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Fasciolosis is an endemic zoonotic parasitic disease with significant impacts on human health and both animal health and production. Early post-infection impacts on the host remain unclear. The objective of this study was to determine the changes, if any, to levels of endotoxin in cattle plasma in response to early-stage infection with Fasciola hepatica. Thirty-six (36) commercial bred cattle were experimentally infected with approximately 400 viable metacercariae. Plasma lipopolysaccharide (endotoxin) levels were examined on 24 occasions from 0 h before infection to 336 h after infection using the Limulus Amoebocyte Lysate chromogenic end point assay and compared with that of six (6) uninfected control animals. Peak lipopolysaccharide levels in infected animals were reached at 52 h after infection and returned to pre-infection levels at time 144 h after infection. Infected animals had significantly elevated lipopolysaccharide levels between 24 and 120 h after infection when compared to uninfected animals. The mean change in endotoxin units (EU)/mL over time after infection was statistically significant in infected animals. Elevations of lipopolysaccharide occurred in all infected animals suggesting a possible repeatable and titratable endotoxemia conducive to therapeutic agent model development.  相似文献   
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We hypothesised that horses affected with summer pasture-associated obstructive pulmonary disease (SPAOPD) react to an allergen or allergens in their summer environment that is either absent or present at lower levels in their winter environment; and that such allergens stimulate SPAOPD-affected horses to produce a different T helper lymphocyte cytokine profile from that of control horses. The primary objective of this study was to determine the cytokine mRNA profile of T helper lymphocytes obtained from summer pasture-associated obstructive pulmonary disease (SPAOPD) affected horses when 1) the horses were showing signs of disease (summer) and 2) they were in clinical remission (winter). A further objective was to determine the differences between cytokine mRNA T helper lymphocyte profiles of control and affected horses in the summer and winter seasons. Interleukin 4 (IL-4) and interferon-gamma (IFN-gamma) mRNA expression levels were increased in bronchoalveolar lavage fluid (BALF) and peripheral blood mononuclear cell (PBMC) samples of affected horses during disease expression. No significant amounts of IL-5 mRNA were detected in any of the samples. These results suggest that there is an allergic component to SPAOPD of horses and that appropriate manipulation of the immune system could offer hope for treatment and prevention of the disease in the future. Further research studies will be needed to determine the most appropriate treatments to use to alter the antigen-stimulated cytokine profile being expressed by SPAOPD-affected horses or to alter the effects that these cytokines produce.  相似文献   
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The spatial and temporal distribution of dicarboximide-resistant strains of Monilinia fructicola were investigated in six peach and nectarine orchard blocks in 1987–89 using a dispersion index (Lloyd's Patchiness Index, LPI), and spatial, temporal and spatio-temporal autocorrelation analyses (Moran's Coefficient, I ). The LPI values indicated that resistant strains were aggregated in all blocks in all years. Spatial correlations were not significant beyond one quadrat for any spatial proximity pattern in five of six blocks. Thus the spread of resistant strains was mostly restricted to the vicinity of the original focus. An absence of significant temporal correlation between years in five of the six blocks indicated poor persistence of resistant strains at specific locations. Only one significant temporal correlation was detected at one block and this could have arisen by chance. Significant spatio-temporal correlation was not detected, suggesting that there was no focus expansion or carry-over of resistant strain inoculum from the previous sampling date. Spatial, temporal and spatio-temporal autocorrelation analyses were consistent with previously reported laboratory results that resistant strains had not acquired all the necessary characteristics to remain in, or dominate, field populations. The spatial pattern of brown rot incidence was investigated at one block in a separate study in 1988 and 1989. There were no significant spatial correlations for brown rot incidence in 1988 for any of the spatial proximity patterns analysed. In 1989, however, significant correlations indicated ellipsoid aggregates of brown rot orientated along the orchard rows.  相似文献   
5.
Bluetongue virus serotypes 1 and 3 infection in Poll Dorset sheep   总被引:1,自引:0,他引:1  
Objective To study the clinical signs following bluetongue virus serotypes 1 and 3 infection in Poll Dorset sheep.
Design A clinical and pathological study.
Procedure Twenty Poll Dorset sheep were inoculated with bluetongue virus serotypes 1 or 3, each inoculum having a different passage history. The sheep were examined daily and their clinical appearance and rectal temperatures recorded. Heparinised and non-heparinised blood samples were taken at intervals for virological and serological study. Gross pathological findings were recorded for several sheep at necropsy and tissue samples were collected from three sheep for virological studies.
Results All inoculated sheep developed clinical disease. The clinical signs and gross pathological changes varied considerably but were consistent with damage to the vascular endothelial system. There was a decline in the titres of infectious bluetongue virus and of antigen in tissues collected between 7 and 12 days after infection.
Conclusions The severity of disease was related to the speed of onset and duration of pyrexia and not the development or titre of viraemia. Generally, those animals with sensitive mouths, depression, coronitis, recumbency and reluctance to move were the most debilitated. Whole blood was the most reliable source of infectious virus from acutely and chronically infected and convalescent animals. However, tissue samples particularly spleen, collected from dead or killed animals suffering from either peracute or acute forms of disease were most appropriate for the rapid confirmation of a clinical diagnosis.  相似文献   
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Inhibitors of cyclin‐dependent kinases, as roscovitine, have been used to prevent the spontaneous resumption of meiosis in vitro and to improve the oocyte developmental competence. In this study, the interference of oil overlay on the reversible arrest capacity of roscovitine in sheep oocytes as well as its effects on cumulus expansion was evaluated. For this, cumulus‐oocyte complexes (COCs) were cultured for 20 h in TCM 199 with 10% foetal bovine serum (Control) containing 75 μm roscovitine (Rosco). Subsequently, they were in vitro matured (IVM) for further 18 h in inhibitor‐free medium with LH and FSH. The culture was performed in Petri dishes under mineral oil (+) or in 96 well plates without oil overlay (?) at 38.5°C and 5% CO2. At 20 and 38 h, the cumulus expansion and nuclear maturation were evaluated under stereomicroscope and by Hoechst 33342 staining, respectively. No group presented cumulus expansion at 20 h. After additional culture with gonadotrophins, a significant rate of COCs from both Control groups (+/?) exhibited total expansion while in both Rosco groups (+/?) the partial expansion prevailed. Among the oocytes treated with roscovitine, 65.2% were kept at GV in the absence of oil overlay while 40.6% of them reached MII under oil cover (p < 0.05). This meiotic arrest was reversible, and proper meiosis progression also occurred in the Control groups (+/?). So, the culture system without oil overlay improved the meiotic inhibition promoted by roscovitine without affecting the cumulus expansion rate or the subsequent meiosis progression.  相似文献   
8.
A 2.5‐year‐old intact male Roborovski hamster (Phodopus roborovskii) was presented with a large subcutaneous mass overlying the abdomen, affecting the animal's ambulation and access to different compartments of the cage through narrow tubing. Ultrasound examination delineated a well‐circumscribed mass in the subcutis of the caudoventral abdominal region. The mass was surgically excised and on cytologic examination showed, in a background of blood, a small population of individually arranged oval to spindle‐shaped cells that exhibited a moderate degree of anisokaryosis, coarsely stippled chromatin, one or more prominent nucleoli, and lightly basophilic well‐defined cytoplasmic processes. Histologically, the mass was composed of interlacing streams and bundles of pleomorphic spindle cells (ganglion‐like cells) with variable amounts of collagenous stroma. The neoplastic cells exhibited moderate features of malignancy. These cells stained intensely with vimentin, but not with any other markers, including antibodies to cytokeratin AE1/AE3, S100 protein, desmin, smooth muscle actin, synaptophysin, neurofilament, and androgen receptor. Based on histologic features, the mass was diagnosed as an atypical fibrosarcoma. This is the first report of an atypical fibrosarcoma in a Roborovski hamster and one of few reports of atypical fibrosarcoma in domesticated hamsters overall.  相似文献   
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The long term metabolism of [14C]MCPA and [14C]flamprop in wheat (Triticum aestivum) straw was found to involve incorporation of radioactivity as residues that were insoluble in acetone+water (1+1 by volume). A chemical and an enzymic solubilisation procedure were critically evaluated in attempts to release these residues for further examination. The chemical procedure resulted in complete solubilisation of all the radioactivity of both compounds in association with more than one cell wall fraction. However, routine quantitative analysis was found to be difficult for some fractions. Furthermore, the extracts did not appear to be suitable for investigation of the nature of the binding with the plant constituents. None of the enzymes employed in the enzymic procedures released significant amounts of the residues insoluble in the aqueous acetone. Despite these problems, the residues of MCPA that were insoluble in aqueous acetone were found to contain both the parent MCPA and its major metabolite 4-chloro-α-hydroxy-o-tolyloxyacetic acid.  相似文献   
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