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22.
Effect of different mini‐volume colloid centrifugation configurations on flow cytometrically sorted sperm recovery efficiency and quality using a computer‐assisted semen analyzer
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LB Ferré JL Chitwood C Fresno HH Ortega ME Kjelland PJ Ross 《Reproduction in domestic animals》2018,53(1):26-33
Straws of sex‐sorted sperm are usually packaged at a low concentration (e.g., ~2.1 × 106 sperm/ml) and cost significantly more than unsorted conventional semen from the same sire. In order to maximize the efficiency of using sex‐sorted sperm under in vitro fertilization conditions, the selection of an appropriate sperm separation technique is essential. In this study, the effect of using different silane‐coated silica colloid dilutions and layering configurations during centrifugation of sex‐sorted sperm was examined over an extended period of incubation time. Sperm recovery and viability after centrifugation using the colloid separation technique were measured along with several sperm motility parameters using CASA. For this purpose, frozen and thawed sex‐sorted sperm samples were centrifuged using mini‐volume single‐layer (40%, 60% and 80%) and mini‐volume two‐layer (45%/90%, 40%/80% and 30%/60%) separation configurations using PureSperm®. A single layer of 40% PureSperm® recovered significantly more sex‐sorted sperm (78.07% ± 2.28%) followed by a single layer of 80% PureSperm® (68.43% ± 2.33%). The lowest sperm recovery was obtained using a two‐layer PureSperm® dilution of 45%/90% (47.57% ± 2.33%). Single‐layer centrifugation recovered more sorted sperm (68.67% ± 1.74%) than two layer (53.74% ± 1.74%) (p < .0001). A single layer of 80% PureSperm® exhibited the highest sorted sperm viability (72.01% ± 2.90%) after centrifugation (p < .05). The mini‐volume single layer of 80% PureSperm® was determined to be an effective alternative to a two‐layer centrifugation configuration for sex‐sorted sperm selection. In addition, single‐layer colloid dilution of 80% performed either as well as or significantly outperformed the other treatments, as well as the control, with regard to motility (MOT) for all time periods of analysis. 相似文献
23.
Cystic ovarian disease (COD) is one of the main causes of infertility in dairy cattle. It has been shown that intra‐ovarian factors may contribute to follicular persistence. Transforming growth factor‐beta (TGFB) isoforms are important paracrine and autocrine signalling molecules that regulate ovarian follicle growth and physiology. Considering the importance of these factors in the ovarian physiology, in this study, we examined the expression of TGFB isoforms (TGFB1, TGFB2 and TGFB3) in the ovary of healthy cows and animals with spontaneous and adrenocorticotrophic hormone (ACTH)‐induced COD. In the oestrous‐synchronized control group, the expression of TGFB1 in granulosa and theca cells was higher in spontaneous cysts than in atretic or tertiary follicles. When we compared TGFB2 expression in granulosa cells from atretic or tertiary follicles from the oestrous‐synchronized control group with that in ACTH‐induced or spontaneous follicular cysts, we found a higher expression in the latter. The expression of the TGFB isoforms studied was also altered during folliculogenesis in both the spontaneous and ACTH‐induced COD groups. As it has been previously shown that TGFB influences steroidogenesis, ovarian follicular proliferation and apoptosis, an alteration in its expression may contribute to the pathogenesis of this disease. 相似文献
24.
Quantitative analysis of N-phenylpropenoyl-L-amino acids in roasted coffee and cocoa powder by means of a stable isotope dilution assay 总被引:1,自引:0,他引:1
Since recent reports on the role of N-phenylpropenoyl-L-amino acids as powerful antioxidants and key contributors to the astringent taste of cocoa nibs, there is an increasing interest in the concentrations of these phytochemicals in plant-derived foods. A versatile analytical method for the accurate quantitative analysis of N-phenylpropenoyl-L-amino acids in plant-derived foods by means of HPLC-MS/MS and synthetic stable isotope labeled N-phenylpropenoyl-L-amino acids as internal standards was developed. By means of the developed stable isotope dilution assay (SIDA), showing recovery rates of 95-102%, 14 N-phenylpropenoyl-L-amino acids were quantified for the first time in cocoa and coffee samples. On the basis of the results of LC-MS/MS experiments as well as cochromatography with the synthetic reference compounds N-[3',4'-dihydroxy-(E)-cinnamoyl]-L-tryptophan, N-[4'-hydroxy-(E)-cinnamoyl]-L-tryptophan, and N-[4'-hydroxy-3'-methoxy-(E)-cinnamoyl]-L-tyrosine, respectively, were detected for the first time in cocoa powder, and (-)-N-[4'-hydroxy-(E)-cinnamoyl]-L-tyrosine, (-)-N-[3',4'-dihydroxy-(E)-cinnamoyl]-L-tyrosine, N-[4'-hydroxy-3'-methoxy-(E)-cinnamoyl]-L-tyrosine, (+)-N-[3',4'-dihydroxy-(E)-cinnamoyl]-L-aspartic acid, (+)-N-[4'-hydroxy-(E)-cinnamoyl]-L-aspartic acid, N-[3',4'-dihydroxy-(E)-cinnamoyl]-L-tryptophan, N-[4'-hydroxy-(E)-cinnamoyl]-L-tryptophan, and N-[4'-hydroxy-3'-methoxy-(E)-cinnamoyl]-L-tryptophan, respectively, were detected for the first time in coffee beverages. 相似文献
25.
CG Barbeito HH Ortega V Matiller EJ Gimeno NR Salvetti 《Reproduction in domestic animals》2013,48(5):850-857
Numerous experimental models in different species have been developed for the study of polycystic ovarian syndrome. In this study, we used a model of induction of polycystic ovaries (PO) in rats by exposure to constant light to study the distribution and variations of glycosylated residues present in the different ovarian structures. Seven biotinylated lectins were used (Con‐A, WGA, DBA, SBA, PNA, RCA and UEA‐I) on tissue sections, and detection was performed using the streptavidin/peroxidase method. In tissue sections was observed an increase in affinity for Con‐A in the granulosa and theca interna of growing follicles and cysts in animals with PO in relation to the control group. Follicular cysts showed higher affinity for WGA and RCA‐I which growing follicles in the same group, and there was a decrease in affinity for PNA in the cysts in relation to the growth of follicles in both groups. Atretic follicles in both groups showed greater labelling with lectins PNA, SBA and RCA‐I in relation to healthy follicles. It could also be noted that the zona pellucida of cystic follicles lost the affinity for the lectin Con‐A. There was no staining on follicles in any category with the lectins DBA and UEA‐I, although it was staining in the corpus luteum (control group) and in the mesothelium and interstitial glands of both groups with DBA. These observations probably reflect changes in the glycosaminoglycans present in the different ovarian compartments or in the glycosylation of cellular components essential for proper follicular dynamics. 相似文献
26.
Benjamin Emmanuel O. Grabenweger Giselher Strasser Hermann Wesseler Justus 《植物病害和植物保护杂志》2018,125(3):273-285
Journal of Plant Diseases and Protection - Innovative biological pest control of the western corn rootworm (WCR) Diabrotica virgifera virgifera and wireworms Agriotes spp. in maize and potato... 相似文献
27.
Fuentes VL Corcoran B French A Schober KE Kleemann R Justus C 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2002,16(3):255-261
A double-blind, randomized, placebo-controlled study was conducted to examine the effect on heart failure class and survival of pimobendan, an oral calcium-sensitizing inodilator, in dogs with dilated cardiomyopathy (DCM). Pimobendan (0.3-0.6 mg/kg body weight/d) or placebo was administered to English Cocker Spaniels (CSs; n = 10) and Doberman Pinschers (DPs: n = 10) that had DCM in addition to background therapy of furosemide, enalapril, and digoxin. Addition of pimobendan to standard triple therapy was associated with a significant improvement in heart failure class, regardless of breed (P < .02, Mann-Whitney rank sum test). Overall, 8 of 10 animals in the pimobendan-treated group, and 1 of 10 animals in the placebo group improved their heart failure status by at least I modified New York Heart Association functional class after initial stabilization (P = .005, Fisher's exact test). Pimobendan had no significant effect on survival in the CSs (P = 0.77, log-rank test), but DPs treated with pimobendan had significantly longer survival times compared with placebo (P < .02, log-rank test), with a median survival time of 329 days in the pimobendan group compared with 50 days in the placebo group, and a hazard ratio of 3.4 (95% confidence interval 1.4-39.8). Pimobendan resulted in significant improvement in heart failure class when added to standard therapy in this group of dogs with DCM, and may have contributed to improved survival in DPs. 相似文献
28.
HH Ortega JA Lorente GA Mira C Baravalle NR Salvetti 《Reproduction in domestic animals》2004,39(6):417-423
The objective of this work was to study the changes that occur in the Leydig cells of rats exposed to continuous light. The laboratory rat is considered a non-photoperiodic species because exposure to short photoperiod has little or no effect on the reproductive status. However, exposure of adult female rats to constant light induces polycystic ovaries, indicating that extreme changes in the photoperiod affect the reproductive function seriously. Adult male rats were placed under continuous light conditions for a duration of 15 weeks. After this period, the animals were killed and testicles were dissected and processed by routine histologic protocols. Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) serum levels were determined by radioimmunoassay (RIA). The visualization of antigens was achieved by the streptavidin-peroxidase immunohistochemical method. Antibodies against chromogranin A, S-100 protein, P substance, synaptofisin, neurofilament protein-200, gliofibrillary acidic protein and neurone-specific enolase were used. The mean LH serum concentration was significantly lower, while the mean FSH level was significantly higher in treated animals. The expression of S-100, NSE, CrA, SP and SYN was significantly lower in treated animals. In conclusion, the constant light exposure acting directly at the pituitary level decreases LH secretion. The increased FSH secretion may be due to a partial reduction of the negative androgen feedback in the pituitary gland. Moreover, the constant light exposure affects the expression of some immunomarkers in Leydig cells, possibly because of the changes found in the gonadotrophin level and feedback mechanism. 相似文献
29.
30.
Long-term agroecosystem experiments: assessing agricultural sustainability and global change 总被引:3,自引:0,他引:3
PE Rasmussen KWT Goulding JR Brown PR Grace HH Janzen M Korschens 《Science (New York, N.Y.)》1998,282(5390):893-896
Long-term agroecosystem experiments can be defined as large-scale field experiments more than 20 years old that study crop production, nutrient cycling, and environmental impacts of agriculture. They provide a resource for evaluating biological, biogeochemical, and environmental dimensions of agricultural sustainability; for predicting future global changes; and for validating model competence and performance. A systematic assessment is needed to determine the merits of all known experiments and to identify any that may exist in tropical and subtropical environments. The establishment of an international network to coordinate data collection and link sites would facilitate more precise prediction of agroecosystem sustainability and future global change. 相似文献