February 12, 2009, 5:38 AM CT
Starving those cancer cells to death
The development of malignant tumours is highly dependent on the nutrients the tumours receive through the blood. The team of Dr. Janusz Rak, of the Research Institute of the McGill University Health Centre (MUHC) at the Montreal Children's Hospital, including Dr. Khalid Al-Nedawi and Brian Meehan, has just discovered a new mechanism that tumours use to stimulate the growth of the blood vessels that feed them. The scientists have also proposed a new way to control this process, which may translate into future therapies. These findings were published this week in the Proceedings of the National Academy of Sciences
).An innovative method
As per the researchers, tumour cells can release "bubbles" called microvesicles, which allow the tumours to communicate with the endothelial cells of blood vessels and stimulate changes in their behaviour. The microvesicles are armed with specific cancer proteins as they leave the tumour. When they are taken up by endothelial cells, the specific cancer proteins that they carry can trigger mechanisms that promote the abnormal formation of new blood vessels. The vessels then grow towards the tumour and supply it with the nutrients it requires to grow.
"We had already demonstrated the existence of these vesicles as well as their importance in the communication process between cancer cells and their environment. But this new discovery is much more targeted and represents a new direction in terms of treatment," said a delighted Dr. Rak.........
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February 12, 2009, 5:36 AM CT
Elevated blood sugar level leads to decreased brain funciton
Results of a recent study conducted by scientists at Wake Forest University Baptist Medical Center and his colleagues show that cognitive functioning abilities drop as average blood sugar levels rise in people with type 2 diabetes.
The study appears in this month's issue of Diabetes Care
The ongoing Memory in Diabetes (MIND) study, a sub-study of the Action to Control Cardiovascular Risk in Diabetes Trial (ACCORD), found a statistically significant inverse relationship between A1C levels (average blood glucose levels over a period of two to three months) and subjects' scores on four cognitive tests. No association, however, was found between daily blood glucose levels (measured by the fasting plasma glucose test) and test scores.
For the study, scientists at 52 of the 77 ACCORD sites throughout the United States and Canada administered a 30-minute battery of cognitive tests to nearly 3,000 individuals ages 55 years and older.
"The tests used in the study measured several aspects of memory function," said Jeff Williamson, M.D., M.H.S., principal investigator for the study at the Wake Forest clinical site. "For example, we tested one's ability to switch back and forth between memory tasks or to 'multitask,' an important skill for people needing to manage their diabetes".........
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February 12, 2009, 5:29 AM CT
Improved quality assurance for multivitamins
The National Institute of Standards and Technology (NIST) has developed a new certified reference material that can be an important quality assurance tool for measuring the amounts of vitamins, carotenoids, and trace elements in dietary supplements. The new Standard Reference Material (SRM) 3280 for multivitamin/multimineral tablets was created in collaboration with the Office of Dietary Supplements (ODS) at the National Institutes of Health (NIH).
Demand from a growing number of Americans concerned that they are not getting all the prescribed nutrients from their food has created a multibillion-dollar dietary supplement industry. Eventhough manufacturers have their own testing methods and materials to ensure that their products contain the nutrients in the amounts listed on their labels, they have had no definitive, independently certified standard with which to verify their testing methods and calibrate their equipment. The new reference standard will help fill that gap.
A manufacturer of multivitamin/multimineral tablets prepared the source material for SRM 3280 as a non-commercial batch of tablets as per their normal procedures. NIST researchers tested and certified the concentrations of 24 elements and 17 vitamins and carotenoid compounds in the tablets.........
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February 12, 2009, 5:26 AM CT
DHEA may prevent prostate cancer
DHEA is a natural circulating hormone and the body's production of it decreases with age. Men take DHEA as an over-the-counter supplement because it has been suggested that DHEA can reverse aging or have anabolic effects since it can be metabolized in the body to androgens. Increased consumption of dietary isoflavones is linked to a decreased risk of prostate cancer. Red clover (Trifolium pretense) is one source of isoflavones. Both supplements may have hormonal effects in the prostate and little is known about the safety of these supplements.
In a recent report in Cancer Prevention Research
, a journal of the American Association for Cancer Research, scientists report that DHEA levels can be manipulated in cells in the laboratory to understand its effects.
Julia Arnold, Ph.D., a staff scientist at the National Center for Complementary and Alternative Medicine (NCCAM) at the National Institutes of Health, said more research is necessary in an environment where men and women concerned about health problems tend to self-prescribe based on information they find on the Internet.
Towards this end, the NCCAM laboratory is studying signaling between human prostate cancer cells and their supporting stromal cells as they grow together in laboratory culture. "DHEA effects in the prostate tissues may depend on how these two cells types 'talk to each other' and further, it appears to be potentially harmful in tissues containing inflammation or with early cancer lesions because the cells can induce DHEA to become more androgenic," said Arnold.........
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February 12, 2009, 5:18 AM CT
New drug to prevent colon cancer in making
Scientists at the Mayo Clinic campus in Florida have observed that a drug now being tested to treat a range of human cancers significantly inhibited colon cancer development in mice. Because the agent appears to have minimal side effects, it may represent an effective chemopreventive therapy in people at high risk for colon cancer, the researchers say.
Their study, reported in the Feb. 15 issue of Cancer Research, observed that use of the agent, enzastaurin, significantly reduced development of malignant colon tumors in treated animals. Furthermore, the tumors that did develop in the mice were of a lower grade, which meant they were less advanced and aggressive than the tumors seen in animals not given the drug. "There is need for an agent that has a proven ability to reduce colon cancer risk, and this study suggests that enzastaurin could be uniquely effective," says the study's senior investigator, Nicole Murray, Ph.D., of the Department of Cancer Biology.
Individuals at high risk for colon cancer often develop numerous premalignant colon polyps, which must be periodically removed during a colonoscopy, Dr. Murray says.
The laboratories of Dr. Murray, and her collaborator and co-author, Alan Fields, Ph.D., chair of the Department of Cancer Biology, focus on characterizing the genes involved in different stages of colon carcinogenesis. They have zeroed in on the protein kinase C (PKC) family of enzymes as major players in cancer development and progression, but it has taken them years to understand the different roles of each type of PKC molecule or "isozyme."........
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February 11, 2009, 6:27 AM CT
Benefits of exercise on quitting smoking
Research from the University of Exeter reveals for the first time, that changes in brain activity, triggered by physical exercise, may help reduce cigarette cravings. Reported in the journal Psychopharmacology
, the study shows how exercise changes the way the brain processes information among smokers, thereby reducing their cravings for nicotine. For the first time, scientists used functional Magnetic Resonance Imaging (fMRI) to investigate how the brain processes images of cigarettes after exercise.
The study adds weight to a growing body of evidence that exercise can help manage addiction to nicotine and other substances. It backs up prior studies, which have shown that just one short burst of moderate exercise can significantly reduce smokers' nicotine cravings.
Ten regular smokers were asked to cycle at a moderate pace for ten minutes, after 15 hours of abstinence from nicotine. They were then given an fMRI scan while they viewed a series of 60 images. Some visuals featured cigarettes and would normally induce cravings in a smoker. On a second occasion, the same group was given an fMRI scan and shown the same series of images without having undertaken exercise. They were also asked to report on their cravings for nicotine during both phases of the study.........
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February 11, 2009, 6:22 AM CT
Mutation that causes inflammatory bowel disease
A team of researchers at The Scripps Research Institute has linked a mouse mutation to an increased susceptibility for developing inflammatory bowel disease -- represented in humans as Crohn's disease and ulcerative colitis, which together are estimated to affect more than a million people in the United States. The findings may one day lead to new and better therapys for the disease.
The work was reported in the February 6, 2009 Early Edition of the Proceedings of the National Academy of Sciences
Humans have a gene that is very similar to the mouse gene, called Mbtps1, and in certain rare instances, mutations of this gene may contribute to IBD in humans. The disease is linked to painful ulcers and bleeding in people's intestines and can place them at greater risk for colon cancer. Eventhough common, the disease is still somewhat mysterious. The Scripps Research study sheds light on a major mechanism through which it may develop.
"We are just beginning to get a sense of the complexity of inflammatory bowel disease as far as humans are concerned," says Bruce Beutler, M.D., who is the chair of the Scripps Research Department of Genetics.
Researchers have known for a long time that IBD is associated with geneticsit runs in families, for instance. However, there seems to be no single gene responsible. More likely, says Beutler, mutations in a number of different genes have additive effects and cause people to develop variably severe forms of the disease. One of the long-term goals of his laboratory is to identify these genes and the main biological processes they control.........
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February 11, 2009, 6:14 AM CT
Better prenatal care using home pregnancy tests
Mary Nettleman, Department of Medicine, College of Human Medicine. Courtesy photo
Click on an image to view a larger or high-resolution version.
The simple intervention of providing women who are having unprotected sex with a home pregnancy test could have a substantial impact on the health of potential newborns, as per a Michigan State University study.
In research published this month in the February edition of the American Journal of Preventive Medicine, MSU's Mary Nettleman observed that significantly more women who had a home pregnancy test at home not only suspected they could be pregnant but also took tests much more frequently.
"The top reason women do not seek prenatal care is they do not realize they are pregnant," said Nettleman, chairperson of the College of Human Medicine's Department of Medicine. "In addition, women who do not realize they are pregnant will not change harmful behaviors such as drinking and smoking, which can lead to developmental problems in newborns".
Nettleman added that one of the most common reasons for unintended pregnancy is that women don't feel they are at high risk for pregnancy.
"This simple intervention - giving home pregnancy test kits to women who are having unprotected sex - was able to do what no other study has done: Influence women to be more vigilant about potential pregnancy," she said.
Participants in the study, which was funded by the Michigan Department of Community Health, were low-income, adult women who were having unprotected sex and not trying to conceive. Women in the intervention group were given free home-pregnancy tests and were able to order more kits as needed.........
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February 11, 2009, 6:10 AM CT
Improve memory by increasing brain processing speed
Mayo Clinic scientists observed that healthy, elderly adults who participated in a computer-based training program to improve the speed and accuracy of brain processing showed twice the improvement in certain aspects of memory, in comparison to a control group.
"What's unique in this study is that brain-processing activities seemed to help aspects of memory that were not directly exercised by the program -- a new finding in memory research," says Glenn Smith, Ph.D., Mayo Clinic neuropsychology expert and lead researcher on the study.
The research, a controlled, multisite, double-blind study, would be reported in the recent issue of the Journal of the American Geriatrics Society
A copy is available online Feb. 9, 2009.
For an hour a day, five days a week for eight weeks, study participants worked on computer-based activities in their homes. The participants, from Minnesota and California, were age 65 or older. No one had a diagnosis of cognitive impairment, such as early Alzheimer's disease.
The control group, with 245 adults, watched educational videos on art, history and literature topics. They completed quizzes on the content.
The experimental treatment group, with 242 adults, completed six auditory exercises designed to help the brain improve the speed and accuracy of processing. For example, participants were asked to distinguish between high- and low-pitched sounds. To start, the sounds were slow and distinct. Gradually, the speed increased and separation disappeared.........
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February 11, 2009, 6:01 AM CT
Students who interact with peers
Students who feel connected to their peers and teachers are more inclined to alert a teacher or principal if they hear a fellow student "wants to do something dangerous," as per a newly released study published by the American Psychological Association.
But those students who don't feel connected are less likely to act. Scientists from The Pennsylvania State University and Missouri State University looked into why some students adopt a "code of silence" when faced with a fellow student's dangerous intentions. Their findings are reported in the February Journal of Educational Psychology,
published by APA.
The scientists presented a hypothetical scenario of a peer's plan "to do something dangerous" to 1,740 middle and high school students from 13 schools. The students were asked if they would (1) intervene directly, (2) tell a teacher or principal, (3) talk it over with a friend but not tell an adult, or (4) do nothing.
High school students (964) were less likely than middle school students (776) to talk directly to the peer planning to do something dangerous or tell a teacher or principal, said main author Amy K. Syvertsen, MEd. "High schools are generally larger than middle schools and provide less opportunity for teachers and students to interact, which is the foundation for building trust, caring and community between the two."........
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