New 3-D tumor model
|
|
A team of scientists has developed a way to coax tumor cells in the lab to grow into 3-D spheres. Their discovery takes advantage of an earlier technique of producing spherical cavities in a common polymer and promises more accurate tests of new cancer therapies.
As team leader Michael R. King, Ph.D., of Cornell University explains, “Sometimes engineering research tends to be a case of a hammer looking for a nail. We knew our previous discovery was new and it was cool. And now we know it’s useful.”
Three years ago, the team—in collaboration with Lisa DeLouise, Ph.D., MPD, of Rochester, N.Y.—perfected a low-cost, easy fabrication technique to make spherical cavities in PDMS (polydimethylsiloxane), a widely used silicon organic polymer. More recently, the Cornell team discovered that these cavities could be used as a scaffolding to grow numerous tumor spheroids, which could serve as realistic models for cancer cells. The Cornell team’s work appears in the current issue of Biomicrofluidics, a publication of the American Institute of Physics.
Researchers discover potential cause of chronic painful skin
|
|
A new study may explain why only 50% of patients experiencing chronic nerve pain achieve even partial relief from existing therapeutics. The study, published in the June 6 online version of the international research journal PAIN, reveals that certain types of chronic pain may be caused by signals from the skin itself, rather than damage to nerves within the skin, as previously thought.
A Medical Mystery
For years, researchers have known that increased amounts of a molecule called Calcitonin Gene-Related Peptide (CGRP) is found in the skin of chronic pain patients. The source of the increased CGRP was thought to be certain types of sensory nerve fibers in the skin that normally make and release a type or “isoform” called CGRP-alpha. Curiously, however, the authors of the current study found that nerve fibers containing CGRP-alpha are actually reduced under painful conditions – leading them to investigate where the increased CGRP in the skin came from.
The answer, surprisingly, was that the skin cells themselves generate increased amounts of a lesser-known “beta” isoform of CGRP. This skin cell-derived CGRP-beta is increased in painful conditions and may be sending pain signals to remaining sensory nerve fibers in the skin. The discovery of CGRP-beta as a therapeutic target presents a potentially important new treatment approach.
Experts prove link between phosphate intake and heart disease
|
|
This is the first time the connection between a high phosphate diet and atherosclerosis - the cause of heart disease - has been proven. The findings have been published in Arteriosclerosis, Thrombosis and Vascular Biology (2 June 2011).
The research, which was funded by the Sheffield Kidney Association and the National Institute for Health Research, has shown that cholesterol deposits in the wall of arteries are increased following a higher phosphate diet. This leads to narrowing of the arteries, which is the cause of most heart attacks and strokes.
As a result, the research demonstrates the importance of reducing phosphate levels in the human diet or possibly using drugs called binders or other agents that stop phosphate being absorbed. Food high in phosphate includes biscuits, cakes, sweets, dairy products and meats such as offal and veal.
‘Wrong’-time eating reduces fertility in fruit flies
|
|
Dieticians will tell you it isn’t healthy to eat late at night: it’s a recipe for weight gain. In fruit flies, at least, there’s another consequence: reduced fertility.
That’s the conclusion of a new study this week in Cell Metabolism by researchers at the Perelman School of Medicine at the University of Pennsylvania, in which they manipulated circadian rhythms in fruit flies and measured the affect on egg-laying capacity.
Lead author Amita Sehgal, PhD, John Herr Musser Professor of Neuroscience, stresses, though, that what is true in flies grown in a lab does not necessarily hold for humans, and any potential link between diet and reproduction would have to be independently tested.
Study identifies genetic mutations associated with cancer risk for hereditary cancer syndrome
|
|
Among various genetic mutations for individuals with Lynch syndrome, a hereditary cancer syndrome that carries a high risk of colon cancer and an above-normal risk of other cancers, researchers have identified mutations associated with a lower cancer risk and mutations associated with an increased risk for ovarian and endometrial cancer, according to a study in the June 8 issue of JAMA, a theme issue on cancer. The study is being published early online to coincide with the American Society of Clinical Oncology 2011 Annual Meeting.
The Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer syndrome, accounts for 3 percent to 5 percent of all colorectal cancers. “Providing accurate estimates of cancer risks is a major challenge in the clinical management of Lynch syndrome,” according to background information in the article. “Having more accurate knowledge of the age-dependent cancer risks associated with mismatch repair [MMR; a system within the cell for correcting errors in DNA] gene mutations would help in improving preventive strategies.”
Valerie Bonadona, M.D., Ph.D., of the Centre National de la Recherche Scientifique, Villeurbanne, France, and colleagues conducted a study to estimate the specific cancer risks associated with mutations in the genes MLH1, MSH2, and MSH6 by analyzing a large sample of families with Lynch syndrome. The study included 537 families with segregating mutated genes (248 with MLH1; 256 with MSH2; and 33 with MSH6). The families were enrolled between January 2006 and December 2009 from 40 French cancer genetics clinics.
Cellphone study raises profile on safety lawsuits
|
|
The Supreme Court is considering the fate of litigation against cellphone makers over safety risks, just as the industry comes under more scrutiny in the wake of a health report from the World Health Organization.
A working group of WHO cancer experts suggested on Tuesday that cellphone use should be classified as “possibly carcinogenic” after reviewing of all the available scientific evidence.
The classification puts mobile phone use in the same broad cancer risk category as lead, chloroform and coffee, and it garnered extensive media coverage. Industry groups immediately sought to play down the announcement, saying it does not mean that cellphones cause cancer.
Scripps Research scientists find way to block stress-related cell death
|
|
Scientists from the Florida campus of The Scripps Research Institute have uncovered a potentially important new therapeutic target that could prevent stress-related cell death, a characteristic of neurodegenerative diseases such as Parkinson’s, as well as heart attack and stroke.
In the study, published recently in the journal ACS Chemical Biology, the scientists showed they could disrupt a specific interaction of a critical enzyme that would prevent cell death without harming other important enzyme functions.
The enzyme in question is c-jun-N-terminal kinase (JNK), pronounced “junk,” which has been implicated in many processes in the body’s response to stresses, such as oxidative stress, protein misfolding, and metabolic disorder. JNK also plays an important role in nerve cell survival and has become a target for drugs to treat neurodegenerative disorders such as Parkinson’s disease.
New study looks at disconnect between medical and lay expertise
|
|
The Internet is empowering its users more than ever, but the same technology that allows people access to limitless information has also enabled some to combat scientific or medical authority with their personal experiences.
In a recent study published in the journal Social Science & Medicine, Oregon State University sociologist Kristin Barker and graduate student Tasha Galardi looked at the reactions of breast cancer survivors in the wake of the new guidelines published in 2009 by the United States Preventative Service Task Force. Departing from established recommendations, the new guidelines recommend against routine screening mammography for women in their 40s, and suggest that women ages 50 to 74 be screened every other year instead of annually. The guidelines generated media attention and elicited intense anger from breast cancer survivors.
Sampling some of the most popular online breast cancer discussion forums, the researchers found that women used the Internet not only for solidarity and sharing their personal stories, but also to collect their own experiences as a type of evidence to contradict the task force’s recommendations. The women were upset because their shared experiences with breast cancer confirmed established wisdom that mammography saves lives, especially theirs.
Cholera outbreaks closely follow temperature rise, rainfall
|
|
Moderate increases in temperature and rainfall can herald cholera epidemics, a study in East Africa has found, and researchers urged governments to use those environmental cues to better protect vulnerable populations.
The researchers matched cholera outbreaks which occurred in Zanzibar between 1999 and 2008 against temperature and rainfall records over the same period and found that the environmental changes were closely followed by disease.
“We found that when temperature goes up by 1 degree Celsius, there is a chance of cholera cases doubling in four months’ time and if rainfall goes up by 200 millimetres, then in two months’ time, cholera cases will go up by 1.6 folds,” Mohammad Ali, a senior scientist at the International Vaccine Institute in Seoul, South Korea, said by telephone.
