双歧杆菌的耐药性与质粒

目的：研究双歧杆菌的耐药性与质粒的关系。方法 对１７株５种来自微生态制剂的双歧杆菌进行抗生素药敏试验和质粒检测,利用溴化乙锭消除其质粒;比较质粒消除前后耐药性的改变。结果１７株双歧杆菌对氨基糖式类和多肽类抗生素呈强抗性;除１株短型双歧杆菌Ｂ１５７存有２．７Ｋｂ和５．６Ｋｂ两种质粒外,其余菌株均未质粒,消除后持粒的Ｂ１５７株菌对抗生素的敏感性并未改变。结论 此１７株双歧杆菌的耐药性与质粒无直接相关性     

革兰阴性杆菌同产超广谱β-内酰胺酶和AmpC酶的耐药性分析

目的了解革兰阴性杆菌同时表达超广谱β-内酰胺酶(ESBLs)和AmpC酶(AmpCs)情况及耐药性。方法采用ESBLs确认试验检测ESBLs,头孢西丁三维试验检测AmpCs,用KB法进行药敏试验。结果4098株革兰阴性杆菌中,检出同产ESBLs+AmpCs株739株,占18.0%;其中ESBLs+高产AmpCs508株,占12.4%,主要见于不动杆菌、大肠埃希菌和肺炎克雷伯菌,检出率分别为50.8%、44.1%和42.2%;ESBLs+诱导AmpCs231株,占5.6%,粘质沙雷菌、不动杆菌检出率分别为35.1%、27.7%;产ESBLs+高产AmpCs菌株对亚胺培南(IMP)、头孢哌酮-他唑巴坦(CSL)和头孢吡肟(FEP)的耐药率分别为3.54%、6.30%和51.8%,均显著低于其余抗生素的耐药率(均P<0.001);产ESBLs+诱导AmpCs菌株对亚胺培南、头孢哌酮-他唑巴坦和头孢吡肟的耐药率分别为1.30%、6.06%和38.5%,均显著低于其余抗生素的耐药率(均P<0.001)结论同时产生超广谱β-内酰胺酶和AmpCs菌株对多重药物耐药,IMP、CSL和FEP对其具有良好的抗菌活性。     

农杆菌质粒DNA提取方法的优化

目的：为了减化操作过程,减少药品对操作人员有直接或间接危害,提高农杆菌质粒DNA的产率和实验结果的稳定性。方法：对常规碱裂解法进行了改动,改进的方法通过加大菌液的收集量,利用LiCl沉淀RNA,简化操作流程和严格反映环境条件,并且在操作过程中去除了酚、氯仿等对人体有害的试剂。结果：提取时间缩短,结果稳定,产率在1．5μg／μL以下。结论：用这种方法提取的质粒可以满足大多数分子生物学常规实验如DNA的酶切、PCR鉴定的要求。     

广州地区淋球菌抗生素耐药性及质粒图谱研究

目的：了解广州地区淋球菌对抗生素的耐药性及质粒图谱。方法：用琼脂稀释法测定5种抗生素对167株菌的最低抑菌浓度（MIC）及用破裂解法分析160株菌的质粒图谱。结果：167株淋球菌检出PPN9株（5．4％）,TRNG16株（9．6％）,环丙沙星耐药率达78．4％,头孢三嗪,壮观霉素未发现耐药菌株。160株菌其质粒谱型2．6Md 4.5Md(24.4%),2.6Md 4.5Md 24.5Md(20.6%),2.6Md 24.5Md(20.6%),4.5Md检出率（45％）24.5Md检出率（41．3％）。结论：表明了广州地区淋球菌抗生素的耐药性和质粒图谱,有助于淋病的治疗和防治。     

超广谱β-内酰胺类抗生素的耐药性与耐药质粒介导

目的：观察超广谱β-内酰胺类抗生素的敏感性与耐药质粒的关系,探讨耐药质粒在细菌之间传递的方式。方法：(1)配制耐药质粒提取试剂;(2)对LB细菌培养液进行耐药质粒的提取与检测;(3)对从12株ESBL细菌中提取的质粒进行质粒转化、质粒接合传递及药敏试验。结果：(1)此12株ESBL细菌中提取的耐药质粒进行电泳显示此质粒较大,约20．0kb。(2)质粒转化后,其转化子对β-内酰胺类抗生素全部耐药,对氨基糖甙类、喹诺酮类和磺胺类全部敏感。质粒结合传递体的耐药谱与以上相同。结论：β-内酰胺类抗生素的敏感性与耐药质粒介导密切相关,耐药质粒能把耐药基因传递给其他细菌,在细菌之间相互传递。     

变形杆菌的耐药性及接合性R质粒的检测

本文报告了从烧伤病人感染创面分离、鉴定的35株变形杆菌的药敏试验及接合性R质粒的检测结果。35株变形杆菌双测试的6种抗菌药物都具有不同程度的耐药性。其中,对6种药物同时耐受的有26株(74.3％)。对其中的27株做了接合试验,接合性R质粒的检出率为70.4%。     

氧化硫硫杆菌质粒的分离

用碱法对分离到的7株氧化硫硫杆菌进行质粒检测,在6株中分离到了18个质粒,质粒DNA的分子量为1.3×10~4-98×10~6。     

70株淋球菌的质粒及对青霉素敏感性的检测

本文检测的70株淋球菌含三种质粒,质粒总检出率为95.7％(67株)。均含2.6Md者有67株,占94.29％,可能是隐蔽质粒。含3.2Md及23.1Md者20株均对青霉素耐药,故含此两种质粒的淋球菌有可能成为哈市耐青霉素的流行株。提取2.6Md质粒有希望制备诊断的探针。     

MMP-7基因真核表达载体的构建及其在HeLa细胞中的表达与鉴定

目的：构建MMP-7基因真核重组质粒,检测并鉴定MMP-7在人宫颈癌HeLa细胞中的表达。方法：提取宫颈癌组织总RNA,通过基因克隆构建MMP-7基因真核表达重组质粒pcDNA3.1（＋）/MMP-7,酶切、PCR及基因测序鉴定,用阳离子脂质体介导采用基因转染技术转染人宫颈癌Hela细胞,RT-PCR检测外源基因的表达、间接免疫荧光法检测对表达产物进行鉴定。结果：成功构建了重组表达质粒pcDNA3.1（＋）/MMP-7并转染了人宫颈癌Hela细胞,通过RT-PCR可以检测到MMP-7 mRNA在Hela细胞中的表达,经间接免疫荧光反应可检测到明显的阳性反应,而转染空载体组表达阴性。结论：构建的重组质粒pcDNA3.1（＋）/MMP-7能在Hela细胞中表达,为该蛋白在人子宫癌后续的功能研究奠定了基础。     

几类快生型根瘤菌质粒的研究

用一种重现性好而较简便的方法,对国内的紫云英、豌豆、三叶草、大豆等快生型根瘤菌及根癌农杆菌共40多号菌进行了质粒分离,所得质粒图谱具有一定的菌株特异性。每株菌有1—3个质粒,其中至少有一个大质粒或巨大质粒。用质粒消除法获得失去结瘤(或致癌)能力的变异株,均缺少一个大质粒。快生型根瘤菌的结瘤基因定位在大质粒或巨大质粒上。用接合法将Rpl：：Tn501等质粒转入根瘤菌中,能诱动根瘤菌的结瘤基因转移给失去结瘤能力的变异株,可表达功能,质粒图谱也发生变化,与供体或受体都不同。     

Is the Exact Test Better than the Asymptotic Test for Testing Marginal Homogeneity in 2 × 2 Tables?

McNemar test is commonly used to test for the marginal homogeneity in 2 × 2 contingency tables. McNemar test is an asymptotic test based either on standard normal distribution or on the chi‐square distribution. When the total sample size is small, an exact version of McNemar test is available based on the binomial probabilities. The example in the paper came from a clinical study to investigate the effect of epidermal growth factor for children who had microvillus inclusion diseases. There were only six observations available. The test results differ between the exact test and the asymptotic test. It is a common belief that with this small sample size the exact test be used. However, we claim that McNemar test performs better than the exact test even when the sample size is small. In order to investigate the performances of McNemar test and the exact test, we identify the parameters that affect the test results and then perform sensitivity analysis. In addition, through Monte Carlo simulation studies we compare the empirical sizes and powers of these tests as well as other asymptotic tests such as Wald test and the likelihood ratio test.     

Adjusting O'Brien's test to control type I error for the generalized nonparametric Behrens-Fisher problem

O'Brien (1984, Biometrics 40, 1079-1087) introduced a simple nonparametric test procedure for testing whether multiple outcomes in one treatment group have consistently larger values than outcomes in the other treatment group. We first explore the theoretical properties of O'Brien's test. We then extend it to the general nonparametric Behrens-Fisher hypothesis problem when no assumption is made regarding the shape of the distributions. We provide conditions when O'Brien's test controls its error probability asymptotically and when it fails. We also provide adjusted tests when the conditions do not hold. Throughout this article, we do not assume that all outcomes are continuous. Simulations are performed to compare the adjusted tests to O'Brien's test. The difference is also illustrated using data from a Parkinson's disease clinical trial.     

Testing for Poisson Zero Inflation in Disease Mapping

When analyzing mortality data due to rare diseases in small areas, it is common to find several health zones with no mortality cases. In these circumstances, the classical homogeneous model based on the Poisson distribution used to estimate the relative risks within each area may encounter lack of fit due to a disproportionately large frequency of zeros. To cope with these zeros, the zero inflated Poisson model can be used. In this paper, we propose a test for detecting zero inflation in the context of disease mapping which is based on bootstrap techniques. The test is illustrated using male mortality data due to brain cancer in Navarra, Spain. In addition, comparisons with other tests for Poisson zero inflation such as the score test and the likelihood ratio test are carried out in terms of empirical power and size using the brain cancer scenario. The proposed bootstrap test has good power and size and works well when detecting the excess of zeros in small area data sets. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

A Multivariate Goodness-of-Fit Test for Stochastically Ordered Distributions

There are a number of nonparametric procedures known for testing goodness-of-fit in the univariate case. Similar procedures can be derived for testing goodness-of-fit in the multivariate case through an application of the theory of statistically equivalent blocks (SEB). The SEB transforms the data into coverages which are distributed as spacings from a uniform distribution on [0,1], under the null hypothesis. In this paper, we present a multivariate nonparametric test of goodness-of-fit based on the SEB when the multivariate distributions under the null hypothesis and the alternative hypothesis are “weakly” ordered. Empirical results are given on the performance of the proposed test in an application to the problem of assessing the reliability of a p-component system.     

Development of a validation protocol to determine the ability of screw-top containers to be watertight and to withstand impact damage from accidental dropping

Polypropylene screw-top containers are used to collect, transport and store a variety of tissues within tissue banks. These containers are validated for use by tissue banks but no standard validation protocol is used. We present here a protocol for testing screw-top containers for leakage, evaporation and the ability to withstand accidental impact damage. Three different containers were tested, MedFor S072, MedFor S277 and MacoPharma PROT0483. The validation can detect differences between different manufacturer’s containers and this protocol will be used in future validations of screw-top containers within National Blood Service Tissue Services.     

羟基磷灰石生物安全性试验研究

为了评价羟基磷灰石的生物安全性,依据相关的医疗器械行业标准和GB/T16886系列标准,对该材料进行了迟发型超敏反应试验、热原试验、急性全身毒性试验、细胞毒性试验等一系列生物安全性试验,并对试验数据进行了分析评价,结果表明,羟基磷灰石具有良好的安全性。     

Simultaneous Randomization Tests

Randomization analyses have been developed for testing main effects and interactions in standard experimental designs. However, exact multiple comparisons procedures for these randomization analyses have received little attention. This article proposes a general procedure for constructing simultaneous randomization tests that have prescribed type I error rates. An application of the procedure does provide for multiple comparisons in the randomization analyses of designed experiments. This application is made to data collected in a biopharmaceutical experiment.