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Biomedical subjects

T Ohmoto

Publications and source records attributed to T Ohmoto.

At least 253 records · Page 14Linked to original sources
PubMed1991

Increase of extracellular insulin-like growth factor I (IGF-I) concentration following electrolytical lesion in rat hippocampus.

The change of extracellular insulin-like growth factor I (IGF-I) level following electrolytical lesion in rat hippocampus was studied by intracerebral microdialysis technique. The microdialysis probes were inserted into the lesioned and normal side of hippocampus on the day and each week after making the lesion for a period of four weeks. The content of IGF-I in the dialysis perfusate was measured by a radioimmunoassay. One week after surgery, IGF-I level (mean +/- S.E.M.) increased from 235.6 +/- 25.4 pg/100 microliters perfusate (day 0) to 305.5 +/- 15.6 pg/100 microliters perfusate (day 7), and then decreased gradually. This suggests that there is accumulation or increase in secretion of IGF-I at the lesioned site, and that IGF-I might have an important role in vivo in the brain tissue recovery from damage.

Animals↗
PubMed1991

Monitoring of cortical blood flow during temporary arterial occlusion in aneurysm surgery by the thermal diffusion method.

During aneurysm surgery, regional cortical blood flow (CoBF) was continuously monitored in 12 patients with a thermal diffusion flow probe in an attempt to assess the effects of temporary major arterial occlusion on blood flow and outcome. When the CoBF was above 30 ml/100 g/min, the safe period for temporary clipping applied distal to the perforators was 15 minutes. The occlusion time should be shortened when the CoBF is below 30 ml/100 g/min. Two patients suffered basal infarction, which was not detected by CoBF monitoring. Attention should be paid to the blood flow in the deep structures when a temporary clip is applied at a site proximal to the perforating branches. Direct measurement of CoBF may be of value in estimating the time that temporary occlusion of a major vessel can be tolerated.

Aged↗
PubMed1991

Exposure of the intracavernous carotid artery in aneurysm surgery.

The pterional intradural approach was used in five cases of large and giant carotid-ophthalmic aneurysms and in two cases of intracavernous aneurysms that arose from the anterior siphon knee in the cavernous sinus (CS) and extended into the carotid cistern. In four cases of large carotid-ophthalmic aneurysms removal of the anterior clinoid process and the roof of the optic canal gave easy access to the pericarotid ring. The anteromedial part of the pericarotid ring was dissected to expose the extradural portion of the internal carotid artery (ICA) proximal to the neck and to make enough room between the wall of the CS and the extradural portion of the ICA, thus allowing easy clipping of the neck. In one case of a giant carotid-ophthalmic aneurysm extending into the CS with an extradural origin of the ophthalmic artery and in two cases of an intracavernous aneurysm arising from the siphon knee, neck clipping was performed by opening the lateral wall and roof of the CS after removal of the optic strut. The opening of the lateral wall anterior to the 3rd nerve facilitated wide exposure of the anterior siphon knee. The horizontal portion of the intracavernous ICA as well as the whole aspect of the aneurysm could be exposed as a result of the extended opening of the cavernous roof anterior to the posterior clinoid process. Successful operative results were obtained in all seven patients. A visual field detect as an operative complication was noted in one patient. No disturbance of ocular movements was noted.

Adult↗
PubMed1991

Effects of prolonged treatment with beta-adrenoceptor antagonist, carteolol on systemic and regional hemodynamics in stroke-prone spontaneously hypertensive rats.

The present study was designed to determine the regional hemodynamic effects of prolonged beta-adrenergic receptor inhibition in conscious stroke-prone spontaneously hypertensive rats (SHRSP) using a radioactive microsphere method. When the regional blood flow was compared between 10 and 30 weeks of age, the age-related changes in organ blood flow were observed in several organs, i.e., the reduction of flow rate in kidney, adrenal gland and intestines. The reduction of flow rate in these organs contributes strongly to the age-related rise of total peripheral resistance. Carteolol, a beta-adrenoceptor antagonist, was given at a dose of 10 mg/kg/d from 10 to 30 weeks of age. These animals gained more weight than the untreated control SHRSPs, and heart rate was reduced significantly. Blood pressure was not affected. However, the prolonged treatment with carteolol prevented the age-related reduction of the blood flow rate in the kidney, adrenal gland and intestines. Thus, our findings indicate that carteolol had appreciable and beneficial effects on the maintenance of flow rates in the above organs of SHRSP without any change in blood pressure.

Animals↗
PubMed1991

Inhibition of adenosine 3',5'-cyclic monophosphate phosphodiesterase by flavonoids from licorice roots and 4-arylcoumarins.

Isoliquiritigenin, glabridin, licoarylcoumarin and licoricidin were identified as strong inhibitors of adenosine 3',5'-cyclic monophosphate (cAMP) phosphodiesterase in waste materials which were obtained during the industrial extraction of glycyrrhizin from licorice roots. The structure-activity relationships of 12 flavonoids from licorice roots and 34 4-arylcoumarins were studied. In 4-arylcoumarins, 5,7-dihydroxy derivatives were generally highly inhibitory towards cAMP phosphodiesterase.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1991

[The study of Chinese herbal medicinal prescription with enzyme inhibitory activity. V. The study of hange-shashin-to, kanzo-shashin-to, shokyo-shashin-to with adenosine 3',5'-cyclic monophosphate phosphodiesterase].

Fifty-nine species of extracts of Chinese herbal medicinal prescription were tested for inhibitory activity of adenosine 3',5'-cyclic monophosphate (cAMP) phosphodiesterase (PDE). Kanzo-shashin-to showed the highest activity in these prescriptions. Kanzo-shashin-to, Hange-shashin-to and Shokyo-shashin-to, whose contracting crude drugs were very similar, were especially studied among these prescriptions. Pinellia tuber acted as an ascent component for Scutellaria root and a mitigatory component for Giycyrrhiza. Jujube acted as a mitigatory component for Glycyrrhiza. Ginger acted as an additional component for Scutellaria root in cAMP PDE test. This additional effect of 6-gingerol, 6-shogaol from Ginger and baicalin from Scutellaria root were investigated.

Catechols↗
PubMed1991

Treatment of malignant glioma with high dose intra-arterial ACNU and autologous bone marrow transplantation--case report.

A 44-year-old female with malignant astrocytoma received subtotal removal and high dose (200 mg/m2) intra-arterial 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2- chloroethyl)-3-nitrosourea hydrochloride (ACNU) with autologous bone marrow transplantation. Tumor remission with minimal bone marrow suppression was achieved. However, she developed severe encephalopathy and computed tomographic scans revealed a low-density area at the ACNU delivery site. She received glycerol solution to treat the brain edema and recovered completely from the encephalopathy. Intra-arterial ACNU exceeding 200 mg/m2 possibly causes neurotoxicity.

Adult↗
PubMed1991

[Carotid-cavernous fistula successfully treated with embolization and radiation therapy: report of three cases].

Three cases of mixed internal and external carotid-cavernous fistula (CCF) were successfully treated with embolization of feeders from the external carotid artery (ECA) and focal irradiation to the cavernous sinus (CS). Cases 1 and 2 were females, 63 and 69 years old respectively, both with spontaneous left CCF. Case 3 was a 55 year old male with posttraumatic left CCF. Symptoms of case 1 were double vision, left chemosis and exophthalmos; those of case 2 were double vision, left retroobital pain, left forehead dysesthesia and blurred vision; and case 3 complained of double vision, left chemosis, left exophthalmos and pulsatile tinnitus. In all three cases, angiography disclosed left CCF fed by ipsilateral dural branches from the internal maxillary artery (IMA) and the internal carotid artery (ICA). In case 1, small branches from the ascending pharyngeal artery also fed the CS. In cases 2 and 3, feeders from the ECA were arising only from branches of the IMA. In case 3, hypertrophy of the meningohypophyseal trunk was visible. In cases 1 and 2, although the CS was opacified, feeders from the ICA were not clearly visible. Embolizations of branches of the IMA were performed in all cases using Ivalon under selective catheterization. In case 1, symptoms partially improved, but in cases 2 and 3, visual symptoms were transiently aggravated. Focal irradiation to the CS was done with total doses of 30, 30 and 40 Gy each for cases 1, 2, and 3 respectively. In case 1, clinical symptoms gradually improved about one third way through irradiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Insulin-like growth factor I (IGF-I) distribution in the tissue and extracellular compartment in different regions of rat brain.

The regional distribution of insulin-like growth factor I (IGF-I) was examined in the tissue and extracellular compartment of rat brain. The tissue content of IGF-I was the highest in the pituitary gland, followed by the olfactory bulb, upper brainstem, cerebellum, striatum, hippocampus, lower brainstem, and cerebral cortex. The extracellular concentration was studied by intracerebral microdialysis technique, and the highest content was found in the hippocampus, followed by the olfactory bulb, hypothalamus, cerebellum, striatum, and cerebral cortex. The tissue and extracellular contents were significantly correlated in the olfactory bulb, hypothalamus, cerebellum, striatum, and cerebral cortex. IGF-I might act by paracrine and/or autocrine regulatory mechanisms in these regions.

Animals↗
PubMed1990

[The study of Chinese herbal medicinal prescription with enzyme inhibitory activity. IV. The study of the prescription containing mineral drug with adenosine 3',5'-cyclic monophosphate phosphodiesterase].

Twenty five Chinese herbal medicinal prescriptions containing gypsum, kaolin, longgu, oyster shell and sodium sulfate were studied for the inhibitory activity of adenosine 3',5'-cyclic monophosphate phosphodiesterase. The inhibitory activity of 15 prescriptions without mineral drug was higher than that of each original prescription. On the contrary, four were lower and six were not recognized to be different. All 11 prescriptions containing gypsum with an exception increased the inhibitory activity by removing gypsum. The half prescriptions containing kaolin or sodium sulfate also increased the inhibitory activity by removing the drug.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1990

[The study on Chinese herbal medicinal prescription with enzyme inhibitory activity. II. The study of kanbaku-taiso-to with adenosine 3',5'-cyclic monophosphate phosphodiesterase].

A Chinese herbal medicinal prescription, Kanbaku-taiso-to, was studied for the inhibitory activity of adenosine 3',5'-cyclic monophosphate (cAMP) phosphodiesterase. The effect for the inhibitory activity of cAMP phosphodiesterase in combination with constituent crude drugs and difference in kind of crude drugs of the prescription were studied. The inhibitory activity of the prescriptions which were combined with low protein content wheat were higher than that with high protein content wheat.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1990

[The study on Chinese herbal medicinal prescription with enzyme inhibitory activity. III. The study of mao-to with adenosine 3',5'-cyclic monophosphate phosphodiesterase].

Mao-to, a Chinese herbal medicinal prescription was studied for the inhibitory activity of adenosine 3',5'-cyclic monophosphate (cAMP) phosphodiesterase. The inhibitory activity for this enzyme depended mainly on Ephedra herb and Glycyrrhiza in this prescription. Apricot kennel acted as a mitigatory component for Ephedra herb in cAMP phosphodiesterase inhibitory test. In ephedrine and the related compounds the inhibitory activity of cAMP phosphodiesterase was not shown.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1990

In vivo analysis of extracellular proteins in rat brains with a newly developed intracerebral microdialysis probe.

Peptides and proteins in the extracellular space in the central nervous system were investigated in vivo using an intracerebral microdialysis probe. The molecular cut-off of the hollow fiber which was used for the probe was approximately 100 kDa. We examined recovery rates of several compounds in vitro. The recovery rates of proteins and peptides were between 7-28%, with the exceptions of substance P and insulin-like growth factor I. The recovery rates of monoamines and their metabolites were 22-40%. In in vivo studies, two major proteins with apparent molecular weights of 62 kDa and 12 kDa, and several minor proteins (28 kDa, 43 kDa, 52 kDa and 70 kDa) were detected by SDS-polyacrylamide gel electrophoresis in the dialysate from a probe implanted in the striatum of anesthetized rats. These results suggest that the newly developed, intracerebral microdialysis probe might be useful for investigating the dynamic changes of peptides and proteins in the central nervous system.

Animals↗
PubMed1989

Monitoring of cortical blood flow during excision of arteriovenous malformation by thermal diffusion method.

The cortical blood flow adjacent to arteriovenous malformations was monitored in six patients before, during, and after excision of arteriovenous malformations using a thermal diffusion probe. In a large arteriovenous malformation, a progressive increase in cortical blood flow up to two times the preexcision value was noted with occlusion of the feeding arteries. Lowering arterial pressure to keep normal cortical blood flow during and after operation resulted in minimum brain edema and an excellent result. Direct measurement of cortical blood flow is of value in determining the precise level of hypotension to prevent brain edema and ischemia that may occur with excision of a large arteriovenous malformation.

Adult↗
PubMed1989

Stimulation of the medullary reticular formation in cold-injured brain.

The vasopressor response (Cushing) in patients with high intracranial pressure (ICP) has been thought to be a result of lower brainstem dysfunction. This study was carried out to study the effect of stimulation of the reticular formation of the medulla oblongata on ICP and cerebral blood volume (CBV) in injured brain with increased ICP. The CBV was measured by the photoelectric method from the uni- or bilateral parietal lobe. Seventeen hours prior to the experiments, cold-induced edema was produced to increase basal ICP. In 15 cats, electric stimulation produced temporary increases in blood pressure (BP), ICP, and CBV and progressive intracranial hypertension was never observed (group A). In 9 animals, progressive increases in CBV and ICP up to 50-100 mmHg occurred after cessation of stimulation (group B). Prestimulation ICP in group B was significantly higher than that of group A (p less than 0.01). Rapid and simultaneous increases in ICP and CBV following stimulation strongly suggested that global increments of CBV secondary to loss of cerebral vasomotor tonus were responsible for producing progressive intracranial hypertension. In group B, the stimulation electrodes were invariably located at the area of the nucleus reticularis parvocellularis and gigantocellularis. Our experimental results show that under conditions of increased ICP, a stimulated or irritable condition of the medullary reticular formation will cause temporary or progressive intracranial hypertension.

Action Potentials↗
PubMed1989

Inhibition of adenosine 3',5'-cyclic monophosphate phosphodiesterase by flavonoids. III.

Sixty-one flavanones, twenty-six isoflavones and eight other flavonoids, obtained from Sophora tomentosa, S. flavescens, Scutellaria baicalensis and other medicinal plants or synthesized, were tested for their inhibitory activity against adenosine 3',5'-cyclic monophosphate (cAMP) phosphodiesterase from beef heart. The structure-activity relationships were investigated.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1989

Saponins from Chinese folk medicine, "zhu jie xiang fu," Anemone raddeana REGEL.

From the Chinese folk medicine "Zhu jie xian fu" (roots of Anemone raddeana REGEL, Ranunculaceae), two new oleanane-type glycosides, named raddeanosides R8 (1) and R9 (2), were isolated. The structures of 1 and 2 were determined as 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-beta-D-glucopyranosyl- (1----2)-alpha-L-arabinopyranosyl oleanolic acid 28-O-alpha-L-rhamnopyranosyl-(1----4)-O-beta-D-glucopyranosyl-(1----6)-b eta-D- glucopyranoside and 3-O-alpha-L-rhamnopyranosyl-(1----2)-O-beta-D-glucopyranosyl-(1----2)-al pha-L- arabinopyranosyl 27-hydroxyoleanolic acid 28-O-alpha-L-rhamnopyranosyl-(1----4)-O-beta-D-glucopyranosyl-(1----6)-b eta-D- glucopyranoside, respectively.

Drugs, Chinese Herbal↗