Fibroblasts induce the assembly of the macromolecules of the basement membrane

The mechanism regulating the deposition of basement membrane components (BMCs) in a polymeric structure at the junction with the connective tissues is not yet understood. Cultures and cocultures of epithelial BMC-producing cells (L2 or PER cells) and fibroblasts were prepared in several experimental conditions and the organization of BMCs was studied by immunofluorescence. The pattern of BMCs in pure cultures of L2 or pulmonary epithelial rat (PER) cells consisted of intra- and extracellular granular deposits. At very high density, the cell contours were also underlined by a disrupted network of BMC deposits. A different fibrillar plexus--containing laminin, collagen type IV, and heparan-sulfate proteoglycan resistant to deoxycholate treatment and distant from the cell membrane--was observed in cocultures of L2 or PER cells with fibroblasts. Fibrils of fibronectin and/or collagen type I were most often dissociated from this plexus of BMCs. Similar results were obtained by adding a conditioned medium of L2 or PER cells to confluent fibroblasts, even when the cells were killed. Pure laminin also bound to the fibroblast layer. A coated film of fibronectin or polymeric collagen type I was unable to bind BMC provided by a conditioned medium. It is suggested that molecule(s) synthesized by fibroblasts and deposited in the pericellular matrix are involved in the assembly of BMCs.     

阿维A治疗重症银屑病临床疗效与安全性评价

目的　评价阿维A治疗重症银屑病的临床疗效与安全性。方法　24例重症银屑病患者采用阿维A治疗,剂量为 20~50mg/d,平均疗程 4~8周。结果　治疗重症银屑病有效率为 79. 2%,其中斑块状寻常性银屑病、红皮病型银屑病、泛发性脓疱型银屑病、掌跖脓疱病有效率分别为 62. 5%, 75. 0%, 100%, 88. 9%;且阿维A治疗剂量与副作用间有相关性。结论　阿维A治疗重症银屑病临床疗效显著,长时间于临床监测下服用阿维A未出现严重的毒副作用。