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July 29, 2009, 11:13 PM CT

College students who feel 'invincible' unlikely to accept vaccines

College students who feel 'invincible' unlikely to accept vaccines
Vaccines to protect against sexually transmitted diseases, including HIV and herpes, are being developed and may soon be available to college students. However, limited research has been conducted to determine if students will accept the vaccines once they are available. In a newly released study, a University of Missouri researcher has observed that students who feel invulnerable, or invincible, to physical harm are unlikely to get an HIV vaccine. Alternately, students who feel invulnerable to psychological harm are more likely to get the vaccine.

"Prior scientists have used invulnerability measures to predict health-endangering behaviors in students, but this study is unique in that it considers the role of invulnerability in students' health-protective or preventative behaviors," said Russell Ravert, assistant professor in the MU College of Human Environmental Sciences.

In the study, Ravert measured two invulnerability factors: danger and psychological. Students with increased danger invulnerability, those who viewed themselves as physically invincible, were more likely to decline the vaccine. One explanation is that strong feelings of danger invulnerability appears to be linked to decreased threat, which can diminish protective behaviors, Ravert said.

Students who felt psychological invulnerability, those who didn't care what others thought, were more likely to accept a vaccine. Students' psychological invulnerability may protect against the possible stigma linked to getting vaccinated for HIV, or other sexually transmitted diseases, Ravert said.........

Posted by: Mark      Read more         Source


July 29, 2009, 11:07 PM CT

Immune responses to flu vaccine

Immune responses to flu vaccine
Patients with the autoimmune disease systemic lupus erythematosus (SLE) have an increased risk of infection, due to both disturbances in their immune responses and therapy with immunosuppressive drugs. Because morbidity and mortality correlation to influenza are increased in immunocompromised patients, it is recommended that patients with SLE get annual flu shots, which are safe and do not increase disease activity. Both antibody and cell-mediated responses are involved in the immune response to influenza; in SLE, antibody responses to the vaccine are diminished, but it is not known if the same effect is seen in cell-mediated responses. A newly released study was the first to examine cell-mediated responses in SLE patients previous to and following influenza vaccination. The study was reported in the recent issue of Arthritis & Rheumatism (http://www.interscience.wiley.com/journal/arthritis).

Led by Albert Holvast, of the University of Groningen in The Netherlands, the study involved 54 patients with SLE and 54 healthy controls who received subunit flu vaccine, out of a total of 78 patients in each group. Patients were randomized 2:1 to receive a flu vaccine or serve as a nonvaccinated control. Patients and controls were followed up at 28 days and three to four months following vaccination, at which time blood was drawn.........

Posted by: Mark      Read more         Source


July 20, 2009, 11:39 PM CT

Insights into failed HIV-1 vaccine trial

Insights into failed HIV-1 vaccine trial
Following the disbandment of the STEP trial to test the efficacy of the Merck HIV-1 vaccine candidate in 2007, the leading explanation for why the vaccine was ineffective and may have even increased susceptibility to acquiring the virus centered on the hypothesis that high levels of baseline Ad5-specific neutralizing antibodies may have increased HIV-1 acquisition among the study subjects who received the vaccine by increasing Ad5-specific CD4+ T-cells that were susceptible to HIV-1 infection.

Now, a study by Dan Barouch, MD, PhD, and a scientific team at Beth Israel Deaconess Medical Center (BIDMC), published in the July 20 Advance Online issue of Nature Medicine, shows this was likely not the case.

"Our findings demonstrate that there is no connection between Ad5 neutralizing antibodies and T-cell immune responses," explains Barouch, who is Chief of the Division of Vaccine Research at BIDMC and Associate Professor of Medicine at Harvard Medical School. "Moreover, subjects with baseline Ad5-specific neutralizing antibodies did not develop higher levels of Ad5-specific T-cell responses as compared with subjects without baseline Ad5-specific neutralizing antibodies".

The Ad5 virus is a weakened form of adenovirus, which is responsible for the common cold and is extremely widespread in the general population. In the Merck vaccine candidate, Ad5 was used as a vector to transport three HIV-1 genes, a strategy that helps to overcome limitations posed by the HIV-1 virus.........

Posted by: Mark      Read more         Source


July 14, 2009, 7:39 AM CT

How staph infections alter immune system?

How staph infections alter immune system?
Here is Dr. Monica Ardura, instructor of pediatrics and lead author of the study (left), Dr. Asuncion Mejias, assistant professor of pediatrics, and Dr. Octavio Ramilo, former professor of pediatrics.
Infectious disease specialists at UT Southwestern Medical Center have mapped the gene profiles of children with severe Staphylococcus aureus infections, providing crucial insight into how the human immune system is programmed to respond to this pathogen and opening new doors for improved therapeutic interventions.

In recent years, much research has focused on understanding precisely what the bacterium S aureus does within the host to disrupt the immune system. Despite considerable advances, however, it remained unclear how the host's immune system responded to the infection and why some people are apt to get more severe staphylococcal infections than others.

By using gene expression profiling, a process that summarizes how individual genes are being activated or suppressed in response to the infection, UT Southwestern scientists pinpointed how an individual's immune system responds to a S. aureus infection at the genetic level.

"The beauty of our study is that we were able to use existing technology to understand in a real clinical setting what's going on in actual humans not models, not cells, not mice, but humans," said Dr. Monica Ardura, instructor of pediatrics at UT Southwestern and main author of the study available online in PLoS One, the Public Library of Science's online journal. "We have provided the first description of a pattern of response within an individual's immune system that is very consistent, very reproducible and very intense".........

Posted by: Mark      Read more         Source


June 21, 2009, 8:44 PM CT

Combined antiviral and targeted chemotherapy

Combined antiviral and targeted chemotherapy
A discovery by a team of Canadian and American scientists could provide new ways to fight HIV-AIDS. As per a newly released study published in Nature Medicine, HIV-AIDS could be treated through a combination of targeted chemotherapy and current Highly Active Retroviral (HAART) therapys. This radical new treatment would make it possible to destroy both the viruses circulating in the body as well as those playing hide-and-seek in immune system cells.

The study was led by Dr. Rafick-Pierre Skaly, of the Universit de Montral. Dr. Jean-Pierre Routy of the Research Institute of the McGill University Health Centre (RI-MUHC) and researchers from the National Institutes of Health (NIH) and the University of Minnesota in the United States also collaborated on the investigation.

To date, anti-AIDS therapys have been stymied by "HIV reservoirs" immune system cells where the virus hides and where existing HAART therapys cannot reach. The scientists successfully identified the cells where HIV hides and the "stealth" mechanisms that allow the virus to escape existing therapys. This breakthrough opens the way towards innovative therapies that are completely different from current approaches.

"Our results argue in favour of a strategy similar to the one used against leukemia, which is targeted chemotherapy, linked to a targeted immune therapy. This would make it possible to destroy the cells containing a virus, while giving the immune system time to regenerate with healthy cells," says Dr. Rafick-Pierre Skaly, a professor at the Universit de Montral, researcher at the Centre Hospitalier de Universit de Montral (CHUM), director of INSERM 743 and scientific director of the Vaccine and Gene Therapy Institute of Florida.........

Posted by: Mark      Read more         Source


June 16, 2009, 9:38 PM CT

Statins don't lower risk of pneumonia

Statins don't lower risk of pneumonia
Taking popular cholesterol-lowering statin drugs, such as Lipitor (atorvastatin), does not lower the risk of pneumonia. That's the new finding from a study of more than 3,000 Group Health patients published online on June 16 in advance of the British Medical Journal's June 20 print issue.

"Previous research based on automated claims data had raised some hopeand maybe some hypefor statins as a way to prevent and treat infections including pneumonia," said Sascha Dublin, MD, PhD, a doctor at Group Health and assistant investigator at Group Health Center for Health Studies. "But when we used medical records to get more detailed information about patients, our findings didn't support that approach".

In fact, Dublin's population-based case-control study observed that pneumonia risk was, if anything, slightly higher (26%) in people using a statin than in those not using any; and this extra risk was even higher (61%) for pneumonia severe enough to require being hospitalized.

"As a doctor, I'm a fan of statins for what they've been proven to do: lowering cholesterol and risk of heart disease and stroke in people who've had either disease or are at risk for them," said Dublin. Statins are HMG coenzyme A reductase inhibitors, which also include Zocor (simvastatin) and Mevacor (lovastatin). This class of medications lessens inflammation, which plays a role in infections.........

Posted by: Mark      Read more         Source


June 16, 2009, 5:06 AM CT

Predicting Fatal Fungal Infections

Predicting Fatal Fungal Infections
This image shows two human

neutrophils. The circular object

about to be engulfed by the

upper neutrophil is a

Cryptococcus neoformans cell.
As per a research findings published in The Journal of Infectious Diseases, scientists from Albert Einstein College of Medicine of Yeshiva University have identified cells in blood that predict which HIV-positive individuals are most likely to develop deadly fungal meningitis, a major cause of HIV-related death. This form of meningitis affects more than 900,000 HIV-infected people globally-most of them in sub-Saharan Africa and other areas of the world where antiretroviral treatment for HIV is not available.

A major cause of fungal meningitis is Cryptococcus neoformans, a yeast-like fungus usually found in soil and in bird droppings. Virtually everyone has been infected with Cryptococcus neoformans, but a healthy immune system keeps the infection from ever causing disease.

The risk of developing fungal meningitis from Cryptococcus neoformans rises dramatically when people have weakened immunity, due to HIV infection or other reasons including the use of immunosuppressive drugs after organ transplantation, or for treating autoimmune diseases or cancer. Knowing which patients are most likely to develop fungal meningitis would allow costly drugs for preventing fungal disease to be targeted to those most in need. (In the U.S., the widespread use of antiretroviral treatment by HIV-infected people, and their preventive use of anti-fungal drugs, has dramatically reduced their rate of fungal meningitis from Cryptococcus neoformans to about 2%.).........

Posted by: Mark      Read more         Source


June 10, 2009, 9:31 PM CT

HIV-1's 'hijacking mechanism

HIV-1's 'hijacking mechanism
Scientists at McGill University and the affiliated Lady Davis Institute for Medical Research at Montreal's Jewish General Hospital along with colleagues at the University of Manitoba and the University of British Columbia may have found a chink in the armour of the human immunodeficiency virus type 1 (HIV-1), the microorganism which causes AIDS. They have pinpointed the key cellular machinery co-opted by HIV-1 to hijack the human cell for its own benefit. Their study was published in May in the Journal of Biological Chemistry

Once a cell is infected with HIV-1, activation of the virus's gene generates a large HIV-1 RNA molecule known as the RNA genome. This is then transported from the cell nucleus to the inner surface of the plasma membrane. The RNA genome can produce both structural proteins and enzymes, but once it arrives at the plasma membrane it can also assemble into new copies of the virus that actually bud out of the cell. Dr. Andrew J. Mouland and colleagues have discovered how the RNA genome gets transported or trafficked from the nucleus to the plasma membrane.

"There is a highway inside the human cell," explained Dr. Mouland, Associate Professor at McGill's Departments of Medicine and Microbiology and Immunology and head of the HIV-1 RNA Trafficking Laboratory at the Lady Davis Institute. "When you drive your car to Toronto you're 'trafficking' the items in your trunk. Similarly, what we have shown is that HIV-1 commandeers the host cell's endosomal machinery to traffic its structural proteins and RNA genome. Imagine that it's essentially jumping on board for the ride and directing it to where it needs to go. This trafficking can occur very fast in cells; so this is how these key components of HIV-1 so efficiently get to the plasma membrane, where the virus can begin to assemble.........

Posted by: Mark      Read more         Source


June 3, 2009, 5:08 AM CT

Efforts to quickly develop swine flu vaccine

Efforts to quickly develop swine flu vaccine
Researchers around the world are accelerating their efforts to develop a vaccine against the H1N1 influenza virus (Swine flu) as rapidly as possible, reports Genetic Engineering & Biotechnology News (GEN). The need for such a vaccine received a strong impetus from the World Health Organization, which has issued a Phase 5 pandemic alert, a strong signal that the WHO believes a pandemic is imminent, as per the June 1 issue of GEN (www.genengnews.com/articles/chitem.aspx?aid=2938).

"It can take five or six months to come up with an entirely novel influenza vaccine," says John Sterling, Editor in Chief of GEN. "There is a great deal of hope that biotech and pharma companies might be able to have something ready sooner".

One company, Replikins, actually predicted over a year ago that significant outbreaks of the H1N1 flu virus would occur within 6-12 months. The predictions were based on correlations of flu virus specimens and PubMed documentation of major outbreaks during the past 90 years, focusing on concentrations of, and spacings between, replikinsthe lysine and histidine residues in the hemagglutinin (HA) unit genetic sequences of the eight major genes in the influenza virus. Replikins' officials say the company's PanFLu vaccine is ready for clinical trials.........

Posted by: Mark      Read more         Source


May 27, 2009, 9:08 PM CT

New cellular targets for HIV drug development

New cellular targets for HIV drug development
Focusing HIV drug development on immune cells called macrophages instead of traditionally targeted T cells could bring us closer to eradicating the disease, as per new research from University of Florida and five other institutions.

In the largest study of its kind, scientists observed that in diseased cells such as cancer cells that are also infected with HIV, almost all the virus was packed into macrophages, whose job is to "eat" invading disease agents.

What's more, up to half of those macrophages were hybrids, formed when pieces of genetic material from several parent HIV viruses combined to form new strains.

Such "recombination" is responsible for formation of mutants that easily elude immune system surveillance and escape from anti-HIV drugs.

"Macrophages are these little factories producing new hybrid particles of the virus, making the virus probably even more aggressive over time," said co-author of study Marco Salemi, Ph.D., an assistant professor in the department of pathology, immunology and laboratory medicine at the UF College of Medicine. "If we want to eradicate HIV we need to find a way to actually target the virus specifically infecting the macrophages".

The work was published recently in the journal PLoS ONE........

Posted by: Mark      Read more         Source



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Did you know?
Scientists at Baylor College of Medicine in Houston have found a genetic marker that may identify individuals at greater risk for life-threatening infection from the West Nile virus. Results of the study are reported in the Nov. 15 print edition of Journal of Infectious Diseases.

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