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Biomedical subjects

M Taneda

Publications and source records attributed to M Taneda.

At least 19 recordsLinked to original sources
PubMed1992

Detection and partial purification of ischaemia-related neurotrophic activity in the periinfarcted brain tissue.

In the rat model of middle cerebral artery (MCA) occlusion, axons originating from the ipsilateral cortical and thalamic neurons are injured by ischaemia. The cortical neurons survive thereafter without retrograde degeneration, but thalamic neurons slowly die because of retrograde degeneration. The fate of these two neurons is remarkably different and may be related to neurotrophic activity induced by ischaemia. We detected ischaemia-related neurotrophic activity, and partially purified the factor. Tissue samples were obtained from the cortex adjacent to the infarction and contralateral corresponding site at 4, 8 and 12 days after occlusion of the MCA. They were homogenated with a culture medium and ultracentrifuged. The supernatant was obtained and used for neurotrophic assay. Foetal cortical neurons were obtained from 17 days rat embryo and cultured. Neurotrophic activity was assayed by applying tissue extract to the culture medium. Application of periischaemic cortical extract obtained at 8 and 12 days after ischaemia improved neuronal survival by 50% and 200% as compared to contralateral cortical extract, respectively. The activity was not detectable at 4 days after ischaemia. The neurotrophic activity disappeared by heating the extract at 90 degrees C for 10 min. We fractionated the extract by saturated ammonium sulphate precipitation, followed by gel-filtered with Superose 12 column. The neurotrophic activity was detected in the precipitation of 30 to 60% saturation fraction of ammonium sulphate. With gel-filtration we separated neurotrophic activity in several fractions, which included marker proteins of 8, 22 and 30 kilodaltons. The activities were only detected in the lesioned side but not in the contralateral side.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Direct approach to a traumatic giant internal carotid artery aneurysm associated with a carotid-cavernous fistula. Case report.

The case is reported of a giant intracranial internal carotid artery aneurysm associated with a carotid-cavernous fistula following a closed head injury. The aneurysm and the fistula disappeared after only the neck of the aneurysm was clipped. This is the first case in which a direct surgical approach was successful in sparing the internal carotid flow. Reports of similar cases are reviewed.

Adult↗
PubMed1992

Absorption, plasma concentration, and excretion after single administration of 14C-(+-)-3-(benzylmethylamino)-2,2-dimethylpropyl methyl 4-(2-fluoro-5- nitrophenyl)-1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate hydrochloride in rats and dogs.

The absorption, plasma concentrations, and excretion of a newly synthesized calcium antagonist, TC-81 ((+-)-3-(benzylmethylamino)-2,2-dimethylpropyl methyl 4-(2-fluoro-5-nitrophenyl)-1,4-dihydro-2,6-dimethyl-3,5- pyridinedicarboxylate hydrochloride, CAS 96515-74-1) were studied following a single oral or intravenous administration of 14C-labelled compound. After oral administration, 14C-TC-81 was rapidly and well absorbed from the gastrointestinal tract. The peak plasma concentrations of radioactivity were observed at 0.5-1 h (rats) and 1-2 h (dogs) h after dosing. The elimination of the radioactivity in plasma was biphasic with a half-life of 3.8-5.2 h (a phase) and 42.9-56.2 h (beta phase) in the rats or 3.2 h (a phase) and 61.5 h (beta phase) in dogs. Maximum plasma concentrations of unchanged drug after oral administration of TC-81 to male rats at the doses of 0.5, 1.0, and 3.0 mg/kg were 1.7, 7.3 and 15.6 ng/ml, respectively. They were attained at 0.5 h after dosing in every dose examined. Plasma levels of unchanged drug declined with a half-life of 0.39-1.15 h. When TC-81 was orally administered to male dogs at the doses of 0.1, 0.2 and 0.5 mg/kg, plasma concentrations of unchanged drug reached the maximum level at 0.5 h after dosing and the values were 0.8, 3.3 and 9.6 ng/ml, respectively. They were eliminated with a half-life of 2.4-2.8 h. The absolute bioavailability of unchanged drug was estimated to be 2.6-7.0% (rats) and 5.3-15.5% (dogs) of the dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1991

Gd-DTPA-enhanced MR imaging of cryptococcal meningoencephalitis.

This report describes magnetic resonance (MR) imaging of biopsy-proved cryptococcal central nervous system (CNS) infection in a 31-year-old HIV negative man. Initial MR imaging revealed multi-focal Gd-DTPA enhancement and showed more lesions than contrast enhanced CT. The lesions regressed after antifungal therapy. MR imaging aids in diagnosis as well as helps to monitor the response to the pharmacological therapy of cryptococcal meningoencephalitis and possibly provides valuable insights into the pathophysiology of this condition.

Adult↗
PubMed1991

Four forms of cytochrome P-450 in human fetal liver: purification and their capacity to activate promutagens.

Four forms of cytochrome P-450 were separated and purified to electrophoretic homogeneity from human fetal livers. These forms of cytochrome P-450, termed P-450HFLa, P-450HFLb, P-450HFLc and P-450HFLd, were distinguishable from each other in their molecular weights, spectral properties, immunochemical properties and mutagen-producing activities from promutagens. The molecular weights of P-450HFLa, b, c and d were estimated to be 51,500, 49,000, 51,500 and 50,000, respectively. Antibodies to P-450HFLa recognized P-450HFLc but not P-450HFLb or d, and antibodies to rat P-448-H (P-450IA2) cross-reacted with P-450HFLb but not with other forms of cytochrome P-450. The N-terminal amino acid sequence of P-450HFLc was highly homologous, but not identical, to that of P-450HFLa. Each form of cytochrome P-450 catalyzed mutagenic activation of aflatoxin B1 (AFB1), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and 2-amino-6-methyldipyrido-[1,2-a:3',2'-d]imidazole (Glu-P-1) at different rates. P-450 HFLa showed activities to produce mutagen(s) from AFB1, IQ and to a lesser extent from Glu-P-1. P-450 HFLb activated IQ at a faster rate than did the other forms. P-450 HFLc produced a mutagen from AFB1 and Glu-P-1 but not from IQ. P-450 HFLd did not activate these promutagens at significant rates.

Chromatography, DEAE-Cellulose↗
PubMed1979

Enlargement of intracerebral haematomas following surgical removal of epidural haematomas.

Postoperative follow-up computerized tomographic (CT) scans were performed in 16 cases of acute epidural haematomas to assess the efficacy of surgical treatment. Particular attention was paid to postoperative intracerebral haematomas that were detected in four cases on the preoperative CT scans. The intracerebral haematomas were found to have enlarged in all four cases on CT scans performed immediately after removal of the epidural haematomas. In the other 12 patients in whom no apparent abnormalities other than epidural haematomas were detected on preoperative CT scans, postoperative CT scans did not show development of intracerebral bleeding. The results indicate that bleeding may be encouraged in areas of intracerebral haemorrhage when coexisting epidural haematomas are evacuated. The possible pathophysiology of enlargement of intracerebral haematomas after decompression is discussed.

Aged↗
PubMed1979

Semiquantitative evaluation of ophthalmic collateral flow in carotid artery occlusion: ultrasonic doppler study.

The reliability of quantitative evaluation by doppler ultrasound with regard to the ophthalmic collateral blood flow in patients with carotid artery occlusion was estimated. The ultrasonic doppler flow signals of the ophthalmic collateral flow of 54 carotid occlusions were classified into four types and three degrees--high, moderate, and low reversed flow patterns--and were compared with the angiographic findings of the collateral flow classified into three grades--good, poor, and none. With the exception of three cases, the ultrasonic doppler flow patterns of the collateral flow correlated well with the angiographic findings in 54 occluded carotid arteries.

Carotid Artery Thrombosis↗
PubMed1977

Angiographic manifestations in postrecanalized cerebral infarction.

In 14 stroke patients showing angiographic recanalization of the occluded internal carotid artery or middle cerebral arterial axis, the postrecanalized angiograms demonstrated several findings that have been considered to be generally rare in cerebral infarction. These findings principally consisted of narrowing of arterial caliber in six cases (43 percent), mass effect in eight cases (57 percent) and capillary blush in five cases (36 percent).

Aged↗