Health Highlights: June 2, 2004
Genetic Engineering Protects Calves From Mad Cow Kraft Alters Portion Reductions Poor Building Ventilation Increases Cold Risk Study: Prozac Helps Depressed Teens Yo-Yo Dieting May Affect Immune System
Here are some of the latest health and medical news developments, compiled by editors of HealthDay:
Genetic Engineering Protects Calves From Mad Cow
A genetically engineered bovine embryo free of both copies of the gene that activates prion proteins -- which can cause mad cow disease -- has been created by Hematech, LLC of Sioux Falls, S.D.
Live animals produced from such embryos would not have prions and would be unable to contract mad cow disease, which can be caused by misfolded prion proteins, according to a company news release.
Animals created using these genetically engineered fetuses could prove ideal for the production of human polyclonal antibodies, which may be used to treat cancer, autoimmune diseases, infectious diseases and immune deficiency.
"Our goal is to develop a bovine productions system that will enable Hematech to rapidly produce unlimited quantities of safe, fully human antibodies for a variety of therapeutic uses," Hematech CEO James Barton said in a prepared statement.
Kraft Alters Portion Reductions
Kraft Foods Inc., the largest food company in the United States, has altered plans to reduce single-serve package portion sizes as part of its anti-obesity actions announced last year.
The company announced Tuesday that it will not reduce some portion sizes in single-serve packages. Kraft said that's because consumers want to be able to choose whether to buy smaller packages, the Associated Press reported.
"After conducting consumer research and gathering other stakeholder input, Kraft plants to implement a new, twofold approach to smaller packages, rather than its previously announced plan to cap the portion size of single-serve packages," the company explained in a written statement.
Kraft plans to offer a wide range of portion-size choices, and to provide nutrition information for entire packages instead of for individual portions, in order to help consumers make informed choices, the AP reported.
As part of its anti-obesity efforts, Kraft has also promised to alter some product recipes, stop snack giveaway marketing efforts at schools, and encourage people to adopt healthier habits.
Poor Building Ventilation Increases Cold Risk
People who work in buildings with a low supply of outdoor air may have an increased risk of exposure to fellow workers' cold viruses that are spread through the ventilation system, says a study in the June issue of the American Journal of Respiratory and Critical Care Medicine.
Researchers gathered air samples from three different buildings during the workday. They detected airborne viruses in 32 percent of air sampling filters in the buildings. They concluded that there was a significant link between the degree of building ventilation and the frequency of virus detection in the air filters.
Respiratory infections caused by cold viruses are the most common infectious disease in the United States and rack up $25 billion in direct and indirect costs each year, according to the researchers.
Colds result in 20 million lost days of work each year in the country and cause excessive and inappropriate use of antibiotics.
Study: Prozac Helps Depressed Teens
The antidepressant Prozac is significantly more effective than psychotherapy alone in treating teenage depression, according to a landmark U.S. government study cited by The New York Times.
Preliminary results of the study, financed by the National Institute of Mental Health, are sure to fuel the growing debate over whether Prozac and similar medications may trigger suicidal tendencies in some younger users.
Prozac is the only drug in its class to be approved by the U.S. Food and Drug Administration for treating childhood depression. It belongs to a group of drugs known as selective serotonin reuptake inhibitors (SSRIs), which also includes brand names like Paxil and Zoloft. Recent studies have indicated that these drugs may lead to suicidal behavior in teenagers, and the FDA recently advised doctors to carefully monitor younger patients who begin these drugs or change doses.
The new government study may make psychiatrists, pediatricians and the millions of families with youngsters who take these medicines rest a bit easier, the newspaper speculates. The researchers found that talk therapy by itself was no more effective than a non-medicinal placebo in combating childhood depression. Use of Prozac led to far better results, and a combination of the medication and talk therapy produced the best results of all, the Times reported.
The 36-week study involved 439 people ages 12 to 17 who had been diagnosed with moderate to severe depression. While the authors calculated an increased risk of suicide among a small number of Prozac users, lead investigator Dr. John March said the medication's benefits far outweighed its risks, the newspaper reported. March is a professor of psychiatry at Duke University.
"Although each death is a tragedy, the number of people who have benefited from these medications is significantly greater than the number who have been harmed by them," Dr. Marvin Lipkowitz, chair of psychiatry at Maimonides Medical Center in New York City, told HealthDay.
Yo-Yo Dieting May Affect Immune System
People who are locked in a constant cycle of losing and regaining weight may be doing long-term damage to their immune systems, according to early findings by scientists at the Fred Hutchinson Cancer Research Center.
The practice of yo-yo dieting appears to affect the activity of so-called "natural-killer" cells, which offer immune system protection against viruses and even cancer cells, the Seattle-based center said in a prepared statement. Frequent bouts of weight loss/gain over a 20-year period were associated with decreased natural-killer cell activity among the 114 women studied, the researchers found.
By contrast, study participants who had maintained a stable weight were found to have better-than-average immune function, the scientists said.
The researchers, writing in the June issue of the Journal of the American Dietetic Association, noted that their results are only preliminary. Their statement cautioned that it is still not known whether it's better to carry around a few extra pounds or risk the health effects of yo-yo dieting.