Publications by authors named "Ryoichi Iwata"

A dissecting aneurysm in the P4 segment of the posterior cerebral artery (PCA) is extremely rare, and its treatment is sometimes challenging. Endovascular parent artery occlusion (PAO) was performed for an unruptured P4 segment dissecting PCA aneurysm presenting with ischemic stroke and rapid growth. A 70-year-old man was rushed to our emergency department due to a right-sided headache and a visual field defect.

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Glioblastoma multiforme (GBM) is the most prevalent malignant primary brain tumor with a high recurrence rate. Despite multimodal therapy including surgical resection, chemotherapy, and radiotherapy, the median survival time after the initial diagnosis of GBM is approximately 14 months. Since cancer stem cells (CSCs) are considered the leading cause of cancer recurrence, glioblastoma stem cell-targeted therapy is a promising strategy for the treatment of GBM.

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Background: In order to remove a foreign body in the ventricle, such as a ventricular drainage catheter, craniotomy and corticotomy are required to access the ventricle. A case in which a catheter in the 4th ventricle was safely removed with a flexible neuroendoscope is reported.

Case Description: A 47-year-old man underwent coil embolization and ventricular drainage for subarachnoid hemorrhage.

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Objective: Blood blister-like aneurysms (BBA) often develop on the anterior wall of the internal carotid artery, and few cases have been reported at other sites. We report a case of stent-assisted coil embolization in the acute phase for a ruptured BBA of the basilar artery.

Case Presentation: A 53-year-old woman underwent emergency stent-assisted coil embolization for subarachnoid hemorrhage due to a ruptured BBA in the main trunk of the basilar artery.

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Background: Targeting immune checkpoint proteins has recently gained substantial attention due to the dramatic success of this strategy in clinical trials for some cancers. Inducible T-cell co-stimulator ligand (ICOSLG) is a member of the B7 family of immune regulatory ligands, expression of which in cancer is implicated in disease progression due to regulation of antitumor adaptive immunity. Although aberrant ICOSLG expression has been reported in glioma cells, the underlying mechanisms that promote glioblastoma (GBM) progression remain elusive.

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Lenalidomide (LEN), an immunomodulatory drug (IMiD), is currently used for treatment of multiple myeloma (MM). LEN potentiates T cell and natural killer cell functions. However, the cellular and molecular mechanisms underlying the immunomodulatory effects of LEN remain unclear.

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Rathke's cleft cyst is a cystic disease that occurs in the sella turcica or, occasionally, in the suprasellar area. An ectopic Rathke's cleft cyst is extremely rare, and its nature is less well understood. The authors report the case of a 14-year-old girl who presented with a growing cystic lesion in the prepontine cistern, immediately behind the dorsum sellae.

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5-Aminolevulinic acid (5-ALA) fluorescence-guided surgery is widely used for detection and planning of resection of malignant gliomas and other brain tumors. However, no reports have described 5-ALA fluorescence-guided surgery or direct visualization of germ cell tumors. Here, we report two cases of germ cell tumors in which a positive 5-ALA fluorescent signal was visualized with a neuroendoscope.

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Neuroendocrine tumors are rare, and little is known about the existence of cancer stem cells in this disease. Identification of the tumorigenic population will contribute to the development of effective therapies targeting neuroendocrine tumors. Surgically resected brain metastases from a primary neuroendocrine tumor of unknown origin were dissociated and cultured in serum-free neurosphere medium.

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Activation of nuclear factor κB (NF-κB) induces mesenchymal (MES) transdifferentiation and radioresistance in glioma stem cells (GSCs), but molecular mechanisms for NF-κB activation in GSCs are currently unknown. Here, we report that mixed lineage kinase 4 (MLK4) is overexpressed in MES but not proneural (PN) GSCs. Silencing MLK4 suppresses self-renewal, motility, tumorigenesis, and radioresistance of MES GSCs via a loss of the MES signature.

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A 67-year-old woman presented with symptomatic infarction in the territory of the anterior inferior cerebellar artery manifesting as vertigo, vomiting, and right facial weakness. Basiparallel anatomic scanning (BPAS) magnetic resonance (MR) imaging combined with MR angiography demonstrated the occluded anterior inferior cerebellar artery. Common anatomic variations and limited detection of the smaller branches on MR angiography sometimes hinder evaluation of the occluded artery.

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The preventive effect of aggressive blood pressure lowering on hematoma enlargement was investigated in patients with ultra-acute spontaneous intracerebral hemorrhage (ICH). Retrospective review of 248 patients (145 males, 103 females) with spontaneous ICH treated in our hospital between 2005 and 2008 identified patients with ultra-acute ICH who were directly taken to our institute by ambulance within 3 hours after onset. Patients who could not be assessed twice by computed tomography (CT) within 24 hours after arrival were excluded.

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Purpose: Those who have brain metastases smaller than 30 mm in diameter and less than 5 in number can be treated less invasively with radiosurgery. This retrospective study evaluated the optimal brain magnetic resonance image (MRI) follow-up interval for non-small cell lung cancer (NSCLC) patients to detect radiosurgically manageable metachronous brain metastases (MBM).

Patients And Methods: The records of 551 patients with primary NSCLC, treated in our institute between 2002 and 2007, were reviewed.

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Aim: The aim of this study was to clarify the relationship between platelet-derived microparticles (PDMPs) and the Framingham 10-yr coronary heart disease (CHD) risk score.

Methods: A cross-sectional study of healthy volunteers free of medication, and cardiovascular or cerebrovascular disease was conducted. The subjects were 190 Japanese men (median age 41).

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Introduction: The aim of this study was to clarify the correlation and association of plasma IL-6 and PDMPs, both of which are associated with metabolic syndrome, in healthy individuals.

Materials And Methods: We conducted a cross-sectional study of 464 healthy Japanese volunteers (210 men and 254 women, median age 39 and 35years, respectively) who had no signs, symptoms or history of cardiovascular- or cerebrovascular disease and took no medications. We assayed their IL-6 levels with a conventional ELISA kit and their PDMP levels by ELISA and monoclonal antibodies against CD42b and CD42a (glycoprotein Ib and IX).

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Purpose: To characterize the spatial and temporal course of ictal high-frequency oscillations (HFOs) recorded by subdural EEG in children with intractable neocortical epilepsy.

Methods: We retrospectively studied nine children (four girls, five boys; 4-17 yr) who presented with intractable extrahippocampal localization-related epilepsy and who underwent extraoperative video subdural EEG (1000 Hz sampling rate) and cortical resection. We performed multiple band frequency analysis (MBFA) to evaluate the frequency, time course, and distribution of ictal HFOs.

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Long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen reportedly decrease a risk for the progression of Alzheimer's disease (AD), whose mechanisms are still controversial. We previously reported that pathophysiological concentrations (1-10 nM) of amyloid beta proteins (Abetas) increased intracellular Cl- concentration ([Cl-]i) and aggravated glutamate neurotoxicity in the rat brain neuronal culture. In this study, we examined the effects of therapeutic concentrations of ibuprofen and other drugs with cyclo-oxygenase (COX)-1 and/or COX-2 inhibiting activities on 10 nM Abeta25-35-induced changes in cultured rat hippocampal neurons.

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