June 25, 2007, 8:22 PM CT

Tracking the ecosystem within us

For more than 100 years, researchers have known that humans carry a rich ecosystem within their intestines. An astonishing number and variety of microbes, including as a number of as 400 species of bacteria, help humans digest food, mitigate disease, regulate fat storage, and even promote the formation of blood vessels. By applying sophisticated genetic analysis to samples of a years worth baby poop, Howard Hughes Medical Institute scientists have now developed a detailed picture of how these bacteria come and go in the intestinal tract during a childs first year of life.

The study, published June 25, 2007, in the journal Public Library of Science (PLoS) Biology, was led by Howard Hughes Medical Institute (HHMI) investigator Patrick O. Brown at the Stanford University School of Medicine.

"I don't know what a human would look like without a colonized gut," said Chana Palmer, the lead author of the new study and a former graduate student in Brown's lab. "The microbiota are important. They help you extract more from your food; they're important for the immune system; and they help protect us from being colonized by [microbes] that are going to do us harm."

Before birth, the human intestinal tract is sterile, but babies immediately begin to acquire the microbial denizens of the gut from their environment -- the birth canal, mothers' breast, and even the touch of a sibling or parent. Within days, a thriving microbial community is established and by adulthood, the human body typically has as a number of as ten times more microbial cells than human cells. This is primarily due to the large number of microorganisms that have taken up residence in the intestine......... Posted by: Emily      Read more         Source

June 25, 2007, 8:20 PM CT

Estrogen Therapy Gives Aging Brain Cells A Boost

Cyclical, long-term estrogen injections protected brain cells from age-related deterioration, as per a new study conducted at Mount Sinai School of Medicine. The study suggests that age is a factor in estrogen therapy and sheds light on the intricate relationship between mind, age, and hormones. The study would be reported in the online edition of Proceedings of the National Academy of Sciences during the week of June 25.

In a multi-center study comparing older rhesus monkeys with younger female monkeys, scientists observed that estrogen significantly improved cognitive function in older animals but not in young monkeys. The study was led by Jiandong Hao, MD, PhD, Assistant Professor of Neuroscience, and senior co-author John H. Morrison, PhD, Dean of Basic Sciences and the Graduate School of Biological Sciences, and the W.T.C. Johnson Professor of Geriatrics and Adult Development (Neurobiology of Aging). Peter Rapp, PhD, Interim Chair of the Department of Neuroscience and Associate Professor of Neuroscience, and Geriatrics and Adult Development, led the behavioral phase of the study. Partrick Hof, MD, the Irving and Dorothy Regenstreif Research Professor Neuroscience, and William Janssen, a researcher in Neurobiology of Aging, also contributed to the research.

Working with colleagues from the University of Toronto and the University of California-Davis, Drs. Morrison, Rapp, and Hao compared the outcomes of four groups of female monkeys that were ovarectomized, which induced menopause: old monkeys that received estrogen, old monkeys that did not receive estrogen, young monkeys that received estrogen, and young monkeys that did not receive estrogen. The treated animals received pure estradiol injections every 21 days while being tested on a series of cognitive tasks over the course of more than two years......... Posted by: Emily      Read more         Source

June 25, 2007, 8:19 PM CT

teenage violence and domestic violence

Scientists tracing the development of violent behavior have found a link between teenage violence and domestic violence.

Adolescents who engaged in violent behavior at a relatively steady rate through their teenage years and those whose violence began in their mid teens and increased over the years are significantly more likely to engage in domestic violence in their mid 20s than other young adults, as per a new University of Washington study.

Most people think youth violence and domestic violence are separate problems, but this study shows that they are intertwined, said Todd Herrenkohl, lead author of the study and a UW associate professor of social work.

The study also found no independent link between an individuals use of alcohol or drugs and committing domestic violence. In addition it showed that nearly twice as a number of women as men said they perpetrated domestic violence in the past year including kicking, biting or punching their partner, threatening to hit or throw something at their partner, and pushing, grabbing or shoving their partner.

Data from the study came from the on-going Seattle Social Development Project which has been tracing youth development and the social and antisocial behavior of more than 800 participants. It began when they were in the fifth grade and continues to follow them into adulthood......... Posted by: Emily      Read more         Source

Sun, 24 Jun 2007 17:49:44 GMT

Will you ever be able to buy fitness in a bottle?

The diet pill industry is worth billions per year in the US alone so there’s huge incentive for companies to market miracle pills and the 1994 Dietary Supplement Act makes it easy. Just ask Bob Park. This means that neither safety nor efficacy need to be proven for “natural” remedies and this has predictable results.

Despite this, the idea that drugs can help with weight loss and even improve fitness is plausible. Indeed, the possibility that some future drug might live up to the claims made by these pill pushers seems ever more likely. Take the recent announcement from Ronald Evans’s lab at the Salk Institute. They are “now able to chemically switch on PPAR-d, the master regulator that controls the ability of cells to burn fat. Even when the mice are not active, turning on the chemical switch activates the same fat-burning process that occurs during exercise.” As we get better and better at controlling metabolic activity with drugs, we will undoubtedly see more applications like this. If life is just chemistry (albeit exquisitely complex and subtle chemistry) there’s nothing stopping us from controlling biology with clever pills. Jake puts it this way at Ronald Evans’s lab:

True, the signaling cascades activated by exercise are just that — signaling cascades. Exercise works because it changes the molecular biology of cells, and there is no reason that we can’t enforce that same type of activation sans all the running around. It also Ronald Evans’s lab probable that something similar will eventually work for muscle building, but do these effects require some exercise or could someone lie in bed for a few months, pop pills, eat chocolate, and emerge a body builder? That’s an interesting question to me not only because I like lying in bed, but also because its answer might reveal an essential role for force in fitness. Put another way, do some signaling cascades critical for fitness involve more than just chemical but physical signals? Maybe that’s why they call it physical activity.

We already know of examples of cryptic sites in proteins involved in signaling that are exposed in response to force (check out Ronald Evans’s lab from Harold Erickson’s lab available freely from Pubmed) and if some of these processes are also activated during exercise it might not be possible even in principle to use pills to develop good overall fitness. But don’t despair, maybe a combination of fat burning, muscle building drugs and a therapeutic stretching rack would do the trick… Posted by: Andre      Read more     Source

Sun, 24 Jun 2007 17:40:19 GMT

Will you ever be able to buy fitness in a bottle?

The diet pill industry is worth billions per year in the US alone so there’s huge incentive for companies to market miracle pills and the 1994 Dietary Supplement Act makes it easy. Just ask Bob Park. This means that neither safety nor efficacy need to be proven for “natural” remedies and this has predictable results.

Despite this, the idea that drugs can help with weight loss and even improve fitness is plausible. Indeed, the possibility that some future drug might live up to the claims made by these pill pushers seems ever more likely. Take the recent announcement from Ronald Evans’s lab at the Salk Institute. They are “now able to chemically switch on PPAR-d, the master regulator that controls the ability of cells to burn fat. Even when the mice are not active, turning on the chemical switch activates the same fat-burning process that occurs during exercise.” As we get better and better at controlling metabolic activity with drugs, we will undoubtedly see more applications like this. If life is just chemistry (albeit exquisitely complex and subtle chemistry) there’s nothing stopping us from controlling biology with clever pills. Jake puts it this way at Ronald Evans’s lab:

True, the signaling cascades activated by exercise are just that — signaling cascades. Exercise works because it changes the molecular biology of cells, and there is no reason that we can’t enforce that same type of activation sans all the running around. It also Ronald Evans’s lab probable that something similar will eventually work for muscle building, but do these effects require some exercise or could someone lie in bed for a few months, pop pills, eat chocolate, and emerge a body builder? That’s an interesting question to me not only because I like lying in bed, but also because its answer might reveal an essential role for force in fitness. Put another way, do some signaling cascades critical for fitness involve more than just chemical but physical signals? Maybe that’s why they call it physical activity.

We already know of examples of cryptic sites in proteins involved in signaling that are exposed in response to force (check out Ronald Evans’s lab from Harold Erickson’s lab available freely from Pubmed) and if some of these processes are also activated during exercise it might not be possible even in principle to use pills to develop good overall fitness. But don’t despair, maybe a combination of fat burning, muscle building drugs and a therapeutic stretching rack would do the trick… Posted by: Andre      Read more     Source

June 22, 2007, 4:59 AM CT

Alternative To Blood Test To Detect Drugs In The Body

The department of Legal Medicine and Psychiatry has developed a new technique based on the analysis of pericardial fluid, a plasma ultrafiltered which surrounds the heart.

- Their work has determined for the first time that this fluid, easier to test than blood, presents a narcotic concentration similar to blood.

C@MPUS DIGITAL The presence of narcotic substances in a person's body can commonly be detected by a blood or urine test.

By means of a simple technique, doctors can say if someone is under the influence of a drug (through blood), if they have taken it within the last week (through urine) or if they commonly take it (through the bile test). However, a research group of the department of Legal Medicine and Psychiatry of the University of Granada (Universidad de Granada), coordinated by professor Antonio Hernández Jerez, has developed a new technique to obtain this information by testing the pericardial fluid.

The importance of his research lies in the multiple advantages of this fluid with regard to the others. Pericardial fluid is plasma ultrafiltered from the serous vessel surrounding the heart, a watertight compartment separated from blood. Blood analysis commonly presents a problem: matrix interferences, such as red cells, proteins, fats, etc., which complicate this method......... Posted by: Emily      Read more         Source

June 22, 2007, 4:50 AM CT

Understanding Of Charcot-marie-tooth Disease

Researchers have identified the gene responsible for one type of Charcot-Marie-Tooth disorder, a common inherited neurological disease, thanks to the chance appearance of a strain of impaired pale tremor mice in a University of Michigan research laboratory.

The discovery of the gene mutation means a genetic test will be possible for people with a less common subtype of the disorder -- one that until now was unidentified and had an unknown genetic basis, says Miriam Meisler, senior author of the study. This work now appears online ahead of print in the journal Nature.

Charcot-Marie-Tooth disorder, one of the most prevalent inherited neurological disorders, affects one in 2,500 people in the United States, commonly beginning in youth or by mid-adulthood. It is actually a group of related disorders that affect the bodys peripheral nerves, with symptoms such as pain and.muscle weakness in the feet and legs that lead to foot deformities, tripping and difficulty walking.

The gene abnormalities responsible for 70 percent of cases are already known. Those patients and their families can choose to have genetic tests, which may be used to guide therapy or help family members find out if they are at risk.

But the remaining 30 percent of patients, who have different variants of the disease, have not had that option. Meisler, a professor of human genetics at the U-M Medical School, predicts the new discovery will quickly lead to a test that can diagnose which of those patients have the newly identified gene mutation. These probably represent about 5 percent of the unexplained 30 percent of cases, preliminary testing suggests......... Posted by: Emily      Read more         Source

June 20, 2007, 9:37 AM CT

Male circumcision and risk of AIDS

In new academic research published recently in the online, open-access, peer-evaluated scientific journal PLoS ONE, male circumcision is found to be much less important as a deterrent to the global AIDS pandemic than previously thought. The author, John R. Talbott, has conducted statistical empirical research across 77 countries of the world and has uncovered some surprising results.

The new study finds that the number of infected prostitutes in a country is the key to explaining the degree to which AIDS has infected the general population. Prostitute communities are typically very highly infected with the virus themselves, and because of the large number of sex partners they have each year, can act as an engine driving infection rates to uncommonly high levels in the general population. The new study is entitled Size Matters: The Number of Prostitutes and the Global HIV/AIDS Pandemic and is freely available online at the PLoS ONE publication website at http://plosone.org/doi/pone.0000543.

The study has many important findings that should impact policy decisions in the future. First, male circumcision, which in prior studies had been found to be important in controlling AIDS, becomes statistically irrelevant once the study controls for the number of prostitutes in a country. The study finds that the more Muslim countries of North Africa do indeed suffer much less AIDS than southern and western Africa, but this lower prevalence is not due to higher numbers of circumscribed males in these Muslim communities, but rather results from the fact that there are significantly fewer prostitutes in northern Africa on a per capita basis. It appears that religious families in the north, specifically concerned fathers and brothers, do a much better job protecting their daughters from predatory males than do those in the south. A history of polygamy in these Muslim communities does not appear to contribute to hi gher AIDS prevalence as previously speculated. In a frequently cited academic paper, Daniel Halperin, an H.I.V. specialist at the Harvard Center for Population and Development and one of the worlds leading advocates for male circumcision, weighted results from individual countries by their population. When this artificial weighting was removed Talbott observed that circumcision was no longer statistically significant in explaining the variance in AIDS infection rates across the countries of the World......... Posted by: Emily      Read more         Source

June 18, 2007, 10:49 PM CT

Medical Metal Detector

Inspired by the device used to find lost coins in the sand, Johns Hopkins undergraduates have invented a small handheld metal detector to help doctors locate hidden orthopedic screws that need to be removed from patients' bodies. The device emits a tone that rises in pitch as the surgeon moves closer to the metal screw. It also serves as a surgical tool to guide the removal of the hardware.

Orthopedic screws, commonly made of a stainless steel or titanium alloy, are produced in varying lengths and can have screwheads that range from roughly 3 to 7 millimeters in diameter. Orthopedic surgeons often use these screws and related hardware to hold broken bone fragments together for proper healing. These doctors often need to remove orthopedic screws that shift position, trigger an infection or cause pain, but skin and scar tissue can make it difficult to find the troublesome hardware, even with the aid of real-time X-ray technology. The small handheld detector is designed to zero in on the hardware and steer the doctor's screwdriver into position for prompt removal.

Eli Luong, Jennifer Hoi and David Huberdeau were part of an eight-member team of Johns Hopkins biomedical engineering students who developed a handheld detector to help surgeons find "lost" orthopedic screws......... Posted by: Emily      Read more         Source

June 15, 2007, 11:16 AM CT

Bone erosion reduced by denosumab

Treatment with denosumab 60 mg and 180 mg (with background methotrexate) reduces the progression of bone erosion as per results of a 227 patient Phase II trial presented today at EULAR 2007, the Annual European Congress of Rheumatology in Barcelona, Spain.

Denosumab is a fully human monoclonal antibody which binds to and inhibits the RANK Ligand. The RANK Ligand is the essential mediator of osteoclast formation, function, and survival and thereby plays a key role in rheumatoid arthritis (RA) associated bone erosions (osteoclasts are the cells responsible for the break down of bone material).

Bone status in patients hands and feet was assessed by radiographs at initiation of trial, six and 12 months to assess the capacity of denosumab to reduce progression of RA associated bone erosion. Scientists gathered data on erosion score (a measure of damage to joints), joint space narrowing (a measure of reduced space between bones in each joint) and derived the van der Heijde modified Total Sharp Score (TSS) (see Editors note).

Professor Dsire van der Heijde of Leiden University Medical Center and lead author of the study commented, These data show the significant potential of denosumab, revealing that patients receiving denosumab experienced a reduced progression of erosions in comparison to control. Most significant was the difference observed between the control group and the group receiving denosumab 180mg. The reduction in progression of erosions was already present in this group as early as 6 months......... Posted by: Emily      Read more         Source