December 9, 2008, 9:25 PM CT
Genetic underpinnings of nicotine addiction
A new study from the Abramson Cancer Center and Department of Psychiatry in the University of Pennsylvania School of Medicine shows that smokers who carry a particular version of a gene for an enzyme that regulates dopamine in the brain may suffer from concentration problems and other cognitive deficits when abstaining from nicotine a problem that puts them at risk for relapse during attempts to quit smoking. The findings, newly reported in the journal Molecular Psychiatry,
pave the way to identify novel medications to treat nicotine addiction.
"These findings also provide an important step toward personalized treatment for nicotine addiction by clarifying the role of inherited genetic variation in smoking abstinence symptoms that promote relapse," says senior author Caryn Lerman, PhD, the Mary W. Calkins Professor in Penn's Department of Psychiatry and Scientific Director of Penn's Abramson Cancer Center.
"The new data identify a novel brain-behavior mechanism that plays a role in nicotine dependence and relapse during quitting attempts," says lead author James Loughead, PhD, assistant professor in the Department of Psychiatry. Loughead and Lerman studied groups of smokers with different inherited variations in a gene which influences levels of dopamine in the prefrontal cortex, the part of the brain that governs working memory and complex decision-making. Spurred by their prior findings that carriers of the catechol-O-methyltransferase (COMT) val gene variant are more susceptible to smoking relapse, the Penn scientists set out to learn if smokers with this genetic background would be more likely to exhibit altered brain function and cognitive deficits during periods of abstinence from smoking.........
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December 9, 2008, 9:22 PM CT
Boy-girl bullying in middle grades common
Philip C. Rodkin
Photo by L. Brian Stauffer
Much more cross-gender bullying - specifically, unpopular boys harassing popular girls - occurs in later elementary school grades than previously thought, meaning educators should take reports of harassment from popular girls seriously, as per new research by a University of Illinois professor who studies child development.
Philip C. Rodkin, a professor of child development at the U. of I.'s College of Education, said that while most bullies are boys, their victims, counter to popular conception, are not just other boys.
"We observed that a lot of male bullies between fourth and sixth grade are bullying girls - more than people would have anticipated - and a substantial amount of that boy-girl, cross-gender bullying goes unreported," he said.
Rodkin, who along with Christian Berger, a professor at the Universidad Alberto Hurtado in Santiago, Chile, published the paper "Who Bullies Whom? Social Status Asymmetries by Victim Gender" in the most recent issue of the International Journal of Behavioral Development, said cross-gender bullying hasn't been fully explored because of the ways scientists have thought about the social status dynamic of bullying in the past.
"Bullies are generally more popular than their victims, and have more power over their victim, whether it's physical strength or psychological power," Rodkin said. "Scientists have taken it for granted that a bully will also have a higher social status than their victims. Based on our research, that's not necessarily the case".........
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December 8, 2008, 10:33 PM CT
Are men hardwired to overspend?
Bling, foreclosures, rising credit card debt, bank and auto bailouts, upside down mortgages and perhaps a mid-life crisis new Corvette-all symptoms of compulsive overspending.
University of Michigan researcher Daniel Kruger looks to evolution and mating for an explanation. He theorizes that men overspend to attract mates. It all boils down, as it has for hundreds of thousands of years, to making babies.
Kruger, an assistant research scientist in the School of Public Health, tested his hypothesis in a community sample of adults aged 18-45 and observed that the degree of financial consumption was directly correlation to future mating intentions and past mating success for men but not for women.
Financial consumption was the only factor that predicted how a number of partners men wanted in the next five years and also predicted the number of partners they had in the prior five years, Kruger said. Being married made a difference in the frequency of one-time sexual partners in the last year, but not in the number of partners in the past or desired in the future.
The 25 percent of men with the most conservative financial strategies had an average of three partners in the past five years and desired an average of just one in the next five years. The 2 percent of men with the riskiest financial strategies had double those numbers.........
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December 8, 2008, 10:30 PM CT
Men with wives more likely to be screened for prostate cancer
Eventhough the link between early screening and prostate cancer survival is well established, men are less likely to go for early screening unless they have a wife or significant other living with them, as per a research studypublished in Cancer Epidemiology, Biomarkers and Prevention
, a journal of the American Association for Cancer Research.
"In terms of motivating people to get screened, there may be benefit in targeting wives or significant others as well as men," said lead author Lauren P. Wallner, M.P.H., a graduate research associate at the University of Michigan.
Prostate cancer is the second leading cause of cancer deaths among men in the United States, and early detection is linked to drastically improved five-year survival rates. However, what motivates a man to get screened is not known.
Wallner and his colleagues identified 2,447 Caucasian men ages 40 years to 79 years from Olmstead County, Minnesota. These men completed questionnaires containing queries on family history of prostate cancer, concern about getting prostate cancer and marital status.
If men had a family history of prostate cancer, they were 50 percent more likely to be screened. If men said they were worried about prostate cancer, they were nearly twice as likely to be screened.........
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December 8, 2008, 10:28 PM CT
Selenium may prevent high risk-bladder cancer
A study reported in the recent issue of Cancer Prevention Research
, a journal of the American Association for Cancer Research, suggests that selenium, a trace mineral found in grains, nuts and meats, may aid in the prevention of high-risk bladder cancer.
Scientists from Dartmouth Medical School compared selenium levels in 767 individuals newly diagnosed with bladder cancer to the levels of 1,108 individuals from the general population. Findings showed an inverse association between selenium and bladder cancer among women, some smokers and those with p53 positive bladder cancer.
In the entire study population, there was no inverse association between selenium and bladder cancer, but women (34 percent), moderate smokers (39 percent) and those with p53 positive cancer (43 percent) had significant reductions in bladder cancer with higher rates of selenium.
"There are different pathways by which bladder cancer evolves and it is thought that one of the major pathways involves alterations in the p53 gene," said corresponding author Margaret Karagas, Ph.D., professor of community and family medicine of the Norris Cotton Cancer Center at Dartmouth. "Bladder cancers stemming from these alternations are linked to more advanced disease."
While other studies have shown a similar association between selenium and bladder cancer among women, this study is one of the first to show an association between selenium and p53 positive bladder cancer.........
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December 8, 2008, 10:26 PM CT
Women are more likely than men to die in hospital from severe heart attack
Men and women have about the same adjusted in-hospital death rate for heart attack - but women are more likely to die if hospitalized for a more severe type of heart attack, as per a report in Circulation: Journal of the American Heart Association.
Among patients with ST elevation myocardial infarction (STEMI) in a recent study, the death rate was 10.2 for women in comparison to 5.5 for men. Scientists said the women were older and had higher overall baseline risk profiles than men. After adjustment for these and other differences, women with STEMI had a 12 percent higher relative risk for in-hospital death in comparison to men.
The study also observed that some recommended therapys are delayed and underused in women.
Scientists analyzed data from the American Heart Association's Get With The Guidelines (GWTG) program to determine if recent efforts to improve heart attack care at hospitals had closed the gender disparity gap. They evaluated the clinical characteristics, therapys and outcomes of more than 78,000 patients diagnosed with myocardial infarction admitted to 420 hospitals between 2001 and 2006.
"The finding that bears the most emphasis is that among both men and women presenting to Get With The Guidelines participating hospitals, there were no clinically meaningful differences in in-hospital survival after heart attack, once we factored in differences, such as age and other existing illnesses," said Hani Jneid, M.D., lead author of the study and assistant professor of Cardiovascular Medicine at Baylor College of Medicine in Houston, Texas.........
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December 8, 2008, 10:21 PM CT
Men Are Red, Women Are Green
Male or female?
Test subjects tended to confirm subtle color differences associated with gender. Even when viewing pixelated or distorted images, subjects identified redder images as male and greener images as female. Top left: gender-ambiguous face; top-right: random noise over the ambiguous face; bottom-left: reconstructed male face; bottom-right: reconstructed female face.
Credit: Michael J. Tarr/Brown University
Michael J. Tarr, a Brown University scientist, and graduate student Adrian Nestor have discovered this color difference in an analysis of dozens of faces. They determined that men tend to have more reddish skin and greenish skin is more common for women.
The finding has important implications in cognitive science research, such as the study of face perception. But the information also has many potential industry or consumer applications in areas such as facial recognition technology, advertising, and studies of how and why women apply makeup.
"Color information is very robust and useful for telling a man from a woman," said Tarr, the Sidney A. and Dorothea Doctors Fox Professor of Ophthalmology and Visual Sciences and professor of cognitive and linguistic sciences at Brown. "It's a demonstration that color can be useful in visual object recognition".
Tarr said the idea that color may help us to identify objects better has been controversial. But, he said, his and related findings show that color can nonetheless provide useful information.
Tarr and Nestor's research is published in the journal Psychological Science. The paper will be published online Dec. 8 and in print a few weeks later.
To conduct the study, Tarr needed plenty of faces. His lab analyzed about 200 images of Caucasian male and female faces (100 of each gender) compiled in a data bank at the Max Planck Institute in Tübingen, Gera number of, photographed using a 3-D scanner under the same lighting conditions and with no makeup. He then used a MatLab program to analyze the amount of red and green pigment in the faces.........
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December 8, 2008, 10:18 PM CT
Oldest old 'hanging in the balance?'
A lack of clear-cut, scientific evidence illustrating the benefits of mammography screening in women over 80 has created a trail of controversy leading to a disturbing conclusion about cancer care in America. "We are ill-prepared from a scientific knowledge perspective to provide cancer health care rationally, ethically, equitably and humanely to the 'booming' older population," say two leading cancer researchers.
In an editorial published online today in the Journal of Clinical Oncology
), Jeanne S. Mandelblatt , MD, MPH, of Georgetown's Lombardi Comprehensive Cancer Center, and co-author Rebecca Silliman, MD, MPH, PhD, of Boston University Medical Center, address the lack of scientific evidence available regarding cancer screening interventions for older Americans an issue at the heart of a controversial breast cancer screening study reported in the JCO
earlier this year.
This study used observational data to provide evidence about the effectiveness of mammography screening in older women, in the absence of clinical trials.
In the current editorial, Mandelblatt and Silliman explore the study's biases, all of which make screening seem more beneficial than it may actually be. If, as the editorial authors conclude, reduction in mortality is the appropriate metric to determine the effectiveness of screening then "at this time, we are left with the fact that there is no evidence that screening women 80 and older with mammography results in reductions in mortality".........
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December 8, 2008, 10:14 PM CT
An Achilles heel in cancer cells
A protein that shields tumor cells from cell death and exerts resistance to chemotherapy has an Achilles heel, a vulnerability that can be exploited to target and kill the very tumor cells it commonly protects, scientists from the University of Illinois at Chicago show in a new study reported in the Dec. 9 issue of Cancer Cell
Akt is a signaling protein, called a kinase, that is hyperactive in the majority of human cancers.
"Akt is perhaps the most frequently activated oncoprotein (cancer-promoting protein) in human cancer," says Nissim Hay, professor of biochemistry and molecular genetics at the UIC College of Medicine. Pharmaceutical companies have been trying to find ways to inhibit Akt to improve cancer treatment, he said, but most candidate drugs have acted too broadly and proved toxic.
"One of Akt's major functions in tumor cells is promoting cell survival," Hay said. "Tumor cells with hyperactive Akt are not only resistant to the external stresses that can induce cell death but also to chemotherapy."
But Akt is also mandatory for metabolism and the proliferation of cancer cells, and it was as a byproduct of its role in metabolism that the scientists were able to exploit Akt hyperactivity against the tumor cell.
"We observed that cells with hyperactive Akt have increased intracellular levels of reactive oxygen species (ROS) and at the same time impaired ability to scavenge ROS," Hay said. These ROS are highly reactive byproducts of metabolism that can damage the cell. Cells commonly respond to high levels of ROS by undergoing cell suicide, or apoptosis.........
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December 8, 2008, 10:10 PM CT
Breaking the silence after a study ends
While an estimated 2.3 million people in the United States take part in clinical trials every year, there currently exists no formal requirement to inform them of study results, an oversight that leaves participants confused, frustrated, and, in some cases, lacking information that may be important to their health. In an article published recently in the Archives of Neurology,
scientists at the University of Rochester Medical Center have proposed a novel and effective approach to disseminate the results of clinical trials to study volunteers.
Industry, government, and academic scientists are dependent upon the willing participation of millions of individuals to fill the estimated 50,000 clinical trials conducted every year that evaluate the safety and efficacy of experimental drugs and medical devices.
Scientists are only mandatory to inform participants in instances when new information arises that may affect their willingness to continue participation. However, neither federal guidelines nor institutional review boards generally require disclosure of results at the conclusion of a study even if the study is halted. Consequently, a number of research participants never learn the outcome of studies in which they volunteer.
"Individuals who volunteer to participate in clinical research frequently expose themselves to risks, both known and unknown," said neurologist Ray Dorsey, M.D., the report's author. "Because of their participation, they should be informed of the results of these studies in a timely and personalized manner."........
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