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T Tanishima

Publications and source records attributed to T Tanishima.

At least 55 records · Page 3Linked to original sources
PubMed1982

Wound-healing of the corneal endothelium in the monkey: a morphometric study.

Topographical aspects and the time course of the healing processes in the corneal endothelium were studied in 31 cynomolgus monkey eyes. The corneal endothelium was damaged at the center by transcorneal freezing, using a probe with a tip diameter of 2.5 mm. Flat preparations of the endothelium stained with silver nitrate were made at various time intervals after freezing. Panoramic photographs of the corneal endothelium along the entire length of one meridian were made, and the sizes of individual cells were calculated by a computerized image analyzer. The size and shape of the endothelial cells showed marked changes around the wound edge, and the cells migrated to the duodenal area, which was covered by the endothelial cells in 3 days. Subsequently, the cell size distribution recovered toward the normal pattern, but multinucleated giant cells persisted in the center of the wound after one year. A slow enlargement of the cells occurred in the periphery, where final average cell size was about 25% larger than the original level. It was thought that the cells of a very wide area were mobilized in the wound-healing processes and that cell proliferation probably played a minor role.

Animals↗
PubMed1980

Lipid peroxidation as a cause of cerebral vasospasm.

In the present study, the vasocontractile activities of purified oxyhemoglobin, methemoglobin, peroxides of linoleic and arachidonic acid, and hydrogen peroxide were examined in vitro, using the canine basilar artery. It was shown that all of them possess a vasocontractile capacity in a dose-dependent fashion. Fresh canine arterial blood was incubated at 37 degree C for 2 weeks, and the daily change of its vasocontractile capacity and the amount of TBA-reactive substance was studied. This study revealed a gradual and parallel increase in both of them. In a clinical study with 32 SAH patients, the amount of TBA-reactive substance in the CSF was more elevated when angiographically confirmed vasospasm was present. The angiographical and histological responses of the basilar artery to the cisternal injection of 15-HPAA were studied in dogs. The cisternal injection of 15-HPAA (0.2 and 2.0 mg dissolved in bovine serum) caused a mild initial contraction of the basilar artery that lasted about 7 hours. On the third day, a stronger contraction occurred, persisting thereafter until sacrifice. Electronmicroscopy of those arterial samples revealed the disappearance of myofibrils, pyknotic changes of nuclei, and the appearance of vacuoles as well as electron-dense granules in the tunica media. The prolonged arterial contraction was always associated with remarkable destruction of the endothelial cells. These changes were essentially the same as those in experimental and clinical vasospasm. These data strongly indicate that free radical reactions initiated by clot lysis, represented by lipid peroxidation, plays an important role in the genesis of chronic vasospasm in subarachnoid hemorrhage.

Animals↗
PubMed1980

[Selective venous sampling of pituitary hormones under provocative tests after retrograde cavernous sinus sinography (author's transl)].

In 22 subjects, selective venous sampling from the inferior petrosal sinus was performed under provocative tests along with simultaneous sampling of pituitary blood from the antecubital vein, after retrograde cavernous sinography. The difference of hormonal levels between sinus blood (Bs) and peripheral blood (Bv) was measured by two antibody radioimmunoassay. Most extreme difference of hormonal levels was observed in acromegalic subjects, where Bs/Bv ratio of GH was 6.0 in the basal value and 4.9 in the peak value, and that of PRL 3.5 and 4.6, respectively. In subjects who reacted to provocative tests, the average ratio of Bs/Bv ranged from 6.9 to 1.1 in the order of GH, PRL, LH, TSH and FSH. Non-reactive subjects showed no significant difference in the hormonal levels between Bs and Bv. From the results obtained above, we assume a possible relationship between Bs/Bv ratio and metabolic clearance rate and between difference of Bs-Bv and basal production. The integral of Bs-Bv difference measured from time zero to the time returned to the basal value under provocative tests represents the sum of basal production and pituitary reserve according to compartment analysis.

Adolescent↗
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↗