Archive for November 2010
Just in time for the holidays, here’s a new reason to get children to eat their veggies.
Children who eat a lot of fruit and vegetables have healthier, less stiff arteries as young adults compared to children who don’t load up on fruit and veggies, according to a new study.
Researchers say arterial stiffness is tied to atherosclerosis or hardening of the arteries, which is a key factor in heart disease. When arteries become stiff, the heart has to work harder to pump blood effectively.
In the study, published in Circulation: Journal of the American Heart Association, Finnish researchers compared childhood and adult lifestyle factors, including fruit and vegetable intake, alcohol use, and smoking with arterial stiffness in 1,622 Finns who were followed for 27 years from a baseline age of between 3 and 18.
In the past 40 years, scientists have learned a great deal about how cells become cancerous. Some of that knowledge has translated to new treatments, but most of the time doctors are forced to rely on standard chemotherapy and radiation, which can do nearly as much damage to the patients as they do the tumors. This series looks at targeted treatments that are on the horizon, and what needs to be done to make them a reality.
When a virus invades the human body, the immune system springs into action. Specialized cells called killer T cells roam the body, identifying and killing infected cells, with help from countless other cells and molecules.
Cancer biologists have long been intrigued by the prospect of harnessing those T cells to attack tumors, either to supplement or replace traditional chemotherapy. Using T cells to wipe out tumor cells could avoid the side effects often seen with chemotherapy.
“It has great potential,” says Jianzhu Chen, an MIT biology professor working on T-cell therapies for cancer. However, success has been limited, he says, because the exquisite coordination needed to launch a T-cell attack has proven difficult to replicate.
MIT engineers have developed a way to attach drug-carrying pouches (yellow) to the surfaces of cells.
Image: Darrell Irvine and Matthias Stephan
By tweaking enzymes that prevent chromosome tips from unraveling, researchers have shown age-related tissue degeneration can be reversed in some mice.
Medical breakthroughs involving mice must be taken with rock-sized grains of salt because, despite their genetic similarity, the rodents aren’t humans. The latest findings, published online by the journal Nature on November 28, are no exception. Nevertheless, they provide the first compelling evidence of aging’s reversal — not just delay — in a high-level organism.
The work represents an “unprecedented reversal of age-related decline in the central nervous system and other organs vital to adult mammalian health,” wrote the team led by Ronald DePinho, a cancer geneticist at Harvard Medical School.
Image: Fluorescent markers signify enzyme activation in the tips of telomeres./Nature.
If you’re using the anticlotting drug warfarin, tell your doctor about any herbal or dietary supplements you may be taking.
That’s the strong advice of researchers who say that nine of the 10 top-selling supplements can change the effectiveness of warfarin, potentially causing a dangerous bleed, a deadly blood clot, or even a stroke.
In a survey, nearly three-fourths of 100 people on warfarin reported they used over-the-counter multivitamins or other supplements, yet supplement use was not documented on the medical charts of nearly 70% of them, says Jennifer Strohecker, PharmD, a clinical pharmacist at Intermountain Healthcare in Salt Lake City.
Previous research has shown that fewer than one in three people tell their doctor about dietary supplement use, she tells WebMD.
Ellen Goode and her colleagues at the Mayo Clinic found a surprise while studying the human genome: four chromosomal locations with mutations that could lead to an increased risk of ovarian cancer. But the biggest surprise was a number of SNPs on chromosome 8 that seem to act through a different mechanism than other polymorphisms to influence cancer risk. Genome Technology’s Christie Rizk spoke with Goode about her study, which appeared in Nature Genetics in October.
There’s a chemical that can subtly shift your childhood memories of your own mother. In some people, it paints mum in a more saintly light, making them remember her as closer and more caring. In others, the chemical has a darker influence, casting mum as a less caring and more distant parent.
All of this becomes heavily ironic when you consider that the chemical in question – a hormone called oxytocin – is often billed as the “hormone of love”, and even marketed as “Liquid Trust”. As a new study shows, the reality is much more complicated. Describing oxytocin as the “hormone of love” is like describing a computer as a “writing tool” – it does other things too, some of which aren’t pleasant.
Oxytocin is a versatile actor, whose resume includes all sorts of jobs in sex, reproduction, social behaviour and emotions. It can increase trust among people and make them more cooperative (this works in meerkats, too). It can increase the social skills of autistic people. It’s released during orgasm. It affects lactating breasts, contracting wombs and the behaviour of sheep mothers towards their newly born lambs. The list goes on: drug addiction, generosity, depression, empathy, learning, memory.
An international team of immunologists studying the effects of cannabis have discovered how smoking marijuana can trigger a suppression of the body’s immune functions. The research, published in the European Journal of Immunology, reveals why cannabis users are more susceptible to certain types of cancers and infections.
The team, led by Dr Prakash Nagarkatti from the University of South Carolina, focused their research on cannabinoids, a group of compounds found inside the cannabis plant, including THC (delta-9 tetahydrocannabinol) which is already used for medical purposes such as pain relief.
“Cannabis is one of the most widely used drugs of abuse worldwide and it is already believed to suppress immune functions making the user more susceptible to infections and some types of cancer,” said Dr Nagarkatti. “We believe the key to this suppression is a unique type of immune cell, which has only recently been identified by immunologists, called myeloid-derived suppressor cells, MDSCs.” Read the rest of this entry »