地方性砷中毒膜毒理学研究

以红细胞膜作为观察标志，从膜毒理学角度探讨地方性砷中毒的发病机理。砷中毒病人血砷０．１１±０．０５５μｇ／ｍｌ，红细胞膜砷０．１０１±０．０５μｇ／ｍｇ膜蛋白，胞浆砷０．００１２±０．０００７μｇ／ｍｇＨｂ；电子显微镜观察到红细胞膜破损，异形红细胞，细胞表面毛刺样改变；胞膜的损伤，引起红细胞免疫功能下降，血液流变学的变化，细胞膜ＡＴＰａｓｅ活性下降，红细胞电泳速度减慢和微循环变化，且甲皱微循环的变     

锤头状核酶对肝癌突变基因p53的抑制作用

目的 探讨p53核酶对肝癌细胞突变型抑癌基因p53的抑制作用。方法 应用计算机设计并合成针对突变型p53(249位密码子AGG→AGT)的锤头状核酶RZ，构建其体外转录和真核表达载体，检测核酶对突变型p53(mtp53)的体外切割作用，并在Lipofect AMINE^TM2000的介导下转染肝癌细胞MHCC97，应用逆转录聚合酶联反应(RT—PCR)检测核酶对肝癌细胞突变型p53的抑制作用。结果 测序证实核酶基因被正确克隆人体外转录载体pBSKU6和真核载体pEGFPC1中。体外切割效率为42％，而野生型p53(wtp53)没有被切割。在Lipofect AMINETM2000的介导下成功转染肝癌细胞MHCC97，RT—PCR检测证实突变型p53的mRNA水平明显下降，细胞内的切割效率为69％。结论 p53核酶可成功抑制肝癌细胞中突变型p53的表达，为肝癌的基因治疗提供了一个新的选择。     

The structure of a minimum amyloid fibril core formed by necroptosis-mediating RHIM of human RIPK3

Receptor-interacting protein kinases 3 (RIPK3), a central node in necroptosis, polymerizes in response to the upstream signals and then activates its downstream mediator to induce cell death. The active polymeric form of RIPK3 has been indicated as the form of amyloid fibrils assembled via its RIP homotypic interaction motif (RHIM). In this study, we combine cryogenic electron microscopy and solid-state NMR to determine the amyloid fibril structure of RIPK3 RHIM-containing C-terminal domain (CTD). The structure reveals a single protofilament composed of the RHIM domain. RHIM forms three β-strands (referred to as strands 1 through 3) folding into an S shape, a distinct fold from that in complex with RIPK1. The consensus tetrapeptide VQVG of RHIM forms strand 2, which zips up strands 1 and 3 via heterozipper-like interfaces. Notably, the RIPK3-CTD fibril, as a physiological fibril, exhibits distinctive assembly compared with pathological fibrils. It has an exceptionally small fibril core and twists in both handedness with the smallest pitch known so far. These traits may contribute to a favorable spatial arrangement of RIPK3 kinase domain for efficient phosphorylation.

Necroptosis is an important form of regulated necrotic cell death, dysregulation of which is closely associated with a variety of human diseases, including neurodegenerative diseases (1, 2), inflammatory disorders (3–5), and cancers (6, 7). RIPK3 (receptor-interacting protein kinase 3) serves as the central node to converge multiple upstream signals to induce necroptosis (8–11). RIPK3 is activated via interactions with proteins that contain the RIP homotypic interaction motif (RHIM) such as RIPK1 (receptor-interacting protein kinase 1), TRIF (TIR-domain-containing adapter-inducing interferon-β), and ZBP1/DAI (Z-DNA-binding protein 1/DNA-dependent activator of IFN-regulatory factors). RIPK1 mediates RIPK3 activation downstream of death receptors, such as TNFR1 (12). TRIF links RIPK3 to the TLR3 and TLR4 signaling pathway (8). ZBP1/DAI mediates RIPK3 activation in response to certain viruses, such as influenza A virus (9, 10). RIPK3 is composed of a well-defined N-terminal kinase domain and a RHIM-containing C-terminal domain (CTD) (13). Previous studies show that RHIM plays an important role in the interactions of RIPK3 with its upstream mediators and amyloid fibrillation of RIPK3 (9, 10, 14, 15). A previous solid-state NMR (ssNMR) study has revealed the structure of a heterofibril core formed by the CTDs of RIPK3 and RIPK1, where the RHIM domains of both proteins adopt a serpentine fold and stack alternatively along the fibril axis (15). The structure provides insights into how RIPK1 recruits and activates RIPK3 for signaling transduction. However, it remains unknown how RIPK3 assemblies into fibril in the absence of RIPK1.In this work, by using cryo-EM and ssNMR, we determined the structures of two amyloid fibrils formed by RIPK3-CTD. Despite the different fibril preparation, the RIPK3-CTD fibrils present a nearly identical structure. The fibril core exhibits an exceptionally small S-shaped fold of RHIM, which is distinct from that in the heterofibril of RIPK1 and RIPK3 CTDs. The consensus tetrapeptide VQVG forms the central strand 2 of the S-shaped structure and forms heterosteric zipper interfaces with the adjacent strands 1 and 2 within the same subunit. Intriguingly, the RIPK3-CTD fibril presents in both left and right handedness and features a minimum fibril core among the 50 different cryo-EM fibril structures reported previously and also represents the smallest fibril pitch and largest twist angle. By analyzing the reported cryo-EM fibril structures, we observed a strong positive correlation between the size of fibril core and the fibril pitch. Furthermore, we discussed how the small RIPK3 fibril core leads to a highly twisted fibril, which may display the N-terminal kinase domains in a favorable geometry to increase the efficiency of RIPK3 phosphorylation.     

Impact of the supine position versus left horizontal position on colonoscopy insertion: a 2-center,randomized controlled trial

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大肠癌组织中HLA-I类分子的表达及意义

目的探讨大肠癌组织中HLA-Ⅰ类分子表达及其在大肠癌转移中的意义。方法以化学发光法检测81例大肠癌患者术前血清癌胚抗原(CEA)含量;每例患者术中取癌组织及癌旁组织．采用免疫组化SP法检测HLA-Ⅰ类分子．结果大肠癌组织中HLA-Ⅰ阳性率为43．2%(35/81),其中A期73．3%、B期55．6%、C期25．9%,D期16．7%．各期间相比P均＜0．01。转移组大肠癌患者HLA-Ⅰ类分子阳性率为23．1%,未转移组为61．9%,二者比较,P均＜0．01．在转移组大肠癌患者中．癌组织HLA-Ⅰ类分子缺失率(76．9%)高于血清CEA阳性率(51．3%)．结论大肠癌组织中HLA-Ⅰ类分子的表达缺失是大肠癌发生及转移的重要因素．检测HLA-Ⅰ类分子表达还有助于大肠癌转移及预后判断。     

海南省某医院103株鲍曼不动杆菌复合群-内酰胺类耐药性与碳青霉烯酶携带情况分析

目的 鲍曼不动杆菌复合群细菌是临床可造成感染的重要条件性致病菌,本研究旨在调查和分析我国海南省临床来源鲍曼不动杆菌复合群细菌对常用-内酰胺类药物的耐药性及菌株碳青霉烯酶携带情况,探讨其耐药流行性特点。方法 采用微量肉汤稀释法对103株采集自2012-2013年海南省三亚市人民医院的非重复鲍曼不动杆菌复合群细菌进行7种抗菌药物的药敏检测;应用聚合酶链反应(PCR)对收集的鲍曼不动杆菌复合群细菌进行9种碳青霉烯酶编码基因的筛查。结果 103株鲍曼不动杆菌复合群细菌对哌拉西林、头孢他啶、头孢噻肟的耐药率较高(接近50%),对头孢吡肟、哌拉西林/他唑巴坦的耐药率为40%,对亚胺培南和美罗培南的耐药率均在20%左右;PCR检测显示有38株携带blaOXA-58基因,62株blaOXA-66基因,其中25株同时携带有这两种基因;其余7种碳青霉烯酶编码基因筛查结果为阴性。结论 本研究中鲍曼不动杆菌复合群细菌对-内酰胺类药物耐药性较高,菌株携带的blaOXA-58和blaOXA-66基因编码的碳青霉烯酶对菌株的耐药表型有一定贡献意义,但仍有其他耐药机制参与到碳青霉烯酶耐药表型的贡献中。     

Suppressor of cytokine signaling 3 A+930-->G (rs4969168) polymorphism is associated with apolipoprotein A1 and low-density lipoprotein cholesterol

This study aimed to detect the association of the suppressor of cytokine signaling 3 gene (SOCS3) A+930-->G (rs4969168) single nucleotide polymorphism (SNP) and environmental factors with serum lipid levels in the Han and Mulao populations. Genotyping of the SOCS3 A+930-->G (rs4969168) SNP was performed in 752 of Han and 690 of Mulao participants using polymerase chain reaction and restriction fragment length polymorphism. The genotype and allele frequencies were significantly different between the Han and Mulao populations (GG, 57.71% vs. 51.16%, GA, 36.97% vs. 41.16%, AA, 5.32% vs. 7.68%, P = 0.023; G, 76.20% vs. 71.74%, A, 23.80% vs. 28.26%; P = 0.006; respectively). Serum apolipoprotein (Apo) A1 levels in Han were different among the genotypes (P < 0.05). Subgroup analyses showed that the levels of ApoA1 in Han females, and ApoA1 and low-density lipoprotein cholesterol (LDL-C) in Mulao males were different among the genotypes (P < 0.05). Serum lipid parameters were also associated with several environmental factors in both ethnic groups (P < 0.05-0.001). These findings suggest that there may be a racial/ethnic- and/or sex-specific association between the SOCS3 A+930-->G (rs4969168) SNP and serum lipid parameters in some populations.     

Spatial and temporal differences of HMGB1 expression in the pancreas of rats with acute pancreatitis

We aimed to investigate the spatial and temporal differences in expression between HMGB1 and early-stage inflammatory cytokines (IL-1, IL-6 and TNF-α) in pancreas tissue in rats with acute pancreatitis. SD rats (BW 350 ± 30 g, n = 48) were randomly divided into the experimental group (n = 36) which were injected with 5% sodium taurocholate into the bilipancreatic duct retrogradely to produce acute necrotic pancreatitis (ANP) rat models, and the sham-operated (SO) group (n = 12) injected with equal dose of saline. The rats were sacrificed at different time points at 0 h, 3 h, 6 h, 12 h, and 24 h post modeling, respectively. The peripheral blood amylase and different inflammatory factors in ANP rats at different time points were detected by ELISA, and the expression of HMGB1 in the pancreatic tissue was detected by immunohistochemistry, Western blot and Q-PCR methods. Results showed that the serum amylase in the ANP model rats was significantly higher than the sham-operated group (P < 0.05). The early inflammatory factors (IL-1, TNF-α and IL-6) increased quickly at 3 h after the model induction, reached the peak level at 6 h (higher than SO group, P < 0.05), then decreased at 12 h, and at 24 h the levels were lower than those at 12 h (P < 0.05). The HMGB1 level in the pancreatitis tissue did not change significantly at 3 h and 6 h (P > 0.05), however, it increased remarkably at 12 h, and maintained up to 24 h (P > 0.05). As a late inflammatory factor, the expression of HMGB1 in acute pancreatitis was obviously later than the early inflammatory factors IL-1, TNF-α and IL-6. HMGB1 may play a key role in maintaining the development of the acute pancreatitis.     

Predictive role of miR-146a rs2910164 (C>G), miR-149 rs2292832 (T>C), miR-196a2 rs11614913 (T>C) and miR-499 rs3746444 (T>C) in the development of hepatocellular carcinoma

We conducted a case-control study to evaluate the association of miR-146a rs2910164 (C>G), miR-149 rs2292832 (T>C), miR-196a2 rs11614913 (T>C) and miR-499 rs3746444 (T>C) polymorphisms with the risk of hepatocellular carcinoma. A total of 274 patients with HCC were collected between January 2013 and December 2014. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was taken to determine the polymorphism of miR-146a C>G, miR-149 T>C, miR-196a2 T>C and miR-499 T>C. By comparing with control groups, patients with HCC were more likely to be males (OR=2.01, 95% CI=1.38-2.95), have older age (OR=1.52, 95% CI=1.09-2.13), have a history of alcohol drinking (OR=2.09, 95% CI=1.49-2.93), and be infected with HBV (OR=32.98, 95% CI=19.70-55.46) and HCV (OR=56.26, 95% CI=23.28-152.98) infection. By conditional regression analysis, individuals carrying the TC and CC genotypes of miR-196a2 T>C were found to be associated with an elevated risk of HCC compared to the TT genotype, and the adjusted odds ratio were 1.50 (1.03-2.17) and 2.86 (1.60-5.16), respectively. Moreover, the TC+CC genotype was correlated with an increased risk of HCC (OR=1.69, 95% CI=1.19-2.41) compared to the wide-type genotype. In conclusion, our results suggested that miR-196a2 T>C polymorphism is associated with HCC risk in Chinese population.     

支气管哮喘患者自我管理能力与病情控制水平相关性研究

目的探讨支气管哮喘患者自我管理能力与病情控制水平的关系,为支气管哮喘患者自我管理教育及有效预防、控制支气管哮喘提供理论依据。方法采用一般资料调查表、哮喘自我管理能力调查问卷于2014年6月15日-2014年11月15日对170例非急性发作期的支气管哮喘患者进行问卷调查,采集病史、症状,并由医生根据患者的日间症状、活动受限情况、夜间症状、每周使用缓解药次数、第1秒用力呼气量(FEV1)、急性发作次数对哮喘控制水平进行分级。结果支气管哮喘患者自我管理能力得分为(77.070±13.891)分;支气管哮喘病人完全控制68例(40.0%),部分控制39例(22.9%),未控制63例(37.1%);支气管哮喘病人自我管理能力与疾病控制水平呈正相关(R=0.843,P0.05),自我管理能力量表各维度与疾病控制水平相关系数由大到小排列依次为用药(R=0.666)就诊(R=0.660)自我监测(R=0.640)避免诱因(R=0.601)症状的识别及处理(R=0.404)。结论随着支气管哮喘病人自我管理能力的提高,疾病控制水平也相应提高。