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Biomedical subjects

N Yasui

Publications and source records attributed to N Yasui.

At least 199 records · Page 11Linked to original sources
PubMed1991

[A case of Klippel-Feil syndrome with crossed renal ectopia with fusion and unilateral vertebral artery occlusion].

A case of Klippel-Feil syndrome with crossed renal ectopia with fusion and unilateral vertebral artery occlusion is reported. A 61-year-old female was admitted because of having developed myelopathy, gait and sensory disturbance. The physical examination on admission revealed spastic gait and hypesthesia of the lower extremities. A hand size, elastic hard tumor mass was palpable at the right lower abdomen. The cervical radiogram showed fused 5th, 6th and 7th cervical vertebrae and severe spondylotic changes. Laminectomy was performed because of severe compressions of the cervical cord, evaluated by Metrizamide CT scans and MRI. The left subclavian angiogram showed occlusion of the left vertebral artery, and excretory pyelogram and abdominal CT scans showed crossed renal ectopia with fusion. 99mTc-DTPA renoscintigram revealed poor RI uptake and low glomerular filtering rate of ectopic kidney. The patients with Klippel-Feil syndrome are at greater risk of having a renal anomaly and a vascular accident of the vertebral artery. Examinations of urogenitary organs and vertebral arteries are necessary for the treatment of this syndrome.

Abnormalities, Multiple↗
PubMed1991

Clinical value of PET with 18F-fluorodeoxyglucose and L-methyl-11C-methionine for diagnosis of recurrent brain tumor and radiation injury.

We studied 15 patients clinically suspected to have recurrent brain tumor or radiation injury, using positron emission tomography (PET) with 18F-fluorodeoxyglucose (18FDG) and L-methyl-11C-methionine (11C-Met). PET with 11C-Met (Met-PET) clearly delineated the extent of recurrent brain tumor as focal areas of increased accumulation of 11C-Met, and was useful for early detection of recurrent brain tumor. PET with 18FDG (FDG-PET) showed focal 18FDG-hypermetabolism in one patient with malignant transformation of low grade glioma, and demonstrated its usefulness for evaluation of malignant transformation. 18FDG-hypometabolism was observed in all patients with radiation injury, but was also found in one patient with recurrent malignant brain tumor. 11C-Met uptake in 3 patients with radiation injury was similar to that of the normal cortical tissue. FDG-PET can be used to initially exclude recurrent brain tumor which is seen as 18FDG-hypermetabolism. The combined use of Met-PET in addition to FDG-PET can improve the accuracy of differentiation of recurrent brain tumor with 18FDG-hypometabolism from radiation injury.

Adolescent↗
PubMed1990

The Goltz syndrome associated with giant cell tumour of bone. A case report.

The Goltz syndrome is a rare condition in which there are congenital anomalies in skin, teeth, eyes and bone. We report an unusual case of a 17 year old girl who had various anomalies associated with the syndrome. She sustained a pathological fracture of the left femur at the site of a giant cell tumour. Another lesion occurred in the right fibula, but resolved spontaneously.

Adolescent↗
PubMed1990

Clinical application of EEG topography in cerebral ischemia: detection of functional reversibility and hemodynamics.

To detect the functional reversibility and hemodynamic process in cerebral ischemia, the EEG topography cased on % time and amplitude was applied. % time and amplitude were obtained by the wave-form recognition method/EEGs were recorded under the resting state and during drug-induced conditions in 18 patients with steno-occlusion of main cerebral artery. The type of ischemic attack was TIA in 2 patients, RIND in 4, minor stroke in 7 and major stroke in 5. Six of 11 patients showed the improvement of EEG under induced hypertension. Four of those 6 patients were operated on ECIC bypass surgery, and all of them showed the improvement of clinical and EEG findings postoperatively. Twelve patients showed the deterioration of EEG under induced hypotension. Eight of them were operated on ECIC bypass surgery, and none of them suffered from reattack of cerebral ischemia postoperatively. Those preoperative EEG changes were observed mainly on the EEG topography of % time. And, the analysis of the EEG topography of % time under drug-induced conditions was available to study the pathophysiology of cerebral ischemia for selecting the suitable treatment.

Adult↗
PubMed1990

Clinical and long-term follow-up study in patients with spontaneous subarachnoid haemorrhage of unknown aetiology.

Clinical characteristics and the outcomes of 50 patients with confirmed subarachnoid haemorrhage (SAH) of unknown aetiology were evaluated. Twenty-nine of these patients were interviewed with a mean follow-up of 7.7 years. Seven patients experienced early rebleeding during hospitalization, and one patient experienced late rebleeding during the follow-up period. On admission to the hospital the consciousness level was "clear" in 43 of the patients, "drowsy" in 6, and "semicomatose" in only 1. Of 10 patients who underwent computerized tomography (CT) within 3 days after SAH, 6 showed no abnormal CT findings and 3 had mild subarachnoid blood. Another patient showed severe SAH. Neurological deficit due to symptomatic vasospasm persisted in only 1 case. Two patients died after re-bleeding during hospitalization, and two others died during the follow-up, thereby representing an overall mortality rate of 8%. Of the latter cases, one died of an unrelated disease, and the other died suddenly from an unknown cause. The remaining forty-six patients (92%) had a good outcome. These results confirm previously reported clinical characteristics, namely that the symptoms of the majority of such cases are mild, the incidence of symptomatic vasospasm is rare, the risk of late re-bleeding is very low (less than 1% per year), and the prognosis is good. The CT findings suggest that some of these features resulted from only mild SAH. Thus, SAH of unknown aetiology seems to be a disease entity with a good prognosis.

Adult↗
PubMed1990

Therapeutic effects of hyperbaric oxygenation on acute focal cerebral ischemia in rats.

The effects of hyperbaric oxygenation on acute focal cerebral ischemia in rats were investigated. All rats suffered 4-hour middle cerebral artery occlusion. Nontreated controls had a 27.9% +/- 5.5% infarct volume, and a left/right hemispheric volume ratio of 109% +/- 3%. Animals treated between 2.5 and 3.5 hours following occlusion had an 18.1% +/- 9.7% infarct volume (p less than 0.01), and a 105% +/- 3% left/right hemispheric volume ratio (p less than 0.001). In conclusion, at least until 4 hours following an ischemic insult, hyperbaric oxygenation reduces ischemic neuronal injury and brain edema following middle cerebral artery occlusion in rats treated between 2.5 and 3.5 hours following occlusion.

Animals↗
PubMed1990

A case of medullary venous malformations with an arterial component coexisting with arteriovenous malformations.

We present a rare case of medullary venous malformations with an arterial component coexisting with two small arteriovenous malformations in the same area. The onset was abrupt with subcortical hematoma due to the rupture of one arteriovenous malformation in the frontal area. Single photon emission computed tomography using 99mTc-hexamethylpropyleneamine oxime showed a high-uptake area around the hematoma suggesting increased blood flow. Two types of vascular malformation coexisting in the same area support a theory of congenital malformation originating in intrauterine life.

Brain↗
PubMed1990

Distal posterior inferior cerebellar aneurysms--report of 12 cases.

The authors review 12 cases of distal posterior inferior cerebellar artery (PICA) aneurysm. Nine of the aneurysms were discovered after their rupture and three were incidentally detected. Seven (78%) of the nine ruptured aneurysms rebled, leading in four cases to coma and respiratory arrest. Computed tomography revealed intraventricular hematomas, mainly in the fourth ventricle, and a subarachnoid clot at the cisterna magna. In five of the nine cases involving aneurysm rupture, radical surgery was performed. The remaining four, whose clinical status was poor, were treated conservatively and subsequently died. Two patients were rendered partially dependent as a result of perioperative complications. A high incidence of rebleeding is characteristic of ruptured distal PICA aneurysms, and for this reason the prognosis for these patients is rather poor.

Aged↗
PubMed1990

Contrast medium extravasation during cerebral angiography for ruptured intracranial aneurysm--clinical analysis of 26 cases.

Since 1976, the authors performed angiography on 837 patients with ruptured intracranial aneurysm, among which extravasation (EV) of contrast medium occurred in 26. Eleven patients underwent radical surgery within 3 hours after the EV, and four recovered well. The other 15 patients were conservatively treated, and all died. A large quantity of EV occurred when consciousness was severely disturbed and angiography was performed within 3 hours of the last attack. Most EV resulted in poor outcome. However, some patients with mildly disturbed consciousness before angiography, even with severe temporary disturbance of consciousness after the EV, recovered well after emergency radical surgery.

Adult↗
PubMed1990

Hyperdynamic therapy for cerebral vasospasm.

The effects of hyperdynamic therapy on patients with cerebral vasospasm following subarachnoid hemorrhage (SAH), under normal blood pressure (BP) and normal blood volume conditions, are reported. Forty-four patients, who underwent surgery for aneurysms in acute stage, received hydroxyethyl starch (500 ml/day) postoperatively to prevent dehydration. Twenty-four of the 44 patients with prominent SAH on the computed tomographic (CT) scan, anticipating to develop cerebral ischemia due to vasospasm, were given dobutamine (DOB). The BP was maintained within the normal range, and the heart rate was kept below 130/min. In the 24 patients treated with DOB, cerebral blood flow (CBF) was measured repeatedly by the 133Xe intravenous injection method. In 8 of these 24 patients, the cardiovascular function was monitored with Swan-Ganz (S-G) catheters. Twelve of the 44 patients (27%) developed delayed neurological deficits associated with cerebral vasospasm. The neurological deficits were reversed by the administration of DOB, at a dose of 8-25 (average 12.4) micrograms/kg/min. In 43 patients, the ischemic lesions associated with vasospasm did not appear on CT scan and the patients were of normal condition at discharge. However, one patient showed multiple low-density lesions on CT scan. This was because of the failure of hyperdynamic therapy due to pulmonary complications. No case of pulmonary edema or heart failure due to volume overload was noted. In the 24 patients with prominent SAH, CBF increased significantly by up to 20% following DOB administration, although the BP stayed in the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Early surgery in elderly patients with ruptured intracranial aneurysms--preoperative clinical evaluation and prognosis.

Numerous clinical classification systems have been developed for patients with ruptured intracranial aneurysms. However, most systems do not take age into account and are less reliable in elderly than in younger patients in terms of indications for early surgery and predicting the clinical outcome. The authors have studied this problem using our clinical classification system and, present here the results of 38 elderly patients (greater than or equal to 65 years of age) who underwent neck clipping and implementation of continuous ventricular drainage within 3 days of aneurysm rupture. The clinical outcome at 1 year after onset was considered "good" if the patient was able to function independently and "poor" if he or she was partially or fully dependent or had died. The preoperative level of consciousness was not significantly correlated with the outcome according to Spearman's nonparametric statistical analysis. Age, however, was a significant factor: the incidence of poor outcome was significantly higher in patients over age of 70 years than in those between 65 and 70 (p less than 0.05). Postoperative complications, which were previously found to be significantly related to the outcome in elderly patients, were significantly more common in patients who had a history of cardiac, pulmonary, hepatic, and/or renal disease than in those without such a history (p less than 0.005). The authors found that the prognostic accuracy of clinical classification systems, based on preoperative level of consciousness, is improved in geriatric cases if one point is added for patients over age of 70 years or those with a history of systemic diseases. Additional relevant factors included computed tomographic findings and pre-existing cerebral dysfunction.

Aged↗
PubMed1990

[Combination of serial transcranial Doppler examinations and cerebral blood flow studies in the management of cerebral vasospasm after subarachnoid hemorrhage].

In 13 patients who had ruptured intracranial aneurysms, serial transcranial Doppler (TCD) and cerebral blood flow (CBF) examinations were performed in order to evaluate the degree of cerebral vasospasm. All patients showed some extent of vasospasm on angiography, which was performed between Day 7 and 10. The flow velocities of either the middle cerebral arteries or the anterior cerebral arteries, measured by TCD, began to increase on post hemorrhage Day 5, and maximum flow velocities were recorded between Day 9 and 13, with normalization occurring within the following 2 weeks. In 5 cases of symptomatic vasospasm, a rapid increase of flow velocities preceded clinical manifestation of the vasospasm. Maximum flow velocities of the 5 cases were at a higher level in the range of 119-184cm/sec (mean 149cm/sec) that the cases where there were no symptoms. Consequently, serial TCD examinations were very useful for the early detection of vasospasm after subarachnoid hemorrhage. And it was confirmed that the change of flow velocities was more important than the value itself, and that the rapid increase of flow velocities indicated severe ischemia. However, for judging when vessel narrowing was resolving, the usefulness of the TCD examinations were doubtful. This is because flow velocities measured by TCD are thought to be fairly much influenced by multiple factors such as the change of blood pressure, blood volume, which were caused by the active treatment for the vasospasm. Serial measurements of CBF were also made 2-7 times (mean 3.1 times) during the first two weeks following subarachnoid hemorrhage using the 133Xe intravenous injection method.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Regional effects of craniotomy on cerebral circulation and metabolism: PET study on the un-ruptured aneurysmal surgery].

Regional effects of craniotomy on cerebral circulation and metabolism, such as regional cerebral blood flow (rCBF), regional cerebral oxygen consumption (rCMRO2), regional oxygen extraction fraction (rOEF), and regional cerebral blood volume (rCBV) were examined by a PET (positron emission tomography) study concerning surgery that was performed on unruptured aneurysm patients. Eight patients with intracranial un-ruptured aneurysms were studied pre- and post-operatively by the 15O labelled-gas steady-state method, using HEADTOME-III. All patients underwent aneurysmal surgery performed by the transsylvian approach. There was a significant increase in the mean OEF values taken from the whole-brains of 8 patients, but there was not a significant change in CBF, CMRO2 or CBV. The increase in OEF was caused by decrease of O2 content, which was caused by post-operative decrease in the Hb value. So, this OEF increase was not the direct effect of craniotomy. In 2 patients, the rCBF and rCMRO2, in the fronto-temporal region (where craniotomy was performed) increased post-operatively. This regional effect suggests transient reactive hyperemia following compressive ischemia during the operative procedure, and metabolic demands for recovery of brain function. In 2 other patients, who had relatively low rCBFs during the pre-operative study, rCBF and rCMRO2 in the bi-frontal region had decreased more at the post-operative study. This change appears to have been caused by removal of cerebrospinal fluid and depression of the frontal lobe. From this study, it becomes evident that the regional effect of craniotomy on cerebral circulation and metabolism is not so great, when adequate microsurgical techniques are used.

Adult↗
PubMed1990

[Intraventricular hematomas associated with hypertensive intracerebral hemorrhages: with special reference to third ventricular hematoma].

Intraventricular hematoma (IVH) is often associated with many kinds of intracranial hemorrhage; for example, hypertensive intracerebral hemorrhage, subarachnoid hemorrhage, and so on. In this paper we discuss the clinical significance of IVH in the third ventricle, as well as the effects of surgical treatment. Forty-five patients were treated in our hospital because of massive IVH associated with small or mode-rate-size (hematoma volume less than or equal to 15 ml) thalamic or caudate-head hemorrhage between April, 1983 and April, 1988. All cases had an intraventricular cast in at least one ventricle. The patients were divided into two subgroups (depending on the site of the dominant IVH): the third-fourth ventricle dominant type-IVH group, and the lateral ventricle dominant type-IVH group. The former was further divided into two subgroups based on the thickness of the IVH in the third ventricle (its thickness being greater than or equal to 1 cm and less than 1 cm), and the area of IVH in the fourth ventricle (its area being greater than or equal to 1 cm2 and less than 1 cm2) as determined by CT scan monitoring. All cases were also divided according to continuous ventricular drainage (CVD), position of the catheter tip (in either the third ventricle or the lateral ventricle), and the intraventricular administration of urokinase (UK). For each group we checked the consciousness grade using the Glasgow Coma Scale (GCS) on day 0 and on day 7, as well as the interval between day 0 and the day on which the IVH in the third ventricle disappeared on the CT scan.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral Hemorrhage↗
PubMed1990

[Value of 11C-methionine and PET in the diagnosis of low grade gliomas].

Ten patients with low grade glioma were examined with positron emission tomography (PET) using 11C-methyl-L-methionine (11C-Met). In 4 cases, follow-up study was performed after radiation therapy. 11C-Met uptake index was calculated by sequential arterial blood sampling and PET image on 45 minutes after injection. The tumor was clearly seen in the images, and uptake index in the tumor lesion was higher than that in the normal cortex. The uptake of 11C-Met was observed in a recurrent lesion that was confirmed by operation. 11C-Met uptake indices were decreased in the tumor lesions after radiation therapy. From these results PET with 11C-Met is a useful clinical tool for diagnosis of low grade gliomas.

Adolescent↗
PubMed1989

Repair of rabbit articular surfaces with allograft chondrocytes embedded in collagen gel.

In an attempt to repair articular cartilage, allograft articular chondrocytes embedded in collagen gel, were transplanted into full-thickness defects in rabbit articular cartilage. Twenty-four weeks after the transplantation, the defects were filled with hyaline cartilage, specifically synthesising Type II collagen. These chondrocytes were autoradiographically proven to have originated from the transplanted grafts. Assessed histologically the success rate was about 80%, a marked improvement over the results reported in previous studies on chondrocyte transplantation without collagen gel. By contrast, the defects without chondrocyte transplantation healed with fibrocartilage. Immunological enhancement induced by transplanted allogenic chondrocytes or collagen was not significant at eight weeks after treatment, so far as shown by both direct and indirect blastformation reactions. Thus, allogenic transplantation of isolated chondrocytes embedded in collagen gel appears to be one of the most promising methods for the restoration of articular cartilage.

Animals↗
PubMed1989

[Clinical analysis of 24 cases of caudate hemorrhage].

Twenty-four patients with caudate hemorrhage, in whom such definite organic lesions as arteriovenous malformations or ruptured cerebral aneurysms could not be proved, were analyzed. These cases comprise 2.0% of 1202 cases of hypertensive intracerebral hemorrhage diagnosed by computed tomography and experienced from 1976 through 1987. Thirteen patients were male and 11 were female. Their average age was 61 years. Headache (67%) and nausea and vomiting (50%), which were often the initial symptoms, were similar to those of subarachnoid hemorrhage. The main clinical symptoms were signs of meningeal irritation. Ten patients (42%) had transient disturbance of consciousness, and nine (38%) of these were somnolent; only one patient, who had a massive hematoma, was stuporous. When the hematoma extended to the internal capsule, the patient showed motor disturbance (38%). Two patients (8%) had Horner's sign, five (21%) exhibited diminished activity, and one (4%) suffered anosognosia. The volume of the intracerebral hematoma averaged 4.7 ml and was less than 5 ml in 17 patients (71%). In 20 patients (83%), the hematoma was confined to the head of the caudate nucleus. The hemorrhage tended to rupture into the anterior horn of the lateral ventricle, and in nearly all cases (96%), intraventricular hematoma was observed. Seventeen patients (71%) underwent cerebral angiography. There were no instances of dilation of the recurrent artery of Heubner. Twenty patients (83%) were treated conservatively. Continuous ventricular drainage was employed in four patients (17%), and ventriculoperitoneal shunting in three (13%). However, it was judged retrospectively that continuous ventricular drainage had been necessary in only two cases in which disturbance of consciousness was progressed due to acute hydrocephalus.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗