|
|
|
 CELL BIOLOGY: Drug Stops Motor Protein, Shines Light on Cell Division
Scientists studying how cells know when and where to divide have a new tool to study the final, fast stages of cell division. The first experiments using this tool reveal some of the molecular conversation that helps a cell tightly choreograph the time and place of pinching into two cells. In the March 14 Science, Aaron Straight, Tim Mitchison (l to r), and colleagues report the discovery of a small compound, blebbistatin, that blocks the final cleavage motion of myosin II after cells have duplicated and separated their chromosomes. Using the new drug, they show that timing of the cleavage depends on the cell's protein-disposing machinery, the proteasomes.
|
 MATERNAL MEDICINE: Protein Implicated in Life-threatening Pregnancy Complication
Researchers at Harvard Medical School and Beth Israel Deaconess Medical Center have identified a protein that may lead to preeclampsia, a complication of pregnancy characterized by hypertension, edema, and protein in the urine that afflicts five to eight percent of pregnant women. No treatment exists except premature delivery; the condition is both the leading cause of maternal death worldwide and a major cause of infant mortality in developing countries. The protein, sFlt1, works by blocking the activity of two growth factors that normally allow maintenance of the placenta's blood vessels, which deliver nutrients to the fetus. While shedding light on the cause of the disease at the molecular level, the discovery also suggests strategies for early diagnosis and treatment. Led by S. Ananth Karumanchi, the study is published in the March 3 Journal of Clinical Investigation.
|
 OCCUPATIONAL HEALTH: Cotton Mill Dust May Be Carrier as Well as Culprit in Respiratory Ills
A series of studies in China by David Christiani has found that the asthmalike condition that cotton mill workers frequently contract, byssinosis, is only partially a result of the dust raised in cotton milling. The other major offender is endotoxin carried by the dust. A component of the cell wall of certain bacteria, endotoxin is released when bacterial cells die and disintegrate, a process by which cotton-dwelling bacteria release endotoxin onto the plant. The findings have implications for other occupations, too, since endotoxin levels may be high in other industrial settings such as agriculture, waste disposal, and biotechnology.
|
Copyright 2003 by the President and Fellows of Harvard College
|
|
