Search PubMed⌕ Search

Biomedical subjects

K Meguro

Publications and source records attributed to K Meguro.

At least 55 records · Page 3Linked to original sources
PubMed1999

Postoperative brainstem high intensity is correlated with poor outcomes for patients with spontaneous cerebellar hemorrhage.

OBJECTIVE: The outcomes for patients with cerebellar hemorrhage are thought to be influenced by anatomic damage to the brainstem. In this study, we investigated the magnetic resonance imaging findings in the brainstem, to examine the relationship between the degree of brainstem damage and the outcomes for patients with spontaneous cerebellar hemorrhage who are in poor-grade condition. METHODS: The results for 31 patients with spontaneous cerebellar hemorrhage, with Glasgow Coma Scale scores of 8 or less at admission, who underwent magnetic resonance imaging examinations were reviewed. All patients underwent surgical intervention. The patients were divided into two groups according to their Glasgow Outcome Scale scores at the time of discharge, i.e., patients who experienced good recoveries or exhibited moderate disabilities (Group I, n = 8) and patients who exhibited severe disabilities, were in a persistent vegetative state, or had died (Group II, n = 23). We investigated obliteration of the fourth ventricle and the perimesencephalic cistern and the presence of hydrocephalus in initial computed tomographic scans and the presence of areas of high signal intensity in the brainstem in T2-weighted images. RESULTS: Eight patients experienced good outcomes, and 23 patients experienced poor outcomes. The overall mortality rate was 32.3%. There were no significant differences between groups with respect to computed tomographic findings such as hematoma size, but the incidence of high signal intensities in the pons and midbrain in T2-weighted images for Group II was significantly higher than that for Group I (P < 0.01). CONCLUSION: Magnetic resonance imaging clearly demonstrated brainstem damage, and high signal intensity in the brainstem was a significant prognostic factor for determining outcomes for patients with spontaneous cerebellar hemorrhage who were in poor-grade condition.

Aged↗
PubMed1999

Image-guided procedures in brain biopsy.

Image-guided procedures, such as computed tomography (CT)-guided stereotactic and ultrasound-guided methods, can assist neurosurgeons in localizing the relevant pathology. The characteristics of image-guided procedures are important for their appropriate use, especially in brain biopsy. This study reviewed the results of various image-guided brain biopsies to ascertain the advantages and disadvantages. Brain biopsies assisted by CT-guided stereotactic, ultrasound-guided, Neuronavigator-guided, and the combination of ultrasound and Neuronavigator-guided procedures were carried out in seven, eight, one, and three patients, respectively. Four patients underwent open biopsy without a guiding system. Twenty of 23 patients had a satisfactory diagnosis after the initial biopsy. Three patients failed to have a definitive diagnosis after the initial procedure, one due to insufficient volume sampling after CT-guided procedure, and two due to localization failure by ultrasound because the lesions were nonechogenic. All patients who underwent biopsy using the combination of ultrasound and Neuronavigator-guided methods had a satisfactory result. The CT-guided procedure provided an efficient method of approaching any intracranial target and was appropriate for the diagnosis of hypodense lesions, but tissue sampling was sometimes not sufficient to achieve a satisfactory diagnosis. The ultrasound-guided procedure was suitable for the investigation of hyperdense lesions, but was difficult to localize nonechogenic lesions. The combination of ultrasound and Neuronavigator methods improved the diagnostic accuracy even in nonechogenic lesions such as malignant lymphoma. Therefore, it is essential to choose the most appropriate guiding method for brain biopsy according to the radiological nature of the lesions.

Aged↗
PubMed1999

External carotid endarterectomy with patch angioplasty using internal jugular vein--two case reports.

A 59-year-old male and a 74-year-old male presented with occlusion of the right internal carotid artery and stenosis at the origin of the ipsilateral external carotid artery manifesting as cerebral ischemia. External carotid endarterectomy with patch angioplasty using the internal jugular vein was performed. Special care was taken to obliterate the stump of the carotid artery using a Weck clip in one case and plication with non-absorbable sutures in the other. Cerebral blood flow in the affected hemisphere was increased after surgery and the patients remained asymptomatic. External carotid endarterectomy has several special aspects such as patch angioplasty and elimination of the stump which must be understood.

Aged↗
PubMed1999

Anomaly of the axis causing cervical myelopathy. Case report.

Although the craniovertebral junction is one of the most common sites at which anomalies develop, spina bifida occulta of the axis (C-2) associated with cervical myelopathy is extremely rare. The authors present the case of a 46-year-old man who developed progressive tetraparesis caused by a cervical canal stenosis at the level of the axis. The spinal cord was compressed by an invaginated bifid lamina of the axis. The patient made a remarkable recovery after undergoing decompressive laminectomy of C-3 and removal of the bifid posterior arch of the axis.

Axis, Cervical Vertebra↗
PubMed1999

[A case of multiple myeloma presenting with a subcutaneous mass: significance of "dural tail sign" in the differential diagnosis of the meningeal tumors].

A 65-year-old female was admitted to our hospital with a 6-month history of a gradually enlarging subcutaneous mass in the frontal region. Neurological examination on admission showed no significant abnormality. Skull X-P showed an osteolytic lesion of the frontal bone. External carotid angiogram demonstrated a tumor stain fed by the middle meningeal artery. Computed tomography (CT) showed a slightly high density mass with a marked homogeneous enhancement. MRI revealed an iso-intensity mass on both T1- and T2-weighted images. Gd-DTPA-enhanced T1-weighted images showed a mass with a marked homogeneous enhancement with the "dural tail sign" in the dura adjacent to the tumor. The tumor was totally removed; this mass was diagnosed as a multiple myeloma. No tumor cells were seen in the dura adjacent to the tumor and the mechanism of dural enhancement around the tumor was not clear. However, it is possible that the "dural tail" is due to increased vascular permeability of the dural vessels. Although the "dural tail" sign has been considered as a highly specific feature of meningioma, multiple myeloma can show the same findings on MRI. Therefore, it is important to consider the possibility of multiple myeloma in the differential diagnosis of meningeal tumors.

Aged↗
PubMed1998

Overexpression of AML1 renders a T hybridoma resistant to T cell receptor-mediated apoptosis.

The AML1 gene, which encodes the DNA binding subunit of the heterodimeric transcription factor, PEBP2/CBF, is involved in several types of chromosomal translocations associated with human acute myeloid leukemia, and has been shown by gene targeting to be essential for the development of definitive hematopoiesis in the murine fetal liver. In addition, the gene is expressed abundantly in T lymphocytes and has been implicated in T cell specific gene expression. In the present study we examined the function of AML1 in T cell receptor (TCR)-mediated, Fas/Fas-ligand dependent apoptosis of a T hybridoma line, DO11.10. Several independent cell clones overexpressing the AML1 protein were isolated by transfecting AML1 cDNA into these cells. These clones possessed an increased level of PEBP2/CBF DNA binding activity and were found to be resistant to apoptosis induced by anti-CD3 antibody treatment. Northern blot analysis revealed that induction of the Fas-ligand transcript was markedly suppressed in the anti-CD3 treated clones. Instead, expression of IL-2 receptor alpha subunit (IL-2R alpha), which is a manifestation of proliferative TCR signaling, was induced. This was in contrast to the parental, anti-CD3 treated DO11.10 cells where induction of Fas-ligand but not of IL-2R alpha was observed. Resistance of the AML1 overexpressing cell clones to TCR-mediated apoptosis is most likely attributable to the lack of Fas-ligand induction, since simultaneous treatment with anti-CD3 and anti-Fas antibodies caused apoptosis of the clones. The overall results suggest that the AML1 protein may play a pivotal role in switching TCR signaling between apoptosis and cell proliferation in T lymphocytes.

Animals↗
PubMed1998

Cerebral blood flow correlated with carotid blood flow in neurologically normal elderly with severe white matter lesions.

Previous studies of white matter signal hyperintensity (WMSH) on T2-weighted MRI (magnetic resonance imaging) have shown it to be related to decreased cerebral blood flow (CBF). However, there have been few studies on the relationship of WMSH and the internal carotid blood flow (CaBF). Doppler ultrasound sonography is widely used for evaluation of CaBF. We analyzed the relationship between CBF, CaBF, and WMSH. The subjects had not suffered cerebral ischemic episodes although they had some risk factors for stroke. They received MRI and were classified into three groups, i.e. mild, moderate, and severe WMSH. The % stenosis of the internal carotid artery (ICA) was measured with angiography. Doppler sonography was used to measure the mean bilateral CaBF. The oxygen-15 steady-state technique and PET (positron emission tomography) were used to measure CBF. There were significant correlations between the % stenosis of ICA and the ipsilateral CaBF and between the % stenosis of ICA and hemispheric CBF. There was a significant relationship between CBF and CaBF in the severe WMSH group, remaining significant after partialling out of the effects of the % stenosis. This indicated that an atherosclerotic change of the cerebral artery occurred in a way that carotid vascular resistence and cerebrovascular resistence were 'proportional'. Copyright Rapid Science Ltd

Journal Article↗
PubMed1998

A cutaneous agranular CD2- CD4+ CD56+ "lymphoma": report of two cases and review of the literature.

We report 2 cases of agranular CD2- CD4+ CD56+ non-Hodgkin lymphoma in which skin seemed to be the primary site. A 21-year-old woman's initial symptom was a skin nodule on the right cheek. She also had tumors in the nasopharynx, and the bone marrow subsequently became involved. No lymphadenopathy was present. She experienced complete remission after dose-intensified therapy with cyclophosphamide, hydroxydaunomycin, vincristine [Oncovin], and prednisone (CHOP), but the disease relapsed in the central nervous system 6 months later. An 81-year-old man experienced an 11-month history of skin nodules in the left forearm. On admission, he had a bone marrow infiltration of lymphoma cells. He died of pneumonia during chemotherapy. The malignant cells of the 2 patients had similar morphologic features, with a monocytoid nucleus and no cytoplasmic granules. The cells in both cases showed a unique phenotype: CD2-, CD3-, CD4+, CD8-, CD13-, CD14-, CD34-, CD16-, CD56+, CD57-, HLA-DR-positive. Staining for peroxidase and alpha-naphthyl butyrate esterase was negative. The T-cell receptor beta, gamma, delta, IgH, kappa, lambda genes were of germ line configurations. The DNA of Epstein-Barr virus was not detected from the bone marrow cells by polymerase chain reaction. Only 3 other cases with similar phenotypes have been reported; all had skin lesions. Although the origin of these cells remains unknown, we propose that this is a distinct clinicopathologic entity.

Adult↗
PubMed1998

A normative, community-based study of Mini-Mental State in elderly adults: the effect of age and educational level.

We investigated community-based data of the Mini-Mental State Examination (MMSE) scores of elderly residents along with the effects of age and educational level. MMSE was planned for all residents over 65 years of age in a town in northern Japan. The number of elders who took the MMSE was 2,266 (90%). The score significantly declined with age and lower educational level, although no effect of sex was apparent. For the MMSE subitems, all the values except for that of naming showed effects of both age and educational level. Those screened by MMSE who fell in the range of cognitive impairment (< 24) accounted for 21.8% and those with severe cognitive impairment (< 18) constituted 6.0%. Despite the differences in language and culture, the mean scores are remarkably similar between Japan and other countries. This is the first normative, community-based study of MMSE among elderly adults in Japan.

Aged↗
PubMed1998

Kanji-predominant alexia in advanced Alzheimer's disease.

OBJECTIVES: Oral reading is preserved until the late stage of Alzheimer's disease (AD). However, it is unknown whether reading of kanji and kana is differentially impaired in Japanese AD patients. The purpose of this study was to examine alexic pattern in AD as related to two script systems. MATERIAL AND METHODS: In 18 severe AD patients, reading performance was compared among kana characters, monographic kanji words, and kana-transcribed words. Auditory comprehension was also examined. RESULTS: With increased severity of dementia, kanji reading was clearly more impaired than kana reading, which was relatively unaffected. Graphic complexity and frequency of the kanji influenced the performance variously among the patients. Dissociation between kanji reading and comprehension was also noted. CONCLUSION: As a result of multiple cognitive deficits, kanji reading is more impaired than kana reading in AD, but the difference is apparent only in the very late stage. Our findings suggest that kanji can be read correctly without meaning.

Adult↗
PubMed1998

Combined carotid endarterectomy and coronary artery bypass graft.

Atherosclerosis is a generalized disease which afflicts a considerable number of patients in both the carotid and coronary arteries. Although the risk of stroke or death use to combined carotid endarterectomy (CEA) and coronary artery bypass graft (CABG) is thought to be higher than that of each individual operation, the combined procedure is generally preferred over staged operations to treat such patients. We performed the combined procedure safely with the aid of intraoperative portable digital subtraction angiography (DSA). This report describes our experience with the operative strategy of simultaneous CEA and CABG. Ninety CEA and 404 CABG were carried out between January 1989 and December 1997. A total of six patients received the combined procedure with the aid of intraoperative DSA; they were studied retrospectively. Postoperative mortality and morbidity after the combined procedure was 0%. In the combined procedure, neurological complications are difficult to detect after CEA because the patient must be maintained under general anesthesia and extracorporeal circulation during the subsequent CABG. However, intraoperative DSA can confirm patency of the internal carotid artery and absence of flap formation after CEA, and the CABG can be performed safely. Intraoperative portable DSA between CEA and CABG is helpful in preventing perioperative stroke in the combined procedure.

Aged↗
PubMed1998

Reassessment of non-hodgkins's lymphoma with a "nodular" growth variant: a clinicopathologic study of follicular, mantle cell and marginal zone lymphomas prospectively diagnosed with multiparameter analyses.

Although three subtypes of non-Hodgkin's lymphoma (NHL), follicular lymphoma (FL), mantle cell lymphoma (MCL) and marginal zone lymphoma (MZL), are now well recognized as independent categories, their biological behavior has not been fully compared. One of the reasons for this may be that subclassification by histological examination alone is often difficult since they all have a common variant of a "nodular" growth pattern and occasionally show similar cytological morphology. Recently, we reviewed patients with FL, MCL and MZL, who were prospectively diagnosed, using multiparameter analyses with unfixed fresh biopsy materials. Of 407 NHL patients, 101 (24.8%) belonged to these three categories and 80 could be followed; FL (n=27), MCL (n=27) and MZL (n=26). Twenty eight cases with diffuse large B-cell (DL-B) lineage lymphoma were selected as control at random. The frequency of the MCL patients with performance status (PS) 2 to 4 (41%) was significantly higher than MZL patients (4%) [P< 0.001]. The 3 year survival rate with FL, MCL, MZL and DL-B was 71.5%, 57.4%, 93.3% and 53.1%, respectively. The survival rate for MZL was significantly better than both FL (p = 0.048) and MCL (p = 0.0085). Significant differences were also found in the overall survival rates among the four risk groups as defined by the International Index [I2](low, low-intermediate, high-intermediate and high; 97.4%, 79.6%, 39.4% and 18.2%, respectively). A multivariate analysis revealed that the International Index may be a significant predictor for short survival (p=0.0001) in the patients with FL, MCL or MZL. These results suggest that MZL shows an apparently better prognosis than FL and MCL and is found to be a prognostically independent category. In contrast, the clinical outcome in MCL is the worst among the three subtypes and was closer to that of DL-B. The International Index can be applied to a wide spectrum of NHL, including MCL, MZL and FL, to and can predict prognosis in these cases.

Adolescent↗
PubMed1998

Basal perforating artery aneurysm within the cavum septi pellucidi. Case report.

The authors describe the case of a 16-year-old boy presenting with clinical onset of subarachnoid hemorrhage. The patient was found to have a small aneurysm arising from the distal portion of a basal perforating branch of the anterior cerebral artery (ACA), lying within a cavum septi pellucidi. Neuroimaging demonstrated a hematoma within the cavum septi pellucidi and the aneurysm was resected via a transcallosal approach guided by an intraoperative portable digital subtraction angiography (DSA) system. The origin of the aneurysm was presumed to be idiopathic. This report is the first to describe an aneurysm of a basal perforating artery arising from the ACA that resulted in an intracaval hematoma. When approaching small vascular lesions during surgery, intraoperative DSA is the method of choice to identify the precise trajectory and distance to the lesions.

Adolescent↗
PubMed1998

Anterior spinal artery syndrome associated with severe stenosis of the vertebral artery.

We describe a 55-year-old man with quadriparesis and impaired pain and temperature sensation in whom T2-weighted MR images revealed a high-intensity lesion in the cord at C3-4. Angiography showed occlusion of the right vertebral artery and severe stenosis of the left vertebral artery. We concluded that the stenosis of the vertebral artery led to the anterior spinal artery syndrome and to a disturbance of consciousness.

Angiography↗