CHECKUP : CHILDREN CAUGHT IN THE CROSS-FIRE NEWS, TIPS AND TRENDS.

Children often end up in the cross-fire of fighting between parents, a new study has found, and even subtle injuries may signal that a child lives in a home with domestic violence.

After studying emergency room records, researchers from the University of Pennsylvania School of Medicine found that children are often injured as bystanders in fights between parents, family members and even family friends. The doctors found that 48 percent of children injured this way were younger than 2, and most children were injured from being hit directly, although unintentionally.

More than half of the younger children were unintentionally hit as they were held by a parent, and 39 percent were injured because they were trying to intervene in a parental fight.

The researchers estimate that more than 3 million children between the ages of 3 and 17 are at risk of injury from parental violence each year, and that detailed questions about all injuries may help identify violent homes.

Heart disease on decline: Thanks to better treatments, the number of people who died from heart disease in the United States decreased by a third from 1980 to 1990. Surgical procedures to restore proper blood flow to the heart, such as angioplasty, and medications, such as clot-busting drugs, accounted for about 70 percent of the nationwide decline in heart disease mortality, the researchers said.

High on literature: The fungi that feed on old paper may be mildly hallucinogenic, and the ``fungal hallucinogens'' may cause an ``enhancement of enlightenment'' in readers, says a report in the British medical journal The Lancet cited in Men's Fitness magazine. The source of inspiration for many great literary figures may have been nothing more than a quick sniff of the bouquet of moldy books, the report says.

Licking leukemia: Leukemia cells may not have to disappear for the disease to be cured, Houston scientists have reported.

Using an ultrasensitive test to detect cancer cells, researchers from the University of Texas M.D. Anderson Cancer Center studied 24 children with acute lymphoblastic leukemia, the most common form of childhood cancer. After their initial chemotherapy, seven patients had relapsed and 17 were in remission. And of those 17, the scientists found, 15 had high levels of leukemic cells in their bloodstream - as many as 100,000 or even 1 million cells.

``That was absolutely an unexpected result in my mind,'' said pediatrician Dr. Mark Roberts, one of the study leaders.

The results were reported in a recent issue of the New England Journal of Medicine.

The researchers would now like to find out how some patients can have cancer cells left in their body and remain healthy.

``We have to rethink how we are curing these patients,'' Dr. Roberts said. ``The cure of leukemia must be more complicated than eradicating every last leukemia cell.''

Learning more about how leukemia is cured could help improve the 75 percent cure rate of the disease.

A cold reception: Scientists have found a statistical link between a communication system in the brain and how cold and aloof we are. The work focused on a type of dopamine receptor called D2. Scientists report in the journal Nature that the lower the density of receptors a person had, the higher he or she tended to score in a measure of a personality trait called detachment.