Quantitative Determination of Bovine Plasma Fibrinogen by Rocket Immunoelectrophoresis and by Refractometry after Heat-Precipitation

A standard syneresis method for measuring plasma fibrinogen concentrations in cattle was compared with a rocket Immunoelectrophoresis method and with a simple refractometer method; the correlations between the results obtained by the standard method and by the other 2 methods were high (r = 0.94 and 0.89 respectively, p < 0.001). The immunoelectrophoretic method is efficient and simple to perform. In contrast with the standard syneresis method, the other methods allow for the fibrinogen degradation products produced by fibrinolysis in vitro; they can therefore tolerate longer sample storage before analysis. The refractometer method is exceptionally simple and rapid and can be recommended for use under field conditions.     

一测多评法测定番石榴叶中6种黄酮类成分的含量

为建立同时测定番石榴叶中6种黄酮类成分(金丝桃苷、异槲皮苷、瑞诺苷、番石榴苷、萹蓄苷、槲皮素)的一测多评法。本研究以金丝桃苷为内参物,采用HPLC法,确定金丝桃苷与另外5种成分的相对校正因子,并通过获得的校正因子计算后5种成分的量;同时采用外标法测定11批番石榴叶的含量。结果表明11批番石榴叶的QAMS法与外标法测定结果间无显著性差异,证明该法可用于番石榴叶6种黄酮类成分的定量分析。     

一种利用Profile-1生物发光仪快速测定土壤中微生物量的改良方法

开发了一种利用Profile-1生物发光仪测定土壤中微生物量的改良方法,并以此方法分别测定了标准大肠杆菌茵液以及3种不同类型的土壤(九段沙湿地土壤,崇明东滩大田土壤和崇明实验地改良土壤)的微生物量,并将结果与Profile-1生物发光仪自带的标准分析方法以及传统的菌落计数法进行比较。结果显示,改良的ATP提取方法(BAB改良分析法)和Profile-1生物发光仪自带的标准分析方法都可用于液体样品中微生物量的测定,其灵敏度和准确度无显著差异(P0.05)。但在测定土壤样品时,菌落计数法测定结果大约占BAB改良分析法测定结果的1%～5%,占Profile-1生物发光仪自带的标准分析方法的测定结果的22%～99%。这表明在分析土壤样品时,BAB改良分析法较Profile-1生物发光仪自带的标准分析方法的ATP提取效率更高,可显著提高仪器检测土壤样品的灵敏度和可靠性,因此可有效应用于各类土壤的微生物量的监测,为土壤环境监控提供微生物量的可靠数据。     

Lowry protein determination on membrane preparations: need for standardization by amino acid analysis

The protein content of three membrane protein preparations has been determined by the Lowry method with bovine serum albumin as a standard and also by quantitative amino acid analysis as an absolute method. The results differ considerably, the Lowry method giving 29–42% higher values. This implies that many published data for such proteins, based on Lowry protein determinations with bovine serum albumin as the generally applied standard, are in error. Suggestions are made on how to standardize the Lowry method so that reliable values can be obtained for membrane protein.     

Digital image processing for rapid analysis of differentially expressed transcripts on high-density cDNA arrays.

Usage of filter arrays is becoming increasingly attractive for many research laboratories involved in determination of gene-expression profiles. However, analysis of numerous spots, representing genes or partial gene sequences (ESTs), is still tedious work involving the ordered analysis of vast amounts of numerical tabular data. We present a rapid and efficient method for the visual identification of differentially expressed targets on high-density cDNA filter arrays using standard laboratory equipment and standard software, which is available for free. The method we introduce provides an inexpensive alternative, and no changes in the experimental set up are required. Our results were verified by densitometric analyses performed with an established system.     

Determination of rhodanese activity using a pH-STAT apparatus.

A new method for the assay of the rhodanese activity is described. The method uses a pH-STAT apparatus to monitor the rates of enzyme catalyzed reaction under controlled conditions. A standard kinetic analysis of the bovine kidney enzyme, including pH and temperature dependence, gave results which are in agreement with those obtained by the classic spectrophotometric method.     

一测多评法测定不同产地黄柏炭中4种生物碱含量

为建立同时测定不同产地黄柏炭中4种生物碱成分(黄柏碱、木兰花碱、小檗红碱、小檗碱)的一测多评法。实验以小檗碱为内参物,基于HPLC法建立小檗碱与其它成分的相对校正因子,并用校正因子计算4种成分的含量;用外标法和一测多评法同时测定30批黄柏炭样品的含量。结果表明30批黄柏炭样品的外标法与一测多评法结果之间无明显差异,说明了一测多评法的准确性和可行性。因此在缺乏对照品的情况下,以小檗碱为内参物同时测定黄柏碱、木兰花碱、小檗红碱的含量是可行的。该方法准确性和重复性良好,可用于黄柏炭的质量控制。     

复合季铵盐消毒剂含量的测定与滴定误差分析

研究复合季铵盐消毒剂含量的测定与滴定误差分析。探讨了四苯硼钠标准液配制及对滴定分析终点颜色的影响,并与单季铵盐定量分析方法进行了对比。结果表明:四苯硼钠两相滴定法适合于复合季铵盐定量分析,但要注意四苯硼钠标准液配制的正确性及滴定终点颜色的判断。     

A study of the suitability of gas chromatography-electron capture detection for the analysis of deoxynivalenol in cereals

A gas chromatographic-electron capture detection (GC-ECD) method for the analysis of deoxynivalenol (DON) in cereals was investigated. The sample was extracted with a mixture of acetonitrile-water and purified with a MycoSep #225 column. The silylation was performed with Tri-Sil-TBT reagent, followed by dilution with hexane and a washing step with buffer. By using Tri-Sil-TBT reagent no double peaks were observed for DON in the gas chromatograms, in comparison with two other silylation reagents TMSI and Tri-Sil-Z. The use of trichothecolone (TRI) as an internal standard for DON was studied in order to indicate possible problems in the derivatisation reaction. TRI proved to be a relatively good internal standard for DON in cereal samples, as well as 1,1-bis-(4-chlorophenyl)-2,2-dichloroethylene (DDE), which was used as a GC standard for ensuring the function of GC-ECD. During the study, a matrix effect was clearly observed between the cereal matrix-assisted calibration curve and the calibration curve prepared without cereal matrix. The results of spiked and reference material samples, quantified with the calibration curve prepared without and with matrix, demonstrated that the matrix affects the results. However, after recovery correction the results were comparable. The validation results demonstrated that the GC-ECD method for DON analysis in cereals is sufficiently reliable.     

Comparison of Membrane Filtration and Multiple-Tube Fermentation by the Colilert and Enterolert Methods for Detection of Waterborne Coliform Bacteria, Escherichia coli, and Enterococci Used in Drinking and Bathing Water Quality Monitoring in Southern Sweden

A total of 338 water samples, 261 drinking water samples and 77 bathing water samples, obtained for routine testing were analyzed in duplicate by Swedish standard methods using multiple-tube fermentation or membrane filtration and by the Colilert and/or Enterolert methods. Water samples came from a wide variety of sources in southern Sweden (Skåne). The Colilert method was found to be more sensitive than Swedish standard methods for detecting coliform bacteria and of equal sensitivity for detecting Escherichia coli when all drinking water samples were grouped together. Based on these results, Swedac, the Swedish laboratory accreditation body, approved for the first time in Sweden use of the Colilert method at this laboratory for the analysis of all water sources not falling under public water regulations (A-krav). The coliform detection study of bathing water yielded anomalous results due to confirmation difficulties. E. coli detection in bathing water was similar by both the Colilert and Swedish standard methods as was fecal streptococcus and enterococcus detection by both the Enterolert and Swedish standard methods.     

海洋真菌产油脂中DHA含量的准确快速测定

选用DB-23毛细管色谱柱,设置合适的载气压力,采用气相色谱(GC)分析了海洋真菌中脂肪酸的组成,并对二十二碳六烯酸(DHA)进行了定量分析。测定结果表明:能有效分离37种脂肪酸,分析时间仅需20min,DHA的回收率为96.95%～100.22%,相对标准偏差为1.33%,海洋真菌中DHA的含量为365.78mg/g,相对标准偏差为2.54%。     

Determination of free and total 7-hydroxycoumarin in urine and serum by capillary electrophoresis

A new method for the rapid determination of 7-hydroxycoumarin, the predominant metabolite of coumarin in humans, was developed for analysis in urine and serum, based on separation by capillary electrophoresis, with UV detection at 210 nm. The linear detection range for 7-hydroxycoumarin was 0–50 μg/ml while the limit of quantitation was 1 μg/ml. An internal standard, 3-(α-acetonylbenzyl)-4-hydroxycoumarin, was utilised for the determination of free 7-hydroxycoumarin, but it was found not to be suitable in the analysis of total 7-hydroxycoumarin present. Urine from two volunteers, who had been administered coumarin, was analysed by both capillary electrophoresis and by HPLC. The results from the two methods were compared and contrasted. The CE method was found to decrease the analysis time in comparison to HPLC analysis, with results available after 1.5 min as compared to 12 min with HPLC. There was no statistical difference between the results determined by either method.     

Using half-normal probability plot and regression analysis to differentiate complex traits: differentiating disease response of multigenic resistance and susceptibility in tomatoes to multiple pathogen isolates

The need for a new analytical approach was encountered in the course of characterizing newly developed tomato lines resistant to late blight. Late blight resistant tomato lines were created in independent breeding programs using the accession Solanum pimpinellifolium L. (formerly Lycopersicon pimpinellifolium (L.) Miller) L3708 as the source of the resistance. However, initial field observation suggested that the late blight resistance in the lines produced by two independent breeding programs differed. Possible causes included a partial transfer of the late blight resistance derived from S. pimpinellifolium L3708 or the possibility of race specificity of this resistance. A crucial issue was determining the most appropriate and robust analytical method to use with data from laboratory analyses of the responses of nine tomato lines against five P. infestans isolates. Prior analysis by standard ANOVA revealed significant differences across tomato lines but could not determine whether the disease responses in the CLN-R lines were different from those of the heterozygous F₁ hybrids, created by crossing susceptible tomatoes with the fixed CU-R lines. A different analytical method was needed. Therefore, sporangia numbers/leaflet and diseased area data were analyzed using a half-normal probability plot and regression analysis. The results of this analysis show its utility for genetic or pathology studies. Considering only populations of the uniform tomato lines, this method confirms the results obtained by using a standard ANOVA, but provides a clearer demonstration of the distributions of the individuals within the populations and how this distribution impacts variance and the difference among the populations. This method also allows a joint analysis of the uniform lines with an additional population that is less uniform, because it is segregating. Such an analysis would be invalid using a standard ANOVA. The results of this joint analysis determined that the additional population was divergent from the fixed CU-R lines, and, against some isolates, against the CLN-R lines as well. Half-normal probability plot analysis method would be applicable more broadly beyond analysis of disease resistance data. It could be useful for data from populations that are not normally distributed, for traits which are affected by epistatic gene action, and could be useful for selection of extremes.     

Kinematic analysis of over-determinate biomechanical systems

In this paper, we introduce a new general method for kinematic analysis of rigid multi body systems subject to holonomic constraints. The method extends the standard analysis of kinematically determinate rigid multi body systems to the over-determinate case. This is accomplished by introducing a constrained optimisation problem with the objective function given as a function of the set of system equations that are allowed to be violated while the remaining equations define the feasible set. We show that exact velocity and acceleration analysis can also be performed by solving linear sets of equations, originating from differentiation of the Karush-Kuhn-Tucker optimality conditions. The method is applied to the analysis of an 18 degrees-of-freedom gait model where the kinematical drivers are prescribed with data from a motion capture experiment. The results show that significant differences are obtained between applying standard kinematic analysis or minimising the least-square errors on the two fully equivalent 3D gait models with only the way the experimental data is processed being different.     

Differential gas-liquid chromatography method for determination of uronic acids in carbohydrate mixtures

An integrated gas-liquid chromatography method is described for the quantitation of mixtures containing simple monosaccharides in addition to mannuronic, glucuronic, and/or galacturonic acids. A hydrolyzed sample is divided into two portions. One portion is analyzed by the standard aldononitrile method. Glucuronic, galacturonic, and mannuronic acids are converted into compounds that do not chromatograph in the region of the standard aldononitrile acetates. Thus, this analysis gives an accurate estimation of the neutral monosaccharide content. The second portion is analyzed by a modified alditol acetate procedure. The reduction step is repeated three times to convert mannuronic, galacturonic, and glucuronic acids to their corresponding alditols via their intermediate lactones. The results of this gas-liquid chromatography analysis reflect the sum of the monosaccharides present plus their corresponding uronic acids. The difference between the values obtained by the aldononitrile acetate method and the modified alditol acetate method, therefore, is a measure of the uronic acid(s) present.     

Comparison of methods for the calculation of energy storage and return in a dynamic elastic response prosthesis

The standard method used to calculate the ankle joint power contains deficiencies when applied to dynamic elastic response prosthetic feet. The standard model, using rotational power and inverse dynamics, assumes a fixed joint center and cannot account for energy storage, dissipation, and return. This study compared the standard method with new analysis models. First, assumptions of inverse dynamics were avoided by directly measuring ankle forces and moments. Second, the ankle center of rotation was corrected by including translational power terms. Analysis with below-knee amputees revealed that the conventional method overestimates ankle forces and moments as well as prosthesis energy storage and return. Results for efficiency of energy return were varied. Large differences between models indicate the standard method may have serious inadequacies in the analysis of certain prosthetic feet. This research is the first application of the new models to prosthetic feet, and suggests the need for additional research in gait analysis with energy-storing prostheses.     

Detection of gonadal mosaicism in parents of offspring with down syndrome

A review of data of a standard clinical karyological analysis and study of QFQ chromosomal polymorphism in 151 families of children with Down syndrome is performed. A total of eight families with proved and predicted trisomy 21 gonadal mosaicism were identified; in all the cases the mothers were younger than 35 years of age. The prevalence of carriers of mosaicism in young families amounted to 6.5% (8/123). In a standard analysis, if the capabilities of the QFQ method had not been employed, this prevalence would have amounted to only 1%. A comparison of the results of a retrospective analysis of the data obtained by the QFQ method with the expected results of molecular testing of the same families leads to the conclusion that both methods should be used.     

Matrix interferences in the analysis of digested biological tissues with inductively coupled plasma-mass spectrometry

To investigate the physiological roles or toxicity of trace or toxic elements, multielement analysis of limited quantities of samples in the biological tissues is required. Inductively coupled plasma mass spectrometry (ICP-MS) suits this requirement, but spectral and nonspectral interferences are inevitable. We examined correction methods for the nonspectral interferences by analyzing signals of 21 elements in various concentrations of HNO₃ as well as five major elements (Na, K, P, Ca, and Cl). Using internal standards, the interferences caused by the major elements were corrected, but the interferences caused by HNO₃ were impossible to correct for elements with high ionization potentials. The analytical results using the standard addition method on 14 elements in standard reference materials and fresh brain tissues confirmed the accuracy of this method. Thus, we concluded that the standard addition method is useful to correct for the nonspectral interferences.     

A modified system for analyzing ionizing radiation-induced chromosome abnormalities

The analysis of dicentric chromosomes in human peripheral blood lymphocytes (PBLs) by Giemsa staining is the most established method for biological dosimetry. However, this method requires a well-trained person because of the difficulty in detecting aberrations rapidly and accurately. Here, we applied a fluorescence in situ hybridization (FISH) technique, using telomere and centromere peptide nucleic acid (PNA) probes, to solve the problem of biological dosimetry in radiation emergency medicine. A comparison by a well-trained observer found that FISH analysis of PBLs for the dose estimation was more accurate than the conventional Giemsa analysis, especially in samples irradiated at high doses. These results show that FISH analysis with centromeric/telomeric PNA probes could become the standard method for biological dosimetry in radiation emergency medicine.     

不同营养评价方法对住院患者营养状况评价的比较及意义

目的:分析比较身高标准体重法、体质指数法(BMI法)、体质指数校正法与生物电阻抗测量方法在住院患者营养评价中的意义。方法:随机抽取我院内科176名患者作为观察对象,用以上4种方法分别进行营养状况评价,测量结果采用单因素卡方分析法和Ridit分析比较。结果:用4种方法评价同一群体住院病人的营养状况时,其结果的差异有显著意义。结论:评判体脂和肥胖时应该首选能反映身体脂肪量及比例和身体内脂肪分布的腰臀比指标。标准体重法、BMI法和BMI校正法三种方法,在评价住院患者的营养状况时,最好能将腰臀比指标与其他指标共同使用。