PubMed Health⌕ Search

Biomedical subjects

M Mase

Publications and source records attributed to M Mase.

At least 55 records · Page 3Linked to original sources
PubMed1995

Endovascular stent placement for multiple aneurysms of the extracranial internal carotid artery: technical case report.

A patient with multiple extracranial internal carotid artery aneurysms that caused cerebral infarction was treated by endovascular placement of a metallic stent. Complete disappearance of the aneurysms was angiographically confirmed within 15 weeks. Endovascular observation 6 months after the stent placement revealed that the endoluminal surface was totally covered by normal endothelium. The patient returned to his regular work routine and had no complication or neurological deterioration during the 17-month follow-up period.

Carotid Artery, Internal↗
PubMed1994

Analysis of intracranial pressure pulse wave in experimental hydrocephalus.

Much has been written about the relationship between the pulse pressure (PP) of the intracranial pressure pulse wave (ICPPW) and ventricle dilatation. Some data suggest that high PP is the cause of ventricle dilatation, and other authors have reported that high PP results from decreased intracranial compliance. In order to clarify these points, the amplitude of PP and pressure-volume response (PVR: an indicator of intracranial compliance) were measured in bilateral ventricles using Hochwald's hydrocephalic model (right-left difference in ventricle size is clear due to hemicraniectomy). Hydrocephalus was induced by means of intracisternal injection of a kaolin powder solution to dogs. The mean ICP, amplitude of the PP, PVR and ventricle size (estimated by MR imaging) were evaluated in pathologic conditions induced by the following procedures. Group A, control: kaolin-induced hydrocephalus without craniectomy; group B: kaolin-induced hydrocephalus with right-sided craniectomy; group C: kaolin-induced hydrocephalus with right-sided craniectomy and dural resection; group D: kaolin-induced hydrocephalus with right-sided craniectomy, dura resection and temporal muscle resection. Using MR imaging, the same degree of symmetrical ventricle dilatation was identified in all groups except group D. Group D alone demonstrated a difference in ventricular size (craniectomy side > non-craniectomy side). There was no appreciable difference in mean ICP between any two groups. However, the amplitude of PP and the PVR decreased stepwise from group A to group D. The difference in the amplitude of the PP and PVR between the right and left ventricles was not significant in any group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

A previous potassium stimulation enhances the increases of striatal extracellular dopamine and 5-hydroxytryptamine during global ischaemia under simulated penumbral conditions.

The effect of a previous K+ stimulation on striatal extracellular monoamine levels during global ischaemia, under simulated penumbral conditions, was investigated. Rats were implanted with microdialysis probes in both striata, monoamine release was stimulated unilaterally by adding K+ (100 mM, 20 min) to the artificial CSF perfused through one probe, and bilateral partial ischaemia was imposed after monoamine levels had returned to basal values or below. Resultant increases in dialysate levels of dopamine and 5-hydroxytryptamine were markedly and significantly greater on the side previously exposed to K+, even though electrophysiological measurements indicated similarly severe ischaemia on both sides. Associated monoamine metabolite changes did not differ significantly between the two sides. There was no evidence of greater neuronal loss in the K(+)-stimulated striata 7 days after ischaemia. However, striatal tissue probably exposed to the highest concentrations of K+ could not be examined because of extensive gliosis around the probe.

Animals↗
PubMed1992

Atypical Moyamoya disease associated with brain tumor.

A 4-year-old boy with right retinal hemorrhage, mental retardation, and multiple minor anomalies was referred to our hospital. Computed tomography scanning revealed a cystic brain tumor at the vermis. Angiography showed stenosis of both internal carotid arteries at the supraclinoid portion and the Moyamoya vessels. The right ophthalmic artery was dilated as wide as the internal carotid artery. Stenosis of the basilar artery was also observed. Collateral circulation via the posterior inferior cerebellar artery and Moyamoya vessels in the area of the posterior cerebral artery was observed.

Abnormalities, Multiple↗
PubMed1992

[Analysis of intracranial pressure pulse wave in experimental hydrocephalus].

PURPOSE: Much has been written about the relationship between the pulse pressure (PP) of the intracranial pressure pulse wave (ICPPW) and ventricular dilatation. Some data suggest that high PP is the cause of ventricular dilatation, and other authors have reported that high amplitude of PP results from decreased intracranial compliance. In order to clarify these points, the amplitude of PP and Pressure-Volume Response (PVR: an indicator of intracranial compliance) were measured in bilateral ventricles using Howchwald's hydrocephalic model (right-left difference in ventricle size is clear, due to hemicraniectomy). METHODS: Hydrocephalus was developed by means of intracisternal injection of a Kaolin powder solution using dogs. The mean ICP, amplitude of the PP, PVR and ventricular size (studied by MR image) were evaluated under pathological conditions induced by the following procedures. Group A: control. Kolin induced hydrocephalus without craniectomy. Group B: Kaolin induced hydrocephalus with right side craniectomy. Group C: Kaolin induced hydrocephalus with right side craniectomy and dural resection. Group D: Kaolin induced hydrocephalus with right side craniectomy, dural resection and temporal muscle resection. RESULTS: Using MR imaging, the same degree of symmetrical ventricle dilatation were identified in all groups except Group D. Group D alone demonstrated the difference of ventricular size (craniectomy side > non craniectomy side). There was no appreciable difference in mean ICP between each group. However the amplitude of PP and the PVR decreased stepwise from Group A to Group D. The difference of the amplitude of the PP and PVR between the right and left ventricles in each group was not significant. Even in the larger ventricle side (right) of Group D, the amplitude of PP was same as that of the left ventricle, and much smaller than that of other groups. CONCLUSION: The results of our research suggest that: 1) There was no relation between the ventricular dilatation and the amplitude of PP. This means that the increased amplitude of PP was not the cause of the ventricular dilatation in this model. 2) These evidences suggest that a high degree of correlation exists between the amplitude of PP and the PVR. This means that PP can be a good parameter of the intracranial compliance in this model.

Animals↗
PubMed1991

Serum neuron-specific enolase levels after subarachnoid hemorrhage.

We examined serum levels of neuron-specific enolase by enzyme immunoassay in 29 patients with subarachnoid hemorrhage due to ruptured cerebral aneurysm. Serum neuron-specific enolase levels were significantly higher in patients with a poor neurological status than in patients with a good neurological status on admission, and the greater the amount of subarachnoid blood, the higher the serum neuron-specific enolase level. Patients with a good outcome had low serum neuron-specific enolase levels throughout their courses. Serum neuron-specific enolase levels increased with development of delayed ischemic neurological deficits and, especially in poor outcome patients, high levels persisted until 3 weeks after the subarachnoid hemorrhage.

Adult↗
PubMed1991

Brain metastasis of thyroid papillary carcinoma--case report.

A rare case of brain metastasis of thyroid papillary carcinoma is reported. The cerebral metastasis was surgically treated without irradiation despite the presence of a spinal metastasis. No recurrence was demonstrated by computed tomography 1 year postoperatively. We suggest that surgery is indicated for a brain metastasis of thyroid papillary carcinoma even if other metastatic lesions are present.

Adenocarcinoma, Papillary↗
PubMed1990

Changes in epidural pulse pressure in brain oedema following experimental focal ischaemia.

This study was carried out to clarify the changes of pulse pressure of the intracranial pressure pulse wave in ischaemic brain oedema. Intracranial pressure and PP were measured in two groups of anaesthetized dogs; 1) increased volume of cerebrospinal fluid by cisternal saline injection (control group), 2) brain oedema caused by focal ischaemia (oedema group). Ischaemia was induced by 2 hours of occlusion of the anterior, middle cerebral and internal carotid arteries. The canine focal ischaemic model showed consistent ischaemic damage in the caudate nucleus and produced brain oedema successfully. PP increased linearly with rising ICP to 35 mm Hg, and PP in the oedema group was significantly smaller than that in the control group at the same ICP value. The slopes of the regression equation of ICP and PP were significantly different between the oedema and control group (oedema: 0.057 +/- 0.029, control: 0.106 +/- 0.009), mean +/- SD, P less than 0.005). These results suggest that PP is easily affected by ischaemic brain oedema, which indicates increase of the brain tissue in the cranium. We conclude that PP is affected even at the same ICP value when intracranial components have altered.

Animals↗
PubMed1990

[Effect of NIK-242 inj. (20% erythritol) on intracranial pressure in dogs with acute obstructive hydrocephalus].

The effects of NIK-242 inj. (20% erythritol) on intracranial pressure (ICP) and serum osmotic pressure (Osm. P) were investigated in dogs with acute obstructive hydrocephalus, and they were compared with those of 20% mannitol or 10% glycerol in 5% fructose and 0.9% saline. Animals were divided into 5 groups (n = 6 in each group) and treated with either NIK-242 inj. (0.5 g/kg, 1.0 g/kg, 2.0 g/kg), mannitol (1.0 g/kg) or glycerol (0.5 g/kg). These drugs were administrated intravenously for 10 min. NIK-242 inj. rapidly reduced ICP and increased Osm. P. There was correlation between changes of ICP and Osm. P. The regression equation was Y = -6.489 X + 726.206 (n = 104, p less than 0.00001, R = -0.655). The effects were dose-dependent, but there were no significant differences between the effects of NIK-242 inj. 1.0 g/kg infusion and 2.0 g/kg infusion. The most appropriate dose of NIK-242 inj. was 1.0 g/kg, in which group ICP was significantly lower than the initial pressure until 120 minutes after administration (p less than 0.05). The maximum reduction rate of ICP [(initial ICP-minimum ICP)/initial ICP X 100] was 83.6 +/- 10.6% at 22.7 +/- 3.0 min. after administration. It was 61.6 +/- 6.9% at 19.3 +/- 1.6 min. in mannitol group and 77.1 +/- 7.4% at 15.0 +/- 0.8 min. in glycerol group. There was no rebound phenomenon on ICP during 150 min., but there was one in mannitol group and five in glycerol group. NIK-242 inj.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1990

[Changes in epidural pulse pressure in brain edema following experimental focal ischemia].

It is well known that epidural pulse pressure (PP) increases with rising intracranial pressure (ICP). However, PP at the same ICP is not always identical in various intracranial pathologies. Many authors have investigated PP at increased states of ICP, but few studies related to brain edema have been done. This study was carried out in order to clarify the changes of PP in brain edema following focal ischemia. ICP and PP were measured in two groups of anesthetized dogs; 1) increased volume of CSF by cisternal saline injection (control, n = 5), 2) brain edema caused by focal ischemia (edema, n = 11). Ischemia was induced by electro-coagulation of the right anterior cerebral artery and by clipping the right middle cerebral artery and right internal carotid artery transorbitaly. The brain was recirculated for 6 hours after 2 hours of ischemia. The ischemic areas were identified by Evans blue, triphenyl tetrazolium chloride (TTC) or histological examination. Water content of the brain was measured by the wet-dry weight method. The canine focal ischemic model showed consistent ischemic damage in the caudate nucleus and produced brain edema successfully. PP increased linearly with rising ICP to 35 mmHg, and PP in the edema group was significantly smaller than that in the control group at the same ICP value. The slopes of the regression equation of ICP and PP were significantly different between the edema and control group (edema: 0.061 +/- 0.030, control: 0.107 +/- 0.015, mean +/- SD, p less than 0.01). These results suggest that PP is easily affected by ischemic brain edema.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Magnetic resonance imaging of lumbosacral lipomas in infants].

Magnetic resonance imaging (MRI) was conducted on infants with lumbosacral lipomas. Based on Chapman's classification (1982), these MRIs were classified into three representative types: caudal, dorsal and transitional. As confirmed by intraoperative observations, the relation between the lipomas and the spinal cord was clearly disclosed in the preoperative MRI. However, in the dorsal type, the intraoperative view of the margin between the lipomas and spinal cord was different from the MRI findings. Postoperative MRI disclosed the existence of residual lipomas and the change in the low conus medullaris. Moreover, preoperative and postoperative changes in the hydromyelia could be observed.

Child↗