尿酸酶—一鲁米诺化学发光传感器

研制了依赖于鲁米诺化学发光反应和固定化尿酸酶柱的测定血清尿酸的生物传感器。其测定血清样品响应时间４７ｓ。测定每份样品需时１．５ｍｉｎ,样品体积１７ｕｌ。工作曲线的线性范围１￣２０ｍｇ／ｄｌ。批内不精密度３．２２％￣４．３６％;批间６．１８％￣７．８％。测定值回收率为９３％￣１０９％。与医院常规酶试剂盒方法比较相关系数ｒ＝０．９９０９。固定化尿酸酶柱室温使用,４℃冰箱保存,连续使用５个半月测定样品２     

固定化尿酸酶丝素膜的性质及其尿酸传感器

应用电化学分析法对固定化酶丝素膜的性质进行了分析,结果表明这种酶经丝素膜固定后,活性得率高、性能稳定、能长期存放.用这种酶膜和氧电极等组成的流动注射分析式尿酸传感器对生物样品进行的百次重复分析结果表明,这种传感器的重现性良好,每小时能分析60个人血清样品.     

固定化酶一化学发光分析法测定葡萄糖和一种新型葡萄糖传感器的研制

本文提出用固定化酶－化学发光分析法测定葡萄糖并在此基础上构建了一种新型葡萄糖传感器。这种传感器系由固定化酶膜,光敏二极管及醋酸纤维滤膜构成。与其他类型的葡萄糖传惑器相比,它具有灵敏度高、响应速度快、工作稳定等特点,其线性工作范围可达4个数量级,检测下限为O．5ppm,可连续测定200个样品,测定结果与邻甲苯胺法所得结果相一致。     

过氧亚硝基-鲁米诺化学发光体系的改进

建立了一个测定过氧亚硝基阴离子（ONOO^－）化学发光的改进体系,测试了某些抗氧化剂清除ONOO^－的作用,其体系的组成和启动发光的程序如下：向pH 10.5碳酸缓冲液配的0.01 mol/L浓度NaN₃溶液通O₃ 30 s,取其800 μl原位注入含有100 μl水配样品和100 μl的0.001 mol/L鲁米诺溶液中,启动化学发光（chemiluminescence, CL）,立即测定每6秒的脉冲数（CP6S）,连续测定10～30次.根据实际需要,选其某一次的CL强度作为评判指标,对比抗氧化剂的活性.该发光体系灵敏、简便、且较稳定,最低可检测限为8.74 μmol/L的ONOO^－量,线性范围为8.74～74.04 μmol/L.批内变异系数3.35%（n=10）,批间变异系数5.52%（n=10）.测得维生素C(Vit.C)、茶多酚（EGCG）、原花菁素、硫脲皆有抑制CL,即清除ONOO^－的作用.     

流动注射化学发光法检测剑麻皂苷元

采用Luminol-K3Fe(CN)6化学发光体系,建立流动注射化学发光法检测从剑麻残渣和麻膏中分离得到的皂苷元。当用0.1 mol·L-1NaOH作为溶剂配制鲁米诺浓度为1.0×10-5mol·L-1,用去离子水作为溶剂配制K3Fe(CN)6浓度为1.6×10-5mol·L-1,主副蠕动泵转数均在50~80 r·min-1时,用无水乙醇溶解的皂苷元流入体系具有最强的化学发光。在该条件下,剑麻皂苷元最低检出限为3.0×10-3mg·mL-1,标准曲线相关系数为0.999 6,平均回收率为98.5%,相对标准偏差在2.9%~4.2%之间。同时与HPLC检测方法对样品检测结果进行了比较。     

谷氨酶传感器及在流动注射分析中的应用

利用谷氨酸氧化酶共价偶联于硅烷化铂化铂丝表面。构建一种简单的微酶电极,该电极具有良好的操作性能,应用于流动注射分析系统,可用来测量谷氨酸含量,测量范围０－２．０ｍｍｏｌ／Ｌ,精度、响应时间小于６０秒,使用寿命大于２０天,实际测量发酵液中谷氨酸含量,回收率为９８．７％－１０７．５％。     

固定化虫荧光素酶光纤传感器

固定化虫荧光素酶光纤传感器蔡谨,王顺光,杨歧生,吉鑫松（浙江大学化工系生化教研室,杭州３１００２７;中国科学院上海生物化学研究所,２０００３１）关键词虫荧光素酶,ＡＴＰ,固定化酶,光纤生物传感器ＡＴＰ是生物体内极为重要的能量物质。如何准确快速地定量Ａ...     

谷氨酸传感器及在流动注射分析中的应用

利用谷氨酸氧化酶(简称GO)共价偶联于硅烷化铂化铂丝(Φ0．5mm)表面。构建一种简单的微酶电极,该电极具有良好的操作性能;应用于流动注射分析系统(FIA),可用来测量谷氨酸含量,测量范围。0－2．0mmo1/L,精度(CV为o．4％)、响应时间小于60秒,使用寿命大于20天,实际测量发酵液中各氨酸含量,回收率为98．7％一107．5％。     

Chemiluminescence inhibition assay for folic acid using flow injection analysis

A new flow injection method for the determination of folic acid is described. A fast oxidation reaction occurred when folic acid was mixed with potassium ferricyanide generating ferrocyanide which then inhibited the chemiluminescent reaction of ferricyanide and luminol in alkaline medium. The decrease of chemiluminescence intensity was correlated with the folic acid concentration in the range 0.1-21 microg/mL; the detection limit for the assay was 0.03 microg/mL (3sigma). A complete analysis of folic acid, including sampling and washing, could be performed within 2 min with a relative standard deviation of less than 4.0%. The proposed method has been applied successfully to the determination of folic acid in pharmaceutical preparations.     

急性非ST 段抬高性心肌梗死患者血清尿酸水平与N末端B 型钠尿肽原的相关性分析

目的:探讨急性非ST段抬高性心肌梗死(NSTEMI)患者血清尿酸水平与N末端B型钠尿肽原(NT-pro BNP)的相关性分析。方法:将143例NSTEMI患者按照入院时血清尿酸四分位数分为四组:Ⅰ组(尿酸284.18μmol/L)、Ⅱ组(284.19~336.53μmol/L),Ⅲ组(336.54~390.78μmol/L),Ⅳ(尿酸390.79μmol/L);按照血清NT-pro BNP中位数分为2组:NT-pro BNP571.56 pg/m L组和NT-pro BNP≥571.56 pg/m L组;比较各组相关指标的差异。结果:Ⅰ组、Ⅱ组、Ⅲ组及Ⅳ组四组的NT-pro BNP、GRACE危险评分、CK-MB、LEVF、c Tn I比较统计学差异(P0.05),Ⅳ组NT-pro BNP、GRACE危险评分、c Tn I、CK-MB高于Ⅰ组、Ⅱ组、Ⅲ组,Ⅲ组高于Ⅰ组、Ⅱ组(P0.05);NT-pro BNP≥571.56 pg/m L组血清尿酸、GRACE危险评分、c Tn I、CK-MB高于NT-pro BNP571.56pg/m L组(P0.05)。血清尿酸分别与NT-pro BNP、GRACE危险评分呈现正相关(P0.05)。结论:血清尿酸水平与NSTEMI患者的NT-pro BNP密切相关,临床检测血清尿酸水平对于评估NSTEMI患者NT-pro BNP水平具有重要的意义。     

一株人肠源性高效尿酸降解菌的分离、鉴定及降尿酸条件优化

摘要 目的：肠道作为人体的重要消化器官,其内定植的微生物在尿酸合成和代谢过程中发挥着重要作用,本研究利用含尿酸靶向培养基筛选正常人群肠道内具有降尿酸功能的细菌并鉴定。方法：依据尿酸的摩尔质量制备含不同浓度尿酸的BHI培养基,液体培养基扩增并驯化肠道粪便微生物,固体培养基分离和纯化具有尿酸降解功能的细菌。挑取固体培养基上形态一致的单个菌落进行革兰氏染色和镜检,筛选出已纯化菌株,在需氧和厌氧培养条件下测定尿酸降解率,选取降解率≥50%以上的菌株为高效尿酸降解菌的候选菌株,再测定不同温度和pH值条件下的尿酸降解率,进行降尿酸条件优化。利用16S rDNA序列测定法对尿酸降解菌进行鉴定,药敏实验测定该菌对抗生素的敏感性。结果：正常人群粪便微生物中分离获得一株高效尿酸降解菌B5C,第5天需氧条件下的尿酸降解率均>50%,与初始尿酸浓度相比具有统计学意义（P＜0.05）。优化降尿酸条件后,在37℃、pH7.0时,降解率可达88.7%,经鉴定为粪肠球菌,对常见的抗生素如阿莫西林、氨苄西林和青霉素G等具有较高的敏感性。结论：本研究利用含不同尿酸浓度的靶向培养基驯化、分离和鉴定出一株人肠源性细菌,在需氧条件下也具有较高的尿酸降解率,可为今后临床降尿酸微生物制剂的开发和利用提供新的菌种资源。     

Determination of sulphite using an immobilized enzyme with flow injection chemiluminescence detection

A ?ow injection method is reported for the determination of sulphite‐based on chemiluminescent detection. Hydro‐gen peroxide is produced from sulphite using on‐line covalently bound immobilized sulphite oxidase packed in a mini‐column, which was mixed downstream and detected via cobalt(II)‐catalysed chemiluminescent oxidation of luminol. The limit of detection (2 × standard deviation of the blank) was 1 × 10^?3 mmol/L with sample throughput 60 h^?1. The calibration data was linear over the range of 0.2–1.0 mmol/L with relative standard deviation (n = 4) in the range 0.9–2.0%. Copyright © 2004 John Wiley & Sons, Ltd.     

Determination of free cholesterol based on a novel flow‐injection chemiluminescence method by immobilizing enzyme

A novel flow injection chemiluminescence method is proposed for determination of cholesterol in this paper. The cholesterol oxidase was immobilized onto sol–gel and prepared as an enzymatic reaction column. The determination of cholesterol was performed by quantitative determination of hydrogen peroxide produced from an enzymatic reaction. The luminol–H₂O₂–metal chelate diperiodatocuprate(III) system ensured that the method was highly sensitive and selective. Free cholesterol was determined over the range 5.0 × 10^–8 mol/L–5.0 × 10^–7 mol/L, with a limit of detection (3σ) of 1.9 × 10^–8 mol/L. The relative standard deviation (RSD) for 2.5 × 10^–7 mol/L was 2.7% (n = 7). The proposed method offered the advantages of sensitivity, selectivity, simplicity and rapidity for free cholesterol determination, and was successfully applied to the direct determination of free cholesterol in serum. Copyright © 2008 John Wiley & Sons, Ltd.     

Flow injection chemiluminescent assays for glycerol and triglycerides using a co‐immobilized enzyme reactor

A flow injection method for the determination of glycerol using a co‐immobilized enzyme reactor containing glycerokinase and glycerol‐3‐phosphate oxidase is described. The hydrogen peroxide produced is monitored by using a luminol chemiluminescence reaction in the presence of catalyst such as Co(II). The detection limit (2.5 × blank noise) for glycerol is 7 × 10^?3 mmol/L with a sample throughput of 40/h. The calibration graph is linear over the range studied (0.2–1.0 mmol/L) with relative standard deviation 1.2–2.4%. The method is applied to the determination of glycerol in blood serum produced off‐line from triglycerides using lipase isolated from bovine pancreas. Copyright © 2003 John Wiley & Sons, Ltd.     

Uric Acid: The Oxidant-Antioxidant Paradox

Uric acid, despite being a major antioxidant in the human plasma, both correlates and predicts development of obesity, hypertension, and cardiovascular disease, conditions associated with oxidative stress. While one explanation for this paradox could be that a rise in uric acid represents an attempted protective response by the host, we review the evidence that uric acid may function either as an antioxidant (primarily in plasma) or pro-oxidant (primarily within the cell). We suggest that it is the pro-oxidative effects of uric acid that occur in cardiovascular disease and may have a contributory role in the pathogenesis of these conditions.     

Analysis of Excretion Fraction of Uric Acid

Excretion fraction of uric acid (EF_UA), is one of the most important hallmarks for diagnosis of familial juvenile hyperuricemic nephropathy (FJHN) and hereditary renal hypouricemia. EF_UA was measured in 20 patients with FJHN. However, low excretion fraction (<6%) was found also in healthy FJHN family members and healthy controls (ref. ranges EF_UA: men 6–12%, women 6–20%). Similar finding of low EF_UA was reported recently. Distribution of EF_UA was further studied in 2,416 healthy controls, which were selected from 6,000 samples and divided according to age. In conclusion, finding of low EF_UA in family members is a risk factor for renal damage and indication for purine metabolic investigations with subsequent molecular biology analysis. As EF_UA could be found also in healthy controls—it should be interpreted with care and other features of FJHN (such as hyperuricemia, progressive renal disease in family) should be taken to account.