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Biomedical subjects

M Fukui

Publications and source records attributed to M Fukui.

At least 379 records · Page 21Linked to original sources
PubMed1994

Children with unilateral occlusion or stenosis of the ICA associated with surrounding moyamoya vessels--"unilateral" moyamoya disease.

The clinical features of 6 children who are probable sufferers of "unilateral" Moyamoya disease are here reported. They showed angiographic findings which were compatible with those of Moyamoya disease, albeit only on one side. They did not, however, show any basic aetiologic factors. The age of onset, the clinical symptoms and the findings of electroencephalography, angiography, and positron emission tomography in these cases were also quite similar to those in the cases of Moyamoya disease except for unilateral involvement. All 6 patients underwent either direct or indirect EC-IC bypass surgery. In 3 children who received encephalo-duro-arterio-synangiosis, an indirect bypass procedure, the collateral circulation was well formed postoperatively. In the follow-up study, 2 of the 6 cases starting with a unilateral lesion developed bilateral involvement later. However, the other 4 cases persisted in showing only unilateral involvement. These 4 cases may suggest the existence of "unilateral" Moyamoya disease in the paediatric age, and it is recommended that such cases be treated similarly to those of bilateral Moyamoya disease.

Carotid Artery, Internal↗
PubMed1994

Degradation of tri-n-butyltin in Ise Bay sediment.

The vertical distribution patterns of the transformation products of tri-n-butyltin (TBT) in sediment cores collected from 6 sites in Ise Bay, Japan indicated that TBT was transformed by two pathways: methylation and debutylation. Anaerobic incubation of sediment spiked with TBT showed that the methylation was mainly supported by sulfate reducing activity and debutylation was mainly supported by nitrate reducing activity. These results showed that contribution of the two transformation reactions of TBT varied according to the dominant microbial activities in the sediment. The two types of vertical distribution of butyltins observed in the sediment cores appear to be the result of different dominant microbial activity in the sediment.

Alkylation↗
PubMed1994

Malignant lymphoma of the scalp at the site of a previous blunt trauma: report of two cases.

We describe two cases with malignant lymphoma presented as scalp tumors. Both patients had slowly growing subcutaneous lymphoma masses in the scalp after head trauma. In the first case, the scalp lymphoma presented as a recurrent disease during complete remission of her systemic lymphoma after chemotherapy. In the second case, the tumor involved the scalp, subjacent skull, and intracranial space without systemic manifestation. These cases represent examples of a possible relationship between head trauma and the development of between head trauma and the development of tumors involving the brain and its coverings.

Aged↗
PubMed1994

Choroidal fissure cyst in the temporal horn associated with complex partial seizure.

We describe two cases presenting with small cysts in the choroidal fissure of the temporal horn (choroidal fissure cyst). Both patients manifested solely complex partial seizure. On magnetic resonance imaging, the signal intensity of the cyst was identical to that of the cerebrospinal fluid, and the underlying hippocampus was compressed by the cyst. Since the cyst was thought to be of a neuroepithelial type, and therefore of benign nature, surgical intervention was avoided since satisfactory medical control of the seizures was obtained.

Adult↗
PubMed1994

Low protein diet blunts the rise in glomerular gene expression in focal glomerulosclerosis.

The present study was designed to assess whether expression of mRNA for extracellular matrix (ECM) components, metalloproteinases (MMP) and tissue inhibitor of metalloproteinases (TIMP) in glomeruli is affected by a low protein diet during the course of focal glomerulosclerosis (FGS). Puromycin aminonucleoside (PAN) was injected intraperitoneally in rats and the right kidney was removed on day 22. Nephrotic rats received successive intraperitoneal injections of PAN on days 27, 34, and 41. Control rats were subjected to a nephrectomy or a sham operation on day 22. Animals were divided into six groups. In group 1, the PAN-injected rats were fed a standard diet containing 22% protein. In group 2, the PAN-injected rats were fed a low protein diet containing 6% protein, starting on the same day as the first PAN injection. In group 3, the nephrectomized rats without PAN were fed a standard diet. In group 4, the nephrectomized rats without PAN were fed a low protein diet for the same period. In group 5, the sham operated rats were fed a standard diet. In group 6, the sham operated rats were fed a low protein diet for the same period. Rats were sacrificed on days 0, 60 or 80 after the initial PAN or saline injection. The percentage of sclerotic glomeruli in group 1 rats increased markedly with time, reaching 77% on day 80. The mRNA levels encoding for alpha 1(I), alpha 1(III), alpha 1(IV) collagen chains, laminin B1 and B2 chains, heparan sulfate proteoglycan (HSPG), MMP-2, TIMP-1 and TIMP-2 increased significantly as glomerulosclerosis progressed, whereas MMP-1 and MMP-3 mRNA levels were unchanged, and no MMP-9 mRNA was detected throughout the experiments. In group 2, the low protein diet reduced the prevalence of glomerulosclerosis and attenuated the increased mRNA expression for ECM components, MMP-2, TIMP-1 and TIMP-2 in FGS glomeruli. In groups 3 through 6, mRNA levels for ECM components decreased with age, whereas those for MMPs and TIMPs changed little throughout the experiments. Immunofluorescence studies revealed the accumulation of types I, III and IV collagens, laminin, and HSPG in the sclerotic area and low protein diet attenuated the accumulation of these proteins. These data suggest that glomerulosclerosis may result from an imbalance among ECM components, MMPs and TIMPs and that a low protein diet attenuates the otherwise increased levels of mRNA for ECM components, MMP-2, TIMP-1 and TIMP-2 in glomerulosclerosis.

Animals↗
PubMed1994

Intracarotid histamine infusion increases blood tumour permeability in RG2 glioma.

Histamine will alter blood flow and permeability in systemic and cerebral vessels. We reported that intracarotid infusion of histamine selectively increased the blood flow in experimental brain tumours and caused extravassation of Evans blue within tumours. In this study, the effects of histamine on tumour and brain capillary permeability were quantified using autoradiography. RG2 glioma cells were implanted in female Wistar rats. Seven days after implantation, either low doses of histamine (1 or 10 micrograms kg-1 min-1) or saline as a control was infused through the carotid artery of rats. Regional permeability was measured by autoradiography using [14C] aminoisobutyric acid, and the unidirectional transfer constant, Ki (microliters g-1 min-1), was calculated. Intracarotid infusion of 10 micrograms kg-1 min-1 histamine resulted in significant increase in brain tumour permeability, compared to controls. The permeability, Ki, for the 10 micrograms kg-1 min-1 histamine group, the 1 micrograms kg-1 min-1 histamine group, and the control group was 18.8 +/- 4.6 (p < 0.05), 14.9 +/- 5.2, 13.9 +/- 3.7 microliters g-1 min-1, respectively. There was no significant change in blood brain permeability in other brain regions. The effect of increased permeability by 10 micrograms kg-1 min-1 histamine was suppressed by the H2-blocker, cimetidine. This suggests that the effect of histamine on tumour capillaries is mediated by H2-receptors. Intracarotid histamine infusion selectively increases permeability in brain tumours.

Animals↗
PubMed1994

P-glycoprotein expression in brain capillary endothelial cells after focal ischaemia in the rat.

P-glycoprotein (P-gp) is expressed not only in tumour cells but also in some normal tissues including brain capillaries. We investigated whether or not P-gp was expressed in the capillary endothelial cells of a rat focal ischaemic brain. The brains were immunohistochemically studied for Factor VIII, glial fibrillary acidic protein (GFAP), and P-gp. Endothelial gamma-glutamyl transpeptidase (gamma-GTP) activity, which is thought to be induced by glial cells, was also studied histochemically. The P-gp positive endothelial cells disappeared in the ischaemic lesion by post-ischaemic day 3. Factor VIII-positive regenerating capillaries were first observed on day 3 without P-gp expression. The P-gp positive endothelial cells began to reappear on day 5, and were detected in all the endothelial cells by day 8. The P-gp expression in endothelial cells showed a similar pattern as that of gamma-GTP, and seemed to correlate with GFAP-positive reactive astrocytes. The newly-formed brain capillaries thus appeared to have a potential to express P-gp in abnormal pathogenic conditions as cerebral infarction, and our present study also suggested that P-gp in the brain capillaries might therefore be expressed in conjunction with glial cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1994

Microcystic meningioma: clinicopathological features of 6 cases.

The clinical and morphological features of 6 patients with unusual meningiomas with extensive microcystic formation are presented. There were 4 males and 2 females, ranging in age from 30 to 64 years. The clinical and neuro-imaging features of these tumours were identical with those of meningiomas in general. Morphological examinations disclosed that the tumour cells in 4 cases had many ultrastructural characteristics in common with the arachnoid cap cells, viz. prominent and complex interdigitation of the fine cytoplasmic processes, many desmosomes, and intracytoplasmic microfilaments. In contrast, the tumour cells of 2 cases had characteristic structures in common with trabecular arachnoid cells, viz. stellate in shape, a small number of intracytoplasmic filaments, relatively thick cytoplasmic processes, and occasional desmosomes. The tumour cells in these 2 cases were considered to recapitulate the subarachnoid structure and showed microcystic appearance. Although the histogenesis of microcysts in meningiomas is considered not to be uniform, the biological behaviour of these 6 tumours corresponded to those of meningiomas in general.

Adult↗
PubMed1994

Selective and prolonged MRI enhancement by Mn-TPPS in an experimental rat brain tumour with peripheral benzodiazepine receptors.

Synthesized Mn-TPPS, a paramagnetic metalloporphyrin, is expected to be a tumour specific contrast media for magnetic resonance (MR) imaging. We investigated the enhancing characteristics of Mn-TPPS using a transplanted rat C6 glioma model with peripheral type benzodiazepine (PBD) receptors since porphyrins are thought to possibly be endogenous ligands for PBD receptors. An Mn-TPPS enhancement study was then performed either with or without pretreatment while using peripheral and central type benzodiazepine receptor specific ligands (PK11195 and clonazepam, respectively). A signal intensity analysis disclosed the selective and prolonged enhancement of the brain tumour even at 17 h after the Mn-TPPS injection. This specific enhancement of the tumour, however, was not inhibited nor replaced by benzodiazepines. The tissue concentration of Mn-TPPS was significantly higher in the glioma tissue than the other tissues, while PK11195 pretreatment could not reduce the intratumoural Mn-TPPS concentration. A subcellular distribution study disclosed that Mn-TPPS was readily incorporated into the tumour cells. On the other hand, Mn-TPPS was not specifically distributed in the mitochondrial fraction where PBD receptors exist. The present study therefore indicates that Mn-TPPS could be incorporated into tumour cells and supports the potential use of this agent to improve the diagnostic specificity of MR imaging for brain tumours.

Animals↗
PubMed1994

An exon 8-spliced out transcript of neurofibromatosis 2 gene is constitutively expressed in various human tissues.

We succeeded in cloning the exon 8-spliced out transcript of neurofibromatosis 2 (NF2) gene in human glioma cell lines. We then investigated the expression of the spliced out form in various human tissues by PCR analysis followed by Southern blot hybridization and sequencing to evaluate whether it was generated by normal alternative splicing or by a splicing mutation. The analysis revealed the splicing out of exon 8 in the various tissues, and the transcript missing exon 8 should thus be considered as a product of normal alternative splicing. Our results further support the possibility that the NF2 gene expresses multiple alternatively-spliced transcripts variantly in different tissue types.

Base Sequence↗
PubMed1994

Radiological implications of readings with a NaI(Tl) monitor set on an ion exchange resin column for purifying primary coolant water.

Changes in readings of a NaI(Tl) monitor set on the surface of an ion exchange resin column used to purify primary coolant water at the Kyoto University Research Reactor were examined with mathematical models to clarify the radiological meanings. The concentration distributions of the nuclides in the interstitial water of the resin bed and those adsorbed on the resins were determined by use of the dispersion-convection theory coupled with the linear isotherm adsorption relation. The adsorbed amount that was assessed by this model was theoretically related to that made by a compartmental model. The buildup concentrations of nuclides in the core water and the decreased accompanying power operation and shut-down were modeled using the value representing the cleanup rate by the purification circuit. The values of this parameter were determined by the least squares method for observed concentrations of 24Na, a major radionuclide in the core water. Recognizing that the adsorption band had remained within the top 10 cm during the circulation of water through the column, the change in the amount of radionuclide adsorbed on the resin was calculated using a compartmental model. The amount of radionuclide adsorbed on the resin predicted by the model agreed well with the readings of the NaI(TI) monitor. Factors that affect the reading are discussed in relation to early detection of fuel defects.

Adsorption↗
PubMed1994

Oxygen desaturation following voluntary hyperventilation in normal subjects.

To investigate the severity of oxygen desaturation following voluntary hyperventilation (VHV) in normal subjects and its possible relation to chemoresponsiveness, we examined respiration following VHV in 16 normal male subjects. Monitoring was performed according to the standard polysomnography protocol including measurements of arterial oxygen saturation (SaO2) and transcutaneous PCO2 (PtcCO2). The subjects hyperventilated voluntarily for 3 min, and were then observed for more than 15 min. They hyperventilated again for another 3 min, and were followed again for more than 15 min. Eleven subjects fell into non-REM sleep after VHV, and their mean lowest SaO2 was 67.6 +/- 13.0% (n = 15 trials in 11 subjects, mean +/- SD). Falling asleep during hypocapnia caused desaturation, and periodic breathing was invariably observed soon after. The difference between the PtcCO2 during non-REM sleep with stable breathing and the PtcCO2 when the SaO2 was 90% following VHV was defined as the delta PtcCO2 (90). The delta PtcCO2 (90) and hypoxic ventilatory response (HVR) were positively and significantly correlated (r = 0.73, p < 0.01). While the subjects were awake, the mean lowest SaO2 was 73.5 +/- 17.4% (17 trials in 12 subjects). Remaining awake induced oxygen desaturation in some subjects but not in others. In one subject, desaturation during the waking state was caused by hypoventilation, not by central apnea. In the seven subjects whose respiration following VHV was monitored during the waking state in one trial and during the sleeping state in another trial, plots of the PtcCO2-SaO2 relationship for the waking state were generally positioned above those made for the sleeping state.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Presurgical three-dimensional magnetic source imaging of the somatosensory cortex in a patient with a peri-Rolandic lesion: technical note.

We report a case in which three-dimensional (3-D) magnetic source imaging, using the combined techniques of magnetoencephalography and 3-D magnetic resonance imaging, was employed to localize precisely a structural lesion in the precentral gyrus. The lesion was primarily a hematoma located in the right frontal lobe and was associated with a cryptic arteriovenous malformation that had produced repeated seizures with progressive left hemiparesis. 3-D magnetic source imaging mapped the entire somatosensory homunculus and localized the hematoma in the precentral gyrus. Both this relationship and the deduced localization were confirmed by a cortical recording of somatosensory evoked potentials at the time of surgery. 3-D magnetic source imaging proved to be useful in localizing cortical lesions precisely and in determining preoperatively the best form of treatment for the peri-Rolandic lesions.

Adult↗
PubMed1994

Acute purulent discitis with epidural abscess of the cervical spine in an adult--case report.

A 52-year-old male presented with acute purulent discitis and epidural abscess of the cervical spine manifesting as neck pain and slight fever, followed by sudden onset of quadriparesis. Magnetic resonance (MR) imaging showed a low-signal-intensity area in the C6/7 disc space and epidural space ventral to the spinal cord with peripheral enhancement. Surgical exploration using an anterior approach revealed local discitis and epidural abscess, but no osteomyelitis of the neighboring vertebral bodies. Six months after the decompressive procedure to treat the purulent disc and epidural abscess, he had achieved almost full recovery. Such lesions are rare in adults, but should be considered especially when painful spinal symptoms are associated with fever. Early and definitive diagnosis can be achieved by MR imaging with enhancement.

Brain Abscess↗
PubMed1994

Follow-up study of patients with "unilateral" moyamoya disease.

Sixty-four patients with "unilateral" occlusive disease of the circle of Willis were studied to evaluate progression to bilateral disease. Seventeen patients developed bilateral lesions during a period of 1-7 years after the diagnosis of unilateral lesion. Most of these patients had ischemic attack as the initial episode and had repeated attacks before admission. Young children, mostly less than 10 years of age, tended to develop bilateral lesions within 1-2 years, but adults tended to have only a unilateral lesion. Children or young adults with unilateral occlusive lesion of the terminal portion of the internal carotid artery are likely to develop bilateral disease within 1-5 years.

Adolescent↗
PubMed1994

Cerebral circulation and oxygen metabolism in childhood moyamoya disease: a perioperative positron emission tomography study.

Thirteen children with moyamoya disease who had no apparent cerebral infarction or hemorrhage were examined pre- and postoperatively by means of positron emission tomography (PET) to investigate the underlying cerebral circulation and metabolism and the effect of bypass surgery. The preoperative regional cerebral blood flow (rCBF) and mean transit time were significantly decreased and increased, respectively, in the cerebral cortex of these patients compared to control values. The regional cerebral blood volume (rCBV) and the regional oxygen extraction fraction (rOEF) had significantly increased to compensate for the reduced rCBF and perfusion pressure and also to maintain the regional cerebral metabolic rate of oxygen (rCMRO2). In the basal ganglia, rCBV elevation was more prominent than that in the cerebral cortex, although changes in rCBF, rOEF, and rCMRO2 were relatively minor. Postoperative improvements were observed predominantly near the cortex where bypass surgery had been performed and in the basal ganglia. Direct and combined indirect bypass procedures improved cerebral circulation more effectively than single indirect bypass surgery. Although the angiographic findings were not always compatible with the clinical results, the postoperative improvements on PET scans correlated with the disappearance of transient ischemic attacks. In addition to the clinical courses and angiographic findings, PET analysis was indispensable in evaluating the cerebral circulation and metabolism in childhood moyamoya disease.

Adolescent↗