The vaccine against Lyme disease, approved last year for use by adults, appears safe and effective for children, according to a pilot study involving 250 youngsters.

The Lyme vaccine "was well tolerated and highly immunogenic [immunity-producing] in children," researchers concluded. "All side effects were mild or moderate and spontaneously resolved within a few days," they reported in this month's Journal of Pediatrics.

Lyme disease, an inflammatory infection caused by bacteria that live in the deer tick's gut, usually starts with a reddish "bull's-eye" rash around a tick bite. Symptoms include headache, fever, fatigue and muscle and joint aches. The most severe cases can lead to arthritis, heart abnormalities and neurological complications.

About 13,000 confirmed cases of Lyme disease were reported in 1997, according to the Centers for Disease Control and Prevention. About one-third of the reported cases are in children.

A vaccine called Lymerix was approved by the Food and Drug Administration last December for people aged 15 to 70. Approval for use in children will depend on the results of separate and more elaborate tests due to be completed next year in about 4,000 children in the United States.

The pilot study was led by Lyme disease experts at the University of Connecticut School of Medicine in Farmington, and the Connecticut Children's Medical Center in Hartford. The testing took place at University Hospital in Hradec Kralove, Czech Republic.

The vaccine was tested on 250 healthy children aged 5 to 15. Half received the adult dose; the others received a half-dose.

No severe side effects were reported in any of the children. The most common symptoms were headache and malaise, and all went away within four days.

--Don Colburn


Premenopausal women with breast cancer may have a better chance of survival if surgery to remove their tumors is not done during the first part of their menstrual cycle, a new British study suggests.

Previous research on whether the timing of breast cancer surgery affects long-term survival has yielded conflicting results. Researchers theorize that the timing could influence survival because levels of the hormones estrogen and progesterone, which vary during a woman's menstrual cycle, may affect the likelihood of tumor cells' spreading at the time of surgery.

In the new study of 112 premenopausal women, those whose breast tumors were removed on days 3 to 12 of their menstrual cycles had a 10-year survival rate of 45 percent, while women whose tumors were removed on other days of the cycle had a 10-year survival rate of 75 percent.

An average menstrual cycle lasts 28 days. The first day of a woman's menstrual period is usually counted as day 1. Hormone levels are low as the cycle begins. Estrogen levels rise steadily during the first part of the cycle, with progesterone rising more gradually. After ovulation, during the second part of the cycle, progesterone becomes the predominant hormone.

Breast cancer cells sometimes have molecules on their surfaces called receptors that make them responsive to estrogen or progesterone, but the presence or absence of such receptors did not account for the observed relationship between timing of surgery and survival rates. For instance, the presence of estrogen receptors has usually been found to influence survival favorably. But among women who had surgery in the first part of their cycle, 10-year survival was equally low whether estrogen receptors were present or absent.

The study's authors, researchers at London's Guy's Hospital, speculate that during the second part of the cycle, high levels of progesterone may act on tissue in a way that keeps the tumor contained, while high estrogen levels present during the first part may increase shedding of cancer cells from the tumor or encourage the growth of nearby blood vessels.

The study was published in the Nov. 15 issue of the journal Cancer.

--Susan Okie


African American teenage boys who had been trained in problem-solving skills were less likely to have their blood pressure increase during stressful situations than those who received other support, according to a study.

Blacks are twice as likely to develop high blood pressure by age 40 as whites. They have nearly twice the risk of suffering a fatal stroke and five times greater risk of developing end stage kidney disease, both complications of high blood pressure.

Studies have shown that children and teens who have high-normal blood pressure readings are at increased risk for developing high blood pressure as adults. As part of an ongoing effort to better understand the development of high blood pressure among African Americans, a team of investigators from Virginia Commonwealth University has been studying children and teens in Richmond.

In this latest study of 48 healthy teens, aged 13 to 16, the researchers used a laboratory setting to duplicate life stresses, such as talking to a teacher about a bad grade or confronting a friend who failed to keep a promise.

All participants were healthy teens. They were equally divided between girls and boys.

The study found that boys who had earlier received problem-solving skills were less likely to show an increase in blood pressure during these stressful situations than those who were given emotional support at the time or no support. By contrast, the study found that girls benefited equally from either problem-solving skills or from emotional support.

--Sally Squires