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FRO de Barros RA Worst GCP Saurin CM Mendes MEOA Assumpção JA Visintin 《Reproduction in domestic animals》2012,47(6):887-890
The study of spermatogonial stem cells (SSCs) provides a model to better understand adult stem cell biology. Besides the biomedical potential to perform studies of infertility in many species, SSCs hold a promising application at animal transgenesis. Because stem cells are thought to be associated with basement membranes, expression of α‐6 integrin has been investigated as a marker of type A spermatogonial cells, which are considered SSCs because of their undifferentiated status and self‐renewal ability. In this manner, the aim of this study was to isolate type A SSCs from adult bulls by a two‐step enzymatic procedure followed by a discontinuous Percoll density gradient purification and verify the expression of α‐6 integrin by flow cytometry and real‐time RT‐PCR before and after Percoll purification. Spermatogonial cells were successfully obtained using the two‐step enzymatic digestion. An average of 1 × 105 viable cells per gram of testis was isolated. However, the discontinuous Percoll did not purify isolated cells regarding α‐6 integrin expression. Flow cytometry analysis demonstrated no differences in the α‐6 integrin expression between cell samples before and after Percoll purification (p = 0.5636). The same was observed in the real‐time PCR analysis (p > 0.05). In addition to α‐6 integrin, the expression of GFRa‐1 and PGP9.5, known bovine SSCs markers, was detected in all samples studied. Considering that Percoll can reduce cell viability, it is possible to conclude that Percoll density gradient is not suitable to purify bovine SSC, according to α‐6 integrin expression. 相似文献
73.
Justin L. Voge A. Kendrick Sudderth Steven P. Brinsko Patrick J. Burns Terry L. Blanchard 《Journal of Equine Veterinary Science》2012
Between February 15 and May 17, 2011, a total of 88 broodmares (10 maiden, 10 barren, and 68 foaling) maintained on pasture in southeast Texas were examined three times weekly (Tuesday, Thursday, Saturday) by transrectal palpation and ultrasonography. On Tuesday or Thursday, mares in estrus with uterine edema, a relaxed cervix, and a dominant follicle ≥34 mm in diameter were alternately assigned to treatment with the following: group (1) 2,500-unit human chorionic gonadotropin (hCG), intravenous; group (2) 1.0-mg BioRelease Histrelin (Biorelease Technologies, Lexington, KY), intramuscular; or group (3) 0.5-mg BioRelease Histrelin, intramuscular. Ovulation was confirmed by ultrasonographic examination. The percentage of mares ovulating within 2 days appeared to be similar between maiden, barren, and foaling mares, so responses for all mares were totaled for analysis. A nonsignificant trend for higher ovulation rates within 2 days was noted for both dose rates of histrelin compared with hCG treatment (31/37, 84%; 34/37, 92%; and 33/36, 92% for groups 1-3, respectively) (P = .45). Ovulatory responses appeared to improve for both products as the season progressed, yet no differences were detected between response rates to histrelin or hCG for any month (P ≥ .50). The use of 1.0- or 0.5-mg BioRelease Histrelin was found to be at least equally effective as hCG treatment for inducing ovulation within 2 days of treatment throughout the breeding season. 相似文献
74.
Sevoflurane has recently been introduced in feline anesthesia. However, its cardiovascular effects have not, to our knowledge, been reported in this species. Six healthy cats, aged 1.81 ± 0.31 years (mean ± SEM) and weighing 3.47 ± 0.11 kg, were studied. Anesthesia was induced and maintained with sevoflurane in oxygen. Body temperature was maintained between 38.5 and 39.55 °C. After instrumentation, end‐tidal sevoflurane concentration was randomly set at 1.25, 1.5, and 1.75 times the individual minimum alveolar concentration (MAC), determined in a previous study, according to a Latin Square Design. Thirty minutes of stabilization was allowed after each change of concentration. ECG and heart rate, systemic and pulmonary arterial pressures, central venous pressure (CVP), and core body temperature were continuously monitored and recorded. Inspired and end‐tidal oxygen, carbon dioxide, and sevoflurane concentrations were measured using a Raman spectrometer, calibrated every 80 minutes with three calibration gases of known sevoflurane concentration (1, 2, and 5%). Moreover, at selected times, pulmonary artery occlusion pressure and cardiac output (thermodilution) were measured, and arterial and mixed venous blood samples were collected for pH and blood gas analysis, hemoglobin concentration, hemoglobin oxygen saturation, packed cell volume (PCV) and total protein determination, and lactate concentration measurement. Cardiac index (CI), stroke index (SI), systemic and pulmonary vascular resistance indices, rate‐pressure product, left and right ventricular stroke work indices (LVSWI and RVSWI, respectively), arterial and mixed venous oxygen contents, oxygen delivery, oxygen consumption, and oxygen utilization ratio were calculated. Data were analyzed by a Repeated Measure Latin Square Design followed by a Tukey's test for 2 × 2 comparisons. Arterial pH significantly decreased from 7.40 ± 0.05 to 7.29 ± 0.07 with the administration of increasing concentrations of sevoflurane. Similarly, LVSWI decreased from 3.72 ± 0.60 to 2.60 ± 0.46 g m?2. Mean arterial pressure, PaO2, mixed venous pH, CI, SI, and oxygen delivery tended to decrease dose‐dependently, whereas CVP, PaCO2, Pv CO2, PCV, and arterial and mixed venous hemoglobin concentrations tended to increase dose‐dependently with the administration of sevoflurane. However, these trends did not reach statistical significance, possibly because of the limited number of animals studied. Sevoflurane seemed to induce dose‐dependent cardiovascular depression in cats. 相似文献
75.
Luke A. Schneider Paul H. Delfabbro Nicholas R. Burns 《Journal of Veterinary Behavior: Clinical Applications and Research》2013,8(3):124-134
The authors investigated the relationship between paw preference (the paw with which dogs prefer to hold a food object) and temperament in the domestic dog (Canis familiaris). Hypotheses were based on the Valence-Specific Hypothesis, which broadly states that negative emotions are associated with the right hemisphere, and positive emotions are associated with the left hemisphere. To assess each dog's temperament, an owner-rated temperament questionnaire was administered to the owners of 73 pet dogs. The same dogs were tested for paw preference using a Kong (KONG Company, Golden, CO) stuffed with food and were subsequently classified as left-pawed, right-pawed, or ambilateral. A laterality index (LI) value was also calculated for each dog in the study to provide an indication of the strength and direction of its paw preference. Positive LI values reflected a preference for the right paw, whereas negative LI values reflected a preference for the left paw. The LI ranged from ?100 to +100, with numbers closer to either extreme reflecting a stronger paw preference and a score of 0 indicating no preference. The absolute value of LI reflects the strength, but not direction, of paw preference and was included in some analyses.We found no evidence to support a relationship between paw preference and temperament, with the exception that lateralized dogs scored marginally higher than ambilateral dogs on a measure of stranger-directed aggression. We suggest that the temperament assessment used in this study may not be sensitive enough to detect differences between individuals based on their lateralization. Temperament factors were also compared with a number of “demographic” variables (e.g., age, sex, whether the dog was a purebred or a crossbreed, and the frequency of exercise) to determine the effect of these variables on temperament outcomes. 相似文献
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Phytochemical composition and metabolic performance-enhancing activity of dietary berries traditionally used by Native North Americans 总被引:1,自引:0,他引:1
Burns Kraft TF Dey M Rogers RB Ribnicky DM Gipp DM Cefalu WT Raskin I Lila MA 《Journal of agricultural and food chemistry》2008,56(3):654-660
Four wild berry species, Amelanchier alnifolia, Viburnum trilobum, Prunus virginiana, and Shepherdia argentea, all integral to the traditional subsistence diet of Native American tribal communities, were evaluated to elucidate phytochemical composition and bioactive properties related to performance and human health. Biological activity was screened using a range of bioassays that assessed the potential for these little-known dietary berries to affect diabetic microvascular complications, hyperglycemia, pro-inflammatory gene expression, and metabolic syndrome symptoms. Nonpolar constituents from berries, including carotenoids, were potent inhibitors of aldose reductase (an enzyme involved in the etiology of diabetic microvascular complications), whereas the polar constituents, mainly phenolic acids, anthocyanins, and proanthocyanidins, were hypoglycemic agents and strong inhibitors of IL-1beta and COX-2 gene expression. Berry samples also showed the ability to modulate lipid metabolism and energy expenditure in a manner consistent with improving metabolic syndrome. The results demonstrate that these berries traditionally consumed by tribal cultures contain a rich array of phytochemicals that have the capacity to promote health and protect against chronic diseases, such as diabetes. 相似文献
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