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A 2-year-old Standardbred gelding was referred for a mass on the palmaromedial right front pastern which was accompanied by progressively worsening lameness. The mass was firm to palpation and covered by normal skin. Ultrasonographically, a smooth encapsulated mass was present, medial to the flexor tendons and palmar to the neurovascular bundle. Because of a poor prognosis for future athletic performance without surgical or chemotherapeutic intervention and economic constraints preventing further diagnostics and treatment, the horse was euthanised. Post-mortem magnetic resonance imaging, histopathology and immunohistochemistry revealed the mass to be a perivascular wall tumour, the first record of such a neoplasia in the horse.  相似文献   
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Hereford x Angus crossbred steers (n = 36) were stunned, exsanguinated, and infused via the carotid artery either with an aqueous solution containing 98.52% water, 0.97% saccharides, 0.23% sodium chloride, and 0.28% phosphates (MPSC; n = 12) or with 0.3 M CaCl2 (n = 12). The remaining 12 steers served as noninfused controls. At 48 h postmortem, the quadriceps muscles and subcutaneous fat were removed from the carcasses, frozen, and later made into ground beef (18 to 20% fat). The longissimus lumborum (LL), semimembranosus, and psoas major (PM) also were removed, vacuum packaged, aged until 14 d postmortem, and then one steak was sliced from each muscle for visual and instrumental color evaluations. The inside (ISM) and outside (OSM) portions of the SM were evaluated separately. The LL and OSM steaks from MPSC-infused carcasses had a lighter red (P < 0.05) initial appearance than steaks from the other treatments. The LL steaks from noninfused carcasses had the most (P < 0.05) uniform color; the MPSC treatment was intermediate, and the CaCl2 treatment was the most two-toned. Steaks from both infusion treatments had higher (P < 0.05) L* values for the LL, ISM, and OSM muscles compared with noninfused carcasses. In general, the LL from CaCl2-infused carcasses had lower (P < 0.05) a* values, saturation indices, and 630 nm to 580 nm reflectance values, and had larger (P < 0.05) hue angles. Infusion with MPSC increased (P < 0.05) hue angles in the LL and OSM. Display color stability was lowest (P < 0.05) for LL steaks from CaCl2-infused carcasses, whereas steaks from MPSC-infused carcasses were lighter red in initial color, but otherwise had display color stability similar to those from noninfused carcasses. No differences (P > 0.05) due to infusion were found for any color traits for the PM muscle and ground beef. Carotid artery vascular infusion of carcasses with CaCl2 resulted in undesirable meat colors, whereas the MPSC solution lightened loin and inside round color in a desirable way, but the color stability was slightly less compared to muscle from noninfused carcasses. Infusion effects were not consistent among muscles, and further research will be needed to determine what caused these differences.  相似文献   
6.
An enzyme-linked immunosorbent assay (ELISA) was developed for detecting antibody to type A avian influenza (AI) virus. The sensitivity and group specificity of the AI-ELISA were compared with those of the agar-gel-precipitin test (AGPT) and the hemagglutination-inhibition (HI) test under conditions of both controlled and field exposure. During the course of temporal experimental infection (0-76 days) of specific-pathogen-free (SPF) chickens with AI subtype Hav9N2, the AI-ELISA was able to detect specific AI antibody as early as 8 days postinoculation (PI), and it measured rising levels of antibody through 35 days PI, at which time the chickens were re-exposed to AI virus. Conversely, AGP tests were negative through 35 days PI, and HI tests began to detect low levels of AI antibody only at 21 days PI. Following a secondary infection at 35 days PI with the same AI subtype, all tests measured rising levels of AI-specific antibody (35-76 days PI). However, the AGP test was positive at only the 7- and 14-day samplings postsecondary immunization. Under field conditions, the AI-ELISA was able to detect serum AI antibody in flocks from which highly pathogenic AI was isolated, but the AGP tests of these sera were negative.  相似文献   
7.
The prevalence of endocrine‐disrupting chemicals (EDCs) in the aquatic environment has been associated with the wide detection of alterations in the development and physiology of vertebrates. Zebrafish, as a model species, has been extensively used in toxicological research. In this review, we focus on recent published evidence of the harmful effects of EDCs on reproductive function in zebrafish, including skewed sex ratio, immature gonads, diminished sexual behaviour, decreased sperm count, reduced spawning and fertilization. These impairments mostly result from disruption to sex‐steroid hormones induced by endocrine disruptors. We also discuss other effects of exposure to EDCs. In EDC exposure research, despite incomplete assessments of altered gonad histopathology and sexual behaviour, these present potential effective biomarkers or pathways for evaluating the reproductive function in zebrafish on EDC exposure. To date, the pernicious effects of some EDCs on the reproductive performance in laboratory zebrafish are well understood; however, similar alterations remain for further determination in wild‐type fish and more kinds of EDCs. More studies should be performed under established scientific regulatory criteria to investigate the impact of EDCs on reproduction in zebrafish. Moreover, further research is required to explain the definite mechanism of sexual differentiation, which helps in understanding the shift of sexual phenotype with EDC exposure.  相似文献   
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Ceftiofur hydrochloride was tested for effectiveness against induced colibacillosis in neonatal swine. In this model, pigs less than 12 hours old were inoculated via stomach tube with a virulent, K99+, nalidixic acid-resistant strain of Escherichia coli. Six hours after challenge exposure, 1 dose of ceftiofur was administered either IM or orally in experiment 1 and orally only in experiment 2. Mortality, shedding of bacteria, fecal consistency scores, and body weight changes were monitored for 10 days. In experiment 1 (n = 383 pigs), all treatments at dosage that ranged between 0.5 and 64.0 mg of ceftiofur/kg of body weight significantly (P less than 0.001) reduced mortality, bacterial shedding, and diarrhea and increased weight gain, compared with findings in untreated controls. There were no detectable differences between oral and IM routes, except that there was greater reduction in bacteria shedding associated with the oral route of administration. In experiment 2 (n = 505 pigs), ceftiofur was administered orally either once at 6 hours after challenge exposure or twice at 6 and at 48 hours after the first dose. Dosage of ceftiofur was 0, 5, 10, 20, 30, or 60 mg/kg administered once, or half the same dose was administered at each of 2 times. At the optimal dosage (10 mg/kg), a single dose was as effective as 2 doses. The single administration at all dosages reduced mortality, bacterial shedding, and diarrhea scores and increased body weight gain, compared with findings in untreated pigs (P less than 0.01). In this induced infection model, the optimal treatment dosage was determined to be 10 mg/kg administered once.  相似文献   
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An investigation of sheep flocks in the main sheep raising areas of New South Wales showed that the itchmite Psorergates ovis was frequently associated with fleece derangement. In 26 of the 41 flocks examined, P. ovis was the only ectoparasite detected. P. ovis and the sheep body louse Damalinia ovis, were found in 5 flocks. No external parasites were found on sheep examined from the 10 remaining flocks. The type of fleece derangement most frequently recorded was rubbing which in some cases was combined with areas of chewed fleece. Among flocks, there were positive relations between the prevalence of fleece derangement and prevalence of itchmite or scurf and between itchmite count and mean scurf score. Within flocks, itchmite infested sheep or sheep with scurf had higher prevalences of fleece derangement than sheep on which no mites or no scurf were found. Itchmite infested sheep had a higher prevalence of scurf than those with no detectable mite infestation. There were no significant differences in itchmite populations or fleece derangement between untreated flocks and flocks treated with synthetic pyrethroids, organophosphates or arsenic and rotenone.  相似文献   
10.
Chlamydiosis in workers at a duck farm and processing plant   总被引:4,自引:0,他引:4  
SUMMARY An outbreak of chlamydiosis was Investigated in workers at a duck farm and processing plant during winter 1989. Chlamydia psittaci was isolated from ducks, but there was little evidence of clinical chlamydiosis in the ducks. Serological tests showed that 76% of workers had been exposed to Infection, 12% recently, 16% had not been exposed and 8% had inconclusive test results. There was a strong association (P < 0.05) between years of employment and exposure to Infection. Infection appeared to be contracted during the first year of employment. Measures were Implemented to reduce shed contamination and control rodents and wild birds. At the same time, ducks were medicated, the processing plant was modified, work practices were altered and workers were advised about chlamydiosis to reduce the risk of human infection.  相似文献   
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