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Biomedical subjects

T Kojima

Publications and source records attributed to T Kojima.

At least 937 records · Page 52Linked to original sources
PubMed1982

[Stenosis of the intracranial internal carotid artery by a craniopharyngioma: report of a case].

Stenosis of the intracranial internal carotid artery by other tumors than meningiomas and pituitary adenomas is a rare occurrence. We present here a case with craniopharyngioma, which developed severe stenosis of the intracranial internal carotid artery 7 years following partial removal and irradiation. This severe stenosis of the intracranial internal carotid artery would result from combination of compression of the arterial walls against the surrounding bony structures and radiation effect on the arterial walls. A 29-year-old male was found to have a craniopharyngioma, which was treated by partial removal in 1971. He had suffered bilateral optic atrophy, right homonymous hemianopsia and panhypopituitarism. Angiography revealed elevation of the A-1 and opening of the carotid siphon on both sides. He had a course of 5,000 rads of Lineac irradiation in 1972. He showed no clinical improvement. He became totally blind in 1976. He was admitted again in 1979, because of left sided weakness and Korsakoff syndrome. Examination disclosed that there were bilateral optic atrophy, left hemiplegia with hyperreflexia and pathological reflexes, hypesthesia in the left side of the face and Korsakoff syndrome, chiefly consisting of confabulation. Angiography showed that the right internal carotid artery was markedly elevated and stenosed. The left internal carotid artery was elevated and the left A-1 was stenotic. The territory of the left distal anterior cerebral artery was filled from the anterior falx artery of the ophthalmic artery. The right A-1, M-1 and M-2 were filled through the left A-1. The territory of the right anterior cerebral artery was filled through the right posterior pericallosal artery and that of the right middle cerebral artery was partly filled through the posterior temporal and occipito-parietal arteries of the posterior cerebral artery. A right superficial temporal-middle cerebral artery bypass surgery was performed with some clinical improvement.

Adult↗
PubMed1982

Immune electron microscopic study of hepatitis B virus associated antigens in hepatocytes.

In order to elucidate the localization of HBV-associated antigens including nonstructural forms, immune electron microscopic study was carried out in liver tissues obtained from 96 cases of chronic liver diseases with persistent HBs antigenemia and asymptomatic HBsAg carriers. The results obtained were as follows. 1) HBsAg was localized in the cytoplasm with two different patterns: an intracytoplasmic localization and a diffuse membranous localization. 2) Most cases showing membranous localization of HBsAg were associated with HBeAg in serum and the existence of core and Dane particles in the hepatocytes. 3) Antigenicity of HBsAg was found on the outer coat of Dane particles and cisternal membrane of dilated endoplasmic reticulum (ER) in addition to the plasma membrane. Some of the antigen positive ER were detected close to the plasma membrane, suggesting that the membranous localization of HBsAg was presumably resulted from the exocytosis of the antigen positive ER. These findings suggest that HBsAg expressed on the plasma membrane is a very likely target antigen in the course of cytolysis mediated by immunological mechanism. 4) HBcAg and HBeAg were localized in the cytosol of the hepatocyte in addition to the nucleus, but never found on the plasma membrane.

Adolescent↗
PubMed1981

Ultrasonic degradation of schizophyllan, an antitumor polysaccharide produced by Schizophyllum commune Fries.

Schizophyllan, a water-soluble beta-D-glucan elaborated by Schizophyllum commune Fries, was partially depolymerized by ultrasonic irradiation to a low-molecular-weight polysaccharide, designated "sonic-degraded schizophyllan". Both native and degraded polysaccharides exhibited essentially the same antitumor activities against Sarcoma-180 ascites. Both glucans are comprised solely of D-glucose residues and have a main chain of (1 leads to 3)-beta-D-glucopyranosyl residues, one out of three glucose residues being attached as single, (1 leads to 6)-beta-D-glucopyranosyl groups. Although both glucans have similar structural features, significant differences are observed in such physical properties as molecular weight and intrinsic viscosity. End-group analysis by using radioisotope-labeled glucans suggests that ultrasonic degradation occurs mainly by cleavage of glycosidic bonds of the main chain of schizophyllan. The molecular weights of the native and sonic-degraded schizophyllan were shown to be 75% of those of corresponding, original schizophyllan preparations, suggesting that there is no anomalous linkage sensitive to periodate oxidation, and ultrasonic irradiation may cause random hydrolysis of (1 leads to 3)-beta-D-glucosidic linkages in the main chain.

Animals↗
PubMed1981

Dosage form design for improvement of bioavailability of levodopa IV: Possible causes of low bioavailability of oral levodopa in dogs.

Several potential mechanisms for reduced levodopa bioavailability following oral administration to dogs and humans were investigated by studying the influence of the administration route on plasma levodopa levels after intravenous, hepatoportal, and duodenal administrations to dogs. The observed average areas under the plasma concentration-time curves (AUC) of levodopa following hepatoportal injection and intravenous injection were virtually identical; but following duodenal administration a decrease in the AUC of levodopa was observed with a concomitant increase in the AUC of total dopamine. The possible involvement of intestinal microorganisms in levodopa metabolism was explored in dogs that had been administered a combination of paromomycin and kanamycin to reduce intestinal microflora. Similar patterns of plasma level profiles and urinary excretion were observed between control and treated dogs. As measured by the release of [14C]carbon dioxide from [14C]levodopa, the distribution of levodopa decarboxylase enzyme activity in various parts of the intestine was studied in homogenates prepared from isolated intestinal segments of the duodenum and upper, middle, and lower parts of the jejunum and ileum. The jejunum showed the highest decarboxylase activity followed by the ileum and duodenum. These data indicate that the reduced bioavailability of orally administered levodopa occurs as a result of metabolism by levodopa decarboxylase enzyme in the gut wall.

Administration, Oral↗
PubMed1981

Aneurysm on a persistent hypoglossal artery.

The authors report a patient with saccular aneurysm on a left persistent hypoglossal artery who suffered subarachnoid haemorrhage from an aneurysm of the right distal anterior cerebral artery. A review of the literature emphasizes the rarity of the occurrence of an aneurysm on a persistent primitive hypoglossal artery itself.

Angiography↗
PubMed1981

Mitotic index in gastric carcinoma of the scirrhous type.

For the purpose of studying the clinical and pathological specificities of the scirrhous type in gastric carcinoma, 96 patients with gastric carcinoma were studied according to age, sex, stage, macroscopic types and mitotic index. Scirrhous carcinoma was diagnosed in 45 patients. There were higher incidences of scirrhous carcinoma in the younger generation and among women. In the scirrhous type, the percentage of stages III and IV was higher than that of stages I and II (p less than 0.005). In Borrmann's categories III and IV, patients with the scirrhous type were more numerous than those with the other types. Mitotic indices were 18.4 +/- 8.1 in scirrhous type, 52.8 +/- 13.5 in medullary type, 54.1 +/- 16.9 in intermediate type and 53.3 +/- 11.5 in non-cancerous gastric mucosa. The low rate of mitotic index in those with scirrhous carcinoma was statistically significant compared to those of other types and that of the non-cancerous gastric mucosa (P less than 0.001). Mitotic index is apparently related to the extent and the degree of degeneration of interstitial connective tissue. The speed of the growth of the tumor mass in gastric carcinoma is not so closely related to the mitotic index, and relates to a greater extent the number of dissociated cells entering the digestive canal.

Adenocarcinoma↗
PubMed1981

Eye movement as an indicator of brain function.

The level of consciousness between the alert and drowsy states was classified into four stages (Alert, Resting I, Resting II, Drowsy) by studying three factors of the EEG patterns on 23 normal subjects. The eye movements recorded by electro-oculograph were divided into two groups, i.e. rapid eye movements (R type, r type) and slow eye movements (S type, s type). The occurrence of each type of eye movements was confirmed to change in close correspondence to the stages of consciousness. The eye movement on 43 cases with a disturbance of consciousness by metabolic disease were recorded longitudinally according to clinical states. The S type movements were predominantly observed in a state of clouding of consciousness, while the R type and R-S type were observed in a delirious state.

Adult↗
PubMed1981

Antitumor activity of mitomycin C-dextran conjugate against various murine tumors.

The antitumor activity of a high molecular weight pro-drug of mitomycin C(MMC), MMC-dextran conjugate (MMC-D), was examined against various murine tumors under different experimental conditions. A single intraperitoneal injection of MMC-D exhibited higher antitumor activity against intraperitoneally inoculated B16 melanoma, Ehrlich ascites carcinoma, and P388 leukemia than MMC, but lower activity against BDF1 mouse-transplanted L1210 leukemia. Intratumoral injection of MMC-D showed a superior effect on subcutaneously implanted B16 melanoma, while intravenous injection of MMC-D exhibited reduced activity against P388 and L1210 leukemia compared with MMC. Prior administration of MMC-D at 24 hr before tumor inoculation resulted in a significant increase of the life span of mice bearing L1210 leukemia, suggesting that it shows sustained pharmacological activity. These differences between the activities of MMC-D and MMC in various tumor systems are considered to reflect the improved biopharmaceutical properties of MMC-D resulting from the modification of MMC into a polymeric drug.

Animals↗