阪崎肠杆菌能力验证样品均匀性和稳定性的研究

目的制备出以脱脂奶粉为基质的均匀性好、稳定性强的阪崎肠杆菌(Enterobacter sakazakii)能力验证样品。方法研究奶粉基质的粒度、奶粉和菌粉的混合比例,得到阪崎肠杆菌能力验证样品的最佳均匀性条件;研究包装形式及贮存温度对样品稳定性的影响,得到阪崎肠杆菌能力验证样品的最佳稳定性条件。结果要保证样品足够均匀,奶粉最佳粒径范围为120μmD180μm,1 g菌粉最多与300 g奶粉进行混合;贮存温度对样品稳定性有较大影响,高温明显降低样品稳定性;真空包装可以显著提高样品稳定性。结论以奶粉为基质的阪崎肠杆菌能力验证样品的制备能够更准确地考查乳品微生物检验人员的检测水平,为国内微生物能力验证水平的提高奠定了基础。     

实验小鼠肾匀浆中酯酶-3的实验室测定能力验证结果评价

目的通过实验小鼠肾匀浆中酯酶-3项目的检测比对,了解全国实验动物质量检测实验室的水平,促进各实验室加强质控。方法按照CNAS批准的能力验证方案,制备样品并将稳定性和均匀性合格的样品作为能力验证样品,进行随机编号,随作业指导书一起发放给参加单位。在规定时限提交检验报告和原始记录复印件,其结果与样品预检结果完全一致的判为优秀结果;除杂合型判定以外的结果均一致的判定为满意结果,否则判为不满意结果。结果共10个实验室报名参加本次比对试验,其中优秀结果 0个实验室;满意结果的有9个实验室,占参加比对实验室的90.0%;不满意结果 1个实验室,占参加比对实验室的10.0%。结论本次能力验证项目反映了各参与实验室在实验小鼠肾匀浆中酯酶-3的总体检测能力较高,但检测细节及部分实验室技术水平还有待提高。     

实验动物金黄色葡萄球菌的实验室检测能力验证结果评价

目的通过实施实验动物金黄色葡萄球菌检出能力验证计划,了解实验动物检测机构检验能力,提高实验动物质量检测水平。方法按照CNAS批准的能力验证方案,通过低温冻干制备样品,经过稳定性和均匀性检验合格,作为能力验证样品。采用随机编号,发样给参加单位,并附作业指导书。在规定时限提交检验报告和原始记录复印件,其结果与样品预检结果一致的判为满意结果,不一致或未能提交结果的判为不满意结果。结果共有28个实验室参加本次能力验证项目,其中获得满意验证结果的实验室为22个,占总参加机构的78.57%;未得到满意验证结果的实验室为6个,占21.43%。采用国标检测方法的有27个,采用PCR检测方法的有1个。结论实验动物质量检测机构对金黄色葡萄球菌的检测能力较高,实施能力验证计划能够反映实验室的检测水平。     

实验动物中沙门菌的实验室检测能力验证的结果与分析

目的通过实验动物中沙门菌检测能力验证计划,了解实验动物检测机构对沙门菌的检验能力,提高实验动物质量检测水平。方法按照CNAS批准的能力验证方案,通过冷冻干燥法制备含有沙门菌及干扰菌的实验动物粪便样品,经过稳定性和均匀性检验合格,作为能力验证样品。采用随机编号,经冷链运输发放给参加单位,并附作业指导书。在规定时限提交检验报告和原始记录复印件,其结果与样品预检结果一致的判为满意结果,不一致或未能提交结果的判为不满意结果。结果全国共有20个省市的30个实验室参加沙门菌能力验证项目,其中28个实验室获满意结果,占总参加机构的93.3%,不满意的2个实验室,占6.7%。采用分离培养方法的有29个实验室,采用PCR方法的有2个实验室。结论实验动物质量检测机构沙门菌检测能力较高,实施能力验证计划能够反映实验室的检测水平。     

实验小鼠肾匀浆中苹果酸酶-1和异柠檬酸脱氢酶-1实验室检测能力验证结果评价

目的通过实验小鼠肾匀浆中苹果酸酶-1和异柠檬酸脱氢酶-1检测能力验证计划,了解实验动物检测机构检验能力,提高实验动物质量检测水平。方法按照CNAS批准的能力验证方案,通过样品制备,经过稳定性和均匀性检验合格,作为能力验证样品。采用随机编号,发样给参加单位,并附作业指导书。在规定时限提交检验报告和原始记录复印件,其结果与样品预检结果一致的判为满意结果,不一致或未能提交结果的判为不满意结果。结果共有10个实验室参加本次能力验证项目,其中满意结果的实验室8个,占总参加机构的80%,不满意的实验室有2个,占20%。结论实验动物质量检测机构在实验小鼠肾匀浆中苹果酸酶-1和异柠檬酸脱氢酶-1的检测能力较高,实施能力验证计划能够反映实验室的检测水平。     

兔出血症病毒抗体的实验室检测能力验证结果评价

目的通过兔出血症病毒抗体检测能力验证计划,了解实验动物检测机构检验能力,提高实验动物质量检测水平。方法按照CNAS批准的能力验证方案,通过筛选血清制备样品,经过稳定性和均匀性检验合格,作为能力验证样品。采用随机编号,发样给参加单位,并附作业指导书。在规定时限提交检验报告和原始记录复印件,其结果与样品预检结果一致的判为满意结果,不一致或未能提交结果的判为不满意结果。结果来自14个省市自治区的20个实验室报名参加本次比对实验,均在规定时间内反馈了检测结果,17个实验室检测结果为合格或优秀,占参加比对实验室的85%。在20个实验室中,14个实验室采用了酶联免疫吸附实验(ELISA)方法,6个实验室采用血凝抑制实验(HAI)方法。结论全国各实验动物检测机构兔出血症病毒抗体总体检测能力较高,实施能力验证计划能够反映实验室的检测水平。     

枳实中辛弗林分离纯化及其标准样品定值与不确定度研究

为了提高枳实药材、柑橘类水果中辛弗林分析测定的准确度和质量评价的一致性等,本研究开展了辛弗林标准样品的研究。利用现代分离纯化手段,从枳实中分离得到辛弗林高纯度单体化合物,分别采用质量平衡法和定量核磁法两种不同原理定值方法对辛弗林标准样品进行纯度定值。利用高效液相色谱,通过F检验和t检验对辛弗林标准样品的均匀性进行考察,利用模拟长途运输条件,对辛弗林的短期稳定性和长期稳定性进行考察,并对辛弗林标准样品的定值、均匀性和稳定性研制过程中的不确定度进行评定。结果表明,辛弗林标准样品的定值结果为99.62%,均匀性良好,在6个月内稳定性较好,扩展不确定度为0.8%(k=2),量值准确、均匀性和稳定性符合标准样品的技术要求。     

婴幼儿配方奶粉菌落总数检验中不确定度的评定

分析样品中菌落总数不确定度的来源,采用合并样品标准差的方法来评定菌落总数的不确定。研究表明：实验中的扩展不确定度为0．046％,采用此法适合于菌落总数检验结果的评定。且该法简便,适合于每一个样本的检验结果,随着检验结果的不断增加,可随时加入到合并样本中,重新计算合并样本标准差,更新不确定度的取值范围。     

妇科凝胶类微生物限度检测方法的验证

目的:建立妇科凝胶的微生物限度检查方法。方法:按2010?年版《中国药典(二部)》相关要求进行试验,以枯草芽孢杆菌、金黄色葡萄球菌、大肠埃希氏菌、白色念珠菌、黑曲霉为试验菌,铜绿假单胞菌和金黄色葡萄球菌为控制菌对样品进行微生物限度检查的方法学验证。结果:细菌、霉菌和酵母菌计数方法验证试验中,试验菌的回收率均大于70%;控制菌检查结果符合《药典》相关要求。结论:该方法准确可靠,适用于妇科凝胶类微生物限度的检测。     

实验小鼠呼肠孤病毒Ⅲ型抗体的实验室检测能力验证结果评价

目的通过实验小鼠呼肠孤病毒Ⅲ型抗体检测能力验证计划,了解实验动物检测机构检验能力,提高实验动物质量检测水平。方法按照CNAS批准的能力验证方案,血清经过标定后,经过稳定性和均匀性检验合格,作为能力验证样品。采用随机编号,发样给参加单位,并附作业指导书。在规定时限提交检验报告和原始记录复印件,其结果与样品预检结果一致的判为满意结果,不一致或未能提交结果的判为不满意结果。结果共有17个省市的27个实验动物检测机构报名参加本次能力验证项目。27个检测机构均提交了满意结果,占总参加机构的100%。采用酶联免疫吸附实验(ELISA)方法的有26个检测机构,采用免疫荧光实验(IFA)方法的有1个检测机构。结论实验动物质量检测机构实验小鼠呼肠孤病毒Ⅲ型抗体检测能力较高,实施能力验证计划能够反映实验室的检测水平。     

Evaluation of PetrifilmTM methods for enumeration of aerobic flora and coliforms in a wide range of foods

C. DE W. BLACKBURN, C.L. BAYLIS AND S.B. PETITT. 1996. Petrifilm^TM is a ready-to-use alternative to traditional microbial enumeration methods. The Petrifilm^TM Aerobic Count Plate (ACP) and Coliform Count Plate (CCP) were compared with standard methods for the enumeration of the aerobic mesophilic flora and coliform bacteria in 91 foods covering a wide range of different food commodities. There was good correlation between the Petrifilm^TM ACP and the standard aerobic colony count method ( r = 0.989) and between the Petrifilm^TM CCP and the standard Violet Red Bile Agar plating method ( r = 0.872). In both cases, the Petrifilm^TM methods had a better repeatability than the standard methods. The Petrifilm^TM ACP and CCP were shown to be practical and accurate alternatives to standard enumeration methods in a wide range of foods, with benefits of saving time, labour and incubator space.     

Estimating variance components and predicting breeding values for eventing disciplines and grades in sport horses

Eventing competitions in Great Britain (GB) comprise three disciplines, each split into four grades, yielding 12 discipline-grade traits. As there is a demand for tools to estimate (co)variance matrices with a large number of traits, the aim of this work was to investigate different methods to produce large (co)variance matrices using GB eventing data. Data from 1999 to 2008 were used and penalty points were converted to normal scores. A sire model was utilised to estimate fixed effects of gender, age and class, and random effects of sire, horse and rider. Three methods were used to estimate (co)variance matrices. Method 1 used a method based on Gibbs sampling and data augmentation and imputation. Methods 2a and 2b combined sub-matrices from bivariate analyses; one took samples from a multivariate Normal distribution defined by the covariance matrix from each bivariate analysis, then analysed these data in a 12-trait multivariate analysis; the other replaced negative eigenvalues in the matrix with positive values to obtain a positive definite (co)variance matrix. A formal comparison of models could not be conducted; however, estimates from all methods, particularly Methods 2a/2b, were in reasonable agreement. The computational requirements of Method 1 were much less compared with Methods 2a or 2b. Method 2a heritability estimates were as follows: for dressage 7.2% to 9.0%, for show jumping 8.9% to 16.2% and for cross-country 1.3% to 1.4%. Method 1 heritability estimates were higher for the advanced grades, particularly for dressage (17.1%) and show jumping (22.6%). Irrespective of the model, genetic correlations between grades, for dressage and show jumping, were positive, high and significant, ranging from 0.59 to 0.99 for Method 2a and 0.78 to 0.95 for Method 1. For cross-country, using Method 2a, genetic correlations were only significant between novice and pre-novice (0.75); however, using Method 1 estimates were all significant and low to moderate (0.36 to 0.70). Between-discipline correlations were all low and of mixed sign. All methods produced positive definite 12 × 12 (co)variance matrices, suitable for the prediction of breeding values. Method 1 benefits from much reduced computational requirements, and by performing a true multivariate analysis.     

COMPARISON OF THE MILLIPORE DIGITAL TOTAL COUNT SYSTEM AND STANDARD MEMBRANE FILTRATION PROCEDURE TO ENUMERATE MICROORGANISMS IN WATER SAMPLES FROM COSMETIC/PHARMACEUTICAL ENVIRONMENTS

A study was performed to compare the Millipore Digital Total Count System with a standard membrane filtration procedure in enumerating the number of microorganisms present in several types of water samples (e.g., Hot/Cold Deionized, Tap, and RO/Ultra Filtration). Water samples were collected over a 4 month period. Statistical data analysis demonstrated an overall correlation of greater than 82% between the two test methodologies. The linearity of the microbial counts between both test methods was compared by artificially contaminating sterile water samples with Pseudomonas aeruginosa. The linearity of the microbial counts between both methods was found to be greater than 96%. The Millipore Digital Total Count System was found to be comparable to the standard membrane filtration method in determining the number of microorganisms in a water sample. In conclusion, the Millipore Digital Total Count System was able to provide a 24 h enumeration of microorganisms present in a water sample. This rapid enumeration allows for a faster quality evaluation of water samples from an industrial water system that is used in the manufacture of cosmetic/pharmaceutical products.     

An Evaluation of a Technical Holding Time for the Preparation and Analysis of Hexavalent Chromium in Soils/Sediments

Chromium (Cr) is routinely measured during environmental investigations involving soils and other solid matrix sampling. Regulatory-approved analytical methods are available to extract and quantify total Cr in various environmental media. However, due to significant toxicity differences between trivalent [Cr(III)] and hexavalent [Cr(VI)] valences, it is compelling that the two can be quantitatively distinguished. SW-846 Method 3060A is an effective extraction technique for soluble and insoluble Cr(VI). Several regulatory-approved methods exist for quantitating the Cr(VI) in extracts or aqueous samples. Although a 6-month holding time for total Cr is not encumbering, investigators are challenged by the typical 24-h holding time (sample collection through analysis) for Cr(VI) in aqueous samples and the 24- to 96-h holding time range for solid matrix samples typically set by regulators. This research report addresses quantitating Cr(VI) in solid matrices. Using SW-846 Methods 3060A/7196A, a scientifically defensible basis has been established for designating a 30-day holding time for Cr(VI) extraction from solid matrices and a 7-day holding time for Cr(VI) analysis once solubilized in the alkaline digestate. The study results indicate that a 30-day holding time, from sample collection to preparation, and a 7-day holding time, from digestion to analysis, are appropriate for Cr(VI) analysis.     

Aerobic capacities and anthropometric characteristics of elite female soccer players

Ingebrigtsen, J, Dillern, T, and Shalfawi, SAI. Aerobic capacities and anthropometric characteristics of elite female soccer players. J Strength Cond Res 25(12): 3352-3357, 2011-This study investigated aerobic capacities and anthropometric characteristics within a group of 29 elite female soccer players. The purpose was to identify and establish aerobic capacities and anthropometric characteristics for these players and to look for possible positional differences between keepers, defenders, midfielders, and attackers. We did this by measuring standard anthropometrical variables and maximal oxygen (VO(2)max) and anaerobic threshold (AT). One-way analysis of variance revealed no significant differences among anthropometric or physiological variables. However, a trend (p = 0.062) toward positional differences was found within running speed at AT. A subsequent Tukey post hoc test showed differences (p = 0.04) between keepers and defenders, with the latter running faster (～1.7 km·h) at AT. The present results suggest that few anthropometric and physiological differences exist between playing positions in elite female soccer players. Furthermore, the current results indicate that present elite players' physiological characteristics are similar to those previously shown, despite the rapid changes of the female soccer game. Based on well-established knowledge that different playing positions within a soccer team ought to have distinct capacities, we recommend regular testing programs to be able to construct and implement tailored training programs for players' physical capacities with respect to the demands of their playing positions.     

MORPHOLOGY OF SOME MAIZE-TRIPSACUM HYBRIDS

Diploid (2n = 20) and tetraploid (2n = 40) Zea mays L. were crossed with diploid (2n = 36) and tetraploid (2n = 72) Tripsacum dactyloides (L.) L. to produce a series of hybrids combining different numbers of haploid genomes from each parent. Eight hybrid groups and three parental groups were studied morphologically. Twenty-nine quantitative characters were recorded for each sample. Data were analyzed by univariate analysis of variance, multivariate analysis of variance, and discriminant function analysis, in an attempt to evaluate hybrid differences objectively and determine which morphological characters contribute statistically to group separation. The overall MANOVA F test was significant, establishing the presence of real differences between the hybrids; discriminant function analysis indicated that the percent of paired pistillate spikelets/cupule in the lateral inflorescence was the main variable which differentiated hybrids. Duncan's Multiple Range Tests for significant differences between means were applied to five variables contributing maximally to group discrimination, using the appropriate univariate ANOVAs. Pronounced maize-like attributes of backcross hybrids, as compared with corresponding F₁'s possessing similar genome constitutions, gave possible evidence of gene transfer between Zea mays and Tripsacum during backcrossing to maize.     

Population genetics of the HRAS1 minisatellite locus.

Several years ago it was reported that rare HRAS1 VNTR alleles occurred more frequently in U.S. Caucasian cancer patients than in unaffected controls. Such an association, in theory, could be caused by undetected population heterogeneity. Also, in a study clearly relevant to this issue, it was recently reported that significant deviations from Hardy-Weinberg equilibrium exist at this locus in a sample of U.S. Caucasians. These considerations motivate our population genetic analysis of the HRAS1 locus. From published studies of the HRAS1 VNTR locus, which classified alleles into types, we found only small differences in the allele frequency distributions of samples from various European nations, although there were larger differences among ethnic groups (African American, Caucasian, and Oriental). In an analysis of variation of rare-allele frequencies among samples from four European nations, most of the variance was attributable to molecular methodology, and very samples from four European nations, most of the variance was attributable to molecular methodology, and very little of the variance was accounted for by nationality. In addition, we showed that mixture of European subpopulations should result in only minor deviations from expected genotype proportions in a Caucasian database and demonstrated that there was no significant deviation from Hardy-Weinberg equilibrium in our HRAS1 data.     

Heritability and Selection on Body Size in a Natural Population of Drosophila Buzzatii

An attempt was made to assess whether the phenotypic differences in body size (as measured by wing length) between wild-caught mating and single Drosophila buzzatii males could be attributed to genetic differences between the samples. Mating males were found to be larger and less variable than a random sample of the population. The progeny of the mating males (produced by crossing to a random female from a stock derived from the same population) were on average larger than those of the single males, but not significantly so (P = 0.063), and less phenotypically variable. This difference in variance between the samples suggests that there are indeed genetic differences between the paternal samples but tests for significant differences in the additive genetic component of variance proved inconclusive. For both samples it was found that while the ratio of additive genetic variation in the laboratory to phenotypic variation in the field yielded estimates of h(s(N))(2) 10% the regression of offspring reared in the laboratory on parents from the wild was not significantly different from zero. In addition, it was found that the average development time of the progeny of the mating males is shorter than that of the random sample.