Development of an immunochemical method for determination of human kepsinogen isozynogens and its clinical application

1.对人胃蛋白酶原A基因进行克隆和分析。结果表明，人类染色体DNA上至少存在三种不同的基因，其中至少有两种基因倾向于同源.克隆了大鼠胰蛋白酶原C基因，并对所有外显子的碱基序列及其功能进行了分析.克隆了人胃蛋白酶原C基因，并对所有外显子及其邻近区域的碱基序列进行了分析。4.用Southern杂交分析了92名日本人血细胞DNA的限制性核酸酶差异，证明日本人存在三种不同的胃蛋白酶原A基因.本文研究了人、猴和猪胃蛋白酶原A的激活机制。结果表明，不同种属间胃蛋白酶原同工酶的作用机制存在显著差异，不同人胃蛋白酶原同工酶的作用机制也存在显著差异.用抗人胃蛋白酶原A（Ⅰ）的杂交瘤单克隆抗体建立了酶联免疫吸附试验（ELISA）。健康对照组血清胃蛋白酶原A浓度范围为15-100 μ g/l。活动性十二指肠溃疡和胃溃疡患者血清胃蛋白酶原水平显著高于对照组，而胃癌患者血清胃蛋白酶原水平显著低于对照组。认为该测定法可用于筛选工作，以确定十二指肠溃疡和胃溃疡胃癌风险增加的受试者。7将胃蛋白酶原A（PGA）和胃蛋白酶原C（PGC）的血清水平以及PGA/PGC比值与胃底粘膜表面积进行比较，胃底粘膜表面积通过刚果红方法进行内镜测定。PGA值和PGA/PGA比值对慢性胃炎和胃癌的诊断有一定的参考价值。

1. Human pepsinogen A genes were clones and analyzed. The results showed that there exist at least three different genes and that at least two of them are tendemly aligend on a human chromosomal DNA.2. Rat prpsinogen C gens was cloned and the base sequences of all the exons and their veicnities were elucidated.3. Human pepsinogen C gene was cloned and the base suquences of all the xons and their vicinities were elucidated. 4. Restrriction nuclease difests of human blood cell DNA from 92 Japanese subjects were analyzed by Southern-blot analysis, demonstrating the presence of three different pepsinogen A genes in Japanese.5. The activation mechamisms of human, monkey and pocine pepsinogens A were investigated. The results showed that the mechanism differs significantly among species and that among human pepsinogen isozymogens the mechanism also differs significantly.6. An enzyme-linked immunsorbent assay (ELISA) for human pepsinogen A (of I) was developed by using a hybridoma monoclonal antibody against the zymogen. The concentration range of serum pepsinogen A in gealthy controls was 15-100 ug/1. Serum pepsinogen Levels were significantly higher in the subjects who developed active duodenal ulcer or active gastric ulcer, but significantly lower in those who had gastric cance, than in control subjects. This assay is thought to be useful in the screening work to identify subjects at incrteased tisk for gastric cancer of duodenal and gastric ulce.7 The serum level of pepsinogen A (PGA) and pepsinogen C (PGC) and the PGA/PGC ratio were compared with the surface area of the fundic mucosa, as determined endoscopically by the Congo red method. The PGA velue as well as the PGA/PGA ratio were shown to be useful in detection of chronic gastritis and gastric cancer.