February 19, 2007, 8:46 PM CT

attempted suicide and genetics

A Johns Hopkins-led study has observed evidence that a genetic tendency toward suicide has been associated with a particular area of the genome on chromosome 2 that has been implicated in two additional recent studies of attempted suicide.

Were hoping our findings will eventually lead to tests that can identify those at high risk for attempting suicide, says Virginia Willour, Ph.D., an assistant professor in the Department of Psychiatry at the Johns Hopkins University School of Medicine and lead author of the study. An estimated 4.6 percent of Americans ages 15 to 54 have tried to take their lives, as per Willour.

The researchers conducted a family linkage study in which they searched for commonalities in the genomes of family members with bipolar disorder and a history of attempted suicide. The same gene region on chromosome 2 that was identified by this bipolar disorder and attempted suicide study was recently identified by two complementary family studies that looked at attempted suicide in families with major depression and alcohol dependence.

Family linkage studies are not always consistent, so the fact that all three studies, including ours, point to the same region of the genome is a good indication that we are on the right track toward identifying a gene or genes that play a role in why a person chooses to take his or her own life, says Willour......... Posted by: Jessica      Read more         Source

February 13, 2007, 8:38 PM CT

Schizophrenia-Related Gene Variation

University of Iowa scientists have learned more about a genetic variation that is a small risk factor for a mild form of schizophrenia, yet also is linked to improved overall survival.

The findings, which appear online in the American Journal of Medical Genetics, could help lead to therapys for schizophrenia and even other illnesses, and ways to leverage the gene variation's advantages. An abstract of the article is available at http://www3.interscience.wiley.com/cgi-bin/abstract/114112711/ABSTRACT.

This HOPA12pb gene variation advance drew on a genetic database that was about five times larger than sample sizes used in prior research, said Robert Philibert, M.D., Ph.D., associate professor of psychiatry in the UI Roy J. and Lucille A. Carver College of Medicine and the study's co-author.

"The study used the National Institute of Mental Health's largest publicly available sample, and thus it provides even more convincing evidence that the gene variation is worth studying," Philibert said.

The genetic variation causes a change in the portion of the protein that regulates the development of dopamine-releasing neurons. Antipsychotic drugs work by blocking dopamine, but drug therapys have limited success, and so researchers seek other ways to treat patients......... Posted by: Jessica      Read more         Source

February 11, 2007, 9:23 PM CT

New Technology Guides Cancer Treatment

Scientists from Dana-Farber Cancer Institute and Broad Institute of the Massachusetts Institute of Technology and Harvard University in combination has created a new technology screening tumors for cancer-related gene abnormalities that might be treated with "targeted" drugs.

These findings were recently published on the Nature Genetics Web site. This new finding might help relieve a problem between scientists' expanding knowledge of the genetic mutations linked to cancer and the still nascent ability of doctors to use that knowledge to benefit patients. The results constitute an important step toward the era of "personalized medicine," in which cancer treatment will be guided by the particular set of genetic mutations within each patient's tumor, the authors suggest.

"It's universally recognized that cancer is a disease of the genome, of mutations within genes responsible for cell growth and survival, and a great deal of effort has gone into finding those mutations, to the point where several hundred to a thousand are now known," said the study's senior author, Levi Garraway, MD, PhD, of Dana-Farber and the Broad Institute. "The challenge has been how to determine which of them are involved in each of the hundreds of kinds of cancer that occur in humans -- and to develop accurate, affordable methods of detecting key mutations in tumor samples. This study suggests that such a method is feasible on a large scale".........

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February 8, 2007, 10:07 PM CT

Lung Cancer Rates Among Female Nonsmokers

Not all lung cancer is due to a lifetime of smoking cigarettes. Sometimes the diagnosis is a mystery, and the stigma surrounding the disease makes it hard for patients to talk about. Now, researchers at the Stanford University School of Medicine and the Northern California Cancer Center have taken the first steps toward analyzing why people who never smoked get lung cancer.

Their data, would be published in the Feb. 10 issue of the Journal of Clinical Oncology, shows that never-smokers get lung cancer more often than thought, with women even more at risk than men.

"People tend to banter about this number of 10 to 15 percent of lung cancer cases being in people who have never smoked," explained lead author Heather Wakelee, MD, assistant professor of medicine at Stanford. "But when you actually try to find the hard data to show that, it's very limited".

The team of researchers used multiple collections of data from both the United States and Sweden that, in total, tracked the incidence of lung cancer in more than 1 million people from the ages of 40 to 79. They calculated the lung cancer incidence rates in terms of new cases per person-year, representing every year that someone was included in the study.

They found that for women, the lung cancer incidence rate in never-smokers ranged from 14.4 to 20.8 cases per 100,000 person-years. In men, it ranged from 4.8 to 13.7 incidents. For current smokers, the rates were about 10 to 30 times higher. To put these numbers in perspective, Wakelee pointed out that the rates for cervical and thyroid cancer in women of the same age range are comparable, at 15.4 and 17.3 cases per 100,000 person-years, respectively.........

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February 5, 2007, 7:25 PM CT

Nanoparticles To Battle Cancer

On a quest to modernize cancer therapy and diagnosis, an MIT professor and her colleagues have created new nanoparticles that mimic blood platelets. The team wants to use these new multifunctional particles to carry out different medical missions inside the body, from imaging to drug delivery.

After years of research, "we still treat cancer with surgery, radiation and chemotherapy," said Sangeeta Bhatia, an associate professor in MIT's Department of Electrical Engineering and Computer Science and the Harvard-MIT Division of Health Sciences and Technology. "People are now starting to think more in terms of 'Fantastic Voyage,' that sci-fi movie where they miniaturized a surgical team and injected it into someone."

The National Cancer Institute has recognized the value of Bhatia's work and has awarded her a grant to continue this line of research. Bhatia and collaborators Michael J. Sailor, chemist and materials scientist at the University of California at San Diego, and Erkki Ruoslahti, tumor biologist at the Burnham Institute for Medical Research, will receive $4.3 million in funding over five years.

The grant will allow the team to continue work on promising nanoparticle solutions that, while not quite miniature surgical teams, do have the potential to help identify tumors and deliver chemotherapy locally.........

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February 1, 2007, 8:18 PM CT

Improved Breast Cancer Screening

It's a known fact that the key to curing breast cancer is early detection and prompt treatment. Hence, recent reports suggesting that screening for breast cancer is declining among women in the U.S. is worrying health officials. The reasons cited for this decline include insufficient access to mammography facilities and, surpisingly, apathy and indifference among women about the entire process. The second reason could be related to the fact that mammography screening methods have always suffered from higher costs, dangers from increased exposure to harmful radiation and confusion over the diagnostic accuracy.

The solution to tackling these issues may lie with the new breast screening device from Z-Tech. The device works on the principle that the breast tissue has electrical properties, and when malignancy sets in these tissues, electricity flows more easily through it. So by comparing the relative electrical impedance between the two breasts (in simpler words, the one that allows more electricity to flow through it), it is possible to detect the cancerous one. The actual physical setup consists of 12 flower-petal shaped sensors that fit around the breast. Each of these petals is equipped with electrodes that send and receive an imperceptible, low level electrical current into and out of a breast. The impedance data collected by these sensors are transmitted to a computer that does the number crunching and presents the diagnosis in real time.........

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January 24, 2007, 6:49 PM CT

Genetic Risk Factor For Smoking-linked Head And Neck Cancer

A simple blood test may be able to identify those most at risk for developing head and neck cancer as a result of smoking. This was the finding of a recent study by Prof. Zvi Livneh, Head of the Weizmann Institute's Biological Chemistry Department, Dr. Tamar Paz-Elizur of the same department, and their research team that worked in collaboration with Dr. Rami Ben-Yosef of Tel Aviv-Sourasky Medical Center, Prof. Laurence Freedman of Sheba Medical Center and Prof. Edna Schechtman of Ben-Gurion University of the Negev.

Livneh's research deals with repair mechanisms for DNA, the material of genes. Cells maintain sophisticated repair systems to prevent the accumulation of mutations that might lead to cancer. In these systems, molecular detectors scan the DNA for injury. A sort of local operation is then performed to cut out and dispose of the damaged segment and replace it with a new one.

In their study, which appeared in Cancer Research, the scientists asked whether a reduced individual ability (non-inherited) to repair DNA damage increases chances of getting head and neck cancer. Smoking damages DNA and is known to be a major cause of this disease, which can affect the throat, mouth and larynx. The researchers focused on a DNA repair enzyme called OGG1, for which they had previously developed a blood test to measure activity levels. By comparing OGG activity in healthy people with those in head and neck cancer patients, the research team found that the test was able to single out those with a heightened risk of this type of cancer: Weak levels were correlated with greater risk. According to Prof. Livneh, a smoker with low OGG activity is 70 times more likely to develop head and neck cancer than a non-smoker with normal OGG levels.........

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January 24, 2007, 6:05 PM CT

Turning A Cellular Sentinel Into A Cancer Killer

Howard Hughes Medical Institute researchers have developed two strategies to reactivate the p53 gene in mice, causing blood, bone and liver tumors to self destruct. The p53 protein is called the "guardian of the genome" because it triggers the suicide of cells with damaged DNA.

Inactivation of p53 can set the stage for the development of different types of cancer. The researchers' findings show for the first time that inactivating the p53 gene is necessary for maintaining tumors. While the researchers caution that cancers can mutate to circumvent p53 reactivation, they believe their findings offer ideas for new approaches to cancer therapy.

The research was carried out independently by two Howard Hughes Medical Institute (HHMI) research teams led by Tyler Jacks at the Massachusetts Institute of Technology and Scott Lowe at Cold Spring Harbor Laboratory. Both papers were published online January 24, 2007, in advance online publication articles in the journal Nature. Although researchers have long known that p53 inactivation plays a central role in the development of cancer, little was known about whether p53 inactivation played a role in maintaining cancers. And researchers were not sure whether switching p53 back on in tumor cells would have any therapeutic effect.........

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January 16, 2007, 9:31 PM CT

Marker For Head And Neck Cancer

Researchers have found a marker on head and neck tumor cells that indicates which cells are capable of fueling the cancer's growth. The finding is the first evidence of cancer stem cells in head and neck tumors.

Cancer stem cells are the small number of cancer cells that replicate to drive tumor growth. Researchers believe current cancer treatments sometimes fail because they are not attacking the cancer stem cells. By identifying the stem cells, researchers can then develop drugs to target and kill these cells.

"Our treatment results for head and neck cancer are not as good as we'd like them to be. A lot of people still die of head and neck cancer. This finding will impact our understanding of head and neck cancer, and we hope it will lead to treatments that will be more effective," says study author Mark Prince, M.D., assistant professor of otolaryngology at the University of Michigan Medical School and section chief of otolaryngology at the VA Ann Arbor Healthcare System.

Results of the study appear in the Jan. 16 issue of the Proceedings of the National Academy of Sciences.

Researchers at the U-M Comprehensive Cancer Center and Stanford University School of Medicine took tumor samples from patients undergoing surgery for head and neck squamous cell carcinoma, including cancers of the tongue, larynx, throat and sinus. Cells from the samples were separated based on whether they expressed a marker on their surface called CD44. The sorted cells were then implanted into immune-deficient mice to grow tumors.........

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January 12, 2007, 4:47 AM CT

High-Power MRI in Unusual Tumor Cases

A Mayo Clinic surgical team has found that using a 3-Tesla MRI in surgical decision making provides a new level of capability to predict surgical outcomes that improves patient care by minimizing the potential for unsuccessful tumor-removal surgeries. The Mayo Clinic report appears in the recent issue of the Journal of Neurosurgery www.thejns-net.org/jns/issues/current/toc.html.

In their report, Mayo physicians describe a case study of five patients. Four had neurofibromatosis, a condition with a predisposition to nerve-related tumors. All patients suffered from growths called "sciatic notch dumbbell-shaped" tumors. The tumors were benign, but resulted in neurologic dysfunction and disabling pain.

"In the past, if surgeons couldn't tell prior to surgery where the exact location of the large tumor was in relation to the sciatic nerve, it meant they couldn't predict in which cases surgery could be performed safely," explains Robert Spinner, M.D., the lead neurosurgeon on the Mayo Clinic team.

The team used an advanced magnetic resonance imaging (MRI) system performed on a 3-Tesla magnet to help identify suitable candidates for a difficult tumor-removal surgery. A Tesla is a unit of magnet strength. A 3-Tesla is one of the strongest commercially available.........

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