Dexmedetomidine or medetomidine premedication before propofol-desflurane anaesthesia in dogs

The objective of this study was to evaluate dexmedetomidine as a premedicant in dogs prior to propofol-desflurane anaesthesia, and to compare it with medetomidine. Six healthy dogs were anaesthetized. Each dog received intravenously (i.v.) five preanaesthetic protocols: D1 (dexmedetomidine, 1 microg/kg, i.v.), D2 (dexmedetomidine, 2 microg/kg, i.v.), M1 (medetomidine, 1 microg/kg, i.v.), M2 (medetomidine, 2 microg/kg, i.v.), or M4 (medetomidine, 4 microg/kg, i.v.). Anaesthesia was induced with propofol (2.3-3.3 mg/kg) and maintained with desflurane. The following variables were studied: heart rate (HR), mean arterial pressure, systolic arterial pressure, diastolic arterial pressure, respiratory rate (RR), arterial oxygen saturation, end-tidal CO2, end-tidal concentration of desflurane (EtDES) required for maintenance of anaesthesia and tidal volume. Arterial blood pH (pHa) and arterial blood gas tensions (PaO2, PaCO2) were measured during anaesthesia. Time to extubation, time to sternal recumbency and time to standing were also recorded. HR and RR decreased significantly during sedation in all protocols. Cardiorespiratory variables during anaesthesia were statistically similar for all protocols. EtDES was significantly different between D1 (8.1%) and D2 (7.5%), and between all doses of medetomidine. Desflurane requirements were similar for D1 and M2, and for D2 and M4 protocols. No statistical differences were observed in recovery times. The combination of dexmedetomidine, propofol and desflurane appears to be effective for induction and maintenance of general anaesthesia in healthy dogs.     

A Case of Successful Pregnancy in a Ewe with Uterus Didelphys

Uterus didelphys is a rare congenital abnormality of the reproductive tract. Although it occurs in various species, there are no published reports describing pregnancy outcome in association with this abnormality. Herein we describe a case of successful unilateral singleton pregnancy in a ewe incidentally found to have uterus didelphys during the course of a biomedical research study. The pregnancy was established using assisted reproductive techniques and interrupted in late gestation, at which point the abnormality was identified. Serial ultrasound assessment of foetal biometry revealed a normal foetal growth trajectory. Despite a 45% reduction in placentome number, total placentome weight was near normal secondary to compensatory placentome growth and development. To our knowledge, this is the first detailed report of normal foetal growth in an animal with uterus didelphys and illustrates the ability of the ovine placenta to adapt to a reduced number of placentomes and maintain foetal nutrient supply.     

Characterization and growth conditions of Vibrio parahaemolyticus strains with different virulence degrees that cause acute hepatopancreatic necrosis disease in Litopenaeus vannamei

The phenotypic characteristics and growth kinetics at several temperatures, salinities, and pH values of three Vibrio parahaemolyticus (Vp) strains with different virulence and one nonpathogenic strain were evaluated. Independent of the virulence of the strain, a high metabolic diversity was found, which yielded different colored phenotypes on the CHROMagar? Vibrio. All strains were resistant to ampicillin and carbenicillin, and Vp AHPND+ organisms were the most sensitive to enrofloxacin. The exponential growth of Vp strains started at 1–2 hr of incubation, although no relationship was observed between the bacterial density and degree of virulence. Moreover, the growth of the most virulent strain was independent of the nutrients in the incubation media during the initial hour postinoculation. No strain grew at 4°C in 0% NaCl and pH 4, but only Vp AHPND+ grew at 44°C. For all strains, the lag phase was proportional to the NaCl concentration, and the growth was better at pH 8–9. However, the Vp AHPND? strain displayed a greater variability, was more sensitive to extreme conditions, and showed a lag phase of 9 hr independent of the pH.     

In Vitro Fertilization (IVF) in Straws and a Short Gamete Coincubation Time Improves the Efficiency of Porcine IVF

The present study was designed to evaluate three different in vitro fertilization (IVF) systems: a straw‐IVF system with 10 min of coincubation, a straw‐IVF system with 6‐h coincubation and the microdrop‐IVF system with 6‐h coincubation (the traditional IVF system used routinely in most of IVF laboratories) in an attempt to reduce polyspermic penetration ( Experiment 1 ). When the straw‐IVF system was tested in combination with two coincubation times, the use of 10 min of coincubation significantly increased (p < 0.001) the penetration rate and the efficiency of fertilization (67.7 ± 6.4% vs 31.9 ± 6.5% and 41.5 ± 2.5% vs 17.6 ± 2.5% for 10 min and 6 h, respectively), while there were no significant differences in the incidence of monospermy between both systems (64.3 ± 5.1% and 67.7 ± 3.4%, for 10 min and 6 h, respectively). The penetration rate in the 6‐h microdrop‐IVF system was higher (93.8 ± 3.6%; p < 0.001) compared with the 10‐min straw‐IVF system (67.7 ± 6.4%), however, monospermy was severely reduced (25.0 ± 4.3% vs 67.7 ± 3.4%, for the 6‐h microdrop‐IVF system and 10‐min straw‐IVF system, respectively). The efficiency of the IVF showed similar values between microdrop and 6‐h straw‐IVF systems, but efficiency was significantly improved (p < 0.05) when the 10‐min straw‐IVF system was used. Experiment 2 was designed to compare porcine in vitro embryo production in two IVF systems, the 6‐h microdrop‐IVF system (1000 sperm per oocyte) and 10‐min straw‐IVF system (30 000 sperm per oocyte). The blastocyst formation rates tended (p = 0.06) to be higher when the 10‐min straw‐IVF system was used compared with the 6‐h microdrop‐IVF system. In addition, the number of total cells per blastocyst increased significantly (p < 0.05) in the 10‐min straw‐IVF system. These results showed that the 10‐min straw‐IVF system is an effective way to decrease polyspermic penetration, and improve the efficiency of fertilization and the quality of blastocysts in terms of cell number per embryo.     

Ordering of ruthenium cluster carbonyls in mesoporous silica

The anionic ruthenium cluster carbonylates [Ru6C(CO)16]2- or [H2Ru10(CO)25]2- interspersed with bis(triphenylphosphino)iminium counterions (PPN+) are incorporated from solution into the pores of MCM-41 mesoporous silica (3 nanometers in diameter), where they form tightly packed arrays. These arrays were shown by high-resolution transmission electron microscopy, Fourier transform optical diffraction, and computer simulations to be well ordered both along and perpendicular to the axis of the cylindrical pores. In their denuded state produced by gentle thermolysis, the cluster carbonylates yield nanoparticles of ruthenium that are less well ordered than their assimilated precursors but show good activity as hydrogenation catalysts for hexene and cyclooctene. In both their as-prepared and denuded states, these encapsulated clusters are likely to exhibit interesting electronic and other properties.