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81.
乙醇对人绒毛孕酮分泌的影响 总被引:1,自引:0,他引:1
本工作利用灌流技术观察了四种不同浓度的乙醇(0.5%、1%、2.5%、5%)对妊娠早期人工流产新鲜胎盘绒毛分泌孕酮的影响。结果表明,乙醇具有促进孕酮分泌的作用,并存在剂量依赖的关系。提示乙醇可能破坏胎盘激素内分泌的平衡,从而影响胎儿的正常生长与发育。 相似文献
82.
本实验选用具有生育力成年雄性猕猴7只,在直视下行双侧HFMC输精管内注射,每侧剂量分别为30mg1只,60mg和100mg各3只;于注射后2.5年和3.5年分别处死动物,取睾丸组织进行光镜和电镜观察.结果发现:猕猴注射HFMC2.5年后,睾丸光镜大部分曲细精管生精上皮结构完整,排列整齐。仅见局部少数管腔生精上皮层数减少,上皮细胞轻度水样变性等病理改变。电镜下曲细精管内除支持细胞内脂褐素增多,轻度基底膜增厚和精母细胞内质网扩张外,各级生精细胞,支持细胞及细胞间连接复合体等超微结构未见明显异常。注射HFMC3.5年后猕猴的光镜、电镜结果与注射后2.5年结果相似,但局部改变较2.5年组轻。上述结果表明:猕猴输精管内注射一定剂量HFMC节育不会引起睾丸组织的严重病理改变。但是,由于注射HFMC后,HFMC释放H+及其对输精管的暂时阻塞,改变了精子生存的内环境,使睾丸出现局部轻度病理改变,随着HFMC逐渐溶解排出,睾丸功能相继恢复正常,配对产仔。为HFMC应用提供了安全性依据。 相似文献
83.
老年学习记忆减退大鼠齿状回突触的定量研究 总被引:2,自引:0,他引:2
据老年大鼠在Morris水迷宫中的行为表现,将其分为老年学习记忆减退和学习记忆正常两部分,采用透射电镜观察、拍片,对齿状回中分子层触的数量和大小进行体视学定量分析。 相似文献
84.
Schecter AD Berman AB Yi L Ma H Daly CM Soejima K Rollins BJ Charo IF Taubman MB 《Journal of leukocyte biology》2004,75(6):1079-1085
Monocyte chemoattractant protein-1 (MCP-1, CCL2) is a mediator of inflammation that has been implicated in the pathogenesis of a wide variety of human diseases. CCR2, a heterotrimeric G-coupled receptor, is the only known receptor that functions at physiologic concentrations of MCP-1. Despite the importance of CCR2 in mediating MCP-1 responses, several recent studies have suggested that there may be another functional MCP-1 receptor. Using arterial smooth muscle cells (SMC) from CCR2(-/-) mice, we demonstrate that MCP-1 induces tissue-factor activity at physiologic concentrations. The induction of tissue factor by MCP-1 is blocked by pertussis toxin and 1,2-bis(O-aminophenyl-ethane-ethan)-N,N,N',N'-tetraacetic acid-acetoxymethyl ester, suggesting that signal transduction through the alternative receptor is G(alphai)-coupled and dependent on mobilization of intracellular Ca(2+). MCP-1 induces a time- and concentration-dependent phosphorylation of the mitogen-activated protein kinases p42/44. The induction of tissue factor activity by MCP-1 is blocked by PD98059, an inhibitor of p42/44 activation, but not by SB203580, a selective p38 inhibitor. These data establish that SMC possess an alternative MCP-1 receptor that signals at concentrations of MCP-1 that are similar to those that activate CCR2. This alternative receptor may be important in mediating some of the effects of MCP-1 in atherosclerotic arteries and in other inflammatory processes. 相似文献
85.
Osteogenic Cells Derived From Embryonic Stem Cells Produced Bone Nodules in Three-Dimensional Scaffolds 下载免费PDF全文
An approach for 3D bone tissue generation fromembryonic stem (ES) cells was investigated. The ES cells wereinduced to differentiate into osteogenic precursors, capable ofproliferating and subsequently differentiating into bone-formingcells. The differentiated cells and the seeded scaffolds werecharacterized using von Kossa and Alizarin Red staining, electronmicroscopy, and RT-PCR analysis. The results demonstrated thatES-derived bone-forming cells attached to and colonized thebiocompatible and biodegradable scaffolds. Furthermore, thesecells produced bone nodules when grown for 3–4 weeks inmineralization medium containing ascorbic acid andbeta-glycerophosphate both in tissue culture plates and inscaffolds. The differentiated cells also expressed osteospecificmarkers when grown both in the culture plates and in 3Dscaffolds. Osteogenic cells expressed alkaline phosphatase,osteocalcin, and osteopontin, but not an ES cell-specific marker,oct-4. These findings suggest that ES cell can be usedfor in vitro tissue engineering and cultivation of graftable skeletal structures. 相似文献
86.
动脉导管溶栓治疗急性肢体动脉栓塞14例分析 总被引:3,自引:0,他引:3
目的 探讨动脉导管溶栓治疗急性肢体动脉栓塞的方法和疗效。方法回顾性分析14例肢体动脉栓塞的诊断方法和介入手术治疗方案。结果治愈11例,治愈率78.6%(11/14);2例好转。无患肢缺血坏死或截肢,无术后因肾功能衰竭死亡。结论动脉导管溶栓是治疗急性肢体动脉栓塞有效的方法,值得进一步开展和探索。 相似文献
87.
Modification of collagen matrices for enhancing angiogenesis 总被引:3,自引:0,他引:3
Yao C Prével P Koch S Schenck P Noah EM Pallua N Steffens G 《Cells, tissues, organs》2004,178(4):189-196
The vascularization of engineered tissues in many cases does not keep up with the ingrowth of cells. Nutrient and oxygen supply are not sufficient, which ultimately leads to the death of the invading cells. The enhancement of the angiogenic capabilities of engineered tissues therefore represents a major challenge in the field of tissue engineering. The immobilization of angiogenic growth factors may be useful for enhancing angiogenesis. The most potent angiogenic growth factor specific to endothelial cells, vascular endothelial growth factor (VEGF), occurs in several splice variants. The variant with 165 amino acids both has a high angiogenic activity and a high affinity for heparin. We therefore incorporated heparin molecules into collagen matrices by covalently cross-linking them to amino functions on the collagen. Physical binding of VEGF to the heparin may then prevent a rapid clearance from the implant, while the release rate may become coupled to the degradation of the collagen matrix. The modified matrices were characterized by determination of the extent of the heparin immobilization, the in vitro degradation rate by collagenase. For testing the angiogenic properties, non-modified and heparinized collagen specimens were--either loaded with VEGF or non-loaded--subcutaneously implanted on the back of rats. Specimens were explanted after varying periods of implantation, the dry weights and the hemoglobin contents, as well as immunostained histological sections were evaluated: heparinized collagen matrices loaded with VEGF are vascularized to a substantially higher extent as compared to non-modified matrices. 相似文献
88.
乙型肝炎病毒前S1抗原检测及其临床意义 总被引:10,自引:0,他引:10
为探讨检测乙型肝炎病毒前S1抗原(Pre-S1Ag)的临床意义,本文对338例各型乙型肝炎患者进行Pre-S1Ag检测,同时检测HBV标志物和HBV-DNA,对其阳性率及相互关系进行分析比较.结果表明:338例患者,Pre-S1Ag阳性检测率为63.02%,HBeAg阳性检测率为48.52%,HBV-DNA阳性检测率为68.05%.Pre-S1Ag阳性与HBV-DNA阳性的符合率为78.56%;Pre-S1Ag与HBeAg阳性的符合率为81.17%;Pre-S1Ag与HBeAg、HBV-DNA具有显著相关性(P<0.01),提示Pre-S1Ag能够较好地反映病毒复制状况,有可能作为体内病毒复制存在的实验室指标. 相似文献
89.
Multi-virulence-locus sequence typing clarifies epidemiology of recent listeriosis outbreaks in the United States 总被引:2,自引:0,他引:2
Multi-virulence-locus sequence typing (MVLST) was used to analyze isolates from two major listeriosis outbreaks in the United States in 1998 and 2002 that were due to consumption of contaminated hot dogs and turkey deli meat, respectively. MVLST demonstrated high epidemiological relevance and indicated that the two outbreaks were the result of one epidemic. 相似文献
90.
氧化苦参碱对LAK细胞活性的影响 总被引:18,自引:0,他引:18
LAK细胞具有很强的广谱杀瘤作用,而氧化苦参碱具有较强的免疫抑制作用。本文研究了氧化苦参碱对LAK细胞活力的影响,结果表明:氧化苦参碱可抑制IL-2对小鼠脾细胞的促增殖作用,并且对IL-2活化LAK细胞杀伤P815的能力也有抑制作用。当IL-2(500u/ml)与200μg/ml的氧化苦参碱共同孵育4d后,可使LAK细胞杀瘤能力(在效靶比为100:1时)的82.5%被抑制。同时氧化苦参碱本身对P8 相似文献