奶牛结核病诊断方法的比较研究

旨在比较目前实验室用于检测牛结核方法及PPD皮内变态反应检测牛结核的敏感性和特异性.对145头进行了PPD结核菌素实验的牛进行了IFN-γ体外释放试验,ELISA方法检测ESAT-6,CFP-10,MPB70,MPB83四个蛋白的抗体,胶体金检测两种相似蛋白MPB70和MPB83.结果表明,IFN-γ体外释放试验的敏感性和特异性最高,与PPD皮内变态反应有较高的符合性.在抗体检测方面,iELISA的敏感性高于胶体金方法.虽然抗体检测(iELISA和胶体金方法)比细胞介导的免疫方法(IFN-γ和PPD)敏感性要低,前者更适合于检测处于结核病程发展后期的样本,并且可以有效降低假阳性反应.     

肺外结核病微生物学诊断方法的研究和应用进展

肺外结核病指由结核分枝杆菌（Mycobacterium tuberculosis, MTB）感染所引起的发生在肺部以外器官和部位的结核病。近年来肺外结核的发病率逐渐升高,未能得到早期有效治疗的肺外结核病患者可能并发畸形、截瘫甚至死亡等严重后果。微生物学检测方法对从病原学角度诊断肺外结核病至关重要。基于此,总结了近年来肺外结核病细菌学检查方法、结核分枝杆菌的抗原检测与分子生物学检测等微生物学诊断方法的概况及应用进展,并对这些检测方法的优缺点及适用范围进行了分析、比较,以期为今后肺外结核病病原学诊断的研究提供相关信息。     

遗传参数不同估计方法的比较

利用模拟方法比较了5种方差组分估计方法(ANOVA,Henderson-Ⅲ,MLMT,R EMLMT和MIVQUE)对遗传参数的估计效果。结果表明:REMLMT法在各种情况下均能得到较好的参数估值,估计的准确度相对较高;ANOVA方法在小群体和不均衡资料情况下估计效果最差。同时,群体含量和结构能影响各种方法的估计效果, 群体含量较小或资料来源的公畜数太少,将导致遗传参数的估计误差增大,准确性降低。 Abstract:Five methods for estimating components of (Co) variance,including ANOVA,Henderson-III,MLMT,REMLMT and MIVQUE were compared using computer simulation.The results showed that REMLMT could obtain more accurate estimates for all data sets,while the estimates obtained by ANOVA always had greater deviations from the true values,especial for small and well-unbalanced data sets.Also,the effects of estimation were dependent on structure of population size,accuracy of estimates would be decreased when number of sires was too few or data contained small number of animals.     

Comparison of Several Methods for Preserving Bacteriophages

A wide variety of bacteriophages were processed and stored under different conditions to compare methods for long-term preservation. Specimens were stored for 2 years at room temperature (24 to 28 C) and at 4 C as broth lysates in 50% glycerol, dried, and freeze-dried. Titers determined after processing indicated that, of the broth, glycerol, and freeze-dry methods, freeze-drying was most damaging to the phages tested, glycerol less damaging, and the broth method least damaging. After 2 years, titers of broth lysates were generally higher than those of glycerol or freeze-dried preparations. Dried preparations generally did not prove satisfactory. Preparations stored at 4 C showed better titers than those kept at room temperature. All titers declined with time regardless of the conditions of preservation.     

Comparison of Methods for Enumerating Fluorescent Bacteria

Comparable numbers of fluorescent bacteria may be obtained by either the most-probable-number procedure or by preparing spread plates on modified Henrici agar.     

The Influence of Methods of Collection and Storage on the Bacteriology of Human Milk

Staphylococcus epidermidis and other organisms from the skin were found to be the commonest contaminants in 21 samples of human milk donated to a milk bank. Only 2 samples contained enterobacteria; no β-haemolytic streptococci were isolated. Data presented show the difference between bacterial numbers in the first 10 ml and subsequent secretions of milk when drawn sequentially. Refrigerated storage led to the growth of some organisms in the milk; no growth occurred in milk stored at −18°C. A miniaturized resazurin dye test was devised but preliminary observations showed that it had a limited value in detecting rapidly milk of poor bacteriological quality.     

Comparison of Methods for Coccidioidomycosis Complement Fixation

A Laboratory Branch Task Force of the National Communicable Disease Center has proposed a standardized complement fixation procedure (LBCF) and an adaptation of this to microtitration techniques (MT) as uniform methods for performing complement fixation (CF) tests. A common procedure should make CF results from one laboratory more comparable to another. In addition, it would be preferable if the common procedure reproduced the titer levels of a testing procedure which is to be replaced, particularly when valid clinical interpretations have been derived from the latter. Replicated sets of sera were tested by the LBCF, MT, and the standard Smith CF procedure for coccidioidomycosis. Results with all three procedures were highly reproducible within an acceptable one-tube variation of a twofold dilution series, but the frequency of one-tube variations was greater with the MT method than with the other two. There was no statistical difference in the titers obtained with the Smith and LBCF procedures, but there was a significant difference when the MT results were compared to those with the Smith method. The LBCF method should be acceptable as a standardized and uniform CF procedure for coccidioidomycosis, subject to comparative testing between different laboratories.