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Biomedical subjects

S Abiko

Publications and source records attributed to S Abiko.

At least 19 recordsLinked to original sources
PubMed1992

Direct surgery for giant aneurysm exhibiting progressive enlargement after intraaneurysmal balloon embolization.

A case of giant intracranial carotid artery aneurysm exhibiting progressive enlargement after incomplete intraaneurysmal balloon embolization is presented. The patient was successfully treated by the trapping and decompression of the aneurysm with a superficial temporal artery-middle cerebral artery anastomosis. The thrombus surrounding the intraluminal balloons was very soft and poorly organized. Either direct surgery with extracranial-intracranial arterial bypass or complete intravascular surgery should be performed for giant aneurysms when direct clipping is impossible.

Aged↗
PubMed1991

The effect of EC-IC bypass surgery on resting cerebral blood flow and cerebrovascular reserve capacity studied with stable XE-CT and acetazolamide test.

Cerebral blood flow (CBF) and cerebrovascular reserve capacity (CRC) were measured by stable xenon computerized tomography (Xe-CT) and acetazolamide test in 15 patients with cerebrovascular disease before and after extracranial-intracranial (EC-IC) bypass surgery for minor stroke, reversible ischemic neurological deficit or transient ischemic attack. All had angiographically shown occlusive lesions of the major arterial trunk. In the present series, global analysis showed that the bypass did not increase the resting rCBF, but did increase the rCRC. We divided the patients into four groups according to the preoperative resting rCBF and rCRC. All 3 patients with normal resting rCBF and reduced rCRC showed postoperative improvement of rCRC. Of 6 patients with reduced CBF and reduced CRC, three had postoperative increase in resting CBF and four had increased CRC. One of two patients with reduced CBF and normal CRC showed only an increase in CRC. We propose that reduced CRC or reduced CBF with reduced CRC are criteria for selection of candidates for bypass surgery. We conclude that Xe-CT with the Diamox test is a useful and simple method for evaluating cerebral hemodynamics. Preoperative grouping with a combination of preoperative resting rCBF and preoperative rCRC is useful for predicting the effect of EC-IC bypass surgery.

Acetazolamide↗
PubMed1991

True posterior communicating artery aneurysm.

Two rare cases of true posterior communicating artery aneurysm are reported. One case was a saccular aneurysm, which was successfully clipped. The other was a case of fusiform trapped aneurysm, and hemiparesis and oculomotor palsy appeared transiently after surgery. In general, this type of aneurysm is included in the category of internal carotid-posterior communicating aneurysm, although some special considerations are necessary in surgical treatment.

Cerebral Angiography↗
PubMed1991

Changes in brain stem blood flow under various grades of brain stem ischemia.

This report describes a study of brain stem blood flow (BBF) change under various grades of brain stem ischemia in a new experimental rat model. The main damage was caused by occlusion of the median and paramedian perforating arteries of the basilar artery. In this model, hyperperfusion was generally observed in cases of mild or moderate ischemia within 1 hr after recirculation and lasted for approximately 1 hr. During hyperperfusion, BBF increased to over 60 ml/100 g brain/min and was significantly greater than basal values (p less than 0.01). The fact that hyperperfusion was unobserved in some cases might be due to the degree of damage to the medulla oblongata. Hypoperfusion or lack of reflow phenomena was also followed by severe ischemia with remarkable hypotension. It is fairly clear from our results that the pattern of postischemic hyperperfusion is responsible for decreased oxygen availability in the brain stem and dysfunction of autoregulation. Acetazolamide reactivity was disturbed and had an inverse response during hyperperfusion. Such phenomena can be explained by paralytically dilated vessels due to ischemia. If BBF falls below a critical level, as we have seen, postischemic hyperperfusion may be induced with dysfunction of autoregulation and inverse acetazolamide reactivity due to vasoparalysis in the brain stem.

Acetazolamide↗
PubMed1991

[A study of ionized calcium in the whole blood of patients with subarachnoid hemorrhage].

In 14 normal volunteers and 22 consecutive patients with subarachnoid hemorrhage (SAH) due to a ruptured cerebral aneurysm, ionized calcium (Ca2+) concentrations in whole blood were measured using an automatic calcium analyzer. The values were corrected against pH 7.4. The relationships between the Ca2+ concentration and the following aspects were studied: neurological grading by Hunt and Kosnik, grade of SAH on computed tomography scan by Fisher's definition, and the presence of vasospasm. Clinical vasospasm was recognized in eight cases. The averaged Ca2+ value of the control group was 1.23 +/- 0.02 mmol/l. In patients with a poor neurological grade or severe SAH, the Ca2+ level was apt to be lower than that of the control group. In patients with vasospasm, the values of Ca2+ were significantly decreased, especially between 8 and 14 days after SAH, compared with those patients without vasospasm and the control group (p less than 0.05). These results indicate that measurement of Ca2+ concentration in whole blood may give a useful clue to treatment of vasospasm by calcium antagonist and that it may also provide a possible indicator as to the time of vasospasm in patients with severe SAH. However, it is very difficult to conclude whether decreased level of Ca2+ in patients with vasospasm is caused by the vasospasm itself.

Adult↗
PubMed1991

[An examination of change in blood flow in the brainstem of rats under various grades of ischemia].

UNLABELLED: A study was made of changes in brainstem blood flow (BBF) under various grades of ischemia in a rat recirculation model. MATERIALS AND METHODS: Adult male Wistar rats were anesthetized with pentobarbital sodium (40mg/kg i.p.). After exposure of the cervical vertebra (C2 portion), embolic threads of various sizes prepared were inserted into the vertebral artery. By the hydrogen clearance technique, changes in BBF were measured in 30 rats before, during and after brainstem ischemia. RESULTS AND DISCUSSION: The mean arterial blood pressure (MABP) was 113 +/- 5.8mmHg, and the mean BBF was 35.5 +/- 2.4ml/100g/min before ischemia. The alteration of BBF during and after ischemia was classified into three groups. The mildly ischemic group showed no significant changes in MABP; BBF was above 15ml/100g/min during ischemia, with slight reactivity revealed by acetazolamide after recirculation. In the moderately ischemic group, MABP dropped significantly to 62.0 +/- 12.4mmHg. After recirculation, it increased gradually to almost the control level. BBF decreased to below 15ml/100g/min immediately after ischemia, followed by a gradual increase to hyperperfusion after recirculation. After 1hr of recirculation, BBF increased to more than 60ml/100g/min with inverse acetazolamide reactivity. In the severely ischemic group, both BBF and MABP decreased irreversibly even after recirculation. These data indicate that the changes in MABP and BBF could be classified according to the degree of ischemic damage in the brainstem, where the vasomotor center is located. Acetazolamide reactivity was disturbed during hyperperfusion. Such phenomena could be explained by the presence of paralytically dilated vessels. If BBF falls below the critical level, as we showed here, it may induce postischemic hyperperfusion associated with dysfunction of autoregulation and vasoparalysis in the brainstem.

Animals↗
PubMed1990

Subependymal giant cell astrocytoma associated with tuberous sclerosis: with special reference to cell kinetic studies--case report.

The authors report a case of subependymal giant cell astrocytoma associated with tuberous sclerosis in a 15-year-old boy. Computed tomographic scans showed a large intraventricular mass with peritumoral calcification and a cyst in the left lateral ventricle. Left dominant unilateral hydrocephalus was also revealed. Magnetic resonance images clearly demonstrated the lesion. The tumor was subtotally removed and a ventriculoperitoneal shunt was performed because of the hydrocephalus. The proliferation potential was assessed by measuring the bromodeoxyuridine (BUdR) labeling index employing the in vitro labeling method, and determining the deoxyribonucleic acid (DNA) content by flowcytometry. BUdR-positive cells were found to be rare, and the DNA histogram demonstrated no evidence of high proliferative activity or aneuploidy.

Adolescent↗
PubMed1990

[Ischemic cerebrovascular complication in tuberculous meningitis; a case of Fröhlich syndrome and hemiparesis].

A 34-year-old man came to our hospital with an episode of focal convulsion of the left arm. He had suffered from tuberculous meningitis in childhood and developed left hemiparesis and Fröhlich syndrome as sequelae. CT scan showed a calcified mass in the suprasellar cistern and a low density area suggestive of cerebral infarction in the right anterior cerebral artery distribution. The left carotid angiograms showed severe stenosis of the left internal carotid artery in the supra-clinoid segment and occlusion of the proximal middle and anterior cerebral arteries with development of moyamoya vessels as collateral circulation. The right carotid angiograms showed similar findings with less collateral circulation. At surgery, the anterior part of the Willis ring was found embedded in the suprasellar calcified granuloma. Recognition of cerebrovascular complication in tuberculous meningitis is important and an early modification of the therapy may improve the outcome.

Adult↗
PubMed1990

[Anastomosis of the superficial temporal artery to the middle cerebral artery for occlusive disease of the bilateral internal carotid arteries with dementia].

Two cases are reported of occlusive disease of the bilateral internal carotid arteries with dementia in which the anastomosis of the superficial temporal artery to the middle cerebral artery (STA-MCA bypass) resulted in marked improvement in clinical aspects. One patient was a 29-year-old male who complained of transient weakness of the extremities and memory impairment. Computerized tomography (CT) scans showed multiple small infarctions, while cerebral angiography demonstrated findings of Moya-like disease. The cognitive function tests were subnormal and the study of cerebral blood flow (CBF study) showed diffuse low flow in both hemispheres. Based on his clinical symptoms and CBF study, the STA-MCA bypass was performed on both sides in two stages without complications. Postoperatively, his clinical symptoms and cognitive function improved gradually, in accordance with increased CBF in both hemispheres. Six months after the operation, cognitive function tests were within normal limits. Another patient was a 61-year-old hypertensive male who complained of motor weakness, impairment of memory and urinary incontinence. CT scans showed multiple small infarctions, while cerebral angiography revealed occlusion of both internal carotid arteries at the cervical portion. The cognitive function was at the pre-dementia level, and CBF study revealed diffuse low flow in both hemispheres. Based on the clinical symptoms and CBF study, the STA-MCA bypass was performed on both sides in two stages. Postoperatively, clinical symptoms and cognitive function markedly improved. From our results, the diagnosis of vascular dementia, and indications for the use of STA-MCA bypass in this category of patients are discussed.

Adult↗
PubMed1989

Improved separation of alpha chains of collagen type I, type III, and type V by noninterrupted electrophoresis using thioglycolic acid as a negatively charged reducer.

Improved separation of alpha chains of collagen type I (alpha 1 [I]2 alpha 2[I]), type III(alpha 1[III]3), and type V (alpha 1[V]alpha 3[V])was achieved by noninterrupted sodium dodecyl sulfate-polyacrylamide gel electrophoresis with a negatively charged reducer, thioglycolic acid. The thioglycolic acid, added to the running buffer of the cathodic reservoir, in the middle of electrophoresis quickly migrated in the gel anode, reducing interchain disulfide linkages in collagen type III and dissociating it into its alpha chain monomer, alpha 1[III], without an interruption of electrophoresis. The alpha chain, alpha 1[III], migrated more slowly than the alpha 1 [I] and alpha 2[I] chains of collagen type I, resulting in an excellent separation of alpha 1[III] from alpha 1[I]. The mobility of alpha 1[III] could be controlled by varying the time of thioglycolic acid addition to the running buffer. This enabled us not only to separate alpha 1[III] from alpha 1[I] and alpha 1[V], but also to precisely quantitate these alpha chains, even at low protein loading of mixed samples.

Collagen↗
PubMed1989

Infrasellar craniopharyngioma.

A rare case of infrasellar craniopharyngioma mainly occupying the paranasal sinuses, the infratemporal fossa and the skull base is presented. The patient had been treated by an otolaryngologist as a case of mucocele of the sphenoid and ethmoid sinuses because the biopsy specimens obtained at endonasal surgery failed to confirm the true diagnosis. Computed tomography (CT) showed multi-lobulated low density cysts in the paranasal sinuses, infratemporal fossa and skull base, and the cyst wall was enhanced. Magnetic resonance Imaging (MRI) revealed the cysts to have high intensity in both T1- and T2-weighted images, and excellent three-dimensional visualization was obtained. Characteristic motor-oil-like fluid was aspirated during transnasal surgery and the diagnosis of craniopharyngioma was confirmed by histological examination.

Child↗
PubMed1989

[Coagulation and fibrinolysis in chronic subdural hematoma. Measurement of fibrinopeptides].

The pathogenesis of chronic subdural hematoma is not fully understood. It is thought that fibrinolytic hyperactivity within the hematoma capsule plays an important role. However, since this hyperactivity has not been found in the systemic blood, accelerated fibrinolysis is thought to occur only locally. To evaluate coagulant and fibrinolytic activities in the peripheral blood, the authors measured fibrinopeptide A (FPA) and fibrinopeptide B beta 15-42 (FPB beta), which are relatively sensitive hematologic factors, in 14 patients with chronic subdural hematoma. Peripheral venous blood was collected within 24 hours before surgery and FPA and FPB beta levels were determined. In the eight cases followed for more than 1 month after surgery, pre- and postoperative FPA and FPB beta values were compared. The possible relationship between preoperative FPB beta and hematoma density as well as elevated intracranial pressure (judged by preoperative computed tomography) was also examined. The following results were obtained: 1) Preoperative FPA and FPB beta values were both statistically significantly elevated suggesting systemic acceleration of coagulant and fibrinolytic activities. FPB beta levels exceeded those of FPA in almost all cases, indicating that fibrinolysis was more dramatically enhanced. 2) Many patients with high FPB beta values had high-density areas on computed tomography scans. 3) Patients with choked disc had high FPB beta values, suggesting a correlation between chronic intracranial hypertension and FPB beta. 4) Postoperatively, there was a marked decrease in FPA values, whereas FPB beta values remained above normal, which may reflect persistence of accelerated systemic fibrinolytic activity in patients with chronic subdural hematoma.

Adult↗
PubMed1989

Interposition of a saphenous vein graft for early recurrent carotid stenosis--report of two cases.

The main cause of recurrent stenosis within 24 months of carotid endarterectomy is myointimal hyperplasia. In these cases, reoperation is technically difficult because there is no true plane of dissection between the recurrent plaque and the remaining vessel wall. The authors present two cases of early recurrent stenosis after carotid endarterectomy, both of which were successfully treated by an interposed saphenous vein graft. In the first case, angiography suggested that the recurrent stenosis was due to atherosclerosis. In the second case, however, myointimal hyperplasia was suspected to be the cause, and this was confirmed by histological examination of the surgical specimen. The authors' experience indicates that anastomosis with an interposed saphenous vein graft is a reliably effective treatment for early recurrent carotid stenosis.

Arterial Occlusive Diseases↗
PubMed1988

Bilateral intracranial fibrous xanthoma.

We present a case of fibrous xanthoma in a 6-year-old boy who showed disturbance of consciousness and signs of increased intracranial pressure. A computed tomographic (CT) scan showed bitemporal enhanced masses and hydrocephalus. The patient was operated on in two stages. The tumors were located intradurally and extracerebrally and were firmly attached to the dura mater at the base of the middle fossa. Glial fibrillary acidic protein stain was negative, and histologic examination suggested a diagnosis of bilateral fibrous xanthoma. Postoperative CT scan showed residual tumors and an enlarged choroid plexus adjacent to it. A CT scan at 12 years of age showed no enhanced tumor, but disclosed bitemporal high-density areas and diffuse brain atrophy; the choroid plexus reverted to normal size. The patient showed mental and physical retardation, perhaps owing to the compression of the hypothalamus during early childhood. This would appear to be the first known case of bilateral intracranial fibrous xanthoma.

Brain Neoplasms↗
PubMed1988

[A case of hemorrhage into a brain abscess].

A rare case of hemorrhage into a brain abscess in a 23-year-old man is reported. The patient complained of headache and low-grade fever on February 26, 1986. Two days later, he developed right hemiparesis and right hemisensory disturbance with mild consciousness disturbance and was admitted to a local hospital. Seven days after the onset, he suddenly became semicomatose, developed anisocoria and was consequently transferred to the University Hospital. On admission, his temperature was 37.5 degrees C and neurological examination revealed semicoma, anisocoria and right hemiparesis without nuchal rigidity. Enhanced CT scan showed a high density area within an irregular ring enhancement at the left basal ganglia. At that time, malignant glioma was diagnosed and an emergency operation was performed by left frontotemporal craniectomy. During the operation blood clot was found in the posterior part of the basal ganglia. After operation, a histological examination was made and a brain abscess was diagnosed. Gram staining revealed gram-positive bacillus. By aspiration of the abscess and chemotherapy, recovery was gradually made. He was discharged with motor dysphasia and mild right hemiparesis three months later. Differentiation between abscess and malignant glioma and the cause of the hemorrhage are discussed.

Adult↗
PubMed1988

[Intracranial neurinomas of the jugular foramen and hypoglossal canal].

Intracranial neurinomas of the jugular foramen and the hypoglossal canal are relatively rare. Most reports have been of either single cases or of only two or three patients, and few large series exist in the literature. Although some of these tumors present palsies of the ninth, tenth, and eleventh cranial nerves as a jugular foramen syndrome, this is not always present. Unexpectedly, symptoms involving the eighth nerve are more frequently than those of ninth, tenth and eleventh nerves. This variability of clinical symptoms frequently leads to an initial misdiagnosis of glomus jugulare, acoustic or hypoglossal neurinoma. We report 2 cases of jugular foramen neurinomas and 2 cases of hypoglossal neurinomas. Our review of literature has tabulated 92 jugular foramen neurinomas and 34 hypoglossal neurinomas. These neurinomas had become considerably large in size by the time they were detected. So, we should endeavor, by clinical or neuroradiological finding to detect them at the early stage when they exert less influence on the brain. In this series we discuss clinical pictures of these neurinomas.

Accessory Nerve↗
PubMed1988

Intrasphenoidal encephalocele: report of a case.

The diagnosis of intrasphenoidal encephalocele may be difficult because of its rarity and its nonspecific signs and symptoms. The authors report a patient with intrasphenoidal encephalocele who was operated on by the transsphenoidal approach with a good result. They also review five reported cases, with discussion of their clinical characteristics and operative indications.

Encephalocele↗