Study on the Role of Mast Cells in the Development of Liver Fibrosis During Diethylnitrosamine （DEN）－induced Hepatocarcinogen

The mast cells(MC)and their roles in the development of liver fibrosis during experimental hepatocarcinogenesis in rats have been studied immunohistochemically and electron microscopically.Pronounced MC hyperplasia occurred after beginning of the treatment of DEN. The vast majority of mast cells in fibrotic livers was present in thickened fibrous septa.Intracellular or pericytial collagen tape IV and laminin staining were found in mast cells,collagen types I,III and fibronectin were negative.Mast cells mainly distributed in proximity to basement membrane and the electron microscopical observation revealed a close topographic relationship between mast cells and fibroblasts. The fibroblasts phagocytized the granules released by mast cells and thus were activated, showing enhanced formation of collagenous fibrils.The mast cells may be derived from blood circulation or replicated in situ. Those findings indicated that mast cells take part in the process of fibrosis at least by two ways:(1)It directly synthesizes the basement membrane components;(2)It stimulates the fibroblasts or other types of cells which have the potential functions in fibrogenesis by releasing granule mediators or cytokines acting upon the fibrosis process.

EWING’S SARCOMA CAN EXPRESS BONE MORPHOGENETIC PROTEIN

Paraffin sections from 6 cases of Ewing's sarcoma were immunostained by ABC method using BMP -McAb for investigating the existence of BMP in Ewing' s sarcoma. All cases were positive. The result was coincided with human tumor transplants in athymic nude mouse by Bauer. It is shown that Ewing' s sarcoma can express BMP. So we support the hypothesis that Ewing' s sarcoma originates from primitive multipotential cells and can pluripotentially differentiate.

Immunological studies on the cellular phenotype involved in corneal allograft rejection

Objective To investigate the cellular phenotype involved in corneal allograft rejection using wholemounts analysis.Methods Corneal transplantation was performed between Sprague Dawley (SD) and Wistar rats. Corneal wholemounts were prepared from control rats and those after corneal transplantation on day 7 and 12. Immunohistochemical stain was performed on these wholemounts using monoclonal antibodies to transforming growth factor β1(TGF β1), CD3, CD4, CD8, B lymphocytes, macrophages, dendritic cells and major histocompatibility complex (MHC) class Ⅱ antigen.Results Corneal allograft rejection started on day 7 and reached its maximum from 10 to 14 days after corneal transplantation. Presence of TGF β1 , CD3 , CD4 , CD8 , MHC class Ⅱ positive cells, macrophages and dendritic cells were noted at the limbus of both SD rats and Wistar rats. No positive cell was present in the central cornea of normal rats. All positive cells but B lymphocyte were noted in large numbers in the cornea after corneal allograft transplantation. Marked staining for TGF β1 was noted during graft rejection.Conclusion The corneal wholemounts technique provides a good visualization for the cellular phenotype involved in corneal allograft rejection. A variety of cells including TGF β1, CD3, CD4, CD8, MHC class Ⅱ antigen positive cells, macrophages and dendritic cells are involved in corneal allograft rejection. TGF β1 positive cell might be an important immunosuppressive factor after corneal transplantation and also involved in the induction of fibrosis.

Expression of T cell factor-4 in non-small-cell lung cancer

Background T cell factor 4 (TCF 4) plays an important role in development and carcinogenesis Recently, the role of TCF 4 has been described in colon cancer and other cancers However, whether TCF 4 plays a similar role in lung cancer is unknown To answer this question, we studied the expression of TCF 4 protein and mRNA in nonsmallcell lung cancer (NSCLC) and the relation of TCF 4 expression pattern to histological type and cell differentiation Methods Tissue samples from sixty cases of pathologically diagnosed NSCLC and eight normal tissue samples were obtained between September 2001 and March 2003 Immunohistochemistry was used to investigate the distribution of TCF 4 protein The staining patterns of the tumors were divided into 4 categories: nuclear staining alone or nuclear staining greater than cytoplasmic staining; cytoplasmic staining or cytoplasmic staining greater than nuclear staining; equal nuclear and cytoplasmic staining; no nuclear staining or cytoplasmic staining The integrated optical density (OD) values of all sections were analyzed by UIC MetaMorph image analysis software The expression of TCF 4 mRNA was detected by onestep reverse transcriptionpolymerase chain reaction (RTPCR) The integrated density values of the PCR products were analyzed semiquantitatively Results Immunohistochemistry showed that there was no expression of TCF 4 in normal tissue However, TCF 4 was expressed in 86.7% (52/60) of NSCLC samples, mainly in the nuclei of tumor cells Furthermore, there was a significant difference in TCF 4 localization patterns between squamous cell carcinomas and adenocarcinomas (P<005) The integrated OD values of TCF 4 expression was significantly higher in tumors with moderatepoor cell differentiation than in well differentiated tumors (5163±667 vs 4613±1231, P<001) There was no TCF 4 mRNA expression in normal tissue However, 63.9% (23/36) of carcinoma samples expressed TCF 4 mRNA TCF 4 mRNA expression was significantly higher in tumors with moderatepoor cell differentiation than in well differentiated tumors (P<005) There were no significant differences in mRNA expression in comparison with histological type Conclusions The subcellular distribution of TCF 4 may correlate with NSCLC histological type High expression of TCF 4 mRNA and protein may be associated with the degree of cell differentiation in NSCLC