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Biomedical subjects

M Fukui

Publications and source records attributed to M Fukui.

At least 19 recordsLinked to original sources

Rolling mouse Nagoya as a mutant animal model of basal ganglia dysfunction: determination of absolute rates of local cerebral glucose utilization.

In order to elucidate the neuronal mechanism of the motor disturbances of the Rolling mouse Nagoya (rolling), a neurological mutant mouse (genotype rol/rol) showing frequent lurching and falling over on walking, we determined absolute rates of local cerebral glucose utilization (LCGU) with the [14C]deoxyglucose method. The rates were compared with those of heterozygote (+/rol) with normal behavior, and of normal mice (+/+) of the same strain (C3Hf/Nga). Rolling showed marked and significant increases in LCGU in the structures of the basal ganglia such as the globus pallidus, entopeduncular nucleus, substantia nigra pars compacta and pars reticulata, and subthalamic nucleus, confirming our previous finding with semiquantitative LCGU determination. Additional significant but much less marked increases in LCGU of rolling were found in some structures of the brainstem and limbic system, such as the pedunculopontine nucleus, red nucleus, ventral tegmental area, lateral habenula, and CA1 and CA3 of the hippocampus. Although rolling has been regarded as an animal model of cerebellar ataxia, rolling showed no alterations of LCGU in the cerebellum. The heterozygote showed intermediate increases in LCGU between rolling and normal mice in the basal ganglia structures such as the globus pallidus, substantia nigra pars reticulata and subthalamic nucleus. Our findings indicate that rolling has a definite, genetically determined dysfunction of the basal ganglia. The primary site of the basal ganglia dysfunction might probably be in the striatum, involving both the neostriatum and limbic striatum, and resulting in secondary dysfunction in their target structures.

Animals

[MR imaging of stereotactic thalamotomy using radiofrequency methods].

Sixty-eight stereotactic radiofrequency (rf) thalamic lesions in 57 patients with movement disorders were evaluated by magnetic resonance (MR) imaging. Postoperative periods ranged from 5 days to 4 years and 9 months. All 68 rf lesions were clearly detected on T2-weighted images (T2WI). Changes in signal intensity on T2WI were classified into five patterns, as follows: Pattern I: lesions with three concentric zones consisting of an inner hypointense, middle hyperintense and outer hypointense zone (31 lesions); Pattern II: lesions consisting of an inner hypointense and outer hyperintense zone (4 lesions); Pattern III: lesions consisting of an inner hyperintense and outer hypointense zone (27 lesion); Pattern IV: lesions of a hyperintense area alone (2 lesions); Pattern V: lesions of a hypointense area alone (4 lesions). The outer hypointense rim in Patterns I and III is thought to represent hemosiderin deposition. The abnormal signal intensity on T2WI caused by rf ranged from 2 to 12 mm in diameter, and lesions in the late phase were smaller than lesions in the early phase.

Adolescent

Cerebral neurocytoma. A new subset of benign neuronal tumors of the cerebrum.

Three cases of patients with unusual neuronal tumors in the cerebral hemisphere are reported. All were associated with long-standing epileptic seizures. Computed tomography disclosed low-density lesions without contrast enhancement, which were interpreted as either arachnoid cysts or a cerebral infarction at initial diagnosis. Magnetic resonance imaging scans, however, revealed the lesions to be solid tumors. At surgery, the tumors were found to be relatively well demarcated, soft, and gelatinous. Histologically, all tumors were composed of small uniform stellate cells, which proliferated in a loose myxoid fibrillary matrix and resembled either oligodendroglial or astrocytic tumors. Ultrastructurally, however, all tumors showed neuronal differentiation, including numerous clear and occasional dense-core vesicles, microtubules, and a number of synapses. A review of the literature uncovered no other such cases, and therefore it was decided to classify these tumors as a distinct group of benign neuronal tumors, designated as "cerebral" neurocytoma compared with "intraventricular" neurocytoma. Related nosologic problems of neuronal tumors of the central nervous system and their possible histogenesis are also discussed.

Adult

Acute megakaryoblastic leukemia with translocation t(1;22)(p13;q13) in a 10-week-old infant.

A 10-week-old girl without Down syndrome developed an acute megakaryoblastic leukemia (AMKL). Bone marrow aspirates and biopsy showed megakaryoblastic infiltration with myelofibrosis. The diagnosis was made based on the findings that the positive reactions of leukemic cells to platelet peroxidase and to monoclonal antibodies which recognize platelet-specific surface glycoprotein (GP) IIb/IIIa and GP78. The blasts also showed myeloid and monocytoid differentiation antigens. The leukemic cells had a karyotype of 46,XX,t(1;22)(p13;q13). Our case and two other infantile cases reported by other investigators establish the novel association of the t(1;22) with AMKL.

Antibodies, Monoclonal

Liquid chromatographic/atmospheric pressure chemical ionization mass spectrometric analysis of synthetic elastase inhibitor peptide.

A liquid chromatographic/atmospheric pressure chemical ionization mass spectrometric method for the determination of tert-butyloxycarbonyl-Tyr-Leu-Val-CH2Cl (Boc-YLV-CH2Cl) was investigated. Boc-YLV-CH2Cl was eluted from a Cosmosil 5C8 column in a solvent system of 0.1% acetic acid-methanol (30: 70, v/v). The positive ion spectrum of Boc-YLV-CH2Cl showed a quasi-molecular ion at m/z 526 with fragment ions which provided structural information. Boc-YLV-CH2Cl was purified from blood and tissue samples with Sep-Pak C18 cartridges. The analysis in biological samples was performed by focusing the characteristic ion at m/z 526. The calibration graphs were linear over the concentration range studied (injected amounts of 9.5-190 pmol). The method was applied to the determination of Boc-YLV-CH2Cl in biological samples.

Amino Acid Sequence

Oxidative metabolism of polymorphonuclear leukocytes (PMN) in patients with IgA nephropathy.

The production of hydrogen peroxide (H2O2) by neutrophilic polymorphonuclear leukocytes (PMN) after stimulation and the infiltration of PMN in glomeruli were determined in 20 patients with primary IgA nephropathy. The H2O2 production of PMN after the stimulation was measured with a spectrophotometer using horseradish peroxidase as substrate. The results were as follows: 1) when PMN were pretreated with cytochalasin B, H2O2 production after stimulation with heat-aggregated IgG (IgG) or serum-treated zymosan (STZ) was significantly higher in patients with IgA nephropathy than in controls, and 2) there was an increased amount of PMN localized in glomeruli in patients with IgA nephropathy using immunofluorescence of monoclonal anti-PMN antibody. It appeared that the increased renal infiltration of PMN which have a high potential for production of reactive oxygen species might induce the glomerular injuries in patients with IgA nephropathy.

Adult

The 56 kd platelet-derived growth factor (PDGF)-related protein is phosphorylated and the most stable form in human glioma cells.

We report herein the presence of a 56 kd platelet derived growth factor (PDGF)-related protein as a phosphorylated form in human glioma cells. The phosphorylation of the 56 kd form was found to be the longest of all PDGF-related proteins. By Western blotting using a monoclonal anti-PDGF B-chain, the 80 kd, 56 kd, 40 kd, 28 kd and 17 kd PDGF-related proteins were detected, while after treatment among the nitrocellulose membrane transblotted cell extracts with alkaline phosphatase, 40 kd was the most densely observed while the 56 kd and 80 kd PDGF-related proteins were also detected. In a 32P flush labeling study, it was revealed that PDGF-related proteins incorporated with 32P were detected at 28, 32, 35, 40, 56 and 80 kd but the 17 kd monomer was not labeled. Among the labeled PDGF-related proteins, the 56 kd PDGF-related protein alone remained intracellularly for at least 16 hours. These results indicated that the PDGF-related proteins in human glioma cells are synthesized in a phosphorylated form and partly remain in a 56 kd phosphorylated form intracellularly. The 56 kd form may thus be the most stable form and likely has a substantial biological effect.

Glioma

Hypophyseal metastatic hypernephroma mimicking a pituitary adenoma. Case report.

A patient with a remote history of nephrectomy for hypernephroma presented a visual field defect with hypopituitarism. Neuro-imaging studies showed a highly vascularized sellar mass with suprasellar extension. Surgery, which was performed via the subfrontal approach, disclosed the pituitary tumor to be a hypernephroma. Although anterior pituitary involvement is rare, chiasmal compression is much rarer in metastatic pituitary carcinomas, a review of previously reported cases of metastatic pituitary hypernephroma and our own case indicated that pituitary metastasis from this carcinoma, in contrast to other metastatic pituitary tumors, often mimics pituitary adenoma.

Adenoma

Anaplastic large cell Ki-1 lymphoma in the central nervous system: report of an autopsy case.

A 45-year old immunocompetent man presented with multiple lesions in the brain. A histological examination of the tumors showed a diffuse infiltrate of lymphoid cells with cellular polymorphism and of multinucleated giant cells. These cells were immunolabeled with antibodies against B cell lineage and with a monoclonal antibody, Ber-H2 (CD30), which showed the presence of Ki-1 antigen. Recently, among systemic non-Hodgkin's lymphomas, attention has been given to Ki-1-positive lymphomas, which have been incorporated in the up-dated Kiel classification. We report here a case of Ki-1-positive lymphoma arising in the CNS and review previously reported cases.

Humans

MR imaging and angiography of cerebral venous angiomas associated with brain tumors.

MR study of 6 patients with concurrent venous angioma and brain tumor revealed that in 2 of the 6 cases, the draining vein of the venous angioma was located near to the tumor and was displaced by the tumor. Two of the 6 venous angiomas were too small to visualize prior to contrast enhancement, but could be detected following administration of Gd-DTPA. Angiography was required for definitive diagnosis of the venous angiomas. When a venous angioma is suspected or is detected incidentally, especially when very near a brain tumor, angiography should be considered before performing surgery to avoid surgical complications. Otherwise, ligation of the vein draining the venous angioma may lead to venous infarction.

Adolescent

Natural history and choice of treatment in forty patients with medullary venous malformation (MVM).

Follow-up studies of forty patients with forty-one medullary venous malformations (MVM's) are described. The patients included nineteen males and twenty-one females in an age range from eight to seventy-two years (mean 43.4 years). All cases were diagnosed angiographically. Of the forty-one lesions, twenty-five were located in supratentorial and sixteen in infratentorial regions. In twenty-five supratentorial MVM's, thirteen had superficial drainage, eight deep drainage and three both superficial and deep drainage. Fifteen patients presented with intracranial hemorrhage and eleven patients with complaints or symptoms not related to hemorrhage. Fourteen hemorrhages were found incidentally. The mean follow-up period was three years and eleven months and the longest was sixteen years. No patient died of recurrent hemorrhage and only two had recurrent hemorrhage after a short interval. One patient died of malignant glioma. Thirty-seven out of thirty-nine patients (95%) were in an excellent or good clinical condition with a score above 80% on the Karnofsky Performance Test. This study indicates the low incidence of rebleeding in ruptured MVM's (2/15, 13.3%) and of bleeding in incidentally found unruptured MVM's (0/25, 0%). However, this evidence may be sufficient to support aggressive radical surgery for MVM's.

Adolescent

Effects of theophylline on the selective increases in intratumoral blood flow induced by intracarotid infusion of adenosine and adenosine triphosphate in C6 glioma-transplanted rat brains.

We have previously reported that the intracarotid administration of adenosine or adenosine triphosphate (ATP) selectively increased blood flow in intracerebrally transplanted C6 glioma cells in rats, using the hydrogen clearance method. In the present paper, we studied the difference between the effects of adenosine and ATP, using theophylline, a P1 purinoceptor blocker. The selective enhancement of the tumor blood flow by intracarotid administration of adenosine was almost totally inhibited by theophylline. In contrast, the selective enhancement by ATP was shown definitely not to be inhibited by theophylline. Therefore, it is supposed that the selective increase of intratumoral blood flow by the intracarotid infusion of adenosine is closely related to the P1 purinoceptor, and the effect of the intracarotid infusion of ATP is composed not only of the effect as degraded into adenosine but also of the effect of ATP itself.

Adenosine

Hemifacial spasm due to tumor, aneurysm, or arteriovenous malformation.

The authors report eight cases of so-called symptomatic hemifacial spasm. They had gross pathological lesions such as a tumor (one epidermoid, one neurinoma, and two meningiomas), vascular malformation (one medullary venous malformation and two arteriovenous malformations), and aneurysm. In all four cases with a tumor, no artery compressed the facial nerve at the root exit zone. In three of the four cases, the hemifacial spasm disappeared after removal of the tumor in contact with the facial nerve. Compression or encasement of the facial nerve by the tumor was the pathogenesis of the hemifacial spasm in these three cases. The remaining case with tumor (tentorial meningioma) did not have a mass or vessel that directly compressed the facial nerve at the root exit zone. However, the hemifacial spasm disappeared after the removal of the tumor. In a case with a medullary venous malformation with arterial component, an engorged draining vein compressed the root exit zone of the facial nerve. In the remaining three vascular cases--two cases of arteriovenous malformation and a case of saccular aneurysm--enlarged feeding arteries and an aneurysm directly compressed the root exit zone of the facial nerve. Not only arterial or venous but also mass compression can cause hemifacial spasm in some symptomatic cases. Surgical decompression of the facial nerve from the causative organic lesion is the primary choice of treatment.

Adult

Primary yolk sac tumor of the cerebellar vermis: case report.

A rare case of yolk sac tumor in the cerebellar vermis is reported. A 2-year-old boy developed headaches, vomiting, and an unsteady gait. Later a tumor was demonstrated in the medial part of the cerebellum by gadolinium-enhanced magnetic resonance imaging (MRI). The tumor was totally removed, and the surgery was followed by chemotherapy. Soon after surgery the elevated alphafetoprotein (AFP) levels in the serum and cerebrospinal fluid were observed to decrease to normal levels. Three months later enhanced MRI showed a lesion in the vermis without any elevation of AFP, and the lesion turned out to be a granuloma. Six months after the second surgery a tumor recurred that could not be totally removed. Cranial radiotherapy was given together with chemotherapy, which resulted in a decrease of AFP to the normal range. The patient is doing well without any elevation in AFP at 1 year 6 months after onset. Related problems in the diagnosis and treatment of yolk sac tumors are discussed.

Cerebellar Neoplasms

Effects of L-NMMA and L-NNA on the selective ATP-induced enhancement of intratumoral blood flow.

We studied the effects of NG-monomethyl-L-arginine (L-NMMA) and N omega-nitro-L-arginine (L-NNA) on the selective ATP and adenosine-induced enhancement of intratumoral blood flow in rats measured by the hydrogen clearance method. Both adenosine and ATP produced a selective enhancement of the intratumoral blood flow. Neither L-NMMA nor L-NNA had a significant effect on either the CBF or the intratumoral blood flow. Adenosine-induced enhancement was not inhibited by L-NMMA or L-NNA. On the other hand, the ATP-induced enhancement was totally inhibited by both L-NMMA and L-NNA. The inhibitory action of L-NMMA against ATP was blocked by L-arginine, but not by D-arginine. It is suggested that the ATP-induced increase of intratumoral blood flow is evoked by nitric oxide synthesized from the endothelium of the intratumoral blood vessels.

Adenosine

Leukotriene C4 contents, synthase and catabolic activity in human meningiomas.

Leukotriene has been proposed as a factor of tumour induced brain oedema. Independently of its size, meningioma occasionally shows various extents of peritumoural oedema. We investigated LTC4 tissue contents, LTC4 catabolic and synthetic activity in 12 human meningiomas and their correlation with peritumoural oedema was studied. LTC4 contents were varied from 0.01 to 8.21 pg/mg tissue. When LTA4, an unstable expoxide intermediate was incubated with tumour homogenate, LTC4 was rapidly synthesized. However, LTC4 levels generated by incubating LTA4 with each homogenate were much different in each case. Degradation of LTC4 to LTD4, LTE4, and other polar materials was also rapid by incubation with tumour homogenates. Approximately 70% of added LTC4 was transformed to LTD4, LTE4 nor 6-trans LTB4 diastereoisomers during 30 min incubation at 37 degrees C. The results suggested that there were significant LTC4 tissue contents and LTC4 synthetic and catabolic activity in meningiomas. Oedema index ranged from 1.0 (no peritumoural oedema) to 67.5. No significant correlation, however, was observed not only between the LTC4 tissue contents and LTC4 synthetic or catabolic activities but also between each of these three parameters and peritumoural oedema. Thus, these results do not support a significant correlation of sulfidopeptide LTs with oedema formation in meningioma patients. Since leukotrienes are extremely unstable compounds, LTC4 tissue contents should be carefully discussed along with a consideration of rapid LTC4 synthesis and catabolism. Further role of leukotrienes in meningioma tissue should be studied.

Chromatography, High Pressure Liquid

Modeling the behavior of tritiated water vapor in a research reactor containment building.

Mathematical models were developed to predict the changes in tritiated water (HTO) concentrations in water pools and of HTO vapor in the Kyoto University Reactor (KUR) containment building in which approximately 3.4 x 10(2) GBq of HTO vapor had leaked from a heavy water facility for more than 1 y. Models reveal that the mechanism of HTO vapor transfer between air and water is controlled by two key parameters: the kinetic constant for HTO exchange and the evaporation rate constant from water to air. A model was constructed based on laboratory experiments using small glass dishes containing various volumes of HTO and was validated by comparing estimates to actual measurements for HTO concentration in water pools of various depths in the containment building. After the leakage from the heavy water facility had been stopped, the decrease in HTO concentration in the sub-pool could be described by this model with a half-life of 15 wk. A mathematical model was also developed to estimate the average HTO vapor concentration in air, which is strongly dependent on the ventilation system's operation even after the removal of the HTO sources. This is due to the continued release of HTO from the concrete material and is analogous to the dynamics of radon emanation. The amount of HTO that has emerged from the concrete was estimated using a model developed for HTO concentration changes in the containment building air, based on long-term monitoring.

Air Pollution, Indoor

The effect of serum Ca2+ compensation on the efficacy of chlorpropamide in alloxan-diabetic rabbits.

A decrease in serum Ca2+ concentration was observed in alloxan-diabetic rabbits, with recovery of serum Ca2+ levels achieved following insulin therapy. This suggested that the diabetic condition directly relates to the decrease in serum Ca2+ levels. The efficacy of chlorpropamide in alloxan-diabetic rabbits after intravenous injection (150 mumol kg-1) was less than that in normal rabbits as measured by the serum insulin levels, and the efficacy did not change when the dose was increased. However, compensation of serum Ca2+ levels in alloxan-diabetic rabbits caused an increase in the efficacy of chlorpropamide observed as an increase in serum insulin and a decrease in serum glucose levels.

Animals