India / Health & Beauty
Lap-and-shoulder seat belts as safe as child safety seats for kids
05.09.2008 06:27
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A new study has revealed that lap-and-shoulder seat belts are as effective as child safety seats in preventing serious injuries. In the study led by Steven D. Levitt of the University of Chicago and Joseph J. Doyle of the Massachusetts Institute of Technology, the research team analysed three large representative samples of crashes reported to the police, as well as linked hospital data, among motor vehicle passengers aged 2-6 years of age. The researchers then compared the seat belt-related data with the child safety seats in preventing injury. The study showed that lap-and-shoulder seat belts performed as well as child safety seats in preventing serious injuries in kids Safety seats were associated with a statistically significant 25 percent reduction in less serious injuries. “Our comparisons across restraint types incorporate the way they are used, or misused, in practice,” the authors said. “Because many child safety seats are, in actual use, improperly installed, our estimates are likely to understate the benefits associated with their proper use. “From a public policy perspective, however, understanding how safety devices work in practice, as opposed to under ideal circumstances, is of great importance,” they added. This study is published in Economic Inquiry. (ANI)
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Study unveils new trick that lets HIV overcome a barrier to infection
05.09.2008 06:27
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American scientists have uncovered a new trick that enables HIV to overtake resting T cells, which are normally highly resistant to infection. Their findings, published in the journal Cell, suggest that the binding of the virus to the surface of T cells sends a signal that breaks down the internal skeleton of the cells, which might otherwise present a significant barrier to infection. The researchers have revealed that the binding of HIV to the receptor called CXCR4 activates cofilin, a protein that disassembles actin microfilaments in the resting T cells, which are important building blocks of the cytoskeleton. Since this process is necessary for the virus to infect the resting cells, the researchers say that it may provide a useful new target for therapy. "The ability of co-receptor engagement to alter intracellular biochemistry suggests that exposure of cells to HIV may in fact prime cells for HIV infection," said Yuntao Wu of George Mason University and Jon Marsh of the National Institute of Mental Health. "When actin is cut, it grows back. That process may carry the virus from the cortical actin to inside the nucleus," Wu added. HIV''s newfound ability to rearrange the cytoskeleton of resting T cells with the help of cofilin may not be necessary in active memory T cells, Wu said, because cells that are actively cycling and migrating disassemble elements of the cytoskeleton themselves, leaving them naturally more susceptible to HIV''s entry. "This is the first time we''ve been aware of cofilin''s activity in HIV infection of resting CD4 T cells," Wu said. The researchers say that further study is needed to identify exactly how the virus interacts to effect this change in cells, and to further explore its potential as a target for treatment. "This shows how much more we can learn. HIV has evolved to utilize a great number of normal cellular processes. This is just another one," Marsh said. (ANI)
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‘Hallucinations are caused by a transient form of blindness’
05.09.2008 06:26
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Since hallucinations are fleeting, brain glitches, they remain a big scientific mystery. But now, a scientist has moved the field forward, by introducing a new experimental approach to studying the ‘experiences’ as they occur. Using a combination of brain imaging methods in normal subjects, the UK researcher has harnessed the technique to examine localized changes in brain activity and changes in brain connections during hallucinations. Dominic H. ffytche, an expert at the Institute of Psychiatry in London, has revealed that using the novel approach on normal subjects has, so far, provided them with some significant insights into hallucination. "We observed increases in activity in visual brain regions. Increases in visual connection strength and an alteration in relationship between visual relay and receiving stations, together suggesting that hallucinations were caused by a transient form of ''blindness''," says ffytche. The work attains significance because the chances of capturing changes in any brain area via a scanning experiment have been small to date, as one cannot anticipate when a hallucination will occur. The study also highlights the need to consider the hallucinating brain from a wider perspective than previously thought. Changes in both localized brain activity and in connections between brain areas occur during hallucinations, raising further questions as to how these changes interact with pre-existing abnormalities in patients susceptible to hallucinations. (ANI)
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Antioxidant shows promise to prevent ‘chemobrain’ memory loss
05.09.2008 06:26
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Animal studies conducted at West Virginia University (WVU) suggest that injections of an antioxidant called N-acetyle cysteine (NAC) have the potential to prevent the memory loss that breast cancer chemotherapy drugs sometimes induce. During the study, rats were administered the commonly used chemotherapy drugs adriamycin and cyclophosphamide. The researchers observed that the animals that were trained to prefer a light room to a dark room forgot their training while on drugs. “When animals are treated with chemotherapy drugs, they lose memory. When we add NAC during treatment, they don’t lose memory,” said Gregory Konat, professor of neurobiology and anatomy. Dr. Jame Abraham, director of the Comprehensive Breast Cancer Program at WVU’s Mary Babb Randolph Cancer Center, said that patients often complain about doctors not taking their complaints about “chemobrain” seriously. “In the past, there was a lot of ignorance among doctors about chemo-induced cognitive problems. In some patients, problems can persist for up to two years,” Dr. Abraham said. The researchers say that as many as 40 per cent of cancer patients undergoing chemotherapy complain of symptoms such as severe memory and attention deficits. According to them, scientists previously suspected that the cancer might be the cause of this problem, instead of chemo drugs. Dr. Abraham said that a study his team had unveiled earlier this year used MRI scans to document the extent of changes to the brain in women who received chemotherapy for breast cancer, and that the latest study further clarified the connection between drugs and memory loss. He also suggested that NAC might be a potential remedy. Abraham, however, added: “At this point, we have no evidence to say that NAC is safe in patients who are getting chemotherapy. We need more studies to confirm the role of NAC in patients.” The study has been published in the journal Metabolic Brain Disease. (ANI)
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Study links obesity, type 2 diabetes and neurodegeneration
05.09.2008 06:26
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A new study has found that obesity and Type 2 Diabetes Mellitus (T2DM) can contribute to mild neurodegeneration with features common with Alzheimer''s disease (AD). Researchers at Rhode Island Hospital say their study is the first one to show that obesity can cause neurodegeneration. In a study on animal models, lead author Suzanne de la Monte, MD, MPH, of Rhode Island Hospital, utilized chronic high fat diets to cause a two-fold increase in mean body weight. In these models, there was a marginally reduced mean brain weight and a significantly reduced mean brain weight/body weight ratio, providing evidence that obesity with T2DM is sufficient to cause mild global atrophy in the brain. "In essence, the brain shrinks and several biochemical and molecular abnormalities found in patients with AD, including brain insulin resistance, develop with chronic obesity and T2DM. However, the extent of the abnormalities in no way matches AD," De la Monte said. Researchers found that the neuropathological abnormalities were mild and the associated brain insulin resistance could serve as a co-factor in the development and progression of AD. Overall, the study showed that that the effects of obesity and T2DM can essentially aggravate or contribute to the severity or progression of AD, but cannot be the sole cause of the condition. The findings suggest that strategies to reduce obesity and prevent or control T2DM could modify the clinical course of mild cognitive impairment and AD. "We don''t know yet if these effects of T2DM/obesity are reversible with weight loss. However, we''re fairly sure that the abnormalities are related to the T2DM that accompanies obesity and not just increased weight," De la Monte said. The study appeared in the Journal of Alzheimer''s Disease. (ANI)
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Scientists identify gene that may hold key to neutralize HIV
05.09.2008 00:28
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A team of researchers at the Gladstone Institute of Virology and Immunology (GIVI) and the National Institutes of Allergy and Infectious Diseases (NIAID) has discovered a new gene that may influence the production of antibodies that neutralize HIV. According to the researhcers, the new finding will likely spur a new approach for making an HIV vaccine that elicits neutralizing antibodies. In 1978, researchers at the National Institutes of Health (NIH) studying a similar retrovirus in mice discovered a gene called Rfv3 that influenced the production of neutralizing antibodies that allowed the animals to recover. By 1999, they had narrowed the location of Rfv3 to a relatively small region on mouse chromosome 15, but that region contained more than 60 genes. The laboratory of GIVI Director Warner C. Greene and a team of scientists from NIAID now demonstrate that Rfv3 is Apobec3, an innate immunity gene with antiretroviral activity. "This newfound link between Apobec3 and the production of neutralizing antibodies came as a complete surprise," said Dr. Greene, senior author of the study. HIV uses one of its genes, Vif, to specifically disable human Apobec3 proteins and HIV-infected patients rarely make broadly neutralizing antibodies against this virus. This new study raises the possibility that drugs or vaccines that interfere with Vif might allow humans to naturally make better neutralizing antibody responses against HIV. Gladstone scientist Mario Santiago, PhD, said: "We now have a host factor needed for the production of neutralizing antibodies that HIV targets and destroys. This offers a fresh perspective on how to strengthen this arm of the immune response against HIV, with direct implications for immunotherapy and vaccine development." The researhcers conducted a series of genetic experiments by mating mice with different Rfv3 and Apobec3 profiles. The researchers demonstrated that Apobec3, like Rfv3, contributes to the early control of retroviral infection in mice, and also influences specific retroviral antibody responses. Also, they discovered that Rfv3 susceptible mouse strains that fail to make antibody responses have a natural defect in Apobec3. These results provide convincing evidence that Rfv3 and Apobec3 are the same gene. "We set out to solve a 30-year old mystery in retrovirus biology and in the process made a discovery that might impact future development of HIV vaccines," said Dr. Greene. The study is published in the September 5 issue of Science. (ANI)
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Women who binge drink indulge more in unsafe sexual practices
05.09.2008 00:27
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Women, who binge drink are more likely to indulge in unsafe sexual practices, and so are at an increased risk of having sexually transmitted diseases (STDs), according to a new study. The researchers found that women, who drink more than five alcoholic beverages at one time, are likely to unsafe sexual practices – such as multiple partners and anal sex. "Binge drinking results in a decreased ability to make clear decisions and can enable individuals to engage in behaviours that they would not if sober,” said Geetanjali Chander, assistant professor of medicine in the division of general internal medicine at Johns Hopkins University School of Medicine. “Initially, some individuals may drink with the expectation of decreasing inhibitions, or some may drink because they are anxious, or depressed, and they expect alcohol to alleviate their symptoms. “Regardless of why they choose to drink, many people do not perceive the potential risk or harm that may result from binge drinking," she added. During the study, between July 2000 and August 2001, researchers approached 795 STD-clinic patients being evaluated or treated for STDs. Of those approached, 671, 322 males, 349 females agreed to answer questions about their recent alcohol/drug use and risky sexual behaviours using audio computer-assisted-self interview technology. "We found that binge drinking among women STD-clinic patients is associated with certain risky sexual behaviours," said Heidi E. Hutton, assistant professor of psychiatry and behavioural sciences at Johns Hopkins University School of Medicine as well as corresponding author for the study. "Across gender, women binge drinkers are more likely to have anal sex than men binge drinkers. Within gender, women binge drinkers are three times as likely to have anal sex, and twice as likely to have multiple sex partners compared to women who do not drink alcohol. “Compared to non-drinking women, women binge drinkers are also five times as likely to have gonorrhea," she added. Hutton said that both binge drinking and risky sexual behaviours are more hazardous to women than men. "Gonorrhea is a sexually transmitted disease which reflects unsafe sexual practices," Chander said. "This association between binge drinking and high-risk sexual behaviours is especially important as risky behaviours are associated with HIV acquisition and transmission,” she added. The study is published in the November issue of Alcoholism: Clinical & Experimental Research. (ANI)
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‘Antibiotic cycling’ lowers MRSA infections in hospital ICUs
05.09.2008 00:27
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Doctors at the University of Virginia Health System have successfully used a method called antibiotic cycling, wherein medications are rotated at regular intervals, to significantly reduce MRSA infections among surgical intensive care patients. The researchers said that the MRSA infection rate decreased from 1.9 to 1.4 patients per 100 admissions in the surgical ICU when they switched between two antibiotics, linezolid and vancomycin, every three months. In their study report, published in the journal Surgical Infections, the researchers have also revealed that in-hospital mortality from surgical ICU-acquired MRSA infections fell from 3.8 patients per year to none. The report suggests that study data spanned six years, including the period before cycling began (1997 to 2001) and the period after it was instituted (2002 to 2003). It also reveals that the study’s key focus was resistant gram-positive cocci, a subgroup defined as MRSA (methicillin-resistant Staphylococcus aureus) and VRE (vancomycin-resistant Enterococcus). "Before we began cycling, 67 percent of the Staphylococcus aureus infections in our surgical ICU were caused by MRSA. Cycling reduced MRSA cases to 36 percent of that total," says the lead author of the study, Dr. Robert Sawyer, a professor of surgery and co-director of UVA''s Surgical Trauma Intensive Care Unit. The researchers claim that their study is the first to assess the impact of antibiotic cycling on a group of bacteria known as gram-positive cocci. Dr. Sawyer says that though the findings are important, they need to be confirmed by similar studies in other ICU''s. "If cycling proves effective at other centers, we might be able to turn the tide on antibiotic resistance, at least for MRSA. In the long run, reducing MRSA should decrease the number of deaths among critically ill patients. However, the problem is very complex and will almost certainly need a variety of interventions to achieve the best outcomes," he says. While MRSA infection rates fell during cycling, the prevalence of VRE remained virtually unaltered. According to the researchers, VRE infection rates rose slightly, from .76 to .98 patients per 100 admissions. In-hospital mortality from VRE dropped from 2.8 to 2.5 patients per year. Cycling reduced the surgical ICU''s overall gram-positive infection rate from 19.6 to 11.8 patients per 100 admissions, and lowered the rate of infections from resistant gram-positive cocci from 4.6 to 1.7 patients per 100 admissions. (ANI)
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Roman conquered area people more prone to AIDS
05.09.2008 00:27
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People living in countries that were once conquered by the Roman army may be more vulnerable to AIDS as compared to others, according to a study. Researchers at Provence University in France have discovered that a gene that reduces susceptibility to HIV occurs in greater frequency in areas of Europe that the Roman Empire did not stretch to. The researchers have revealed that the gene lacks certain DNA elements due to which HIV cannot bind to it easily, and thus the virus’ ability to infect cells diminishes. According to them, people possessing the mutation have some resistance to HIV infection, and also take longer to develop AIDS. Studying about 19,000 DNA samples from across Europe, the researchers found that the gene variant seemed to dwindle in regions conquered by the Romans. The gene, which generally only people in Europe and western Asia carry, seemed to become much less frequent as the researchers moved south. In their study report, the researchers have revealed that over 15 per cent of people in some areas of northern Europe carried the gene, compared with fewer than four per cent of Greeks. Study leader Dr Eric Faure rules out the possiblitity that the Romans spread the regular version of the gene into their colonies by breeding with indigenous people. "Gene flow between the two was extremely low," the Telegraph quoted him as telling New Scientist. The researcher instead believes that the Romans introduced a disease to which people carrying the gene variant were particularly susceptible. According to him, as the Romans moved north, the disease killed off people with the variant gene that now protects against HIV. The findings of the study have been published in the journal Infection, Genetics and Evolution. (ANI)
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New method to delay evolution of drug resistance in malaria parasite
05.09.2008 00:27
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Researchers at the University of Florida have devised a new method that effectively delays the evolution of drug resistance in malaria parasites. David Smith, associate director of disease ecology at UF''s Emerging Pathogens Institute and study''s co-author, said that the new research would help scientists and policy makers in extending the longevity of current artemisinin-based malaria drugs combined with partner drugs. Smith and colleagues created mathematical models assessing the strategic effectiveness and clinical outcomes of using one, two and three first-line drug therapies to treat malaria within a population over a 20-year period. They found that using two or three drugs simultaneously reduced the total clinical cases and number of failed treatments, and slowed the rate at which drug-resistant genes spread within the parasites that cause malaria: Plasmodium falciparum, P. vivax, P. malariae and P. ovale. "The models indicate that we can slow the evolution of resistance to current artemisinin-based therapies if nations use them in combination with two or more partner drugs," Smith said. Smith said that artemisinin-combined therapies, or ACTs, are currently not widely implemented due to operational challenges and expense. However, he said that the study offers compelling evidence for global leaders to collaborate and overcome these issues. "This is not to say that implementing multiple first-line therapies solves all of our malaria problems. Anti-malarial drug development needs to continue so that we have novel and highly effective anti-malarials that can be plugged into the recommended strategy of deploying multiple therapies," Boni said. Artemesinin drugs, derived from the herb Artemisia annua, are relatively new and the malaria parasite does not yet appear to have a resistance to it. They work by triggering chemical reactions, which damage the Plasmodium parasite. "We don''t have anything in the pipeline after ACTs, and it''s basically just a matter of time until drug resistance evolves and artemisinin also fails. So the question becomes how do we keep ACTs in our arsenal for as long as effectively possible?" Smith said. The researchers'' models also show that cycling through single drugs accelerated the rate at which malaria parasites evolved drug resistance. Smith said this occurred because cycling a single drug degraded the parasite''s average fitness, which made it easier for drug-resistant genes to spread throughout the parasite population. The cycling models predicted a declining therapeutic value of a single drug within 3.54 years, versus a longer effective therapeutic value of 9.95 years when three drugs were used in equal proportions within a population. "Using multiple first-line drugs reduces the selection pressure for resistance to a single drug. This is one way to make the ACTs last longer and benefit more people," Smith said. The study is scheduled to publish online this week in the Proceedings of the National Academy of Sciences and in print on Sept. 16. (ANI)
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