T细胞亚群CD4测定方法的研究

为比较外周血T淋巴细胞亚群CD4不同测定方法的差别,以流式细胞术为定量手段,测定了猴外周血中三种不同方法处理后CD4的表达.结果表明：先标后溶法——先用异硫氰荧光素标记的单克隆抗体（FITC-CD4 McAb）标记后,再加入红细胞溶解液溶掉红细胞的处理方法,结果基本等同于传统的淋巴细胞分离法,但样本用量仅为传统方法的1/5,且操作简单.激光共焦显微术的形态学研究也证实：先标后溶法与淋巴细胞分离法相似,其细胞膜表面荧光标记清晰,优于先溶后标法.     

华东地区根结线虫寄生真菌调查*

通过对5种分离根结线虫寄生真菌的方法的比较,发现通过雌成虫平板分离法和卵平板分离法有较高的成功率,其他三种自幼虫上或土壤中分离的方法很少取得成功。从华东地区104个根结线虫样品中分离得到根结线虫寄生真菌638个菌株, 鉴定为14个属22个种,其中Cylindrocarpon destructans, C.heteronema, Fusarium equiseti, F.lateritium, F.proliferatum, Gliocladium virens, Humicola fuscoatra, Idriella lunata, Trichoderma hamatum, T.harzianum, Verticillium catenulatum, Volutella ciliata 为首次报道在根结线虫上寄生。通过种群分析发现Fusarium solani出现频率最高, F. oxysporum, Paceilomyces lilacinus 和 Acremonium strictum为常见种,这些种在根结线虫上广泛分布。同时还发现卵和成虫寄生真菌有所不同,Gliocladium virens 和Trichoderma harzianum仅在卵上分离到,而Volutella ciliata, Trichoderma hamatum 和Idriella lunata仅在雌成虫分离到,从幼虫上仅分离一次Paecilomyces lilacinus。其它真菌在卵和成虫上均可分离得到,真菌种类在三种根结线虫上和在不同地区有所不同。     

PACS辅助教学在医学影像学实习教学中的应用探讨

尝试应用影像存储及传输系统(Picture Archiving and Communication System,PACS),对我院临床本科生进行影像学实习教学。首先应用PACS建立电子影像学图片库,学生在PACS联网的计算机上学习教学内容,通过定期随堂测验、期末考试和课后问卷调查评估PACS辅助教学的教学效果,对PACS辅助教学在医学影像学实习教学中的应用价值进行探讨。与以往传统医学影像学实习教学方法相比,PACS辅助教学在医学影像学实习教学中具有激发学生学习主动性、提高学习效率和学生读片能力的优越性,显著提高教学效果和教学质量,对促进医学影像学教学改革具有重要意义。     

Comparison of 2 methods of determining the kinetics of a bicompartmental system. Application to the measurement of cutaneous blood flow

Peeling method and a non linear regressions method (Newton's method) have been tested on experimental and simulated data. Newton's method is the most accurate and precise when running on simulated data. Experimental curves artefacts make Newton's algorithm automatically running less efficient than classical peeling algorithm working in interactive mode.     

Highly sensitive histamine-sensitization test for residual activity of pertussis toxin in acellular pertussis vaccine

Histamine-sensitization test method based on histamine-sensitizing death is widely used for controlling residual activity of pertussis toxin in acellular pertussis vaccines. The test method evaluates the residual activity according to the death of mice injected with a test vaccine after histamine challenge and the test result, therefore, depends on the sensitivity of mice. A highly sensitive test method based on change in rectal temperature of mice has been used in Japan for many years but has limited feasibility in other countries. We examined the possibility of a test method using dermal temperature measured by infrared thermometer to reduce animal suffering instead of rectal temperature. The dermal temperature method was shown to be as sensitive as the rectal temperature method. Furthermore, the dermal as well as rectal temperature methods can evaluate the activity of a test vaccine in relative to a reference preparation so as to allow direct comparison of the test results among different laboratories. The activity by means of the dermal temperature method was also found to be well consistent with that by the rectal temperature method.     

Diagnostic value of Gram stain for assessment of vaginal smears during pregnancy

The main aim of this study was to compare the diagnostic value of Giemsa stained method with Gram stained method for the evaluation of vaginal smears among pregnant women. A study population comprised 111 pregnant between 6 and 30 weeks of gestation. The vaginal smears from every subject was diagnosed according to Giemsa and Gram stained method and micro-organisms were isolated by culture. In 29.3% cases diagnosed as normal flora (2a) on the basis of Giemsa method bacterial vaginosis was detected in Gram stains according to Spiegel's criteria and pathological microflora in concentration > or = 10(5) CFU/ml was cultured among 75.9% of them. Among 31.7% women who had grade 3a (abnormal) in Giemsa stains method normal flora was diagnosed on the basis on Gram's method and from 17.1% pregnant women from this group we did not isolated any pathogens. For evaluation of vaginal smears during pregnancy the Giemsa method should be replaced by Gram stained method.     

椰汁体外抑菌效应的研究

目的研究椰汁对常见致病菌的体外抑菌效应。方法采用纸片扩散法（K－B法）、试管稀释法（MIC法）、吸光度值测定法和生长曲线法来观察椰汁对常见致病菌的体外抑菌效应。结果椰汁对4种常见致病菌的生长均表现出抑制效应,尤其对伤寒沙门菌的抑制作用最强。结论椰汁对常见致病菌表现出一定的抑菌效应。     

QTL mapping in outbred half-sib families using Bayesian model selection

In this article, we propose a model selection method, the Bayesian composite model space approach, to map quantitative trait loci (QTL) in a half-sib population for continuous and binary traits. In our method, the identity-by-descent-based variance component model is used. To demonstrate the performance of this model, the method was applied to map QTL underlying production traits on BTA6 in a Chinese half-sib dairy cattle population. A total of four QTLs were detected, whereas only one QTL was identified using the traditional least square (LS) method. We also conducted two simulation experiments to validate the efficiency of our method. The results suggest that the proposed method based on a multiple-QTL model is efficient in mapping multiple QTL for an outbred half-sib population and is more powerful than the LS method based on a single-QTL model.     

Maximum likelihood estimation of reviewers' acumen in central review setting: categorical data

Successfully evaluating pathologists' acumen could be very useful in improving the concordance of their calls on histopathologic variables. We are proposing a new method to estimate the reviewers' acumen based on their histopathologic calls. The previously proposed method includes redundant parameters that are not identifiable and results are incorrect. The new method is more parsimonious and through extensive simulation studies, we show that the new method relies less on the initial values and converges to the true parameters. The result of the anesthetist data set by the new method is more convincing.     

基于热消散探针法的植物水分运输的研究进展

液流是分析树木耗水特性、研究树木水分传输机制的重要途径之一,热消散探针法已广泛用于树干液流变化的监测。热消散探针法是目前研究不同时空尺度上植物蒸腾耗水特性较为灵活、可靠、经济的一种方法。但由于物种特性的差异,可能造成试验过程中出现测量值与实际值相比偏低的状况。此外,相当一部分植物依赖树干储存水进行蒸腾,因此木材含水量的波动很可能会导致蒸腾作用测定的误差。对热消散探针法的工作原理、优势和局限以及使用时需要注意的问题进行了综述,并回顾了基于热消散探针法开展的植物水分运输研究以及针对该方法进行的校正与改进方面的相关成果。     

棉蚜饲养技术——笼罩法

在长期的试虫饲养过程中 ,摸索出一种新的棉蚜饲养方法———笼罩法。利用A4幅面的透明胶片和纱网制成笼罩。并于室内催芽 ,培育棉花种苗 ,可利用自制笼罩于光照培养箱内隔离饲养棉蚜 ,经与琼脂叶片法和自制Blackmanbox方法比较 ,笼罩法具有省时省力、不受季节限制、棉蚜生长条件好以及取食活体植株等许多突出的优点。     

应用于贝类生理生态学研究的生物沉积法

绝大多数软体动物门瓣鳃纲Ｌａｍｅｌｌｉｂｒａｎｃｈｉａ(又名双壳纲Ｂｉｖｉｌｖｉａ)动物 ,如贻贝 (Ｍｙｔｉｌｉｄａｅ)、扇贝 (Ｐｅｃｔｉｎｉｄａｅ)、牡蛎 (Ｏｓｔｒｅｉｄａｅ)等 ,属于滤食性动物 ,这些动物通过纤毛摆动、鳃和唇瓣过滤水体中的悬浮颗粒物 (包括浮游藻类、浮游细菌、中型动物和有机碎屑等 ) ,代表着一种摄食机制。双壳贝类在自然界水域的栖息范围比较广泛 ,包括河流、淡水湖、咸水湖、河口湾以及各种浅海和深海环境 ,但以沿岸海水环境为最重要的栖息地 ,其种类多 ,数量大[3] 。近些年来 ,海水双壳贝类养殖在世界范…     

基于HNP模型及相对熵的蛋白质设计方法在不同蛋白质体系中的应用

详细考察了基于HNP(H:hydtophobic,N:neutral,P:hydrophilic)模型及相对熵的蛋白质设计方法对于不同结构类型蛋白质的适用性,并与基于HP模型的结果进行了比较.通过对190个4种不同结构类型的蛋白质进行预测,结果表明,基于HNP模型及相对熵的设计方法对于不同结构类型的蛋白质具有普适性.进一步的研究发现,对于α螺旋、β折叠等规则的二级结构,该方法的预测成功率高于无规卷曲结构预测成功率.另外,还比较了对不同氨基酸的预测差异,结果显示亲水残基的预测成功率较高.此外,研究表明该方法对于蛋白质保守残基的预测成功率高于非保守残基.在以上分析的基础上,进一步讨论了导致这些差异的原因.这些研究为基于相对熵的蛋白质设计方法的实际应用和进一步的发展打下了良好基础.     

Scanning microfluorometric measurement of immunofluorescently labelled microtubules in cultured cells. Dependence of microtubule content on cell density

A method for evaluation of microtubule content in cultured cells has been developed. The method is based on scanning microfluorometric measurement of immunofluorescently labelled microtubules. The method has been applied to the comparison of microtubule content in epithelial XTH-2 cells grown in culture at various cell densities. The results have shown that the microtubule content in the cells is not dependent on their proliferative state rather than it depends on cellular contacts.     

Blood-sucking bugs as a gentle method for blood-collection in water budget studies using doubly labelled water

During doubly-labelled water (DLW) experiments, blood collection by venous puncture may traumatize animals and consequently affect the animals' behaviour and energy budget. Recent studies have shown that blood-sucking bugs (Triatominae; Heteroptera) can be used instead of conventional needles to obtain blood from animals. In this paper, we validate the bug method in captive nectar-feeding bats, Glossophaga soricina, for water budget analysis by comparing the daily water flux estimated with the DLW method with values measured by an energy balance method. As the mean daily water flux of the DLW method was not significantly deviating from the expected value, blood-sucking bugs may substitute more invasive methods of blood collection in DLW experiments. Based on the DLW estimates, daily energy and water intake rates were calculated and compared to values measured with the energy balance method. The DLW method and the energy balance method yielded on average similar results regarding the daily energy intake (DLW method: 48.8+/-14.2 kJ d(-1) versus energy balance method: 48.1+/-9.9 kJ d(-1)) and daily water intake (DLW method: 13.7+/-2.4 mL d(-1) versus energy balance method: 14.7+/-3.0 mL d(-1)). Based on the calculated water and sugar intake per day, we estimated the sugar concentration of ingested nectar to equal on average 16.2+/-2.4% (mass/mass), which fell close to the measured sugar concentration of 17% (mass/mass) bats fed on during the experiment. We conclude that it is possible to extrapolate mean daily energy and water intake for animal groups, populations and species based on DLW estimates, but due to the large variance of results (low accuracy), it seems inadequate to calculate values for single individuals.     

Mapping mutations on phylogenies

Mapping of mutations on a phylogeny has been a commonly used analytical tool in phylogenetics and molecular evolution. However, the common approaches for mapping mutations based on parsimony have lacked a solid statistical foundation. Here, I present a Bayesian method for mapping mutations on a phylogeny. I illustrate some of the common problems associated with using parsimony and suggest instead that inferences in molecular evolution can be made on the basis of the posterior distribution of the mappings of mutations. A method for simulating a mapping from the posterior distribution of mappings is also presented, and the utility of the method is illustrated on two previously published data sets. Applications include a method for testing for variation in the substitution rate along the sequence and a method for testing whether the d(N)/d(S) ratio varies among lineages in the phylogeny.     

Chromatographic separation of ribonucleic acids from bacterial and animal cells on MAB columns]

Practicable and efficient method of the chromatographic separation of ribonucleic acids from animal and bacterial cells on columns with MAB-methylated albumin adsorbed on bentonite basis is developed. Distinct separation of transport and ribosomal RNAs was obtained on MAB columns. Ribosomal RNA from bacterial cells was, in its turn, separated in two fractions. Effect of pH, elution rate and temperature on the efficiency of the fractionation is studied. The method proposed is shown to have a number of advantages as compared with well-known method of RNA fractionation on MAK columns. The essence of the method described is irreversible inactivation of RNAse by AMB, which is confirmed in the series of special experiments.     

A hierarchical method for molecular docking using cloud computing

Discovering small molecules that interact with protein targets will be a key part of future drug discovery efforts. Molecular docking of drug-like molecules is likely to be valuable in this field; however, the great number of such molecules makes the potential size of this task enormous. In this paper, a method to screen small molecular databases using cloud computing is proposed. This method is called the hierarchical method for molecular docking and can be completed in a relatively short period of time. In this method, the optimization of molecular docking is divided into two subproblems based on the different effects on the protein–ligand interaction energy. An adaptive genetic algorithm is developed to solve the optimization problem and a new docking program (FlexGAsDock) based on the hierarchical docking method has been developed. The implementation of docking on a cloud computing platform is then discussed. The docking results show that this method can be conveniently used for the efficient molecular design of drugs.     

The relative efficiency of the Hardy-Weinberg equilibrium-likelihood and the conditional on parental genotype-likelihood methods for candidate-gene association studies.

Selecting a control group that is perfectly matched for ethnic ancestry with a group of affected individuals is a major problem in studying the association of a candidate gene with a disease. This problem can be avoided by a design that uses parental data in place of nonrelated controls. Schaid and Sommer presented two new methods for the statistical analysis using this approach: (1) a likelihood method (Hardy-Weinberg equilibrium [HWE] method), which rests on the assumption that HWE holds, and (2) a conditional likelihood method (conditional on parental genotype [CPG] method) appropriate when HWE is absent. Schaid and Sommer claimed that the CPG method can be more efficient than the HWE method, even when equilibrium holds. It can be shown, however that in the equilibrium situation the HWE method is always more efficient than the CPG method. For a dominant disease, the differences are slim. But for a recessive disease, the CPG method requires a much larger sample size to achieve a prescribed power than the HWE method. Additionally, we show how the relative risks for the various candidate-gene genotypes can be estimated without relying on iterative methods. For the CPG method, we represent an asymptotic power approximation that is sufficiently precise for planning the sample size of an association study.