紫外分光光度计法与酶标仪微量法测定酚氧化酶蛋白含量及活力的比较

分别采用紫外分光光度计比色法与酶标仪微量法测定菜青虫Pieris rapae(L.)体内酚氧化酶蛋白含量和活力,以水杨醛缩对硝基苯胺为抑制剂,对2种方法的结果进行比较。结果表明,微量法和比色法在检测酚氧化酶(PO)蛋白含量、酶活力和抑制剂对PO抑制作用时结果无显著性差异。因此,微量法可以替代比色法,使用试剂量大大降低,重复性好,操作简单、快捷。     

双波长微孔板赖氏法检测人血浆丙氨酸氨基转移酶含量的方法学验证

目的采用双波长(492 nm/630 nm)微孔板赖氏法检测人血浆中丙氨酸氨基转移酶(alanine aminotransferase, ALT)的含量,并对该方法进行系统性的评价。方法按照ALT测定试剂盒的要求加样,应用双波长(492 nm/630 nm)微孔板赖氏法测定人血浆中的ALT含量,并对检测系统的专属性、线性范围、准确度和精密度进行验证。结果专属性分析结果显示,血浆样品与不同比例的抗凝剂混合,其中的ALT均能有效被检出,回收率分别为100%、95%和90%;对28和150个单位丙酮酸钠标准溶液进行倍比稀释5个梯度以制作标准曲线,采用多项式对标准曲线进行拟合,结果显示丙酮酸钠标准溶液分别在9.375～150、1.75～28和1.75～150个单位范围内线性关系均良好,相关系数r均达到0.99以上;准确度检测结果显示,已知含量的厂家质控血清和国家能力验证样品的实测值和理论值相比,回收率均在90%～110%之间;同一样品,重复加样18孔,重复性检测结果变异系数(CV)为5.29%;两位试验人员在不同日期对同一样品重复测定6次,中间精密度检测结果变异系数为5.49%。结论该检测方法专属性强、检测结果稳定可靠、线性良好、重复性好、检测通量大,可以有效降低成本,提高工作效率,适用于大规模检测人血浆中ALT的含量。     

比色法与核磁共振法测定A、C、Y、W135群脑膜炎球菌荚膜多糖氧乙酰基含量的比较

目的比较Hestrin比色法(简称比色法)和核磁共振(nuclear magnetic resonance,NMR)法在检测A、C、Y、W135群脑膜炎球菌荚膜多糖氧乙酰基(O-Acetyl,OAc)含量的相关性和精密度。方法用比色法和NMR法测定A、C、Y、W135群脑膜炎球菌荚膜多糖及其多糖衍生物,Y、W135群荚膜多糖水解物的OAc含量,比较分析两种方法的相关性及精密度。结果两种方法检测A、C、Y、W135群脑膜炎球菌荚膜多糖OAc含量的决定系数分别为R~2≥0.954、R~2≥0.960、R~2≥0.969、R~2≥0.972;比色法检测3批C群脑膜炎球菌荚膜多糖(PSC)OAc含量的精密度,SD值分别为0.21、0.21、0.18,对应CV值分别为9.03%、9.01%、8.70%(95%置信区间);NMR法检测3批A群脑膜炎球菌荚膜多糖(PSA)OAc含量的精密度,SD值分别为0.66、0.78、0.83,对应CV值分别为0.72%、0.85%、0.93%(95%置信区间);结论比色法和NMR法在检测A、C、Y、W135群脑膜炎球菌荚膜多糖OAc含量方面相关性良好,精密度良好,核磁法较比色法精密度更高。     

血浆miR-122表达与肝癌手术前后肝损伤的相关性

目的:探讨血浆中micro RNA-122(miR-122)表达与肝癌根治切除术前后肝损伤的相关性。方法:选取2015年1月-2016年1月在我院择期行肝癌根治切除术的肝癌患者36例,作为研究组,另选择同期健康体检者30例作为对照组。分别取研究组患者术前、术后第1 d、7 d及对照组入组时的清晨肘静脉血,采取荧光定量PCR(RT-PCR)技术检测血浆中miR-122表达水平,并检测两组血浆丙氨酸氨基转移酶(ALT)及转化生长因子-β1(TGF-β1)水平,分析手术前后研究组中各指标的相关性。结果:研究组术前血浆miR-122表达水平与血浆ALT、TGF-β1水平均高于对照组(P0.05)。与术前比较,研究组术后1 d血浆miR-122表达水平与血浆ALT、TGF-β1水平均明显上升(P0.05);且与术后1 d比较,肝癌患者术后7 d血浆miR-122、ALT、TGF-β1水平明显下降,且与术前比较差异有统计学意义(P0.05)。肝癌患者术前、术后1 d、7 d血浆miR-122表达水平与血浆ALT、TGF-β1水平均呈正相关(均P0.05)。结论:血浆miR-122与肝癌根治切除术前后肝功能损伤有关,可作为一种新型生物学指标。     

RT套式PCR检测血浆HCV RNA及与抗HCV检测的比较

应用微量血清热变性法提取核酸,逆转录套式聚合酶链反应(RT-nest PCR)检测血浆HCV RNA,并与抗HCV ELISA检测结果比较,对HCV RNA阳性标本进行HGV RNA的筛查.结果在32例抗HCV阳性和20例抗HCV阴性血浆中,HCV RNA分别检出18例和2例,总符合率为70%,20例HCV RNA阳性者中有2例合并感染HBV,1例合并感染HGV.证明血浆样本中抗HCV与HCV RNA间存在很大的相关性.     

改良的微量氨扩散法

在生物固氮过程中已证实氨是直接产物。完整的有机体可将固定的氮迅速地转变成氨基酸并进而合成蛋白质,而固氮有机体的提取物和纯化的固氮酶制备物能定量地生成氨。这种氨的增加可作固氮指标。氨的定量测定方法有好多种,我们选择了微量扩散法结合比色法,并将容器进行适当改进,建立了比较简易的微量氨测定法。     

乙肝患者HBsAg定量与乙肝病毒DNA定量及谷丙转氨酶水平的相关性研究

目的:探讨乙型肝炎患者血清中乙肝表面抗原(HBs Ag)定量与乙肝病毒(HBV)DNA定量及谷丙转氨酶(ALT)水平的相关性。方法:收集124例乙肝患者血清,采用化学发光法检测HBs Ag水平,采用实时荧光定量PCR法检测HBV-DNA水平,采用全自动生化分析仪检测ALT水平,分析三者之间的相关性。结果:HBs Ag水平与HBV-DNA含量存在正相关性,HBV-DNA含量与ALT水平存在正相关性,而HBs Ag水平与ALT水平无明显相关性。结论:联合检测3项指标可对乙肝患者HBV感染、复制、传染性以及机体的免疫性做出准确判断。     

儿童白血病患者血浆循环DNA定量分析

目的:通过对儿童白血病患者血浆循环DNA定量检测,分析血浆循环DNA含量用于儿童白血病诊断的价值.方法:用血液微量DNA抽提试剂盒提取血浆循环DNA,以SYBR GreenI荧光染色法分别检测46例儿童急性白血病患者、20例健康对照标本血浆循环DNA含量;利用受试者工作特征(ROC)曲线评价血浆循环DNA对儿童白血痛的诊断价值.结果:儿童白血病患者血浆循环DNA含量为(30.04±15.13)ng/mL,高于对照组(12.22±7.10)ng/mL,二者差异有统计学意义(P＜0.05);循环DNA含量16.31 ng/mL为诊断儿童白血病最佳临界值,敏感性和特异度分别为86.96%和75.00%,ROC曲线下面积(AUC)为0.879.结论:血浆循环DNA定量检测有可能成为一种新的用于儿童白血病诊断方法.     

过氧化氢酶抑制剂氨基三唑减轻急性酒精性肝损伤

本文旨在通过观察过氧化氢酶(catalase,CAT)抑制剂氨基三唑(aminotriazole,ATZ)对酒精诱导的急性肝损伤的影响,初步探讨CAT在酒精性肝损伤中的可能作用。以雄性Sprague Dawley(SD)大鼠为实验对象,采用酒精腹腔注射诱导急性肝损伤,在造模前30 min腹腔注射不同剂量ATZ(100~400 mg/kg)或相同体积溶剂(对照)。造模24 h后,检测大鼠血浆天冬氨酸转氨酶(aspartate transaminase,AST)、丙氨酸转氨酶(alanine transaminase,ALT)及乳酸脱氢酶(lactate dehydrogenase,LDH)水平,用HE染色法观察肝组织病理改变程度,用试剂盒检测肝组织内CAT活性、过氧化氢(hydrogen peroxide,H2O2)水平及丙二醛(malondialdehyde,MDA)含量,ELISA法检测血浆中肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)及白介素-6(interleukin-6,IL-6)水平。结果显示,ATZ处理可剂量依赖性降低酒精暴露大鼠血浆中ALT、AST及LDH水平,并减轻酒精诱导的肝组织病理损伤;ATZ可抑制酒精暴露大鼠肝组织内CAT活性、降低H2O2水平及MDA含量;ATZ也可下调酒精暴露大鼠血浆中TNF-α和IL-6水平。以上结果表明,ATZ可减轻酒精诱导的大鼠急性肝损伤,提示CAT可能在酒精性肝损伤中发挥了重要的致病作用。     

发酵中药渣对围产期母猪和哺乳仔猪血浆生化参数和抗氧化指标的影响

为了探讨发酵中药渣在妊娠母猪饲粮中添加的可行性,试验选用2~4胎次、预产期相近的二元妊娠母猪60头,随机分为对照组、中药渣组和发酵中药渣组,比较研究饲粮添加黄芪、当归、益母草和金银花等中药渣发酵前后对围产期母猪和哺乳仔猪血浆生化参数和抗氧化指标的影响。结果表明:与对照组相比,中药渣组母猪产后14和21 d血浆ALT活性显著升高(P0.05),7日龄仔猪血浆ALP活性显著降低(P0.05);发酵中药渣组母猪产后7 d血浆ALT和CAT活性、产后14 d血浆ALP和GSH-Px活性以及产后21 d血浆ALT和CAT活性均显著升高(P0.05),产后14和21 d血浆MDA含量显著降低(P0.05),14日龄仔猪血浆MDA含量显著降低(P0.05)、T-AOC活性显著升高(P0.05),21日龄仔猪血浆CAT活性显著升高(P0.05)。证实了饲粮添加发酵中药渣可改变围产期母猪及哺乳仔猪的机体代谢、增强机体抗氧化能力。     

Quantification of streptavidin adsorption in microtitration wells

Streptavidin-coated microtitration plates have an important role as a solid phase in clinical diagnostics. We have designed techniques for evaluating quantitative and functional aspects of streptavidin adsorbed in microtitration wells. The theoretical monolayer adsorption capacity was modeled based on the molecular dimensions of the protein. Adsorbed streptavidin was quantified by direct labeling of protein with terbium chelate and with a sensitive bicinchoninic acid-based protein assay. A new small molecular weight (1037Da) reporter molecule, a europium-labeled biotin (Eu-biotin), was synthesized and used for monitoring adsorption and for determination of biotin-binding capacities of the streptavidin-coated wells. The theoretical monolayer adsorption of streptavidin yielded 6.20 pmol/cm(2) (370 ng) and consequently the theoretical adsorption capacity of a C12-format microtitration well (200 microl liquid, coated area 1.54 cm(2)) was 9.55 pmol/well (570 ng). Adsorption properties of streptavidin from two suppliers were tested, one of which yielded 350-380 ng/well while the other yielded over 500 ng/well. The biotin binding capacities were about 11 and 14 pmol/well, respectively. We managed to quantify surface-adsorbed streptavidin with sensitive fluorescence and protein measurement methods in the microtitration well. The new Eu-biotin reporter molecule enabled an exact and convenient determination of the biotin-binding capacities of streptavidin surfaces.     

Immunoaffinity chromatography and a biotin-streptavidin amplified enzymeimmunoassay for sensitive and specific estimation of estradiol-17β

A sensitive test system has been developed for estimation ofestradiol-17β (E₂) in bovine plasma. Plasma extracts are first purified by a selective immunoaffinity chromatography (IAC) using an antibody raised against estradiol-6-carboxymethyloxime-bovine serum albumin and immobilized to Sepharose. The eluate was analysed by a competitive enzyme immunoassay (EIA) on microtitration plates. For the assay the wells of microtitration plates were coated with affinity purified sheep IgG (antirabbit IgG) that binds the hormone specific antibody raised in rabbits against estradiol-17-hemisuccinate-bovine serum albumin. E₂ is estimated by displacement of biocytinyl-E₂, that was produced by ligation of estradiol-17β, d-glucuronic acid and biocytin. Bound biocytinyl-E₂ is detected after binding of streptavidin-peroxidase and colour production by the enzyme. A very high amplification was possible with this technique and the absolute detection limit amounted to ≈120fg/well at 94% relative binding. By combination of IAC and EIA the following levels of E₂ were found in bovine plasma: male or female calves <2.7pg/ml, cycling cow 0.5–7 pg/ml, cow during last month of pregnancy 9–310 pg/ml, mature bull 5–30 pg/ml. However, up to 1110 pg E₂/ml were found in plasma of a calf after treatment with an illicit hormone preparation used for growth promotion; after 21 days levels declined to 6 pg/ml which is hardly different from controls. In conclusion, the IAC/EIA can be used for sentitive estimation ofestradiol-17β in plasma from all type of cattle and for control of improper use of E₂ after commitment of a threshhold level.     

An enzyme-linked immunosorbent assay for quassin and closely related metabolites

A microtitration plate enzyme-linked immunosorbent assay has been developed for quassin and closely related seco-triterpenes. The method is much more sensitive than conventional chromatographic techniques and enables the routine analysis of large numbers of samples with a detection limit of 5 ng quassin. Antibody production was elicited by injecting a conjugate of iso-quassinic acid linked to bovine serum albumin into rabbits. Important features of the technique are (a) the use of a double-antibody, noncompetitive enzyme-linked immunosorbent assay for a low-molecular-weight, nonantigenic compound using microtitration plates; and (b) that the initial incubation of samples with primary antiserum can be carried out in buffer containing up to 20% ($\text{v}\text{v}$) methanol with minimal loss of sensitivity. The structural requirements for recognition of the hapten by the antiserum are considered based on the levels of cross-reaction found with a wide range of other quassinoids.     

Automated Microtitration Test for Antistreptolysin O

A commercially available instrument that automatically makes serial dilutions and delivers reagents was used for the determination of antistreptolysin O titers in serum. The automated method was compared with tube-dilution and manual microtitration techniques. It gave higher reproducibility of results and was quicker to perform than both the other tests; and it was much more economical in reagents than the tube test. The automated technique is considered to be the best of the three methods when more than a small number of specimens are examined at one time. It is now in routine use in our laboratory.     

α-酮戊二酸减轻脂多糖/D-半乳糖胺诱导的小鼠急性肝损伤

该文旨在探讨α-酮戊二酸对脂多糖(lipopolysaccharide,LPS)及D-半乳糖胺(d-galac-tosamine,D-Ga1)诱导的急性肝损伤发生发展的影响及其可能机制.实验分组:正常对照组、AKG单独处理组、LPS/D-Ga1组、LPS/D-Ga1+AKG组.在雄性BALB/c小鼠中,经腹腔注射LPS...     

Comparison of the Immulite and RIA assay methods for measuring peripheral blood progesterone levels in Greyhound bitches

Determination of optimal breeding time in bitches earmarked for single insemination only is based on measurement of peripheral blood serum or plasma progesterone concentration. In this paper a comparison is made between radioimmune assay (RIA) and chemoluminescent assay (Immulite) for determination of P4 concentrations in the bitch. The Immulite assay is shown to be an accurate and reliable method for serum or plasma P4 measurement. It compares favourably with other methods in terms of turn-around time, cost and accessibility for veterinarians in practice.     

Potential Role of Interleukin‐18 in Liver Disease Associated with Insulin Resistance

Objective: Interleukin (IL)‐18 has been associated with obesity and insulin resistance, both risk factors for the development of liver disease, but the role of IL‐18 in liver disease associated with insulin resistance is presently unknown. We hypothesized that circulating IL‐18 would be related to serum concentrations of liver chemistry tests (LCTs) in apparently healthy subjects and wished to study whether this correlation was dependent on insulin sensitivity (S_I). Research Methods and Procedures: One hundred six apparently healthy white men consecutively enrolled in a cross‐sectional, population‐based study dealing with S_I in men were studied, and S_I (minimal model analysis), LCTs (colorimetry), and IL‐18 serum concentrations (immunoassay) were assessed. Results: Compared with subjects in the lowest quartile for serum IL‐18, subjects in the highest quartile exhibited increased serum triglycerides and decreased S_I, in addition to higher serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) (all p < 0.05). The direct association between both ALT and AST and IL‐18 was further confirmed by examining the distribution of serum IL‐18 by quartiles of ALT and AST. Subjects in the highest quartile for serum ALT and AST had higher IL‐18 concentrations compared with subjects in the lowest quartile for these LCTs (both p = 0.01). In multiple regression analysis, IL‐18, but not S_I, was an independent predictor of serum concentrations of ALT and AST, explaining 7% and 4% of their variance, respectively. Discussion: In summary, IL‐18 serum concentrations are associated in apparently healthy humans with plasma concentrations of various LCTs. IL‐18 could contribute to the development of liver disease associated with insulin resistance.     

Interactions between 1-benzoyl-4-p-chlorophenyl thiosemicarbazide and serum albumin: investigation by fluorescence spectroscopy

The interactions between 1-benzoyl-4-p-chlorphenyl thiosemicarbazide (BCPT) and bovine serum albumin (BSA) or human serum albumin (HSA) have been studied by fluorescence spectroscopy. By the analysis of fluorescence spectrum and fluorescence intensity, it was showed that BCPT has a strong ability to quench the intrinsic fluorescence of both bovine serum albumin and human serum albumin through a static quenching procedure. The binding constants of BCPT with BSA or HSA were determined at different temperatures based on the fluorescence quenching results. The binding sites were obtained and the binding force were suggested to be mainly hydrophobic. The effect of common ions on the binding constants was also investigated. A new fluorescence spectroscopy assay of the proteins is presented. The linear range is 5.36-67.0 microg mL(-1) with recovery of 101.1% for BSA, and the linear range is 8.28-144.9 microg mL(-1) with recovery of 102.6% for HSA. Determination of the proteins in bovine serum or in human serum by this method gives results which are very close to those obtained by using Coomassie Brilliant Blue G-250 colorimetry. A practical method was proposed for the determination of BCPT in human serum samples.     

Sequential measurement of aminotransferase activities by amperometric biosensors

An l-glutamate biosensor modified by cation exchanger membrane on a palladium (Pd) electrode was designed for the purpose of preventing interferences and electrode fouling during the measurement of serum AST and ALT activities. The rate of signal increase obtained by our sensor for the determination of AST and ALT activity was 0.259 and 0.596 nA/min U(-1)l and the response of the sensor to AST and ALT activity were linear over the range of 8-200 and 8-250 Ul(-1), respectively. Both AST and ALT activities could be measured sequentially by injecting the serum into a solution containing l-aspartate and alpha-ketoglutarate. The rate of current increase was relative to AST activity. The activity of ALT was sequentially determined after addition of l-alanine into the solution. The change in the current increase rate after the addition of l-alanine was proportional to the ALT activity. By using the proposed biosensor, the interference of 1mM ascorbic acid was negligible on a dynamical aminotransferase determination when the dynamic data are taken after the steady state of an elevated baseline has been reached. The proposed l-glutamate biosensor provides adequate sensitivity for the measurement of AST and ALT and is expectable to be applied for rapid blood screening of AST and ALT activity in clinical sample.