浙江省在鼠中检测到埃立克体及无形体DNA片段并测序分析

目的:了解鼠中自然感染埃立克体及无形体的状况。方法:用巢式PCR扩增鼠中埃立克体属及嗜粒细胞无形体属16S rDNA的5′末端片段,对阳性产物克隆后测序。结果:在浙江省金华市金东区捕到鼠128只。在黄毛鼠中检到阳性4份,阳性率为3.125%,并对其进行克隆后测序。与Genbank上比对分析,三份与牛埃立克体相同基因区最为接近,属无形体科,无形体属。一份与反刍动物埃立克体相同基因区最为接近,属无形体科,埃立克体属。均为国内首次报道。结论:初步认为浙江省存在埃立克体及无形体病原。黄毛鼠可能为埃立克体及无形体宿主,尚需进一步调查。     

Various V-J rearrangement efficiencies shape the mouse λ B cell repertoire

The diversity of the B cell repertoire of C_x knockout mice is limited by the expression of four λ light chain types. Among the spleen B cells, λ1 is expressed by the majority (58%) of cells, and λ3 by the minority (8%), while λ2(V2) and λ2(Vx) are expressed in intermediate quantities (18% and 16%, respectively). To assess the influence of mechanistic pressures on the λ subtype distribution, the proportions of the different λ rearrangements were determined in various B cell subpopulations divided on the basis of the λ subtype expressed, and the VλJλ junction sequences were studied at different steps of B cell differentiation (pre-B, immature and mature B cells). The data show that (1) the ratio of productive/non-productive VJ junctions is determined by the nature of the λ segments that are rearranged as can be observed in the pre-B cells, (2) V1-J1 non-productive rearrangements are often found in the λ1-negative B cells in the periphery, and (3) V1J3 junctions are often non-productive regardless of the nature of the cells analyzed. Our results, therefore, suggest that a strong probability of initiating a V1-J1 rearrangement and a weak probability of giving a productive V1J3 junction are responsible for the λ1 dominance and the λ3 under-expression, respectively. The intermediate proportion of λ2(V2) subtype is most likely due to a probability of obtaining a productive joint that is better than that for V1J3 and a probability of initiating a rearrangement that is lower than that for V1J1. However, the λ2(Vx) cell proportion cannot be determined only by these parameters.     

A comparision of brain biopsy and CSF-PCR in the diagnosis of CNS lesions in AIDS patients

Twenty patients with AIDS who had intracranial lesions underwent both brain biopsy and cerebro-spinal fluid (CSF) examination to compare histological diagnosis with the polymerase chain reaction (CSF-PCR) for the identification of infectious agents. CSF-PCR was performed for herpes simplex virus, varicella zoster virus, cytomegalovirus (CMV), JC virus (JCV), Epstein-Barr virus (EBV), Toxoplasma gondii and Mycobacterium tuberculosis. A definitive diagnosis was obtained by brain biopsy in 14 patients (2 with astrocytoma, 12 with brain infection). CSF-PCR was positive for EBV DNA in 3 of 3 cases of primary cerebral lymphoma, positive for JCV DNA in 6 of 7 biopsy-proven (and one autopsy-proven) cases of progressive multifocal leukoencephalopathy (PML). CSF-PCR was positive for CMV DNA in one biopsy-proven and one autopsy-proven case of CMV encephalitis (the former also had PML) and positive for M. tuberculosis DNA in one case of tuberculous encephalitis. None of the five toxoplasmic encephalitis cases (one definite, four presumptive) were T. gondii DNA positive. There was close correlation between histology and CSF-PCR for CMV encephalitis, PML and PCL. Antitoxoplasma therapy affected the sensitivity of both histological and CSF-PCR methods. Received: 8 November 1995 Received in revised form: 9 July 1996 Accepted: 19 July 1996     

AmpliSensor-聚合酶链反应技术检测结核分支杆菌及临床应用

目的探讨Ａｍｐｌｉｓｅｎｓｏｒ－聚合酶链反应（ＡｍｐｌｉＳｅｎｓｏｒ－ＰＣＲ）在结核病诊断中的价值。方法采用ＡｍｐｌｉＳｅｎｓｏｒ－ＰＣＲ对７８４例结核病患者及１６０例肺癌患者的标本进行检测，并与ＰＣＲ（凝胶电泳后，经溴化乙锭染色）、涂片、培养等法比较。结果ＡｍｐｌｉＳｅｎｓｏｒ－ＰＣＲ的敏感性显著高于涂片及培养（Ｐ＜０．０１）。特异性较ＰＣＲ法高。结论ＡｍｐｌｉＳｅｎｓｏｒ－ＰＣＲ可以通过标准曲线划定检出下限，并可换算出标本中原始的靶ＤＮＡ值，同时具有较高的特异性和敏感性，对肺结核尤其是肺外结核的诊断有一定的临床意义。     

链置换式扩增检测羊水中巨细胞病毒DNA

目的：介绍一种简便快速准确检测羊水中ＣＭＶ－ＤＮＡ的改良ＰＣＲ－链置换式扩增用于诊断胎儿先天感染ＣＭＶ。方法，将组成套式ＰＣＲ的外内两对引物按照一定比例（外：内＝１：５０－１００）加在同一试管中一次扩增羊水和胎儿组织中ＣＭＶ－ＤＮＡ。结果：９０例异常孕产史的孕妇羊水检测ＣＭＶ－ＤＮＡ，阳性率为３８．９％（３５／９０），其中合并染色数目异常２例（４７，ＸＹＹ和４７，ＸＸ，＋２１）（已引产）核型及染色     

聚合酶链反应诊断单纯疱疹病毒性脑炎

用聚合酶链反应（ＰＣＲ）扩增患者脑脊液（ＣｈＦ）中病毒特异性ＤＮＡ可早期快速诊断单纯疱疹病毒性脑炎（ＨＳＥ）。１９例临床确诊的病毒性脑炎患者，经ＰＣＲ在ＣＳＦ中检出单纯疱疹病毒（ＨＳＶ）１３例，全部阳性标本均经分子杂交证实为ＨＳＶ－ＤＮＡ，而１４例其他神经疾病（ＯＮＤ）对照组均为阴性，显示了这一方法的特异性。其中７例病毒性脑炎ＣＳＦ标本分别用ＰＣＲ分子杂交和病毒分离等三种方法检测ＨＳＶ；显示ＰＣＲ最为敏感。表明ＰＣＲ技术的广泛应用将提高ＨＳＥ的早期诊断水平，指导临床正确治疗。     

Point mutation in the band 4.2 gene associated with autosomal recessively inherited erythrocyte band 4.2 deficiency

Abstract: A patient who represented acute hemolytic crisis was studied. Analysis of the erythrocyte membrane proteins by SDS-PAGE revealed a deficiency of band 4.2. In the family, the sister of the patient who had been clinically normal was also shown to be deficient in band 4.2. Binding studies showed that the propositus' membranes were able to bind normal band 4.2 protein as much as control. It was suggested that the binding sites for the protein were prepared on the membrane. We analyzed the band 4.2 cDNA of the propositus and detected a mutation that changes a codon for alanine to one for threonine at residue 142. Band 4.2 exon III of genomic DNA which included the mutation site was amplified and sequenced directly in the family members, and it was revealed that only the homozygotes of the mutation allele manifested band 4.2 deficiency and the parents, who were heterozygotes, showed normal amounts of band 4.2. Recently, the same mutation was reported as Protein 4.2^NIPPON in another 4 cases (Bouhassira et al. Blood 1992: 79: 1846–1854). This study supports the hypothesis that this mutation is the pathogenetic cause of band 4.2 deficiency and not a polymorphism.     

创面异体移植培养表皮细胞后存活的判定

应用４种方法判定烧伤创面异体移植的培养表皮细胞存活情况：１．聚合酶链反应（ＰＣＲ）查Ｙ染色体特异性ＤＮＡ片段；２．ＰＣＲ扩增ＰＭＣＴ１１８长度多态性基因位点；３．ＰＣＲ／ＳＳＯＨＬＡ－ＤＱａ分型；４．ＤＮＡ指纹。共检测１６例病人的２７个活检标本，均证实有供者的ＤＮＡ，最长时间为移植后９２天。初步实验结果表明：培养表皮异体移植后可存活较长时间。     

输送链的结构与齿形探讨(三)——修正齿形链传动特性及完善齿形修正设计

本文讨论用“包络一轨迹”法设计的修正齿形链的传动特性,并提出了完善齿形修正设计的方法,基本上实现消除链传动申的“多边形效应”。     

抗乙酰胆碱受体单链抗体对致病性抗体结合活性的抑制作用

为探讨单链抗体 (ScFv )对重症肌无力 (MG )的特异性免疫治疗作用 ,从分离自MG患者胸腺的抗乙酰胆碱受体(AchR )抗原结合片段Fab6 37构建单链抗体ScFv6 37。应用放射免疫测定法测定了ScFv6 37与刺激抗原人AchR的特异性结合活性以及与相关抗原大鼠AchR和电鳐AchR的交叉反应 ,应用竞争性ELISA测定抑制致病性抗AchR完整抗体IgG6 37与人AchR结合活性。结果发现ScFv6 37只能与人AchR结合 ,不能与大鼠和电鳐的AchR结合。对IgG6 37与人AchR结合的抑制率为 17 5 %～ 32 9%。表明单链抗体对AchR具有一定的“保护”作用。