幽门螺杆菌受体样物质的研究

目的 研究胃，肝，肠组织细胞上的幽门螺旋力（ＨＰ）受体样物质。方法 采用酶免疫亲和配体法及用大肠杆菌，空肠弯曲菌作特异性阻断试验，结果 ＨＰ受体样物质仅存在于胃粘膜细胞，不能被大肠杆菌，空肠弯曲菌阻断，同时发现采用高碘酸氧化法检测表明此物质与粘多糖蛋白有关，在体外试验中能够增强ＨＰ的抗吞噬能力，结论 ＨＰ受体样物质具有组织和细菌种属特异性。     

纳络酮在抢救新生儿窒息中的应用

纳络酮为特异性阿片受体拮抗剂,具有竞争性阻断并取代阿片样物质与受体的结合的作用,可消除阿片类药物中毒症状。本文作者自1996～1999年在新生儿窒息时应用纳络酮,取得了较为理想的效果。 1 资料与方法 新生儿出生1分钟Apgar评分小于7天,经清理呼吸道、面     

空肠弯曲菌抗体对正常结肠神经节细胞结合的病理学观察

目的:通过观察空肠弯曲菌抗体在正常结肠神经节细胞上的结合,初步探讨空肠弯曲菌抗体影响结肠神经节细胞发育,导致神经节细胞变性的可能性.方法:取正常结肠标本60例,随机分为实验组和对照组,免疫组织化学方法处理.实验组利用空肠弯曲菌抗体作用于正常结肠神经节细胞,观察抗体与神经节细胞的结合情况;对照组利用PBS液代替空肠弯曲菌抗体,其他同实验组.比较两组空肠弯曲菌抗体的结合有无不同.结果:空肠弯曲菌抗体可以和正常结肠的神经节细胞结合,结合的阳性率为83.3%.实验组和对照组比较差异有统计学意义(P<0.05).结论:空肠弯曲菌抗体可与神经节细胞结合,可能影响神经节细胞发育及导致神经节细胞变性.     

空肠弯曲菌感染与Guillain—Barre综合征

目的：探讨空肠弯曲菌感染与Ｇｕｉｌｌａｉｎ－Ｂａｒｒｅ综合征（ＧＢＳ）发病的关系以及空肠弯曲菌感染和抗－ＧＭ１抗体与疾病严重程度的关系。方法：用ＥＬＩＳＡ方法检测８５例ＧＢＳ患者血清中的空肠弯曲菌ＩｇＧ、ＩｇＭ、ＩｇＡ抗体及抗－ＧＭ１抗体,同时从患者的大便中培养空肠弯曲菌;根据Ｈｕｇｈｅｓ报道的方法对病情轻重进行评分。结果：ＧＢＳ患者空肠弯曲菌感染率为５１．８％,抗－ＧＭ１抗体检出率为４２．４％;     

空肠弯曲菌致病分子机制研究进展

空肠弯曲菌(Campylobacter jejuni)是人类的食源性病原菌,感染后主要引起急性肠炎,与人类格林-巴利综合症也有密切关系.研究表明,空肠弯曲菌致病性是多种毒力因子共同作用的结果.作者从分子生物学研究水平综述空肠弯曲菌黏附、定植、侵入、产细胞毒素、分子模拟等致病机制.     

酪氨酸激酶受体抑制剂STI571对胰腺癌细胞生长的抑制作用

STI571（CGP57148）是特异性酪氯酸激酶受体抑制剂，特异性阻断Abl、血小板衍化生成因子、c-kit受体。本研究旨在探讨应用STI571对胰腺癌细胞生长的影响。     

可溶性Fas阻断肝癌细胞通过Fas/FasL 途径触发T淋巴细胞的凋亡

目的　通过阻断Fas介导T细胞凋亡 ,建立快速大量激活制备肿瘤特异性细胞毒性T淋巴细胞 (CTL)的方法。方法　分离肝癌细胞和肿瘤浸润淋巴细胞 (TIL)。选择FasL表达阳性的肝癌标本 ,在体外将两者混合 ,并在CD2 8单抗共刺激下 ,激活制备特异性CTL。应用可溶性Fas受体阻断肝癌细胞通过Fas FasL途径触发激活T细胞凋亡 ,与对照组比较观察阻断凋亡作用 ,通过3H掺入法和51 Cr释放法了解T细胞增殖杀伤活性。结果　流式细胞术仪检测未阻断组较阻断组和未阻断对照组凋亡率明显升高 ,未阻断组凋亡率达 4 7 82 %± 0 13% ,静息性T淋巴细胞组为 3 76 %± 0 2 5 % ,阻断组为 8 2 2 %± 0 2 6 % (P <0 0 1) ,DNAladder显示未阻断组T淋巴细胞出现明显梯状条带 ,阻断组为阴性。51 Cr释放法表明阻断后T淋巴细胞杀伤活性增加 ,较未阻断组及未阻断对照组差异有显著性 (P<0 0 1)。3H掺入法检测证实可溶性Fas受体阻断激活T细胞凋亡后 ,细胞增殖明显升高 ,较未阻断组差异有显著性 (P <0 0 1)。结论　体外实验可获得大量激活T细胞 ,并可杀伤肿瘤细胞 ,     

Hedgehog信号通路对胰腺癌细胞增殖的影响

目的 研究特异性阻断hedgehog信号通路对人胰腺癌Mia PaCa-2细胞增殖的影响.方法 用Western blot方法检测7种胰腺癌细胞系中hedgehog信号蛋白表达情况,筛选出hedgehog通路活化明显的Mia PaCa-2细胞系进行研究;应用特异性hedgehog通路阻断剂KAAD-cyclopamine阻断Mia PaCa-2细胞的hedgehog信号通路,Western blot方法检测Gli1蛋白表达变化;MTT法检测阻断hedgehog信号通路对胰腺癌细胞增殖的影响;RT-PCR方法检测胰岛素样生长因子2(IGF2)mRNA表达的变化.结果 KAAD-cyclopamine处理后hedgehog信号通路中关键效应蛋白Gli1表达水平明显下调(P=0.032);KAAD-cyclopamine明显抑制胰腺癌Mia PaCa-2细胞增殖,其作用呈剂量及时间依赖性;阻断hedgehog信号通路后,胰腺癌细胞中胰岛素样生长因子2(IGF2)mRNA表达水平下调(P=0.037).结论 Hedghog信号通路异常活化参与促进胰腺癌细胞增殖;特异性阻断hedgehog信号通路后胰腺癌细胞增殖明显受抑制,其部分机制可能通过下调IGF2表达水平实现.     

253例HIV感染合并慢性腹泻患者粪便标本的病原微生物检测分析

目的 探讨HIV感染者慢性腹泻的病原学种类及其特点,使患者得到及时的预防和治疗.方法 对253例慢性腹泻HIV感染者的粪便标本首先进行了涂片及染色检测,直接涂片检测蓝氏贾第鞭毛虫,采用革兰染色检测真菌孢子及菌丝,抗酸染色(萋-尼氏染色法)检测分枝杆菌,用改良抗酸染色法检测隐孢子虫,采用常规粪便培养检测志贺菌、沙门菌、肠侵袭性大肠埃希菌及真菌,采用微需氧培养检测空肠弯曲菌,采用金标法检测难辨梭状芽孢杆菌毒素(A+B).结果 本研究共检测出各种病原微生物159株,其中真菌最多,占45%(114/253),隐胞子虫占12.6%(32/253),结核分枝杆菌占2.4%(6/253),难辨梭状芽孢杆菌占1.58%(4/253),空肠弯曲菌占0.8%(2/253),沙门菌占0.4%(1/253).结论 真菌、隐胞子虫、分枝杆菌、难辨梭状芽孢杆菌等是HIV感染者慢性腹泻的主要病原菌,积极寻找病原,以期使患者得到及早的预防和治疗.     

以VEGF及其受体为靶点的抗肿瘤血管形成治疗

血管内皮细胞生长因子（VEGF）调控血管生长作用强、特异性高,在正常组织和肿瘤细胞中的表达差异显著;VEGF特异性受体也绝大部分只在内皮细胞表达。因此,VEGF及其受体就成为肿瘤治疗的理想靶点。通过抑制VEGF的释放、中和刚释放出的VEGF以及阻断VEGF与其受体的结合等途径,可以抑制肿瘤血管形成,达到治疗肿瘤的目的。     

人三叶因子1融合蛋白对烧伤小鼠胃黏膜的保护作用

目的 了解人三叶因子1(hTFF1)融合蛋白在减轻烧伤小鼠胃黏膜损害中的作用.方法 利用原核重组表达质粒pET32α-hTFF1,诱导表达基因重组hTFF1(rhTFF1)融合蛋白.采用小鼠30%TBSAⅢ度烧伤模型,按照随机数字表法分为烧伤治疗组:给予一定时间和一定剂量的rhTFF1融合蛋白灌胃治疗;烧伤对照组:方式同前,改用等渗盐水灌胃.另设正常对照组.通过胃黏膜外观、损伤指数和病理切片结果,比较前2组小鼠胃黏膜损伤前后的情况,并以正常对照组相应指标为参照. 结果 能够获得具有良好特异性的rhTFF1融合蛋白.伤后1 d小鼠胃黏膜损伤达峰值,烧伤治疗组和烧伤对照组小鼠胃黏膜糜烂发生率分别为22.2%和77.8%,损伤指数分别为2.0±1.2和6.2±2.0.正常对照组小鼠上述指标为0. 结论 rhTFF1融合蛋白能够在大肠杆菌系统表达,对小鼠烧伤后损害的胃黏膜有明显的治疗作用.     

Receptors for Escherichia coli adhesins in the genitourinary tract in a non-human primate

OBJECTIVE: To study the expression of receptors allowing adhesin-mediated binding of Escherichia coli to urogenital tissues ranging from the kidney to the vagina in cynomolgus monkeys using an in situ assay. MATERIAL AND METHODS: Receptors specific for four relevant adhesins were investigated: PapG and PrsG of P-fimbriae binding to gal-alpha(1-4)gal glycosphingolipids (preferentially globoside and the Forssman antigen, respectively): and two variants of FimH of type 1 fimbriae, one binding to monomannose/trimannose and the other to trimannose only. To ascertain the specificity of the observed bindings we used adhesion inhibition by receptor analogues as well as E. coli adhesin knockout mutants. RESULTS: The distributions of PapG and FimH receptors in monkey tissues showed great similarities to available data in humans. Whilst monomannose receptors were expressed on the surface epithelium in both the monkey bladder and ureter, trimannose receptors were not. The different distribution of FimH isoreceptors and the heterogeneity of FimH adhesin variants among E. coli may explain contradictory earlier findings in type 1 fimbriae-mediated adhesion to the human bladder and to renal tissues. We also found evidence of a hitherto unknown type of host-aggressor interaction on vaginal and urethral mucosa, which was not discovered until type 1 fimbriae had been eliminated. CONCLUSIONS: A precise molecular fit between host receptors and bacterial lectins is important in infectious pathogenesis. We conclude that urinary tract infection in the cynomolgus monkey is a relevant model of the human disease because of the similarity in the expression of receptors for E. coli adhesins on epithelial surfaces in the two species.     

The urokinase plasminogen activator receptor is crucially involved in host defense during acute pyelonephritis

The urokinase plasminogen activator receptor (uPAR) is expressed at the cell surface of inflammatory cells and plays an important role in neutrophil migration. To investigate the in vivo role of uPAR during urinary tract infection, acute pyelonephritis was induced in uPAR-/- and wild-type (WT) mice by intravesical inoculation with 1 x 10(9) colony-forming units (CFU) of uropathogenic Escherichia coli. Mice were killed after 24 and 48 h, after which bacterial outgrowth and cytokine levels in kidney homogenates were determined. Influx of neutrophils was quantified by myeloperoxidase-enzyme-linked immunosorbent assay. uPAR-/- kidneys had significantly higher numbers of E. coli CFU, accompanied by higher levels of interleukin-1beta (IL-1beta), IL-6, keratinocyte-derived chemokine (KC), macrophage inflammatory protein-2 (MIP-2), and tumor necrosis factor-alpha (TNF-alpha). However, the number of infiltrating neutrophils was similar in uPAR-/- and WT mice at both time points, suggesting that uPAR-/- neutrophils have a lower ability to eliminate E. coli. To further investigate this, neutrophil oxidative burst and phagocytosis was measured. The generation of reactive oxygen species upon stimulation with E. coli was not diminished in uPAR-/- neutrophils compared with WT. Interestingly, uPAR-/- neutrophils displayed significantly impaired phagocytosis of E. coli organisms compared with WT neutrophils. We conclude that uPAR is crucially involved in host defense through phagocytosis during E. coli induced acute pyelonephritis.     

Morphological changes in the stomach and duodenum in ulcer disease with Helicobacter infection

In 119 gastroduodenal ulcer disease (UD) patients the presence of Helicobacter pylori (HP) was determined and the morphological changes of gastric mucosa were studied up. The rapid test with urease, cytological investigation of the smear prints and histological examination of the operational material biopsies were done for the HP elimination detection. In gastric UD with nonsignificant HP dissemination the mucosal morphological changes are limited mainly by the cell infiltration of various degree. While the duodenal UD observation, as a rule, there were revealed the HP dissemination of the III-IV degree and significant morphological changes, extended in deep layers of gastric wall, stroma, significant dystrophic and necrobiotic processes in superficial layer.     

Interleukin 2 toxin: a step toward selective immunomodulation

We have used protein engineering and recombinant DNA methodologies to genetically replace the eukaryotic cell receptor binding domain of diphtheria toxin with interleukin 2 (IL-2). The toxin-related T cell growth factor fusion gene has been cloned in Escherichia coli K12. Recombinant strains of E coli produce a 68,086 K hybrid toxin, IL-2 toxin that retains immunologic properties intrinsic to both its diphtheria toxin and IL-2 components. IL-2 toxin has been found to selectively inhibit protein synthesis in both human and murine T cell lines that bear high affinity IL-2 receptors, whereas the hybrid toxin is not active against cells that do not bear this receptor. The cytotoxic action of IL-2 toxin is specifically blocked by free IL-2 and monoclonal antibodies that bind to the p55 (Tac antigen) subunit of the high affinity IL-2 receptor. In addition, IL-2 toxin, like diphtheria toxin itself, must pass through an acidic compartment in order to deliver its adenosine diphosphate ribosyl transferase activity to the cytosol of target T cells. In a murine delayed type hypersensitivity (DTH) model system, we have shown that IL-2 toxin treatment induces a marked immunosuppression.     

Helicobacter pylori infection in various groups of patients studied, estimated by 14C-urea breath test

The aim of this study was the detection of helicobacter pylori (HP) infection and estimation of the clinical validity and the accuracy of the 14C-urea breath test in the groups of patients studied. A total of 248 patients with gastric diseases were examined. There were 38 patients with gastric ulcer, 41 with duodenal ulcer, 43 with gastroduodenitis erosiva, 26 with hiatus hernia, 36 with gastric carcinoma and 64 patients with gastritis. There were 103 true positive (TP), 139 true negative (TN), 4 false negative (FN) and 2 false positive (FP) patients. There was no significant difference in the incidence of the HP infection between the groups of patients studied (p > 0.05). Sensitivity of the method was 96.3%, specificity 98.6%, positive predictive value 98.1%, negative predictive value 97.2% and accuracy 97.6%. Our results point out that the method is very accurate for the detection of HP infection.     

Bacterial infection and male infertility: absence of immunoglobulin A with specificity for common Escherichia coli 0-serotypes in seminal fluid of infertile men

We used an indirect solid phase radioimmunoassay to detect and quantitate immunoglobulin A (IgA) in male genital secretions with specificity for Escherichia coli (E. coli) antigen. We assayed the seminal fluid and expressed prostatic secretion (EPS) of a patient with chronic bacterial prostatitis (CBP) due to an 01 E. coli, the seminal fluid of 24 fertile men, and the seminal fluid of 62 men of infertile marriages. IgA directed apparently against the 0-antigen of the infecting E. coli was measurable in both the seminal fluid and EPS of the CBP patient. IgA in these specimens also bound to antigen in a mix of 8 common E. coli 0-serotypes that included an 01 E. coli. IgA with specificity for antigen in the mix of common E. coli 0-serotypes could not be detected in the seminal fluid of the fertile men or the men of infertile marriages. These data suggest that subclinical E. coli infections of the male reproductive tract are not commonly associated with infertility.     

Construction and preliminary screening of a human phage single-chain antibody library associated with gastric cancer.

BACKGROUND: The aim of this study was to construct a phage library of human single-chain antibodies associated with gastric cancer and screen such a library for CEA binding scFv. MATERIALS AND METHODS: The cDNA library of antibody variable regions was constructed using mRNA from metastatic lymph nodes or spleen of patients with stomach cancer by RT-PCR. These cDNA were assembled into a single-chain format and cloned into phagemid pCANTAB-5 and then transformed into Escherichia coli TG1. The scFv gene library was rescued by M13KO7 helper phage. CEA and the viable CEA-positive gastric cancer cell line MKN-28 were used to screen the phage antibody library. Indirect and tumor cell ELISA was used to determine the specificity of phage antibody. Fixed cell immunofluorescence and live cell FACS analysis were used to further characterize the binding of phage scFv. RESULTS: After transformation into E. coli TG1, 2.5 x 10(7) cfu/microg ampicillin-resistant clones grew. Sequences of those positive insert clones showed that the V(H) genes were derived from the V(H) III subgroup, while the V(L) genes belonged to the V(kappa) III subgroup. After four rounds of panning, the titer of eluted binding phage increased 135- to 158-fold and ELISA results showed that 20/95 clones can bind CEA and 47/95 clones can bind fixed tumor cells. Immunofluorescence and FACS analysis results showed that these phage scFv fragments could bind CEA-positive cells. CONCLUSIONS: We successfully constructed a human phage antibody library from lymph nodes of stomach cancer patients. Such kinds of library prove useful for generating tumor-antigen-specific human antibody fragments.     

Immunohistochemical localization of interleukin-1 and lipopolysaccharide (LPS) of experimental arthritis in the ankles of rats immunized with LPS extracted from Escherichia coli]

Sprague Dawley (SD) rats were immunized by subcutaneous injections with heat-killed E. coli 0:14 and lipopolysaccharide (LPS) extracted from E. coli for 15, 29 and 39 weeks which induced arthritis in the ankle. Localization of interleukin-1 (IL-1) and LPS in the ankle joints were investigated immunohistochemically. Serum IgM rheumatoid factor-like substance (RFLS) and anti-LPS IgM were detected by enzyme-linked immunosorbent assay (ELISA). Rats immunized with LPS for 39 weeks developed synovial lining cell hyperplasia in 25 of 40 ankles and lymphoid cell infiltration in 25 and pannus formation in 23, the rates of which were significantly higher than those of control and rats immunized with LPS for 15 and 29 weeks. The induction rate of arthritis in rats immunized with LPS was the same as that in rats immunized with E. coli. LPS and IL-1 were located in synovial cells and pannus in arthritic joints. Changes of RFLS level in rats immunized with LPS were elevated more gradually than those in rats immunized with E. coli. These findings suggest that LPS could stimulate IL-1 and RFLS production and may induce arthritis in rats resembling rheumatoid arthritis.     

荧光PCR技术在粪便幽门螺杆菌ureA基因检测中的应用

目的 评价荧光PCR技术检测粪便幽门螺杆菌（Helicobacter pylori,HP）urea基因的价值.方法 采用荧光PCR技术检测50例消化内科住院患者的粪便样本,其中23例通过胃黏膜活检组织尿素酶及病理组织染色确诊为HP感染.同时进行HP培养和血清HP尿素酶抗体检测.四格表x2检验比较3种方法的敏感性、特异性、阳性预测值和阴性预测值.结果 荧光PCR技术检测粪便HP感染的敏感性、特异性、阳性预测值和阴性预测值分别为1.00、0.96、96%和100%,而HP培养检测的敏感性、特异性、阳性预测值和阴性预测值分别为0.78、1.00、100%和84%,其中敏感性和阴性预测值与荧光PCR法相比,差异具有统计学意义（X2=5.60和4.44,P值均〈0.05）.血清HP尿素酶抗体检测的敏感性、特异性、阳性预测值和阴性预测值分别为0.96、0.74、76%和95%,其特异性和阳性预测值与荧光PCR法比较,差异具有统计学意义（X2=5.28和4.08,P值均〈0.05）.结论 粪便HPureA基因检测对诊断HP感染具有较高的临床价值.