[A case of allergic fungal sinusitis caused by Bipolaris spicifera].

We describe a case of allergic fungal sinusitis (AFS) caused by Bipolaris spicifera, the first case reported in Japan. A 70-year-old man was admitted to our hospital because of diplopia following bilateral nasal obstruction and discharge. Radiological studies using computed tomographic scan showed a large soft tissue mass occupying the right frontal, bilateral ethmoid and sphenoid sinuses. He underwent drainage surgery and histopathological examination of the contents of the paranasal sinuses revealed scattered fungal hyphae within "allergic mucin". By cytological examination, these hyphae showed septation at irregular intervals, and were swollen to various sizes. Microbiological studies identified the fungus as Bipolaris spicifera. The presence of allergic mucin and scattered fungal hyphae were very important findings in making a diagnosis of AFS histopathologically, so squash cytology of the contents of the paranasal sinuses was quite useful to observe fungal elements and identify the strain in this case.

Allergic fungal sinusitis caused by Bipolaris spicifera and Schizophyllum commune.

There have been very few reports in Japan of patients with allergic fungal sinusitis (AFS). We describe two cases caused by Bipolaris spicifera and Schizophyllum commune. The patients were a 70-year-old male (Case 1) and a 55-year-old female (Case 2). Both presented with nasal obstruction and purulent nasal discharge. CT scans revealed each to have a soft tissue mass extending from the ethmoid sinus to the sphenoid sinus. In addition, pathological studies on the contents of the paranasal sinuses of both patients revealed the presence of fungal elements in the allergic mucin. Microbiological studies resulted in the recovery of Bipolaris spicifera from Case 1 and Schizophyllum commune from Case 2. To date there have been no reports of AFS due to these two fungi in Japan. It is very important in the diagnosis of AFS to demonstrate the presence of fungal elements in the allergic mucin. Squash cytology of the paranasal sinus contents was especially useful for proving the presence of fungi.

Interaction between mesothelial cells and macrophages in the initial process of pleural adhesion: ultrastructural studies using adhesion molecules.

Detachment of mesothelial cells is an early step in adhesion of the human pleura. To elucidate this process, we used adhesion molecules as the targets of primary antibody and performed immunohistochemical staining of the mesothelial cells that cover the surface of the sites of pleural adhesion and the macrophages that migrate from connective tissue. The surface of the adhesion site that was formed as a result of edematous and villiform elongation of the connective tissue underlying the visceral pleura was covered with mesothelial cells. However, there was partial detachment of the mesothelial cells caused by adherence to macrophages that had migrated from within the connective tissue, and that adherence was mediated by adhesion molecules. We demonstrated that both mesothelial cells and macrophages each express both CD54 and CD11a, important adhesion molecules. It was surmised that the detachment of the mesothelial cells is the result of interaction with the macrophages via those adhesion molecules and that over time it progresses to pleural adhesion.

Immunohistochemical and ultrastructural studies of the effects of prednisolone on transformation of fibroblast to regenerated mesothelial cells.

We have proposed in the past that chest wall fibroblasts are transformed to regenerated mesothelial cells. This study was conducted to investigate the effects of prednisolone on the differentiation and migration of fibroblasts in their transformation to mesothelial cells. Rat fibroblasts harvested from intercostal thoracic wall specimens were cultured in culture medium until cell spheroids were formed. An experimental cell spheroid group to whose culture medium prednisolone had been added and a control spheroid group with no addition of prednisolone were then subjected to immunohistochemical and ultrastructural studies of the changes in the fibroblasts with the passage of time. On days 1 and 2 of culture, the fibroblasts in each group were cytokeratin negative. However, on day 3 the control group became cytokeratin positive, and ultrastructural observations revealed formation of macula adherens and microvilli. In contrast, the experimental group fibroblasts remained cytokeratin negative even on day 3, but became cytokeratin positive on day 5 of culture. Macula adherens and microvilli also manifested on day 5. Prednisolone inhibited the differentiation and migration of fibroblasts, but it was surmised that fibroblasts that have resisted from the effects of prednisolone finally differentiate into mesothelial cells which have formed macula adherens.

Immunohistochemical and ultrastructural study on effect of fibroblast growth factor on transformation of fibroblasts to regenerated mesothelial cells.

To elucidate the effect of fibroblast growth factor on the phenotypical conversion of fibroblasts to mesothelial cells, both immunohistochemical and ultrastructural examinations were carried out on cultured spheroids that were composed of fibroblasts obtained from the parietal pleura of rats with and without addition of antifibroblast growth factor receptor antibody. In the present study, antifibroblast growth factor receptor antibody was employed to block the effect of the autocrine component of fibroblast growth factor in the culture medium. Phenotypical conversion from fibroblast to mesothelial cells was clearly blocked in the experimental group, to which culture medium had been added with antifibroblast growth factor receptor antibody, whereas the control group, cultured without addition of antifibroblast growth factor receptor antibody, showed phenotypical conversion of fibroblasts that was confirmed by the development of macula adherens, microvilli, and positive expression of cytokeratin. These results indicate the possibility that fibroblast growth factor plays a key role in the process of phenotypic conversion of fibroblasts to regenerated mesothelial cells.