同型半胱氨酸对血管平滑肌细胞基质金属蛋白酶1活性的影响

观察同型半胱氨酸对血管平滑肌细胞基质金属蛋白酶1活性的影响，并探讨其作用机制。采用体外培养的大鼠血管平滑肌细胞，加入不同浓度的同型半胱氨酸作用48h，通过酶谱分析和半定量逆转录聚合酶链反应的方法观察同型半胱氨酸对基质金属蛋白酶1活性及其mRNA表达的影响。结果发现，同型半胱氨酸抑制基质金属蛋白酶1活性，下调其mRNA表达，并有剂量依赖效应。提示同型半胱氨酸通过减少基质金属蛋白酶1的合成，抑制其活性，从而减少胶原降解而使胶原蓄积。表明同型半胱氨酸减少胶原降解可能是致动脉粥样硬化的发病机制之一。     

肝素对大鼠血管平滑肌细胞同型半胱氨酸诱导的基质金属蛋白酶-2表达的影响

目的研究肝素对大鼠血管平滑肌细胞同型半胱氨酸诱导的基质金属蛋白酶一2（MMP-2）表达的影响。方法利用免疫印迹法和明胶酶谱分析法研究大鼠血管平滑肌细胞中不同浓度的同型半胱氨酸（0～1000umol／L）及不同浓度的肝素（0～1D0ug／m1）对MMP-2表达的影响。结果同型半胱氨酸的浓度在50umol／L、100umol／L、500umol／L、1000umol／L时,MMP-2分别为1．32±012、1．65±0．17、2．48士0．21、2．71±0．24,MMP-2的表达可随同型半胱氨酸浓度的增高而显著增加;作用72hMMP-2的表达与24h和48h比,差异有显著统计学意义（P〈0．01）。在细胞外加入肝素后同型半胱氨酸对MMP-2表达的诱导增强作用可被抑制,当肝素浓度为1．0umol／L、10．Oumol／L、50．0umol／L、100．0umol／L时,MMP-2浓度分别为2．17±0．19、1．67±0．14、1．34±0．14、0．65±0．04。结论大鼠血管平滑肌中同型半胱氨酸可增加MMP-2的表达。细胞外加入肝素可抑制此作用。高同型半胱氨酸血症与动脉粥样硬化发生相关;肝素可防止动脉粥样硬化的发生,对血管具有保护作用。     

同型半胱氨酸干扰胰岛素样生长因子2和H19的印迹表达及其与血管平滑肌细胞增殖的关系

目的采用动脉粥样硬化的独立危险因子同型半胱氨酸刺激脐静脉血管平滑肌细胞,观察同型半胱氨酸对血管平滑肌细胞胰岛素样生长因子2和H19表达的干扰作用,分析二者与血管平滑肌细胞增殖的关系及其在动脉粥样硬化发病中的可能作用。方法将培养的脐静脉血管平滑肌细胞分为0、50、100、200、500及1000μmol/L同型半胱氨酸组,以0μmol/L同型半胱氨酸组为空白对照组。用不同浓度的同型半胱氨酸刺激血管平滑肌细胞48 h后,MTT法检测血管平滑肌细胞的增殖水平;半定量逆转录聚合酶链反应法检测血管平滑肌细胞胰岛素样生长因子2和H19的mRNA表达水平,Western Blotting法检测血管平滑肌细胞胰岛素样生长因子2的蛋白表达水平。结果与空白对照组相比较,同型半胱氨酸各浓度组血管平滑肌细胞的增殖活力明显增加,以高浓度(500及1 000μmol/L)组为著(P0.05)。同时,同型半胱氨酸组血管平滑肌细胞H19的mRNA表达水平增加,500及1000μmol/L浓度组(0.548 6±0.063 3及0.733 3±0.049 6)明显高于空白对照组(0.202 2±0.012 4)(P0.05);胰岛素样生长因子2的mRNA和蛋白表达均下降,尤以高浓度组为著,500及1 000μmol/L浓度组的mRNA(0.258 8±0.024 8及0.168 9±0.069 6)和蛋白(0.116 7±0.015 5及0.083 7±0.018 0)表达水平均明显低于空白对照组(0.515 8±0.018 9和0.244 3±0.042 3)(P0.05)。结论同型半胱氨酸能干扰胰岛素样生长因子2和H19的表达,并可能进一步促进血管平滑肌细胞的增殖。     

同型半胱氨酸促进血管平滑肌细胞增殖的机制及辛伐他汀的干预作用

目的:探讨同型半胱氨酸促进大鼠血管平滑肌细胞(VSMC)增殖的机制及辛伐他汀的干预作用。方法:贴壁培养的大鼠原代VSMC随机分为3组。(1)对照组:用含10%胎牛血清的DMEM培养基(完全培养基);(2)同型半胱氨酸组:在完全培养基中加入同型半胱氨酸(0.05 mmol/L);(3)辛伐他汀组:在完全培养基中加入同型半胱氨酸(0.05 mmol/L)和辛伐他汀(10μmol/L)。培养24 h后,光学显微镜下观察各组细胞的形态;采用半定量PCR法检测c-myc、P27kip1的mRNA水平;用Western blot检测细胞周期蛋白(cyclin)D1、cyclin E、cyclin A和核增殖抗原(PCNA)的蛋白表达水平。结果:与对照组相比,同型半胱氨酸组c-myc mRNA水平上调,P27kip1 mRNA水平下调,下游cyclin D1、cyclin E、cyclin A和PCNA蛋白表达增加。与同型半胱氨酸组相比,辛伐他汀组上述检测指标均得到逆转。结论:同型半胱氨酸可促进大鼠VSMC c-myc、cyclin D1、cyclin E、cyclin A等增殖相关基因的表达,抑制P27kip1表达。辛伐他汀可逆转上述效应。     

同型半胱氨酸血症对人脐静脉内皮细胞增殖活性的影响

目的 观察不同浓度的同型半胱氨酸对人脐静脉内皮细胞(HUVEC)作用不同时间后对细胞增殖和形态结构的影响.方法 在含有不同浓度的同型半胱氨酸培养环境及对照培养环境中,分别孵育内皮细胞24 h、48 h、72 h后,采用四甲基偶氮唑盐(MTT)比色法检测同型半胱氨酸对内皮细胞增殖活性的影响,并进行细胞形态学观察.结果 同型半胱氨酸低浓度时对细胞生长的抑制不明显,随着浓度的增高,细胞生长抑制越明显,且呈浓度、时间依赖性.结论 高同型半胱氨酸可损伤内皮细胞,抑制细胞生长,有助于糖尿病和胰岛素抵抗致动脉粥样硬化等血管病变的发生和发展.     

同型半胱氨酸抑制培养的大鼠血管平滑肌细胞牛磺酸转运

为了研究同型半胱氨酸对血管平滑肌细胞牛磺酸转运的影响 ,采用培养的大鼠血管平滑肌细胞和3 H标记的牛磺酸 ,并测定血管平滑肌细胞牛磺酸转运。实验发现 ,同型半胱氨酸呈浓度依赖性抑制血管平滑肌细胞转运牛磺酸 ,1 0 0 μmol L和 50 0 μmol L同型半胱氨酸组血管平滑肌细胞牛磺酸转运的最大速率 (Vmax)较对照组分别降低 31 % (P <0 .0 5)和 51 % (P <0 .0 1 ) ,但组间Km值无显著差异 ;5mmol LH2 O2 亦抑制血管平滑肌细胞牛磺酸摄入 ,Vmax较对照组降低 48% (P <0 .0 1 ) ,但Km值增加 45 % (P <0 .0 1 ) ,其转运效率 (Vmax Km)较 50 0 μmol L同型半胱氨酸组更低 (3 .72± 0 .32比 5 .33± 0 .69,P <0 .0 1 )。 2 0mmol L牛磺酸和 50 0 μmol L同型半胱氨酸同时孵育 ,血管平滑肌细胞牛磺酸转运较 50 0 μmol L同型半胱氨酸组增加 ,Vmax增加 35 % (P <0 .0 5) ,两组间Km值亦无显著差异 ,转运效率增加 40 % (P <0 .0 5)。结果提示 ,同型半胱氨酸抑制血管平滑肌细胞牛磺酸转运 ,其机制不能用同型半胱氨酸产生过氧化物来解释 ,外源性给予牛磺酸可拮抗同型半胱氨酸抑制血管平滑肌细胞牛磺酸转运障碍     

高同型半胱氨酸血症对大鼠主动脉平滑肌细胞中MIP-1α及其受体CCR1表达的影响

目的:探讨高同型半胱氨酸血症(HHcy)对大鼠主动脉平滑肌细胞中巨噬细胞炎性蛋白1α(MIP-1α)和CC型趋化因子受体1(CCR1)表达的影响及机制。方法:将16只SD大鼠随机分为正常对照组和HHcy组。正常对照组给予普通饲料喂养,HHcy组在普通饲料基础上加2蛋氨酸喂养。60d后,采用高压液相色谱法测定血浆同型半胱氨酸(Hcy)浓度,采用免疫组织化学方法检测主动脉平滑肌细胞中MIP-1α、CCR1、核转录因子-κB(NF-κB)蛋白的表达,采用RT-PCR法检测主动脉平滑肌细胞中MIP-1α、CCR1mRNA的表达。结果:HHcy组血浆Hcy浓度(45.74±9.65)mmol/L明显高于正常对照组(7.38±2.28)mmol/L,P<0.01;HHcy组主动脉平滑肌细胞中的MIP-1α、CCR1蛋白及mRNA表达均较正常对照组明显增加(P<0.01);HHcy组主动脉平滑肌细胞中NF-κBP65蛋白的表达显著高于正常对照组(P<0.01)。结论:HHcy可能通过激活NF-κB诱导SD大鼠主动脉平滑肌细胞表达MIP-1α及受体CCR1增多,进而诱发动脉粥样硬化形成。     

二苯乙烯苷对同型半胱氨酸诱导的人脐静脉内皮细胞MCP-1、ICAM-1和VCAM-1表达的影响

目的 观察何首乌二苯乙烯苷对同型半胱氨酸诱导培养的人脐静脉内皮细胞株单核细胞趋化蛋白1(MCP-1)、细胞间黏附分子1(ICAM-1)和血管细胞黏附分子1(VCAM-1) mRNA表达的影响.方法 在人脐静脉内皮细胞的培养基中加入不同浓度的二苯乙烯苷处理2h再加入3.0 mmol/L同型半胱氨酸作用36 h.Hoechst33342核染色检测细胞核损伤;以RT-qPCR检测不同浓度二苯乙烯苷处理对同型半胱氨酸诱导的人脐静脉内皮细胞MCP-1、ICAM-1及VCAM-1 mRNA表达的影响.结果 10 μmol/L浓度以内,二苯乙烯苷预孵育呈浓度依赖性降低3.0 mmol/L同型半胱氨酸所致人脐静脉内皮细胞核损伤加重,抑制同型半胱氨酸所致MCP-1、ICAM-1及VCAM-1 mRNA的表达升高(P＜0.05或P＜0.01).结论 二苯乙烯苷具有明显抑制同型半胱氨酸所致人脐静脉内皮细胞MCP-1、ICAM-1、VCAM-1 mRNA表达增加的作用.     

同型半胱氨酸对血管内皮细胞血凝素样氧化型低密度脂蛋白受体1 mRNA表达及氧化型低密度脂蛋白摄取的影响

为了研究同型半胱氨酸对血管内皮细胞血凝素样氧化型低密度脂蛋白受体1mRNA表达及对氧化型低密度脂蛋白摄取的影响，分别在培养的人脐静脉内皮细胞中加入不同浓度的同型半胱氨酸孵育48h后，利用逆转录-聚合酶链反应检测血凝素样氧化型低密度脂蛋白受体1mRNA表达的改变；采用放射配基法检测细胞对氧化型低密度脂蛋白的摄取。结果发现，随着同型半胱氨酸浓度的增加。提示同型半胱氨酸能促进脐静脉血管内皮细胞血凝素样氧化型低密度脂蛋白受体1mRNA的表达和对氧化型低密度脂蛋白的摄取，此效应可能与同型半胱氨酸致动脉粥样硬化作用有关。     

氧化型低密度脂蛋白对大鼠血管平滑肌细胞基质金属蛋白酶-2和9表达的影响

为探讨氧化型低密度脂蛋白致动脉粥样硬化的作用是否与基质金属蛋白酶表达活性改变有关,应用Northern blot、Dot blot、Westorn blott和明胶酶图分析方法观察氧化型低密度脂蛋白对体外培养的大鼠血管平滑肌细胞表达基质金属蛋白酶－2和9的影响。结果显示,10mg/L氧化型低密度脂蛋白作用于血管平滑骨细胞24h,可明显增强基质金属蛋白酶－2和9mRNA的表达、蛋白分泌和酶的活性,高浓度的氧化型低密度脂蛋白对基质金属蛋白酶－2和9表达的影响不同,氧化型低密度脂蛋白浓度为50mg／L时,基质金属蛋白酶－9表达活性仍然高于对照细胞,但于10mg／L氧化型低密度脂蛋白的作用强度无显著差别;相同条件下,基质金属蛋白酶－2的基因表达和蛋白分泌明显降低。以上结果提示,氧化型低密度脂蛋白可诱导血管平滑肌细胞基质金属蛋白酶－2和9的表达,并可促进细胞外基质降解。     

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.     

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。     

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。     

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.