January 18, 2006, 0:17 AM CT

Complex Infection Fighting Mechanisms

Yale School of Medicine scientists report in Nature Immunology how infection fighting mechanisms in the body can distinguish between a virus and the healthy body, shedding new light on auto immune disorders.

The infection fighters in question, toll-like receptors (TLRs), function by recognizing viral, bacterial or fungal pathogens and then sending signals throughout the immune system announcing that an infection has occurred.

Viruses change features to avoid being recognized, thereby triggering the immune response. But TLRs recognize the highly conserved features of pathogens, features that are often difficult to change without affecting the punch of the pathogen, said lead author of the study, Gregory Barton of the University of California at Berkeley who performed the research while in the Section of Immunobiology at Yale School of Medicine.

He said that one exception to the general view of how TLRs work is the way TLRs recognize viruses since viruses lack the unique features of bacterial or fungal pathogens. Because of this, the immune system has had to find other ways to recognize viral infection.

"In particular, the DNA or RNA that comprise viral genomes can stimulate certain TLRs," Barton said. "This strategy comes at an enormous cost. By targeting the DNA or RNA of viruses, the immune system runs the risk of accidentally recognizing its own DNA and RNA as foreign and inappropriately making an immune response against itself. This autoimmune condition is called systemic lupus erythematosus or SLE, and can be devastating for those unfortunate enough to suffer from it".........

Posted by: Mark      Permalink


January 15, 2006, 3:05 PM CT

Hope For Children Facing Immune System Disorders

For 11 of Lacey Conners's 12 years of life, she's had to visit a hospital every three weeks for an antibody replacement treatment to treat her primary immunodeficiency (PI). On top of being diagnosed with Crohn's disease and heart disease, Lacey's immune system is unable to adequately produce the specific antibodies needed to fight off infection. With the establishment of the Jeffrey Modell Diagnostic Center for Primary Immunodeficiencies, the Emory Children's Center joins children like Lacey on the front line of the fight against PI disorder.

The new Jeffrey Modell Diagnostic Center for Primary Immunodeficiencies at the Emory Children's Center was made possible by a donation from the Jeffrey Modell Foundation (JMF). The center is the only of its kind in Georgia dedicated to the diagnosis and therapy of patients with PI. Emory was designated as a location for one of 23 Jeffrey Modell Diagnostic Centers worldwide because of its excellence in patient care and research into the complex disorders of PI. To date, physicians at Emory have diagnosed and treated over 250 children living with the disorder.

PI includes more than 120 genetic defects that cause a reduced or absent ability for the immune system to produce specific antibodies to fight off infection. It is often misdiagnosed as common chronic childhood illnesses such as sinus and ear infections, pneumonia, fever, and bronchitis. PI illnesses can range from chronic sinusitis to "bubble boy disease," the common term used to describe severe combined immune deficiency.........

Posted by: JoAnn      Permalink


December 26, 2005

Minority Patients And Children And Latest Asthma Technologies

Study analyzes how usage of new technology may contribute to health care disparities Inhaled steroid medications for asthma, which have greatly reduced the need for patients to be hospitalized with serious symptoms, were significantly less likely to be prescribed for minority patients and children during the years soon after their introduction. In the January 2006 issue of the journal Medical Care, researchers from the Massachusetts General Hospital Institute for Health Policy report one of the first studies to examine how disparities in health care change over time, reflecting how the introduction of a new technology differs among racial, ethnic or other groups. "Prior studies of health care disparities have tended to look at one point in time, but a longer-term picture allows us to see whether disparities are a static or dynamic problem," says Timothy Ferris, MD, of the MGH Institute for Health Policy, the article's lead author. "Our results support the theory that disparities might be greater in the early stages after a technology is introduced and that attempts to reduce disparities might focus on this important period".

In order to track the adoption of inhaled steroid medications for asthma after their introduction in the 1980s, the scientists analyzed data from the National Ambulatory Medical Care Survey from 1989 to 1998. In this annual survey, conducted by the National Center for Health Statistics, physicians complete a form after outpatient visits during a randomly selected week, answering questions about patients' diagnoses and the therapys provided. The scientists identified 3,671 doctor visits by patients with asthma during the years studied, determined whether or not inhaled steroids were prescribed or administered during those visits, and also analyzed information on patients' age and race or ethnicity.........

JoAnn      Permalink


December 25, 2005, 10:32 AM CT

Merry Christmas To All Our Readers

Medicineworld wishes all our readers merry Christmas.

Oh, jingle bells, jingle bells

Jingle all the way

Oh, what fun it is to ride

In a one horse open sleigh

Jingle bells, jingle bells

Jingle all the way

Oh, what fun it is to ride

In a one horse open sleigh........

Daniel      Permalink


December 23, 2005

Langerhans Cells And Immune System

The langerhans cells are marked in red and another cell type are in green. Wild-type mice are on the bottom and have both the red and green cells. Then transgenic mice are on the top and still have the green cells but the red cells are missing.

New Haven, Conn. - Scientists at Yale School of Medicine have demonstrated that Langerhans cells in the skin, which had been thought to alert the immune system to pathogens, instead dampen the skin's reaction to infection and inflammation.

This has the potential to significantly alter understanding of the mechanisms underlying a number of skin disorders such as psoriasis, lupus and skin cancer.

Dendritic cells are found throughout the body and are extremely efficient at alerting the immune system to the presence of pathogens and other foreign materials. Langerhans cells are dendritic cells in the skin. Skin is an important barrier to infection and it has been generally assumed that the Langerhans cells only serve to warn the immune system of skin pathogens.

According to the study, featured on the cover of the December 15 issue of Immunity, Langerhans cells are not mandatory and, in fact, inhibit or modulate immune responses in the skin.

Daniel H. Kaplan, M.D., and Mark J. Shlomchik, M.D., used a technology called Bacterial Artificial Chromosome transgenics to develop a mouse model that lacks Langerhans cells in the skin from birth. They stimulated the skin of these mice to create hypersensitivity similar to a poison ivy reaction. They expected that mice without Langerhans cells would have less immune response in the skin.

"Unexpectedly, instead of a decreased immune response to contact hypersensitivity, we found a reproducible and significant increase," said first author Kaplan, assistant professor in the Department of Dermatology at Yale School of Medicine. "Langerhans cells are thus not mandatory to generate immune responses in the skin and more profoundly, they actually regulate immune responses in the skin".........

JoAnn      Permalink


December 23, 2005

genetic link between asthma and obesity

A study about the relationship between asthma and obesity, which uses a community-based twin registry from the University of Washington in Seattle, has found a strong genetic link between the two disorders, according to findings published in the recent issue of the Journal of Allergy and Clinical Immunology.

While this study replicates prior findings that have shown asthma to be more common in obese individuals, it goes on to show that the largest portion of the association between the two disorders could be explained by a common set of genetic factors.

Dr. Teal Hallstrand, assistant professor of pulmonary and critical care medicine at the University of Washington in Seattle, led the study, which compared the frequency of asthma and obesity in both identical and fraternal, or non-identical, twins. The scientists analyzed 1001 identical and 383 fraternal same-sex twin pairs within the University of Washington Twin Registry. They found that the largest portion of the association between asthma and obesity could be attributed to a common set of genetic factors, referred to as genetic pleiotropy, which implies that the same genetic factors may have a causal influence on both asthma and obesity.

Asthma and obesity are increasingly common disorders, particularly in Westernized societies. A fundamental question about the relationship between obesity and asthma is whether the association between these two disorders is predominantly genetic or environmental.

The scientists also report that the effects of environmental exposures on asthma and obesity are likely to occur primarily in the context of a specific genetic background, referred to as gene-by-environment effects.
........

JoAnn      Permalink


December 20, 2005

Neighborhoods May Affect Asthma

Educational level, housing status and other socioeconomic factors are thought to affect the health of people with asthma, but a new study finds that one's neighborhood and surrounding area may also play a significant role, even after taking into account personal economic well-being.

While study findings showed worse health and poorer quality of life among people living in lower-income areas, they also showed poorer lung function among those living in suburbs, where people tended to own newer homes in less densely populated neighborhoods.

The study, conducted by scientists from the University of California, San Francisco, is published in the recent issue of the European Respiratory Journal.

The analysis did not pinpoint exposures that might be linked to these population effects, but most scientists believe water-damaged housing stock, proximity to high traffic flow, industrial pollution, and social environmental stress are key contributors to health problems in poorer neighborhoods. The study raises the possibility that more frequent household pet ownership may be one factor in lower lung function in suburban-related health exposures, eventhough larger backyards with more allergenic plants could be a contributor.

"Our research could be subtitled 'No Man is an Island,'" said Paul Blanc, MD, UCSF professor of occupational and environmental medicine and lead author of the study. "The study findings underscore that asthma is a complex problem that does not simply affect people in isolation."

"Even if individual risk factors such as poor access to medical care can be overcome, different communities have different asthma patterns, and strategies for prevention and therapy must take this into account," he said.

Blanc cites the need for studies to nail down the community-wide physical and social environmental factors that contribute to asthma and poorer respiratory health.........

Sue      Permalink


December 19, 2005

Stress impairs Human Body's Ability To Heal

The stress a typical married couple feels during an ordinary half-hour argument is enough to slow their bodies' ability to heal from wounds by at least one day, a new study has shown.

Moreover, if the couple's relationship is routinely hostile toward each other, the delay in that healing process can be even doubled. The results of this study have major financial implications for medical centers and health care insurers.

The new study, reported in the current issue of the Archives of General Psychiatry, is the latest discovery in a three-decade-long series of experiments underway at the Ohio State University 's Institute for Behavioral Medicine Research. The work is aimed at identifying and then explaining the ways psychological stress can affect human immunity.

Jan Kiecolt-Glaser, a professor of psychiatry and psychology, and partner Ronald Glaser, a professor of molecular virology, immunology and medical genetics, both at Ohio State, say the findings provide important recommendations for patients facing surgery.

"This shows specifically why it is so important that people be psychologically prepared for their surgeries," Kiecolt-Glaser explained.

Colleague Glaser added, "We have enough data now from all of our past studies to basically suggest that hospitals need to modify existing practices in ways that will reduce stress previous to surgery." Both scientists said such stress reduction could lead to shorter hospital stays -- with corresponding lower medical bills -- and a reduced risk of infections among patients.

The scientists focused on a group of 42 married couples who had been together an average of at least 12 years. Each couple was admitted into the university's General Clinical Research Center for two, 24-hour-long visits. The visits were separated by a two-month interval.........

JoAnn      Permalink

Anaphylaxis Requires Prompt Treatment (December 6, 2005)

Boyfriend Unaware of Deadly Peanut Allergy (December 2, 2005)