New Vaccine Portends Efficacy Against Autoimmune Disorders
Working with rats, Alabama researchers have developed a vaccine that may eventually be used for treating and preventing myasthenia gravis, an autoimmune disease that causes muscle weakness in about 36,000 Americans. The approach might also be useful against a variety of other autoimmune diseases, including diabetes, arthritis, lupus and multiple sclerosis.
Autoimmune diseases occur when a person’s own immune system begins attacking parts of the body. In myasthenia gravis, immune-system cells attack special docking sites on muscle cells that normally receive and process nerve signals that trigger muscle activity. Victims have a fluctuating muscle weakness, and the disorder can be life-threatening if it severely affects breathing or swallowing. Current treatments involve drugs that suppress the immune system, plasmapheresis to remove harmful antibodies from the blood, and medications that prolong the effects of chemicals that transmit nerve signals.
Immunologist J. Edwin Blalock and his colleagues at the University of Alabama at Birmingham developed molecules that are similar to key parts of immune-system cells involved in attacking the docking sites. They vaccinated rats with chemicals, then attempted to give them myasthenia gravis.
The team reports in the January issue of the FASEB Journal that half the vaccinated rats did not develop myasthenia gravis and the rest had only unusually mild symptoms. All of the control animals given the disease developed it. In work that has not yet been published, Blalock also found that the vaccine can reduce symptoms, and even induce remissions, in rats and dogs that have already developed myasthenia gravis.
Gum-Chewing Might Help Burn Fat
Chewing noncaloric gum all day, every day, could lead to the loss of 11 pounds of body fat over the course of a year, according to researchers from the Mayo Clinic. They reached that conclusion by actually measuring the energy expenditure associated with chewing.
Nutritionist James Levine and his colleagues studied seven non-obese patients in a temperature-controlled, darkened, quiet laboratory. The subjects breathed through masks attached to a device that monitored the amount of oxygen required. Energy consumption was measured for 30 minutes while the subjects rested with their arms and legs supported. Each subject was then given 8.4 grams of noncaloric gum and told to chew for 12 minutes at precisely 100 chews per minute with the aid of a metronome.
The team reported in Thursday’s New England Journal of Medicine that the subjects’ energy expenditure increased from an average of 58 kilocalories an hour at rest to 70 kilocalories an hour while they were chewing the gum, a 19.4% increase. By comparison, standing upright increased energy consumption by 11%, while walking at 1 mph increased it by 106%.
Researchers Compare Fertility Treatments
For couples with low fertility of unknown origin or with low male fertility, intrauterine insemination, or IUI, is as effective as in vitro fertilization, or IVF, but is safer and cheaper, according to Dutch researchers. In IUI, semen is inserted into the uterine cavity through a catheter at a precisely determined time. In IVF, an egg is fertilized in a laboratory dish before being implanted in the woman.
Dr. Angelique Goverde and her colleagues from Vrije University in Amsterdam studied 86 couples assigned to simple IUI, 85 assigned to IUI with hormone-stimulated release of eggs and 87 assigned to IVF.
They report in Saturday’s Lancet that IVF resulted in a higher pregnancy rate per treatment cycle, but that this was offset by a higher dropout rate among IVF couples. Overall, the cost of treatment per live birth was $5,000 for IUI, compared with $14,679 for IVF. Given the increased health risks of multiple births associated with both IVF and IUI accompanied by hormonal stimulation, they concluded that simple IUI was the best treatment approach.
Reusable Tourniquets Carry Infection Threat
The reusable tourniquets used by hospital technicians in drawing blood and starting IVs represent a serious potential source of infection and should be replaced with disposable devices, according to British researchers.
Dr. Ian Chrystie of St. Thomas Hospital in London and his colleagues collected nearly 80 tourniquets from a teaching hospital and two large district hospitals in the city.
Examining 50 of the tourniquets, they found that 25 had visible blood stains. All 50 carried common skin bacteria and 17 carried toxic strains of bacteria that could prove very dangerous if transmitted to another patient, the team reported in Saturday’s Lancet. The other 27 tourniquets were tested for the presence of HIV and hepatitis B, but no viruses were found.
The High Cost of Cigarette Smoking
Every cigarette a man smokes takes 11 minutes off his life, according to researchers from the University of Bristol in England. Dr. Mary Shaw and her colleagues calculated that if a man smokes an average number of cigarettes every year (5,772, or about 16 a day) from the average starting age of 17 until his death at 71, he will consume 311,688 cigarettes during his lifetime. Given that, on average, a male smoker loses 6 1/2 years of life, they report in Saturday’s British Medical Journal, each cigarette costs a male smoker 11 minutes of life.
Liver Transplants Best at Experienced Hospitals
Hospitals that do a lot of liver transplants are better at it than those who do fewer, a finding that has previously been demonstrated for a variety of other transplants and surgeries. Practice does, indeed, make perfect, is the general theory.
Dr. Erick B. Edwards and colleagues from the United Network for Organ Sharing reviewed all 9,623 liver transplants performed in the United States from 1987 to 1994. They reported in Thursday’s New England Journal of Medicine that the yearly death rate was 20% in hospitals that performed more than 20 transplants each year, but 26% in those that performed fewer than 20. Thirteen centers, all of them low volume, had death rates above 40%, and one had a death rate of 100%. The hospitals were not identified.
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Medical writer Thomas H. Maugh II can be reached at thomas.maugh@latimes.com.
