ABSTRACT
PURPOSE: The goal of this study was to characterize the morphology of the mucinous layer on rabbit, bovine, owl, and human corneal endothelial cells. METHODS: Corneoscleral buttons were fixed using cetylpyridinium chloride to stabilize "mucus" and the tissue was prepared for transmission electron microscopy. Photomicrographs were measured to determine the thickness of the endothelial and epithelial mucinous layer in the central cornea. RESULTS: The endothelial mucinous layer was seen as a nearly uniform electrodense region on the apical aspect of the endothelium. It was found to be 0.9 microm, 0.9 microm, 0.9 microm, and 0.5 microm thick in rabbit, bovine, owl, and human, respectively. The owl endothelium had an additional less electrodense layer with a granular appearance and a thickness of about 200 microm. The mucinous layer on the epithelium was similar in appearance to that on the endothelium and across species. CONCLUSIONS: The morphologic similarity of the endothelial and epithelial mucinous layers is a serendipitous finding that should prove valuable in experimental design. Ultimately, it is hoped that studies of the posterior corneal surface will deepen our knowledge of endothelial protection.
Subject(s)
Adult , Humans , Rabbits , Animals , Cytokines/pharmacology , Endothelium, Corneal/ultrastructure , Endothelium, Corneal/metabolism , Endothelium, Corneal/cytology , Microscopy, Electron , Mucins/ultrastructure , Mucins/metabolism , Strigiformes , Staining and LabelingABSTRACT
AIMS: To study mucin histochemistry of the normal esophagus, esophageal adenocarcinoma, and carcinoma exhibiting glandular and squamous elements, to ascertain the origin of these tumors. METHODS: Mucin histochemistry was studied in sections of the normal cardioesophageal junction obtained from 25 post-mortem specimens and in 12 mucin-secreting esophageal carcinomas. RESULTS: The normal submucosal esophageal glands and three adenocarcinomas secreted predominantly sulfomucins; a mixture of neutral and sialomucins was seen in the nine carcinomas with squamous and glandular traits. Barrett's metaplasia was not encountered. CONCLUSIONS: In the absence of Barrett's metaplasia, esophageal adenocarcinoma probably arises from the submucosal glands, whereas squamous carcinomas with mucin-secreting component could arise from metaplastic change in squamous epithelium, cardiac glands, or multipotent stem cells in the epithelium.