Dynamics of motile-sperm subpopulation structure in boar ejaculates subjected to "in vitro" capacitation and further "in vitro" acrosome reaction.

Incubation of diluted boar sperm from fresh ejaculates in a previously established "in vitro" capacitation medium induced a significant, time-dependent increase in several mean parameters of sperm motility, such as curvilinear velocity (VCL), linear velocity (VSL), mean velocity (VAP), linearity coefficient (LIN), straightness coefficient (STR) and wobble coefficient (WOB). Furthermore, motile boar-sperm semen samples were structured in four definite subpopulations. Subpopulation 1 showed the lowest values of VCL, VSL and VAP and also low values of linearity. Subpopulation 2 showed the second lowest values of VCL and VAP and higher values of LIN and STR. Subpopulation 3 was characterized by high values of velocity and low values of linearity. Finally, Subpopulation 4 was characterized by high values of velocity and linearity. "In vitro" capacitation and further acrosome reaction induced changes in the motility characteristics of each subpopulation as well as in their percentage distribution, Subpopulations 3 and 4 being those that showed the most significant changes. However, despite these changes, the observed, overall four-subpopulation structure was firmly maintained during the entire "in vitro" capacitation and acrosome-reaction process. Our results suggest that capacitation-induced motility changes are related to specific changes in the percentage of each motile-sperm subpopulation in the ejaculate without losing the overall, specific four-subpopulation structure. In this way, the maintenance of a four-subpopulation structure seems to be important in the control of the whole ejaculate physiology.

Effects of exposing boars to different artificial light regimens on semen plasma markers and "in vivo" fertilizing capacity.

This study was designed to assess the effects of exposing boars to an artificial photoperiod on semen quality in terms of sperm concentration, sperm vitality, sperm motility and acrosome integrity. We also determined biochemical semen plasma variables, such as total protein concentration, phosphorylated tyrosine residues and fructose, glucose and sorbitol contents, along with their effects on the fertility, prolificacy and libido of the boars. Three groups of 10 males were kept for 3 months under experimental conditions of 24, 12 and 0 h of artificial light, and a constant temperature of 21 +/- 1 degrees C and 60-75% humidity. The animals were fed a nutritious diet and subjected to semen collection twice per week. Semen samples were analyzed throughout the entire experimental period. Our results indicate that, while the extreme photoperiods (0 and 24 h of light) affected semen quality in terms of sperm concentration, acrosome integrity and semen volume, its fertilizing capacity was only significantly reduced under conditions of absolute darkness. Sperm motility was found to be a poor indicator of fertilizing ability, while other sperm factors, such as acrosome integrity or other functional variables seemed to behave better. The photoperiod was found to affect the production of accessory sex gland secretions more than their composition. In addition, light effects on fertility, prolificacy and libido seemed to be achieved through independent mechanisms.

[Hyperammonemic encephalopathy associated with valproate acid]. / Encefalopatía hiperamoniémica asociada al uso de valproato sódico.

We report 4 clinical cases of hyperammonemic encephalopathy (HE) associated with valproate acid (VPA) and review the literature on its pathophysiology. In all four cases, hepatic function was normal and valproic levels were within the therapeutic range. Elevated ammonium levels were found as the only biochemical abnormality. Patients showed decreased level of consciousness, confusion, ataxia and seizures. In 1 case the EEG showed diffused triphasic waves with frontal predominance. After suppression of treatment with VPA there was remission of clinical manifestations, and ammonium levels returned to normal. In order to obtain the correct diagnosis of HE, in all patients treated with either VPA mono or polytherapy, ammonium levels should be considered.

Encefalopatía hiperamoniémica asociada al uso de valproato sódico / Hyperammonemic encephalopathy associated with valproate acid

Se describen 4 casos clínicos de encefalopatía hiperamoniémica (EH) asociada al uso de valproato sódico y se revisa la literatura respecto a los mecanismos fisiopatológicos implicados. En todos los casos la función hepática fue normal y los niveles de valproato se encontraron dentro del rango terapéutico, hallándose solamente niveles elevados de amonio. Los pacientes presentaron clínica de disminución del nivel de conciencia, cuadro confusional, ataxia y, en 1 caso, aumento del número de crisis. Uno de los casos presentó un registro electroencefalográfico con ondas trifásicas difusas de predominio frontal bilateral. Tras la supresión del tratamiento con valproato sódico se normalizó la clínica y los niveles de amonio volvieron a la normalidad. Para el correcto diagnóstico de la EH, ante todo paciente que esté en tratamiento con valproato sódico, en mono o politerapia y que presente clínica compatible con encefalopatía, se aconseja determinar los niveles de amonio. (AU)