No abstract

Oral administration of sodium tungstate is an e¡ec-tive treatment for diabetes in animal models. We examined the e¡ects of 6 weeks of oral administration of tungstate on glucose transporters (GLUT) in streptozotocin-induced diabetic rat diaphragm. Diabetes decreased GLUT4 expression while tungstate treatment normalized not only GLUT4 protein but also GLUT4 mRNA in the diabetic rats. Furthermore, treatment increased GLUT4 protein in plasma and internal membranes, suggesting a stimulation of its translocation to the plasma membrane. Tungstate had no e¡ect on healthy animals. There were no di¡er-ences in the total amount of GLUT1 transporter in any group. We conclude that the normoglycemic e¡ect of tungstate may be partly due to a normalization of the levels and subcellular localization of GLUT4, which should result in an increase in muscle glucose uptake. ß

No abstract

A thin mucous layer covers the ciliary body and iris epithelium and becomes thicker in the anterior chamber where it covers the anterior surface of the iris, the chamber angle and corneal endothelial surface. It is especially thick at the chamber angle, where it adopts a meniscus shape with the concavity towards the anterior chamber. Cetylpiridinium chloride along with glutaraldehyde was used to precipitate this layer of mucous substance lining the anterior and posterior chambers of the human eye. The staining of the precipitate by cationic dyes suggests that glycosaminoglycans are main components. The specific characterisation with anti-hyaluronic acid monoclonal antibody labelled with colloidal gold reveals the presence of hyaluronic acid in the precipitate. Long unbranched hyaluronic acid molecules may form the skeleton of a gel able to trap and hold virtually any other macromolecule suspended in the aqueous humour. A possible role of such a gel in the regulation of aqueous humour outflow is discussed.

Four cases of primary small cell carcinoma of the skin (PSCCS) are presented (ages ranging from 60 to 68 years). Ultrastructurally, two cell types were identified, with both presenting electron‐dense secretory granules and paranuclear intermediate filaments. Argyrophylia was positive in one case. Intense solar elastosis in two cases and actinic keratosis in one case suggest a possible role from solar damage in the pathogenesis of this tumor. According to comparative ultrastructural features, different histogenetic possibilities in Merkel cells (MC), peripheral neuroblastic tissue, and totipotential cells are discussed. Some neurosecretory‐like granules were observed in basal cell carcinoma (BCC). We consider that PSCGS reproduces cells similar to MC and probably originates in stern cells with totipotential capacity.