Experimental and field trials were conducted to evaluate an ELISA for its ability to detect Trichinella-infected domestic swine and to compare ELISA results with muscle-digestion test results. The ELISA used was a commercial double-antibody kit, containing an excretory-secretory antigen, and was evaluated principally for epidemiologic use. Experimentally induced infection in swine (4 groups of 3 pigs each; inoculated with 0, 50, 500 or 5,000 larvae) was detected as early as postinoculation week 4, with seroconversion of all inoculated swine by postinoculation week 8. The rate of seroconversion appeared to be affected by initial larval dose, time after inoculation, and immunocompetence of the individual host. Determination of antibody kinetics generally revealed rapidly increasing antibody titer, followed by its steady decrease in most pigs. Once seropositive, however, all pigs remained seropositive for the duration of the 10-week study. Presence of muscle larvae was confirmed in all infected pigs at termination of the study. We recognize that the experimental conditions may not be truly representative of those under which natural infection develops in pigs; however, the ELISA detected an infected pig with muscle larval density of 0.87 larvae/g of tissue. Results of a field trial (n = 310) indicated no muscle digestion test-positive pigs (35 g of diaphragm muscle digested/pig), but 3 samples tested positive by ELISA for specificity of 99.0%. 相似文献
A 450-kg yearling Clydesdale filly was determined to have bilateral ectopic ureters. The resulting incontinence caused severe malodorous perineal dermatitis. Bladder capacity was measured at 800 ml. The urethral sphincter lacked tone, and the horse was seen to urinate in a normal manner only 2 or 3 times a week. A midline celiotomy was performed, and the ureters were identified by cannulation from the ectopic openings. The ureters were ligated, and the cut ends were anastomosed to the dorsal bladder surface by an extravesicular end-to-side technique. A partial thickness seromuscular layer of the bladder was sutured over the ureters in a cranial direction from the anastomosis site for 15 mm. This fixed the ureters to the dorsal surface of the bladder and protected the anastomosis site from tension. After surgery, the horse urinated n a normal manner many times a day. Urinary incontinence continued, but gradually improved. Bladder capacity increased over 13 months to 4.3 L. Surgical (urethral extension) and medical (phenylpropanolamine and estrogen) treatments were instigated to increase urethral sphincter tone. Urinary incontinence continued to improve and, at 11 months after surgery, incontinence was negligible, and the perineal dermatitis had healed. 相似文献
Moderate to extremely low levels of selenium in hay were related to marginally deficient levels of selenium in sera from cattle in the Windermere Valley of southeastern British Columbia. Deficiency was most pronounced in cattle fed local hay during the winter or grazed on fertilized/irrigated pastures. Cattle on range had adequate levels of serum selenium. When sodium selenite was fed at 1.0 and 3.5 mg per head per day, serum selenium levels increased commensurate with the dose. Clinical observations indicated that a variety of clinical problems disappeared after injection or supplementation with selenium/vitamin E. 相似文献
Merino wether weaners, 5-months old at the start of the experiment and fed lucerne-based pellets at 600 g per head per day, developed resistance to Haemonchus contortus given as a continuous or "trickle" infection at the rate of 500 larvae 3 times per week over a period of 17 weeks. By contrast, the development of resistance was impaired in weaners fed pellets at 400 g per head per day. Low food intake and protein-energy deprivation, therefore, have a major effect in impairing the development and expression of host-protective immunity against haemonchosis. The point at which low food intake causes outbreaks of haemonchosis in sheep at pasture is critical in determining procedures for prevention and control of the disease. 相似文献
1. A study has been made of changes occurring in the numbers and types of faecal streptococci in the intestines of chicks from hatching to 23 d of age, when fed on a diet containing 50 mg bacitracin/kg.
2. It was found that Streptococcus faecalis sub‐species liquefaciens predominated in chicks prior to feeding and in control birds the organism remained as a significant part of the flora throughout the experiment.
3. Strep. faecalis s.s. liquefaciens was not found after the first week in birds given dietary bacitracin.
4. Although outnumbered initially in the caeca by Strep, faecalis s.s. liquefaciens, other streptococci were present at 106 to 107/g contents from 14 d onwards in both control and bacitracin‐treated birds; these included Strep. faecium biotypes and two other unidentified but related groups.
5. Tests made in vitro showed that Strep. faecalis s.s. liquefaciens was more sensitive to bacitracin than Strep. faecium.
6. The possible effects of Strep. faecalis s.s. liquefaciens on the developing bird are discussed. 相似文献
The present study was carried out to investigate the pattern of apoptosis in the healthy antral and atretic follicles of Philippine swamp buffaloes (BU) in comparison with Holstein-Friesian (HF) cows. Paraffin sections of healthy follicles and various stages of atretic follicles were stained using the terminal deoxynucleotidyl transferase (TdT)-mediated biotinylated deoxyuridine triphosphates (dUTP) nick end-labelling (TUNEL) method to detect DNA fragmentation and cleaved caspase-3 antibody to detect cells committed to undergo apoptosis. Five equidistant areas of a follicle were counted for the presence of TUNEL- and caspase-3-positive cells. Healthy follicles of BU and HF contained no TUNEL-positive cells in the granulosa and theca layer but showed some caspase-3 positivity. The granulosa layer of advanced atretic follicles showed a significantly higher frequency of caspase-3 positivity than the healthy and early atretic follicles in both breeds. The frequency of caspase-3-positive cells of BU was significantly higher than HF in the granulosa layer of healthy, early atretic and advanced atretic follicles. In the theca interna layer, BU and HF showed a significantly lower and higher frequency of TUNEL-positive cells in the late atretic follicles compared with advanced atretic follicle, respectively. However, the frequency of caspase-3-positive cells of both BU and HF in the late atretic follicles was significantly higher than the advanced atretic follicles in the theca interna layer. These results indicate that caspase-3 and DNA fragmentation is involved in the buffalo ovarian apoptotic process. 相似文献
The present study was carried out to describe the proliferative activity of granulosa and theca cells in healthy antral and atretic follicles of Philippine buffaloes (BU) and Holstein-Friesian (HF) cows. Paraffin sections of ovary were immunostained with mouse monoclonal antibody to proliferating cell nuclear antigen (PCNA). Then the follicles were classified into healthy and various stages of atretic follicles. The granulosa layer of healthy follicles had a significantly higher frequency of PCNA-positive cells than the early and advanced atretic follicles in both breeds. In the theca interna, significantly reduced populations of the PCNA-positive cells were found in both breeds as atresia progressed. Moreover, HF had significantly higher PCNA-positive cells in the theca interna of healthy, early atretic and advanced atretic follicles than BU. A reduction of PCNA-positive cells during atresia was also noted in the theca externa in both animals although differences were not significant. The results of the present work suggest that the proliferative activity of granulosa and theca cells decreases in association with follicular atresia in the BU similar to HF. Furthermore, a significantly deficient cell proliferative activity of theca interna was found in BU compared with HF. 相似文献
AIM: To investigate a possible interaction between lolitrem B and ergovaline by comparing the incidence and severity of ryegrass staggers in sheep grazing ryegrass (Lolium perenne) containing lolitrem B or ryegrass containing both lolitrem B and ergovaline.
METHODS: Ninety lambs, aged approximately 6 months, were grazed on plots of perennial ryegrass infected with either AR98 endophyte (containing lolitrem B), standard endophyte (containing lolitrem B and ergovaline) or no endophyte, for up to 42 days from 2 February 2010. Ten lambs were grazed on three replicate plots per cultivar. Herbage samples were collected for alkaloid analysis and lambs were scored for ryegrass staggers (scores from 0–5) weekly during the study. Any animal which was scored ≥4 was removed from the study.
RESULTS: Concentrations of lolitrem B did not differ between AR98 and standard endophyte-infected pastures during the study period (p=0.26), and ergovaline was present only in standard endophyte pastures. Ryegrass staggers was observed in sheep grazing both the AR98 and standard endophyte plots, with median scores increasing in the third week of the study. Prior to the end of the 42-day grazing period, 22 and 17 animals were removed from the standard endophyte and AR98 plots, respectively, because their staggers scores were ≥4. The cumulative probability of lambs having scores ≥4 did not differ between animals grazing the two pasture types (p=0.41).
CONCLUSIONS AND CLINICAL RELEVANCE: There was no evidence for ergovaline increasing the severity of ryegrass staggers induced by lolitrem B. In situations where the severity of ryegrass staggers appears to be greater than that predicted on the basis of concentrations of lolitrem B, the presence of other tremorgenic alkaloids should be investigated. 相似文献