October 19, 2009, 6:50 AM CT
Making better stem cells from adult tissue
A team led by researchers from The Scripps Research Institute has developed a method that dramatically improves the efficiency of creating stem cells from human adult tissue, without the use of embryonic cells. The research makes great strides in addressing a major practical challenge in the development of stem-cell-based medicine.
The findings were published in an advance, online issue of the journal Nature Methods
on October 18, 2009.
The new technique, which uses three small drug-like chemicals, is 200 times more efficient and twice as fast as conventional methods for transforming adult human cells into stem cells (in this case called "induced pluripotent stem cells" or "iPS cells").
"Both in terms of speed and efficiency, we achieved major improvements over conventional conditions," said Scripps Research Associate Professor Sheng Ding, Ph.D., who led the study. "This is the first example in human cells of how reprogramming speed can be accelerated. I think that the field will quickly adopt this method, accelerating iPS cell research significantly".
In addition to its significant practical advantages, the development of the technique deepens the understanding of the biology behind the transformation of adult human cells into stem cells.........
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October 19, 2009, 6:47 AM CT
Metals could form an effective treatment against cancer
Professor Peter Sadler, University of Warwick
Credit: University of Warwick
Drugs made using unusual metals could form an effective therapy against colon and ovary cancer, including malignant cells that have developed immunity to other drugs, as per research at the University of Warwick and the University of Leeds.
The study, reported in the Journal of Medicinal Chemistry
, showed that a range of compounds containing the two transition metals Ruthenium and Osmium, which are found in the same part of the periodic table as precious metals like platinum and gold, cause significant cell death in ovarian and colon cancer cells.
The compounds were also effective against ovary cancer cells which are resistant to the drug Cisplatin, the most successful transition metal drug, which contains the metal platinum.
Dr Patrick McGowan, one of the main authors of the research from the School of Chemistry at the University of Leeds, explains: "Ruthenium and Osmium compounds are showing very high levels of activity against ovary cancer, which is a significant step forward in the field of medicinal chemistry.
Sabine H. van Rijt, lead researcher in the laboratory of Professor Peter Sadler in the Department of Chemistry at the University of Warwick, said:.
"Most interestingly, malignant cells that have shown resistance to the most successful transition metal drug, Cisplatin, show a high death rate with these new compounds."........
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October 15, 2009, 5:42 PM CT
Cost Effectiveness of Blood Pressure Device
The Rheos High Blood Pressure or Hypertension Therapy System
A study conducted by the University of Rochester Medical Center (URMC) demonstrates that, for certain patient populations, an experimental device that lowers blood pressure appears to be a cost effective therapy. The implantable device, called Rheos, is in advanced stages of testing for individuals with drug resistant hypertension.
The study - which appears this month in the Journal of Clinical High blood pressure - used data from two large population-based studies and compared the occurence rate of adverse health events such as stroke and heart attack for groups of individuals with and without the blood pressure lowering benefit of the device. Scientists then projected the health care costs linked to those events over a patient's lifetime. The results show that if Rheos continues to perform at a level consistent the initial findings in ongoing clinical trials, then the device is a cost effective way to control hypertension.
"Our goal was to determine whether or not the benefit of Rheos would offset the higher upfront costs," said Kate C. Young, Ph.D., MPH, an instructor in the departments of Surgery and Neurology at URMC and main author of the study. "What we found is that the device's cost effectiveness is dependent upon the degree to which it can reduce blood pressure and the starting point of the patient".........
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October 15, 2009, 5:39 PM CT
Girls aware of HPV vaccine's benefits
Contrary to concerns that the human papillomavirus vaccine might promote promiscuity, a national survey of girls and young women observed that the majority of respondents did not believe the HPV vaccine protected them against other sexually transmitted infections.
The study, conducted by University of Illinois at Chicago and University of Chicago researchers, appears online and in the recent issue of the Journal of Adolescent Health
The findings are reassuring in that girls and young women did not believe that the vaccine provided benefits beyond protecting them from HPV, said Dr. Rachel Caskey, assistant professor of pediatrics and general internal medicine at UIC and main author of the study. "We also observed that they did not believe that they could stop cervical cancer screening, or pap smears, which is critical".
Scientists used a national sample, representative of the U.S. population, to conduct an online survey of more than 1,000 females ages 13 to 26.
The data provide some of the first nationally representative estimates of both adolescents' and young women's adoption of the HPV vaccine, barriers to vaccination, and sources of information about HPV and the HPV vaccine, as per the researchers.
Knowledge about the HPV virus itself ran the gamut, said Caskey. Some people knew absolutely nothing and a few people were moderately informed. Knowledge about the HPV vaccine, however, was better.........
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October 15, 2009, 5:33 PM CT
Skin cells may provide early warning for cancer risk
Berkeley -- While some researchers have argued that cancer is such a complex genetic disease that you'd have to sequence a person's complete genome in order to predict his or her cancer risk, a University of California, Berkeley, cell biologist suggests that the risk appears to be more simply determined by inexpensively culturing a few skin cells.
Harry Rubin, professor emeritus of molecular and cell biology at UC Berkeley, acknowledges that cancer cells have mutations in hundreds of genes, making it hard to determine which are the key triggers and making prognosis and therapy equally difficult. Even normal tissue differs from person to person because of a myriad of less disruptive mutations and because of different environmental exposures, both of which affect future cancer risk.
But in the recent issue of the journal Cancer Epidemiology, Biomarkers and Prevention
, Rubin argues that, while it appears to be hard to dissect the role of each of these mutations, their collective effect should be observable in tissue before any cancers develop.
Specifically, increases in how densely the cells grow, which Rubin argues are a prelude to cancer, appears to be detectable even before the cancer appears, warning of risks that could be lessened by behavioral changes.........
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October 15, 2009, 5:31 PM CT
Misuse of antibiotics not the only cause of resistance
The perception that antibiotic resistance is primarily the undesirable consequence of antibiotic abuse or misuse is a view that is simplistic and inaccurate, as per a recent report by the American Academy of Microbiology. The reasons behind the spread of resistance are much more complex, including appropriate antibiotic use, lack of proper sanitation and hygiene, and even the environment.
The report, "Antibiotic Resistance: An Ecological Perspective on an Old Problem," is based on a colloquium convened by the Academy in October 2008. It states that resistance development is founded in the inevitability of microbial evolution. There are no scapegoats, and responsibility is partly due to medical practice, including patient demand, industrial practices, politics, and antibiotics themselves.
"Antibiotic resistance is an international pandemic that compromises the therapy of all infectious diseases. At the present time, resistance essentially is uncontrollable. The reasons behind the establishment and spread of resistance are complex, mostly multi-factorial, and mostly unknown. The colloquium consensus was that efforts must target both the bacterial transmission and antimicrobial use," states colloquium co-chair, Jacques F. Acar, M.D. More research bridging medical, chemical, and environmental disciplines is needed now as per the Academy report.........
Posted by: Mark Read more Source
October 15, 2009, 5:30 PM CT
Paradigm shift needed to combat drug resistance
When people travel, bacteria and other infectious agents travel with them. As about a billion people cross international borders each year, a number of more billions of the bugs come along for the ride.
However, the trend is contributing to substantial domestic and international public health threats and risks, as seen with SARS and more recently with the H1N1 flu virus.
In a paper published recently in Emerging Infectious Diseases
(EID), a journal of the U.S. Centers for Disease Control and Prevention, a McMaster University infectious disease expert explores the relationship between population mobility, globalization and antimicrobial drug resistance.
In collaboration with a team of international scientists, Douglas MacPherson, an associate professor in the Department of Pathology and Molecular Medicine of the Michael G. DeGroote School of Medicine, assesses the link between human travel and the international movement of drug-resistant infectious diseases around the world.
Citing published data, the authors conclude that population mobility affects the spread and distribution of resistant organisms. But despite this, it has not been considered a primary factor in developing approaches for disease control. The authors propose a paradigm shift is needed to tackle the problem, as well as greater international collaboration and standardization across borders.........
Posted by: Mark Read more Source
October 15, 2009, 5:19 PM CT
Treating HIV-AIDS patients with interleukin-2 is Ineffective
An international research team has demonstrated that treating HIV-AIDS with interleukin-2 (IL-2) is ineffective. As a result, the scientists recommend that clinical trials on this compound be stopped. Their finding was reported in the New England Journal (NEJM) in an article co-authored by 14 researchers, including Dr. Jean-Pierre Routy of the Research Institute of the McGill University Health Centre (RI-MUHC).
IL-2 is currently used as a complement to highly active antiretroviral treatment (known as HAART), which is administered to patients with HIV-AIDS. Since HAART controls replication of viruses in the blood, doctors thought that IL-2 would help regenerate more CD4+ immune cells, which serve as an indicator of viral progression. It was thought that IL-2 increased the natural immunity of patients by helping immune cells mature and multiply.
"Our results show that IL-2 has no effect on the development of AIDS or on patient survival," says Dr. Routy. "More precisely, while the presence of IL-2 leads to a faster increase of CD4+ immune cells, these cells are less functional than the CD4+ cells that regenerate naturally in patients who do not receive IL-2. This means that IL-2 therapy provides no benefit and does not prevent AIDS-related infectious diseases".........
Posted by: Mark Read more Source
October 14, 2009, 7:19 AM CT
Candy bar or healthy snack?
If you think choosing between a candy bar and healthy snack is totally a matter of free will, think again. A newly released study in the Journal of Consumer Research
shows that the choices we make to indulge ourselves or exercise self-control depend on how the choices are presented.
Author Juliano Laran (University of Miami) tested subjects to determine how certain words and concepts affected consumers' decisions for self-control or indulgence. He observed that consumer choices were affected by the actions most recently suggested to them by certain key words.
The tests involved a word-scramble containing words that suggested either indulgence ("weight") or self-control ("delicious"). "Participants who unscrambled sentences linked to self-control were more likely to choose a healthy snack (a granola bar) to be consumed right now, but an indulgent snack (a chocolate bar) to be consumed in the future," writes Laran. Participants who unscrambled sentences linked to indulgence were more likely to choose an indulgent snack to be consumed right now but a healthy snack to be consumed in the future".
A second study examined the same phenomenon, but it involved information linked to saving versus spending money. Again, when information about saving money was active (participants had been exposed to words linked to saving money), participants said that they imagined themselves trying to save money while shopping in the present, but spending a lot of money while shopping in the future. When words about spending money were suggested, the study showed the opposite result.........
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October 14, 2009, 7:17 AM CT
Self-esteem in overweight and underweight women
Overweight women's self-esteem plummets when they view photographs of models of any size, as per a newly released study in Journal of Consumer Research
And underweight women's esteem increases, regardless of models' size.
Authors Dirk Smeesters (Erasmus University, the Netherlands), Thomas Mussweiler (University of Cologne, Gera number of), and Naomi Mandel (Arizona State University) researched the ways individuals with different body mass indexes (BMIs) felt when they were exposed to thin or heavy media models.
"Our research confirms earlier research that observed that normal body mass index (BMI) females' self-esteem can shift upwards or downwards depending on the model they are exposed to," the authors write. "Normal BMI females (with BMIs between 18.5 and 25) have higher levels of self-esteem when exposed to moderately thin models (because they feel similar to these models) and extremely heavy models (because they feel dissimilar to these models). However, they have lower levels of self-esteem when exposed to moderately heavy models (because they feel similar) and extremely thin models (because they feel dissimilar)".
This research provides important new insights into how media exposure affects the self-esteem of overweight and underweight women. "Underweight women's self-esteem always increases, regardless of the model they look at," the authors explain. "Conversely, overweight women's self-esteem always decreases, regardless of the model they look at." Perhaps surprisingly, overweight and underweight women showed comparable levels of self-esteem when they weren't looking at models.........
Posted by: JoAnn Read more Source