Metrizamide CT cisternography and perioptic subarachnoid space imaging.

Opacification of the perioptic subarachnoid space (PSAS) is a normal occurrence. Opacification depends on the anatomy of the meningeal layers surrounding the optic nerves. To determine the reliability and the most efficacious technique for opacifying the PSAS, a retrospective study of 200 computed tomographic cisternography studies with water soluble contrast medium (metrizamide or iopamidol) was undertaken.

Traumatic aneurysms of cavernous internal carotid artery with secondary epistaxis.

The syndrome of delayed epistaxis and monocular blindness following nonpenetrating head injury is reviewed. Bleeding results from rupture of a traumatic cavernous internal carotid artery aneurysm into the sphenoid sinus. There were 96 patients with this syndrome found in the literature and another four are added in this report.

Radiologic characteristics of primary cerebral neuroblastomas.

Primary cerebral neuroblastomas should be considered in the differential diagnoses of calcified, cystic, supratentorial masses in young patients. The authors review radiologic data for 11 patients with such lesions.

The normal and abnormal left superior intercostal vein.

A study of 500 normal erect posteroanterior chest radiographs was undertaken to determine the incidence of visualization and size of the left superior intercostal vein in normal individuals. The vein produces a small "nipple" lateral to the aortic knob on 1.4% of normal erect posteroanterior chest films; its diameter can be up to 4.

The role of divalent cations in activation of the sea urchin egg. I. Effect of fertilization on divalent cation content.

The Ca and Mg content of unfertilized sea urchin eggs (3 and 21 mumole/ml eggs) remains remarkably constant over periods of hours, even when the eggs are suspended in Ca- or Mg-free sea water. After fertilization the Ca content of eggs in regular sea water increases sharply by about 20%, followed by a decrease to the unfertilized level by 40 minutes. However, if the fertilized eggs are washed three minutes in Ca-free sea water a sharp decrease in the Ca content occurs amounting to 30% of the total in the first 40 minutes, with little change thereafter.

Na is essential for activation of the inseminated sea urchin egg.

The presence of at least 2.5 mM Na during the first several min after insemination is required for the activation of sea urchin eggs. Of those chemical species examined that exist entirely as cations, and which did not activate the unfertilized egg, only Li substitutes for Na.

Studies on solute transfer in the vascular endothelium.

Barium chromate, Prussian blue, and cobalt-cobalticyanide can be precipitated in vivo in the endothelium of mesenteric vessels by injection of the appropriate anions into the blood stream, and topical application of the precipitating cations to the exposed mesenteries of mice and frogs. Precipitation in the endothelium occurs in the form of a diffuse fine punctate precipitate, and also as continuous lines demarcating endothelial cell outlines. A striking feature is the frequent occurrence of this type of precipitation in a tapering zone downstream from mural thrombi in the veins.