Differentiation of mycobacterial species by PCR-restriction analysis of DNA (342 base pairs) of the RNA polymerase gene (rpoB)

PCR amplification-restriction analysis (PRA) of rpoB DNA (342 bp), which comprises the Rif(r) region, was used for the differential identification of 49 mycobacteria. The DNA had been used previously for the identification of mycobacterial species by comparative sequence analysis (B. J. Kim et al., J. Clin. Microbiol. 37:1714-1720, 1999). Digestion with four restriction enzymes (HaeIII, HindII, MvaI, and AccII), which were selected on the basis of rpoB DNA sequences, generated distinctive PRA patterns that allowed not only the reference strains but also the clinical isolates of mycobacteria to be distinguished. Both rapidly and slowly growing mycobacteria were distinctly differentiated by HaeIII digestion of the amplified rpoB DNA. By HindII digestion the Mycobacterium tuberculosis complex was distinguished from the other mycobacteria. Furthermore, six subspecies of Mycobacterium kansasii (subspecies I to VI) as well as the closely related Mycobacterium gastri, and other closely related species, were distinguished by simultaneous digestion of MvaI and AccII. According to the rpoB PRA scheme, 240 strains of clinical isolates could be identified. It was also possible to detect and identify M. tuberculosis directly from sputa and bronchoalveolar lavage specimens. These results suggest that PRA of rpoB DNA is a simple and feasible method not only for the differentiation of culture isolates but also for the rapid detection and identification of pathogenic mycobacteria in primary clinical specimens.     

Inhibition of experimental autoimmune encephalomyelitis in Lewis rats by nasal administration of encephalitogenic MBP peptides: synergistic effects of MBP 68-86 and 87-99

Induction of mucosal tolerance by inhalation of soluble peptides with defined T cell epitopes is receiving much attention as a means of specifically down-regulating pathogenic T cell reactivities in autoimmune and allergic disorders. Experimental autoimmune encephalomyelitis (EAE) induced in the Lewis rat by immunization with myelin basic protein (MBP) and Freund's adjuvant (CFA) is mediated by CD4+ T cells specific for the MBP amino acid sequences 68-86 and 87-99. To further define the principles of nasal tolerance induction, we generated three different MBP peptides (MBP 68-86, 87-99 and the non- encephalitogenic peptide 110-128), and evaluated whether their nasal administration on day -11, -10, -9, -8 and -7 prior to immunization with guinea pig MBP (gp-MBP) + CFA confers protection to Lewis rat EAE. Protection was achieved with the encephalitogenic peptides MBP 68-86 and 87-99, MBP 68-86 being more potent, but not with MBP 110-128. Neither MBP 68-86 nor 87-99 at doses used conferred complete protection to gp-MBP-induced EAE. In contrast, nasal administration of a mixture of MBP 68-86 and 87-99 completely blocked gp-MBP-induced EAE even at lower dosage compared to that being used for individual peptides. Rats tolerized with MBP 68-86 + 87-99 nasally showed decreased T cell responses to MBP reflected by lymphocyte proliferation and IFN-gamma ELISPOT assays. Rats tolerized with MBP 68-86 + 87-99 also had abrogated MBP-reactive IFN-gamma and tumor necrosis factor-alpha mRNA expression in lymph node cells compared to rats receiving MBP 110-128 nasally, while similar low levels of MBP-reactive transforming growth factor-beta and IL-4 mRNA expressing cells were observed in the two groups. Nasal administration of MBP 68-86 + 87-99 only slightly inhibited guinea pig spinal cord homogenate-induced EAE, and passive transfer of spleen mononuclear cells from MBP 68-86 + 87-99-tolerized rats did not protect naive rats from EAE. Finally, we show that nasal administration of MBP 68-86 + 87-99 can reverse ongoing EAE induced with gp-MBP, although higher doses are required compared to the dosage needed for prevention. In conclusion, nasal administration of encephalitogenic MBP peptides can induce antigen-specific T cell tolerance and confer incomplete protection to gp-MBP-induced EAE, and MBP 68-86 and 87-99 have synergistic effects. Non-regulatory mechanisms are proposed to be responsible for tolerance development after nasal peptide administration.      

Cytogenetic and molecular cytogenetic studies of a case of interstitial deletion of proximal 15q

A 4-month-old child with multiple anomalies was determined to have an interstitial deletion of chromosome 15, i.e., del(15) (q12q14). The deletion appears not to be a typical deletion of 15q12 such as seen in Angelman and Prader-Willi syndromes, but appears to be more distal, involving either loss of all of 15q12 and part of 15q14, or part of 15q12 and most of 15q14. In either case, 15q13 is missing. Fluorescent in situ hybridization with probes for 15 centromere (D15Z), pericentromeric satellite sequences (D15Z1), and chromosome 15 painting probes shows the deleted chromosome to involve only 15 and no other acrocentric chromosome. Hybridization with probes for the AS and PWS loci (D15S11 and GABAB3, Oncor) show both sites to be intact in the deleted 15. The case is compared with two other reports with overlapping interstitial deletions of proximal 15q, neither of which shows typical features of Angelman or Prader-Willi syndromes.     

骨折愈合塑形的力学机理I^＊——骨表面再造理论的应用

深入探讨长骨骨折愈合塑形阶段的力学机理,采用骨表面再造理论与有限元结合的方法。我们选取用应变能密度作为力学激励的骨表面再造理论,有限元分析采用三维的空间模型,利用我们编制的长骨表面再造系统“BRSS97”对长骨骨折愈合塑形阶段的三种类型：外骨痂型、骨内缺损型和骨外缺损型的力学机理进行研究。结果表明：骨痂可以完全吸收,骨缺损可以恢复,三种情况下骨均可以恢复到正常状态。由此说明长骨骨折愈合塑形过程就是骨材料对力学激励的适应过程。     

赤芝中新颖杂萜-三萜杂聚体的分离纯化及其改善C2C12细胞胰岛素抵抗作用

目的 赤芝 (Ganoderma lucidum) 在民间被用于糖尿病治疗,但缺乏数据支撑,需探索其化学成分及其是否具有抗糖尿病作用以利于临床推广。方法 采用多种分离技术,如 MCI gel CHP 20P、RP-18、Sephadex LH-20、硅胶柱色谱、 制备薄层色谱 (Preparative Thin-Layer Chromatography,PTLC) 和高效液相色谱 (High Performance Liquid Chromatography, HPLC) 等,对云南产赤芝的低极性成分进行研究,利用一维 (One Dimensional,1D) 和二维 (Two Dimensional,2D) 核磁共振波谱 (Nuclear Magnetic Resonance Spectroscopy,NMR) 等方法鉴定化合物结构,在C2C12细胞胰岛素抵抗体外模型中研究其活性。结果 从云南2个产地赤芝中分离鉴定8个杂萜-三萜杂聚体类新化合物,ganolucinins D-K (1-8),其中化合物7和8可上调胰岛素受体底物1 (Insulin Receptor Substrate 1,IRS1) 和蛋白激酶B (Protein Kinase B,PKB/Akt) 磷酸化, 8可促进C2C12细胞葡萄糖摄取。结论 赤芝中可能存在一系列杂萜-三萜杂聚体类化合物,其中化合物8具有改善胰岛素抵抗潜力,可能是灵芝抗糖尿病的药效物质之一。     

The generation and characterization of a cell line derived from a sporadic renal angiomyolipoma: use of telomerase to obtain stable populations of cells from benign neoplasms

Angiomyolipomas are benign tumors of the kidney derived from putative perivascular epithelioid cells, that may undergo differentiation into cells with features of melanocytes, smooth muscle, and fat. To gain further insight into angiomyolipomas, we have generated the first human angiomyolipoma cell line by sequential introduction of SV40 large T antigen and human telomerase into human angiomyolipoma cells. These cells show phenotypic characteristics of angiomyolipomas, namely differentiation markers of smooth muscle (smooth muscle actin), adipose tissue (peroxisome proliferator-activator receptor gamma, PPARgamma), and melanocytes (microophthalmia, MITF), thus demonstrating that a single cell type can exhibit all of these phenotypes. These cells should serve as a valuable tool to elucidate signal transduction pathways underlying renal angiomyolipomas.     

慢性乙肝患者NK,ADCC活性及其对IFN—α,IFN—γ的反应

本文用Hela细胞乳酸脱氢酶释放法测定了42例慢性乙肝病人外周血NK、ADCC活性及其对IFN-α100U/ml、500U/ml及IFN-γ500U/ml预处理4小时后的反应。结果显示,病人PBL NK,ADCC活性与正常对照有显著差别,经IFNs处理后,其NK或/和ADCC活性均有不同程度的升高反应,从而提示了IFNs在慢性肝病治疗中的重要作用。     

空肠弯曲菌HSP43诱导自身免疫机理──分子模拟和抗原优势

我们曾发现空肠弯曲菌４３ｋＤ热休克蛋白（ＨＳＰ４３）能诱导小鼠产生自身免疫应答，本文则进一步分析了这种诱导作用的机理。二株针对ＨＳＰ６０保守区序列的单克隆抗体ＩＩＨ９和ＭＬ－３０不但能结合人及小鼠细胞中ＨＳＰ６０家族成员，而且也能结合ＨＳＰ４３，表明ＨＳＰ４３、人及小鼠ＨＳＰ６０三者均属同一家族成员，具有序列上的高度同源性。小鼠用空肠弯曲菌免疫后出现了针对１０种菌体蛋白的抗体，其中最早被诱导的抗体是针对ＨＳＰ４３的，并且该种抗体在随后８０ｄ观察期间内保持了较高活性，表明ＨＳＰ４３是优势抗原。本文结果提示，ＨＳＰ４３较易被免疫系统识别而产生应答，通过和宿主ＨＳＰ６０高度序列同源性而可能呈现分子模拟，从而诱导自身免疫损伤。     

6024例分娩的方式选择与新生儿结局

目的探讨阴道分娩和剖宫产对新生儿的风险。方法对6024例妊娠的分娩方式、剖宫产指征以及新生儿结局回顾性分析。结果剖宫产率为35.3%,其指征主要是头盆不称、社会因素、宫内窘迫、臀位等。分娩新生儿6016例,其中因各种疾患转儿科822例,占13.5%。主要转科原因为早产儿低体重、窒息、高胆红素血症和吸入综合症,各疾病发病率与分娩方式无关。结论剖宫产没有增加新生儿的风险,仍是解决难产的重要手段,但应严格控制手术指征。