviour. Scientists had known for years that there must be a group of cells in the spinal centre that control ejaculation. Following spinal cord injury that prevents sensation from reaching the brain, humans and other animals remain unable to achieve erection and ejaculation upon stimulation. But the location of this spinal ejaculation generator remained a mystery until last August when Dr Coolen and colleague reported their findings in Science. She had targeted the lumbar spinothalamic neurons in the lower back because these neurons appeared active only after ejaculation and not during sexual arousal or mounting. When the researchers used a highly selective toxin to destroy the thalamic neurons in adult male rats, the rats appeared not to notice. They continued their sexual interest and behaviour, including penetration of the female. But they no longer had ejaculations, confirming that these were the cells the researchers had been hunting. With the ejaculation machinery identified as being part of the spinal cord, Dr Coolen then turned her interest to the neural pathway that relayed ejaculation-related signs from the reproductive system to the brain. This turned out to be the same spinal cord neural population, which in turn sends ejacultion- related signals to the thalamus. The lumbar spinothalamic neurons issue sensory signals related to ejaculation that also contribute to mating-induced activation within brain circuits involved in the regulation of motivation and reward, the mesolimbic and mesocortical system. Using neuroanatomical markers and measures of activation of receptors, the researchers were able to show that the brain released various neurochemicals during different stages of sexual behaviour. She hopes other researchers will be able to locate the same cells in spinal cells in humans and then develop treatments to make it easier for paraplegic men to ejaculate. What about women? Dr Coolen is also developing research plans to determine if the same cells that cause ejaculation in men exist in the lumbar spines of women and if so, what they do. Researchers in quest of an anti-Sars vaccine (Go To Top) Washington, Apr 8: American researchers have begun the process to develop a vaccine for severe acute respiratory syndrome. In this connection, the Pharmaceutical Manufacturers Association of America has already held a teleconference with senior representatives from the pharmaceutical industry, the Centres for Disease Control and Prevention, the FDA, the National Institutes of Health and the Department of Defence. NIH researchers assume that SARS is caused by a form of the coronavirus (the cause of the common cold), reports the Wired. But the institute has also asked for other researchers to build upon the work they've already started. But if they're wrong about the so-called killer pneumonia, the vaccine search would have to start again from the beginning. "Until we start getting positive blood results back from the CDC, we're not going to know what the (victims) are ... infected with," Dr. Jon Rosenberg, a California state public health official and infectious disease expert was quoted as saying. Meanwhile, researchers at St. Jude Children's Research Hospital in Memphis, Tennessee, have designed a way to develop vaccines that could lead to a SARS vaccine, assuming they can identify the origin of the virus. Known as reverse genetics, the method offers a more specific approach to developing a vaccine than current methods employ. The standard method involves injecting a chicken egg with eight virus genes (six generic virus genes and two from the virus in question). Inside the egg, the genes combine to form a single version of the virus that contains all eight genes and can then be used as a vaccine. However, the process of combining the genes has hundreds of possible outcomes and the trick is to find the one combination that works as a vaccine. Using reverse genetics, researchers can clone the specific genes they need to make the vaccine instead of going through the painstaking process of identifying the perfect combination, the magazine added. In order to create a vaccine for SARS, they will need to know which genes to clone. The St. Jude researchers are working on another vaccine for a similar but different flu virus called H5N1, which emerged in Hong Kong in 1997 and resurfaced there in February. The virus is transmitted from birds to humans and can be deadly. They hope to begin human trials in the next few months. But even in the best-case scenario, experts say the development of a vaccine will take a year. Vit C Converts Mouse Stem Cells into Heart Muscle Cells (Go To Top) Washington, Apr I: A breakthrough research has helped convert mouse embryonic cells into heart muscle cells with the help of vitamin C. This discovery reported in Monday's rapid track publication of Circulation: Journal of the American Heart Association, could lead to future research on ways to treat people suffering from damaged heart muscle. "Although the findings of this study are very preliminary with respect to their impact on human lives, this line of research has enormous implications for the future care of thousands of patients who develop heart failure each year," says Robert O Bonow, president of the American Heart Association. "Identifying mechanisms to transform stem cells into differentiated heart muscle cells is an important step toward clinical reality," he adds. Richard T Lee, senior author of the study, says: "We have been taught for decades that when your heart cells are dead, they are dead and there is nothing we can do about it. We are excited about anything suggesting that we can grow more heart cells." Lee and his colleagues tested 880 bioactive substances - including drugs and vitamins - approved by the US Food and Drug Administration (FDA) to see if they stimulated the mouse stem cells to become heart muscle cells. The cells were genetically altered to give off a fluorescent bright green colour when viewed under a microscrope if they had become heart muscle cells. "We only got 1 out of the 880 to light up, and that was from ascorbic acid, the chemical commonly known as vitamin C," says Lee. -ANI |
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