RESUMEN
The El Plomo mummy was a pre-Columbian Incan child who was found mummified in the Andes Mountains above an altitude of 17,700 feet. In the environment, natural mummification occurred due to low temperatures and strong winds. Dating measurements (relative dating) by experts from the National Museum of Natural History of Chile established that the mummified body corresponds the Inca period (1,450 to 1,500 AD). In 2003, the body was transferred to the University of Chile Medical School for exhaustive medical examination. Tissue samples from the right quadriceps muscle were extracted and fixed in glutaraldehyde and postfixed in osmium tetroxide to obtain ultrathin sections to be observed by transmission electron microscope. Images were recorded on photographic paper, digitalized and analyzed by experts on morphology. Results showed a preservation of cell boundaries in striated muscle cells, but specific subcellular organelles or contractile sarcomeric units (actin and myosin) were unable to be recognized. However, the classical ultrastructural morphology of the polypeptide collagen type I was preserved intact both in primary and secondary organization. Therefore, we concluded that the process of natural mummification by freezing and strong winds is capable of damaging the ultrastructure of muscle cells and preserving collagen type I intact.
Asunto(s)
Momias/parasitología , Fibras Musculares Esqueléticas/parasitología , Trichinella/fisiología , Triquinelosis/parasitología , Animales , Chile , Colágeno Tipo I/metabolismo , Colágeno Tipo I/ultraestructura , Historia Antigua , Humanos , Momias/historia , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/ultraestructura , Trichinella/ultraestructuraRESUMEN
<p><b>AIM</b>To observe the cytotoxic effect of the organophosphate insecticide malathion in the reproductive tissues of the earthworms, Eisenia foetida.</p><p><b>METHODS</b>Worms were nourished in soil treated with malathion at single sub-lethal doses of 0, 80, 150, 300 and 600 mg/kg soil. (LD50=880 mg/kg soil) and evaluated on days 1, 5, 15 and 30 after exposure. The body weights were recorded and male reproductive organs evaluated.</p><p><b>RESULTS</b>Malathion-treated animals showed a significant reduction in body weight in a dose-dependent manner. Malathion treatment modified the disposition of spermatozoa in the basal epithelium of the spermatheca. The Br-deoxyuridine test showed a significant rise in cells in phase S on days 5 and 15. Also, a higher percentage of spermatogonia with fragmented DNA were observed by means of the TdT-mediated dUTP nick-end labeling (TUNEL) technique in the spermatheca of treated animals.</p><p><b>CONCLUSION</b>Treatment with malathion decreased the body weight and the spermatic viability in spermatheca, altering the cell proliferation and modifying the DNA structure of spermatogonia.</p>