Monday, May 31, 2010

Acupuncture relieves discomfort in mice with a sore paw

And great generalizations are being drawn from that. The original heading on the article below was: "Acupuncture does work as it stimulates a natural pain killer, scientists find". Save us!

How do they measure discomfort in mice with a sore paw anyway? The researchers used a number of methods, suggesting no great confidence in any of them. See the journal article here. As a psychometrician, I would be very interested to see how well the various methods correlated with one-another but I could not find that information. Failure to correlate indicates invalid measures.

There is also no indication that the measurements were done under double-blind conditions -- thus leaving the way wide-open for experimenter expectation effects.

Note that in humans, acupuncture gets results no better than placebo

Acupuncture works by stimulating a natural painkiller in the body that swells arteries and allows more blood to flow through, scientists have discovered. The identification of the chemical adenosine as a central player could also make the ancient Chinese therapy even more effective at relieving pain.

Scientists were able to triple the beneficial effects of simply sticking needles in mice by adding a leukaemia medication that increased their amounts of the molecule.

Dr Maiken Nedergaard, a neuroscientist at the University of Rochester, New York, said: "Acupuncture has been a mainstay of medical treatment in certain parts of the world for 4,000 years, but because it has not been understood completely, many people have remained sceptical. "In this work, we provide information about one physical mechanism through which acupuncture reduces pain in the body.

"What we found is that adenosine, a natural pain killer, is released during acupuncture and that adenosine may be the primary way acupuncture reduces pain. "The most important observation is that acupuncture worked almost three times as long if we gave a drug that slow down the removal of adenosine."

Adenosine, which also helps to regulate sleep and keep the heart healthy, becomes active in the skin after an injury to inhibit nerve signals and ease pain.

The researchers, whose findings are published in Nature Neuroscience, performed acupuncture treatments on mice that had discomfort in one paw, giving them each a thirty minute acupuncture treatment near the knee, with very fine needles rotated gently every five minutes, much as is done in standard acupuncture treatments with people.

In mice with normal functioning levels of adenosine, acupuncture reduced discomfort by two-thirds, while in those engineered not to produce the chemical it had no effect. And when adenosine was turned on in the tissues, discomfort was reduced even without acupuncture.

During and immediately after an acupuncture treatment, the level of adenosine in the tissues near the needles was 24 times greater than before.

Once the scientists recognised adenosine's role, the team explored the effects of a cancer drug called deoxycoformycin, which makes it harder for the tissue to remove it. The compound boosted the effects of acupuncture treatment dramatically, nearly tripling the accumulation of adenosine in the muscles and more than tripling the length of time the treatment was effective.

Dr Josephine Briggs, director of the National Centre for Complementary and Alternative Medicine at the National Institutes of Health in the US, said: "It is clear that acupuncture may activate a number of different mechanisms. "This carefully performed study identifies adenosine as a new player in the process. It is an interesting contribution to our growing understanding of the complex intervention which is acupuncture."


Women may get vaccine to protect against breast cancer

A vaccine designed to protect against breast cancer is expected to be tested on women within the next two years. It has been tested on mice and results suggest that it could prevent tumours appearing and attack those that are already present. If tests on women show similar results, it could be offered to women around the age of 40, when the risk of developing the disease rises.

Researchers hope that it will kill off up to 70 per cent of breast cancers and save more than 8,000 lives a year in Britain. Vincent Tuohy, an immunologist who developed the vaccine at the Cleveland Clinic in Ohio, said: “We truly believe that a preventive breast cancer vaccine will do to breast cancer what the polio vaccine has done to polio. We think that it will provide substantial protection. Our view is that breast cancer is a completely preventable disease.”

Dr Tuohy said that his vaccine made the patient’s immune system attack a specific protein found in most breast cancer cells and the mammary tissues of breastfeeding women. For this reason, it would not be given to women who planned to breastfeed.

“The frequency of women who breastfeed in their early forties and above is very low, so we are looking at vaccinating women against the disease from this stage of life onwards,” Dr Tuohy said.

He said that he hoped to test the vaccine on women in two small clinical trials next year to evaluate its safety and dosage levels. Even if the tests are successful it is unlikely that a vaccine would be available for at least ten years.

The research is reported in the latest edition of the journal Nature Medicine. The vaccine was tested on mice bred to develop breast cancer. Researchers injected six mice with a vaccine made from the protein alpha-lactalbumin and another chemical to boost the immune system’s response to the vaccine. Six other mice were also given a dummy vaccine. After ten months, all mice that received the dummy had developed serious breast tumours. None of the mice given the real vaccine showed any signs of similar tumours.

Breast cancer is the most common form of cancer in Britain and kills about 12,000 women every year.

Caitlin Palframan of Breakthrough Breast Cancer, said: “This research could have important implications for how we might prevent breast cancer in the future. However, this is an early stage study, and we look forward to seeing the results of large-scale clinical trials to find out if this vaccine would be safe and effective in humans.


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