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31.
S. M. CORMIER R. N. RACINE C. E. SMITH W. P. DEY T. H. PECK 《Journal of fish diseases》1989,12(2):105-116
Abstract. The livers of Atlantic tomcod, Microgadus tomcod (Walbaum), from the Hudson and Pawcatuck Rivers were evaluated histologically and described using paraffin and plastic sections. Fatty infiltration, basophilic foci, areas of cellular alteration and hepatocellular carcinoma were widespread in Hudson River samples. In fact, no truly normal tissues were found. Pawcatuck samples had variable levels of lipid and a low prevalence of other alterations. Evaluation of the histological evidence suggests that hepatocellular carcinoma in Hudson River tomcod results from multiple DNA lesions and that areas of cellular alteration give rise to the larger, more invasive form of hepatocellular carcinoma. Glutaraldehyde and OsO4 fixed livers were used to determine differences in cell types and lipid levels. Pawcatuck samples possessed hepatocytes and dark cells forming the parenchymal tissue, whereas Hudson samples lacked dark cells. Hepatic lipid levels were significantly higher in Hudson River fish than in Pawcatuck fish, 36·3 and 11·0% respectively. The elevated hepatic lipid levels in Hudson River tomcod may represent a metabolic response to detoxification. 相似文献
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J. L. BARTHOLOMEW C. E. SMITH J. S. ROHOVEC J. L. FRYER 《Journal of fish diseases》1989,12(5):509-522
Abstract. The tissue response of Salmo gairdneri Richardson, against the myxosporean parasite. Ceratomyxa shasta (Noble), was investigated using histological techniques, scanning electron microscopy and immunological methods. The progress of infection in C. shasta -susceptible and resistant steelhead and rainbow trout was examined by standard histological techniques and by indirect fluorescent antibody methods using monoclonal antibodies directed against C. shasta antigens. Trophozoite stages were first observed in the posterior intestine and there was indication that resistance was due to the inability of the parasite to penetrate this tissue rather than to an inflammatory response. Examination of a severely infected intestine by scanning electron microscopy showed extensive destruction of the mucosal folds of the posterior intestine. Western blotting and indirect fluorescent antibody techniques were used to investigate the immunological component of the host response. No antibodies specific for C. shasta were detected by either method. 相似文献
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The isolation of a rickettsia-like organism causing disease and mortality in Chilean salmonids and its confirmation by Koch's postulate 总被引:5,自引:0,他引:5
Abstract. A rickettsia-like organism (RLO) was isolated from infected coho salmon, Oncorhynchus kisutch (Walbaum), in cultures from six fish cell lines, but could not be cultured on 41 artificial media. The organism was confirmed by Koch's postulates as the aetiological agent of a systemic disease causing signifieant mortality among coho in Chile. The organism was a Gram-negative, obligate intracellular pathogen frequently observed within intracyto-plasmic vacuoles or inclusions of host cells, and appears to belong to the order Rickettsiales, family Rickettsiaceae and possibly the tribe Ehrlichiae. The organism, as well as the clinical signs and pathology it produces, is described. The disease, originally observed only in coho raised in seawater net pens, was reproduced experimentally in fish in both freshwater and seawater aquaria. Horizontal transmission without parasite vectors was observed in fish in both aquaria. The organism was shown, for the first time, to cause disease and mortality in Atlantic, Salmo salar L., and Chinook, O. tshawytscha (Walbaum), salmon and rainbow trout, O. mykiss (Walbaum). Because of the systemic nature of the disease, it is proposed that it be called 'salmonid rickettsial septicaemia'. 相似文献
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P. A. SMITH 《Fisheries Management and Ecology》2002,9(5):261-266
Abstract Twelve anglers fishing in a UK navigation canal for a total of 42 h caught 567 fish, mainly gudgeon, Gobio gobio (L.) ( n =306) and roach, Rutilus rutilus (L.) ( n =253) at an average catch rate of 13.4 fish angler-h−1 or 128.5 g angler-h−1 . The species and size of fish caught were compared with the numbers determined by depletion estimates at six sections of canal using micromesh seine netting. Fifty four percent of fish caught in the net were < 60 mm FL. Gudgeon (60–99 mm) were over-represented in the anglers' catches whilst roach (60–99 mm) were under-represented. The size distribution of roach and gudgeon caught by anglers using two types of bait (small maggots and chironomid larvae) was examined and smaller fish were found to be caught using the latter. 相似文献
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BARBARA L. SMITH DVM MS JOERG A. AUER DrMedVet MS DiplomateACVS JEFFREY P. WATKINS DVM MS DiplomateACVs 《Veterinary surgery : VS》1990,19(2):117-121
Four horses, 2 to 17 years old, were treated for unilateral avulsion fractures of the tibial tuberosity. Two horses were treated successfully with tension band wiring or plating in combination with lag screw fixation. One horse was euthanatized because of implant failure during recovery and one was euthanatized on day 11 because a longitudinal fracture of the tibial tuberosity occurred through the plane of the screws used for stabilization. 相似文献
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