founding father of molecular biology, a surgeon who developed the standard operation for removing cataracts and three researchers who unmasked an elaborate genetic control system within the cell are the winners of this year's Lasker awards for medical research.
The awards, many of whose recipients have gone on to win Nobel Prizes, are being announced today by the Albert and Mary Lasker Foundation.
The molecular biologist is Dr. Matthew S. Meselson of Harvard, who is cited both for his scientific discoveries and for a long public career aimed at eliminating chemical and biological weapons. Dr. Meselson, 74, was among the group of scientists who, in the heady days after the discovery of the structure of DNA in 1953, worked out the finding's major consequences. He was a leading contributor to the discovery of messenger RNA, the cell's agent for executing the orders encoded in the genes, and he later identified the first restriction enzyme, one of a set of natural substances now essential for many laboratory manipulations of DNA.
He is mentioned in many biology textbooks for the Meselson-Stahl experiment, a memorably elegant demonstration in which he and Dr. Franklin Stahl proved that DNA is duplicated at cell division in the manner predicted by Dr. James D. Watson and Dr. Francis H. C. Crick.
Believing that scientists should act to prevent misuse of the knowledge they create, he lobbied intensively to reduce herbicide spraying in Vietnam and, in the 1980's, to defuse misapprehension about "yellow rain." When officials in Washington asserted that a mysterious poison supplied by the Soviet Union was being sprayed over tribespeople in Southeast Asia, Dr. Meselson, the Lasker citation says, "identified this substance as bee droppings - pollen eaten by the insects, which they then excreted in massive showers."
A second award winner is the late Charles D. Kellman, an eye surgeon who over more than 20 years solved one puzzle after another to develop the cataract-removal operation that now benefits some three million people a year in the United States and a similar number in Europe.
The operation once required a week's hospitalization, with the patient's head immobilized by sandbags, followed by weeks of recovery and the need to wear ultra-thick glasses. With Dr. Kellman's technique, this high-risk operation has been replaced with a 10-minute procedure. Patients can go back to work the same day, and their visual acuity returns almost at once.
Dr. Kellman achieved this transformation by developing techniques for operating through a tiny incision instead of cutting half the eye open. His keyhole-surgery technique has been applied to many other operations with similar benefits.
He died June 1, after he had been nominated. Based on a review of Lasker Foundation records, a spokesman said Dr. Kellman's will be the first posthumous award from the foundation.
The other three winners unraveled how major hormones and other substances turn on genes in the nucleus of the cell. Starting in the 1950's, Dr. Elwood V. Jensen of the University of Chicago used radioactive tracers to show that hormones like estrogen first enter their target cell and then slip inside the cell's nucleus. By the 1970's Dr. Jensen brought his findings to bear on breast cancer by showing that cancers with many estrogen receptors in their cells could be attacked with tamoxifen.
Dr. Pierre Chambon of the Institute of Genetics and Molecular and Cellular Biology in Strasbourg, France, and Dr. Ronald M. Evans of the Salk Institute in California took the next step beyond Dr. Jensen's findings by showing how estrogen and similar substances control the genes in the nucleus.
Once inside the cell's nucleus, the hormone binds to a receptor protein, they found, which in turn clamps itself to DNA and activates a set of target genes. Working independently, Dr. Chambon and Dr. Evans went on to show that a whole family of such receptor proteins exists. The receptors have turned out to be crucial components of the cell's control system and transmit signals in a wide array of vital functions, from the development of organs in the womb, to the control of fat cells and the regulation of cholesterol.
Because of the central role of these nuclear receptors, they have proved to be excellent targets for a variety of drugs, like the glitazones used to treat diabetes.
