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31.
The aim of the present study was to determine the differences in corpus luteum (CL) functionality between the first postpartum estrous cycle and the following cycle in lactating dairy cows. Luteal blood flow (LBF), luteal size and blood progesterone (P4) concentration were monitored during the first and second postpartum estrous cycle. During the first and second postpartum estrous cycle, the mean LBF value increased (p < .05) from early to late dioestrus, while it decreased rapidly in proestrus, resulting statistically lower (p < .05) than those registered in all previous phases. Statistically significant differences were not observed between overall LBF during first and second postpartum estrous cycle (p > .05). During the first postpartum estrous cycle, P4 blood concentrations showed a significant reduction (p < .05) from dioestrus to proestrus. A different trend of P4 concentrations was observed during the second postpartum estrous cycle, where mean P4 value registered in proestrus resulted statistically lower than those registered in the previous cycle phases (p < .05). The mean P4 concentration registered over the first postpartum estrous cycle resulted statistically lower (p < .05) than that registered during the second one. A significant correlation between P4 concentrations and LBF was registered only during the second postpartum estrous cycle. Results indicate that during the first postpartum estrous cycle, P4 concentration was independent of luteal blood flow and luteal size.  相似文献   
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Bone marrow aspiration smears from 15 dogs naturally infected with leishmania were evaluated. Three of the dogs showed no clinical signs, six had up to three clinical signs and six had more than three. The most common pathological features of the bone marrow were megakaryocytic dysplasia in 10 of the dogs, erythrophagocytosis in eight, erythroid dysplasia in two and emperipolesis in two. The megakaryocytic and erythroid dysplasia were probably related to an increased number of marrow macrophages producing high levels of tumour necrosis factor alpha and interferon gamma. Six of the dogs with clinical signs showed bone marrow dysplastic features and erythrophagocytosis, suggesting that leishmaniosis could be the unique cause of both conditions.  相似文献   
34.
The viability of a fungal formulation using the nematode-trapping fungus Duddingtonia flagrans was assessed for the biological control of horse cyathostomin. Two groups (fungus-treated and control without fungus treatment), consisting of eight crossbred mares (3–18 years of age) were fed on Cynodon sp. pasture naturally infected with equine cyathostome larvae. Each animal of the treated group received oral doses of sodium alginate mycelial pellets (1 g/(10 kg live weight week)), during 6 months. Significant reduction (p < 0.01) in the number of eggs per gram of feces and coprocultures was found for animals of the fungus-treated group compared with the control group. There was difference (p < 0.01) of 78.5% reduction in herbage samples collected up to (0–20 cm) between the fungus-treated group and the control group, during the experimental period (May–October). Difference of 82.5% (p < 0.01) was found between the fungus-treated group and the control group in the sampling distance (20–40 cm) from fecal pats. During the last 3 months of the experimental period (August, September and October), fungus-treated mares had significant weight gain (p < 0.01) compared with the control group, an increment of 38 kg. The treatment with sodium alginate pellets containing the nematode-trapping fungus D. flagrans reduced cyathostomin in tropical southeastern Brazil and could be an effective tool for biological control of this parasitic nematode in horses.  相似文献   
35.
We compared total C, N and P, available forms of N and P and dehydrogenase, urease and acid phosphatase activities in soils from primary forests, 26‐year‐old pastures and 26‐year‐old secondary forests in the tropical dry forest region of Chamela, Jalisco, Mexico. We hypothesized that, because of their natural regeneration and greater plant diversity, secondary forest soils would have higher fertility and enzyme activities than pasture soils and would be more similar to primary forest soils. We predicted also that enzymes would be better indicators of land‐use effects on soil fertility than nutrients. Only one nutrient, available phosphorus, and one enzyme, acid phosphatase, were significantly and consistently affected by land use. As expected, these parameters were greater in primary and secondary forests than in pastures. Principal components analysis using all variables placed secondary forests intermediate between primary forests and pastures, as predicted, and total C, N and P, available P, ammonium, phosphatase, urease and the C:P ratio were the variables associated with this spatial arrangement of land uses. We conclude that secondary forest soils showed improved fertility and were overall closer to primary forests than to pastures in most variables measured.  相似文献   
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Abstract: An 8-year-old intact male mongrel dog with alopecia and weight loss was referred to the Veterinary Faculty of Naples. The dog had pale mucous membranes, enlarged prescapular lymph nodes, and splenomegaly. Laboratory abnormalities included anemia, thrombocytopenia, and hyperglobulinemia. Bone marrow aspirate smears contained numerous Leishmania amastigotes and an immunofluorescent antibody titer was strongly positive (1:1280) for leishmaniasis. The dog was treated with a combination of meglumine antimoniate and allopurinol for 60 days and showed clinical improvement. Two months after the end of treatment the dog was again referred because of relapse of leishmaniasis and the presence of a firm subcutaneous mass on the medial right thigh. Based on cytologic examination of fine needle aspirates of the mass, a diagnosis of large-cell lymphoma was made. Flow cytometry of tumor cells revealed γδ-T-cell lymphoma with a CD5+, CD3+, TCRγδ+, CD4−, CD8−, CD45RA+ immunophenotype. Using nested PCR, amastigotes were not detected in the neoplastic tissue. An association between leishmaniasis and hematopoietic tumors has been described rarely. γδ-T cells may be involved in the host response to this parasite, and prolonged antigenic stimulation and chronic immunosuppression (typical of leishmaniasis) play a crucial role in the etiopathogenesis of T-cell lymphoma.  相似文献   
38.
The dissipation rate of endosulfan isomers (α and β) in seawater and sediment was studied. The disappearance rate of both isomers from seawater and pure water was compared, and the same measurements were made in both sterile and unsterile marine sediment. Flasks of water and sediment, fortified with a dispersion of a commercial endosulfan 350 g litre−1 EC, Protodan 35®, were incubated under laboratory light at room temperature for 82 days. A micro on‐line extraction method and GC‐ECD was used to determine the pesticide and its metabolites. The dissipation of endosulfan (in two phases of first‐order kinetics) occurred more rapidly in seawater than in pure water. At the end of the experiment, the concentration of α‐endosulfan in sterile sediment was four times greater than in unsterile sediment, while the dissipation rate of β‐endosulfan in unsterile sediment was approximately double that observed in sterile sediment. The dissipation of both forms in sediment occurred in a single stage. Endosulfan β‐isomer was more persistent than α‐isomer in both sterile and unsterile sediment. Dissipation of endosulfan sum of α‐ and β‐isomers in sediment at the end of the experiment ranged from 80% (sterile) to 95% (unsterile). Endosulfan sulfate was detected in water and sediment as the main metabolite. © 2000 Society of Chemical Industry  相似文献   
39.
Effect of pesticide residues on the aromatic composition of red wines.   总被引:1,自引:0,他引:1  
The influence of pesticide residues on the aromatic composition (major and minor volatiles) of red wines made from Vitis vinifera (Monastrell var.) was studied by comparing the concentration of aromas in wines made from grapes subjected (or not) to phytosanitary treatment with chlorpyrifos, fenarimol, mancozeb, metalaxyl, penconazole, and vinclozolin, according to the agricultural practice of the area. The analytical determination of the major volatiles was made by gas chromatography using a flame ionization detector, while the minor volatiles were determined by adsorption-thermal desorption gas chromatography using a mass selective detector. There were significant differences between the ethyl acetate, methanol, isobutanol, and diethylacetal levels of the control wine and that containing chlorpyrifos residues, although only the ethyl acetate exceeded the olfactory threshold. With regard to the minor volatiles, significant differences were detected in the concentrations of some esters, aldehydes, and acids. However, only isoamyl acetate exceeded the olfactory threshold in wines containing residues of chlorpyrifos, fenarimol, and vinclozolin.  相似文献   
40.
This study was undertaken to evaluate the effect of dietary lipid source [linseed oil (LO, rich in 18:3 n?3); corn oil (CO, rich in 18:2 n?6); olive oil (OO, rich in 18:1n?9); and fish oil (FO, rich in LC‐PUFA)] and level (9% L and 18% L) on growth, body composition and selected plasma biochemistry parameters in hybrid catfish (Pseudoplatystoma reticulatum × Leiarius marmoratus) juveniles. Moreover, liver histology (lipids, glycogen, cell vacuolization) and key metabolic enzyme activities were also evaluated. After 8 weeks of feeding, there were no differences in growth performance and whole‐body composition between groups. Plasma lipoprotein, muscle and liver composition, and G6PD and ME activity were affected by lipid level and source. No differences were observed between groups in hepatic ALT activity; however, AST activity was lower in fish fed the 9% L diets. Overall, liver and muscle fatty acid composition reflected that of diet FA composition, with increased n3/n6 ratio, high HUFA and low MUFA in fish fed FO compared with the VO diets. Higher liver glycogen content was observed in fish fed the 18% L than the 9% L diets, except for fish fed FO diet. Considering the experimental diets used, these results indicate that hybrid catfish can efficiently utilize VO supplementation as an energy source, without affecting growth performance and fillet composition.  相似文献   
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