Identification and characterization of microsatellite markers in the Chagas disease vector Triatoma infestans (Heteroptera: Reduviidae).

Triatoma infestans, the main vector of Chagas disease in the southern cone countries, is the principal target of a regional elimination program. A better understanding of its dispersal, sources of reinfestation, and insecticide resistance is key to an effective control program. To address such problems, we identified and characterized 13 microsatellite loci of T. infestans. For each locus, primer sequences and PCR conditions are presented. Allele variability and frequency were analyzed in 59 T. infestans specimens from different rural communities in northwestern Argentina; nine loci were considered suitable for population genetic studies. Departure from Hardy-Weinberg equilibrium was detected in 10/13 loci with F(IS) values ranging from 0.04 to 0.91, indicating heterozygote deficit and a possible grade of sub-structure in the sample analyzed. Presence of null alleles in some loci cannot be discarded. The present work provides a promising tool to develop a population genetic study of natural populations of T. infestans in tandem with field studies and analyses of bug dispersal and the reinfestation process.

Veterans Administration cooperative study of surgery for coronary arterial occlusive disease: view from a noncooperating hospital.

Wadsworth Veterans Administration Hospital (VA-W) dropped out of the VA Coronary Cooperative Study (VA-Coop) in 1971 because of difficulty adhering to selection criteria, and because of the lack of standardization of surgical methods. Comparison of results from 1972-1974 showed the following differences: cardiopulmonary bypass time per graft, 61 minutes (VA-Coop) vs 33 minutes (VA-W); perioperative myocardial infarction (MI), 18% vs 6%; hospital mortality, 6% vs 1%; revascularization index (patent grafts per patient determined by postoperative angiography divided by diseased arteries per patient), 0.55 (VA-Coop) vs 0.84 (VA-W). However, the slopes of the actuarial survival curves were similar after the first year. In a group of patients operated on at UCLA and VA-W (UC-VA) during 1969-1971, the 1-year survival rate was 85%, but the annual death rate thereafter was also approximately 2% per year. The survival of VA-Coop surgical patients with three-vessel disease without left main lesions was significantly better (p less than 0.05 by Wilcoxon test) than the medical group with the 6-month (surgical) mortality adjusted to a more acceptable level (5%). These results indicate that coronary bypass surgery produces an annual mortality of approximately 2% per year after the first year. Differences in survival rates are due primarily to variations in first-year mortality, which is influenced by operative mortality as well as morbidity, incomplete revascularization, and low graft patency rate. In our view, the surgical results reported by the VA Cooperative Study are representative of an intermediary step in the development of coronary bypass surgery. The data, however, still indicate that surgical treatment results in better survival in patients with multivessel coronary disease.

An interactive data management and analysis system for clinical investigators.

An interactive minicomputer-based system has been developed that enables the clinical research investigator to personally explore and analyze his research data and, as a consequence of these explorations, to acquire more information. This system, which does not require extensive training or computer programming, enables the investigator to describe his data interactively in his own terms, enter data values while having them checked for validity, store time-oriented patient data in a carefully controlled on-line data base, retrieve data by patient, variable, and time, create subsets of patients with common characteristics, perform statistical analyses, and produce tables and graphs. It also permits data to be transferred to and from other computers. The system is well accepted and is being used by a variety of medical specialists at the three clinical research centers where it is operational. Reported benefits include less elapsed and nonproductive time, more thorough analysis of more data, greater and earlier insight into the meaning of research data, and increased publishable results.