Effects of melatonin on morphology and development of primordial follicles during in vitro culture of bovine ovarian tissue

This study aims to investigate the effect of melatonin on activation, growth and morphology of bovine primordial follicles, as well as on stromal cells density in ovarian tissues after in vitro culture. Ovarian fragments were cultured in α‐MEM⁺ alone or supplemented with melatonin (250, 500, 1,000 or 2,000 pM) for a period of six days. Non‐cultured and cultured tissues were processed for histological analysis; according to developmental stages, follicles were classified as primordial or growing follicles. These follicles were further classified as morphologically normal or degenerated. Ovarian stromal cell density was also evaluated. The percentages of primordial and developing follicles, as well as those classified of normal follicles, were compared by Fisher's exact test, and the differences were considered significant when p < .05. The results showed that the presence of 1,000 and 2,000 pM melatonin in culture medium promoted a reduction in the percentage of primordial follicles and an increase in the percentage of development follicles, when compared to follicles cultured in control medium. On the other hand, the presence of 250 or 500 pM melatonin did not show a significant effect on the percentage of primordial and developing follicles. Besides that, the presence of 500, 1,000 and 2,000 pM melatonin maintained the percentage of normal follicles similar to those seen uncultured control. Moreover, tissues cultured in presence of 1,000 pM melatonin showed a higher percentage of normal follicles when compared to follicles cultured in the presence of 250 pM melatonin. It was observed a similar profile of stromal density in both uncultured tissues and those cultured in vitro in the presence of melatonin. In conclusion, melatonin (1,000 and 2,000 pM) promotes bovine primordial follicles activation and maintains the stromal cell density during in vitro culture of ovarian cortical tissue.     

Effects of isoflurane on echocardiographic parameters in healthy dogs

Objective To study the echocardiographic effects of isoflurane at an end‐tidal concentration approximating 1.0 times the minimum alveolar concentration (MAC) in healthy unpremedicated dogs. Study design Prospective experimental trial. Animals Sixteen mature mongrel dogs of either sex weighing 11.06 ± 2.72 kg. Methods After performing a baseline echocardiogram in the awake animal, anesthesia was induced with increasing inspired concentrations of isoflurane via a face mask until tracheal intubation was possible. Following intubation, the end‐tidal concentration was decreased to 1.4% for the rest of the anesthetic period. Serial echocardiograms were recorded at 25, 40, and 55 minutes after the end‐tidal concentration was reached. Results No changes were observed in heart rate. However, significant decreases were seen in left ventricular end‐diastolic diameter (Mean maximal change: 13.8%), interventricular septal thickness during systole (15.2%), interventricular septal thickening fraction (72.2%), left ventricular free wall thickening fraction (63.5%), ejection fraction (39.9%), and fractional shortening (46.7%). In addition, peak flow velocities across mitral, pulmonic, and aortic valves were significantly lower than baseline values. Decreases were also observed in end‐diastolic left ventricular volume index (approximately 32.1% from the awake value), stroke index (58.2%), and cardiac index (55.3%) when compared with awake measurements. Conclusions and clinical relevance Our results indicate that 1 × MAC isoflurane caused significant myocardial depression in healthy dogs. These changes in myocardial function need to be considered carefully when isoflurane is to be used in dogs with poor cardiovascular reserve.     

Virulence-associated factors of uropathogenic Escherichia coli strains isolated from pigs

Thirty one Escherichia coli strains isolated from pigs with urinary tract infections were investigated for presence of virulence factors and plasmid DNA profile. The most frequent virulence factors presented by these strains were mannose-resistant fimbriae, including P. fimbriae (54.8%) and aerobactin production (45.2%). The pap) operon, detected by PCR, was found in 54.8% of the strains, which is similar to its frequency in human strains. Other characteristics such as the presence of mannose-sensitive hemagglutinin (16.1%), indicative of type 1 pili, and production of hemolysin (25.8%), colicin (38.7%) and toxins (22.6% for LT and for VT) were less frequent. No strains were positive for STa production. Plasmid profiles were variable among isolates from either the same or different farms.     

ISO‐Based Assessment of Accuracy and Precision of Glucose Meters in Dogs

Background

Portable blood glucose meters (PBGMs) allow easy glucose measurements. As animal‐specific PBGMs are not available everywhere, those for humans are widely used.

Objectives

To assess the accuracy and precision of 9 PBGMs in canine whole blood (WB) and plasma, based on the ISO 15197:2013.

Animals

Fifty‐nine client‐owned dogs attending the Veterinary Teaching Hospital.

Methods

Analytical evaluation of 100 blood samples was performed for accuracy and 23 for precision (glucose 29–579 mg/dL) following ISO recommendations. A PBGM was considered accurate if 95% of the measurements were within ±15 mg/dL from the reference when glucose was <100 mg/dL and within ±15% when it was ≥100 mg/dL, and if 99% of them were within zones A and B in error grid analysis (EG). A hexokinase‐based analyzer was used as reference. Ninety samples were assessed for hematocrit interferences.

Results

Accuracy requirements were not fulfilled by any PBGM in WB (74% of measurements within the limits for the most accurate) and by 1 only in plasma. However, the EG analysis in WB was passed by 6 PBGM and by all in plasma. The most accurate were also the most precise, with coefficients of variation <5% in WB and <3% in plasma. Hematocrit correlated with bias against the reference method in 4 PBGM (r = −0.243 − [−0.371]; P < .021).

Conclusions and Clinical Importance

This disparity among PBGM suggests that meters approved for humans need to be evaluated before use in other species.     

Effects of isoflurane on Tei-index of myocardial performance in healthy dogs

Recently, the Tei-index, a noninvasive index that combines systolic and diastolic time intervals, has been proposed to assess global cardiac performance. However, the effects of isoflurane on the Tei-index have not been characterized. This study aimed at studying the effects of 1.0 minimal alveolar concentration isoflurane anesthesia on the pre-ejection period (PEP), left ventricular ejection time (LVET), PEP/LVET ratio, isovolumic relaxation time (IVRT), stroke index (SI), cardiac index (CI), heart rate (HR), and the Tei-index in healthy unpremedicated dogs. We observed significant increases in PEP, PEP/LVET ratio, IVRT, and TEI, whose maximal increases obtained throughout the study were 47%, 48%, 78%, and 56%, respectively. The LVET and HR did not change significantly, whereas the SI and CI decreased during anesthesia (29% and 26%, respectively). In conclusion, isoflurane produced direct effects on the Tei-index. The changes in systolic and diastolic parameters were supportive of this finding and were consistent with an overall impairment of left ventricular function during anesthesia.     

Simulating the effects of using different types of species distribution data in reserve selection

In a perfect world, systematic conservation planning would use complete information on the distribution of biodiversity. However, information on most species is grossly incomplete. Two main types of distribution data are frequently used in conservation planning: observed and predicted distribution data. A fundamental question that planners face is - which kind of data is better under what circumstances? We used simulation procedures to analyse the effects of using different types of distribution data on the performance of reserve selection algorithms in scenarios using different reserve selection problems, amounts of species distribution known, conservation targets and costs. To compare these scenarios we used occurrence data from 25 amphibian and 41 reptile species of the Iberian Peninsula and assumed the available data represented the whole truth. We then sampled fractions of these data and either used them as they were, or converted them to modelled predicted distributions. This enabled us to build three other types of species distribution data sets commonly used in conservation planning: “predicted”, “transformed predicted” and “mixed”. Our results suggest that reserve selection performance is sensitive to the type of species distribution data used and that the most cost-efficient decision depends most on the reserve selection problem and on how much we have of the species distribution data. Choosing the most appropriate type of distribution data should start by evaluating the scenario circumstances. While there is no one best approach for every scenario, we discovered that using a mixed approach usually provides an acceptable compromise between species representation and cost.     

Summer survival of arbuscular mycorrhiza extraradical mycelium and the potential for its management through tillage options in Mediterranean cropping systems

The potential to manage arbuscular mycorrhizal colonization within Mediterranean agricultural systems depends on the summer survival of extraradical mycelium. To investigate this further a three‐stage experiment was undertaken. The first stage was the creation of two contrasting levels of extraradical mycelium development, achieved by two contrasting levels of soil disturbance (typifying full tillage and no‐till). In the second stage, this differential mycelial inoculum was subjected to Mediterranean summer temperature and soil water regimes representing the post‐harvest fallow. During the third stage, corresponding to the next growing season, survival was evaluated without further soil disturbance (typifying no‐till conditions) using wheat as host crop. The results clearly indicate that the extraradical mycelium survived the prevailing summer conditions. The knowledge that extraradical mycelium can survive the Mediterranean summer encourages the use of tillage systems that minimize mechanical disturbance of the soil, such as no‐till. The results from this study suggest that by making the appropriate choice of crops to establish a mycorrhizal‐supportive rotation there can be opportunities for agro‐ecosystem management to benefit from the symbiotic relationship.     

Genetic diversity and erosion in lima bean (Phaseolus lunatus L.) in Northeast Brazil

Genetic Resources and Crop Evolution - Lima bean (Phaseolus lunatus L.) is a crop that stands out for its economic and social importance throughout the world, including in Northeast Brazil....     

Genetic characterisation of olive trees from Madeira Archipelago using flow cytometry and microsatellite markers

In this study, native olive plants from Olea maderensis (≡ O. europaea ssp. cerasiformis) and O. cerasiformis (≡ O. europaea ssp. guanchica), wild olives (O. europaea ssp. europaea var. sylvestris) and cultivated olives (O. europaea ssp. europaea var. europaea) were analysed with respect to genome size and microsatellite markers. The mean nuclear DNA content of O. maderensis was estimated as 5.97 ± 0.191 pg/2C, while the remaining studied taxa presented mean genome sizes ranging from 2.99 to 3.18 pg/2C. These data and the obtained simple sequence repeats (SSR) profiles, i.e., with 2–4 alleles in O. maderensis and a maximum of two alleles in the other taxa, enabled the identification of a new ploidy level, tetraploidy, for a species belonging to the Olea genus. Cluster analysis of the microsatellite data revealed a clear separation of each species in different clusters and a high genetic dissimilarity could be observed among genotypes belonging to different species. This work contributed to a better characterization of olive species and the obtained data can be helpful to support taxonomic studies, and to develop germplasm preservation strategies in endangered populations of O. maderensis from Madeira Archipelago.