Salvador E. Luria, 78, a physician who shared the 1969 Nobel Prize in medicine for work that helped explain the genetic mechanism of viruses and the manner in which they reproduce, died of a heart attack Feb. 6 at his home in Lexington, Mass.

Dr. Luria's work and that of his colleagues, Max Delbruck of the California Institute of Technology and Alfred D. Hershey of the Carnegie Institution's genetics facility at Cold Spring Harbor, N.Y., "set the solid foundation on which modern molecular biology rests," according to the Nobel citation.

It was a major contribution in the fight against viral diseases, and it helped steer scientists toward later discoveries about how more complex organisms reproduce and pass on genetically controlled characteristics to subsequent generations.

It also helped point the way toward discovery of the molecular building blocks of life, DNA, a nucleic acid in which genetic information is encoded.

The three scientists began their research into the nature of viruses in a loose collaboration in the early 1940s.

At the time there was little known about the tiny disease-causing organisms that live and reproduce by preying on the cells of other organisms.

Working separately but consulting often, the three men concentrated their research on a group of viruses called bacteriophages, rapidly multiplying viruses that infect bacteria rather than ordinary cells.

During 10 years of basic study on the life processes of these tiny organisms, they found a pattern of growth and multiplication basic to all life, laying a foundation for research into virus-caused diseases, which range from cancer to the common cold.

A native of Turin, Italy, Dr. Luria received his medical degree at the University of Turin with highest honors. He was a medical officer in the Italian army from 1935 to 1938, then studied physics and radiology for a year at the University of Rome.

As a Jew, he became increasingly concerned by the rise of antisemitism in fascist Italy, and he left to continue his studies in Paris before the outbreak of World War II.

In 1940 he fled Paris on a bicycle before the arrival of invading German armies, then immigrated to the United States from the south of France.

In the United States he did graduate study at Columbia, Vanderbilt and Princeton universities, then in 1943 joined the faculty at Indiana University.

While at Indiana, Dr. Luria taught, did research and supervised graduate students, including James D. Watson, who in 1962 shared a Nobel Prize for his discovery of DNA.

In 1959 he joined the faculty at the Massachusetts Institute of Technology. He retired there in 1978 and was made professor emeritus. He had continued to remain professionally active.

Although he made his professional reputation as a scientist, Dr. Luria was also deeply committed to the study of the humanities. He taught world literature courses at Harvard Medical School and at MIT. In 1974 he won the National Book Award for a nonacademic book, "Life: The Unfinished Experiment."

He was also an outspoken opponent of U.S. participation in the war in Vietnam. In 1969 he was one of a group of several prominent scientists who were blocked from serving on Department of Health, Education and Welfare scientific advisory panels by means of an internal security screening policy.

This practice led to accusations of blacklisting from members of the academic and scientific community, and it was abandoned in 1970. No reason was ever given for Dr. Luria's having been declared ineligible to serve.

The ethical implications of possible genetic manipulation also were of deep concern to Dr. Luria. He warned in a letter to Science magazine last November of "the possible emergence of an establishment program to invade the rights and privacy of individuals . . . to 'perfect' human individuals by 'correcting' their genomes in conformity, perhaps, to an 'ideal white, Judeo-Christian, economically successful' genotype."

Dr. Luria's survivors include his wife, Zella, and a son, Daniel.


Drug Co. Representative

C. Wayne Hood, 89, a retired Navy lieutenant who was wounded in World War II and who later became a service representative for the Smith Kline Pharmaceutical Co., died Feb. 6 at Washington House retirement home in Alexandria. He had suffered several strokes.

Mr. Hood, who lived in Falls Church for 28 years before moving to the Washington House in 1989, was born in Cedar Grove, Tenn. He enlisted in the Navy in 1919. In the years before World War II, he served in China and the Philippines and rose to the rank of chief hospital corpsman and chief pharmacist's mate.

During the war, he was commissioned an officer. He served in North Africa, Europe and the Pacific. He was aboard the aircraft carrier Randolph when it was hit by a Japanese kamikaze plane off Okinawa. He was sent to Bethesda Naval Hospital to recover from his wounds, and he retired from the service in 1947.

He joined Smith Kline at that time and was a service respresentative in the Washington area until retiring in 1966.

Mr. Hood was a member of the Military Order of the Carabao, the Disabled American Veterans and the Retired Officers Association. A 32d degree Mason, he was a member of the York Valley of the Scottish Rite, the Kena Temple of the Shrine and the National Sojourners.

His first wife, the former Antoinette V. Tuttleman, died in 1962.

Survivors include his wife, Maybelle L. Hood, whom he married in 1963, of Alexandria, and two sisters, Mary Hardick of Evansville, Ind., and Jeptha Brewer of Huntingdon, Tenn.


Account Executive

Michael F. O'Farrell, 49, an account executive with Merrill Lynch & Co. Inc. in Washington, died of cancer Feb. 2 at Rochester Methodist Hospital in Rochester, Minn. A resident of Dumfries, he was in Rochester for medical treatment.

Mr. O'Farrell was born in Alpena, Mich. He graduated from the University of Michigan and received a master's degree in business from Wayne State University. He worked for General Motors' Pontiac Division as a zone manager before moving to the Washington area and joining the staff of Merrill Lynch in 1988.

Survivors include his wife of 24 years, Carol Horvath O'Farrell, and three children, Caroline, Michael F. Jr. and Daniel O'Farrell, all of Dumfries; his mother, Helen O'Farrell of Alpena; a sister, Mary Ellen Orlandi of Rochester Hills, Mich.; and two brothers, John and Tom O'Farrell, both of Dumfries.



Isabelle M. Walker, 99, a former substitute teacher who was a member of Northeastern Presbyterian Church in Washington, died of congestive heart failure Feb. 4 at Wisconsin Avenue Nursing Home. She lived in Washington.

Mrs. Walker, who came here in 1913, was born in Camden, N.J. She graduated from Howard University and taught in Bowling Green, Va., during the 1920s. She then returned here and was a substitute teacher in the 1930s for D.C. public schools.

Her husband, Dr. Micajah T. Walker, died in 1958. Survivors include a son, M. Theodore Walker of Washington; two daughters, Marguerite W. Stewart of Birmingham and Elizabeth W. Stone of Arlington; four grandchildren; and four great-grandchildren.


School Watchman

Joseph S. Kerins, 84, a retired night watchman at Visitation High School and member of the parish of Holy Trinity Catholic Church in Washington, died of congestive heart failure Feb. 4 at his home in Washington.

Mr. Kerins was a lifelong Washington resident. As a young man, he drove a laundry truck. He then was a building engineer for the D.C. public school system.

During World War II, he became a driver for Diamond Cab Co. He continued that until the early 1960s, when he became night watchman at Visitation High School. He retired in 1978.

Survivors include a sister, Sister Mary Stephanie of Baltimore; and a brother, Matthew A. Kerins of Washington.


Federal Clerical Employee

Elizabeth Celeste Knipe, 88, who worked as a secretary at federal agencies for 40 years, died of complications after a stroke Feb. 4 at her home in Washington.

Mrs. Knipe, who retired from the Federal Communications Commission in 1970, had previously worked at the House of Representatives, the Federal Bureau of Investigation, and the Treasury Department.

She was born in Clarksburg, W.Va., and moved in 1927 to Washington, where she attended Martha Washington Seminary and Temple Business School.

Survivors include her husband, Neil H. Knipe of Washington.