Presence of apocrine epithelial antigen (AEA) in type II pneumocytes and in hyaline membranes of neonatal RDS

"Candida Albicans Interactions With The Host: Crossing The Intestinal Epithelial Barrier"

Formerly a commensal organism of the mucosal surfaces of most healthy individuals, Candida albicans is an opportunistic pathogen that causes infections ranging from superficial to the more life-threatening disseminated infections, especially in the ever-growing population of vulnerable patients in the hospital setting. In these situations, the fungus takes advantage of its host following a disturbance in the host defense system and/or the mucosal microbiota. Overwhelming evidence suggests that the gastrointestinal tract is the main source of disseminated C. albicans infections. Major risk factors for disseminated candidiasis include damage to the mucosal intestinal barrier, immune dysfunction, and dysbiosis of the resident microbiota. A better understanding of C. albicans' interaction with the intestinal epithelial barrier will be useful for designing future therapies to avoid systemic candidiasis. In this review, we provide an overview of the current knowledge regarding the mechanisms of pathogenicity that allow the fungus to reach and translocate the gut barrier.

Papillary pneumocytoma of the lung. An immunohistochemical and electron microscopic study

Papillary pneumocytoma, so-called sclerosing hemangioma of the lung, is a benign pulmonary neoplasm. In the present study, clinical aspects, immunohistochemical characteristics, and ultrastructural findings of two cases of such tumors are described. Using a panel of various antibodies, the authors found that cytokeratin, Leu-M1 and Ber-EP4 were expressed only in papillary areas. Similarly, apocrine epithelial antigen was positive in cells lining papillary stalks. In contrast, epithelial membrane antigen (EMA) stained cells both in solid and papillary areas. CD 31, Ulex 1 and factor VIII-related antigen were positive only in stromal vessels, as desmin and muscle actin. Vimentin was positive in stromal cells and in papillary areas in one case. KP 1 staining was negative in neoplastic cells. Ultrastructurally, both neoplastic cell types showed features of epithelial cells, and the cells lining papillary stalks contained lamellar bodies characteristic to type II pneumocytes. The evidence obtained clearly shows that the neoplastic cells of this tumor are of epithelial type; one cell type represents neoplastic type II pneumocytes, and another cell type represents the heterogeneous group of epithelial cells, also sharing features of type I pneumocytes.