重量法测定血苯-白蛋白加合物的初步研究

苯进入人体内形成有很高活性的环氧化物，可与多种蛋白形成加合物。有研究用同位素标记的苯（Ｃ６２Ｈ６）白蛋白为内标衍生后，用气质联仪（ＧＣＭＳ）测定血液中的苯白蛋白加合物［１］。由于采用昂贵的仪器和同位素内标物，在一般实验室难以进行。本研究采用重...     

茶叶对黄曲霉毒素B_1-DNA加合物生成的影响

本研究在体外实验条件下,测定了乌龙茶水等12种茶样对黄曲霉毒素 B_1(AFB_1)-DNA加合物生成的影响。结果表明,受试样品在高浓度下均有明显抑制AFB_1-DNA加合物生成的作用,随着浓度下降,抑制作用亦随之降低,有明显的剂量-反应关系。本实验结果提示,茶叶对AFB_1的致癌性可能具有一定的抑制作用。     

影响三地居民黄曲霉毒素B1-白蛋白加合物的相关因素分析

[目的]分析影响存在肝癌发病率梯度的三地居民个体黄曲霉毒素生物效应的相关因素.[方法]对广西扶挼两个自然村农民、南宁和四川成都城市居民采用酶联免疫法检测血浆黄曲霉毒素B1-白蛋白加合物(AFB1-Albumin Adducts,AAA)水平、肝炎病毒(hepatitis virus,HV)标志物(HBV两对半,HCV、HDV、HEV和HGV抗体)及肝功能.[结果]扶挼47.2%(42/89)的居民至少1种HV感染标志物阳性;南宁和成都分别为15.8%(31/196)和22.7%(27/119).Log(AAA)水平(n,x±s)为扶挼(89,2.44±0.16)和南宁(196,2.45±0.15)均高于成都(118,2.20±0.24),(P=0.000);但扶挼与南宁间差别无显著性(P=0.859).南宁(P=0.023)、成都(P=0.026)两地男性AAA水平均高于女性.扶挼和成都两地HV感染者AAA水平均高于非感染者(P分别为0.447和0.041).HV(-)组中,AAA水平与年龄(r=-0.199,P=0.000)和BMI(r=-0.158,P=0.006)负相关.HV(+)组AAA分别与白蛋白(P=0.000)、球蛋白(P=0.012)和天冬氨酸转氨酶(P=0.052)相关,而HV(-)组AAA分别与直接胆红素、间接胆红素、白蛋白、γ-谷氨酰转肽酶、总胆汁酸和碱性磷酸酶相关(P＜0.05).[结论]AFB1暴露的生物效应可能受肝炎病毒感染、性别、年龄和代谢等因素的影响.AAA与肝功能指标的相关性提示AFBl对肝脏实质或胆道细胞的损害作用.     

血清前白蛋白的测定及其临床应用

血清前白蛋白(prealbumin,PA)在体内总含量极少,其更新率高且半衰期短(仅1.9d),可敏感地反映机体营养状况改变。用于营养评定效果明显优于常规使用的指标如白蛋白,为目前国际上评价营养状况和监测营养支持效果的重要指标之一[1,2]。本组与检验科合作,采用速率散射比浊法,首次建立前白蛋白分析方法,测定了287例不同年龄段正常人群PA水平及外科手术患者手术前后血清前白蛋白变化,以观察营养支持疗效。材料和方法研究对象(1)随机选择从事轻等和中等体力劳动或脑力劳动、无肝肾功能不良、心肺功能大致正常的健康志愿者287例,根据年龄分为青年…     

启东肝癌中黄曲霉毒素白蛋白加成物水平和p53蛋白表达的研究

对３０例启东肝癌病例和１６例对照用竞争抑制放射免疫法检测血清黄曲霉毒素白蛋白加成物，７例血清ＨＢｓＡｇ、抗－ＨＢｃ均阳性的手术病例的石蜡包埋组织用免疫组化法检测ｐ５３蛋白表达。结果表明，病例组黄曲霉毒素白蛋白加成物水平在１．０７～３．４６ｐｍｏｌＡＦＢ１／ｍｇ白蛋白之间，对照组在０．８５～２．９９ｐｍｏｌＡＦＢ１／ｍｇ白蛋白之间，两组比较无显著性差异。６例癌组织、４例癌旁组织ｐ５３蛋白表达阳性，且这６例阳性者黄曲霉毒素白蛋白加成物平均水平为１．８１５±０．６２２ｐｍｏｌＡＦＢ１／ｍｇ白蛋白。提示较长时间内病例和对照黄曲霉毒素暴露的蓄积剂量并无显著性差异。启东肝癌病例ｐ５３蛋白表达率很高，但引起ｐ５３高蛋白表达率的原因尚不能确定     

同时测定花生中的黄曲霉、寄生曲霉以及黄曲霉毒素

黄曲霉毒素以其毒性和致癌性严重威胁着人类和动物的健康 ,因此长期以来食品和饲料中黄曲霉毒素的污染一直为人们所关注。花生及其它食品和饲料中黄曲霉毒素的污染主要是由于黄曲霉的侵染和繁殖 ,此外寄生曲霉也是引起黄曲霉毒素污染的重要原因 ,尤其是在花生中。但是关于花生中黄曲霉和寄生曲霉的侵染与黄曲霉毒素污染之间的关系并不十分清楚。以往的研究中 ,黄曲霉和寄生曲霉的侵染率是通过样品外部杀菌后 ,根据单个花生点种平板的霉菌生长情况而测定 ,而黄曲霉毒素的污染率则只能对同批样品中其它花生样品进行测定 ,导致了黄曲霉和寄生曲…     

血清前白蛋白和白蛋白测定在原发性肾病综合征中的临床意义

血清前白蛋白（PA）和白蛋白（ALB）均在肝细胞内合成,但在原发性肾病综合征时,PA、AIJ3也发生改变,本文就我院收治的肾病综合征患者的PA、ALB检验结果与正常人群作一对照,现报告如下。1材料和方法回．1检测对象健康对照组7百名,年龄在D一刀岁;肾病综合征患者为我院近半年来收治的病人对例,年龄ZI－56岁。1．2方法PA用上海玉兰生物技术研究所生产的免疫比浊法试剂盒,Alll用澳甲酚绿法,全部在日本岛津Cb－xx－x一全自动生化分析仪上测定,统计方法用均数t检验和相关分析。2结果健康对照组和肾综患者的PA、AIJ3均值见表1…     

食品中黄曲霉毒素高效液相色谱法测定

黄曲霉毒素是具有极强致癌性的次生代谢产物,主要存在于粮油制品中。食品中黄曲霉毒素的检测方法主要有薄层色谱法、酶联免疫法、液相色谱法等^[1-2] 。薄层色谱法操作繁琐,而酶联免疫法特异性差。     

食品中黄曲霉毒素B1的抽样调查

为了了解部队食品卫生状况,1988年7月至8月我们对两个市驻军部分食品中的黄曲霉毒素B_1进行了抽样调查,现报告如下: 一般情况     

Biological monitoring in workers in a nitrobenzene reduction plant: haemoglobin versus serum albumin adducts

The high priority of monitoring workers exposed to nitrobenzene is a consequence of clear findings of experimental carcinogenicity of nitrobenzene and the associated evaluations by the International Agency for Research on Cancer. Eighty male employees of a nitrobenzene reduction plant, with potential skin contact with nitrobenzene and aniline, participated in a current medical surveillance programme. Blood samples were routinely taken and analysed for aniline, 4-aminodiphenyl (4-ADP) and benzidine adducts of haemoglobin (Hb) and human serum albumin (HSA). Also, levels of methaemoglobin (Met-Hb) and of carbon monoxide haemoglobin (CO-Hb) were monitored. Effects of smoking were straightforward. Using the rank sum test of Wilcoxon, we found that very clear-cut and statistically significant smoking effects (about 3-fold increases) were apparent on CO-Hb (P=0.00085) and on the Hb adduct of 4-ADP (P=0.0006). The mean aniline-Hb adduct level in smokers was 1.5 times higher than in non-smokers; the significance (P=0.05375) was close to the 5% level. The strongest correlation was evident between the Hb and HSA adducts of aniline (r_s=0.846). Less pronounced correlations (but with P values < 0.02) appeared between aniline-Hb and 4-ADP-Hb adducts (r_s=0.388), between 4-ADP and 4-ADP-HSA adducts (r_s=0.373), and between 4-ADP-Hb and aniline-HSA adducts (r_s=0.275). In view of the proposal for additional use of the aniline-HSA adduct for biological monitoring, particularly in cases of acute overexposures or poisonings, the strong correlation of the Hb and HSA conjugates is noteworthy; the ratio aniline-HSA:aniline-Hb was 1:42 for the entire cohort. Received: 2 June 2000 / Accepted: 21 April 2001     

ELISA法快速检测黄曲霉毒素B_1

利用ＥＬＩＳＡ法的ＡＦＢ１试剂盒测定了食品、饲料等样品中的ＡＦＢ１含量。本方法重复性好，ＲＳＤ＝７．８％，灵敏度为２．５ｐｇ，平均回收率为８９％～９５％，其结果与ＴＬＣ法比较有较好的相关性，且灵敏度高于ＴＬＣ法１６０倍。本法具有快速、简便和一次可批量定性定量的优点，适用于食品、饲料等样品的ＡＦＢ１的分析测定     

DNA adducts and human atherosclerotic lesions.

It has been hypothesized that mutational events may be involved in the atherogenetic process and that at least a portion of atherosclerotic plaques may be the results of monoclonal proliferation of a single mutated smooth muscle cell (SMC). Therefore, atherosclerosis may be similar to carcinogenesis and may have an environmental etiology. We have analyzed bulky-aromatic DNA adducts in human thoracic aortas from male subjects, aged between 30-60 years, who died suddenly or accidentally, and who had been examined by autopsy within 24 h after death. We found significantly (P < 0.001) higher DNA adduct levels in the samples from subjects with frequent atherosclerotic changes in the whole body ("Cases", N = 76) compared with those having few atherosclerotic changes ("Controls", N = 57). We also observed a significantly elevated weight of heart and plasma levels of total and LDL cholesterol in "Cases" vs "Controls". Significant differences in DNA adduct levels between smokers and nonsmokers were observed in "Controls" only. Multivariate linear regression analyses with age-adjusted data confirmed a significant influence of LDL cholesterol (P < 0.001), vitamin A (P < 0.01), smoking behavior (P < 0.05; evaluated as plasma cotinine levels) and NAT2 genotypes (P < 0.05) on bulky-aromatic DNA adduct levels. The induction of DNA adducts suggests that alterations at the DNA level may contribute to the development of atherosclerosis. Furthermore, atherogenesis and carcinogenesis may share a similar etiology, i.e. genotoxic action of environmental chemicals.     

食品中黄曲霉毒素B_1单克隆抗体酶联免疫测定方法的建立及初步应用

用抗 AFB_1的单克隆抗体 AFB_1-2H8,建立了检测食品(玉米、花生、小麦、大米、植物油)中 AFB_1的 ELISA 间接竞争法。该方法最低检出浓度为0.01ng/g,敏感范围为0.2～50ng/g,平均回收率为83.0%～110.3%,精密度为2.0%～24.3%。用该法测定了分布于淮河以北地区的145份样品,并对25份植物油样品用 TLC 和 ELISA 两种方法进行了对比测定。     

武汉地区孕妇血清中人微小病毒B19检测状况及传播途径的研究

为了解武汉地区异常妊娠史孕妇及胎儿人微小病毒 B1 9感染状况及传播途径 ,运用聚合酶链反应(PCR)对既往有异常妊娠史的孕妇进行母血检测人微小病毒 B1 9- DNA。结果显示 :在 68例既往有异常妊娠史的孕妇血清中 ,有 1例检测到人微小病毒 B1 9- DNA,检出率为 1 .47%。提示 :武汉地区孕妇存在人微小病毒 B1 9的感染 ,有必要在武汉地区开展人微小病毒 B1 9的研究     

Analysis of macromolecular ethylene oxide adducts

Summary Ethylene oxide is a carcinogenic compound which is also an ethylene metabolite. Ethylene oxide forms macromulecular adducts with proteins and nucleic acids. Targets in proteins are the amino acids cysteine, histidine and valine (if N-terminal, as in hemoglobin). The major DNA adduct is 7-(2-hydroxyethyl)-guanine. Methods for detection of this adduct include radiolabelling and GC-MS. The sensitivity of current GC/MS methods can be improved by selective enrichment of adducts from DNA samples. Studies in this direction are presently being performed.     

乙型肝炎病毒前S1抗原与HBV DNA及HBeAg关系

目的　探讨乙型肝炎病毒 (HBV)前S1抗原 (PreS1Ag)与HBVDNA和HBeAg之间的关系 ,以评价其在乙肝诊疗中的作用。方法　用ELISA法对 2 2 5例HBeAg阳性标本进行PreS1Ag和HBV血清标志物的检测 ,用PCR-ELISA法测定HBVDNA。结果　PreS1Ag在HBVDNA和HBsAg阳性组织中的检出率均明显高于相应的阴性组(均为P <0 0 1)。HBeAg阴性组中PreS1Ag的检出率为 4 3 0 % ,PreS1Ag与HBVDNA的符合率为 70 6 % ,与HBeAg的符合率为 6 8 4 %。结论　PreS1Ag与HBVDNA、HBeAg呈良好的相关性。作为反映HBV感染和复制的指标 ,PreS1Ag较HBeAg更敏感。     

黄曲霉毒素B_1抗原的构建

黄曲毒素Ｂ１是只有反应原性而无免疫原性的半抗原，不能直接刺激动物抗体，只有和牛血清蛋白（ＢＳＡ）、卵清白蛋白（ＯＶ）等载体蛋白连接后才能刺激动物产生分泌抗体，黄曲霉毒素Ｂ１抗原的构建是黄曲霉毒素Ｂ１免疫学检测研究的第一步。本文首先研究了回流温度和时间对黄曲霉毒素Ｂ１肟产生的影响，通过统计分析得到８５℃，回流２ｈ时黄曲霉毒素Ｂ１肟的产率最高，产率高达８９％。在此基础上进一步研究了黄曲霉毒素Ｂ１肟与载体蛋白—牛血清白蛋白反应的起始摩尔比对产物摩尔比的影响，随着反应起始摩尔比的增加，产物的摩尔比也稍有增加，但是增加幅度不显著，而黄曲霉毒素Ｂ１肟的利用率则随着起始摩尔比的增加而减少，选择３０∶１为黄曲霉毒素Ｂ１肟与牛血清白蛋白的反应起始摩尔比得到摩尔比为６．５∶１的黄曲霉毒素Ｂ１肟与牛血清蛋白的连接物。     

Aflatoxin exposure may contribute to chronic hepatomegaly in Kenyan school children

Background: Presentation with a firm type of chronic hepatomegaly of multifactorial etiology is common among school-age children in sub-Saharan Africa.Objective: Aflatoxin is a liver toxin and carcinogen contaminating staple maize food. In this study we examined its role in chronic hepatomegaly.Methods: Plasma samples collected in 2002 and again in 2004 from 218 children attending two schools in neighboring villages were assayed for aflatoxin exposure using the aflatoxin-albumin adduct (AF-alb) biomarker. Data were previously examined for associations among hepatomegaly, malaria, and schistosomiasis.Results: AF-alb levels were high in children from both schools, but the geometric mean (95% confidence interval) in year 2002 was significantly higher in Matangini [206.5 (175.5, 243.0) pg/mg albumin] than in Yumbuni [73.2 (61.6, 87.0) pg/mg; p < 0.001]. AF-alb levels also were higher in children with firm hepatomegaly [176.6 (129.6, 240.7) pg/mg] than in normal children [79.9 (49.6, 128.7) pg/mg; p = 0.029]. After adjusting for Schistosoma mansoni and Plasmodium infection, we estimated a significant 43% increase in the prevalence of hepatomegaly/hepatosplenomegaly for every natural-log-unit increase in AF-alb. In 2004, AF-alb levels were markedly higher than in 2002 [539.7 (463.3, 628.7) vs. 114.5 (99.7, 131.4) pg/mg; p < 0.001] but with no significant difference between the villages or between hepatomegaly and normal groups [539.7 (436.7, 666.9) vs. 512.6 (297.3, 883.8) pg/mg], possibly because acute exposures during an aflatoxicosis outbreak in 2004 may have masked any potential underlying relationship.Conclusions: Exposure to aflatoxin was associated with childhood chronic hepatomegaly in 2002. These preliminary data suggest an additional health risk that may be related to aflatoxin exposure in children, a hypothesis that merits further testing.     

Exposure to urban and rural air pollution: DNA and protein adducts and effect of glutathione-S-transferase genotype on adduct levels

Ambient air in urban areas is polluted by agents suspected of causing cancer in humans. A number of epidemiological studies have revealed an increased cancer risk in urban communities, especially in lung cancer. The relative risk have been estimated to be in the order of 1.5. The objective of this study was to evaluate differences in genotoxic exposure through air pollution in urban and rural areas using DNA and protein adducts as biomarkers. Another objective was to investigate whether the GSTM1 genotype has any effect on adduct level. The analyses included ³²P postlabelling of DNA adducts in lymphocytes, enzyme-linked immunosorbent assay for measuring benzo[a]pyrene protein adducts and polymerase chain reaction amplification of the GSTM1 genotype. The study was a cross-sectional study of non-smoking, healthy males from rural and urban Danish areas and from Athens, Greece. All individuals in the study were healthy, non-smoking males. The Danish urban group included 74 university students, the rural group 29 students from agricultural colleges and the Greek group 17 individuals. Adduct levels differed significantly in the three groups with median levels of 0.152 fmol/g DNA (rural), 0.205 fmol/g (urban) and 0.285 fmol/g (Athens). The adduct patterns showed some identical spots, but also specific adducts. Here we report increasing DNA adduct levels comparing residents in rural, small urban and large urban residential areas; we found no influence of GSTM1 genotype on DNA or protein adduct levels in non-smokers exposed to low levels of air pollution.