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91.
Anti-rat thymocyte antibody-induced injury of glomerular mesangial cells is characterized initially by lysis (1 h) and is followed by proliferation (beginning at 3 to 4 days), with resolution that can include a focal increase in mesangial matrix (by 28 days). Chronic administration (every 12 h) of heparin (anticoagulant or nonanticoagulant) resulted in a decrease in antibody-induced mesangial cell proliferation, which, in turn, was associated with a decrease in the size and number of areas of focal mesangial matrix increase. The effect could not be attributed to the effect of heparin on complement, to alterations in the small numbers of la-positive cells that characterize the lesion, or to binding of antibody to glomeruli. The beneficial effects of heparin in reducing mesangial cell proliferation, with a subsequent reduction in matrix increase, suggest that mesangial cell responses are a major element in the development of at least some forms of glomerulosclerosis. The possible mechanisms by which these effects of heparin may be achieved are discussed. 相似文献
92.
Lynn R. Sorbara Zhichun Tang Alessandro Cama Jinru Xia Esther Schenker Ronald A. Kohanski Leonid Poretsky Elizabeth Koller Simeon I. Taylor Andrea Dunaif 《Metabolism: clinical and experimental》1994,43(12)
Women with polycystic ovary syndrome (PCOS) are markedly insulin-resistant, but the molecular mechanisms of these changes and their relationship to the hyperandrogenic state remain to be clarified. Mutations have recently been identified in the insulin receptor gene of patients with extreme forms of insulin resistance associated with hyperandrogenism (eg, type A insulin resistance), and these mutations account for the insulin resistance in such patients. We performed this study to determine whether mutations in the coding portion of the insulin receptor gene were responsible for insulin resistance in PCOS. Insulin binding studies using cultured skin fibroblasts of three obese (body mass index > 27 kg/m2) women with PCOS (ie, mild hyperandrogenemia and chronic anovulation of unknown etiology) and documented insulin resistance showed no apprarent abnormalities in either the number or affinity of insulin binding sites. Direct sequencing of all 22 exons of the insulin receptor gene from two of the women with PCOS did not reveal any mutations. Furthermore, both alleles of the gene were expressed at equal levels. In a third insulin-resistant PCOS woman, there was no evidence for a mutation in the coding portion of the insulin receptor gene as determined by denaturing gradient gel electrophoresis (DGGE). We conclude that the insulin resistance in these PCOS women was caused by a defect extrinsic to the insulin receptor. 相似文献
93.
Chih-Hsin Tang Rong-Sen Yang Houng-Chi Liou Wen-Mei Fu 《Journal of bone and mineral research》2003,18(3):502-511
The skeletal extracellular matrix produced by osteoblasts contains the glycoprotein fibronectin (Fn), which regulates the adhesion, differentiation, and function of osteoblasts. Fn fibrillogenesis is involved in the process of bone mineralization. Bone morphogenetic proteins (BMPs) can be isolated from organic bone matrix and are able to initiate de novo cartilage and bone formation. In this study, the effect of BMP-4 on Fn fibrillogenesis in cultured rat osteoblasts was examined. BMP-4 enhanced Fn synthesis and extracellular Fn assembly in primary cultured osteoblasts. In addition, the extracellular assembly of Fn from exogenously applied soluble human Fn was also increased by BMP-4. It has been reported that alpha5beta1 integrin is related to Fn fibrillogenesis. The synthesis of both alpha5 and beta1 integrins was upregulated by BMP-4. Immunocytochemistry showed that the clustering of alpha5 and beta1 integrins was also increased by BMP-4. BMP-4 increased fibril formation of Fn and the adhesion of osteoblasts onto Fn matrix, which was inhibited by disintegrin triflavin and Gly-Arg-Gly-Asp-Ser (GRGDS) peptide. Phosphorylation of extracellular signal-regulated kinase (ERK) and focal adhesion kinase (FAK) was increased by BMP-4. Enhancement of extracellular Fn fibrillogenesis and the mRNA expression of beta1 integrin by BMP-4 were inhibited by ERK kinase (MEK) inhibitor PD98059. These results suggest that the enhancement of extracellular Fn fibrillogenesis by BMP-4 in cultured osteoblasts is related to the increase of the synthesis of Fn and clustering of alpha5 and beta1 integrins. ERK is involved in the signaling pathway of BMP-4 in regulating Fn fibrillogenesis in osteoblasts. 相似文献
94.
95.
Distinguishment of A 42 Capsomere Structure of Icosohedral Virion from A 32 One by Electron Microsco
DistinguishmentofA42CapsomereStructureofIcosohedralVirionfromA32OnebyElectronMicroscopeCnenBingying(陈丙莺);ZhouTong(周)(Departme... 相似文献
96.
单向中频电加助透液防治瘢痕增生 总被引:6,自引:0,他引:6
为防治瘢痕增生,寻求有效治疗方法,我们采用单向中频电加助透液治疗瘢痕增生患者33例,痊愈显效率为64%,总有效率为88%。结果表明,单向中频电加助透液能增强导入作用,是防治瘢痕增生的有效方法。 相似文献
97.
98.
小檗碱对大鼠阴茎海绵体磷酸二酯酶5mRNA水平的影响 总被引:3,自引:0,他引:3
目的 :检测大鼠阴茎海绵体中磷酸二酯酶 5 (PDE5 )mRNA的表达 ,进而探讨小檗碱 (berberine ,Ber)的分子作用机制。 方法 :通过逆转录酶链反应 (RT PCR)技术检测大鼠阴茎海绵体中PDE5mRNA的表达。 结果 :大鼠阴茎海绵体中有PDE5A1和PDE5A2mRNA的表达 ,以PDE5A2为主要的异构酶。与内参照 β 肌动蛋白相比 ,对照组、Ber孵育 1和 3h组的PDE5A1及PDE5A2基因mRNA的相对表达量分别为 :0 .2 2± 0 .0 2 ,0 .4 1± 0 .0 1 ;0 .1 5± 0 .0 1 ,0 .34± 0 .0 2 ;0 .1 0± 0 .0 1 ,0 .1 2± 0 .0 1。与对照组相比 ,PDE5A1、PDE5A2的mRNA表达 ,在Ber孵育 1h组降低了 32 %和 1 7%,3h组降低了 5 5 %和 71 %,其中尤以应用Ber 3h后PDE5A2的mRNA减少最为明显 (n =5 ,P <0 .0 1 )。 结论 :Ber对NO cGMP信号通路的下游关键酶 (PDE5 )具有一定的调控作用 ,尤其是抑制PDE5A2的mRNA表达 ,为Ber治疗勃起功能障碍的分子机制之一。 相似文献
99.
Liu Wenen Tang Yin Wang Lange Tan Deming Xiangya Hospital Central South University Changsha 《中国现代医学杂志》2003,13(8):18-20
Extended -spectrum β -lactamases(ESBLs)aremainlyproducedbymembersofthefamilyEnter obacteriaceaewhichcanhydrolyzeβ -lactamantibi oticsincludingthethird - generationcephalosporinandaztreonam ,theESBLs- producingbacillishowedmedian -highresistancetoceftazidimeandaztreonamparticularly[1] .NowadaystheprevalenceofESBLs -producingstrainshavebeenreportedinmanyareasaroundtheworld[2 ] .ButthereisfewinformationabouttherelationshipbetweentheuseofantibioticandtheproductionofESBLs .Weperformedastud… 相似文献
100.
目的 观察糖尿病性视网膜病变(DR)不同分期者接受氩激光治疗的临床效果。方法 采用科以人2000型氩激光组合激光机对170例263只患眼分别做如下处理:(1)对非增殖期糖尿病视网膜病变(NPDR)30眼行局部氩激光凝固术(光凝);(2)对增殖前期糖尿病视网膜病变(PPDR)156眼行次全视网膜光凝;(3)对增殖期糖尿病视网膜病变(PDR)77眼行全视网膜光凝,对合并黄斑局限或弥漫性水肿者给予局灶性光凝或格栅样光凝。于光凝后3个月检查。进行视力、眼底、视网膜荧光血管造影,并与治疗前各项结果对比。结果 视力提高92眼(35%)、无变化144眼(55%)、下降27眼(10%)。眼底检查、荧光血管造影复查示:NPDR、PPDR眼视网膜微血管瘤、水肿、渗出消退,荧光渗漏消退占89%。其余11%需补充光凝。PDR眼视网膜、视盘新生血管消退占67%,33%为部分消退需补充光凝。黄斑水肿完全或部分消退占91%,光凝后出现视网膜前灶性出血占8%,玻璃体积血为1%。结论 氩激光对不同分期DR均有效。NPDR、PPDR效果好于PDR眼,后者光凝后荧光血管造影复查以及补充光凝对提高疗效非常必要。 相似文献