Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:

Another Manufacturer Warns of Defibrillator Problems

St. Jude Medical Inc. is warning doctors and patients that some of its older implantable defibrillators may suddenly lose power if exposed to significant levels of environmental radiation, the Associated Press reported Friday. Excessive environmental radiation occurs naturally, caused by decay in the earth’s core.

Defibrillators are small devices that send electric jolts to the heart when the organ begins beating irregularly. St. Jude, headquartered in St. Paul, Minn., said the affected devices — the Photon DR, Photon Micro VR/DR, and the Atlas VR/DR — may soon be recalled by the U.S. Food and Drug Administration. An FDA spokesman was not available for comment, the wire service said.

Testing has indicated that about 60 of the 36,000 devices produced by St. Jude may be affected, the AP said. The problem lies with a faulty memory chip. The company has advised doctors to remove the device if they find it has been automatically reset because of a power drain.

In June, another defibrillator manufacturer, Guidant Corp. of Indianapoplis recalled 88,000 heart defibrillators, also because of electrical defects. The FDA is investigating whether Guidant deliberately withheld knowledge of the defects, HealthDay has reported.

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Legionnaire’s Disease Most Likely Cause of Canadian Nursing Home Deaths

Legionnaire’s disease is most likely behind a recent series of deaths at a Toronto nursing home, city health officials said Friday.

On Wednesday, six more elderly residents at the Seven Oaks Home for the Aged died from the respiratory illness, bringing the total to 16 fatalities. Dr. David McKeown, chief medical officer for Public Health Toronto, said there could be more deaths before the lethal bacteria that causes the disease was contained, the Associated Press reported.

In all, some 70 residents, 13 employees and five visitors to the home have been stricken, and at least 45 remain hospitalized, the AP said.

After preliminary tests, officials had initially ruled out Legionnaires, but changed their minds after autopsy cultures came back positive, the wire service said.

Legionnaire’s is a type of pneumonia named after it was first diagnosed in 1976 at a meeting of the American Legion in Philadelphia. Thirty-four people who attended that convention died from the disease. The germ grows in warm water and tends to harbor in plumbing, heating and air conditioning systems.

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Politics Trumping Science in ‘Plan B’ Decision: Ex-FDA Consultant

Politics is overriding science in delaying approval of the “Plan B” contraceptive for over-the-counter sales in the United States, said Dr. Frank Davidoff, who cited the issue as his reason for resigning as consultant to the U.S. Food and Drug Administration’s Nonprescription Drugs Advisory Committee.

Davidoff, editor emeritus of the journal Annals of Internal Medicine, resigned in September after the FDA said it was indefinitely delaying a decision on over-the-counter sales of Plan B, an emergency, morning-after contraception, the Associated Press reported.

The FDA announcement was made despite recommendations from scientists that Plan B is safe. Many U.S. religious conservatives oppose the drug.

“There wasn’t any observable scientific or procedural reason for (the FDA) to first decline and then further delay the decision. I had to make the inference this was a decision that was made on the basis of political pressure, and it seemed to me that was unacceptable,” Davidoff told the AP.

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