Efecto de diferentes variables sobre la preñez en búfalas sometidas a sincronización del celo e inseminación artificial a tiempo fijo

El presente trabajo tuvo como objetivo evaluar el efecto de diferentes variables sobre la tasa de preñez de búfalas sometidas a un protocolo de sincronización del celo y ovulación e inseminación artificial a tiempo fijo (IATF). A partir de los 50 días posparto, 235 búfalas fueron sometidas al siguiente esquema de sincronización: 10 µg de GnRH (día 0); 15 mg de PGF2α (día 7); 10 µg de GnRH (día 9); IATF (día 10, dieciséis horas después de la segunda aplicación de GnRH). Las variables consideradas fueron condición corporal, cantidad de partos previos, presencia o ausencia de mucus genital y dificultad a la inseminación. La preñez total lograda fue del 53%. La ausencia o presencia de mucus se tradujo en tasas de preñez de 50 y 89% respectivamente. Según el número de partos (primíparas, 2 y 3 o más partos) los resultados fueron de 40, 50 y 58% respectivamente (p<0,05). Las condiciones corporales (><3, 3 a 4 y >4) obtuvieron 45, 55 y 56% de preñez respectivamente. Cuando se evaluó la preñez de acuerdo a la dificultad en la inseminación (sin dificultad, dificultad media y dificultad severa) los resultados fueron de 63, 50 y 0% respectivamente. Se concluye que al optimizar las variables estudiadas, la inseminación a tiempo fijo se convierte en una herramienta capaz mejorar el desempeño reproductivo en búfalos.

DNA multigene characterization of Fasciola hepatica and Lymnaea neotropica and its fascioliasis transmission capacity in Uruguay, with historical correlation, human report review and infection risk analysis

Fascioliasis is a highly pathogenic zoonotic disease emerging in recent decades, in part due to the effects of climate and global changes. South America is the continent presenting more numerous human fascioliasis endemic areas and the highest Fasciola hepatica infection prevalences and intensities known in humans. These serious public health scenarios appear mainly linked to altitude areas in Andean countries, whereas lowland areas of non-Andean countries, such as Uruguay, only show sporadic human cases or outbreaks. To understand this difference, we characterized F. hepatica from cattle and horses and lymnaeids of Uruguay by sequencing of ribosomal DNA ITS-2 and ITS-1 spacers and mitochondrial DNA cox1, nad1 and 16S genes. Results indicate that vectors belong to Lymnaea neotropica instead of to Lymnaea viator, as always reported from Uruguay. Our correlation of fasciolid and lymnaeid haplotypes with historical data on the introduction and spread of livestock species into Uruguay allow to understand the molecular diversity detected. We study the life cycle and transmission features of F. hepatica by L. neotropica of Uruguay under standardized experimental conditions to enable a comparison with the transmission capacity of F. hepatica by Galba truncatula at very high altitude in Bolivia. Results demonstrate that although L. neotropica is a highly efficient vector in the lowlands, its transmission capacity is markedly lower than that of G. truncatula in the highlands. On this baseline, we review the human fascioliasis cases reported in Uruguay and analyze the present and future risk of human infection in front of future climate change estimations

Olazarri, “Weaning from mechanical ventilation in pediatric intensive care patients,” Intensive Care Med

Abstract Objective: The development of weaning predictors in mechanically ventilated children has not been sufficiently investigated. The purpose of this study was to evaluate the accuracy of some weaning indices in predicting weaning failure. Design: Prospective, interventional study. Setting: University-affiliated children's hospital with a 19-bed intensive care unit. Patients: 84 consecutive infants and children requiring mechanical ventilation for at least 48 h and judged ready to wean by their primary physicians. Interventions: Patients who met the criteria to start weaning underwent a trial of spontaneous breathing lasting up to 2 h. Bedside measurements of respiratory function were obtained immediately before discontinuation of mechanical ventilation and within the first 5 min of spontaneous breathing. The primary physicians were blinded to those measurements, and the decision to extubate a patient at the end of the spontaneous breathing trial or reinstitute mechanical ventilation was made by them. Failure to wean was defined as the requirement for mechanical ventilation at any time during the trial of spontaneous breathing (trial failure) or needing reintubation within 48 h of extubation (extubation failure). Measurements and main results: Seventy-five patients had neither signs of respiratory distress nor deterioration in gas exchange during the trial and were extubated. Twelve patients required reintubation within 48 h. In 9 patients, mechanical ventilation was reinstituted after a median duration of the spontaneous breathing trial of 35 min. The only independent predictor of trial failure was tidal volume indexed to body weight [odds ratio 2.60, 95 % confidence interval (CI) 1.40 to 24.9]. The only independent predictor of extubation failure was frequency-to-tidal volume ratio indexed to body weight (odds ratio 1.23, 95 % CI 1.11 to 1.36). The sensitivity, specificity, and positive and negative predictive values to predict weaning failure were calculated for each of the above variables. These values were 0.48, 0.86, 0.53, and 0.83, respectively, for a frequency-to-tidal volume ratio higher than 11 breaths/min per ml per kg and 0.43, 0.94, 0.69, and 0.83, respectively, for a tidal volume lower than 4 ml/kg. Conclusions: Three-quarters of ventilated children can be successfully weaned after a trial of spontaneous breathing lasting 2 h. Both tidal volume and frequency-to-tidal volume ratio indexed to body weight were poor predictors of weaning failure in the study population

Distribuição sazonal e reprodução de Neocorbicula limosa (Maton) (Bivalvia, Corbiculidae) no Lago Guaíba, Rio Grande do Sul, Brasil Seasonal distribution and reproduction of Neocorbicula limosa (Maton) (Bivalvia, Corbiculidae) in the Guaíba Lake, Rio Grande do Sul, Brazil

<abstract language="eng">Neocorbicula limosa (Maton, 1811) is the only species of that South American genus that occurs in the hydrographic basins of Rio Grande do Sul State, Brazil. Seasonal quantitative collections between 1995 and 1996 in the lake Guaiba were accomplished, with the aim to know the reproductive dynamics and environmental preferences of populations of N. limosa. A substratum constituted by medium to coarse sands at an 'average depth around 2m shown to be favorable to installation of population of N. limosa. The largest population density (2.496 ind./m²) was registered in summer. Embryos at various development phases were registered inside individuals. The shell sizes of these individuals started from 8mm in length. The embryo's size could reach ¼ of the shell-mother's size, and their liberation occurs through the rupture of the gills

Control of Buffalo Follicular Dynamics for Artificial Insemination, Superovulation and In Vitro Embryo Production

Currently, timed ovulation induction and timed artificial insemination (TAI) can be performed in buffalo using GnRH or estradiol plus progesterone/progestin (P4)-releasing devices and prostaglandin F-2 alpha (PGF(2 alpha)). The control of the emergence of follicular waves and of ovulation at predetermined times, without the need for estrus detection, has facilitated the management and improved the efficiency of AI programs in buffalo during the breeding and nonbreeding season. Multiple ovulations, embryo transfer, ovum collection and in vitro embryo production have been shown to be feasible in buffalo, although low efficiency and limited commercial application of these techniques have been documented as well. These results could be associated with low ovarian follicular pools, high levels of follicular atresia and failures of the oocyte to enter the oviduct after superstimulation of follicular growth. This review discusses a number of key points related to the manipulation of ovarian follicular growth to improve pregnancy rates following TAI and embryo transfer of in vivo- and in vitro-derived embryos in buffalo