October 12, 2009, 7:19 AM CT
Mending broken hearts
This is the mold used to create the heart patch.
Credit: Brian Liau
By mimicking the way embryonic stem cells develop into heart muscle in a lab, Duke University bioengineers believe they have taken an important first step toward growing a living "heart patch" to repair heart tissue damaged by disease.
In a series of experiments using mouse embryonic stem cells, the bioengineers used a novel mold of their own design to fashion a three-dimensional "patch" made up of heart muscle cells, known as cardiomyocytes. The new tissue exhibited the two most important attributes of heart muscle cells - the ability to contract and to conduct electrical impulses. The mold looks much like a piece of Chex cereal in which scientists varied the shape and length of the pores to control the direction and orientation of the growing cells.
The scientists grew the cells in an environment much like that found in natural tissues. They encapsulated the cells within a gel composed of the blood-clotting protein fibrin, which provided mechanical support to the cells, allowing them to form a three-dimensional structure. They also observed that the cardiomyocytes flourished only in the presence of a class of "helper" cells known as cardiac fibroblasts, which comprise as much as 60 percent of all cells present in a human heart.
"If you tried to grow cardiomyocytes alone, they develop into an unorganized ball of cells," said Brian Liau, graduate student in biomedical engineering at Duke's Pratt School of Engineering. Liau, who works in the laboratory of assistant professor Nenad Bursac, presented the results of his latest experiments during the annual scientific sessions of the Biomedical Engineering Society in Pittsburgh.........
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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.........
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October 12, 2009, 7:10 AM CT
Using imagination to reduce abdominal pain
Miranda van Tilburg, Ph.D. is a researcher at University of North Carolina School of Medicine.
Credit: UNC Center for Functional GI & Motility Disorders
Children with functional abdominal pain who used audio recordings of guided imagery at home in addition to standard medical therapy were almost three times as likely to improve their pain problem, in comparison to children who received standard therapy alone.
And those benefits were maintained six months after therapy ended, a newly released study by University of North Carolina at Chapel Hill and Duke University Medical Center scientists has found.
The study is reported in the November 2009 issue of the journal Pediatrics
The main author is Miranda van Tilburg, Ph.D., assistant professor in the Division of Gastroenterology and Hepatology in the UNC School of Medicine and a member of the UNC Center for Functional GI & Motility Disorders.
"What is particularly exciting about our study is that children can clearly reduce their abdominal pain a lot on their own with guidance from audio recordings, and they get much better results that way than from medical care alone," said van Tilburg. "Such self-administered therapy is, of course, very inexpensive and can be used in addition to other therapys, which potentially opens the door for easily enhancing therapy outcomes for a lot of children suffering from frequent stomach aches".
The study focused on functional abdominal pain, defined according tosistent pain with no identifiable underlying disease that interferes with activities. It is very common, affecting up to 20 percent of children. Previous studies have observed that behavioral treatment and guided imagery (a therapy method similar to self-hypnosis) are effective, when combined with regular medical care, to reduce pain and improve quality of life. But for a number of children behavioral treatment is not available because it is costly, takes a lot of time and requires a highly trained therapist.........
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October 12, 2009, 7:08 AM CT
Challenging traditional bladder treatment decision
ATLANTA--A statistical model can accurately predict which patients will have poor outcomes after bladder surgery and can determine the need for chemotherapy. The analysis, to be reported in the December 1, 2009 issue of CANCER
, a peer-evaluated journal of the American Cancer Society, concludes that the model, which considers both how far the cancer has spread and other information, such as how the cancer cells look under the microscope and the time between diagnosis and surgery, could better identify patients who need to undergo further therapy.
A number of individuals with bladder cancer have surgery to remove the bladder as an initial therapy. Following surgery, doctors must decide whether to recommend that the patient receive chemotherapy to kill any remaining cancer cells. Chemotherapy is typically recommended only for patients with higher stage disease. However, it is widely accepted that while a number of patients receive chemotherapy unnecessarily, some patients with low stage disease who are not referred to chemotherapy nonetheless experience a cancer recurrence.
Scientists led by Andrew J. Vickers, PhD, of Memorial Sloan-Kettering Cancer Center in New York City set out to determine whether use of a previously published prediction model to inform medical decision making would lead to superior clinical outcomes. To demonstrate their findings, they compared the clinical outcomes of the different routes in which bladder cancer patients would be referred to chemotherapy: based only on cancer stage, as is current practice, or based on the bladder cancer prediction model.........
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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.........
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October 9, 2009, 7:13 AM CT
Patients who received refurbished pacemakers
Patients who received refurbished pacemakers donated from Detroit area funeral homes survived without complications from the devices, as per a case series reported by the University of Michigan Cardiovascular Center.
The pacemakers were implanted in 12 patients at the University of Philippines- Philippine General Hospital who could not afford advanced cardiac care and were confined to their beds as they waited for a permanent pacemaker.
All donated pacemakers functioned normally at six months, and most importantly there were no device complications such as infections. The study appears online ahead of print in the Oct. 13 issue of the Journal of the American College of Cardiology
The argument for pacemaker reuse has been debated for decades. But the idea is gaining ground as U-M cardiology experts report promising results of providing donated pacemakers to underserved nations.
"In light of the widening health care disparity seen between the industrialized world and developing nations, we feel that pacemaker reuse is an ethical obligation to address the medical needs of those who could not afford treatment otherwise," says co-author Timir Baman, M.D., cardiology fellow at the U-M Cardiovascular Center.
Based on surveys showing a majority of heart patients were interested in donating their pacemakers after death, U-M has launched Project My Heart Your Heart.........
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October 8, 2009, 7:50 AM CT
Overweight, breathing and sleep disorders
Overweight individuals are not just at greater risk of having sleep-disordered-breathing (SDB), they are also likely to suffer greater consequences, as per new research.
As per the study, to be reported in the October 15 issue of the American Journal of Respiratory and Critical Care Medicine
, an official publication of the American Thoracic Society, excess weight increased the severity of oxygen desaturation in the blood of individuals with SDB during and after apneas and hypopneas.
"We knew that excess body weight is strongly correlation to more frequent breathing eventsapneas and hypopneasin persons with SDB," said main author Paul E. Peppard, Ph.D., assistant professor of population health sciences at the University of Wisconsin-Madison. "In this study, we wanted to go a step further and measure how much the excess weight contributes to the severity of individual breathing events".
Dr. Peppard and his colleagues recruited 750 adults from the Wisconsin Sleep Cohort study, an ongoing epidemiological investigation into the natural history of SDB, to have their breathing, blood-oxygen levels and sleep analyzed. Participants were also reviewed on several measures of physiquebody mass index (BMI), neck -circumference and waist-to-hip ratio.
Among the participants in the overnight study, 40 percent of whom were obese, there were more than 37,000 SDB events. The scientists observed that many factors influenced the severity of blood oxygen desaturation linked to these events, including age, gender, body position and sleep phase (REM or non-REM sleep). However, even after these other factors were accounted for, the scientists observed that BMI predicted the degree to which the body's tissues were "starved" of oxygen during apneas and hypopneas. In fact, each 10-point increase in BMI predicted a 10 percent increase in the severity of oxygen depletion linked to SDB events.........
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October 8, 2009, 7:49 AM CT
Triple therapy for COPD
Patients with moderate to severe chronic obstructive pulmonary disease (COPD) can benefit from triple treatment that includes a long-acting β-agonist (LABA), an inhaled corticosteroid (ICS) and an anti-muscarinic agent, as per scientists in Gera number of.
In the study, which will appear in the October 15 issue of the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine
, scientists observed that adding budesonide, an ICS, and formoterol, a LABA, to the anti-muscarinic agent, tiotropium, reduced the rate of severe exacerbations in COPD patients by 62 percent. Triple treatment also resulted in significant improvements on many outcome parameters in COPD patients, including lung function, signs and symptoms, and quality of life.
"This approach is of interest because the goal of COPD management is to achieve optimal control," wrote main author, Prof. Tobias Welte, M.D., head of the Department of Respiratory Medicine of the Hannover Medical School in Gera number of.
While current guidelines suggest using both LABA and/or muscarinic antagonists and ICS in only a small number of patients, triple treatment is more widely used in clinical practice than officially recommended, but the benefits have never been demonstrated in a randomized controlled trial.........
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October 8, 2009, 7:45 AM CT
Treatment for early stage acute liver failure
This is Dr. William M. Lee from UT Southwestern Medical Center.
Credit: UT Southwestern Medical Center
The antidote for acute liver failure caused by acetaminophen poisoning also can treat acute liver failure due to most other causes if given before severe injury occurs, UT Southwestern Medical Center scientists and their colleagues at 21 other institutions have found.
Acute liver failure occurs when cells in the liver die quickly, resulting in toxins being released into the bloodstream and brain. Patients often end up in a hepatic coma as a result of toxins not being cleared by the failing liver. Known causes of acute liver failure include autoimmune hepatitis, drug-induced liver injury, hepatitis A and B, and acetaminophen poisoning.
As per a research findings reported in the recent issue of Gastroenterology,
scientists observed that acute liver failure patients in early stages of hepatic comas, when treated with the medicine N-acetylcysteine (NAC), were nearly 2.5 times more likely to survive than those treated only with a placebo.
"NAC is safe, easy to administer, doesn't require intensive care and can be given in community hospitals," said Dr. William M. Lee, professor of internal medicine at UT Southwestern and main author of the study. "NAC is an excellent therapy for non-acetaminophen acute liver failure if the disease is caught early".........
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October 7, 2009, 8:50 PM CT
While adolescents may reason as well as adults
A 16-year-old might be quite capable of making an informed decision about whether to end a pregnancy a decision likely to be made after due consideration and consultation with an adult but this same adolescent may not possess the maturity to be held to adult levels of responsibility if she commits a violent crime, as per new research into adolescent psychological development.
"Adolescents likely possess the necessary intellectual skills to make informed choices about terminating a pregnancy but may lack the social and emotional maturity to control impulses, resist peer pressure and fully appreciate the riskiness of dangerous decisions," said Laurence Steinberg, PhD, a professor of developmental psychology at Temple University and main author of the study. "This immaturity mitigates their criminal responsibility".
The findings are reported in the recent issue of American Psychology expert,
published by the American Psychological Association.
Steinberg and his co-authors address this seeming contradiction in a study showing that cognitive and emotional abilities mature at different rates. They recruited 935 10- to 30- year-olds to examine age differences in a variety of cognitive and psychosocial capacities.
The participants took different tests measuring psychosocial maturity and cognitive ability to examine age patterns in numerous factors that affect judgment and decision-making. The maturity measures included tests of impulse control, sensation-seeking, resistance to peer influence, future orientation and risk perception. The cognitive battery included measures of basic intellectual abilities.........
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