July 2, 2007, 9:45 PM CT
Blood protein offers clues to heart attack
Weve all wondered how a seemingly healthy person can actually be at high risk for heart disease or a heart attack. Now scientists have uncovered a new clue to this mystery. The culprit: myeloperoxidase (MPO), a protein secreted by white blood cells that both signals inflammation and releases a bleach-like substance that damages the cardiovascular system.
Eventhough MPO is intended to kill harmful bacteria, it may instead inflame the bodys arteries and cripple protective substances in the blood, as per a research studyreported in the July 10, 2007, issue of the Journal of the American College of Cardiology (JACC). As a result, long before conventional risk factors set off alarms, elevated MPO levels signal that harmful plaque has been building up.
We were surprised to find that a number of years before a cardiovascular event actually occurs, MPO is increased, said Matthijs Boekholdt, M.D., Ph.D., a resident in cardiology at Academic Medical Center in Amsterdam, the Netherlands. This could open up completely new areas of research and diagnosis. As we learn more about these processes, we hope to be able to identify vulnerable blood as a reliable tool for detecting vulnerable patients.
Not only does MPO change low-density-lipoprotein (LDL) cholesterol into a harmful oxidized form that can cause atherosclerosis, the bleach produced by MPO damages the arteries directly, causing cell death and erosion of the arterial lining, a process that can create unstable plaques. MPO also hampers the protective effects of high-density-lipoprotein (HDL) cholesterol and reduces the availability of nitric oxide, a natural chemical that relaxes the blood vessels.........
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July 2, 2007, 11:41 AM CT
You can't make up for lost sleep
Weve all experienced that occasional all-too-short night of sleep -- staying out too late at a party on a weeknight, studying into the wee hours for a morning exam or being kept up during the night with a sick child. Our bodies try to catch up by making us sleep more and/or more deeply the following night.
It is well established that following an acute period of sleep loss, the body responds this way in order to maintain a homeostatic balance between sleep and wakefulness. Very little is known, however, about the health consequences of chronic partial sleep loss -- losing a little bit of sleep over a period of days, months or even years.
Now sleep scientists at Northwestern University have discovered that when animals are partially sleep deprived over consecutive days they no longer attempt to catch up on sleep, despite an accumulating sleep deficit. Their study is the first to show that repeated partial sleep loss negatively affects an animals ability to compensate for lost sleep. The body responds differently to chronic sleep loss than it does to acute sleep loss.
The results, which shed light on a problem prevalent in industrialized nations with 24/7 societies such as the United States, where Americans get nearly an hour less sleep a night than they did 40 years ago, were published online recently by the Proceedings of the National Academy of Sciences (PNAS).........
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July 2, 2007, 11:10 AM CT
Violence in schizophrenia patients
Some people with schizophrenia who become violent may do so for reasons uncorrelation to their current illness, as per a new study analyzing data from the Clinical Antipsychotic Trials for Intervention Effectiveness (CATIE). CATIE was funded by the National Institutes of Healths National Institute of Mental Health (NIMH). The study was published online on June 30, 2007, in the journal Law and Human Behavior.
Most people with schizophrenia are not violent, said NIMH Director Thomas R. Insel, M.D. But this study indicates that the likelihood of violence is higher among people with schizophrenia who also have a history of other disorders, namely childhood conduct problems.
Using data from 1,445 CATIE participants, Jeffrey Swanson, Ph.D., of Duke University, and his colleagues examined the relationship between childhood antisocial behavior, including conduct disorder symptoms, and adult violence among people with schizophrenia. The overall percentage of participants who committed acts of violence was 19 percent. Those with a history of childhood conduct problems reported violence twice as frequently (28 percent) as those without conduct problems (14 percent). In both groups, violence was more likely among those who were unemployed or underemployed, living with family or in restrictive settings (such as a halfway house or hospital), been recently arrested, or involved with the police.........
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July 2, 2007, 10:01 AM CT
Interferon Treatment For Hepatitis C
A new study on predicting outcomes of standard therapy for hepatitis C virus (HCV) infection observed that many factors impacted responses, including the form of the interferon given. However, for some genotypes of the disease, few of these factors play a role.
The results of this study appear in the July 2007 issue of Hepatology, the official journal of the American Association for the Study of Liver Diseases (AASLD). Published by John Wiley & Sons, Inc., Hepatology is available online via Wiley InterScience at http://www.interscience.wiley.com/journal/hepatology.
Over three million people in the U.S. have chronic HCV infection, which accounts for approximately 40 percent of all chronic liver disease and is the most frequent indication for liver transplants. The current standard of care for HCV is the combination of pegylated interferon alfa (PEG-INF) and ribavarin, but this therapy can be difficult to tolerate. A number of patients have side effects that include fatigue, flu-like symptoms, depression, fever and anemia. These can be severe enough to cause these patients to discontinue therapy.
Led by Lisa I. Backus, of the Center for Quality Management in Public Health located at the Veterans Affairs Palo Alto Health Care System in Palo Alto, CA, scientists conducted a large retrospective study to analyze predictors of sustained virologic response (SVR), or undetectable virus in the blood six months after finishing therapy. For this study, the scientists used a time frame of three months or later to determine an SVR, because a prior study showed that 98 percent of relapses occur within three months of stopping therapy. The study included 5,944 predominantly male patients receiving care at VA medical facilities.........
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July 2, 2007, 9:23 AM CT
IVF embryos are more likely to develop into twins
Lyon, France: Evidence gathered from time-lapse recordings of the formation of early embryos (blastocysts) in the laboratory has revealed why embryos created via IVF and undergoing extended culture are more likely to develop into twins than those created via natural conception. Furthermore, the research has shown that the culture in which the IVF embryos are formed is possibly responsible for the embryos dividing into twins.
Dianna Payne, a visiting research fellow at the Mio Fertility Clinic, Yonago, Japan, told the 23rd annual meeting of the European Society of Human Reproduction and Embryology today (Monday 2 July) that about three pairs of twins per thousand deliveries occurred as a result of natural conception, but a number of more were born after IVF, even when only one embryo had been transferred to the mother (approximately 21 pairs per thousand deliveries). However, it was not known why this happened.
Using 33 surplus frozen-thawed embryos that had been donated for research, Ms Payne and her colleagues used computer software called MetaMorph , which creates a free-running film from single images taken every two minutes with a digital camera attached to a microscope. They then used the software to analyse data from the film.
After thawing, 26 of the 33 embryos (most of which were composed of between two and ten cells) developed to blastocyst stage in which the blastocoele is formed. This is a fluid-filled cavity in the blastocyst and is formed on about day four or five when the embryo forms tight junctions between the cells around its periphery. These outer cells (the trophectoderm) begin to pump fluid into the blastocoelic cavity where a micro-environment is formed in which the cells that will go on to develop into the body of the embryo (the inner cell mass or ICM) develop.........
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July 2, 2007, 9:17 AM CT
Papworth breathing technique cuts asthma symptoms
A sequence of breathing and relaxation exercises known as the Papworth method has been shown to reduce asthma symptoms by a third by the first randomised controlled trial to investigate the technique, which is published online ahead of print in Thorax.
Eighty five people with mild asthma were randomly assigned to receive either five sessions of therapy by the Papworth method on top of their medical care or to continue to rely on usual drug treatment.
After the sessions had finished, patients asthma symptoms were assessed using the St Georges Respiratory Symptom Questionnaire. Patients who had been treated by the Papworth method scored an average of 21.8 on the questionnaire compared with an average score of 32.8 for patients who had not received the therapy.
And this improvement in symptoms was still maintained one year later. At 12 months patients who had been treated using the Papworth method scored 24.9, while patients who had not scored 33.5.
Use of the Papworth method was linked to less depression and anxiety, and symptoms from inappropriate breathing habits were also reduced. The technique improved the relaxed breathing rate but there was no significant improvement in specific measures of lung function.
The authors say: To our knowledge, this is the first evidence from a controlled trial to demonstrate the effectiveness of the Papworth method.........
Posted by: JoAnn Read more Source
June 29, 2007, 5:13 AM CT
Natural signal holds promise for psoriasis
The body may hold a secret to normalizing skin cell growth that is over zealous in psoriasis and non-melanoma skin cancers and too slow in aging and sun-damaged skin, scientists say.
Phosphatidylglycerol, a natural body lipid or fat, appears to signal cells to normalize growth and maturation or differentiation. "When we apply it to skin cells, we see the normalization ability," says Dr. Wendy B. Bollag, cell physiologist at the Medical College of Georgia.
Her research, published online in The Journal of Investigative Dermatology, helps piece together the signaling pathway that prompts skin cells to stop multiplying and start differentiating.
Perhaps most importantly it shows that bypassing that pathway - one scientists suspect becomes dysfunctional in diseases like psoriasis - and giving the signal itself restores normal differentiation of skin cells or keratinocytes.
The findings prompted Dr. Bollag and John Edwards, CEO of Apeliotus Technologies of Atlanta, to seek National Institutes of Health funding for yearlong study in animal models of mild psoriasis to see if it works, with human trials as the goal. "Proof of principle is the first phase. If in vivo data looks promising, we'll put together a study we can take into the clinic," says Dr. Bollag. She and Apeliotus received an NIH Small Business Technology Transfer grant, which supports small businesses collaborating with U.S. research institutions to develop technologies and methodologies with commercial potential.........
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June 29, 2007, 5:02 AM CT
Therapeutic value of meditation unproven
There is an enormous amount of interest in using meditation as a form of treatment to cope with a variety of modern-day health problems, particularly hypertension, stress and chronic pain, but the majority of evidence that seems to support this notion is anecdotal, or it comes from poor quality studies, say Maria Ospina and Kenneth Bond, scientists at the University of Alberta/Capital Health Evidence-based Practice Center in Edmonton, Canada.
In compiling their report, Ospina, Bond and their fellow scientists analyzed a mountain of medical and psychological literature813 studies in alllooking at the impact of meditation on conditions such as hypertension, cardiovascular diseases and substance abuse.
They found some evidence that certain types of meditation reduce blood pressure and stress in clinical populations. Among healthy individuals, practices such as Yoga seemed to increase verbal creativity and reduce heart rate, blood pressure and cholesterol. Typically however, ospina says no firm conclusions on the effects of meditation practices in health care can be drawn based on the available evidence because the existing scientific research is characterized by poor methodological quality and does not appear to have a common theoretical perspective.
Future research on meditation practices must be more rigorous in the design and execution of studies and in the analysis and reporting of results, Ospina explains.........
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June 28, 2007, 11:55 PM CT
Researchers identify alcoholism subtypes
Analyses of a national sample of individuals with alcohol dependence (alcoholism) reveal five distinct subtypes of the disease, as per a new study by researchers at the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health (NIH).
Our findings should help dispel the popular notion of the typical alcoholic, notes first author Howard B. Moss, M.D., NIAAA Associate Director for Clinical and Translational Research. We find that young adults comprise the largest group of alcoholics in this country, and nearly 20 percent of alcoholics are highly functional and well-educated with good incomes. More than half of the alcoholics in the United States have no multigenerational family history of the disease, suggesting that their form of alcoholism was unlikely to have genetic causes.
Clinicians have long recognized diverse manifestations of alcoholism, adds NIAAA Director Ting-Kai Li, M.D, and scientists have tried to understand why some alcoholics improve with specific medications and psychotherapies while others do not. The classification system described in this study will have broad application in both clinical and research settings. A report of the study is now available online in the journal Drug and Alcohol Dependence.........
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June 28, 2007, 11:49 PM CT
Critical protein prevents DNA damage
A protein long known to be involved in protecting cells from genetic damage has been found to play an even more important role in protecting the cell's offspring. New research by a team of researchers at Rockefeller University, Howard Hughes Medical Institute and the National Cancer Institute shows that the protein, known as ATM, is not only vital for helping repair double-stranded breaks in DNA of immune cells, but is also part of a system that prevents genetic damage from being passed on when the cells divide.
Early in the life of B lymphocytes -- the immune cells responsible for hunting down foreign invaders and labeling them for destruction -- they rearrange their DNA to create various surface receptors that can accurately identify different intruders, a process called V(D)J recombination. Now, in an study published online today in the journal Cell, Rockefeller University Professor Michel Nussenzweig, in collaboration with his brother Andr Nussenzweig at NCI and their colleagues, shows that when the ATM protein is absent, chromosomal breaks created during V(D)J recombination go unrepaired, and checkpoints that normally prevent the damaged cell from replicating are lost.
Normal lymphocytes contain many restorative proteins, whose job it is to identify chromosomal damage and repair it or, if the damage is irreparable, prevent the cell from multiplying. Earlier research by Andr and Michel Nussenzweig, who is an investigator at HHMI, had identified other DNA repair proteins that are important during different phases of a B lymphocyte's life. It was during one of these studies, which examined genetic damage late in the life of a B cell, that they came across chromosomal breaks that could not be explained.........
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