1.Oculodentodigital Dysplasia Presenting as Spastic Paraparesis: The First Genetically Confirmed Korean Case and a Literature Review.
Kye Won PARK ; Ho Sung RYU ; Juyeon KIM ; Sun Ju CHUNG
Journal of Movement Disorders 2017;10(3):149-153
Oculodentodigital dysplasia (ODDD) is a rare autosomal dominant inherited disease caused by mutations of the human gap junction alpha 1 gene, which encodes the protein Connexin-43. Patients with ODDD may present with neurological deficits with a typical pleiotropic combination of characteristic craniofacial, ophthalmological, phalangeal, and dental anomalies. In this report, we describe the first genetically confirmed Korean ODDD patient, who presented with spastic paraparesis. We will also review the neurological aspects of ODDD as reported in the literature.
Gap Junctions
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Humans
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Muscle Spasticity*
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Paraparesis, Spastic*
2.Short-term Observation of Histological Changes on the Rabbit Retina after Endocryopexy.
Jeong II KIM ; Hokyung LEE ; Jin Hyung YOO
Journal of the Korean Ophthalmological Society 1993;34(10):1023-1028
The aim of this study was to evaluate the histopathologic changes of the pigmented rabbit ratina after endocryopexy. We investigated the differences or similarity among endocryopexy, transscleral cryopexy and laser phocoagulation. Their ultrastructural changes were observed with light and electron microscope. The results were as follows; 1. The first day after endocryopexy, we observed rupture of the internal limiting membrane, breakdown the inner and outer retina, separation of intercellular gap junction of pigment epithelial cells, and accumulation of exudation within subretinal space. 2. In the 8th days, there are mull iplication of retinal pigment epithelial cell layer and development of basal infolding. 3. The present study suggested that effects of endocryopexy on the retina to cause chorioretinal adhesion was similar to transscleral cryopexy or laser photocoagulation However it should be operated on the premise that in requires technical skill for the purpose of clinical application.
Epithelial Cells
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Gap Junctions
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Light Coagulation
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Membranes
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Retina*
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Retinaldehyde
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Rupture
3.Morphology and Distribution of Gap Junction in Horizontal Cells of the Rabbit Retina.
Korean Journal of Anatomy 2008;41(4):271-277
Horizontal cells (HCs) of the mammalian retina are interneurons that provide negative feedback to photoreceptors in the outer plexiform layer (OPL) where the first synapse occurs and contribute to the center surround antagonism that underlies the receptive field properties of many retinal neurons. These functions of HCs are thought to be attributed to their coupled network via gap junctions. Two kinds of connexin (Cx) proteins, Cx50 and 57 are known to form gap junctions of HCs. However, little is known about precise localization of gap junctions within HCs. Thus, this study was designed to determine the localization of HC gap junctions at subcellular level. In vertical ultrathin sections of the rabbit retina, gap junctions composed of Cx50 and 57 were identified in the OPL by the electron-dense reaction products. Each Cx50 and 57 gap junction on putative HC processes showed its own distinct features. Cx50 gap junction was bigger in size and localized more proximally than Cx57. In addition, Cx57 gap junctions had distinct shape. That is, about a half of them appeared to be invaginated or endocytosed in shape. The differences in shape, size and subcellular localization between Cx50 and 57 gap junctions may provide the insights into the function of different types of horizontal cell.
Gap Junctions
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Interneurons
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Proteins
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Retina
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Retinal Neurons
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Synapses
4.Bisphenol A and 4-tert-Octylphenol Inhibit Cx46 Hemichannel Currents.
The Korean Journal of Physiology and Pharmacology 2015;19(1):73-79
Connexins (Cx) are membrane proteins and monomers for forming gap junction (GJ) channels. Cx46 and Cx50 are also known to function as conductive hemichannels. As part of an ongoing effort to find GJ-specific blocker(s), endocrine disruptors were used to examine their effect on Cx46 hemichannels expressed in Xenopus oocytes. Voltage-dependent gating of Cx46 hemichannels was characterized by slowly activating outward currents and relatively fast inward tail currents. Bisphenol A (BPA, 10 nM) reduced outward currents of Cx46 hemichannels up to ~18% of control, and its effect was reversible (n=5). 4-tert-Octylphenol (OP, 1 microM) reversibly reduced outward hemichannel currents up to ~28% (n=4). However, overall shapes of Cx46 hemichannel current traces (outward and inward currents) were not changed by these drugs. These results suggest that BPA and OP are likely to occupy the pore of Cx46 hemichannels and thus obstruct the ionic fluxes. This finding provides that BPA and OP are potential candidates for GJ channel blockers.
Connexins
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Endocrine Disruptors
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Gap Junctions
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Membrane Proteins
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Oocytes
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Xenopus
5.Intercellular gap junctions in corporal smooth muscle.
National Journal of Andrology 2002;8(2):136-138
The contractility of corporal smooth muscle plays a critical role in human penile erectile process. Understanding the initiation, maintenance and modulation of corporal smooth muscle tone is a prequisite to improve understanding, diagnosis and treatment of erectile dysfunction. Despite this fact, indentification of both the precise mechanistic basis by which various agents exert their effects on individual corporal smooth muscle cells, moreover, the process by which these signals are spread among the diverse array of parenchymal cells in the paired corporal, remain somewhat of a physiological enigma. Therefore, this article aims at: 1. to review current knowledge of the regulation of corporal smooth muscle tone at the cellular and molecular level; 2. to review various methods used in the study of gap junction channel.
Animals
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Connexins
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physiology
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Gap Junctions
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physiology
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Humans
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Intercellular Junctions
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physiology
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Male
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Muscle, Smooth
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physiology
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Penis
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cytology
8.Expression of connexin 36 in central nervous system and its role in epileptic seizure.
Yu-Fen PENG ; Jiong-Xing WU ; Heng YANG ; Xuan-Qi DONG ; Wen ZHENG ; Zhi SONG
Chinese Medical Journal 2012;125(13):2365-2370
OBJECTIVEThis review discusses the experimental and clinical studies those show the expression of connexin 36 in the central nervous system and the possible role of connexin 36 in epileptic seizure.
DATA SOURCESAll articles used in this review were mainly searched from PubMed published in English from 1996 to 2012.
STUDY SELECTIONOriginal articles and reviews were selected if they were related to the expression of connexin 36 in the central nervous system and its role in epilepsy.
RESULTSThe distribution of connexin 36 is developmentally regulated, cell-specific and region-specific. Connexin 36 is involved in some neuronal functions and epileptic synchronization. Changes in the connexin 36 gene and protein were accompanied by seizures. Selective gap junction blockers have exerted anticonvulsant actions in a variety of experiments examined in both humans and experimental animals.
CONCLUSIONSConnexin 36 plays an important role in both physiological and pathological conditions in the central nervous system. A better understanding of the role of connexin 36 in seizure activity may contribute to the development of new therapeutic approaches to treating epilepsy.
Animals ; Central Nervous System ; metabolism ; Connexins ; metabolism ; Gap Junctions ; metabolism ; Humans ; Seizures ; metabolism
9.Erythrokeratodermia Variabilis Showing Gradual Disappearance of Erythema.
Hyojin KIM ; In Ho PARK ; Jeong Nan KANG ; Jung Eun SEOL ; Ho Suk SUNG
Korean Journal of Dermatology 2014;52(4):260-263
Erythrokeratodermia variabilis is an autosomal-dominant inherited disease associated with a mutation in gap junction beta (GJB) 3 and 4. It shows two characteristic features: migratory and irregularly shaped erythematous lesions usually accompanied by a burning sensation and fixed, symmetrically located hyperkeratotic plaques. A 6-year-old boy had developed erythematous scaly patches with a geographic pattern on the entire body at age 1, and the lesions had migrated with an irregular pattern. Accompanying hyperkeratotic plaque developed on the trunk and both legs when he was 4 years old. As he grew older, the erythematous patches progressively disappeared and the hyperkeratotic plaque dominantly remained. His family history was unidentifiable because he was adopted at birth. Pathologic findings showed hyperkeratosis and superficial perivascular inflammation. Based on the clinical and pathologic features, we diagnosed erythrokeratodermia variabilis in this patient. Herein, we report a case of erythrokeratodermia variabilis showing gradual disappearance of erythema.
Burns
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Child
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Erythema*
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Erythrokeratodermia Variabilis*
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Gap Junctions
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Humans
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Inflammation
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Leg
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Male
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Parturition
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Sensation
10.Gap junction and diabetic foot.
Xiao-rong ZOU ; Jian TAO ; Yun-kai WANG
Journal of Zhejiang University. Medical sciences 2015;44(6):684-688
Gap junctions play a critical role in electrical synchronization and exchange of small molecules between neighboring cells; connexins are a family of structurally related transmembrane proteins that assemble to form vertebrate gap junctions. Hyperglycemia changes the structure gap junction proteins and their expression, resulting in obstruction of neural regeneration, vascular function and wound healing, and also promoting vascular atherosclerosis. These pathogenic factors would cause diabetic foot ulcers. This article reviews the involvement of connexins in pathogenesis of diabetic foot.
Atherosclerosis
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Connexins
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metabolism
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Diabetic Foot
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pathology
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Gap Junctions
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metabolism
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Humans
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Hyperglycemia
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physiopathology
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Regeneration
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Wound Healing