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81.
Enteric chlamydial infections of pigs with Chlamydia (C.) suis are frequent and often subclinical. The enteric pathogenicity of C. suis strain S45 was investigated in gnotobiotic piglets. Piglets from three litters (n=31) were inoculated with egg-grown chlamydiae at 2-3 days of age (n=17) or used as controls (n=14). They were observed for clinical signs, killed and necropsied sequentially at 2-13 days postinoculation (DPI). Feces were collected daily and investigated with an ELISA for chlamydial antigen. At necropsy, specimens were collected for histopathology and for immunohistochemical, PCR-based, and serological (complement fixation test, ELISA) detection of chlamydiae. Chlamydial replication and associated symptoms and lesions were observed from 2 to 13 DPI and were particularly pronounced within the first week PI. Clinical symptoms consisted of moderate-to-severe diarrhea, slight and transient anorexia, weakness and body weight loss. Immunohistochemistry and ELISA revealed that chlamydial replication was particularly marked at 2-4 DPI and primarily located in the small intestinal villus enterocytes. Further sites of replication included large intestinal enterocytes, the lamina propria and Tunica submucosa, and the mesenteric lymphnodes. Histopathological changes included moderate-to-severe villus atrophy with flattened enterocytes and focal villus tip erosions, and moderate mucosal inflammatory cell infiltrates and lymphangitis in the small intestine. PCR of spleen tissue and blood was mostly negative for chlamydiae, indicating that they did not substantially disseminate into the host up to 13 DPI. All sera were negative for anti-chlamydial antibodies. In conclusion, C. suis strain S45 elicited significant enteric disease and lesions in gnotobiotic piglets indicating its pathogenic potential for swine. 相似文献
82.
The effect of three commonly used anthelmintics, levamisole hydrochloride, ivermectin and closantel, on the development of the sheep blowfly, Lucilia cuprina, was determined. Sheep were treated with each anthelmintic using the manufacturers' recommended dose for helminth control. Both ivermectin and closantel significantly (p < 0.05) reduced the growth rate of larvae of L cuprina cultured in vitro on serum from these sheep. Levamisole hydrochloride had no effect. Ivermectin was effective for less than 6 days after treatment, whereas closantel significantly reduced larval growth 21 days after treatment. Dose-response experiments showed that lower concentrations of both ivermectin and closantel were not as effective in reducing larval growth. 相似文献
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A Ortega-Pacheco ME Bolio-González RF Colin-Flores CH Sauri-Arceo E Gutiérrez-Blanco M Jiménez-Coello C Linde Forsberg 《Reproduction in domestic animals》2006,41(3):227-232
A Burdizzo castrator was evaluated for the neutering of dogs. Histological and morphological changes of spermatic cells and peripheral serum testosterone after challenge with a GnRH-analogue (gonadorelin) were assessed. There was a control group (G1), a surgically castrated group (G2) and a Burdizzo group (G3) divided in two, G3a receiving two crunches in each spermatic cord and G3b receiving one crunch in each spermatic cord. Sixteen days after application of the Burdizzo blood samples were taken from the dogs at 30 min interval during 2 h; after the second sample the dogs were treated with 1 mug/kg body weight of gonadorelin i.v. The same protocol of gonadorelin challenge was performed in G1 and G2 dogs. The G2 dogs were surgically castrated after the second blood sample, before the gonadorelin treatment, and the G1 dogs after the last blood sample. The excised gonads were examined histologically, and sperm smears were prepared from the caudae epididymidis. The testes and plexus pampiniformis of the G1 and G2 dogs had a normal histological appearance, and they had morphologically normal epididymal sperm cells. In all G3 dogs, there was an acute fibrosis with an inflammatory reaction in the plexus pampiniformis. The testes from the G3a dogs showed diffuse areas of infarction and degeneration of the parenchyma. Similar but less diffuse lesions were seen in group 3b dogs. The deferent ducts from all G3 dogs showed vasitis and/or sperm granulomas. Azoospermia or sperm malformations were observed in the epididymal smears from the G3 dogs. Testosterone concentration in the G1 dogs increased after gonadorelin application (p < 0.0001). The G2 dogs had basal testosterone levels after castration (p < 0.001) and did not respond to gonadorelin. Groups 3a and b showed a slight but non-significant increase in testosterone concentration after gonadorelin challenge, supposedly due to the reduction of testicular blood flow and loss of testicular interstitial tissue. 相似文献
85.
Extract Ectoparasites known to cause skin lesions in alpacas (Vicugna pacos) include the mites Sarcoptes scabiei, Chorioptes bovis and Psoroptes spp., and the lice Microthoracius mazzai and Bovicola breviceps (Cicchino et al. 1998; Foster et al. 2007). Occasionally, Demodex spp. infestations have been reported or mentioned as incidental fi ndings in llamas (Lama glama) (Atlee et al. 1997) and alpacas (Foster et al. 2007). So far, only Sarcoptes scabiei (McKenna et al. 2005), Chorioptes bovis (Arthur 1997, non-peer reviewed) and Bovicola breviceps (Palma et al. 2006) have been recorded on lamoids in New Zealand. Here, we report the first record of Demodex spp. infestation of an alpaca in New Zealand. 相似文献
86.
Pospischil A Djamei V Rütten M Sydler T Vaughan L 《Journal of veterinary medical education》2007,34(4):445-449
The teaching of pathology within the veterinary medical curriculum extends through the entire training period and has a dual role. General pathology deals with principles of disease processes as a basis for understanding the reactions of a multi-cellular organism to adverse effects; organ pathology builds on the principles of general pathology and explains the malfunctions of individual organs. Pathology is heavily image dependent and best taught in a highly interactive manner. The Institute of Veterinary Pathology, University of Zurich (IVPZ), has been actively developing concepts for teaching pathology in the new veterinary curriculum, which demands more active participation from students, with 20% of their study time devoted to individual study using traditional materials (books, articles, etc.) and e-learning modules. The Swiss Virtual Animal Pathologist is designed to cover and support the central elements of the Veterinary Pathology curriculum of the Vetsuisse Faculty. The needs of students and staff of the participating institutions for an interactive learning platform to supplement the existing face-to-face lectures and tutorials are the highest priority of this initiative. 相似文献
87.
88.
Biodiversity assessment and conservation strategies 总被引:2,自引:0,他引:2
van Jaarsveld AS S Freitag SL Chown C Muller S Koch H Hull C Bellamy M Kruger S Endrody-Younga MW Mansell CH Scholtz 《Science (New York, N.Y.)》1998,279(5359):2106-2108
The efficient representation of all species in conservation planning is problematic. Often, species distribution is assessed by dividing the land into a grid; complementary sets of grids, in which each taxon is represented at least once, are then sought. To determine if this approach provides useful surrogate information, species and higher taxon data for South African plants and animals were analyzed. Complementary species sets did not coincide and overlapped little with higher taxon sets. Survey extent and taxonomic knowledge did not affect this overlap. Thus, the assumptions of surrogacy, on which so much conservation planning is based, are not supported. 相似文献
89.
90.
The Mars Odyssey Thermal Emission Imaging System (THEMIS) has discovered water ice exposed near the edge of Mars' southern perennial polar cap. The surface H2O ice was first observed by THEMIS as a region that was cooler than expected for dry soil at that latitude during the summer season. Diurnal and seasonal temperature trends derived from Mars Global Surveyor Thermal Emission Spectrometer observations indicate that there is H2O ice at the surface. Viking observations, and the few other relevant THEMIS observations, indicate that surface H2O ice may be widespread around and under the perennial CO2 cap. 相似文献