First, "Chemicals Called Main Cause of Parkinson's Disease," which points up the fact that cancer is not the only disease corporate polluters are responsible for.
Second, "FDA To Curbs Animal Antibiotics" is a timely indication of much-belated action on another issue I raised in response to blanket praise for antibiotics.
-- Paul
============== Wednesday, January 27, 1999
Chemicals Called Main Cause of Parkinson's Disease: Genes trigger only a small number of cases, study finds. Pesticides are cited as possible culprit. By THOMAS H. MAUGH II, Times Medical Writer
Most cases of Parkinson's disease are not caused by a defective gene, but rather by exposure to as yet unknown chemicals in the environment, California scientists reported today.
The discovery should provide some comfort to family members of Parkinson's victims who fear for their own future health, said the research team from the Parkinson's Institute in Sunnyvale. The study also suggests that research should focus on potential environmental causes, such as pesticides and herbicides, they added.
Genetics is a factor, however, in the relatively small number of patients--less than 10%--whose familial Parkinson's begins under the age of 50. Their disease is caused by a gene that has been identified.
Based on previous studies with small numbers of twins, scientists have long suspected that genetics did not play an important role in the disease, which affects more than a million Americans. The new study of nearly 20,000 white male twins who fought in World War II seems to confirm that definitively.
Dr. Caroline M. Tanner and her colleagues at the Parkinson's Institute report in today's Journal of the American Medical Assn. that the disorder most commonly affected only one member of a twin pair, whether the pair consisted of identical or fraternal twins.
If the disease were genetic in origin, both members of a pair of identical twins--who share all their genes--would be expected to develop it. This "landmark study . . . provides guidance that is extremely important," said Dr. Michael D. Walker of the National Institute of Neurological Diseases and Stroke. "For patients over the age of 50, it means that we are going to have to look elsewhere for causes."
But the study of the younger patients with a familial form of the disease will remain important, said Dr. Neal Hermanowicz, medical director of the movement disorders program at Good Samaritan Hospital in Los Angeles. "Any time you have a gene for a disease, whether it applies to all cases or not, it gives you a huge leg up in understanding the disease process." Parkinson's disease results from the death of certain brain cells that secrete dopamine, a chemical messenger used for controlling movements. The major symptoms include tremor, stiffness of muscles and bradykinesia, or slowness of movement.
It is most commonly treated with drugs that replace the lost dopamine. Transplants of fetal tissues that secrete dopamine have also been helpful. Tremors can sometimes be controlled by pallidotomies, in which a small section of the brain is destroyed, or by implanting electrodes. But there is no cure and the disease is usually fatal.
An estimated 60,000 people develop Parkinson's each year, and that number is expected to climb as the population grows older. The idea that Parkinson's might be caused by chemicals in the environment got a major boost in 1982 when Dr. J. William Langston, now president of the institute and a coauthor of the current paper, discovered several young people who developed Parkinson's symptoms literally overnight after using tainted heroin. He found that the symptoms were caused by a contaminant called MPTP, which bears a strong chemical similarity to many pesticides and other environmental chemicals.
Two years ago, researchers also discovered that the disease could be caused, at least in some Italian and Greek families, by defects in the gene for a protein called alpha-synuclein.
Many authorities who had supported an environmental cause "flip-flopped" back to favoring a genetic origin, Hermanowicz said.
To clear up the confusion, Tanner and her colleagues studied 19,842 surviving white male twins who are enrolled in the National Academy of Sciences/National Research Council World War II Veterans Twin Registry.
They identified 193 individuals who had a confirmed case of Parkinson's disease. Among those who developed the disorder after age 50, the likelihood that their twin brother would also have Parkinson's was no greater than the risk for the population at large, whether the twin was identical or fraternal.
Such results normally mean that there is little or no genetic contribution to the disease.
"For the first time, we can say that typical Parkinson's disease is most commonly caused by environmental factors," Tanner said.
Among the 16 twins who were under 50 when they developed the disorder, however, there was a high likelihood that the second identical twin would contract it, and a lower, but still elevated, risk that a fraternal twin would. The finding indicates that for these families the disorder is genetic in origin. The team has collected a great deal of information about environmental exposures among the twins, Tanner added, and will begin plowing through the data in hopes of narrowing down the number of potential causes.
Copyright 1999 Los Angeles Times. All Rights Reserved
============== Wednesday, January 27, 1999
FDA To Curbs Animal Antibiotics By LAURAN NEERGAARD, AP Medical Writer
WASHINGTON--The government plans to impose strict new rules on antibiotics given to farm animals to combat concerns that the medicines are creating drug-resistant germs that wind up in the meat people eat.
Antibiotics are fast losing their ability to fight infections, mostly because people misuse the vital drugs: Doctors often overprescribe them and patients often don't take them properly.
But scientists say antibiotics used on the farm now are causing foodborne bacteria to mutate into treatment-resistant forms -so the Food and Drug Administration is preparing rules to try to curb the problem.
"It's an issue that won't go away and can no longer be ignored," said Michigan veterinarian Keith Sterner, who chaired a panel of FDA's advisers that backed most of the agency's plans Tuesday.
The advisory committee said FDA's plan to force antibiotic manufacturers to conduct on-the-farm testing of drug resistance probably would never work. But overall, the FDA has proposed "a sound framework" of more strict animal drug regulation, Sterner said.
A two-day meeting to deliberate the FDA's proposals highlighted how bitter a controversy the issue is. On one side, the animal drug industry denies there is any serious risk to consumers, noting that no one has died from eating meat tainted with untreatable germs. On the other side, public health experts say they must act to protect consumers from that ever happening.
Critics "never stood at the bedside of a critically ill patient ... hoping the antibiotics will work and having to deal with the consequences when they don't," said Dr. David Bell of the Centers for Disease Control and Prevention. He pleaded with the industry to find a compromise that protects consumers while still providing farmers with drugs vital for animal health. Manufacturers adamantly oppose many of FDA's plans, saying the rules would make it too difficult -and expensive -to create new antibiotics for animals. They argued that the government instead should study whether on-the-farm antibiotics really pose an imminent threat, and educate farmers and veterinarians to more prudently use the drugs.
"We believe the agency is overreacting," said Dr. Brendan Fox, president of Elanco Animal Health.
That prompted a fierce reaction from one of FDA's advisors: "If there is no risk, you shouldn't be afraid of" the FDA's rules, said CDC's Dr. Frederick Angulo.
Almost half the 50 million pounds of U.S.-produced antibiotics is used in animals. Eighty percent is used, not to treat sick animals, but to promote animals' growth by adding small doses into their feed.
Already, Europe has drawn the ire of the animal health industry by banning six antibiotics used as animal growth promoters, including one closely related to the vital human antibiotic vancomycin.
Among the FDA's proposals to tackle the issue:
-Companies seeking to sell a new animal antibiotic would have to prove it is not expected to cause significant resistance.
-The government would test today's level of foodborne drug resistance, and then set limits on how much resistance could increase before an implicated animal antibiotic would be restricted, even banned.
-FDA would rank animal drugs, giving those most closely related to vital human antibiotics extra scrutiny. Some companies might be ordered to conduct on-the-farm animal tests.
FDA advisers said Tuesday that on-the-farm testing may be too complicated to ever work, but agreed with most of FDA's approach.
Sterner stressed that animal antibiotics closely related to vital human drugs would have "a zero threshold" for increasing resistance.
The FDA will decide which rules to adopt after a public comment period ends in April.
Copyright 1999 Associated Press. All Rights Reserved
-- Paul Rosenberg Reason and Democracy rad at gte.net
"Let's put the information BACK into the information age!"