BOSTON, Aug. 20 -- The start of each new school year brings with it an increased risk that your child will be among the 6-12 million youngsters nationwide who come home with head lice. And to make matters worse, mutant strains of head lice that are resistant to conventional treatment are on the rise in the United States.

In an all-out effort to learn how to defeat resistance in lice, scientists at the University of Massachusetts say they are the first to come up with a way to actually grow colonies of mutated lice in their laboratory for closer study. Kyong Yoon, a Ph.D. student at the University of Massachusetts at Amherst, described the work to scientists attending the 224th national meeting of the American Chemical Society, the world's largest scientific society.

The most common ingredient in various products used to treat head lice is permethrin, an insecticide derived from natural compounds in chrysanthemum flowers, according to John Clark, Ph.D., a professor in the university's department of entomology and Yoon's faculty advisor.

The researchers hope their work will lead to new ways to control head lice.

In limited sampling studies of people in various parts of the United States, resistance to permethrin has ranged from 50 percent in some Los Angeles school children to about 98 percent in a migrant workers' camp in Florida, Clark noted during a telephone interview. Clark's research group also did sampling in Texas where resistance was found to be 75-80 percent. His group is aware of resistance in Boston and western Massachusetts although they have not yet measured the level of resistance, he added.

Clark and Yoon are the first researchers to develop an artificial feeding system that allows them to raise their own mutant lice for study.

"Our work is the first report of artificially rearing human head lice and carrying out a molecular linkage study in U.S. populations," according to Clark.

"We have a mem
'"/>


20-Aug-2002

Page: 1 2 3 4
Related biology news :

1. Researchers determine genetic cause of Timothy syndrome
2. Researchers find color sensitive atomic switch in bacteria
3. Researchers identify protein promoting vascular tumor growth
4. Researchers devise potent new tools to curb ivory poaching
5. Researchers create nanotubes that change colors, form nanocarpet and kill bacteria
6. Researchers ID chlorophyll-regulating gene
7. Researchers develop fast track way to discover how cells are regulated
8. Researchers identify distinctive signature for metastatic prostate cancer
9. Researchers report new gene test for isolated cleft lip and palate
10. Researchers discover why mutant gene causes colon cancer
11. Researchers identify the genomes controlling elements