Electron microscopic study of the arterial wall in the cerebral aneurysms.

The ultrastructural modifications were observed in electron microscopy of the congenital aneurysm of the internal carotid artery with subarachnoid hemorrhage. The tunica intima very enlarged contains in the endothelial cells numerous microvesicles of pinocytosis, and rare cell organelles. The internal elastic lamina presented ruptured or absence zones. The luminal face of the cells appeared irregular with large evaginations and deep and narrow invaginations. Under the endothelial lining, large masses of extracellular matrix with different degrees of edema, and fragmented collagen fibrils realize a metabolic barrier between the tunica intima and media. The muscle fibers of the tunica media and the myofilaments in each myocyte are in reduced number.

Histochemical and histopathological study of the gastric mucosa in the portal hypertensive gastropathy.

It has been studied "in situ" the action of NADH2-cytochrome C reductase, an aerobe oxidative enzyme, in comparison to lactate dehydrogenase, a glycolitic enzyme in the gastric mucosa and with portal hypertensive gastropathy (PHG) accompanied by morpho-pathological observations. In the normal gastric mucosa, the aerobe oxidative metabolism is predominant over the anaerobe one in all types of cells, but in different intensities (medium in the surface epithelium and low in the vascular endothelium, weak, medium, intense and very intense in fibroblasts and in secretory cells of fundic glands and macrophages). In the portal hypertensive gastropathy, this type of metabolism decreases and the anaerobe metabolism increases, tending to equal the first, especially in the glandular cells. The oxidative activity decreases in the surface epithelium and in the vascular endothelium, increases in cells of the inflammatory infiltrate and in fibroblasts and mast cells.