December 31, 2008, 7:14 AM CT

Taking one gene at a time in lung cancer

While examining patterns of DNA modification in lung cancer, a team of international scientists has discovered what they say is a surprising new mechanism. They say that "silencing" of a single gene in lung cancer led to a general impairment in genome-wide changes in cells, contributing to cancer development and progression.

In the January 1, 2009, issue of Cancer Research, a journal of the American Association for Cancer Research, they also report finding a strong link between modification of the key gene, MTHFR, and tobacco use by patients with lung cancer even if the patient had smoked for a short period of time.

The findings reinforce tobacco's link to lung cancer development, but show that deactivating one specific gene through a process known as hypermethylation causes systemic dysfunction, or hypomethylation, in a number of genes, said the study's senior investigator, Zdenko Herceg, Ph.D., head of the Epigenetics Group at the International Agency for Research on Cancer (IARC).

"We observed that tobacco-mediated hypermethylation of MTHFR, and consequent partial or complete silencing of the gene, may trigger global hypomethylation and deregulation of DNA synthesis, both of which may contribute to cancer development," he said.

This methylation process, which involves chemically modifying normal DNA in order to change its activity, is seen as an increasingly important factor contributing to so-called "epigenetic inheritance" in cancer development, Herceg said. An epigenetic event is when non-genetic factors cause a gene to change its expression, and this is different from cancer caused by mutated genes that produce errant protein......... Posted by: Scott      Read more         Source

December 31, 2008, 7:11 AM CT

Reason for failure of hormonal therapy of prostate cancer

The hormone deprivation treatment that patients with prostate cancer often take gives them only a temporary fix, with tumors commonly regaining their hold within a couple of years. Now, scientists at Johns Hopkins have discovered critical differences in the hormone receptors on prostate cancer cells in patients who no longer respond to this treatment. The findings, published in the Jan. 1 issue of Cancer Research, could lead to a way to track disease progression, as well as new targets to fight prostate cancer.

Prostate cancer cells rely on androgens, male hormones that include testosterone, to survive and grow, explains Jun Luo, Ph.D., an assistant professor at Johns Hopkins' James Buchanan Brady Urological Institute. Since 1941, doctors have taken advantage of this dependency to battle prostate cancer by depriving patients of androgens, either by castration or chemical methods. For most patients, this hormone deprivation treatment causes tumors to shrink, sometimes dramatically. However, it's never a curetumors eventually regrow into a stronger form, becoming resistant to this and other forms of therapy.

Seeking the reason why this treatment eventually fails, Luo and colleagues at the Johns Hopkins University School of Medicine, the University of Washington and Puget Sound VA Medical Center looked to a key player: the androgen receptors on prostate cancer cells......... Posted by: Mark      Read more         Source

December 30, 2008, 11:05 PM CT

Nanoparticles aimed at cancer goes with a glitter

Using tiny gold particles and infrared light, MIT scientists have developed a drug-delivery system that allows multiple drugs to be released in a controlled fashion.

Such a system could one day be used to provide more control when battling diseases usually treated with more than one drug, as per the researchers.

"With a lot of diseases, particularly cancer and AIDS, you get a synergistic effect with more than one drug," said Kimberly Hamad-Schifferli, assistant professor of biological and mechanical engineering and senior author of a paper on the work that recently appeared in the journal ACS Nano.

Delivery devices already exist that can release two drugs, but the timing of the release must be built into the device -- it cannot be controlled from outside the body. The new system is controlled externally and theoretically could deliver up to three or four drugs.

The new technique takes advantage of the fact that when gold nanoparticles are exposed to infrared light, they melt and release drug payloads attached to their surfaces.

Nanoparticles of different shapes respond to different infrared wavelengths, so "just by controlling the infrared wavelength, we can choose the release time" for each drug, said Andy Wijaya, graduate student in chemical engineering and main author of the paper......... Posted by: Janet      Read more         Source

December 30, 2008, 11:01 PM CT

Are chemotherapy errors common?

Seven percent of adults and 19 percent of children taking chemotherapy drugs in outpatient clinics or at home were given the wrong dose or experienced other mistakes involving their medications, as per a newly released study led by Kathleen E. Walsh, MD, assistant professor of pediatrics at the University of Massachusetts Medical School, and reported in the January 1, 2009 issue of the Journal of Clinical Oncology

"As cancer care continues to shift from the hospital to the outpatient setting, the complexity of care is increasing, as is the potential for medicine errors, especially in the outpatient and home settings," said Dr. Walsh, who is also a Robert Wood Johnson Clinician Faculty Scholar.

An analysis of data on nearly 1,300 patient visits at three adult oncology outpatient clinics and 117 visits at one pediatric facility between September 1, 2005 and May 31, 2006 showed that errors in medicine were more common than previously reported by oncology patients.

Of the 90 medicine errors involving adults, 55 had the potential to harm the patient and 11 did cause harm. The errors included administration of incorrect medicine doses due to confusion.

over conflicting orders one written at the time of diagnosis and the other on the day of administration. Patients were also harmed by over-hydration previous to administration of medication, resulting in pulmonary edema and recurrent complaints of abdominal pain and constipation. More than 50 percent of errors involving adults were in clinic administration, 28 percent in ordering of medications, and 7 percent in use of the drugs in patients' homes......... Posted by: Janet      Read more         Source

December 30, 2008, 7:15 AM CT

Food additive may increase speed spread of lung cancer

New research in an animal model suggests that a diet high in inorganic phosphates, which are found in a variety of processed foods including meats, cheeses, beverages, and bakery products, might speed growth of lung cancer tumors and may even contribute to the development of those tumors in individuals predisposed to the disease.

The study also suggests that dietary regulation of inorganic phosphates may play an important role in lung cancer therapy. The research, using a mouse model, was conducted by Myung-Haing Cho, D.V.M., Ph.D., and colleagues at Seoul National University, appears in the first issue for January of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.

"Our study indicates that increased intake of inorganic phosphates strongly stimulates lung cancer development in mice, and suggests that dietary regulation of inorganic phosphates appears to be critical for lung cancer therapy as well as prevention," said Dr. Cho.

Lung cancer is the number one cause of cancer deaths in the world and is also the most frequently diagnosed solid tumor. Nonsmall cell lung cancer (NSCLC) constitutes over 75 percent of lung cancers and has an average overall 35-year survival rate of 14 percent. Earlier studies have indicated that approximately 90 percent of NSCLC cases were linked to activation of certain signaling pathways in lung tissue. This study revealed that high levels of inorganic phosphates can stimulate those same pathways......... Posted by: Scott      Read more         Source

December 30, 2008, 7:13 AM CT

Anti-fungal drug against asthma

Some patients with severe asthma who also have allergic sensitivity to certain fungi enjoy great improvements in their quality of life and on other measures after taking an antifungal drug, as per new research from The University of Manchester in England.

The findings were published in the first issue for January of the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine

"We knew that a number of people with severe asthma are sensitized to several airborne fungi which can worsen asthma without overt clinical signs. The question was: does antifungal treatment provide any clinical benefit," said David Denning, F.R.C.P., F.R.C.Path., professor of medicine and medical mycology at The University of Manchester and lead investigator of the study.

In 2006, the most recent year for which official statistics are available, there were more than 16 million adults with self-reported asthma in the U.S.; about 20 percent of them have severe asthma.

A small number of severe asthmaticsabout one percent are known to have a syndrome called allergic bronchopulmonary aspergillosis, an extreme allergy to Aspergillus fumigatus fungus that is linked to the long-term colonization of their respiratory tracts with the fungus. But a number of more 20 to 50 percent are sensitized to a variety of fungi without showing overt clinical signs or demonstrable colonization. It is these patients with severe asthma with fungal sensitization, or "SAFS", as the scientists named the syndrome, who are most likely to enjoy marked improvement with the antifungal treatment......... Posted by: JoAnn      Read more         Source

December 30, 2008, 7:11 AM CT

How your facial expressions are formed?

Facial expressions of emotion are hardwired into our genes, as per a research studypublished recently in the Journal of Personality and Social Psychology The research suggests that facial expressions of emotion are innate rather than a product of cultural learning. The study is the first of its kind to demonstrate that sighted and blind individuals use the same facial expressions, producing the same facial muscle movements in response to specific emotional stimuli.

The study also provides new insight into how humans manage emotional displays as per social context, suggesting that the ability to regulate emotional expressions is not learned through observation.

San Francisco State University Psychology Professor David Matsumoto compared the facial expressions of sighted and blind judo athletes at the 2004 Summer Olympics and Paralympic Games. More than 4,800 photographs were captured and analyzed, including images of athletes from 23 countries.

"The statistical connection between the facial expressions of sighted and blind individuals was almost perfect," Matsumoto said. "This suggests something genetically resident within us is the source of facial expressions of emotion."

Matsumoto observed that sighted and blind individuals manage their expressions of emotion in the same way as per social context. For example, because of the social nature of the Olympic medal ceremonies, 85 percent of silver medalists who lost their medal matches produced "social smiles" during the ceremony. Social smiles use only the mouth muscles whereas true smiles, known as Duchenne smiles, cause the eyes to twinkle and narrow and the cheeks to rise......... Posted by: JoAnn      Read more         Source

December 28, 2008, 11:21 PM CT

Use your unconscious brain to make the best bets

Scientists at the University of Rochester have shown that the human brainonce believed to be a seriously flawed decision makeris actually hard-wired to allow us to make the best decisions possible with the information we are given. The findings appear in today's issue of the journal Neuron

Neuroresearchers Daniel Kahneman and Amos Tversky received a 2002 Nobel Prize for their 1979 research that argued humans rarely make rational decisions. Since then, this has become conventional wisdom among cognition researchers.

Contrary to Kahnneman and Tversky's research, Alex Pouget, associate professor of brain and cognitive sciences at the University of Rochester, has shown that people do indeed make optimal decisionsbut only when their unconscious brain makes the choice.

"A lot of the early work in this field was on conscious decision making, but most of the decisions you make aren't based on conscious reasoning," says Pouget. "You don't consciously decide to stop at a red light or steer around an obstacle in the road. Once we started looking at the decisions our brains make without our knowledge, we observed that they almost always reach the right decision, given the information they had to work with".

Pouget says that Kahneman's approach was to tell a subject that there was a certain percent chance that one of two choices in a test was "right." This meant a person had to consciously compute the percentages to get a right answersomething few people could do accurately......... Posted by: JoAnn      Read more         Source

December 28, 2008, 11:15 PM CT

What triggers Alzheimer's disease?

A slow, chronic starvation of the brain as we age may be a main triggers of a biochemical process that causes some forms of Alzheimer's disease.

A newly released study from Northwestern University's Feinberg School of Medicine has found when the brain doesn't get enough sugar glucose -- as might occur when cardiovascular disease restricts blood flow in arteries to the brain -- a process is launched that ultimately produces the sticky clumps of protein that appear to be a cause of Alzheimer's.

Robert Vassar, main author, discovered a key brain protein is altered when the brain has a deficient supply of energy. The altered protein, called elF2alpha, increases the production of an enzyme that, in turn, flips a switch to produce the sticky protein clumps. Vassar worked with human and mice brains in his research.

The study is reported in the December 26 issue of the journal Neuron

"This finding is significant because it suggests that improving blood flow to the brain might be an effective therapeutic approach to prevent or treat Alzheimer's," said Vassar, a professor of cell and molecular biology at the Feinberg School.

A simple preventive strategy people can follow to improve blood flow to the brain is getting exercise, reducing cholesterol and managing hypertension......... Posted by: Daniel      Read more         Source

December 28, 2008, 11:12 PM CT

Take care of that childhood anxiety disorder

Anxiety disorders in children and adolescents should be recognized and treated to prevent educational underachievement and adult substance abuse, anxiety disorders and depression, says a nationally recognized child psychiatry expert from UT Southwestern Medical Center.

In an editorial appearing in the Dec. 25 issue of New England Journal (NEJM), Dr. Graham Emslie, professor of psychiatry and pediatrics at UT Southwestern, urges awareness that children need to be treated for anxiety disorders and recommends that related empirical evidence be integrated into therapy guidelines.

"Anxiety disorders may cause children to avoid social situations and age-appropriate developmental milestones," said Dr. Emslie. "Further, the avoidance cycle can lead to less opportunity to develop social skills necessary for success during the later part of life. Treatment would help children learn healthy coping skills".

Up to 20 percent of children and adolescents are affected by persistent and excessive worry that can manifest as generalized anxiety disorder, separation anxiety disorder and social phobia. Research has shown that failure to identify these disorders early leads to educational underachievement and increased rates of anxiety disorders, depression and substance abuse during the later part of life......... Posted by: Scott      Read more         Source