脑缺血大鼠海马超微结构的形态定量研究

对大鼠双侧颈总动脉夹闭2小时,经透射电镜观察海马,用Weibel氏形态定量法分别测量了海马1区和3区的线粒体和突触的表面积密度(Svi)、表面积—体积比(Si/Vi),并与对照组进行了比较。结果表明:缺血时海马1区受损较严重,表现为线粒体体积缩小,数量减少,Svi下降;突触数量有增多的趋势,但突触的Svi与Si/Vi变化不明显。缺血组海马3区受损较轻,线粒体和突触的结构基本正常,其Svi、Si/Vi与对照组差别不显著,提示了3区对缺血有较强的耐受性。     

人肿瘤细胞与正常细胞内微管的PAP免疫酶细胞化学观察

我们利用兔抗微管蛋白抗体和兔抗辣根过氧化物酶(HRP)抗血清制备的HRP—抗HRP(PAP)复合物,建立了微管的PAP免疫酶细胞化学方法。应用此法观察到人食管癌ECa 109、胃癌SGC 7901,乳腺癌MCF 7和成骨肉瘤OS 732细胞间期胞质微管减少或消失,只有大量弥散分布的微管蛋白棕色反应产物,在微管组织中心(MTOC)附近十分密集,而正常成纤维细胞和胎儿胃粘膜上皮细胞间期,都有发达的胞质微管结构(CMTC)。在分裂期,这些肿瘤细胞都显示纺锤体微管,与正常细胞比较无明显差异。本研究应用PAP方法进一步证明,以前用免疫荧光细胞化学方法观察到的人肿瘤细胞间期胞质微管缺陷的特征。除去低温(4℃)或秋水仙酰胺处理后,解聚的CMTC又可恢复,表明本方法与免疫荧光染色法,同样具有很高的特异性。本工作在细胞固定及免疫反应的某些步骤上有所改进。     

J chain deficiency in human IgM monoclonal antibodies produced by Epstein-Barr virus-transformed B lymphocytes

Six human IgM monoclonal antibodies against Pseudomonas aeruginosa were purified and characterized. On agarose-acrylamide sodium dodecyl sulfate (SDS) gels run under nonreducing conditions, IgM monoclonal antibodies showed variable amounts of a slower migrating form of IgM in addition to the one co-migrating with plasma IgM. Protein blotting with anti-J chain antibody showed that the slower migrating form did not contain J chain. Analysis of one of the monoclonal antibodies by sucrose gradient centrifugation showed that the J chain-deficient form sedimented faster than the complete IgM. It is known that IgM preparations lacking J chain sediment faster by sucrose gradient centrifugation analysis and tend to form hexamers. The slower migrating form of IgM we observed on SDS gels under nonreducing conditions could be hexameric IgM. Further evaluation of this monoclonal antibody demonstrated that both forms of IgM had the same antigen-binding activity. Glycosylation of the light chain was demonstrated in two of the monoclonal antibodies.     

淋巴结血管内T细胞淋巴瘤1例报道及文献复习

目的　探讨血管内淋巴瘤 (IVL)的临床病理特征。方法　对 1例腹股沟淋巴结IVL临床、病理组织学及免疫表型进行观察分析并复习文献。结果　男性 31岁 ,不明原因高热伴消瘦 5 0天 ,右腹股沟直径 1cm淋巴结 1枚 ,B超示肝脏轻度增大 ,血LDH明显升高伴ESR及转氨酶轻度升高 ,外周血WBC 3 3× 10 7/L ,骨髓像、多种病原及各肿瘤相关抗原检测均无异常。病理活检 :腹股沟淋巴结大部分破坏 ,代之以大量扩张的中小血管 ,腔内充满大量异型淋巴样细胞 ,局部伴管壁、管周浸润并累及结外脂肪组织。瘤细胞免疫表型CD4 5、CD4 5RO、CD3阳性 ,CK、CD6 8、CD79α、CD2 0均阴性 ,血管壁及内皮细胞CD31、CD34阳性。行CHOP化疗后症状缓解 ,现仍在随访中。结论　IVL是一罕见的非霍奇金淋巴瘤 ,好发于中枢神经系统及皮肤 ,其他部位少见 ,绝大数为B细胞型 ,T型罕见 ,以浅表淋巴结活检确诊者尚无报道。临床表现有一定提示性 ,确诊靠组织病理学检查 ,部分病例对化疗敏感 ,但多数病例预后差     

Adult-onset type II citrullinemia and idiopathic neonatal hepatitis caused by citrin deficiency: involvement of the aspartate glutamate carrier for urea synthesis and maintenance of the urea cycle

Citrin is a mitochondrial aspartate glutamate carrier primarily expressed in the liver, heart, and kidney. We found that adult-onset type II citrullinemia is caused by mutations in the SLC25A13 gene that encodes for citrin. In this report, we describe the frequency of SLC25A13 mutations, the roles of citrin as a member of the urea cycle and as a member of the malate-aspartate shuttle, the relationship between its functions and symptoms of citrin deficiency, and therapeutic issues.     

Prevalence of Antibodies to Hepatitis E Virus in Veterinarians Working with Swine and in Normal Blood Donors in the United States and Other Countries

Hepatitis E virus (HEV) is endemic in many developing and some industrialized countries. It has been hypothesized that animals may be the source of infection. The recent identification of swine HEV in U.S. pigs and the demonstration of its ability to infect across species have lent credence to this hypothesis. To assess the potential risk of zoonotic HEV infection, we tested a total of 468 veterinarians working with swine (including 389 U.S. swine veterinarians) and 400 normal U.S. blood donors for immunoglobulin G anti-HEV. Recombinant capsid antigens from a U.S. strain of swine HEV and from a human HEV strain (Sar-55) were each used in an enzyme-linked immunosorbent assay. The anti-HEV prevalence assayed with the swine HEV antigen showed 97% concordance with that obtained with the human HEV antigen (kappa = 92%). Among the 295 swine veterinarians tested from the eight U.S. states (Minnesota, Indiana, Nebraska, Iowa, Illinois, Missouri, North Carolina, and Alabama) from which normal blood donor samples were available, 26% were positive with Sar-55 antigen and 23% were positive with swine HEV antigen. In contrast, 18% of the blood donors from the same eight U.S. states were positive with Sar-55 antigen and 17% were positive with swine HEV antigen. Swine veterinarians in the eight states were 1.51 times more likely when tested with swine HEV antigen (95% confidence interval, 1.03 to 2.20) and 1.46 times more likely when tested with Sar-55 antigen (95% confidence interval, 0.99 to 2.17) to be anti-HEV positive than normal blood donors. We did not find a difference in anti-HEV prevalence between veterinarians who reported having had a needle stick or cut and those who had not or between those who spent more time (> or = 80% of the time) and those who spent less time (< or = 20% of the time) working with pigs. Similarly, we did not find a difference in anti-HEV prevalence according to four job categories (academic, practicing, student, and industry veterinarians). There was a difference in anti-HEV prevalence in both swine veterinarians and blood donors among the eight selected states, with subjects from Minnesota six times more likely to be anti-HEV positive than those from Alabama. Age was not a factor in the observed differences from state to state. Anti-HEV prevalence in swine veterinarians and normal blood donors was age specific and paralleled increasing age. The results suggest that swine veterinarians may be at somewhat higher risk of HEV infection than are normal blood donors.     

Characterization of antimicrobial resistance among Escherichia coli O111 isolates of animal and human origin

Fifty isolates of Escherichia coli serogroup O111 recovered from humans and various animal species over a 24-year period (1976-1999) were examined for typical virulence-associated factors and susceptibilities to antimicrobials of human and veterinary significance. Nine H (flagellar) types were identified including nonmotile (n = 24), 32 (n = 12), negative (n = 5), and 56 (n = 3). Thirty-five (70%) isolates possessed at least one Shiga-toxin-producing E. coli (STEC)-associated virulence determinants (eae, stxl, stx2, hlyA) via PCR analysis. Of these 35 isolates, 20 possessed eae, stxl, and hlyA genes, whereas three isolates possessed eae, stxl, stx2, and hylA genes. Multiple antibiotic resistance was observed in 70% of the 50 E. coli O111 isolates. The majority of isolates displayed resistance to streptomycin, sulfamethoxazole, tetracycline, and kanamycin. Bacterial resistance to ampicillin, gentamicin, chloramphenicol, trimethoprim and apramycin was also observed. Integrons were identified in 23 (46%) of the E. coli isolates assayed, with a 1-kb amplicon being most frequently observed. DNA sequencing of these integrons revealed the presence of the aadA gene, encoding resistance to streptomycin. Two integrons of 1.5 and 2 kb contained the aadA2 and either dfrI or dfrXII genes, encoding resistance to streptomycin and trimethoprim, respectively. Integrons were also identified from isolates dating back to 1982. Isolates were further genetically characterized via ribotyping, which identified 15 distinct ribogroups, with 62% of isolates clustering into four major ribogroups. Certain riboprint patterns from different animal species, including humans, were observed in isolates spanning the 24-year collection period, suggesting the dissemination of specialized pathogenic O111 clones.