September 14, 2001

Dorn and grad join efforts in lab

_Juan José Chavez, a biology graduate of the Universidad de San Carlos de Guatemala, spent two weeks in June in the laboratory of Dr. Patricia Dorn, associate professor of biology at Loyola. Chavez came to Loyola to learn a technique for separating and visualizing DNA fragments from Triatoma dimidiata, the bug that transmits Chagas' disease in Guatemala.

Chagas' disease, a leading cause of heart disease in South and Central America, is caused by the parasite Trypanosoma cruzi, and transmitted to humans by the bloodsucking T. dimidiata. Chavez and his colleagues are trying to determine if bugs that look identical are actually the same or different. "After the houses are fumigated, we find reinfestation. We have to know if the fumigation was not effective, or if different bugs are colonizing the houses," said Chavez. Re-infestation can occur when forest-dwelling bugs migrate to or are carried into the villages on wood brought in for domestic use.

For two weeks, Chavez, along with undergraduate researchers Debra Salvia and Crescent Combe, learned to run polyacrylamide gels, a technique for separation and visualization of DNA fragments that gives a higher resolution than the technique he was using previously. He brought samples of DNA from forest and house dwelling bugs from different regions in Guatemala to run on polyacrylamide gels. Upon his return to Guatemala, Chavez will teach the technique to others in his lab.