60 research outputs found

    Potential Involvement of the Stem Cell Factor Receptor c-kit in Alopecia Areata and Androgenetic Alopecia: Histopathological, Immunohistochemical, and Semiquantitative Investigations

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    Alopecia areata (AAR) and androgenetic alopecia (AGA) are two major forms of alopecia based on altered hair growth condition. In general, the cell cycle is regulated by several mechanisms including the stem cell factor/c-kit signaling. To assess a role for stem cell activity in alopecia, we performed histopathological, immunohistochemical, and semiquantitative analyses of c-kit as well as Ki-67 in scalp biopsy specimens obtained from 14 patients with AAR, 18 patients with AGA, and 6 age-matched control subjects, using the specific antibodies. Formalin-fixed, paraffin-embedded skin sections were examined. Immunoreactivities for Ki-67 and c-kit were localized in keratinocytes and melanocytes in the outermost layer of hair follicles. The mean length of hair follicles was significantly shorter in the AAR and AGA groups than in the control group. The mean number of Ki-67-immunoreactive cells per follicle was significantly reduced in the AAR and AGA groups as compared with the control group. The mean number of c-kit-immunoreactive cells per follicle was significantly increased in the AAR and AGA groups as compared with the control group. Our results indicate that c-kit is upregulated in the hair follicle cells in these forms of alopecia, and suggest that the upregulation reflects a negative feedback mechanism in response to possible downregulation of the ligand stem cell factor

    Pentosidine Accumulation in Human Oocytes and Their Correlation to Age-Related Apoptosis

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    Age-related atresia of ovarian follicles is characterized by apoptosis of the constituent cells. Recent studies have indicated that dysfunction of the proteasome and endoplasmic reticulum and subsequent apoptosis in the presence of oxidative stress have relevance to aging. The aim of this study was to assess the involvement of these processes in age-related follicular atresia. Formalin-fixed, paraffin-embedded sections of ovaries obtained at surgery from 74 women (age: 21–54 y) were examined with the terminal deoxynucleotidyl transferase-mediated, dUTP-biotin nick-end labeling (TUNEL) method and an immunohistochemical technique. Primary antibodies used in immunohistochemistry were against pentosidine, ubiquitin and caspase 12. Histological localization of these substances in oocytes was observed by light microscopy, and labeling indices of these cells were evaluated by regression analysis. Positive signals for pentosidine, ubiquitin, caspase 12, and TUNEL were detectable in oocytes of the primordial, primary and their atretic follicles. Regression analysis revealed an age-related increase in the labeling indices for pentosidine, ubiquitin, caspase 12, and TUNEL. These results suggest that pentosidine accumulation in human oocytes is related to apoptosis and increases with age. Further studies will be necessary to clarify the involvement of pentosidine accumulation, proteasome inhibition, and endoplasmic reticulum stress in age-related apoptosis of oocytes in human ovaries

    Immunohistochemical Demonstration of Membrane-bound Prostaglandin E2 Synthase-1 in Papillary Thyroid Carcinoma

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    Microsomal prostaglandin E2 synthase-1 (mPGES-1) is an inducible enzyme that catalyzes the conversion of prostaglandin (PG) H2 to PGE2 in downstream of cyclooxygenase-2 (COX-2). Recent studies have obtained in vitro evidence that PGE2 participates in carcinogenesis, angiogenesis, and induction of matrix metalloproteinase-9 (MMP-9), which plays a crucial role in cancer invasion. However, implications for mPGES-1 in thyroid carcinomas remain to be determined. To address this issue, we performed an immunohistochemical analysis for mPGES-1, COX-2 and MMP-9 in 20 papillary thyroid carcinoma (PTC) patients. mPGES-1 immunoreactivity was localized in the cytoplasm of carcinoma cells in 19 cases, with an intensity that tended to be distinct at the interface between the tumor and the surrounding non-neoplastic tissue. Staining was more intense in regions with papillary arrangement, while it was less intense in regions with trabecular or solid arrangement. In many cases, immunohistochemical localization of COX-2 and MMP-9 resemble that of mPGES-1. Taken together, our results suggest the involvement of mPGES-1 in proliferation and differentiation of PTC as well as local invasion of PTC

    Roles of Fukutin, the Gene Responsible for Fukuyama-Type Congenital Muscular Dystrophy, in Neurons: Possible Involvement in Synaptic Function and Neuronal Migration

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    Fukutin is a gene responsible for Fukuyama-type congenital muscular dystrophy (FCMD), accompanying ocular and brain malformations represented by cobblestone lissencephaly. Fukutin is related to basement membrane formation via the glycosylation of α-dystoglycan (α-DG), and astrocytes play a crucial role in the pathogenesis of the brain lesion. On the other hand, its precise function in neurons is unknown. In this experiment, the roles of fukutin in mature and immature neurons were examined using brains from control subjects and FCMD patients and cultured neuronal cell lines. In quantitative PCR, the expression level of fukutin looked different depending on the region of the brain examined. A similar tendency in DG expression appears to indicate a relation between fukutin and α-DG in mature neurons. An increase of DG mRNA and core α-DG in the FCMD cerebrum also supports the relation. In immunohistochemistry, dot-like positive reactions for VIA4-1, one of the antibodies detecting the glycosylated α-DG, in Purkinje cells suggest that fukutin is related to at least a post-synaptic function via the glycosylation of α-DG. As for immature neurons, VIA4-1 was predominantly positive in cells before and during migration with expression of fukutin, which suggest a participation of fukutin in neuronal migration via the glycosylation of α-DG. Moreover, fukutin may prevent neuronal differentiation, because its expression was significantly lower in the adult cerebrum and in differentiated cultured cells. A knockdown of fukutin was considered to induce differentiation in cultured cells. Fukutin seems to be necessary to keep migrating neurons immature during migration, and also to support migration via α-DG

    Onset of Dandy-Walker Syndrome in Adult following Head Trauma: A .

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    Although head trauma is suggested to precipitate hydrocephalus in adult-onset Dandy Walker syndrome (DWS), the clear mechanism is not verified. A 56-year-old female recovered completely after evacuation of acute epidural hematoma until development of dementia 7 days after operation. At day 20, she underwent ventriculo-peritoneal shunting to treat progressive hydrocephalus and has been free from neurologic symptoms for 2 years. The serial CT examinations indicate that after head trauma without subarachnoid hemorrhage, hydrocephalus can develop in a case of previously silent DWS. Rapid changes of intracranial pressure in trauma may affect cerebrospinal fluid outflow through a DWS-related valve mechanism at the foramina of Luschka, which results in hydrocephalus

    Activation of the Non-receptor Tyrosine Kinase cSrc in Macrophage-rich Atherosclerotic Plaques of Human Carotid Arteries

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    To determine the involvement of the non-receptor tyrosine kinase cSrc in plaque destabilization in carotid atherosclerosis (CAS), which is responsible for cerebral infarction, we performed quantitative and morphological detection of phosphorylated active cSrc (p-cSrc) and histopathological examination in CAS lesions. We examined carotid endarterectomy specimens obtained from 32 CAS patients. Each specimen was used for immunoblot and immunohistochemical analyses of p-cSrc, histopathological analysis, and image analysis of macrophage content. There was a strong positive correlation between cSrc activation on blots and macrophage content on sections. When we defined the macrophage-rich plaque (MRP) and the macrophage-poor plaque (MPP) as having macrophage content more and less than 5%, respectively, the p-cSrc density and the occurrence of plaque hemorrhage and thrombus formation were significantly increased in the MRP group (n=18) compared to the MPP group (n=14). p-cSrc immunoreactivity was localized in lesional endothelial cells, macrophages, and smooth muscle cells, which contained proinflammatory substances: the upstream oxidized low density lipoprotein, tissue factor and osteopontin, and the downstream active forms of extracellular signal-activated kinase and p38 and nuclear factor-κB. Our results suggest that cSrc activation in lesional cells contributes to plaque destabilization in CAS via persistent inflammation

    Involvement of 4-hydroxy-2-nonenal Accumulation in Multiple System Atrophy

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    Recent studies have suggested implications for α-synuclein cytotoxicity in the pathomechanism of multiple system atrophy (MSA). Given in vitro evidence that α-synuclein generates oxidative stress, it is proposed that lipid peroxidation may be accelerated in MSA. To address this issue, we performed an immunohistochemical analysis of protein-bound 4-hydroxy-2-nonenal (P-HNE) in sections of archival, formalin-fixed, paraffin-embedded pontine materials of eight sporadic MSA patients and eight age-matched control subjects. In the MSA cases, P-HNE immunoreactivity was localized in all of the neuronal cytoplasmic inclusions and glial cytoplasmic inclusions, both of them identified with α-synuclein and ubiquitin. It was also detectable in reactive astrocytes and phagocytic microglia but undetectable in activated microglia. By contrast, P-HNE immunoreactivity in the control cases was only very weak or not at all in the parenchyma including neurons and glia. The present results provide in vivo evidence that HNE participates in α-synuclein-induced cytotoxicity and neuroinflammation in MSA

    Significance of High-frequency Electrical Brain Activity

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     Electroencephalogram (EEG) data include broadband electrical brain activity ranging from infra-slow bands (200 / 250 Hz, respectively) are particularly of note due to their very close relationship to epileptogenicity, with the possibility that they could function as a surrogate biomarker of epileptogenicity. In contrast, physiological high-frequency activity plays an important role in higher brain functions, and the differentiation between pathological / epileptic and physiological HFOs is a critical issue, especially in epilepsy surgery. HFOs were initially recorded with intracranial electrodes in patients with intractable epilepsy as part of a long-term invasive seizure monitoring study. However, fast oscillations (FOs) in the ripple and gamma bands (40-80 Hz) are now noninvasively detected by scalp EEG and magnetoencephalography, and thus the scope of studies on HFOs /FOs is rapidly expanding

    Kissing Aneurysm of the Distal Anterior Cerebral Artery: Preoperative CT Angiography and Surgical Management: A

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    We describe a patient with mirror-image aneurysms in the bilateral distal anterior cerebral artery (ACA). The larger aneurysm was clearly disclosed with digital subtraction angiography (DSA), but the smaller one could not be definitely identified. The bilateral aneurysms were confirmed with computed tomographic (CT) angiography, which showed the right ACA aneurysm to be hidden behind the left ACA aneurysm, likely buried in the cingulate gyrus. During surgery, the left ACA aneurysm was clipped first. The right ACA aneurysm was exposed by a small subpial resection of the cingulate gyrus, and the right ACA aneurysm, which strongly adhered to the surrounding tissue, was safely dissected. Multiple aneurysms associated with a distal ACA aneurysm are not rare. We conclude that further examination with CT angiography is important when kissing aneurysms are suggested by DSA
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