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B Skopets J Li W W Thatcher R M Roberts P J Hansen 《Veterinary immunology and immunopathology》1992,34(1-2):81-96
Bovine trophoblast protein-1 (bTP-1) is a Type I interferon secreted by the bovine trophoblast from about Day 15 of pregnancy. It is not known whether bTP-1 has functional properties in common with other interferons. The aim of the present study was to determine whether bTP-1 inhibits proliferation of lymphocytes induced by mitogens, mixed lymphocyte cultures (MLC) and interleukin-2 (IL-2) and, if so, whether this activity is similar to that of a related interferon, bovine interferon-alpha I1 (bIFN-alpha I1). Stimulation of lymphocyte proliferation caused by phytohemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) was inhibited by bTP-1 and bIFN-alpha I1 without any reduction in cell viability. Maximum or near-maximum inhibition (less than 50%) was achieved at concentrations of 0.5-5.0 nM of bTP-1 and bIFN-alpha I1. Cells stimulated with PWM were less inhibited than cells stimulated with PHA and Con A. Both bTP-1 and bIFN-alpha I1 inhibited MLC to a greater degree than lectin-stimulated cells (maximum inhibition was 78% or greater). Also, bTP-1 and bIFN-alpha I1 slightly inhibited incorporation of [3H]thymidine ([3H]TdR) induced by the combination of phorbol ester, 12-O-tetradecanoylphorbol 13-acetate (TPA), and calcium ionophore A23187. Finally, bTP-1 and bIFN-alpha I1 had bimodal effects on incorporation of [3H]TdR by IL-2-induced lymphocytes. Incorporation of [3H]TdR was increased at 0.005 nM and 0.05 nM concentrations while higher concentrations caused a slight decrease in [3H]TdR incorporation. Results confirm that bTP-1 inhibits lymphocyte proliferation in a manner similar to that caused by the leukocyte-derived interferon, bIFN-alpha I1. Incomplete inhibition of mitogen-induced proliferation and differences in degree of inhibition between various stimulators suggest that bTP-1 and bIFN-alpha I1 preferentially inhibit certain lymphocyte subpopulations. Local inhibition of lymphocyte proliferation caused by bTP-1 may help protect the allogeneic conceptus from immune responses to fetal antigens or regulate the release of cytokines from endometrial lymphocytes. 相似文献
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Chiaradia E Gaiti A Scaringi L Cornacchione P Marconi P Avellini L 《Veterinary research》2002,33(6):661-668
To better define the species-specific antioxidant systems and to ascertain the influence of the intracellular redox status on the immune system of different animal species, we determined lymphocyte glutathione peroxidase (GSHPx) activity, plasmatic glutathione levels (GSH) and the effect of H2O2 on the responsiveness of lymphocytes to proliferative stimuli. Among the three species considered, sheep presented the lowest plasmatic GSH and the highest lymphocyte GSHPx activity. On the contrary, dogs showed an inverted pattern (high GSH - low GSHPx). Horses displayed intermediate values for both parameters analysed. The effect of H2O2 on the proliferative capacity of lymphocytes was the same for all three species; the 200 microM dose in particular was strongly inhibiting. Each species, however, showed different rates of inhibition: sheep exhibited the highest sensitivity to the antiproliferative effect of H2O2. Our results confirmed that high H2O2 concentrations (200 microM) are noxious for the cellular functions of all animals; however this effect is mediated by a rigorously species-specific relationship between the intracellular reactive oxygen species (ROS) and the molecular systems involved in cell proliferation. 相似文献
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分离妊娠山羊子宫内膜淋巴细胞(Endometrial lymphocyte,EML)后,分别加入4、8、12、16 mg/L的亚硒酸钠进行体外培养,探讨硒对EML的活化作用及其对分泌细胞因子IL-2I、L-4、TGFβ1及TGFβ2的影响。结果显示,8~16 mg/L的亚硒酸钠可显著地促进山羊EML的体外活化(P<0.01),并呈剂量依赖性。EML活化后,对IL-2的分泌呈微弱的促进作用;对IL-4、TGFβ1、TGFβ2的分泌有显著的促进作用。 相似文献
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E R Collins 《Veterinary Clinics of North America: Food Animal Practice》1990,6(3):635-654
Good ventilation is an important part of any livestock housing system. It may be accomplished by either natural or mechanical means. Generally, except for buildings that must be kept at warm, nonfluctuating temperatures, naturally ventilated cold housing is satisfactory for sheep and goats provided it is dry and draft-free in pen and resting areas, and air exchange is taking place at a rate high enough to remove moisture, gases, and airborne disease organisms from the building. Understanding the importance of site location, building orientation, and principles of ventilation design increases the likelihood of successful barn ventilation. 相似文献
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Enhancement of Leptospira hardjo agglutination titers in sheep and goat serum by heat inactivation. 总被引:1,自引:0,他引:1 下载免费PDF全文
K Malkin 《Canadian journal of veterinary research》1984,48(2):208-210
Heat inactivation of sheep serum samples resulted in the detection of an additional 9% reactors to Leptospira hardjo that were negative on the initial test of fresh samples. Treatment with EDTA gave results generally similar to heat inactivation suggesting that complement was responsible for the inhibition of agglutination. Tests on heat inactivated serum from experimentally infected sheep and goats revealed enhanced titers or reactions which were not detected in fresh serum. 相似文献
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The faecal egg count reduction test (FECRT) was conducted on 39 sheep farms and 9 goat farms located in Peninsular Malaysia. The anthelmintic groups used in these tests were the benzimidazoles, levamisole, the benzimidazole/levamisole combination, macrocyclic lactones and closantel. Results indicated that the prevalence of resistance to the benzimidazole group was high, with approximately 50% of the sheep farms and 75% of the goat farms having resistant nematode parasite populations present. Resistance to levamisole, closantel and ivermectin was also detected. Differentiation of the infective larvae derived from faecal cultures indicated that by far the most predominant parasite species was Haemonchus contortus. 相似文献
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H Murata 《The British veterinary journal》1989,145(3):257-262
The effect of sera from 4-h road-transported calves on mitogen-induced blastogenesis of bovine lymphocytes was investigated. Sera collected just after transportation showed a significant suppression (P less than 0.05) on blastogenesis. The immunosuppressive activity was reduced from those sera when they were treated with dextran-coated charcoal. Fractionation of the sera by ultrafiltration revealed that the activity was mainly concentrated in the fractions of molecular weights less than 50 kD. 相似文献
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D C Hirsh B B Baker N Wiger S G Yaskulski B I Osburn 《American journal of veterinary research》1975,36(11):1591-1595
Serum from dogs with generalized demodicosis suppressed the in vitro reactivity of peripheral lymphocytes to phytohemagglutinin. Suppression occurred with peripheral lymphocytes from normal dogs or from dogs with generalized demodicosis. Serums from dogs in remission were no longer suppressive. The data indicate that peripheral lymphoid cells obtained from dogs with generalized demodicosis do not respond differently in vitro to phytohemagglutinin than do lymphoid cells from normal dogs when either is cultured in the presence of serum from normal dogs. 相似文献
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A study was undertaken on the capacity of platelet-activating factor (PAF) to induce eosinophil accumulation in the mammary glands of non-lactating sheep. Platelet-activating factor induced dose-dependent accumulation of eosinophils in mammary exudates 24 h after infusion. Infection, by intraruminal injection of 20,000 infective Trichostrongylus colubriformis larvae, did not modify the responsiveness of outbred sheep to intramammary infusion of PAF. Mature ewes from high and low responder lines of a flock of sheep, selected on the basis of their responses to vaccination and experimental challenge with T. colubriformis as lambs, did not differ in the magnitude of the eosinophil responses to doses of PAF from 5 x 10(-13) to 5 x 10(-7) mol per gland. Intramammary infusion of an extract from third stage larvae of Haemonchus contortus elicited inflammatory exudates containing five- to ten-fold more eosinophils than that elicited by the highest dose of PAF tested. The experiments indicate that the eosinophil chemotactic agonist PAF can induce tissue eosinophilia in sheep and thus may play a role in directing the accumulation of eosinophils in tissues during disease states such as gastrointestinal parasitism. 相似文献