October 13, 2009, 8:15 AM CT
Alzheimer's disease: Declines in thinking and learning skills
Cognitive abilities other than memory, including visuospatial skills needed to perceive relationships between objects, may decline years previous to a clinical diagnosis in patients with Alzheimer's disease, as per a report in the recent issue of Archives of Neurology,
one of the JAMA/Archives journals.
"Recent studies have focused on identifying the beginning of the transition from healthy aging to dementia," the authors write as background information in the article. "As new interventions become available, it will become important to identify the disease as early as possible." Loss of episodic memoryremembering events in one's life that can be explicitly statedis usually associated with Alzheimer's disease, but it is not the only aspect of cognition (thinking, learning and memory) that is affected.
David K. Johnson, Ph.D., of the University of Kansas, Lawrence, and his colleagues assessed 444 individuals who did not have dementia when they were enrolled in the study, between 1979 and 2006. Upon enrolling, each participant underwent a clinical assessment and a psychometric evaluation including tests of four cognitive factors: global cognition, verbal memory, visuospatial skill and working memory. Participants were then reviewed at least one additional time before November 2007.........
Posted by: Daniel Read more Source
October 13, 2009, 7:48 AM CT
Parkinsonism and urate level
Parkinson disease progresses more slowly in patients who have higher levels of urate, a chemical that at very high level is linked to gout, researchers have found. While it's unknown whether the high levels actually somehow protect patients or simply serve as a marker of protection, the finding supports the idea that patients and doctors may one day be able to better predict the course of the illness.
The study, led by researchers at Massachusetts General Hospital and the Harvard School of Public Health and including physicians at the University of Rochester Medical Center, was published online in the Archives of Neurology
The new findings are based on biological samples, primarily blood and cerebrospinal fluid, collected from people with Parkinson disease who participated in a landmark study known as DATATOP, which was conducted two decades ago.
DATATOP, conceived and led by Rochester neurologist Ira Shoulson, M.D., is best known for shifting the landscape of neurology clinical research. Shoulson convinced dozens of researchers around the world to work together, pooling their resources to ask questions about potential new therapys for the disease big questions that could be answered only with participation by hundreds of people with the disease.........
Posted by: Daniel Read more Source
October 12, 2009, 7:17 AM CT
Clues to human disease from blood counts
A new genome-wide association study published recently in Nature Genetics
begins to uncover the basis of genetic variations in eight blood measurements and the impact those variants can have on common human diseases. Blood measurements, including the number and volume of cells in the blood, are routinely used to diagnose a wide range of disorders, including anaemia, infection and blood cell cancers.
An international team of researchers measured haemoglobin concentration, the count and volume of red and white cells and the sticky cells that prevent bleeding - platelets, in over 14,000 individuals from the UK and Gera number of. They uncovered 22 regions of the human genome implicated in the development of these blood cells. Of the 22 regions, 15 had not previously been identified.
The study represents the first genome-wide association of blood measurements to be completed in cohorts with large sample sizes.
"This study has been made possible by a great collaboration of researchers from the UK and Gera number of, and the contribution of clinical colleagues working in the field of heart disease, diabetes and coeliac disease in the UK, Gera number of and the United States," explains Dr Nicole Soranzo, group leader at the Wellcome Trust Sanger Institute and co-lead of the HaemGen consortium. "This unique collaboration has allowed us to discover novel genetic determinants of blood cell parameters, providing important insights into novel biological mechanisms underlying the formation of blood cells by the blood stem cells and their role in disease.........
Posted by: Janet Read more Source
October 9, 2009, 7:17 AM CT
Amyotrophic lateral sclerosis
Premature aging of the immune system appears to play a role in the development of amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease, as per research researchers from the Maxine Dunitz Neurosurgical Institute at Cedars-Sinai Medical Center, the Weizmann Institute of Science in Israel, and Sheba Medical Center in Israel.
A study reported in the Journal of Cellular and Molecular Medicine
shows that CD4+ T cells, which grow and mature in the thymus before entering the bloodstream, are reduced in number in patients who have ALS as the thymus shrinks and malfunctions. Theoretically, devising therapies to support or replace these cells could be a strategy in treating the disease.
The research was led by Michal Schwartz, Ph.D., a visiting professor at the Center of Neuroimmunology and Neurogenesis in the Department of Neurosurgery at Cedars-Sinai and professor of neuroimmunology at the Weizmann Institute in Rehovot, Israel.
The findings are consistent with evidence collected over a decade by Schwartz's group suggesting that a well-functioning immune system plays a pivotal role in maintaining, protecting and repairing cells of the central nervous system. Studies conducted in animals have shown that boosting immune T-cell levels may reduce symptoms and slow progression of certain neurodegenerative diseases.........
Posted by: Daniel Read more Source
October 7, 2009, 8:01 PM CT
Why African American lung cancer patients respond differently?
Clinical research out of University Hospitals Case Medical Center has observed that African Americans with a common form of lung cancer have a lower frequency of drug-sensitizing genetic mutations, which may impact response to new cancer-fighting drugs. Published online in the Journal of Clinical Oncology,
the study by Rom Leidner, MD, and his colleagues report that ethnicity plays a significant role in non-small cell lung cancer (NSCLC) genetics and more personalized therapys appears to be beneficial to cancer patients.
African American patients with NSCLC are significantly less likely than Caucasian counterparts to harbor activating mutations of the epidermal growth factor receptor (EGFR) gene in their cancers, which suggests that common oral EGFR inhibitor drugs, such as Tarceva (erlotinib), are unlikely to yield dramatic remissions. Additionally, cancer biopsy testing revealed that African American patients with NSCLC are significantly more likely to have increased copies of the EGFR gene than Caucasians. Detection of increased copies of the Her2 gene in breast cancer, a gene closely correlation to EGFR, has been the basis for major advances in treatment using drugs which target Her2.
"We are finding that ethnicity may play a significant role in a variety of cancers," says Dr. Leidner, an oncologist with Ireland Cancer Center of University Hospitals Case Medical Center and Visiting Instructor at Case Western Reserve University School of Medicine. "It was already known that a higher proportion of East Asian NSCLC patients harbor mutations of the EGFR gene than Caucasians, and that these mutations are linked to a higher likelihood of major responses to EGFR inhibitors. Before our study, however, surprisingly little data existed for African American patients with this common type of lung cancer."........
Posted by: Scott Read more Source
October 6, 2009, 7:16 AM CT
Resveratrol, brain and diabetes
Resveratrol, a molecule found in red grapes, has been shown to improve diabetes when delivered orally to rodents. Until now, however, little has been known about how these beneficial changes are mediated in the body. A newly released study accepted for publication in Endocrinology
, a journal of The Endocrine Society, shows that the brain plays a key role in mediating resveratrol's anti-diabetic actions, potentially paving the way for future orally-delivered diabetes medications that target the brain.
Resveratrol activates sirtuins, a class of proteins that are thought to underlie a number of of the beneficial effects of calorie restriction. Prior studies in mice have provided compelling evidence that when sirtuins are activated by resveratrol, diabetes is improved. Sirtuin activators are now being tested in humans as anti-diabetic compounds.
Sirtuins are expressed virtually everywhere throughout the body and until now, little has been known about what tissues mediate resveratrol's beneficial effects. Knowing where in the body the beneficial effects of activated sirtuins are mediated could help in the development of more effective targeted diabetes medications.
"We know that sirtuins are expressed in parts of the brain known to govern glucose metabolism, so we hypothesized that the brain could be mediating resveratrol's anti-diabetic actions," said Roberto Coppari, PhD, of the University of Texas Southwestern Medical Center and co-author of the study. "To test the hypothesis, we assessed the metabolic consequences of delivering resveratrol directly into the brain of diabetic mice. We observed that resveratrol did activate sirtuins in the brain of these mice which resulted in improving their high levels of blood sugar and insulin".........
Posted by: JoAnn Read more Source
October 1, 2009, 6:58 AM CT
Infliximab reduces need for surgery in ulcerative colitits
A newly released study led by Mayo Clinic scientists has observed that ulcerative colitis patients had a 41 percent reduction in colectomy after a year when treated with infliximab, as per a research studyreported in the October 2009 issue of Gastroenterology.
Typically ulcerative colitis, an inflammatory bowel disease (ibd) that causes chronic inflammation of the colon, is characterized by abdominal pain and diarrhea. Like Crohn's disease, another common IBD, ulcerative colitis can be debilitating and often lead to colectomy or surgical removal of the colon.
"Our purpose in this study was to see if the use of infliximab for ulcerative colitis would reduce the need for surgery," says William Sandborn, M.D., a Mayo Clinic gastroenterologist and main author of the study. "We observed that therapy with infliximab reduced the need for colectomy by 41 percent in comparison to patients treated with placebo."
In this multi-center, international study, 728 patients received placebo or infliximab (5 or 10 mg/kg) for 46 weeks and were monitored for hospitalization or surgical outcomes. Eighty-seven percent (630 of 728) had complete follow-up for the endpoint of whether or not they had colectomy, while the remaining 13 percent (98 of 728) of patients had follow-up for less then a year, with a median follow-up of 6.2 months in these patients. The research showed that therapy with infliximab at 0, 2 and 6 and then every 8 weeks reduced the occurence rate of colectomy through 54 weeks by 41 percent in outpatients with moderately-to-severe active ulcerative colitis.........
Posted by: Sue Read more Source
September 30, 2009, 6:56 AM CT
How old is your muscle?
Young, healthy muscle (left column) appears pink and red. In contrast, the old muscle is marked by scarring and inflammation, as evidenced by the yellow and blue areas. This difference between old and young tissue occurs both in the muscle's normal state and after two weeks of immobilization in a cast. Exercise after cast removal did not significantly improve old muscle regeneration; scarring and inflammation persisted, or worsened in many cases.
Credit: Photos by Morgan E. Carlson and Irina M. Conboy, UC Berkeley
A study led by scientists at the University of California, Berkeley, has identified critical biochemical pathways associated with the aging of human muscle. By manipulating these pathways, the scientists were able to turn back the clock on old human muscle, restoring its ability to repair and rebuild itself.
The findings will be published in the Sept. 30 issue of the journal EMBO Molecular Medicine
, a peer-evaluated, scientific publication of the European Molecular Biology Organization.
"Our study shows that the ability of old human muscle to be maintained and repaired by muscle stem cells can be restored to youthful vigor given the right mix of biochemical signals," said Professor Irina Conboy, a faculty member in the graduate bioengineering program that is run jointly by UC Berkeley and UC San Francisco, and head of the research team conducting the study. "This provides promising new targets for forestalling the debilitating muscle atrophy that accompanies aging, and perhaps other tissue degenerative disorders as well".
Prior research in animal models led by Conboy, who is also an investigator at the Berkeley Stem Cell Center and at the California Institute for Quantitative Biosciences (QB3), revealed that the ability of adult stem cells to do their job of repairing and replacing damaged tissue is governed by the molecular signals they get from surrounding muscle tissue, and that those signals change with age in ways that preclude productive tissue repair.........
Posted by: Janet Read more Source
September 29, 2009, 10:35 PM CT
Stem cell success to regenerate parathyroid glands
An early laboratory success is taking University of Michigan scientists a step closer to parathyroid gland transplants that could one day prevent a currently untreatable form of bone loss linked to thyroid surgery.
The researchers were able to induce embryonic stem cells to differentiate into parathyroid cells that produced a hormone essential to maintaining bone density. The laboratory results in live cell cultures, published in Stem Cells and Development
, need to be tested in further pre-clinical studies.
Parathyroid glands, four glands each the size of a rice grain that lie next to the thyroid in the neck, are easily damaged when surgeons operate on patients with malignant or non-malignant thyroid tumors. Without their calcium-regulating hormone, patients can develop osteomalacia, a severe form of bone loss similar to rickets that affects tens of thousands of people in the United States with muscle cramps and numbness in the hands and feet.
"We used human embryonic stem cells as a model for ways to work out the recipe to make parathyroid cells," says Gerard M. Doherty, M.D., chief of endocrine surgery and Norman W. Thompson Professor of Endocrine Surgery at U-M Medical School.
The research illustrates the payoff of rapidly increasing knowledge about how embryonic stem cells give rise to other kinds of cells. That knowledge can be the springboard for influencing other cells to regenerate damaged parts of the body.........
Posted by: Scott Read more Source
September 24, 2009, 7:12 AM CT
Acetaminophen rmay prevent muscle loss
Recent studies conducted by Dr. Eric Blough and colleagues at Marshall University have shown that use of the common pain reliever acetaminophen may help prevent age-associated muscle loss and other conditions.
Their study examined how acetaminophen may affect the regulation of protein kinase B (Akt), an enzyme known to play an important role in regulation of cellular survival, proliferation and metabolism.
The researchers' data indicates that aging skeletal muscles experience a decrease in the proper functioning of the enzyme and that acetaminophen intervention in aged animals could be used to restore Akt activity to a level comparable to that seen in young animals. In turn, this improvement in Akt activity was linked to improvements in muscle cell size and decreased muscle cell death.
"Using a model that closely mimics a number of of the age-associated physiological changes observed in humans, we were able to demonstrate that chronic acetaminophen therapy in a recommended dosage is not only safe but might be beneficial for the therapy of the muscle dysfunction a number of people experience as they get older," said Blough, an associate professor in the university's Department of Biological Sciences.
The lab's work, which was reported in the July 29 issue of the international research journal PLoS One, is the first study to show that acetaminophen ingestion, at least in animals, can be safely used for the therapy of age-related muscle loss. This finding could have far-reaching implications, given the fact that people age 65 and older make up the fastest-growing segment of the U.S. population.........
Posted by: Janet Read more Source