幽门螺杆菌空泡毒素受体的研究进展

空泡变性细胞毒素(VacA)是幽门螺杆茵(Hp)的主要毒力因子,VacA受体的研究成为近年来Hp致病机制研究的新热点。本文综述了初步确认的VacA受体(RPTPβ)的特性及其可能的作用机制。     

PTP抑制剂对VacA空泡活性的影响

近期在VacA的研究中发现,该毒素对多种生长因子(尤其是EGF)作用于胃粘膜上皮细胞的信号转导通路有显影响,VacA对EGF诱导的受体蛋白酪氨酸激酶(receptor protin．tyrosmeHnase,RPTK)自身磷酸化及随后一系列的信号转导过程有明显的抑制作用。国外学已初步分离并克隆出胃癌细胞株膜表面的VacA受体,分子量大小约250kDa,氨基酸序列同源性分析显示该受体属于受体蛋白酪酸磷酸酶家族(receptor prodn-tyrosine phosphatase,RPTP)。     

原钒酸钠对成骨细胞株MC 3T3-E1增殖的影响及其与一氧化氮浓度的关系

目的　探讨原钒酸钠对成骨细胞株MC3T3 E1增殖的影响及其是否与一氧化氮 (NO)浓度有关。　方法　以噻唑蓝 (MTT)比色法检测MC3T3 E1细胞增殖及增殖抑制情况 ,用酶还原法测定细胞培养物上清液中NO的浓度。　结果　在低浓度 (2 5～ 10 0 μmol/L)原钒酸钠作用 2 4h后 ,MC3T3 E1细胞MTT测定值 (2 5 μmol/L时为 0 3380± 0 0 0 4 5、5 0 μmol/L时为 0 340 0±0 0 14 1、10 0 μmol/L时为 0 384 0± 0 0 313)较对照组 (0 2 5 4 0± 0 0 16 7)明显增加 (P均 <0 0 0 1) ;高浓度 (≥ 5 0 0 μmol/L)时则明显下降 ,5 0 μmol/L时为 0 2 16 0± 0 0 182 ,10 0 μmol/L时为 0 192 0±0 0 179(P均 <0 0 1) ;且作用 2 4、4 8和 12 0h细胞增殖趋势一致。细胞培养上清液中的NO浓度与MTT测定值成正比。 2 5 μmol/L原钒酸钠时NO浓度为 (17 2 0 8± 0 70 1) μmol/L ,5 0 μmol/L时为(7 386± 1 0 39) μmol/L ,空白对照组为 (15 341± 0 0 4 1) μmol/L。且低浓度原钒酸钠能减弱NO合酶(NOS)抑制剂L 硝基精氨酸甲酯 (L NAME)的细胞增殖抑制作用。　结论　低浓度原钒酸钠能促进MC3T3 E1细胞的增殖 ,高浓度则抑制增殖。NO可能参与调节原钒酸钠对MC3T3 E1增殖的作用。     

幽门螺杆菌VacA蛋白的纯化

目的对幽门螺杆菌(Hp)相对分子质量(Mv)95×10~2的VacA蛋白进行分离纯化。为进一步研究VaGA的作用机制奠定基础.方法采用经硫酸铵沉淀及透析后得到的Hp ccUG17874菌株浓缩上清,应用吸附层析、疏水层析、阴离子交换层析及凝胶过滤等液相层析方法进行VacA蛋白的纯化.每步层析后得到的样品均检测蛋白浓度及空泡毒素活性并行SDS-PAGE电泳检测蛋白成分.结果纯化蛋白的Mr为95×10~3,电泳纯,具有明显的空泡毒性,比活力达20480,与上清原液相比纯化倍数提高了4550倍,产率约为5μg/L.结论采用吸附层析、疏水层析、离子交换层析及凝胶过滤的纯化流程,可以成功分离纯化Hp液体培养上清液中的VacA,纯化的VacA蛋白可用于Hp致病机理的研究.     

血清铁、铁蛋白和脂肪肝关系的研究

目的　研究血清铁、血清铁蛋白与酒精性、非酒精性脂肪肝的关系。方法　采用 1秒钟快速肝穿刺 ,对 97例脂肪肝患者取肝组织标本 ,行HE和铁染色 ,分别用原子吸收光谱法和放射免疫法检测患者的血清铁和血清铁蛋白。结果　中重度酒精性脂肪肝 (AFL)血清铁、血清铁蛋白测定值 [(2 0 .9± 9.3) μmol/L ,(2 17.6± 71.8)ng/ml;(2 9.1± 6 .5 ) μmol/L ,(2 84 .7± 77.9)ng/ml]与对照组 [(10 .5± 5 .7) μmol/L ,(14 3.3± 71.9)ng/ml]比较明显升高 (P <0 .0 1)。重度非酒精性脂肪肝 (NAFL)的血清铁和血清铁蛋白 [(2 1.5± 11.1) μmol/L ,(199.3±72 .1)ng/ml]和对照组 [(10 .5± 5 .7) μmol/L ,(14 3.3± 71.9)ng/ml]比较亦显著升高 (P <0 .0 1) ,而且AFL多出现肝细胞灶性坏死 (6 7% )和肝铁过载(87% )。结论　重度NAFL及中重度AFL多出现血清铁和铁蛋白增高 ,AFL多合并肝铁过载 ,血清铁、铁蛋白可以作为肝铁过载的重要指标。     

大黄素对结肠癌血管内皮生长因子受体的影响及对结肠癌抑制作用的研究

[目的]研究大黄素对血管内皮生长因子(VEGF)受体(VEGFR)阻断作用及对结肠癌细胞抑制作用的机制.[方法]软琼脂集落实验法,流式细胞术检测大黄素对结肠癌细胞增殖和凋亡的影响;酪氨酸激酶活性分析,Western blot方法检测大黄素对VEGFR的抑制作用.[结果]大黄素抑制结肠癌细胞生长,引起细胞凋亡,凋亡率由对照组(0 μmol/L)的(8.1±2.7)%上升至大黄素40 μmol/L时的(27.8±10.9)%(P＜0.01),呈浓度依赖性.大黄素抑制VEGFR酪氨酸激酶活性,VEGFR-1相对活性由对照组的100%降至大黄素40μmol/L时的22.4%(P＜0.01),VEGFR-2降至58.5%(P＜0.01),VEGFR-3降至31.6%(P＜0.01),大黄素作用后,VEGFR酪氨酸磷酸化状态蛋白量减少.[结论]大黄素能够通过抑制VEGFR酪氨酸激酶活性而抑制结肠癌生长,可作为一种有效的肿瘤血管生成抑制剂.     

幽门螺杆菌及其培养上清液粗提蛋白对兔离体胃壁细胞酸分泌的影响

目的 通过研究幽门螺杆菌(Hp)及其培养上清液粗提蛋白(BCF-P)对兔离体胃壁细胞酸分泌的影响,探讨Hp感染引起宿主胃酸分泌状态改变的可能机制.方法 兔胃体黏膜经Ⅰ型胶原酶消化、离心淘洗后获得新鲜分离的壁细胞,并进行短期培养.提取Hp培养上清液粗提蛋白(BCF-P)并进行真空干燥浓缩,HeLa细胞以中性红摄取试验鉴定其细胞空泡活性.兔离体壁细胞与Hp及BCF-P(100μg/ml)分别共孵育2、16 h和1、12 h,应用14C-氨基比林(14C-AP)摄取法测定Hp和BCF-P对组胺(1.0×10-4 mol/L)刺激的壁细胞酸分泌的影响;同时应用RT-PCR方法分析Hp和BCF-P对壁细胞H+-K+ ATP酶α亚基mRNA表达的影响.结果 (1)BCF-P中含有细胞空泡毒素(VacA),对HeLa细胞表现出细胞空泡活性.(2)与Hp共孵育2 h和16 h均能抑制组胺刺激的壁细胞酸分泌(P<0.05),抑制作用随孵育时间延长而增强,2 h抑制率为81%,16 h为94%;BCF-P作用1 h和12 h,均能抑制壁细胞酸分泌(P<0.05),抑制作用也随孵育时间延长而增强,1 h抑制率为24%,12 h为58%.(3)尽管与Hp孵育2 h能上调壁细胞H+-K+ATP酶α亚基mRNA表达(P<0.05),但孵育16 h则表现为下调其表达(P<0.05);BCF-P作用1 h和12 h,均抑制H+-K+ATP酶α亚基mRNA的表达(P<0.05).结论 Hp及其分泌的VacA可能通过下调壁细胞H+-K+ ATP酶表达水平来抑制组胺刺激的壁细胞酸分泌.     

内皮素受体拮抗剂BMS-182874对大鼠心肌缺血再灌注损伤的保护作用

为观察选择性内皮素A受体拮抗剂BMS 182 874对离体灌注心脏缺血再灌损伤的影响 ,并进一步探讨其可能的作用机制。按照Langendorff方式灌注离体大鼠心脏 ,全心缺血 30min后再灌注 30min诱导急性心肌缺血模型。给予BMS 182 874 (10 μmol/L或 5 0 μmol/L)持续灌注离体心脏 ,连续记录心功能 ,检测冠状动脉流出液中的肌酸激酶和心肌组织中的肿瘤坏死因子α含量。结果发现 ,与对照组相比 ,缺血再灌注组心功能显著下降 ,左心室内压和左心室内压最大变化率 (±dp/dtmax)、冠状动脉流量明显降低 (P <0 .0 1) ,肌酸激酶 (2 3.9± 2 .2比 2 17.5± 14 .1,P<0 .0 1)以及心肌组织中肿瘤坏死因子α含量明显增加 (6 4 5± 4 5比 192 6± 14 1,P <0 .0 1) ,而 10 μmol/L和 5 0 μmol/L的BMS 182 874显著减轻缺血后心功能的损害 ,升高左心室内压和左心室内压最大变化率 (±dp/dtmax) (P <0 .0 1) ,同时降低肌酸激酶 (185± 14和 14 3± 11,与缺血再灌注组相比P <0 .0 5和P <0 .0 1)和心肌组织中的肿瘤坏死因子α含量 (12 2 2± 6 7和 110 8± 5 7,与缺血再灌注组相比P <0 .0 1)。结果提示 ,内皮素A受体拮抗剂能显著减轻心肌缺血再灌注损伤 ,其保护作用可能与抑制心肌组织中肿瘤坏死因子α生成有关。     

卡维地洛对冠状动脉成形术后患者外周血内皮素及一氧化氮的影响

为探讨卡维地洛对冠心病患者经皮腔内冠状动脉成形术后血中内皮素及一氧化氮的影响 ,本文选择经冠状动脉造影证实有一支或二支以上≥ 70 %狭窄需行经皮腔内冠状动脉成形术的患者 5 1例 ,随机分成卡维地洛组2 8例和常规治疗组 2 3例 ,测定经皮腔内冠状动脉成形术前后及用药前后外周血内皮素及一氧化氮含量。结果发现 ,经皮腔内冠状动脉成形术后血中内皮素 (卡维地洛组为 84 .9± 14 .7μg/L、常规治疗组为 85 .6± 15 .4 μg/L)较术前 (卡维地洛组为 70 .6± 12 .8μg/L、常规治疗组为 71.5± 13.3μg/L)增高 ;一氧化氮 (卡维地洛组为 5 0 .3± 13.4μmol/L、常规治疗组为 5 0 .9± 12 .6 μmol/L)较术前 (卡维地洛组为 6 2 .9± 14 .2 μmol/L、常规治疗组为 6 3.5± 13.1μmol/L)降低 (P <0 .0 5 ) ;卡维地洛组内皮素为 74 .6± 15 .6 μg/L ,较用药前 (84 .4± 14 .9μg/L)降低 ;一氧化氮为 6 2 .7± 12 .8μmol/L ,较用药前 (5 1.6± 12 .5 μmol/L)增高 (P <0 .0 5 ) ,常规治疗组内皮素和一氧化氮观察两周均无显著变化 (P >0 .0 5 )。提示卡维地洛具有改善冠状动脉成形术后血管内皮功能的作用     

胃内pH值对肝硬化伴幽门螺杆菌感染患者血氨的影响

目的研究胃内pH值对肝硬化伴幽门螺杆菌(Hp)感染患者血氨的影响.方法对37例Hp阳性的肝硬化患者及40例Hp阴性的肝硬化患者,测定基础血氨后,静脉注奥美拉唑针40 mg,同时动态监测胃内pH值的变化,待胃内pH＞6 且持续1 h后,复测血氨.结果Hp阴性与阳性肝硬化患者的基础血氨水平差异无显著性(P＞0.05).胃内pH升高后,发现Hp阴性的肝硬化患者及Hp阳性的肝硬化Child-Pugh A级患者,血氨水平与实验前差异无显著性(P＞0.05).Hp阳性的肝硬化Child-Pugh B、Child-Pugh C级患者血氨水平较前明显升高,分别由 26.33±6.49 μmol/L、35.30±10.25 μmol/L升高至35.80±6.25 μmol/L、52.20±17.01 μmol/L,差异有非常显著性意义(P＜0.01).结论肝功能状况和胃内pH值是影响Hp感染肝硬化患者血氨水平的两个重要因素.     

胰岛素瘤的解剖分布特点分析

目的胰岛素瘤是最常见的胰腺神经内分泌肿瘤，因其临床表现多样，导致诊断困难。影像学诊断尤其是超声内镜(EUS)在胰岛素瘤的诊断中起着重要作用，拥有较高的敏感性和特异性。本研究拟通过明确胰岛素瘤的解剖分布特点，以期有助于提高影像学的诊断准确率和降低漏诊率，尤其是在教育和培训实践中对于EUS的学习者更具有指导价值。 方法回顾性分析解放军总医院第一医学中心病案资料数据库1993年1月至2019年11月经外科手术、病理确诊为胰岛素瘤的患者的临床资料，检索方法采取搜索术后病理诊断为"胰岛素瘤"的病例，通过查阅病例的方法，提取出胰岛素瘤的大小和解剖分布等数据，进一步分析其特点。 结果共检索到确诊为胰岛素瘤的患者116例，其中，男45例、女71例，年龄13～76岁，平均年龄(44.4±14.85)岁。胰岛素瘤单发110例(94.8%)、多发6例(5.2%)。位置分布：头颈部46例(39.7%)，单发45例、多发1例；体尾部68例(58.6%)，单发65例、多发3例；全胰腺多发2例(1.7%)。病变大小特点：最大径0.4～3.4 cm，平均大小(1.53±0.58)cm。≤1 cm 29例、>1 cm而≤1.5 cm41例、>1.5 cm而≤2.0 cm28例，≤3 cm 15例，>3 cm 3例。年龄与肿瘤的大小相关，≤44岁患者肿瘤平均大小为(1.36±0.51)cm、>44岁患者肿瘤平均大小为(1.70±0.60)cm，P<0.05。头颈部的肿瘤大于体尾部的肿瘤，头颈部肿瘤平均大小(1.66±0.63)cm，体尾部(1.42±0.52)cm，P<0.05。 结论胰岛素瘤在胰腺体尾部较头颈部更好发；绝大多数单发，但可以全胰腺多发；多数小于1.5 cm，肿瘤的大小与患者年龄和肿瘤的解剖分布相关。     

Pathogenesis of carcinoma of the papilla of Vater

Most adenomas and carcinomas of the small intestine and extrahepatic bile ducts arise in the region of the papilla of Vater. In familial adenomatous polyposis (FAP) it is the main location for carcinomas after proctocolectomy. In many cases symptoms due to stenosis lead to diagnosis at an early tumor stage. In about 80%, curative intended resection is possible. Operability is the most relevant prognostic factor. Most ampullary carcinomas resp. carcinomas of the papilla of Vater develop from adenomatous or flat dysplastic precursor lesions. They can be sited in the ampulloduodenal part of the papilla of Vater, which is lined by intestinal mucosa. They also can develop in deeper parts of the ampulla, which are lined by pancreaticobiliary duct mucosa. Intestinal-type adenocarcinoma and pancreaticobiliary-type adenocarcinoma represent the main histological types of ampullary carcinoma. Furthermore, there exist unusual types and undifferentiated carcinomas. Many carcinomas of intestinal type express the immunohistochemical marker profile of intestinal mucosa (keratin 7?, keratin 20+, MUC2+). Carcinomas of pancreaticobiliary type usually show the immunohistochemical profile of pancreaticobiliary duct mucosa (keratin 7+, keratin 20?, MUC2?). Even poorly differentiated carcinomas, as well as unusual histological types, may conserve the marker profile of the mucosa they developed from. These findings underline the concept of histogenetically different carcinomas of the papilla of Vater which develop either from intestinal- or from pancreaticobiliary-type mucosa of the papilla of Vater. Molecular alterations in ampullary carcinomas are similar to those of colorectal as well as pancreatic carcinomas, although they appear at different frequencies. In future studies, molecular alterations in ampullary carcinomas should be correlated closely with the different histologic tumor types. Consequently, the histologic classification should reflect the histogenesis of ampullary tumors from the two different types of papillary mucosa.     

Demonstration of the mechanism of action of biguanides

Summary Palmitic acid oxidation in rat diaphragm homogenate is depressed by biguanide concentrations that are still incapable of inhibiting oxidative phosphorylation. Glucose oxidation is not directly effected by the same biguanide concentrations: however, the inhibitory effect of palmitic acid on glucose oxidation is partly removed by biguanides. Inhibition of fatty acid oxidation, which accounts for most of the metabolic effects caused by these drugs, can be regarded as the fundamental mechanism of action of biguanides. There is some evidence suggesting that these drugs might interact with carnitine, thus preventing long-chain fatty acids from being transported across the mitochondrial membrane to the site of oxidation. Traduzione a cura degli AA.     

Lack of correlation of degree of villous atrophy with severity of clinical presentation of coeliac disease

BACKGROUND AND AIM: Both the clinical presentation and the degree of mucosal damage in coeliac disease vary greatly. In view of conflicting information as to whether the mode of presentation correlates with the degree of villous atrophy, we reviewed a large cohort of patients with coeliac disease. PATIENTS AND METHODS: We correlated mode of presentation (classical, diarrhoea predominant or atypical/silent) with histology of duodenal biopsies and examined their trends over time. RESULTS: The cohort consisted of 499 adults, mean age 44.1 years, 68% females. The majority had silent coeliac disease (56%) and total villous atrophy (65%). There was no correlation of mode of presentation with the degree of villous atrophy (p=0.25). Sixty-eight percent of females and 58% of males had a severe villous atrophy (p=0.052). There was a significant trend over time for a greater proportion of patients presenting as atypical/silent coeliac disease and having partial villous atrophy, though the majority still had total villous atrophy. CONCLUSIONS: Among our patients the degree of villous atrophy in duodenal biopsies did not correlate with the mode of presentation, indicating that factors other than the degree of villous atrophy must account for diarrhoea in coeliac disease.     

氯硝柳胺悬浮剂的毒性评价

目的评价氯硝柳胺悬浮剂的毒性，为现场大规模应用灭螺提供依据。方法按照中华人民共和国国家标准GB 15670-1995《农药登记毒理学试验方法》和鱼类毒性试验方法进行。结果经口、经皮肤的LDso雌、雄性大鼠均>5 000 mg/kg，经呼吸道的LCso雌、雄性大鼠均>5 000mg/m3，该药经口、经皮肤、经呼吸道毒性均属微毒类药物；兔眼用药后，观察期内无不良反应，对眼无刺激性；皮肤用药后对皮肤无刺激性。与氯硝柳胺原药、氯硝柳胺乙醇胺盐原药和氯硝柳胺乙醇胺盐可湿性粉剂相比，氯硝柳胺悬浮剂对鱼急性毒性最低。结论氯硝柳胺悬浮剂属微毒类药物，对鱼的毒性低于其乙醇胺盐可湿性粉剂，适合于现场应用。     

血吸虫童虫生长发育及其机制的研究进展

血吸虫童虫是宿主免疫系统攻击的重要靶标,包括皮肤型、肺型和肝门型童虫。宿主分子对童虫生长发育具有重要作用。童虫生长发育机制包括免疫调节、信号转导、性别发育及凋亡等。肌动蛋白、组织蛋白酶、烯醇化酶和葡萄糖基转移酶等分子为血吸虫童虫生长发育的重要分子。本文对血吸虫童虫生长发育及其机制的研究进展做一综述。     

124例耐多药结核分枝杆菌基因突变特征分析

目的对临床分离的耐多药结核分枝杆菌相关基因的突变特征进行分析。方法对124例耐多药结核分枝杆菌以及50株敏感株的耐药相关基因(包括异烟肼inh A、kat G、oxyR-ahp C间隔区以及利福平rpo B)进行序列测定,分析其基因突变情况。结果异烟肼耐药inh A基因突变率为14.5%;kat G基因突变率为70.2%(87/124),主要位于315位;oxyR-ahp C间隔区突变率为15.3%;inh A、kat G两种基因同时突变率75.0%,三种基因同时突变率为89.5%。利福平rpo B基因突变的检出率高达95.2%,突变主要发生在531、526、516位点。结论我省耐多药菌异烟肼耐药相关基因最常见突变为kat G 315、inh A C-T(-15)、axyR-ahp C间隔区(-10)C-T,利福平为rpo B531、526、516。结合MDR-TB耐药相关基因的特征分析,可以建立一种快速、准确、特异的适合于我省的检测结核菌耐多药性的新方法。     

Assessment of quality of life of parents of children with juvenile chronic arthritis

The aim of the study was to assess the quality of life (QOL) and the psychological status of parents of children with juvenile chronic arthritis (JCA). The QOL, anxiety and depression of the parents of 28 children with JCA were evaluated and compared to those of the parents of 28 healthy children. Mothers of JCA children and mothers of healthy children reported similar QOL. The reported anxiety and depression levels were similar for mothers and fathers in both groups. The parents of children with pauciarticular-type JCA reported lower QOL and higher levels of anxiety and depression than the parents of children with other types, namely polyarticular and systemic JCA. These findings may be explained by the fact that the pauciarticular patients had shorter disease duration and were less frequently seen in the outpatient clinic. The QOL of mothers of children with JCA was found to be slightly impaired in the group of children with pauciarticular JCA. Future larger studies are needed to confirm these results, as the number of subjects in the three groups was rather low. Received: 26 September 2001 / Accepted: 8 February 2002     

Numerical Simulation of the Effect of Rate of Change of Glucose on Measurement Error of Continuous Glucose Monitors

Background

A 5-day in-patient study designed to assess the accuracy of the FreeStyle Navigator® Continuous Glucose Monitoring System revealed that the level of accuracy of the continuous sensor measurements was dependent on the rate of glucose change. When the absolute rate of change was less than 1 mg•dl⁻¹•min⁻¹ (75% of the time), the median absolute relative difference (ARD) was 8.5%, with 85% of all points falling within the A zone of the Clarke error grid. When the absolute rate of change was greater than 2 mg•dl⁻¹•min⁻¹ (8% of the time), the median ARD was 17.5%, with 59% of all points falling within the Clarke A zone.

Method

Numerical simulations were performed to investigate effects of the rate of change of glucose on sensor measurement error. This approach enabled physiologically relevant distributions of glucose values to be reordered to explore the effect of different glucose rate-of-change distributions on apparent sensor accuracy.

Results

The physiological lag between blood and interstitial fluid glucose levels is sufficient to account for the observed difference in sensor accuracy between periods of stable glucose and periods of rapidly changing glucose.

Conclusions

The role of physiological lag on the apparent decrease in sensor accuracy at high glucose rates of change has implications for clinical study design, regulatory review of continuous glucose sensors, and development of performance standards for this new technology. This work demonstrates the difficulty in comparing accuracy measures between different clinical studies and highlights the need for studies to include both relevant glucose distributions and relevant glucose rate-of-change distributions.     

Study of constancy of hydrogen-consuming flora of human colon

The constancy of the hydrogen consuming flora of the human colon was studied in 15 healthy subjects via two measurements obtained 18 to 36 months apart. Hydrogen disappearance rate and the major products of H₂-consuming bacteria, methane and sulfide, were measured during incubation of fecal homogenates with excess hydrogen and sulfate. In 11/15, the hydrogen consumption rate and the predominant hydrogen-consuming pathway (methanogenesis, sulfate reduction, or neither) remained constant. However, major shifts in these pathways were observed in four subjects, with two losing and two gaining the ability to produce methane. Methanogenesis was associated with the highest hydrogen consumption rate. This study demonstrates that clinically unrecognizable, major alterations of the colonic flora occur in healthy subjects. Understanding of the factors responsible for these alterations might allow for therapeutic manipulation of the colonic flora.Supported in part by the Department of Veterans Affairs and NIDDKD RO1 DK 13309-25.