Text 6. New Method to Find Alzheimer’s Disease.

Alzheimer’s disease usually appears late in life. In the United States alone, experts say about four million people have this brain disorder. Over time, it robs people of their memory and ability to think. There are no cures.

Until now, Alzheimer's could be confirmed only by examining brain tissue after death or by taking brain tissue from a living patient. Now, a new test offers hope that Alzheimer’s may be found earlier.

Experts currently give written and spoken tests to help decide if a person has the disease. They also use a process called magnetic resonance imaging to see the brain changes that may mean Alzheimer’s.

Many patients already have been seriously affected by the time the disease shows up on these M-R-I’s. Most of the materials believed linked to the disease are present on the image. They are called protein clumps.

But the new test makes it possible to see the protein clumps before they could be found by M-R-I. The new test might identify the disease before a person shows signs of Alzheimer’s. Treatment could begin earlier. Doctors could see if the treatment is helping. New or improved drugs may be developed.

William Klunk of the University of Pittsburgh School of Medicine in Pennsylvania helped invent the test. It calls for patients to receive a small amount of a radioactive molecule called Pittsburgh Compound B. It is administered through the blood.

Doctor Klunk says it connects itself to proteins called amyloid plaques. These plaques exist in the brains of Alzheimer’s patients. Doctors can see them with an examination called a PET scan. Proteins affected by Alzheimer’s show as yellow and red.

For years, Doctor Klunk and his team searched for a substance that could connect with the amyloid. Finally they found a material that can reach the brain through the blood. This Pittsburgh Compound B can color the amyloid.

The finding led to a test of sixteen suspected Alzheimer’s patients. The researchers say the test found amyloid in those patients. It also found small amounts in one of nine healthy people tested for comparison. Testing on more people is needed. The United States Food and Drug Administration currently is considering approval of the process.

Text 7. Obesity as a Social Disease?

When one person gains weight, close friends often do, too. Researchers say they have found that fatness can spread from person to person in social groups. When one person gains weight, close friends often gain weight, too. The study was published last month in the New England Journal of Medicine.

The researchers looked at records from the Framingham Heart Study. It gathered health information about more than twelve thousand people from nineteen seventy-one to two thousand three. The information was very detailed. It listed changes in the body-mass index for each individual. The body mass index measures a person's body fat.

The Framingham study also provided information about changes in family and events like marriages and deaths. There was also contact information for close friends of the subjects in the study. As a result, the researchers were able to examine more than forty thousand social ties.

The study showed that when a person becomes severely overweight, there is a fifty-seven percent increased chance that one of their friends will be, too. A sister or brother of the overweight person has a forty percent increased chance of becoming fat. The increased risk for a wife or husband is a little less than that.

Nicholas Christakis of Harvard Medical School was a lead investigator in the study. He says his research showed that fat people are not choosing fat friends. He says there is a direct causal relationship between a person getting fat and being followed in weight gain by a friend.

The study found that the sex of the friends is also an influence. In same-sex friendships, a person has a seventy-one percent increased risk of getting fat. The same was true for brothers and sisters separately. A man has a forty-four percent increased risk of becoming obese after a weight gain in his brother. In sisters, the increased risk is sixty-seven percent.

The study also showed that physical closeness of family members and friends did little to increase a person's risk. The other lead investigator was James Fowler of the University of California at San Diego. Mister Fowler says a friend who lives a few hundred kilometers away has as much influence as one in your neighborhood. He says the study demonstrates the need to consider that a major part of a person`s health is tied to his or her social connections.