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Y Kanemoto

Publications and source records attributed to Y Kanemoto.

At least 19 recordsLinked to original sources
PubMed2001

[The effect of C 1 esterase inhibitor on ischemia: reperfusion injury in the rat brain].

BACKGROUND: Despite the current interest in thrombolytic therapy for acute stroke, ischemia-reperfusion injury remains a potentially hazardous complication. The complement system is thought to play a major role in initiating some of the inflammatory events occurring in the reperfusion injury. This study was conducted to explore the effect of C 1 esterase inhibitor (C 1 INH) on the reperfusion injury in rat middle cerebral artery (MCA) occlusion-reperfusion model. METHODS: Twenty-nine male Wistar rats were used. Intraluminal MCA occlusion was performed for 60 minutes. Just before the reperfusion, C 1 INH(50 IU/kg, C 1 INH group, n = 15) or saline (control group, n = 14) was administrated. Forty-eight hours after the reperfusion, infarct volume and myeloperoxidase(MPO) activity of the brain were evaluated. RESULT: Infarct volume and MPO activity were significantly smaller in the C 1 INH group(86.5 +/- 76.8 mm3, 0.38 +/- 0.30 U/g) than in control group(179 +/- 92.8 mm3, 1.37 +/- 0.46 U/g) (p < 0.01). CONCLUSION: The results of this study provided the first evidence that C 1 INH reduced polymorphonuclear leukocytes(PMN) accumulation and reperfusion damage in the brain.

Animals↗
PubMed2001

Nanomolar concentrations of tri-n-butyltin facilitate gamma-aminobutyric acidergic synaptic transmission in rat hypothalamic neurons.

Tri-n-butyltin (TBT), an environmental pollutant, is accumulated in edible mollusks and fishes. It has also become a health concern in today's society. In the present study, to elucidate the possible neurotoxic action of TBT, the effect on spontaneous gamma-aminobutyric acid (GABA) release from GABAergic nerve terminals projecting to rat ventromedial hypothalamic neurons was examined using "synaptic bouton" preparation with a nystatin perforated patch recording mode under voltage-clamp conditions. The threshold concentration of TBT to affect the synaptic transmission was 10 to 30 nM. TBT at 30 nM or higher concentrations increased the frequency of GABAergic miniature inhibitory postsynaptic currents in a dose-dependent manner, whereas the current amplitude and current kinetics were not affected. The removal of either external Ca2+ or application of Cd2+ attenuated the TBT-induced facilitation of neurotransmission. TBT at 1 microM induced an inward current in more than one-half of the cells. This current persisted even after TBT was washed out. The present results indicate that TBT at environmentally relevant concentrations (30-100 nM) facilitates the GABAergic neurotransmission in the mammalian brain and the external Ca2+ is needed in this facilitation. Because the concentration of TBT accumulated in some mollusks and fishes has been reported to reach levels of 100 nM or more, such accumulation of TBT in some mollusks and fishes is thus suggested to be hazardous to the health of humans.

Animals↗
PubMed2000

Giant aneurysm of the azygos anterior cerebral artery--case report.

A 77-year-old female presented with a giant aneurysm of the azygos anterior cerebral artery (ACA) manifesting as acute onset of akinetic mutism caused by enlargement of the aneurysm resulting from rapid thrombus formation within the aneurysmal sac. Thrombus removal to obtain decompression of the aneurysmal bulk and tension was performed before parent artery occlusion to prevent thromboembolic events. The aneurysmal neck was completely clipped with preservation of the parent artery and all branches. This strategy for direct neck clipping of a giant thrombosed distal ACA aneurysm can reduce the possibility of ischemic sequelae.

Aged↗
PubMed2000

Direct clipping of a large basilar trunk aneurysm via the posterior petrosal (extended retrolabyrinthine presigmoid) approach--case report.

A 53-year-old female presented with an unruptured, large basilar trunk aneurysm manifesting only as headache with no neurological deficits, including absence of cranial nerve dysfunction. Cerebral angiography disclosed a large aneurysm with a wide neck arising from the midbasilar artery. We treated the aneurysm surgically via the posterior petrosal approach. Five angled clips were applied sequentially to the aneurysm and the basilar artery was successfully reconstructed. Electrophysiological monitoring was continued during the operation and showed no changes. Following the operation, the patient suffered from transient right abducens nerve palsy, which persisted for 3 months. Postoperative angiography showed that the aneurysm was obliterated, and the patency of the basilar artery was preserved.

Basilar Artery↗
PubMed2000

[A case of high flow CCF with congestive hemorrhage].

The authors report a case of high flow CCF with intracerebral hemorrhage during treatment with endovascular coil embolization. A 52-year-old woman had been in good health until a sudden onset of orbital bruit and left orbital tinnitus occurred. Conjunctival chemosis and diplopia caused by left abducens palsy gradually progressed. Left internal carotid arteriography revealed a carotid-cavernous sinus fistula with direct high-flow shunt. The fistula drained into the superior orbital vein, inferior petrosal sinus, intercavernous sinus and sphenoparietal sinus with significant cortical reflux. The attempt at transarterial balloon occlusion failed. Then transvenous coil embolization was performed. During the course of endovascular treatment, follow up CT depicted intracerebral hemorrhage. Intracerebral hemorrhage was asymptomatic and thought to be caused by venous hypertension from cortical reflux. The patient underwent direct occlusion of the left sphenoparietal sinus for prevention of further hemorrhage via craniotomy. Lastly, the cavernous sinus was completely occluded by transvenous coil embolization. The signs and symptoms resolved 3 months after the procedures.

Carotid-Cavernous Sinus Fistula↗
PubMed1999

Ventral T-1 neurinoma removed via hemilaminectomy without costotransversectomy--case report.

A 39-year-old male presented with a spinal neurinoma originating from the T-1 anterior root and located ventral to the spinal cord. The tumor was removed by hemilaminectomy with only partial facetectomy without costotransversectomy. No stabilization was necessary, and no complications secondary to surgery occurred. Costotransversectomy is not necessary for neurinoma ventral to the spinal cord within the spinal canal at T-1 level because the transverse process protrudes more laterally and the spinal canal of the T-1 vertebra is wider than at other thoracic levels.

Adult↗
PubMed1999

[Brain surface clear cell ependymoma: case report].

We report a case of brain surface clear cell ependymoma. A 13-year-old boy presented with complaints of right hypesthesia. Computed tomography and magnetic resonance image showed a left fronto-parietal cystic, calcified mass lesion. He underwent total resection of the tumor including cyst wall. The tumor located on the surface of the parietal lobe was sharply demarcated from the surrounding brain tissue and there was no continuity with the ventricular wall. Histological examination of the surgical specimens showed oligodendroglioma-like cells that had round unclei, clear cytoplasm which formed perivascular pseudorosettes, and immunoreactivity for glial fibrillary acidic protein (GFAP). Electromicroscopically, microvilli were seen. The findings were compatible with clear cell ependymoma. The cyst wall was lined with a layer of single cuboidal cells and, immunohistochemically, had no basal membrane. The inner surface of the cyst was positive for EMA, and the cuboidal cells were positive for GFAP. We discuss possible mechanisms for tumor growth in our case and the histogenesis of its cyst.

Adolescent↗
PubMed1999

[Angiographically occult high cervical dural arteriovenous malformation secondary to intracranial hypertension: a case report].

We have recently encountered a case of high cervical arteriovenous malformation which caused subarachnoid hemorrhage. A 54-year-old male was admitted to our hospital due to sudden onset of severe headache. Neurological examination revealed right sixth nerve palsy which suggested elevated intracranial pressure. A CT scan showed subarachnoid hemorrhage predominantly in the posterior fossa, massively ventral to the brain stem, with reflux into the fourth ventricle. No abnormal vascular lesions were found in the first cerebral angiography which included four vessels and bilateral thyrocervical trunks. Ten days later, the second cerebral angiography demonstrated an arteriovenous shunt via the right vertebral artery draining into the epidural space of the upper cervical region. A suboccipital craniotomy and laminectomy of the atlas were performed. An abnormally dilated vein along the right C1 nerve ventral root which drained into the tortuous dilated coronary venous plexus on the ventral side of the spinal cord was found. We made a diagnosis of dural arteriovenous malformation fed by the C1/C2 radicular artery via the right vertebral artery and draining into the radiculomedullary vein and the epidural venous plexus. The interruption of both intra- and extradural draining veins was carried out. The postoperative course was uneventful.

Arteriovenous Malformations↗
PubMed1998

Primarily extracranial jugular foramen neurinoma manifesting with marked hemiatrophy of the tongue: case report.

BACKGROUND: There have been no detailed descriptions of the clinical symptoms of a primarily extracranial jugular foramen neurinoma (JFN), because this type of tumor is extremely rare. CASE DESCRIPTION: Although the 51-year-old woman presented with only mild complaints of dysphagia and hoarseness, neurologic examination revealed marked left hemiatrophy of the tongue. Although magnetic resonance imaging suggested a JFN, the patient's mild symptoms and normal jugular foramen were potentially misleading in the diagnosis of this patient. Surgical exploration demonstrated that the tumor originated from the extracranial portion of the 10th cranial nerve, extending into the jugular foramen. Subtotal resection ameliorated the 12th cranial nerve palsy. CONCLUSION: The authors present a case of a primarily extracranial JFN manifesting as a 12th nerve palsy. The clinical symptoms and signs produced by a tumor in this extremely rare location are discussed.

Atrophy↗
PubMed1998

The effects of nonsteroidal anti-inflammatory drugs on immune functions of human peripheral blood mononuclear cells.

It is generally accepted that the nonsteroidal anti-inflammatory drugs (NSAIDs) exhibit anti-inflammatory effects primarily through inhibition of prostaglandin (PG) synthesis. However, effects of NSAIDs on immune responses are not fully understood. This study investigated effects of indomethacin and a new NSAID (d-2-[4-(3-methyl-2-thienyl)phenyl]propionic acid, termed as M-5011 in this study) on cytokine production, lymphocyte proliferation, activities of natural killer (NK) and lymphokine activated killer (LAK) cells and secretion of immunoglobulin (Ig). Both indomethacin and M-5011 augmented interleukin (IL)-2 production, whereas they suppressed IL-6 production both at the protein and mRNA levels. These two NSAIDs augmented proliferation of phytohemagglutinin (PHA)-stimulated PBMC and enhanced NK and LAK cell activities. In contrast, indomethacin was more potent than M-5011 in inhibition of both PG synthesis and Ig secretions by pokeweed mitogen (PWM)-stimulated PBMC. These results suggest that these two NSAIDs equally augment cell-mediated immunity, whereas indomethacin was more potent than M-5011 in the inhibition of humoral immunity and PG synthesis.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1998

Association of a dolichoectatic middle cerebral artery and an intracranial cavernous hemangioma--case report.

A normotensive, non-smoking 41-year-old female with a history of generalized seizures from the age of 4 years presented with a left middle cerebral artery (MCA) fusiform aneurysm and an ipsilateral frontal lobe cavernous hemangioma. Surgical exploration demonstrated that the fusiform aneurysm-like lesion was a dolichoectatic MCA with no arteriosclerotic change. The pathogenesis of dolichoectasia is obscure, but the association of a dolichoectatic MCA and an intracranial cavernous hemangioma is suggestive of congenital factors.

Adult↗
PubMed1998

[Bilateral aplasia of the internal carotid artery: a case report].

We report a case of bilateral aplasia of the internal carotid arteries. A 59-year-old man was admitted with generalized convulsions. Computed tomography and magnetic resonance imaging of the head showed normal findings. Three-dimensional computed tomography, angiography, and intra-arterial digital subtraction angiograms showed bilateral aplasia of the internal carotid arteries. The bilateral ophthalmic arteries were filled from the hypoplastic carotid arteries, and the anterior and middle cerebral arteries were filled from the basilar artery via the posterior communicating arteries. Associated with this bilateral aplasia of the internal carotid arteries, intracranial aneurysms and megadolicho-basilar anomaly were reported. Angiography is to be recommended if IC aplasia is suspected.

Carotid Artery, Internal↗
PubMed1997

De novo vertebral artery-posterior inferior cerebellar artery aneurysm: a case report.

BACKGROUND: There have been few reports of de novo aneurysms in the posterior circulation since most de novo aneurysms occur in the anterior circulation. CASE DESCRIPTION: At the age of 46 years, the patient suffered a subarachnoid hemorrhage due to a ruptured right middle cerebral artery aneurysm, which was subsequently clipped. Eight years later, the patient experienced another subarachnoid hemorrhage of the posterior fossa predominance. A cerebral angiogram demonstrated a right vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysm that had not been noted on the previous study. CONCLUSIONS: The first case of a subarachnoid hemorrhage from a right de novo VA-PICA aneurysm is presented. The characteristics of de novo aneurysms in the posterior circulation are discussed.

Cerebellum↗
PubMed1997

[Ruptured traumatic aneurysms of the peripheral anterior cerebral artery: study of delayed hemorrhage after closed head injury].

We report three cases of ruptured traumatic aneurysms of the peripheral anterior cerebral artery after closed head injury. These cases were all young men with closed head injury due to traffic accidents. Consciousness level on admission was coma in all three cases. Case 1 was a 19-year-old man with interhemispheric hematoma on initial CT, then 7 days later his consciousness cleared. However, 14 days later he suddenly lapsed into a deep coma with a severe frontal hemorrhage. Case 2 was a 13-year-old boy. Plain skull films demonstrated a frontal depressed fracture, but CT scan showed no bleeding. Four days later his consciousness cleared but 11 days after trauma, he lapsed into a deep coma with a frontal hemorrhage. Case 3 was a 22-year-old man. Initial CT showed a slight ventricular hemorrhage. Fourteen days later, his consciousness had almost cleared, but then he lapsed into a deep coma with a large frontal hemorrhage 11 weeks after the trauma. These patients all died within a few days after intracranial bleeding. All patients underwent cerebral angiography but none of them showed filling defect. Autopsy was performed and ruptured aneurysms were found on the distal anterior cerebral artery that had no relation to the branch of bifurcation. Histological examination demonstrated a lack of elastic lamina and media in all of these three cases, so each of them was a victim of so-called false aneurysm. Twenty reported cases of ruptured traumatic aneurysms of the peripheral cerebral artery with delayed hemorrhage after closed head injury were reviewed. Factors in the traumatic aneurysm showed no relation to the duration of disturbed consciousness. Within one month, delayed hemorrhage due to ruptured traumatic aneurysm occurred. None of the delayed hemorrhages involved subarachnoid hemorrhage. Subdural hematoma was seen in the distal middle cerebral artery and frontal hemorrhage was found in the distal anterior cerebral artery. We consider that frontal hemorrhage is a predictive finding for the type of delayed hemorrhage due to traumatic aneurysm in the distal anterior cerebral artery.

Accidents, Traffic↗
PubMed1995

[The mechanism of cardiorespiratory arrest due to subarachnoid hemorrhage].

This report describes the clinical course of patients with sudden cardiorespiratory arrest (CRA) due to subarachnoid hemorrhage (SAH). We have seen fifteen patients of SAH that presented initially as CRA. All of them were diagnosed as SAH by CT scan. The patients were divided into two groups; one group (early DOA group) included 11 patients, who had been recognized as CRA within 60 minutes from the onset of SAH, the other group (late DOA group) consisted of 4 patients, who developed CRA more than 60 minutes after the initial onset. The major mechanism leading to delayed CRA in the late DOA group appeared to have been from brain stem herniation, but another mechanism appeared to be involved in sudden CRA in the early DOA group. Sixty percent of our patients with CRA due to SAH had a low serum potassium concentration, though hypokalemia was observed in only 4 out of 100 patients with CRA due to diseases other than SAH. These facts suggest that sympathetic hyperstimulation might result not only from stress but also from a disorder of the central autonomic nervous system. We speculate that the mechanism leading to early CRA after SAH appears to result from a disorder of the central autonomic nerve system.

Aged↗
PubMed1994

[Neurinoma of the short ciliary nerve: a case report].

Intraorbital neurinoma is a rare tumor and constitutes nearly 1.5% of the orbital tumors. A case of orbital neurinoma is reported. A 70-year-old woman was admitted with the chief complaint of impairment of visual acuity and proptosis of the left eye. A CT scan and MRI revealed a retrobulbar mass. Total removal of the tumor via the transcranial approach to the orbita resulted in improvement of the symptoms. The tumor was considered to be a neurinoma originating from the left short ciliary nerve.

Aged↗