Messenger - Vol. 2, No. 3, Page 9
Summer 1993
On Research
Midget monitors record heart dysfunction in chick embryos

     By conducting research on embryonic distress in chickens, Harold White
may provide insight into Sudden Infant Death Syndrome (SIDS) among humans.
     The professor of chemistry and biochemistry studies fertilized eggs
that lack riboflavin, or Vitamin B2, because of a genetic defect in the
hens that lay them. Without this essential vitamin, the chicken embryos die
approximately 13 days after fertilization, instead of hatching in the usual
21 days.
     For his research, he must monitor the embryos, study the onset and
progress of heart dysfunction and determine precisely the time of death.
"The heartbeat of a chick embryo is so difficult to detect that a heart
monitor that amplifies the sound a half million times must be attached to
the egg to record it," White says.
     The heart monitor, or miniature microphone, feeds information into a
computer. White currently has one monitor, and a recent American Heart
Association grant will enable him to design and build 16 monitors to study
the hearts of several embryos simultaneously.
     The computer analysis of an embryo heart resembles a miniature EKG,
showing a sharp dip when the heart ceases to function and the embryo dies.
By comparing these print-outs, White looks for consistent signs of the
onset of embryonic distress. He also compares these riboflavin-deficient
eggs with viable eggs from the same flock that have received riboflavin
injections.
     "The heart is a muscle that requires oxygen to function," White says.
"If there is no riboflavin, an inability to use oxygen occurs and the heart
stops."
     While no SIDS deaths have been linked to riboflavin deficiency, there
are some metabolic similarities between the rapidly developing chicken
embryo and infants at the age when most SIDS deaths occur, White says.
     White's development of more sophisticated heart monitors for his
riboflavin research may also have an impact on other research areas that
use a heart monitor. "Sydney Brenner, the Nobel Prize-winning molecular
biologist, once said, 'Progress in science depends on new techniques, new
discoveries and new ideas, probably in that order,'" White says.
                                   -Sue Swyers Moncure