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Ben Khalaf N, Pham S, Romeo G, Abdelghany S, Intagliata S, Sedillo P, Salerno L, Gonzales J, Fathallah DM, Perkins DJ, Hurwitz I, Pittalà V. A computer-aided approach to identify novel Leishmania major protein disulfide isomerase inhibitors for treatment of leishmaniasis. J Comput Aided Mol Des 2021; 35:297-314. [PMID: 33615401 DOI: 10.1007/s10822-021-00374-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 01/15/2021] [Indexed: 12/19/2022]
Abstract
Leishmaniasis is an infectious disease caused by parasites of the genus Leishmania and transmitted by the bite of a sand fly. To date, most available drugs for treatment are toxic and beyond the economic means of those affected by the disease. Protein disulfide isomerase (PDI) is a chaperone protein that plays a major role in the folding of newly synthesized proteins, specifically assisting in disulfide bond formation, breakage, or rearrangement in all non-native proteins. In previous work, we demonstrated that Leishmania major PDI (LmPDI) has an essential role in pathogen virulence. Furthermore, inhibition of LmPDI further blocked parasite infection in macrophages. In this study, we utilized a computer-aided approach to design a series of LmPDI inhibitors. Fragment-based virtual screening allowed for the understanding of the inhibitors' modes of action on LmPDI active sites. The generated compounds obtained after multiple rounds of virtual screening were synthesized and significantly inhibited target LmPDI reductase activity and were shown to decrease in vitro parasite growth in human monocyte-derived macrophages. This novel cheminformatics and synthetic approach led to the identification of a new series of compounds that might be optimized into novel drugs, likely more specific and less toxic for the treatment of leishmaniasis.
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Affiliation(s)
- Noureddine Ben Khalaf
- Department of Life Sciences, Health Biotechnology Program, College of Graduates Studies, King Fahd Chair for Health Biotechnology, Arabian Gulf University, Road 2904 Building 293, Manama, 329, Kingdom of Bahrain.
| | - Susie Pham
- Center for Global Health, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Giuseppe Romeo
- Department of Drug Sciences, University of Catania, V.le A. Doria 6, 95125, Catania, Italy
| | - Sara Abdelghany
- Department of Molecular Medicine, Princess Al-Jawhara Center for Genetics and Inherited Diseases, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Bahrain
| | - Sebastiano Intagliata
- Department of Drug Sciences, University of Catania, V.le A. Doria 6, 95125, Catania, Italy
| | - Peter Sedillo
- Center for Global Health, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Loredana Salerno
- Department of Drug Sciences, University of Catania, V.le A. Doria 6, 95125, Catania, Italy
| | - Jessica Gonzales
- Center for Global Health, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Dahmani M Fathallah
- Department of Life Sciences, Health Biotechnology Program, College of Graduates Studies, King Fahd Chair for Health Biotechnology, Arabian Gulf University, Road 2904 Building 293, Manama, 329, Kingdom of Bahrain
| | - Douglas J Perkins
- Center for Global Health, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Ivy Hurwitz
- Center for Global Health, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Valeria Pittalà
- Department of Drug Sciences, University of Catania, V.le A. Doria 6, 95125, Catania, Italy
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Makhdoumi P, Hossini H, Ashraf GM, Limoee M. Molecular Mechanism of Aniline Induced Spleen Toxicity and Neuron Toxicity in Experimental Rat Exposure: A Review. Curr Neuropharmacol 2019; 17:201-213. [PMID: 30081786 PMCID: PMC6425079 DOI: 10.2174/1570159x16666180803164238] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 01/17/2018] [Accepted: 08/02/2018] [Indexed: 01/04/2023] Open
Abstract
Aniline exposure leads to neuron and spleen toxicity specifically and makes diverse neurological effects and sar-coma that is defined by splenomegaly, hyperplasia, and fibrosis and tumors formation at the end. However, the molecular mechanism(s) of aniline-induced spleen toxicity is not understood well, previous studies have represented that aniline expo-sure results in iron overload and initiation of oxidative/nitrosative disorder stress and oxidative damage to proteins, lipids and DNA subsequently, in the spleen. Elevated expression of cyclins, cyclin-dependent kinases (CDKs) and phosphorylation of pRB protein along with increases in A, B and CDK1 as a cell cycle regulatory proteins cyclins, and reduce in CDK inhibitors (p21 and p27) could be critical in cell cycle regulation, which contributes to tumorigenic response after aniline exposure. Aniline-induced splenic toxicity is corre-lated to oxidative DNA damage and initiation of DNA glycosylases expression (OGG1, NEIL1/2, NTH1, APE1 and PNK) for removal of oxidative DNA lesions in rat. Oxidative stress causes transcriptional up-regulation of fibrogenic/inflammatory factors (cytokines, IL-1, IL-6 and TNF-α) via induction of nuclear factor-kappa B, AP-1 and redox-sensitive transcription factors, in aniline treated-rats. The upstream signalling events as phosphorylation of IκB kinases (IKKα and IKKβ) and mito-gen-activated protein kinases (MAPKs) could potentially be the causes of activation of NF-κB and AP-1. All of these events could initiate a fibrogenic and/or tumorigenic response in the spleen. The spleen toxicity of aniline is studied more and the different mechanisms are suggested. This review summarizes those events following aniline exposure that induce spleen tox-icity and neurotoxicity.
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Affiliation(s)
- Pouran Makhdoumi
- Research Center for Environmental Determinants of Health (RCEDH), School of Public Health, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Hooshyar Hossini
- Research Center for Environmental Determinants of Health (RCEDH), School of Public Health, Kermanshah University of Medical Sciences, Kermanshah, Iran.,Department of Environmental Health Engineering, Faculty of Health, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Ghulam Md Ashraf
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mojtaba Limoee
- Research Center for Environmental Determinants of Health (RCEDH), School of Public Health, Kermanshah University of Medical Sciences, Kermanshah, Iran.,Department of Environmental Health Engineering, Faculty of Health, Kermanshah University of Medical Sciences, Kermanshah, Iran
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3
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Watanabe Y, Nakajima K, Ito Y, Akahori Y, Saito F, Woo GH, Yoshida T, Shibutani M. Twenty-eight-day repeated oral doses of sodium valproic acid increases neural stem cells and suppresses differentiation of granule cell lineages in adult hippocampal neurogenesis of postpubertal rats. Toxicol Lett 2019; 312:195-203. [PMID: 31085223 DOI: 10.1016/j.toxlet.2019.05.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 04/17/2019] [Accepted: 05/10/2019] [Indexed: 02/06/2023]
Abstract
Developmental exposure to valproic acid (VPA), a model compound for experimental autism, has shown to primarily target GABAergic interneuron subpopulations in hippocampal neurogenesis of rat offspring. The VPA-exposed animals had revealed late effects on granule cell lineages, involving progenitor cell proliferation and synaptic plasticity. To investigate the possibility whether hippocampal neurogenesis in postpubertal rats in a protocol of 28-day repeated exposure is affected in relation with the property of a developmental neurotoxicant by developmental exposure, VPA was orally administered to 5-week-old male rats at 0, 200, 800 and 900 mg/kg body weight/day for 28 days. At 900 mg/kg, GFAP+ cells increased in number, but DCX+ cells decreased in number in the granule cell lineages. Moreover, CHRNB2+ cells and NeuN+ postmitotic neurons decreased in number in the hilus of the dentate gyrus. Transcript level examined at 900 mg/kg in the dentate gyrus was increased with Kit, but decreased with Dpsyl3, Btg2, Pvalb and Chrnb2. These results suggest that VPA increased type-1 stem cells in relation to the activation of SCF-KIT signaling and suppression of BTG2-mediated antiproliferative effect on stem cells. VPA also decreased type-3 progenitor cells and immature granule cells probably in relation with PVALB+ interneuron hypofunction and reduced CHRNB2+ interneuron subpopulation in the hilus, as well as with suppression of BTG2-mediated terminal differentiation of progenitor cells. Thus, the disruption pattern of VPA by postpubertal exposure was different from developmental exposure. However, disruption itself can be detected, suggesting availability of hippocampal neurogenesis in detecting developmental neurotoxicants in a 28-day toxicity study.
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Affiliation(s)
- Yousuke Watanabe
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan; Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193, Japan.
| | - Kota Nakajima
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan; Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193, Japan.
| | - Yuko Ito
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan; Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193, Japan.
| | - Yumi Akahori
- Chemicals Evaluation and Research Institute, Japan, 1-4-25 Koraku, Bunkyo-ku, Tokyo 112-0004, Japan.
| | - Fumiyo Saito
- Chemicals Evaluation and Research Institute, Japan, 1-4-25 Koraku, Bunkyo-ku, Tokyo 112-0004, Japan.
| | - Gye-Hyeong Woo
- Laboratory of Histopathology, Department of Clinical Laboratory Science, Semyung University, 65 Semyung-ro, Jecheon-si, Chungbuk 27136, Republic of Korea.
| | - Toshinori Yoshida
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.
| | - Makoto Shibutani
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan; Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.
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Watanabe Y, Abe H, Nakajima K, Ideta-Otsuka M, Igarashi K, Woo GH, Yoshida T, Shibutani M. Aberrant Epigenetic Gene Regulation in GABAergic Interneuron Subpopulations in the Hippocampal Dentate Gyrus of Mouse Offspring Following Developmental Exposure to Hexachlorophene. Toxicol Sci 2019; 163:13-25. [PMID: 29301063 PMCID: PMC5917777 DOI: 10.1093/toxsci/kfx291] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Maternal hexachlorophene (HCP) exposure causes transient disruption of hippocampal neurogenesis in mouse offspring. We examined epigenetically hypermethylated and downregulated genes related to this HCP-induced disrupted neurogenesis. Mated female mice were dietary exposed to 0 or 100 ppm HCP from gestational day 6 to postnatal day (PND) 21 on weaning. The hippocampal dentate gyrus of male offspring was subjected to methyl-capture sequencing and real-time reverse transcription-polymerase chain reaction analyses on PND 21. Validation analyses on methylation identified three genes, Dlx4, Dmrt1, and Plcb4, showing promoter-region hypermethylation. Immunohistochemically, DLX4+, DMRT1+, and PLCB4+ cells in the dentate hilus co-expressed GAD67, a γ-aminobutyric acid (GABA)ergic neuron marker. HCP decreased all of three subpopulations as well as GAD67+ cells on PND 21. PLCB4+ cells also co-expressed the metabotropic glutamate receptor, GRM1. HCP also decreased transcript level of synaptic plasticity-related genes in the dentate gyrus and immunoreactive granule cells for synaptic plasticity-related ARC. On PND 77, all immunohistochemical cellular density changes were reversed, whereas the transcript expression of the synaptic plasticity-related genes fluctuated. Thus, HCP-exposed offspring transiently reduced the number of GABAergic interneurons. Among them, subpopulations expressing DLX4, DMRT1, or PLCB4 were transiently reduced in number through an epigenetic mechanism. Considering the role of the Dlx gene family in GABAergic interneuron migration and differentiation, the decreased number of DLX4+ cells may be responsible for reducing those GABAergic interneurons regulating neurogenesis. The effect on granule cell synaptic plasticity was sustained until the adult stage, and reduced GABAergic interneurons active in GRM1–PLCB4 signaling may be responsible for the suppression on weaning.
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Affiliation(s)
- Yousuke Watanabe
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan.,Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu-shi, Gifu 501-1193, Japan
| | - Hajime Abe
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan
| | - Kota Nakajima
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan.,Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu-shi, Gifu 501-1193, Japan
| | - Maky Ideta-Otsuka
- Life Science Tokyo Advanced Research Center (L-StaR), Hoshi University School of Pharmacy and Pharmaceutical Sciences, Shinagawa-ku, Tokyo 142-5801, Japan
| | - Katsuhide Igarashi
- Life Science Tokyo Advanced Research Center (L-StaR), Hoshi University School of Pharmacy and Pharmaceutical Sciences, Shinagawa-ku, Tokyo 142-5801, Japan
| | - Gye-Hyeong Woo
- Laboratory of Histopathology, Department of Clinical Laboratory Science, Semyung University, Jecheon-si, Chungbuk 27136, Republic of Korea
| | - Toshinori Yoshida
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan
| | - Makoto Shibutani
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan.,Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan
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5
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Abstract
The diverse, structurally unrelated chemicals that cause toxic myelinopathies have been investigated and can be categorized into two types of primary demyelinators. Some demyelinating chemicals seem to leave intact the myeli-nating cells (oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system), while others damage the myelinating cells as well as the myelin. The significance between the two is that with the myelinating cells still in tact, repair of the myelin sheath can occur. However, if the myelinating cells are destroyed, repair and reversal of the neuropathy may not occur. Histologically, these chemicals produce an edema of the white matter of the brain, and in some cases the peripheral nervous system, that appears spongy by light microscopy. By electron microscopy, vacuoles can be seen in the myelin surrounding axons. These vacuoles are characterized as fluid-filled separations (splitting) of myelin lamellae at the intraperiod line. In some cases these vacuoles can degenerate further to full demyelination, affecting conduction through those axons. Regeneration of the myelin layers can occur, and in some cases occurs at the same time other axons are undergoing toxic demyelination. Several of these chemicals, however, have been shown to increase cerebrospinal fluid pressure in the brain, optic nerve, and spinal cord, and/or intraneuronal pressure in the perineurium surrounding the axons in the peripheral nervous system. This increased pressure has been correlated with decreased conduction capacity through the axon, ischemia to the neuronal tissue from decreased blood flow because of pressure against the blood vessels, and, if unrelieved, permanent axonal damage. Several of these chemicals havebeen shown to inhibit oxidative phosphorylation, while others uncouple oxidative phosphorylation. One chemical appears to inhibit an enzyme critical to cholesterol synthesis, thus destabilizing myelin. Another hypothesis for a mechanism of action may be in the ability of these compounds to alter membrane permeability.
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Kato M, Abe H, Itahashi M, Kikuchihara Y, Kimura M, Mizukami S, Yoshida T, Shibutani M. Maternal exposure to hexachlorophene targets intermediate-stage progenitor cells in the hippocampal neurogenesis involving myelin vacuolation of cholinergic and glutamatergic inputs in mice. J Appl Toxicol 2015; 36:211-22. [PMID: 25943520 DOI: 10.1002/jat.3162] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 03/16/2015] [Accepted: 03/16/2015] [Indexed: 11/11/2022]
Abstract
Hexachlorophene (HCP) has been shown to induce myelin vacuolation due to intramyelinic edema of the nerve fibers in animal neural tissue. We investigated the maternal exposure effect of HCP on hippocampal neurogenesis in the offspring of pregnant mice supplemented with 0 (control), 33 or 100 ppm HCP in diet from gestational day 6 to day 21 after delivery. On postnatal day (PND) 21, offspring as examined in males exhibited decreased granule cell lineage populations expressing paired box 6, sex-determining region Y-box 2 and eomesodermin in the hippocampal subgranular zone (SGZ) accompanied by myelin vacuolation involving white matter tracts of the hippocampal fimbria at ≥ 33 ppm. However, SGZ cellular populations expressing brain lipid binding protein and doublecortin were unchanged at any dose. Transcript expression of cholinergic receptor genes, Chrna4 and Chrnb2, and glutamate receptor genes, Grm1 and Grin2d, examined at 100 ppm, decreased in the dentate gyrus. HCP exposure did not alter the number of proliferating or apoptotic cells in the SGZ, or reelin- or calcium-binding protein-expressing γ-aminobutyric acid (GABA)ergic interneurons in the dentate hilus, on PND 21 and PND 77. All neurogenesis-related changes observed in HCP-exposed offspring on PND 21 disappeared on PND 77, suggesting that maternal HCP exposure at ≥ 33 ppm reversibly decreased type 2 intermediate-stage progenitor cells in the hippocampal neurogenesis. Myelin vacuolation might be responsible for changes in neurogenesis possibly by reducing nerve conduction velocity of cholinergic inputs from the septal-hippocampal pathway to granule cell lineages and/or GABAergic interneurons, and of glutamatergic inputs to granule cell lineages.
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Affiliation(s)
- Mizuho Kato
- Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan
| | - Hajime Abe
- Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan.,Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu-shi, Gifu, Japan
| | - Megu Itahashi
- Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan.,Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu-shi, Gifu, Japan
| | - Yoh Kikuchihara
- Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan
| | - Masayuki Kimura
- Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan.,Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu-shi, Gifu, Japan
| | - Sayaka Mizukami
- Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan.,Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu-shi, Gifu, Japan
| | - Toshinori Yoshida
- Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan
| | - Makoto Shibutani
- Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo, Japan
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7
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Itahashi M, Abe H, Tanaka T, Mizukami S, Kimura M, Yoshida T, Shibutani M. Maternal exposure to hexachlorophene targets intermediate-stage progenitor cells of the hippocampal neurogenesis in rat offspring via dysfunction of cholinergic inputs by myelin vacuolation. Toxicology 2015; 328:123-34. [DOI: 10.1016/j.tox.2014.12.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Revised: 12/07/2014] [Accepted: 12/09/2014] [Indexed: 10/24/2022]
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Popescu BFG, Guo Y, Jentoft ME, Parisi JE, Lennon VA, Pittock SJ, Weinshenker BG, Wingerchuk DM, Giannini C, Metz I, Brück W, Shuster EA, Carter J, Boyd CD, Clardy SL, Cohen BA, Lucchinetti CF. Diagnostic utility of aquaporin-4 in the analysis of active demyelinating lesions. Neurology 2014; 84:148-58. [PMID: 25503621 DOI: 10.1212/wnl.0000000000001126] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE To assess, in a surgical biopsy cohort of active demyelinating lesions, the diagnostic utility of aquaporin-4 (AQP4) immunohistochemistry in identifying neuromyelitis optica (NMO) or NMO spectrum disorder (NMOSD) and describe pathologic features that should prompt AQP4 immunohistochemical analysis and AQP4-immunoglobulin G (IgG) serologic testing. METHODS This was a neuropathologic cohort study of 20 surgical biopsies (19 patients; 11 cord/9 brain), performed because of diagnostic uncertainty, interpreted as active demyelinating disease and containing 2 or more of the following additional features: tissue vacuolation, granulocytic infiltrates, or astrocyte injury. RESULTS AQP4 immunoreactivity was lost in 18 biopsies and increased in 2. Immunopathologic features of the AQP4 loss cohort were myelin vacuolation (18), dystrophic astrocytes and granulocytes (17), vascular hyalinization (16), macrophages containing glial fibrillary acid protein (GFAP)-positive debris (14), and Creutzfeldt-Peters cells (0). All 14 cases with available serum tested positive for AQP4-IgG after biopsy. Diagnosis at last follow-up was NMO/NMOSD (15) and longitudinally extensive transverse myelitis (1 each relapsing and single). Immunopathologic features of the AQP4 increased cohort were macrophages containing GFAP-positive debris and granulocytes (2), myelin vacuolation (1), dystrophic astrocytes (1), Creutzfeldt-Peters cells (1), and vascular hyalinization (1). Diagnosis at last follow-up was multiple sclerosis (MS) and both tested AQP4-IgG seronegative after biopsy. CONCLUSIONS AQP4 immunohistochemistry with subsequent AQP4-IgG testing has diagnostic utility in identifying cases of NMO/NMOSD. This study highlights the importance of considering NMOSD in the differential diagnosis of tumefactive brain or spinal cord lesions. AQP4-IgG testing may avert biopsy and avoid ineffective therapies if these patients are erroneously treated for MS.
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Affiliation(s)
- Bogdan F G Popescu
- From the Department of Anatomy and Cell Biology and Cameco MS Neuroscience Research Center (B.F.G.P.), University of Saskatchewan, Saskatoon, Canada; the Departments of Neurology (Y.G., J.E.P., V.A.L., S.J.P., B.G.W., S.L.C., C.F.L.), Laboratory Medicine and Pathology (M.E.J., J.E.P., V.A.L., S.J.P., G.G.), and Immunology (V.A.L.), Mayo Clinic, Rochester, MN; the Department of Neurology (D.M.W., J.C.), Mayo Clinic, Scottsdale, AZ; the Department of Neuropathology (I.M., W.B.), University Medical Center, Georg August University, Göttingen, Germany; the Department of Neurology (E.A.S.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (C.D.B.), Columbia University Medical Center, New York, NY; and the Department of Neurology (B.A.C.), Feinberg School of Medicine, Northwestern University, Evanston, IL
| | - Yong Guo
- From the Department of Anatomy and Cell Biology and Cameco MS Neuroscience Research Center (B.F.G.P.), University of Saskatchewan, Saskatoon, Canada; the Departments of Neurology (Y.G., J.E.P., V.A.L., S.J.P., B.G.W., S.L.C., C.F.L.), Laboratory Medicine and Pathology (M.E.J., J.E.P., V.A.L., S.J.P., G.G.), and Immunology (V.A.L.), Mayo Clinic, Rochester, MN; the Department of Neurology (D.M.W., J.C.), Mayo Clinic, Scottsdale, AZ; the Department of Neuropathology (I.M., W.B.), University Medical Center, Georg August University, Göttingen, Germany; the Department of Neurology (E.A.S.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (C.D.B.), Columbia University Medical Center, New York, NY; and the Department of Neurology (B.A.C.), Feinberg School of Medicine, Northwestern University, Evanston, IL
| | - Mark E Jentoft
- From the Department of Anatomy and Cell Biology and Cameco MS Neuroscience Research Center (B.F.G.P.), University of Saskatchewan, Saskatoon, Canada; the Departments of Neurology (Y.G., J.E.P., V.A.L., S.J.P., B.G.W., S.L.C., C.F.L.), Laboratory Medicine and Pathology (M.E.J., J.E.P., V.A.L., S.J.P., G.G.), and Immunology (V.A.L.), Mayo Clinic, Rochester, MN; the Department of Neurology (D.M.W., J.C.), Mayo Clinic, Scottsdale, AZ; the Department of Neuropathology (I.M., W.B.), University Medical Center, Georg August University, Göttingen, Germany; the Department of Neurology (E.A.S.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (C.D.B.), Columbia University Medical Center, New York, NY; and the Department of Neurology (B.A.C.), Feinberg School of Medicine, Northwestern University, Evanston, IL
| | - Joseph E Parisi
- From the Department of Anatomy and Cell Biology and Cameco MS Neuroscience Research Center (B.F.G.P.), University of Saskatchewan, Saskatoon, Canada; the Departments of Neurology (Y.G., J.E.P., V.A.L., S.J.P., B.G.W., S.L.C., C.F.L.), Laboratory Medicine and Pathology (M.E.J., J.E.P., V.A.L., S.J.P., G.G.), and Immunology (V.A.L.), Mayo Clinic, Rochester, MN; the Department of Neurology (D.M.W., J.C.), Mayo Clinic, Scottsdale, AZ; the Department of Neuropathology (I.M., W.B.), University Medical Center, Georg August University, Göttingen, Germany; the Department of Neurology (E.A.S.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (C.D.B.), Columbia University Medical Center, New York, NY; and the Department of Neurology (B.A.C.), Feinberg School of Medicine, Northwestern University, Evanston, IL
| | - Vanda A Lennon
- From the Department of Anatomy and Cell Biology and Cameco MS Neuroscience Research Center (B.F.G.P.), University of Saskatchewan, Saskatoon, Canada; the Departments of Neurology (Y.G., J.E.P., V.A.L., S.J.P., B.G.W., S.L.C., C.F.L.), Laboratory Medicine and Pathology (M.E.J., J.E.P., V.A.L., S.J.P., G.G.), and Immunology (V.A.L.), Mayo Clinic, Rochester, MN; the Department of Neurology (D.M.W., J.C.), Mayo Clinic, Scottsdale, AZ; the Department of Neuropathology (I.M., W.B.), University Medical Center, Georg August University, Göttingen, Germany; the Department of Neurology (E.A.S.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (C.D.B.), Columbia University Medical Center, New York, NY; and the Department of Neurology (B.A.C.), Feinberg School of Medicine, Northwestern University, Evanston, IL
| | - Sean J Pittock
- From the Department of Anatomy and Cell Biology and Cameco MS Neuroscience Research Center (B.F.G.P.), University of Saskatchewan, Saskatoon, Canada; the Departments of Neurology (Y.G., J.E.P., V.A.L., S.J.P., B.G.W., S.L.C., C.F.L.), Laboratory Medicine and Pathology (M.E.J., J.E.P., V.A.L., S.J.P., G.G.), and Immunology (V.A.L.), Mayo Clinic, Rochester, MN; the Department of Neurology (D.M.W., J.C.), Mayo Clinic, Scottsdale, AZ; the Department of Neuropathology (I.M., W.B.), University Medical Center, Georg August University, Göttingen, Germany; the Department of Neurology (E.A.S.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (C.D.B.), Columbia University Medical Center, New York, NY; and the Department of Neurology (B.A.C.), Feinberg School of Medicine, Northwestern University, Evanston, IL
| | - Brian G Weinshenker
- From the Department of Anatomy and Cell Biology and Cameco MS Neuroscience Research Center (B.F.G.P.), University of Saskatchewan, Saskatoon, Canada; the Departments of Neurology (Y.G., J.E.P., V.A.L., S.J.P., B.G.W., S.L.C., C.F.L.), Laboratory Medicine and Pathology (M.E.J., J.E.P., V.A.L., S.J.P., G.G.), and Immunology (V.A.L.), Mayo Clinic, Rochester, MN; the Department of Neurology (D.M.W., J.C.), Mayo Clinic, Scottsdale, AZ; the Department of Neuropathology (I.M., W.B.), University Medical Center, Georg August University, Göttingen, Germany; the Department of Neurology (E.A.S.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (C.D.B.), Columbia University Medical Center, New York, NY; and the Department of Neurology (B.A.C.), Feinberg School of Medicine, Northwestern University, Evanston, IL
| | - Dean M Wingerchuk
- From the Department of Anatomy and Cell Biology and Cameco MS Neuroscience Research Center (B.F.G.P.), University of Saskatchewan, Saskatoon, Canada; the Departments of Neurology (Y.G., J.E.P., V.A.L., S.J.P., B.G.W., S.L.C., C.F.L.), Laboratory Medicine and Pathology (M.E.J., J.E.P., V.A.L., S.J.P., G.G.), and Immunology (V.A.L.), Mayo Clinic, Rochester, MN; the Department of Neurology (D.M.W., J.C.), Mayo Clinic, Scottsdale, AZ; the Department of Neuropathology (I.M., W.B.), University Medical Center, Georg August University, Göttingen, Germany; the Department of Neurology (E.A.S.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (C.D.B.), Columbia University Medical Center, New York, NY; and the Department of Neurology (B.A.C.), Feinberg School of Medicine, Northwestern University, Evanston, IL
| | - Caterina Giannini
- From the Department of Anatomy and Cell Biology and Cameco MS Neuroscience Research Center (B.F.G.P.), University of Saskatchewan, Saskatoon, Canada; the Departments of Neurology (Y.G., J.E.P., V.A.L., S.J.P., B.G.W., S.L.C., C.F.L.), Laboratory Medicine and Pathology (M.E.J., J.E.P., V.A.L., S.J.P., G.G.), and Immunology (V.A.L.), Mayo Clinic, Rochester, MN; the Department of Neurology (D.M.W., J.C.), Mayo Clinic, Scottsdale, AZ; the Department of Neuropathology (I.M., W.B.), University Medical Center, Georg August University, Göttingen, Germany; the Department of Neurology (E.A.S.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (C.D.B.), Columbia University Medical Center, New York, NY; and the Department of Neurology (B.A.C.), Feinberg School of Medicine, Northwestern University, Evanston, IL
| | - Imke Metz
- From the Department of Anatomy and Cell Biology and Cameco MS Neuroscience Research Center (B.F.G.P.), University of Saskatchewan, Saskatoon, Canada; the Departments of Neurology (Y.G., J.E.P., V.A.L., S.J.P., B.G.W., S.L.C., C.F.L.), Laboratory Medicine and Pathology (M.E.J., J.E.P., V.A.L., S.J.P., G.G.), and Immunology (V.A.L.), Mayo Clinic, Rochester, MN; the Department of Neurology (D.M.W., J.C.), Mayo Clinic, Scottsdale, AZ; the Department of Neuropathology (I.M., W.B.), University Medical Center, Georg August University, Göttingen, Germany; the Department of Neurology (E.A.S.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (C.D.B.), Columbia University Medical Center, New York, NY; and the Department of Neurology (B.A.C.), Feinberg School of Medicine, Northwestern University, Evanston, IL
| | - Wolfgang Brück
- From the Department of Anatomy and Cell Biology and Cameco MS Neuroscience Research Center (B.F.G.P.), University of Saskatchewan, Saskatoon, Canada; the Departments of Neurology (Y.G., J.E.P., V.A.L., S.J.P., B.G.W., S.L.C., C.F.L.), Laboratory Medicine and Pathology (M.E.J., J.E.P., V.A.L., S.J.P., G.G.), and Immunology (V.A.L.), Mayo Clinic, Rochester, MN; the Department of Neurology (D.M.W., J.C.), Mayo Clinic, Scottsdale, AZ; the Department of Neuropathology (I.M., W.B.), University Medical Center, Georg August University, Göttingen, Germany; the Department of Neurology (E.A.S.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (C.D.B.), Columbia University Medical Center, New York, NY; and the Department of Neurology (B.A.C.), Feinberg School of Medicine, Northwestern University, Evanston, IL
| | - Elizabeth A Shuster
- From the Department of Anatomy and Cell Biology and Cameco MS Neuroscience Research Center (B.F.G.P.), University of Saskatchewan, Saskatoon, Canada; the Departments of Neurology (Y.G., J.E.P., V.A.L., S.J.P., B.G.W., S.L.C., C.F.L.), Laboratory Medicine and Pathology (M.E.J., J.E.P., V.A.L., S.J.P., G.G.), and Immunology (V.A.L.), Mayo Clinic, Rochester, MN; the Department of Neurology (D.M.W., J.C.), Mayo Clinic, Scottsdale, AZ; the Department of Neuropathology (I.M., W.B.), University Medical Center, Georg August University, Göttingen, Germany; the Department of Neurology (E.A.S.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (C.D.B.), Columbia University Medical Center, New York, NY; and the Department of Neurology (B.A.C.), Feinberg School of Medicine, Northwestern University, Evanston, IL
| | - Jonathan Carter
- From the Department of Anatomy and Cell Biology and Cameco MS Neuroscience Research Center (B.F.G.P.), University of Saskatchewan, Saskatoon, Canada; the Departments of Neurology (Y.G., J.E.P., V.A.L., S.J.P., B.G.W., S.L.C., C.F.L.), Laboratory Medicine and Pathology (M.E.J., J.E.P., V.A.L., S.J.P., G.G.), and Immunology (V.A.L.), Mayo Clinic, Rochester, MN; the Department of Neurology (D.M.W., J.C.), Mayo Clinic, Scottsdale, AZ; the Department of Neuropathology (I.M., W.B.), University Medical Center, Georg August University, Göttingen, Germany; the Department of Neurology (E.A.S.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (C.D.B.), Columbia University Medical Center, New York, NY; and the Department of Neurology (B.A.C.), Feinberg School of Medicine, Northwestern University, Evanston, IL
| | - Clara D Boyd
- From the Department of Anatomy and Cell Biology and Cameco MS Neuroscience Research Center (B.F.G.P.), University of Saskatchewan, Saskatoon, Canada; the Departments of Neurology (Y.G., J.E.P., V.A.L., S.J.P., B.G.W., S.L.C., C.F.L.), Laboratory Medicine and Pathology (M.E.J., J.E.P., V.A.L., S.J.P., G.G.), and Immunology (V.A.L.), Mayo Clinic, Rochester, MN; the Department of Neurology (D.M.W., J.C.), Mayo Clinic, Scottsdale, AZ; the Department of Neuropathology (I.M., W.B.), University Medical Center, Georg August University, Göttingen, Germany; the Department of Neurology (E.A.S.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (C.D.B.), Columbia University Medical Center, New York, NY; and the Department of Neurology (B.A.C.), Feinberg School of Medicine, Northwestern University, Evanston, IL
| | - Stacey Lynn Clardy
- From the Department of Anatomy and Cell Biology and Cameco MS Neuroscience Research Center (B.F.G.P.), University of Saskatchewan, Saskatoon, Canada; the Departments of Neurology (Y.G., J.E.P., V.A.L., S.J.P., B.G.W., S.L.C., C.F.L.), Laboratory Medicine and Pathology (M.E.J., J.E.P., V.A.L., S.J.P., G.G.), and Immunology (V.A.L.), Mayo Clinic, Rochester, MN; the Department of Neurology (D.M.W., J.C.), Mayo Clinic, Scottsdale, AZ; the Department of Neuropathology (I.M., W.B.), University Medical Center, Georg August University, Göttingen, Germany; the Department of Neurology (E.A.S.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (C.D.B.), Columbia University Medical Center, New York, NY; and the Department of Neurology (B.A.C.), Feinberg School of Medicine, Northwestern University, Evanston, IL
| | - Bruce A Cohen
- From the Department of Anatomy and Cell Biology and Cameco MS Neuroscience Research Center (B.F.G.P.), University of Saskatchewan, Saskatoon, Canada; the Departments of Neurology (Y.G., J.E.P., V.A.L., S.J.P., B.G.W., S.L.C., C.F.L.), Laboratory Medicine and Pathology (M.E.J., J.E.P., V.A.L., S.J.P., G.G.), and Immunology (V.A.L.), Mayo Clinic, Rochester, MN; the Department of Neurology (D.M.W., J.C.), Mayo Clinic, Scottsdale, AZ; the Department of Neuropathology (I.M., W.B.), University Medical Center, Georg August University, Göttingen, Germany; the Department of Neurology (E.A.S.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (C.D.B.), Columbia University Medical Center, New York, NY; and the Department of Neurology (B.A.C.), Feinberg School of Medicine, Northwestern University, Evanston, IL
| | - Claudia F Lucchinetti
- From the Department of Anatomy and Cell Biology and Cameco MS Neuroscience Research Center (B.F.G.P.), University of Saskatchewan, Saskatoon, Canada; the Departments of Neurology (Y.G., J.E.P., V.A.L., S.J.P., B.G.W., S.L.C., C.F.L.), Laboratory Medicine and Pathology (M.E.J., J.E.P., V.A.L., S.J.P., G.G.), and Immunology (V.A.L.), Mayo Clinic, Rochester, MN; the Department of Neurology (D.M.W., J.C.), Mayo Clinic, Scottsdale, AZ; the Department of Neuropathology (I.M., W.B.), University Medical Center, Georg August University, Göttingen, Germany; the Department of Neurology (E.A.S.), Mayo Clinic, Jacksonville, FL; the Department of Neurology (C.D.B.), Columbia University Medical Center, New York, NY; and the Department of Neurology (B.A.C.), Feinberg School of Medicine, Northwestern University, Evanston, IL.
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9
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Harkins KD, Valentine WM, Gochberg DF, Does MD. In-vivo multi-exponential T2, magnetization transfer and quantitative histology in a rat model of intramyelinic edema. NEUROIMAGE-CLINICAL 2013; 2:810-7. [PMID: 24179832 PMCID: PMC3777678 DOI: 10.1016/j.nicl.2013.06.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 06/10/2013] [Accepted: 06/12/2013] [Indexed: 11/26/2022]
Abstract
Two MRI methods, multi-exponential analysis of transverse relaxation (MET2) and quantitative magnetization transfer (qMT), were used along with quantitative evaluation of histology in a study of intra-myelinic edema in rat spinal white matter. The results showed a strong linear correlation between a distinct long-T2 signal from MET2 analysis and the edema water volume fraction as measured by histology, although this analysis overestimated the edema water content by ≈ 100% relative to quantitative histological measurements. This overestimation was reasoned to result from the effects of inter-compartmental water exchange on observed transverse relaxation. Commonly studied MRI markers for myelin, the myelin water fraction (from MET2 analysis) and the macromolecular pool size ratio (from qMT analysis) produced results that could not be explained purely by changes in myelin content. The results demonstrate the potential for MET2 analysis as well as the limits of putative myelin markers for characterizing white matter abnormalities involving intra-myelinic edema. We studied a rat model of intra-myelinic edema induced by hexachlorophene ingestion. We used multi-exponential T2 (MET2) and quantitative magnetization transfer MRI. Histology was quantitatively evaluated to measure edema volume and myelin content. MET2 provides a measure that correlates but overestimates with edema volume fraction. MET2 measure of edema is affected by microscopic water dynamics.
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10
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Kanno T, Sasaki S, Yamada N, Kawasako K, Tsuchitani M. Hexachlorophene and cuprizone induce the spongy change of the developing rat brain by different mechanisms: the role of 2', 3'-cyclic nucleotide 3'-phosphodiesterase (CNPase). J Vet Med Sci 2012; 74:837-43. [PMID: 22313968 DOI: 10.1292/jvms.11-0469] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The goal of this research was to identify mechanisms responsible for the spongy change induced in rats after repeated hexachlorophene (HCP) or cuprizone (CPZ) dosing. Rats were dosed with 35 mg/kg HCP for 5 days followed by drug withdrawal for 7 days suffered spongy changes to the white matter of the cerebrum, cerebellum, medulla oblongata, and spinal cord that were accompanied by degeneration of oligodendroglia. The severity of both lesions increased prominently on day 5; however, the spongy change decreased and degeneration of oligodendroglia reversed on day 12 (7 days after dosing ceased). On day 12, cerebral cortex oligodendroglia were stained strongly by anti-CNPase. Other rats were fed for 8 days with powdered chow containing 1% (w/w) CPZ, which was then withdrawn for 16 days. The rats exhibited the spongy change in the white matter of the cerebrum and cerebellum as well as oligodendroglial cell death from day 3. The severity of both lesions increased prominently on day 8. Cerebral cortex oligodendroglia were stained strongly by anti-CNPase on days 3 to 8 and decreased to the control levels by day 24 (16 days after dosing ceased). Electron microscopy revealed that oligodendroglia frequently displayed apoptotic morphology. These findings suggest that CNPase expression was induced in the course of restoration following HCP-induced insults to oligodendroglia and the myelin sheath, and in the course of demyelination by CPZ-induced damage to oligodendroglia. However, the role of CNPase on both courses is unclear.
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Affiliation(s)
- Takeshi Kanno
- Kashima Laboratory, Mitsubishi Chemical Medience Corp., 14 Sunayama, Kamisu, Ibaraki 314-0255, Japan.
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11
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Kanno T, Kurotaki T, Yamada N, Yamashita K, Wako Y, Tsuchitani M. Activity of 2′, 3′-Cyclic Nucleotide 3′-Phosphodiesterase (CNPase) in Spinal Cord with Spongy Change Induced by a Single Oral Dose of Aniline in Rats. Toxicol Pathol 2010; 38:359-65. [DOI: 10.1177/0192623310362245] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A spongy change in the spinal cord white matter was observed in four-week-old rats treated with aniline. Although this change was found to be a result of the myelin sheath splitting at the ultrastructural level, the mechanism is unknown. This study was conducted to identify the mechanism of the spongy change in aniline-treated rats. The spongy change in the spinal cord white matter was first detected on day 5 in the histopathologic examination. The incidence and severity of the lesions, especially in the lateral and ventral funiculi of the thoracic spinal cord white matter, increased prominently from day 8 to day 10. In all rats, immunohistochemical staining by anti-2′, 3′-cyclic nucleotide 3′-phosphodiesterase (CNPase) occurred along the cytoplasmic boundaries of the normal oligodendroglia. However, mild to moderate anti-CNPase staining extended to the swollen cytoplasm of the oligodendroglia in the aniline-treated rats from day 2 to day 4. In the electron microscopic examination, free ribosomes and rough endoplasmic reticula in the cytoplasm of the oligodendroglia increased on days 3 and 4. These changes were considered to be related to CNPase expression. However, CNPase expression decreased, whereas the spongy changes were detected from day 5. The reduction in CNPase expression may contribute to the changes in the myelin morphology observed in aniline intoxication.
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Affiliation(s)
- Takeshi Kanno
- Kashima Laboratory, Mitsubishi Chemical Medience Corp., Kamisu-shi, Ibaraki-ken, Japan
| | - Tetsuro Kurotaki
- Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Naoaki Yamada
- Kashima Laboratory, Mitsubishi Chemical Medience Corp., Kamisu-shi, Ibaraki-ken, Japan
| | - Kotaro Yamashita
- Kashima Laboratory, Mitsubishi Chemical Medience Corp., Kamisu-shi, Ibaraki-ken, Japan
| | - Yumi Wako
- Kashima Laboratory, Mitsubishi Chemical Medience Corp., Kamisu-shi, Ibaraki-ken, Japan
| | - Minoru Tsuchitani
- Kashima Laboratory, Mitsubishi Chemical Medience Corp., Kamisu-shi, Ibaraki-ken, Japan
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12
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Gandolfi AJ, Buhler DR. Biliary Metabolites and Enterohepatic Circulation of Hexachlorophene in the Rat. Xenobiotica 2008. [DOI: 10.3109/00498257409052084] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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13
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van der Lugt JJ, Venter I. Myelin vacuolation, optic neuropathy and retinal degeneration after closantel overdosage in sheep and in a goat. J Comp Pathol 2007; 136:87-95. [PMID: 17270202 DOI: 10.1016/j.jcpa.2006.11.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Accepted: 11/24/2006] [Indexed: 11/24/2022]
Abstract
Toxicity of closantel, a halogenated salicylanilide anthelmintic, is described in 11 sheep and a goat, humanely killed 4-70 days after accidental overdosage. Status spongiosis of the cerebrum and cerebellum was present, its severity decreasing with time after treatment. Ultrastructurally, vacuoles in the cerebral white matter were seen to be intramyelinic due to splitting of myelin lamellae at the intraperiod lines, indicating myelin oedema. In the optic nerves, Wallerian degeneration and eventual fibrosis and atrophy of the nerves followed myelin vacuolation. Lesions in the optic nerves were particularly advanced in the intracanalicular portion, indicating a compressive neuropathy within the optic canal. Acute retinal lesions consisted of papilloedema, necrosis of the outer retinal layers (especially the photoreceptor layer), and retinal separation in tapetal and non-tapetal areas. In more chronic cases, the outer nuclear layer was diffusely attenuated and generally reduced to a single row of cells.
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Affiliation(s)
- J J van der Lugt
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X05, 0110 Onderstepoort, South Africa.
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14
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Powell HC, Garrett RS, Brett FM, Chiang CS, Chen E, Masliah E, Campbell IL. Response of glia, mast cells and the blood brain barrier, in transgenic mice expressing interleukin-3 in astrocytes, an experimental model for CNS demyelination. Brain Pathol 2006; 9:219-35. [PMID: 10219739 PMCID: PMC8098132 DOI: 10.1111/j.1750-3639.1999.tb00220.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Transgenic mice overexpressing cytokines facilitate analysis of the effects of these immunomodulators on indigenous cells of the central nervous system. This study examines morphological aspects of demyelination and permeability changes, in a recently described transgenic model (termed GFAP-IL3). GFAP-IL3 mice develop progressive motor disease at approximately 5 months. Lesions identified after disease onset, showed activation of microglia, astroglial proliferation with phagocytosis of lipids, and immigration of macrophages and mast cells into neural parenchyma. Lymphocytes failed to appear until the later stages of the disease. Later, cerebellar and brain stem white matter contained focal demyelinating lesions with intense macrophage infiltration and a proliferative astrocytosis. Dystrophic axonal changes were noted, in addition to demyelination in heavily infiltrated lesions. Mast cells, variably present in the thalamus and meninges of wild type mice, were greatly increased at these sites in GFAP-IL3 mice. Blood-brain barrier (BBB) defects were documented with leakage of intravenously injected horseradish peroxidase. Mast cell infiltration into the CNS and their degranulation at the site of injury, may represent initial events in a spontaneous process of macrophage mediated demyelination in which glial cells and macrophages are both involved in the phagocytic process.
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Affiliation(s)
- H C Powell
- Veterans Administration Research Service, VAMC San Diego, La Jolla, CA, USA.
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Okazaki Y, Yamashita K, Sudo M, Tsuchitani M, Narama I, Yamaguchi R, Tateyama S. The Progression and Recovery of Neurotoxicity Induced by A Single Oral Dose of Aniline in Rats. J Toxicol Pathol 2001. [DOI: 10.1293/tox.14.19] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Yoshimasa Okazaki
- Mitsubishi Chemical Safety Institute Ltd
- Department of Veterinary Pathology, Faculty of Agriculture, Miyazaki University
| | | | | | | | - Isao Narama
- Research Institute of Drug Safety, Setsunan University
| | - Ryoji Yamaguchi
- Department of Veterinary Pathology, Faculty of Agriculture, Miyazaki University
| | - Susumu Tateyama
- Department of Veterinary Pathology, Faculty of Agriculture, Miyazaki University
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Häntzschel A, Andreas K. Efficacy of glutamate receptor antagonists in the management of functional disorders in cytotoxic brain oedema induced by hexachlorophene. PHARMACOLOGY & TOXICOLOGY 1998; 82:80-8. [PMID: 9498236 DOI: 10.1111/j.1600-0773.1998.tb01402.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The hexachlorophene-induced cytotoxic brain oedema is an experimental model of brain damage, suitable for testing cerebroprotective substances (Andreas 1993). In order to examine whether glutamate receptors are involved in mediating functional disorders due to neurotoxic brain damage, we have studied the protective effects of several competitive and non-competitive antagonists using adult male Wistar rats in a simple "ladder-test" for assessing coordinative motor behaviour. Hexachlorophene-induced brain damage was verified by histological examination of the cerebellum with vacuolation of white matter, astrocyte hypertrophy and astrocyte proliferation taken as signs of neurotoxic injury. The non-competitive N-methyl-D-aspartate (NMDA) antagonist dizocilpine maleate (MK-801) decreased the motor disturbance on the first and second day of the "ladder-test" when applied in the doses 0.1 mg/kg and 0.2 mg/kg intraperitoneally for 3 weeks during the hexachlorophene treatment. Acute MK-801 administration (0.1 mg/kg intraperitoneally) after 3 weeks hexachlorophene exposure improved the coordinative motor response only on the first day. When testing the competitive NMDA receptor antagonist 2-amino-5-phosphonopentanoic acid (AP-5) in the dose 1.0 mg/kg intraperitoneally the motor disturbance was lowered significantly earlier than in spontaneous remission. Similar effects were observed with 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) in the dose of 0.8 mg/kg intraperitoneally, an antagonist interacting both with the strychnine-insensitive binding site for glycine within the NMDA receptor complex and with the kainate(+/-)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor complex. Concurrent MK-801 administration decreased the vacuolation of white matter. The results suggest that NMDA receptors and non-NMDA receptors are involved in development of functional disorders induced by hexachlorophene.
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Affiliation(s)
- A Häntzschel
- Institute of Pharmacology and Toxicology, Faculty of Medicine, Technical University Dresden, Germany
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17
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Furudate S, Nishimaki T, Muto T. 125I uptake competing with iodine absorption by the thyroid gland following povidone-iodine skin application. Exp Anim 1997; 46:197-202. [PMID: 9250480 DOI: 10.1538/expanim.46.197] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Povidone-iodine solution is widely used to disinfect the skin surface or prevent suppuration during human and animal surgery. Using radioisotope 125I, we examined whether iodine may be absorbed and then concentrated in the thyroid gland when povidone-iodine solution is applied to the skin of rats or mice. The competition for 125I uptake was examined in mice and rats after the application of povidone iodine to the skin. We also traced the process of absorbed 125I in the thyroid glad during the fixation for tissue preparations. Povidone-iodine applied to the skin significantly reduced the uptake of 125I both in mice and rats. Significant flux of 125I from the thyroid gland in povidone-iodine treated animals was noted during the thyroid fixation of tissue preparations. From these results, povidone-iodine application to the skin instead of stable KI administration may be practical for preventing the uptake of 125I by the thyroid gland during 125I compound administration for medical therapy. In animal experiments concerning thyroid functions, careful attention must be paid when povidone-iodine is used for disinfection in animal surgery.
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Affiliation(s)
- S Furudate
- Department of Laboratory Animal Sciences, Kitasato University School of Medicine, Kanagawa, Japan
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Abstract
The physicochemical properties of water enable it to act as a solvent for electrolytes, and to influence the molecular configuration and hence the function--enzymatic in particular--of polypeptide chains in biological systems. The association of water with electrolytes determines the osmotic regulation of cell volume and allows the establishment of the transmembrane ion concentration gradients that underlie nerve excitation and impulse conduction. Fluid in the central nervous system is distributed in the intracellular and extracellular spaces (ICS, ECS) of the brain parenchyma, the cerebrospinal fluid, and the vascular compartment--the brain capillaries and small arteries and veins. Regulated exchange of fluid between these various compartments occurs at the blood-brain barrier (BBB), and at the ventricular ependyma and choroid plexus, and, on the brain surface, at the pia mater. The normal BBB is relatively permeable to water, but considerably less so to ions, including the principal electrolytes Brain fluid regulation takes place within the context of systemic fluid volume control, which depends on the mutual interaction of osmo-, volume-, and pressure-receptors in the hypothalamus, heart and kidney, hormones such as vasopressin, renin-angiotensin, aldosterone, atriopeptins, and digitalis-like immunoreactive substance, and their respective sites of action. Evidence for specific transport capabilities of the cerebral capillary endothelium, for example high Na+K(+)-ATPase activity and the presence at the abluminal surface of a Na(+)--H+ antiporter, suggests that cerebral microvessels play a more active part in brain volume regulation and ion homoeostasis than do capillaries in other vascular beds. The normal brain ECS amounts to 12-19% of brain volume, and is markedly reduced in anoxia, ischaemia, metabolic poisoning, spreading depression, and conventional procedures for histological fixation. The asymmetrical distributions of Na+ K+ and Ca2+ between ICS and ECS underlie the roles of these cations in nerve excitation and conduction, and in signal transduction. The relatively large volume of the CSF, and extensive diffusional exchange of many substances between brain ECS and CSF, augment the ion-homeostasing capacity of the ECS. The choroid plexus, in addition to secreting CSF principally by biochemical mechanisms (there is an additional small component from the extracellular fluid), actively transports some substances from the blood (e.g. nucleotides and ascorbic acid), and actively removes others from the CSF. In contrast with CSF secretion, CSF reabsorption is principally a biomechanical process, passively dependent on the CSF-dural sinus pressure gradient. Pathological increases in intracranial water content imply development of an intracranial mass lesion. The additional water may be distributed diffusely within the brain parenchyma as brain oedema, as a cyst, or as increase in ventricular volume due to hydrocephalus. Brain oedema is classified on the basis of pathophysiology into four categories, vasogenic, cytotoxic, osmotic and hydrostatic. The clinical conditions in which brain oedema presents the greatest problems are tumour, ischaemia, and head injury. Peritumoural oedema is predominantly vasogenic and related to BBB dysfunction. Ischaemic oedema is initially cytotoxic, with a shift of Na+ and CI- ions from ECS to ICS, followed by osmotically obliged water, this shift can be detected by diffusion-weighted MRI. Later in the evolution of an ischaemic lesion the oedema becomes vasogenic, with disruption of the BBB. Recent imaging studies in patients with head injury suggest that the development of traumatic brain oedema may follow a biphasic time course similar to that of ischaemic oedema. Hydrocephalus is associated in the great majority of cases with an obstruction to the circulation or drainage of CSF, or, occasionally, with overproduction of CSF by a choroid plexus papilloma. In either case, the consequence is a ris
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Affiliation(s)
- K G Go
- Department of Neurosurgery, University of Groningen, The Netherlands
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19
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van der Lugt JJ, Olivier J, Jordaan P. Status spongiosis, optic neuropathy, and retinal degeneration in Helichrysum argyrosphaerum poisoning in sheep and a goat. Vet Pathol 1996; 33:495-502. [PMID: 8885175 DOI: 10.1177/030098589603300503] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Lesions of natural Helichrysum argyrosphaerum poisoning were studied in eight sheep and one goat. Light microscopic examination revealed widespread, bilaterally symmetrical status spongiosis of the white matter of the brain consistently present in the subependymal area adjacent to the lateral ventricles, cerebellar peduncles, and brain stem in all animals. In three animals, the ultrastructural finding of intramyelinic vacuolation due to splitting of the myelin lamellae at the intraperiod lines indicated myelin edema. There was also mild distension of perivascular and extracellular spaces in the severely affected areas. Significant changes were absent in neurons, glial cells, axons, or blood vessel walls. Myelin edema associated with degeneration and loss of axons and myelin and astrocytic gliosis was present in the intraorbital and intracranial portions of the optic nerves. In the intracanalicular portions of the nerves in three animals that were studied, more chronic lesions consisting of fibrosis and atrophy of the nerve suggested that the optic neuropathy follows compression of the nerve in the optic canal as a result of myelin edema. The toxic principle of the plant also caused a degenerative retinopathy in five animals. The essential histopathologic change was degeneration and loss of the photoreceptor outer segments predominantly in the nontapetal retina. These retinal lesions were associated with hyperplasia and hypertrophy and with migration of the pigmented epithelium, focal retinal separation, and depletion and loss of the nuclear layers.
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Affiliation(s)
- J J van der Lugt
- Section of Pathology, Onderstepoort Veterinary Institute, Onderstepoort, South Africa
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20
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Obermaier G, Kretzschmar HA, Hafner A, Heubeck D, Dahme E. Spongiform central nervous system myelinopathy in African dwarf goats. J Comp Pathol 1995; 113:357-72. [PMID: 8746958 DOI: 10.1016/s0021-9975(05)80121-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A novel spongiform myelinopathy of the central nervous system (CNS) of eleven African dwarf goats was examined by light and electron microscopy. Histological lesions consisted of extensive vacuolation predominantly of the white matter of the diencephalon, midbrain and cerebellar peduncles, as well as of spinal white matter. Ultrastructurally, vacuoles were shown to be intramyelinic, resulting from the splitting of the outer myelin lamellae at the intraperiod line. A few oligodendrocytes showed vacuolar degeneration of cell bodies and processes. Inflammatory reactions were absent. The observed lesions point to an unknown primary damage of oligodendroglia and central myelin. A hereditary background of the disorder is suspected as all investigated dwarf goats were half-brothers or -sisters and partly descended from the mating of adult females with their own sire.
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Affiliation(s)
- G Obermaier
- Department of General Pathology and Neuropathology, Ludwig-Maximilians-University, Munich, Germany
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21
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van der Knaap MS, Valk J, Barth PG, Smit LM, van Engelen BG, Tortori Donati P. Leukoencephalopathy with swelling in children and adolescents: MRI patterns and differential diagnosis. Neuroradiology 1995; 37:679-86. [PMID: 8748906 DOI: 10.1007/bf00593394] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In children, several neurological disorders are characterised by spongiform leukoencephalopathy. MRI of the brain typically shows white matter swelling, but does not enable differentiation of the various underlying disorders. The aim of this article is optimisation of the diagnostic value of MRI in leukoencephalopathy accompanied by swelling. MRI-based inclusion criteria were met by 20 patients in our database. The images were analysed using a detailed scoring list. In 13 of the 20 patients the clinical diagnosis was known (11 definite and 2 probable diagnoses). Characteristic MRI abnormalities could be defined in these patients. Of the 7 patients without a diagnosis, 5 had identical MRI abnormalities: diffuse hemisphere swelling and typical cysts in frontoparietal subcortical white matter and the tips of the temporal lobes. The clinical picture was also similar in these patients, suggesting a similar disease.
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Affiliation(s)
- M S van der Knaap
- Department of Child Neurology, Free University Hospital, HV Amsterdam, The Netherlands
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22
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O'Brien DP, Kroll RA, Johnson GC, Covert SJ, Nelson MJ. Myelinolysis after correction of hyponatremia in two dogs. J Vet Intern Med 1994; 8:40-8. [PMID: 8176662 DOI: 10.1111/j.1939-1676.1994.tb03194.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Two dogs developed delayed neurological deterioration after rapid correction of severe hyponatremia. Sequential magnetic resonance imaging showed the development of lesions in the thalamus. One dog was necropsied, and the lesions were characterized by myelinolysis with sparing of axons and neurons. The second dog gradually recovered with no detectable neurological deficits. The syndrome seems analogous to central pontine myelinolysis in human beings. Guidelines for correction of hyponatremia to prevent development of myelinolysis are given.
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Affiliation(s)
- D P O'Brien
- Department of Veterinary Medicine, University of Missouri, Columbia
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23
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Milhorat TH. Classification of the cerebral edemas with reference to hydrocephalus and pseudotumor cerebri. Childs Nerv Syst 1992; 8:301-6. [PMID: 1394275 DOI: 10.1007/bf00296558] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Cerebral edema is a common clinical disorder that results from an abnormal increase in water content within the extracellular (EC) compartment of the brain. It is distinguished from two other types of brain bulk enlargement: (1) vascular swelling, caused by arterial dilatation or venous obstruction; and (2) cellular swelling, caused by cytotoxic injuries or metabolic storage. Under normal conditions, the EC compartment has two fluids, the interstitial fluid (ISF) and the cerebrospinal fluid (CSF), and extends from the blood brain barrier (BBB) through a series of 100 to 150-A-wide intercellular spaces that are anatomically continuous with the CSF spaces. There are four primary types of EC edema: (1) vasogenic edema, which results from an increase in brain capillary permeability, the most common type, in which leakage of plasma constituents into the brain follows the pathways of ISF bulk flow and is governed by the interaction of systemic arterial pressure and tissue resistance; (2) osmotic edema, which results from an unfavorable osmotic gradient between the plasma and ISF across an intact BBB; (3) compressive edema, which results from obstruction of ISF bulk flow pathways; and (4) hydrocephalic edema, which results from obstruction of CSF bulk flow pathways. In this latter type of edema, distension of the collecting channels proximal to the block leads to retrograde flooding of the EC compartment with the formation of periventricular edema. The syndrome of pseudotumor cerebri includes several different types of brain bulk enlargement.
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Affiliation(s)
- T H Milhorat
- Department of Neurosurgery, State University of New York Health Science Center, Brooklyn 11203
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Andreas K. Cytotoxic brain oedema as a model in the examination of cerebroprotective substances. ARCHIVES OF TOXICOLOGY. SUPPLEMENT. = ARCHIV FUR TOXIKOLOGIE. SUPPLEMENT 1991; 14:25-9. [PMID: 1805742 DOI: 10.1007/978-3-642-74936-0_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- K Andreas
- Institute of Pharmacology and Toxicology, Medical Academy Carl Gustav Carus, Dresden, FRG
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25
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Hagen G, Blakemore WF, Bjerkås I. Ultrastructural findings in spongy degeneration of white matter in silver foxes (Vulpes vulpes). A naturally occurring demyelinating disease with oligodendrocyte vacuolation. Acta Neuropathol 1990; 80:590-6. [PMID: 1703382 DOI: 10.1007/bf00307625] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Spongy degeneration of white matter in silver foxes is a naturally occurring, hereditary disorder. We report ultrastructural findings in the upper cervical cord of five perfusion-fixed foxes that were examined between 5 weeks and 2 1/4 years after the onset of clinical signs. Large cytoplasmic vacuoles in oligodendrocytes were present in the foxes examined 5, 12 and 20 weeks after the onset. Other early features of the disease were severe vacuolation of myelin sheaths, demyelination, expansion of extracellular spaces and hypertrophy of astrocytes. Evidence of partial demyelination as well as demyelination of entire internodes was found. In the later stages of the disease, the vacuolation was largely resolved but a marked astrogliosis persisted and numerous remyelinated axons were present in the gliotic areas. Vacuolation of oligodendrocytes and partial demyelination has not previously been seen together in a single disease process. The relationship between oligodendrocyte vacuolation, myelin sheath vacuolation and demyelination is discussed. It is concluded that the present condition is due to a primary damage to oligodendrocytes; however, the underlying biochemical lesion is not known.
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Affiliation(s)
- G Hagen
- Department of Pathology, Norwegian College of Veterinary Medicine, Oslo
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Mizisin AP, Kalichman MW, Myers RR, Powell HC. Role of the blood-nerve barrier in experimental nerve edema. Toxicol Pathol 1990; 18:170-85. [PMID: 2195637 DOI: 10.1177/019262339001800123] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Nerve edema is a common response to the nerve injury seen in many peripheral neuropathies and is an important component of Wallerian degeneration. However, independent pathologic effects of nerve edema that aggravate or induce nerve injury extend the role of edema beyond that of an epiphenomenon of injury. New insights into the mechanism and impact of nerve edema come largely from animal models. In the following review, we discuss the cause and consequences of nerve edema with particular reference to endoneurial fluid pressure and its relevance to the nerve microenvironment. Experimental models of nerve edema include conditions with increased vascular permeability such as lead poisoning, experimental allergic neuritis, and murine globoid leukodystrophy. Increased perineurial permeability induced by local anesthetics and neurolytic drugs can also induce nerve edema sufficient to increase endoneurial fluid pressure. Both perineurial and vascular permeability are increased after damage induced by crush, freeze, or laser injury. One of the most important forms of nerve edema is induced by external compression; the significance of this change is that edema has local compressive effects that persist after the external pressure has been relaxed. Nerve edema and increased endoneurial fluid pressure also occur in conditions in which vascular permeability appears to be unchanged such as experimental diabetic neuropathy and in hexachlorophene intoxication. In both of these conditions, reduced nerve blood flow has been demonstrated in rats and is viewed as a consequence of increased endoneurial fluid pressure. Whatever its mechanism, endoneurial edema has important structural and functional consequences for nerve fibers. A clear understanding of the underlying pathology of the nerve microenvironment may provide useful insights into treatment of clinical neuropathies.
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Affiliation(s)
- A P Mizisin
- Department of Pathology (Neuropathology), University of California, San Diego, School of Medicine 92093
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Arezzo JC, Schroeder CE, Litwak MS, Steward DL. Effects of vigabatrin on evoked potentials in dogs. Br J Clin Pharmacol 1989; 27 Suppl 1:53S-60S. [PMID: 2757910 PMCID: PMC1379680 DOI: 10.1111/j.1365-2125.1989.tb03462.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
1. The purpose of this study was to evaluate possible changes in brain morphology and evoked potentials associated with daily administration of 300 mg kg-1 vigabatrin in dogs. 2. Somatosensory evoked potentials (SEP) and auditory evoked potentials (AEP) were recorded at baseline and weekly for 12 weeks of treatment and every 2 weeks for 17 weeks of recovery. Morphology was assessed immediately after treatment for two treated dogs and after recovery for the remaining five treated and two control dogs. 3. Vigabatrin produced a significant slowing of the central transmission measure of the SEP with no alteration in the AEP. Vigabatrin was associated with microvacuolation in select regions of the brain including the fornix, septum, optic tract, hypothalamus, thalamus and cortex. In addition, some microglial proliferation was noted. 4. Changes in SEP and the microvacuolation fully recovered after 17 weeks of treatment. 5. The study confirms vigabatrin-induced microvacuolation in the dog and suggests these changes are associated with functional slowing of conduction in the somatosensory pathways.
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Affiliation(s)
- J C Arezzo
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
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28
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Abstract
Weanling male Wistar rats fed a diet containing 0.5-2% cuprizone developed intramyelinic edema of the cerebellar white matter, hilum of the dentate nucleus and superior cerebellar peduncle. Oligodendrocytes in these regions showed hyperchromatic nuclei and abnormally dense cytoplasm, with an increase in the number of free ribosomes and enlargement of mitochondria. Unlike the lesions produced by cuprizone in weanling mice, those in the rat did not lead to demyelination. Cuprizone caused a distal peripheral axonopathy, with degeneration of myelinated axons in the sciatic nerve but preservation of the spinal nerve roots, dorsal root ganglia, posterior spinal funiculi and anterior horn cells. Unmyelinated fibers were largely spared. Some axonal regeneration occurred despite the continued administration of cuprizone. The intramyelinic edema and the nuclear and cytoplasmic abnormalities of the oligodendrocytes disappeared after the resumption of a normal diet.
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Affiliation(s)
- S Love
- Department of Pathology, University of California, San Diego, La Jolla 92093
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Komoly S, Jeyasingham MD, Pratt OE, Lantos PL. Decrease in oligodendrocyte carbonic anhydrase activity preceding myelin degeneration in cuprizone induced demyelination. J Neurol Sci 1987; 79:141-8. [PMID: 2440995 DOI: 10.1016/0022-510x(87)90268-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Both immunohistochemical and biochemical evidence is presented to show for the first time that carbonic anhydrase II (CA II) activity falls in the brain of mice in cuprizone (bis(cyclohexanone)oxalyldihydrazone) induced demyelination well before demyelination develops. This fall began during the first week, whereas the first signs of myelin degeneration induced by cuprizone did not appear until 3 weeks and demyelination in the superior cerebellar peduncle in the mouse took 6-8 weeks to develop. The findings suggest that oligodendrocyte CA II activity is essential either for the survival of oligodendrocytes or for the maintenance of central myelin.
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31
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Harper PA, Healy PJ, Dennis JA. Ultrastructural findings in maple syrup urine disease in Poll Hereford calves. Acta Neuropathol 1986; 71:316-20. [PMID: 3799144 DOI: 10.1007/bf00688055] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Ultrastructural findings in the nervous systems of two Poll Hereford calves affected with maple syrup urine disease or branched chain ketoacid decarboxylase deficiency are described. The calves were affected within 2 days of birth with a severe generalised central nervous system (CNS) disorder characterised by dullness and weakness, progressing to recumbency and opisthotonus. The urine had an odour of burnt sugar. Analysis of plasma and cerebrospinal fluid demonstrated significantly elevated levels of the branched chain amino acids leucine, isoleucine and valine. Status spongiosus affecting mainly the white matter was recorded at microscopic examination of the CNS, with ultrastructural examination confirming the presence of intramyelinic vacuole formation, suggesting myelin oedema.
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32
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Ethylene oxide polyneuropathy: clinical follow-up study with morphometric and electron microscopic findings in a sural nerve biopsy. J Neurol 1985; 232:83-90. [PMID: 2991474 DOI: 10.1007/bf00313906] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A case is reported of ethylene oxide polyneuropathy after 5 months of exposure. There was symmetrical distal weakness of both lower extremities and transitory reduced nerve conduction velocities with increased latencies. Sural nerve biopsy revealed nerve fibre degeneration of the Wallerian type, associated with reduction of axonal cross-sectional areas and some degree of nerve fibre regeneration that could be confirmed morphometrically. In addition, there was conspicuous paranodal vesicular disintegration of individual myelin lamellae. Unusual cisternae with introverted hemidesmosomes were noted in endoneurial fibroblasts.
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33
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King RH, Thomas PK. The occurrence and significance of myelin with unusually large periodicity. Acta Neuropathol 1984; 63:319-29. [PMID: 6433641 DOI: 10.1007/bf00687340] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The occurrence of myelin with an unusually large periodicity has been noted in a variety of human and animal diseases by many authors. It has also proved possible to create regular alterations in periodicity by various treatments of fresh unfixed nerve. We have quantified the changes found in material from a variety of sources and conclude that they are compatible with the occurrence of physicochemical changes in the myelin membranes, leading to overhydration.
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Torack RM. Computed tomography and stroke edema: case report with an analysis of water in acute infarction. COMPUTERIZED RADIOLOGY : OFFICIAL JOURNAL OF THE COMPUTERIZED TOMOGRAPHY SOCIETY 1982; 6:35-41. [PMID: 7075169 DOI: 10.1016/0730-4862(82)90179-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
An index case and 13 other cases of acute ischemic cerebral infarction have been examined following the occurrence of death 1-6 days postictus. Histologic studies and water content assay involved both the infarct and peri-infarct tissue. The primary site of fluid accumulation was the infarcted white matter; however, after 3 days, edema in the adjacent white matter may be significant. The reduced attenuation of CT scans is caused only by edema since necrosis of the white matter is not present. Reactive vascular changes that occur in the cortex appear to be the basis of early contrast enhancement. Three different mechanisms of edema formation have been proposed to be involved in the mass effect.
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Lock EA, Scales MD, Little RA. Observations on 2'-chloro-2,4-dinitro-5',6-di(trifluoromethyl)-diphenylamine-induced edema in the white matter of the central nervous system of the rat. Toxicol Appl Pharmacol 1981; 60:121-30. [PMID: 7281170 DOI: 10.1016/0041-008x(81)90142-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Tripier MF, Bérard M, Toga M, Martin-Bouyer G, Le Breton R, Garat J. Hexachlorophene and the central nervous system. Toxic effects in mice and baboons. Acta Neuropathol 1981; 53:65-74. [PMID: 7211199 DOI: 10.1007/bf00697186] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
A study on hexachlorophene encephalopathy in mice and baboons is reported. By light microscopy, a severe spongiform lesion of the central nervous system (CNS) was localized in the white matter, without myelin breakdown or cellular reaction. By electron microscopy, the myelin alteration was characterized by wide intralamellar spaces or "splitting" developed in the intraperiod line of compact sheaths. The acute changes described were induced by administration of the drug by the digestive or cutaneous routes at various dosage levels in an aqueous solution or in talcum powder. The toxic effects depended on the age of the animals, the survival times and the concentrations of hexachlorophene, i.e., 6%, 3%, and 0.5%. The findings are compared with previous reports on the neurotoxicity of hexachlorophene and other chemicals in human and experimental animals. Hexachlorophene cannot be recommended for use in young infants because of its neurotoxicity in very low doses as demonstrated in the present report.
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Tripier MF, Berard M, Toga M, Martin-Bouyer G, Le Breton R, Garat J. Experimental hexachlorophene encephalopathy in mice and baboons: light and electron microscopic study. ACTA NEUROPATHOLOGICA. SUPPLEMENTUM 1981; 7:40-3. [PMID: 6939279 DOI: 10.1007/978-3-642-81553-9_12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
An experimental study on acute Hexachlorophene (HCP) neurotoxicity is reported in mice and baboons: - by light microscopy, a severe spongiform lesion of the central nervous system is localized in the white matter without myelin breakdown or cellular reaction; - by electron microscopy, the myelin alteration is characterized by the presence of vacuolation of "splitting" in the intralamellar spaces of compact sheaths; myelinated axons are occasionally involved. The changes described are discussed according to various reports on HCP neurotoxicity in humans and experimental animals. The effects of this chemical agent on the central nervous system is related to the percentage of HCP in talcum powder or solution for topical use. The toxicity of very low dosage level is demonstrated in baboons. Therefore HCP use cannot be recommended for young infants.
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Anderson JM, Cockburn F, Forfar JO, Harkness RA, Kelly RW, Kilshaw B. Neonatal spongioform myelinopathy after restricted application of hexachlorophane skin disinfectant. J Clin Pathol 1981; 34:25-9. [PMID: 7462435 PMCID: PMC1146403 DOI: 10.1136/jcp.34.1.25] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
At least four out of 97 low birth weight (less than 1750 g) newborn infants who had received only limited skin disinfection with 3% hexachlorophane (HCP) emulsion developed spongioform myelinopathy in association with detectable amounts of HCP in their brains. These four cases were found in a post-mortem survey of 20 out of the 27 infants who died. Another nine of these infants had detectable amounts of HCP in the brain but no myelinopathy. It is at present not possible to define a 'safe" level of exposure to 3% HCP emulsion for small preterm infants in the first 2 weeks of life.
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Abstract
Cycloleucine, a non-metabolizable amino acid analogue produces status spongiosus in cerebral white matter of rats and mice as well as a distinctive lesion of astrocytes. Its mechanisms of action include competition with natural amino acids from transport across the blood-brain barrier leading to inhibition of entry of circulating amino acids into brain, interference with ribosomal RNA maturation, and blockage of transmethylation reactions, including the conversion of homocystine to methionine. Cycloleucine also affects the kidney, producing aminoaciduria. Electron microscopy of cerebral white matter reveals spongiform changes of myelin sheaths caused by separation of myelin lamellae along intraperiod lines and accumulation of whorls of filaments in astrocytes. The myelinopathy is dose related and its toxicity is cumulative due to its long half-life in animals. The findings are discussed with reference to other spongiform myelinopathies, including status spongiosus observed in homocystinuria and other aminoacidurias.
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Huxtable CR, Dorling PR, Slatter DH. Myelin oedema, optic neuropathy and retinopathy in experimental Stypandra imbricata toxicosis. Neuropathol Appl Neurobiol 1980; 6:221-32. [PMID: 7402438 DOI: 10.1111/j.1365-2990.1980.tb00292.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Rats experimentally poisoned with the toxic plant Stypandra imbricata developed acute oedema of central and peripheral myelin and extensive axonal degeneration in the optic nerves. The oedema developed with vacuolation and splitting of myelin lamellae at the intraperiod line. Following recovery from acute intoxication, myelin oedema resolved after 6 to 12 weeks, but severe retinal degeneration and optic nerve atrophy remained. Morphological abnormalities in glial cells and axons were only found in the optic nerves. It was concluded that there is probably also a direct toxic effect on the axons of the optic nerve and the photoreceptor cells of the retina. The chemical nature of the toxin remains to be defined but the marked similarity of its toxic effects to those of hexachlorophene are noted.
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Lock EA. Toxic action of 2'-chloro-2,4-dinitro-5',6-di(trifluoromethyl) diphenylamine in the rat. Chem Biol Interact 1979; 28:35-46. [PMID: 498364 DOI: 10.1016/0009-2797(79)90112-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
2'-Chloro-2,4-dinitro-5',6-di(trifluoromethyl)diphenylamine (CDTD) is a potent uncoupler of oxidative phosphorylation in isolated rat liver or brain mitochondria. The concentration of CDTD causing 50% uncoupling in vitro is dependent on the mitochdonrial protein concentration and is 2 nM at 0.9 mg protein/ml for rat liver mitochondria. Oxidative phosphorylation can be restored to CDTD uncoupled liver mitochondria by the addition of a 10 000-fold molar excess of bovine serum albumin to DCTD. Rats given a lethal dose (7.0 mumol/kg) of CDTD intrapertioneally show signs of toxicity typical of uncoupling agents. Mitochondria isolated from the livers of these rats show almost complete inhibition of ATP synthesis and mitochondria obtained from the livers of rats at various times after a single oral dose show maximal inhibition of ATP synthesis 4 h after dosing with complete recovery by about 24 h. A single oral administration of 58 mumol/kg or above, but not intraperitoneal injection, of CDTD into rats produced an increase in the water content of the brain and spinal cord. The additional fluid has been shown to contain Na+ ions. The increase in cerebral fluid is dose related, no effect being seen at 23 mumol/kg. This extra fluid is thought to be responsible for the hind limb weakness observed in these rats. These observations suggest that there are two facets to CDTD toxicity: early deaths (within 2 h), which appear to be due to uncoupling of oxidative phosphorylation, and delayed deaths, 2--3 days after dosing which are probably related to an increase in fluid in the brain and spinal cord.
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Maxwell IC, Le Quesne PM. Conduction velocity in hexachlorophane neuropathy: correlation between electrophysiological and histological findings. J Neurol Sci 1979; 43:95-110. [PMID: 521831 DOI: 10.1016/0022-510x(79)90075-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
After 2-3 weeks exposure to hexachlorophane, maximum motor nerve conduction velocity in sciatic nerves of rats was reduced by 7.5% and evoked muscle action potential amplitude by 9%. Histological examination at this stage showed intramyelin oedema affecting some fibres and axonal degeneration of other fibres. After longer periods of exposure velocity and amplitude fell further. Velocity was reduced by 27% after 6-7 months treatment. In addition to intramyelin oedema and axonal degeneration, segmental demyelination was present in animals intoxicated for more than three months. There was no correlation between the degree of oedema and reduction of conduction velocity. It is concluded that intramyelin oedema has little or no effect on conduction velocity. Nodes of Ranvier are normal in the early stages of the lesion and this may contribute to the preservation of normal conduction. The electrophysiological findings can be attributed to secondary changes of axonal degeneration and segmental demyelination.
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Yajima K, Suzuki K. Ultrastructural changes of oligodendroglia and myelin sheaths induced by ethidium bromide. Neuropathol Appl Neurobiol 1979; 5:49-62. [PMID: 431767 DOI: 10.1111/j.1365-2990.1979.tb00613.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Intracisternal injection of ethidium bromide, an inhibitor of mitochondria associated RNA, DNA and protein synthesis, produced status spongiosus in the subpial surface of the CNS of rats. Ultrastructurally, numerous intra-myelinic vacuoles and prominent degenerative changes of oligodendroglia were observed. The vacuoles were formed between the myelin lamellae by splitting of the intraperiod lines, between the axolemma and the innermost myelin lamellae, and/or between the inner tongue of oligodendroglia and myelin lamellae. In the degenerating oligodendroglia, proliferation and alteration of the endoplasmic reticulum were prominent. In places, altered membranes of the endoplasmic reticulum formed concentrical scroll-like structures. These ultrastructural changes in ethidium bromide treated rats were compared with other similar previously described changes in animals treated with TET, cuprizone, hexachlorophene, hypocholesterolaemic drugs and actinomycin D.
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Miller TL, Gaughan PL, Buhler DR. Effects of halogenated antibacterials on the erythrocyte membrane. Chem Biol Interact 1978; 22:167-83. [PMID: 699171 DOI: 10.1016/0009-2797(78)90123-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The influence of halogenated antibacterials on membrane structure and function was investigated using the human erythrocyte membrane as a model. Measurements of hemolysis in isotonic solution, altered membrane permeability, and stabilization against hypotonic hemolysis resulting from exposure of erythrocytes to halogenated antibacterials served as criteria of membrane-related effects. The hemolytic potency of the compounds studied differed widely, decreasing in the order hexachlorophene (HCP) greater than 2,2'-methylenebis(3,5-dichlorophenol) (3,5-TCP) greater than 2,2'-methylenebis(3,4-dichlorophenol) (3,4-TCP) approximately equal to 2,2'-methylenebis(4,6-dichlorophenol) (4,6-TCP) greater than 2,2'-methylenebis(4-chlorophenol) (DCP) greater than 3,4'-tribromosalicylanilide (TBS) approximately equal to 3,3',4',5-tetrachlorosalicylanilide (TCSA). Each of the antibacterials tested stabilized the erythrocyte against hypotonic hemolysis, although there were marked differences in the concentrations required to afford maximum stabilization as well as in the extent of protection. The observed order of protective effectiveness was HCP greater than 3,4-TCP greater than 4,6-TCP greater than DCP approximately equal to TCS greater than TBS. As shown by measurements of the first-order rate constant for K+ efflux, the permeability of the erythrocyte membrane to K+ was increased upon exposure to the antibacterials, with the effect of HCP greater than 3,4-TCP greater than 4,6-TCP approximately equal to 3,4-TCP greater than DCP approximately equal to TCS greater than TBS. These results indicate that halogenated antibacterials are capable of perturbing mammalian membranes, a feature which may account in part for their mammalian toxicity.
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Tabira T, Cullen MJ, Reier PJ. An experimental analysis of interlamellar tight junctions in amphibian and mammalian C.N.S. myelin. JOURNAL OF NEUROCYTOLOGY 1978; 7:489-503. [PMID: 690675 DOI: 10.1007/bf01173993] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The distribution of interlamellar tight junctions was examined in myelin sheaths of Xenopus tadpole optic nerve and rabbit epiretinal tissue fixed with aldehydes, postfixed with osmium ferrocyanide and embedded in a water-soluble medium, Durcupan. Intramyelinic zonulae occludentes were clearly formed by fusion of adjacent intraperiod lines which corresponded to the external leaflets of oligodendrocytes. These occurred in register with other tight junctions present within successive lamellae and appeared as a series of radial lines extending either partially or totally across the thickness of the myelin sheath. This distribution of zonulae occludentes corresponded with that of tight junctional particle strands observed in freeze-fracture replicas. Analysis of intramyelinic vacuolation induced by hexachlorophene (HCP) intoxication indicated that lamellar splitting was frequently limited by the tight junctions. The intramyelinic zonulae occludentes also restricted the diffusion of colloidal lanthanum which had penetrated the myelin intraperiod gap following in vivo perineural injection. The results of this study provide evidence favouring a correspondence between interlamellar tight junctions and the 'radial component' of myelin described earlier by other investigators. Furthermore, observations of swollen myelin sheaths, resulting from HCP intoxication, suggest that these junctions may play a major role in maintaining myelin sheath integrity and limiting the extent of breakdown during certain pathological conditions.
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Trapp BD, Bernsohn J. Essential fatty acid deficiency and CNS myelin. Biochemical and morphological observations. J Neurol Sci 1978; 37:249-66. [PMID: 681979 DOI: 10.1016/0022-510x(78)90207-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Essential fatty acid (EFA) deficiency was induced by feeding pregnant rats a fat-free diet 10--12 days after impregnation and maintaining the offspring on this diet until 120 days of age. EFA-deficiency rats demonstrated marked alterations in the fatty acid composition of ethanolamine phosphoglycerides (EPG's) from myelin subfractions. A decrease in the fatty acids of the linoleic (n-6) and linolenic (n-3) families was accompanied by an increase in the non-essential fatty acids of the oleic (n-9) family. These alterations decreased the unsaturation index of heavy myelin by 23% and that of light myelin by 10%. The EPG fatty acid composition of heavy myelin from control animals contained a higher percentage of polyunsaturated fatty acids than the light myelin which contained more monounsaturated fatty acids. These differences may be a reflection of distinct anatomical locations or functional properties of the subfractions. The differences between light and heavy myelin EPG fatty acids were not maintained during EFA deficiency. Morphologically, 1 mum thick sections revealed vacuoles within the optic nerve of EFA-deficient rats. Ultrastructurally these vacuoles were identified as fibers undergoing Wallerian degeneration and fibers demonstrating intramyelinic splitting. No qualitative changes were found in oligodendrocytes, astrocytes or vascular elements within EFA-deficient optic nerve. EFA deficiency did not alter the diameter of fibers within the optic nerve. These results show that although there is no apparent decrease in the degree of myelination within the optic nerve, morphological changes do occur in fibers of EFA-deficient optic nerve concomitantly with alterations in the EPG fatty acids of myelin subfractions.
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Cummings JF, de Lahunta A. Hereditary myelopathy of Afghan hounds, a myelinolytic disease. Acta Neuropathol 1978; 42:173-81. [PMID: 676666 DOI: 10.1007/bf00690354] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A disease described previously as hereditary necrotizing myelopathy and myelomalacia was studied in four Afghan hounds. Light and electron microscopic investigation revealed sieve-like degeneration of spinal white matter. Despite extensive spongiform degeneration of myelin that progressed to micro- and macro-cavitation, substantial numbers of axons were preserved. This canine myelopathy was compared and contrasted with various toxic/metabolic conditions including subacute combined degeneration.
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