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21.
The immune responsiveness of cows with hepatic lipidosis (fatty liver) in comparison to control cows with a normal liver fat content was tested by applying skin allotransplants to the skin of the back of cows on day 3 after parturition. Immunoreactivity was determined by semiquantitative counting of the number of infiltrating lymphocytes in the recipient skin adjacent to the allotransplants during a period of 21 days. There were more invading lymphocytes in samples from control cows than there were in samples from cows with hepatic lipidosis. It was concluded that cows with hepatic lipidosis have a reduced lymphoid response to skin allotransplants.  相似文献   
22.
A five-and-a-half-month-old male weimaraner with severe recurrent bacterial infections was assessed for immunocompetence. Results revealed a low serum immunoglobulin G concentration and defective neutrophil phagocytosis.  相似文献   
23.
The bovine cervix contains a large amount of smooth muscle cells distributed over an outer muscular layer and within a stromal layer. The stromal layer exhibits no electromyographic (EMG) activity at parturition. This leads to the question whether the stromal smooth muscle cells of the bovine cervix are prepared to contract with parturition, or whether they have another function. To this end, cervical biopsies were repeatedly taken from 10 pregnant cows at day-185 and -275 of gestation, at spontaneous, uncomplicated calving and at 30 days after calving. The smooth muscle bundles of the stroma were immunohistochemically analysed (n = 5) with regard to their integrity and cellular density, and the degree of staining for connexin-43, smooth muscle actin α (SMA), desmin and vimentin. Additionally, the mRNA expression for connexin-43, SMA, desmin and vimentin was determined with RT-PCR (n = 5). The smooth muscle tissue was arranged in bundles, also at parturition. However, the cellular density of these bundles and the SMA mRNA expression were decreased at parturition. Additionally, the SMA staining and connexin-43 expression and staining remained constant during pregnancy and at parturition. This might indicate that stromal smooth muscle cells are not prepared to contract with parturition, in contrast to the myometrial smooth muscle cells. The smooth muscle cells, stained for SMA, also expressed vimentin, and the proportion of co-expression was increased at day-275 of pregnancy. This suggests that the stromal smooth muscle cells predominantly have a secretory function in cows.  相似文献   
24.
The final stages of cervical ripening and parturition resemble an inflammatory process. Although the role of cytokines in both spontaneous and experimentally induced parturitions has been described in several small laboratory animals and humans, the involvement of pro‐inflammatory and regulatory cytokines in physiologic parturition in cows has not been determined. In this study, the cytokine expression profiles were assessed in bovine cervical tissue at several stages of pregnancy and at parturition. Serial biopsy samples of the cervix were obtained from 10 cows on day 185 and day 275 of pregnancy (which was on average 5.4 days before parturition) and at parturition. Messenger RNA expression levels of interleukin (IL)‐1β, IL‐6, IL‐8, IL‐10 and tumour necrosis factor (TNF)α were determined using real‐time polymerase chain reaction and the number of neutrophils and eosinophils was estimated by Luna and Sirius Red staining. At parturition, IL‐8 expression had increased 430‐fold (p < 0.001) when compared with that of the day 185 of pregnancy, large numbers of neutrophils had invaded the cervix while eosinophils remained scarce, IL‐1β had increased eightfold (p < 0.05) and IL‐6 had not changed significantly. Additionally, IL‐10 was increased by 10‐fold (p < 0.001) and TNFα decreased by 57% (p < 0.05) when compared with that of the day 185 of pregnancy. The large increase in expression of IL‐8, enabling the influx of neutrophils, is indicative of its important role in the final stage of cervical ripening and at parturition. As previous studies have shown that neutrophils excrete matrix metalloproteinases (MMP), this might contribute to softening of the cervix. In contrast, the only slightly increased levels of IL‐1, steady concentrations of IL‐6 and decreased TNFα, the potential consequences of increased IL‐10 expression, indicate that final cervical of cows in ripening at term parturition is an inflammatory process influenced by regulatory cytokines.  相似文献   
25.
Strong anti glycolipid IgG responses can occur in humans and animals, but contrary to anti protein responses and anti glycoprotein responses, the exact mechanism of induction is unknown. We have previously shown that experimental immunization with the glycolipid glucose monomycolate (GMM) causes the development of specific T cell responses, but not of anti GMM antibodies. However, cattle naturally infected with Mycobacterium avium ssp. paratuberculosis produce high levels of anti GMM IgG. In the present study, we tested whether vaccination with GMM conjugated to a protein mimics natural infection in its capacity to induce the production of antibodies against GMM. Cattle were immunized (n=5 per group) with GMM conjugated to a protein, or GMM and protein non-conjugated and administered at contralateral locations, or carrier only. Although immunization with the GMM-protein conjugate vaccine and the non-conjugated vaccine induced protein specific antibody responses, GMM specific antibodies were not detected in either of the groups. In conclusion, the generation of isotype-switched anti lipid antibodies appears to require more than providing peptide epitopes for T helper cells to support glycolipid specific B cells in antibody production.  相似文献   
26.
Bovine paratuberculosis is a highly prevalent chronic infection of the small intestine in cattle, caused by Mycobacterium avium subspecies paratuberculosis. Current control strategies based on test-and-cull and biosecurity measures do not suffice in lowering the prevalence of paratuberculosis in an adequate manner. Therefore, control programmes are in need of an effective vaccine, but at the moment no vaccine is registered for use in cattle in the European Union. This review provides a brief overview of the microbiology, epidemiology and immunology of bovine paratuberculosis, and focuses on recent advances in the development of vaccines against paratuberculosis.  相似文献   
27.
28.
Neutrophil emigration from the pulmonary vasculature, is mediated by cellular adhesion molecules (CAM) expressed on the outer membranes of endothelial cells and neutrophils. Although beta(2)-integrin-dependent migration is a major mechanism of neutrophil migration, which was demonstrated by extensive invasion of neutrophils in pulmonary tissue of calves suffering from a genetic deficit in expression of beta(2)-integrins, termed bovine leukocyte adhesion deficiency (LAD), the role of alternative CAM is still unclear. We investigated whether an alternate CAM for beta(2)-integrin function, i.e. the alpha(4)-integrin, was expressed on peripheral blood neutrophils of calves. As we detected basal but significant expression, the effect of naturally acquired pulmonary infection on the expression of either integrin was determined, as an indication for its function in the migration process. In our experiments, basal expression of alpha(4)-integrins on peripheral blood neutrophils from clinically healthy calves was detected. On neutrophils of calves, experiencing field outbreaks of enzootic bronchopneumonia, higher expression of the alpha(4)-integrin was detected, which returned to normal after successful treatment of the disease. In addition, its level of expression was linearly related to plasma acute phase protein (haptoglobin) concentrations, which is a sensitive parameter for severity of respiratory inflammation. Increased expression of the alpha(4)-integrin on peripheral blood neutrophils during pulmonary inflammation indicates a role for this CAM in neutrophil migration in the lung.  相似文献   
29.
Lesional skin of cats with allergic dermatitis has a cellular infiltrate and a CD4/CD8 ratio comparable to that in humans with atopic dermatitis. CD4+ helper T cells and in particular cells belonging to the Th2 subset play an important role in disease pathogenesis in humans. We investigated the cytokine pattern of CD4+ T cells in situ, with special emphasis on the putative presence of cells producing interleukin 4 (IL4), in cats with allergic dermatitis. Immunohistochemical procedures were used to determine that CD4+ T cells in lesional and nonlesional skin of cats with allergic dermatitis can produce IL4, as occurs in humans. Lesional and nonlesional skin of cats with allergic dermatitis had significantly more IL4+ T cells (P = 0.001) than did skin of healthy control cats. Double staining indicated that all IL4+ cells were positive for pan-T or CD4 markers. Double labeling for mast cell chymase and IL4 stained primarily different cells. Western blotting demonstrated cross-reactivity between the antibody against human IL4 and a feline recombinant IL4. These results indicate that IL4 is primarily produced by CD4+ T cells and is also present in clinically uninvolved skin, indicating a role in the pathogenesis of allergic dermatitis in cats.  相似文献   
30.
The aim of this study was to investigate whether dietary n-6 polyunsaturated fatty acids (PUFA) alter immune functions as lymphocyte blastogenesis, expression of lymphocyte and monocyte markers, and cell adhesion molecules of the integrin family in goats. Dutch White castrated male goats received a diet either rich in olive oil (control group, n = 4) or rich in corn oil (test group, n = 4) over a period of 3 weeks. The animals in the test group had significantly higher linoleic acid (LA, 18:2n-6) levels in plasma on days 7, 14 and 21 of the diet than control animals. This was also true for washed erythrocyte membranes at day 21. A significant reduction in the percentage of alpha-4 integrin (CD49d) expressing lymphocytes was observed in goats fed LA rich corn oil at day 21. However, no changes were observed in either lymphocyte proliferative responses to ConA and PHA or the expression of other lymphocyte/monocyte markers. In conclusion, feeding corn oil rich in LA caused significant increases in the proportion of LA in the fatty acid composition of plasma and erythrocyte membranes and was accompanied by a significant decrease of the adhesion molecule alpha-4 integrin (CD49d) on lymphocytes but not on monocytes.  相似文献   
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