Richard Knox

Forty-seven-year-old Celeste Corcoran is propped up in her hospital bed. In a nearby window is a forest of blooming white orchids from well-wishers. On the opposite wall, a big banner proclaims "Corcoran Strong."

She's recalling how thrilled she was to be near the finish line of the Boston Marathon, waiting for her sister Carmen Accabo to run by. "I just remember standing there, wanting to be as close as I could to catch her," Corcoran says. "I really just needed to see her face."

The largest current study of an AIDS vaccine, involving 2,500 people, is being stopped.

After an oversight committee took a preliminary peek at the results this past Monday, they concluded there was no way the study would show that the vaccine prevents HIV infection.

Nor would the vaccine suppress the wily virus among people who get infected despite being vaccinated.

The work is only in mice so far, but it sure is intriguing.

A newly found hormone revs up production of cells that make insulin — the very kind that people with advanced diabetes lack.

An international dream team of flu experts assembled in China today.

Underscoring the urgency that public health agencies feel about the emergence of a new kind of bird flu, the team is headed by Dr. Keiji Fukuda, the World Health Organization's top influenza scientist.

Before he left Geneva, Fukuda explained the wide-open nature of the investigation in an interview with NPR.

Boston hospitals always staff up their emergency rooms on Marathon Day to care for runners with cramps, dehydration and the occasional heart attack.

But Monday, those hospitals suddenly found themselves with more than 100 traumatized patients — many of them with the kinds of injuries seen more often on a battlefield than a marathon.

Like most big-city hospitals these days, Tufts Medical Center runs regular disaster drills, featuring simulated patients smeared with fake blood.

A precious package arrived at the Centers for Disease Control and Prevention last Thursday afternoon.

Inside, packed in dry ice to keep it frozen, was a vial containing millions of viruses derived from a 35-year-old Chinese housewife who died last Tuesday of respiratory and kidney failure.

Federal officials say a large study of premature infants was ethically flawed because doctors didn't inform the babies' parents about increased risks of blindness, brain damage and death.

The study involved more than 1,300 severely premature infants at nearly two dozen medical institutions between 2004 and 2009. The infants were randomly assigned to receive two different levels of oxygen to see which was better at preventing blindness without increasing the risk of neurologic damage or death.

Sixteen cases of a new flu around Shanghai have touched off a major effort to determine what kind of threat this new bug might be.

The victims range in age from 4 to 87 years old. Six have died. It is a tragedy for them and their families, but is it a global crisis?

To understand why so few cases are generating so much concern, the first thing to know is that no flu virus like this one — called H7N9 — has ever been known to infect humans before.

India's Supreme Court says drug maker Novartis can't hold onto its patent for the pricey cancer drug Gleevec simply by tweaking its chemical formula. That means generic drug makers can keep making a form of the drug at a tenth of Novartis's price — for the Indian market and for other low- and middle-income markets. Consumer advocates call it a major advance for access to generic drugs. Novartis and drug industry allies say it will chill companies' willingness to produce innovative products.

Most people (including a lot of doctors) think of a stroke as something that happens to old people. But the rate is increasing among those in their 50s, 40s and even younger.

In one recent 10-year period, the rate of strokes in Americans younger than 55 went up 84 percent among whites and 54 percent among blacks. One in 5 strokes now occurs in adults 20 to 55 years old — up from 1 in 8 in the mid-1990s.