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T Ohmoto

Publications and source records attributed to T Ohmoto.

At least 217 records · Page 12Linked to original sources
PubMed1993

Steroidal saponins from the bulbs of Lilium regale and L. henryi.

Two new and three known steroidal saponins were isolated from the fresh bulbs of Lilium regale and two known saponins from those of L. henryi. The structures of the new saponins were established by extensive spectral data, hydrolysis and chemical correlation as (25R)-27-O-[(S)-3-hydroxy-3-methylglutaroyl]-spirost-5 -ene-3 beta,27-diol 3-O-alpha-L-rhamnopyranosyl-(1-->2)-O-[beta-D-glucopyranosyl-(1-->3)]- beta-D-glucopyranoside and (25S)-spirost-5-ene-3 beta,17 alpha,27-triol 3-O-alpha-L-rhamnopyranosyl-(1-->2)-O-[beta-D-glucopyranosyl-(1-->2)-O- beta-D-glucopyranosyl-(1-->4)]-beta-D-glucopyranoside. Inhibitory activity of the saponins on cyclic AMP phosphodiesterase was evaluated.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1993

Long-term outcome in surgically treated spina bifida cystica.

This report describes the long-term operative outcome of 72 patients with spina bifida cystica. The period of follow-up was between 4 and 20 years. In our series, 17 patients died, with the mortality rate increasing as the lesions were more rostral. All cases involving only a meningocele are living without handicap. The cases of spina bifida cystica with hydrocephalus had higher morbidity and mortality when compared to those without hydrocephalus. We conclude that the rostro-caudal location, the content of the sac, and whether there is associated hydrocephalus are important factors influencing the long-term prognosis of spina bifida cystica.

Child↗
PubMed1993

Long-term outcome in surgically treated encephalocele.

This report describes long-term operative outcome of 24 cases with occipital encephalocele. The follow-up periods are between 4 and 20 years. Of the 24 patients with occipital encephalocele, two have died. Of the 22 living patients, 16 are living without neurological deficit, while six are disabled mentally and/or physically. Four cases of encephalocele developed hydrocephalus, and two of them died while the other two are still living with severe handicap. The presence of gross brain tissue in the sac of encephalocele and the size of the sac were also unfavorable factors for the prognosis. We conclude that the size and the content of the sac and associated hydrocephalus are the important factors that influence the long-term prognosis of occipital encephalocele.

Encephalocele↗
PubMed1993

A case of pontine lacunar infarction with ulcerative colitis.

We present the case of a young man who experienced a sudden onset of pure motor hemiplegia in association with ulcerative colitis. Based on a review of earlier reports, ulcerative colitis was suspected to be the background disease leading to cerebral infarction. A cerebral infarction of the lacunar type in the right ventromedial aspect of the upper pons was seen on magnetic resonance images. These images detected small lesions in the brain stem, and were used to follow-up their transitions.

Adolescent↗
PubMed1993

Natural history and risk factors of unruptured cerebral aneurysms.

We report the results of a statistical analysis of the long-term outcome of 54 patients with 72 unruptured cerebral aneurysms, and identify the factors for predicting subsequent ruptures. Twenty-two patients died during the observation period, which averaged 43.7 months. The 5-year survival rate was 56%. Aneurysms ruptured in 11 patients (20.4%), 10 of whom died without undergoing surgery. The annual bleeding rate was 1.92%. The average size of the 11 ruptured aneurysms was 13.1 mm. In 4 patients, however, bleeding occurred in unruptured cerebral aneurysms of 4 and 5 mm, which suggests that leaving unruptured cerebral aneurysms of less than 10 mm in size untreated is hazardous. According to the Cox proportional hazards model, the shape and location of the aneurysm and the presence of hypertension were the most important factors for predicting a subsequent rupture. Our data suggest that unruptured cerebral aneurysms arising from the vertebrobasilar and middle cerebral arteries of 10-19 mm size and of multilobes had a statistically high probability of subsequent bleeding. Although 20 patients with 28 unruptured cerebral aneurysms were followed through repeated examinations, we could not correlate the risk of subsequent bleeding with changes in the size of the aneurysm.

Adult↗
PubMed1993

Surgical treatment of moyamoya disease: operative technique for encephalo-duro-arterio-myo-synangiosis, its follow-up, clinical results, and angiograms.

Moyamoya syndrome is defined as the development of collateral anastomosis pathways at the base of the brain, associated with chronic progressive stenosis of the carotid fork. Both reconstructive vascular surgery and conservative strategies are used to treat this syndrome, but the latter cannot prevent the disease from progressing. We describe the procedure of encephalo-duro-arterio-myo-synangiosis (EDAMS), and report the results in 17 patients (28 sides) who underwent EDAMS. The clinical symptoms of moyamoya disease include transient ischemic attacks, reversible ischemic neurological deficits, stroke, seizures, Gerstmann's syndrome, involuntary movements, or mental retardation resulting from the lack of cerebral blood flow. The clinical results of EDAMS were poor in one patient, fair in two, good in five, excellent in eight, and fair on one side and excellent on the other side in one patient. Postoperative angiograms showed widespread collateral circulation on the ischemic brain surface in patients undergoing EDAMS.

Adolescent↗
PubMed1993

Long-term effects of cografts of pretransected peripheral nerve with adrenal medulla in animal models of Parkinson's disease.

Trophic factor supplementation has been reported to enhance the survivability of grafted adrenal chromaffin cells. Because the content of nerve growth factor in the distal stump of a pretransected peripheral nerve increases markedly 1 day after transection, we injected cografts of adrenal medulla with pretransected peripheral nerve into the striata of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice and performed follow-up histological and neurochemical analyses over a 12-month period. Adrenal medullary chromaffin cells cografted with pretransected peripheral nerve survived better than in adrenal grafts alone at 1, 3, and 12 months after transplantation. Host dopaminergic fiber recovery adjacent to the grafts was more prominent in mice with cografts than in mice with adrenal grafts alone at 1 and 3 months after transplantation. Twelve months after transplantation, however, there was no significant difference between the two groups of animals because of the natural recovery of intrinsic dopaminergic fibers from MPTP toxicity. Dopamine concentration in the striata of cografted mice was higher than in mice with adrenal grafts alone at 1 month after transplantation. At 3 and 12 months after transplantation, the natural recovery of dopamine concentration from MPTP toxicity was apparent in both groups of animals and no significant difference was observed between the groups. We conclude that adrenal medullary chromaffin cells can survive for at least 12 months after grafting when cografted with pretransected peripheral nerve. Cografts enhanced the recovery of the host nigrostriatal dopaminergic system up to 3 months after transplantation, but this enhancement was not apparent at 12 months because of the natural recovery of dopaminergic fibers from MPTP toxicity.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1993

Agapanthussaponins A-D, new potent cAMP phosphodiesterase inhibitors from the underground parts of Agapanthus inapertus.

The saponin fraction prepared from the methanolic extract of the underground parts of Agapanthus inapertus was found to exhibit inhibitory activity on cAMP phosphodiesterase (55.2%) at a concentration of 100 micrograms/ml. From this fraction, four new steroidal saponins, designated as agapanthussaponin A (1), B (2), C (3) and D (4), were isolated as the active principles, along with an inactive new furostanol saponin (5). The structures of 1-5 were determined by spectroscopic data and hydrolysis. The IC50 of 1-4 on cAMP phosphodiesterase were 0.7, 1.2, 1.1 and 2.0 (x 10(-5) M), respectively, which are more potent than that of papaverine (IC50 3.0 x 10(-5) M).

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1993

Astrocytic gliomas: MRI and pathological grade.

The relationship between MR configuration and pathological grade was studied in 41 histologically verified supratentorial astrocytic gliomas with a 0.5T superconductive MR system. The gliomas included 13 low-grade astrocytomas (LGAs), 14 anaplastic astrocytomas (AAs) and 14 glioblastoma multiformes (GBMs). MRI configurations were classified into nine criteria which were scored and statistically analyzed. The mean values of LGAs, AAs and GBMs were 0.45 +/- 0.31, 1.18 +/- 0.20 and 1.47 +/- 0.22. In each grade, MRI score increased as pathological grades increased (p < 0.01-0.001). LGAs had significantly lower values than AAs in five of the nine criteria (55.6%); heterogeneity, cyst or necrosis, edema or mass effect, border definition, and the degree of contrast enhancement, and lower values than GBMs in eight criteria (88.9%) except for hemorrhage. Three criteria (33.3%), heterogeneity, cyst or necrosis, and flow void sign were significantly higher in GBMs than AAs. The four variables, heterogeneity, cyst or necrosis, edema or mass effect and border definition, proved to be important factors related to the pathological grade in a multiple regression analysis.

Adolescent↗
PubMed1993

Quantitative measurement of normal and hydrocephalic cerebrospinal fluid flow using phase contrast cine MR imaging.

Measurements of the cerebrospinal fluid (CSF) flow using phase contrast cine magnetic resonance (MR) imaging were performed on a phantom, 12 normal subjects and 20 patients with normal pressure hydrocephalus (NPH). The phantom study demonstrated the applicability of phase contrast in quantitative measurement of the slow flow. The CSF flows of the normal subjects showed a consistent pattern with a to-and-fro movement of the flow in the anterior subarachnoid space at the C2/3 level, and they were dependent on the cardiac cycle in all subjects. However, the patients with NPH showed variable patterns of the CSF pulsatile flow and these patterns could be divided into four types according to velocity and amplitude. The amplitudes of each type were as follows: type 0 (n = 1), 87.6mm; type I (n = 2), 58.2mm (mean); type II (n = 6), 48.0 +/- 5.0mm (mean +/- SEM); and type III (n = 11), 19.9 +/- 1.8mm (mean +/- SEM). The decrease of the amplitudes correlated to a worsening of the clinical symptoms. After the shunting operation, the amplitude of to-and-fro movement of the CSF increased again in the patients with NPH who improved clinically. Some of the type III cases were reclassified type II, I and 0 and also one of the type II cases changed type I after the shunting operation. We conclude that the phase contrast cine MR imaging is a practically and clinically applicable technique for the quantitative measurement of the CSF flow.

Adolescent↗
PubMed1993

Contralateral external carotid-to-middle cerebral artery graft using the saphenous vein. Case report.

A variation of the extracranial-intracranial arterial bypass, using a long saphenous vein graft, is presented. The saphenous vein graft was inserted from the contralateral external carotid artery to the distal middle cerebral artery to replace the common and internal carotid arteries in a patient with a large neck tumor that invaded the common and internal carotid arteries, the esophagus, and the trachea. The patient had a positive balloon Matas' test. The saphenous vein was covered with an artificial vascular graft so that turning of the head or movement of the mandible did not displace or compress the graft. A large volume of flow began immediately after anastomosis. A description of the case and the operative technique is presented herein.

Aged↗
PubMed1993

Superficial temporal artery interposition graft after resection of bilateral anterior cerebral arteries. Case report.

A patient with an olfactory neuroblastoma in the frontal skull base was treated with primary tumor excision and partial resection of the A2 segment of both anterior cerebral arteries (ACA's). Revascularization was carried out using a superficial temporal artery (STA) interposition graft between the proximal and distal stumps with A3 segment-to-A3 segment end-to-side anastomosis. This technique established flow to the peripheral territories of the ACA's through the interposed STA graft. The technical aspects and possible role of this procedure are presented.

Adult↗
PubMed1993

[A case of low grade glioma with Takayasu disease (aortitis syndrome)].

We experienced a rare case of Takayasu disease with low grade glioma. A 36 year-old female had an episode of right hemiconvulsion. On admission, she complained a slight memory disturbance, urination difficulty and motor weakness of right extremities. CT scan demonstrated a low density lesion in the left frontal lobe. MRI showed an inhomogeneous low intense mass on T 1 WI and a homogeneous high intense mass on T2 WI in the same site. No abnormal contrast enhancement was observed in both CT and MRI. Bilateral carotid angiograms demonstrated a filling defect of the left anterior cerebral artery. An aortogram revealed moderate stenosis of the left carotid artery and the brachiocephalic artery, and complete obstruction of the left subclavian artery. CT-guided stereotactic biopsy was performed using BRW stereotactic system and histological diagnosis was astrocytoma grade II. She was followed by interstitial irradiation of 50 Gy at tumor periphery for 10 days. Her neurological symptoms gradually improved, and she is doing well without neurological deficits at the time of this report. The CT scan obtained 13 months after the brachytherapy revealed a decrease in the extent of low density. Brachytherapy seems to be useful for patients with low grade glioma in the eloquent area of the brain.

Adult↗
PubMed1993

[Two cases of metastatic brain tumor treated by interstitial brachytherapy].

The prognosis of patients with metastatic brain tumor is very poor. Median survival of these patients has ranged from 1 month with no therapy, to 2 months with steroid, and from 3 to 6 months with brain radiation therapy of the whole brain. A more recent study comparing radiation therapy alone with surgery plus radiation, has shown good results in the combined surgery and radiation therapy group. But surgical excision is usually limited to patients with a surgically accessible solitary metastasis. And therapeutic options are limited once the tumor recurs locally after whole brain irradiation. Interstitial irradiation allows the delivery of a high dose of localized irradiation in the area of tumor recurrence with minimal risk of radiation damage to the surrounding brain tissue. But brachytherapy for brain metastasis has been performed in few cases. We reported two patients with unresectable metastatic brain tumors who were successfully treated with iridium-192 interstitial brachytherapy, and we discuss the strategy of the treatment. Case 1: A 78 year-old-man underwent a total gastrectomy for gastric cancer. Five months after surgery, he developed right hemiparesis. CT scan revealed a left occipital tumor with massive brain edema and a tiny nodule of tumor in the left thalamic region. The primary site was well-controlled and no systemic disease was seen during subsequent whole body examination. The occipital lesion was surgically excised and he received a postoperative radiation therapy of 50 Gy to the whole brain. The thalamic tumor had not responded to the irradiation and the size of tumor rapidly increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1993

[A case of glial microtumor treated with brachytherapy using MRI guided stereotactic system].

A 34 year old male suffered from convulsion on his right side with loss of consciousness. Neither plain nor enhanced CT could clearly demonstrate a lesion. However, a Gd-DTPA enhanced T1 weighted image (T1WI) demonstrated an enhancing lesion (2 cm in diameter) in the left frontal lobe including the motor cortex. This lesion was not identified on plain T1WI. A T2 weighted image (T2WI) showed a high intensity lesion without mass effect slightly larger than the enhanced area on T1WI. This lesion was suspected to be a glial microtumor, but, because it was difficult to differentiate it from a cerebral infarction, it was confirmed to be a neoplasm by means of an MRI guided stereotactic biopsy. The histological diagnosis of the frozen section was a grade 2 astrocytoma. Subsequently brachytherapy with 192Ir seeds was performed, and about 80Gy of interstitial irradiation was given to the edge of the enhanced area on MRI. The minimum dose in the high intensity area on T2WI was about 50Gy. The patient was discharged with no neurological deficits. The Gd-DTPA enhanced lesion decreased in size six months after the treatment. MRI guided stereotactic system makes it possible to target a high intensity lesion on T2WI in brachytherapy. Brachytherapy using this system is considered to be useful in the treatment of glial microtumor in an area in which it is difficult to identify it on CT.

Adult↗
PubMed1992

Fluorescent dye rhodamine 6G as a molecular probe to study drug resistance of C6 rat glioma cells.

A study was made of the membrane transport of cytoplasm and mitochondria stained fluorescence dye Rhodamine 6G (R6G). In rat glioma C6 cells and 1-(4-amino-2-methyl-5-pyrymidinyl)-methyl-3-(2-chloroethyl) -3-nitrosourea hydrochloride (ACNU) and vincristine (VCR) resistant cell lines (C6/ACNU, C6/VCR), the rate of uptake of R6G decreased in C6/VCR cells, but verapamil increased the intracellular accumulation of R6G in C6/VCR. The intracellular accumulation of R6G of C6/ACNU cells was essentially the same as that of wild-type cells. C6/ACNU cells did not show cross resistance and were sensitive to VCR and cisplatin. C6/VCR cells showed cross resistance to ACNU and CDDP, but C6/VCR cells in the presence of verapamil were more sensitive to drugs than C6/VCR cells in the absence of verapamil. We conclude that the reduction of R6G fluorescence staining intensity in C6/VCR cells compared to wild-type cells may be associated with the mechanism of multidrug resistance (MDR) but does not reflect the mechanism of resistance to ACNU. Verapamil increased the accumulation of R6G in C6/VCR cells and overcame MDR, suggesting that there is a correlation between the MDR overcoming effect and enhancement of R6G accumulation, and that this correlation validates the use of the R6G staining test for clinical and laboratory investigation of MDR.

Animals↗