Junkoh Yamashita

Kanazawa University | Kindai

There are many reports on position-related complications in neurosurgical literature but so far, continuous quantification of the patient’s position during the surgery has not been reported. This study aims to explore the utility of a new surgical table system and its software in displaying the patient’s body positions during surgery on real-time b...

Little is known about the pathogenesis and clinical course of fusiform compared with saccular aneurysms. The case of a ruptured fusiform aneurysm accompanied by dissection at the M2 portion of the middle cerebral artery (MCA) is reported, along with pathological findings. A 41-year-old female presenting with subarachnoid hemorrhage was revealed to...

To investigate whether the ocular dominance affects laterality in the activity of the primary visual cortex, we examined the relationship between the ocular dominance and latency or dipole moment measured by checkerboard-pattern and magnetoencephalography in 11 right-handed healthy male participants. Participants with left-eye dominance showed a di...

A 50-year-old female presented with right painful abducens nerve palsy persisting for 4 months and mild panhypopituitarism with diabetes insipidus for 6 months. T(1)-weighted magnetic resonance (MR) imaging of the sellar region showed a homogeneously enhanced mass lesion in the right cavernous sinus which seemed to extend from the swollen pituitary...

Aquaporins (AQPs) is a water channel family which facilitates the passage of water across cell membranes. Recently, expression of aquapporin 1 (AQP1) was found to be involved in not only water transport but also tumorigenesis. In present study, we analyzed the expression of AQP1 in 26 consecutive cases of human hemangioblastomas. Significant upregu...

Endothelial tight junctions form the main barrier of the blood-brain barrier (BBB). In human hemangioblastomas, cyst formation is a common and important clinical manifestation. Although most researchers consider that the cyst formation in hemangioblastomas may be caused by the breakdown of the BBB, the underlying molecular mechanisms for cyst forma...

A case of psammoma body rich gliofibroma is reported. Computed tomography (CT) showed a high-density mass without contrast enhancement in the right cerebellar hemisphere. Magnetic resonance images (MRI) demonstrated a mass with a mixture of high- and iso-intensity regions without meningeal attachment on both T1- and T2-weighted images. Pathological...

Advances in skull base surgical techniques and radiosurgery have led to significant improvements in the treatment of skull base meningioma. However, as the natural history and the biological behavior of skull base meningiomas are not well known, the selection of and timing for postoperative additional treatment are still controversial. Herein we di...

Glioblastoma (GB) often has loss of heterozygosity on the chromosomes, 1p, 10p, 10q, 11p, 17p, 19q, 22q, and several others. In the case of chromosome 12q; however, it remains to be seen whether LOH occurs. Apaf-1, the apoptotic protease activating factor-1, located at chromosome 12q22-23, is a major effecter of the p53 mediated apoptosis pathway,...

Of the intracranial germ cell tumors (IGCTs), 10% of germinomas and most nongerminomatous tumors remain refractory to multimodality therapy. The authors investigated the mutation of c-kit and the expression of its product KIT in IGCTs to identify tumors susceptible to imatinib mesylate, a synthetic agent targeting KIT. The authors investigated 26 I...

Clinical records of 61 cases with suprasellar tumors that also had visual field defects were reviewed to determine whether statokinetic dissociation (SKD) could be used to predict recovery of the visual field after transsphenoidal surgery. Static and kinetic visual field testing was performed with Humphrey perimetry (HP) and Goldmann perimetry (GP)...

A 59-year-old woman with type IIA von Willebrand's disease (VWD) presented with subarachnoid hemorrhage (SAH). Computed tomography showed SAH in the right sylvian fissure and intracranial hemorrhage in the right temporal lobe. Angiography demonstrated an aneurysm at the bifurcation of the right middle cerebral artery. Neck clipping was performed on...

Checkpoint kinase 1 (Chk1) is a cell cycle regulator and a heat shock protein 90 (Hsp90) client. It is essential for cell proliferation and survival. In this report, we analyzed the mechanisms of Chk1 regulation in U87MG glioblastoma cells using Geldanamycin (GA), which interferes with the function of Hsp90. GA reduced Chk1 protein level but not it...

Selective cleavage of the Glu395-Ser396 bond of brevican, one of the major proteoglycans in adult brain tissues, is thought to be important for glioma cell invasion. Our previous biochemical study demonstrated that ADAMTS-4, a member of the ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) family, has such an activity. In the...

The aim of this study is to investigate the efficacy of dynamic computed tomography (CT) during selective angiography (CT-arteriography) of orbital tumors in the evaluation of intratumoral vascular anatomy, feeding artery territory, and histological diagnosis. Among 35 consecutive cases with various orbital lesions, those cases showing tumor staini...

Although atypical teratoid/rhabdoid tumor (AT/RT) is known to generate through inactivation of the hSNF5/INI1 gene on chromosome 22q, the downstream molecular mechanism remains unclear. We histologically and molecularly reviewed our pediatric brain tumors for unrecognized AT/RTs and evaluated the role of cyclin D1, a potential molecular target of h...

Cyanotic breath-holding spell is a benign and self-limiting disease of young children but occasionally associated with sudden, unexpected death. The authors report a rare case in a 2-year-old girl with a severe form that started after radical resection of a cervicomedullary ganglioglioma. She was admitted to our hospital because of delayed and unst...

The anticonvulsant agent phenytoin (5,5-diphenylhydantoin) is mainly excreted as 5-(4'-hydroxyphenyl)-5-phenylhydantoin (4'-HPPH) O-glucuronide in humans. Previously, we demonstrated that the glucuronidation of 4'-HPPH is catalyzed by multiple UDP-glucuronosyltransferases (UGTs) of UGT1A1, UGT1A4, UGT1A6, and UGT1A9. Since 4'-HPPH may be bioactivat...

Medulloblastoma is a malignant cerebellar tumor of childhood and is difficult to cure due to frequent cerebrospinal fluid dissemination. Amplification of the c-myc gene (4%) and messenger (mRNA) overexpression (50%) are known to be adverse prognostic indicators. Because mRNA overexpression cannot be explained by gene amplification alone, mechanisms...

The decoy receptor 3 (DcR3) gene is amplified at high frequency in human lung, colon, and liver cancers. DcR3 has been demonstrated to produce a secreted member of the tumor necrosis factor receptor superfamily that negatively regulates Fas-mediated apoptosis. In this study we examined DcR3 gene amplification, DcR3 mRNA expression, and DcR3 protein...

Methods. Immunohistochemical and cytogenetic examinations of β- and γ-catenin, c-myc, N-myc, and cyclin D1 in 24 primary medulloblastomas were conducted, and their clinical relevance was evaluated. Cytoplasmic/membranous staining of β- and γ-catenin was detected in 19 (79%) and nine (37%) cases, respectively, and nuclear expression of cyclin D1 and...

In this study, we evaluated the usefulness of dynamic studies for the preoperative diagnosis of tumor lesions adjacent to the pituitary gland. We examined 13 tumors. We obtained pre- and post-contrast thin slice T1-weighted images of the sellar regions. FSE sequences were used for dynamic study. The capability to distinguish the tumor from the pitu...

This study was aimed to understand ultrastructural pathology of nerves of tumor origin of spinal schwannomas, which has not been reported so far, in order to understand the mechanism of the postoperative functional restoration after the nerve transection. From 13 patients who underwent sacrifice of an affected nerve root at total removal of spinal...

Solitary fibrous tumor (SFT) is a benign and rare neoplasm. To date, only 37 patients with intracranial SFTs have been reported. Although a number of the tumors were recurrent and some later underwent malignant transformation, none of these lesions progressed to cerebrospinal fluid (CSF) dissemination. In this paper the authors report a case of SFT...

A 44-year-old man presented with a rare subfrontal schwannoma with headache. He had undergone radiation therapy for a pineal lesion 30 years previously, but the histology was not verified. On admission, neurological examination revealed no focal deficits including hyposmia. Computed tomography demonstrated a mass measuring 5 x 3 cm in the right ant...

Glioblastoma can be divided into genetic subsets. The most prominent criterion for dividing glioblastomas into subsets is the dichotomy between TP53 mutation and EGFR amplification, two genetic alterations that almost never coincide in the same tumor. Approximately one third of glioblastomas have TP53 mutations, one third have EGFR amplification, a...

We present a case of a symptomatic frontal arachnoid cyst associated with hydrocephalus in an elderly patient. It is well known that symptomatic arachnoid cysts usually develop at an early age. This condition is rarely observed in the elderly. The authors hypothesized that compression of the brain and obstructive hydrocephalus caused the arachnoid...

The human UDP-glucuronosyltransferase, UGT1A9, catalyses glucuronidations of various endobiotics and xenobiotics. In the present study, all exons, exon-intron junctions, and the 5'-flanking region (-273 bp) of the UGT1A9 gene in a Japanese subject were sequenced. One base insertion of thymidine in a promoter region of the UGT1A9 gene resulting in A...

Amniotic membrane can be used as autologous reconstruction graft material when aseptically obtained. We introduce here a novel repair technique using autologous amnion graft, and report a case presentation of myelomeningocele successfully treated with this graft material. Amniotic membrane, which was composed of amnion and chorion, was aseptically...

The human UDP-glucuronosyltransferase, UGT1A9, catalyses glucuronidations of various endobiotics and xenobiotics. In the present study, all exons, exon-intron junctions, and the 5′-flanking region (-273 bp) of the UGT1A9 gene in a Japanese subject were sequenced. One base insertion of thymidine in a promoter region of the UGT1A9 gene resulting in A...

A 55-year-old man presented with esthesioneuroblastoma in the right paranasal sinuses and orbita, extending into the right anterior and middle cranial fossa. He received a partial resection of tumour and post-operative radiotherapy, which was set with a central focus on the right orbit. Five years later, he came to our hospital with a complaint of...

A novel method for the simulation of the clipping position for cerebral aneurysms based on three-dimensional computed tomography (3D CT) angiography was evaluated. Rotating the regional 3D CT angiography images including the aneurysm provided the virtual intraoperative views of 36 cerebral aneurysms that were eligible for clipping through a pterion...

Glioblastoma (GB) often has loss of heterozygosity on the chromosomes, 1p, 10p, 10q, 11p, 17p, 19q, 22q, and several others. In the case of chromosome 12q, however, it remains to be seen whether LOH occurs. Apaf-1, the apoptotic protease activating factor-1, located at chromosome 12q22-23, is a major effecter of the p53 mediated apoptosis pathway,...

Intraosseous lipomas of the skull are quite rare and only eight cases have been reported. The lipoma in our case was different from that in others in that it showed remarkable proliferation of collagen tissue. This is the first report of meningioma occurring after removal of an intraosseous lipoma of the skull. This report concerns a rare case of a...

The authors report a case of the rhabdoid predisposition syndrome (RPS) secondary to a germline hSNF5/INI1 mutation, whose brain tumor was originally unclassified but finally diagnosed as an atypical teratoid/rhabdoid tumor (AT/RT) by molecular analysis. A 7-month-old infant presented with hydrocephalus secondary to a huge pineal tumor and subseque...

Testican family proteins are putative extracellular heparan/chondroitin sulfate proteoglycans of unknown function. We identified recently N-Tes, which is a product of testican 3 splicing variant gene, as an inhibitor of membrane-type matrix metalloproteinases (MT-MMPs). The inhibitory function is common among testican family members except for test...

The human crk gene is translated into crkI and crkII by alternative splicing. crkII mRNA was detected both in normal brain and glioblastoma tissues, whereas crkI mRNA levels were quite low in normal brain and up-regulated in glioblastoma tissues. Expression of CrkI but not CrkII in glioblastoma U87MG cells induced transformation that stimulated cel...

We evaluated contrast-enhanced MRA (enhanced 3-D fast gradient-echo [efgre3d] with spectral inversion recovery) for identification of 15 intracranial arteriovenous malformations (AVMs) in 14 patients. Demonstration of the feeding arteries was classified as good for 16 examinations on maximum-intensity projections and multiprojection volume reconstr...

Oxidized galectin-1 has recently been identified as a key factor that plays important roles in initial axonal growth in injured peripheral nerves. The aim of this study was to investigate the effects of oxidized galectin-1 on regeneration of rat spinal nerves using acellular autografts (containing no viable cells) and allografts (containing no cell...

The matrix metalloproteinase (MMP) family plays an important role in the degradation of extracellular matrix (ECM) in various physiological and pathological conditions. Accumulated evidence has suggested that MMPs contribute to cancer cell invasion of the surrounding normal tissues and metastasis through the cell-surface ECM degradation. Strong cor...

Because of their histological similarities, it is occasionally difficult to differentiate neurocytoma and dysembryoplastic neuroepithelial tumor (DNT) from oligodendroglial tumors. This study was conducted to investigate genetic differences among these tumor types in terms of loss of heterozygosity on chromosomes 1p and 19q, and p53 gene mutation....

The results of radiosurgery for treatment of patients with non-small-cell lung cancer with brain metastasis as the initial relapse were evaluated. Twenty-three patients were included in the study. The dominant pathologic type was adenocarcinoma (56.5%). In the mean interval of 13.7 months (range, 3-52 months) between the lung operation and treatmen...

Metastasis of systemic cancer to intracranial tumors is a rare event. The authors report a case of 49-year-old woman with such occurrence, whose breast cancer metastasized to a preexisting parasagittal meningioma at a postoperative interval of 1.5 years. She was admitted to our hospital because of progressive right hemiparesis. Magnetic resonance i...

It has been reported that due to premature synostosis of the lambdoid suture in the first 24 months of life, more than 70% of patients with Crouzon syndrome concurrently suffer from chronic tonsillar herniation (Chiari Type I malformation) and some (20%) associated syringomyelia. The goal of the present study was to examine mutations in the fibrobl...

The subject of this report is a rare case of a 5-year-old girl who developed an arachnoid cyst with a bony and dural defect in the parietal convexity. She had no history of head trauma or infection. Surgical exploration revealed the bulging lesion to consist of cerebrospinal fluid-containing spongy subcutaneous tissue and to extend into the bony an...

Vitamin B6 derivatives protect the retinal neurons from excitotoxic injury in vitro. However, their in vivo role in a process involving excitotoxicity, such as ischemia, remains unknown. We studied potential protective effects of pyridoxal 5'-phosphate (PLP) and pyridoxal hydrochloride (pyridoxal) on the retinal neurons in a monkey model of transie...

Opening the temporal part of the choroidal fissure (CF) makes it possible to expose the crural cistern, the ambient cistern, and the medial temporal lobe. We examined the microsurgical anatomy and the surgical indications for use of the trans-CF approach. The microsurgical anatomy encountered in the trans-CF approach for lesions in and around the a...

OBJECTIVE : Opening the temporal part of the choroidal fissure (CF) makes it possible to expose the crural cistern, the ambient cistern, and the medial temporal lobe. We examined the microsurgical anatomy and the surgical indications for use of the trans-CF approach. METHODS : The microsurgical anatomy encountered in the trans-CF approach for lesio...

Twenty-six adult diaphragma sellae and infundibulae were examined by MRI parallel to the transsphenonidal surgical plane with attention given to the diaphragmal opening. The diaphragmal opening was observed in 11 cases (42.3%). The anteroposterior diame ter of the opening ranged from 4.0 to 14.0 mm (mean 8.8 mm), and the lateral diameter ranged fro...

A 16-year-old girl presented with multiple cerebral cavernous angiomas with calcifications due to repeated hemorrhages and a thrombosed cerebral arteriovenous malformation (AVM). Her 18-year-old elder sister also had multiple cerebral cavernous angiomas associated with calcifications, which suggested presence of repeated previous hemorrhages. Surgi...

We evaluated contrast-enhanced MRA (enhanced 3-D fast gradient echo, EFGRE3D, with spectral IR) for the identification of unruptured cerebral aneurysms. We examined 22 aneurysms from 15 patients. In its ability to identify aneurysms, contrast-enhanced MRA was superior to 3-D-time of flight (3D-TOF) MRA in 4 instances, equal in 17, and inferior in 1...

The Ca2+-dependent cell adhesion molecule E-cadherin has been known to express in normal and reactive Schwann cells in rodents, and to play an important role in Schwann cell-Schwann cell adhesion and maintenance of peripheral nervous tissue architecture. However, little is known about expression of E-cadherin in schwannomas. The aim of the present...

The aim of the present study was to visualize postischemic hippocampal neuronal death in the living monkey brain, using a high-resolution positron emission tomography (PET) and novel radioligands. In preceding papers, we reported on postischemic hippocampal neuronal death in a model of Japanese monkeys (Macaca fuscata) undergoing a 20-min complete...

The choice of surgical approach to treat medial tentorial meningiomas is crucial and sometimes difficult to make. Although the subtemporal approach is most commonly used for lesions that extend mostly supratentorially, it risks injury to the vein of Labbé or the veins coursing along the subtemporal surface. To avoid venous injury, a medial tentoria...

Using expression cloning to screen a human fetal kidney cDNA library for regulator(s) of pro-matrix metalloproteinase (MMP)-2 processing mediated by membrane-type (MT) 1 MMP, we isolated a cDNA whose product interfered with pro-MMP-2 activation. It encodes the NH(2)-terminal 313-amino acid region of a calcium-binding proteoglycan, testican 3, with...

The purpose of this study is to indicate that oxidative stress may contribute to occurrence of meningiomas. Recently, it was reported that aside from the neurofibromatosis type 2 (NF2) gene mutations, the calpain-dependent proteolysis of the NF2 gene product, merlin might be closely related to the development of certain NF2-related tumors. Although...

Ets transcription factors are associated with tumor malignancy. We reported previously that the stable transfection of the dominant-negative form of Ets-1 (Ets-DN) in the glioma cell line U251 induced down-regulation of urokinase-type plasminogen activator mRNA expression and invasiveness (M. Nakada et al., J. Neuropathol. Exp. Neurol., 58: 329-334...

OBJECTIVE : Although spinal schwannomas are often encountered, the pathology of the tumor capsule has not been reported. In this study, we describe the ultrastructural pathology of the tumor capsule of spinal schwannomas. METHODS : In 18 patients who underwent total removal of spinal schwannomas (C2-conus), the tumor capsule was collected and exami...

The purpose of this study is to indicate that oxidative stress may contribute to occurrence of meningiomas. Recently, it was reported that aside from the neurofibromatosis type 2 (NF2) gene mutations, the calpain-dependent proteolysis of the NF2 gene product, merlin might be closely related to the development of certain NF2-related tumors. Although...

We present three cases of glioblastoma with CSF dissemination that contrast-enhanced fluid-attenuated inversion recovery MRI was sensitive enough to detect compared with contrast-enhanced T1-weighted MRI. An autopsy was performed on one patient, and its histologic findings proved the existence of CSF dissemination.

Our aim was to investigate the usefulness of helical CT during selective angiography (CT arteriography) in pretreatment assessment of unruptured intracranial aneurysms. We studied 47 unruptured aneurysms in 34 prospectively recruited patients for whom endovascular embolisation was initially considered. As pretreatment assessment, we performed rotat...

A gangliocytoma/ganglioglioma with no atypical or malignant features was subtotally resected from the right temporal lobe of a 16-year-old woman. A second resection was performed 8 years later to treat a locally recurrent lesion with increased cellularity that was diagnosed as a World Health Organization Grade II ganglioglioma on the basis of neuro...

Recent advances in stent technology have allowed the introduction of more flexible stents that may be tracked more easily in the intracranial vessels. We present a patient with improved cerebral blood flow and metabolism as assessed by positron emission tomography after stent-assisted angioplasty for symptomatic basilar artery stenosis. A 62-year-o...

OBJECTIVE Recent advances in stent technology have allowed the introduction of more flexible stents that may be tracked more easily in the intracranial vessels. We present a patient with improved cerebral blood flow and metabolism as assessed by positron emission tomography after stent-assisted angioplasty for symptomatic basilar artery stenosis....

Acquisition of invasive and metastatic potentials through proteinase expression is an essential event in tumor progression. Among proteinases, matrix metalloproteinases (MMPs) are thought to play a key role in tumor progression through the degradation of the extracellular matrix. In the present study, the authors examined the role of MMP-2 (gelatin...

Thoracic disc herniations are relatively rare disease. In particular, dorsally herniated thoracic discs are even more infrequent. We report a 70-year-old man who presented with a three weeks' history of paraparesis which was caused by a dorsal disc herniation. Magnetic resonance imaging demonstrated a limb-enhanced intraspinal mass with a "tent-lik...

An 81-year-old female presented with a giant aneurysm of the distal anterior cerebral artery (A3) which grew from a small saccular aneurysm to a huge aneurysm within 36 months before manifesting as a mass lesion. The thrombosed portion of the aneurysm showed growth, whereas the aneurysmal cavity did not change in size. Computed tomography and magne...

Only a few reports have been published on molecular genetic alterations in primary central nervous system lymphomas (PCNSLs) of the diffuse large B-cell type and no reports have addressed the correlation between the genetic alterations and clinical course of the patients with this neoplasm. Thus, the molecular background of the PCNSL and its import...

We performed perfusion imaging of 20 examinations in 18 patients with intracranial lesions. Forty-seven images were obtained by subtracting the fourth to the fiftieth image from the third image. The subtraction images showed increases or reductions in the blood flow, delay of cerebral circulation in 17 examinations of 15 cases, while the other thre...

The authors report an extremely rare case of de novo spinal teratoma after treatment for intracranial germ cell tumor. A 17-year-old male developed pain of bilateral lower extremities and urinary retention 18 months after complete remission of intracranial mixed germ cell tumor. Magnetic resonance imaging revealed a huge spinal tumor associated wit...

The relationship between the grade of astrocytic tumor and the expression of deoxyribonucleic acid methyltransferase (DNA-MTase) gene was examined. The levels of DNA-MTase messenger ribonucleic acid (mRNA) were measured by semiquantitative reverse transcriptase-polymerase chain reaction in surgical specimens from 12 astrocytic tumors (4 astrocytoma...

The authors describe the clinical, radiological, and pathological findings of ruptured cerebral aneurysms with irregular configurations. Eight patients with subarachnoid hemorrhage due to ruptured irregularly shaped aneurysms were examined. The preoperative radiological findings in these cases were compared with the pathological and operative findi...

The aim of this study was to investigate the advantages and disadvantages of a two-stage treatment for ruptured cerebral aneurysms; partial embolization in acute stage followed by clipping in chronic stage of subarachnoid hemorrhage. Between April 1997 and August 1999, twenty ruptured cerebral aneurysms were initially treated endovasculary using Gu...