November 17, 2009, 7:47 AM CT
What makes pandemic H1N1 tick?
Dr. Richard Scheuermann, professor of pathology and clinical sciences at UT Southwestern Medical Center.
As the number of deaths correlation to the pandemic H1N1 virus, usually known as "swine flu," continues to rise, scientists have been scrambling to decipher its inner workings and explain why the incidence is lower than expected in elderly adults.
In a study available online and appearing in a future issue of Proceedings of the National Academy of Sciences, a UT Southwestern Medical Center researcher and his collaborators in California show that the molecular makeup of the current H1N1 flu strain is strikingly different from prior H1N1 strains as well as the normal seasonal flu, particularly in structural parts of the virus normally recognized by the immune system.
Previous research has shown that an individual's immune system is triggered to fight off pathogens such as influenza when specific components of the immune system - namely antibodies, B-cells and T cells - recognize parts of a virus known as epitopes. An individual's ability to recognize those epitopes - spurred by past infections or vaccinations - helps prevent future infections. The challenge is that these epitopes vary among flu strains.
"We hypothesize that older people are somewhat protected because the epitopes present in flu strains before 1957 appears to be similar to those found in the current H1N1 strain, or at least similar enough that the immune system of the previously infected person recognizes the pathogen and knows to attack," said Dr. Richard Scheuermann, professor of pathology and clinical sciences at UT Southwestern and a co-author of the paper. "Those born more recently have virtually no pre-existing immunity to this pandemic H1N1 strain because they have never been exposed to anything like it".........
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November 10, 2009, 8:48 AM CT
New direction for HIV vaccine research
A very close and detailed study of how the most robust antibodies work to block the HIV virus as it seeks entry into healthy cells has revealed a new direction for scientists hoping to design an effective vaccine.
"Our study clearly showed that we've been overlooking a very important component of antibody function," says S. Munir Alam, Ph.D., an associate professor of medicine at Duke University Medical Center and main author of the paper appearing in the Proceedings of the National Academy of Sciences
Alam, a member of the Duke Human Vaccine Institute and study senior author Bing Chen, Ph.D., assistant professor of pediatrics, Harvard Medical School and Children's Hospital Boston, studied two potentially powerful antibodies against HIV, 2F5 and 4E10. Both of these are rare, broadly neutralizing antibodies, meaning that they can block many different strains of the HIV virus. They accomplish that by binding to the "Achilles heel" of the virus the so-called outer coat membrane proximal region a part of the outer protein coating next to the viral membrane that opens up and is exposed to the antibodies for just a few minutes during the process of cell fusion and infection.
But the problem for infection control is that such powerful antibodies are rare in HIV infection, and current experimental vaccines have been unable to generate such antibodies. In addition, the window of opportunity for such antibodies to act is very narrow.........
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November 9, 2009, 8:18 AM CT
Learning bacterial communications
Peiter C. Dorrestein, PhD is a researcher at University of California - San Diego.
Credit: UC San Diego School of Medicine
Using imaging mass spectrometry, scientists at the University of California, San Diego have developed tools that will enable researchers to visualize how different cell populations of cells communicate. Their study shows how bacteria talk to one another an understanding that may lead to new therapeutic discoveries for diseases ranging from cancer to diabetes and allergies.
In the paper reported in the November 8 issue of Nature Chemical Biology,
Pieter C. Dorrestein, PhD, assistant professor at UC San Diego's Skaggs School of Pharmacy and Pharmaceutical Sciences, and his colleagues describe an approach they developed to describe how bacteria interface with other bacteria in a laboratory setting. Dorrestein and post-doctoral students Yu-Liang Yang and Yuquan Xu, along with Paul Straight from Texas A&M University, utilized technology called natural product MALDI-TOF (Matrix Assisted Laser Desorption Ionization-Time of Flight) imaging mass spectrometry to uniquely translate the language of bacteria.
Microbial interactions, such as signaling, have generally been considered by researchers in terms of an individual, predominant chemical activity. However, a single bacterial species is capable of producing a number of bioactive compounds that can alter neighboring organisms. The approach developed by the UCSD research team enabled them to observe the effects of multiple microbial signals in an interspecies interaction, revealing that chemical "conversations" between bacteria involve a number of signals that function simultaneously.........
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November 6, 2009, 8:56 AM CT
New Synthetic Molecules Trigger Immune Response
Scientists at Yale University have developed synthetic molecules capable of enhancing the body's immune response to HIV and HIV-infected cells, as well as to prostate cancer cells. Their findings, published online in the Journal of the American Chemical Society, could lead to novel therapeutic approaches for these diseases.
The molecules - called "antibody-recruiting molecule targeting HIV" (ARM-H) and "antibody-recruiting molecule targeting prostate cancer" (ARM-P) - work by binding simultaneously to an antibody already present in the bloodstream and to proteins on HIV, HIV-infected cells or cancer cells. By coating these pathogens in antibodies, the molecules flag them as a threat and trigger the body's own immune response. In the case of ARM-H, by binding to proteins on the outside of the virus, they also prevent healthy human cells from being infected.
"Instead of trying to kill the pathogens directly, these molecules manipulate our immune system to do something it wouldn't ordinarily do," said David Spiegel, Ph.D., M.D., assistant professor of chemistry and the corresponding author of both papers.
Because both HIV and cancer have methods for evading the body's immune system, therapys and vaccinations for the two diseases have proven difficult. Current therapy options for HIV and prostate cancer - including antiviral drugs, radiation and chemotherapy - involve severe side effects and are often ineffective against advanced cases. While there are some antibody drugs available, they are difficult to produce in large quantities and are costly. They also must be injected and are accompanied by severe side effects of their own.........
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November 6, 2009, 8:54 AM CT
Air pollution and infants' bronchiolitis
Infants who are exposed to higher levels of air pollution are at increased risk for bronchiolitis, as per a newly released study.
The study appears in the November 15 issue of the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine.
"There has been very little study of the consequences of early life exposure to air pollution," said Catherine Karr, M.D. PhD, assistant professor of pediatrics at the University of Washington and the paper's main author. "This study is unique in that we were able to look at multiple sources including wood smoke in a region with relatively low concentrations of ambient air pollution overall".
The scientists analyzed nearly 12,000 diagnoses of infant bronchiolitis between 1999 and 2002 in southwestern British Columbia, with respect to the individual's ambient pollution exposure based on monitored levels of nitric oxide (NO), nitrogen dioxide (NO2), carbon monoxide (CO), sulfur dioxide (SO2), and particulate matter from monitoring stations within 10 km of the infants' homes. They also used land-use regression maps to assess concentrations of ambient pollution with respect to traffic and wood smoke. They analyzed pollution exposure by dividing subjects into four categories, or quartiles, of concentration.........
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November 4, 2009, 8:11 AM CT
Enjoying the bounty of colorful fruits and vegetable
Hoping to keep the flu at bay? A strong immune system helps. Enjoying the bounty of colorful fruits and vegetables available right now can be an important step toward supporting your family's immune system this cold/flu season.
In addition to vitamins, minerals and fiber, fruits and vegetables contain phytonutrients, believed to come from the com-pounds that give these foods their vibrant colors. These phytonutrients provide a wide range of health benefits, includ-ing supporting a healthy immune system.
A newly released study, America's Phytonutrient Report, found eight in 10 Americans are missing out on the health benefits of a diet rich in colorful fruits and veggies, resulting in a phytonutrient gap. The report looked at fruit and vegetable consumption in five color categories, specifically green, red, white, blue/purple and yellow/orange, and the phytonutrients found in each color category.
Eating a variety of colorful fruits and vegetables is one way to help keep you and your family healthy. Foods in the red category are particularly helpful to our immune systems, in addition to supporting heart health. Tomatoes, pomegranate, red cabbage, cranberries, even pink grapefruit provide the phytonutrients lycopene and ellagic acid.
The health benefits of foods in the yellow/orange category support a health immune function tooalong with vision and heart health. And they help maintain skin hydrationimportant as we head into these cold, dry months. These foods pro-vide beta-carotene, alpha-carotene, lutein, quercetin and other phytonutrients that can be converted into Vitamin A. Deli-cious and nutritious yellow/orange fruits and vegetables available now include: carrots, squash, sweet potatoes and pi-neapple.........
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November 2, 2009, 11:35 PM CT
Flu vaccine to women during pregnancy
Infants born to women who received influenza vaccine during pregnancy were hospitalized at a lower rate than infants born to unvaccinated mothers, as per preliminary results of a research study that's ongoing by scientists at Yale School of Medicine. The team presented the study October 29 at the 47th annual meeting of the Infectious Diseases Society of America in Philadelphia.
Influenza is a major cause of serious respiratory disease in pregnant women and of hospitalization in infants. Eventhough the flu vaccine is recommended for all pregnant women and children, no vaccine is approved for infants less than six months of age. Preventive strategies for this age group include general infection control and vaccination of those coming in close contact with them. Few studies have examined the effectiveness of the flu vaccine during pregnancy.
Led by Marietta Vzquez, M.D., assistant professor of pediatrics at Yale School of Medicine, this newly released study is a case-control trial of the effectiveness of vaccinating pregnant women to prevent hospitalization of their infants. During nine flu seasons from 2000 to 2009, Vzquez and his colleagues identified and tracked over 350 mothers and infants from 0 to 12 months of age who were hospitalized at Yale-New Haven Hospital. They compared 157 infants hospitalized due to influenza to 230 influenza-negative infants matched by age and date of hospitalization. The team interviewed parents to determine risk factors for influenza and evaluated medical records of both infants and their mothers to determine rates of vaccination with the influenza vaccine.........
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November 2, 2009, 8:52 AM CT
Hepatitis B does not increase pancreatic cancer risk
A Henry Ford Hospital study observed that hepatitis B does not increase the risk for pancreas cancer and that only age is a contributing factor.
The results contradict a prior study in 2008 that suggested a link between pancreas cancer and prior hepatitis B infection. Hepatitis B is an inflammation of the liver caused by a viral infection.
Study results will be presented at the American Association for the Study of Liver Diseases' Annual Meeting in Boston.
Using data from Henry Ford Health System, physicians looked at more than 74,000 patients who were tested for hepatitis B between 1995 and 2008. In the overall analysis, only age was found to be a significant predictor for pancreas cancer.
"We looked at the occurence rate of pancreas cancer among hepatitis B-infected patients over a 13-year period and observed that we could not confirm a higher risk for those with a prior exposure to hepatitis B, as a previous study suggested," says Jeffrey Tang, M.D., gastroenterologist at Henry Ford Hospital and main author of the study.
"When other factors are considered such as age, race, sex, HIV status, and the presence of diabetes only older age and presence of diabetes proved significant, whereas previous exposure to hepatitis B was no longer an important variable".........
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October 29, 2009, 10:39 PM CT
Antioxidants against the flu virus
As the nation copes with a shortage of vaccines for H1N1 influenza, a team of Alabama scientists have raised hopes that they have found an Achilles' heel for all strains of the fluantioxidants. In an article appearing in the November 2009 print issue of the FASEB Journal
(http://www.fasebj.org) they show that antioxidantsthe same substances found in plant-based foodsmight hold the key in preventing the flu virus from wreaking havoc on our lungs.
"The recent outbreak of H1N1 influenza and the rapid spread of this strain across the world highlights the need to better understand how this virus damages the lungs and to find new therapys," said Sadis Matalon, co-author of the study. "Additionally, our research shows that antioxidants may prove beneficial in the therapy of flu".
Matalon and his colleagues showed that the flu virus damages our lungs through its "M2 protein," which attacks the cells that line the inner surfaces of our lungs (epithelial cells). Specifically, the M2 protein disrupts lung epithelial cells' ability to remove liquid from inside of our lungs, setting the stage for pneumonia and other lung problems. The scientists made this discovery by conducting three sets of experiments using the M2 protein and the lung protein they damage. First, frog eggs were injected with the lung protein alone to measure its function. Second, scientists injected frog eggs with both the M2 protein and the lung protein and observed that the function of the lung protein was significantly decreased. Using molecular biology techniques, researchers isolated the segment of the M2 protein responsible for the damage to the lung protein. Then they demonstrated that without this segment, the protein was unable to cause damage. Third, the full M2 protein (with the "offending" segment intact) and the lung protein were then re-injected into the frog eggs along with drugs known to remove oxidants. This too prevented the M2 protein from causing damage to the lung protein. These experiments were repeated using cells from human lungs with exactly the same results.........
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October 29, 2009, 10:05 PM CT
Learn from past flu season
Pregnant women who catch the flu are at serious risk for flu-related complications, including death, and that risk far outweighs the risk of possible side effects from injectable vaccines containing killed virus, as per an extensive review of published research and data from prior flu seasons.
The review, a collaboration among researchers from the Johns Hopkins Children's Center, Emory University and Cincinnati Children's Hospital, and published online Oct. 22 in the American Journal of Obstetrics & Gynecology,
found substantial and persistent evidence of high complication risk among pregnant women -- both healthy ones and those with underlying medical conditions -- infected with the flu virus, while confirming vaccine safety. The findings, scientists say, solidify existing CDC recommendations that make pregnant women the highest-priority group to receive both the H1N1 and seasonal flu vaccines.
"The lessons learned from flu outbreaks in the distant and not-too-distant past are clear and so are the messages," says lead investigator Pranita Tamma, M.D., an infectious disease specialist at the Johns Hopkins Children's Center. "If you are an expectant mother, get vaccinated. If you are a doctor caring for pregnant women, urge your patients to get vaccinated".........
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