ACE2基因A9570G多态性与2型糖尿病及糖尿病心肌病的相关性研究

目的 探讨血管紧张素转化酶2(angiotensin l converting enzyme 2,ACE2) 基因A9570G多态性与2型糖尿病(Type 2 diabetes,T2DM)及糖尿病心肌病(diabetic cardiomyopathy,DCM)的相关性.方法选择广东地区无血缘关系的T2DM患者共358例,其中84例并发DMC,所有病人按是否并发DMC分为DMC组和DM组,应用聚合酶链反应和限制性内切酶片段长度多态性的方法检测ACE2基因A9570G多态性,并结合临床、生化指标及超声心动图参数进行分析.结果在男性,对照组和T2DM组等位基因频率及基因型构成差异无统计学意义(χ2=0.002,P=0.964),但DCM组G等位基因频率/G基因型分布高于对照组及T2DM组,差异有统计学意义(χ2=4.409,P=0.036,χ2=6.105,P=0.013).在女性,三组间等位基因频率及基因型构成差异无统计学意义(χ2=0.037,P=0.981及χ2=0.890,P=0.926).根据不同基因型对DMC组患者进行亚组分析发现,男性G基因型患者反映心脏早期舒张功能的室间隔舒张末期厚度(IVSTd)值明显高于A等位基因,差异有统计学意义(t=2.243,P=0.029);女性则未观察到这种差异(F=1.156,P=0.324).结论 ACE2基因A9750G多态性可能与男性T2DM并发DCM的遗传易感性相关,并且与其早期舒张功能不全严重程度有一定关系.     

血管紧张素—1转换酶基因多态性与老年人糖尿病及糖尿病肾病的关系

目的 探讨血管紧张素－1转换酶（ACE）基因多态性与老年人2型糖尿病（T2DM）及糖尿病肾病（DN）易感性之间的关系。方法 应用PCR三条引物法对172例正常老年人（年龄≥60岁）,140例5型糖尿病（T2DM）患（其中62例合并DN）的ACE基因多态性进行分析、比较。结果 健康对照组与糖尿病组ACE基因型、等位基因频率无显差异（P＞0．05）。在T2DM组中,DD基因型在合并DN患中显增高（P＜0．05）。结论 ACE基因多态性与糖尿病易感性无关,但与并发症DN的发病密切相关。     

脂联素受体1基因多态性与2型糖尿病相关性研究

目的研究西安地区汉族人群中脂联素受体1（AdipoR1）的两个单核苷酸多态性（SNP）位点与2型糖尿病（T2DM）的关系。方法采用突变特异性扩增系统（ARMS）结合测序方法对西安地区100例T2DM患者（T2DM组）及84名正常对照者（NC组）AdipoRl基因的两个SNP位点进行分析。结果（1）AdipoR1基因SNP-106A／G、SNP 5843A／G在DM组与NC组间基因型频率及等位基因频率差异无统计学意义。（2）AdipoR1基因5843G／G型T2DM患者的诊断年龄明显早于A／A型＋A／G型。结论在西安地区的汉族人群中，AdipoR1基因-106A／G、5843A／G的单个核苷酸多态性可能与T2DM的发病无关。携带5843G／G基因型的T2DM患者发病年龄较早。     

ACE基因、AT1R基因多态性与2型糖尿病肾病的关系

目的研究血管紧张素I转化酶(ACE)基因/D多态及血管紧张素受体1型(AT1R)A1166C多态性与中国汉族人2型糖尿病肾病(DN)的关系。方法运用聚合酶链反应(PCR)和PCR/DdeI酶切技术,检测93例DN患者(DN组)与94例2型糖尿病患者(DM组)ACE基因及AT1R基因多态基因型。结果DN组ACE基因DD基因型频率(34.4%)、D型等位基因频率(54.3%)较DM组(19.1%,40.4%)均升高(P<0.05,<0.01);两组间AT1R基因A1166C多态基因型频率和等位基因频率分布均无差异(P>0.05);ACE和AT1R基因多态与DN的分层分析显示,同时携带ACE纯合子缺失基因型(DD)和AT1R突变基因型(AC+CC)者发生DN的危险较大,OR值为8.569。结论ACE基因/D多态性与2型DM并发DN有关,携带DD基因型和D型等位基因的2型DM患者是DN的易感人群。ATlR基因A1166C多态性虽与我国汉族人2型DM并发DN无关,但AT1R与ACE基因多态存在协同效应,携带AC+CC与DD基因型的个体有更高的患DN风险。     

抵抗素基因多态性与中国东北地区汉族老年人群2型糖尿病患病的相关性

目的 探讨抵抗素基因多态性与中国东北地区汉族老年人群2型糖尿病(T2DM)患病的相关性.方法 选取中国东北地区汉族人群老年2型糖尿病患者115例及正常对照者99例,采用直接测序法对抵抗素基因作单核苷酸多态性(SNP)筛查,并作进一步的基因分型.结果 抵抗素基因启动子区发现5个SNP( - 638G＞A,-537A＞C,-420C＞G,- 358G＞A,-238G＞A),这些SNP的等位基因频率在T2DM和正常对照组之间无显著相关性(P＞0.05).结论 抵抗素基因的SNP与中国东北地区汉族老年人群T2DM无显著相关性.     

血管紧张素转换酶基因多态性与2型糖尿病肾病的相关性

应用PCR技术检测144例2型糖尿病患者（T2DM组）的血管紧张素转换酶（ACE）基因插入/缺失（I／D）多态性,并与67例健康人（对照组）比较,结果两组间ACE等位基因、基因型频率无显著性差异（P〉0．05）;T2DM组伴DN者（80例）DD基因型频率显著高于不伴DN者（64例）（P〈0．05）;DN患者中肾功能不全者DD基因型及D等位基因频率均明显高于肾功能稳定者（P〈0．05）。提示ACE基因I／D多态性与T2DM的易感性无关,与DN的发生、发展密切相关。     

2型糖尿病肾病对氧磷酶基因多态性的研究

目的 探讨对氧磷酶基因2（PON2）多态性与单纯2型糖尿病（T2DM）及2型糖尿病肾病（DN）的关系。方法 选取单纯T2DM患者154例、DN患者145例，并选取97例健康者进行对照所有样本试剂盒提取DNA，进行PCR扩增，PCR扩增产物有限制性内切酶水解，最后通过凝胶成像分析基因多态性。结果 PON2（G148A）各基因型频率三组间差异有显著性（P〈0．001），PON2（C311S）各基因型频率三组间差异有显著性（P〈0．001）。结论 PON2（G148A）和PON2（C311S）基因多态性均可能作为糖尿病肾病的预测指标。     

广西壮族人Caveolin-3基因多态性与2型糖尿病的关系

目的探讨广西壮族人Caveolin-3基因外显子单核苷酸多态性（SNP）与2型糖尿病（T2DM）的关系。方法选择24例T2DM（T2DM组）患者及10例正常对照者（对照组）,应用PCR法对两组广西壮族人Caveolin-3基因外显子SNP进行PCR扩增后测序。结果 Caveolin-3基因第2外显子非编码区有2个位点发生突变,分别是12842 A→G和12715 A→T。2位点的等位基因频率在糖尿病组和正常对照组存在统计学差异（P〈0.05）。12842A→G和12715 A→T位点有三种联合基因型（AT、GT、GA）,其中AT、GA型的分布频率在两组中比较P〈0.05。结论 Caveolin-3基因12842 A→G和12715 A→T位点突变可能与T2DM的发病有关。     

广西地区汉族2型糖尿病血管并发症与血管紧张素转换酶Ⅰ基因多态性关系的研究

目的　探讨 2型糖尿病 (DM)及血管并发症与ACE基因插入 /缺失 (I/D)多态性的相关情况。方法　采用多聚酶链反应 (PCR)技术 ,对 12 0名广西地区汉族 2型DM组及 10 0名汉族正常对照组ACE基因I/D多态性进行检测。结果　 2型糖尿病肾病 (DN)组ACE基因D等位基因及DD基因型频率高于正常对照组 ,Ⅰ等位基因及Ⅱ基因型频率低于正常对照组 ;2型DM合并冠心病 (CHD)组ID基因型频率高于无CHD组 ,Ⅱ型基因频率低于无CHD组。 2型DM并视网膜病变 (DR)组ACE基因各等位基因及基因型频率与无DR组及正常对照组比较无统计学意义 ;2型DM并高血压组 (HP)ACE基因各等位基因及基因型频率与无HP组及正常对照组比较无统计学意义。结论　①广西地区汉族 2型DM合并DN及合并CHD与ACE基因I/D多态性有关 ;②DD基因型及D等位基因可能为 2型DM合并DN的易感基因 ,Ⅱ型及Ⅰ型等位基因可能为 2型DM合并DN的保护基因 ;ID型基因可能为 2型DM合并CHD的易感基因 ,Ⅱ型基因可能为 2型DM合并CHD的保护基因。③广西汉族 2型DM合并HP及合并DR与ACE基因I/D多态性无关联。     

乙酰辅酶A羧化酶β基因多态性与2型糖尿病易感性关系的初步研究

目的 研究上海地区汉族人群中乙酰辅酶A羧化酶B（ACC-β）的2个单核苷酸多态性（SNP）位点与2型糖尿病（T2DM）易感性的关系。方法 采用等位基因专一性实时PCR的方法对上海地区438例T2DM患者及328名正常对照者（NC）ACC-β基因的2个SNP位点进行分析。结果 （1）ACC-β基因16号内含子区存在SNP位点116／73C＞T，T2DM组和NC组两组间基因型频率比较，差异有统计学意义（P=0．031）。且CC型＋CT型与TT型的分组比较在两组间的差异也有统计学意义（P=0．027）。（2）ACC-B基因16号内含子区还存在另-SNP位点：116／288A〉G，T2DM组G等位基因的频率高于NC组，但无统计学意义。结论 在上海地区的汉族人群中，ACC-β基因可能是T2DM的易感基因之一，其16号内含子区的116／73C＞T多态性（rs2268393）可能与T2DM的发病相关。     

Classification and characterization of hereditary types 2A, 2B, 2C, 2D, 2E, 2M, 2N, and 2U (unclassifiable) von Willebrand disease.

All variants of type 2 von Willebrand disease (VWD) patients, except 2N, show a defective von Willebrand factor (VWF) protein (on cross immunoelectrophoresis or multimeric analysis), decreased ratios for VWF:RCo/Ag and VWF:CB/Ag and prolonged bleeding time. The bleeding time is normal and FVIII:C levels are clearly lower than VWF:Ag in type 2N VWD. High resolution multimeric analysis of VWF in plasma demonstrates that proteolysis of VWF is increased in type 2A and 2B VWD with increased triplet structure of each visuable band (not present in types 2M and 2U), and that proteolysis of VWF is minimal in type 2C, 2D, and 2E variants that show aberrant multimeric structure of individual oligomers. VWD 2B differs from 2A by normal VWF in platelets, and increased ristocetine-induced platelet aggregation (RIPA). RIPA, which very likely reflects the VWF content of platelets, is normal in mild, decreased in moderate, and absent in severe type 2A VWD. RIPA is decreased or absent in 2M, 2U, 2C, and 2D, variable in 2E, and normal in 2N. VWD 2M is usually mild and characterized by decreased VWF:RCo and RIPA, a normal or near normal VWF multimeric pattern in a low resolution agarose gel. VWD 2A-like or unclassifiable (2U) is distinct from 2A and 2B and typically featured by low VWF:RCo and RIPA with the relative lack of high large VWF multimers. VWD type 2C is recessive and shows a characteristic multimeric pattern with a lack of high molecular weight multimers, the presence of one single-banded multimers instead of triplets caused by homozygosity or double hereozygosity for a mutation in the multimerization part of VWF gene. Autosomal dominant type 2D is rare and characterized by the lack of high molecular weight multimers and the presence of a characteristic intervening subband between individual oligimers due to mutation in the dimerization part of the VWF gene. In VWD type 2E, the large VWF multimers are missing and the pattern of the individual multimers shows only one clearly identifiable band, and there is no intervening band and no marked increase in the smallest oligomer. 2E appears to be less well defined, is usually autosomal dominant, and accounts for about one third of patients with 2A in a large cohort of VWD patients.     

Structure-function of Hb Marseille-Long Island [alpha 2 beta 2 N-methionyl-2(NA2) His----Pro

Suspensions of red cells containing Hb Marseille-Long Island showed decreased oxygen affinity and low interaction with 2,3-diphosphoglycerate. Oxygen equilibrium studies of the purified component confirmed these abnormalities. Oxidation rate measurements of carbonmonoxy-Hb Marseille and carbonmonoxy-Hb A by ferricyanide showed an increased rate for the former, suggesting an increased dissociation constant for carbon monoxide. Nuclear Magnetic Resonance spectra in the high field region revealed small changes in the proximal region of the heme pocket. These results indicated that the mutation causes a perturbation at a distance from the mutation site.     

Different RBC aggregating properties of the Aalpha2Bbeta2gammaA2 and Aalpha2Bbeta2gammaAgamma' subpopulations of human fibrinogen

Human fibrinogen (TF) has been separated into two fractions: F1 - homodimers with respect to the gamma chain, and F2 - heterodimers composed of gammaA and gamma' polypeptides. Their rouleaux-inducing properties were as follows: (1) both, at the same concentration of 0.8%, were less effective than TF; (2) F1 produced larger rouleaux even under static conditions of a hemocytometer where F2 was silent; (3) F2 induced the process when a suspension was gently sheared between microscopic slides. Since the synthetic peptide gamma'(414-427) inhibited the rouleau formation in a mixture with F2, the C-terminal amino acids of the gamma' polypeptide probably bind the molecule to the cell. The inhibition was feebly visible in the native ratio of F1/F2, implicating a compensatory effect of F1.     

Identification of SH2B2beta as an inhibitor for SH2B1- and SH2B2alpha-promoted Janus kinase-2 activation and insulin signaling

The SH2B family has three members (SH2B1, SH2B2, and SH2B3) that contain conserved dimerization (DD), pleckstrin homology, and SH2 domains. The DD domain mediates the formation of homo- and heterodimers between members of the SH2B family. The SH2 domain of SH2B1 (previously named SH2-B) or SH2B2 (previously named APS) binds to phosphorylated tyrosines in a variety of tyrosine kinases, including Janus kinase-2 (JAK2) and the insulin receptor, thereby promoting the activation of JAK2 or the insulin receptor, respectively. JAK2 binds to various members of the cytokine receptor family, including receptors for GH and leptin, to mediate cytokine responses. In mice, SH2B1 regulates energy and glucose homeostasis by enhancing leptin and insulin sensitivity. In this work, we identify SH2B2beta as a new isoform of SH2B2 (designated as SH2B2alpha) derived from the SH2B2 gene by alternative mRNA splicing. SH2B2beta has a DD and pleckstrin homology domain but lacks a SH2 domain. SH2B2beta bound to both SH2B1 and SH2B2alpha, as demonstrated by both the interaction of glutathione S-transferase-SH2B2beta fusion protein with SH2B1 or SH2B2alpha in vitro and coimmunoprecipitation of SH2B2beta with SH2B1 or SH2B2alpha in intact cells. SH2B2beta markedly attenuated the ability of SH2B1 to promote JAK2 activation and subsequent tyrosine phosphorylation of insulin receptor substrate-1 by JAK2. SH2B2beta also significantly inhibited SH2B1- or SH2B2alpha-promoted insulin signaling, including insulin-stimulated tyrosine phosphorylation of insulin receptor substrate-1. These data suggest that SH2B2beta is an endogenous inhibitor of SH2B1 and/or SH2B2alpha, negatively regulating insulin signaling and/or JAK2-mediated cellular responses.     

Influence of Mixed Na2O/K2O on Chemical Durability and Spectral Properties of P2O5-Al2O3-BaO-K2O-Na2O-Nd2O3 Phosphate Glasses

A series of 56P₂O₅-7.5Al₂O₃-5.9BaO-(28.56-x)K₂O-xNa₂O-1.51Nd₂O₃ phosphate glasses with different Na/(Na+K) ratios, which were specially designed for high-power laser application, were prepared by a high-temperature melting method. Except for the density, refractive index, glass transition temperature, and DC conductivity, the chemical durability and spectral properties, as emphasized by high-power and high-energy laser material, were further measured and analyzed. Regarding the chemical durability, the dissolution rates of these glasses do not show an evident mixed alkali effect with increasing the Na/(Na+K) ratio, although the effect is obvious for the glass transition temperature and DC conductivity. To better understand the nature of the dissolution mechanism, the ionic release concentrations of every element are determined. Both Na and K undergo ion exchange, but the ion exchange rate of K is much larger than that of Na. In terms of the spectral properties, the J–O parameters, emission cross-section, radiation lifetime, fluorescence lifetime, effective bandwidth, fluorescence branching ratio, and quantum efficiency are determined from absorption and emission spectra. The trend of Ω₂ deviating from linearity indicates that the coordination environment symmetry of Nd³⁺ ions and the covalence of Nd-O also present an evident mixed alkali effect. The most important finding is that the emission cross-section and fluorescence lifetime of Nd³⁺ ions at 1053 nm were not affected by the change in the Na/K ratio. According to the above experimental results, the optimized value of the Na/K ratio was determined, based on which the 56P₂O₅-7.5Al₂O₃-5.9BaO-(28.56-x)K₂O-xNa₂O-1.51Nd₂O₃ glass maintains a high emission cross-section with good chemical durability.