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T Yoshimoto

Publications and source records attributed to T Yoshimoto.

At least 145 records · Page 8Linked to original sources
PubMed2000

[Spinal dermoid cyst secondary to myelomeningocele repair: a case report].

Dermoid and epidermoid tumors arise from the invagination of epidermal elements into the neural tube during the embryonic period. However, many studies have reported that dermoid and epidermoid tumors occur 5 to 10 years after the first operation on myelomeningocele patients. A seven-year-old male with myelomeningocele which had been repaired in his neonatal period, presented leg pain and deterioration of gait disturbance and urinary incontinence. Neuroradiological examinations revealed a spinal dermoid cyst at the repaired myelomeningocele and tethered spinal cord. We removed the tumor and untethered the tethered spinal cord. Postoperatively, the patient's leg pain, gait disturbance and urinary incontinence improved immediately. Inappropriate surgical treatment of spina bifida may cause a second lesion, which leads to tethered-cord syndrome. We suggest that proper surgical treatment, early checkup and neuroradiological evaluations are very important for spina bifida patients who show signs of neurological deterioration. For the best treatment, neurological, urological and orthopedical follow-up study after the first repair operation is necessary.

Child↗
PubMed2000

[An arterial dissection of the distal anterior inferior cerebellar artery treated by endovascular therapy].

A rare case of a dissection of the distal anterior inferior cerebellar artery (AICA) is presented. A 68-year-old woman with sudden onset of headache was admitted. Computed tomographic (CT) scan demonstrated no subarachnoid hemorrhage. Seven days later, CT scan revealed subarachnoid and intraventricular hemorrhage. Left vertebral angiogram showed an aneurysmal dilatation on the distal AICA with a diagnosis of suspected arterial dissection. At that time, we chose delayed craniotomy to observe the lesion directly. However, rebleeding causing aggravation of the patient's systemic condition delayed radical treatment. 19 days after rebleeding, by a superselective angiogram, endovascular treatment was selected to prevent further bleeding. The lesion was diagnosed as dissection of the AICA. The parent AICA was occluded with a Guglielmi detachable coil and fibered platinum coils. Dissection of the distal portion of the cerebellar artery is rare. Only six cases have been reported in the posterior inferior cerebellar artery (PICA) and two cases in the superior cerebellar artery (SCA). However, to our knowledge, no such case has been reported in the AICA. Ruptured dissection of distal PICA or SCA is reported to require early treatment to prevent further bleeding. Ruptured dissection of the distal AICA also requires early treatment. Two cases of distal dissection of PICA and SCA successfully treated by endovascular treatment are reported. Endovascular treatment has some benefits in that it does not always require general anesthesia and in that it can follow diagnostic angiography. On the other hand, saccular aneurysms of the distal AICA do not always require early treatment, such as removal of hematoma because of low incidence of vasospasm. So, to decide the treatment, precise diagnosis of the dissection is very important.

Aged↗
PubMed2000

Correlation between choline level measured by proton MR spectroscopy and Ki-67 labeling index in gliomas.

BACKGROUND AND PURPOSE: The clinical relevance of proton MR spectroscopy needs further clarification as to its usefulness and limitations. The purpose of this study was to investigate the correlation between the semiquantitative choline-containing compound level (Cho value) measured by MR spectroscopy and the Ki-67 labeling index in gliomas. METHODS: Localized proton spectra were obtained in 26 consecutive patients with glioma who subsequently underwent surgery for tumor removal. Metabolic values in the spectra were measured semiquantitatively using an external standard of reference. The Ki-67 labeling index was measured in the surgical specimen. Because the semiquantitative metabolic values may be affected by tissue components included in the spectroscopic voxel, the MR imaging appearance of the voxel within the tumor was classed as homogeneous or heterogeneous through visual evaluation of the presence of necrosis, cyst, hemorrhage, and calcification, and pattern of enhancement. RESULTS: We found a strong linear correlation between the Cho value and the Ki-67 labeling index in the 18 homogeneous gliomas, but no correlation was found in the eight heterogeneous gliomas, which turned out to be malignant. CONCLUSION: The semiquantitative Cho value is a reliable predictor of proliferative activity of gliomas when the tumor appears homogeneous on MR images.

Adult↗
PubMed2000

Hypofixation and hyperfixation of 99mTc-hexamethyl propyleneamine oxime in subacute cerebral infarction.

UNLABELLED: The relationship between hypofixation and hyperfixation of 99mTc-hexamethyl propyleneamine oxime (99mTc-HMPAO) remains unclear. The purpose of this study was to compare 99mTc-HMPAO SPECT with regional cerebral blood flow (CBF) imaging using 133Xe inhalation in patients with subacute cerebral infarction and to investigate the behavior of 99mTc-HMPAO in the infarct area using dynamic SPECT. METHODS: 133Xe and consecutive 99mTC-HMPAO SPECT studies, the latter of which consisted of dynamic and static scanning, were performed on 51 patients (22 women, 29 men; age range, 40-83 y; mean age, 61 y) with cortical infarction in the middle cerebral artery territory 13-15 d after stroke onset. One region of interest (ROI) was drawn in the infarct area. The control ROI was mirrored to the contralateral side, and the same set of ROIs was applied to all SPECT studies. Fractional fixation of 99mTc-HMPAO in the infarct area was evaluated relatively as the ratio of the infarct-to-control region in 99mTc-HMPAO static tomograms/the ratio of the infarct-to-control region in CBF images using 133Xe inhalation and was classified as hyperfixation when this value was >1.1 and hypofixation when this value was <0.9. To investigate the behavior of 99mTc-HMPAO in the infarct area, the second (36-72 s after tracer injection) and eighth (252-288 s after tracer injection) of 8 dynamic scans were selected, and the washout rate was calculated using the formula: 1 - (mean count in the eighth scan/mean count in the second scan). RESULTS: The infarct area showed hyperfixation of 99mTc-HMPAO when CBF in the area was 35 mL/100 g/min or less and showed hypofixation when CBF was >45 mL/U100 g/min. The washout rate was usually negative when CBF imaging using 133Xe inhalation was <20 mL/100 g/min but was positive when it was >45 mUL/100 g/min. The washout rate was negative when the infarct area showed hyperfixation of 99mTc-HMPAO but was positive when it showed hypofixation. CONCLUSION: 99mTc-HMPAO SPECT underestimates CBF in high-flow regions and overestimates CBF in low-flow regions of subacute cerebral infarction. 99mTc-HMPAO hypofixation and hyperfixation are associated with backdiffusion from the brain to blood and gradual accumulation of hydrophilic metabolites, respectively. Dynamic images should be useful for discriminating between 99mTc-HMPAO hypofixation and hyperfixation.

Adult↗
PubMed2000

Chronic graft-versus-host disease in children and adolescents after bone marrow transplantation from HLA-matched donors.

We analyzed 98 pediatric patients who underwent bone marrow transplantation (BMT) from serologically HLA-matched related donors (RD) or unrelated donors (UD) at our institute to clarify the actual status of chronic graft-versus-host disease (cGVHD). There were 36 evaluable cases of RD-BMT and 35 of UD-BMT. cGVHD was observed in 8 RD-BMT cases (22.2%) and in 23 UD-BMT cases (65.7%). In the RD-BMT cases, the limited and extensive types of cGVHD were observed in 4 cases each, whereas in the UD-BMT cases, the limited type was seen in 11 cases and the extensive type in 12. Prior acute GVHD was observed in 6 RD-BMT cases and in 18 UD-BMT cases. Two RD-BMT patients with extensive type cGVHD died of relapse and cytomegalovirus infection, and 4 UD-BMT patients died because of bronchiolitis obliterans, fungal infection, liver failure, and multiple organ failure, respectively. The incidence of cGVHD in these pediatric patients was as high as that in adult patients when UD-BMT was performed. Some UD-BMT patients required long-term immunosuppressive therapy after BMT. These findings suggest that cGVHD is a serious problem in pediatric UD-BMT. Therefore, intensive prophylaxis and treatment of GVHD must always be performed after UD-BMT.

Adolescent↗
PubMed2000

Usefulness of a toothbrush as a source of evidential DNA for typing.

We investigated the usefulness of a toothbrush as a source of DNA for an unidentified cadaver. Ten toothbrushes were obtained from ten individuals along with their peripheral blood. We recovered from 10 to 430 ng of DNA from all but one of the toothbrushes. All ten toothbrushes, including the one containing no detectable DNA by fluorometry, were typed correctly at all of the loci tested, including nine STRs. Three toothbrushes obtained in two actual deaths also identified two victims and one suspect. Therefore, toothbrushes seem to be useful as a source of evidential DNA for personal identification.

Cadaver↗
PubMed2000

[Systemic and cerebral hemodynamic changes during craniotomy under mild hypothermia].

Systemic and cerebral hemodynamics were evaluated through pulmonary artery and jugular bulb catheters in 31 patients with cerebral aneurysms. The temperature of the pulmonary artery was lowered to 33-34 degrees C during surgeries. Systemic circulation deteriorated during mild hypothermia, but cerebral circulation showed a little improvement. Cardiac function recovered by rewarming, but the balance between systemic oxygen supply and demand did not always improve. Therefore, a strict monitoring of systemic circulation is necessary even when the hypothermia is only mild and vasodilator or inotropics would be indicated. Rapid rewarming should be avoided, especially when surgical retraction of the brain is strong or temporary occlusion is prolonged.

Adult↗
PubMed2000

[Genetic analysis of a patient with dyskeratosis congenita].

Dyskeratosis congenita (DKC) is a rare inherited disease characterized by reticulated pigmentation of the skin, nail dystrophy and oral leukoplakia. More than 90% of DKC cases are inherited as an X-linked recessive trait. Half the patients develop progressive pancytopenia by the age of 11 yr, and this is the leading cause of death. We experienced a 11-year-old boy with the above symptomatic triad of DKC, complicated by progressive pancytopenia as well as cerebellar ataxia. Genetic analysis of mRNA from his cultured peripheral lymphocytes revealed a missense mutation resulting in substitution of 1,150 C with T in the DKC1 gene. This is identical to the mutation reported by Knight et al. to be prevalent in X-linked cases of DKC (11 out of 21 patients). Existence of the identical mutation in Japan suggests that this mutation has been selected on the basis of not only the DNA structural sequence of dyskerin, but also its biological function. We report the detailed clinical course of this Japanese DKC patient with a mutation in the DKC1 gene, and describe the results of genetic analysis.

Cerebellar Ataxia↗
PubMed2000

[Hyperlexia in an adult patient with lesions in the left medial frontal lobe].

A 69-year-old right-handed woman developed a transcortical motor aphasia with hyperlexia following resection of a glioma in the left medial frontal lobe. Neurological examination revealed grasp reflex in the right hand and underutilization of the right upper extremity. An MRI demonstrated lesions in the left medial frontal lobe including the supplementary motor area and the anterior part of the cingulate gyrus, which extended to the anterior part of the body of corpus callosum. Neuropsychologically she was alert and cooperative. She demonstrated transcortical motor aphasia. Her verbal output began with echolalia. Furthermore hyperlexia was observed in daily activities and during examinations. During conversation she suddenly read words written on objects around her which were totally irrelevant to the talk. When she was walking in the ward with an examiner she read words written on a trash bag that passed by and signboards which indicated a name of a room. Her conversation while walking was intermingled with reading words, which was irrelevant to the conversation. She also read time on analog clocks, which were hung on a wall in a watch store. In a naming task, she read words written on objects first and named them upon repeated question about their names. When an examiner opened a newspaper in front of her without any instructions she began reading until the examiner prohibited it. Then she began reading again when an examiner turned the page, although she remembered that she should not read it aloud. She showed mild ideomotor apraxia of a left hand. Utilization behavior, imitation behavior, hypergraphia, or compulsive use of objects was not observed throughout the course. Hyperlexic tendency is a prominent feature of this patient's language output. Hyperlexia was often reported in children with pervasive developmental disorders including autism. There are only a few reports about hyperlexia in adults and some of them were related to diffuse brain dysfunction. Hyperlexia of our patient was associated with echolalia but not with the other "echo" phenomena, which may be because the lesion was unilateral on the left side. Dysfunction of the left supplementary motor area could lead to disinhibition of regulatory mechanism of verbal output in response to auditory and visual stimuli.

Aged↗
PubMed2000

Intraoperative mild hypothermia ameliorates postoperative cerebral blood flow impairment in patients with aneurysmal subarachnoid hemorrhage.

OBJECTIVE: Intraoperative mild hypothermia has been used during cerebral aneurysm surgery to reduce ischemic injury induced by temporary vessel occlusion and brain retraction. However, the clinical effects on cerebral hemodynamics are unclear. This study investigated the effects of intraoperative mild hypothermia on cerebral blood flow (CBF) after surgery to treat aneurysmal subarachnoid hemorrhage. METHODS: Twenty-four patients with ruptured internal carotid or middle cerebral artery aneurysms, of preoperative Hunt and Hess Grade II or III, underwent aneurysm clipping within 72 hours after the onset of subarachnoid hemorrhage. During surgery, patients were randomly assigned to either intraoperative mild hypothermia (33.5 degrees C, n = 12) or normothermia (37 degrees C, n = 12). Brain single photon emission computed tomography with 99mTc-hexamethylpropylenamine oxime or 99mTc-L,L-ethylcysteinate dimer was performed on Days 4, 7, and 14 after subarachnoid hemorrhage. Regional CBF was determined in the basal ganglia and cingulate, frontal, and frontoparietal cortices, using a semiquantitative method. RESULTS: CBF in the frontal cortex ipsilateral to the aneurysm was significantly higher in the hypothermia group than in the normothermia group on Day 4 (P<0.01) but not Day 7 or 14. There was a similar trend in the ipsilateral frontoparietal cortex, but it was not significant. There were no differences in regional CBF in the ipsilateral cingulate cortex or basal ganglia or in any contralateral region during the study period. CONCLUSION: Intraoperative mild hypothermia may reduce the severity of ischemia induced by intraoperative temporary vessel occlusion and brain retraction, thus ameliorating postoperative CBF impairment.

Adult↗
PubMed2000

Serial follow-up MR imaging after gamma knife radiosurgery for vestibular schwannoma.

BACKGROUND AND PURPOSE: Gamma knife radiosurgery has become an important treatment option for vestibular schwannoma. The effect of treatment can be assessed only by neuroimaging. We analyzed the evolution of follow-up MR imaging findings after gamma knife radiosurgery to provide information for the clinical management of these tumors. METHODS: Changes in tumor volume and enhancement were assessed visually on 341 follow-up MR studies obtained in 78 of 86 consecutive patients with unilateral vestibular schwannoma who underwent gamma knife radiosurgery. RESULTS: Follow-up MR studies were obtained between 10 and 63 months (mean, 34 months) after treatment. Tumor control rate was 81%. Changes in tumor volume were classified as temporary enlargement (41%), no change or sustained regression (34%), alternating enlargement and regression (13%), or continuous enlargement (12%). Temporary enlargement occurred within 2 years after radiosurgery. Changes in tumor enhancement were classified as transient loss of enhancement (84%), continuous increase in enhancement (5%), or no change in enhancement (11%). There was no significant correlation between changes in tumor volume and tumor enhancement. Areas of T2 hyperintensity in adjacent brain tissue appeared in 31% of patients. CONCLUSION: Dynamic changes in vestibular schwannoma are seen on serial follow-up MR studies obtained after gamma knife radiosurgery. An increase in tumor size up to 2 years after radiosurgery is likely to be followed by regression. Changes in contrast enhancement are not predictive of clinical outcome. Neuroimaging follow-up is recommended.

Adult↗
PubMed2000

[Intraaneurysmal embolization and parent artery trapping to treat a giant partial thrombosed vertebral artery aneurysm after surgical proximal clipping].

We encountered a case with a giant partially-thrombosed vertebral artery aneurysm successfully treated by endovascular trapping following a surgical parent artery clipping two years previously. The patient complained only of headache on her admission. Initial CT showed no subarachnoid hemorrhage, and MRI of the left anterior aspect of the pons showed flow void and hematoma. The angiogram showed fusiform dilatation of the left vertebral artery just proximal to the vertebral union. At first, the patient was treated by surgical proximal clipping of the left vertebral artery, under a diagnosis of arterial dissection. Her symptom improved and the angiogram showed a slight retrograde aneurysmal filling after the operation. Two years later, she complained of dysphasia, right hemiparesis, and hemidysesthesia caused by the compression of the brain stem. On MRI study, a partially-thrombosed giant aneurysm was detected in the left anterior aspect of the brain stem. The retrograde filling did not change remarkably on the angiogram. We performed the GDC embolization of the left distal vertebral artery and non-thrombosed residual neck with an assisting balloon positioned through the right vertebral artery to the basilar artery. After the embolization, the patient's neurological deficits caused by the compression of the brain stem disappeared. MRI study showed the mass volume reducing gradually over a two-years follow-up period. Treatment for a partially-thrombosed giant vertebral artery aneurysm is difficult and controversial. It is necessary to shut off the blood flow into the aneurysm completely, so we consider that endovascular trapping with intraaneurysmal embolization is the most effective procedure.

Embolization, Therapeutic↗
PubMed2000

Functional evaluation of p53 and PTEN gene mutations in gliomas.

We screened mutations of two major tumor suppressor genes, p53 and PTEN, in 66 human brain tumors using a yeast-based functional assay and cDNA-based direct sequencing, respectively. The frequency of p53 mutations was 28.8% (19 of 66) and was higher in anaplastic astrocytoma (9 of 14, 64.3%,) than in glioblastoma multiforme (GBM; 7 of 27, 25.9%,), supporting previous speculation that there are at least two genetic pathways leading to GBM, a de novo pathway without p53 mutation and a "progressive" pathway with p53 mutation. PTEN mutation was observed in 8 of 64 tumors (12.5%), mainly GBMs (7 of 26, 26.9%), both with and without p53 mutation. These results suggest that mutation of the PTEN gene is a later event than that of the p53 gene in glioma progression and is associated with both the genetic pathways. All of the detected PTEN missense mutations and an in-frame small deletion inactivated PTEN phosphoinositide phosphatase activity in vitro. Because the tumors containing PTEN mutations also showed loss of heterozygosity in the chromosome 10q23 region flanking the PTEN gene, our data clearly indicate that inactivation of both PTEN alleles occurs in a subset of high-grade gliomas, therefore confirming the previous idea that PTEN acts as a tumor suppressor gene.

Adolescent↗
PubMed2000

[Acute epidural hematoma caused by contrecoup injury].

We report a rare case of the acute epidural hematoma caused by contrecoup injury. A 59-year-old woman came to our hospital on foot because of her head injury. She slipped on a stone and hit her occiput against the concrete floor without loss of consciousness. On admission she was alert and complained of dizziness and nausea without neurological deficits. She had a subcutaneous hematoma in the occiput. There was no Battle's sign nor cerebrospinal fluid leakage. Skull film revealed a linear fracture of the occipital bone. Computed Tomography(CT) of the brain showed the acute epidural hematoma at the left frontal region. She was treated conservatively and discharged 19 days after injury without neurological deficits. The mechanism of this lesion is speculated as follows: the deformation of the skull and the negative pressure produced in the frontal region with the occipital injury stripped the dura mater from the calvarium, which lead to the rupture and hemorrhage of the small interposed vessels resulting in the epidural hematoma.

Accidental Falls↗
PubMed1999

12-Lipoxygenase overexpression in rodent NG108-15 cells enhances membrane excitability by inhibiting M-type K+ channels.

1. 12-Lipoxygenase produces 12-hydroperoxy acid from arachidonic acid released from membrane phospholipids. To elucidate the role of the enzyme in neuronal functions, mouse neuroblastoma x rat glioma hybrid NG108-15 cells were permanently transfected with the cDNA for human 12-lipoxygenase. 2. The number of action potentials evoked by depolarizing current steps in a current-clamp mode was strikingly increased in 12-lipoxygenase-expressing NG108-15 cells as compared with the wild-type cells which hardly had the enzyme activity. 3. In the transformed cells, the M-type voltage-dependent K+ current was significantly reduced with little or no change in other ion channel currents. 4. Treatment of the transformed cells with a 12-lipoxygenase inhibitor recovered the action potential frequency and the M-current amplitude to the control level. 5. These results indicate that 12-lipoxygenase and/or its metabolites target K+ channels and upregulate the membrane excitability, and thereby modulate neuronal signalling.

Action Potentials↗