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Biomedical subjects

E Tani

Publications and source records attributed to E Tani.

At least 127 records · Page 7Linked to original sources

Plasma-cell granuloma of the fourth ventricle. Case report.

The case is presented of a 36-year-old woman with a plasma-cell granuloma arising in the fourth ventricle. The mass appeared on computerized tomography as a well circumscribed area of slightly high density that was markedly enhanced with contrast medium. Microscopic examination showed a mixed-cell population with a predominance of plasma cells, and the tumor was characterized immunohistochemically by polyclonal plasma-cell proliferation.

Adult↗

Effect of selective inhibitor of thromboxane A2 synthetase on cerebral vasospasm after early surgery.

The authors report the results of inhibition of thromboxane A2 synthetase in 49 consecutive patients with subarachnoid hemorrhage (SAH). These unselected Grade I to IV patients all had a ruptured aneurysm of the anterior circle of Willis, and were operated on within 72 hours after SAH. Twenty-seven patients were treated postoperatively by an intravenous infusion of sodium (E)-3- [4-(3-pyridylmethyl)-phenyl] -2- propenoate (OKY-1581), a selective inhibitor of thromboxane A2 synthetase, at 5 micrograms/kg/min for 10 to 14 days, and the remaining 22 patients did not receive this drug. Both groups of patients had similar age distribution and preoperative neurological conditions. A suggestive but statistically insignificant improvement was found in postoperative angiographic vasospasm, ischemic symptoms, and overall outcome in the group receiving OKY-1581. The incidence of low-density areas on the postoperative computerized tomography scans was significantly decreased in patients treated with OKY-1581 infusion.

Acrylates↗

Effects of chlorpromazine on experimental delayed cerebral vasospasm.

Experimental delayed cerebral vasospasm was produced in the canine basilar artery by intracisternal injections of blood 2 days apart. The spastic basilar artery was exposed via the transclival route under a surgical microscope, and was dilated by topical application of chlorpromazine, a calmodulin antagonist. Dilatation was dose-dependent, with a median effective dose of 37 +/- 16 microM. In addition, 100 microM chlorpromazine was inserted into the cisterna magna until the intracranial pressure (ICP) reached 200 mm H2O for 30 minutes, inducing a complete reversal of angiographic delayed cerebral vasospasm in two of five animals. In other studies, the intracisternal perfusion of 100 microM chlorpromazine at 1.48 ml/min for 30 minutes with an ICP of less than 200 mm H2O induced no serious abnormalities in mean arterial blood pressure and pulse rate of normal animals. Electroencephalography during the intracisternal perfusion of chlorpromazine showed a slight to moderate increase in occurrence of theta waves. No neurological deficits or significant histological abnormalities ascribable to intracisternal chlorpromazine were found.

Animals↗

Capillary hemangioma of the optic disc.

Two cases of capillary hemangioma of the optic disc (one endophytic and the other exophytic) unassociated with central nervous system involvement are reported. Ophthalmoscopic and fluorescein angiographic findings of capillary hemangiomas of the optic disc are summarized to aid in differentiating them from cavernous and racemose hemangiomas. Therapeutic problems are also discussed.

Adolescent↗

Immunohistochemical study of fibronectin in human glioma and meningioma.

The presence of fibronectin (FN) and glial fibrillary acidic protein (GFAP) in two astrocytomas, 17 glioblastomas, and five meningiomas was studied by indirect immunoperoxidase staining of formalin-fixed and paraffin-embedded surgical specimens. Angiogenesis in tumor was scored by the microscopic angiogenesis grading system (MAGS), and plasma FN levels were measured by single radial immunodiffusion. In astrocytomas and glioblastomas, GFAP-positive tumor cells had no FN expression and FN was confined to proliferating vessel walls and the leptomeninges, showing a mutually exclusive FN and GFAP expression. GFAP-positive tumor cells were occasionally surrounded by a network of FN-positive matrix produced by cells derived from the leptomeninges or blood vessels. In meningiomas, FN expression was found in vessel walls and meningioma cells including whorl formations and psammoma bodies. In general, deep immunoperoxidase staining for FN was shown in the endothelial cells and the psammoma bodies. Plasma FN levels were correlated significantly not to the degree of leptomeningeal proliferation but to the MAGS scores in gliomas.

Astrocytoma↗

Effects of prostacyclin and indomethacin on experimental delayed cerebral vasospasm.

Isolated canine basilar artery contracted by prostaglandin E2, hemoglobin, or serum was relaxed in a dose-dependent manner by the addition of 10(-8)M to 10(-6)M prostacyclin (PGI2), and was scarcely relaxed by 10(-9)M PGI2. In other studies, intravenous administration of PGI2 (25 or 75 ng/kg/min), indomethacin (4 mg/kg), or indomethacin (4 mg/kg) plus PGI2 (25 ng/kg/min) failed to reverse angiographic delayed vasospasm produced in vivo in the canine basilar artery by an intracisternal injection of blood. In addition, no significant increase occurred in mean values of regional cerebral blood flow (rCBF) with any treatments, and mean rCBF difference in dogs treated by PGI2 infusion at 25 ng/kg/min was 2.5 +/- 1.2 ml/100 gm/min and only significantly increased (p less than 0.01). Mean arterial blood pressure was significantly reduced by PGI2 infusion at 25 (p less than 0.05) or 75 ng/kg/min (p less than 0.005).

Animals↗

Translational mobility of concanavalin A receptors in normal and neoplastic glial cells.

The dynamics of cell-associated Concanavalin A (Con A) in astrocytes of the newborn rat (RNA), the rat glioma (AC), and the human glioblastoma (GB) were studied in vitro by fluorescence and electron microscopy. Con A receptors on the cell surface were seen usually as a continuous thin layer, and Con A accumulations in fluorescence microscopy were actually Con A receptors on complicatedly infolded cell membrane and collection of Con A pinosomes. No capping occurred in the three types of glial cells. The translational movement of Con A receptors on the cell surface was rapid in the AC, slow in the RNA, and intermediate in the GB, and partly associated with Con A internalization. Con A pinosomes were more numerous in the RNA compared with those in the AC and the GB. Colchicine accelerated the translational mobility of surface Con A receptors more markedly in the AC and the GB than in the RNA. The translational movement Con A receptors, when treated with cytochalasin B, was retarded in the RNA and the GB and rather accelerated in the AC. Con A pinosomes were decreased in the three types of glial cells by treatment with colchicine or cytochalasin B.

Animals↗

Prostaglandin metabolism in experimental cerebral vasospasm.

Experimental cerebral vasospasm was produced in the canine basilar artery by an intracisternal injection of fresh autogenous arterial blood, and prostaglandins generated in spastic and nonspastic arteries were assessed by thin-layer chromatography. Prostaglandins synthesized in normal arteries were 6-keto-prostaglandin (PG)F1 alpha, PGF2 alpha, PGE2, and PGD2; 6-keto-PGF1 alpha was the most abundant prostaglandin. The study of platelet aggregation suggested that prostacyclin (PGI2)-like activity was manufactured by the normal basilar artery. At 5 minutes after the intracisternal blood injection, no significant changes were evident in syntheses of prostaglandins generated by spastic artery. However, PGE2 synthesis was significantly increased in spastic artery 2 days after the intracisternal blood injection, and 6-keto-PGF1 alpha and PGF2 alpha synthesis and PGE2 synthesis were significantly decreased and increased, respectively, in spastic artery 6 days after the intracisternal blood injection. No significant changes were found in syntheses of 6-keto-PGF1 alpha, PGF2 alpha, and PGE2 manufactured by nonspastic arteries at any stage. Formation of thromboxane B2 was not detected in normal, spastic, or nonspastic arteries.

Animals↗

In vitro assay of contractile activities of spastic canine basilar artery and its surrounding blood clot.

A prolonged vasospasm was produced in the canine basilar artery by injection of fresh autogenous arterial blood into the chiasmatic cistern. Homogenates of lyophilized blood clot around the spastic artery, were made, and their contractile activities were studied in vitro. The homgenates of the lyophilized spastic arteries usually induced a dose dependent sustained contraction, whereas those of the lyophilized normal arteries often produced a dose-dependent transient contraction, and those of the lyophilized blood clot induced a dose-dependent transient or sustained contraction. The initial maximum contractions produced by the homogenates of the lyophilized normal and spastic arteries were significantly different in their values, suggesting the presence of a vasoactive agent in the spastic artery itself. Preliminary pharmacological analysis of the vasoactive agent was attempted using methysergide and phentolamine.

Animals↗

[Pineal teratoma--case report (author's transl)].

A 3-year-old boy had a history of nausea and vomiting for 1 month. After two episodes of tonic cramp, he became drowsy and then semicomatous. Physical examination on admission revealed a dehydrated semicomatous boy with fixed, dilated pupils of equal size, horizontal nystagmus, and left hemiparesis with bilateral Babinski signs. Plain skull films showed a separation of coronal and sagittal sutures. A high density area surrounded by cyst was found in the pineal region in CT scan. Angiography demonstrated stretching of the posterior choroidal arteries, backward displacement of the Galen, the posterior mesencephalic and the precentral vein. The right occipital transtentorial approach was selected to remove the tumor totally. Histology revealed epidermis, hair follicle, sebaceus and sweat glands, columar gland, bone, cartilage, muscle, fatty tissue, nervous tissue, and connective tissue, indicating a pineal teratoma. There was no evidence of germinoma.

Brain Neoplasms↗

Cell membrane structure of human giant-celled glioblastoma.

A giant-cell glioblastoma was examined by electron microscopy and by the freeze-fracture technique. The cell membranes bordering the extensive extracellular space often showed complicated undulations and peripheral vacuoles as well as occasional microvilli or filopodia. The undulations were mainly composed of plasmalemmal vesicles as well as of large (400--800 nm in diameter) and small (30--50 nm in diameter) localized protrusions and invaginations of the cell membrane. Deep invaginations of the cell membrane apparently resulted in two separate cytoplasmic portions. Locking of protruded cytoplasmic tongues and adherens junctions were sometimes seen in closely approximated cell membranes. The average number of membrane particles per micrometer2 was 630 +/- 130 on the P face and 180 +/- 30 on the E face. The membrane particles were occasionally aggregated to form clusters about 30 to 150 micrometer in diameter. Gap junctions were occasionally found, but there were no tight junctions. Large particles about 30 nm in diameter were found in places.

Cell Membrane↗

Tension pneumocephalus complicating ventriculoperitoneal shunt for cerebrospinal fluid rhinorrhoea: case report.

A case of spontaneous nontraumatic cerebrospinal fluid rhinorrhoea secondary to aqueductal stenosis is reported. The patient required direct repair of the fistula after the insertion of a ventriculoperitoneal shunt for aqueductal stenosis. We emphasise an unusual complication of tension pneumocephalus in a case where the shunt patency had been substantiated. Intracranial pressure fall due to the siphon effect in the ventriculoperitoneal shunt tubing in the erect position might be responsible for ingress of an excessive amount of air.

Adult↗

Intercellular granules and vesicles in prolonged cerebral vasospasm.

Prolonged vasospasm was produced in the dog basilar arteries by introduction of fresh arterial blood or norepinephrine into the chiasmatic cistern. Myonecrosis was limited to a small number of smooth-muscle cells, and a large number of muscle cells appeared intact. The most characteristic change was the appearance of aggregated granules and vesicles in the widened extracellular space between smooth-muscle cells, particularly near the adventitia and the elastic lamina. The granules were spherical, 50 to 100 nm in diameter, often surrounded by a single membrane, and contained a dense osmiophilic core, about 40 to 90 nm in diameter. In addition, the elastic lamina often became loose and corrugated or broken.

Animals↗

Cytochemical demonstration of adenylate and guanylate cyclases in vascular smooth muscle of circle of Willis.

The cytochemical localization of adenylate cyclase and guanylate cyclase was studied in the arteries of the circle of Willis in dogs. The reaction products of both adenylate and guanylate cyclases were similarly distributed and selectively localized predominantly adjacent to sarcoplasmic reticulum and sparsely to mitochondria and outer nuclear membranes of vascular smooth muscles. The observations could suggest a close association of the intracellular localizations of both cyclases and the intracellular calcium storage sites, and ultimately contribute to our complete understanding of regulation of cerebral blood flow and vasospasm.

Adenylyl Cyclases↗