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Biomedical subjects

T Tanishima

Publications and source records attributed to T Tanishima.

9 recordsLinked to original sources
PubMed1979

Vasospasm assessed by angiography and computerized tomography.

In 44 consecutive cases of ruptured cerebral aneurysm, vasospasm was demonstrated pre- or postoperatively. These cases were examined by bilateral carotid angiography and computerized tomography (CT), and the relationship between the angiographically visualized distribution of vasospasm, the neurological symptoms, and infarction seen on CT was evaluated. Vasospasm occurred in only some intracranial portions of the cerbral arteries that were immersed in blood-stained cerebrospinal fluid. Angiographically, diffuse vasospasm extensively involving bilateral carotid systems indicated the gravest prognosis for patients. Vasospasm affecting one carotid system and the anterior cerebral arteries on the opposite side often produced permanent neurological deficits. On the contrary, when vasospasm was restricted to one carotid system or to bilateral anterior cerebral arteries, it was usually associated with temporary neurological symptoms; however, it always produced residual neurological symptoms if it extended to the ascending branches (M3) of the middle cerebral arteries. Computerized tomography definitely demonstrated a low-density area or infarction in the territory of the spastic arteries in 25 (71%) of 35 cases with vasospasm. A low-density area was always detected when vasospasm occurred in M3 segments.

Adult↗
PubMed1978

Possible regulatory mechanisms of the cornea. I. Epithelial-stromal interaction in vitro.

Electron microscopic studies of pure epithelial and stromal cultures and of combined cultures demonstrated that keratocytes activity was inhibited by the presence of epithelial cells in culture. The degradation of collagen and the formation of clear zones around the keratocytes within the explants of pure stroma is interpreted as an indication for the production of a collagenolytic substance by the active keratocytes. The collagenolytic activity of the keratocytes was not observed within the stroma of combined cultures and was probably inhibited by the activity of epithelial cells in these cultures. Furthermore, using a microculture method for the assessment of the metabolic activity of corneal cells in vitro, supernatants of epithelial cell cultures were shown to have a marked inhibitory effect on the capacity of keratocytes to synthesize DNA. No effect of stromal cell supernatant on epithelial cell activity could be detected by the same methods. It is suggested that this "one way" influence as observed in vitro might, in certain conditions, play a role as a regulatory mechanism in vivo.

Animals↗
PubMed1978

Ocular cryptococcosis.

We studied ocular cryptococcosis in a 59-year-old man who had received extensive chemotherapy for abdominal malignant lymphoma. Mucinous lesions containing abundant cryptococci, but no inflammatory cells, formed in the posterior choroid of the eye. Electron microscopy revealed that mucin, a filamentous substance, coated the encapsulated organisms. Except for a few degenerating ones in histiocytes, most cryptococci appeared in the extracellular space.

Antineoplastic Agents↗
PubMed1978

Axoplasmic flow during chronic experimental glaucoma. 1. Light and electron microscopic studies of the monkey optic nervehead during development of glaucomatous cupping.

The anterior optic nerve and the macular region of the retina of glaucomatous eyes of five rhesus monkeys (Macaca mulatta) have been examined by light and electron microscopy. The experimental glaucoma had been induced by argon laser treatment of the anterior chamber angle. The eyes were examined 3 to 11 weeks after the onset of sustained elevation of intraocular pressure above 20 mm Hg. Severe degenerative changes were seen in eyes with higher intraocular pressure and longer duration of glaucoma. Eyes with a lesser elevation of intraocular pressure and shorter duration of glaucoma showed changes sharply localized to the axon bundles in the scleral lamina cribrosa. Accumulation of mitochondria and dense bodies occurred anterior and posterior to collagenous septae. The location of these changes is in agreement with the localization of block of axoplasmic transport identified by autoradiographic studies. It is speculated that these cytologic changes reflect blockage of axoplasmic flow in the optic nerve of eyes with glaucoma.

Animals↗
PubMed1977

Aldose reductase in retinal mural cells.

Cultured mural cells (intramural pericytes) from adult rhesus retinal capillaries were examined for the presence of the sorbitol pathway. A radioimmunoassay for human aldose reductase, cross-reactive with rhesus lens aldose reductase, showed the presence of this enzyme in our cultured cells. Mural cells grown in culture media containing normal (10 mM) and high (40 mM) levels of glucose were examined for polyol accumulation by gas-liquid chromatography. Cells incubated in high glucose medium showed a threefold increase in sorbitol concentration over cells grown at low glucose levels. After 30 days in high glucose medium, mural cells formed dense multilayered areas with extensive cellular debris. These findings suggest the presence of the sorbitol pathway in cultured retinal mural cells and cellular degeneration in high glucose medium; this may have possible implications in the pathogenesis of diabetic retinopathy.

Alcohol Oxidoreductases↗