A Novel and Highly Sensitive Resonance Scattering Spectral Assay for Horseradish Peroxidase Using Cationic Surfactant

A novel and ultrasensitive resonance scattering (RS) spectral assay was proposed for detection of horseradish peroxidase (HRP) activity. It was based on that the HRP strongly catalyze H₂O₂ oxidation of excess I⁻ to form , the resulting combined with four cationic surfactant (CS), including tetradecyl pyridinium bromide (TPB), cetyltrimethyl ammonium bromide (CTMA), cetylpyridinium chloride (CPCM) and tetradecyl dimethylbenzyl ammonium chloride (TDMBA) to produce association particles (TPB-I₃) _n , (CTMA-I₃) _m , (CPCM-I₃)_l and (TDMBA-I₃) _k , which exhibit a strongest resonance scattering peak at 478, 423, 538 and 491 nm, respectively. For the four systems of TPB, CPCM, CTMBA and TDMBA, the HRP activity determined was in the linear range of 0.004–5.6, 0.04–3.2, 0.04–8.0, 0.08–8.0 ng/mL, with a detection limit of 0.0034, 0.040, 0.033, 0.016 ng/mL, respectively. The TPB resonance scattering spectral assay was best and has been applied to the analysis of HRP in real samples, with satisfactory results.     

Quantitative determination of phospholipids in mitochondria using HPTLC and fluorimetric assay in situ

A method is described for quantitative determination of phospholipids of mitochondria following one-dimensional thin-layer chromatography without previous elution. Using high performance thin-layer chromatography (HPTLC) and an in situ fluorescence technique, the time needed for quantitative determination is relatively short. As the method is rather sensitive, small amounts of the extracts can be applied (about 200 ng of total phospholipids per spot). The reproducibility for the phospholipid fractions determined was in the range of 8–17%. The procedure was tested with lipid extracts of rat liver mitochondria. The method allows the determination of cardiolipin, phosphatidyl ethanolamine, phosphatidyl inositol, phosphatidyl choline, and sphingomyelin.     

淮河淮南段水域诱变物污染的生物学初评

用蚕豆根尖微核(VMN_s)法,对淮河淮南段水域两个不同水期的6个采样点水质情况分别进行了监测。结果表明:除淮南段水域上游峡山口基本没有致突变物污染外,其余各点均有不同程度的污染。两个水期各点的污染情况基本一致。同时将VMN_s与综合化学指标BOD_5及COD_cr进行了比较,对所用的启豆1号蚕豆品系的本底微核千分率(MCN‰)及其对诱变剂丝裂霉素C的敏感性作了测定。     

A nonlinear regression model applied to kinetic multi-component analysis of esters with a SAW-impedance sensor

A kinetic nonlinear regression model for multi-component assay of esters was proposed based on their different alkaline-catalysed hydrolysis rate. The reaction rate was determined by monitoring the conductance change in solution with a liquid-purpose surface acoustic wave impedance sensor(SAW). The model was tested theoretically and experimentally with the mixture of methyl acetate and n-propyl acetate. The experimental detection limit of methyl acetate and n-propyl acetate (within 10 min) was 0.5 umol/L and 1.0 umol/L respectively and the recovery of the sensor system ranged from 93% to 106% (n=6).     

Preparation and Characterization of Branched β-Cyclodextrins Having Manno-Oligosaccharide Side Chains Derived from Yeast Mannan and Study of Their Functions

Branched -cyclodextrins (-CDs) having manno-oligosaccharide side chains were investigated. Three kinds of monobranched -CDs and five kinds of dibranched -CDs were chemically synthesized using the trichloroacetimidate method. Their structures were analyzed by HPLC, MS, and NMR spectroscopies. The specific interaction between those compounds and mannose-binding lectins (Concanavalin A and Pisum sativum agglutinin) was investigated by inhibition tests of hemagglutinating activity and by using an optical biosensor of the IAsys apparatus with a resonant mirror detector. The results showed that all branched -CDs interactedwith lectins. The binding affinity was 6¹,6⁴-(Man₃)₂- 6¹,6⁴-(Man₂)₂- > 6¹,6⁴-(Man₄)₂--CD when the derivatives were compared on the basis of side chain length and 6¹,6³- 6¹,6⁴- > 6¹,6²-(Man₂)₂--CD when compared on the basis of side chain position.     

蛋鸡粪中尿酸含量定氮测定方法研究

取烘干粉碎的蛋鸡粪样２５０～３００ｍｇ，加于４０ｍｌ６ｍｏｌ／ＬＨＣｌ中１２１℃水解３０ｍｉｎ之后，过滤取不溶残留物消化定氮，按公式Ｕ＝ＣＨＣｌ·ＶＨＣｌ×１４．０１×３＋４．７６２６×Ｖ０．２２６２ＨＣｌ即可计算得尿酸量（Ｕ）。若取样量大于３００ｍｇ时，公式中需减去一个吸附校正项Ａ［Ａ＝０．０１５２（Ｗ－３００），（３００≤Ｗ≤６００）］，使该方法的适用取样范围扩大到２５０～６００ｍｇ。     

降低PARP酶活性对培养细胞SCE及微核效应的影响

聚腺苷二磷酸核糖基化作用是细胞内的一种重要的核蛋白转译后加工修饰，它参与细胞内很多重要的生物事件．催化该反应的酶是聚腺苷二磷酸核糖合酶（ＰＡＲＰ），底物为ＮＡＤ．本文使用ＰＡＲＰ酶的抑制剂苯甲酰胺处理培养细胞，研究了降低ＰＡＲＰ酶活性对培养细胞姐妹染色单体交换及微核效应的影响，为全面评价ＰＡＲＰ酶抑制剂在细胞内的功效打下基础．     

气味沙雷氏菌蛋白组分分离及其体外抗癌活性

用ＳＤＳ－ＰＡＧＥ对经超声波处理的气味沙雷氏菌全菌体进行分离，切胶分别洗脱，经丙酮沉淀、脱盐处理后得到九个蛋白组分，将九个组分分别用Ｌ９２９，ＱＧＹ肿瘤细胞为靶细胞进行细胞毒性试验（ＭＴＴ），经初步鉴定从此且分具有抗癌细胞活性，组分Ｆ６相对分子质量范围为２８０００－３３０００，其抑制５０％细胞生长的蛋白浓度（ＩＣ５０）；对Ｌ９２９细胞为０．０４６ｍｇ／ｍｌ对ＱＧＹ细胞为０．０１２５０ｍｇ／ｍｌ，活     

污水诱发花背蟾蜍蝌蚪红细胞微核率变化的初探

用污水对花背蟾蜍蝌蚪染毒7天后,对其诱发的红细胞微核率进行检测,结果表明:除1/15污水组外,其余各组红细胞的微核率和出现微核的细胞率都显示有明显意义的升高(x~2≥13.85,p<0.001)。对不同剂量的污水诱发红细胞微核率变化的敏感性进行比较,排列顺序是:1/45污水组<1/40污水组<1/35污水组>1/30污水组>1/25污水组>1/20污水组>对照组>1/15污水组。