BACKGROUND The zona pellucida (ZP), the mammalian oocyte coat, consists of a restricted number of highly glycosylated proteins. In vitro sperm binding studies suggest a higher binding affinity for the outer region of the ZP compared to its inner region in different species. However, the reason for this difference in binding distribution remains unresolved.… (More)
Fertility rates have dramatically decreased in the last two decades, especially in men. It has been described that environmental factors, as well as life habits, may affect semen quality. Artificial intelligence techniques are now an emerging methodology as decision support systems in medicine. In this paper we compare three artificial intelligence… (More)
Fertility rates have dramatically decreased in the last two decades, especially in men. It has been described that environmental factors as well as life habits may affect semen quality. In this paper we use artificial intelligence techniques in order to predict semen characteristics from environmental factors, life habits and health status, as a possible… (More)
The present study was conducted by using light and transmission electron microscopy to examine the morphologic development of turtle retina from embryonic stage 18 (S18) to S26 (hatching). Particular attention was paid to the formation of functional structures such as neurites, synapses, photoreceptors, among others, and the moment that chemical synapses… (More)
BACKGROUND Fertilization is a key physiological process for the preservation of the species. Consequently, different mechanisms affecting the sperm and the oocyte have been developed to ensure a successful fertilization. Thus, sperm acrosome reaction is necessary for the egg coat penetration and sperm-oolema fusion. Several molecules are able to induce the… (More)
The aim of this study was to describe morphologic sperm changes observed via scanning electron microscopy and the acrosomal status resulting from immobilization and micromanipulation. The manipulations made on sperm before intracytoplasmic sperm injection were the possible cause of sperm ultrastructural damages and could trigger an acrosome reaction.