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Biomedical subjects

T Ohmoto

Publications and source records attributed to T Ohmoto.

At least 181 records · Page 10Linked to original sources
PubMed1994

Efficacy of pretransection of peripheral nerve for promoting the survival of cografted chromaffin cells and recovery of host dopaminergic fibers in animal models of Parkinson's disease.

Nerve growth factor (NGF) concentration in the distal stump of the transected peripheral nerve has been shown to increase more than 20 times one day after transection. We performed adrenal medullary alone grafts or cografts of adrenal medulla and acutely transected or pretransected (24 h before) sciatic nerve into the striatum of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice, and compared the survival of chromaffin cells and the recovery of the host-intrinsic dopaminergic fibers using tyrosine hydroxylase immunocytochemistry and high-performance liquid chromatography. We also performed peripheral nerve alone grafting (acutely transected or pretransected) for comparison. Adrenal medullary chromaffin cells cografted with pretransected sciatic nerve survived better than those in adrenal grafts alone or those cografted with acutely transected sciatic nerve. Host dopaminergic fiber recovery was also most prominent in mice cografted with pretransected peripheral nerve. Animals receiving grafts of peripheral nerve alone showed limited recovery of host dopaminergic fibers and the degree of recovery was lower than that of animals receiving cografts of adrenal medulla with pretransected peripheral nerve. We conclude that pretransected peripheral nerve enhanced the survival of cografted chromaffin cells and this increased survival led to promote the recovery of host-intrinsic dopaminergic fibers. This grafting procedure might be promising in application to patients with Parkinson's disease.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1994

Long-term outcome of surgically treated unruptured cerebral aneurysms.

We report the surgical morbidity and mortality and the results of statistical analysis based on the long-term outcome (average 50.1 months) of 69 patients with unruptured cerebral aneurysms. These patients harbored a total of 76 unruptured cerebral aneurysms, 72 larger than 3 mm in diameter. All the latter were surgically treated. There was no operative mortality. Operative morbidity occurred in 5 patients (7.2%), including hemiplegia in 2 from obliteration of perforator vessels, transient memory impairment in 2 due to brain retraction, and transient oculomotor nerve palsy in 1 patient resulting from an unknown etiology. During the observation period, 53 patients (76.8%) had a good or fair outcome, 11 (15.9%) had a poor outcome, and 5 (7.3%) died from causes unrelated to the aneurysms, such as pneumonia, gastrointestinal bleeding, and heart failure. The 5-year survival rate was 94%. Statistical analysis of the long-term outcome of all patients showed no significantly important factor influencing long-term morbidity. Prophylactic surgery of aneurysm is recommended for low-risk patients who may develop eventual rupture of an aneurysm, but perforator vessels around the aneurysm should be preserved, clips should be properly placed, and brain retraction should be minimized.

Adult↗
PubMed1994

Stable expression in rat glioma cells of sense and antisense nucleic acids to a human multifunctional DNA repair enzyme, APEX nuclease.

We have cloned mouse and human cDNAs for a multifunctional DNA repair enzyme (APEX nuclease) having apurinic/apyrimidinic (AP) endonuclease, 3',5' exonuclease, DNA 3' repair diesterase and DNA 3'-phosphatase activities. To investigate the biological role of APEX nuclease, sense or antisense APEX RNA was stably expressed at a high level in cultured rat glioma cells by introducing plasmids (pABWN-HAPX1F for expression of sense RNA or pABWN-HAPX2R for expression of antisense RNA) constructed from the human APEX cDNA and an expression vector pABWN. Multiple copies of the construct were integrated into the glioma cells transfected with pABWN-HAPX1F or pABWN-HAPX2R. These transfectants showed markedly high expression of RNA hybridizable to human APEX cDNA, indicating the expression of the sense or antisense RNA. Activity blotting analyses of salt extracts of these transfectants showed that the sense RNA-expressed cells had higher AP endonuclease activity and that the antisense RNA-expressed cells had extremely lower AP endonuclease activity than the control cells. The APEX nuclease-depressed glioma cells became more sensitive to methyl methanesulfonate and hydrogen peroxide than the control cells or the APEX nuclease-overexpressed cells. The results indicate that APEX nuclease plays an important role in repair of DNA damage caused by these genotoxic agents. The present stable expression systems for the sense and antisense APEX RNAs should be useful for analyzing the biological functions such as an antimutagenic function of the enzyme.

Animals↗
PubMed1994

Canthin-6-one alkaloids from Brucea mollis var. tonkinensis.

Three new alkaloids were isolated from the root-wood of Brucea mollis var. tonkinensis collected in China. Their structures were determined to be 11-O-beta-D-glucopyranosyl-(1-->6)-beta- D-glucopyranosylcanthin-6-one, 5-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosylcanthin-6-o ne and 11-hydroxycanthin-6-one-N-oxide, by chemical and spectral methods. In addition, two known alkaloids, canthin-6-one and canthin-6-one-N-oxide, were isolated.

Alkaloids↗
PubMed1994

Triterpenoid saponins from Ardisia crenata.

Two novel triterpenoid saponins, ardisicrenoside A [3 beta-O-(alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-glucopyranosyl- (1-->4)-[beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)- 13 beta,28-epoxy-16 alpha,30-oleananediol] and ardisicrenoside B [3 beta-O-(beta-D-xylopyranosyl-(1-->2)-[beta-D- glucopyranosyl-(1-->4)-[beta-D-glucopyranosyl-(1-->2)]- alpha-L-arabinopyranosyl)-13 beta,28-epoxy-16 alpha,30-oleananediol] were isolated from the roots of Ardisia crenata. Two known triterpenoid saponins, ardisiacrispins A and B were also isolated from this source. Their structures were determined mainly by 2D NMR (COSY, HOHAHA, HETCOR, HMBC and ROESY) experiments. The aglycones are the new 13 beta,28-epoxy-3 beta,16 alpha,30-oleananetriol for ardisicrenosides A and B.

Carbohydrate Sequence↗
PubMed1994

Triterpenoid saponins from Dianthus chinensis.

Two novel triterpenoid saponins, dianchinenoside C [23-O-beta-D-glucopyranosyl 3 beta, 16 alpha-dihydroxyolean-12-ene 23 alpha, 28 beta-dioic acid 28-O-beta-D-glucopyranoside] and dianchinenoside D [3 beta, 16 alpha-dihydroxyolean-12-ene 23 alpha, 28 beta-dioic acid 28-O-beta-D-glucopyranosyl [1-->6)-beta-D-glucopyranoside] were isolated from the aerial parts of Dianthus chinensis. Their structures were determined by spectroscopic methods and chemical evidence. We also report the revision of a previous misassignment of hainanenside, isolated from Ilex hainanensis Merr. In addition, known compounds, 3-O-alpha-L-arabinopyranosyl hederagenin 28-O-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranoside, sitosterol 3 beta-O-beta-D-glucopyranoside, isoorientin-2"-O-glucoside, isovitexin-2"-O-glucoside, and chrysoeriol-7-O-glucoside, were also identified.

Carbohydrate Sequence↗
PubMed1994

Cellulose acetate polymer thrombosis for the emergency treatment of aneurysms: angiographic findings, clinical experience, and histopathological study.

Cellulose acetate polymer solution is a liquid thrombotic material that hardens into the shape of an aneurysm into which it is injected. Therapy using this solution is a rapid technique that helps prevent the rupture of aneurysms, especially those that extravasate contrast material during angiography in the acute stage of subarachnoid hemorrhage. Using this polymer solution and an endovascular technique, we treated two patients who had aneurysms of the basilar and anterior communicating arteries with extravasation of contrast material during angiography a few hours after the initial subarachnoid hemorrhage. In one patient with an aneurysm of the anterior communicating artery, the aneurysm's wall was perforated with the catheter during neurointerventional procedures. In both patients, postoperative angiograms demonstrated obliteration of the aneurysmal dome, including the site of extravasation or perforation. The parent artery and surrounding perforating branches were preserved. Although we do not advocate aggressive therapy for patients who bleed during angiography, we pursued this therapy in these two patients because of the opportunity to introduce cellulose acetate polymer in an attempt to preserve the patients' lives. Unfortunately, both patients died. Histopathological studies performed at the time of autopsy demonstrated that the luminal surface of cellulose acetate polymer was covered with thrombus by 6 days after cellulose acetate polymer thrombosis. By 10 days, the thrombus had a prominent fibrin network, a concentrated plasma component, and few fibrocytes adhering to its luminal surface.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Direct thrombosis of a pseudoaneurysm after obliteration of a carotid-cavernous fistula with cellulose acetate polymer: technical case report.

A 55-year-old man who suffered a head injury resulting in a left traumatic carotid-cavernous fistula was successfully treated with an intravascular detachable balloon. A pseudoaneurysm formed adjacent to the balloon. Seven months after the initial procedure, treatment with cellulose acetate polymer, a new liquid thrombotic material, occluded the pseudoaneurysm and preserved the internal carotid artery.

Aneurysm, False↗
PubMed1994

Superoxide scavenging activity in the extracellular space of the brain in forming edema.

We carried out a time course study of cerebral superoxide scavenging activity using a modified microdialysis technique. Twelve cats were divided into two groups; six were the reperfusion injury models, and six were cold injury models. In the reperfusion injury model, dialysates were collected during 60 minutes of middle cerebral artery occlusion and at 300 minutes during reperfusion. In the cold injury model, dialysates were collected 240 minutes after the injury. Regional cerebral blood flow on the injured side decreased during occlusion in the reperfusion injury model and 60 minutes after injury in the cold injury model. In the reperfusion model, superoxide scavenging activity, as determined with electron spin resonance, increased in the first 30 minutes and decreased 300 and 330 minutes after occlusion. In the dialysate, albumin increased 180 minutes after cold injury, which may show the progress of vasogenic edema. An increase in water content was observed on the injured side of both models, and a correlation between water content and superoxide scavenging activity was found in the reperfusion injury model. By this technique, a method of detecting the alteration of superoxide scavenging activity in the extracellular space of the brain was established.

Animals↗
PubMed1994

Three new furostanol saponins from the bulbs of Ipheion uniflorum.

Phytochemical screening of the bulbs of Ipheion uniflorum (Liliaceae) has led to the isolation of three new furostanol saponins (2-4) along with a known phytoecdysteroid, ecdysterone (1). The structures of the new compounds were determined by two-dimensional NMR techniques, 1H-1H correlation spectroscopy (COSY), homonuclear Hartmann-Hahn (HOHAHA), phase-sensitive nuclear Overhauser effect spectroscopy (NOESY), heteronuclear multiple quantum coherence (HMQC) and heteronuclear multiple-bond correlation (HMBC) spectra, and hydrolysis to be 3 beta-hydroxy-22 alpha-methoxy-26-O-beta-D- glucopyranosyloxy-5 alpha-furost-25(27)-en-2-one 3-O-[O-alpha-L-rhamnopyranosyl-(1-->2)-O-[O-alpha-L-arabinopyranosyl+ ++- (1-->2)-O-[beta-D-xylopyranosyl-(1-->3)]-beta-D-glucopyranosyl-(1-->4)]- beta-D-galactopyranoside) (2) and its 25(27)-dihydro derivatives (3: 25S; 4: 25R). The inhibitory activity exhibited by compounds 1-4 and the corresponding spirostanol saponins (2a and 3a) of 2 and 3 on cAMP phosphodiesterase was assayed as a primary screening test to identify new compounds with medicinal potential.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1994

Studies on the constituents of Ailanthus integrifolia.

A new phenolic glycoside, 3,4,5-trimethoxyphenol-1-(6-xylopyranosyl)glucopyranoside, was isolated together with twenty known compounds identified as koaburaside, 3,4,5-trimethoxyphenol, 5,7-dihydroxychromone-7-neohesperidoside, naringin, neoeriocitrin, p-coumaric acid, vanillin, vanillic acid, coniferyl aldehyde, ferulic acid, trans-triacontyl-4-hydroxy-3-methoxycinnamate, p-methoxycinnamic acid, 2,6-dimethoxybenzoquinone, 2-(1-hydroxyethyl)naphtho[2,3-b]furan-4,9-dione, 2-acetylnaphtho[2,3-b]furan-4,9-dione, 2-(1-hydroxyethyl)-6-methoxynaphtho[2,3-b]furan-4,9-dione, 2-acetyl-6-methoxynaphtho[2,3-b]furan-4,9-dione, specioside, jioglutin C and rehmaglutin D from the bark of Ailanthus integrifolia Lamk (Simaroubaceae).

Glycosides↗
PubMed1994

Triterpenoid saponins from Ardisia crenata and their inhibitory activity on cAMP phosphodiesterase.

Two novel triterpenoid saponins, ardisicrenoside C (1) [3 beta-O-(alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->4)- [beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl)-16 alpha, 28-dihydroxy-olean-12-en-30-oic acid 30-O-beta-D-glucopyranosyl ester] and ardisicrenoside D (2) [3 beta-O-(beta-D-xylopyranosyl-(1-->2)- beta-D-glucopyranosyl-(1-->4)-[beta-D-glucopyranosyl-(1-->2)]-alpha-L- arabinopyranosyl)-16 alpha, 28-dihydroxy-olean-12-en-30-oic acid 30-O-beta-D-glucopyranosyl ester] were isolated from the roots of Ardisia crenata. Structure assignments are based on spectroscopic data including 2D-NMR (correlation spectroscopy (COSY), homonuclear Hartmann-Hahn spectroscopy (HOHAHA), heteronuclear correlated spectroscopy (HETCOR), heteronuclear multiple bond correlation (HMBC) and rotating frame NOE spectroscopy (ROESY)) experiments and some chemical reactions. In addition, the isolated saponins along with their prosapogenins and sapogenins have been evaluated for their inhibitory activity on cAMP phosphodiesterase as a primary screening test for new medicinal compounds.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1994

New steroidal saponins from the bulbs of Allium giganteum exhibiting potent inhibition of cAMP phosphodiesterase activity.

A new spirostanol saponin and two new furostanol saponins were isolated from the fresh bulbs of Allium giganteum together with several known saponins. The structures of the new compounds were determined on the basis of spectroscopic data, the products formed on hydrolysis and by comparing their properties with those of known compounds. The isolated saponins and their derivatives were evaluated for inhibitory activity by examining their action on cAMP phosphodiesterase as a primary screening test to identify new medicinal agents.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1994

Steroidal constituents from the underground parts of Reineckea carnea and their inhibitory activity on cAMP phosphodiesterase.

Phytochemical analysis of the underground parts of Reineckea carnea resulted in the finding of twelve steroidal constituents, five of which appeared to be new compounds and one to be the first isolation from a natural source. The identification and structural determination of the steroidal compounds were established by spectroscopic analysis and hydrolysis. The isolated saponins were evaluated for inhibitory activity on cAMP phosphodiesterase as a primary screening test to find new medicinal materials.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1994

Growth and rupture of unruptured cerebral aneurysms based on the intraoperative appearance.

The growth and rupture of 40 cerebral aneurysms was studied in 36 patients (14 men, 22 women; were average age, 51.8 years). Aneurysms were classified into five types according to the intraoperative findings: type 1, uniformly thin, smooth surface; type 2, thin neck and thick wall, smooth surface with or without red and/or transparent portions; type 3, uniformly thick wall, smooth surface with or without red portions; type 4, thick neck, bubbled or loculated thin wall at dome with or without red and/or transparent portions; type 5, thick wall in entirety, irregular surface with or without red portions. Five were type 1, six type 2, and 12 type 3. In four of the type 2 aneurysms, turbulence could be seen at the neck. In seven of the type 3 aneurysms, red and/or transparent portions were observed in the wall. Thirteen were type 4; nine of which had a bubbled or loculated wall with or without red and/or transparent portions. Four were type 5, with scattered red portions but a thick wall. Type 1 aneurysms were 2-5 mm, most of types 2 and 3 were 3-6 mm, type 4 were 3-13 mm, and type 5 were more than 9 mm. Types 1 and 2 had few local changes in the wall, suggesting that aneurysms at this stage are stable. Type 3 is considered to be a transitional stage to type 4 from type 2. Type 4 aneurysms had some local changes within the wall including bubbles or loculi. We concluded that aneurysms exceeding 4 mm have local pathologic changes in the wall and are critical.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Selection and combination of techniques for treating spontaneous carotid-cavernous sinus fistulas.

Twenty-eight patients with spontaneous carotid-cavernous sinus fistulas (CCFs) were treated using a variety of techniques. Three of four patients with direct CCFs underwent intravascular embolization with a detachable balloon. Embolization with polyvinyl alcohol particles through an external carotid endoarterial route was used in six patients with indirect CCFs, and with ethylene-vinyl alcohol copolymer solution in two. Patients undergoing these conventional treatments, including embolization of the meningeal branches of the external carotid artery, had less satisfactory outcomes. The transvenous approach using minicoils through the inferior petrosal sinus was successful in eight patients. One patient treated using the transvenous approach using copper wire through the ophthalmic vein had worsening of visual acuity and field. Unsuccessful transvenous embolization in four patients required direct surgical exposure and embolization with spring coils. Spontaneous cures occurred in four patients. Direct CCFs with high flow rates were best treated with the detachable balloon or coil technique through a internal carotid endoarterial route. Indirect CCFs were best treated with the minicoil through the inferior petrosal sinus. If these techniques fail, direct surgical exposure allows placement of coils into the cavernous sinus.

Adult↗
PubMed1994

Acute effects of interstitial hyperthermia on normal monkey brain--magnetic resonance imaging appearance and effects on blood-brain barrier.

The magnitude and time course of histological and neuroradiological changes due to interstitial hyperthermia in normal cerebral white matter were investigated in eight adult Japanese monkeys. A cooling system enveloping a 2450-MHz microwave antenna was inserted stereotactically into the brain under general anesthesia. A point located 5 mm away from the surface of the cooling system was used as the reference point (RP). Hyperthermia was given to maintain the RP at 43 degrees C for 60 minutes. Two animals were sacrificed under general anesthesia following the intravenous administration of Evans blue, immediately and 1, 3, and 7 days after treatment. After removing the brain, histological changes were investigated. Magnetic resonance (MR) imaging was performed at 1, 3, and 7 days after treatment. Evans blue extravasation was most prominent in the region heated to 43 degrees C or above immediately after treatment. MR imaging showed obvious enhancement in the region heated to 43 degrees C or above 1 day after treatment, related to the disruption of the blood-brain barrier (BBB) by hyperthermia. Three days after treatment, ring-like enhancement with a central low-intensity area was seen in the region heated to about 43 degrees C, caused by BBB disruption and slight neovascularization. One week after treatment, an enhanced ring was observed in the region heated to less then 43 degrees C which surrounded a low-intensity area. The enhancement seen 1 week after treatment was caused by prominent neovascularization. T2-weighted imaging showed a high-intensity area, caused by edema, most prominent 3 days after treatment. Thus chemotherapeutic agents should be given just before the end of hyperthermia.

Animals↗