April 15, 2007, 8:36 PM CT
DNA Test Can Be Early Predictor Of Liver Cancer
Scientists at Columbia Universitys Mailman School of Public Health have discovered a means for early detection of liver cancer. Using DNA isolated from serum samples as a baseline biomarker, the researchers examined changes in certain tumor suppressor genes that have been linked to the development of liver carcinomas. This is the first study to prospectively examine potential biomarkers for early detection of liver cancer in high-risk populations, including those with chronic hepatitis B and C virus infections.
Since most hepatocellular or liver carcinomas (HCC) are diagnosed at an advanced and commonly fatal stage, the development of screening methods for early detection is critical. HCC is one of the most common and rapidly fatal human malignancies. Worldwide, the almost 500,000 new cases and nearly equivalent number of fatalities illustrates the lack of effective therapeutic alternatives for this disease.
The Mailman School scientists and his colleagues studied the blood of patients enrolled in a cancer screening program in Taiwan, who provided repeated blood samples previous to diagnosis. A total of 12,000 males and over 11,900 females recruited in 1991-2 are being followed. Screenings performed by the team of Mailman School researchers found changes linked to cancer in serum DNA, presumably released from the tumor, one to nine years before actual clinical diagnosis.........
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April 15, 2007, 8:33 PM CT
Factors Attributed To Later Stage Cancer Diagnosis
Scientists from the Keck School of Medicine of the University of Southern California (USC) observed that patients who received a later stage cancer diagnosis were likely to be living in an unsafe neighborhood, using public transportation and traveling at least 45 minutes to get to a doctor's office. The study will be presented at this week's American Association of Cancer Research (AACR) in Los Angeles on April 15.
A survey of more than 350 stomach and kidney cancer patients in Los Angeles revealed patients were more likely to receive a later stage cancer diagnosis because of a combination of personal risk factors and neighborhood conditions.
"In this study, we looked at three types of factors that may cause late detection of cancer, including personal risk factors, neighborhood factors and the combination of both, " says lead author Ann Hamilton, Ph.D., assistant professor of preventive medicine of the Keck School of Medicine. "Using census tract, we wanted to see if where someone lived posed any risks for later stage diagnosis in addition to personal risk factors".
The study cites two general types of personal risk factors that correlate to later detection. Socio-ecological and cultural factors, including unsafe neighborhoods, lower level of education, language barriers and lack of transportation, were linked to a higher risk. Also, patients who gave medical care low priority because of busy work or family lives demonstrated a higher risk for late diagnosis.........
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April 15, 2007, 8:30 PM CT
Genetic Risk Factors For Crohn's Disease
An international research team including researchers from Massachusetts General Hospital (MGH) and the Broad Institute of Harvard University and Massachusetts Institute of Technology has identified several novel genetic variations linked to the risk of Crohn's disease. One of the identified genes establishes a role for autophagy, a previously unsuspected biological pathway, in Crohn's disease pathology; and the report documents functional studies which establish that this gene is integral to immune responses to intestinal bacteria. The report will appear in the journal Nature Genetics and is receiving early online release.
"Our discovery of several new genetic risk factors for Crohn's should improve understanding of the true causes of this disease and reveal new causal pathways that can be targeted therapeutically," says Mark Daly, PhD, of the MGH Center for Human Genetics Research and the Broad Institute, co-senior author of the Nature Genetics paper. "The study takes advantage of new knowledge of genetic variation patterns and new technology for assessing genetic variation that have only recently become available."
A chronic inflammatory bowel disease for which no single causative factor has been identified, Crohn's commonly affects the small intestine, causing abdominal pain and chronic diarrhea. Serious symptoms can include ulceration, bleeding, the development of fistulas openings from affected areas into other organs or intestinal blockage. About half a million people in the U.S.are affected by Crohn's, and another half-million have a related condition called ulcerative colitis. Since Crohn's can run in families and is more common in some ethnic populations, it is likely to have genetic components. Prior studies have identified two genetic variations as increasing the risk for Crohn's, but those factors only account for a small percentage of inherited cases.........
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April 13, 2007, 5:17 PM CT
How Microbes start immune response
Immune cells that are the bodys front-line defense dont necessarily rest quietly until invading bacteria lock onto receptors on their outside skins and rouse them to action, as previously thought. In a new paper, University of Michigan researchers describe their findings that bacteria can barge inside these guard cells and independently initiate a powerful immune response.
The study, published online ahead of print in the recent issue of the journal Immunity and accompanied by a special commentary, adds important new details to an emerging picture of how the body recognizes invading bacteria and responds. The work of the U-M team and scientists elsewhere now taking place in laboratory animal studies offers a different way of thinking about how best to design future human vaccines, as well as drugs that could more precisely target the bodys inflammatory response in rheumatoid arthritis and some other autoimmune diseases.
In our study, the presence of bacterial microbes inside the cell is what triggers the immune response. That creates a new perspective for developing new drugs, says senior author Gabriel Nunez, M.D., the Paul H. de Kruif professor of pathology at the U-M Medical School and a member of the U-M Comprehensive Cancer Center.
For years, researchers have believed that when bacteria invade the body, they set off alarms in the immune system by interacting with receptors on a cells surface. But, now new studies are revealing that bacteria can also plunge inside immune system cells and trigger the immune response there. In the new study, Nunez team sheds light on one major pathway in which this process occurs.........
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April 13, 2007, 4:57 PM CT
Hope For Early Diagnosis Of Alzheimer's
Research by faculty and staff at Rowan University, Glassboro, N.J.; the University of Pennsylvania School of Medicine; and Drexel University may lead to better diagnosis of early-stage Alzheimers disease.
In a $1.1-million National Institutes of Healths National Institute on Aging study that team members conducted during the last three years, they determined early Alzheimers could be diagnosed with a high rate of accuracy evaluating electroencephalogram (EEG) signals. The study may lead to an earlier diagnosis, and therefore earlier therapy and improved quality of life, for people at the earliest stages of the disease.
As per the Alzheimers Association, the condition affects more than 5 million Americans, approximately 1.5 percent of the population. That number is only expected to grow.
Rowan University electrical and computer engineering associate professor Dr. Robi Polikar conducted the research with Dr. Christopher Clark, associate professor of neurology, associate director of the NIH-sponsored Alzheimer's Disease Center at Penn and director of the Penn Memory Center, and with Dr. John Kounios, a Drexel psychology professor.........
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April 13, 2007, 4:54 PM CT
Childhood obesity among Quebec Cree
Childhood obesity is increasing among the general population in Canada, but the statistics are even more alarming among First Nations, Inuit and Mtis children. As per a research findings published recently in the American Journal of Public Health, University of Alberta scientists observed that up to 65 per cent of Cree preschoolers in northern Quebec communities were overweight or obese.
Dr. Noreen Willows, a community nutritionist at the University of Alberta, and her colleagues also studied obesity levels in Cree schoolchildren aged 9 to 12 living in two Cree Nations north of Montreal, Canada. The scientists measured height, body mass, waist circumference and skinfold thickness, and also assessed the childrens levels of physical activity and physical fitness. The results from one community, reported in the International Journal of Circumpolar Health, indicated of the 82 participating children, 33 per cent were overweight and 38 per cent were obese.
High waist circumferences were of particular concern, as this measure is often associated with the development of cardiovascular diseases and diabetes. Further study is needed to identify the causes behind the high obesity rates, but in general, the elementary school students exhibited very low levels of physical fitness and physical activity. Diet is another obvious possibility to consider.........
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April 13, 2007, 4:48 PM CT
Not Just a Menopausal Symptom
new study in Psychophysiology confirms a surprising fact - men who have undergone chemical castration for conditions such as prostate cancer experience hot flashes similar to those experienced by menopausal women. Using a technique called sternal skin conductance, doctors were able to positively identify hot flashes in males, a positive step toward providing treatment for those patients in need.
"Most people are unaware that men can have hot flashes," says study author Dr. Laura Hanisch. "Even the patients themselves are often unaware that they are having them." Having a test that objectively measures when hot flashes are occurring can help both doctors and patients identify the episodes, and can assist scientists in finding their root cause.
"If we can use sternal skin conductance to monitor the frequency and perception of hot flashes, the data could then be used to develop safe and effective therapys that would be a better alternative than taking hormone therapys or discontinuing cancer-related therapys," says Hanisch.
Hanisch also says that hot flashes going unnoticed may be a sign that people can adapt to them. Therefore, patients could possibly benefit from cognitive behavioral treatment in addition to pharmacological therapys.........
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April 13, 2007, 4:43 PM CT
New Reflux Guidelines Released
New, updated guidelines for esophageal reflux testing appear in The American Journal of Gastroenterology. Developed and approved by the American College of Gastroenterology, these guidelines summarize advances in gastroesophageal reflux disease (GERD) diagnostic testing and how they have modified the clinical management of esophageal disorders.
"Gastroenterologists are confronted with an increasing number of patients presenting symptoms of GERD that are unresponsive to drug treatment," says lead author Dr. Ikuo Hirano. "These patients may have typical reflux symptoms of heartburn and regurgitation but also may complain of chest pain, asthma, chronic cough and chronic laryngitis." This confusing list of symptoms, coupled with the fact that a number of of these patients do not have visible esophageal erosions, makes diagnosis and therapy of GERD a challenge. Furthermore, non-gastrointestinal entities, such as cardiac or pulmonary disease, may produce symptoms that are similar to those attributable to GERD.
Some new technologies offer opportunities for more accurate diagnoses. "Wireless capsule pH monitoring, bile acid reflux monitoring devices and esophageal impedance can all improve the detection of reflux," says Dr. Hirano. These technologies have helped gastroenterologists to discover new forms of reflux, and to better characterize traditional acid reflux.........
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April 11, 2007, 11:09 PM CT
Stress may help cancer cells resist treatment
Researchers from Wake Forest University School of Medicine are the first to report that the stress hormone epinephrine causes changes in prostate and breast cancer cells that may make them resistant to cell death.
"These data imply that emotional stress may contribute to the development of cancer and may also reduce the effectiveness of cancer therapys," said George Kulik, D.V.M., Ph.D., an assistant professor of cancer biology and senior researcher on the project.
The study results are reported on-line in the Journal of Biological Chemistry and will appear in a future print issue.
Levels of epinephrine, which is produced by the adrenal glands, are sharply increased in response to stressful situations and can remain continuously elevated during persistent stress and depression, as per prior research. The goal of the current study was to determine whether there is a direct link between stress hormones and changes in cancer cells.
While a link between stress and cancer has been suggested, studies in large groups of people have been mixed.
"Population studies have had contradictory results," said Kulik. "We asked the question, If stress is associated with cancer, what is the cellular mechanism? There had been no evidence that stress directly changes cancer cells".........
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April 11, 2007, 11:06 PM CT
Genes set scene for metastasis
Biologists at Memorial Sloan-Kettering Cancer Center (MSKCC) have identified a set of genes expressed in human breast cancer cells that work together to remodel the network of blood vessels at the site of the primary tumor. These genes were also found to promote the spread of breast cancer to the lungs. The study, conducted in mice and reported in this week's Nature, helps to explain how cancer metastasis can occur and highlights targets for therapeutic therapy.
Metastasis the leading cause of mortality in cancer patients entails numerous biological functions that collectively enable malignant cells from a primary site to disseminate and overtake distant organs. Many genes are already known to contribute to the spread of breast cancer cells to the lungs.
Using genetic and pharmacological approaches, Joan Massagu, PhD, Chair of MSKCC's Cancer Biology and Genetics Program and a Howard Hughes Medical Institute Investigator, and his colleagues showed how four genes facilitate the formation of new tumor blood vessels, the release of cancer cells into the bloodstream, and the penetration of tumor cells from the bloodstream into the lung. The gene set comprises EREG (an epidermal growth factor receptor ligand), the cyclooxygenase COX2, and MMP1 and MMP2 (matrix enzymes that are expressed in human breast cancer cells).........
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