钴合金和钛合金的细胞毒性研究

对植入材料磨损态的Co-29Cr-5Mo(CCM)和Ti-6Al-4V(Ti64)的细胞毒性进行研究。与固溶态相比,在完全培养液中,通过噻唑蓝(MTT)法研究两种合金在不同浸提浓度、不同浸提时间下的材料浸提液对小鼠成纤维细胞(L929)的毒性及影响机制。扫描电子显微镜(SEM)观察腐蚀前后材料表面的变化,ICP发射光谱仪(ICP-MS)检测CCM和Ti64合金中主要金属离子的释放,电化学工作站(CHI760E)表征两种磨损态合金在完全培养液中的腐蚀情况。MTT实验结果表明:磨损态的两种合金随材料浸提浓度和时间的增大,细胞的相对增殖率(RGR)均减小,其中CCM的RGR由98.36%减小至73.28%,细胞毒性由0级升至2级;Ti64的RGR减小至85.86%,细胞毒性升至1级。ICP-MS结果表明,磨损态合金有害离子的释放量随着浸提时间不断上升,浸提至168 h时,磨损态CCM合金Co和Cr释放量分别高达1 249.7和293.9 μg/L;磨损态Ti64合金Al和V释放量分别为30.7和19.7 μg/L。CCM的Tafel曲线和SEM分析表明,在完全培养液中,CCM表面化学位较高的棱、尖角以及微米级沟壑位置发生了缝隙腐蚀,造成金属离子的释放,并对L929细胞的生长和分裂产生抑制作用。     

侗族左交臂人群的掌纹分析

目的　对湖南侗族左扣手人群的掌纹分布特点进行研究 ,积累侗族群体遗传学与民族学资料。方法用油墨拓印法捺印手纹 ,放大镜下观察分析。结果侗族左交臂人的普通型及过渡Ⅱ型掌褶纹的百分率存在明显的性差 (p <0 0 1) ;TH/I1区及I3 区的真实花纹出现率在左右手之间存在明显差异 (p <0 0 5或p <0 0 1)。过渡Ⅰ型掌褶纹的百分率与对照组比较存在明显的差异 (p <0 0 5 )。结论湖南侗族左交臂人群的掌纹有其自身的特征     

Clinical implications of viral quasispecies heterogeneity in chronic hepatitis C

To determine the clinical significance of viral quasispecies heterogeneity, 59 patients with chronic hepatitis C were studied using single-stranded conformational polymorphism (SSCP) analysis of the HCV E2 hypervariable region 1 (HVR1); of these, 48 were subsequently treated with interferon-α. The SSCP method was validated using clones of known nucleotide sequence. HVR1 was amplified in 54 of 59 (92%) patients. The median number of SSCP bands per sample was 6 (range: 2–12). Increased quasispecies heterogeneity correlated with the estimated duration of HCV infection (P < 0.05), parenteral-acquired HCV infection (vs. sporadic, P < 0.05), serum HCV RNA levels (P < 0.05), and HCV genotype 1 infection (P < 0.05), but not with age, serum AST, ALT, or Knodell score. Patients who had complete and sustained response to interferon-α (n = 11) had lower pre-treatment quasispecies heterogeneity compared to patients who had complete response with relapse (n = 18, P < 0.05) or no complete response (n = 16, P < 0.01). However, multivariate analysis revealed that HCV viremia was a stronger predictor of response to interferon-α. These findings indicate that the estimated duration of HCV carriage, serum HCV RNA levels, and HCV type 1 are important determinants for the evolution of HCV quasispecies heterogeneity; and that increased HCV quasispecies heterogeneity is another marker associated with a poor subsequent response to interferon-α. © 1996 Wiley-Liss, Inc.     

肠道细菌基因间重复序列基因分型方法研究副溶血性弧菌的基因多态性

目的 采用肠道细菌基因间重复序列(enterobacterial repetitive intergenic consensus,ERIC)基因分型技术对副溶血性弧菌进行分型,评估其基因多态性,探讨其在鉴别该菌散发和暴发中的应用.方法 采用ERIC-PCR分型方法对187例分离自患者、海产品和环境中的副溶血性弧菌基因组模板进行扩增,根据PCR产物中不同产物片段组合模式获得基因型,采用进化树分析软件直观评价不同基因型的相似性,并根据离散程度分为不同的族,同时进行血清分型.结果 187例菌株可获得产物长度160～2780 bp共16种大小不同的PCR产物片段,所有菌株根据扩增片段分布可分为59种基因指纹模式,通过进化树软件可分为12族,血清分型结果表明O3∶K6为86％ (161/187),O2、O4和O12占4％ (8/187),10％ (18/187)无法分型.结论 ERIC-PCR分型结果表明,我国分离的副溶血性弧菌具有较高基因多态性,ERIC-PCR具有高分辨力,可用于快速基因分型.     

Arginine functionalized peptide dendrimers as potential gene delivery vehicles

The quest for highly efficient and safe gene delivery systems has become the key factor for successful application of gene therapy. Peptide dendrimers are currently investigated as excellent candidates for non-viral gene delivery vectors. In this study, we report the synthesis and characterization of arginine functionalized peptide dendrimer-based vectors ranging from 5th generation (G5A) to 6th generation (G6A) via click chemistry, and their use for gene transfection in vitro and in vivo. The dendrimers can condense plasmid DNA (pDNA) and protect pDNAs from nuclease digestion. Both atomic force microscopy (AFM) and dynamic light scattering (DLS) revealed that the sizes of dendrimer/DNA particles were within 180-250 nm range. In vitro studies showed that the functionalized peptide dendrimers provided serum independent and high transfection efficiency on all studied cells, as over 2 fold higher than that of branched polyetherimide (PEI) in the presence of serum. Dendrimer G5A with molecular weight of 17 kDa demonstrated 6-fold transfection activity than PEI in breast tumor models, as well as good biosafety proved by in vitro and in vivo toxicity evaluation. However, G6A with molecular weight of 46 kDa showed much higher cytotoxicity. The functionalized dendrimer G5A with optimal generation may be therefore a potential candidate for gene delivery vehicle.     

丝素蛋白/壳聚糖复合支架材料的细胞相容性**

背景：大量研究表明丝素蛋白、壳聚糖为天然高分子材料,具有良好的细胞生物相容性。 目的：探讨丝素蛋白/壳聚糖复合支架材料与诱导的兔骨髓间充质干细胞的生物相容性。 方法：将兔骨髓间充质干细胞分离培养、诱导后,与丝素蛋白/壳聚糖三维支架材料体外共培养,以材料的细胞毒性、细胞增殖活力、材料细胞黏附率及扫描电镜等检测评价材料的细胞相容性。 结果与结论：经诱导后的骨髓间充质干细胞在支架材料上黏附、生长良好,保持正常的分裂增殖速度;随时间的增加,细胞黏附率增加,材料组较对照组黏附率强,差异有显著性意义(P < 0.05)。扫描电镜观察发现细胞接种48 h后细胞生长良好,与支架黏附紧密,增殖分裂活跃。说明丝素蛋白/壳聚糖三维支架材料具有良好的细胞相容性。     

内侧髌股韧带重建治疗复发性髌骨脱位疗效观察

目的 探讨内侧髌股韧带重建治疗复发性髌骨脱位的临床效果.方法 回顾性分析湖北省荆州市中心医院2017年1月至2019年6月通过关节镜辅助下内侧髌股韧带双束重建治疗的29例复发性髌骨脱位患者的临床资料.其中,男10例,女19例,年龄14.0～29.5岁,平均19.4岁.测量TT-TG距离、髌骨倾斜角,计算Caton指数....     

Association between type 1 diabetes and GWAS SNPs in the southeast US Caucasian population

The present study was conducted to assess genetic associations for type 1 diabetes (T1D) reported in previous genome-wide association studies (GWAS). A total of 21 previously reported single-nucleotide polymorphisms (SNPs) were genotyped by TaqMan assays in 1434 Caucasian T1D patients and 1864 normal controls from Georgia. Analysis of the samples identified 18 SNPs (PTPN22, INS, IFIH1, SH2B3, ERBB3, CTLA4, C14orf181, CTSH, CLEC16A, CD69, ITPR3, C6orf173, SKAP2, PRKCQ, RNLS, IL27, SIRPG and CTRB2) with putative association.     

Synthesis of poly(glutamic acid)-tyramine hydrogel by enzyme-mediated gelation for controlled release of proteins

An in situ-formed hydrogel was synthesized by enzymatic cross-linking of poly(γ-glutamic acid)–tyramine conjugates (PGA–Tyr) using horseradish peroxidase (HRP) and hydrogen peroxide (H₂O₂). The gelation time ranged from 25 s to 5 min was accomplished by tuning the concentration of HRP, H₂O₂/Tyr molar ratio and the degree of substitution (DS) of Tyr groups. The storage modulus (G′), cross-link density, and mesh size can be tailored by controlling the H₂O₂/Tyr ratio and DS. The rheological analysis indicated that the storage modulus (G′) can be tailored from approximately 40 to over 1100 Pa with the increasing H₂O₂/Tyr ratio and DS. The bovine serum albumin (BSA) was used as model protein and encapsulated into the hydrogel during the enzyme-mediated cross-linking reaction. Controlled release of BSA in vitro from the PGA–Tyr hydrogel was obtained. The release rate and cumulative release amount of encapsulated BSA were manipulated by controlling the H₂O₂/Tyr ratio and DS. More than 90% of encapsulated BSA was released from the hydrogel with low cross-link density and lager mesh size in 60 h, while only 68% of BSA was released from the hydrogel with high cross-link density and small mesh size. The results indicated that the PGA–Tyr hydrogel is a promising material for the controlled release of therapeutic protein or peptides.     

A new, previously undescribed monopartite begomovirus infecting Premna serratifolia in Vietnam

The complete genome sequence of a monopartite begomovirus isolate infecting Creek Premna (Premna serratifolia L.) plants that exhibited leaf curl, vein swelling, and enation symptoms in Nha Trang, Vietnam, was cloned and sequenced. It comprises 2,753 nucleotides (JQ793786) and has a typical organization of begomoviruses DNA-A with AV1 and AV2 open reading frames (ORFs) in the viral-sense strand and AC1, AC2, AC3, AC4 and AC5 ORFs in the complementary-sense strand. The full-length genome sequence of the isolate (clone VN7) shared the highest level of nucleotide sequence identity (83 %) with the isolate IN:Pusa:Tb:10 of tobacco leaf curl Pusa virus (HQ180391). The phylogenetic relationship of VN7 to other begomoviruses was also investigated. VN7 grouped most closely with a clade containing begomoviruses from China, India and Japan. According to the current taxonomic criteria for the genus Begomovirus, family Geminiviridae, the isolate VN7 represents a new species, herein named “Premna leaf curl virus” (PrLCV).