June 10, 2009, 9:32 PM CT
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 10, 2009, 9:02 PM CT
Now you can buy a kit to test for prostate cancer
Photo: Jacque Brund
Dr. Qun "Treen" Quo works with gold nanoparticles in her lab.
An over-the-counter prostate cancer test kit could be coming to a pharmacy near you, thanks to the collaborative work of a University of Central Florida chemist and M.D. Anderson Cancer Center Orlando researchers.
UCF's Qun "Treen" Huo and M.D. Anderson-Orlando's Dr. Cheryl Baker and Jimmie Colon teamed up about 18 months ago with a very ambitious plan. Huo wanted to develop an effective, inexpensive test to screen for prostate cancer that would be easy enough to use at home or a local pharmacy.
"Now cancer tests are so inconvenient and expensive, and a lot of people don't have insurance, so they are not likely to test if they have no symptoms," Huo said. "Cancer is really scary because there aren't a lot of symptoms in the early stages. So I said, 'Why not create a test that is easy and inexpensive? Then more people can test and catch cancer early so it can be treated early.'".
Prostate cancer affects one of every six men and is the second-most common cancer among men in the United States, as per the American Cancer Society. It is estimated that more than 2 million American men are currently living with prostate cancer and that one new case occurs every 2.7 minutes. More than 27,000 men die from the disease each year, as per the American Cancer Society.........
Posted by: Mark Read more Source
June 10, 2009, 8:44 PM CT
Tamoxifen is a widely used and highly successful drug in the treatment of breast cancer, though resistance to tamoxifen is still a concern in recurrent disease (affecting 25-35% of patients), since therapy resistant metastatic tumor cells are a major cause of death. In a study in this month's Molecular and Cellular Proteomics,
researchers have uncovered a protein profile that may accurately predict whether a cancer will be tamoxifen resistant.
Arzu Umar and colleagues in the Netherlands and Washington examined thousands of tumor cells taken from 51 tamoxifen therapy-sensitive and therapy-resistant tumors using a combination of proteomic and mass-spectrometry approaches. Their analysis revealed a set of 100 proteins that were expressed at different abundance levels in the two tumor groups, highlighting a potential profile for tamoxifen resistance.
In addition, they analyzed the most significantly altered protein, called extracellular matrix metalloproteinase inducer, or EMMPRIN, in a separate set 156 breast tumor tissue samples. EMMPRIN levels were higher in tamoxifen-resistant tumors and significantly associated with an earlier tumor progression following first line tamoxifen treatment and poor clinical outcome, suggesting EMMPRIN may be a reliable marker for highly aggressive breast cancer.........
Posted by: Janet Read more Source
June 9, 2009, 5:14 AM CT
Diabetes patients should have regular exercise
To reduce their cardiovascular risk, people with type 2 diabetes should do at least two-and-a-half hours per week of moderate-intensity or one-and-a-half hours per week of vigorous-intensity aerobic exercises, plus some weight training, as per an American Heart Association scientific statement published in Circulation: Journal of the American Heart Association.
The global increase in overweight and obesity has led to an "unprecedented epidemic" in type 2 diabetes (when the body is unable to use insulin efficiently to help turn glucose, or blood sugar, into energy for the body's cells). In 2007, type 2 diabetes in the United States cost an estimated $174 billion in direct medical costs and indirect costs such as disability, lost productivity and premature death. That amount represents a 30 percent increase from the $132 billion estimated in 2002, as per the statement.
Furthermore, heart and blood vessel disease is responsible for nearly 70 percent of deaths in people with type 2 diabetes.
"Given the observed increases in type 2 diabetes in adults over the last few decades in developed countries, and the increasing numbers of overweight and obese individuals throughout the world, we must look at ways to reduce the cardiovascular complications of diabetes, and exercise is one of those ways," said Thomas H. Marwick, M.D., Ph.D., chair of the writing group and professor of medicine and director of the Centre of Clinical Research Excellence in Cardiovascular and Metabolic Disease at the University of Queensland School of Medicine in Brisbane, Australia.........
Posted by: JoAnn Read more Source
June 9, 2009, 5:02 AM CT
Computer-related injuries on the rise
While back pain, blurred vision and mouse-related injuries are now well-documented hazards of long-term computer use, the number of acute injuries connected to computers is rising rapidly. As per a research studyreported in the July 2009 issue of the American Journal of Preventive Medicine
, scientists from the Center for Injury Research and Policy and The Research Institute at Nationwide Children's Hospital; and The Ohio State University College of Medicine, Columbus have found a more-than-sevenfold increase in computer-related injuries due to tripping over computer equipment, head injuries due to computer monitor falls and other physical incidents.
As per data from the National Electronic Injury Surveillance System database, over 78,000 cases of acute computer-related injuries were treated in U.S. emergency departments from 1994 through 2006. Approximately 93% of injuries occurred at home. The number of acute computer-related injuries increased by 732% over the 13-year study period, which is more than double the increase in household computer ownership (309%).
Injury mechanisms included hitting against or catching on computer equipment; tripping or falling over computer equipment; computer equipment falling on top of the patient; and the straining of muscles or joints. The computer part most often linked to injuries was the monitor. The percentage of monitor-related cases increased significantly, from 11.6% in 1994 to a peak of 37.1% in 2003. By 2006, it had decreased to 25.1%. The decrease since 2003 corresponds to the replacement of heavier cathode ray tube (CRT) monitors with smaller and easier-to-lift liquid crystal display (LCD) monitors.........
Posted by: Janet Read more Source
June 9, 2009, 5:00 AM CT
Dynamic stroma microenvironment in prostate cancer
As stroma the supportive framework of the prostate gland react to prostate cancer, changes in the expression of genes occur that induce the formation of new structures such as blood vessels, nerves and parts of nerves, said scientists at Baylor College of Medicine in a report that appears in the current issue of the journal Clinical Cancer Research
In this study, using special techniques and gene chips that allowed them to sample the entire genome, the scientists found changes in 1,141 genes. They were either upregulated meaning that there was more of the protein with which they were associated than expected or downregulated, which meant the opposite, said Dr. Michael Ittmann, professor of pathology at BCM and a senior author of the report. These gene changes may explain why men with reactive stroma face a more aggressive disease, said Ittmann and Dr. Gustavo Ayala, professor in the departments of pathology and urology at BCM and another senior author.
"Often in prostate cancer, you don't see much change in the stromal cells," said Ittmann. "However, in this subgroup of patients (in which the stroma become visibly reactive), you see a histologically recognizable change in the appearance of the stroma. Dr. Ayala has shown previously that this correlates with a bad prognosis. We know the stroma are doing something to promote bad behavior in cancer cells".........
Posted by: Mark Read more Source
June 8, 2009, 10:10 PM CT
Fatal brain disease at work
University of Florida scientists David Borchelt and Mercedes Prudencio have discovered why a paralyzing brain disorder speeds along more rapidly in some patients than others -- a finding that may finally give researchers an entry point toward an effective treatment for amyotrophic lateral sclerosis, often referred to as ALS or Lou Gehrig's disease.
Credit: Sarah Kiewel/University of Florida
University of Florida researchers have discovered why a paralyzing brain disorder speeds along more rapidly in some patients than others a finding that may finally give scientists an entry point toward an effective therapy for amyotrophic lateral sclerosis, often referred to as ALS or Lou Gehrig's disease.
Of more than 100 possible mutations of a single gene inherited by people with familial ALS, the mutations most inclined to produce clumps of problematic cellular debris known as "protein aggregates" appear to be linked to quicker progress of the disease, as per scientists with the University of Florida's McKnight Brain Institute writing online this week in Human Molecular Genetics
Meanwhile, in a separate study recently online in the Proceedings of the National Academy of Sciences,
researchers describe how these protein clumps long considered a defining characteristic of ALS do not cause the disease, but appear later on, increasing in number between onset of weakness and paralysis in patients.
Together, these findings suggest that the deadly course of the disease is associated with the formation of these protein clumps, even though the sickness may have been well under way.
"Blocking aggregation of these proteins could be a therapeutic target for individuals with this genetic mutation," said David Borchelt, Ph.D., a professor of neuroscience and director of the SantaFe HealthCare Alzheimer's Disease Research Center at UF's McKnight Brain Institute. "Right now, there is little that can be done to help these patients".........
Posted by: Daniel Read more Source
June 5, 2009, 5:05 AM CT
Crowded Emergency Departments and Patients with Heart Attacks
Patients with heart attacks and other forms of chest pain are three to five times more likely to experience serious complications after hospital admission when they are treated in a crowded emergency department (ED), as per a newly released study reported in the journal Academic Emergency Medicine. The authors say that this dramatic difference in rates of serious complications underscores the need for action on the part of hospital administrators, policymakers and emergency physicians to find solutions to what has been termed "a national public health problem." More than six million patients per year come to U.S. emergency departments with chest pain.
"What shocked us is that these complications were not explained by what goes on in the ED, like getting aspirin or a rapid electrocardiogram," says main author Jesse M. Pines, M.D., MBA, an assistant professor of emergency medicine and epidemiology at the Hospital of the University of Pennsylvania and a senior fellow at the Leonard Davis Institute of Health Economics. "The adverse events occurred after the patient had been admitted to the hospital. Emergency department crowding is really more of a marker of a dysfunctional hospital".
The study followed 4,574 patients who were admitted to the Hospital of the University of Pennsylvania for symptoms of chest pain over an eight-year period. Ultimately, 802 were diagnosed with an acute coronary syndrome (chest pain of cardiac origin); of those, 273 had a true heart attack. There were 251 complications that occurred in the hospital after initial emergency department therapy. Complications included serious events, such as heart failure, delayed heart attacks, dangerously low blood pressure, heart arrhythmias and cardiac arrest.........
Posted by: Daniel Read more Source
June 5, 2009, 5:03 AM CT
Pesticide Exposure and Parkinson's Disease
The cause of Parkinson's disease (PD), the second most frequent neurodegenerative disease after Alzheimer's disease, is unknown, but in most cases it is believed to involve a combination of environmental risk factors and genetic susceptibility. Laboratory studies in rats have shown that injecting the insecticide rotenone leads to an animal model of PD and several epidemiological studies have shown an association between pesticides and PD, but most have not identified specific pesticides or studied the amount of exposure relating to the association.
A new epidemiological study involving the exposure of French farm workers to pesticides observed that professional exposure is linked to PD, particularly for organochlorine insecticides. The study is published in Annals of Neurology, the official journal of the American Neurological Association.
Led by Alexis Elbaz M.D., Ph.D., of Inserm, the national French institute for health research in Paris, and University Pierre et Marie Curie (UPMC, Paris 6), the study involved individuals affiliated with the French health insurance organization for agricultural workers who were frequently exposed to pesticides in the course of their work. Occupational health physicians constructed a detailed lifetime exposure history to pesticides by interviewing participants, visiting farms, and collecting a large amount of data on pesticide exposure. These included farm size, type of crops, animal breeding, which pesticides were used, time period of use, frequency and duration of exposure per year, and spraying method.........
Posted by: Daniel Read more Source
June 5, 2009, 4:44 AM CT
Risks of sharing personal genetic information online
With just $399 and a bit of saliva in a cup, consumers can learn about their genetic risk for diseases from breast cancer to diabetes. Now, thanks to social networking sites set up by personal genomics companies, they can also share that information with family, friends and even strangers on the Internet.
Bonding over a similar genetic background sounds relatively harmless. But as per bioethicists from the Stanford University School of Medicine, sharing genetic information online raises a host of ethical questions.
"Genetic information is unique in that it's not only relevant for the individuals who receive the information, but also for their family members, their children and even their children's children," said Sandra Soo-Jin Lee, PhD, senior research scholar at the school's Center for Biomedical Ethics.
Because genetic information applies to more than one person, issues of privacy and consent become complicated. "For example," Lee said, "if you receive information on your breast cancer risk and share it with others, you might also be sharing information about your daughter's risk for breast cancer even though she never consented to have that information shared".
In cooperation with assistant professor of pediatrics and bioethicist LaVera Crawley, MD, MPH, Lee has been studying the potential implications of exchanging genetic information online. To fully understand the effects of sharing, the scientists say we need more data on who's giving out information and how it's being used. Their recommendations will be published in a special double-issue of the American Journal of Bioethics
on June 5.........
Posted by: Scott Read more Source