Publications by authors named "Arifumi Kosakai"

Objective: To report the distinctive clinical features of cryptogenic new-onset refractory status epilepticus (C-NORSE) and the C-NORSE score based on initial clinical assessments.

Methods: A retrospective study was conducted for 136 patients with clinically suspected autoimmune encephalitis who underwent testing for autoantibodies to neuronal surface antigens between January 1, 2007, and August 31, 2016. Eleven patients with C-NORSE were identified.

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IgG4-related disease was recently proposed under the classification of systemic chronic inflammatory disease. In the field of otolaryngology, organ-specific diagnostic criteria have been established for the occurrence of this condition in the salivary glands, but not in the sinonasal cavity. Here we report a case involving a 70-year-old man with IgG4-related disease in the sinonasal cavity.

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Cytomegalovirus (CMV) enteritis (or colitis) is generally diagnosed in immunocompromised patients in association with human immunodeficiency virus infection as well as in recipients of solid organ or hematopoietic stem cell transplant. CMV enteritis has been reported only sporadically in immunocompetent individuals. We encountered a 76-year-old woman who developed CMV enteritis without any previously identified immunocompromised states.

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Immunoglobulin G4-related disease (IgG4-RD) is a novel clinical disease entity characterized by elevated serum IgG4 concentration and tumefaction or tissue infiltration by IgG4-positive plasma cells. IgG4-RD can occur in various organs, including the pancreas, lacrimal gland, salivary gland, thyroid, lung, bile duct, liver, gastrointestinal tract, kidney, prostate, retroperitoneum, arteries, lymph nodes, skin, and breast. Steroid therapy is often effective.

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Background: Parkinson's disease (PD) is a neurodegenerative disease characterized by selective degeneration of dopaminergic neurons in the substantia nigra (SN). The familial form of PD, PARK2, is caused by mutations in the parkin gene. parkin-knockout mouse models show some abnormalities, but they do not fully recapitulate the pathophysiology of human PARK2.

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Induced pluripotent stem cell (iPSC) technology can be used to model human disorders, create cell-based models of human diseases, including neurodegenerative diseases, and in establishing therapeutic strategies. To detect subtle cellular abnormalities associated with common late-onset disease in iPSCs, valid control iPSCs derived from healthy donors free of serious late-onset diseases are necessary. Here, we report the generation of iPSCs from fibroblasts obtained immediately postmortem from centenarian donors (106- and 109-years-old) who were extremely healthy until an advanced age.

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Parkinson's disease (PD), which is characterized by degeneration of mesencephalic dopaminergic neurons of unclear etiology, is primarily an age-related neurodegenerative disorder, while the normal process of aging is also known to decrease the number of dopaminergic neurons in the substantia nigra pars compacta (SNc) and the ventral tegmental area (VTA). However, no consensus exists regarding how advancing age may predispose the dopaminergic system to PD. The Klotho-insufficient (klotho) mouse exhibits a syndrome that resembles human aging.

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This study examines the alteration of oligodendrocyte progenitor cells (OPCs), mature oligodendrocytes (OLGs) and myelination after focal ischemia in the rat brain. Adult male Sprague-Dawley rats were subjected to 90-min occlusion of the middle cerebral artery, followed by reperfusion time of up to 2 weeks. The infarct core showed a rapid and progressive decrease in the number of OPCs, OLGs, as well as the myelin density after 48 h of recirculation.

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Binding of cyclic AMP to the regulatory subunit of cyclic AMP-dependent protein kinase (PKA) is an essential step in cyclic AMP-mediated intracellular signal transduction. This binding is, however, rapidly inhibited in the acute phase of cerebral ischemia, indicating that the signal transduction via PKA is very vulnerable to ischemia, although this signal pathway is very important for neuronal survival in the brain. Several lines of evidence suggest that the activation of voltage-sensitive Na+ and Ca(2+) channels is an important mediator of acute ischemic brain damage.

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