Mast cells are believed to play a novel part in the development of destructive synovial pannus in rheumatoid arthritis (RA). This study was undertaken to investigate the localization of vascular endothelial growth factor (VEGF) in the synovial membrane using a unique immunostaining technique. Synovial specimens of RA patients were examined immunohistochemically and were compared with specimens from non-RA controls. Multi-labelling subtraction immunostaining, a modification of double- and triple-labelling immunostaining, revealed that the VEGF-positive cells were identical to tryptase-positive cells (mast cells). No other cell types were found to be positive for VEGF. The synovium of RA patients showed a larger number of VEGF-positive mast cells than that of non-RA controls (P<0.001). The study suggests that mast cell-derived VEGF may contribute to the development of synovial pannus in RA.
Although peptide growth factors play an important role in the morphogenesis of gallbladder, little is known about how they effect the morphogenesis of gallbladder epithelial cells. Rabbit gallbladder epithelial cells (RGEC) were isolated and cultured in monolayer or collagen gels. Epidermal growth factor (EGF), hepatocyte growth factor (HGF), epimorphin, transforming growth factor-beta 1 (TGF-beta 1), and fibroblast-conditioned medium (FCM) were added to the cultured cells to clarify the effects of these peptides and FCM on morphogenesis of RGEC. RGEC suspended in collagen gels form spherical cysts with morphologic polarity. EGF, HGF, epimorphin, and FCM promoted cyst maturation by accelerating the proliferation and aggregation of clear, polarized vesicles. In contrast, TGF-beta 1 markedly inhibited DNA synthesis in both monolayer and collagen gel cultures and promoted formation of branching structures in collagen gels. Furthermore, in the presence of EGF, TGF-beta 1 induced a drastic change in morphogenesis, with the formation of branching networks that showed cell-cell contact only at sites where branches touched. RGEC-forming multicellular cysts did not express vimentin but expressed significant amounts of cytokeratin and regained junctional complexes. In contrast, TGF-beta 1-treated cells strongly expressed vimentin along with branching structures and showed decreases in cytokeratin expression and junctional complexes. Thus, TGF-beta 1 induces a mesenchyme-like cell shape accompanied by cytoskeletal molecular changes, with loss of both epithelial polarization and junctional complexes. These results suggest that the morphogenetic program of RGEC is likely to be determined by the interaction of these peptides and the timing of their presence.
The use of laparoscopic splenectomy has increased in recent years, primarily for patients with idiopathic thrombocytopenic purpura (ITP). We describe herein the first known case of a laparoscopic splenectomy to be performed in Japan for a patient with a giant splenic epidermoid cyst. A 26-year-old woman presented to our hospital with the major complaint of a feeling of abdominal fullness. Prior to surgery, an ultrasound-guided splenic cyst puncture was conducted for diagnostic purposes as well as to reduce the size of the cyst. The carbohydrate antigen 19-9 (CA 19-9) level was found to be elevated in the cystic contents and in the serum. Under laparoscopic guidance, the splenic vessels were ligated using a device for extracorporeal ligation, then divided. After the resected spleen had been placed in a retrieval bag, it was delivered out of the abdominal cavity without fragmentation. Following surgery, the patient's serum CA 19-9 level returned to normal. Splenic epidermoid cysts are most often encountered in young women, and laparoscopic surgery to remove cysts of this type is both minimally invasive and excellent from a cosmetic standpoint. Thus, laparoscopic surgery should be considered as the method of choice for the majority of patients diagnosed with a splenic epidermoid cyst.
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