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AIM: To determine the weight, volume, density and cross-sectional area (CSA) of the digital flexor tendons, common digital extensor tendon (CDET) and suspensory ligament (SL) of the forelimb of young Thoroughbred horses in early training, and to assess the response to a training programme of known parameters of superficial digital flexor tendon (SDFT) tissue at mid-metacarpal level. METHODS: The tendons of seven 2-year-old Thoroughbred horses in training were inspected, transected into segments of known length, and compared with those from seven untrained horses matched for age, sex and breed. The weight, volume, density and CSA of each segment, and the crimp angle, histological features, and biomechanical ultimate stress and stiffness of tendon samples from the mid-metacarpal region of the SDFT were determined. RESULTS: There was no macroscopic evidence of swelling or discolouration in any of the tendon segments or cut surfaces. The volumes of SDFT and CDET segments of horses in the trained group were significantly greater than those in the untrained group (p=0.036 and p=0.039, respectively). A greater increase in volume than weight resulted in a lower density in the SDFT but not CDET in trained compared with untrained horses (p=0.038). CSA of these two tendons was significantly greater in the trained group (p=0.002 and 0.036, respectively), the percentage increase being greater in the CDET than the SDFT. The number of tenocytes at four sites in the mid-metacarpal SDFT region was less in trained than untrained horses (p=0.025). There was no histological evidence of inflammation, and no difference in crimp angle between groups. There was no significant between-group difference in stiffness or ultimate stress of tendon strips. CONCLUSIONS: Volume and CSA of the SDFT and CDET were larger in trained than untrained horses. The SDFT was less dense in the trained group. Because no evidence of tendonitis was detected and training appeared to have no significant effect on crimp angle or biomechanical properties of tendon strips, the size and density changes were presumed to be adaptive and induced by the training. CLINICAL RELEVANCE: Although evident in this in vitro study, the detection of adaptive from initial pathological increase in size of the SDFT is likely to be difficult in vivo. 相似文献
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Abstract AIM: To assess the stability of creatine kinase (CK) activity in plasma collected from healthy foals and frozen at ?20°C for up to 12 weeks. METHODS: Samples of venous blood drawn from 25 foals were analysed for CK activity soon after collection, and again after 1 and 12 weeks of freezing at ?20°C. RESULTS: CK activity decreased (p<0.001) between Week 0 and Week 1 and between Week 0 and Week 12. CONCLUSIONS AND CLINICAL RELEVANCE: Decreases in CK activity were statistically significant but clinically insignificant. 相似文献
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The clinical manifestations of equine pituitary pars intermedia dysfunction (PPID) in temperate climates are well described. The classic presentation is that of an older animal with hirsutism, laminitis, poor muscle tone, pendulous abdomen and weight loss. This case series highlights the additional clinical signs of anhidrosis and heat stress with secondary exercise intolerance that were seen as primary presenting problems in equids with PPID in the hot, humid conditions of a tropical climate. The clinical signs resolved with medical treatment for PPID. 相似文献
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Variation in the immune status of two Australian pig breeds 总被引：1，自引：0，他引：1
Objective To investigate the variation in immune competence of two Australian pig breeds.
Design A panel of immune tests were used to assess breed and sire differences in weaner piglets of Large White and Duroc breeds.
Procedure All piglets were immunised against porcine leptospirosis. Blood samples were taken for studies on lymphocyte phenotypes, mitogenic responses of blood cells and serological analysis.
Results Significantly larger blood leucocyte numbers were found in Large White piglets compared with Duroc piglets after vaccinations. No significant difference in concanavalin A induced blood cell proliferation was found between these two breeds before or after vaccinations. Some significant breed variation in blood lymphocyte phenotypes was found. While the age-related changes of lymphocyte phenotypes were similar for the two breeds, the Large White breed had significantly larger numbers of CD2+ and CD4+ cells than the Duroc breed after the two vaccinations. There were also significant sire effects on CD8+ cells within the Large White breed after the first vaccination. No significant breed difference was detectable in serum IgG concentrations but sire differences within each breed before the primary vaccination were found. The serum antibody response to vaccination against leptospirosis was generally small, and showed no variations due to either breed or sire. No gender effects were found during the entire study.
Conclusion The study demonstrated significant differences in some important immune components of the pig breeds studied. This may in turn indicate the variation in their immune competence or disease resistance. However, further investigation into the heritability and correlation with specific immune responses is required. 相似文献
Design A panel of immune tests were used to assess breed and sire differences in weaner piglets of Large White and Duroc breeds.
Procedure All piglets were immunised against porcine leptospirosis. Blood samples were taken for studies on lymphocyte phenotypes, mitogenic responses of blood cells and serological analysis.
Results Significantly larger blood leucocyte numbers were found in Large White piglets compared with Duroc piglets after vaccinations. No significant difference in concanavalin A induced blood cell proliferation was found between these two breeds before or after vaccinations. Some significant breed variation in blood lymphocyte phenotypes was found. While the age-related changes of lymphocyte phenotypes were similar for the two breeds, the Large White breed had significantly larger numbers of CD2+ and CD4+ cells than the Duroc breed after the two vaccinations. There were also significant sire effects on CD8+ cells within the Large White breed after the first vaccination. No significant breed difference was detectable in serum IgG concentrations but sire differences within each breed before the primary vaccination were found. The serum antibody response to vaccination against leptospirosis was generally small, and showed no variations due to either breed or sire. No gender effects were found during the entire study.
Conclusion The study demonstrated significant differences in some important immune components of the pig breeds studied. This may in turn indicate the variation in their immune competence or disease resistance. However, further investigation into the heritability and correlation with specific immune responses is required. 相似文献
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Objective To describe the buller steer syndrome in a Western Canadian feedlot. Design A retrospective epidemiological study. Animals 78,445 male cattle that entered a 24,000-head feedlot in western Canada from 1991 to 1993. Procedure All cattle were given a hormonal growth promotant containing 20 mg oestradiol benzoate and 200 mg progesterone within 24 h of arrival at the feedlot. A ‘buller’ was a steer that was observed at daily pen checking to be ridden persistently by pen mates or had evidence of having been persistently ridden by pen mates. At the completion of the feeding period, animal health records for bullers were collected and analysed. Results The prevalence of bullers in the total population was 2139/78,445 (2.7%, range per pen 0 to 11.2%). The prevalence of bullers increased with increasing weight and age. The relapse risk after first treatment (three days in the feedlot hospital plus treatment for concurrent disease) was 30% on average (27 to 35%). Individual records from 9734 yearling steers that entered the feedlot in 1991 and 1992 showed that bullers were significantly (P < 0.05) heavier at processing than non-bullers. Bullers occurred as a point source epidemic with the cause occurring soon after cattle arrived at the feedlot and were mingled into pen groups. This gave a ‘days on feed’ distribution. The peak incidence of bullers occurred much sooner after arrival and dropped off much quicker in older cattle. The daily incidence of bullers was temporal, but was not related to season of the year, weather conditions or any other feedlot management practice. It was related to the seasonal arrival of cattle at the feedlot, their age at entry to the feedlot and the post arrival occurrence of bullers. Reimplantation with hormonal growth promotants and castration of intact bulls did not produce an epidemic of bullers. Conclusion The findings of this study support the theory that bullers are the result of agonistic interactions, which occur concurrent with the establishment and maintenance of a social hierarchy within pens of feedlot cattle. 相似文献
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Precambrian sponges with cellular structures 总被引：2，自引：0，他引：2
Sponge remains have been identified in the Early Vendian Doushantuo phosphate deposit in central Guizhou (South China), which has an age of approximately 580 million years ago. Their skeletons consist of siliceous, monaxonal spicules. All are referred to as the Porifera, class Demospongiae. Preserved soft tissues include the epidermis, porocytes, amoebocytes, sclerocytes, and spongocoel. Among thousands of metazoan embryos is a parenchymella-type of sponge larvae having a shoe-shaped morphology and dense peripheral flagella. The presence of possible amphiblastula larva suggests that the calcareous sponges may have an extended history in the Late Precambrian. The fauna indicates that animals lived 40 to 50 million years before the Cambrian Explosion. 相似文献