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Biomedical subjects

O Kubo

Publications and source records attributed to O Kubo.

At least 19 recordsLinked to original sources
PubMed2001

[A case of thrombosed arteriovenous malformation in the brain stem].

A rare operative case of thrombosed arteriovenous malformation (AVM) in the brain stem was reported focusing on its differential diagnosis from cavernous malformation. A 49-year-old woman had developed pontine hemorrhage twice during the last two years. She was diagnosed by neurologists as having cavernous malformation in the brain stem, and then referred to our institute. Neurological examinations showed left hemi motor and sensory disturbance, right abducent palsy and right auditory disturbance. A computed tomography (CT) scan revealed a high density mass in the brain stem considered as a hematoma with slight enhancement. Magnetic resonance imaging (MRI) revealed a high intensity mass in T1 and T2 weighted MRI with marginal hemosiderin rim, but neither flow void sign nor enhancement effect was detected. Angiography depicted no abnormal vasculature in the posterior fossa. The patient underwent surgical resection of the lesion 43 days after a second hemorrhage. Midline sub-occipital craniotomy and the infrafacial route were chosen. Surgery was troubled by arterial bleeding, and pathological examination revealed a thrombosed AVM. She newly developed right facial palsy, right abducent palsy and disturbance of right conjugate gaze, but she is recovering step by step. Although the radiological feature of thrombosed AVM in the brain stem is similar to that of cavernous malformation, the operative procedure for thrombosed AVM is very difficult due to aggressive arterial bleeding that easily leads to surgical injury in the small surgical corridor in the brain stem. We reported a rare case that was pathologically well identified as thrombosed AVM in the brain stem focusing on its differential diagnosis and surgical treatment.

Arteriovenous Malformations↗
PubMed2000

Expression of cadherin and CSF dissemination in malignant astrocytic tumors.

Cadherins are Ca2+-dependent cell adhesion molecules that play an important role in tissue construction and morphogenesis in multicellular organisms. Because in recent years there have been reports of cadherin involvement in tumor metastasis, we conducted an immunostain for E-cadherin and N-cadherin monoclonal antibodies in paraffin-embedded surgical specimens of primary and recurrent lesions in 13 cases of glioblastoma and nine cases of anaplastic astrocytoma. No expression of E-cadherin was detected in the tumor cells. On the other hand, expression of N-cadherin was observed in malignant astrocytic tumor cells, but the N-cadherin positive rate tended to be less at the time of recurrence. Decreased expression of N-cadherin was detected at the time of recurrence in 11 of the 13 cases in the glioblastoma group. Cerebrospinal fluid (CSF ) dissemination and extracranial metastasis were observed in nine (81.8%) of these 11 patients. Therefore, we tried to analyze the clinical backgrounds and the N-cadherin positive rates by statistics. We concluded that decreased expression of N-cadherin at the time of recurrence correlates with dissemination in malignant astrocytic tumors.

Adult↗
PubMed2000

Malignant melanoma arising from the sphenoidal sinus--case report.

Malignant melanomas arising from the sella turcica or sphenoidal sinus with bilateral invasion of the base of the skull or cavernous sinus are extremely rare. Whether the sella turcica or sphenoidal sinus is the site of origin is difficult to determine based on neuroradiological findings. An 83-year-old Japanese female presented with headache as the initial symptom. She suffered rapid progression of bilateral obstruction of the nasal cavity, left nasal bleeding, and bilateral visual field defects. The preoperative diagnosis was pituitary adenoma, metastatic tumor, or malignant paranasal tumor. Biopsy was performed. The histological diagnosis was malignant melanoma. Postoperatively, the tumor progressed rapidly. She suffered several cranial nerve pareses and hypopituitarism. She died within 6 months. Tumors arising from the sphenoidal sinus cause obstruction of the nasal cavity or nasal bleeding first, and then cause cranial nerve pareses by invasion of the cavernous sinus. This sequence of clinical manifestations can be attributed to the anatomical relationships between the sphenoidal sinus, nasal cavity, and cavernous sinus. Differential diagnosis of the origin in the sella turcica or sphenoidal sinus appears to be relatively easy based on further observation of the clinical course and symptoms.

Aged↗
PubMed2000

Subepicranial varix mimicking sinus pericranii: usefulness of three-dimensional computed tomography angiography and bone window computed tomography--case report.

A 16-year-old female presented with a rare case of subepicranial varix in the left temporal area manifesting as a soft mass in the left temporal area when she laid down in the left lateral position. Bulging of the mass was observed when intracranial venous pressure was raised by the Valsalva maneuver, the left lateral position, or the prone position. Bone window computed tomography (CT) revealed a tiny hole, 1 mm in diameter, in the outer bone table. Three-dimensional CT (3D-CT) angiography clearly visualized a mass with a diameter of approximately 10 mm connected to the diploic vein. The mass was totally resected by operation. Venous bleeding was observed from the tiny hole. Histological examination revealed a venous lesion mimicking sinus pericranii and containing endothelial cells. No communication with the intracranial venous sinuses was identified, so the diagnosis was subepicranial varix. Radiological examination by direct injection of contrast medium is usually performed to identify subepicranial varix, but 3D-CT angiography is a non-invasive preoperative examination that can visualize this small venous lesion. Adjustment of the CT acquisition conditions may allow 3D-CT angiography to identify sinus pericranii in the future.

Adolescent↗
PubMed2000

Identification of the full-length KIAA0591 gene encoding a novel kinesin-related protein which is mapped to the neuroblastoma suppressor gene locus at 1p36.2.

The distal region of a short arm of chromosome 1p is frequently deleted in many human cancers including neuroblastoma (NBL), in which it has been narrowed down to the smallest region of overlap between D1S244 and D1S214 (approximately 7 cM). During the search for the candidate tumor suppressor genes mapped within the region, we found the KIAA0591 gene which encoded a new human kinesin-related protein with a homology to human axonal transporter of synaptic vesicles (ATSV). The kinesin is an intracellular motor protein and often associated with neuronal differentiation and survival. Here we identified a complete open reading frame of the KIAA0591 gene by screening a cDNA library derived from human substantia nigra. The KIAA0591 protein contains a possible pleckstrin homology (PH) domain at its carboxy-terminus. However, it did not possess a force-generating motor domain which is well conserved among kinesin superfamily members (KIFs). Northern blot analysis demonstrated that KIAA0591 mRNA was preferentially expressed in both adult and fetal brains, kidney, skeletal muscle and pancreas. KIAA0591 was expressed in favorable NBLs at higher levels than in unfavorable NBLs, although RT-PCR SSCP analysis showed no mutation within the coding region of the KIAA0591 gene, when 8 neuroblastoma tissues and 15 neuroblastoma-derived cell lines were examined. Thus, the full-length KIAA0591 gene may be a novel member of human KIF superfamily which lacks motor domain and might function as a tumor suppressor in an epigenetic but not a classic Knudson's manner.

Amino Acid Sequence↗
PubMed2000

[Left Sylvian fissure meningioma in a one-year-eight-month old child].

We report a case of a Sylvian fissure meningioma in a one-year-eight-month old child who experienced the onset of a convulsive seizure. He had no neurological deficit and no developmental disorders. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a large left temporal tumor which was well enhanced and without dural attachment. Angiography revealed a slight tumor stain in the left Sylvian fissure supplied by branches of the internal carotid artery. Total removal of the tumor was performed, and we found that the tumor had no dural attachment, but was strongly attached to the M2 segment of the left middle cerebral artery. Pathological examinations revealed it to be a fibrous meningioma without malignancy. This is the youngest case among the reported five pediatric deep Sylvian meningiomas. Introducing this case, we discuss the clinical features of pediatric meningiomas.

Brain Neoplasms↗
PubMed2000

[Primary central nervous system malignant lymphoma originating from the cerebellum and extending along the lower cranial nerves].

We report a case of primary central nervous system (CNS) malignant lymphoma of the central nervous system originating from the cerebellum and growing along the lower cranial nerves. A 67-year-old woman presented with hoarseness, vertigo, nausea, and vomiting. Gd-DTPA enhanced MRI showed a homogeneous enhanced mass lesion extending from the cerebellum to the medulla oblongata around the jugular foramen on the right side. Although pre- and intra-operative diagnosis had been schwannoma, histopathological examination revealed a B-cell, diffuse malignant lymphoma. The growth pattern of malignant lymphoma in the present case, which extended extra-axially, is considered to be rare. We discuss here the growth patterns and difficulties of diagnosis of primary CNS malignant lymphoma in this area.

Aged↗
PubMed1999

A case of endolymphatic sac tumor with long-term survival.

A 72-year-old man developed left facial palsy at age 14 and left-sided hearing loss at age 20. At the age of 59, he presented with gait disturbance, and a large left cerebellopontine angle tumor was detected, which had markedly destroyed the pyramidal bone. The tumor was subtotally resected, but he required two more operations at the ages of 64 and 69 because of tumor regrowth. At the present time, recurrent tumor has destroyed the occipital bone and is invading the scalp. However, even though he has several cranial nerve palsies and cerebellar ataxia, he remains in stable condition and demonstrates long-term survival. The patient's surgical specimens revealed a papillary adenoma, which was recently thought to be of endolymphatic sac origin, although the origin of this kind of tumor, whether arising from the middle ear or from the endolymphatic sac, has not been established with certainty so far. In this paper, we provide further evidence that this tumor originates from the endolymphatic sac, based on anatomical, histopathological, and embryological evidence.

Adenoma↗
PubMed1999

Gamma Knife radiosurgery for pituitary adenomas.

Ninety-two patients with pituitary adenomas have been treated during the last 5 years. Sixty-three of these patients had more than 6 months follow-up, and they form the basis of this report. Eighteen had non-functioning adenomas (NFA), and 36 had functioning adenomas (FA). The mean marginal dose was 22.5 Gy (NFA 19.5 Gy, FA 23.9 Gy). Control of tumor growth was achieved in 92%. A significant decrease of excessive hormone production was seen in 75.6%, and the endocrinopathy normalization rate was 26.7%. Post-radiosurgical complications were seen in 4.7%.

Acromegaly↗
PubMed1999

Primary central nervous system T-cell lymphoma. Case report.

A 46-year-old male presented with a rare primary non-Hodgkin's lymphoma of the central nervous system of T-cell lineage, localized primarily in the right parietal region. There was no evidence of acquired immunodeficiency syndrome. Biopsy of the tumor allowed immunohistochemical confirmation of the diagnosis. Irradiation and chemotherapy were given, and the patient has remained well for 24 months. The clinical manifestations, management, and outcome of T-cell lymphoma are very similar to those of B-cell lymphoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

[Lymphoplasmacyte-rich meningioma: a report of three cases and a review of the literature].

We report three patients (a 36-year-old man, a 41-year-old woman, and a 22-year-old man) with lymphoplasmacyte-rich meningioma who manifested characteristics on radiological and blood examinations. Two were hospitalized with gradual deterioration of hemiparesis and one with general convulsive seizure. Radiological examination revealed typical meningiomas of convexity in two and that of falx in one. Two of the patients showed large perifocal edema. Anemia was found in one patient and an elevated level in the zinc sulfate turbidity test was noted in all cases. Abnormal findings in laboratory examination improved quickly, whereas perifocal edema remained for six months after tumor removal. The tumors were histologically confirmed to be meningioma with massive infiltrates of plasma cells and lymphocytes. Seventeen cases of lymphoplasmacyte-rich meningioma that have been reported to date including our three cases were reviewed.

Adult↗
PubMed1999

Detection of mammosomatotrophs in paraffin-embedded specimens of various pituitary adenomas.

BACKGROUND: There are various classification systems for pituitary adenomas based on whether mammosomatotroph cells, which simultaneously express both prolactin (PRL) and growth hormone (GH), can be found. Until the present, the identification of such cells required special techniques and could not be performed in paraffin-embedded specimens. This hindered large-scale studies for detection of mammosomatotrophs in various pituitary adenomas and, as a result, such classification has remained controversial. To establish a methodology for the detection of mammosomatotrophs in paraffin-embedded specimens and to propose a more logical classification for pituitary adenomas, the authors conducted this retrospective study. METHODS: We performed double immunofluorescence staining of PRL and GH in paraffin-embedded specimens of various pituitary adenomas with subsequent observation with a confocal laser-scanning microscope. RESULTS: Mammosomatotrophs were found in four of the 10 GH-secreting adenomas and one of the 10 clinically nonfunctioning adenomas. However, mammosomatotrophs were not identified in all 10 cases of prolactinoma. CONCLUSIONS: This is the first report in the literature that successfully demonstrates the presence of mammosomatotrophs in routine paraffin-embedded pituitary adenomas. The new methodology is important for future study of the function and role of these cells. A large-scale study for mammosomatotrophs in various pituitary adenomas with this method and a more logical classification of pituitary adenomas are proposed.

Adenoma↗
PubMed1999

[Immunohistochemical evaluation of intracranial recurrent meningiomas: correlation of topoisomerase II alpha expression and cell proliferative potential].

Most of meningiomas belong to benign tumor. But inspite of Simpson grade I surgical resection, it had been reported that a part of these cases recurred after initial operation. In discussing tumor recurrence in meningioma, it is important to evaluate not only the extent of surgical resection and malignancy but also cell proliferative potential, which had been studied immunohistochemically by using BudR, PCNA and MIB-1. Recently, it is known that topoisomerase (Topo) II alpha expression becomes remarkable in tumorigenesis. The correlation with cell proliferative potential has been reported. In this paper we evaluated the relationship of cell proliferative potential and tumor recurrence immunohistochemically by using Topo II alpha and MIB-1 monoclonal antibody in the 21 recurrent cases of meningiomas and hemangiopericytomas. As a result, mean Topo II alpha staining index (SI) and MIB-1 SI initial surgical resection were 2.29% and 3.41%, respectively, at recurrence these SIs had risen at 4.3% and 6.25%, respectively. As to the interval from initial surgical resection to recurrence, in the cases which recurred under 3 years Topo II alpha SI and MIB-1 SI were 3.13% and 5.00%, on the other hand, in the cases which recurred later than 3 years were 1.16% and 1.30%, respectively. Topo II alpha SI and MIB-1 SI 1 of former cases were higher than latter cases. Furthermore good correlation between the Topo II alpha SI and MIB-1 SI was found. It is concluded that Topo II alpha expression was as well available for the marker of cell proliferative potential and for one of the predicting factors for tumor recurrence in meningioma and hemangiopericytoma as MIB-1 SI.

Adult↗
PubMed1998

Involvement of 5-hydroxytryptamine7 receptors in inhibition of porcine myometrial contractility by 5-hydroxytryptamine.

1 5-Hydroxytryptamine (5-HT; 1 nM - 100 microM) concentration-dependently inhibited the amplitude and frequency of spontaneous contractions in longitudinal and circular muscles of the porcine myometrium. The circular muscle (EC50; 68-84 nM) was more sensitive than the longitudinal muscle (EC50; 1.3-1.44 microM) to 5-HT. To characterize the 5-HT receptor subtype responsible for inhibition of myometrial contractility, the effects of 5-HT receptor agonists on spontaneous contractions and of 5-HT receptor antagonists on inhibition by 5-HT were examined in circular muscle preparations. 2 Pretreatment with tetrodotoxin (1 microM), propranolol (1 microM), atropine (1 microM), guanethidine (10 microM) or L-NAME (100 microM) failed to change the inhibition by 5-HT, indicating that the inhibition was due to a direct action of 5-HT on the smooth muscle cells. 3 5-CT, 5-MeOT and 8-OH-DPAT mimicked the inhibitory response of 5-HT, and the rank order of the potency was 5-CT>5-HT>5-MeOT>8-OH-DPAT. On the other hand, oxymethazoline, alpha-methyl-5-HT, 2-methyl-5-HT, cisapride, BIMU-1, BIMU-8, ergotamine and dihydroergotamine had almost no effect on spontaneous contractions, even at 10-100 microM. 4 Inhibition by 5-HT was not decreased by either pindolol (1 microM), ketanserin (1 microM), tropisetron (10 microM), MDL72222 (1 microM) or GR113808 (10 microM), but was antagonized by the following compounds in a competitive manner (with pA2 values in parentheses): methiothepin (8.05), methysergide (7.92), metergoline (7.4), mianserin (7.08), clozapine (7.06) and spiperone (6.86). 5 Ro 20-1724 (20 microM) and rolipram (10 microM) significantly enhanced the inhibitory response of 5-HT, but neither zaprinast (10 microM) nor dipyridamole (10 microM) altered the response of 5-HT. 6 5-HT (1 nM - 1 microM) caused a concentration-dependent accumulation of intracellular cyclic AMP in the circular muscle. 7 From the present results, the 5-HT receptor, which is functionally correlated with the 5-HT7 receptor, mediates the inhibitory effect of 5-HT on porcine myometrial contractility. This inhibitory response is probably due to an increase in intracellular cyclic AMP through the activation of adenylate cyclase that is positively coupled to 5-HT7 receptors.

Adenylyl Cyclases↗
PubMed1998

[Clinical evaluation of intraoperative radiotherapy using photon radiosurgery system for brain tumors].

The photon radiosurgery system is a miniature X-ray generator that can be placed stereotactically and intraoperatively into intracranial tumors to deliver a single fraction of high-dose interstitial irradiation. This battery-powered device produces low energy X-ray photons in a spherical and symmetrical pattern at the probe tip. Dose rates of up to 200 cGy/Mim are possible, allowing for the administration of 15 Gy to a lesion 3 cm in diameter in less than 1 hr. Background exposure is minimal, and no special shielding of the patient or health care personnel is required. Thirty-nine patients with brain tumor were treated in this method. There were no adverse effects. During the follow-up period of 1-30 months, 3 cases with 5 metastatic brain tumors died about 8 months after this treatment. Five recurrent cases of 21 malignant gliomas died about 4 months after treatment. Interstitial radiotherapy using photon the radiosurgery system promises to be a useful treatment for brain tumors.

Aged↗