Biomedical subjects

Takashi Ohmoto

Publications and source records attributed to Takashi Ohmoto.

At least 19 recordsLinked to original sources

PubMed2007

Biodegradation of bisphenol A and related compounds by Sphingomonas sp. strain BP-7 isolated from seawater.

A bacterium capable of assimilating 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), strain BP-7, was isolated from offshore seawater samples on a medium containing bisphenol A as sole source of carbon and energy, and identified as Sphingomonas sp. strain BP-7. Other strains, Pseudomonas sp. strain BP-14, Pseudomonas sp. strain BP-15, and strain no. 24A, were also isolated from bisphenol A-enrichment culture of the seawater. These strains did not degrade bisphenol A, but accelerated the degradation of bisphenol A by Sphingomonas sp. strain BP-7. A mixed culture of Sphingomonas sp. strain BP-7 and Pseudomonas sp. strain BP-14 showed complete degradation of 100 ppm bisphenol A within 7 d in SSB-YE medium, while Sphingomonas sp. strain BP-7 alone took about 40 d for complete consumption of bisphenol A accompanied by accumulation of 4-hydroxyacetophenone. On a nutritional supplementary medium, Sphingomonas sp. strain BP-7 completely degraded bisphenol A and 4-hydroxyacetophenone within 20 h. The strain degraded a variety of bisphenols, such as 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, and 1,1-bis(4-hydroxyphenyl)cyclohexane, and hydroxy aromatic compounds such as 4-hydroxyacetophenone, 4-hydroxybenzoic acid, catechol, protocatechuic acid, and hydroquinone. The strain did not degrade bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)sulfone, or bis(4-hydroxyphenyl)sulfide.

Benzhydryl Compounds↗

PubMed2005

Adult unilateral moyamoya disease with familial occurrence in two definite cases: a case report and review of the literature.

We documented an interesting case of adult "unilateral (probable)" moyamoya disease displaying familial occurrence in two "definite" cases. A 55-year-old female presented with motor aphasia, involuntary movement of the right hand and right homonymous hemianopia due to cerebral infarction. Cerebral angiography revealed typical angiographic findings on the left side and normal findings on the right side; consequently, the patient was diagnosed with probable moyamoya disease. Previously, her mother and nephew had been diagnosed with definite moyamoya disease with bilateral involvement. The patient continued to exhibit unilateral involvement on angiography for more than 4 years. Clinical features such as absence of familial occurrence suggest that most cases of probable moyamoya disease are distinct from definite cases, especially in adults. To the best of our knowledge, this report appears to be the first involving an adult probable case characterized by familial occurrence. The literature pertaining to adult probable moyamoya disease was reviewed and the etiology of this disease was discussed.

Aphasia, Broca↗

PubMed2005

Mode of action on deacetylation of acetylated methyl glycoside by cellulose acetate esterase from Neisseria sicca SB.

The regioselective deacetylation of purified cellulose acetate esterase from Neisseria sicca SB was investigated on methyl 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranoside and 2,3,4,6-tetra-O-acetyl-beta-D-galactopyranoside. The substrates were used as model compounds of cellulose acetate in order to estimate the mechanism for deacetylation of cellulose acetate by the enzyme. The enzyme rapidly deacetylated at position C-3 of methyl 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranoside to accumulate 2,4,6-triacetate as the main initial reaction product in about 70% yield. Deacetylation was followed at position C-2, and generated 4,6-diacetate in 50% yield. The enzyme deacetylated the product at positions C-4 and C-6 at slower rates, and generated 4- and 6-monoacetates at a later reaction stage. Finally, it gave a completely deacetylated product. For 2,3,4,6-tetra-O-acetyl-beta-D-galactopyranoside, CA esterase deacetylated at positions C-3 and C-6 to give 2,4,6- and 2,3,4-triacetate. Deacetylation proceeded sequentially at positions C-3 and C-6 to accumulate 2,4-diacetate in 55% yield. The enzyme exhibited regioselectivity for the deacetylation of the acetylglycoside.

Acetylation↗

PubMed2004

The relationship between peritumoral brain edema and the expression of vascular endothelial growth factor and its receptors in intracranial meningiomas.

We examined the radiological and histological features of, and the influences of the expression of VEGF and its two major receptors, Flt-1 and Flk-1, on the development of peritumoral brain edema (PTBE) in patients with intracranial meningiomas. The expressions of VEGF and VEGF receptors in the immunohistochemical study were analyzed in relation to several factors, including tumor size, location, vascularity, and blood supply, as seen on digital subtraction angiographic studies. The edema volume (P = 0.0003) and edema index (P < 0.0001) had a significantly positive relation to VEGF expression. The positivity of Flt-1 and Flk-1 was mainly observed in tumor vessels; 44 cases (37.2%) were positive for the Flt-1 antibody and 37 cases (31.4%) for the Flk-1 antibody. The mean value of the edema index of the positive-Flt-1 group (5.220 +/- 11.586) was significantly higher than that of the negative-Flt-1 group (1.782 +/- 2.559) (P < 0.0001). The mean value of the edema index of the positive-Flk-1 group (3.925 +/- 5.870) was slightly higher than that of the negative-Flk-1 group (2.671 +/- 8.136) (P < 0.0001). Our data suggest that the expressions of VEGF and VEGF receptors positively relate to each other and to the formation of PTBE in patients with meningiomas.

Adult↗

PubMed2004

Rebleeding of a vertebral artery dissecting aneurysm during stent-assisted coil embolization: a pitfall of the "stent and coil" technique.

BACKGROUND: A stent-assisted coil embolization has been applied as a novel choice of treatment for vertebral artery dissecting aneurysms (VADAs). CLINICAL PRESENTATION: A 45-year-old man suffered from subarachnoid hemorrhage three times within 2 hours. The left vertebral angiogram showed a VADA at the distal origin of the posterior inferior cerebellar artery. The right vertebral artery was hypoplastic, and collateral circulation to the posterior fossa was poor. INTERVENTION: Stent-assisted coil embolization was performed under general anesthesia. The aneurysm was excluded from the circulation with good patency of the vertebral artery, although the fourth coil caused rebleeding from the aneurysmal dome during the procedure. CONCLUSION: This is the first case report that demonstrates rebleeding from VADA during stent-assisted coil embolization in the acute stage of its rupture. We have to be aware of the risks and be ready to prevent fatal complications with this novel technique.

Aortic Dissection↗

PubMed2004

Apoptosis induction with 5-fluorocytosine/cytosine deaminase gene therapy for human malignant glioma cells mediated by adenovirus.

Previously, we evaluated the therapeutic efficacy of the adenovirus-mediated transduction of the cytosine deaminase (CD) gene and 5-fluorocytosine (5-FC) for malignant gliomas. However, the molecular pathways that mediate the 5-FC/CD gene therapy-induced cell death remains to be elucidated. In this study, we examined the induction of apoptosis and the role of caspases in 5-FC/CD gene therapy using human malignant glioma cells [Gli36delta5 (mutated p53) and U87MG (wild p53)]. The treatment with 5-FC/CD gene-therapy-induced apoptosis both in Gli36delta5 cells and in U87MG cells according to flow cytometric analysis. Immunoblot analysis revealed that caspases 3 and 9 were processed in response to 5-FC/CD in a concentration- and time-dependent manner, but caspase 8 was not. Each caspase 3 and 9 inhibitor significantly reduced apoptosis triggered by 5-FC/CD, but the caspase 8 inhibitor did not affect apoptosis induction. 5-FC/CD significantly promoted the release of cytochorme c from mitochondria in a concentration-dependent manner. These results indicate that 5-FC/CD gene therapy induces apoptosis in human malignant glioma cells and that the apoptotic cell death is mediated by the activation of mitochondrial caspase cascades involving caspases 3 and 9. This is the first report concerning the apoptotic mechanism of 5-FC/CD gene therapy, and these findings could be used to increase the efficacy of suicide gene therapy systems for the treatment of malignant glioma.

Adenoviridae↗

PubMed2004

Combined use of electrolytically and mechanically detachable platinum coils for endovascular treatment of cerebral aneurysms--technical note.

The combined use of Guglielmi detachable coils (GDCs) and newly developed mechanically detachable platinum coils (Detach Coil System: DCS) was evaluated for the endovascular treatment of 10 patients with cerebral aneurysms. The number and total length of detachable coils placed into the aneurysms, the detaching time for each coil, and any technical problems were recorded and evaluated. Sixty GDCs and 60 DCSs were used. The detachment time for the DCS (mean 21 seconds) was faster than that for the GDC (mean 2 minutes 35 seconds). One DCS moved inside the aneurysm during the mechanical detachment maneuver, but was successfully placed. Neither detachment system influenced the behavior of the other system during coil implantation. The DCS includes a useful J-shape coil, whereas the GDC can be detached safely in fragile aneurysms. The DCS is also cheaper. The coil systems complemented one another and the combination optimized cost and operating time.

Adult↗

PubMed2004

[A case of convulsion during selective intra-arterial infusion of fasudil hydrochloride for treatment of vasospasm following subarachnoid hemorrhage].

The authors report a case of convulsion during intra-arterial selective infusion of fasudil hydrochloride (FSD) for treatment of vasospasm following subarachnoid hemorrhage (SAH). A 47-year-old man (Hunt and Kosnik grade I) presented with sudden onset of headache and was diagnosed with SAH on CT, and admitted to our hospital. Digital subtraction angiography (DSA) performed on admission revealed an anterior communicating artery aneurysm. Neck clipping of the aneurysm was performed on the same day and no neurological deficits were noted postoperatively. Motor aphasia appeared on day 11 after the operation, and emergency DSA revealed vasospasm of the left middle cerebral artery and its branches. Emergency percutaneous transluminal angioplasty was performed with successful dilation of the left M1 artery, and 25 milligrams of FSD was injected into the left M1 artery selectively. During this injection, right hemifacial convulsion appeared, and three minutes later disappeared. No treatment was needed for the seizure. Additional injection of 30 milligrams of FSD into the left internal carotid artery resulted in vasodilatation of the left M1 artery and its branches, improvement of their blood flow on angiography, and recovery from motor aphasia. The patient was discharged 1 month later with no neurological deficits. Intra-arterial selective infusion of FSD plays an important role in treatment for vasospasm following SAH, however, we must be aware of risks of complications such as convulsion.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed2004

Loss of heterozygosity on chromosome 10q associated with malignancy and prognosis in astrocytic tumors, and discovery of novel loss regions.

Certain tumor suppressor genes (TSG) residing on human chromosome 10q are implicated in astrocytic tumors. We thoroughly examined loss of heterozygosity (LOH) on chromosome 10q in astrocytic tumors to determine the extent of deletion and their relation to prognostic variables of patients. We analyzed 63 astrocytic tumors, including 9 diffuse astrocytomas, 36 anaplastic astrocytomas, and 18 glioblastomas. DNAs from tumors and leukocytes were analyzed for LOH at 18 microsatellite loci by polymerase chain reaction using fluorescence-labeled primers. Then correlation between LOH and clinicopathological variables was examined statistically. Twenty-four (66.7%) anaplastic astrocytomas and 15 (83.3%) glioblastomas had at least one LOH on chromosome 10q. However, diffuse astrocytomas exhibited no LOH. Nineteen tumors (10 anaplastic astrocytomas and 9 glioblastomas) were believed to have a total loss of one chromosome 10. Analyses on 20 tumors with interstitial LOH revealed that most of the high LOH regions matched the location of known TSGs, while some novel LOH regions were found preferentially in anaplastic astrocytoma. The median survivals of the total, partial, and no loss groups were 10.1, 14.8, and 46.8 months, respectively, indicating a significant difference in the survivals of these groups (P=0.0289). Thus, analyzing chromosome 10q loss is helpful for diagnosing malignancy in astrocytic tumors and for predicting patients' survival. Our data also suggested that there are novel TSGs for anaplastic astrocytoma at 10q24 and 10q26.

Adolescent↗

PubMed2003

Effects of lecithinized superoxide dismutase on neuronal cell loss in CA3 hippocampus after traumatic brain injury in rats.

BACKGROUND: The protective effect of excitatory amino acid antagonists for CA3 hippocampal neuronal loss has been well documentated. From a clinical point of view, however, alternative therapies should also be explored because excitatory amino acid antagonists have relatively deleterious side effects. Administration of lecithinized superoxide dismutase (PC-SOD) has recently been demonstrated to reduce brain edema after traumatic brain injury (TBI) in the cerebral cortex. In this study, we investigated the effectiveness of PC-SOD on CA3 hippocampal cell loss by examining hematoxylin and eosin-stained sections. METHODS: Rats were divided at random into three groups. The first group received 1 mL of saline (contusion + saline group, n = 5). Rats of the second group were treated with 3000 IU/kg of PC-SOD (contusion + SOD 1 group, n = 5), while the third group received 5000 IU/kg of PC-SOD (contusion + SOD 2 group, n = 5). All agents were administered intraperitoneally 1 minute after traumatic insult and every 24 hours until 2 or 3 days post-TBI. Animals were sacrificed 3 or 7 days after contusion injury. RESULTS: PC-SOD prevented CA3 neuronal loss 3 days after TBI, and increased the number of surviving CA3 neurons 7 days after TBI. CONCLUSION: Our findings suggest that PC-SOD may serve as a pharmacological agent in the treatment of neuronal loss after TBI.

Animals↗

PubMed2003

Angioplasty and coiling of ruptured aneurysm with symptomatic vasospasm: technical case report.

BACKGROUND: Treating a ruptured cerebral aneurysm during symptomatic vasospasm is very difficult. We describe the successful endovascular treatment of such a case and discuss its efficacy. CASE PRESENTATION: A 34-year-old man had a sudden onset of severe headache. One week later, he was referred to our institute with gradually progressing right hemiparesis and global aphasia. Cerebral angiography demonstrated severe vasospasm of the left internal carotid artery system and an anterior communicating artery aneurysm. With the patient under general anesthesia, 90% occlusion of the aneurysm was achieved with detachable coils after successful dilatation of the spastic vessels. The patient had an uneventful postoperative course and his neurologic symptoms were improved. Seven months after the endovascular treatment, the enlarged neck remnant of the aneurysm was successfully clipped without difficulty. CONCLUSION: The simultaneous treatment of a ruptured aneurysm and vasospasm with percutaneous transluminal angioplasty and coils can produce a better outcome for the patient.

Adult↗

PubMed2003

Inhibition of excitatory neuronal cell death by cell-permeable calcineurin autoinhibitory peptide.

In glutamate-mediated excitatory neuronal cell death, immunosuppressants (FK506, Cys-A) are powerful agents that protect neurons from apoptosis. Immunosuppressants inhibit two types of enzyme, calcium/calmodulin-dependent protein phosphatase (calcineurin: CaN), and peptidyl-prolyl cis-trans-isomerase (PPIase) activity such as the FKBP family. In this study, we used a protein transduction approach to determine the functional role of CaN and to produce a potential therapeutic agent for glutamate-mediated neuronal cell death. We created a novel cell-permeable CaN autoinhibitory peptide using the 11 arginine protein transduction domain. This peptide was highly efficient at transducing into primary culture neurons, potently inhibited CaN phosphatase activities, and inhibited glutamate-mediated neuronal cell death. These results showed that CaN plays an important role in excitatory neuronal cell death and cell-permeable CaN autoinhibitory peptide could be a new drug to protect neurons from excitatory neuronal death.

Active Transport, Cell Nucleus↗

PubMed2003

Time course of the diameter of the major cerebral arteries after subarachnoid hemorrhage using corrosion cast technique.

In this report, we examined whether corrosion cast method is also applicable for the measurement and estimation of the rat major arteries in which subarachnoid hemorrhage (SAH) is produced. Additionally, we have examined the diameters of the rat major arteries following SAH. A total of 0.3 ml autologous blood was injected into the cisterna magna of male Sprague-Dawley rats for the SAH model. A perfusion of a semi-polymerized casting medium was performed, 10 min, 30 min, 1 h, 4 h, 8 h, 1 day, 2 days, 3 days, 5 days, and 7 days after SAH. The brains were corroded in a 10% NaOH solution. The BA and the other major arteries were then measured using scanning electron microscopy (SEM). Macroscopic observation and hematoxylin-eosin (HE) staining were also performed. Using the corrosion cast method, the biphasic contractile response was observed in the BA; 8.3% and 11.6% contractions were observed 30 min and 1 day after SAH, respectively. In addition, there was almost no smooth muscle or adventitial thickening in the chronic stage. In contrast, the dilative response was observed in the internal carotid artery and middle cerebral artery 10 min after SAH. Macroscopic findings and HE staining revealed that the extensive basal subarachnoid hematoma had almost disappeared by day 2. These results indicate that in this model, the minimal spasm, which occurs one day after SAH, can be explained by the small capacity of the rat subarachnoid space and the rapid cerebrospinal fluid washout around major vessels at the cerebral base. Moreover, the present data also show the compensatory dilatation in the ICA and MCA in the early stage after SAH.

Animals↗

PubMed2003

Role of endo-1,4-beta-glucanases from neisseria sicca SB in synergistic degradation of cellulose acetate.

An enzyme hydrolyzing beta-1,4 bonds in cellulose acetate was purified 10.5-fold to electrophoretic homogeneity from a culture supernatant of Neisseria sicca SB, which assimilate cellulose acetate as the sole carbon and energy source. The enzyme was an endo-1,4-beta-glucanase, to judge from the substrate specificity and hydrolysis products of cellooligosaccharides, we named it endo-1,4-beta-glucanase I (EG I). Its molecular mass was 50 kDa, 9 kDa larger than EG II from this strain, and its isoelectric point was 5.0. Results of N-terminal and inner-peptide sequences of both enzymes, and a similarity search, suggested that EG I contained a carbohydrate-binding module at the N-terminus and that EG II lacked this module. The pH and temperature optima of EG I were 5.0-6.0 and 45 degrees C. It hydrolyzed water-soluble cellulose acetate (degree of substitution, 0.88) and carboxymethyl cellulose. The Km and Vmax for these compounds were 0.296% and 1.29 micromol min(-1) mg(-1), and 0.448% and 13.6 micromol min(-1) mg(-1), respectively. Both glucanases and cellulose acetate esterase from this strain degraded water-insoluble cellulose acetate synergistically.

Adsorption↗

PubMed2003

Experimental study of the pathogenesis of moyamoya disease: histological changes in the arterial wall caused by immunological reactions in monkeys.

Moyamoya disease is a progressive vascular disorder of unknown etiology. Theories of inflammatory and immunologic mechanisms have been proposed as the pathogeneses. We have designed a new method of administering N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP) for experimental induction of moyamoya disease using an intravascular interventional technique combined with rod-shaped embolic materials made from lactic acid-glycolic acid copolymer. The embolic materials containing MDP were repeatedly injected into the right internal carotid artery of monkeys in the embolic group. Intravenous injections of MDP solution alone were performed in the intravenous group. Histological examination of the arteries demonstrated reduplication and lamination of the internal elastic laminae, which corresponded with findings of moyamoya disease in both groups. These histological changes occurred not only in the intracranial arteries on the embolization side, but also in the contralateral intracranial and even extracranial arteries. The changes were more prominent in the intravenous group than in the embolic group. We conclude that the systemic humoral factors induced by MDP in this study may be important in the pathogeneses of moyamoya disease. Our observations suggest that moyamoya disease is a systemic vascular disease and has an etiologic factor affecting both intracranial and extracranial arteries

Acetylmuramyl-Alanyl-Isoglutamine↗

PubMed2003

Attempt to establish an experimental animal model of moyamoya disease using immuno-embolic material--histological changes of the arterial wall resulting from immunological reaction in cats.

In this study, we investigated the relationship between intimal thickening of the internal carotid artery (ICA) and immunological reaction, and between occlusion of the ICA and development of basal collateral vessels in moyamoya disease. Rod-shaped lactic acid-glycolic acid copolymer (LGA-50) and N-acetylmuramyl-L-alanyl-D-isoglutamine (muramyl dipeptide: MDP), and immuno-embolic material, were injected into cats unilaterally via the common carotid artery. Histological changes of duplication of the internal elastic lamina could be seen mainly in the terminal portion of the ICA in the animals injected with rod-shaped LGA-50 containing MDP. No angiographic changes were seen in any of the animals. These findings suggest that the immunological reaction induced by MDP caused histological changes in the intima of the ICA similar to those observed in moyamoya disease. This experimental study, however, could not clarify the development of the basal collateral vessels.

Acetylmuramyl-Alanyl-Isoglutamine↗

PubMed2003

Radiation damage to the normal monkey brain: experimental study induced by interstitial irradiation.

Radiation damage to normal brain tissue induced by interstitial irradiation with iridium-192 seeds was sequentially evaluated by computed tomography (CT), magnetic resonance imaging (MRI), and histological examination. This study was carried out in 14 mature Japanese monkeys. The experimental area received more than 200-260 Gy of irradiation developed coagulative necrosis. Infiltration of macrophages to the periphery of the necrotic area was seen. In addition, neovascularization, hyalinization of vascular walls, and gliosis were found in the periphery of the area invaded by the macrophages. All sites at which the vascular walls were found to have acute stage fibrinoid necrosis eventually developed coagulative necrosis. The focus of necrosis was detected by MRI starting 1 week after the end of radiation treatment, and the size of the necrotic area did not change for 6 months. The peripheral areas showed clear ring enhancement with contrast material. Edema surrounding the lesions was the most significant 1 week after radiation and was reduced to a minimum level 1 month later. However, the edema then expanded once again and was sustained for as long as 6 months. CT did not provide as clear of a presentation as MRI, but it did reveal similar findings for the most part, and depicted calcification in the necrotic area. This experimental model is considered useful for conducting basic research on brachytherapy, as well as for achieving a better understanding of delayed radiation necrosis.

Animals↗

PubMed2003

Glioblastoma with metastasis to the spleen--case report.

A 47-year-old woman presented with headache and left homonymous hemianopsia. T1-weighted magnetic resonance (MR) imaging with contrast medium showed a mass lesion with ring-like enhancement in the right temporo-occipital lobe. The patient underwent surgery, focal irradiation, and chemotherapy. The histological diagnosis was glioblastoma. Four months after the operation, the patient again developed headache and left homonymous hemianopsia in addition to vomiting and mild left hemiparesis. MR imaging showed recurrence of the tumor and hydrocephalus. The patient underwent a second craniotomy and placement of a ventriculoperitoneal shunt. Intraoperative findings revealed that the transverse-sigmoid sinus was occluded by tumor invasion. The patient died of intraventricular dissemination 2 months after the second operation. Autopsy revealed metastases in the spleen and lungs. Glioblastoma with metastases to the spleen is very rare. The prognosis for patients is poor. Excessive therapy should not be used for patients with extracranial metastases from glioblastoma.

Brain Neoplasms↗