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A rapid biological assay based on incubation time has been developed for determination of the potency of Newcastle disease
virus strain I-2 vaccine. It is based on the observation that the interval between inoculation and the first detection of
haemagglutinin (HA) depends on the titre of the vaccine inoculated. Chicken embryonated eggs were inoculated with different
titres (109, 106 and 103 EID50/0.1 ml) of vaccine and incubated for 24 h. At hourly intervals, 5 eggs from each vaccine titre were tested for the presence
of HA. The results showed that the HA activity was detected from 5, 11 and 15 h after inoculation with vaccine doses of 109, 106 and 103 EID50, respectively. On the basis of these results it is suggested that if there is no HA detected from 5 to 11 h after inoculation
of eggs with the vaccine virus, the vaccine should not be used to vaccinate chickens as it might have an infectivity titre
of less than 106 EID50/0.1 ml, which is equivalent to the recommended single chicken dose. It is concluded that measuring the time between inoculation
of the vaccine virus and the onset of HA activity might provide an estimate of the titre of the vaccine within 24 h. 相似文献
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目前,我国猪瘟活疫苗效力检验最常用的方法是测定猪瘟疫苗中病毒的兔体感染量(RID),但是用该方法易受到检验兔品种、个体和饲养环境的影响。为了探索一种不依赖动物的疫苗效力检验新方法,本研究将待检猪瘟活疫苗系列稀释后分别接种易感细胞,使用抗原捕获ELISA、RT-nest PCR和RT-PCR三种方法检测不同稀释度疫苗中活病毒在感染细胞后增殖的子代病毒,计算疫苗病毒的最高细胞感染剂量,建立了猪瘟疫苗病毒的细胞感染量(CID)的效力检验方法。结果显示:疫苗中活病毒粒子越多,CID就越高;对不同类型猪瘟疫苗的检测结果表明,该方法适用于传代细胞源和细胞源猪瘟活疫苗的效力效检。使用CID和RID两种检测方法同时对12批猪睾丸传代细胞源(传代细胞源)和3批牛睾丸原代细胞源(细胞源)猪瘟活疫苗进行了比对效检,结果表明,用CID测定方法检验,12批猪瘟活疫苗(传代细胞源)每头份均含105CID,3批猪瘟活疫苗(细胞源)每头份含量均为104CID;用兔子感染体温测定法,12批猪瘟活疫苗(传代细胞源)每头份含量在2.6×104~3.0×104RID之间,3批猪瘟活疫苗(细胞源)每头份含7.0×103~8.0×103RID。试验证明:本实验室建立的CID检测结果与现有质量标准RID的结果存在良好的相关性,能够较好反映疫苗中活病毒的含量,有望成为RID的替代方法。 相似文献
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H. A. W. Hazewinkel I. Schoenmakers D. Pelling M. Snijdelaar J. Wolfswinkel J. A. Mol 《Domestic animal endocrinology》1999,17(4):1173-344
Calcitonin (CT) is a major calcitropic hormone. Because of low cross reactivity of canine CT (cCT) in radioimmunoassays (RIA) developed for other species, a homologous RIA is needed. Synthesis of cCT allowed study of its biologic potency using a rat bioassay and its plasma half-life in dogs. The availability of cCT also made possible the development of a homologous RIA for measurement of basal and stimulated plasma CT concentrations in dogs. The biologic potency of the synthesized cCT in rats is 24 IU/mg of peptide, which is low in comparison with the 4,000 IU/mg of the salmon CT standard. In the dog, an even lower potency of 4.4 IU/mg of cCT was found. Measurement of the disappearance of iv-injected radioiodinated or nonradioiodinated cCT revealed a short biologic half-life of less than 3 min, followed by a long half-life of 20 min. A polyclonal antiserum against synthetic cCT was raised in a goat. Using a final antiserum dilution of 1:12,000 and 125I-labeled synthetic cCT, the RIA had a detection limit of 6.5 ng/l. The antibody did not crossreact with standard human CT and had <0.1% cross reactivity with porcine CT. For measurement of plasma cCT concentrations, an extraction procedure was developed using ethanol. Dilutions of synthetic cCT and canine plasma extracts revealed parallelism over a wide range of concentrations. Size exclusion chromatography of canine plasma extracts on Biogel P-10 revealed a single cCT peak at the same position as [125I]-cCT, showing that there was little interference by other proteins or cCT prohormone. Basal plasma CT concentrations were 12-80 ng/l, and there was an 8- and 20-fold increase after calcium (1 and 2.5 mg/kg body weight) bolus infusion. 相似文献
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J Terré C Stellmann J P Soulebot A Brun Y Moreau P Precausta J Fontaine 《Comparative immunology, microbiology and infectious diseases》1979,1(3):197-203
Vaccination schedules and a challenge carried out in laboratory animals are necessary to test the Rabies vaccines for potency.Two main techniques, described by W.H.O., are compared:—The Habel test is a system involving a constant vaccine and a variable virus.—The N.I.H. test is the inverse system with a few major differences during the immunization phase.Although the Habel test is easier to implement, it is quite impossible to make a rigourous statistical interpretation of its results.Although it is more difficult to implement the N.I.H. test as it requires a reference vaccine and a titrated viral suspension, the statistical interpretation is simple.For a same vaccine, the variation amplitude is 1 to 250 for the Habel test and 1 to 7,6 for the N.I.H. test. The N.I.H. test is preferred to the Habel test 相似文献
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桑枝皮提取物对急性高血脂症小鼠血脂水平的影响 总被引：1，自引：0，他引：1
采用单次静脉注射400 mg/kg Triton WR-1339的方法,建立急性高血脂症小鼠模型,灌胃给予桑枝皮提取物(MBBE),18 h后测定小鼠血清中的甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)的浓度,并计算动脉粥样硬化指数(AI)和LDL-C/HDL-C的比值,研究MBBE的降血脂作用。试验结果表明,灌胃MBBE的急性高血脂症小鼠血清中的TG浓度水平得到显著抑制(P<0.05),其中高剂量组(600 mg/kg MBBE)小鼠血清中的TG浓度下降36.6%;灌胃MBBE后,小鼠血清中的TC、LDL-C浓度有所下降,而HDL-C浓度略有增加,其中高剂量组小鼠血清中的TC、LDL-C浓度分别下降8.3%、18.3%,HDL-C浓度升高9.3%;灌胃MBBE后,小鼠血清的AI值和LDL-C/HDL-C比值也明显下降,其中高剂量组分别下降45.6%和28.1%。结果显示,给急性高血脂模型小鼠灌胃给予桑枝皮提取物具有明显的降血脂作用以及降低动脉粥样硬化风险的作用,并且呈现剂量效应。 相似文献
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