Influence of porcine spermadhesins on the susceptibility of boar spermatozoa to high dilution.

The effect of heparin-binding and non-heparin-binding spermadhesins on the viability, motility, and mitochondrial activity of boar spermatozoa at the high dilution (300,000 sperm/ml) to which sperm are exposed during the process of sex sorting by flow cytometry was investigated. Incubation of spermatozoa with heparin-binding spermadhesins caused a time- and dose-dependent decrease in the percentage of functional spermatozoa. The percentage of viable spermatozoa incubated at 38 degrees C with heparin-binding spermadhesins diluted in PBS (1 mg/ml) dropped from 75% (0.5 h) to 4% (5 h), whereas the percentage of viable spermatozoa incubated in PBS without proteins (control) decreased from 85% (0.5 h) to 19% (5 h). Addition of non-heparin-binding PSP-I/PSP-II spermadhesin to the PBS resulted in a concentration-dependent increment of the percentage of viable cells (65% after 5-h incubation), with maximum effect at 1.5 mg/ml. The heparin-binding spermadhesins totally suppressed sperm motility and mitochondrial activity after 5 h of incubation. The same parameters of sperm incubated in the presence of 1.5 mg/ml of PSP-I/PSP-II were 50% and 58%, respectively, and the percentages of control sperm displaying motility and mitochondrial activity were 21% and 26%, respectively. Moreover, the viability, motility, and mitochondrial activity all decreased on incubation of spermatozoa with mixtures of PSP-I/PSP-II and heparin-binding spermadhesins as the concentration of the latter increased. We conclude that PSP-I/PSP-II and the heparin-binding spermadhesins exert antagonistic effects on the functionality of highly diluted boar spermatozoa. The finding that PSP-I/PSP-II contributes to maintaining sperm with high viability, motility, and mitochondrial activity for at least 5 h at physiological temperature points to its potential use as an additive for sperm preservation, specifically of highly diluted, flow-sorted spermatozoa for sex preselection.

Trasplante Hepático experimental en modelo animal : resultados preliminares de la fase 1 de un programa / Annual Reports 1997 / Experimental liver transplantation in animals : preliminar y results of a program

Esta comunicación, basada en los resultados de la primera fase del proyecto y cuyo diseño reproduce lo publicado por otro grupo, tiene por objetivo incentivar la creación de la condiciones médicas, legales y financieras adecuada para la puesta en marcha de un programa de trasplante hepático en el Paraguay. La serie incluye 26 cerdos intervenidos quirúrgicamente en el hospital de la Facultad de Ciencias Veterinarias entre junio de 1996 y diciembre 1997 por un grupo de médicos y veterinarios; se realizaron 8 ablaciones hepáticas (en donantes), 8 hepatectomías (en receptores) y 5 trasplantes (donantes y receptores). Los resultados indican que la cirugía del trasplante hepático puede ser realizada con seguridad en cerdos y que las similitudes de estos animales con el hombre autoriza la incorporación de esta cirugía a un programa nacional de trasplante