settings, even if only for a little while, can save lives.

That's the simple lesson from the Midwest heat wave last year that killed more than 700 people in Chicago, according to a study by public health authorities.

"A lot of the people who were hooked into some city service already -- Meals on Wheels or visiting nurses -- still died,'' said Carol Rubin, an epidemiologist at the Centers for Disease Control and Prevention. "Just because the Meals on Wheels were being delivered doesn't mean that the prevention message was being delivered.'' A study of the Chicago deaths published in the New England Journal of Medicine found that those most likely to die were socially isolated, ill or disabled elderly people.

The authors estimated more than half the deaths could have been prevented by an air conditioner in the home. An air conditioner in the building lobby or the ability to get to an air-conditioned environment for a few hours a day, such as a movie theatre, also helped. Fans apparently made no difference.

*** Brain scans conducted on men as they read aloud have found evidence for several competing explanations for stuttering.

Current theories have linked stuttering to glitches in particular brain circuits, like those involved in the movements required to speak or in perception of sound, said neurologist Dr. Peter Fox.

"We're saying that each of those is accurate and the next step is to figure out how they can all be simultaneously correct,'' said Fox, whose findings were reported in the journal Nature.

A better understanding of what happens in the brain to produce stuttering could lead to better therapies, Fox said.

*** Scientists say they have identified a key chemical player in the brain's control of eating, a finding that could lead to an obesity drug.

The long-sought protein lets a natural substance called neuropeptide Y tell the brain that it's time to eat.

Neuropeptide Y, or NPY, powerfully stimulates feeding.

Scientists have known that NPY must bind to a particular protein structure on brain cells to deliver its time-to-eat message, and they have been trying to find this so-called feeding receptor for at least five years.

Researchers have already capitalised on the discovery of the receptor, called Y5. They have found substances that latch onto the receptor and block NPY's access to it, reducing appetite in rats, said Synaptic researcher Christophe Gerald.

It will be at least two years before researchers can begin studies in people of the most promising receptor blockers, with an eye toward developing an obesity drug.

*** Cold sufferers who took zinc lozenges got over their symptoms about three days sooner, a study found.

At least seven previous studies of zinc and colds yielded conflicting results.

The latest study looked at lemon-flavoured zinc gluconate lozenges, marketed by Quigley Corp. of Doylestown under the brand name COLD-EEZE.

The participants -- 100 employees of the Cleveland Clinic -- were given either 13.3 mg zinc lozenges or dummy lozenges. They started using the lozenges within 24 hours after symptoms appeared and took them every two hours while awake.

The median time for all symptoms to disappear was 7.6 days in the placebo group and 4.4 days in the zinc group.

*** A drug derived from a Chinese herb appears to be as effective as quinine in preventing malaria deaths, researchers found.

The need for an alternative to quinine has become urgent because the mosquito-borne parasite is becoming resistant to quinine, a bark extract that was the standard treatment for 300 years until the end of the Second World War.

In two studies, researchers found nearly identical death rates in patients with severe malaria who were treated with quinine or artemether, a derivative of the traditional Chinese remedy qinghaosu.

HEALTH AND SOCIAL ISSUES HTH