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Biomedical subjects

M Fukui

Publications and source records attributed to M Fukui.

At least 109 records · Page 6Linked to original sources
PubMed2000

Radiation-induced brain calcification: paradoxical high signal intensity in T1-weighted MR images.

BACKGROUND: Irradiation to the central nervous system (CNS) in childhood is known to induce cerebral calcification after a latent period. Calcification has been generally found to show nil or a reduction in signal intensity in magnetic resonance (MR) images. However, we have studied three patients with radiation-induced brain calcification, who manifested increased signal intensity on T1-weighted MR images. METHOD: Three girls had each been diagnosed as having a suprasellar germ cell tumour and were treated with conventional fractionated radiotherapy in their childhood. In one case, chemotherapy was given prior to the CNS irradiation. FINDINGS: All three patients survived their disease, and a follow-up CT scan revealed calcification in the brain, which has shown an increased signal intensity in the T1-weighted images of MR. INTERPRETATION: Cerebral calcification may be presented as a high signal intensity in the T1-weighted MR images. This may be explained by a surface-relaxation effect by the calcium salt particle, precipitated in the brain due to radiation-induced mineralising microangiopathy.

Adolescent↗
PubMed2000

Association between type 1 diabetes age-at-onset and intercellular adhesion molecule-1 (ICAM-1) gene polymorphism.

We investigated the intercellular adhesion molecule-1 (ICAM-1) gene polymorphism in 90 patients with young-onset type 1 diabetes, 74 with adult-onset type 1 diabetes, and 171 control subjects. The distribution of C-T genotypes and allele frequencies in exon 6 of the ICAM-1 gene was significantly different between adult-onset type 1 diabetes patients and controls (chi(2) = 9.76, p = 0.0076), and between patients with adult-onset and young-onset type 1 diabetes (chi(2) = 11.28, p = 0.0036). In contrast, we failed to detect any association between patients with young-onset type 1 diabetes and controls. Our data suggest that ICAM-1 exon 6 gene polymorphism affects the age-at-onset of type 1 diabetes and that different pathogenetic mechanisms may exist between young-onset and adult-onset type 1 diabetes.

Adolescent↗
PubMed2000

Cerebellar neuroblastoma in an infant.

A cerebellar neoplasm in an 8-month-old boy is reported. While this tumour was composed of small cells and had regions resembling desmoplastic medulloblastoma, it showed ultrastructural neuronal characteristics including bundles of microtubules in the cell processes, numerous synaptic vesicles, and occasional abortive or complete synapses. These characteristic features warranted the diagnosis of a neuroblastoma of the cerebellum. The nature of this rare intraparenchymal tumour in infants is also briefly discussed.

Cerebellar Neoplasms↗
PubMed2000

Metastatic spinal intramedullary germinoma with elevated cerebrospinal fluid chorionic gonadotropin: a case report.

We treated a patient whose unusual recurrent germinoma illustrates the diagnostic value of measuring human chorionic gonadotropin beta subunit (HCG-beta) in cerebrospinal fluid (CSF) and serum. A 25-year-old man with a suprasellar germinoma and ventricular dissemination was treated successfully with systemic chemotherapy and cranial irradiation. Six years later he developed progressive numbness and weakness in both upper extremities. Magnetic resonance imaging (MRI) disclosed an intramedullary spinal cord tumor in the cervical region. The CSF concentration of HCG-beta was elevated and exceeded that in serum. After completion of systemic chemotherapy and spinal irradiation, symptoms subsided and the tumor was no longer evident on MRI. Based on the patient's history and the rapid response of the tumor to treatment, the spinal cord tumor was considered a metastatic intramedullary spinal germinoma representing CSF dissemination via the central canal.

Adult↗
PubMed2000

Correlation between proton magnetic resonance spectroscopic lactate measurements and vascular reactivity in chronic occlusive cerebrovascular disease: a comparison with positron emission tomography.

The purpose of this study is to investigate the correlation between lactate levels and cerebral vascular reactivity (VR) in regions outside an area of chronic cerebral infarction. Multivoxel proton magnetic resonance spectroscopy ((1)H-MRS) and positron emission tomography (PET) were performed in 11 patients who suffered chronic cerebral infarction. Of these 11 patients, 4 were examined before and after bypass surgery. Two regions-of-interests (ROIs) were placed outside the area of chronic infarction. One ROI was placed within a control region on the contralateral side. A lactate peak area was obtained in all ROIs. An N-acetyl aspartate (NAA) peak area was obtained in the ROI within the control region. The ratio of the lactate peak area and NAA peak area (Lct/NAA) was calculated for normalization of the lactate level, and was found to be 0.13 +/- 0. 10 (range, 0 to 0.43). The VR was recorded at 13.3 +/- 20.7% (range, - 44.3 to 68.9%), utilizing PET and administering acetazolamide. A significant negative correlation was observed between the Lct/NAA ratio and VR (r = - 0.709, p < 0.0001). These results suggest that lactate levels and VR are closely related in regions outside areas of chronic cerebral infarction.

Adolescent↗
PubMed2000

Differential interaction of somatosensory inputs in the human primary sensory cortex: a magnetoencephalographic study.

OBJECTIVE: Somatosensory evoked magnetic fields (SEFs) were recorded to investigate the interaction of the somatosensory inputs using the modality of electrical finger stimulation in 6 normal subjects. METHODS: Electrical stimuli were given to the index (II), middle (III) or little (V) fingers individually, and also to pairs of either the II and III simultaneously, or the II and V simultaneously. The interaction ratio (IR) was calculated as the ratio of the SEF amplitude by simultaneous two-finger stimulation to the arithmetically summed SEF amplitudes of two individual-finger stimulations. RESULTS: SEFs showed 3 major components: N22m, P30m and P60m. The N22m and P60m revealed a clear somatotopic organization in the primary sensory cortex (S1) in the sequence of II, III and V, while the P30m showed a cluster with medial location compared with N22m and P60m in S1. The N22m had a significantly greater IR in II and III stimulation compared to that in II and V stimulation. The P60m also showed a similar trend in the IR but was greater than that of N22m. In contrast, the IR in P30m showed no such tendency. CONCLUSION: The interaction of S1 was most influenced when adjacent receptive fields were activated in the modality of electrical finger stimulation. Our results were consistent with the concept that the Brodmann's areas in S1 which produce the 3 components of the SEFs have different functional organization.

Adult↗
PubMed2000

Magnetoencephalographic analysis of periodic lateralized epileptiform discharges (PLEDs).

OBJECTIVE: To clarify the spatial and temporal distribution of the electroencephalographic (EEG) pattern termed 'periodic lateralized epileptiform discharges' (PLEDs), we performed magnetoencephalography (MEG) to analyze PLEDs in a patient with a right parietal metastasis associated with meningeal carcinomatosis. METHODS: A 37-channel biomagnetometer was used to simultaneously record the EEG and MEG. Equivalent current dipole (ECD) source localization was calculated based on a single-dipole model and mapped onto a magnetic resonance image. Single-photon emission computed tomography with technetium-99-hexamethyl-propyleneamine oxime (HMPAO-SPECT study) was also performed during both presence and absence of PLEDs according to an EEG monitor. RESULTS: By EEG the PLEDs, predominantly right-sided, consisted of a typical negative triphasic spike followed by a slow negative wave. By MEG the PLEDs had a sequence with 3 distinct components. ECDs in the 3 components were localized to the cortex around the lesion, although exact localization and dipole direction varied between components. HMPAO-SPECT demonstrated hypoperfusion of the lesion and adjacent cortex during both quiescence and appearance of PLEDs. CONCLUSION: Our results indicate that PLEDs originated from the hypoperfused cortex surrounding the lesion.

Brain Mapping↗
PubMed2000

Microbial succession during a composting process as evaluated by denaturing gradient gel electrophoresis analysis.

Microbial succession during a laboratory-scale composting process of garbage was analysed by denaturing gradient gel electrophoresis (DGGE) combined with measurement of physicochemical parameters such as temperature, pH, organic acids, total dissolved organic carbon and water-soluble humic substance. From the temperature changes, a rapid increase from 25 to 58 degrees C and then a gradual decrease, four phases were recognized in the process as follows; mesophilic (S), thermophilic (T), cooling (C) and maturing (M). The polymerase chain reaction-amplified 16S rDNA fragments with universal (907R) and eubacterial (341F with GC clamp) primers were subjected to DGGE analysis. Consequently, the DGGE band pattern changed during the composting process. The direct sequences from DGGE bands were related to those of known genera in the DNA database. The microbial succession determined by DGGE was summarized as follows: in the S phase some fermenting bacteria, such as lactobacillus, were present with the existing organic acids; in the T phase thermophilic bacillus appeared and, after the C phase, bacterial populations were more complex than in previous phases and the phylogenetic positions of those populations were relatively distant from strains so far in the DNA database. Thus, the DGGE method is useful to reveal microbial succession during a composting process.

Bacteria↗
PubMed2000

Effects of the new hydroxy-3-methylglutaryl coenzyme a reductase inhibitor fluvastatin on anti-oxidant enzyme activities and renal function in streptozotocin-induced diabetic rats.

1. The effects of 11 week treatments with the new hydroxy3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor fluvastatin on renal intrinsic anti-oxidant enzyme (AOE) activities and renal function were evaluated in streptozotocin (STZ)-induced diabetic rats. 2. Renal intrinsic AOE activities, creatinine clearance and urinary albumin excretion were examined in STZ-induced diabetic rats. The levels of total cholesterol (TC), triglyceride (TG) and phospholipid (PL) were also examined. 3. In general, renal AOE activities and function were lower in diabetic rats than in non-diabetic Sprague-Dawley rats. 4. Decreases in TC, TG and PL levels and urinary albumin excretion by the HMG-CoA reductase inhibitor fluvastatin improved renal function and produced a non-uniform alteration in renal AOE; only glutathione peroxidase (GSH-Px) activity increased significantly with fluvastatin treatment. 5. It appears that the improvement in renal function and albuminuria may be related to increases in GSH-Px activity, but there was no correlation between changes in renal function and changes in the activity of Mn-superoxide dismutase or catalase.

Animals↗
PubMed2000

Moyamoya disease.

Moyamoya disease is a specific chronic cerebrovascular occlusive disease first reported by Japanese surgeons in 1957. The disease is characterized by stenosis or occlusion of the terminal portions of the bilateral internal carotid arteries and abnormal vascular network in the vicinity of the arterial occlusion. It may cause ischemic attacks or cerebral infarction, which is more frequent in children than in adults. In adults, cerebral hemorrhage may occur. The disease is distributed in all age groups, but the highest peak is in childhood at less than 10 years of age. The characteristic histopathologic features of the steno-occlusive arteries are fibrocellular thickening of the intima containing proliferated smooth muscle cells and prominently tortuous and often duplicated internal elastic lamina. There is usually no atheromatous plaque in the arterial wall. Etiology of the disease is still unknown; however, multifactorial inheritance is considered possible because of a higher incidence of the disease in Japanese and Koreans and approximately 10% of familial occurrence among the Japanese. Recent genetic studies suggest some responsible genetic foci in chromosomes 3, 6 and 17.

Carotid Artery, Internal↗
PubMed2000

Clinicopathological features of solitary fibrous tumor of the meninges: An immunohistochemical reappraisal of cases previously diagnosed to be fibrous meningioma or hemangiopericytoma.

Cases of solitary fibrous tumor (SFT) of the meninges are increasingly being reported. However, the real incidence of SFT among meningeal tumors has yet to be determined. We therefore clinicopathologically re-examined 64 meningeal tumors originally diagnosed to be either fibrous meningioma (FM group, n = 46) or hemangiopericytoma (HPC group, n = 18) while paying special attention to SFT. We thus reclassified one case from the FM group (2%) and one case from the HPC group (6%) to be SFT, both of which showed diffuse CD34-immunoreactivity and dense intercellular reticulin fibers but neither epithelial membrane antigen nor S-100 protein expression. The MIB-1 staining index of these cases were 6. 2% and 3.9%, respectively. The former recurred 15 years after the initial surgery and the patient underwent a second removal of the tumor. The patient has been alive with no evidence of recurrence for 7 years after the second surgery. The latter patient has been alive with no evidence of recurrence for 3 years postoperatively. The results confirmed that the incidence of SFT among meningeal tumors is relatively low, however, because of its clinically indolent nature, a careful histochemical examination is necessary to differentiate SFT from other neoplasms with a more aggressive nature. Our findings emphasize the need to clinically recognize this lesion as a distinct entity.

Adult↗
PubMed2000

Spinal cord gliomas: management and outcome with reference to adjuvant therapy.

The authors review their experience with 19 consecutive cases with either astrocytic tumour (glioblastoma multiforme one, anaplastic astrocytoma one, astrocytoma 4, pilocytic astrocytoma 4) or ependymoma (10 tumours in 9 patients) of the spinal cord who were treated during the period from 1982 to 1996. The patients included 10 male and 9 female patients with a median age of 38 years. The main tumour locations included the cervicomedullary region 5 the cervical cord (8), the thoracic cord (5) and one each in the thoracolumbar region and conus medullaris. While a total removal of the tumour was achieved in 8 out of 10 ependymomas, the initial treatment for astrocytic tumours was a partial resection in 5, and biopsy in the remaining 5. As adjuvant treatment, 8 patients received radiation therapy and 2 received chemotherapy. Two patients with an astrocytic tumour received chemotherapy only, while the remaining 9 received neither radiation therapy nor chemotherapy initially. After these treatments, 6 out of the 8 patients with low grade astrocytoma have remained alive for 1.3-12.6 years, while 2 patients with high grade astrocytic tumours died within 15 months following surgery. Eight out of 9 patients with an ependymoma have remained alive for 3.0-12.3 years, while one committed suicide 2 years after surgery. As a result, 14 patients are still alive; half of them are accompanied by a mild neurological dysfunction, while the remaining one has a moderate deficit. The postoperative results and the rationale for surgery is discussed, and an approach for utilising adjuvant therapy for high grade tumours is also suggested.

Adolescent↗
PubMed2000

Spinal intradural perimedullary arteriovenous fistula with varix in infant.

A rare occurrence of type IV spinal arteriovenous malformation (intradural perimedullary arteriovenous fistula) is described in an 18-month-old boy initially misdiagnosed with Guillain-Barré syndrome. An intramedullary mixed-intensity mass lesion at Th1 was demonstrated by magnetic resonance imaging together with flow voids over the dorsal aspect of the swollen spinal cord. Angiography demonstrated an intradural perimedullary arteriovenous fistula including an intraparenchymal vascular pocket. After partial embolisation of the posterior spinal arteries through the left intercostal-radicular artery, the arteriovenous fistula was removed completely together with an organised haematoma. The fistula directly opened into a vascular pocket, which was confirmed pathologically to be a varix. The postoperative course was uneventful, and the patient resumed ambulation within 4 months. The case, subclassifiable as a type IVb spinal perimedullary AVF, was unique given its location and the patient's age at presentation.

Central Nervous System Vascular Malformations↗
PubMed2000

Surgical management of intractable epilepsy associated with cerebral neurocytoma.

Neuronal neoplasms of the CNS constitute a rarely encountered group of tumors. This report concerns the surgical management of seizures encountered in four cases (ranging from 2 to 10 years-of-age at onset; consisting of two males and two females) of a recently recognized morphologically unique tumor, called 'cerebral neurocytoma'. All patients were associated solely with intractable complex partial seizures. The tumor involved the temporal lobe in two cases, and the frontal in two. Magnetoencephalography (MEG) clearly demonstrated an accumulation of equivalent current dipoles originating from the interictal spikes on the cortex around the tumor. On intra-operative electrocorticography (ECoG), the epileptogenic zone was topographically distinct from the region of the tumor. No definite ECoG activities were observed at the tumor site, although this tumor did consist of small mature neuronal cells. Either a complete or a subtotal resection of the tumor and the epileptogenic cortex was performed and, post-operatively, universal freedom from seizures was demonstrated in all patients. A histological examination of the epileptogenic cortex revealed the presence of minute cortical dysplasia or tumor involvement in the hippocampus. A resection of the epileptogenic cortex along with the tumor was thus found to improve the seizure outcome in patients with neurocytoma-associated epilepsy without inducing any identifiable neurological deficits attributable to the incremental resection.

Adult↗
PubMed2000

High incidence of hyponatremia in patients with ruptured anterior communicating artery aneurysms.

We studied the incidence and timing of hyponatremia (Na < 135 mEq l-1) after subarachnoid hemorrhage (SAH) with special reference to ruptured anterior communicating artery (A-com) aneurysms. Hunt and Kosnik (HK) grading, symptomatic vasospasm in A-com aneurysm, and hydrocephalus were analyzed for connections to hyponatremia in 55 patients with ruptured A-com aneurysms, 65 with ruptured internal cerebral artery (ICA) aneurysms, and 49 with ruptured middle cerebral artery (MCA) aneurysms. Hyponatremia occurred in 28 (51%) of 55 patients with A-com aneurysms and in nine (18%) of 49 patients with MCA aneurysms. Severe hyponatremia (Na < 130 mEq l-1) occurred in 16 patients (29%) in the A-com group, four patients (6%) in the ICA group, and three patients (6%) in the MCA group. The A-com aneurysm group had a significantly higher incidence of mild hyponatremia (p < 0.01) and severe hyponatremia (p < 0.001) than other groups. Among A-com cases, hyponatremia occurred significantly more often in HK grade III and IV cases (p < 0.05), in cases with vasospasm (p < 0.001), and in cases with hydrocephalus (p < 0.01). Respective days of onset for symptomatic vasospasm and for hyponatremia were day 7.6 +/- 4.4 and day 10.6 +/- 5.8 following SAH, representing a 3-day delay for hyponatremia (p < 0.05). In most patients hyponatremia resolved within 28 days following SAH. Hyponatremia occurred more often with A-com aneurysms, possibly because of vasospasm around the A-com or hydrocephalus causing hypothalamic dysfunction. Since hypervolemic therapy can cause hyponatremia, particularly careful observation is required during such therapy in patients with A-com aneurysm.

Aneurysm, Ruptured↗
PubMed2000

Vascular endothelial growth factor and malignant transformation of a meningioma: case report.

Although meningiomas are common benign intracranial tumors which grow slowly, we occasionally encountered aggressive or malignant ones. One of these cases showed an interesting relationship to vascular endothelial growth factor (VEGF). A 39-year-old woman underwent resection of a sphenoid ridge meningioma; the residual tumor showed evidence of malignant transformation 14 years later. We immunohistochemically examined six successive surgical specimens plus the autopsy specimen of this patient's tumor for proliferative potential, vascularity, and expression of various growth factors. In the latter stage of clinical courses, proliferative potential and vascularity was seen to increase year by year. Expression of VEGF was upregulated and correlated with vascularity. On the other hand, basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF), and epidermal growth factor (EGF) were not overexpressed in this tumor. This case suggests that overexpression of VEGF and increased angiogenic potential might be involved in malignant transformation of meningiomas.

Adult↗