Prevalence of hypertension,obesity and smoking in three Indian communities in northwestern Ontario.

Hypertension is perceived to be an important problem among native people in Canada, but specific prevalence data have not been accumulated. A study was carried out to determine community levels of blood pressure and to document the prevalence of hypertension, obesity and cigarette smoking in nonurban Indians in three communities in northwestern Ontario. Of the 678 people present in the communities at the time of the survey 668 (98.5%) participated. Age- and sex-specific mean diastolic and systolic blood pressure readings are presented. The overall prevalence rate of hypertension was 13%; in 9.6% of those with hypertension the condition had previously been diagnosed. Blood pressure generally rose with increasing age, but diastolic pressure declined after age 50 in both sexes. The rate of obesity increased with increasing age; 70% of women aged 35 to 64 years and 50% of men aged 35 to 44 years were obese. Over half (56.4%) of the study population smoked, and most smokers were less than 35 years old.     

Molecular characterization of the murine T cell antigen receptor and associated structures

Previous studies have demonstrated that the T cell antigen-specific receptor is a disulfide-linked heterodimer with subunits of 40-48 kilodaltons. We have produced a series of antiserums and monoclonal antibodies to epitopes carried by the molecule, including clonotypic epitopes specific to individual T lymphomas as well as epitopes shared by different T cell lines. Using these reagents we have isolated the heterodimers from a variety of T cells for comparison of primary structure via two-dimensional peptide mapping. The results indicate that the peptide maps of the alpha and beta subunits are extremely different, indicating that the subunits are encoded by different genes, and both subunits contain constant as well as variable peptides. To determine whether the murine T cell receptor is associated with other cell surface structures, C6VL lymphoma cells were radioiodinated, cross-linked with the cleavable reagent dimethyl-3,3'-dithiobispropionimidate, solubilized, and subjected to immunoprecipitation with the clonotypic antibody 124-40, and the precipitates were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Cross-linked samples, but not sham-treated precipitates, contained structures similar to the human Leu-4/T3 structure in addition to the receptor subunits. These results indicate that similar structures may be associated with the receptor in the human and the mouse.     

Left-right asymmetry of fly wings and the evolution of body axes.

The body plan of Drosophila, and presumably that of other insects, develops under the control of anterio-posterior and dorsal ventral axes, but no evidence for a left-right axis has yet been found. We used geometric morphometrics to study the wings in three species of flies: Drosophila melanogaster, Musca domestica and Glossina palpalis gambiensis. In all three species, we found that both size and shape showed subtle, but statistically significant directional asymmetry. For size, these asymmetries were somewhat inconsistent within and between species, but for shape, highly significant directional asymmetry was found in all samples examined. These systematic left-right differences imply the existence of a left-right axis that conveys distinct positional identities to the wing imaginal discs on either body side. Hence, the wing discs of Drosophila may be a new model to study the developmental genetics of left-right asymmetry. The asymmetries of shape were similar among species, suggesting that directional asymmetry has been evolutionarily conserved since the three lineages diverged. We discuss the implications of this evolutionary conservatism in conjunction with results from earlier studies that showed a lack of genetic variation for directional asymmetry in Drosophila.