利用正交方法进行藻类细胞生长抑制试验制定塘入水标准的研究

藻类细胞生长抑制试验在单项毒物条件下进行时,常未考虑毒物对藻类细胞的联合作用（拮抗效应、叠加效应和协同效应）。本研究采用单项毒物试验和多种毒物同时存在时的正交试验（Ｌ１６＜４＾５＞）,评价了进入武汉市黑水湖中试稳定塘的主要污染物（硫化物、挥发酚、石油类）对羊角月牙藻的９６ｈ的毒性效应。效果表明,正交试验的ＥＣ５０值都比单项毒物试验低多,其９６ｈＥＣ５０降低２０－８０％,受试的几种主要污染物对藻类有     

CD自杀基因系统对胶质瘤细胞作用的实验研究

将含大肠杆菌胞嘧啶脱氨酶（ＥＣ－ＣＤ）基因的重组逆转录病毒感染大鼠神经胶质瘤细胞Ｃ６,获得稳定表达ＣＤ的克隆细胞Ｃ６／ＣＤ。ＣＤ可以将无毒性的原药５－氟胞嘧啶（５－ＦＣ）转化成高度细胞毒性物质５－氟尿嘧啶（５－ＦＵ）。生长抑制试验表明Ｃ６／ＣＤ细胞对５－ＦＣ高度敏感。ＩＣ５０为３μｍｏｌ／Ｌ,５－ＦＣ对Ｃ６细胞基本无毒性,ＩＣ５０近６０００μｍｏｌ／Ｌ;而Ｃ６／ＣＤ和Ｃ６细胞均低浓度５０ＦＵ敏感。     

稀有鮈鲫──一种新的鱼类毒性试验材料

本文研究了稀有鲫（Ｇｏｂｉｏｃｙｐｒｉｓｒａｒｕｓ）作为毒性试验材料的可行性。采用换水式试验,在硬度为２００ｍｇ／Ｌ（以ＣａＣＯ３计）、ｐＨ７．８±０．２、温度２４－２５℃条件下研究了铬、铜、锌和五氯酚（ＰＣＰ）对稀有鲫的急性毒性。重铬酸钾对２日龄稀有鲫的２４ｈ和９６ｈ和ＬＣ５０控制范围分别２６３．６－３３４．７和１１５３－１７８．５ｍｇ／Ｌ（ｎ＝８）。铬、铜、锌和五氯酚对２日龄稀有鲫的急性毒性值（９６ｈＬＣ５０）范围,从铜的５２．２μｇ／Ｌ到铬的５２０００μｇ／Ｌ,毒性大小的顺序是铜＞五氯酚＞锌＞铬。研究结果表明,稀有鲫有可能发展成为一种较为理想的毒性试验材料。     

五氯酚对大型溞的急性亚慢性和慢性毒性

本文采用换水式试验研究了五氨酚溞（ＰＣＰ）对大型（Ｄａｐｈｎｉａｍａｇｎａ）的急性、亚慢性和慢性毒性,稀释水硬度为８０─１００ｍｇ／Ｌ（以ＣａＣＯ３计）。急性和慢性试验均使用小于一日龄的幼溞,试验温度为２５─２６℃,慢性试验进行了２０ｄ。用小于一日龄幼溞进行的亚慢性试验暴露了１９ｄ,而用四日龄幼溞的亚慢性试验则进行了１６ｄ,水温均保持在１９─２０℃。ＰＣＰ对大型溞的２４ｈ和４８ｈＥＣ５０分别是４８９和２４５μｇ／Ｌ。依据第１胎所产幼溞数求得的最低可观察效应浓度（ＬＯＥＣ）和无可观察效应浓度（ＮＯＥＣ）,在慢性试验中分别是１６０和８０μｇ／Ｌ,在１９ｄ亚慢性试验中分别为２００和１００μｇ／Ｌ,二者相近。试验结果表明,第１胎所产幼溞数是敏感的指标。     

单宁酶的固定化及其在酯型儿茶素水解反应中的应用

采用自制的壳聚糖为载体对单宁酶（ＴＡ）固定化,ＴＡ与壳聚糖配比１：２．５,３０℃固定２ｈ,活力回收达２３．６％～３３．１％;偶联效率为８４．９％～８８．０％。固定化单宁酶（ＩＴＡ）的表观Ｋｍ值（以没食子酸丙酯为底物）为２２．２×１０－６ｍｏｌ／Ｌ,ＴＡ的Ｋｍ值（以没食子酸丙酯为底物）为１０×１０－６ｍｏｌ／Ｌ,ＴＡ和ＩＴＡ的最适反应温度分别为４０℃和５０℃;６０℃处理１５ｍｉｎ,残存活性分别为１３．６％和６０．３％。ＴＡ和ＩＴＡ的最适ｐＨ值分别为５．８和６．４;ＴＡ在ｐＨ４．８～７．８活力稳定,而ＩＴＡ活力稳定范围在ｐＨ４．８～６．８．ＩＴＡ作用于ＥＧＣＧ的半衰期为７８．７ｈ,ＥＧＣＧ水解率达９０．３％。对茶多酚提取物进行水解,其所含的酯型儿茶素ＥＧＣＧ和ＥＣＧ水解率分别为９６．４％和９６．８％,非酯型儿茶素ＥＧＣ和ＥＣ的含量显著增加。     

生态毒理试验中的连续流系统设计及控制

长期连续流试验中,毒物浓度波动主要归因于毒物稀释系统的故障。为了提高毒性数据质量,毒物浓度水平监控是必不可少的.本文对现有连续流试验系统中的毒物稀释器作了改进,采用计量泵输送毒物和稀释水,提高毒物稀释系统的精确度。同时,在连续流试验系统中配置了实时监控系统(RTMS).RTMS由泵、样品室、分析仪器、记录仪等组成.在56d试验中,RTMS随时提供毒物稀释器运行的最新情况,各级毒物浓度变异系数在2.16%-6.13%之间。系统的运行成功为规范中、长期毒性试验提供了技术保证.       

综合生物塘中的藻类研究Ⅱ

治理城镇污水的综合生物塘中试运转三年中,共发现藻类１０２种。绿藻种类最多（占５５％）。全塘年均藻类细胞密度为１８．４×１０′个／１,现存生物量为３２．７ｍｇ／ｌ（鲜重）,两者峰值均出现在四、五月。每年多数时间内以绿藻（主要是小球藻）为数量优势种类,生物量常以隐藻占优势。利用水生维管植物对出水进行生态修饰,能明显抑制藻类生长和改善出水水质。发现藻类在藻菌塘中的明显分层现象。     

加压素片段类似物对C6细胞生长的影响

本文采用显微镜观察和逐个细胞突起长度测量及ＭＴＴ等方法研究了添加肽对无血清培养的Ｃ８细胞生长的影响：在培养早期（９－３６ｈ）,１０＾－８ｍｏｌ／Ｌ的ＡＶＰ、ＮＬＰＲ或ＺＮＣ（Ｃ）ＰＲ等都能刺激生长;同浓度的ＯＸＴ或ＺＤＣ（Ｃ）ＰＲ在起始时（９－１７ｈ）无明显影响,但稍后（３６ｈ）显示抑制作用。ＭＴＴ染色法分析的结果指出：神经肽促生长作用主要表现在细胞生长前期（１７ｈ）并且是肽浓度依赖的,ＺＮＣ（Ｃ     

三甲基苯基磷酸酯对神经毒性酯酶的抑制及其酶促动力学分析

以可使人和敏感动物产生迟发性神经毒性的有机磷化合物三甲基苯基磷酸酯（ＴＯＣＰ）为测试药物,研究其在体外对成年产卵来航母鸡不同神经组织神经毒性酯酶（ＮＴＥ）活性抑制敏感性及其抑制的动力学,结果表明,外周神经ＮＴＥ对于ＴＯＣＰ的抑制比中枢神经ＮＴＥ敏感得多,ＴＯＣＰ对鸡脑、脊髓和坐骨神经中ＮＴＥ抑制的Ｉ５０值分别为：１．９３２３、２．３９５０和０．００３５ｍｍｏｌ／Ｌ、ＮＴＥ酶促动力学研究显示,鸡脑Ｎ     

人主动脉硫酸乙酰肝系蛋白聚糖对培养人的脐静脉内皮细胞生长…

为探讨硫酸乙酰肝素蛋白聚糖（ＨＳＰＧ）对内皮细胞生长的作用,用解聚提取及墩子交换柱层析法分离出人主动脉ＨＳＰＧ,用倒置显微镜,细胞计数,及＾３Ｈ－ＴｄＲ参入观察其对培养的第一代人脐静脉内皮细胞（ｈＵＶＥＣ）生长的影响,结果表明,（１）倒置显微镜下观察,加入ＨＳＰＧ（１．７０μｇ己糖醛酸／ｍｌ）的ｈＵＶＥＣ生长密度高于对照组（未加ＨＳＰＧ）（２）随着培养时间增加（２４,４８及７２ｈ）根据细胞计数计算     

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.     

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.     

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。