TNF-α诱导脑胶质瘤细胞凋亡过程中NF-κB、IκB活性的研究

目的探讨核转录因子-κB（NF-κB）及其抑制因子（ⅠκB）在肿瘤坏死因子-α（TNF-α）诱导人脑胶质瘤细胞株U251细胞凋亡过程中生物活性的变化。方法应用流式细胞仪检测TNF-α对U-251细胞生长的抑制和诱导凋亡作用。用免疫组化方法检测肿瘤细胞p65的表达，用Western blot检测IκB蛋白的变化。结果TNF-α可诱导U251细胞凋亡，激活细胞中p65并诱导ⅠκB降解；抗氧化剂二硫碳吡咯烷醇（PDTC）可抑制TNF-α诱导的ⅠκB的降解及NF—κB的激活，增强TNF-α诱导U251细胞的凋亡。结论TNF-α在诱导U251细胞凋亡的过程中可激活NF—κB。抑制NF—κB活性。可增强TNF-α诱导细胞凋亡的作用。     

血管紧张素Ⅱ诱导胰腺星状细胞炎性活化的分子机制研究

目的探讨血管紧张素Ⅱ对大鼠胰星状细胞（PSC）核因子κB（NF-κB）信号转导通路活化的影响.方法采用电泳迁移率改变分析（electrophoretic mobility shift assay,EMSA）检测细胞NF-κB的DNA结合活性,Western印迹方法检测NF-κB抑制蛋白（IκBs）降解.单核细胞趋化蛋白-1（MCP-1）基因和蛋白表达分别采用Northern印迹和ELISA方法检测.结果血管紧张素Ⅱ可诱导大鼠PSC内NF-κB发生双相活化,活化高峰分别出现在15 min和6 h后.NF-κB活化伴有IκBα和IκB β联合降解.抗氧化剂吡咯烷二硫基甲酸盐（PDTC）、二碘基苯（DPI）和N-乙酰丝氨酸可明显抑制血管紧张素Ⅱ诱导的NF-κB活化,提示氧化应激反应在NF-κB活化中发挥了重要作用.NF-κB抑制剂MG132和PDTC可显著下调血管紧张素诱导的MCP-1基因表达.结论血管紧张素Ⅱ可通过氧化应激机制活化PSC内NF-κB信号通路,诱导MCP-1表达,从而参与胰腺炎症和纤维化的发生.     

核转录因子NF-κB在IL-1β及其他细胞因子介导的INS-1细胞损害中的作用

目的 研究转录因子NF—κB在细胞因子[白细胞介素1β(IL-1β)、肿瘤坏死因子β(TNF-α)和干扰素γ(IFN-γ)]诱导的INS—1胰岛β细胞损害中的作用。方法 构建携有NF—κB的抑制物IκBα的突变体IκBα△N的逆转录病毒，采用免疫印迹分析、κB报告基因荧光分析、四甲基偶氮唑盐细胞活力分析等方法进行研究。结果 IL—1β可诱导INS—1细胞的IκBα降解和NF—κB激活，而对感染IκBα△N逆转录病毒的INS—1／IκBα△N细胞则无此作用。IL—1β加IFN-γ或TNF—α加IFN—γ可致INS-1细胞活力降低，而INS—1／IκBα△N细胞可抵抗这些细胞因子导致的细胞损害。结论 IL—1β、TNF—α可导致β细胞活力降低，IFN—γ可能起促进作用，抑制NF—κB活性可能保护β细胞免于上述细胞因子介导的损害。     

IKKε/TBK1信号通路调控与致癌作用的研究进展

<正>IKKε和TBK1是2个IκB激酶(IKK)相关激酶,他们之间形成异源二聚体,共同参与调控干扰素调节因子(IRF)与核因子(NF)-κB的信号级联,从而调控天然免疫和炎症代谢疾病,甚至肿瘤的形成。IKKε和TBK1在NF-κB信号通路活化过程中与经典的IKK(IKKα、IKKβ)都具有磷酸化靶点的作用,所以国外学者多把IKKε和TBK1称为NF-κB的额外活化激酶,     

同型半胱氨酸对血管平滑肌细胞白细胞介素6表达和核转录因子-κB活性的影响

目的：探讨同型半胱氨酸（HCY）对大鼠血管平滑肌细胞（VSMCs）白细胞介素－6（IL－6）表达和核转录因子κB（NF-κB）活性的影响。方法：在大鼠主动脉平滑肌细胞培养基中加和不同浓度的HCY，并孵育不同时间。用ELISA法检测培养上清液中IL－6蛋白浓度，用半定量RT－PCR法检测IL－6　mRNA表达，用电泳迁移率改变法检测NF－κB活性的变化。结果：（1）HCY呈剂量依赖关系（0．01－0．25mmol/L）和时间依赖关系（0－48h）增加大鼠VSMCs IL-6蛋白合成和mRNA表达。（2）HCY可迅速诱导VSMCs NF-κB活化。密度扫描提示，NF－κB活性30min时为对照1．76倍，1h为对照1．91倍，2h为对照1．84倍。（3）HCY刺激VSMCs IL-6mRNA表达的效应能被NF－κB特异性抑制剂吡咯啉烷二甲基硫脲阻滞。结论：HCY能直接增强NF－κB介导的VSMCs IL-6蛋白合成和基因表达，提示高水平IL－6表达引起的血管壁炎性激活可能是HCY致动脉粥样硬化的重要机制之一。     

NF-κB在高浓度葡萄糖、TNF-α、IL-1β介导的血管内皮细胞损害中的作用

目的研究核转录因子κB(NFκB)在高糖、肿瘤坏死因子(TNFα)、白细胞介素1β(IL1β)诱导ECV304血管内皮细胞损害中的作用。方法以构建含NFκB抑制物IκBα突变体(IκBαM)的重组腺病毒感染ECV304细胞,用Western印迹、凝胶电泳迁移率实验(EMSA)、四甲基偶氮唑盐(MTT)等方法研究NFκB在高糖、TNFα、IL1β介导血管内皮细胞损害中的作用。结果TNFα可诱导ECV304细胞的IκBα降解和NFκB的激活(P<0.01),而对ECV304/IκBαM细胞则无此作用;高糖可导致ECV304细胞NFκB的激活(P<0.05),而对ECV304/IκBαM细胞则无此作用;单独使用高糖、TNFα、IL1β导致ECV304细胞活力的降低(均P<0.01),而ECV304/IκBαM细胞可抵抗这些因素对细胞的损害(均P<0.05)。结论高糖、TNFα、IL1β可致血管内皮细胞活力降低,IκBα能有效抑制上述有害因素导致的ECV304细胞NFκB的过度活化,抵抗内皮细胞的损害。抑制NFκB活性可能有助于保护血管内皮细胞的功能。     

霉酚酸对内皮细胞核因子—κB及其抑制因子ⅠκBα的影响

目的：研究霉酚酸（mycophenolic acid,MPA)对内皮细胞核因子－κB（NF－κB）活力及其抑制因子ⅠκBα的影响。方法：利用凝胶迁移率实验（electrophoretic mobility shift assay,EMSA)检测不同浓度的MPA对于一般培养状态和佛波酯（phorbol myristate acetate,PMA)激活的内皮细胞的NF－κB的活力,并用Western Blot方法检测MPA对NF－κB抑制因子ⅠκBα的作用。结果：PMA显著激活内皮细胞中的NF－κB活力,降低ⅠκBα的蛋白水平。MPA可以降低一般培养状态下和PMA激活状态下的NF－κB活力并抑制两种状态下ⅠκBα蛋白的降低。结论：MPA可以增加内皮细胞的ⅠκBα蛋白水平,降低NF－κB的活力。     

罗格列酮对糖尿病大鼠肾脏中磷酸化IKK和IκBα表达及肾组织超微结构改变的影响

将24只雄性Wistar大鼠随机分为（C）（、DM）和（R）,DM组和R组一次性腹腔注射链尿佐菌素（STZ）50mg/kg制备糖尿病大鼠模型。用免疫组化检测12周后肾组织中磷酸化IKK和磷酸化IκBα表达的改变,用电镜观察肾组织超微结构的改变。结果与C组相比,DM组及R组IKK及IκBα表达增加（P〈0.05）;而R组IKK及IκBα表达低于DM组（P〈0.05）;与DM组相比,R组基底膜变薄（P〈0.05）,足突融合程度减轻。结论 T2D可通过抑制IKK活化,进而抑制IκBα降解,降低NF-κB活化水平,从而延缓肾脏损伤。R酮能够改善糖尿病大鼠肾脏超微结构的改变,对DM肾病具有一定的保护作用。     

低剂量长期砷暴露对HaCat细胞PKB/Akt及其下游信号因子IKK、IκB和NF-κB的影响

目的探讨低剂量长期砷暴露对人皮肤角质形成细胞系（HaCat）细胞蛋白激酶B（PKB/Akt）及其下游信号因子IKK、IκB和NF-κB的影响。方法将HaCat细胞暴露于浓度为0、0.05、0.10μmol/L的NaAsO215周后,采用Western Blot法检测细胞磷酸化Akt（p-Akt）、磷酸化IKK（p-IKK）和磷酸化IκB（p-IκB）及胞核和胞浆中核转录因子NF-κB的蛋白表达水平。结果 0.05、0.10μmol/L染砷组细胞内p-Akt、p-IKK、p-IκB及胞核NF-κB蛋白表达水平与对照组相比均显著增高（P〈0.05）;胞浆NF-κB蛋白表达水平与对照组相比均显著降低（P〈0.05）。结论长期低剂量砷暴露可诱导HaCat细胞Akt蛋白磷酸化活化,激活其下游信号因子IKK,进而诱导IκB的磷酸化及核转录因子NF-κB的入核表达。     

蛋白磷酸酶2A抑制剂对胰腺癌细胞活力的影响及其机制

目的 研究蛋白磷酸酶2A(PP2A)抑制剂对胰腺癌细胞系PANC-1活力的影响及其机制.方法 用PP2A抑制剂斑蝥素和冈田酸处理PANC-1细胞.通过Western印迹检测核因子(NF) -κB通路的激活程度.通过转染PP2A活性亚基cα(PP2A cα)表达质粒、NF-κB抑制蛋白激酶(IKK)α和NF-κB抑制蛋白(IκB)α的显性负性突变体、p65干扰质粒,分别从各环节阻断NF-κB通路,通过四甲基偶氮唑盐比色法(MTT法)检测细胞活力.结果 PP2A抑制剂可使IKKa磷酸化,进一步使IκBa磷酸化并降解,继而释放p65入核.过表达PP2Acα、IKKα显性负性突变体、IκBα显性负性突变体或干扰p65可分别使斑蝥素对细胞活力的抑制率下降(31.85±13.37)％、(23.48±8.98)％、(22.63±5.81)％、(20.88±3.24)％,使冈田酸对细胞活力的抑制率下降(40.17±11.65)％、(27.34±14.28)％、(24.85±3.39)％、(27.08±3.81)％.结论 PP2A抑制剂通过PP2A/IKKα/IκBα/p65依赖性通路发挥抗胰腺癌作用.     

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.     

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.     

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.     

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.     

Angiographic diagnosis of the degree of serosal invasion of carcinoma of the colon

Angiography using Prostaglandin El^® was performed on 38 patients with carcinoma of the colon in order to diagnose the degree of serosal cancer invasion. The findings at angiography were classified into four groups:1) AG-S3, abnormal change (irregularity and/or encasement) up to marginal vessels; 2) AG-S2, abnormality up to vasa recta; 3) AG-S1, abnormality of penetrating branches of vasa recta within the wall of the colon; and 4) AG-S0, no distinct findings of abovementioned vessels. These angiographic findings were compared with both macroscopic and microscopic serosal cancer invasion. Angiographic diagnosis is in accord with the macroscopic findings in 84.2 percent of cases. Angiographic diagnosis is in accord with the microscopic findings in 32.4 percent of cases. Macroscopic findings confirm the angiographic diagnosis precisely but the conflict with microscopic findings should not be overlooked. This may be the result of inflammatory change, adhesion, and fibrosis around carcinoma of the colon.     

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.