CYP2J2基因和EPHX2基因多态性与缺血性脑卒中的遗传易感性

目的 研究我国汉族人群细胞色素P450表氧化酶2J2(CYP2J2),可溶性环氧化物水解酶2(EPHX2)基因多态性与缺血性脑卒中的关系.方法 选择200例缺血性脑卒中患者和350例健康人群,采用PCR-RFLP技术分析两个基因CYP2J2 G-50T,EPHX2 G860A多态性的基因型.结果 仅EPHX2 860A等位基因频率在缺血性脑卒中组与对照组比较有显著性差异.多元Logistic回归分析表明,携带EPHX2 860A等位基因的人群患缺血性脑卒中相对风险率下降50%(OR=0.5).当个体同时携带CYP2J2-50GG和EPHX2 860A (A 示A等位基因)联合基因型时,其患缺血性脑卒中相对风险率下降53.9%(OR=0.461).结论 虽然EPHX2 860A等位基因与缺血性脑卒中有相关性并且为缺血性脑卒中一个独立的保护因子,但联合基因型CYP2J2-50GG/EPHX2 860A 的协同作用对缺血性脑卒中有更强的保护作用.     

CYP2J2基因和EPHX2基因多态性与肺癌易感性研究

目的探讨CYP2J2基因启动子区G-50T多态性和EPHX2基因G860A多态性与肺癌发生的关系。方法经病理检查确诊为肺癌患者150例（肺癌组）,300名本院健康体检者作为对照组,检测其CYP2J2基因启动子区G-50T多态性和EPHX2基因G860A多态性,并进行统计学分析。结果肺癌组和对照组比较,CYP2J2启动子区G-50T多态性差异无统计学意义,而肺癌组患者EPHX2 860G等位基因频率显著高于对照组人群（96％比78．3％,P〈0．01）,多元回归分析方法显示,肺癌的发生与EPHX2 G860A多态性显著相关（校正OR值=0．164,95％CI 0．079～0．342,P〈0．001）。结论EPHX2 G860A多态件与肺痛密切相关．可作为肺癌高毹患者的预涮指标．     

The effects of changes of maternal PaO2 and PaCO2 on the fetal PaO2 and PaCO2--in vivo study

Umbilical PaO2 and PaCO2 were continuously monitored in vivo in acute fetal lamb preparations with a semipermeable membrane connected to a mass spectrometer. The response time of this system (0 to 90% of final value) was 36 sec. In seven pregnant sheep (128--135 days gestation) the maternal inspired mixture was abruptly changed and the following changes in fetal PaO2 and PaCO2 were observed: (1) 100% O2 to room air: PaO2 decreased from 21.5 +/- 0.8 (mean +/- SEM) to 14 +/- 1.1 mm Hg at a rate of 1.63 +/- 0.33 mm Hg/min. Following return to 100% O2 the PaO2 returned to 21 +/- 1.1 mm Hg at a rate of 2.44 +/- 0.4 mm Hg/min. (2) 100% O2 to 12% O2/10% CO2: after 6 min the PaO2 fell from 19.3 +/- 1.3 to 6.3 +/- 0.3 mm Hg at a rate of 4.65 mm Hg/min and the PaCO2 rose from 37 +/- 8 to 70 +/-5 mm Hg. At 100% O2 the PaO2 returned to 19 +/- 1.0 mm Hg at a rate of 11.76 +/- 0.086 mm Hg, the PaCO2 to 39 +/- 7 mm Hg. (3) 100% O2 to 90% O2/10% CO2. The PaO2 and PaCO2 increased by 4.7 and 22 mm Hg, respectively. The changes of fetal PaO2 and PaCO2 occurred after 1 minute of changing in maternal inspired mixture except in the transition from 12% O2/10% CO2 to 100% O2 (34 +/- 12 sec). Following the reinstitution of 100% the fetal PaO2 and PaCO2 returned to their previous values within 4 and 16 min, respectively.     

Effects of neuraminidase on O2 consumption and release of O2 and H2O2 from phagocytosing human polymorphonuclear leukocytes

Neuraminidase type X (NMD-type-X, Sigma Chemical Co., St. Louis, Mo.), which is obtained from a further purification of neuraminidase type V (NMD-type-V, Sigma), markedly enhanced the release of O2- and H2O2 from phagocytosing human polymorphonuclear leukocytes (PMN). In contrast, O2 consumption by NMD-type-X-treated PMN was identical to that of untreated PMN. Morphological observations suggested that the enhancement of O2- and H2O2 release was caused by excessive release of the oxygen metabolites into the extracellular medium from incompletely formed phagocytic vacuoles as was observed with cytochalasin-B-treated cells. Our observations are in contrast to the previous reports of Tsan et al. that showed complete inhibition of both O2- and H2O2 release from phagocytosing PMN by the treatment with NMD-type-V.     

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.     

Expirograms of O2, CO2 and intravenously infused C2H2 and Freon-22 during panting in dogs

To study pulmonary gas transport in panting, expirograms of several inert and respiratory gases were simultaneously measured in panting dogs. The experiments were performed on 5 conscious dogs (mean body weight 34.4 kg) provided with a chronic tracheostomy. Panting at a mean frequency of 312/min (5.2 Hz) was induced by elevated room temperature (mean 28.1 degrees C). Isotonic saline equilibrated with 50% acetylene and 50% Freon-22 was infused intravenously at a constant rate (4 ml/min). Fractional concentrations in the tracheostomy tube were measured by a respiratory mass spectrometer, using a special sampling system designed for quasi-continuous analysis of rapidly changing gas concentrations. Air flow was monitored by an ultrasonic transit-time flowmeter. A tracing of expired gas concentrations versus expired volume showed no alveolar plateau, displaying a steep increase of Freon-22, acetylene and CO2 (decrease of O2) up to the onset of inspiration. The small but statistically highly significant differences between the expirograms of CO2 and O2, and of Freon-22 and acetylene, could be qualitatively explained by ventilation-perfusion inequalities with sequential emptying, by Taylor dispersion and by reversible solution in airway mucosa in the course of the respiratory cycle.     

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.     

Characterization of two types of fetal hemoglobin: alpha 2G gamma 2 and alpha 2A gamma 2

The effect of differences in G gamma and A gamma fractions of fetal hemoglobin (HbF) on the kinetics of polymerization of HbS-HbF mixtures was studied. We also examined their effect on oxygen affinity, surface hydrophobicity, mechanical stability, and solubility of HbF. Differences in G gamma:A gamma ratio did not affect the polymerization of mixtures of HbF and HbS, suggesting that the inhibitory effect of HbF on the polymerization of HbS is independent of the G gamma:A gamma ratio of HbF and is totally dependent on the fraction of HbF in the mixture. The oxygen equilibrium curve of HbF was not affected by differences in the ratios of G gamma and A gamma in HbF. In contrast, surface hydrophobicity, mechanical stability, and solubility of HbF were affected by differences in the G gamma:A gamma ratio. The higher the G gamma:A gamma ratio, the smaller the elution volume on a TSK Gel SW hydrophobic column in high phosphate buffer. The mechanical stability of HbF was also dependent on the ratio of G gamma:A gamma; stability was greater at higher fractions of A gamma. Differences in the G gamma:A gamma ratio also affected solubility of HbF: HbF containing the higher fraction of G gamma was the more soluble. These data indicate that although alanine at the 136th position of the gamma chains has a stronger surface hydrophobicity than does glycine, this difference does not affect either the polymerization of HbS or the oxygen affinity of HbF.     

Expression of MMP—2,TIMP—2 protein and the ratio of MMP—2／TIMP—2 in gallbladder carcinoma and their significance

AIM: To study the correlation between expression of MMP-2, TIMP-2 protein and the ratio of MMP-2/TIMP-2 and clinicalpathological parameters of patients with gallbladder carcinoma.METHODS: Carcinomas (n=45) and polypoid lesions (n=15) of the gallbladder were studied for the expression of MMP-2 and TIMP-2 protein by immunohistochemical avidin-biotin-complex method and image analysis. Clinicalpathological data of patients with gallbladder carcinoma such as histological type, grade of differentiation, level of infiltration, liver invasion and lymph node involvement, etc, were recorded.RESULTS: There was significant difference between the average level (1.123±0.108 VS 1.030±0.054, P=0.002) of MMP-2, the ratio (1.050±0.013 VS0.937±0.078, P=0.003) of MMP-2/TIMP-2 in gallbladder carcinomas and in polypoid lesions of the gallbladder. Significant difference was found between the expression of MMP-2 in early stage and advanced tumors, but there was no correlation between MMP-2 protein expression and histological type, differentiation degree, infiltration level, lymph node involvement or liver invasion. Although no difference was observed between TIMP-2 expression and histological type or differentiation degree, signific ant difference was found between TIMP-2 expression and different Nevin stage, infiltration level, local lymph node involvement or liver invasion (1.168±0.067 VS1.048±0.075, 1.170±0.062 vs 1.039±0.06g, 1.039±0.076 VS1.147±0.083, 1.048±0.074 vs 1.103±0.095, P＜0.05). MMP-2/TIMP-2 ratio did not correlate with histological type, grade of differentiation and liver invasion, but significant differences were found between MMP-2/TIMP-2 ratio and different Nevin stage, infiltration level and lymph node involvement in patients with carcinoma of gallbladder.CONCLUSION: TIMP-2 and MMP-2/TIMP-2 ratio could reflect more accurately biological characteristic of gallbladder carcinoma and MMP-2/TIMP-2 ratio might be a new significant marker in early diagnosis, in the judgment of invasion or metastasis and the estimate of prognosis in patients with gallbladder carcinomas.     

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.     

Antileukemic and immunosuppressive activity of 2-chloro-2''-deoxyadenosine.

The adenosine deaminase-resistant purine deoxynucleoside 2-chloro-2'-deoxyadenosine (CdA) is markedly toxic in vitro to nondividing and proliferating normal human lymphocytes and to many leukemia cell specimens. The CdA is also effective against mouse L1210 leukemia in vivo. The present investigations have examined the pharmacology, chemotherapeutic activity, and toxicity of CdA in nine patients with advanced hematologic malignancies refractory to conventional therapy. When administered by continuous intravenous infusion, the deoxyadenosine analog was well tolerated. As monitored by radioimmunoassay, plasma CdA levels rose gradually during the infusions. The CdA was not deaminated significantly. In all patients with leukemia, the CdA lowered the blast count by at least 50%. In one patient with a T-cell leukemia-lymphoma, and in another patient with chronic myelogenous leukemia in blast crisis, the CdA infusion eliminated all detectable blasts from the blood and bone marrow. In a patient with a diffuse lymphoma complicated by severe autoimmune hemolytic anemia, CdA treatment quickly terminated the hemolytic process. Bone marrow suppression represented the dose-limiting toxicity, and was related to plasma CdA levels, cumulative drug dosage, and the rapid release of CdA that accompanied tumor cell lysis.     

IGF2BP2 and IGF2 genetic effects in diabetes and diabetic nephropathy

ObjectiveThe IGF2BP2 gene is located on chromosome 3q27.2 within a region linked to type 1 diabetes (T1D), type 2 diabetes (T2D) and diabetic nephropathy (DN). Its protein functionally binds to 5’-UTR of the imprinting IGF2 gene. The present study aims to evaluate the IGF2BP2-IGF2 genetic effects in diabetes and DN.Materials and MethodsThree cohorts including T1D with and without DN (n = 1139) of European descents from the GoKinD study, Swedish T1D with and without DN (n = 303) and Czech control subjects without diabetes, T1D, T2D with and without DN (n = 1418) were enrolled in TaqMan genotyping experiments for IGF2BP2 rs4402960 and IGF2 rs10770125. Igf2bp2 gene expression in kidney tissues of db/db and control mice at the ages of 5 and 26 weeks was examined with real time RT-PCR and Western blot.ResultsAn association of IGF2BP2 rs4402960 with T2D in the Czech population was replicated. This IGF2BP2 polymorphism (P = 0.037, OR = 0.69 95% CI 0.49–0.98) was found to be associated with DN in male not in female patients with T1D selected from the GoKinD study. In the analyses of combined the GoKinD, Czech and Swedish populations, the association between IGF2BP2 polymorphism and DN in male patients with T1D was still significant (P = 0.030, OR = 0.73, 95% CI 0.54–0.97). IGF2 rs10770125 was also associated with DN in male T1D patients of the GoKinD population (P = 0.038, OR = 0.67 95% CI 0.46–0.98). There might be a genetic interaction between IGF2BP2 and IGF2 (P = 0.05). The Igf2bp2 gene expression levels were increased in the kidneys of db/db mice compared to controls at the age of 5 weeks but not at 26 weeks.ConclusionsThe present study has replicated the association of IGF2BP2 rs4402960 with T2D in the Czech population and provided data suggesting that IGF2BP2 may have genetic interaction with IGF2 with a protective effect against DN in male patients with T1D.