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91.
ObjectiveTo understand the mechanism of liver cirrhosis after the infection of hepatitis B virus.MethodsMouse fibroblast NIH3T3 cells were transfected with 3.2 kb HBV DND by exposure of the cells to calcium phosphate.The change of the levels of mRNA for tissue inhibitor of metalloproteinase 1and 2(TIMP1,2) was detected in mouse fibroblast NIH3T3 cells and the cells of transfection with HBV Genome by in situ hybridization.ResultsThe levels of mRNA for TIMP1 and TIMP2 were increased significantly.ConclusionHBV infection can induce the expression of the mRNA for TIMP1 and TIMP2.  相似文献   
92.
我们对采用PCR和聚丙烯酰胺凝胶电泳鉴别出的37例DNA完全来自父方的遗传学完全性葡萄胎(g-CHM)进行基因组中CTTtriplex系统各基因座位(CSF1PO、TPOX和TH01)等位基因分布的分析,并初步研究了这些等位基因分布与临床预后的关系。结果显示,在37例g-CHM中,CSF1PO座位中3个等位基因(11,12和14)和TPOX座位中的1个等位基因(11)的出现率与它们在北京地区人群中的基因频率差异显著;g-CHM中CSF1PO、TPOX和TH01基因座位杂合度显著低于北京地区人群的杂合度(P值均远小于0.01);在23例良性g-CHM和10例侵袭性g-CHM中:CSF1PO座位的等位基因10、11在良性中的出现率高于在侵袭性g-CHM中(P=0.026148),等位基因12在良性中的出现率低于在侵袭性g-CHM中(P=0.023879);TPOX座位的等位基因8在良性中的出现率高于在侵袭性g-CHM中(P=0.004322),而等位基因11在良性中的出现率低于其在侵袭性g-CHM中(P=0.008671)。上述结果提示,葡萄胎基因组中存在某些等位基因分布与在人群中的分布不同,而且葡萄胎是否具有侵袭性也和某些等位基因的出现率过高或过低有相关性,这些与侵袭性有关的等位基因可能成为预测葡萄胎是否具有侵袭性的标志物。  相似文献   
93.
The modification of hyaluronan (HA) and gelatin using dithiobis(propanoic dihydrazide) (DTP) has provided two thiolated macromolecular components of the extracellular matrix (ECM), specifically HA-DTPH and gelatin-DTPH. Blends of these thiolated ECM components were crosslinked in air to form hydrogels that were interpenetrating disulfide-crosslinked networks. Lyophilization of the hydrogels afforded sponge-like macroporous scaffolds suitable for cell attachment and proliferation. Increasing percentages of gelatin-DTPH (0, 25, 50, and 75%) were blended with HA-DTPH, and the resulting sponges were evaluated in vitro and in vivo as scaffolds for tissue engineering by seeding with human tracheal scar (HTS) fibroblasts. While cells failed to attach and grow in HA-only sponges, the gelatin-modified HA sponges promoted cell adhesion, proliferation, and spreading in vitro. Optimal attachment and growth was observed with 50% gelatin-HA sponges. Cell attachment to the gelatin-HA sponge could be blocked by preincubation of cells with a soluble fibronectin peptide Gly-Arg-Gly-Asp (GRGD). Finally, HTS fibroblast-seeded gelatin-HA sponges were implanted into the flanks of nude mice and evaluated at 2 and 8 weeks postimplantation. The sponges were fully biocompatible and new fibrous tissue formed, gradually replacing the sponge-like scaffold. The gelatin-HA sponges act as synthetic, macroporous, covalent mimics of the ECM and constitute novel scaffolds for cell growth and tissue augmentation.  相似文献   
94.
95.
The paper reports a study of standardization and quality controlof sperm concentration counts and visual motility assessmentsin human semen analyses performed for infertility investigationsand from internal quality control procedures. Sperm concentrationdeterminations were performed in Improved Neubauer haemocytometerson volumetric dilutions made using a positive displacement pipettorfor sampling the liquefied semen. In addition to a standard1+19 dilution a second dilution of either 1+9, 1+19 or 1+49was made according to whether the estimated sperm concentrationwas <20, 20–100 or > 100 x l06/ml respectively.The duplicate determinations of sperm concentration were highlysignificantly correlated (P << 0.001) with <5% variability.Parallel visual sperm motility assessments were made by twopairs of technicians and showed highly significant correlations(P << 0.001) between technicians in the determinationof the percentages of motile and progressive spermatozoa aswell as the subjective rating of sperm progressivity. When thesevalues were incorporated into a calculated motility index whichgave added weight to the progressive spermatozoa and to theirquality of progression the correlations between techniciansremained highly significant (P << 0.001) with averagedifferences of the order of 1.0%. Therefore, provided that sufficientattention is paid to technician training, regular standardizationchecks and the use of only proven reliable procedures, quantitativelyaccurate values for sperm concentration and motility can beobtained in routine semen analyses.  相似文献   
96.
Chaw CS  Tan CW  Yang YY  Wang L  Moochhala S 《Biomaterials》2003,24(7):1271-1277
Physostigmine is an anti-cholinesterase used for the pretreatment of a poisoning caused by highly toxic organophosphorus neurotoxins. The aim of this study is to design a polymeric microparticle system for sustained release of physostigmine. In this paper, we have attempted to encapsulate physostigmine in microparticles made from poly(D,L-lactide-co-glycolide) (PLGA) with various contents of glycolide and poly(D,L-lactide) (PLA) using spray-drying and single emulsion techniques. It was found that during the single emulsion process, most of the physostigmine molecules were lost in the external aqueous phase. However, more than 90% encapsulation efficiency of physostigmine was obtained using the spray-drying technique. SEM micrographs revealed that spherical microparticles containing physostigmine with a smooth surface were yielded with PLA, PLGA 50:50, RG 502 (PLGA 50:50 with a lower molecular weight) and PLGA 65:35 but PLGA 85:15, PLGA 75:25 and PLGA 50:50 with a high concentration produced microparticles with irregular shapes. An increased inlet temperature yielded a higher physostigmine release rate from the PLA microparticles. Physostigmine release from the microparticles showed a biphasic pattern, characterized by an initial burst release followed by a sustained release for PLGA 65:35, PLGA 50:50 and RG 502 or a non-detectable release for PLGA 85:15, PLGA 75:25 and PLA. A sustained-release of physostigmine with a low initial burst over 1 week was achieved from RG 502 microparticles, which would be used as an injectable dosage form in our further animal studies.  相似文献   
97.
目的: 为减少冠状动脉旁路移植术后血栓形成,探讨人组织因子途径抑制因子(TFPI)基因转染对兔移植静脉血栓生成的影响。方法:构建真核表达质粒pCMV-(Kozak)TFPI。采用阳离子脂质体和腔内加压灌注法,转染移植静脉内皮细胞。RT-PCR、Western blotting和免疫组化法检测外源基因在兔移植静脉中的表达。病理标本、扫描电镜观察移植静脉血栓形成情况,血管多普勒观测其通畅率。结果:移植静脉中有人TFPI基因和蛋白表达。静脉移植术后3 d,基因转染组、空载体和空白对照组分别有1条、8条和7条移植静脉发生血栓,术后30 d,以上各组分别有0条、5条和5条移植静脉完全闭塞,前者静脉血栓发生率和闭塞率均低于后两者(P<0.05)。扫描电镜显示两对照组内皮表面有红细胞和血小板黏附、聚集,而转染组基本正常。结论:人TFPI基因干预,减少了兔移植静脉血栓形成,提高了近期通畅率。  相似文献   
98.
HLA-DRB1、DQB1基因与汉族人群寻常型天疱疮的相关性研究   总被引:4,自引:0,他引:4  
目的 探讨 HL A- DRB1、DQB1位点基因在汉族人群寻常型天疱疮易感性中的作用。方法用序列特异性引物 -聚合酶链反应方法 ,对 6 1例寻常型天疱疮 (pemphigus vulgaris,PV)患者和 5 7名正常对照进行了 HL A- DRB1、DQB1等位基因的分型 ,并分析了 DRB1、DQB1基因在两组中的分布。结果 与正常对照组比较 ,PV组 DR4、DRB1* 14 (* 14 0 1、* 14 0 4、* 14 0 5 )基因频率明显增高 (Pc分别 <0 .0 5及P<0 .0 1) ,差异有显著性 ;PV组 DQB1* 0 5 0 3、DQB1* 0 30 2基因频率明显增高 (Pc均 <0 .0 5 ) ,差异有显著性。对 DR4阳性样本的组内基因亚型分型结果发现 ,PV组中 DRB1* 0 4 0 3、DRB1* 0 4 0 6频率显著增高(Pc<0 .0 5 ) ,差异有显著性。 PV患者组单倍型 HL A- DRB1* 0 4 ,DQB1* 0 30 2和 HL A- DRB1* 14 ,DQB1* 0 5 0 3频率明显增高 (P<0 .0 5 )。结论 HL A- DRB1* 0 4 ,DQB1* 0 30 2和 HL A- DRB1* 14 ,DQB1* 0 5 0 3可能是汉族人 PV推测的易感单倍型。  相似文献   
99.
100.
目的:以岗位胜任力为导向,构建超声医学人机对话教学与考试系统,观察应用于超声医师规范化培训中的临床教学效果。方法:选取南京医科大学附属儿童医院规范化培训住院医师30名,2018~2021年规培学员16名为研究组,采用人机对话模式教学,2014~2017年规培学员14名为对照组,采用传统讲授方式教学。对比两组培训后考核成绩的差异,并对所有学员进行问卷调查。结果:第一阶段研究组理论成绩与对照组相比无差异(86.1±4.3分vs. 83.8±4.2分;t=1.625,P>0.05),第二阶段研究组理论与操作成绩均优于对照组(93.8±2.3 vs. 88.2±2.9,t=4.985,P<0.05;94.6±1.5 vs. 89.9±1.4,t=9.358,P<0.05)。问卷调查显示,人机对话教学与考试系统的构建其课程设计及授课方式的满意度较高。结论:构建超声医学人机对话教学与考试系统适用于超声医学的住院医师规范化培训,并能有效提升学员的岗位胜任力。  相似文献   
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