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81.
探索采用血管透明化技术结合粒子图像测速技术(PIV)来研究搭桥血管内血流流场的可行性.结果显示血管透明化技术能完整地保留搭桥血管段在体内的真实立体几何构形,从而更准确地反应搭桥血管段在体内的血流流场,而PIV能很好地获得血流流场的信息.因此,将血管透明化技术与PIV相结合有可能使我们对旁路搭桥术后血管内膜增生的血流动力学成因进行更深入地研究.  相似文献   
82.
Zou C  Weng W  Deng X  Cheng K  Liu X  Du P  Shen G  Han G 《Biomaterials》2005,26(26):5276-5284
Porous beta-tricalcium phosphate (TCP)/collagen composites with different beta-TCP/collagen weight ratio were prepared. The influences of the preparation conditions on the microstructure of porous composite and the joint status of beta-TCP particles with collagen fibrils were characterized by X-ray diffractometer, scanning electron microscopy and transmission electron microscopy. The results showed: (1) an acid treatment could effectively disassemble collagen fibrils; (2) in the resulting porous composites, beta-TCP particles homogenously existed on the skeleton of the collagen fibril network and bonded tightly to both the fibrils and themselves. The tight bonding formation could be due to the reaction between Ca ions in the particles and carboxyl groups in collagen polypeptide chains and due to the reprecipitation of partially dissolved beta-TCP during synthesis. The tight bonding between beta-TCP particles and collagen fibrils in the composites demonstrated an integrated structure, which was reproducible when beta-TCP/collagen ratio ranged from 2 to 4. Such integrated structure would make significant contributions in reliably tailoring properties of the porous composites by varying beta-TCP content. In addition, the porous composites had large porosity (approximately 95%) and appropriate pore size (approximately 100 microm), showed no negative impact in cytotoxicity assay and complete bone tissue regeneration after 12 weeks in animal test.  相似文献   
83.
邓锦波  杨淑华 《解剖学报》1995,26(2):198-201
用银染色法、免疫组织化学及透射电镜技术,对36例人肺的神经内分泌细胞进行了形态学和免疫组织化学观察。提示NE细胞发生了废用性退化,其原因可能与出生前后人肺功能改变有关。  相似文献   
84.
85.
To understand better the role of physical p53 deletion in bladder cancer, 106 formalin-fixed and 45 unfixed bladder tumors were examined using fluorescence in situ hybridization. Probes for centromere 17 and the p53 locus were hybridized simultaneously to interphase tumor cells to analyze p53 and chromosome 17 copy number on a cell by cell basis. 17p deletion was found in four of 43 pTa tumors, 18 of 43 pT1 tumors and 29 of 58 pT2-4 tumors (P = 0.0001). 17p deletion was also highly correlated with grade (P = 0.0001) and with p53 immunostaining (P = 0.0005). Chromosome 17 polysomy was associated with stage, grade, 17p deletions, and p53 immunostaining (P = 0.0001). The strong difference in centromere 17 copy number and 17p deletions between pTa and pT1 tumors supports a relevant biological distinction between pTa and pT1 tumors.  相似文献   
86.
Anticocaine catalytic antibodies   总被引:5,自引:0,他引:5  
Cocaine mediates its reinforcing and toxic actions through a "loss of function" effect at multiple receptors. The difficulties inherent in blocking a pleiotropic blocker pose a great obstacle for the classical receptor-antagonist approach and have contributed to the failure (to date) to devise specific treatments for cocaine overdose and addiction. As an alternative, we have embarked on an investigation of catalytic antibodies, a programmable class of artificial enzyme, as "peripheral blockers" -- agents designed to bind and degrade cocaine in the circulation before it partitions into the central nervous system to exert reinforcing or toxic effects. We synthesized transition-state analogs of cocaine's hydrolysis at its benzoyl ester, immunized mice, prepared hybridomas and developed the first anticocaine catalytic antibodies with the capacity to degrade cocaine to nonreinforcing, nontoxic products. We subsequently identified several families of anticocaine catalytic antibodies and found that the most potent antibody possessed sufficient activity to block cocaine-induced reinforcement, organ dysfunction and sudden death in rodent models of addiction, toxicity and overdose, respectively. With the potential to promote cessation of use, prolong abstinence and provide a treatment for acute overdose, the artificial enzyme approach comprehensively responds to the problem of cocaine.  相似文献   
87.
目的 探讨在押女性毒品犯人格的基本特征、类型特征及其影响因素。方法 以252名在押女性毒品犯为被试,对CPI的测验数据进行t检验、Z检验和F检验。结果 ①女性毒品犯不仅与常模团体相比较具有显著特征.而且与男性毒品犯相比较也存在特殊性;②女性毒品犯在4种人格类型上的分布不平衡.较多地在Delta型;③民族、地域、年龄及关押时间对女性毒品犯的人格特征的变异均有一定影响.但减刑次数未见反映出被试人格积极改变的效果。结论 女性毒品犯广泛而明显的消极性人格特征,并与民族、地域、年龄及关押时间有关。  相似文献   
88.
人胚胎海马发育的形态学研究 Ⅴ.室管膜的发生   总被引:2,自引:0,他引:2  
运用HE和Nissl染色、免疫组织化学法、透射电镜及扫描电镜,对60例6周至足月的人胚胎海马室管膜上皮变化进行了观察。发现胚胎发育过程中室管膜发生了剧烈变化。最早室管层神经上皮细胞为假复层柱状,随着未分化细胞向外迁徙,海马室管膜层神经上皮细胞迅速增殖,形成复层上皮。当室管膜层细胞停止迁徙时,室管膜开始向假复层柱状及单层柱状上皮转变。电镜观察,胚胎早期神经上皮细胞由未分化细胞构成;其特点是,细胞质内各种特化细胞器匮乏,但糖原丰富。15周左右未分化细胞开始向长突细胞及室管膜细胞分化。长突细胞电子密度高,底部有细长突起,表面有微绒毛,胞质内微丝丰富;而室管膜细胞电子密度低,底部无突起,但表面有丰富的纤毛。对长突细胞及免疫组化染色的GFAP阳性细胞进行形态和发育特征的比较,提示两者属同一类细胞。扫描电镜下,15周前室管膜表面微绒毛较多,以后纤毛逐步发育,大量密集纤毛布满于室管膜表面。此外,还能见到一类接触脑脊液神经元,这类神经元可为多极或双极,并有突起伸入室管膜上皮内。  相似文献   
89.
Osteoporosis and obesity are two severe complex diseases threatening public health worldwide. Both diseases are under strong genetic determinants as well as genetically correlated. Aiming to identify pleiotropic genes underlying obesity and osteoporosis, we performed a bivariate genome-wide association (GWA) meta-analysis of hip bone mineral density (BMD) and total body fat mass (TBFM) in 12,981 participants from seven samples, and followed by in silico replication in the UK biobank (UKB) cohort sample (N = 217,822). Combining the results from discovery meta-analysis and replication sample, we identified one novel locus, 17q21.31 (lead SNP rs12150327, NC_000017.11:g.44956910G > A, discovery bivariate P = 4.83 × 109, replication P = 5.75 × 105) at the genome-wide significance level (ɑ = 5.0 × 10−8), which may have pleiotropic effects to both hip BMD and TBFM. Functional annotations highlighted several candidate genes, including KIF18B, C1QL1, and PRPF19 that may exert pleiotropic effects to the development of both body mass and bone mass. Our findings can improve our understanding of the etiology of osteoporosis and obesity, as well as shed light on potential new therapies.Subject terms: Genome-wide association studies, Gene expression profiling  相似文献   
90.
Many studies have shown that genetic susceptibility plays a key role in determining whether bacterial pathogens successfully infect and cause disease in potential hosts. Surprisingly, whether host genetics influence the pathogenesis of attaching and effacing (A/E) bacteria such as enteropathogenic and enterohemorrhagic Escherichia coli has not been examined. To address this issue, we infected various mouse strains with Citrobacter rodentium, a member of the A/E pathogen family. Of the strains tested, the lipopolysaccharide (LPS) nonresponder C3H/HeJ mouse strain experienced more rapid and extensive bacterial colonization than did other strains. Moreover, the high bacterial load in these mice was associated with accelerated crypt hyperplasia, mucosal ulceration, and bleeding, together with very high mortality rates. Interestingly, the basis for the increased susceptibility was not due to LPS hyporesponsiveness, as the genetically related but LPS-responsive C3H/HeOuJ and C3H/HeN mouse strains were also susceptible to infection. Analysis of the intestinal pathology in these susceptible strains revealed significant crypt epithelial cell apoptosis (terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end label staining) as well as bacterial translocation to the mesenteric lymph nodes. Further studies with infection of SCID (T- and B-lymphocyte-deficient) C3H/HeJ mice demonstrated that loss of lymphocytes had no effect on bacterial numbers but did reduce crypt cell apoptosis and delayed mortality. These studies thus identify the adaptive immune system, crypt cell apoptosis, and bacterial translocation but not LPS responsiveness as contributing to the tissue pathology and mortality seen during C. rodentium infection of highly susceptible mouse strains. Determining the basis for these strains' susceptibility to intestinal colonization by an A/E pathogen will be the focus of future studies.  相似文献   
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