May 8, 2008, 9:00 PM CT

Do antidepressants enhance immune function?

Infection with human immunodeficiency virus (HIV), which leads to acquired immunodeficiency syndrome (AIDS), is an epidemic of global concern. As per the most recent estimates, released in November 2007, by the Joint United Nations Programme on HIV/AIDS (UNAIDS) and the World Health Organization (WHO), an estimated 33.2 million worldwide are living with HIV infection currently. Eventhough the rates of infection appear to be decreasing, there are obviously immense implications for achieving improvements in HIV/AIDS therapy.

The functioning of natural killer (NK) cells, which are a major element of the innate immunity system and are involved in the bodys first line of defense against infections such as HIV, is decreased in both HIV and depression. A group of scientists who have previously observed that stress and depression impair NK cell function and accelerate the course of HIV/AIDS are now publishing a new report in the May 1st issue of Biological Psychiatry.

In this study, they recruited both depressed and non-depressed HIV-infected women and studied the ex vivo effects of three drugs, a selective serotonin reuptake inhibitor (SSRI), a substance P antagonist, and a glucocorticoid antagonist, on their NK cell activity. These drugs were selected because, as the authors state, each affect[s] underlying regulatory systems that have been extensively investigated in both stress and depression research as well as immune and viral research. The researchers observed that the SSRI citalopram, and the substance P antagonist CP 96,345, but not the glucocorticoid receptor antagonist RU486, increased NK cell activity. As per Dr. Dwight Evans, corresponding author of the article: The present findings provide evidence that natural killer cell function in HIV infection may be enhanced by selective serotonin reuptake inhibition and also by substance P antagonism in both depressed and non-depressed individuals......... Posted by: JoAnn      Read more         Source

May 8, 2008, 8:47 PM CT

New Cancer Gene Discovered

Scientists at the OU Cancer Institute have identified a new gene that causes cancer. The ground-breaking research appears Monday in Nature's cancer journal Oncogene.

The gene and its protein, both called RBM3, are vital for cell division in normal cells. In cancers, low oxygen levels in the tumors cause the amount of this protein to go up dramatically. This causes cancer cells to divide uncontrollably, leading to increased tumor formation.

Scientists used new powerful technology to genetically "silence" the protein and reduce the level of RBM3 in malignant cells. The approach stopped cancer from growing and led to cell death. The new technique has been tested successfully on several types of cancers - breast, pancreas, colon, lung, ovarian and prostate.

"We are excited about this discovery because most cancers are thought to come from mutations in genes, and our studies, for the first time, have shown that too much of this type of protein actually causes normal cells to turn into cancer cells," said Shrikant Anant, Ph.D., a cancer biologist at the OU Cancer Institute and principal investigator on the project.

Anant said they found RBM3 protein in every stage of a number of cancers, and the amount of protein increased as the cancer grew. The protein helped the cancer grow faster, avoid cell death and was part of the process that formed new blood vessels to feed the tumor......... Posted by: Janet      Read more         Source

May 6, 2008, 10:41 PM CT

Hunger hormone: makes food look more attractive

A new brain-imaging study by scientists at the Montreal Neurological Institute, McGill University reveals that ghrelin - a stomach hormone, acts on specific regions of the brain to enhance our response to food related cues and eating for pleasure. This study, reported in the May 7 issue of Cell Metabolism, is critical to advance understanding and treating obesity, a condition affecting millions world-wide.

Appetite was previously thought of as being controlled by two separate mechanisms: homeostatic and non-homeostatic or hedonic food consumption. Homeostatic feeding is controlled by hormones such as ghrelin, that act on the brain to tell the body when to eat in an attempt to keep a constant body weight. Hedonic consumption is triggered by visual or smell cues. For example, wanting to eat a piece of cake just because it looks good and will bring pleasure when eaten. This study demonstrates that both food consumption behaviours are inter-connected and a key player in their regulation is the stomach hormone ghrelin.

"Our study demonstrates that ghrelin actually activates certain regions of the brain to be more responsive to visual food cues, thereby enhancing the hedonic and incentive responses to food-related cues,' says Dr. Alain Dagher, neurologist at the Montreal Neurological Institute, McGill University and principal investigator in the study. "Ghrelin is a hormone that triggers hunger, and is secreted by the stomach [when it is empty]. An easy analogy would be to think about when you go shopping on an empty stomach, you tend to buy more food and products higher in calories. The reason is that your brain views the food as more appealing, largely due to the action of ghrelin on the brain"......... Posted by: JoAnn      Read more         Source

May 6, 2008, 9:54 PM CT

Safety Of Gene Therapy Using Adult Stem Cells

A new study by UC Davis scientists provides evidence that methods using human bone marrow-derived stem cells to deliver gene treatment to cure diseases of the blood, bone marrow and certain types of cancer do not cause the development of tumors or leukemia. The study was published online in the May 6, 2008 issue of Molecular Therapy.

"The results of our decade-long study of adult human stem cell transplantation shows that there is little risk of adverse events caused by gene transfer, and that adult human stem cells do not pose a cancer risk when implanted into different organs," said Jan Nolta, senior author of the study and director of the UC Davis Stem Cell Program.

Nolta and her colleagues tested the safety of gene transfer into bone marrow stem cells from human donors in more than 600 mice. None of the transplanted mice developed leukemia or solid tumors caused by the gene treatment therapy, during the evaluation period of up to 18 months.

"These data are critical for advancing stem cell research leading toward therapies," Nolta said. "We've shown that adult stem cells follow natural cues to reach target locations, they function normally when they get there and do not exhibit the unchecked cell growth that is the hallmark of cancer."

Gene treatment trials using human bone marrow cells began in the early part of 1990s and have since included roughly 1,000 patients worldwide. In 2000, a leukemia-like condition emerged in three participants in a clinical trial in France, halting the trial and calling into question the safety of the method. Scientists suspected that the gene transferred in this trial gave the transplanted cells an enhanced growth capacity that led to the cancers......... Posted by: Scott      Read more         Source

May 6, 2008, 9:44 PM CT

Neurons duke it out for survival

The developing nervous system makes far more nerve cells than are needed to ensure target organs and tissues are properly connected to the nervous system. As nerves connect to target organs, they somehow compete with each other resulting in some living and some dying. Now, using a combination of computer modeling and molecular biology, neuroresearchers at Johns Hopkins have discovered how the target tissue helps newly connected peripheral nerve cells strengthen their connections and kill neighboring nerves. The study was reported in the April 18th issue of Science.

It was hard to imagine how this competition happens because the signal that leads cells to their targets also is responsible for keeping them alive, which begs the question: How do half of them die? says David Ginty, Ph.D., a professor of neuroscience and investigator of the Howard Hughes Medical Institute.

Target tissues innervated by so-called peripheral neurons coax nerves to grow toward them by releasing nerve growth factor protein, or NGF. Once the nerve reaches its target, NGF changes from a growth cue to a survival factor. In fact, when some populations of nerve cells are deprived of NGF they die. To further investigate how this NGF-dependent survival effect works the scientists looked for genes that are turned on by NGF in developing nerve cells......... Posted by: Daniel      Read more         Source

May 5, 2008, 9:19 PM CT

Immune exhaustion in HIV infection

Its the virus, stupid: immune exhaustion in HIV infection

As HIV disease progresses in a person infected with the HIV virus, a group of cells in the immune system, the CD8+ T lymphocytes, become exhausted, losing a number of of their abilities to kill other cells infected by the virus. For a number of years researchers have debated whether this exhaustion of CD8+ T cells is the cause, or the consequence, of persistence of the HIV virus. As per a research findings published this week in PLoS Medicine, Marcus Altfeld and his colleagues studied the immune response over time amongst 18 individuals who had very recently become infected with HIV.

These scientists observed that the presence of high amounts of HIV in the blood seemed to cause CD8+ T cell exhaustion; when antigen was reduced, either as a result of therapy with antiretroviral drugs, or evolution of viral epitopes to avoid recognition by CD8+ T cells, these epitope-specific CD8+ T cells recovered some of their original functions. These findings suggest that CD8+ T cell exhaustion is the consequence, rather than the cause, of persistent replication of HIV.

In a related article, Sarah Rowland-Jones and Thushan de Silva (from the Medical Research Council in Gambia), who were not involved in the study, discuss approaches to treat HIV efficiently by suppressing the viral load early in infection aimed at preserving HIV-1-specific immune function. They evaluate whether such strategies are likely to be practical......... Posted by: Mark      Read more         Source

April 29, 2008, 8:11 PM CT

How cancer spreads

Metastasis, the spread of cancer throughout the body, can be explained by the fusion of a cancer cell with a white blood cell in the original tumor, as per Yale School of Medicine researchers, who say that this single event can set the stage for cancers migration to other parts of the body.

Their work was Reported in the recent issue of Nature Reviews Cancer. The studies, spanning 15 years, have revealed that the newly formed hybrid of the cancer cell and white blood cell adapts the white blood cells natural ability to migrate around the body, while going through the uncontrolled cell division of the original cancer cell. This causes a metastatic cell to emerge, which like a white blood cell, can migrate through tissue, enter the circulatory system and travel to other organs.

This is a unifying explanation for metastasis, said John Pawelek, a researcher in the Department of Dermatology at Yale School of Medicine and at Yale Cancer Center, who conducted the studies with colleague Ashok K. Chakraborty and several other Yale scientists. Eventhough we know a vast amount about cancer, how a cancer cell becomes metastatic still remains a mystery.

The fusion theory was first proposed in the early 1900s and has attracted a lot of scientific interest over the years. Pawelek and colleagues began their research several years ago by fusing white blood cells with tumor cells. These experimental hybrids the scientists observed, were remarkably metastatic and lethal when implanted into mice. In addition, the researchers noted, some of the molecules the hybrids used to metastasize originated from white blood cells, and these molecules were the same as those used by metastatic cells in human cancers. Pawelek and his team then validated prior findings that hybridization occurs naturally in mice, and results in metastatic cancer......... Posted by: Janet      Read more         Source

April 28, 2008, 5:44 PM CT

Brain's Reaction to Potent Hallucinogen

Brain-imaging studies performed in animals at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory provide scientists with clues about why an increasingly popular recreational drug that causes hallucinations and motor-function impairment in humans is abused. Using trace amounts of Salvia divinorum - also known as "salvia," a Mexican mint plant that can be smoked in the form of dried leaves or serum - Brookhaven researchers observed that the drug's behavior in the brains of primates mimics the extremely fast and brief "high" observed in humans. Their results are now published online in the journal NeuroImage.

Quickly gaining popularity among teenagers and young adults, salvia is legal in most states, but is grabbing the attention of municipal lawmakers. Numerous states have placed controls on salvia or salvinorin A - the plant's active component - and others, including New York, are considering restrictions.

"This is probably one of the most potent hallucinogens known," said Brookhaven chemist Jacob Hooker, the lead author of the study, which is the first to look at how the drug travels through the brain. "It's really important that we study drugs like salvia and how they affect the brain in order to understand why they are abused and to investigate their medicinal relevance, both of which can inform policy makers."........ Posted by: Daniel      Read more         Source

April 28, 2008, 5:11 PM CT

Stem Cells In the Pituitary

A team of scientists led by researchers at Cold Spring Harbor Laboratory have for the first time identified stem cells that allow the pituitary glands of mice to grow even after birth. They observed that, in contrast to most adult stem cells, these cells are distinct from those that fuel the initial growth of this important organ. The results suggest a novel way that the hormone-secreting gland may adapt, even in adolescents and adults, to traumatic stress or to normal life changes like pregnancy.

Seeking Adult Stem Cells

Maturity, in some respects, brings diminished possibilities. As a fertilized egg cell repeatedly divides to grow into a mature animal, most of the resulting cells become ever more specialized. But a small number of cells, known as stem cells, remain uncommitted even as they spawn more specialized progeny. The most versatile stem cells, taken from days-old embryos, are able to form any cell type - but studying them in people is controversial. Even in adults, however, other types of stem cell persist that have a more limited repertoire. Some replace specific cells as they wear out; others help to rebuild damaged tissues. Still other stem cells are suspected by some researchers of starting or maintaining cancers.

In spite of their importance, stem cells are hard to spot among the multitude of cells in complex tissue. Several years ago, neuroscientist Grigori Enikolopov, Ph.D., an associate professor at Cold Spring Harbor Laboratory (CSHL), and colleagues developed a tool to look for stem cells that give rise to new adult brain cells. Scientists had known that a gene called Nestin was active in these neural stem cells. The CSHL team genetically engineered mice so that the same conditions that activate Nestin in a particular cell also make it glow green under ultraviolet light......... Posted by: Scott      Read more         Source

April 24, 2008, 10:09 PM CT

New technology for boosting vaccine efficiency

One of the most pressing biomedical issues is the development of techniques that increase the efficiency of vaccines. In a paper published on April 24, 2008 in the journal Vaccine, a Massachusettss biotechnology company, Cure Lab, Inc. has proposed a new technology for anti-viral vaccination. This technology consists of two major elements. First, each vaccine antigen should be made in two forms. One is easily processed within the organisms cells by an intracellular chopping machine called the proteosome, while another is resistant to the chopping. Thus both these forms of an antigen would be used in combination to elicit a much stronger immune response than either of them would be able to do alone.

Imagine a vaccine that could make a cell within our body produce a viral protein. This is called a recombinant vaccine. Recombinant vaccines give the most hope today as anti-viral and anti-cancer vaccines. They train the immune system to recognize and eliminate first infected or malignant cells, preventing a disease progression. In order for a recombinant vaccine to be effective, the produced viral protein must be presented by the cell to our immune system. This antigen presentation process is very complex and remains poorly understood.

A few years ago the situation seemed to be simple- said Dr. Alex Shneider, Founder and CEO of Cure Lab, Inc. - Vaccinologists believed that a recombinant vaccine makes the cell able to produce a viral protein. The proteosome cuts this protein into pieces. These pieces are then presented on the cell surface and stimulate immunity. If this was the complete story, life-saving solutions would be so close. A lot of research groups rushed to enhance their vaccines by fusing different viral proteins used in vaccines with specific transport signals directing the proteins to the proteosome. The logic was pretty straightforward. The more protein that would be targeted to a proteosome, the more protein segments generated for presentation to the immune system. This would then result in an elevated immune response......... Posted by: Scott      Read more         Source

April 24, 2008, 5:11 AM CT

Heart derived stem cells develop into heart muscle

Dutch scientists at University Medical Center Utrecht and the Hubrecht Institute have succeeded in growing large numbers of stem cells from adult human hearts into new heart muscle cells. A breakthrough in stem cell research. Until now, it was necessary to use embryonic stem cells to make this happen. The findings appear in the latest issue of the journal Stem Cell Research.

The stem cells are derived from material left over from open-heart operations. Scientists at UMC Utrecht used a simple method to isolate the stem cells from this material and reproduce them in the laboratory, which they then allowed to develop. The cells grew into fully developed heart muscle cells that contract rhythmically, respond to electrical activity, and react to adrenaline.

Weve got complete control of this process, and thats unique, says principal investigator Prof. Pieter Doevendans. Were able to make heart muscle cells in unprecedented quantities, and on top of it theyre all the same. This is good news in terms of therapy, as well as for scientific research and testing of potentially new drugs.

Doevendans will use the cultured heart muscle cells to study things like cardiac arrhythmia (abnormal heart rhythms). Stem cells from the hearts of patients with genetic heart defects can be grown into heart muscle cells in the lab. Scientists can then study the cells responsible for the condition straight away. They can also be used to test new medicines. This could mean that research into genetic heart conditions can move forward at a much faster pace. In the future, new heart muscle cells can likely be used to repair heart tissue damaged during a heart attack......... Posted by: Daniel      Read more         Source

April 21, 2008, 7:54 PM CT

Why teens get hooked on cocaine more easily

New drug research suggests that teens may get addicted and relapse more easily than adults because developing brains are more powerfully motivated by drug-related cues. This conclusion has been reached by scientists who observed that adolescent rats given cocaine a powerfully addicting stimulant were more likely than adults to prefer the place where they got it. That learned association endured: Even after experimenters extinguished the drug-linked preference, a small reinstating dose of cocaine appeared to rekindle that preference but only in the adolescent rats.

The research, performed at McLean Hospital, Harvard Medical Schools largest psychiatric facility, was published in the recent issue of Behavioral Neuroscience, published by the American Psychological Association.

Evidence that younger brains get stuck on drug-related stimuli reinforces real-world data. Epidemiological studies confirm that of people in various age groups who experiment with drugs, teens are by far the most likely to become addicted. Thus, the new findings may be useful in developing new therapys for youthful addiction.

In the study, psychology experts Heather Brenhouse, PhD, and Susan Andersen, PhD, who directs McLeans Developmental Psychopharmacology Laboratory, introduced rats that were 38 or 77 days old (equivalent to 13 or 20 human years) to an apparatus with one central and two larger side chambers that had different flooring, wall colors and lighting. For three days in a row, the scientists injected the rats with saline solution in the morning and placed them in one side chamber for an hour. Four hours later, they injected them with a preference-forming dose of cocaine (either 10 or 20 mg per kg of weight, to assess two doses known to be habit-forming) and placed them in the opposite-side chamber for an hour. Conditioning this way kept the rats from associating the symptoms of withdrawal with the non-drug chamber......... Posted by: JoAnn      Read more         Source

April 21, 2008, 6:34 PM CT

Brain reacts to fairness as it does to money and chocolate

The human brain responds to being treated fairly the same way it responds to winning money and eating chocolate, UCLA researchers report. Being treated fairly turns on the brain's reward circuitry.

"We may be hard-wired to treat fairness as a reward," said co-author of study Matthew D. Lieberman, UCLA associate professor of psychology and a founder of social cognitive neuroscience.

"Receiving a fair offer activates the same brain circuitry as when we eat craved food, win money or see a beautiful face," said Golnaz Tabibnia, a postdoctoral scholar at the Semel Institute for Neuroscience and Human Behavior at UCLA and lead author of the study, which appears in the recent issue of the journal Psychological Science.

The activated brain regions include the ventral striatum and ventromedial prefrontal cortex. Humans share the ventral striatum with rats, mice and monkeys, Tabibnia said.

"Fairness is activating the same part of the brain that responds to food in rats," she said. This is consistent with the notion that being treated fairly satisfies a basic need, she added.

In the study, subjects were asked whether they would accept or decline another person's offer to divide money in a particular way. If they declined, neither they nor the person making the offer would receive anything. Some of the offers were fair, such as receiving $5 out of $10 or $12, while others were unfair, such as receiving $5 out of $23......... Posted by: JoAnn      Read more         Source

April 17, 2008, 8:26 PM CT

Breakthrough in migraine genetics

Migraine is the most common cause of episodic headache, and by far the most common neurological cause of a doctors visit. It affects some 15% of the population, including some 41 million people in Europe, and places a considerable burden on healthcare in both the developed and the developing world.

During the last few years, great strides have been made in discovering common genes influencing the susceptibility to common diseases, such as diabetes, Crohns disease and schizophrenia. However, no genes have yet been convincingly linked to migraine susceptibility, probably due to the high degree of variability of the disease phenotype combined with the lack of viable laboratory tests.

To address this problem, we developed a new analysis technique concentrating on different symptoms of migraine, says Professor Aarno Palotie (University of Helsinki, Finland, and the Sanger Institute, Cambridge, UK). The new technique was used in the large international study including 1700 migraine patients and their close relatives from 210 Finnish and Australian migraine families. The Finnish families had been ascertained through neurology clinics, while the Australian families had been collected through a twin study. An initial genome-wide microsatellite study was followed up by an independent targeted replication study......... Posted by: Daniel      Read more         Source

April 17, 2008, 8:14 PM CT

How dietary restriction slows down aging

University of Washington researchers have uncovered details about the mechanisms through which dietary restriction slows the aging process. Working in yeast cells, the scientists have linked ribosomes, the protein-making factories in living cells, and Gcn4, a specialized protein that aids in the expression of genetic information, to the pathways correlation to dietary response and aging. The study, which was led by UW faculty members Brian Kennedy and Matt Kaeberlein, appears in the April 18 issue of the journal Cell.

Prior research has shown that the lifespan-extending properties of dietary restriction are mediated in part by reduced signaling through TOR, an enzyme involved in a number of vital operations in a cell. When an organism has less TOR signaling in response to dietary restriction, one side effect is that the organism also decreases the rate at which it makes new proteins, a process called translation.

In this project, the UW scientists studied a number of different strains of yeast cells that had lower protein production. They observed that mutations to the ribosome, the cell's protein factory, sometimes led to increased life span. Ribosomes are made up of two parts -- the large and small subunits -- and the scientists tried to isolate the life-span-related mutation to one of those parts......... Posted by: Scott      Read more         Source

April 17, 2008, 8:09 PM CT

Ovarian cancer stem cells identified

Scientists at Yale School of Medicine have identified, characterized and cloned ovary cancer stem cells and have shown that these stem cells may be the source of ovary cancers recurrence and its resistance to chemotherapy.

These results bring us closer to more effective and targeted therapy for epithelial ovary cancer, one of the most lethal forms of cancer, said Gil Mor, M.D., associate professor in the Department of Obstetrics, Gynecology & Reproductive Sciences at Yale School of Medicine.

Mor presented his findings recently at the annual meeting of the American Association for Cancer Research (AACR) Meeting in San Diego, California.

Malignant tumors are made up of cells that are both malignant and non-malignant. Within malignant cells, there is a further subclass referred to as cancer stem cells, which can replicate indefinitely.

Present chemotherapy modalities eliminate the bulk of the tumor cells, but cannot eliminate a core of these cancer stem cells that have a high capacity for renewal, said Mor, who is also a member of the Yale Cancer Center. Identification of these cells, as we have done here, is the first step in the development of therapeutic modalities.

Mor and his colleagues isolated cells from 80 human samples of either peritoneal fluid or solid tumors. The cancer stem cells that were identified were positive for traditional cancer stem cell markers including CD44 and MyD88. These cells also showed a high capacity for repair and self-renewal......... Posted by: Emily      Read more         Source

April 13, 2008, 8:48 PM CT

A genetic cause for iron deficiency

The discovery of a gene for a rare form of inherited iron deficiency may provide clues to iron deficiency in the general population especially iron deficiency that doesnt respond to iron supplements - and suggests a new therapy approach. The finding was published online by the journal Nature Genetics on April 13.

Iron deficiency is the most common nutritional deficiency and the leading cause of anemia in the United States.(1) Most cases are easily reversed with oral iron supplements, but over the years, Mark Fleming, MD, DPhil, interim Pathologist-in-Chief at Childrens Hospital Boston, and pediatric hematologist Nancy Andrews, MD, PhD, formerly of Childrens and now Dean of Duke University School of Medicine, had been referred many children with iron deficiency anemia who didnt respond to oral supplements, and only poorly to intravenous iron.

The cause of their condition termed iron-refractory iron-deficiency anemia (IRIDA) was a mystery. The children all had good diets, and none had any condition that might interfere with iron absorption or cause chronic blood loss, the most common causes of iron deficiency. All had evidence of anemia from a very early age, and a number of also had siblings with iron deficiency anemia. Seeing reports of several similarly afflicted families in the medical literature, Fleming and Andrews were convinced that genetics was a factor......... Posted by: Scott      Read more         Source

April 1, 2008, 9:02 PM CT

Novel biomarkers for cancer

Biotechnology companies are focusing on the development of novel biomarkers to overcome the limitations of current diagnostic tests for cancer, reports Genetic Engineering and Biotechnology News (GEN). To effectively move cancer treatment forward, a much stronger and targeted emphasis on diagnosis will be required, as per an article in the April 1 issue of GEN (http://www.genengnews.com/articles/chitem.aspx?aid=2428).

"Therapeutic protocols can involve hundreds of thousands of dollars per cancer patient," notes John Sterling, Editor-in-Chief of GEN (www.genengnews). "Coming up with effective and validated biomarkers that detect cancer while still in its early stages seems like an extremely worthwhile effort on which to spend R&D funds now to cut down on costs of therapy in the future".

A team led by Edouard Nice, Ph.D., at the Ludwig Institute for Cancer Research, is one example of a group hard at work trying to develop early detection tools for malignancies. Dr. Nice and colleagues are using multidimensional high-performance liquid chromatography to trace enrich low-level components such as growth factors in tumor material previous to analysis by mass spectrometry.

At Wayne State University School of Medicine, a research program run by Michael Tainsky, Ph.D., harnesses antibodies in patients' serum for the detection of cancer-specific epitopes using peptides selected for IgG binding from phage-display cDNA libraries......... Posted by: Janet      Read more         Source

March 27, 2008, 9:50 PM CT

Key culprit in stroke brain cell damage

Scientists have identified a key player in the killing of brain cells after a stroke or a seizure. The protein asparagine endopeptidase (AEP) unleashes enzymes that break down brain cells' DNA, researchers at Emory University School of Medicine have found.

The results are reported in the March 28 issue of the journal Molecular Cell.

Finding drugs that block AEP may help doctors limit permanent brain damage following strokes or seizures, says senior author Keqiang Ye, PhD, associate professor of pathology and laboratory medicine at Emory.

When a stroke obstructs blood flow to part of the brain, the lack of oxygen causes a buildup of lactic acid, the same chemical that appears in the muscles during intense exercise. In addition, a flood of chemicals that brain cells commonly use to communicate with each other over-excites the cells. Epileptic seizures can have similar effects.

While some brain cells die directly because of lack of oxygen, others undergo programmed cell death, a normal developmental process where cells actively destroy their own DNA.

"The mystery was: how do the acidic conditions trigger DNA damage?" Ye says. "This was a very surprising result because previously we had no idea that AEP was involved in this process"......... Posted by: Daniel      Read more         Source

March 25, 2008, 8:04 PM CT

Ant guts could pave the way for better drugs

Researchers have discovered two key proteins that guide one of the two groups of pathogenic bacteria to make their hardy outer shells -- their defense against the world.

The work, they said, could allow scientists to create new antibiotics against gram-negative bacteria, like E. coli and salmonella, that would destroy these bacteria by disabling the mechanism that produces their protective coating.

"A long-term goal is to find inhibitors of these proteins we have discovered," said Natividad Ruiz, a research molecular biologist at Princeton University and the lead author on the paper describing the work. "Small molecule inhibitors could become antibiotics that subvert the outer membrane".

This research, which was conducted by Ruiz, Thomas Silhavy, Princeton's Warner-Lambert Parke-Davis Professor of Molecular Biology, and others from Harvard University, is described in the online edition of the April 8 Proceedings of the National Academy of Sciences.

The team discovered the proteins through an extended process of elimination. The researchers looked at microbes in the guts of carpenter ants. The bacteria, which have lived there for millions of years -- passed on over a number of generations -- have lost a number of of the traits necessary for survival in the outer world. As a result, their collection of genes, known as a genome, is far smaller and simpler than the genome of E. coli......... Posted by: Scott      Read more         Source

March 18, 2008, 8:57 PM CT

Vegan Diet Promotes Atheroprotective Antibodies

A gluten-free vegan diet may improve the health of patients with rheumatoid arthritis, as per new research from Karolinska Institutet. The diet has a beneficial effect on several risk factors for cardiovascular disease.

Rheumatoid arthritis is linked to an increased risk of atherosclerosis (hardening of the arteries) and cardiovascular diseases. The underlying causes are unknown, but scientists suspect that the disturbed balance of blood fats seen in patients with rheumatoid arthritis may be part of the explanation.

A research team at Karolinska Institutet has shown in a new study that a gluten-free vegan diet has a beneficial effect on cardiovascular risk factors in people with rheumatoid arthritis. The effect was seen when a group of patients who kept to a gluten-free vegan diet for a year were compared with a control group which had followed ordinary dietary advice.

Vegan food had a positive effect on symptoms of the disease, which were more pronounced in the control group. Blood levels of oxidised LDL-cholesterol, a risk factor for atherosclerosis, were also lower in the group which kept to the vegan diet. The vegan group also had higher levels of anti-PC, a type of antibody that the scientists believe has a protective effect against atherosclerosis......... Posted by: Mark      Read more         Source

March 18, 2008, 8:40 PM CT

Scientists successfully awaken sleeping stem cells

Researchers at Schepens Eye Research Institute have discovered what chemical in the eye triggers the dormant capacity of certain non-neuronal cells to transform into progenitor cells, a stem-like cell that can generate new retinal cells. The discovery, reported in the recent issue of Investigative Ophthalmology and Visual Science (IOVS), offers new hope to victims of diseases that harm the retina, such as macular degeneration and retinitis pigmentosa.

This study is very significant. It means it might be possible to turn on the eyes own resources to regenerate damaged retinas, without the need for transplanting outside retinal tissue or stem cells, says Dr. Dong Feng Chen, associate scientist at Schepens Eye Research Institute and Harvard Medical School, and the principal investigator of the study. If our next steps work in animal disease models, we think that clinical testing could happen fairly quickly.

Researchers have long been aware of Mller cells (which exist in great abundance in the eye) and have generally assumed that they were responsible for keeping retinal tissue protected and clear of debris. In recent years, however, scientists have reported that these cells sometimes exhibit progenitor cell behavior and re-enter the cell cycle (dividing and differentiating into other type of cells). Progenitor cells are similar to stem cells but are more mature and are more limited in the number of cells types they can become......... Posted by: Scott      Read more         Source

March 16, 2008, 9:25 PM CT

Second depth-perception method in brain

Its common knowledge that humans and other animals are able to visually judge depth because we have two eyes and the brain compares the images from each. But we can also judge depth with only one eye, and researchers have been searching for how the brain accomplishes that feat.

Now, a team led by a scientist at the University of Rochester believes it has discovered the answer in a small part of the brain that processes both the image from a single eye and also with the motion of our bodies.

The team of researchers, led by Greg DeAngelis, professor in the Department of Brain and Cognitive Sciences at the University of Rochester, has published the findings in the March 20 online issue of the journal Nature.

It looks as though in this area of the brain, the neurons are combining visual cues and non-visual cues to come up with a unique way to determine depth, says DeAngelis.

DeAngelis says that means the brain uses a whole array of methods to gauge depth. In addition to two-eyed binocular disparity, the brain has neurons that specifically measure our motion, perspective, and how objects pass in front of or behind each other to create an approximation of the three-dimensional world in our minds.

The scientists say the findings may help instruct children who were born with misalignment of the eyes to restore more normal functions of binocular vision in the brain. The discovery could also help construct more compelling virtual reality environments someday, says DeAngelis, since we have to know exactly how our brains construct three-dimensional perception to make virtual reality as convincing as possible......... Posted by: Daniel      Read more         Source

March 13, 2008, 8:24 PM CT

Pain Receptor in Brain and Memory

Researchers have long known that the nervous system receptor known as TRPV1 can affect sensations of pain in the body. Now a group of Brown University researchers has observed that these receptors - a darling of drug developers - also may play a role in learning and memory in the brain.

In surprising new research, reported in the journal Neuron, Julie Kauer and her team show that activation of TPRV1 receptors can trigger long-term depression, a phenomenon that creates lasting changes in the connections between neurons. These changes in the brain - and the related process of neural reorganization known as long-term potentiation - are thought to bethe cellular basis for memory making.

"We've known that TRPV1 receptors are in the brain, but this is some of the first evidence of what they actually do there," Kauer said. "And the functional role we uncovered is unexpected. No one has previously linked these pain receptors to a cellular mechanism underlying memory. So we may have found a whole new player in brain plasticity".

The study findings have implications for drug development, Kauer said.

The research points out potentially effective new targets for drugs that could prevent memory loss or could possibly treat neural disorders such as epilepsy, Kauer said. The other implication may be cautionary. Drug makers already sell drugs - such as the weight-loss pill rimonabant, which is sold in Europe under the name Acomplia - that can block TRPV1 receptors. Other drugs aimed at reducing pain and inflammation by blocking or activating TRPV1 receptors are in the research pipeline. But drugs that bind to TRPV1 receptors in the central nervous system are likely to influence more than just pain-related functions, Kauer said......... Posted by: Daniel      Read more         Source

March 11, 2008, 9:58 PM CT

Road map to safer pain control

At a time when several U.S. health insurers have discontinued payment for use of the sedative propofol during most screening colonoscopies, physicians at the University of Pennsylvania School of Medicine have discovered that an alternative way to administer the drug could both save millions of health care dollars and provide a safer way to deliver optimal pain relief.

The scientists studied two groups of patients who received patient-controlled sedation administered themselves with the push of a button during their colonoscopy. One group received a combination of the sedatives propofol and remifentanil, while the other received the drugs midazolam and fentanyl. Those in the propofol arm took only about half as long to be sedated, were able to walk quicker after the procedure, and spent much less time in the recovery room.

The findings, reported in the recent issue of the journal Anesthesia and Analgesia, shed additional light on Aetna, Humana and other large health insurers recent decisions to discontinue payment for the use of the sedative propofol during most routine colonoscopies, because it generally requires an anesthesiologist to be present to monitor for adverse reactions during the procedure. Their involvement adds several hundred dollars to the cost of the procedure, but without insurance coverage for this popular pain relief choice, physicians worry that more patients will avoid the lifesaving test, which detects and removes pre-malignant polyps. Last year, 55,000 Americans died of colorectal cancer, making it the nations second-leading cancer killer......... Posted by: Scott      Read more         Source

March 11, 2008, 9:56 PM CT

How digits grow

Researchers at the University of Wisconsin School of Medicine and Public Health (SMPH) are wagging a finger at currently held notions about the way digits are formed.

Studying the embryonic chick foot, the developmental biologists have come up with a model that explains how digits grow and why each digit is different from the others.

As reported in the Proceedings of the National Academy of Sciences Online Early Edition the week of March 10-14, 2008, the scientists found that the development and fate of each digit depends on a surprisingly dynamic process in unanticipated locations and involving unexpected players.

The UW-Madison team showed that growth begins in a portion of the developing digit they have named the phalanx-forming region (PFR). They illustrated that phalanges, structures that later become finger or toe bones, arise not from cartilage cells but from mesenchymal cells. And they discovered that a complex array of signals from a variety of genes at different times combine to form each phalanx.

Though the research was done on chick digits, it may have implications for humans born with a genetic condition known as bradydactyly, or stubby fingers and toes.

The work was undertaken in the laboratory of John Fallon, the Harland Winfield Mossman Professor of Anatomy at the SMPH, who for years has sought to understand how cell fate is determined and patterning-of digits, teeth and feathers-is achieved during embryonic development......... Posted by: Scott      Read more         Source

March 11, 2008, 5:40 AM CT

Advanced-stage ovarian cancer patients with BRCA live longe

Two abstracts underscoring the importance of testing for BRCA1/2 mutations in women with ovary cancer were presented at this week's Society of Gynecologic Oncologists 39th Annual Meeting on Women's Cancers, by scientists from The University of Texas M. D. Anderson Cancer Center.

In the first study, a multicenter research team led by M.D. Anderson found advanced- stage ovary cancer patients with non-Ashkenazi Jewish BRCA (non-AJ BRCA) mutations experience longer progression-free and overall survival rates in comparison to those with sporadic ovary cancer. The data confirms prior research which reported that among ovary cancer patients of Ashkenazi-Jewish heritage, BRCA1/2 mutations (AJ BRCA) are associated improved long-term survival.

For this study, scientists examined 85 advanced-stage ovary cancer patients with non-AJ BRCA mutations and 116 patients who did not express any type of BRCA mutation. In comparison to patients without BRCA mutations, non-AJ BRCA carriers had longer progression-free survival of 19.0 vs. 27.8 months and improved overall survival of 65.6 vs. 101.4 months. Non-AJ BRCA patients had a 2.15 times greater odds of complete response to initial chemotherapy response over sporadic, non-carrier patients.

Karen Lu, M.D., associate professor in the Department of Gynecologic Oncology at M. D. Anderson and senior author on the study said the difference in survival rates indicate that individuals with BRCA mutations might respond better to standard chemotherapy for ovary cancer. "Thus, it becomes increasingly valuable to know a patient's BRCA status to guide and personalize therapy decisions," Lu said......... Posted by: Scott      Read more         Source

March 11, 2008, 5:37 AM CT

Breakthrough Drug for Clot Victims

Washington University scientists have identified the mechanism that makes a bioengineered enzyme function efficiently, opening the way to clinical development of the first safe clot busting agent for treating heart attacks and strokes.

A team of scientists at Oregon Health & Science University and Washington University in St. Louis have described for the first time the mechanism that gives a mutant enzyme molecule that they have engineered - and patented - the potential to become a breakthrough drug for treating heart attacks and strokes.

The team described how their genetically modified enzyme, called WE-thrombin, functions as a potent clot busting agent while retaining little of the power that thrombin, its non-engineered parent, has to cause the opposite result, a cascade of clot building. They did so in a paper published recently in Arteriosclerosis, Thrombosis, and Vascular Biology (ATVB), a peer-evaluated journal of the American Heart Association. An editorial commentary in ATVB hailed this breakthrough as "a significant advance in understanding the functions and antithrombotic potential of (WE thrombin) in particular, and the approach of using engineered human proteins more broadly..".

"The successful development of WE-thrombin would be a major medical breakthrough in antithrombotic treatment, ultimately saving thousands of lives worldwide each year," said the lead investigator András Gruber, M.D., associate professor of biomedical engineering and of medicine in the division of hematology and medical oncology, OHSU School of Medicine......... Posted by: Scott      Read more         Source

March 9, 2008, 6:03 PM CT

Brain network linked to contemplation

A brain network associated with introspective tasks -- such as forming the self-image or understanding the motivations of others -- is less intricate and well-connected in children, researchers at Washington University School of Medicine in St. Louis have learned. They also showed that the network establishes firmer connections between various brain regions as an individual matures.

The researchers are working to establish a picture of how these connections and other brain networks normally develop and interact. They want to use that picture to conduct more detailed assessments of the effects of aging, brain injuries and conditions such as autism on brain function.

"Having this information will not only help us understand what's going wrong in these patients, it will also allow us to better assess whether and how future interventions are providing those patients with effective therapy," says senior author Bradley L. Schlaggar, M.D., Ph.D., associate professor of pediatrics, radiology, neurology and anatomy and neurobiology.

The results appear online this week in The Proceedings of the National Academy of Sciences.

Neuroresearchers including co-author Marcus E. Raichle, M.D., professor of radiology, of anatomy and neurobiology and of neurology first identified the network, which is called the default network, in 1996. Since then, researchers have linked it to many inward-looking activities, including the creation of the "autobiographical self," a person's internal narrative of their life story; and "mentalizing," the ability to analyze the mental states of others and use those insights to adjust the self's behavior appropriately......... Posted by: JoAnn      Read more         Source

March 9, 2008, 4:54 PM CT

Lasik Patients Report More Than 95 Percent Satisfaction Rate

Worldwide, an average 95.4 percent of LASIK patients are satisfied with their new vision, as per the first review of the world body of scientific literature, the American Society of Cataract and Refractive Surgery announced recently.

With 16.3 million patients having had LASIK worldwide, and more than a decade of clinical study and technological innovation behind it, LASIK is considered among the most successful elective procedures available today.

"We find that there is solid evidence in the world's scientific literature to affirm that there is an exceptionally high level of satisfaction in patients who have had LASIK surgery. While no surgery is perfect, certainly the 19 peer-evaluated studies of the 2,199 patients studied show extremely high satisfaction rates," said Richard L. Lindstrom, M.D., president of the American Society of Cataract and Refractive Surgery. "While patient satisfaction is extremely high, we recognize that there are patients who have unsatisfactory outcomes. As surgeons, we have taken the Hippocratic Oath. The well being of all of our patients is central to what we do and what we are. As such, and as the history of medicine has shown, we are committed to advancing our technology, patient selection, and surgical techniques so that we can continue to enhance the quality of our patient's lives," Lindstrom added......... Posted by: Mike      Read more         Source

March 7, 2008, 5:29 AM CT

Breakthrough in birth-defect research

Researchers have discovered how to prevent certain craniofacial disorders in what could ultimately lead to at-risk babies being treated in the womb.

University of Manchester researchers, working with colleagues at the Stowers Institute for Medical Research in Kansas, have successfully treated mice with Treacher Collins syndrome a rare genetic disorder characterised by underdeveloped facial bones, absent or deformed ears and occasionally cleft palate.

The team had previously observed that the condition, which affects one in 10,000 individuals, was caused by a mutation in a single gene called TCOF1. They later discovered that this mutation causes cells, known as neural crest cells, to die prematurely in the early stages of pregnancy resulting in the facial anomalies.

Now, writing in the journal Nature Medicine, the scientists have shown that preventing the neural crest cells from dying allowed mice with the Treacher Collins gene to develop normally. The principle, say the authors, could also be applied to other single-gene birth defects.

This is the first time that a congenital defect has been successfully treated and provides genuine hope within a realistic timeframe of one day preventing these conditions in humans, said Professor Mike Dixon in Manchesters Faculty of Life Sciences......... Posted by: JoAnn      Read more         Source

March 5, 2008, 9:28 PM CT

Earlier, More Accurate Diagnosis of Alzheimer's Disease

Scientists involved in a large, multi-institutional study using positron emission tomography (PET) imaging with the radiotracer fluorodeoxyglucose (FDG) were able to classify different types of dementia with very high rates of success, raising hopes that dementia diagnoses may one day be made at earlier stages.

"Previously, researchers have been able to look only at the surface of the brain to differentiate various types of dementia," said Lisa Mosconi, Ph.D., assistant professor of psychiatry at the New York University School of Medicine. "With FDG PET, we were able to develop standardized disease-specific patterns from which we could correctly classify dementia more than 94 percent of the time."

The study, which was published in the recent issue of the Journal of Nuclear Medicine, measured the cerebral metabolic rate of glucose (CMRglc)-the amount of sugar the brain uses to fuel its activities-in various areas of the organ. A decrease in this rate is indicative of a loss of nerve cells and of dysfunction linked to dementia. Because FDG behaves like glucose when injected into the body, its location in the PET scans pinpointed the specific area where glucose utilization had fallen below normal levels as in comparison to an age-appropriate control group.

"Each type of dementia examined-Alzheimer's disease (AD), frontotemporal dementia (FTD), and dementia with Lewy bodies (DLB)-affects a different area of the brain. Based on where in the brain this decrease occurred, we were able to determine which type of dementia a patient had," Mosconi explained......... Posted by: Daniel      Read more         Source

March 4, 2008, 6:18 PM CT

Costly placebo works better than cheap one

A 10-cent pill doesn't kill pain as well as a $2.50 pill, even when they are identical placebos, as per a provocative study by Dan Ariely, a behavioral economist at Duke University.

"Physicians want to think it's the medicine and not their enthusiasm about a particular drug that makes a drug more therapeutically effective, but now we really have to worry about the nuances of interaction between patients and physicians," said Ariely, whose findings appear as a letter in the March 5 edition of the Journal of the American Medical Association.

Ariely and a team of collaborators at the Massachusetts Institute of Technology used a standard protocol for administering light electric shock to participants wrists to measure their subjective rating of pain. The 82 study subjects were tested before getting the placebo and after. Half the participants were given a brochure describing the pill as a newly-approved pain-killer which cost $2.50 per dose and half were given a brochure describing it as marked down to 10 cents, without saying why.

In the full-price group, 85 percent of subjects experienced a reduction in pain after taking the placebo. In the low-price group, 61 percent said the pain was less.

The finding, from a relatively small and simplified experiment, points to a host of larger questions, Ariely said......... Posted by: Scott      Read more         Source

March 4, 2008, 5:34 PM CT

Achievement gaps within racial groups

A University of Michigan study finds that when it comes to achievement gaps within racial groups, catching up over time is common.

In the first known study to analyze reading and math achievement within racial groups during elementary school, scientists found high achievers within all groups and that a substantial proportion of children catch up to the high achievers in their groups over time.

The study, presented today in Washington, D.C. at the annual meeting of the Society for Research on Educational Effectiveness, analyzes data on a national sample of 8,060 students, collected at four points in time, starting in kindergarten and ending in the spring of fifth grade.

"We found significant achievement gaps within racial and ethnic groups," said Pamela Davis-Kean, a developmental psychology expert at the U-M Institute for Social Research (ISR) who conducted the study with U-M post-doctoral fellow Justin Jager.

"We also found a significant proportion of students who caught up to the high achievers in their groups by the end of fifth grade, particularly in reading. This shows that schooling does have an impact in closing the achievement gap for substantial numbers of children".

In reading, the scientists observed that there were high-performing groups in all races. "This is a fact that sometimes gets lost in discussions of the achievement gap between white students and students of other races," Davis-Kean said......... Posted by: Scott      Read more         Source