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Sample records for experimental demyelination models

  1. Experimental models of demyelination and remyelination.

    Science.gov (United States)

    Torre-Fuentes, L; Moreno-Jiménez, L; Pytel, V; Matías-Guiu, J A; Gómez-Pinedo, U; Matías-Guiu, J

    2017-08-29

    Experimental animal models constitute a useful tool to deepen our knowledge of central nervous system disorders. In the case of multiple sclerosis, however, there is no such specific model able to provide an overview of the disease; multiple models covering the different pathophysiological features of the disease are therefore necessary. We reviewed the different in vitro and in vivo experimental models used in multiple sclerosis research. Concerning in vitro models, we analysed cell cultures and slice models. As for in vivo models, we examined such models of autoimmunity and inflammation as experimental allergic encephalitis in different animals and virus-induced demyelinating diseases. Furthermore, we analysed models of demyelination and remyelination, including chemical lesions caused by cuprizone, lysolecithin, and ethidium bromide; zebrafish; and transgenic models. Experimental models provide a deeper understanding of the different pathogenic mechanisms involved in multiple sclerosis. Choosing one model or another depends on the specific aims of the study. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. Experimental Models of Autoimmune Demyelinating Diseases in Nonhuman Primates.

    Science.gov (United States)

    Stimmer, Lev; Fovet, Claire-Maëlle; Serguera, Ché

    2017-01-01

    Human idiopathic inflammatory demyelinating diseases (IIDD) are a heterogeneous group of autoimmune inflammatory and demyelinating disorders of the central nervous system (CNS). These include multiple sclerosis (MS), the most common chronic IIDD, but also rarer disorders such as acute disseminated encephalomyelitis (ADEM) and neuromyelitis optica (NMO). Great efforts have been made to understand the pathophysiology of MS, leading to the development of a few effective treatments. Nonetheless, IIDD still require a better understanding of the causes and underlying mechanisms to implement more effective therapies and diagnostic methods. Experimental autoimmune encephalomyelitis (EAE) is a commonly used animal model to study the pathophysiology of IIDD. EAE is principally induced through immunization with myelin antigens combined with immune-activating adjuvants. Nonhuman primates (NHP), the phylogenetically closest relatives of humans, challenged by similar microorganisms as other primates may recapitulate comparable immune responses to that of humans. In this review, the authors describe EAE models in 3 NHP species: rhesus macaques ( Macaca mulatta), cynomolgus macaques ( Macaca fascicularis), and common marmosets ( Callithrix jacchus), evaluating their respective contribution to the understanding of human IIDD. EAE in NHP is a heterogeneous disease, including acute monophasic and chronic polyphasic forms. This diversity makes it a versatile model to use in translational research. This clinical variability also creates an opportunity to explore multiple facets of immune-mediated mechanisms of neuro-inflammation and demyelination as well as intrinsic protective mechanisms. Here, the authors review current insights into the pathogenesis and immunopathological mechanisms implicated in the development of EAE in NHP.

  3. Fibronectin connecting segment-1 peptide inhibits pathogenic leukocyte trafficking and inflammatory demyelination in experimental models of chronic inflammatory demyelinating polyradiculoneuropathy.

    Science.gov (United States)

    Dong, Chaoling; Greathouse, Kelsey M; Beacham, Rebecca L; Palladino, Steven P; Helton, E Scott; Ubogu, Eroboghene E

    2017-06-01

    The molecular determinants of pathogenic leukocyte migration across the blood-nerve barrier (BNB) in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) are unknown. Specific disease modifying therapies for CIDP are also lacking. Fibronectin connecting segment-1 (FNCS1), an alternatively spliced fibronectin variant expressed by microvascular endothelial cells at sites of inflammation in vitro and in situ, is a counterligand for leukocyte α4 integrin (also known as CD49d) implicated in pathogenic leukocyte trafficking in multiple sclerosis and inflammatory bowel disease. We sought to determine the role of FNCS1 in CIDP patient leukocyte trafficking across the BNB in vitro and in severe chronic demyelinating neuritis in vivo using a representative spontaneous murine CIDP model. Peripheral blood mononuclear leukocytes from 7 untreated CIDP patients were independently infused into a cytokine-treated, flow-dependent in vitro BNB model system. Time-lapse digital video microscopy was performed to visualize and quantify leukocyte trafficking, comparing FNCS1 peptide blockade to relevant controls. Fifty 24-week old female B7-2 deficient non-obese diabetic mice with spontaneous autoimmune peripheral polyneuropathy (SAPP) were treated daily with 2mg/kg FNCS1 peptide for 5days via intraperitoneal injection with appropriate controls. Neurobehavioral measures of disease severity, motor nerve electrophysiology assessments and histopathological quantification of inflammation and morphometric assessment of demyelination were performed to determine in vivo efficacy. The biological relevance of FNCS1 and CD49d in CIDP was evaluated by immunohistochemical detection in affected patient sural nerve biopsies. 25μM FNCS1 peptide maximally inhibited CIDP leukocyte trafficking at the human BNB in vitro. FNCS1 peptide treatment resulted in significant improvements in disease severity, motor electrophysiological parameters of demyelination and histological measures of

  4. Mouse models of multiple sclerosis: experimental autoimmune encephalomyelitis and Theiler's virus-induced demyelinating disease.

    Science.gov (United States)

    McCarthy, Derrick P; Richards, Maureen H; Miller, Stephen D

    2012-01-01

    Experimental autoimmune encephalomyelitis (EAE) and Theiler's Murine Encephalitis Virus-Induced Demyelinating Disease (TMEV-IDD) are two clinically relevant murine models of multiple sclerosis (MS). Like MS, both are characterized by mononuclear cell infiltration into the CNS and demyelination. EAE is induced by either the administration of myelin protein or peptide in adjuvant or by the adoptive transfer of encephalitogenic T cell blasts into naïve recipients. The relative merits of each of these protocols are compared. Depending on the type of question being asked, different mouse strains and peptides are used. Different disease courses are observed with different strains and different peptides in active EAE. These variations are also addressed. Additionally, issues relevant to clinical grading of EAE in mice are discussed. In addition to EAE induction, useful references for other disease indicators such as DTH, in vitro proliferation, and immunohistochemistry are provided. TMEV-IDD is a useful model for understanding the possible viral etiology of MS. This section provides detailed information on the preparation of viral stocks and subsequent intracerebral infection of mice. Additionally, virus plaque assay and clinical disease assessment are discussed. Recently, recombinant TMEV strains have been created for the study of molecular mimicry which incorporate various 30 amino acid myelin epitopes within the leader region of TMEV.

  5. Pain hypersensitivity in rats with experimental autoimmune neuritis, an animal model of human inflammatory demyelinating neuropathy.

    Science.gov (United States)

    Moalem-Taylor, Gila; Allbutt, Haydn N; Iordanova, Mihaela D; Tracey, David J

    2007-07-01

    Experimental autoimmune neuritis (EAN) is a T cell mediated autoimmune disease of the peripheral nervous system that serves as an animal model of the acute inflammatory demyelinating polyradiculoneuropathy in Guillain-Barre syndrome (GBS). Although pain is a common symptom of GBS occurring in 55-85% of cases, it is often overlooked and the underlying mechanisms are poorly understood. Here we examined whether animals with EAN exhibit signs of neuropathic pain including hyperalgesia and allodynia, and assessed their peripheral nerve autoimmune inflammation. We immunized Lewis rats with peripheral myelin P2 peptide (amino acids 57-81) emulsified with complete Freund's adjuvant, or with adjuvant only as control. P2-immunized rats developed mild to modest monophasic EAN with disease onset at day 8, peak at days 15-17, and full recovery by day 28 following immunization. Rats with EAN showed a significant decrease in withdrawal latency to thermal stimuli and withdrawal threshold to mechanical stimuli, in both hindpaws and forepaws, during the course of the disease. We observed a significant infiltration of T cells bearing alphabeta receptors, and a significant increase in antigen-presenting cells expressing MHC class II as well as macrophages, in EAN-affected rats. Our results demonstrate that animals with active EAN develop significant thermal hyperalgesia and mechanical allodynia, accompanied by pronounced autoimmune inflammation in peripheral nerves. These findings suggest that EAN is a useful model for the pain seen in many GBS patients, and may facilitate study of neuroimmune mechanisms underlying pain in autoimmune neuropathies.

  6. Cerebellar white matter inflammation and demyelination in chronic relapsing experimental allergic encephalomyelitis

    DEFF Research Database (Denmark)

    Wanscher, B.; Sørensen, P. S.; Juhler, M.

    1993-01-01

    Experimental allergic encephalomyelitis, demyelination, inflammation, immunology, neuropathology......Experimental allergic encephalomyelitis, demyelination, inflammation, immunology, neuropathology...

  7. NG2 glia generate new oligodendrocytes but few astrocytes in a murine experimental autoimmune encephalomyelitis model of demyelinating disease.

    Science.gov (United States)

    Tripathi, Richa B; Rivers, Leanne E; Young, Kaylene M; Jamen, Francoise; Richardson, William D

    2010-12-01

    The adult mammalian brain and spinal cord contain glial precursors that express platelet-derived growth factor receptor α subunit (PDGFRA) and the NG2 proteoglycan. These "NG2 cells" descend from oligodendrocyte precursors in the perinatal CNS and continue to generate myelinating oligodendrocytes in the gray and white matter of the postnatal brain. It has been proposed that NG2 cells can also generate reactive astrocytes at sites of CNS injury or demyelination. To test this we examined the fates of PDGFRA/NG2 cells in the mouse spinal cord during experimental autoimmune encephalomyelitis (EAE)--a demyelinating condition that models some aspects of multiple sclerosis in humans. We administered tamoxifen to Pdgfra-CreER(T2):Rosa26R-YFP mice to induce yellow fluorescent protein (YFP) expression in PDGFRA/NG2 cells and their differentiated progeny. We subsequently induced EAE and observed a large (>4-fold) increase in the local density of YFP(+) cells, >90% of which were oligodendrocyte lineage cells. Many of these became CC1-positive, NG2-negative differentiated oligodendrocytes that expressed myelin markers CNP and Tmem10/Opalin. PDGFRA/NG2 cells generated very few GFAP(+)-reactive astrocytes (1-2% of all YFP(+) cells) or NeuN(+) neurons (demyelinated spinal cord.

  8. Mouse Models of Multiple Sclerosis: Experimental Autoimmune Encephalomyelitis and Theiler’s Virus-Induced Demyelinating Disease

    Science.gov (United States)

    McCarthy, Derrick P.; Richards, Maureen H.; Miller, Stephen D.

    2013-01-01

    Experimental autoimmune encephalomyelitis (EAE) and Theiler’s Murine Encephalitis Virus-Induced Demyelinating Disease (TMEV-IDD) are two clinically relevant murine models of multiple sclerosis (MS). Like MS, both are characterized by mononuclear cell infiltration into the CNS and demyelination. EAE is induced by either the administration of myelin protein or peptide in adjuvant or by the adoptive transfer of encephalitogenic T cell blasts into naïve recipients. The relative merits of each of these protocols are compared. Depending on the type of question being asked, different mouse strains and peptides are used. Different disease courses are observed with different strains and different peptides in active EAE. These variations are also addressed. Additionally, issues relevant to clinical grading of EAE in mice are discussed. In addition to EAE induction, useful references for other disease indicators such as DTH, in vitro proliferation, and immunohistochemistry are provided. TMEV-IDD is a useful model for understanding the possible viral etiology of MS. This section provides detailed information on the preparation of viral stocks and subsequent intracerebral infection of mice. Additionally, virus plaque assay and clinical disease assessment are discussed. Recently, recombinant TMEV strains have been created for the study of molecular mimicry which incorporate various 30 amino acid myelin epitopes within the leader region of TMEV. PMID:22933080

  9. Myelin debris regulates inflammatory responses in an experimental demyelination animal model and multiple sclerosis lesions

    NARCIS (Netherlands)

    Clarner, T.; Diederichs, F.; Berger, K.; Denecke, B.; Gan, L.; van der Valk, P.; Beyer, C.; Amor, S.; Kipp, M.

    2012-01-01

    In multiple sclerosis (MS), gray matter pathology is characterized by less pronounced inflammation when compared with white matter lesions. Although regional differences in the cytoarchitecture may account for these differences, the amount of myelin debris in the cortex during a demyelinating event

  10. Acutely damaged axons are remyelinated in multiple sclerosis and experimental models of demyelination.

    Science.gov (United States)

    Schultz, Verena; van der Meer, Franziska; Wrzos, Claudia; Scheidt, Uta; Bahn, Erik; Stadelmann, Christine; Brück, Wolfgang; Junker, Andreas

    2017-08-01

    Remyelination is in the center of new therapies for the treatment of multiple sclerosis to resolve and improve disease symptoms and protect axons from further damage. Although remyelination is considered beneficial in the long term, it is not known, whether this is also the case early in lesion formation. Additionally, the precise timing of acute axonal damage and remyelination has not been assessed so far. To shed light onto the interrelation between axons and the myelin sheath during de- and remyelination, we employed cuprizone- and focal lysolecithin-induced demyelination and performed time course experiments assessing the evolution of early and late stage remyelination and axonal damage. We observed damaged axons with signs of remyelination after cuprizone diet cessation and lysolecithin injection. Similar observations were made in early multiple sclerosis lesions. To assess the correlation of remyelination and axonal damage in multiple sclerosis lesions, we took advantage of a cohort of patients with early and late stage remyelinated lesions and assessed the number of APP- and SMI32- positive damaged axons and the density of SMI31-positive and silver impregnated preserved axons. Early de- and remyelinating lesions did not differ with respect to axonal density and axonal damage, but we observed a lower axonal density in late stage demyelinated multiple sclerosis lesions than in remyelinated multiple sclerosis lesions. Our findings suggest that remyelination may not only be protective over a long period of time, but may play an important role in the immediate axonal recuperation after a demyelinating insult. © 2017 The Authors GLIA Published by Wiley Periodicals, Inc.

  11. Behaviour of oligodendrocytes and Schwann cells in an experimental model of toxic demyelination of the central nervous system

    OpenAIRE

    Dominguita Lühers Graça; Eduardo Fernandes Bondan; Luis Antonio Violin Dias Pereira; Cristina Gevehr Fernandes; Paulo César Maiorka

    2001-01-01

    Oligodendrocytes and Schwann cells are engaged in myelin production, maintenance and repairing respectively in the central nervous system (CNS) and the peripheral nervous system (PNS). Whereas oligodendrocytes act only within the CNS, Schwann cells are able to invade the CNS in order to make new myelin sheaths around demyelinated axons. Both cells have some limitations in their activities, i.e. oligodendrocytes are post-mitotic cells and Schwann cells only get into the CNS in the absence of a...

  12. Treatment with metallothionein prevents demyelination and axonal damage and increases oligodendrocyte precursors and tissue repair during experimental autoimmune encephalomyelitis

    DEFF Research Database (Denmark)

    Penkowa, Milena; Hidalgo, Juan

    2003-01-01

    Experimental autoimmune encephalomyelitis (EAE) is an animal model for the human demyelinating disease multiple sclerosis (MS). EAE and MS are characterized by significant inflammation, demyelination, neuroglial damage, and cell death. Metallothionein-I and -II (MT-I + II) are antiinflammatory an...

  13. Severe oxidative stress in an acute inflammatory demyelinating model in the rhesus monkey

    NARCIS (Netherlands)

    Dunham, Jordon; van de Vis, Reinofke; Bauer, Jan; Wubben, Jacqueline; van Driel, Nikki; Laman, Jon D; 't Hart, Bert A; Kap, Yolanda S

    2017-01-01

    Oxidative stress is increasingly implicated as a co-factor of tissue injury in inflammatory/demyelinating disorders of the central nervous system (CNS), such as multiple sclerosis (MS). While rodent experimental autoimmune encephalomyelitis (EAE) models diverge from human demyelinating disorders

  14. EAE is not a useful model for demyelinating disease.

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    Behan, Peter O; Chaudhuri, Abhijit

    2014-09-01

    Experimental allergic encephalomyelitis (EAE) is the commonest, readily induced, organspecific, autoimmune disorder of laboratory animals of its kind. It is an artificial disorder brought about by the immunisation of susceptible animals with brain antigens in complete Freund׳s adjuvant (CFA). Variations can be induced by altering the nature of the antigen and the conditions involving immunisation. Whilst it is often described as a demyelinating disease, in strict terms it is not, since the primary pathologic process is not demyelination but rather an encephalomyelitis that is immunologically induced. Rather, the prototype demyelinating disease is multiple sclerosis and its variants. In this paper, the central question we ask is whether the data gleaned from the EAE model contributes to our understanding of the pathological events in MS. Towards answering this, we describe the historical development of EAE and its hyperacute form, and discuss the findings studied extensively in the non-human primate which show that ordinary EAE is an exact model for ADEM in the human, and that the hyperacute form of EAE is represented by AHLE in the human. Additionally, we shall comment on the latest research on new variants of EAE, and explain our opinion regarding the use of EAE models in research aiming to understand the pathogenesis of multiple sclerosis. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Experimental Optic Neuritis Induced by a Demyelinating Strain of Mouse Hepatitis Virus▿

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    Shindler, Kenneth S.; Kenyon, Lawrence C.; Dutt, Mahasweta; Hingley, Susan T.; Sarma, Jayasri Das

    2008-01-01

    Optic neuritis (ON), an inflammatory demyelinating optic nerve disease, occurs in multiple sclerosis (MS). Pathological mechanisms and potential treatments for ON have been studied via experimental autoimmune MS models. However, evidence suggests that virus-induced inflammation is a likely etiology triggering MS and ON; experimental virus-induced ON models are therefore required. We demonstrate that MHV-A59, a mouse hepatitis virus (MHV) strain that causes brain and spinal cord inflammation and demyelination, induces ON by promoting mixed inflammatory cell infiltration. In contrast, MHV-2, a nondemyelinating MHV strain, does not induce ON. Results reveal a reproducible virus-induced ON model important for the evaluation of novel therapies. PMID:18579591

  16. Five decades of cuprizone, an updated model to replicate demyelinating diseases.

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    Vega-Riquer, Jose M; Mendez-Victoriano, Gerardo; Morales-Luckie, Raul A; Gonzalez-Perez, Oscar

    2017-07-17

    Multiple sclerosis, Guillain-Barré syndrome, peripheral nerve polyneuropathy and others comprise a group of demyelinating diseases characterized by progressive (and eventually irreversible) loss of oligodendrocytes and myelin sheaths in the white matter of the brain. To date, the etiology of these disorders is not well known and no effective treatments are currently available. Therefore, further research is needed to gain a better understand and treat these patients. To accomplish this goal, it is necessary to have appropriate animal models that closely resemble the pathophysiology of these diseases. Herein, we describe the model of toxic demyelination induced by cuprizone, a copper chelator that reduces the cytochrome and monoamine oxidase activity into the brain, produces mitochondrial stress and triggers local immunological responses. These biochemical and cellular changes ultimately result in selective loss of oligodendrocytes, extensive areas of demyelination and reactive gliosis in the corpus callosum, superior cerebellar peduncles and cerebral cortex. Remarkably, some aspects of the histological pattern induced by cuprizone are similar to those found in multiple sclerosis. Cuprizone exposure also provokes behavioral changes, impairs motor skills and affects mood as that observed in several demyelinating diseases. Upon cuprizone removal, the pathological and histological changes gradually revert. Therefore, the cuprizone model allows to partially mimic the disease relapses of some demyelinating diseases. In summary, the model of cuprizone-induced demyelination is a good experimental approach to study demyelinating diseases that has maintained its validity, and is a suitable pharmacological model for reproducing some key features of demyelinating diseases, including multiple sclerosis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  17. Time-Dependent Progression of Demyelination and Axonal Pathology in MP4-Induced Experimental Autoimmune Encephalomyelitis.

    Directory of Open Access Journals (Sweden)

    Johanna Prinz

    Full Text Available Multiple sclerosis (MS is an autoimmune disease of the central nervous system (CNS characterized by inflammation, demyelination and axonal pathology. Myelin basic protein/proteolipid protein (MBP-PLP fusion protein MP4 is capable of inducing chronic experimental autoimmune encephalomyelitis (EAE in susceptible mouse strains mirroring diverse histopathological and immunological hallmarks of MS. Lack of human tissue underscores the importance of animal models to study the pathology of MS.Twenty-two female C57BL/6 (B6 mice were immunized with MP4 and the clinical development of experimental autoimmune encephalomyelitis (EAE was observed. Methylene blue-stained semi-thin and ultra-thin sections of the lumbar spinal cord were assessed at the peak of acute EAE, three months (chronic EAE and six months after onset of EAE (long-term EAE. The extent of lesional area and inflammation were analyzed in semi-thin sections on a light microscopic level. The magnitude of demyelination and axonal damage were determined using electron microscopy. Emphasis was put on the ventrolateral tract (VLT of the spinal cord.B6 mice demonstrated increasing demyelination and severe axonal pathology in the course of MP4-induced EAE. Additionally, mitochondrial swelling and a decrease in the nearest neighbor neurofilament distance (NNND as early signs of axonal damage were evident with the onset of EAE. In semi-thin sections we observed the maximum of lesional area in the chronic state of EAE while inflammation was found to a similar extent in acute and chronic EAE. In contrast to the well-established myelin oligodendrocyte glycoprotein (MOG model, disease stages of MP4-induced EAE could not be distinguished by assessing the extent of parenchymal edema or the grade of inflammation.Our results complement our previous ultrastructural studies of B6 EAE models and suggest that B6 mice immunized with different antigens constitute useful instruments to study the diverse

  18. Intrathecal gene therapy rescues a model of demyelinating peripheral neuropathy.

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    Kagiava, Alexia; Sargiannidou, Irene; Theophilidis, George; Karaiskos, Christos; Richter, Jan; Bashiardes, Stavros; Schiza, Natasa; Nearchou, Marianna; Christodoulou, Christina; Scherer, Steven S; Kleopa, Kleopas A

    2016-04-26

    Inherited demyelinating peripheral neuropathies are progressive incurable diseases without effective treatment. To develop a gene therapy approach targeting myelinating Schwann cells that can be translatable, we delivered a lentiviral vector using a single lumbar intrathecal injection and a myelin-specific promoter. The human gene of interest, GJB1, which is mutated in X-linked Charcot-Marie-Tooth Disease (CMT1X), was delivered intrathecally into adult Gjb1-null mice, a genetically authentic model of CMT1X that develops a demyelinating peripheral neuropathy. We obtained widespread, stable, and cell-specific expression of connexin32 in up to 50% of Schwann cells in multiple lumbar spinal roots and peripheral nerves. Behavioral and electrophysiological analysis revealed significantly improved motor performance, quadriceps muscle contractility, and sciatic nerve conduction velocities. Furthermore, treated mice exhibited reduced numbers of demyelinated and remyelinated fibers and fewer inflammatory cells in lumbar motor roots, as well as in the femoral motor and sciatic nerves. This study demonstrates that a single intrathecal lentiviral gene delivery can lead to Schwann cell-specific expression in spinal roots extending to multiple peripheral nerves. This clinically relevant approach improves the phenotype of an inherited neuropathy mouse model and provides proof of principle for treating inherited demyelinating neuropathies.

  19. Chronic inflammatory demyelinating polyradiculoneuropathy: A new animal model for new therapeutic targets.

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    de Sèze, J; Kremer, L; Alves do Rego, C; Taleb, O; Lam, D; Beiano, W; Mensah-Nyagan, G; Trifilieff, E; Brun, S

    2016-12-01

    Animal models are fundamental to advance knowledge of disease pathogenesis and to test/develop new therapeutic strategies. Most of the current knowledge about the pathogenic mechanisms underpinning autoimmune demyelination processes implicating autoantigens has been obtained using the Experimental Autoimmune Neuritis (EAN) animal model. The most widely used EAN model is obtained by active immunization of Lewis rats using a peptide, P0 (180-199), issuing from the major peripheral nervous system myelin protein. But this model mimics only the classical monophasic acute form of demyelinating polyradiculoneuropathy, i.e. Guillain-Barré syndrome (GBS). We developed a new model by immunizing Lewis rats using the same immunodominant neuritogenic peptide P0 (180-199) but this time with its S-palmitoyl derivative, S-palm P0 (180-199). All of the animals immunized with the S-palm P0 (180-199) peptide developed a chronic relapsing-remitting form of the disease corresponding to the electrophysiological criteria of demyelination (slow sensory nerve conduction velocity, prolonged motor nerve latency, partial motor nerve conduction blocks) with axon degeneration. These findings were confirmed by immunohistopathology study and thus, appear to mimic human chronic inflammatory demyelinating polyradiculopathy (CIDP). This new model opens up new avenues of research for testing new anti-inflammatory and neuroprotective therapeutic strategies. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  20. Disparate Effects of Mesenchymal Stem Cells in Experimental Autoimmune Encephalomyelitis and Cuprizone-Induced Demyelination.

    Directory of Open Access Journals (Sweden)

    Justin D Glenn

    Full Text Available Mesenchymal stem cells (MSCs are pleiotropic cells with potential therapeutic benefits for a wide range of diseases. Because of their immunomodulatory properties they have been utilized to treat autoimmune diseases such as multiple sclerosis (MS, which is characterized by demyelination. The microenvironment surrounding MSCs is thought to affect their differentiation and phenotype, which could in turn affect the efficacy. We thus sought to dissect the potential for differential impact of MSCs on central nervous system (CNS disease in T cell mediated and non-T cell mediated settings using the MOG35-55 experimental autoimmune encephalomyelitis (EAE and cuprizone-mediated demyelination models, respectively. As the pathogeneses of MS and EAE are thought to be mediated by IFNγ-producing (TH1 and IL-17A-producing (TH17 effector CD4+ T cells, we investigated the effect of MSCs on the development of these two key pathogenic cell groups. Although MSCs suppressed the activation and effector function of TH17 cells, they did not affect TH1 activation, but enhanced TH1 effector function and ultimately produced no effect on EAE. In the non- T cell mediated cuprizone model of demyelination, MSC administration had a positive effect, with an overall increase in myelin abundance in the brain of MSC-treated mice compared to controls. These results highlight the potential variability of MSCs as a biologic therapeutic tool in the treatment of autoimmune disease and the need for further investigation into the multifaceted functions of MSCs in diverse microenvironments and the mechanisms behind the diversity.

  1. IFN-beta gene deletion leads to augmented and chronic demyelinating experimental autoimmune encephalomyelitis

    DEFF Research Database (Denmark)

    Teige, Ingrid; Treschow, Alexandra; Teige, Anna

    2003-01-01

    Since the basic mechanisms behind the beneficial effects of IFN-beta in multiple sclerosis (MS) patients are still obscure, here we have investigated the effects of IFN-beta gene disruption on the commonly used animal model for MS, experimental autoimmune encephalomyelitis (EAE). We show that IFN......-beta knockout (KO) mice are more susceptible to EAE than their wild-type (wt) littermates; they develop more severe and chronic neurological symptoms with more extensive CNS inflammation and demyelination. However, there was no discrepancy observed between wt and KO mice regarding the capacity of T cells...... to proliferate or produce IFN-gamma in response to recall Ag. Consequently, we addressed the effect of IFN-beta on encephalitogenic T cell development and the disease initiation phase by passive transfer of autoreactive T cells from KO or wt littermates to both groups of mice. Interestingly, IFN-beta KO mice...

  2. Demyelination induces transport of ribosome-containing vesicles from glia to axons: evidence from animal models and MS patient brains.

    Science.gov (United States)

    Shakhbazau, Antos; Schenk, Geert J; Hay, Curtis; Kawasoe, Jean; Klaver, Roel; Yong, V Wee; Geurts, Jeroen J G; van Minnen, Jan

    2016-06-01

    Glial cells were previously proven capable of trafficking polyribosomes to injured axons. However, the occurrence of such transfer in the general pathological context, such as demyelination-related diseases, needs further evidence. Since this may be a yet unidentified universal contributor to axonal survival, we study putative glia-axonal ribosome transport in response to demyelination in animal models and patients in both peripheral and central nervous system. In the PNS we investigate whether demyelination in a rodent model has the potential to induce ribosome transfer. We also probe the glia-axonal ribosome supply by implantation of transgenic Schwann cells engineered to produce fluorescent ribosomes in the same demyelination model. We furthermore examine the presence of axonal ribosomes in mouse experimental autoimmune encephalomyelitis (EAE), a well-established model for multiple sclerosis (MS), and in human MS autopsy brain material. We provide evidence for increased axonal ribosome content in a pharmacologically demyelinated sciatic nerve, and demonstrate that at least part of these ribosomes originate in the transgenic Schwann cells. In the CNS one of the hallmarks of MS is demyelination, which is associated with severe disruption of oligodendrocyte-axon interaction. Here, we provide evidence that axons from spinal cords of EAE mice, and in the MS human brain contain an elevated amount of axonal ribosomes compared to controls. Our data provide evidence that increased axonal ribosome content in pathological axons is at least partly due to glia-to-axon transfer of ribosomes, and that demyelination in the PNS and in the CNS is one of the triggers capable to initiate this process.

  3. Dietary vitamin D3 supplements reduce demyelination in the cuprizone model.

    Directory of Open Access Journals (Sweden)

    Stig Wergeland

    Full Text Available Vitamin D is emerging as a probably important environmental risk factor in multiple sclerosis, affecting both susceptibility and disease progression. It is not known to what extent this effect is due to a modulation of peripheral lymphocyte function, or to intrathecal effects of vitamin D. We investigated the effect of dietary vitamin D3 content on de/remyelination in the cuprizone model, which is a well established toxic model of demyelination, with no associated lymphocyte infiltration. The mice received diets either deficient of (<50 IU/kg, or supplemented with low (500 IU/kg, high (6200 IU/kg or very high (12500 IU/kg amounts of vit D3. Cuprizone (0.2% was added to the diet for six weeks, starting two weeks after onset of the experimental diets. Mouse brain tissue was histopathologically evaluated for myelin and oligodendrocyte loss, microglia/macrophage activation, and lymphocyte infiltration after six weeks of cuprizone exposure, and two weeks after discontinuation of cuprizone exposure. High and very high doses of vitamin D3 significantly reduced the extent of white matter demyelination (p = 0.004 and attenuated microglia activation (p = 0.001. No differences in the density of oligodendrocytes were observed between the diet groups. Two weeks after discontinuation of cuprizone exposure, remyelination was only detectable in the white matter of mice receiving diets deficient of or with low vitamin D3 content. In conclusion, high dietary doses of vitamin D3 reduce the extent of demyelination, and attenuate microglia activation and macrophage infiltration in a toxic model of demyelination, independent of lymphocyte infiltration.

  4. Demyelination patterns in a mathematical model of multiple sclerosis.

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    Lombardo, M C; Barresi, R; Bilotta, E; Gargano, F; Pantano, P; Sammartino, M

    2017-08-01

    In this paper we derive a reaction-diffusion-chemotaxis model for the dynamics of multiple sclerosis. We focus on the early inflammatory phase of the disease characterized by activated local microglia, with the recruitment of a systemically activated immune response, and by oligodendrocyte apoptosis. The model consists of three equations describing the evolution of macrophages, cytokine and apoptotic oligodendrocytes. The main driving mechanism is the chemotactic motion of macrophages in response to a chemical gradient provided by the cytokines. Our model generalizes the system proposed by Calvez and Khonsari (Math Comput Model 47(7-8):726-742, 2008) and Khonsari and Calvez (PLos ONE 2(1):e150, 2007) to describe Baló's sclerosis, a rare and aggressive form of multiple sclerosis. We use a combination of analytical and numerical approaches to show the formation of different demyelinating patterns. In particular, a Turing instability analysis demonstrates the existence of a threshold value for the chemotactic coefficient above which stationary structures develop. In the case of subcritical transition to the patterned state, the numerical investigations performed on a 1-dimensional domain show the existence, far from the bifurcation, of complex spatio-temporal dynamics coexisting with the Turing pattern. On a 2-dimensional domain the proposed model supports the emergence of different demyelination patterns: localized areas of apoptotic oligodendrocytes, which closely fit existing MRI findings on the active MS lesion during acute relapses; concentric rings, typical of Baló's sclerosis; small clusters of activated microglia in absence of oligodendrocytes apoptosis, observed in the pathology of preactive lesions.

  5. Quantifying Demyelination in NK venom treated nerve using its electric circuit model

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    Das, H. K.; Das, D.; Doley, R.; Sahu, P. P.

    2016-03-01

    Reduction of myelin in peripheral nerve causes critical demyelinating diseases such as chronic inflammatory demyelinating polyneuropathy, Guillain-Barre syndrome, etc. Clinical monitoring of these diseases requires rapid and non-invasive quantification of demyelination. Here we have developed formulation of nerve conduction velocity (NCV) in terms of demyelination considering electric circuit model of a nerve having bundle of axons for its quantification from NCV measurements. This approach has been validated and demonstrated with toad nerve model treated with crude Naja kaouthia (NK) venom and also shows the effect of Phospholipase A2 and three finger neurotoxin from NK-venom on peripheral nerve. This opens future scope for non-invasive clinical measurement of demyelination.

  6. Behaviour of oligodendrocytes and Schwann cells in an experimental model of toxic demyelination of the central nervous system Comportamento de oligodendrócitos e células de Schwann em modelo experimental de desmielinização tóxica do sistema nervoso central

    Directory of Open Access Journals (Sweden)

    Dominguita Lühers Graça

    2001-06-01

    Full Text Available Oligodendrocytes and Schwann cells are engaged in myelin production, maintenance and repairing respectively in the central nervous system (CNS and the peripheral nervous system (PNS. Whereas oligodendrocytes act only within the CNS, Schwann cells are able to invade the CNS in order to make new myelin sheaths around demyelinated axons. Both cells have some limitations in their activities, i.e. oligodendrocytes are post-mitotic cells and Schwann cells only get into the CNS in the absence of astrocytes. Ethidium bromide (EB is a gliotoxic chemical that when injected locally within the CNS, induce demyelination. In the EB model of demyelination, glial cells are destroyed early after intoxication and Schwann cells are free to approach the naked central axons. In normal Wistar rats, regeneration of lost myelin sheaths can be achieved as early as thirteen days after intoxication; in Wistar rats immunosuppressed with cyclophosphamide the process is delayed and in rats administered cyclosporine it may be accelerated. Aiming the enlightening of those complex processes, all events concerning the myelinating cells in an experimental model are herein presented and discussed.Oligodendrócitos e células de Schwann realizam a produção e manutenção das bainhas de mielina, respectivamente no sistema nervoso central (SNC e periférico (SNP. As células de Schwann, à diferença dos oligodendrócitos, são capazes de invadir o SNC para remielinizar axônios desmielinizados, sempre que os astrócitos tenham sido destruídos. O brometo de etídio é uma droga gliotóxica usada para induzir desmielinização com o desaparecimento precoce de astrócitos, de modo que as células de Schwann têm liberdade para invadir o SNC. Em ratos Wistar normais, a remielinização é detectada treze dias após desmielinização; em ratos Wistar imunossuprimidos com ciclofosfamida a reparação do tecido é tardia, enquanto que em animais tratados com ciclosporina ela

  7. Promoting remyelination: utilizing a viral model of demyelination to assess cell-based therapies.

    Science.gov (United States)

    Marro, Brett S; Blanc, Caroline A; Loring, Jeanne F; Cahalan, Michael D; Lane, Thomas E

    2014-10-01

    Multiple sclerosis (MS) is a chronic inflammatory disease of the CNS. While a broad range of therapeutics effectively reduce the incidence of focal white matter inflammation and plaque formation for patients with relapse-remitting forms of MS, a challenge within the field is to develop therapies that allow for axonal protection and remyelination. In the last decade, growing interest has focused on utilizing neural precursor cells (NPCs) to promote remyelination. To understand how NPCs function in chronic demyelinating environments, several excellent pre-clinical mouse models have been developed. One well accepted model is infection of susceptible mice with neurotropic variants of mouse hepatitis virus (MHV) that undergo chronic demyelination exhibiting clinical and histopathologic similarities to MS patients. Combined with the possibility that an environmental agent such as a virus could trigger MS, the MHV model of demyelination presents a relevant mouse model to assess the therapeutic potential of NPCs transplanted into an environment in which inflammatory-mediated demyelination is established.

  8. A review of MRI evaluation of demyelination in cuprizone murine model

    Energy Technology Data Exchange (ETDEWEB)

    Krutenkova, E., E-mail: len--k@yandex.ru; Pan, E.; Khodanovich, M., E-mail: khodanovich@mail.tsu.ru [National Research Tomsk State University, Lenina pr., 36, Tomsk (Russian Federation)

    2015-11-17

    The cuprizone mouse model of non-autoimmune demyelination reproduces some phenomena of multiple sclerosis and is appropriate for validation and specification of a new method of non-invasive diagnostics. In the review new data which are collected using the new MRI method are compared with one or more conventional MRI tools. Also the paper reviewed the validation of MRI approaches using histological or immunohistochemical methods. Luxol fast blue histological staining and myelin basic protein immunostaining is widespread. To improve the accuracy of non-invasive conventional MRI, multimodal scanning could be applied. The new quantitative MRI method of fast mapping of the macromolecular proton fraction is a reliable biomarker of myelin in the brain and can be used for research of demyelination in animals. To date, a validation of MPF method on the CPZ mouse model of demyelination is not performed, although this method is probably the best way to evaluate demyelination using MRI.

  9. Elevation of AQP4 and selective cytokines in experimental autoimmune encephalitis mice provides some potential biomarkers in optic neuritis and demyelinating diseases.

    Science.gov (United States)

    Sun, Li; Weng, Huan; Li, Zhenxin

    2015-01-01

    Idiopathic optic neuritis (ION) is an inflammation of the optic nerve that may result in a complete or partial loss of vision. ION is usually due to the immune attack of the myelin sheath covering the optic nerve. ION acts frequently as the first symptoms of multiple sclerosis (MS) and neuromyelitis optica (NMO), or other inflammatory demyelinating disorders. The pathogenic progression of ION remains unclear. Experimental autoimmune encephalitis (EAE) is a commonly used model of idiopathic inflammatory demyelinating disorders (IIDDs); the optic nerve is affected in EAE as well. The specific mediators of demyelination in optic neuritis are unknown. Recent studies have indicated what T-cell activation in peripheral blood is associated with optic neuritis pathogenesis. The object of the present study was to determine whether certain cytokines (IL-6, IL-17A, and IL-23) and AQP4 contribute to the demyelinating process using EAE model. We have found that IL-6R, AQP4 and IL-23R are significantly increased in mRNA and protein levels in optic nerves in EAE mice compared to control mice; serum AQP4, IL-6, IL-17A, IL-23 are increased whereas transforming growth factor beta (TGF-β) is decreased in EAE mice. These results suggest that AQP4 and selective cytokines in serum are associated with ION pathogenesis in the animal model, and these results shine light for future clinical diagnosis as potential biomarkers in ION patients.

  10. Machine learning approach identifies new pathways associated with demyelination in a viral model of multiple sclerosis.

    Science.gov (United States)

    Ulrich, Reiner; Kalkuhl, Arno; Deschl, Ulrich; Baumgärtner, Wolfgang

    2010-01-01

    Theiler's murine encephalomyelitis is an experimentally virus-induced inflammatory demyelinating disease of the spinal cord, displaying clinical and pathological similarities to chronic progressive multiple sclerosis. The aim of this study was to identify pathways associated with chronic demyelination using an assumption-free combined microarray and immunohistology approach. Movement control as determined by rotarod assay significantly worsened in Theiler's murine encephalomyelitis -virus-infected SJL/J mice from 42 to 196 days after infection (dpi). In the spinal cords, inflammatory changes were detected 14 to 196 dpi, and demyelination progressively increased from 42 to 196 dpi. Microarray analysis revealed 1001 differentially expressed genes over the study period. The dominating changes as revealed by k-means and functional annotation clustering included up-regulations related to intrathecal antibody production and antigen processing and presentation via major histocompatibility class II molecules. A random forest machine learning algorithm revealed that down-regulated lipid and cholesterol biosynthesis, differentially expressed neurite morphogenesis and up-regulated toll-like receptor-4-induced pathways were intimately associated with demyelination as measured by immunohistology. Conclusively, although transcriptional changes were dominated by the adaptive immune response, the main pathways associated with demyelination included up-regulation of toll-like receptor 4 and down-regulation of cholesterol biosynthesis. Cholesterol biosynthesis is a rate limiting step of myelination and its down-regulation is suggested to be involved in chronic demyelination by an inhibition of remyelination.

  11. A herpes simplex virus-derived replicative vector expressing LIF limits experimental demyelinating disease and modulates autoimmunity.

    Science.gov (United States)

    Nygårdas, Michaela; Paavilainen, Henrik; Müther, Nadine; Nagel, Claus-Henning; Röyttä, Matias; Sodeik, Beate; Hukkanen, Veijo

    2013-01-01

    Herpes simplex virus type 1 (HSV-1) has properties that can be exploited for the development of gene therapy vectors. The neurotropism of HSV enables delivery of therapeutic genes to the nervous system. Using a bacterial artificial chromosome (BAC), we constructed an HSV-1(17(+))-based replicative vector deleted of the neurovirulence gene γ134.5, and expressing leukemia inhibitory factor (LIF) as a transgene for treatment of experimental autoimmune encephalomyelitis (EAE). EAE is an inducible T-cell mediated autoimmune disease of the central nervous system (CNS) and is used as an animal model for multiple sclerosis. Demyelination and inflammation are hallmarks of both diseases. LIF is a cytokine that has the potential to limit demyelination and oligodendrocyte loss in CNS autoimmune diseases and to affect the T-cell mediated autoimmune response. In this study SJL/J mice, induced for EAE, were treated with a HSV-LIF vector intracranially and the subsequent changes in disease parameters and immune responses during the acute disease were investigated. Replicating HSV-LIF and its DNA were detected in the CNS during the acute infection, and the vector spread to the spinal cord but was non-virulent. The HSV-LIF significantly ameliorated the EAE and contributed to a higher number of oligodendrocytes in the brains when compared to untreated mice. The HSV-LIF therapy also induced favorable changes in the expression of immunoregulatory cytokines and T-cell population markers in the CNS during the acute disease. These data suggest that BAC-derived HSV vectors are suitable for gene therapy of CNS disease and can be used to test the therapeutic potential of immunomodulatory factors for treatment of EAE.

  12. 2-Arachidonoylglycerol Reduces Proteoglycans and Enhances Remyelination in a Progressive Model of Demyelination.

    Science.gov (United States)

    Feliú, Ana; Bonilla Del Río, Itziar; Carrillo-Salinas, Francisco Javier; Hernández-Torres, Gloria; Mestre, Leyre; Puente, Nagore; Ortega-Gutiérrez, Silvia; López-Rodríguez, Maria L; Grandes, Pedro; Mecha, Miriam; Guaza, Carmen

    2017-08-30

    The failure to undergo remyelination is a critical impediment to recovery in multiple sclerosis. Chondroitin sulfate proteoglycans (CSPGs) accumulate at demyelinating lesions creating a nonpermissive environment that impairs axon regeneration and remyelination. Here, we reveal a new role for 2-arachidonoylglycerol (2-AG), the major CNS endocannabinoid, in the modulation of CSPGs deposition in a progressive model of multiple sclerosis, the Theiler's murine encephalomyelitis virus-induced demyelinating disease. Treatment with a potent reversible inhibitor of the enzyme monoacylglycerol lipase, which accounts for 85% of the 2-AG degradation in the mouse CNS, modulates neuroinflammation and reduces CSPGs accumulation and astrogliosis around demyelinated lesions in the spinal cord of Theiler's murine encephalomyelitis virus-infected mice. Inhibition of 2-AG hydrolysis augments the number of mature oligodendrocytes and increases MBP, leading to remyelination and functional recovery of mice. Our findings establish a mechanism for 2-AG promotion of remyelination with implications in axonal repair in CNS demyelinating pathologies.SIGNIFICANCE STATEMENT The deposition of chondroitin sulfate proteoglycans contributes to the failure in remyelination associated with multiple sclerosis. Here we unveil a new role for 2-arachidonoylglycerol, the major CNS endocannabinoid, in the modulation of chondroitin sulfate proteoglycan accumulation in Theiler's murine encephalomyelitis virus-induced demyelinating disease. The treatment during the chronic phase with a potent reversible inhibitor of the enzyme monoacylglycerol lipase, which accounts for 85% of the 2-arachidonoylglycerol degradation in the mouse CNS, modulates neuroinflammation and reduces chondroitin sulfate proteoglycan deposition around demyelinated lesions in the spinal cord of Theiler's murine encephalomyelitis virus-infected mice. The increased 2-arachidonoylglycerol tone promotes remyelination in a model of progressive

  13. β2-Integrins in demyelinating disease: not adhering to the paradigm

    OpenAIRE

    Hu, Xianzhen; Wohler, Jillian E.; Dugger, Kari J.; Barnum, Scott R.

    2009-01-01

    Experimental autoimmune encephalomyelitis as a model for demyelinating disease challenges the mindset that β2-integrins are redundant in function and potential therapeutic targets for multiple sclerosis.

  14. Plasminogen Activator Inhibitor-1 Antagonist TM5484 Attenuates Demyelination and Axonal Degeneration in a Mice Model of Multiple Sclerosis.

    Directory of Open Access Journals (Sweden)

    Nicolas Pelisch

    Full Text Available Multiple sclerosis (MS is characterized by inflammatory demyelination and deposition of fibrinogen in the central nervous system (CNS. Elevated levels of a critical inhibitor of the mammalian fibrinolitic system, plasminogen activator inhibitor 1 (PAI-1 have been demonstrated in human and animal models of MS. In experimental studies that resemble neuroinflammatory disease, PAI-1 deficient mice display preserved neurological structure and function compared to wild type mice, suggesting a link between the fibrinolytic pathway and MS. We previously identified a series of PAI-1 inhibitors on the basis of the 3-dimensional structure of PAI-1 and on virtual screening. These compounds have been reported to provide a number of in vitro and in vivo benefits but none was tested in CNS disease models because of their limited capacity to penetrate the blood-brain barrier (BBB. The existing candidates were therefore optimized to obtain CNS-penetrant compounds. We performed an in vitro screening using a model of BBB and were able to identify a novel, low molecular PAI-1 inhibitor, TM5484, with the highest penetration ratio among all other candidates. Next, we tested the effects on inflammation and demyelination in an experimental allergic encephalomyelitis mice model. Results were compared to either fingolimod or 6α-methylprednisolone. Oral administration of TM5484 from the onset of signs, ameliorates paralysis, attenuated demyelination, and axonal degeneration in the spinal cord of mice. Furthermore, it modulated the expression of brain-derived neurotrophic factor, which plays a protective role in neurons against various pathological insults, and choline acetyltransferase, a marker of neuronal density. Taken together, these results demonstrate the potential benefits of a novel PAI-1 inhibitor, TM5484, in the treatment of MS.

  15. A novel model of demyelination and remyelination in a GFP-transgenic zebrafish

    Directory of Open Access Journals (Sweden)

    Yangwu Fang

    2014-12-01

    Full Text Available Demyelinating diseases consist of a variety of autoimmune conditions in which the myelin sheath is damaged due to genetic and/or environmental factors. During clinical treatment, some patients undergo partial remyelination, especially during the early disease stages. However, the mechanisms that regulate demyelination remain unclear. The myelin structure, myelin formation and myelin-related gene expression are highly conserved between mammals and zebrafish. Therefore, the zebrafish is an ideal model organism to study myelination. In this study, we generated a transgenic zebrafish Tg(mbp:nfsB-egfp expressing a fusion protein composed of enhanced green fluorescent protein (EGFP and NTR from the myelin basic protein (mbp promoter. Tg(mbp:nfsB-egfp expressed NTR-EGFP reproducibly and hereditarily in oligodendrocytes along the spinal cord. Treatment of zebrafish larvae Tg(mbp:nfsB-egfp with metronidazole (Mtz resulted in the selective ablation of oligodendrocytes and led to demyelination, accompanied by behavioral changes, including decreased total movement distance, velocity, total movement time and fast movement time. After withdrawal of Mtz for a seven day recovery period, the expression of EGFP and MBP protein was observed again which indicates remyelination. Additionally, locomotor capacity was restored. Collectively, Tg(mbp:nfsB-egfp, a heritable and stable transgenic line, provides a novel, powerful tool to study the mechanisms of demyelination and remyelination.

  16. Inhibition of LINGO-1 promotes functional recovery after experimental spinal cord demyelination.

    Science.gov (United States)

    Zhang, Yongjie; Zhang, Yi Ping; Pepinsky, Blake; Huang, Guanrong; Shields, Lisa B E; Shields, Christopher B; Mi, Sha

    2015-04-01

    Blocking LINGO-1 has been shown to enhance remyelination in the rat lysolecithin-induced focal spinal cord demyelination model. We used transcranial magnetic motor-evoked potentials (tcMMEPs) to assess the effect of blocking LINGO-1 on recovery of axonal function in a mouse lysolecithin model at 1, 2 and 4weeks after injury. The role of LINGO-1 was assessed using LINGO-1 knockout (KO) mice and in wild-type mice after intraperitoneal administration of anti-LINGO-1 antagonist monoclonal antibody (mAb3B5). Response rates (at 2 and 4weeks) and amplitudes (at 4weeks) were significantly increased in LINGO-1 KO and mAb3B5-treated mice compared with matched controls. The latency of potentials at 4weeks was significantly shorter in mAb3B5-treated mice compared with controls. Lesion areas in LINGO-1 KO and mAb3B5-treated mice were reduced significantly compared with matched controls. The number of remyelinated axons within the lesions was increased and the G-ratios of the axons were decreased in both LINGO-1 KO and mAb3B5-treated mice compared with matched controls. These data provide morphometric and functional evidence of enhancement of remyelination associated with antagonism of LINGO-1. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Loss of Myelin Basic Protein Function Triggers Myelin Breakdown in Models of Demyelinating Diseases.

    Science.gov (United States)

    Weil, Marie-Theres; Möbius, Wiebke; Winkler, Anne; Ruhwedel, Torben; Wrzos, Claudia; Romanelli, Elisa; Bennett, Jeffrey L; Enz, Lukas; Goebels, Norbert; Nave, Klaus-Armin; Kerschensteiner, Martin; Schaeren-Wiemers, Nicole; Stadelmann, Christine; Simons, Mikael

    2016-07-12

    Breakdown of myelin sheaths is a pathological hallmark of several autoimmune diseases of the nervous system. We employed autoantibody-mediated animal models of demyelinating diseases, including a rat model of neuromyelitis optica (NMO), to target myelin and found that myelin lamellae are broken down into vesicular structures at the innermost region of the myelin sheath. We demonstrated that myelin basic proteins (MBP), which form a polymer in between the myelin membrane layers, are targeted in these models. Elevation of intracellular Ca(2+) levels resulted in MBP network disassembly and myelin vesiculation. We propose that the aberrant phase transition of MBP molecules from their cohesive to soluble and non-adhesive state is a mechanism triggering myelin breakdown in NMO and possibly in other demyelinating diseases. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  18. Loss of Myelin Basic Protein Function Triggers Myelin Breakdown in Models of Demyelinating Diseases

    Directory of Open Access Journals (Sweden)

    Marie-Theres Weil

    2016-07-01

    Full Text Available Breakdown of myelin sheaths is a pathological hallmark of several autoimmune diseases of the nervous system. We employed autoantibody-mediated animal models of demyelinating diseases, including a rat model of neuromyelitis optica (NMO, to target myelin and found that myelin lamellae are broken down into vesicular structures at the innermost region of the myelin sheath. We demonstrated that myelin basic proteins (MBP, which form a polymer in between the myelin membrane layers, are targeted in these models. Elevation of intracellular Ca2+ levels resulted in MBP network disassembly and myelin vesiculation. We propose that the aberrant phase transition of MBP molecules from their cohesive to soluble and non-adhesive state is a mechanism triggering myelin breakdown in NMO and possibly in other demyelinating diseases.

  19. A Unified Frequency Domain Model to Study the Effect of Demyelination on Axonal Conduction

    Directory of Open Access Journals (Sweden)

    Saurabh Chaubey

    2016-01-01

    Full Text Available Multiple sclerosis is a disease caused by demyelination of nerve fibers. In order to determine the loss of signal with the percentage of demyelination, we need to develop models that can simulate this effect. Existing time-based models does not provide a method to determine the influences of demyelination based on simulation results. Our goal is to develop a system identification approach to generate a transfer function in the frequency domain. The idea is to create a unified modeling approach for neural action potential propagation along the length of an axon containing number of Nodes of Ranvier (N. A system identification approach has been used to identify a transfer function of the classical Hodgkin-Huxley equations for membrane voltage potential. Using this approach, we model cable properties and signal propagation along the length of the axon with N node myelination. MATLAB/ Simulink platform is used to analyze an N node-myelinated neuronal axon. The ability to transfer function in the frequency domain will help reduce effort and will give a much more realistic feel when compared to the classical time-based approach. Once a transfer function is identified, the conduction as a cascade of each linear time invariant system-based transfer function can be modeled. Using this approach, future studies can model the loss of myelin in various parts of nervous system.

  20. Selective inhibitors of nuclear export avert progression in preclinical models of inflammatory demyelination

    Science.gov (United States)

    Haines, Jeffery D.; Herbin, Olivier; de la Hera, Belén; Vidaurre, Oscar G.; Moy, Gregory A.; Sun, Qingxiang; Fung, Ho Yee Joyce; Albrecht, Stephanie; Alexandropoulos, Konstantina; McCauley, Dilara; Chook, Yuh Min; Kuhlmann, Tanja; Kidd, Grahame J.; Shacham, Sharon; Casaccia, Patrizia

    2015-01-01

    Axonal damage has been associated with aberrant protein trafficking. This study characterizes a novel class of compounds targeting nucleo-cytoplasmic shuttling, by binding to the catalytic groove of the nuclear export protein XPO1/CRM1 (chromosome region maintenance protein1). Oral administration of novel reversible CRM1 inhibitors in preclinical murine models of demyelination significantly attenuated disease progression, even when started after the onset of paralysis. Clinical efficacy was associated with decreased proliferation of immune cells, characterized by nuclear accumulation of cell cycle inhibitors, and preservation of cytoskeletal integrity even in demyelinated axons. Neuroprotection was not limited to models of demyelination, but observed also in other mouse models of axonal damage (i.e. kainic acid injection) and detected in cultured neurons after knockdown of Xpo1, the gene encoding for CRM1. A proteomic screen for target molecules revealed that CRM1 inhibitors in neurons prevented nuclear export of molecules associated with axonal damage while retaining transcription factors modulating neuroprotection. PMID:25706475

  1. Nuclear export inhibitors avert progression in preclinical models of inflammatory demyelination.

    Science.gov (United States)

    Haines, Jeffery D; Herbin, Olivier; de la Hera, Belén; Vidaurre, Oscar G; Moy, Gregory A; Sun, Qingxiang; Fung, Ho Yee Joyce; Albrecht, Stefanie; Alexandropoulos, Konstantina; McCauley, Dilara; Chook, Yuh Min; Kuhlmann, Tanja; Kidd, Grahame J; Shacham, Sharon; Casaccia, Patrizia

    2015-04-01

    Axonal damage has been associated with aberrant protein trafficking. We examined a newly characterized class of compounds that target nucleo-cytoplasmic shuttling by binding to the catalytic groove of the nuclear export protein XPO1 (also known as CRM1, chromosome region maintenance protein 1). Oral administration of reversible CRM1 inhibitors in preclinical murine models of demyelination significantly attenuated disease progression, even when started after the onset of paralysis. Clinical efficacy was associated with decreased proliferation of immune cells, characterized by nuclear accumulation of cell cycle inhibitors, and preservation of cytoskeletal integrity even in demyelinated axons. Neuroprotection was not limited to models of demyelination, but was also observed in another mouse model of axonal damage (that is, kainic acid injection) and detected in cultured neurons after knockdown of Xpo1, the gene encoding CRM1. A proteomic screen for target molecules revealed that CRM1 inhibitors in neurons prevented nuclear export of molecules associated with axonal damage while retaining transcription factors modulating neuroprotection.

  2. Increased severity of experimental autoimmune encephalomyelitis, chronic macrophage/microglial reactivity, and demyelination in transgenic mice producing tumor necrosis factor-alpha in the central nervous system

    DEFF Research Database (Denmark)

    Taupin, V; Renno, T; Bourbonnière, L

    1997-01-01

    Tumor necrosis factor-alpha (TNF-alpha) is an inflammatory cytokine implicated in a number of autoimmune diseases. Apoptotic cell death is induced by TNF-alpha in vitro, and has been suggested as one cause of autoimmune pathology, including autoimmune demyelinating diseases where oligodendrocytes...... and showed no spontaneous pathology, but they developed experimental autoimmune encephalomyelitis (EAE) with greater severity than nontransgenic controls when immunized with MBP in adjuvant. Unlike nontransgenic controls, EAE then progressed to a nonabating demyelinating disease. Macrophage....../microglial reactivity was evident in demyelinating lesions in spinal cord, but T cells were not detected during chronic disease. The participation of TNF-alpha in the demyelinating process is thus more probably due to the perpetuation of macrophage/microglial activation than to direct cytotoxicity of myelin...

  3. Physiological Dynamics in Demyelinating Diseases: Unraveling Complex Relationships through Computer Modeling

    Directory of Open Access Journals (Sweden)

    Jay S. Coggan

    2015-09-01

    Full Text Available Despite intense research, few treatments are available for most neurological disorders. Demyelinating diseases are no exception. This is perhaps not surprising considering the multifactorial nature of these diseases, which involve complex interactions between immune system cells, glia and neurons. In the case of multiple sclerosis, for example, there is no unanimity among researchers about the cause or even which system or cell type could be ground zero. This situation precludes the development and strategic application of mechanism-based therapies. We will discuss how computational modeling applied to questions at different biological levels can help link together disparate observations and decipher complex mechanisms whose solutions are not amenable to simple reductionism. By making testable predictions and revealing critical gaps in existing knowledge, such models can help direct research and will provide a rigorous framework in which to integrate new data as they are collected. Nowadays, there is no shortage of data; the challenge is to make sense of it all. In that respect, computational modeling is an invaluable tool that could, ultimately, transform how we understand, diagnose, and treat demyelinating diseases.

  4. Physiological Dynamics in Demyelinating Diseases: Unraveling Complex Relationships through Computer Modeling

    Science.gov (United States)

    Coggan, Jay S.; Bittner, Stefan; Stiefel, Klaus M.; Meuth, Sven G.; Prescott, Steven A.

    2015-01-01

    Despite intense research, few treatments are available for most neurological disorders. Demyelinating diseases are no exception. This is perhaps not surprising considering the multifactorial nature of these diseases, which involve complex interactions between immune system cells, glia and neurons. In the case of multiple sclerosis, for example, there is no unanimity among researchers about the cause or even which system or cell type could be ground zero. This situation precludes the development and strategic application of mechanism-based therapies. We will discuss how computational modeling applied to questions at different biological levels can help link together disparate observations and decipher complex mechanisms whose solutions are not amenable to simple reductionism. By making testable predictions and revealing critical gaps in existing knowledge, such models can help direct research and will provide a rigorous framework in which to integrate new data as they are collected. Nowadays, there is no shortage of data; the challenge is to make sense of it all. In that respect, computational modeling is an invaluable tool that could, ultimately, transform how we understand, diagnose, and treat demyelinating diseases. PMID:26370960

  5. Physiological Dynamics in Demyelinating Diseases: Unraveling Complex Relationships through Computer Modeling.

    Science.gov (United States)

    Coggan, Jay S; Bittner, Stefan; Stiefel, Klaus M; Meuth, Sven G; Prescott, Steven A

    2015-09-07

    Despite intense research, few treatments are available for most neurological disorders. Demyelinating diseases are no exception. This is perhaps not surprising considering the multifactorial nature of these diseases, which involve complex interactions between immune system cells, glia and neurons. In the case of multiple sclerosis, for example, there is no unanimity among researchers about the cause or even which system or cell type could be ground zero. This situation precludes the development and strategic application of mechanism-based therapies. We will discuss how computational modeling applied to questions at different biological levels can help link together disparate observations and decipher complex mechanisms whose solutions are not amenable to simple reductionism. By making testable predictions and revealing critical gaps in existing knowledge, such models can help direct research and will provide a rigorous framework in which to integrate new data as they are collected. Nowadays, there is no shortage of data; the challenge is to make sense of it all. In that respect, computational modeling is an invaluable tool that could, ultimately, transform how we understand, diagnose, and treat demyelinating diseases.

  6. Galanin transgenic mice with elevated circulating galanin levels alleviate demyelination in a cuprizone-induced MS mouse model.

    Directory of Open Access Journals (Sweden)

    Lin Zhang

    Full Text Available Multiple Sclerosis (MS is a demyelinating autoimmune disease of the central nervous system (CNS with a presumed autoimmune etiology. Approved treatments for MS are immunoregulatory and are able to reduce the inflammatory components of the disease. However, these treatments do not suppress progressive clinical disability. Approaches that directly protect myelin-producing oligodendrocytes and enhance remyelination are likely to improve long-term outcomes and reduce the rate of axonal damage. Galanin (GAL is a bioactive neuropeptide that is widely distributed throughout the nervous system and has diverse neuromodulatory effects. In this study, using the cuprizone (CPZ demyelination model of MS, we demonstrate that GAL has pronounced neuroprotective effects with respect to demyelination and remyelination. Using our GAL transgenic mouse (GAL-Tg, we identified a novel attenuation of OLs against CPZ induced demyelination, which was exerted independently of progenitor cells. Alleviation of myelin breakdown in the GAL-Tg mice was observed to be significant. Furthermore, we observed changes in the expression of the GAL receptor GalR1 during the demyelination and remyelination processes. Our data strongly indicate that GAL has the capacity to influence the outcome of primary insults that directly target OLs, as opposed to cases where immune activation is the primary pathogenic event. Taken together, these results suggest that GAL is a promising next-generation target for the treatment of MS.

  7. The balance between cathepsin C and cystatin F controls remyelination in the brain of Plp1-overexpressing mouse, a chronic demyelinating disease model.

    Science.gov (United States)

    Shimizu, Takahiro; Wisessmith, Wilaiwan; Li, Jiayi; Abe, Manabu; Sakimura, Kenji; Chetsawang, Banthit; Sahara, Yoshinori; Tohyama, Koujiro; Tanaka, Kenji F; Ikenaka, Kazuhiro

    2017-06-01

    In demyelinating diseases such as multiple sclerosis (MS), an imbalance between the demyelination and remyelination rates underlies the degenerative processes. Microglial activation is observed in demyelinating lesions; however, the molecular mechanism responsible for the homeostatic/environmental change remains elusive. We previously found that cystatin F (CysF), a cysteine protease inhibitor, is selectively expressed in microglia only in actively demyelinating/remyelinating lesions but ceases expression in chronic lesions, suggesting its role in remyelination. Here, we report the effects of manipulating the expression of CysF and cathepsin C (CatC), a key target of CysF, in a murine model of transgenic demyelinating disease, Plp(4e/-) . During the active remyelinating phase, both CysF knockdown (CysFKD) and microglial-selective CatC overexpression (CatCOE) showed a worsening of the demyelination in Plp(4e/-) transgenic mice. Conversely, during the chronic demyelinating phase, CatC knockdown (CatCKD) ameliorated the demyelination. Our results suggest that the balance between CatC and CysF expression controls the demyelination and remyelination process. © 2017 Wiley Periodicals, Inc.

  8. Demyelinating strain of mouse hepatitis virus infection bridging innate and adaptive immune response in the induction of demyelination.

    Science.gov (United States)

    Biswas, Kaushiki; Chatterjee, Dhriti; Addya, Sankar; Khan, Reas S; Kenyon, Lawrence C; Choe, Alexander; Cohrs, Randall J; Shindler, Kenneth S; Das Sarma, Jayasri

    2016-09-01

    The presence of immunoglobulin oligoclonal bands in the cerebrospinal fluid of Multiple Sclerosis (MS) patients supports the hypothesis of an infectious etiology, although the antigenic targets remain elusive. Neurotropic mouse hepatitis virus (MHV) infection in mice provides a useful tool for studying mechanisms of demyelination in a virus-induced experimental model of MS. This study uses Affymetrix microarray analysis to compare differential spinal cord mRNA levels between mice infected with demyelinating and non-demyelinating strains of MHV to identify host immune genes expressed in this demyelinating disease model. The study reveals that during the acute stage of infection, both strains induce inflammatory innate immune response genes, whereas upregulation of several immunoglobulin genes during chronic stage infection is unique to infection with the demyelinating strain. Results suggest that the demyelinating strain induced an innate-immune response during acute infection that may promote switching of Ig isotype genes during chronic infection, potentially playing a role in antibody-mediated progressive demyelination even after viral clearance. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. The Protective Effects of Areca catechu Extract on Cognition and Social Interaction Deficits in a Cuprizone-Induced Demyelination Model

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    Abulimiti Adilijiang

    2015-01-01

    Full Text Available Schizophrenia is a serious psychiatric illness with an unclear cause. One theory is that demyelination of white matter is one of the main pathological factors involved in the development of schizophrenia. The current study evaluated the protective effects of Areca catechu nut extract (ANE on a cuprizone-induced demyelination mouse model. Two doses of ANE (1% and 2% were administered orally in the diet for 8 weeks. Animals subjected to demyelination showed impaired spatial memory and less social activity. In addition, mice subjected to demyelination displayed significant myelin damage in cortex and demonstrated a higher expression of NG2 and PDGFRα and AMPK activation. ANE treatment not only significantly enhanced cognitive ability and social activity, but also protected myelin against cuprizone toxicity by promoting oligodendrocyte precursor cell (OPC differentiation. In addition, ANE treatment demonstrated significant dephosphorylation of AMPKα, indicating a regulatory role for ANE in schizophrenia. This study showed that ANE treatment may enhance cognitive ability and social activity by facilitating OPC differentiation and protecting against myelin damage in cortex. Results also suggest the AMPK signaling pathway may be involved in this process.

  10. Increased demyelination and axonal damage in metallothionein I+II-deficient mice during experimental autoimmune encephalomyelitis

    DEFF Research Database (Denmark)

    Penkowa, M; Espejo, C; Martínez-Cáceres, E M

    2003-01-01

    Metallothioneins I+II (MT-I+II) are antioxidant, neuroprotective factors. We previously showed that MT-I+II deficiency during experimental autoimmune encephalomyelitis (EAE) leads to increased disease incidence and clinical symptoms. Moreover, the inflammatory response of macrophages and T cells,...

  11. Bioluminescence Imaging of Olig2-Neural Stem Cells Reveals Improved Engraftment in a Demyelination Mouse Model

    NARCIS (Netherlands)

    Sher, Falak; van Dam, Go; Boddeke, Erik; Copray, Sjef

    2009-01-01

    A major issue in the potential application of neural stem cell (NSC)-based cell replacement therapy for demyelinating diseases is the question of the survival, functional behavior, and stability of implanted NSC-derived oligodendrocyte precursor cells (OPCs) over an extended period. To address this

  12. PET imaging of glucose metabolism, neuroinflammation and demyelination in the lysolecithin rat model for multiple sclerosis

    NARCIS (Netherlands)

    Faria, Daniele de Paula; de Vries, Erik F. J.; Sijbesma, Jurgen W. A.; Buchpiguel, Carlos A.; Dierckx, Rudi A. J. O.; Copray, Sjef C. V. M.

    2014-01-01

    BACKGROUND: Injection of lysolecithin in the central nervous system results in demyelination accompanied by local activation of microglia and recruitment of monocytes. Positron-emission tomography (PET) imaging, using specific tracers, may be an adequate technique to monitor these events in vivo and

  13. Protracted, relapsing and demyelinating experimental autoimmune encephalomyelitis in DA rats immunized with syngeneic spinal cord and incomplete Freund's adjuvant

    DEFF Research Database (Denmark)

    Lorentzen, J C; Issazadeh-Navikas, Shohreh; Storch, M

    1995-01-01

    , protracted and relapsing EAE (SPR-EAE) after a subcutaneous immunization at the tail base with syngeneic spinal cord and incomplete Freund's adjuvant (IFA). The neurological deficits were accompanied by demyelinating inflammatory lesions in the spinal cord, with infiltrating T lymphocytes and perivascular...... deposition of immunoglobulins and complement. The induction of SPR-EAE was associated with humoral autoreactivity to myelin oligodendrocyte glycoprotein (MOG) and cellular autoreactivity to the rat myelin basic protein (MBP) peptides 69-87 and 87-101. These two peptides, as well as whole rat MBP, were...

  14. Human induced pluripotent stem cells differentiation into oligodendrocyte progenitors and transplantation in a rat model of optic chiasm demyelination.

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    Alireza Pouya

    Full Text Available BACKGROUND: This study aims to differentiate human induced pluripotent stem cells (hiPSCs into oligodendrocyte precursors and assess their recovery potential in a demyelinated optic chiasm model in rats. METHODOLOGY/PRINCIPAL FINDINGS: We generated a cell population of oligodendrocyte progenitors from hiPSCs by using embryoid body formation in a defined medium supplemented with a combination of factors, positive selection and mechanical enrichment. Real-time polymerase chain reaction and immunofluorescence analyses showed that stage-specific markers, Olig2, Sox10, NG2, PDGFRα, O4, A2B5, GalC, and MBP were expressed following the differentiation procedure, and enrichment of the oligodendrocyte lineage. These results are comparable with the expression of stage-specific markers in human embryonic stem cell-derived oligodendrocyte lineage cells. Transplantation of hiPSC-derived oligodendrocyte progenitors into the lysolecithin-induced demyelinated optic chiasm of the rat model resulted in recovery from symptoms, and integration and differentiation into oligodendrocytes were detected by immunohistofluorescence staining against PLP and MBP, and measurements of the visual evoked potentials. CONCLUSIONS/SIGNIFICANCE: These results showed that oligodendrocyte progenitors generated efficiently from hiPSCs can be used in future biomedical studies once safety issues have been overcome.

  15. Pregabalin enhances myelin repair and attenuates glial activation in lysolecithin-induced demyelination model of rat optic chiasm.

    Science.gov (United States)

    Daneshdoust, Danyal; Khalili-Fomeshi, Mohsen; Ghasemi-Kasman, Maryam; Ghorbanian, Davoud; Hashemian, Mona; Gholami, Mohammad; Moghadamnia, Aliakbar; Shojaei, Amir

    2017-03-06

    Multiple sclerosis (MS) is an autoimmune disease in which more than 70% of patients experience visual disturbance as the earliest symptoms. Lysolecithin (LPC)-induced focal demyelination model has been developed to evaluate the effects of different therapies on myelin repair improvement. In this study, the effects of pregabalin administration on myelin repair and glial activation were investigated. Local demyelination was induced by administration of LPC (1%, 2μL) into the rat optic chiasm. Rats underwent daily injection of pregabalin (30mg/kg, i.p) or vehicle. Visual-evoked potentials (VEPs) recordings were performed for evaluating the function of optic pathway on days 3, 7, 14 and 28 post lesions. Myelin specific staining and immunostaining against GFAP and Iba1 were also carried out for assessment of myelination and glial activation respectively. Electrophysiological data indicated that pregabalin administration could significantly reduce the P1-N1 latency and increase the amplitude of VEPs waves compared to saline group. Luxol fast blue staining and immunostaining against PLP, as mature myelin marker, showed that myelin repair was improved in animals received pregabalin treatment. In addition, pregabalin effectively reduced the expression of GFAP and Iba1 as activated glial markers in optic chiasm. The present study indicates that pregabalin administration enhances myelin repair and ameliorates glial activation of optic chiasm following local injection of LPC. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  16. Sildenafil (Viagra Protective Effects on Neuroinflammation: The Role of iNOS/NO System in an Inflammatory Demyelination Model

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    Catarina Raposo

    2013-01-01

    Full Text Available We recently demonstrated that sildenafil reduces the expression of cytokines, COX-2, and GFAP in a demyelinating model induced in wild-type (WT mice. Herein, the understandings of the neuroprotective effect of sildenafil and the mediation of iNOS/NO system on inflammatory demyelination induced by cuprizone were investigated. The cerebella of iNOS−/− mice were examined after four weeks of treatment with cuprizone alone or combined with sildenafil. Cuprizone increased GFAP, Iba-1, TNF-α, COX-2, IL-1β, and IFN-γ expression, decreased expression of glutathione S-transferase pi (GSTpi, and damaged myelin in iNOS−/− mice. Sildenafil reduced Iba-1, IFN-γ, and IL-1β levels but had no effect on the expression of GFAP, TNF-α, and COX-2 compared to the cuprizone group. Sildenafil elevated GSTpi levels and improved the myelin structure/ultrastructure. iNOS−/− mice suffered from severe inflammation following treatment with cuprizone, while WT mice had milder inflammation, as found in the previous study. It is possible that inflammatory regulation through iNOS-feedback is absent in iNOS−/− mice, making them more susceptible to inflammation. Sildenafil has at least a partial anti-inflammatory effect through iNOS inhibition, as its effect on iNOS−/− mice was limited. Further studies are required to explain the underlying mechanism of the sildenafil effects.

  17. Acquired immune demyelinating neuropathies.

    Science.gov (United States)

    Dimachkie, Mazen M; Saperstein, David S

    2014-10-01

    Acquired immune demyelinating neuropathies refer to a group of disorders that share overlapping sensory, motor, and autonomic clinical, laboratory, and electrodiagnostic features. It is important to recognize acquired immune demyelinating neuropathies as they are generally responsive to immunosuppressive or immunomodulatory therapies. This article reviews recently developed early prognostic tools in Guillain-Barré syndrome and discusses the evolving understanding of chronic demyelinating phenotypes with differing treatment responsiveness. While weakness and numbness progress over 2 to 4 weeks in Guillain-Barré syndrome, they continue to evolve beyond 8 weeks in chronic inflammatory demyelinating polyradiculoneuropathy and over 4 to 8 weeks in subacute inflammatory demyelinating polyradiculoneuropathy. Acquired immune demyelinating neuropathies present uncommonly as variants with predominance of ocular, bulbar, sensory, autonomic, or motor manifestations in addition to regional variants, such as paraparetic acquired immune demyelinating neuropathies. Establishing the correct diagnosis is important as these immune disorders differ in response to corticosteroids and other immunosuppressive therapies.

  18. Differential contribution of immune effector mechanisms to cortical demyelination in multiple sclerosis.

    Science.gov (United States)

    Lagumersindez-Denis, Nielsen; Wrzos, Claudia; Mack, Matthias; Winkler, Anne; van der Meer, Franziska; Reinert, Marie C; Hollasch, Heiko; Flach, Anne; Brühl, Hilke; Cullen, Eilish; Schlumbohm, Christina; Fuchs, Eberhard; Linington, Christopher; Barrantes-Freer, Alonso; Metz, Imke; Wegner, Christiane; Liebetanz, David; Prinz, Marco; Brück, Wolfgang; Stadelmann, Christine; Nessler, Stefan

    2017-07-01

    Cortical demyelination is a widely recognized hallmark of multiple sclerosis (MS) and correlate of disease progression and cognitive decline. The pathomechanisms initiating and driving gray matter damage are only incompletely understood. Here, we determined the infiltrating leukocyte subpopulations in 26 cortical demyelinated lesions of biopsied MS patients and assessed their contribution to cortical lesion formation in a newly developed mouse model. We find that conformation-specific anti-myelin antibodies contribute to cortical demyelination even in the absence of the classical complement pathway. T cells and natural killer cells are relevant for intracortical type 2 but dispensable for subpial type 3 lesions, whereas CCR2 + monocytes are required for both. Depleting CCR2 + monocytes in marmoset monkeys with experimental autoimmune encephalomyelitis using a novel humanized CCR2 targeting antibody translates into significantly less cortical demyelination and disease severity. We conclude that biologics depleting CCR2 + monocytes might be attractive candidates for preventing cortical lesion formation and ameliorating disease progression in MS.

  19. DAB389IL-2 recombinant fusion toxin effect on lymphocyte- and macrophage-producing cytokine subpopulation cells in experimentally induced demyelinating disease in mice.

    Science.gov (United States)

    Bhopale, Mahendra K; Hilliard, Brendan; Constantinescu, Cris S; Phillips, S Michael; Rostami, Abdolmohamad

    2017-09-20

    We have reported previously that DAB389IL-2 recombinant fusion toxin targets IL-2R bearing CD4(+) cells, and suppresses demyelinating disease in acute (A) - and chronic (C) - experimental autoimmune encephalomyelitis (EAE) animal models of multiple sclerosis. The present study was undertaken to investigate the effect of DAB389IL-2 treatment on various cytokine-secreting cell populations in A-EAE and C-EAE mice. The effects of DAB389IL-2 at doses of 200-, 800-, or 1600 kU administered i.v. on days 11-13 and 15 on the clinical score and cytokine-secreting cell populations were examined using flow cytometry. C-EAE mice treated with 1600kU DAB389IL-2, but not A-EAE mice treated with 800 kU had significantly reduced disease. The CD3+CD25+ sub-population in spleens and spinal cords of A-EAE mice treated with 800 kU DAB389IL-2 a was increased, whereas in C-EAE mice treated with 1600 kU this population was increased. DAB389IL-2 treatment reduced CD3(+)CD4(+), CD3(+)CD8(+), CD4(+)CD8(+), CD3(+)IL-2(+), CD3(+)IFN-γ(+) and CD3(+)TNF-α(+) T cell subpopulations in the spinal cord in A-EAE, and C-EAE mice on day 16. CD11b+ macrophages that were IL-2-, IFN-γ-, and TNF-α- positive were reduced in A-EAE mice. DAB389IL-2 treatment reduced CD19(+) B-cells positive for IL-2 or CD11b(+) in the spinal cord in acute and chronic disease. DAB389IL-2 treatment also reduced lymph node CD3(+)CD8(+), CD4(+)CD8(+), CD3(+)CD25(+) populations on day 16, and lymph node CD3(+)IL-10(+) and peripheral blood CD3(+)CD25(+) populations on day 24. Our study demonstrates that DAB389IL-2 fusion toxin suppresses EAE in a dose-dependent manner, and alters inflammatory cell sub-populations during disease development.

  20. Neutrophil perversion in demyelinating autoimmune diseases: Mechanisms to medicine.

    Science.gov (United States)

    Casserly, Courtney S; Nantes, Julia C; Whittaker Hawkins, Ryder F; Vallières, Luc

    2017-03-01

    Neutrophils are essential to a healthy life, yet pose a threat if improperly controlled. Neutrophil perversion is well documented in a variety of inflammatory disorders (e.g. arthritis, lupus, psoriasis), but is only beginning to be demystified in autoimmune demyelination, the most common cause of neurological disability in young adults. Using the animal model experimental autoimmune encephalomyelitis (EAE), several molecules that help neutrophils invade the central nervous system (CNS) have been identified. Mechanisms by which neutrophils may contribute to demyelination have also been proposed (e.g. secretion of endothelial/leukocytic modulators, antigen presentation to T cells, myelin degradation and phagocytosis). In human, neutrophils are seen in the CNS of people with neuromyelitis optica spectrum disorder and other severe variants of autoimmune demyelinating diseases. At the time of autopsy for multiple sclerosis (MS) - often many years after its onset - neutrophils appear to have escaped the scene of the crime. However, new clues implicate neutrophils in MS relapses and progression. This warrants further investigating 1) the differential importance of neutrophils among demyelinating diseases, 2) the largely unknown effects of current MS therapies on neutrophils, and 3) the potential of neutrophil proteins as clinical biomarkers or therapeutic targets. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Gliopathy of Demyelinating And Non-Demyelinating Strains Of Mouse Hepatitis Virus.

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    Lawrence Charles Kenyon

    2015-12-01

    Full Text Available Demyelination in the central nervous system induced by neurovirulent strains of Mouse Hepatitis Virus (MHV is mediated by the viral spike glycoprotein, but it is not clear whether the mechanism of this disease pathology involves direct viral infection of oligodendrocytes. Detailed studies of glial cell tropism of MHV are presented, demonstrating that direct MHV infection of oligodendrocytes differs between demyelinating (RSA59 and non-demyelinating (RSMHV2 viral strains both in vitro and in vivo. Our results indicate that direct injury of mature oligodendrocytes is an important mechanism of virus-induced demyelination. In vivo, RSA59 infection was identified in spinal cord gray and white matter, but infected oligodendrocytes were restricted to white matter. In contrast, RSMHV2 infection was restricted to gray matter neurons and was not localized to oligodendrocytes. In vitro, RSA59 can infect both oligodendrocyte precursors and differentiated oligodendrocytes, whereas RSMHV2 can infect oligodendrocyte precursors but not differentiated oligodendrocytes. Viral spreading through axonal means to white matter and release of the demyelinating strain MHV at the nerve end is critical for oligodendrocytes infection and subsequent demyelination. Understanding the mechanisms by which known viruses effect demyelination in this animal model has important therapeutic implications in the treatment of human demyelinating disease.

  2. Suspected Acoustic Neuroma Demyelinating Lesions.

    Science.gov (United States)

    Zhou, Xiuming; Wang, Xiang; Zhang, Xiejun; Wu, Qiang; Huang, Guodong; Li, Weiping

    2016-11-01

    Demyelinating lesions were recognized as a kind of rare central nervous system demyelinating lesion. The diagnosis and differential diagnosis of demyelinating lesions is difficult. Once the diagnosis was delayed or incorrect, it will make a great impact on patients.Demyelinating lesions often involved in young and middle-aged, but this patient was the aged, which is rare.

  3. Tumefactive demyelinating lesions

    Energy Technology Data Exchange (ETDEWEB)

    Dagher, A.P. [Thomas Jefferson Univ. Hospital, Philadelphia, PA (United States). Div. of Neuroradiology; Smirniotopoulos, J. [Thomas Jefferson Univ. Hospital, Philadelphia, PA (United States). Div. of Neuroradiology]|[Armed Forces Inst. of Pathology, Washington, DC (United States). Dept. of Radiological Pathology

    1996-08-01

    We studied 21 cases of pathologically confirmed tumefactive demyelinating lesions and reviewed the spectrum of tumefactive demyelinating lesions in the literature. Radiological features and clinical data were reviewed to characterize the lesions as consistent with a known demyelinating disease, most notably multiple sclerosis. Atypical clinical or radiological features (other than tumefaction) were noted. Most lesions were part of a clinical and/or radiological picture consistent with multiple sclerosis. No case strongly suggestive of variants or related diseases, such as Schilder`s disease or Balo`s concentric sclerosis, were found. There was one case suggestive of acute disseminated encephalomyelitis. Features which help distinguish the lesions from tumour are discussed. (orig.)

  4. The experimental autoimmune encephalomyelitis model for proteomic biomarker studies : From rat to human

    NARCIS (Netherlands)

    Rosenling, Therese; Attali, Amos; Luider, Theo M.; Bischoff, Rainer

    2011-01-01

    Multiple sclerosis (MScl) is defined by central nervous system (CNS) inflammation, demyelination and axonal damage. Some of the disease mechanisms are known but the cause of this complex disorder stays an enigma. Experimental autoimmune encephalomyelitis (EAE) is an animal model mimicking many

  5. A Mechanism of Virus-Induced Demyelination

    Directory of Open Access Journals (Sweden)

    Jayasri Das Sarma

    2010-01-01

    Full Text Available Myelin forms an insulating sheath surrounding axons in the central and peripheral nervous systems and is essential for rapid propagation of neuronal action potentials. Demyelination is an acquired disorder in which normally formed myelin degenerates, exposing axons to the extracellular environment. The result is dysfunction of normal neuron-to-neuron communication and in many cases, varying degrees of axonal degeneration. Numerous central nervous system demyelinating disorders exist, including multiple sclerosis. Although demyelination is the major manifestation of most of the demyelinating diseases, recent studies have clearly documented concomitant axonal loss to varying degrees resulting in long-term disability. Axonal injury may occur secondary to myelin damage (outside-in model or myelin damage may occur secondary to axonal injury (inside-out model. Viral induced demyelination models, has provided unique imminent into the cellular mechanisms of myelin destruction. They illustrate mechanisms of viral persistence, including latent infections, virus reactivation and viral-induced tissue damage. These studies have also provided excellent paradigms to study the interactions between the immune system and the central nervous system (CNS. In this review we will discuss potential cellular and molecular mechanism of central nervous system axonal loss and demyelination in a viral induced mouse model of multiple sclerosis.

  6. Chronic inflammatory demyelinative polyneuropathy

    DEFF Research Database (Denmark)

    Said, Gérard; Krarup, Christian

    2013-01-01

    Chronic inflammatory demyelinative polyneuropathy (CIDP) is an acquired polyneuropathy presumably of immunological origin. It is characterized by a progressive or a relapsing course with predominant motor deficit. The diagnosis rests on the association of non-length-dependent predominantly motor ...

  7. A Pathogenic Role for CD8+ T Cells in a Spontaneous Model of Demyelinating Disease

    DEFF Research Database (Denmark)

    Brisebois, Marcel; Zehntner, Simone P.; Estrada, José

    2006-01-01

    Transgenic (Tg) mice that overexpress the costimulatory ligand B7.2/CD86 on microglia spontaneously develop a T cell-mediated demyelinating disease. Characterization of the inflammatory infiltrates in the nervous tissue revealed a predominance of CD8+ T cells, suggesting a prominent role of this T...

  8. Microglia-Induced Activation of Noncanonical Wnt Signaling Aggravates Neurodegeneration in Demyelinating Disorders

    Science.gov (United States)

    Smits, Ron; Ikenaka, Kazuhiro

    2016-01-01

    Oligodendrocytes are myelinating cells of the central nervous system. Multiple sclerosis (MS) is a demyelinating disease characterized by both myelin loss and neuronal degeneration. However, the molecular mechanisms underlying neuronal degeneration in demyelinating disorders are not fully understood. In the experimental autoimmune encephalomyelitis (EAE) demyelinating-mouse model of MS, inflammatory microglia produce cytokines, including interleukin-1β (IL-1β). Since microglia and noncanonical Wnt signaling components in neurons, such as the coreceptor Ror2, were observed in the spinal cords of mice with EAE (EAE mice), we postulated that the interplay between activated microglia and spinal neurons under EAE conditions is mediated through noncanonical Wnt signaling. EAE treatment upregulated in vivo expression of noncanonical Wnt signaling components in spinal neurons through microglial activation. In accordance with the neuronal degeneration detected in the EAE spinal cord in vivo, coculture of spinal neurons with microglia or the application of recombinant IL-1β upregulated noncanonical Wnt signaling and induced neuron death, which was suppressed by the inhibition of the Wnt-Ror2 pathway. Ectopic noncanonical Wnt signaling aggravated the demyelinating pathology in another MS mouse model due to Wnt5a-induced neurodegeneration. The linkage between activated microglia and neuronal Wnt-Ror2 signaling may provide a candidate target for therapeutic approaches to demyelinating disorders. PMID:27550808

  9. Microglia-induced activation of non-canonical Wnt signaling aggravates neurodegeneration in demyelinating disorders.

    Science.gov (United States)

    Shimizu, Takeshi; Smits, Ron; Ikenaka, Kazuhiro

    2016-08-22

    Oligodendrocytes are myelinating cells of the central nervous system. Multiple sclerosis (MS) is a demyelinating disease characterized by both myelin loss and neuronal degeneration. However, the molecular mechanisms underlying neuronal degeneration in demyelinating disorders are not fully understood. In the experimental autoimmune encephalomyelitis (EAE) demyelinating mouse model of MS, inflammatory microglia produce cytokines including interleukin-1β (IL-1β). Since microglia and non-canonical Wnt signaling components in neurons, such as the co-receptor Ror2, were observed in the spinal cord of EAE mice, we postulated that the interplay between activated microglia and spinal neurons under EAE conditions is mediated through non-canonical Wnt signaling. EAE treatment up-regulated in vivo expression of non-canonical Wnt signaling components in spinal neurons through microglial activation. In accordance with the neuronal degeneration detected in the EAE spinal cord in vivo, co-culture of spinal neurons with microglia or the application of recombinant IL-1β up-regulated non-canonical Wnt signaling, and induced neuronal cell death, which was suppressed by the inhibition of the Wnt-Ror2 pathway. Ectopic non-canonical Wnt signaling aggravated the demyelinating pathology in another MS mouse model due to Wnt5a-induced neurodegeneration. The linkage between activated microglia and neuronal Wnt-Ror2 signaling may provide a possible candidate target for therapeutic approaches to demyelinating disorders. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  10. Cyclin-dependent kinase inhibitor flavopiridol promotes remyelination in a cuprizone induced demyelination model.

    Science.gov (United States)

    Mi, Guiyun; Gao, Yunyun; Liu, Shuai; Ye, Enmao; Li, Yanyan; Jin, Xiao; Yang, Hongju; Yang, Zheng

    2016-10-17

    The cuprizone (CPZ) model has been widely used for the studies of de-and remyelination. The CPZ-exposed mice show oligodendrocyte precursor cells (OPCs) increase and mature oligodendrocytes decrease, suggesting an imbalance between proliferation and differentiation of OPCs. In the first experiment of this study, we examined the expression of cell cycle related genes in brains of mice following CPZ administration for 5 weeks by means of microarray assay. In addition, we performed a double labeling of BrdU and Ki-67 to calculate cell cycle exit index in the mice. Our results showed that CPZ administration up-regulated the expression of 16 cell cycle related genes, but down-regulated the expression of only one in the prefrontal cortex (PFC) of mice compared to control group. The treatment inhibited potential precursor cells exit from cell cycle. In the second experiment, we evaluated effects of a CDK inhibitor flavopiridol (FLA) on CPZ-induced neuropathological changes and spatial working memory impairment in mice.FLA treatment for one week effectively attenuated the CPZ-induced increases in NG2 positive cells, microglia and astrocytes, alleviated the concurrent mature oligodendrocyte loss and myelin breakdown, and improved spatial working memory deficit in the CPZ-exposed mice. These results suggest that CPZ-induced neuropathological changes involve in dysregulation of cell cycle related genes. The therapeutic effects of FLA on CPZ-exposed mice may be related to its ability of cell cycle inhibition.

  11. Neurotropin® Accelerates the Differentiation of Schwann Cells and Remyelination in a Rat Lysophosphatidylcholine-Induced Demyelination Model

    Directory of Open Access Journals (Sweden)

    Hozo Matsuoka

    2018-02-01

    Full Text Available Neurotropin® (NTP, a non-protein extract of inflamed rabbit skin inoculated with vaccinia virus, is clinically used for the treatment of neuropathic pain in Japan and China, although its effect on peripheral nerve regeneration remains to be elucidated. The purpose of this study was to investigate the effects of NTP on Schwann cells (SCs in vitro and in vivo, which play an important role in peripheral nerve regeneration. In SCs, NTP upregulated protein kinase B (AKT activity and Krox20 and downregulated extracellular signal-regulated kinase1/2 activity under both growth and differentiation conditions, enhanced the expression of myelin basic protein and protein zero under the differentiation condition. In a co-culture of dorsal root ganglion neurons and SCs, NTP accelerated myelination of SCs. To further investigate the influence of NTP on SCs in vivo, lysophosphatidylcholine was injected into the rat sciatic nerve, leading to the focal demyelination. After demyelination, NTP was administered systemically with an osmotic pump for one week. NTP improved the ratio of myelinated axons and motor, sensory, and electrophysiological function. These findings reveal novel effects of NTP on SCs differentiation in vitro and in vivo, and indicate NTP as a promising treatment option for peripheral nerve injuries and demyelinating diseases.

  12. Effect of the innate immune response on development of Theiler's murine encephalomyelitis virus-induced demyelinating disease.

    Science.gov (United States)

    Olson, Julie K

    2014-10-01

    Theiler's murine encephalomyelitis virus (TMEV) infection of susceptible mice leads to the development of demyelinating disease in the central nervous system (CNS) associated with an inflammatory immune response. The demyelinating disease in mice has similarities to multiple sclerosis in humans and is used as an experimental model for the human disease. The innate immune response initiates the immune response to TMEV through innate immune receptors on cells that recognize components of the virus and activate intracellular signaling that leads to the expression of innate immune cytokines, chemokines, and effector molecules. The innate immune response directly affects the development of the adaptive immune response, especially the T cell response, which mediates viral clearance. However, infection of Swiss Jim Laboratory (SJL) mice with TMEV leads to a persistent virus infection of the microglia/macrophage in the CNS which contributes to the development of demyelinating disease. Susceptibility to demyelinating disease has been linked to the T cell response against the virus. However, the current studies will examine the role of the innate immune response to TMEV and the affect it has on the adaptive immune response and development of demyelinating disease following TMEV infection. The innate immune cytokines, chemokines, and effector molecules as well as the innate immune cells, both CNS resident and infiltrating peripheral cells, all contribute to the innate immune response following TMEV and may affect susceptibility to demyelinating disease.

  13. Myelin Oligodendrocyte Glycoprotein: Deciphering a Target in Inflammatory Demyelinating Diseases

    Directory of Open Access Journals (Sweden)

    Patrick Peschl

    2017-05-01

    Full Text Available Myelin oligodendrocyte glycoprotein (MOG, a member of the immunoglobulin (Ig superfamily, is a myelin protein solely expressed at the outermost surface of myelin sheaths and oligodendrocyte membranes. This makes MOG a potential target of cellular and humoral immune responses in inflammatory demyelinating diseases. Due to its late postnatal developmental expression, MOG is an important marker for oligodendrocyte maturation. Discovered about 30 years ago, it is one of the best-studied autoantigens for experimental autoimmune models for multiple sclerosis (MS. Human studies, however, have yielded controversial results on the role of MOG, especially MOG antibodies (Abs, as a biomarker in MS. But with improved detection methods using different expression systems to detect Abs in patients’ samples, this is meanwhile no longer the case. Using cell-based assays with recombinant full-length, conformationally intact MOG, several recent studies have revealed that MOG Abs can be found in a subset of predominantly pediatric patients with acute disseminated encephalomyelitis (ADEM, aquaporin-4 (AQP4 seronegative neuromyelitis optica spectrum disorders (NMOSD, monophasic or recurrent isolated optic neuritis (ON, or transverse myelitis, in atypical MS and in N-methyl-d-aspartate receptor-encephalitis with overlapping demyelinating syndromes. Whereas MOG Abs are only transiently observed in monophasic diseases such as ADEM and their decline is associated with a favorable outcome, they are persistent in multiphasic ADEM, NMOSD, recurrent ON, or myelitis. Due to distinct clinical features within these diseases it is controversially disputed to classify MOG Ab-positive cases as a new disease entity. Neuropathologically, the presence of MOG Abs is characterized by MS-typical demyelination and oligodendrocyte pathology associated with Abs and complement. However, it remains unclear whether MOG Abs are a mere inflammatory bystander effect or truly pathogenetic

  14. Myelin Oligodendrocyte Glycoprotein: Deciphering a Target in Inflammatory Demyelinating Diseases

    Science.gov (United States)

    Peschl, Patrick; Bradl, Monika; Höftberger, Romana; Berger, Thomas; Reindl, Markus

    2017-01-01

    Myelin oligodendrocyte glycoprotein (MOG), a member of the immunoglobulin (Ig) superfamily, is a myelin protein solely expressed at the outermost surface of myelin sheaths and oligodendrocyte membranes. This makes MOG a potential target of cellular and humoral immune responses in inflammatory demyelinating diseases. Due to its late postnatal developmental expression, MOG is an important marker for oligodendrocyte maturation. Discovered about 30 years ago, it is one of the best-studied autoantigens for experimental autoimmune models for multiple sclerosis (MS). Human studies, however, have yielded controversial results on the role of MOG, especially MOG antibodies (Abs), as a biomarker in MS. But with improved detection methods using different expression systems to detect Abs in patients’ samples, this is meanwhile no longer the case. Using cell-based assays with recombinant full-length, conformationally intact MOG, several recent studies have revealed that MOG Abs can be found in a subset of predominantly pediatric patients with acute disseminated encephalomyelitis (ADEM), aquaporin-4 (AQP4) seronegative neuromyelitis optica spectrum disorders (NMOSD), monophasic or recurrent isolated optic neuritis (ON), or transverse myelitis, in atypical MS and in N-methyl-d-aspartate receptor-encephalitis with overlapping demyelinating syndromes. Whereas MOG Abs are only transiently observed in monophasic diseases such as ADEM and their decline is associated with a favorable outcome, they are persistent in multiphasic ADEM, NMOSD, recurrent ON, or myelitis. Due to distinct clinical features within these diseases it is controversially disputed to classify MOG Ab-positive cases as a new disease entity. Neuropathologically, the presence of MOG Abs is characterized by MS-typical demyelination and oligodendrocyte pathology associated with Abs and complement. However, it remains unclear whether MOG Abs are a mere inflammatory bystander effect or truly pathogenetic. This article

  15. Fulminant Demyelinating Diseases

    Science.gov (United States)

    Rahmlow, Megan R.; Kantarci, Orhun

    2013-01-01

    Fulminant demyelinating disease is a heading that covers acute disseminated encephalomyelitis and its variant acute hemorrhagic leukoencephalitis (Hurst disease), severe relapses of multiple sclerosis (MS), variants of MS (tumefactive MS, Marburg variant, Balo concentric sclerosis, myelinoclastic diffuse sclerosis), and neuromyelitis optica-spectrum disorders associated with aquaporin autoimmunity. These categories of inflammatory demyelinating disease often prompt hospital admission and many necessitate intensive care monitoring due to the aggressive nature of the illness and associated neurologic morbidity. In this review, we highlight the discriminating clinical, radiographic, and pathologic features of these disorders. Acute management is often accomplished with use of high-dose intravenous steroids and plasma exchange. Aggressive disease may respond to immunosuppression. Prognosis for recovery varies among the disorders but most patients improve. Factors influencing outcome are also discussed. PMID:23983890

  16. Inflammation, demyelination, and degeneration - recent insights from MS pathology.

    Science.gov (United States)

    Stadelmann, Christine; Wegner, Christiane; Brück, Wolfgang

    2011-02-01

    Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system which responds to anti-inflammatory treatments in the early disease phase. However, the pathogenesis of the progressive disease phase is less well understood, and inflammatory as well as neurodegenerative mechanisms of tissue damage are currently being discussed. This review summarizes current knowledge on the interrelation between inflammation, demyelination, and neurodegeneration derived from the study of human autopsy and biopsy brain tissue and experimental models of MS. 2010 Elsevier B.V. All rights reserved.

  17. Models of experimental epilepsy

    Directory of Open Access Journals (Sweden)

    Fatih Ekici

    2011-03-01

    Full Text Available Epilepsy is the most common serious neurological conditionin the world, with an estimated prevalence of 1% ofthe population. A large number of experimental modelsof seizure and epilepsy have been developed. These experimentalmodels are elicited by chemical convulsants,electrical stimulation, genetic models, structural lesions,physical stimuli (cold, pressure, hyperthermia, electricalin animals. Well-characterized animal models may allowthe understanding of the basic mechanisms underlyingepileptogenesis (it refers to the alteration of a normalneuronal network into a hyperexcitable network in whichrecurrent, spontaneous seizures occur. Moreover, thesemodels might also prove useful in identifying novel therapeuticapproaches to treatment of epilepsy. J Clin ExpInvest 2011; 2(1: 118-123

  18. A single dose of neuron-binding human monoclonal antibody improves spontaneous activity in a murine model of demyelination.

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    Aleksandar Denic

    Full Text Available Our laboratory demonstrated that a natural human serum antibody, sHIgM12, binds to neurons in vitro and promotes neurite outgrowth. We generated a recombinant form, rHIgM12, with identical properties. Intracerebral infection with Theiler's Murine Encephalomyelitis Virus (TMEV of susceptible mouse strains results in chronic demyelinating disease with progressive axonal loss and neurologic dysfunction similar to progressive forms of multiple sclerosis. To study the effects of rHIgM12 on the motor function of TMEV-infected mice, we monitored spontaneous nocturnal activity over many weeks. Nocturnal behavior is a sensitive measure of rodent neurologic function because maximal activity changes are expected to occur during the normally active night time monitoring period. Mice were placed in activity boxes eight days prior to treatment to collect baseline spontaneous activity. After treatment, activity in each group was continuously recorded over 8 weeks. We chose a long 8-week monitoring period for two reasons: (1 we previously demonstrated that IgM induced remyelination is present by 5 weeks post treatment, and (2 TMEV-induced demyelinating disease in this strain progresses very slowly. Due to the long observation periods and large data sets, differences among treatment groups may be difficult to appreciate studying the original unfiltered recordings. To clearly delineate changes in the highly fluctuating original data we applied three different methods: (1 binning, (2 application of Gaussian low-pass filters (GF and (3 polynomial fitting. Using each of the three methods we showed that compared to control IgM and saline, early treatment with rHIgM12 induced improvement in both horizontal and vertical motor function, whereas later treatment improved only horizontal activity. rHIgM12 did not alter activity of normal, uninfected mice. This study supports the hypothesis that treatment with a neuron-binding IgM not only protects neurons in vitro, but

  19. Characterization of oligodendroglial populations in mouse demyelinating disease using flow cytometry: clues for MS pathogenesis.

    Science.gov (United States)

    Robinson, Andrew P; Rodgers, Jane M; Goings, Gwendolyn E; Miller, Stephen D

    2014-01-01

    Characterizing and enumerating cells of the oligodendrocyte lineage (OLCs) is crucial for understanding demyelination and therapeutic benefit in models of demyelinating disease in the central nervous system. Here we describe a novel method for the rapid, unbiased analysis of mouse OLCs using flow cytometry. The assay was optimized to maximize viable yield of OLCs and maintain OLC antigen integrity. Panels of antibodies were assembled for simultaneous analysis of seven antigens on individual cells allowing for characterization of oligodendroglial cells throughout the lineage. We verified the utility of the assay with cultured OLCs and through a time course of developmental myelination. Next we employed the assay to characterize OLC populations in two well-characterized models of demyelination: cuprizone-induced demyelination and experimental autoimmune encephalomyelitis (EAE). In EAE we observed a dramatic loss of mature oligodendrocytes coincident with a dramatic expansion of oligodendrocyte progenitors cells (OPCs) at the onset of disease suggesting an attempt of the host to repair myelin. This expanded OPC pool was maintained through remission and relapse suggesting an arrest in differentiation in the face of the chronic autoimmune T cell-mediated inflammatory response. These robust, reproducible changes in OLCs through disease provide a rapid quantitative global analysis of myelin-producing cells in the adult mouse brain and important information regarding effects of disease on oligodendroglial proliferation/differentiation which is useful for defining the pathogenesis and therapy of MS.

  20. Plasminogen Deficiency Delays the Onset and Protects from Demyelination and Paralysis in Autoimmune Neuroinflammatory Disease.

    Science.gov (United States)

    Shaw, Maureen A; Gao, Zhen; McElhinney, Kathryn E; Thornton, Sherry; Flick, Matthew J; Lane, Adam; Degen, Jay L; Ryu, Jae Kyu; Akassoglou, Katerina; Mullins, Eric S

    2017-04-05

    Multiple sclerosis (MS) is a neuroinflammatory, demyelinating disease of the CNS. Fibrinogen deposition at sites of blood-brain barrier breakdown is a prominent feature of neuroinflammatory disease and contributes to disease severity. Plasminogen, the primary fibrinolytic enzyme, also modifies inflammatory processes. We used a murine model of MS, experimental autoimmune encephalomyelitis (EAE), to evaluate the hypothesis that the loss of plasminogen would exacerbate neuroinflammatory disease. However, contrary to initial expectations, EAE-challenged plasminogen-deficient (Plg-) mice developed significantly delayed disease onset and reduced disease severity compared with wild-type (Plg+) mice. Similarly, pharmacologic inhibition of plasmin activation with tranexamic acid also delayed disease onset. The T-cell response to immunization was similar between genotypes, suggesting that the contribution of plasminogen was downstream of the T-cell response. Spinal cords from EAE-challenged Plg- mice demonstrated significantly decreased demyelination and microglial/macrophage accumulation compared with Plg+ mice. Although fibrinogen-deficient mice or mice with combined deficiencies of plasminogen and fibrinogen had decreased EAE severity, they did not exhibit the delay in EAE disease onset, as seen in mice with plasminogen deficiency alone. Together, these data suggest that plasminogen and plasmin-mediated fibrinolysis is a key modifier of the onset of neuroinflammatory demyelination.SIGNIFICANCE STATEMENT Multiple sclerosis is a severe, chronic, demyelinating disease. Understanding the pathobiology related to the autoreactive T-cell and microglial/macrophage demyelinating response is critical to effectively target therapeutics. We describe for the first time that deficiency of plasminogen, the key fibrinolytic enzyme, delays disease onset and protects from the development of the paralysis associated with a murine model of multiple sclerosis, experimental autoimmune

  1. Central canal ependymal cells proliferate extensively in response to traumatic spinal cord injury but not demyelinating lesions.

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    Steve Lacroix

    Full Text Available The adult mammalian spinal cord has limited regenerative capacity in settings such as spinal cord injury (SCI and multiple sclerosis (MS. Recent studies have revealed that ependymal cells lining the central canal possess latent neural stem cell potential, undergoing proliferation and multi-lineage differentiation following experimental SCI. To determine whether reactive ependymal cells are a realistic endogenous cell population to target in order to promote spinal cord repair, we assessed the spatiotemporal dynamics of ependymal cell proliferation for up to 35 days in three models of spinal pathologies: contusion SCI using the Infinite Horizon impactor, focal demyelination by intraspinal injection of lysophosphatidylcholine (LPC, and autoimmune-mediated multi-focal demyelination using the active experimental autoimmune encephalomyelitis (EAE model of MS. Contusion SCI at the T9-10 thoracic level stimulated a robust, long-lasting and long-distance wave of ependymal proliferation that peaked at 3 days in the lesion segment, 14 days in the rostral segment, and was still detectable at the cervical level, where it peaked at 21 days. This proliferative wave was suppressed distal to the contusion. Unlike SCI, neither chemical- nor autoimmune-mediated demyelination triggered ependymal cell proliferation at any time point, despite the occurrence of demyelination (LPC and EAE, remyelination (LPC and significant locomotor defects (EAE. Thus, traumatic SCI induces widespread and enduring activation of reactive ependymal cells, identifying them as a robust cell population to target for therapeutic manipulation after contusion; conversely, neither demyelination, remyelination nor autoimmunity appears sufficient to trigger proliferation of quiescent ependymal cells in models of MS-like demyelinating diseases.

  2. Administration of vitamin D 3 induces CNPase and myelin oligodendrocyte glycoprotein expression in the cerebral cortex of the murine model of cuprizone-induced demyelination

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    Farhad Mashayekhi

    2016-10-01

    Full Text Available In the central nervous system (CNS the main proteins of myelin are proteolipid protein (PLP, myelin basic protein (MBP, myelin oligodendrocyte glycoprotein (MOG and CNPase. Myelin oligodendrocyte glycoprotein is a minor component of the myelin sheath, but is an important autoantigen linked to the pathogenesis of multiple sclerosis (MS. CNPase is expressed exclusively by oligodendrocytes in the CNS, and the appearance of CNPase seems to be one of the earliest events of oligodendrocyte differentiation and myelination. In this study the effects of vitamin D on total protein concentration, CNPase and MOG expression in the cerebral cortex of the murine model of cuprizone-induced demyelination was investigated. The mice were treated by cuprizone for five weeks in order to induce demyelination. The mice were then divided into 3 groups. The first group was injected intraperitoneally (IP with vitamin D diluted in olive oil in the amount of 5 µg/kg/daily body weight. The second group (SHAM was injected IP with olive oil and the third group was left without any injection as the control group (n = 11 for each group. After five weeks the mice were killed and the cerebral cortex was collected and the expression of CNPase and MOG was studied by Western blot. Total protein concentration in the vitamin D injected, SHAM and control groups were 0.918 ± 0.003, 0917 ± 0.004 and 0.916 ± 0.004 g/l, respectively (p > 0.05. However, a significant increase in the MOG and CNPase expression was seen in vitamin D injected group as compared to SHAM and control groups. It is concluded that vitamin D plays a role in the process of remyelination by increasing MOG and CNPase expression in the cortex.

  3. Oligodendrocyte ablation as a tool to study demyelinating diseases

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    Ahdeah Pajoohesh-Ganji

    2016-01-01

    Full Text Available Multiple sclerosis (MS is an autoimmune mediated neurodegenerative disease characterized by demyelination and oligodendrocyte (OL loss in the central nervous system and accompanied by local inflammation and infiltration of peripheral immune cells. Although many risk factors and symptoms have been identified in MS, the pathology is complicated and the cause remains unknown. It is also unclear whether OL apoptosis precedes the inflammation or whether the local inflammation is the cause of OL death and demyelination. This review briefly discusses several models that have been developed to specifically ablate oligodendrocytes in an effort to separate the effects of demyelination from inflammation.

  4. Protective and therapeutic role of 2-carba-cyclic phosphatidic acid in demyelinating disease.

    Science.gov (United States)

    Yamamoto, Shinji; Yamashina, Kota; Ishikawa, Masaki; Gotoh, Mari; Yagishita, Sosuke; Iwasa, Kensuke; Maruyama, Kei; Murakami-Murofushi, Kimiko; Yoshikawa, Keisuke

    2017-07-21

    Multiple sclerosis is a neuroinflammatory demyelinating and neurodegenerative disease of the central nervous system characterized by recurrent and progressive demyelination/remyelination cycles, neuroinflammation, oligodendrocyte loss, demyelination, and axonal degeneration. Cyclic phosphatidic acid (cPA) is a natural phospholipid mediator with a unique cyclic phosphate ring structure at the sn-2 and sn-3 positions of the glycerol backbone. We reported earlier that cPA elicits a neurotrophin-like action and protects hippocampal neurons from ischemia-induced delayed neuronal death. We designed, chemically synthesized, and metabolically stabilized derivatives of cPA: 2-carba-cPA (2ccPA), a synthesized compound in which one of the phosphate oxygen molecules is replaced with a methylene group at the sn-2 position. In the present study, we investigated whether 2ccPA exerts protective effects in oligodendrocytes and suppresses pathology in the two most common mouse models of multiple sclerosis. To evaluate whether 2ccPA has potential beneficial effects on the pathology of multiple sclerosis, we investigated the effects of 2ccPA on oligodendrocyte cell death in vitro and administrated 2ccPA to mouse models of experimental autoimmune encephalomyelitis (EAE) and cuprizone-induced demyelination. We demonstrated that 2ccPA suppressed the CoCl2-induced increase in the Bax/Bcl-2 protein expression ratio and phosphorylation levels of p38MAPK and JNK protein. 2ccPA treatment reduced cuprizone-induced demyelination, microglial activation, NLRP3 inflammasome, and motor dysfunction. Furthermore, 2ccPA treatment reduced autoreactive T cells and macrophages, spinal cord injury, and pathological scores in EAE, the autoimmune multiple sclerosis mouse model. We demonstrated that 2ccPA protected oligodendrocytes via suppression of the mitochondrial apoptosis pathway. Also, we found beneficial effects of 2ccPA in the multiperiod of cuprizone-induced demyelination and the pathology of EAE

  5. Th17 cells in autoimmune demyelinating disease.

    Science.gov (United States)

    Segal, Benjamin Matthew

    2010-03-01

    Recently published studies in multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE) have demonstrated an association between the development of demyelinating plaques and the accumulation of Th17 cells in the central nervous system and periphery. However, a causal relationship has been difficult to establish. In fact, in reports published thus far, interleukin (IL)-17A deficiency or neutralization in vivo attenuates, but does not completely abrogate, EAE. There is growing evidence that clinically similar forms of autoimmune demyelinating disease can be driven by myelin-specific T cells of distinct lineages with different degrees of dependence on IL-17A production to achieve their pathological effects. While such observations cast doubts about the potential therapeutic efficacy of Th17 blocking agents in MS, the collective data suggest that IL-17A expression in peripheral blood mononuclear cells could serve as a surrogate biomarker of neuroinflammation and plaque formation and be a useful outcome measure for future clinical trials.

  6. Transcriptional changes in canine distemper virus-induced demyelinating leukoencephalitis favor a biphasic mode of demyelination.

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    Reiner Ulrich

    Full Text Available Canine distemper virus (CDV-induced demyelinating leukoencephalitis in dogs (Canis familiaris is suggested to represent a naturally occurring translational model for subacute sclerosing panencephalitis and multiple sclerosis in humans. The aim of this study was a hypothesis-free microarray analysis of the transcriptional changes within cerebellar specimens of five cases of acute, six cases of subacute demyelinating, and three cases of chronic demyelinating and inflammatory CDV leukoencephalitis as compared to twelve non-infected control dogs. Frozen cerebellar specimens were used for analysis of histopathological changes including demyelination, transcriptional changes employing microarrays, and presence of CDV nucleoprotein RNA and protein using microarrays, RT-qPCR and immunohistochemistry. Microarray analysis revealed 780 differentially expressed probe sets. The dominating change was an up-regulation of genes related to the innate and the humoral immune response, and less distinct the cytotoxic T-cell-mediated immune response in all subtypes of CDV leukoencephalitis as compared to controls. Multiple myelin genes including myelin basic protein and proteolipid protein displayed a selective down-regulation in subacute CDV leukoencephalitis, suggestive of an oligodendrocyte dystrophy. In contrast, a marked up-regulation of multiple immunoglobulin-like expressed sequence tags and the delta polypeptide of the CD3 antigen was observed in chronic CDV leukoencephalitis, in agreement with the hypothesis of an immune-mediated demyelination in the late inflammatory phase of the disease. Analysis of pathways intimately linked to demyelination as determined by morphometry employing correlation-based Gene Set Enrichment Analysis highlighted the pathomechanistic importance of up-regulated genes comprised by the gene ontology terms "viral replication" and "humoral immune response" as well as down-regulated genes functionally related to "metabolite and energy

  7. Neuroradiological evaluation of demyelinating disease

    Science.gov (United States)

    Tillema, Jan-Mendelt

    2013-01-01

    Central nervous system inflammatory demyelinating disease can affect patients across the life span. Consensus definitions and criteria of all of the different acquired demyelinating diseases that fall on this spectrum have magnetic resonance imaging criteria. The advances of both neuroimaging techniques and important discoveries in immunology have produced an improved understanding of these conditions and classification. Neuroimaging plays a central role in the accurate diagnosis, prognosis, disease monitoring and research efforts that are being undertaken in this disease. This review focuses on the imaging spectrum of acquired demyelinating disease. PMID:23858328

  8. Neuroradiological evaluation of demyelinating disease.

    Science.gov (United States)

    Tillema, Jan-Mendelt; Pirko, Istvan

    2013-07-01

    Central nervous system inflammatory demyelinating disease can affect patients across the life span. Consensus definitions and criteria of all of the different acquired demyelinating diseases that fall on this spectrum have magnetic resonance imaging criteria. The advances of both neuroimaging techniques and important discoveries in immunology have produced an improved understanding of these conditions and classification. Neuroimaging plays a central role in the accurate diagnosis, prognosis, disease monitoring and research efforts that are being undertaken in this disease. This review focuses on the imaging spectrum of acquired demyelinating disease.

  9. Neuroradiological evaluation of demyelinating disease

    OpenAIRE

    Tillema, Jan-Mendelt; Pirko, Istvan

    2013-01-01

    Central nervous system inflammatory demyelinating disease can affect patients across the life span. Consensus definitions and criteria of all of the different acquired demyelinating diseases that fall on this spectrum have magnetic resonance imaging criteria. The advances of both neuroimaging techniques and important discoveries in immunology have produced an improved understanding of these conditions and classification. Neuroimaging plays a central role in the accurate diagnosis, prognosis, ...

  10. Thymosin beta4 promotes oligodendrogenesis in the demyelinating central nervous system.

    Science.gov (United States)

    Zhang, Jing; Zhang, Zheng Gang; Li, Yi; Lu, Mei; Zhang, Yi; Elias, Stanton B; Chopp, Michael

    2016-04-01

    Multiple sclerosis (MS) is a demyelinating disease of the central nervous system (CNS). No effective remyelination therapies are in use. We hypothesized that thymosin beta4 (Tβ4) is an effective remyelination treatment by promoting differentiation of oligodendrocyte progenitor cells (OPCs), and that the epidermal growth factor receptor (EGFR) signaling pathway contributes to this process. Two demyelination animal models were employed in this study: 1) experimental autoimmune encephalomyelitis (EAE), an animal model of MS. EAE mice were treated daily for 30days, with Tβ4 or saline treatment initiated on the day of EAE onset; and 2) cuprizone diet model, a non-inflammatory demyelination model. The mice were treated daily for 4weeks with Tβ4 or saline after fed a cuprizone diet for 5weeks. Immunofluorescent staining and Western blot were performed to measure the differentiation of OPCs, myelin and axons, respectively. To obtain insight into mechanisms of action, the expression and activation of the EGFR pathway was measured. AG1478, an EGFR inhibitor, was employed in a loss-of-function study. Data revealed that animals in both demyelination models exhibited significant reduction of myelin basic protein (MBP(+)) levels and CNPase(+) oligodendrocytes. Treatment of EAE mice with Tβ4 significantly improved neurological outcome. Double immunofluorescent staining showed that Tβ4 significantly increased the number of newly generated oligodendrocytes identified by BrdU(+)/CNPase(+) cells and MBP(+) mature oligodendrocytes, and reduced axonal damage in the EAE mice compared with the saline treatment. The newly generated mature oligodendrocytes remyelinated axons, and the increased mature oligodendrocytes significantly correlated with functional improvement (r=0.73, pdemyelination model, Tβ4 treatment was confirmed that significantly increased OPC differentiation and remyelination, and increased the expression of EGFR and activated the EGFR pathway in the demyelinating

  11. Experimental Object-Oriented Modelling

    DEFF Research Database (Denmark)

    Hansen, Klaus Marius

    and discuss techniques for handling and representing uncertainty when modelling in experimental system development. These techniques are centred on patterns and styles for handling uncertainty in object-oriented software architectures. Tools We present the Knight tool designed for collaborative modelling......This thesis examines object-oriented modelling in experimental system development. Object-oriented modelling aims at representing concepts and phenomena of a problem domain in terms of classes and objects. Experimental system development seeks active experimentation in a system development project...... through, e.g., technical prototyping and active user involvement. We introduce and examine “experimental object-oriented modelling” as the intersection of these practices. The contributions of this thesis are expected to be within three perspectives on models and modelling in experimental system...

  12. Directional diffusivity as a magnetic resonance (MR) biomarker in demyelinating disease

    Science.gov (United States)

    Benzinger, Tammie L. S.; Cross, Anne H.; Xu, Junqian; Naismith, Robert; Sun, Shu-Wei; Song, Sheng-Kwei

    2007-09-01

    Directional diffusivities derived from diffusion tensor magnetic resonance imaging (DTI) measurements describe water movement parallel to (λ ||, axial diffusivity) and perpendicular to (λ⊥radial diffusivity) axonal tracts. λ || and λ⊥ have been shown to differentially detect axon and myelin abnormalities in several mouse models of central nervous system white matter pathology in our laboratory. These models include experimental autoimmune encephalomyelitis (EAE), (1) myelin basic protein mutant mice with dysmyelination and intact axons, (2) cuprizone-induced demyelination, and remyelination, with reversible axon injury (2, 3) and a model of retinal ischemia in which retinal ganglion cell death is followed by Wallerian degeneration of optic nerve, with axonal injury preceding demyelination. (4) Decreased λ|| correlates with acute axonal injury and increased λ⊥ indicates myelin damage. (4) More recently, we have translated this approach to human MR, investigating acute and chronic optic neuritis in adults with multiple sclerosis, brain lesions in adults with multiple sclerosis, and acute disseminated encephalomyelitis (ADEM) in children. We are also investigating the use of this technique to probe the underlying structural change of the cervical spinal cord in acute and chronic T2- hyperintense lesions in spinal stenosis, trauma, and transverse myelitis. In each of these demyelinating diseases, the discrimination between axonal and myelin injury which we can achieve has important prognostic and therapeutic implications. For those patients with myelin injury but intact axons, early, directed drug therapy has the potential to prevent progression to axonal loss and permanent disability.

  13. Cytokine-neuroantigen fusion proteins as a new class of tolerogenic, therapeutic vaccines for treatment of inflammatory demyelinating disease in rodent models of multiple sclerosis.

    Science.gov (United States)

    Mannie, Mark D; Blanchfield, J Lori; Islam, S M Touhidul; Abbott, Derek J

    2012-01-01

    Myelin-specific induction of tolerance represents a promising means to modify the course of autoimmune inflammatory demyelinating diseases such as multiple sclerosis (MS). Our laboratory has focused on a novel preclinical strategy for the induction of tolerance to the major encephalitogenic epitopes of myelin that cause experimental autoimmune encephalomyelitis (EAE) in rats and mice. This novel approach is based on the use of cytokine-NAg (neuroantigen) fusion proteins comprised of the native cytokine fused either with or without a linker to a NAg domain. Several single-chain cytokine-NAg fusion proteins were tested including GMCSF-NAg, IFNbeta-NAg, NAgIL16, and IL2-NAg. These cytokine-NAg vaccines were tolerogenic, therapeutic vaccines that had tolerogenic activity when given as pre-treatments before encephalitogenic immunization and also were effective as therapeutic interventions during the effector phase of EAE. The rank order of inhibitory activity was as follows: GMCSF-NAg, IFNbeta-NAg > NAgIL16 > IL2-NAg > MCSF-NAg, IL4-NAg, IL-13-NAg, IL1RA-NAg, and NAg. Several cytokine-NAg fusion proteins exhibited antigen-targeting activity. High affinity binding of the cytokine domain to specific cytokine receptors on particular subsets of APC resulted in the concentrated uptake of the NAg domain by those APC which in turn facilitated the enhanced processing and presentation of the NAg domain on cell surface MHC class II glycoproteins. For most cytokine-NAg vaccines, the covalent linkage of the cytokine domain and NAg domain was required for inhibition of EAE, thereby indicating that antigenic targeting of the NAg domain to APC was also required in vivo for tolerogenic activity. Overall, these studies introduced a new concept of cytokine-NAg fusion proteins as a means to induce tolerance and to inhibit the effector phase of autoimmune disease. The approach has broad application for suppressive vaccination as a therapy for autoimmune diseases such as MS.

  14. Cytokine-neuroantigen fusion proteins as a new class of tolerogenic, therapeutic vaccines for treatment of inflammatory demyelinating disease in rodent models of multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Mark D. Mannie

    2012-08-01

    Full Text Available Myelin-specific induction of tolerance represents a promising means to modify the course of autoimmune inflammatory demyelinating diseases such as multiple sclerosis (MS. Our laboratory has focused on a novel preclinical strategy for the induction of tolerance to the major encephalitogenic epitopes of myelin that cause experimental autoimmune encephalomyelitis (EAE in rats and mice. This novel approach is based on the use of cytokine-NAg (neuroantigen fusion proteins comprised of the native cytokine fused either with or without a linker to a NAg domain. Several single-chain cytokine-NAg fusion proteins were tested including GMCSF-NAg, IFNbeta-NAg, NAgIL16, and IL2-NAg. These cytokine-NAg vaccines were tolerogenic, therapeutic vaccines that had tolerogenic activity when given as pre-treatments before encephalitogenic immunization and also were effective as therapeutic interventions during the effector phase of EAE. The rank order of inhibitory activity was: GMCSF-NAg, IFNbeta-NAg > NAgIL16 > IL2-NAg > MCSF-NAg, IL4-NAg, IL13-NAg, IL1RA-NAg, and NAg. Several cytokine-NAg fusion proteins exhibited antigen-targeting activity. High affinity binding of the cytokine domain to specific-cytokine receptors on particular subsets of APC resulted in the concentrated uptake of the NAg domain by those APC which in turn facilitated the enhanced processing and presentation of the NAg domain on cell surface MHC class II (MHCII glycoproteins. For most cytokine-NAg vaccines, the covalent linkage of the cytokine domain and NAg domain was required for inhibition of EAE, thereby indicating that antigenic targeting of the NAg domain to APC was also required in vivo for tolerogenic activity. Overall, these studies introduced a new concept of cytokine-NAg fusion proteins as a means to induce tolerance and to inhibit the effector phase of autoimmune disease. The approach has broad application for suppressive vaccination as a therapy for autoimmune diseases such as MS.

  15. Probenecid-treatment reduces demyelination induced by cuprizone feeding.

    Science.gov (United States)

    Hainz, Nadine; Becker, Philipp; Rapp, Daniel; Wagenpfeil, Stefan; Wonnenberg, Bodo; Beisswenger, Christoph; Tschernig, Thomas; Meier, Carola

    2017-11-01

    Recent experiments showed that a pannexin-1 inhibitor, probenecid, reduced clinical symptoms in the murine experimental autoimmune encephalomyelitis when applied during the initial phase of neuronal inflammation. An inflammatory component is also present in a toxically induced inflammation and demyelination using cuprizone diet. Probenecid is a pannexin-1 antagonist and a probenecid therapy was investigated. Mice were fed for 10days with a cuprizone diet. In the following, the diet was continued but combined with a daily injection of a low dose of probenecid or solvent for 10days. Electron microscopy revealed demyelination in the optic nerve. The demyelination as measured by the axonal diameter was significantly reduced in the animals treated with 100mg per kg body weight probenecid. In comparison to controls, the number of leukocytes and lymphocytes in the peripheral blood was reduced in all cuprizone groups including the treatment group. In conclusion, early demyelination in the optic nerve was moderately reduced by 10days treatment with a low dose probenecid. This is a hint for the involvement of pannexin-1 modulated inflammation in cuprizone feeding induced toxic demyelination. Thus, probenecid is a candidate for the treatment of neuro-inflammation and multiple sclerosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Will PEDF Therapy Reverse Chronic Demyelination and Prevent Axon Loss in a Murine Model of Progressive Multiple Sclerosis

    Science.gov (United States)

    2015-12-01

    Multiple Sclerosis ? PRINCIPAL INVESTIGATOR: David Pleasure MD CONTRACTING ORGANIZATION: University of California Davis, CA 95618 REPORT DATE...Murine Model of Progressive Multiple Sclerosis ? 5b. GRANT NUMBER W81XWH-12-1-0566 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) David Pleasure MD 5d...enhance central nervous system (CNS) remyelination and preserve CNS axons in mouse models of multiple sclerosis models. After determining the dosage of

  17. Cytogenetics and experimental models.

    Science.gov (United States)

    Toretsky, J A; Helman, L J

    1997-07-01

    The use of cytogenetics has led to significant improvement in the diagnoses and classification of sarcomas. Many of the major sarcomas have been to have characteristic tumor-specific chromosomal translocations that are currently used in the diagnosis of these tumors. In the past year, a subset of Ewing's family of tumors and myxoid liposarcomas, which lack one of the characteristic translocations, were found to carry related translocations. New technologies such as a spectral karyotyping will likely increase out ability to identify additional tumor-specific translocations. The emergence of genetic alterations as prognostic factors, as illustrated by Ewing's family of tumors, osteosarcoma, and p53 expression in soft tissue sarcomas in general, is discussed. The review concludes with laboratory applications derived from either tumor cytogenetic or gene function abnormalities that are related to tumor-specific translocations. It is anticipated that advances in diagnosis, prognosis, and modeling will translate into future therapeutic advances.

  18. Experimental autoimmune encephalomyelitis (EAE) as a model for multiple sclerosis (MS)

    Science.gov (United States)

    Constantinescu, Cris S; Farooqi, Nasr; O'Brien, Kate; Gran, Bruno

    2011-01-01

    Experimental autoimmune encephalomyelitis (EAE) is the most commonly used experimental model for the human inflammatory demyelinating disease, multiple sclerosis (MS). EAE is a complex condition in which the interaction between a variety of immunopathological and neuropathological mechanisms leads to an approximation of the key pathological features of MS: inflammation, demyelination, axonal loss and gliosis. The counter-regulatory mechanisms of resolution of inflammation and remyelination also occur in EAE, which, therefore can also serve as a model for these processes. Moreover, EAE is often used as a model of cell-mediated organ-specific autoimmune conditions in general. EAE has a complex neuropharmacology, and many of the drugs that are in current or imminent use in MS have been developed, tested or validated on the basis of EAE studies. There is great heterogeneity in the susceptibility to the induction, the method of induction and the response to various immunological or neuropharmacological interventions, many of which are reviewed here. This makes EAE a very versatile system to use in translational neuro- and immunopharmacology, but the model needs to be tailored to the scientific question being asked. While creating difficulties and underscoring the inherent weaknesses of this model of MS in straightforward translation from EAE to the human disease, this variability also creates an opportunity to explore multiple facets of the immune and neural mechanisms of immune-mediated neuroinflammation and demyelination as well as intrinsic protective mechanisms. This allows the eventual development and preclinical testing of a wide range of potential therapeutic interventions. LINKED ARTICLES This article is part of a themed issue on Translational Neuropharmacology. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2011.164.issue-4 PMID:21371012

  19. Influence of type I IFN signaling on anti-MOG antibody-mediated demyelination

    DEFF Research Database (Denmark)

    Berg, Carsten Tue; Khorooshi, Reza M. H.; Asgari, Nasrin

    2017-01-01

    -MOG antibody and mouse complement were stereotactically injected into the corpus callosum of wild-type and type I IFN receptor deficient mice (IFNAR1-KO) with and without pre-established experimental autoimmune encephalomyelitis (EAE). Results Anti-MOG induced complement-dependent demyelination in the corpus...... callosum of wild-type mice and did not occur in mice that received control IgG2a. Deposition of activated complement coincided with demyelination, and this was significantly reduced in IFNAR1-KO mice. Co-injection of anti-MOG and complement at onset of symptoms of EAE induced similar levels of callosal...... demyelination in wild-type and IFNAR1-KO mice. Conclusions Anti-MOG antibody and complement was sufficient to induce callosal demyelination, and pathology was dependent on type I IFN. Induction of EAE in IFNAR1-KO mice overcame the dependence on type I IFN for anti-MOG and complement-mediated demyelination....

  20. [Human herpesvirus-8 DNA in patients with certain demyelinating disorders].

    Science.gov (United States)

    Olut, Ali Ilgin; Ozünlü, Haluk; Tan, Ersin; Kocagöz, Tanal

    2005-04-01

    Infectious etiology of the demyelinating diseases is an intensive matter of research. Among the suspected pathogens, herpesviruses had attracted particular attention because of their capacity to remain latent in nervous tissues, axonal transportation of some members within neurons, relapsing-remitting characteristic of the infections, and capability of inducing demyelination both in human host and animal models. Human herpesvirus-8 (HHV-8) is the least studied of this group even some of the HHV-8 related disorders such as HIV associated Castleman's disease, some lymphomas, monoclonal gammopathy of uncertain significance (MGUS), may be seen in patients with demyelinating conditions. The aim of this study was the investigation of a probable relationship between HHV-8 infection and certain demyelinating diseases. For this purpose, the presence of HHV-8 DNA has been investigated by polymerase chain reaction in the blood samples of 14 multiple sclerosis (MS), six chronic inflammatory demyelinizing polyneuropathy (CIDP), three Guillain-Barre syndrome (GBS), and one Miller-Fisher syndrome patients, together with 24 age- and sex-matched healthy subjects as control. As a result, one of MS, two of CIDP and all of the GBS patients were found HHV-8 DNA positive, whereas all the subjects in control group were negative. Although the interpretation of the results of this study does not seem to be possible owing to the limited number of patients, it emphasizes the need for larger scale, detailed studies on this subject since no other report dealing with this matter has been encountered in the literature.

  1. PET imaging of focal demyelination and remyelination in a rat model of multiple sclerosis: comparison of [{sup 11}C]MeDAS, [{sup 11}C]CIC and [{sup 11}C]PIB

    Energy Technology Data Exchange (ETDEWEB)

    Paula Faria, Daniele de [University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); University of Groningen, University Medical Center Groningen, Department of Neuroscience, Groningen (Netherlands); University of Sao Paulo Medical School, Center of Nuclear Medicine, Sao Paulo (Brazil); Copray, Sjef [University of Groningen, University Medical Center Groningen, Department of Neuroscience, Groningen (Netherlands); Sijbesma, Jurgen W.A.; Willemsen, Antoon T.M.; Dierckx, Rudi A.J.O.; Vries, Erik F.J. de [University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); Buchpiguel, Carlos A. [University of Sao Paulo Medical School, Center of Nuclear Medicine, Sao Paulo (Brazil)

    2014-05-15

    In this study, we compared the ability of [{sup 11}C]CIC, [{sup 11}C]MeDAS and [{sup 11}C]PIB to reveal temporal changes in myelin content in focal lesions in the lysolecithin rat model of multiple sclerosis. Pharmacokinetic modelling was performed to determine the best method to quantify tracer uptake. Sprague-Dawley rats were stereotactically injected with either 1 % lysolecithin or saline into the corpus callosum and striatum of the right brain hemisphere. Dynamic PET imaging with simultaneous arterial blood sampling was performed 7 days after saline injection (control group), 7 days after lysolecithin injection (demyelination group) and 4 weeks after lysolecithin injection (remyelination group). The kinetics of [{sup 11}C]CIC, [{sup 11}C]MeDAS and [{sup 11}C]PIB was best fitted by Logan graphical analysis, suggesting that tracer binding is reversible. Compartment modelling revealed that all tracers were fitted best with the reversible two-tissue compartment model. Tracer uptake and distribution volume in lesions were in agreement with myelin status. However, the slow kinetics and homogeneous brain uptake of [{sup 11}C]CIC make this tracer less suitable for in vivo PET imaging. [{sup 11}C]PIB showed good uptake in the white matter in the cerebrum, but [{sup 11}C]PIB uptake in the cerebellum was low, despite high myelin density in this region. [{sup 11}C]MeDAS distribution correlated well with myelin density in different brain regions. This study showed that PET imaging of demyelination and remyelination processes in focal lesions is feasible. Our comparison of three myelin tracers showed that [{sup 11}C]MeDAS has more favourable properties for quantitative PET imaging of demyelinated and remyelinated lesions throughout the CNS than [{sup 11}C]CIC and [{sup 11}C]PIB. (orig.)

  2. Atypical idiopathic inflammatory demyelinating lesions

    DEFF Research Database (Denmark)

    Wallner-Blazek, Mirja; Rovira, Alex; Fillipp, Massimo

    2013-01-01

    Atypical lesions of a presumably idiopathic inflammatory demyelinating origin present quite variably and may pose diagnostic problems. The subsequent clinical course is also uncertain. We, therefore, wanted to clarify if atypical idiopathic inflammatory demyelinating lesions (AIIDLs) can...... and magnetic resonance imaging data and obtained follow-up (FU) information on 77 of these patients over a mean duration of 4 years. The AIIDLs presented as a single lesion in 72 (80 %) patients and exhibited an infiltrative (n = 35), megacystic (n = 16), Baló (n = 10) or ring-like (n = 16) lesion appearance...... in 77 (86 %) patients. Additional multiple sclerosis (MS)-typical lesions existed in 48 (53 %) patients. During FU, a further clinical attack occurred rarely (23-35 % of patients) except for patients with ring-like AIIDLs (62 %). Further attacks were also significantly more often in patients...

  3. PEMFC modeling and experimental validation

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, J.V.C. [Federal University of Parana (UFPR), Curitiba, PR (Brazil). Dept. of Mechanical Engineering], E-mail: jvargas@demec.ufpr.br; Ordonez, J.C.; Martins, L.S. [Florida State University, Tallahassee, FL (United States). Center for Advanced Power Systems], Emails: ordonez@caps.fsu.edu, martins@caps.fsu.edu

    2009-07-01

    In this paper, a simplified and comprehensive PEMFC mathematical model introduced in previous studies is experimentally validated. Numerical results are obtained for an existing set of commercial unit PEM fuel cells. The model accounts for pressure drops in the gas channels, and for temperature gradients with respect to space in the flow direction, that are investigated by direct infrared imaging, showing that even at low current operation such gradients are present in fuel cell operation, and therefore should be considered by a PEMFC model, since large coolant flow rates are limited due to induced high pressure drops in the cooling channels. The computed polarization and power curves are directly compared to the experimentally measured ones with good qualitative and quantitative agreement. The combination of accuracy and low computational time allow for the future utilization of the model as a reliable tool for PEMFC simulation, control, design and optimization purposes. (author)

  4. Experimental Modeling of Dynamic Systems

    DEFF Research Database (Denmark)

    Knudsen, Morten Haack

    2006-01-01

    An engineering course, Simulation and Experimental Modeling, has been developed that is based on a method for direct estimation of physical parameters in dynamic systems. Compared with classical system identification, the method appears to be easier to understand, apply, and combine with physical...

  5. The myelin sheath aqueous layers improve the membrane properties of simulated chronic demyelinating neuropathies.

    Science.gov (United States)

    Stephanova, D I; Krustev, S M; Negrev, N; Daskalova, M

    2011-03-01

    Recently, patients with chronic demyelinating neuropathies have demonstrated significant abnormalities in their multiple nerve excitability properties measured by a non-invasive threshold tracking technique. In order to expand our studies on the possible mechanisms underlying these abnormalities, which are not yet well understood, we investigate the contributions of the aqueous layers within the myelin sheath on multiple membrane properties of simulated fibre demyelinations. Four degrees of systematic paranodal demyelinations (two mild demyelinations termed PSD1 and PSD2, without/with aqueous layers respectively, and two severe demyelinations termed PSD3 and PSD4, with/without aqueous layers, respectively) are simulated using our previous multi-layered model of human motor nerve fibre. We studied the following parameters of myelinated axonal function: potentials (intracellular action, electrotonic-reflecting the propagating and accommodative fibre processes, respectively) and strength-duration time constants, rheobases, recovery cycles (reflecting the adaptive fibre processes). The results show that each excitability parameter is markedly potentiated when the aqueous layers within their paranodally demyelinated sheaths are taken into account. The effect of the aqueous layers is significantly higher on the propagating processes than on the accommodative and adaptive processes in the fibres. The aqueous layers restore the action potential propagation, which is initially blocked when they are not taken into account. The study provides new and important information on the mechanisms of chronic demyelinating neuropathies, such as chronic inflammatory demyelinating polyneuropathy (CIDP). © Imperial College Press

  6. Direct angiotensin AT2-receptor stimulation attenuates T-cell and microglia activation and prevents demyelination in experimental autoimmune encephalomyelitis in mice

    DEFF Research Database (Denmark)

    Valero-Esquitino, Verónica; Lucht, Kristin; Namsolleck, Pawel

    2015-01-01

    , accelerated re-myelination and reduced the number of microglia. Cytokine synthesis and NO production by microglia in vitro were significantly reduced after C21 treatment. These results suggest that AT2R-stimulation protects the myelin sheaths in autoimmune CNS inflammation by inhibiting the T-cell response...... immunised with myelin-oligodendrocyte-peptide (MOG) and treated for 4 weeks with C21 (0.3mg/kg/day i.p.). Potential effects on myelination, microglia and T-cell composition were estimated by immunostaining and FACS analyses of lumbar spinal cords. The in vivo study was complemented by experiments...... in aggregating brain cell cultures and microglia in vitro. In the EAE model, treatment with C21 ameliorated microglia activation and decreased the number of total T-cells and CD4+ T-cells in the spinal cord. Fluorescent myelin staining of spinal cords further revealed a significant reduction of EAE...

  7. Remyelination in experimentally demyelinated connexin 32 KnockOut mice Remielinização em camundongos KnockOut para conexina 32 desmielinizados experimentalmente

    Directory of Open Access Journals (Sweden)

    Adriano Tony Ramos

    2009-06-01

    Full Text Available The aim of this study was to evaluate the role of connexin 32 (Cx 32 during remyelination of the peripheral nervous system, through a local injection of either 0,1% ethidium bromide solution or saline in the sciatic nerve of Cx 32 knockout mice. Euthanasia was performed ranging from 1, 2, 3, 7, 15, 21 to 30 days after injection. Histochemical, immunohistochemical, immunofluorescence and transmission electron microscopical techniques were used to analyze the development of the lesions. Within the sciatic nerves, Schwann cells initially showed signs of intoxication and rejected their sheaths; after seven days, some thin newly formed myelin sheaths with uneven compactness and redundant loops (tomacula were conspicuous. We concluded that the regeneration of lost myelin sheaths within the PNS followed the pattern already reported for this model in other laboratory species. Therefore, these results suggest that absence of Cx 32 did not interfere with the normal pattern of remyelination in this model in young mice.Este estudo visou avaliar o papel da conexina 32 (Cx 32 durante a remielinização no sistema nervoso periférico. Uma injeção local de 0,1% de solução de brometo de etídio foi realizada no nervo ciático de camundongos deletados para a Cx 32, com eutanásia dos animais aos 1, 2, 3, 7, 15, 21 e 30 dias pós-injeção. Avaliações histoquímicas, imunoistoquímicas, por imunofluorescência e por microscopia eletrônica de transmissão foram utilizadas na análise do desenvolvimento das lesões. Nos nervos ciáticos, células de Schwann mostraram inicialmente sinais de intoxicação e rejeitaram suas bainhas. Após sete dias, observaram-se finas bainhas neoformadas, com compactação desigual e alças redundantes (tomácula. Conclui-se que a regeneração de bainhas de mielina perdidas no SNP seguiu o padrão já relatado deste modelo em outras espécies de laboratório. Portanto, estes resultados sugerem que a ausência da Cx 32 n

  8. Effect of honey bee venom on lewis rats with experimental allergic encephalomyelitis, a model for multiple sclerosis.

    Science.gov (United States)

    Karimi, Akbar; Ahmadi, Farhad; Parivar, Kazem; Nabiuni, Mohammad; Haghighi, Saied; Imani, Sohrab; Afrouzi, Hossein

    2012-01-01

    Multiple sclerosis (MS) is a progressive and autoimmune neurodegenerative disease of the central nervous system (CNS). This disease is recognized through symptoms like inflammation, demyelination and the destruction of neurological actions. Experimental allergic encephalomyelitis (EAE) is a widely accepted animal model for MS. EAE is created in animals by injecting the tissue of myelin basic protein (MBP), CNS, or myelin oligodendrocyte glycoprotein (MOG) along with the adjuvant. EAE and MS are similar diseases. Honey Bee venom (Apis mellifera) contains a variety of low and high molecular weight peptides and proteins, including melittin, apamin, adolapin, mast cell degranulating peptide and phospholipase A2. Bee venom (BV) could exert anti-inflammatory and antinociceptive effects on the inflammatory reactions. The guinea pig spinal cord homogenate (GPSCH) is with the Complete Freund's Adjuvant (CFA), consisting of 1 mg/mL Mycobacterium tuberculosis. It was used for inducting EAE in Lewis rats for creating the MS model. The hematoxylin and eosin and luxol fast blue methods were used respectively in analyses of inflammation and detection of demyelination in the central nervous system. Furthermore, the ELISA and the high performance liquid chromatography (HPLC) were used for the assessment of tumor necrosis factor alpha (TNF-α) and nitrate in rats serum. In this study, we indicated that the treatment of EAE with Bee venom decreased the symptoms of clinical disorder, pathological changes, inflammatory cell infiltration, demyelination in the central nervous system, level of serum TNF-α, and the serum nitrates in rat EAE induced through GPSCH.

  9. Astrogliosis During Acute and Chronic Cuprizone Demyelination and Implications for Remyelination

    Directory of Open Access Journals (Sweden)

    Norah Hibbits

    2012-10-01

    Full Text Available In multiple sclerosis, microglia/macrophage activation and astrocyte reactivity are important components of the lesion environment that can impact remyelination. The current study characterizes these glial populations relative to expression of candidate regulatory molecules in cuprizone demyelinated corpus callosum. Importantly, periods of recovery after acute or chronic cuprizone demyelination are examined to compare conditions of efficient versus limited remyelination, respectively. Microglial activation attenuates after early demyelination. In contrast, astrocyte reactivity persists throughout demyelination and a 6-week recovery period following either acute or chronic demyelination. This astrocyte reaction is characterized by (a early proliferation, (b increased expression of GFAP (glial fibrillary acidic protein, Vim (vimentin, Fn1 (fibronectin and CSPGs (chondroitin sulphate proteoglycans and (c elaboration of a dense network of processes. Glial processes elongated in the axonal plane persist throughout lesion areas during both the robust remyelination that follows acute demyelination and the partial remyelination that follows chronic demyelination. However, prolonged astrocyte reactivity with chronic cuprizone treatment does not progress to barrier formation, i.e. dense compaction of astrocyte processes to wall off the lesion area. Multiple candidate growth factors and inflammatory signals in the lesion environment show strong correlations with GFAP across the acute cuprizone demyelination and recovery time course, yet there is more divergence across the progression of chronic cuprizone demyelination and recovery. However, differential glial scar formation does not appear to be responsible for differential remyelination during recovery in the cuprizone model. The astrocyte phenotype and lesion characteristics in this demyelination model inform studies to identify triggers of non-remyelinating sclerosis in chronic multiple sclerosis

  10. The innate immune response affects the development of the autoimmune response in Theiler’s virus- induced demyelinating disease

    OpenAIRE

    Olson, Julie K.; Miller, Stephen D

    2009-01-01

    Multiple sclerosis (MS) is a human CNS autoimmune demyelinating disease. Epidemiological evidence has suggested a role for virus infection in the initiation and/or exacerbation of MS. Theiler’s murine encephalomyelitis virus (TMEV)- induced demyelinating disease serves as a relevant mouse model for MS. TMEV- infected mice develop a demyelinating disease with clinical symptoms beginning around 35 days post infection which is associated with development of myelin- specific, PLP139–151, CD4+ T c...

  11. THE EXPERIMENTAL MODEL OF OSTEONECROSIS

    Directory of Open Access Journals (Sweden)

    G. I. Netylko

    2010-01-01

    Full Text Available The experimental investigation for the purpose of modeling of knee osteonecrosis were performed in 36 rats. The chronic renal insufficiency by means of left nephrectomy and electrocoagulation in 25% cortical substance of right kidney was induced before 6 months till experiment with subsequent introduction of 0,1% adrenalin solution and methylprednisolone in paraarticular structures. The results of experiment showed the polyetiologic feature of disease.

  12. The updated experimental proteinoid model

    Science.gov (United States)

    Fox, S. W.; Nakashima, T.; Przybylski, A.; Syren, R. M.

    1982-01-01

    The experimental proteinoid model includes new results indicating that polymers sufficiently rich in basic amino acid catalyze the synthesis of peptides from ATP and amino acids and of oligonucleotides from ATP. The need for simulation syntheses of amino acids yielding significant proportions of basic amino acids is now in focus. The modeled simultaneous protocellular synthesis of peptides and polynucleotides is part of a more comprehensive proposal for the origin of the coded genetic mechanism. The finding of membrane and action potentials in proteinoid microspheres, with or without added lecithin, is reported. The crucial nature of a nonrandom matrix for protocells is developed.

  13. Influence of type I IFN signaling on anti-MOG antibody-mediated demyelination.

    Science.gov (United States)

    Berg, Carsten Tue; Khorooshi, Reza; Asgari, Nasrin; Owens, Trevor

    2017-06-24

    Antibodies with specificity for myelin oligodendrocyte glycoprotein (MOG) are implicated in multiple sclerosis and related diseases. The pathogenic importance of anti-MOG antibody in primary demyelinating pathology remains poorly characterized. The objective of this study is to investigate whether administration of anti-MOG antibody would be sufficient for demyelination and to determine if type I interferon (IFN) signaling plays a similar role in anti-MOG antibody-mediated pathology, as has been shown for neuromyelitis optica-like pathology. Purified IgG2a monoclonal anti-MOG antibody and mouse complement were stereotactically injected into the corpus callosum of wild-type and type I IFN receptor deficient mice (IFNAR1-KO) with and without pre-established experimental autoimmune encephalomyelitis (EAE). Anti-MOG induced complement-dependent demyelination in the corpus callosum of wild-type mice and did not occur in mice that received control IgG2a. Deposition of activated complement coincided with demyelination, and this was significantly reduced in IFNAR1-KO mice. Co-injection of anti-MOG and complement at onset of symptoms of EAE induced similar levels of callosal demyelination in wild-type and IFNAR1-KO mice. Anti-MOG antibody and complement was sufficient to induce callosal demyelination, and pathology was dependent on type I IFN. Induction of EAE in IFNAR1-KO mice overcame the dependence on type I IFN for anti-MOG and complement-mediated demyelination.

  14. Epithelial Ovarian Cancer Experimental Models

    Science.gov (United States)

    Lengyel, E; Burdette, JE; Kenny, HA; Matei, D; Pilrose, J; Haluska, P.; Nephew, KP; Hales, DB; Stack, MS

    2014-01-01

    Epithelial ovarian cancer (OvCa) is associated with high mortality and, as the majority (>75%) of women with OvCa have metastatic disease at the time of diagnosis, rates of survival have not changed appreciably over 30 years. A mechanistic understanding of OvCa initiation and progression is hindered by the complexity of genetic and/or environmental initiating events and lack of clarity regarding the cell(s) or tissue(s) of origin. Metastasis of OvCa involves direct extension or exfoliation of cells and cellular aggregates into the peritoneal cavity, survival of matrix-detached cells in a complex ascites fluid phase, and subsequent adhesion to the mesothelium lining covering abdominal organs to establish secondary lesions containing host stromal and inflammatory components. Development of experimental models to recapitulate this unique mechanism of metastasis presents a remarkable scientific challenge and many approaches used to study other solid tumors (lung, colon, and breast, for example) are not transferable to OvCa research given the distinct metastasis pattern and unique tumor microenvironment. This review will discuss recent progress in the development and refinement of experimental models to study OvCa. Novel cellular, three-dimensional organotypic, and ex vivo models are considered and the current in vivo models summarized. The review critically evaluates currently available genetic mouse models of OvCa, the emergence of xenopatients, and the utility of the hen model to study OvCa prevention, tumorigenesis, metastasis, and chemoresistance. As these new approaches more accurately recapitulate the complex tumor microenvironment, it is predicted that new opportunities for enhanced understanding of disease progression, metastasis and therapeutic response will emerge. PMID:23934194

  15. Ethidium bromide-induced demyelination of the sciatic nerve of adult Wistar rats

    Directory of Open Access Journals (Sweden)

    Riet-Correa G.

    2002-01-01

    Full Text Available Peripheral nerve ultrastructure was assessed after single or multiple local injections of the intercalating dye ethidium bromide. Thirty-four adult Wistar rats of both sexes were divided into five groups and maintained in a controlled environment with rat chow and water ad libitum throughout the experiment. The experimental animals were injected with 1 µl of 0.1% ethidium bromide in 0.9% saline into the central third of the left sciatic nerve 1 (group 1, 2 (group 2, 4 (group 3, 6 (group 4 or 8 (group 5 times. In groups 2 to 5 the injections were made at 28-day intervals. Control animals received the same amount of 0.9% saline. The animals were killed at different times after injection: group 1 at 7 days (2 rats and 15 days (2 rats; for groups 2, 3, 4 and 5, all rats were killed 10 days after the last injection and the lesions were investigated by light and transmission electron microscopy. In the acute lesions, intoxicated Schwann cells showed a vacuolated cytoplasm and separation of the sheaths from the axon. Myelin sheaths underwent progressive vesiculation and subsequent segmental demyelination. Myelin debris were withdrawn by macrophages and remyelination by Schwann cells was prominent. With the increase in the number of injections collagen fibers also increased in number and progressively enveloped smaller numbers of remyelinated axons composing new fascicles. Wallerian degeneration of fibers apparently not affected by ethidium bromide was more intense in the nerves from groups 4 and 5. The peripheral nerve repairs itself after demyelinating challenges with a profusion of collagen fibers and new fasciculations. This experimental model is valid to mimic recurrent demyelinating neuropathies.

  16. Human antibodies against the myelin oligodendrocyte glycoprotein can cause complement-dependent demyelination.

    Science.gov (United States)

    Peschl, Patrick; Schanda, Kathrin; Zeka, Bleranda; Given, Katherine; Böhm, Denise; Ruprecht, Klemens; Saiz, Albert; Lutterotti, Andreas; Rostásy, Kevin; Höftberger, Romana; Berger, Thomas; Macklin, Wendy; Lassmann, Hans; Bradl, Monika; Bennett, Jeffrey L; Reindl, Markus

    2017-10-25

    Antibodies to the myelin oligodendrocyte glycoprotein (MOG) are associated with a subset of inflammatory demyelinating diseases of the central nervous system such as acute disseminated encephalomyelitis and neuromyelitis optica spectrum disorders. However, whether human MOG antibodies are pathogenic or an epiphenomenon is still not completely clear. Although MOG is highly conserved within mammals, previous findings showed that not all human MOG antibodies bind to rodent MOG. We therefore hypothesized that human MOG antibody-mediated pathology in animal models may only be evident using species-specific MOG antibodies. We screened 80 human MOG antibody-positive samples for their reactivity to mouse and rat MOG using either a live cell-based assay or immunohistochemistry on murine, rat, and human brain tissue. Selected samples reactive to either human MOG or rodent MOG were subsequently tested for their ability to induce complement-mediated damage in murine organotypic brain slices or enhance demyelination in an experimental autoimmune encephalitis (EAE) model in Lewis rats. The MOG monoclonal antibody 8-18-C5 was used as a positive control. Overall, we found that only a subset of human MOG antibodies are reactive to mouse (48/80, 60%) or rat (14/80, 18%) MOG. Purified serum antibodies from 10 human MOG antibody-positive patients (8/10 reactive to mouse MOG, 6/10 reactive to rat MOG), 3 human MOG-negative patients, and 3 healthy controls were tested on murine organotypic brain slices. Purified IgG from one patient with high titers of anti-human, mouse, and rat MOG antibodies and robust binding to myelin tissue produced significant, complement-mediated myelin loss in organotypic brain slices, but not in the EAE model. Monoclonal 8-18-C5 MOG antibody caused complement-mediated demyelination in both the organotypic brain slice model and in EAE. This study shows that a subset of human MOG antibodies can induce complement-dependent pathogenic effects in a murine ex vivo

  17. Vitamin D status and age of onset of demyelinating disease.

    Science.gov (United States)

    Brenton, J Nicholas; Koenig, Scott; Goldman, Myla D

    2014-11-01

    To evaluate the prevalence of and associated factors impacting vitamin D insufficiency and deficiency in childhood versus adult-onset demyelinating disease. We conducted a retrospective, cross-sectional, chart-review, cohort study on geographically-similar pediatric, young adult, and adult patients with a diagnosis of demyelinating disease identified at the University of Virginia from 2008 to 2013. Group prevalence of vitamin D insufficiency and deficiency as well as relevant factors associated with vitamin D status was analyzed and compared. We identified 24 childhood-onset (CO), 33 young adult-onset (Y-AO), and 59 adult-onset (AO) cases. There was no difference in the prevalence of vitamin D insufficiency or deficiency between the cohorts. Non-Caucasian race and elevated body mass index were significantly associated with low vitamin D levels, regardless of age of onset. In regression models, race and obesity were independent predictors of vitamin D status. The prevalence of obesity was significantly higher in the childhood-onset cohort (CO=58.5%; Y-AO=31%; AO=34%; p=0.02). Our findings demonstrate no difference in the prevalence of vitamin D insufficiency/deficiency between childhood and adult-onset demyelinating disease, suggesting age at disease onset is irrelevant to vitamin D status in demyelinating disease. Both race and obesity are independent factors associated with vitamin D insufficiency/deficiency, regardless of age of disease onset. Obesity, independent of gender, is significantly higher in children compared to adult patients diagnosed with multiple sclerosis and may have a role in the development of childhood-onset demyelinating disease. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Experimental animal models of osteonecrosis.

    Science.gov (United States)

    Fan, Meng; Peng, Jiang; Qin, Ling; Lu, Shibi

    2011-08-01

    Osteonecrosis (ON) or avascular necrosis (AVN) is a common bone metabolic disorder, mostly affecting femoral head. Although many biological, biophysical, and surgical methods have been tested to preserve the femoral head with ON, none has been proven fully satisfactory. It lacks consensus on an optimal approach for treatment. This is due, at least in part, to the lack of ability to systematically compare treatment efficacy using an ideal animal model that mimics full-range osteonecrosis of femoral head (ONFH) in humans with high incidence of joint collapse accompanied by reparative reaction adjacent to the necrotic bone in a reproducible and accessible way. A number of preclinical animal ON models have been established for testing potential efficacy of various modalities developed for prevention and treatment of ON before introduction into clinics for potential applications. This paper describes a number of different methods for creating animal experimental ON models. Advantages and disadvantages of such models are also discussed as reference for future research in battle against this important medical condition.

  19. Intravenous immunoglobulin for chronic inflammatory demyelinating polyradiculoneuropathy

    NARCIS (Netherlands)

    Eftimov, Filip; Winer, John B.; Vermeulen, Marinus; de Haan, Rob; van Schaik, Ivo N.

    2013-01-01

    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) causes progressive or relapsing weakness and numbness of the limbs, developing over at least two months. Uncontrolled studies suggest that intravenous immunoglobulin (IVIg) helps. This review was first published in 2002 and has since

  20. Intravenous immunoglobulin for chronic inflammatory demyelinating polyradiculoneuropathy

    NARCIS (Netherlands)

    Eftimov, Filip; Winer, John B.; Vermeulen, Marinus; de Haan, Rob; van Schaik, Ivo N.

    2009-01-01

    Background Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) causes progressive or relapsing weakness and numbness of the limbs, developing over at least two months. Uncontrolled studies suggest that intravenous immunoglobulin (IVIg) helps. Objectives To review systematically the

  1. The innate immune system in demyelinating disease.

    Science.gov (United States)

    Mayo, Lior; Quintana, Francisco J; Weiner, Howard L

    2012-07-01

    Demyelinating diseases such as multiple sclerosis are chronic inflammatory autoimmune diseases with a heterogeneous clinical presentation and course. Both the adaptive and the innate immune systems have been suggested to contribute to their pathogenesis and recovery. In this review, we discuss the role of the innate immune system in mediating demyelinating diseases. In particular, we provide an overview of the anti-inflammatory or pro-inflammatory functions of dendritic cells, mast cells, natural killer (NK) cells, NK-T cells, γδ T cells, microglial cells, and astrocytes. We emphasize the interaction of astroctyes with the immune system and how this interaction relates to the demyelinating pathologies. Given the pivotal role of the innate immune system, it is possible that targeting these cells may provide an effective therapeutic approach for demyelinating diseases. © 2012 John Wiley & Sons A/S.

  2. Acute inflammatory demyelinating polyradiculoneuropathy following varicella.

    OpenAIRE

    Murthy, J. M.

    1987-01-01

    Four cases of acute inflammatory demyelinating polyradiculoneuropathy following varicella are described. The role of immunosuppression as a contributing factor in triggering an autoimmune disease of the peripheral nervous system following viral infection is discussed.

  3. Ultrasound differentiation of axonal and demyelinating neuropathies.

    Science.gov (United States)

    Grimm, Alexander; Heiling, Bianka; Schumacher, Ulrike; Witte, Otto W; Axer, Hubertus

    2014-12-01

    Ultrasound can be used to visualize peripheral nerve abnormality. Our objective in this study was to prove whether nerve ultrasound can differentiate between axonal and demyelinating polyneuropathies (PNPs). Systematic ultrasound measurements of peripheral nerves were performed in 53 patients (25 with demyelinating, 20 with axonal, 8 with mixed neuropathy) and 8 healthy controls. Nerve conduction studies of corresponding nerves were undertaken. Analysis of variance revealed significant differences between the groups with regard to motor conduction velocity, compound muscle action potential amplitude, and cross-sectional area (CSA) of different nerves at different locations. Receiver operating characteristic curve analysis revealed CSA measurements to be well suited for detection of demyelinating neuropathies, and boundary values of peripheral nerve CSA could be defined. Systematic ultrasound CSA measurement in different nerves helped detect demyelination, which is an additional cue in the etiological diagnosis of PNP, along with nerve conduction studies and nerve biopsy. © 2014 Wiley Periodicals, Inc.

  4. The Innate Immune System in Demyelinating Disease

    OpenAIRE

    Mayo, Lior; Quintana, Francisco J.; Weiner, Howard L

    2012-01-01

    Demyelinating diseases such as multiple sclerosis are chronic inflammatory autoimmune diseases with a heterogeneous clinical presentation and course. Both the adaptive and the innate immune systems have been suggested to contribute to their pathogenesis and recovery. In this review, we discuss the role of the innate immune system in mediating demyelinating diseases. In particular, we provide an overview of the anti-inflammatory or pro-inflammatory functions of dendritic cells, mast cells, nat...

  5. The role of α4 integrin in Theiler's murine encephalomyelitis virus (TMEV)-induced demyelinating disease: an infectious animal model for multiple sclerosis (MS).

    Science.gov (United States)

    Hirano, Yuta; Kobayashi, Kunitoshi; Tomiki, Hiroki; Inaba, Yuhji; Ichikawa, Motoki; Kim, Byung S; Koh, Chang-Sung

    2016-12-01

    Natalizumab, which is an antibody against α4 integrin, has been used for the treatment of multiple sclerosis. In the present study, we investigated both the role of α4 integrin and the therapeutic effect of HCA3551, a newly synthesized orally active small molecule α4 integrin antagonist, in the development of Theiler's murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD). The mRNA levels of α4 integrins were significantly up-regulated in the central nervous system (CNS) of mice with TMEV-IDD as compared with naive mice (*P < 0.05). HCA3551 treatment in the effector phase significantly suppressed both the clinical and histological development of TMEV-IDD. The number of infiltrating mononuclear inflammatory cells in the CNS was significantly decreased in the mice treated with HCA3551 (**P < 0.01). The labeling indices for CD68 antigen and the absolute cell numbers of TNF-α-producing CD4(+) T cells and IFN-γ-producing CD8(+) T cells were significantly decreased in the CNS of mice treated with HCA3551 (*P < 0.05). HCA3551 treatment in the effector phase might inhibit the binding of α4 integrin to vascular cell adhesion molecule-1, thereby decreasing the number of mononuclear cells in the CNS. © The Japanese Society for Immunology. 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Modulation of Multiple Sclerosis and Its Animal Model Experimental Autoimmune Encephalomyelitis by Food and Gut Microbiota

    Directory of Open Access Journals (Sweden)

    Ward J. van den Hoogen

    2017-09-01

    Full Text Available Multiple sclerosis (MS is an autoimmune neurological disease characterized by chronic inflammation of the central nervous system (CNS, leading to demyelination, axonal damage, and symptoms such as fatigue and disability. Although the cause of MS is not known, the infiltration of peripherally activated immune cells into the CNS has a key pathogenic role. Accumulating evidence supports an important role of diet and gut microbiota in immune-mediated diseases. Preclinical as well as clinical studies suggest a role for gut microbiota and dietary components in MS. Here, we review these recent studies on gut microbiota and dietary interventions in MS and its animal model experimental autoimmune encephalomyelitis. We also propose directions for future research.

  7. Nogo receptor inhibition enhances functional recovery following lysolecithin-induced demyelination in mouse optic chiasm.

    Directory of Open Access Journals (Sweden)

    Fereshteh Pourabdolhossein

    Full Text Available Inhibitory factors have been implicated in the failure of remyelination in demyelinating diseases. Myelin associated inhibitors act through a common receptor called Nogo receptor (NgR that plays critical inhibitory roles in CNS plasticity. Here we investigated the effects of abrogating NgR inhibition in a non-immune model of focal demyelination in adult mouse optic chiasm.A focal area of demyelination was induced in adult mouse optic chiasm by microinjection of lysolecithin. To knock down NgR levels, siRNAs against NgR were intracerebroventricularly administered via a permanent cannula over 14 days, Functional changes were monitored by electrophysiological recording of latency of visual evoked potentials (VEPs. Histological analysis was carried out 3, 7 and 14 days post demyelination lesion. To assess the effect of NgR inhibition on precursor cell repopulation, BrdU was administered to the animals prior to the demyelination induction. Inhibition of NgR significantly restored VEPs responses following optic chiasm demyelination. These findings were confirmed histologically by myelin specific staining. siNgR application resulted in a smaller lesion size compared to control. NgR inhibition significantly increased the numbers of BrdU+/Olig2+ progenitor cells in the lesioned area and in the neurogenic zone of the third ventricle. These progenitor cells (Olig2+ or GFAP+ migrated away from this area as a function of time.Our results show that inhibition of NgR facilitate myelin repair in the demyelinated chiasm, with enhanced recruitment of proliferating cells to the lesion site. Thus, antagonizing NgR function could have therapeutic potential for demyelinating disorders such as Multiple Sclerosis.

  8. Interleukin-10 overexpression promotes Fas-ligand-dependent chronic macrophage-mediated demyelinating polyneuropathy.

    Directory of Open Access Journals (Sweden)

    Dru S Dace

    Full Text Available BACKGROUND: Demyelinating polyneuropathy is a debilitating, poorly understood disease that can exist in acute (Guillain-Barré syndrome or chronic forms. Interleukin-10 (IL-10, although traditionally considered an anti-inflammatory cytokine, has also been implicated in promoting abnormal angiogenesis in the eye and in the pathobiology of autoimmune diseases such as lupus and encephalomyelitis. PRINCIPAL FINDINGS: Overexpression of IL-10 in a transgenic mouse model leads to macrophage-mediated demyelinating polyneuropathy. IL-10 upregulates ICAM-1 within neural tissues, promoting massive macrophage influx, inflammation-induced demyelination, and subsequent loss of neural tissue resulting in muscle weakness and paralysis. The primary insult is to perineural myelin followed by secondary axonal loss. Infiltrating macrophages within the peripheral nerves demonstrate a highly pro-inflammatory signature. Macrophages are central players in the pathophysiology, as in vivo depletion of macrophages using clodronate liposomes reverses the phenotype, including progressive nerve loss and paralysis. Macrophage-mediate demyelination is dependent on Fas-ligand (FasL-mediated Schwann cell death. SIGNIFICANCE: These findings mimic the human disease chronic idiopathic demyelinating polyneuropathy (CIDP and may also promote further understanding of the pathobiology of related conditions such as acute idiopathic demyelinating polyneuropathy (AIDP or Guillain-Barré syndrome.

  9. Induction of progressive demyelinating autoimmune encephalomyelitis in common marmoset monkeys using MOG34-56 peptide in incomplete freund adjuvant.

    Science.gov (United States)

    Jagessar, S Anwar; Kap, Yolanda S; Heijmans, Nicole; van Driel, Nikki; van Straalen, Linda; Bajramovic, Jeffrey J; Brok, Herbert P M; Blezer, Erwin L A; Bauer, Jan; Laman, Jon D; 't Hart, Bert A

    2010-04-01

    Experimental autoimmune encephalomyelitis in the neotropical primate common marmoset (Callithrix jacchus) is a relevant autoimmune animal model of multiple sclerosis. T cells specific for peptide 34 to 56 of myelin/oligodendrocyte glycoprotein (MOG34-56) have a central pathogenic role in this model. The aim of this study was to assess the requirement for innate immune stimulation for activation of this core pathogenic autoimmune mechanism. Marmoset monkeys were sensitized against synthetic MOG34-56 peptide alone or in combination with the nonencephalitogenic peptide MOG74-96 formulated in incomplete Freund adjuvant, which lacks microbial components. Experimental autoimmune encephalomyelitis development was recorded by monitoring neurological signs, brain magnetic resonance imaging, and longitudinal profiling of cellular and humoral immune parameters. All monkeys developed autoimmune inflammatory/demyelinating central nervous system disease characterized by massive brain and spinal cord demyelinating white matter lesions with activated macrophages and CD3+ T cells. Immune profiling ex vivo demonstrated the activation of mainly CD3+CD4+/8+CD56+ T cells against MOG34-56. Upon ex vivo stimulation, these T cells produced more interleukin 17A compared with TH1 cytokines (e.g. interferon-gamma) and displayed peptide-specific cytolytic activity. These results indicate that the full spectrum of marmoset experimental autoimmune encephalomyelitis can be induced by sensitization against a single MOG peptide in incomplete Freund adjuvant lacking microbial compounds for innate immune activation and by eliciting antigen-specific T-cell cytolytic activity.

  10. The crucial role of Erk2 in demyelinating inflammation in the central nervous system.

    Science.gov (United States)

    Okazaki, Rentaro; Doi, Toru; Hayakawa, Kentaro; Morioka, Kazuhito; Imamura, Osamu; Takishima, Kunio; Hamanoue, Makoto; Sawada, Yasuhiro; Nagao, Motoshi; Tanaka, Sakae; Ogata, Toru

    2016-09-05

    Brain inflammation is a crucial component of demyelinating diseases such as multiple sclerosis. Although the initiation of inflammatory processes by the production of cytokines and chemokines by immune cells is well characterized, the processes of inflammatory aggravation of demyelinating diseases remain obscure. Here, we examined the contribution of Erk2, one of the isoforms of the extracellular signal-regulated kinase, to demyelinating inflammation. We used the cuprizone-induced demyelinating mouse model. To examine the role of Erk2, we used Nestin-cre-driven Erk2-deficient mice. We also established primary culture of microglia or astrocytes in order to reveal the crosstalk between two cell types and to determine the downstream cascades of Erk2 in astrocytes. First, we found that Erk is especially activated in astrocytes within the corpus callosum before the peak of demyelination (at 4 weeks after the start of cuprizone feeding). Then, we found that in our model, genetic ablation of Erk2 from neural cells markedly preserved myelin structure and motor function as measured by the rota-rod test. While the initial activation of microglia was not altered in Erk2-deficient mice, these mice showed reduced expression of inflammatory mediators at 3-4 model weeks. Furthermore, the subsequent inflammatory glial responses, characterized by accumulation of microglia and reactive astrocytes, were significantly attenuated in Erk2-deficient mice. These data indicate that Erk2 in astrocytes is involved in augmentation of inflammation and gliosis. We also found that activated, cultured microglia could induce Erk2 activation in cultured astrocytes and subsequent production of inflammatory mediators such as Ccl-2. Our results suggest that Erk2 activation in astrocytes plays a crucial role in aggravating demyelinating inflammation by inducing inflammatory mediators and gliosis. Thus, therapies targeting Erk2 function in glial cells may be a promising approach to the treatment of

  11. Demyelination versus remyelination in progressive multiple sclerosis

    DEFF Research Database (Denmark)

    Bramow, Stephan; Frischer, Josa M; Lassmann, Hans

    2010-01-01

    The causes of incomplete remyelination in progressive multiple sclerosis are unknown, as are the pathological correlates of the different clinical characteristics of patients with primary and secondary progressive disease. We analysed brains and spinal cords from 51 patients with progressive...... multiple sclerosis by planimetry. Thirteen patients with primary progressive disease were compared with 34 with secondary progressive disease. In patients with secondary progressive multiple sclerosis, we found larger brain plaques, more demyelination in total and higher brain loads of active demyelination...... compared with patients with primary progressive disease. In addition, the brain density of plaques with high-grade inflammation and active demyelination was highest in secondary progressive multiple sclerosis and remained ~18% higher than in primary progressive multiple sclerosis after adjustments...

  12. Chemokine-like receptor-1 expression by central nervous system-infiltrating leukocytes and involvement in a model of autoimmune demyelinating disease.

    Science.gov (United States)

    Graham, Kareem L; Zabel, Brian A; Loghavi, Sanam; Zuniga, Luis A; Ho, Peggy P; Sobel, Raymond A; Butcher, Eugene C

    2009-11-15

    We examined the involvement of chemokine-like receptor-1 (CMKLR1) in experimental autoimmune encephalomyelitis (EAE), a model of human multiple sclerosis. Upon EAE induction by active immunization with myelin oligodendrocyte glycoprotein amino acids 35-55 (MOG(35-55)), microglial cells and CNS-infiltrating myeloid dendritic cells expressed CMKLR1, as determined by flow cytometric analysis. In addition, chemerin, a natural ligand for CMKLR1, was up-regulated in the CNS of mice with EAE. We found that CMKLR1-deficient (CMKLR1 knockout (KO)) mice develop less severe clinical and histologic disease than their wild-type (WT) counterparts. CMKLR1 KO lymphocytes proliferate and produce proinflammatory cytokines in vitro, yet MOG(35-55)-reactive CMKLR1 KO lymphocytes are deficient in their ability to induce EAE by adoptive transfer to WT or CMKLR1 KO recipients. Moreover, CMKLR1 KO recipients fail to fully support EAE induction by transferred MOG-reactive WT lymphocytes. The results imply involvement of CMKLR1 in both the induction and effector phases of disease. We conclude that CMKLR1 participates in the inflammatory mechanisms of EAE and represents a potential therapeutic target in multiple sclerosis.

  13. New model systems for experimental evolution.

    Science.gov (United States)

    Collins, Sinéad

    2013-07-01

    Microbial experimental evolution uses a few well-characterized model systems to answer fundamental questions about how evolution works. This special section highlights novel model systems for experimental evolution, with a focus on marine model systems that can be used to understand evolutionary responses to global change in the oceans. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  14. Selective accumulation of pro-inflammatory T cells in the intestine contributes to the resistance to autoimmune demyelinating disease

    National Research Council Canada - National Science Library

    Berer, Kerstin; Boziki, Marina; Krishnamoorthy, Gurumoorthy

    2014-01-01

    ...), an animal model for Multiple sclerosis (MS). The factors, responsible for the generation and maintenance of TH17 cells as well as their participation in the pathogenic cascade leading to the demyelinating disease, have been studied extensively...

  15. Assessment of lesion pathology in a new animal model of MS by multiparametric MRI and DTI.

    Science.gov (United States)

    Boretius, Susann; Escher, Angelika; Dallenga, Tobias; Wrzos, Claudia; Tammer, Roland; Brück, Wolfgang; Nessler, Stefan; Frahm, Jens; Stadelmann, Christine

    2012-02-01

    Magnetic resonance imaging (MRI) is the gold standard for the detection of multiple sclerosis (MS) lesions. However, current MRI techniques provide little information about the structural features of a brain lesion with inflammatory cell infiltration, demyelination, gliosis, acute axonal damage and axonal loss. To identify methods for a differentiation of demyelination, inflammation, and axonal damage we developed a novel mouse model combining cuprizone-induced demyelination and experimental autoimmune encephalomyelitis. MS-like brain lesions were assessed by T1-weighted, T2-weighted, and magnetization transfer MRI as well as by diffusion tensor imaging (DTI). T2-weighted MRI differentiated control and diseased mice, while T1-weighted MRI better reflected the extent of inflammation and axonal damage. In DTI, axonal damage and cellular infiltration led to a reduction of the axial diffusivity, whereas primary demyelination after cuprizone treatment was reflected by changes in radial but not axial diffusivity. Importantly, alterations in radial diffusivity were less pronounced in mice with demyelination, inflammation, and acute axonal damage, indicating that radial diffusivity may underestimate demyelination in acute MS lesions. In conclusion, the combined information from different DTI parameters allows for a more precise identification of solely demyelinated lesions versus demyelinated and acutely inflamed lesions. These findings are of relevance for offering individualized, stage-adapted therapies for MS patients. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Analysis of the Host Transcriptome from Demyelinating Spinal Cord of Murine Coronavirus-Infected Mice

    Science.gov (United States)

    Elliott, Ruth; Li, Fan; Dragomir, Isabelle; Chua, Ming Ming W.; Gregory, Brian D.; Weiss, Susan R.

    2013-01-01

    Persistent infection of the mouse central nervous system (CNS) with mouse hepatitis virus (MHV) induces a demyelinating disease pathologically similar to multiple sclerosis and is therefore used as a model system. There is little information regarding the host factors that correlate with and contribute to MHV-induced demyelination. Here, we detail the genes and pathways associated with MHV-induced demyelinating disease in the spinal cord. High-throughput sequencing of the host transcriptome revealed that demyelination is accompanied by numerous transcriptional changes indicative of immune infiltration as well as changes in the cytokine milieu and lipid metabolism. We found evidence that a Th1-biased cytokine/chemokine response and eicosanoid-derived inflammation accompany persistent MHV infection and that antigen presentation is ongoing. Interestingly, increased expression of genes involved in lipid transport, processing, and catabolism, including some with known roles in neurodegenerative diseases, coincided with demyelination. Lastly, expression of several genes involved in osteoclast or bone-resident macrophage function, most notably TREM2 and DAP12, was upregulated in persistently infected mouse spinal cord. This study highlights the complexity of the host antiviral response, which accompany MHV-induced demyelination, and further supports previous findings that MHV-induced demyelination is immune-mediated. Interestingly, these data suggest a parallel between bone reabsorption by osteoclasts and myelin debris clearance by microglia in the bone and the CNS, respectively. To our knowledge, this is the first report of using an RNA-seq approach to study the host CNS response to persistent viral infection. PMID:24058676

  17. Developing Phenomena Models from Experimental Data

    DEFF Research Database (Denmark)

    Kristensen, Niels Rode; Madsen, Henrik; Jørgensen, Sten Bay

    2003-01-01

    unknown functionality behind various phenomena in first engineering principles models using experimental data. The proposed modelling approach has significant application potential, e.g. for determining unknown reaction kinetics in both chemical and biological processes. To illustrate the performance......A systematic approach for developing phenomena models from experimental data is presented. The approach is based on integrated application of stochastic differential equation (SDE) modelling and multivariate nonparametric regression, and it is shown how these techniques can be used to uncover...... of the approach, a case study is presented, which shows how an appropriate phenomena model for the growth rate of biomass in a fed-batch bioreactor can be inferred from data....

  18. Developing Phenomena Models from Experimental Data

    DEFF Research Database (Denmark)

    unknown functionality behind various phenomena in first engineering principles models using experimental data. The proposed modelling approach has significant application potential, e.g. for determining unknown reaction kinetics in both chemical and biological processes. To illustrate the performance......A systematic approach for developing phenomena models from experimental data is presented. The approach is based on integrated application of stochastic differential equation (SDE) modelling and multivariate nonparametric regression, and it is shown how these techniques can be used to uncover...... of the approach, a case study is presented, which shows how an appropriate phenomena model for the growth rate of biomass in a fed-batch bioreactor can be inferred from data....

  19. The Oligodendrocyte Progenitor Response to Demyelination

    Science.gov (United States)

    2006-01-01

    Neuropathol Exp Neurol 65:245-256. Arnett HA, Fancy SP, Alberta JA, Zhao C, Plant SR, Kaing S, Raine CS, Rowitch DH, Franklin RJ, Stiles CD (2004...multiple sclerosis (MS) and control cases. Chapter 3 – Figure 1 – Detection of hPDGF-A trangene in cuprizone demyelinated corpus callosum. 109 Chapter

  20. Acquired Demyelinating Syndromes and Pediatric Multiple Sclerosis

    NARCIS (Netherlands)

    I.A. Ketelslegers (Immy)

    2014-01-01

    markdownabstract__Abstract__ Acquired inflammatory demyelinating diseases of the central nervous system (CNS) cause damage to myelin sheaths and typically result in white matter lesions due to inflammation, myelin loss and axonal pathology. Clinically, this may result in transient, relapsing or

  1. Demyelinating polyneuropathy in Leber hereditary optic neuropathy.

    NARCIS (Netherlands)

    Gilhuis, H.J.; Schelhaas, H.J.; Cruysberg, J.R.M.; Zwarts, M.J.

    2006-01-01

    We report a patient with Leber hereditary optic neuropathy (G11778A mtDNA) and a severe demyelinating neuropathy, for which no other cause except his mitochondrial disorder could be found. The involvement of the peripheral nervous system of patients with LHON, in particular with a 11778 mtDNA, is

  2. Model refinement for offshore platforms: Experimental study

    Science.gov (United States)

    Zhang, Min; Chen, Zongli; Wu, Yanjian

    2017-08-01

    Offshore jacket platforms are widely used in offshore oil and gas exploitation. Finite element models of such structures need to have many degrees of freedom (DOFs) to represent the geometrical detail of complex structures, thereby leading to incompatibility in the number of DOFs of experimental models. To bring them both to the same order while ensuring that the essential eigen- properties of the refined model match those of experimental models, an extended model refinement procedure is presented in this paper. Vibration testing of an offshore jacket platform model is performed to validate the applicability of the proposed approach. A full-order finite element model of the platform is established and then tuned to meet the measured modal properties identified from the acceleration signals. Both model reduction and modal expansion methods are investigated, as well as various scenarios of sensor arrangements. Upon completion of the refinement, the updated jacket platform model matches the natural frequencies of the measured model well.

  3. Paediatric UK demyelinating disease longitudinal study (PUDDLS

    Directory of Open Access Journals (Sweden)

    Likeman Marcus

    2011-07-01

    Full Text Available Abstract Background There is evidence that at least 5% of Multiple sclerosis (MS cases manifest in childhood. Children with MS present with a demyelinating episode involving single or multiple symptoms prior to developing a second event (usually within two years to then meet criteria for diagnosis. There is evidence from adult cohorts that the incidence and sex ratios of MS are changing and that children of immigrants have a higher risk for developing MS. A paediatric population should reflect the vanguard of such changes and may reflect trends yet to be observed in adult cohorts. Studying a paediatric population from the first demyelinating event will allow us to test these hypotheses, and may offer further valuable insights into the genetic and environmental interactions in the pathogenesis of MS. Methods/Design The Paediatric UK Demyelinating Disease Longitudinal Study (PUDDLS is a prospective longitudinal observational study which aims to determine the natural history, predictors and outcomes of childhood CNS inflammatory demyelinating diseases. PUDDLS will involve centres in the UK, and will establish a cohort of children affected with a first CNS inflammatory demyelinating event for long-term follow up by recruiting for approximately 5 years. PUDDLS will also establish a biological sample archive (CSF, serum, and DNA, allowing future hypothesis driven research. For example, the future discovery of a biomarker will allow validation within this dataset for the evaluation of novel biomarkers. Patients will also be requested to consent to be contacted in the future. A secondary aim is to collaborate internationally with the International Paediatric Multiple Sclerosis Study Group when future collaborative studies are proposed, whilst sharing a minimal anonymised dataset. PUDDLS is the second of two jointly funded studies. The first (UCID-SS is an epidemiological surveillance study that already received ethical approvals, and started on the 1st

  4. Paediatric UK demyelinating disease longitudinal study (PUDDLS).

    Science.gov (United States)

    Absoud, Michael; Cummins, Carole; Chong, Wui K; De Goede, Christian; Foster, Katharine; Gunny, Roxanna; Hemingway, Cheryl; Jardine, Philip; Kneen, Rachel; Likeman, Marcus; Lim, Ming J; Pike, Mike; Sibtain, Naomi; Whitehouse, William P; Wassmer, Evangeline

    2011-07-28

    There is evidence that at least 5% of Multiple sclerosis (MS) cases manifest in childhood. Children with MS present with a demyelinating episode involving single or multiple symptoms prior to developing a second event (usually within two years) to then meet criteria for diagnosis. There is evidence from adult cohorts that the incidence and sex ratios of MS are changing and that children of immigrants have a higher risk for developing MS. A paediatric population should reflect the vanguard of such changes and may reflect trends yet to be observed in adult cohorts. Studying a paediatric population from the first demyelinating event will allow us to test these hypotheses, and may offer further valuable insights into the genetic and environmental interactions in the pathogenesis of MS. The Paediatric UK Demyelinating Disease Longitudinal Study (PUDDLS) is a prospective longitudinal observational study which aims to determine the natural history, predictors and outcomes of childhood CNS inflammatory demyelinating diseases. PUDDLS will involve centres in the UK, and will establish a cohort of children affected with a first CNS inflammatory demyelinating event for long-term follow up by recruiting for approximately 5 years. PUDDLS will also establish a biological sample archive (CSF, serum, and DNA), allowing future hypothesis driven research. For example, the future discovery of a biomarker will allow validation within this dataset for the evaluation of novel biomarkers. Patients will also be requested to consent to be contacted in the future. A secondary aim is to collaborate internationally with the International Paediatric Multiple Sclerosis Study Group when future collaborative studies are proposed, whilst sharing a minimal anonymised dataset. PUDDLS is the second of two jointly funded studies. The first (UCID-SS) is an epidemiological surveillance study that already received ethical approvals, and started on the 1st September 2009. There is no direct patient

  5. CONGESTIVE HEART FAILURE: EXPERIMENTAL MODEL

    Directory of Open Access Journals (Sweden)

    Antonio Francesco Corno

    2013-10-01

    Full Text Available INTRODUCTION.Surgically induced, combined volume and pressure overload has been used in rabbits to create a simplified and reproducible model of acute left ventricular (LV failure.MATERIALS AND METHODS.New Zealand white male rabbits (n=24, mean weight 3.1±0.2kg were randomly assigned to either the Control group (n=10 or to the Heart Failure group (HF, n=14. Animals in the Control group underwent sham procedures. Animals in the HF group underwent procedures to induce LV volume overload by inducing severe aortic valve regurgitation with aortic cusp disruption and pressure overload using an occlusive silver clip positioned around the pre-renal abdominal aorta.RESULTS.Following Procedure-1 (volume overload echocardiography confirmed severe aortic regurgitation in all animals in the HF group, with increased mean pulse pressure difference from 18±3mmHg to 38±3mmHg (P

  6. Minocycline reduces remyelination by suppressing ciliary neurotrophic factor expression after cuprizone-induced demyelination.

    Science.gov (United States)

    Tanaka, Tatsuhide; Murakami, Koichi; Bando, Yoshio; Yoshida, Shigetaka

    2013-10-01

    Remyelination is disrupted in demyelinating diseases such as multiple sclerosis, but the underlying pathogenetic mechanisms are unclear. In this study, we employed the murine cuprizone model of demyelination, in which remyelination occurs after removal of the toxin from the diet, to examine the cellular and molecular changes during demyelination and remyelination. Microglia accumulated in the corpus callosum during weeks 2-4 of the cuprizone diet, and these cells remained activated 2 weeks after the change to the normal diet. To examine the role of microglia in remyelination, mice were treated with minocycline to inactivate these cells after cuprizone-induced demyelination. Minocycline treatment reduced the number of CC1-positive oligodendrocytes, as well as levels of myelin basic protein (MBP) and CNPase in the remyelination phase. The expression of CNTF mRNA in the corpus callosum increased after 4 weeks on the cuprizone diet and remained high 2 weeks after the change to the normal diet. Minocycline suppressed CNTF expression during the remyelination phase on the normal diet. Primary culture experiments showed that CNTF was produced by microglia in addition to astrocytes. In vitro, CNTF directly affected the differentiation of oligodendrocytic cells. These findings suggest that minocycline reduces remyelination by suppressing CNTF expression by microglia after cuprizone-induced demyelination. © 2013 International Society for Neurochemistry.

  7. Improving the physiological realism of experimental models.

    Science.gov (United States)

    Vinnakota, Kalyan C; Cha, Chae Y; Rorsman, Patrik; Balaban, Robert S; La Gerche, Andre; Wade-Martins, Richard; Beard, Daniel A; Jeneson, Jeroen A L

    2016-04-06

    The Virtual Physiological Human (VPH) project aims to develop integrative, explanatory and predictive computational models (C-Models) as numerical investigational tools to study disease, identify and design effective therapies and provide an in silico platform for drug screening. Ultimately, these models rely on the analysis and integration of experimental data. As such, the success of VPH depends on the availability of physiologically realistic experimental models (E-Models) of human organ function that can be parametrized to test the numerical models. Here, the current state of suitable E-models, ranging from in vitro non-human cell organelles to in vivo human organ systems, is discussed. Specifically, challenges and recent progress in improving the physiological realism of E-models that may benefit the VPH project are highlighted and discussed using examples from the field of research on cardiovascular disease, musculoskeletal disorders, diabetes and Parkinson's disease.

  8. Lineage-Specific Metabolic Properties and Vulnerabilities of T Cells in the Demyelinating Central Nervous System.

    Science.gov (United States)

    Seki, Scott M; Stevenson, Max; Rosen, Abagail M; Arandjelovic, Sanja; Gemta, Lelisa; Bullock, Timothy N J; Gaultier, Alban

    2017-06-15

    Multiple sclerosis (MS) is a disease that is characterized by immune-mediated destruction of CNS myelin. Current MS therapies aim to block peripheral immune cells from entering the CNS. Although these treatments limit new inflammatory activity in the CNS, no treatment effectively prevents long-term disease progression and disability accumulation in MS patients. One explanation for this paradox is that current therapies are ineffective at targeting immune responses already present in the CNS. To this end, we sought to understand the metabolic properties of T cells that mediate ongoing inflammation in the demyelinating CNS. Using experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice, a well-studied model of MS, we showed that the CD4(+) and CD8(+) T cells that invade the EAE CNS are highly glycolytic. Elevated glycolytic rates in T cells isolated from the EAE CNS correlate with upregulated expression of glycolytic machinery and is essential for inflammatory responses to myelin. Surprisingly, we found that an inhibitor of GAPDH, 3-bromopyruvic acid (3-BrPa), blocks IFN-γ, but not IL-17A, production in immune cells isolated from the EAE CNS. Indeed, in vitro studies confirmed that the production of IFN-γ by differentiated Th1 cells is more sensitive to 3-BrPa than is the production of IL-17A by Th17 cells. Finally, in transfer models of EAE, 3-BrPa robustly attenuates the encephalitogenic potential of EAE-driving immune cells. To our knowledge, these data are among the first to demonstrate the metabolic properties of T cells in the demyelinating CNS in vivo. Copyright © 2017 by The American Association of Immunologists, Inc.

  9. Understanding Leadership: An Experimental-Experiential Model

    Science.gov (United States)

    Hole, George T.

    2014-01-01

    Books about leadership are dangerous to readers who fantasize about being leaders or apply leadership ideas as if they were proven formulas. As an antidote, I offer an experimental framework in which any leadership-management model can be tested to gain experiential understanding of the model. As a result one can gain reality-based insights about…

  10. Therapeutic Approach to the Management of Pediatric Demyelinating Disease: Multiple Sclerosis and Acute Disseminated Encephalomyelitis.

    Science.gov (United States)

    Brenton, J Nicholas; Banwell, Brenda L

    2016-01-01

    Acquired pediatric demyelinating diseases manifest acutely with optic neuritis, transverse myelitis, acute disseminated encephalomyelitis, or with various other acute deficits in focal or polyfocal areas of the central nervous system. Patients may experience a monophasic illness (as in the case of acute disseminated encephalomyelitis) or one that may manifest as a chronic, relapsing disease [e.g., multiple sclerosis (MS)]. The diagnosis of pediatric MS and other demyelinating disorders of childhood has been facilitated by consensus statements regarding diagnostic definitions. Treatment of pediatric MS has been modeled after data obtained from clinical trials in adult-onset MS. There are now an increasing number of new therapeutic agents for MS, and many will be formally studied for use in pediatric patients. There are important efficacy and safety concerns regarding the use of these therapies in children and young adults. This review will discuss acute management as well as chronic immunotherapies in acquired pediatric demyelination.

  11. Challenges in pediatric chronic inflammatory demyelinating polyneuropathy.

    Science.gov (United States)

    Haliloğlu, Göknur; Yüksel, Deniz; Temoçin, Cağri Mesut; Topaloğlu, Haluk

    2016-12-01

    Chronic inflammatory demyelinating neuropathy, a treatable immune-mediated disease of the peripheral nervous system is less common in childhood compared to adults. Despite different sets of diagnostic criteria, lack of a reliable biologic marker leads to challenges in diagnosis, follow-up and treatment. Our first aim was to review clinical presentation, course, response to treatment, and prognosis in our childhood patients. We also aimed to document diagnostic and therapeutic pitfalls and challenges at the bedside. Our original cohort consisted of 23 pediatric patients who were referred to us with a clinical diagnosis of chronic inflammatory demyelinating neuropathy. Seven patients reaching to an alternative diagnosis were excluded. In the remaining patients, diagnostic, treatment and follow-up data were compared in typical patients who satisfied both clinical and electrodiagnostic criteria and atypical patients who failed to meet minimal research chronic inflammatory demyelinating neuropathy electrodiagnostic requirements. Eight of 16 patients (50%) met the minimal chronic inflammatory demyelinating neuropathy research diagnostic requirements. There was only a statistically significant difference (p = 0.010) in terms of European Neuromuscular Centre childhood chronic inflammatory diagnostic mandatory clinical criteria between the two groups. Misdiagnosis due to errors in electrophysiological interpretation (100%, n = 8), cerebrospinal fluid cytoalbuminologic dissociation (100%, n = 4 and/or subjective improvement on any immunotherapy modality (80 ± 19.27%)) was frequent. Pediatric CIDP is challenging in terms of diagnostic and therapeutic pitfalls at the bedside. Diagnostic errors due to electrophysiological interpretation, cerebrospinal fluid cytoalbuminologic dissociation, and/or subjective improvement on immunotherapy should be considered. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Ultrasound of Inherited vs. Acquired Demyelinating Polyneuropathies

    Science.gov (United States)

    Zaidman, Craig M.; Harms, Matthew B.; Pestronk, Alan

    2013-01-01

    Introduction We compared features of nerve enlargement in inherited and acquired demyelinating neuropathies using ultrasound. Methods We measured median and ulnar nerve cross-sectional areas in proximal and distal regions in 128 children and adults with inherited (Charcot-Marie Tooth-1 (CMT-1) (n=35)) and acquired (Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) (n=55), Guillaine-Barre Syndrome (GBS) (n=21) and Multifocal Motor Neuropathy (MMN) (n=17)) demyelinating neuropathies. We classified nerve enlargement by degree and number of regions affected. We defined patterns of nerve enlargement as: none- no enlargement; mild-nerves enlarged but never more than twice normal; regional- nerves normal at at least one region and enlarged more than twice normal at atleast one region; diffuse- nerves enlarged at all four regions with atleast one region more than twice normal size. Results Nerve enlargement was commonly diffuse (89%) and generally more than twice normal size in CMT-1, but not (pdemyelinating polyneuropathy suggests an acquired etiology. Early treatment in CIDP may impede nerve enlargement. PMID:24101129

  13. Modeling of Experimental Adsorption Isotherm Data

    Directory of Open Access Journals (Sweden)

    Xunjun Chen

    2015-01-01

    Full Text Available Adsorption is considered to be one of the most effective technologies widely used in global environmental protection areas. Modeling of experimental adsorption isotherm data is an essential way for predicting the mechanisms of adsorption, which will lead to an improvement in the area of adsorption science. In this paper, we employed three isotherm models, namely: Langmuir, Freundlich, and Dubinin-Radushkevich to correlate four sets of experimental adsorption isotherm data, which were obtained by batch tests in lab. The linearized and non-linearized isotherm models were compared and discussed. In order to determine the best fit isotherm model, the correlation coefficient (r2 and standard errors (S.E. for each parameter were used to evaluate the data. The modeling results showed that non-linear Langmuir model could fit the data better than others, with relatively higher r2 values and smaller S.E. The linear Langmuir model had the highest value of r2, however, the maximum adsorption capacities estimated from linear Langmuir model were deviated from the experimental data.

  14. Experimental Concepts for Testing Seismic Hazard Models

    Science.gov (United States)

    Marzocchi, W.; Jordan, T. H.

    2015-12-01

    Seismic hazard analysis is the primary interface through which useful information about earthquake rupture and wave propagation is delivered to society. To account for the randomness (aleatory variability) and limited knowledge (epistemic uncertainty) of these natural processes, seismologists must formulate and test hazard models using the concepts of probability. In this presentation, we will address the scientific objections that have been raised over the years against probabilistic seismic hazard analysis (PSHA). Owing to the paucity of observations, we must rely on expert opinion to quantify the epistemic uncertainties of PSHA models (e.g., in the weighting of individual models from logic-tree ensembles of plausible models). The main theoretical issue is a frequentist critique: subjectivity is immeasurable; ergo, PSHA models cannot be objectively tested against data; ergo, they are fundamentally unscientific. We have argued (PNAS, 111, 11973-11978) that the Bayesian subjectivity required for casting epistemic uncertainties can be bridged with the frequentist objectivity needed for pure significance testing through "experimental concepts." An experimental concept specifies collections of data, observed and not yet observed, that are judged to be exchangeable (i.e., with a joint distribution independent of the data ordering) when conditioned on a set of explanatory variables. We illustrate, through concrete examples, experimental concepts useful in the testing of PSHA models for ontological errors in the presence of aleatory variability and epistemic uncertainty. In particular, we describe experimental concepts that lead to exchangeable binary sequences that are statistically independent but not identically distributed, showing how the Bayesian concept of exchangeability generalizes the frequentist concept of experimental repeatability. We also address the issue of testing PSHA models using spatially correlated data.

  15. Masquerades of acquired demyelination in children: experiences of a national demyelinating disease program.

    Science.gov (United States)

    O'Mahony, Julia; Bar-Or, Amit; Arnold, Douglas L; Sadovnick, A Dessa; Marrie, Ruth Ann; Banwell, Brenda

    2013-02-01

    The diagnosis of acquired demyelinating syndromes of the central nervous system in children requires exclusion of other acute central nervous system disorders. In a 23-site national demyelinating disease study, standardized clinical, laboratory, and magnetic resonance imaging (MRI) data were obtained prospectively from onset, and serially at 3, 6, and 12 months and annually. Twenty of 332 (6%) participants (mean [SD] age, 10.21 [4.32] years; 12 (60%) female) were ultimately diagnosed with vascular disorders (primary or secondary central nervous system vasculitis, vasculopathy, stroke, or migraine, n = 11 children), central nervous system malignancy (n = 3), mitochondrial disease (n = 2), or central nervous system symptoms in the accompaniment of confirmed infection (n = 4). Red flags that may serve to distinguish disorders in the differential of acquired demyelination are described.

  16. Pain and spinal cord imaging measures in children with demyelinating disease.

    Science.gov (United States)

    Barakat, Nadia; Gorman, Mark P; Benson, Leslie; Becerra, Lino; Borsook, David

    2015-01-01

    Pain is a significant problem in diseases affecting the spinal cord, including demyelinating disease. To date, studies have examined the reliability of clinical measures for assessing and classifying the severity of spinal cord injury (SCI) and also to evaluate SCI-related pain. Most of this research has focused on adult populations and patients with traumatic injuries. Little research exists regarding pediatric spinal cord demyelinating disease. One reason for this is the lack of reliable and useful approaches to measuring spinal cord changes since currently used diagnostic imaging has limited specificity for quantitative measures of demyelination. No single imaging technique demonstrates sufficiently high sensitivity or specificity to myelin, and strong correlation with clinical measures. However, recent advances in diffusion tensor imaging (DTI) and magnetization transfer imaging (MTI) measures are considered promising in providing increasingly useful and specific information on spinal cord damage. Findings from these quantitative imaging modalities correlate with the extent of demyelination and remyelination. These techniques may be of potential use for defining the evolution of the disease state, how it may affect specific spinal cord pathways, and contribute to the management of pediatric demyelination syndromes. Since pain is a major presenting symptom in patients with transverse myelitis, the disease is an ideal model to evaluate imaging methods to define these regional changes within the spinal cord. In this review we summarize (1) pediatric demyelinating conditions affecting the spinal cord; (2) their distinguishing features; and (3) current diagnostic and classification methods with particular focus on pain pathways. We also focus on concepts that are essential in developing strategies for the detection, monitoring, treatment and repair of pediatric myelitis.

  17. Pain and spinal cord imaging measures in children with demyelinating disease

    Directory of Open Access Journals (Sweden)

    Nadia Barakat

    2015-01-01

    Full Text Available Pain is a significant problem in diseases affecting the spinal cord, including demyelinating disease. To date, studies have examined the reliability of clinical measures for assessing and classifying the severity of spinal cord injury (SCI and also to evaluate SCI-related pain. Most of this research has focused on adult populations and patients with traumatic injuries. Little research exists regarding pediatric spinal cord demyelinating disease. One reason for this is the lack of reliable and useful approaches to measuring spinal cord changes since currently used diagnostic imaging has limited specificity for quantitative measures of demyelination. No single imaging technique demonstrates sufficiently high sensitivity or specificity to myelin, and strong correlation with clinical measures. However, recent advances in diffusion tensor imaging (DTI and magnetization transfer imaging (MTI measures are considered promising in providing increasingly useful and specific information on spinal cord damage. Findings from these quantitative imaging modalities correlate with the extent of demyelination and remyelination. These techniques may be of potential use for defining the evolution of the disease state, how it may affect specific spinal cord pathways, and contribute to the management of pediatric demyelination syndromes. Since pain is a major presenting symptom in patients with transverse myelitis, the disease is an ideal model to evaluate imaging methods to define these regional changes within the spinal cord. In this review we summarize (1 pediatric demyelinating conditions affecting the spinal cord; (2 their distinguishing features; and (3 current diagnostic and classification methods with particular focus on pain pathways. We also focus on concepts that are essential in developing strategies for the detection, monitoring, treatment and repair of pediatric myelitis.

  18. Transcriptomic meta-analysis of multiple sclerosis and its experimental models.

    Directory of Open Access Journals (Sweden)

    Barbara B R Raddatz

    Full Text Available BACKGROUND: Multiple microarray analyses of multiple sclerosis (MS and its experimental models have been published in the last years. OBJECTIVE: Meta-analyses integrate the information from multiple studies and are suggested to be a powerful approach in detecting highly relevant and commonly affected pathways. DATA SOURCES: ArrayExpress, Gene Expression Omnibus and PubMed databases were screened for microarray gene expression profiling studies of MS and its experimental animal models. STUDY ELIGIBILITY CRITERIA: Studies comparing central nervous system (CNS samples of diseased versus healthy individuals with n >1 per group and publically available raw data were selected. MATERIAL AND METHODS: Included conditions for re-analysis of differentially expressed genes (DEGs were MS, myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis (EAE in rats, proteolipid protein-induced EAE in mice, Theiler's murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD, and a transgenic tumor necrosis factor-overexpressing mouse model (TNFtg. Since solely a single MS raw data set fulfilled the inclusion criteria, a merged list containing the DEGs from two MS-studies was additionally included. Cross-study analysis was performed employing list comparisons of DEGs and alternatively Gene Set Enrichment Analysis (GSEA. RESULTS: The intersection of DEGs in MS, EAE, TMEV-IDD, and TNFtg contained 12 genes related to macrophage functions. The intersection of EAE, TMEV-IDD and TNFtg comprised 40 DEGs, functionally related to positive regulation of immune response. Over and above, GSEA identified substantially more differentially regulated pathways including coagulation and JAK/STAT-signaling. CONCLUSION: A meta-analysis based on a simple comparison of DEGs is over-conservative. In contrast, the more experimental GSEA approach identified both, a priori anticipated as well as promising new candidate pathways.

  19. Experimental deep brain stimulation in animal models.

    Science.gov (United States)

    Tan, Sonny Kh; Vlamings, Rinske; Lim, Leewei; Sesia, Thibault; Janssen, Marcus Lf; Steinbusch, Harry Wm; Visser-Vandewalle, Veerle; Temel, Yasin

    2010-10-01

    DEEP BRAIN STIMULATION (DBS) as a therapy in neurological and psychiatric disorders is widely applied in the field of functional and stereotactic neurosurgery. In this respect, experimental DBS in animal models is performed to evaluate new indications and new technology. In this article, we review our experience with the concept of experimental DBS, including its development and validation. An electrode construction was developed using clinical principles to perform DBS unilaterally or bilaterally in freely moving rats. The stimulation parameters were adjusted for the rat using current density calculations. We performed validation studies in 2 animal models: a rat model of Parkinson's disease (bilateral 6-hydroxydopamine infusion in the striatum) and a rat model of Huntington's disease (transgenic rats). The effects of DBS were evaluated in different behavioral tasks measuring motor and cognitive functions. The electrode construction developed allows experimental DBS to be performed in freely moving rats. With the current setup, electrodes are placed in the target in 70% to 95% of the cases. Using a rat model, we showed that bilateral DBS of the subthalamic nucleus improves parkinsonian motor disability, but can induce behavioral side effects, similar to the clinical situation. In addition, we showed that DBS of the globus pallidus can improve motor and cognitive symptoms in a rat model of Huntington's disease. Nevertheless, during the process of the development and validation of experimental DBS, we encountered specific problems. These are discussed in detail. Experimental DBS in freely moving animals is an adequate tool to explore new indications for DBS and to refine DBS technology.

  20. Protecting axonal degeneration by increasing nicotinamide adenine dinucleotide levels in experimental autoimmune encephalomyelitis models.

    Science.gov (United States)

    Kaneko, Shinjiro; Wang, Jing; Kaneko, Marie; Yiu, Glenn; Hurrell, Joanna M; Chitnis, Tanuja; Khoury, Samia J; He, Zhigang

    2006-09-20

    Axonal damage is a major morphological alteration in the CNS of patients with multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). However, the underlying mechanism for the axonal damage associated with MS/EAE and its contribution to the clinical symptoms remain unclear. The expression of a fusion protein, named "Wallerian degeneration slow" (Wld(S)), can protect axons from degeneration, likely through a beta-nicotinamide adenine dinucleotide (NAD)-dependent mechanism. In this study, we find that, when induced with EAE, Wld(S) mice showed a modest attenuation of behavioral deficits and axon loss, suggesting that EAE-associated axon damage may occur by a mechanism similar to Wallerian degeneration. Furthermore, nicotinamide (NAm), an NAD biosynthesis precursor, profoundly prevents the degeneration of demyelinated axons and improves the behavioral deficits in EAE models. Finally, we demonstrate that delayed NAm treatment is also beneficial to EAE models, pointing to the therapeutic potential of NAm as a protective agent for EAE and perhaps MS patients.

  1. Prospects of experimentally reachable beyond Standard Model ...

    Indian Academy of Sciences (India)

    2016-01-06

    Jan 6, 2016 ... Home; Journals; Pramana – Journal of Physics; Volume 86; Issue 2. Prospects of experimentally reachable beyond Standard Model physics in inverse see-saw motivated SO(10) GUT. Ram Lal Awasthi. Special: Supersymmetric Unified Theories and Higgs Physics Volume 86 Issue 2 February 2016 pp 223- ...

  2. Prospects of experimentally reachable beyond Standard Model ...

    Indian Academy of Sciences (India)

    2016-01-06

    Jan 6, 2016 ... also fit perfectly in the model framework. Despite the fact that SM has unravelled the gauge origin of fundamental forces and the structure of Universe while successfully confronting numerous experimental tests, it has various limitations. For a good summary on its excellencies and compulsions see [1], and.

  3. The innate immune response affects the development of the autoimmune response in Theiler's virus-induced demyelinating disease.

    Science.gov (United States)

    Olson, Julie K; Miller, Stephen D

    2009-05-01

    Multiple sclerosis (MS) is a human CNS autoimmune demyelinating disease. Epidemiological evidence has suggested a role for virus infection in the initiation and/or exacerbation of MS. Theiler's murine encephalomyelitis virus (TMEV)-induced demyelinating disease serves as a relevant mouse model for MS. TMEV-infected mice develop a demyelinating disease with clinical symptoms beginning around 35 days after infection, which is associated with development of myelin-specific, PLP(139-151), CD4(+) T cell responses. Viruses have been suggested to initiate autoimmune disease through bystander activation of immune cells or through bystander damage to tissue during infection. We examined the effect of the innate immune response on development of autoimmune demyelinating disease by altering the innate immune response through administration of innate immune cytokines, IFN-alpha or IFN-beta, or antiserum against the type I IFNs during the innate immune response to TMEV. Administration of IFN-beta, but not IFN-alpha, to TMEV- infected mice led to reduced myelin-specific CD4(+) T cell responses and reduced demyelinating disease, which was associated with decreased immune cell infiltration into the CNS and increased expression of IL-10 in the CNS. Conversely, administration of antiserum to IFN-beta led to a more severe demyelinating disease. In addition, administration of poly(I:C), which is an innate immune agonist, to TMEV-infected mice during the innate immune response resulted in decreased myelin-specific CD4(+) T cell responses and reduced demyelinating disease. These results demonstrate that activating or enhancing the innate immune response can reduce the subsequent initiation and progression of the autoimmune response and demyelinating disease.

  4. The innate immune response affects the development of the autoimmune response in Theiler’s virus- induced demyelinating disease

    Science.gov (United States)

    Olson, Julie K.; Miller, Stephen D.

    2010-01-01

    Multiple sclerosis (MS) is a human CNS autoimmune demyelinating disease. Epidemiological evidence has suggested a role for virus infection in the initiation and/or exacerbation of MS. Theiler’s murine encephalomyelitis virus (TMEV)- induced demyelinating disease serves as a relevant mouse model for MS. TMEV- infected mice develop a demyelinating disease with clinical symptoms beginning around 35 days post infection which is associated with development of myelin- specific, PLP139–151, CD4+ T cell responses. Viruses have been suggested to initiate autoimmune disease through bystander activation of immune cells or through bystander damage to tissue during infection. We examined the effect of the innate immune response on development of autoimmune demyelinating disease by altering the innate immune response through administration of innate immune cytokines, IFNα or IFNβ, or antiserum against the type I interferons during the innate immune response to TMEV. Administration of IFNβ, but not IFNα, to TMEV- infected mice led to reduced myelin-specific CD4+ T cell responses and reduced demyelinating disease which was associated with decreased immune cell infiltration into the CNS and increased expression of IL-10 in the CNS. Conversely, administration of antiserum to IFNβ led to a more severe demyelinating disease. In addition, administration of polyI:C, which is an innate immune agonist, to TMEV- infected mice during the innate immune response resulted in decreased myelin-specific CD4+ T cell responses and reduced demyelinating disease. These results demonstrate that activating or enhancing the innate immune response can reduce the subsequent initiation and progression of the autoimmune response and demyelinating disease. PMID:19380818

  5. Involvement of β-chemokines in the development of inflammatory demyelination

    Directory of Open Access Journals (Sweden)

    Leist Thomas P

    2005-02-01

    Full Text Available Abstract The importance of β-chemokines (or CC chemokine ligands – CCL in the development of inflammatory lesions in the central nervous system of patients with multiple sclerosis and rodents with experimental allergic encephalomyelitis is strongly supported by descriptive studies and experimental models. Our recent genetic scans in families identified haplotypes in the genes of CCL2, CCL3 and CCL11-CCL8-CCL13 which showed association with multiple sclerosis. Complementing the genetic associations, we also detected a distinct regional expression regulation for CCL2, CCL7 and CCL8 in correlation with chronic inflammation in multiple sclerosis brains. These observations are in consensus with previous studies, and add new data to support the involvement of CCL2, CCL7, CCL8 and CCL3 in the development of inflammatory demyelination. Along with our own data, here we review the literature implicating CCLs and their receptors (CCRs in multiple sclerosis and experimental allergic encephalomyelitis. The survey reflects that the field is in a rapid expansion, and highlights some of the pathways which might be suitable to pharmaceutical interventions.

  6. Olfactory Pathology in Central Nervous System Demyelinating Diseases.

    Science.gov (United States)

    DeLuca, Gabriele C; Joseph, Albert; George, Jithin; Yates, Richard L; Hamard, Marie; Hofer, Monika; Esiri, Margaret M

    2015-09-01

    Olfactory dysfunction is common in multiple sclerosis (MS). Olfactory bulb and tract pathology in MS and other demyelinating diseases remain unexplored. A human autopsy cohort of pathologically confirmed cases encompassing the spectrum of demyelinating disease (MS; n = 17), neuromyelitis optica [(NMO); n = 3] and acute disseminated encephalomyelitis [(ADEM); n = 7] was compared to neuroinflammatory [herpes simplex virus encephalitis (HSE); n = 3], neurodegenerative [Alzheimer's disease (AD); n = 4] and non-neurologic (n = 8) controls. For each case, olfactory bulbs and/or tracts were stained for myelin, axons and inflammation. Inferior frontal cortex and hippocampus were stained for myelin in a subset of MS and ADEM cases. Olfactory bulb/tract demyelination was frequent in all demyelinating diseases [MS 12/17 (70.6%); ADEM 3/7 (42.9%); NMO 2/3 (66.7%)] but was absent in HSE, AD and non-neurologic controls. Inflammation was greater in the demyelinating diseases compared to non-neurologic controls. Olfactory bulb/tract axonal loss was most severe in MS where it correlated significantly with the extent of demyelination (r = 0.610, P = 0.009) and parenchymal inflammation (r = 0.681, P = 0.003). The extent of olfactory bulb/tract demyelination correlated with that found in the adjacent inferior frontal cortex but not hippocampus. We provide unequivocal evidence that olfactory bulb/tract demyelination is frequent, can occur early and is highly inflammatory, and is specific to demyelinating disease. © 2014 International Society of Neuropathology.

  7. 'Wine Glass' sign in recurrent postpartum hypernatremic osmotic cerebral demyelination

    National Research Council Canada - National Science Library

    Saroja, Aralikatte O; Naik, Karkal R; Mali, Rajendra V; Kunam, Sanjeeva R

    2013-01-01

    Osmotic demyelination syndrome resulting from postpartum hypernatremia is a recently described entity wherein young women present with hypernatremic encephalopathy and white matter hyperintensities...

  8. Electrochemical desalination of bricks - Experimental and modeling

    DEFF Research Database (Denmark)

    Skibsted, Gry; Ottosen, Lisbeth M.; Jensen, Pernille Erland

    2015-01-01

    Chlorides, nitrates and sulfates play an important role in the salt-decay of porous materials in buildings and monuments. Electrochemical desalination is a technology able to remove salts from such porous materials in order to stop or prevent the decay. In this paper, experimental and numerical......-contaminated bricks with respect to the monovalent ions is discussed. Comparison between the experimental and the simulation results showed that the proposed numerical model is able to predict electrochemical desalination treatments with remarkable accuracy, and it can be used as a predictive tool...

  9. Helicobacter pylori infection reduces disease severity in an experimental model of multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Katherine eCook

    2015-02-01

    Full Text Available Recent research has demonstrated that infection with the bacterial pathogen Helicobacter pylori is less common amongst patients with multiple sclerosis (MS, an inflammatory demyelinating disease of the central nervous system (CNS. We compared the prevalence of H. pylori amongst MS patients and healthy controls, and also investigated the impact of this infection on an animal model for MS, experimental autoimmune encephalomyelitis (EAE.The H. pylori status of 71 MS patients and 42 healthy controls was determined by serology. Groups of C57BL/6 mice were infected with H. pylori, or given a placebo, prior to inducing EAE. Clinical scores were assessed for all mice, and spleens and spinal cord tissue were harvested. CD4+ T cell subsets were quantified by flow cytometry, and T cell proliferation assays were performed.In MS patients the seroprevalence of H. pylori was half that of healthy controls (p=0.018. Over three independent experiments, prior H. pylori infection had a moderate effect in reducing the severity of EAE (p = 0.012. In line with this, the antigen-specific T cell proliferative responses of infected animals were significantly reduced (p=0.001, and there was a 4-fold reduction in the number of CD4+ cells in the CNS. CD4+ populations in both the CNS and the spleens of infected mice also contained greatly reduced proportions of IFNγ+, IL-17+, T-bet+, and RORγt+ cells, but the proportions of Foxp3+ cells were equivalent. There were no differences in the frequency of splenic CD4+cells expressing markers of apoptosis between infected and uninfected animals.H. pylori was less prevalent amongst MS patients. In mice, the infection exerted some protection against EAE, inhibiting both Th1 and Th17 responses. This could not be explained by the presence of increased numbers of Foxp3+ regulatory T cells, or T cell apoptosis. This is the first direct experimental evidence showing that H. pylori may provide protection against inflammatory demyelination

  10. Traditional Chinese medicine Yisui Tongjing relieved neural severity in experimental autoimmune neuritis rat model.

    Science.gov (United States)

    Zhang, Erli; Li, Mingquan; Zhao, Jianjun; Dong, Yuxiang; Yang, Xueqin; Huang, Jingbo

    2016-01-01

    To study the effect of Yisui Tongjing (YSTJ) prescription on motor nerve conduction velocity (MNCV) and microstructure of the sciatic nerve in experimental autoimmune neuritis (EAN) rats, the Guillain-Barré syndrome classic animal models. In this study, we established an EAN model in Lewis rats by immunization. We evaluated the potential clinical application of a traditional Chinese medicine YSTJ by intragastric administration and compared its effect with immunoglobulin. The sciatic MNCV was measured by electrophysiology experiment. Hematoxylin-eosin staining and transmission electron microscope analysis were used to determine the pathologically morphological changes before and after YSTJ application. We found that application of YSTJ could significantly alleviate the clinical signs in EAN rats. The treatment also increased MNCV in the sciatic nerve compared to that in the untreated nerve. Demyelination in the sciatic nerve in EAN rats was significantly ameliorated, and newly generated myelinated nerve fibers were observed with treatment of high dose of YSTJ. This study showed that the traditional Chinese medicine YSTJ was likely to serve as a therapeutic medicine in autoimmune neuropathies, providing an effective and economic means to the treatment of Guillain-Barré syndrome.

  11. Live imaging of immune responses in experimental models of multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Gabriela Constantin

    2016-11-01

    Full Text Available Experimental autoimmune encephalomyelitis (EAE is the most common animal model of multiple sclerosis (MS, a chronic inflammatory autoimmune disease of the central nervous system (CNS characterized by multifocal perivascular infiltrates that predominantly comprise lymphocytes and macrophages. During EAE, autoreactive T cells first become active in the secondary lymphoid organs upon contact with antigen presenting cells (APCs, and then gain access to CNS parenchyma, through a compromised blood–brain barrier, subsequently inducing inflammation and demyelination. Two-photon laser scanning microscopy (TPLSM is an ideal tool for intravital imaging because of its low phototoxicity, deep tissue penetration and high resolution. In the last decade, TPLSM has been used to visualize the behavior of T cells and their contact with APCs in the lymph nodes and target tissues in several models of autoimmune diseases. The leptomeninges and cerebrospinal fluid represent particularly important points for T cell entry into the CNS and reactivation following contact with local APCs during the preclinical phase of EAE. In this review, we highlight recent findings concerning the pathogenesis of EAE and MS, emphasizing the use of TPLSM to characterize T cell activation in the lymph nodes and CNS, as well as the mechanisms of tolerance induction. Furthermore, we discuss how advanced imaging unveils disease mechanisms and helps to identify novel therapeutic strategies to treat CNS autoimmunity and inflammation.

  12. Live Imaging of Immune Responses in Experimental Models of Multiple Sclerosis.

    Science.gov (United States)

    Rossi, Barbara; Constantin, Gabriela

    2016-01-01

    Experimental autoimmune encephalomyelitis (EAE) is the most common animal model of multiple sclerosis (MS), a chronic inflammatory autoimmune disease of the central nervous system (CNS) characterized by multifocal perivascular infiltrates that predominantly comprise lymphocytes and macrophages. During EAE, autoreactive T cells first become active in the secondary lymphoid organs upon contact with antigen-presenting cells (APCs), and then gain access to CNS parenchyma, through a compromised blood-brain barrier, subsequently inducing inflammation and demyelination. Two-photon laser scanning microscopy (TPLSM) is an ideal tool for intravital imaging because of its low phototoxicity, deep tissue penetration, and high resolution. In the last decade, TPLSM has been used to visualize the behavior of T cells and their contact with APCs in the lymph nodes (LNs) and target tissues in several models of autoimmune diseases. The leptomeninges and cerebrospinal fluid represent particularly important points for T cell entry into the CNS and reactivation following contact with local APCs during the preclinical phase of EAE. In this review, we highlight recent findings concerning the pathogenesis of EAE and MS, emphasizing the use of TPLSM to characterize T cell activation in the LNs and CNS, as well as the mechanisms of tolerance induction. Furthermore, we discuss how advanced imaging unveils disease mechanisms and helps to identify novel therapeutic strategies to treat CNS autoimmunity and inflammation.

  13. The aqueous layers within the myelin sheath modulate the membrane properties of simulated hereditary demyelinating neuropathies.

    Science.gov (United States)

    Stephanova, D I; Krustev, S M; Daskalova, M

    2011-03-01

    To expand our studies on the mechanisms underlying the clinical decline of the nerve excitability properties in patients with hereditary demyelinating neuropathies, the contribution of myelin sheath aqueous layers on multiple membrane properties of simulated fiber demyelinations is investigated. Three progressively greater degrees of internodal systematic demyelinations (two mild and one severe termed as ISD1, ISD2 and ISD3, respectively) without/with aqueous layers are simulated using our previous multi-layered model of human motor nerve fiber. The calculated multiple membrane excitability properties are as follows: potentials (intracellular action, electrotonic), strength-duration time constants, rheobasic currents and recovery cycles. They reflect the propagating, accommodative and adaptive processes in the fibers. The results show that all membrane properties, except for the strength-duration time constants and refractoriness, worsen when the myelin lamellae and their corresponding aqueous layers are uniformly reduced along the fiber length. The effect of the aqueous layers is significantly higher on the accommodative and adaptive processes than on the propagating processes in the fibers. Our multi-layered model better approximated some of the functional deficits documented for axons of patients with Charcot-Marie-Tooth disease type 1A. The study provides new and important information on the mechanisms underlying the pathophysiology of hereditary demyelinating neuropathies. © Imperial College Press

  14. Rituximab use in pediatric central demyelinating disease.

    Science.gov (United States)

    Beres, Shannon J; Graves, Jennifer; Waubant, Emmanuelle

    2014-07-01

    Rituximab is a B-cell therapy used off-label to reduce relapses in adult demyelinating diseases. There is limited knowledge of its clinical use in pediatric neuromyelitis optica and multiple sclerosis. Demyelinating diseases in children can have high morbidity, and B-cell therapies hold promise for those with a severe course. Our study investigates the clinical experience of safety and efficacy with rituximab in children with demyelinating diseases of the central nervous system. This is a retrospective case series of 11 patients with pediatric neuromyelitis optica and multiple sclerosis who received at least one rituximab infusion at the Pediatric Multiple Sclerosis Clinic, University of California, San Francisco. Each patient was infused up to 1000 mg twice 2 weeks apart. Patients were monitored prospectively, and relapse events, laboratories, and adverse reactions were recorded. Eight children with neuromyelitis optica, two with relapsing-remitting multiple sclerosis and one with secondary-progressive multiple sclerosis received rituximab treatment. The median number of cycles was 3. Most patients (82%, n = 9) experienced reduction of relapses after initiating rituximab. There were no serious infections. Infusion reactions were reported in three patients and managed successfully in subsequent infusions with increased pretreatment (dexamethasone and diphenhydramine) and use of slower infusion rates. Rituximab was not discontinued in any child because of side effects; two switched treatment therapy after 4.5 and 11 months because of relapses. The use of rituximab in our pediatric neuromyelitis optica and multiple sclerosis cohort was overall safe and effective. Larger studies should confirm our observations. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Experimental Animal Models in Periodontology: A Review

    Science.gov (United States)

    Struillou, Xavier; Boutigny, Hervé; Soueidan, Assem; Layrolle, Pierre

    2010-01-01

    In periodontal research, animal studies are complementary to in vitro experiments prior to testing new treatments. Animal models should make possible the validation of hypotheses and prove the safety and efficacy of new regenerating approaches using biomaterials, growth factors or stem cells. A review of the literature was carried out by using electronic databases (PubMed, ISI Web of Science). Numerous animal models in different species such as rats, hamsters, rabbits, ferrets, canines and primates have been used for modeling human periodontal diseases and treatments. However, both the anatomy and physiopathology of animals are different from those of humans, making difficult the evaluation of new therapies. Experimental models have been developed in order to reproduce major periodontal diseases (gingivitis, periodontitis), their pathogenesis and to investigate new surgical techniques. The aim of this review is to define the most pertinent animal models for periodontal research depending on the hypothesis and expected results. PMID:20556202

  16. Early identification of 'acute-onset' chronic inflammatory demyelinating polyneuropathy.

    Science.gov (United States)

    Sung, Jia-Ying; Tani, Jowy; Park, Susanna B; Kiernan, Matthew C; Lin, Cindy Shin-Yi

    2014-08-01

    Distinguishing patients with acute-onset chronic inflammatory demyelinating polyneuropathy from acute inflammatory demyelinating polyneuropathy prior to relapse is often challenging at the onset of their clinical presentation. In the present study, nerve excitability tests were used in conjunction with the clinical phenotype and disease staging, to differentiate between patients with acute-onset chronic inflammatory demyelinating polyneuropathy and patients with acute inflammatory demyelinating polyneuropathy at an early stage, with the aim to better guide treatment. Clinical assessment, staging and nerve excitability tests were undertaken on patients initially fulfilling the diagnostic criteria of acute inflammatory demyelinating polyneuropathy soon after symptom onset and their initial presentation. Patients were subsequently followed up for minimum of 12 months to determine if their clinical presentations were more consistent with acute-onset chronic inflammatory demyelinating polyneuropathy. Clinical severity as evaluated by Medical Research Council sum score and Hughes functional grading scale were not significantly different between the two cohorts. There was no difference between the time of onset of initial symptoms and nerve excitability test assessment between the two cohorts nor were there significant differences in conventional nerve conduction study parameters. However, nerve excitability test profiles obtained from patients with acute inflammatory demyelinating polyneuropathy demonstrated abnormalities in the recovery cycle of excitability, including significantly reduced superexcitability (P demyelinating polyneuropathy, a different pattern occurred with the recovery cycle shifted downward (increased superexcitability, P demyelinating polyneuropathy and acute-onset chronic inflammatory demyelinating polyneuropathy could be clearly separated into two non-overlapping groups. Studies of nerve excitability may be able to differentiate acute from acute

  17. Cerebral demyelination in children with collagenous colitis

    Directory of Open Access Journals (Sweden)

    S Sankararaman

    2013-01-01

    Full Text Available Collagenous colitis (CC is a form of microscopic colitis characterized by the presence of inflammatory infiltrate and subepithelial deposition of collagen in the colon and it is a rare condition with a predominant prevalence in the adult population. Only few cases have been reported in children. We report two children with the CC with concomitant neurological manifestations. Both cases demonstrated variable neurological symptoms clinically and significant cerebral demyelination. In both patients, the gastrointestinal manifestations drastically improved with a short course of prednisolone. However, the neurological symptoms were persistent and progressive. To the best of our knowledge, similar association has not been reported in children.

  18. Experimental superficial candidiasis on tissue models.

    Science.gov (United States)

    Jayatilake, J A M S; Samaranayake, L P

    2010-07-01

    Candida species are common pathogens causing superficial mycoses primarily affecting the mucosa and the skin in humans. Crucial steps during pathogenesis of superficial candidiasis comprise fungal adhesion, colonisation and subsequent penetration of the respective tissues. Exploring these pathological events and perhaps fungal and tissue responses towards drug treatment is imperative in the management of this infection. Unfortunately, pathological biopsies of superficial candidiasis do not exhibit the early changes in the host-pathogen interaction as the tissues are already invaded by the fungi. In vivo experimental assessments of pathological processes of superficial candidiasis are also limited because of the difficulties in providing reproducible and comparable conditions in the host environment. Conversely, in vitro models have helped studying fungal-host interactions under more defined and controlled conditions. Some common in vitro models used to simulate superficial candidiasis are chick chorioallantoic membrane, mucosal explants and single layer or multiple layer cell cultures. Interestingly, these experimental approaches share advantages as well as disadvantages when compared with in vivo conditions. Hence, this review intends to discuss about the experimental superficial candidiasis produced in various tissue models and their advantages as well as disadvantages with a particular reference to further improvement of validity and reliability of such experiments.

  19. Seclazone Reactor Modeling And Experimental Validation

    Energy Technology Data Exchange (ETDEWEB)

    Osinga, T. [ETH-Zuerich (Switzerland); Olalde, G. [CNRS Odeillo (France); Steinfeld, A. [PSI and ETHZ (Switzerland)

    2005-03-01

    A numerical model is formulated for the SOLZINC solar chemical reactor for the production of Zn by carbothermal reduction of ZnO. The model involves solving, by the finite-volume technique, a 1D unsteady state energy equation that couples heat transfer to the chemical kinetics for a shrinking packed bed exposed to thermal radiation. Validation is accomplished by comparison with experimentally measured temperature profiles and Zn production rates as a function of time, obtained for a 5-kW solar reactor tested at PSI's solar furnace. (author)

  20. Beyond the standard model, experimental summary

    CERN Document Server

    McPherson, R A

    2003-01-01

    An overview of experimental results in searches for physics beyond the Standard Model is presented. It is impossible to cover all topics in this field, so a set of examples is used to highlight the scope and breadth of the results. Selected topics include searches for compositeness, flavour changing neutral currents, SUSY, exotic Higgs particles, low scale gravity in extra dimensions, and non commutative geometry. Current results are presented from the LEP, Tevatron Run I, and HERA I experiments. No convincing evidence for physics beyond the Standard Model has been observed. Prospects for ongoing and upcoming experiments are discussed. (40 refs).

  1. Experimental in Vivo Models of Candidiasis

    Directory of Open Access Journals (Sweden)

    Esther Segal

    2018-02-01

    Full Text Available Candidiasis is a multifaceted fungal disease including mucosal-cutaneous, visceral, and disseminated infections caused by yeast species of the genus Candida. Candida infections are among the most common human mycoses. Candida species are the third to fourth most common isolates from bloodstream infections in neutropenic or immunocompromised hospitalized patients. The mucosal-cutaneous forms—particularly vaginal infections—have a high prevalence. Vaginitis caused by Candida species is the second most common vaginal infection. Hence, candidiasis is a major subject for research, including experimental in vivo models to study pathogenesis, prevention, or therapy of the disease. The following review article will focus on various experimental in vivo models in different laboratory animals, such as mammals (mice, rats, rabbits, the fruit fly–Drosophila melanogaster, the larvae of the moth Galleria mellonella, or the free-living nematode Caenorhabditis elegans. The review will describe the induction of the different clinical forms of candidiasis in the various models and the validity of such models in mimicking the human clinical situations. The use of such models for the assessment of antifungal drugs, evaluation of potential vaccines to protect before candidiasis, exploration of Candida virulence factors, and comparison of pathogenicity of different Candida species will be included in the review. All of the above will be reported as based on published studies of numerous investigators as well as on the research of the author and his group.

  2. SIRT1 activating compounds reduce oxidative stress mediated neuronal loss in viral induced CNS demyelinating disease.

    Science.gov (United States)

    Khan, Reas S; Dine, Kimberly; Das Sarma, Jayasri; Shindler, Kenneth S

    2014-01-02

    Multiple sclerosis (MS) is characterized by central nervous system inflammation and demyelination, and increasing evidence demonstrates significant neuronal damage also occurs and is associated with permanent functional impairment. Current MS therapies have limited ability to prevent neuronal damage, suggesting additional neuroprotective therapies are needed. Compounds that activate the NAD+-dependent SIRT1 deacetylase prevent neuronal loss in an autoimmune-mediated MS model, but the mechanism of this effect is unknown, and it is unclear whether SIRT1 activating compounds exert similar effects in demyelinating disease induced by other etiologies. We measured neuronal loss in C57BL/6 mice inoculated with a neurotropic strain of mouse hepatitis virus, MHV-A59, that induces an MS-like disease. Oral treatment with the SIRT1 activating compound SRTAW04 significantly increased SIRT1 activity within optic nerves and prevented neuronal loss during optic neuritis, an inflammatory demyelinating optic nerve lesion that occurs in MS and its animal models. MHV-A59 induced neuronal loss was associated with reactive oxygen species (ROS) accumulation, and SRTAW04 treatment significantly reduced ROS levels while promoting increased expression of enzymes involved in mitochondrial function and reduction of ROS. SRTAW04 exerted similar protective effects in EAE spinal cords, with decreased demyelination. Results demonstrate that SIRT1 activating compounds prevent neuronal loss in viral-induced demyelinating disease similar to their effects in autoimmune-mediated disease. One mechanism of this neuroprotective effect involves increasing mitochondrial biogenesis with reduction of oxidative stress. SIRT1 activators represent a potential neuroprotective therapy for MS. Understanding common mechanisms of these effects in distinct disease models will help identify targets for more specific therapies.

  3. Chronic inflammatory demyelinating polyradiculoneuropathy with cholesterol deposits in a dog.

    Science.gov (United States)

    Piñeyro, Pablo; Sponenberg, D Philip; Pancotto, Theresa; King, Rosalind H M; Jortner, Bernard S

    2015-11-01

    Chronic inflammatory demyelinating polyradiculoneuropathy occurred in an 11-year-old Labrador Retriever dog. Spinal cord compression resulted from massive radiculitis with prominent cholesterol granulomas. Cholesterol deposition and associated granuloma formation is unique in chronic inflammatory demyelinating polyradiculoneuropathy, in both its human and canine expressions. © 2015 The Author(s).

  4. Microglial recruitment, activation, and proliferation in response to primary demyelination

    DEFF Research Database (Denmark)

    Remington, Leah T; Babcock, Alicia A; Zehntner, Simone P

    2007-01-01

    antigen-presenting cells in vitro. T cells were recruited to the demyelinated corpus callosum but did not appear to be activated. Our study highlights the role of microglia as a heterogeneous population of cells in primary demyelination, with the capacity to present antigen, proliferate, and migrate...

  5. Endometriose: modelo experimental em ratas Endometriosis: experimental model in rats

    Directory of Open Access Journals (Sweden)

    Eduardo Schor

    1999-06-01

    Full Text Available Objetivo: divulgar a metodologia da indução de endometriose experimental em animais de laboratório. Método: utilizamos ratas albinas, virgens, adultas de aproximadamente três meses de idade, que foram inicialmente anestesiadas pelo éter etílico. Aberta a cavidade abdominal, identificamos os cornos uterinos e retiramos um fragmento de aproximadamente 4 cm do corno uterino direito. Esse fragmento foi mergulhado em solução fisiológica e sob lupa estereoscópica foi separado o endométrio do miométrio e feitos retângulos de aproximadamente 4 por 5 mm. Esses foram fixados por meio de fio de sutura, sobre vasos sangüíneos visíveis a olho nu, na parede lateral do abdômen, tomando-se sempre o cuidado de manter a porção do endométrio livre voltada para a luz da cavidade abdominal. Após 21 dias os animais foram novamente operados para verificarmos o tamanho dos implantes e para retirada do endométrio ectópico para análise histológica. Resultados: macroscopicamente observamos crescimento significativo dos implantes endometriais. Ao exame microscópico pudemos observar a presença de epitélio glandular e estroma semelhantes ao do endométrio tópico. Conclusões: o modelo utilizado reproduz a doença, em ratas, sendo método auxiliar de valia para estudar esta afecção, principalmente a ação de medicamentos sobre esses implantes.Purpose: to demonstrate the experimental endometriosis induction in animals. Method: we used adult female Wistar rats weighing 200 - 250 g anesthetized with ethyl ether to open the abdominal cavity. After identifying the uterine horns, we removed an approximately 4 cm fragment from the right uterine horn. This fragment was placed in physiological saline and, with the aid of a stereoscopic magnifying glass, the endometrium was separated from the myometrium and cut into rectangles of approximately 4 x 5 mm. These rectangles were fastened to the lateral abdominal wall near great blood vessels, taking care

  6. Loss of Saltation and Presynaptic Action Potential Failure in Demyelinated Axons.

    Science.gov (United States)

    Hamada, Mustafa S; Popovic, Marko A; Kole, Maarten H P

    2017-01-01

    In cortical pyramidal neurons the presynaptic terminals controlling transmitter release are located along unmyelinated axon collaterals, far from the original action potential (AP) initiation site, the axon initial segment (AIS). Once initiated, APs will need to reliably propagate over long distances and regions of geometrical inhomogeneity like branch points (BPs) to rapidly depolarize the presynaptic terminals and confer temporally precise synaptic transmission. While axon pathologies such as demyelinating diseases are well established to impede the fidelity of AP propagation along internodes, to which extent myelin loss affects propagation along BPs and axon collaterals is not well understood. Here, using the cuprizone demyelination model, we performed optical voltage-sensitive dye (VSD) imaging from control and demyelinated layer 5 pyramidal neuron axons. In the main axon, we find that myelin loss switches the modality of AP propagation from rapid saltation towards a slow continuous wave. The duration of single AP waveforms at BPs or nodes was, however, only slightly briefer. In contrast, by using two-photon microscopy-guided loose-seal patch recordings from axon collaterals we revealed a presynaptic AP broadening in combination with a reduced velocity and frequency-dependent failure. Finally, internodal myelin loss was also associated with de novo sprouting of axon collaterals starting from the primary (demyelinated) axon. Thus, the loss of oligodendrocytes and myelin sheaths bears functional consequences beyond the main axon, impeding the temporal fidelity of presynaptic APs and affecting the functional and structural organization of synaptic connectivity within the neocortex.

  7. [Acute-Onset Chronic Inflammatory Demyelinating Polyradiculoneuropathy].

    Science.gov (United States)

    Kanbayashi, Takamichi; Sonoo, Masahiro

    2015-11-01

    Chronic inflammatory demyelinating polyneuropathy (CIDP) is characterized by an insidious onset showing progression over two months. However, up to 16% of CIDP patients may show acute presentation similar to Guillain-Barré syndrome (GBS). Such cases are termed acute-onset CIDP (A-CIDP). Distinguishing A-CIDP from GBS, especially the acute inflammatory demyelinating polyneuropathy (AIDP) subtype, is critical because therapeutic strategies and outcomes may differ between the two syndromes. Regarding clinical features, A-CIDP is less likely to have autonomic nervous system involvement, facial weakness, a preceding infectious illness, or the need for mechanical ventilation, in comparison with AIDP. Electrophysiological features are usually quite similar between the two, although follow-up studies may elucidate key differences. Around 8%-16% of GBS patients may show clinical deterioration shortly after improvement or stabilization following initial immunological therapy. Such a situation is termed treatment-related fluctuation (TRF; GBS-TRF). The distinction between GBS-TRF and A-CIDP is an important clinical issue because maintenance treatment is often required in CIDP. The diagnosis of A-CIDP should be considered when the condition of a patient with GBS deteriorates after nine weeks from onset, or when deterioration occurs three times or more.

  8. How to treat tumefactive demyelinating disease?

    Science.gov (United States)

    Siffrin, Volker; Müller-Forell, Wibke; von Pein, Harald; Zipp, Frauke

    2014-04-01

    Glioma-like inflammatory demyelinating lesions can be found in patients with pre-diagnosed multiple sclerosis, but they have also been described as an isolated disease entity. The initial diagnostic work-up usually includes a biopsy for histopathological analysis. However, even after unambiguous histopathologic classification, tumefactive lesions pose a therapeutic challenge. Until now, there have been no guidelines on how to treat patients with these rare and extreme lesion phenotypes. Here we report a patient with a relapsing unifocal tumefactive demyelinating lesion. The patient initially showed a good response to steroid treatment, with full clinical recovery. However, after relapse of the same lesion, recovery was incomplete. Although immunosuppression was initiated, the patient presented with subsequent further deterioration. Only maximal escalation of immunosuppression was able to stop the inflammatory activity. Due to the length of time of the step-wise escalation treatment however, the lengthy lesion activity led to irreversible tissue destruction and residual non-remitting disability. Early aggressive treatment with an induction therapy regimen might be more appropriate for these rare and often strongly disabling lesion subtypes.

  9. Chronic dysimmune neuropathies: Beyond chronic demyelinating polyradiculoneuropathy

    Directory of Open Access Journals (Sweden)

    Khadilkar Satish

    2011-01-01

    Full Text Available The spectrum of chronic dysimmune neuropathies has widened well beyond chronic demyelinating polyradiculoneuropathy (CIDP. Pure motor (multifocal motor neuropathy, sensorimotor with asymmetrical involvement (multifocal acquired demylinating sensory and motor neuropathy, exclusively distal sensory (distal acquired demyelinating sensory neuropathy and very proximal sensory (chronic immune sensory polyradiculopathy constitute the variants of CIDP. Correct diagnosis of these entities is of importance in terms of initiation of appropriate therapy as well as prognostication of these patients. The rates of detection of immune-mediated neuropathies with monoclonal cell proliferation (monoclonal gammopathy of unknown significance, multiple myeloma, etc. have been facilitated as better diagnostic tools such as serum immunofixation electrophoresis are being used more often. Immune neuropathies associated with malignancies and systemic vasculitic disorders are being defined further and treated early with better understanding of the disease processes. As this field of dysimmune neuropathies will evolve in the future, some of the curious aspects of the clinical presentations and response patterns to different immunosuppressants or immunomodulators will be further elucidated. This review also discusses representative case studies.

  10. Experimental animal modelling for TB vaccine development

    Directory of Open Access Journals (Sweden)

    Pere-Joan Cardona

    2017-03-01

    Full Text Available Research for a novel vaccine to prevent tuberculosis is an urgent medical need. The current vaccine, BCG, has demonstrated a non-homogenous efficacy in humans, but still is the gold standard to be improved upon. In general, the main indicator for testing the potency of new candidates in animal models is the reduction of the bacillary load in the lungs at the acute phase of the infection. Usually, this reduction is similar to that induced by BCG, although in some cases a weak but significant improvement can be detected, but none of candidates are able to prevent establishment of infection. The main characteristics of several laboratory animals are reviewed, reflecting that none are able to simulate the whole characteristics of human tuberculosis. As, so far, no surrogate of protection has been found, it is important to test new candidates in several models in order to generate convincing evidence of efficacy that might be better than that of BCG in humans. It is also important to investigate the use of “in silico” and “ex vivo” models to better understand experimental data and also to try to replace, or at least reduce and refine experimental models in animals.

  11. Nonlinear hierarchical modeling of experimental infection data.

    Science.gov (United States)

    Singleton, Michael D; Breheny, Patrick J

    2016-08-01

    In this paper, we propose a nonlinear hierarchical model (NLHM) for analyzing longitudinal experimental infection (EI) data. The NLHM offers several improvements over commonly used alternatives such as repeated measures analysis of variance (RM-ANOVA) and the linear mixed model (LMM). It enables comparison of relevant biological properties of the course of infection including peak intensity, duration and time to peak, rather than simply comparing mean responses at each observation time. We illustrate the practical benefits of this model and the insights it yields using data from experimental infection studies on equine arteritis virus. Finally, we demonstrate via simulation studies that the NLHM substantially reduces bias and improves the power to detect differences in relevant features of the infection response between two populations. For example, to detect a 20% difference in response duration between two groups (n=15) in which the peak time and peak intensity were identical, the RM-ANOVA test had a power of just 11%, and LMM a power of just 12%. By comparison, the nonlinear model we propose had a power of 58% in the same scenario, while controlling the Type I error rate better than the other two methods. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Models for Experimental High Density Housing

    Science.gov (United States)

    Bradecki, Tomasz; Swoboda, Julia; Nowak, Katarzyna; Dziechciarz, Klaudia

    2017-10-01

    The article presents the effects of research on models of high density housing. The authors present urban projects for experimental high density housing estates. The design was based on research performed on 38 examples of similar housing in Poland that have been built after 2003. Some of the case studies show extreme density and that inspired the researchers to test individual virtual solutions that would answer the question: How far can we push the limits? The experimental housing projects show strengths and weaknesses of design driven only by such indexes as FAR (floor attenuation ratio - housing density) and DPH (dwellings per hectare). Although such projects are implemented, the authors believe that there are reasons for limits since high index values may be in contradiction to the optimum character of housing environment. Virtual models on virtual plots presented by the authors were oriented toward maximising the DPH index and DAI (dwellings area index) which is very often the main driver for developers. The authors also raise the question of sustainability of such solutions. The research was carried out in the URBAN model research group (Gliwice, Poland) that consists of academic researchers and architecture students. The models reflect architectural and urban regulations that are valid in Poland. Conclusions might be helpful for urban planners, urban designers, developers, architects and architecture students.

  13. Bortezomib-associated demyelinating neuropathy--clinical and pathologic features.

    Science.gov (United States)

    Thawani, Sujata P; Tanji, Kurenai; De Sousa, Eduardo A; Weimer, Louis H; Brannagan, Thomas H

    2015-06-01

    Bortezomib is a proteasome inhibitor that is frequently used for multiple myeloma and lymphoma. A sensory predominant axonal neuropathy is associated with bortezomib treatment but a demyelinating neuropathy is also described primarily based on electrodiagnostic findings. We report a series of patients treated with bortezomib who developed peripheral neuropathy and were found to have demyelinating features on electrodiagnostic testing. Four patients who developed a bortezomib-induced peripheral neuropathy underwent electrophysiological testing, and 1 patient had a nerve biopsy. The four patients with bortezomib-induced peripheral neuropathy had demyelinating features on their electrophysiological testing. The nerve biopsy performed in 1 patient demonstrated a demyelinating component in a background of axonal degeneration. Although most toxic neuropathies are symmetrical axonal neuropathies, bortezomib is part of a small list of agents that may cause a demyelinating polyneuropathy and axonal degeneration. These findings have been confirmed by nerve biopsy.

  14. One calcitriol dose transiently increases Helios+ FoxP3+ T cells and ameliorates autoimmune demyelinating disease.

    Science.gov (United States)

    Nashold, Faye E; Nelson, Corwin D; Brown, Lauren M; Hayes, Colleen E

    2013-10-15

    Multiple sclerosis (MS) is an incurable inflammatory demyelinating disease. We investigated one calcitriol dose plus vitamin D3 (calcitriol/+D) as a demyelinating disease treatment in experimental autoimmune encephalomyelitis (EAE). Evidence that calcitriol-vitamin D receptor pathway deficits may promote MS, and data showing calcitriol enhancement of autoimmune T cell apoptosis provided the rationale. Whereas vitamin D3 alone was ineffective, calcitriol/+D transiently increased central nervous system (CNS) Helios(+)FoxP3(+) T cells and sustainably decreased CNS T cells, pathology, and neurological deficits in mice with EAE. Calcitriol/+D, which was more effective than methylprednisolone, has potential for reversing inflammatory demyelinating disease safely and cost-effectively. © 2013.

  15. Modeling of Experimental Atherosclerotic Plaque Delamination.

    Science.gov (United States)

    Leng, Xiaochang; Chen, Xin; Deng, Xiaomin; Sutton, Michael A; Lessner, Susan M

    2015-12-01

    A cohesive zone model (CZM) approach is applied to simulate atherosclerotic plaque delamination experiments in mouse abdominal aorta specimens. A three-dimensional finite element model is developed for the experiments. The aortic wall is treated as a fiber-reinforced, highly deformable, incompressible material, and the Holzapfel-Gasser-Ogden (HGO) model is adopted for the aortic bulk material behavior. Cohesive elements are placed along the plaque-media interface along which delamination occurs. The 3D specimen geometry is created based on images from the experiments and certain simplifying approximations. A set of HGO and CZM parameter values is determined based on values suggested in the literature and through matching simulation predictions of the load vs. load-point displacement curve with experimental measurements for one loading-delamination-unloading cycle. Using this set of parameter values, simulation predictions for four other loading-delamination-unloading cycles are obtained, which show good agreement with experimental measurements. The findings of the current study demonstrate the applicability of the CZM approach in arterial tissue failure simulations.

  16. CCR2 gene deletion and pharmacologic blockade ameliorate a severe murine experimental autoimmune neuritis model of Guillain-Barre syndrome.

    Directory of Open Access Journals (Sweden)

    Furong Yuan

    Full Text Available The molecular determinants and signaling pathways responsible for hematogenous leukocyte trafficking during peripheral neuroinflammation are incompletely elucidated. Chemokine ligand/receptor pair CCL2/CCR2 has been pathogenically implicated in the acute inflammatory demyelinating polyradiculoneuropathy variant of Guillain-Barré syndrome (GBS. We evaluated the role of CCR2 in peripheral neuroinflammation utilizing a severe murine experimental autoimmune neuritis (sm-EAN model. Sm-EAN was induced in 8-12 week old female SJL CCR2 knockout (CCR2KO, heterozygote (CCR2HT and wild type (CCR2WT mice, and daily neuromuscular severity scores and weights recorded. In vitro and in vivo splenocyte proliferation and cytokine expression assays, and sciatic nerve Toll-like receptor (TLR 2, TLR4 and CCL2 expression assays were performed to evaluate systemic and local innate immune activation at disease onset. Motor nerve electrophysiology and sciatic nerve histology were also performed to characterize the inflammatory neuropathy at expected peak severity. To further determine the functional relevance of CCR2 in sm-EAN, 20 mg/kg CCR2 antagonist, RS 102895 was administered daily for 5 days to a cohort of CCR2WT mice following sm-EAN disease onset, with efficacy compared to 400 mg/kg human intravenous immunoglobulin (IVIg. CCR2KO mice were relatively resistant to sm-EAN compared to CCR2WT and CCR2HT mice, associated with attenuated peripheral nerve demyelinating neuritis. Partial CCR2 gene deletion did not confer any protection against sm-EAN. CCR2KO mice demonstrated similar splenocyte activation or proliferation profiles, as well as TLR2, TLR4 and CCL2 expression to CCR2WT or CCR2HT mice, implying a direct role for CCR2 in sm-EAN pathogenesis. CCR2 signaling blockade resulted in rapid, near complete recovery from sm-EAN following disease onset. RS 102895 was significantly more efficacious than IVIg. CCR2 mediates pathogenic hematogenous monocyte trafficking

  17. Superficial tension: experimental model with simple materials

    Directory of Open Access Journals (Sweden)

    Tintori Ferreira, María Alejandra

    2012-09-01

    Full Text Available In this work appears a didactic offer based on an experimental activity using materials of very low cost, orientated to achieving that the student understand and interpret the phenomenon of superficial tension together with the importance of the modeling in sciences. It has as principal aim of education bring the student over to the mechanics of the static fluids and the intermolecular forces, combining scientific contents with questions near to the student what provides an additional motivation to the reflection of the scientific investigation.

  18. Activation of Nuclear Receptors RAR, RXR, and LXR Does Not Reduce Cuprizone-Induced Demyelination in Mice

    Directory of Open Access Journals (Sweden)

    Davina Kruczek

    2015-06-01

    Full Text Available Experiments with animal models of multiple sclerosis have shown that the expression of retinoid X receptors (RXR increases during demyelination and that RXR is involved in the regulation of remyelination. After ligand binding RXRs form heterodimeric transcription factors with other nuclear receptor (NR families including the retinoic acid receptors (RAR and liver X receptors (LXR. We tested whether activation of these nuclear receptor complexes reduces pathological demyelination using the cuprizone mouse model. Cuprizone, which causes oligodendrocyte degeneration, was given for three weeks as a food additive. For the activation of nuclear receptors mice were treated with daily i.p. injections of agonists for RXR (9-cis RA, RAR (all-trans RA, and LXR (T0901317. Myelin status, oligodendrocyte survival, astrogliosis, microglial activation, and axon density were monitored with immunohistochemistry and evaluated quantitatively. Three weeks of cuprizone feeding caused severe demyelination and significantly raised the number of Iba1 immunoreactive microglia cells in the caudal corpus callosum. This increase of microglia activity was reduced with 9-cis RA treatment but was enhanced with all-trans RA and was not affected by T0901317. Nuclear receptor activation did not influence the degree of demyelination, oligodendrocyte survival, astrogliosis, or axonal preservation. We conclude that RXR activation, although affecting Iba1-positive microglia, does not protect oligodendrocytes from cuprizone toxicity and does not induce compensatory mechanisms in the initial phase of demyelination.

  19. Muscle injury: review of experimental models.

    Science.gov (United States)

    Souza, Jaqueline de; Gottfried, Carmem

    2013-12-01

    Skeletal muscle is the most abundant tissue in the human body. Its main characteristic is the capacity to regenerate after injury independent of the cause of injury through a process called inflammatory response. Mechanical injuries are the most common type of the skeletal muscle injuries and are classified into one of three areas strain, contusion, and laceration. First, this review aims to describe and compare the main experimental methods that replicate the mechanical muscle injuries. There are several ways to replicate each kind of mechanical injury; there are, however, specific characteristics that must be taken into account when choosing the most appropriate model for the experiment. Finally, this review discusses the context of mechanical injury considering types, variability of methods, and the ability to reproduce injury models. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Organ models in wound ballistics: experimental study.

    Science.gov (United States)

    Ozer, Mustafa Tahir; Oğünç, Gökhan; Eryilmaz, Mehmet; Yiğit, Taner; Menteş, Mustafa Oner; Dakak, Mehmet; Uzar, Ali Ihsan; Oner, Köksal

    2007-01-01

    Effects of various types and diameters of guns and related treatment principles are different. Our study was performed to experimentally demonstrate the effects of different gunshots in body tissues. 9x19 mm hand-gun and 7.62x51 mm G-3 infantry rifle were used in the study. Injury models were created through hand-gun and rifle shootings at isolated soft tissue, lower extremity, liver and intestine tissue simulants made of ballistic candle. High-speed cameras were used to capture 1000 frames per second. Images were examined and wound mechanisms were evaluated. It was observed that the colon content distributed more within the surrounding tissues by the rifle shootings comparing with hand-gun shootings and could be an infection source due to the large size of the cavity in the colon. Especially when the bullets hitting the bone were investigated, it was seen that much more tissue injury occurs with high speed bullets due to bullet deformation and fragmentation. However, no significant difference was found between the effect of hand-gun and rifle bullets passing through the extremity without hitting the bone. To know the type of the gun that caused the injury and its characteristics will allow to estimate severity and size of the injury before the treatment and to focus on different alternatives of treatment. Therefore, use of appropriate models is required in experimental studies.

  1. Genetic models for CNS inflammation

    DEFF Research Database (Denmark)

    Owens, T; Wekerle, H; Antel, J

    2001-01-01

    The use of transgenic technology to over-express or prevent expression of genes encoding molecules related to inflammation has allowed direct examination of their role in experimental disease. This article reviews transgenic and knockout models of CNS demyelinating disease, focusing primarily...

  2. Isolated Extrapontine Myelinolysis of Osmotic Demyelination Syndrome

    Directory of Open Access Journals (Sweden)

    Ömer Yılmaz

    2013-01-01

    Full Text Available The osmotic demyelination syndrome (ODS has been identified as a complication of the rapid correction of hyponatremia for decades (King and Rosner, 2010. However, in recent years, a variety of other medical conditions have been associated with the development of ODS, independent of changes in serum sodium which cause a rapid changes in osmolality of the interstitial (extracellular compartment of the brain leading to dehydration of energy-depleted cells with subsequent axonal damage that occurs in characteristic areas (King and Rosner, 2010. Slow correction of the serum sodium concentration and additional administration of corticosteroids seems to be a major prevention step in ODS patients. In the current report we aimed to share a rare case which we observed in our clinic.

  3. Postural tremor and chronic inflammatory demyelinating polyneuropathy.

    Science.gov (United States)

    Cao, Yiming; Menon, Parvathi; Ching-Fen Chang, Florence; Mahant, Neil; Geevasinga, Nimeshan; Fung, Victor S C; Vucic, Steve

    2017-03-01

    Chronic inflammatory demyelinating polyneuropathy (CIDP) typically presents with a combination of sensory and motor impairments. Tremor is recognized as a common and debilitating feature in CIDP, although the underlying mechanisms are unclear. Clinical tremor severity and disability scores were collected prospectively in 25 CIDP patients and compared with 22 neuromuscular controls. Postural and kinetic tremor were significantly more frequent in CIDP patients (80%) than in neuromuscular controls (35%; P Tremor severity and tremor-related disability were also significantly greater in CIDP patients than in controls. Accelerometry data confirmed the presence of a 5.5 Hz postural tremor and a 5 Hz kinetic tremor. Tremor appears to be a common clinical feature of CIDP that results in significant disability. Sensory and motor impairment may be associated with development of tremor in CIDP. Muscle Nerve 55: 338-343, 2017. © 2016 Wiley Periodicals, Inc.

  4. Different mechanisms of inflammation induced in virus and autoimmune-mediated models of multiple sclerosis in C57BL6 mice.

    Science.gov (United States)

    Kishore, Abhinoy; Kanaujia, Anurag; Nag, Soma; Rostami, A M; Kenyon, Lawrence C; Shindler, Kenneth S; Das Sarma, Jayasri

    2013-01-01

    Multiple sclerosis (MS) is an inflammatory demyelinating disease of the human central nervous system (CNS). Neurotropic demyelinating strain of MHV (MHV-A59 or its isogenic recombinant strain RSA59) induces MS-like disease in mice mediated by microglia, along with a small population of T cells. The mechanism of demyelination is at least in part due to microglia-mediated myelin stripping, with some direct axonal injury. Immunization with myelin oligodendrocyte glycoprotein (MOG) induces experimental autoimmune encephalomyelitis (EAE), a mainly CD4(+) T-cell-mediated disease, although CD8(+) T cells may play a significant role in demyelination. It is possible that both autoimmune and nonimmune mechanisms such as direct viral toxicity may induce MS. Our study directly compares CNS pathology in autoimmune and viral-induced MS models. Mice with viral-induced and EAE demyelinating diseases demonstrated similar patterns and distributions of demyelination that accumulated over the course of the disease. However, significant differences in acute inflammation were noted. Inflammation was restricted mainly to white matter at all times in EAE, whereas inflammation initially largely involved gray matter in acute MHV-induced disease and then is subsequently localized only in white matter in the chronic disease phase. The presence of dual mechanisms of demyelination may be responsible for the failure of immunosuppression to promote long-term remission in many MS patients.

  5. Therapeutic options for chronic inflammatory demyelinating polyradiculoneuropathy: a systematic review.

    Science.gov (United States)

    Bright, Richard J; Wilkinson, Jenny; Coventry, Brendon J

    2014-02-07

    Chronic inflammatory demyelinating polyradiculoneuropathy is a rare acquired immune-mediated progressive or relapsing disorder causing peripheral neuropathic disease of duration more than two months. Many individuals with chronic inflammatory demyelinating polyradiculoneuropathy fail to make a long-term recovery with current treatment regimes. The aim of this study was to prospectively review the literature to determine the effectiveness of therapies for chronic inflammatory demyelinating polyradiculoneuropathy. Articles published from January 1990 to December 2012 were searched for studies to treat adults with chronic inflammatory demyelinating polyradiculoneuropathy. Peer-reviewed full-text articles published in English were included. Nine placebo-controlled double-blinded randomised trials were reviewed to treat subjects with chronic inflammatory demyelinating polyradiculoneuropathy exhibiting various degrees of effectiveness. The most effect treatments were; three randomised controlled trials using intravenous immunoglobulin, a study comparing pulsed dexamethasone and short term prednisolone and rituximab all showed promising results and were well tolerated. IVIg and corticosteroids remain first line treatments for CIDP. Therapies using monoclonal antibodies, such as Rituximab and Natalizumab offer the most promise for treatment of Chronic inflammatory demyelinating polyradiculoneuropathy however they also need further research, as does the use of stem cell therapy for treating Chronic inflammatory demyelinating polyradiculoneuropathy. Large randomised controlled trials and better patient selection are required to address responsiveness of CIDP patients to conventional treatments to elucidate mechanisms of action and future directions for therapeutic improvement.

  6. Experimental Basis for IED Particle Model

    Science.gov (United States)

    Zheng-Johansson, J.

    2009-05-01

    The internally electrodynamic (IED) particle model is built on three experimental facts: a) electric charges present in all matter particles, b) an accelerated charge generates electromagnetic (EM) waves by Maxwell's equations and Planck energy equation, and c) source motion gives Doppler effect. A set of well-kwon basic particle equations have been predicted based on first-principles solutions for IED particle (e.g. arxiv:0812.3951, J Phys CS128, 012019, 2008); the equations are long experimentally validated. A critical review of the key experiments suggests that the IED process underlies these equations not just sufficiently but also necessarily. E.g.: 1) A free IED electron solution is a plane wave ψ= Ce^i(kdX-φT) requisite for producing the diffraction fringe in a Davisson-Germer experiment, and of also all basic point-like attributes facilitated by a linear momentum kd and the model structure. It needs not further be a wave packet which produces not a diffraction fringe. 2)The radial partial EM waves, hence the total ψ, of an IED electron will, on both EM theory and experiment basis -not by assumption, enter two slits at the same time, as is requisite for an electron to interfere with itself as shown in double slit experiments. 3) On annihilation, an electron converts (from mass m) to a radiation energy φ without an acceleration which is externally observable and yet requisite by EM theory. So a charge oscillation of frequency φ and its EM waves must regularly present internal of a normal electron, whence the IED model.

  7. Protein misfolding and clearance in demyelinating peripheral neuropathies

    Science.gov (United States)

    Lee, Samuel M.

    2012-01-01

    Peripheral neuropathies such as Charcot-Marie-Tooth disease (CMT) are a group of neurological disorders that affect the peripheral nervous system. Although demyelinating CMT is the most prevalent hereditary peripheral neuropathy, there are currently no effective treatments for patients suffering from this disease. Recent studies by our group and others have provided a link between protein misfolding and demyelinating CMT and indicate that impairment of the proteasome and aggresome-autophagy pathways may contribute to CMT pathogenesis. These studies suggest that targeting protein quality control systems involved in cytoprotection against CMT-associated misfolded proteins could have therapeutic benefits for treating demyelinating CMT. PMID:22482025

  8. Inflammatory demyelinating pseudotumor with hemorrhage masquerading high grade cerebral neoplasm

    Directory of Open Access Journals (Sweden)

    Amit Agrawal

    2015-03-01

    Full Text Available Demyelinating pseudotumors are rare, benign, solitary intracranial space occupying lesions which masquerade cerebral neoplasms. Contrast MRI shows open ring enhancement which is fairly specific for this entity. Advanced MRI techniques like MR spectroscopy and magnetizing transfer techniques can help differentiating these lesions. NAA/Cr ratio is significantly elevated in central regions of demyelinating pseudotumors than in gliomas and other lesions. Presence of abundant foamy macrophages, lymphoid inflammatory infiltrates around blood vessels, sheets of gemistocytic astrocytes with well-developed processes, well defined border of the lesion absence of neovascularity and necrosis should help us diagnose demyelinating pseudotumor fairly confidently on histopathology.

  9. Experimental models of autoimmune inflammatory ocular diseases

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    Fabio Gasparin

    2012-04-01

    Full Text Available Ocular inflammation is one of the leading causes of blindness and loss of vision. Human uveitis is a complex and heterogeneous group of diseases characterized by inflammation of intraocular tissues. The eye may be the only organ involved, or uveitis may be part of a systemic disease. A significant number of cases are of unknown etiology and are labeled idiopathic. Animal models have been developed to the study of the physiopathogenesis of autoimmune uveitis due to the difficulty in obtaining human eye inflamed tissues for experiments. Most of those models are induced by injection of specific photoreceptors proteins (e.g., S-antigen, interphotoreceptor retinoid-binding protein, rhodopsin, recoverin, phosducin. Non-retinal antigens, including melanin-associated proteins and myelin basic protein, are also good inducers of uveitis in animals. Understanding the basic mechanisms and pathogenesis of autoimmune ocular diseases are essential for the development of new treatment approaches and therapeutic agents. The present review describes the main experimental models of autoimmune ocular inflammatory diseases.

  10. A human experimental model of episodic pain

    DEFF Research Database (Denmark)

    Petrini, Laura; Hennings, Kristian; Li, Xi

    2014-01-01

    were subjected to 45 min of intense painful cutaneous electrical stimulation (episodic pain session), using a stimulus paradigm that in animals has been shown to induce long-term potentiation. These electrical stimulations produced a verbal pain rating of approximately 85 on a 0-100 verbal rating scale......An experimental model of daily episodic pain was developed to investigate peripheral sensitization and cortical reorganization in healthy individuals. Two experiments (A and B) were conducted. Experiments A and B consisted of one and five consecutive days, respectively, in which the participants...... (VRS). Physiological (blood flow and axon flare reflex), psychophysical (perception threshold and verbal pain ratings) and electrophysiological (128 channels recorded somatosensory evoked potential (SEP)) measurements were recorded. The stimulation evoked a visible axon flare reflex and caused...

  11. IL-1 signal affects both protection and pathogenesis of virus-induced chronic CNS demyelinating disease

    Science.gov (United States)

    2012-01-01

    Background Theiler’s virus infection induces chronic demyelinating disease in mice and has been investigated as an infectious model for multiple sclerosis (MS). IL-1 plays an important role in the pathogenesis of both the autoimmune disease model (EAE) and this viral model for MS. However, IL-1 is known to play an important protective role against certain viral infections. Therefore, it is unclear whether IL-1-mediated signaling plays a protective or pathogenic role in the development of TMEV-induced demyelinating disease. Methods Female C57BL/6 mice and B6.129S7-Il1r1tm1Imx/J mice (IL-1R KO) were infected with Theiler’s murine encephalomyelitis virus (1 x 106 PFU). Differences in the development of demyelinating disease and changes in the histopathology were compared. Viral persistence, cytokine production, and immune responses in the CNS of infected mice were analyzed using quantitative PCR, ELISA, and flow cytometry. Results Administration of IL-1β, thereby rending resistant B6 mice susceptible to TMEV-induced demyelinating disease, induced a high level of Th17 response. Interestingly, infection of TMEV into IL-1R-deficient resistant C57BL/6 (B6) mice also induced TMEV-induced demyelinating disease. High viral persistence was found in the late stage of viral infection in IL-1R-deficient mice, although there were few differences in the initial anti-viral immune responses and viral persistent levels between the WT B6 and IL-1R-deficiecent mice. The initial type I IFN responses and the expression of PDL-1 and Tim-3 were higher in the CNS of TMEV-infected IL-1R-deficient mice, leading to deficiencies in T cell function that permit viral persistence. Conclusions These results suggest that the presence of high IL-1 level exerts the pathogenic role by elevating pathogenic Th17 responses, whereas the lack of IL-1 signals promotes viral persistence in the spinal cord due to insufficient T cell activation by elevating the production of inhibitory cytokines and

  12. IL-1 signal affects both protection and pathogenesis of virus-induced chronic CNS demyelinating disease.

    Science.gov (United States)

    Kim, Byung S; Jin, Young-Hee; Meng, Liping; Hou, Wanqiu; Kang, Hyun Seok; Park, Hey Suk; Koh, Chang-Sung

    2012-09-17

    Theiler's virus infection induces chronic demyelinating disease in mice and has been investigated as an infectious model for multiple sclerosis (MS). IL-1 plays an important role in the pathogenesis of both the autoimmune disease model (EAE) and this viral model for MS. However, IL-1 is known to play an important protective role against certain viral infections. Therefore, it is unclear whether IL-1-mediated signaling plays a protective or pathogenic role in the development of TMEV-induced demyelinating disease. Female C57BL/6 mice and B6.129S7-Il1r1tm1Imx/J mice (IL-1R KO) were infected with Theiler's murine encephalomyelitis virus (1 x 106 PFU). Differences in the development of demyelinating disease and changes in the histopathology were compared. Viral persistence, cytokine production, and immune responses in the CNS of infected mice were analyzed using quantitative PCR, ELISA, and flow cytometry. Administration of IL-1β, thereby rending resistant B6 mice susceptible to TMEV-induced demyelinating disease, induced a high level of Th17 response. Interestingly, infection of TMEV into IL-1R-deficient resistant C57BL/6 (B6) mice also induced TMEV-induced demyelinating disease. High viral persistence was found in the late stage of viral infection in IL-1R-deficient mice, although there were few differences in the initial anti-viral immune responses and viral persistent levels between the WT B6 and IL-1R-deficiecent mice. The initial type I IFN responses and the expression of PDL-1 and Tim-3 were higher in the CNS of TMEV-infected IL-1R-deficient mice, leading to deficiencies in T cell function that permit viral persistence. These results suggest that the presence of high IL-1 level exerts the pathogenic role by elevating pathogenic Th17 responses, whereas the lack of IL-1 signals promotes viral persistence in the spinal cord due to insufficient T cell activation by elevating the production of inhibitory cytokines and regulatory molecules. Therefore, the balance of

  13. Targeting insulin-like growth factor 1 leads to amelioration of inflammatory demyelinating disease.

    Directory of Open Access Journals (Sweden)

    Matthew F Cusick

    Full Text Available In patients with multiple sclerosis (MS and in mice with experimental autoimmune encephalomyelitis (EAE, proliferating autoreactive T cells play an important role in the pathogenesis of the disease. Due to the importance of these myelin-specific T cells, these cells have been therapeutic targets in a variety of treatments. Previously we found that Lenaldekar (LDK, a novel small molecule, could inhibit exacerbations in a preclinical model of MS when given at the start of an EAE exacerbation. In those studies, we found that LDK could inhibit human T cell recall responses and murine myelin responses in vitro. In these new studies, we found that LDK could inhibit myelin specific T cell responses through the insulin-like growth factor-1 receptor (IGF-1R pathway. Alteration of this pathway led to marked reduction in T cell proliferation and expansion. Blocking this pathway could account for the observed decreases in clinical signs and inflammatory demyelinating disease, which was accompanied by axonal preservation. Our data indicate that IGF-1R could be a potential target for new therapies for the treatment of autoimmune diseases where autoreactive T cell expansion is a requisite for disease.

  14. CD8+ T Cells Are Required For Glatiramer Acetate Therapy in Autoimmune Demyelinating Disease

    Science.gov (United States)

    Karandikar, Nitin J.

    2013-01-01

    The exact mechanism of glatiramer acetate (GA, Copaxone®), an FDA-approved immunomodulatory therapy for multiple sclerosis (MS), remains unclear after decades of research. Previously, we have shown that GA therapy of MS induces CD8+ T cell responses that can potentially suppress pathogenic CD4+ T cell responses. Using a murine model of MS, experimental autoimmune encephalomyelitis (EAE), we now demonstrate that CD8+ T cells are necessary in mediating the therapeutic effects of GA. Further, adoptive transfer of GA-induced CD8+ T cells resulted in amelioration of EAE, establishing a role as a viable immunotherapy in demyelinating disease. Generation of these cells required indoleamine-2,3-dioxygenase (IDO), while suppressive function depended on non-classical MHC class I, IFN-γ, and perforin expression. GA-induced regulatory myeloid cells, previously shown to activate CD4+ regulatory T cells in an antigen-independent manner, required CD8+ T cells for disease suppression in vivo. These studies demonstrate an essential role for CD8+ T cells in GA therapy and identify their potential as an adoptive immunotherapeutic agent. PMID:23805274

  15. CD8(+) T Cells Are Required For Glatiramer Acetate Therapy in Autoimmune Demyelinating Disease.

    Science.gov (United States)

    Tyler, Andrew F; Mendoza, Jason P; Firan, Mihail; Karandikar, Nitin J

    2013-01-01

    The exact mechanism of glatiramer acetate (GA, Copaxone®), an FDA-approved immunomodulatory therapy for multiple sclerosis (MS), remains unclear after decades of research. Previously, we have shown that GA therapy of MS induces CD8(+) T cell responses that can potentially suppress pathogenic CD4(+) T cell responses. Using a murine model of MS, experimental autoimmune encephalomyelitis (EAE), we now demonstrate that CD8(+) T cells are necessary in mediating the therapeutic effects of GA. Further, adoptive transfer of GA-induced CD8(+) T cells resulted in amelioration of EAE, establishing a role as a viable immunotherapy in demyelinating disease. Generation of these cells required indoleamine-2,3-dioxygenase (IDO), while suppressive function depended on non-classical MHC class I, IFN-γ, and perforin expression. GA-induced regulatory myeloid cells, previously shown to activate CD4(+) regulatory T cells in an antigen-independent manner, required CD8(+) T cells for disease suppression in vivo. These studies demonstrate an essential role for CD8(+) T cells in GA therapy and identify their potential as an adoptive immunotherapeutic agent.

  16. Targeting insulin-like growth factor 1 leads to amelioration of inflammatory demyelinating disease.

    Science.gov (United States)

    Cusick, Matthew F; Libbey, Jane E; Trede, Nikolaus S; Fujinami, Robert S

    2014-01-01

    In patients with multiple sclerosis (MS) and in mice with experimental autoimmune encephalomyelitis (EAE), proliferating autoreactive T cells play an important role in the pathogenesis of the disease. Due to the importance of these myelin-specific T cells, these cells have been therapeutic targets in a variety of treatments. Previously we found that Lenaldekar (LDK), a novel small molecule, could inhibit exacerbations in a preclinical model of MS when given at the start of an EAE exacerbation. In those studies, we found that LDK could inhibit human T cell recall responses and murine myelin responses in vitro. In these new studies, we found that LDK could inhibit myelin specific T cell responses through the insulin-like growth factor-1 receptor (IGF-1R) pathway. Alteration of this pathway led to marked reduction in T cell proliferation and expansion. Blocking this pathway could account for the observed decreases in clinical signs and inflammatory demyelinating disease, which was accompanied by axonal preservation. Our data indicate that IGF-1R could be a potential target for new therapies for the treatment of autoimmune diseases where autoreactive T cell expansion is a requisite for disease.

  17. Experimental validation of model Hortel Whillier; Validacion experimental del model de Hottel-Whillier

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez Munoz, F.; Cejudo Lopez, J. M.; Carrillo andres, A.

    2010-07-01

    Comparing the results of testing of a commercial flat-plate solar collector with a detailed implementation model of Hottel Whillier fin and tube. The validation procedure is based on comparing experimental and theoretical curves and more likely uncertainty bands. the model correctly predicts the end of profits and underestimates the 5% of losses, although a sensitivity analysis shows that this result is not attributable to the model itself but to the inputs with which it was implemented. The model has difficulty differentiating between the terms of linear and quadratic losses that appear in the quadratic fit curve. (Author) 1 refs.

  18. Effects of Anethole in Nociception Experimental Models

    Directory of Open Access Journals (Sweden)

    Alessandra Mileni Versuti Ritter

    2014-01-01

    Full Text Available This study investigated the antinociceptive activity of anethole (anethole 1-methoxy-4-benzene (1-propenyl, major compound of the essential oil of star anise (Illicium verum, in different experimental models of nociception. The animals were pretreated with anethole (62.5, 125, 250, and 500 mg/kg one hour before the experiments. To eliminate a possible sedative effect of anethole, the open field test was conducted. Anethole (62.5, 125, 250, and 500 mg/kg showed an antinociceptive effect in the writhing model induced by acetic acid, in the second phase of the formalin test (125 and 250 mg/kg in the test of glutamate (62.5, 125, and 250 mg/kg, and expresses pain induced by ACF (250 mg/kg. In contrast, anethole was not able to increase the latency time on the hot plate and decrease the number of flinches during the initial phase of the formalin test in any of the doses tested. It was also demonstrated that anethole has no association with sedative effects. Therefore, these data showed that anethole, at all used doses, has no sedative effect and has an antinociceptive effect. This effect may be due to a decrease in the production/release of inflammatory mediators.

  19. Tendon healing in vivo. An experimental model.

    Science.gov (United States)

    Abrahamsson, S O; Lundborg, G; Lohmander, L S

    1989-01-01

    Flexor tendon segments were incubated in a diffusion chamber in the subcutis of rabbits. Tendons incubated up to 6 weeks in the diffusion chamber showed proliferating and migrating cells from the epitenon cell layer as well as viable endotenon cells. Explants frozen in liquid nitrogen prior to incubation showed no signs of extrinsic cell contamination and remained non-viable indicating that no cell penetration occurred through the Millipore filter and that cell division seen in non-frozen and incubated tendons was an expression of intrinsic cellular proliferative capacity of the tendon. In tendon segments incubated in chambers for three weeks, collagen synthesis was reduced by 50% and the rate of cell proliferation measured as 3H-thymidine incorporation, was 15 times that of native tendons. Frozen and incubated tendons showed only traces of remaining matrix synthesis or cell proliferation. With this experimental model we have histologically and biochemically shown that tendons may survive and heal while the nutrition exclusively could be based on diffusion and the tendons have an intrinsic capacity of healing. The described model enables further studies on tendon healing and its regulation.

  20. Spectroscopic magnetic resonance imaging of a tumefactive demyelinating lesion

    Energy Technology Data Exchange (ETDEWEB)

    Law, M.; Meltzer, D.E.; Cha, S. [MRI Department, Department of Radiology, New York University Medical Center, Schwartz Building, Basement HCC, 530 First Avenue, New York, NY 10016 (United States)

    2002-12-01

    Tumefactive demyelinating lesions can present with features similar, clinically and radiologically, to those of brain tumours. Proton MR spectroscopy has been increasingly used to characterize intracranial pathology. As the underlying pathophysiology of neoplasms is different from that of demyelinating disease, one may expect the metabolic composition of neoplasms to be significantly different from that of demyelinating lesions. We report a 49-year-old woman in whom the neurologic and radiologic findings were highly suggestive of a high-grade brain tumor, and the spectroscopic features were sufficiently similar to that of a tumor to convince the neurosurgeon to operate. This case emphasizes the need for caution when confronted with a patient who presents with a differential diagnosis of demyelinating lesion versus neoplasm. (orig.)

  1. Peripheral mechanisms of neuropathic pain – involvement of lysophosphatidic acid receptor-mediated demyelination

    Directory of Open Access Journals (Sweden)

    Ueda Hiroshi

    2008-04-01

    Full Text Available Abstract Recent advances in pain research provide a clear picture for the molecular mechanisms of acute pain; substantial information concerning plasticity that occurs during neuropathic pain has also become available. The peripheral mechanisms responsible for neuropathic pain are found in the altered gene/protein expression of primary sensory neurons. With damage to peripheral sensory fibers, a variety of changes in pain-related gene expression take place in dorsal root ganglion neurons. These changes, or plasticity, might underlie unique neuropathic pain-specific phenotype modifications – decreased unmyelinated-fiber functions, but increased myelinated A-fiber functions. Another characteristic change is observed in allodynia, the functional change of tactile to nociceptive perception. Throughout a series of studies, using novel nociceptive tests to characterize sensory-fiber or pain modality-specific nociceptive behaviors, it was demonstrated that communication between innocuous and noxious sensory fibers might play a role in allodynia mechanisms. Because neuropathic pain in peripheral and central demyelinating diseases develops as a result of aberrant myelination in experimental animals, demyelination seems to be a key mechanism of plasticity in neuropathic pain. More recently, we discovered that lysophosphatidic acid receptor activation initiates neuropathic pain, as well as possible peripheral mechanims of demyelination after nerve injury. These results lead to further hypotheses of physical communication between innocuous Aβ- and noxious C- or Aδ-fibers to influence the molecular mechanisms of allodynia.

  2. Experimental models for Murray’s law

    Science.gov (United States)

    Akita, Dai; Kunita, Itsuki; Fricker, Mark D.; Kuroda, Shigeru; Sato, Katsuhiko; Nakagaki, Toshiyuki

    2017-01-01

    Transport networks are ubiquitous in multicellular organisms and include leaf veins, fungal mycelia and blood vessels. While transport of materials and signals through the network plays a crucial role in maintaining the living system, the transport capacity of the network can best be understood in terms of hydrodynamics. We report here that plasmodium from the large, single-celled amoeboid Physarum was able to construct a hydrodynamically optimized vein-network when evacuating biomass from confined arenas of various shapes through a narrow exit. Increasingly thick veins developed towards the exit, and the network spanned the arena via repetitive bifurcations to give a branching tree. The Hausdorff distance from all parts of the plasmodium to the vein network was kept low, whilst the hydrodynamic conductivity from distal parts of the network to the exit was equivalent, irrespective of the arena shape. This combination of spatial patterning and differential vein thickening served to evacuate biomass at an equivalent rate across the entire arena. The scaling relationship at the vein branches was determined experimentally to be 2.53-3.29, consistent with predictions from Murray’s law. Furthermore, we show that mathematical models for self-organised, adaptive transport in Physarum simulate the experimental network organisation well if the scaling coefficient of the current-reinforcement rule is set to 3. In simulations, this resulted in rapid development of an optimal network that minimised the combined volume and frictional energy in comparison with other scaling coefficients. This would predict that the boundary shear forces within each vein are constant throughout the network, and would be consistent with a feedback mechanism based on a sensing a threshold shear at the vein wall.

  3. Chronic Inflammatory Demyelinating Polyradiculoneuropathy: From Bench to Bedside

    Science.gov (United States)

    Peltier, Amanda C.; Donofrio, Peter D.

    2015-01-01

    Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP) is the most common treatable chronic autoimmune neuropathy. Multiple diagnostic criteria have been established, with the primary goal of identifying neurophysiologic hallmarks of acquired demyelination. Treatment modalities have expanded to include numerous immuno-modulatory therapies, although the best evidence continues to be for corticosteroids, plasma exchange, and intravenous immunoglobulins (IVIg). This review describes the pathology, epidemiology, pathogenesis, diagnosis, and treatment of CIDP. PMID:23117943

  4. A Case Of Infectious Mononucleosis With Acute Inflammatory Demyelinating Polyradiculoneuropathy

    Directory of Open Access Journals (Sweden)

    Somani S K

    2003-01-01

    Full Text Available We report a case of Acute inflammatory demyelinating polyradiculo neuropathy (AIDP, following infectious mononucleosis. A 12 year old girl presented with acute flaccid quadriplegia with bilateral cervical lymphadenopathy and enlarged tonsils six weeks after a febrile illness. Cerebrospinal fluid revealed albuminocytological dissociation and electrophysiology showed evidence of axonal-demyelinating polyradiculoneuropathy. Heterophile antibody test was positive and lymph node biopsy showed non -specific reactive hyperplasia. She was managed conservatively with good outcome.

  5. Acute Demyelinating Disease after Oral Therapy with Herbal Extracts

    Directory of Open Access Journals (Sweden)

    Alex Kostianovsky

    2011-06-01

    Full Text Available Central nervous system demyelinating processes such as multiple sclerosis and acute disseminated encephalomyelitis constitute a group of diseases not completely understood in their physiopathology. Environmental and toxic insults are thought to play a role in priming autoimmunity. The aim of the present report is to describe a case of acute demyelinating disease with fatal outcome occurring 15 days after oral exposure to herbal extracts.

  6. Tumefactive demyelinating lesions: A comprehensive review.

    Science.gov (United States)

    Algahtani, Hussein; Shirah, Bader; Alassiri, Ali

    2017-05-01

    Tumefactive multiple sclerosis or tumefactive demyelinating lesion (TDL) is one of the rare variants of multiple sclerosis (MS) posing a diagnostic challenge and a therapeutic enigma since it is difficult to distinguish from a true central nervous system (CNS) neoplasm or other CNS lesions on magnetic resonance imaging (MRI). The prevalence of TDL is estimated to be 1-3/1000 cases of MS with an annual incidence of 0.3/100,000. This could be an underestimate due to unavailability of a global MS registry and under-reporting of this condition. TDL may occur at any age with the ages between the 20s and 30s being more frequently affected. The pathogenesis of TDL remains unknown, but some speculations have been made. These include the autoimmune theory based on the close relationship between TDLs and MS, Fingolimod use, Fingolimod cessation, and Natalizumab use. The clinical presentation of patients with TDL is variable and atypical for demyelinating disease due to the differences in size and location of the lesion. In this article, we aim to explore TDL comprehensively and provide an evidence-based approach for diagnosis and treatment. This will result in recommendations that may improve the diagnostic accuracy and treatment outcomes. Detailed history, physical examination, and several MRI imaging can spare patients the need for a brain biopsy. Treatment of acute lesions includes corticosteroids and plasma exchange therapy. When a diagnosis of relapsing-remitting MS is fulfilled, conventional first line MS disease modifying therapy should be used. Available recently published data suggests that Fingolimod should not be used in TDL patients, mainly due to the possibility of more than just a chance association between TDLs and initiation of Fingolimod. The use of several new MS disease modifying therapy for the management of TDL remains to be studied. Further well-conducted research including multi-center trials is needed to explain several ambiguous aspects related to

  7. Cutaneous silent period recordings in demyelinating and axonal polyneuropathies.

    Science.gov (United States)

    Lopergolo, Diego; Isak, Baris; Gabriele, Maria; Onesti, Emanuela; Ceccanti, Marco; Capua, Gelsomina; Fionda, Laura; Biasiotta, Antonella; Di Stefano, Giulia; La Cesa, Silvia; Frasca, Vittorio; Inghilleri, Maurizio

    2015-09-01

    To investigate the cutaneous silent period (CSP), a spinal inhibitory reflex mainly mediated by A-delta fibres, in demyelinating and axonal polyneuropathy (PNP) and evaluate whether CSP parameters differ between patients with and without neuropathic pain. Eighty-four patients with demyelinating PNP, 178 patients with axonal PNP and 265 controls underwent clinical examination, DN4 questionnaire, standard nerve conduction study, motor-root stimulation and CSP recordings from abductor digiti minimi. We calculated the afferent conduction time of CSP (a-CSP time) with the formula: CSP latency-root motor evoked potential latency. In the demyelinating PNP group the a-CSP time was significantly longer; in the axonal PNP group, CSP duration was shorter than the demyelinating group (p=0.010) and controls (p=0.001). CSP parameters were not different between patients with and without neuropathic pain. The abnormality of a-CSP time in the demyelinating PNP group suggests the crucial role of A-delta fibres in the mechanism of CSP; the shorter CSP duration in the axonal PNP group supports the strong influence of the number of axons on this parameter. Our study suggests that neuropathic pain could be related to pathophysiological mechanisms differing from mere A-delta fibre loss. CSP evaluation is effective in detecting A-delta fibre dysfunction in axonal as well as demyelinating PNP. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  8. Evaluation of a patient with suspected chronic demyelinating polyneuropathy.

    Science.gov (United States)

    Jani-Acsadi, Agnes; Lewis, Richard A

    2013-01-01

    Demyelinating neuropathies are typically characterized by physiological slowing of conduction velocity and pathologically by segmental loss of myelin and in some instances, evidence of remyelination. Clinically, patients with demyelinating neuropathy can be seen with inherited disorders (Charcot-Marie-Tooth disease) or acquired disorders, typically immune-mediated or inflammatory. The acquired disorders can be either acute or subacute as seen in the acute inflammatory demyelinating polyneuropathy (AIDP) form of Guillain-Barré syndrome or chronic progressive or relapsing disorders such as chronic inflammatory demyelinating polyneuropathy. It is important to develop a logical approach to diagnosing these disorders. This requires an understanding of the clinical, genetic, physiological, and pathological features of these neuropathies. Clinically, important features to consider are the temporal progression, degree of symmetry, and involvement of proximal as well as distal muscles. Genetically, recognizing the different inheritance patterns and age of onset allow for a coordinated approach to determining a specific genotype. Physiologically, besides nerve conduction slowing, other physiological hallmarks of demyelination include temporal dispersion of compound motor action potentials (CMAP) on proximal stimulation, conduction block, and distal CMAP duration prolongation with certain patterns of involvement pointing to specific disorders. This chapter focuses on these various aspects of the evaluation of patients with chronic acquired demyelinating neuropathies to develop a comprehensive and thoughtful diagnostic concept. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Inflammatory demyelinating diseases of the central nervous system.

    Science.gov (United States)

    Höftberger, Romana; Lassmann, Hans

    2017-01-01

    Inflammatory demyelinating diseases are a heterogeneous group of disorders, which occur against the background of an acute or chronic inflammatory process. The pathologic hallmark of multiple sclerosis (MS) is the presence of focal demyelinated lesions with partial axonal preservation and reactive astrogliosis. Demyelinated plaques are present in the white as well as gray matter, such as the cerebral or cerebellar cortex and brainstem nuclei. Activity of the disease process is reflected by the presence of lesions with ongoing myelin destruction. Axonal and neuronal destruction in the lesions is a major substrate for permanent neurologic deficit in MS patients. The MS pathology is qualitatively similar in different disease stages, such as relapsing remitting MS or secondary or primary progressive MS, but the prevalence of different lesion types differs quantitatively. Acute MS and Balo's type of concentric sclerosis appear to be variants of classic MS. In contrast, neuromyelitis optica (NMO) and spectrum disorders (NMOSD) are inflammatory diseases with primary injury of astrocytes, mediated by aquaporin-4 antibodies. Finally, we discuss the histopathology of other inflammatory demyelinating diseases such as acute disseminated encephalomyelitis and myelin oligodendrocyte glycoprotein antibody-associated demyelination. Knowledge of the heterogenous immunopathology in demyelinating diseases is important, to understand the clinical presentation and disease course and to find the optimal treatment for an individual patient. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. HCV-related central and peripheral nervous system demyelinating disorders.

    Science.gov (United States)

    Mariotto, Sara; Ferrari, Sergio; Monaco, Salvatore

    2014-01-01

    Chronic infection with hepatitis C virus (HCV) is associated with a large spectrum of extrahepatic manifestations (EHMs), mostly immunologic/rheumatologic in nature owing to B-cell proliferation and clonal expansion. Neurological complications are thought to be immune-mediated or secondary to invasion of neural tissues by HCV, as postulated in transverse myelitis and encephalopathic forms. Primarily axonal neuropathies, including sensorimotor polyneuropathy, large or small fiber sensory neuropathy, motor polyneuropathy, mononeuritis, mononeuritis multiplex, or overlapping syndrome, represent the most common neurological complications of chronic HCV infection. In addition, a number of peripheral demyelinating disorders are encountered, such as chronic inflammatory demyelinating polyneuropathy, the Lewis-Sumner syndrome, and cryoglobulin-associated polyneuropathy with demyelinating features. The spectrum of demyelinating forms also includes rare cases of iatrogenic central and peripheral nervous system disorders, occurring during treatment with pegylated interferon. Herein, we review HCV-related demyelinating conditions, and disclose the novel observation on the significantly increased frequency of chronic demyelinating neuropathy with anti-myelin-associated glycoprotein antibodies in a cohort of 59 consecutive patients recruited at our institution. We also report a second case of neuromyelitis optica with serum IgG autoantibody against the water channel aquaporin-4. The prompt recognition of these atypical and underestimated complications of HCV infection is of crucial importance in deciding which treatment option a patient should be offered.

  11. HCV-Related Central and Peripheral Nervous System Demyelinating Disorders

    Science.gov (United States)

    Mariotto, Sara; Ferrari, Sergio; Monaco, Salvatore

    2014-01-01

    Chronic infection with hepatitis C virus (HCV) is associated with a large spectrum of extrahepatic manifestations (EHMs), mostly immunologic/rheumatologic in nature owing to B-cell proliferation and clonal expansion. Neurological complications are thought to be immune-mediated or secondary to invasion of neural tissues by HCV, as postulated in transverse myelitis and encephalopathic forms. Primarily axonal neuropathies, including sensorimotor polyneuropathy, large or small fiber sensory neuropathy, motor polyneuropathy, mononeuritis, mononeuritis multiplex, or overlapping syndrome, represent the most common neurological complications of chronic HCV infection. In addition, a number of peripheral demyelinating disorders are encountered, such as chronic inflammatory demyelinating polyneuropathy, the Lewis-Sumner syndrome, and cryoglobulin-associated polyneuropathy with demyelinating features. The spectrum of demyelinating forms also includes rare cases of iatrogenic central and peripheral nervous system disorders, occurring during treatment with pegylated interferon. Herein, we review HCV-related demyelinating conditions, and disclose the novel observation on the significantly increased frequency of chronic demyelinating neuropathy with anti-myelin-associated glycoprotein antibodies in a cohort of 59 consecutive patients recruited at our institution. We also report a second case of neuromyelitis optica with serum IgG autoantibody against the water channel aquaporin-4. The prompt recognition of these atypical and underestimated complications of HCV infection is of crucial importance in deciding which treatment option a patient should be offered. PMID:25198705

  12. Hypoxia Inducible Factor-1α in Astrocytes and/or Myeloid Cells Is Not Required for the Development of Autoimmune Demyelinating Disease(,.)

    Science.gov (United States)

    Le Moan, Natacha; Baeten, Kim M; Rafalski, Victoria A; Ryu, Jae Kyu; Rios Coronado, Pamela E; Bedard, Catherine; Syme, Catriona; Davalos, Dimitrios; Akassoglou, Katerina

    2015-01-01

    Hypoxia-like tissue alterations, characterized by the upregulation of hypoxia-inducible factor-1α (HIF-1α), have been described in the normal appearing white matter and pre-demyelinating lesions of multiple sclerosis (MS) patients. As HIF-1α regulates the transcription of a wide set of genes involved in neuroprotection and neuroinflammation, HIF-1α expression may contribute to the pathogenesis of inflammatory demyelination. To test this hypothesis, we analyzed the effect of cell-specific genetic ablation or overexpression of HIF-1α on the onset and progression of experimental autoimmune encephalomyelitis (EAE), a mouse model for MS. HIF-1α was mainly expressed in astrocytes and microglia/macrophages in the mouse spinal cord at the peak of EAE. However, genetic ablation of HIF-1α in astrocytes and/or myeloid cells did not ameliorate clinical symptoms. Furthermore, conditional knock-out of Von Hippel Lindau, a negative regulator of HIF-1α stabilization, failed to exacerbate the clinical course of EAE. In accordance with clinical symptoms, genetic ablation or overexpression of HIF-1α did not change the extent of spinal cord inflammation and demyelination. Overall, our data indicate that despite dramatic upregulation of HIF-1α in astrocytes and myeloid cells in EAE, HIF-1α expression in these two cell types is not required for the development of inflammatory demyelination. Despite numerous reports indicating HIF-1α expression in glia, neurons, and inflammatory cells in the CNS of MS patients, the cell-specific contribution of HIF-1α to disease pathogenesis remains unclear. Here we show that although HIF-1α is dramatically upregulated in astrocytes and myeloid cells in EAE, cell-specific depletion of HIF-1α in these two cell types surprisingly does not affect the development of neuroinflammatory disease. Together with two recently published studies showing a role for oligodendrocyte-specific HIF-1α in myelination and T-cell-specific HIF-1α in EAE, our

  13. Reg-2, a downstream signaling protein in the ciliary neurotrophic factor survival pathway, alleviates experimental autoimmune encephalomyelitis

    Directory of Open Access Journals (Sweden)

    Hong eJiang

    2016-05-01

    Full Text Available Ciliary neurotrophic factor (CNTF, originally described as a neurocytokine that could support the survival of neurons, has been recently found to alleviate demyelination, prevent axon loss, and improve functional recovery in a rat model of acute experimental autoimmune encephalomyelitis (EAE. However, poor penetration into the brain parenchyma and unfavorable side effects limit the utility of CNTF. Here, we evaluated the therapeutic potential of a protein downstream of CNTF, regeneration gene protein 2 (Reg-2. Using multiple morphological, molecular biology, and electrophysiological methods to assess neuroinflammation, axonal loss, demyelination, and functional impairment, we observed that Reg-2 and CNTF exert similar effects in the acute phase of EAE. Both treatments attenuated axonal loss and demyelination, improved neuronal survival, and produced functional improvement. With a smaller molecular weight and improved penetration into the brain parenchyma, Reg-2 may be a useful substitute for CNTF therapy in EAE and multiple sclerosis.

  14. Disease activity in chronic inflammatory demyelinating polyneuropathy.

    Science.gov (United States)

    Albulaihe, Hana; Alabdali, Majed; Alsulaiman, Abdulla; Abraham, Alon; Breiner, Ari; Barnett, Carolina; Katzberg, Hans D; Lovblom, Leif E; Perkins, Bruce A; Bril, Vera

    2016-10-15

    Evaluation of disease status in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) is often done by a combination of clinical evaluation and electrodiagnostic studies. A CIDP disease activity status (CDAS) was developed to standardize outcomes in CIDP patients. We aimed to determine if the CDAS was concordant with classical evaluation and whether CDAS enables benchmarking of CIDP. We performed a retrospective chart review of 305 CIDP patients and identified 206 patients with >1 visit and applied the CDAS to this cohort. We examined relationships between the CDAS and classical evaluation as to outcomes and compared our cohort to other CIDP cohorts who had CDAS. We found that the CDAS mirrored disease severity as measured by electrophysiology and vibration perception thresholds in that CDAS class 5 had more severe neuropathy. Our results are similar to other cohorts in the middle CDAS strata with the exception of fewer subjects in CDAS 1 and more in CDAS 5. The only demographic factor predicting CDAS 5 in our cohort was age, and the overall treatment response rate using the CDAS classification was 79.3%. CDAS appears to have sufficient face-validity as a grading system to assess disease activity in relation to treatment status. The use of CDAS appears to allow benchmarking of patients with CIDP that may be useful in subject selection for clinical trials and also to highlight differences in practice. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Novel therapeutic approaches to autoimmune demyelinating disorders.

    Science.gov (United States)

    Sanvito, Lara; Constantinescu, Cris S; Gran, Bruno

    2011-01-01

    Multiple Sclerosis (MS) is the most common autoimmune demyelinating disorder in Western countries and can lead to permanent disability. Over the past decades remarkable progress has been made in providing new therapeutic strategies to tackle the burden of the disease. Oral drugs and monoclonal antibodies are the main innovative approaches that have been tested in advanced stage clinical trials. Several new drugs have been shown to be superior to traditional disease modifying treatments (DMTs), in terms of both clinical and imaging outcome measures. Oral drugs have the advantage of offering a convenient route of administration. Recently fingolimod has received approval for the treatment of relapsing remitting (RR)-MS in several countries, becoming the first oral drug available to patients. Whilst the majority of the current studies focus on RR-MS, some trials investigate the primary or secondary progressive subtypes as well as the early forms of the disease aiming at delaying the conversion to clinically definite MS. Overall the future of the treatment options looks promising, although the occurrence of significant adverse events in some instances points to cautious evaluation of risks and benefits. Extension studies for most of the new drugs are under way and will provide evidence on the efficacy and long term effects of the new treatment strategies.

  16. An Occult Malignancy Behind a Demyelinating Disease

    Directory of Open Access Journals (Sweden)

    Saberio Lo Presti MD

    2016-10-01

    Full Text Available We report a case of a 38-year-old man presenting with bilateral lower extremity weakness and paresthesias that progressed during a 4-month period to severe polyneuropathy forcing the patient to be bed bound. Throughout his multiple hospitalizations, he was treated erroneously for chronic inflammatory demyelinating polyneuropathy, without significant improvement in his symptoms. In addition, he developed hepatosplenomegaly (organomegaly; endocrinopathies such as diabetes mellitus, central hypogonadism, and hypothyroidism; monoclonal spike evidenced in the serum electrophoresis; and hyperpigmentation of skin, altogether consistent with POEMS syndrome. During his last hospitalization he developed excruciating pain on his left hip, and imaging revealed the presence of a 9 × 6 cm osteolytic mass with sclerotic rim in the left acetabulum. Biopsy of the mass confirmed an isolated IgG lambda plasmacytoma. The patient received radiation to his left acetabular lesion followed by left hip replacement. Subsequently, the patient underwent autologous bone marrow transplant. Eighteen months after his initial presentation, he had satisfactory clinical response and is functional without significant limitations. POEMS syndrome is a rare paraneoplastic syndrome secondary to an underlying plasma cell disorder, which can oftentimes be overlooked and misdiagnosed. The median age of presentation is 51 years, and only 31% of the cases occur in fairly young patients under the age of 45 as evidenced in this case. As clinicians, we should be aware of the constellation of features associated with POEMS syndrome and be able to recognize them promptly.

  17. Treatment of Theiler's virus-induced demyelinating disease with teriflunomide.

    Science.gov (United States)

    Gilli, Francesca; Li, Libin; Royce, Darlene B; DiSano, Krista D; Pachner, Andrew R

    2017-12-01

    Teriflunomide is an oral therapy approved for the treatment of relapsing remitting multiple sclerosis (MS), showing both anti-inflammatory and antiviral properties. Currently, it is uncertain whether one or both of these properties may explain teriflunomide's beneficial effect in MS. Thus, to learn more about its mechanisms of action, we evaluated the effect of teriflunomide in the Theiler's encephalomyelitis virus-induced demyelinating disease (TMEV-IDD) model, which is both a viral infection and an excellent model of the progressive disability of MS. We assessed the effects of the treatment on central nervous system (CNS) viral load, intrathecal immune response, and progressive neurological disability in mice intracranially infected with TMEV. In the TMEV-IDD model, we showed that teriflunomide has both anti-inflammatory and antiviral properties, but there seemed to be no impact on disability progression and intrathecal antibody production. Notably, benefits in TMEV-IDD were mostly mediated by effects on various cytokines produced in the CNS. Perhaps the most interesting result of the study has been teriflunomide's antiviral activity in the CNS, indicating it may have a role as an antiviral prophylactic and therapeutic compound for CNS viral infections.

  18. Tamoxifen accelerates the repair of demyelinated lesions in the central nervous system

    Science.gov (United States)

    Gonzalez, Ginez A.; Hofer, Matthias P.; Syed, Yasir A.; Amaral, Ana I.; Rundle, Jon; Rahman, Saifur; Zhao, Chao; Kotter, Mark R. N.

    2016-01-01

    Enhancing central nervous system (CNS) myelin regeneration is recognized as an important strategy to ameliorate the devastating consequences of demyelinating diseases such as multiple sclerosis. Previous findings have indicated that myelin proteins, which accumulate following demyelination, inhibit remyelination by blocking the differentiation of rat oligodendrocyte progenitor cells (OPCs) via modulation of PKCα. We therefore screened drugs for their potential to overcome this differentiation block. From our screening, tamoxifen emerges as a potent inducer of OPC differentiation in vitro. We show that the effects of tamoxifen rely on modulation of the estrogen receptors ERα, ERβ, and GPR30. Furthermore, we demonstrate that administration of tamoxifen to demyelinated rats in vivo accelerates remyelination. Tamoxifen is a well-established drug and is thus a promising candidate for a drug to regenerate myelin, as it will not require extensive safety testing. In addition, Tamoxifen plays an important role in biomedical research as an activator of inducible genetic models. Our results highlight the importance of appropriate controls when using such models. PMID:27554391

  19. Tamoxifen accelerates the repair of demyelinated lesions in the central nervous system.

    Science.gov (United States)

    Gonzalez, Ginez A; Hofer, Matthias P; Syed, Yasir A; Amaral, Ana I; Rundle, Jon; Rahman, Saifur; Zhao, Chao; Kotter, Mark R N

    2016-08-24

    Enhancing central nervous system (CNS) myelin regeneration is recognized as an important strategy to ameliorate the devastating consequences of demyelinating diseases such as multiple sclerosis. Previous findings have indicated that myelin proteins, which accumulate following demyelination, inhibit remyelination by blocking the differentiation of rat oligodendrocyte progenitor cells (OPCs) via modulation of PKCα. We therefore screened drugs for their potential to overcome this differentiation block. From our screening, tamoxifen emerges as a potent inducer of OPC differentiation in vitro. We show that the effects of tamoxifen rely on modulation of the estrogen receptors ERα, ERβ, and GPR30. Furthermore, we demonstrate that administration of tamoxifen to demyelinated rats in vivo accelerates remyelination. Tamoxifen is a well-established drug and is thus a promising candidate for a drug to regenerate myelin, as it will not require extensive safety testing. In addition, Tamoxifen plays an important role in biomedical research as an activator of inducible genetic models. Our results highlight the importance of appropriate controls when using such models.

  20. Zebrafish regenerate full thickness optic nerve myelin after demyelination, but this fails with increasing age.

    Science.gov (United States)

    Münzel, Eva Jolanda; Becker, Catherina G; Becker, Thomas; Williams, Anna

    2014-07-15

    In the human demyelinating central nervous system (CNS) disease multiple sclerosis, remyelination promotes recovery and limits neurodegeneration, but this is inefficient and always ultimately fails. Furthermore, these regenerated myelin sheaths are thinner and shorter than the original, leaving the underlying axons potentially vulnerable. In rodent models, CNS remyelination is more efficient, so that in young animals (but not old) the number of myelinated axons is efficiently restored to normal, but in both young and old rodents, regenerated myelin sheaths are still short and thin. The reasons for these differences in remyelination efficiency, the thinner remyelinated myelin sheaths compared to developmental myelin and the subsequent effect on the underlying axon are unclear. We studied CNS remyelination in the highly regenerative adult zebrafish (Danio rerio), to better understand mechanisms of what we hypothesised would be highly efficient remyelination, and to identify differences to mammalian CNS remyelination, as larval zebrafish are increasingly used for high throughput screens to identify potential drug targets to improve myelination and remyelination. We developed a novel method to induce a focal demyelinating lesion in adult zebrafish optic nerve with no discernible axonal damage, and describe the cellular changes over time. Remyelination is indeed efficient in both young and old adult zebrafish optic nerves, and at 4 weeks after demyelination, the number of myelinated axons is restored to normal, but internode lengths are short. However, unlike in rodents or in humans, in young zebrafish these regenerated myelin sheaths were of normal thickness, whereas in aged zebrafish, they were thin, and remained so even 3 months later. This inability to restore normal myelin thickness in remyelination with age was associated with a reduced macrophage/microglial response. Zebrafish are able to efficiently restore normal thickness myelin around optic nerve axons after

  1. Injury Based on Its Study in Experimental Models

    Directory of Open Access Journals (Sweden)

    M. Mendes-Braz

    2012-01-01

    Full Text Available The present review focuses on the numerous experimental models used to study the complexity of hepatic ischemia/reperfusion (I/R injury. Although experimental models of hepatic I/R injury represent a compromise between the clinical reality and experimental simplification, the clinical transfer of experimental results is problematic because of anatomical and physiological differences and the inevitable simplification of experimental work. In this review, the strengths and limitations of the various models of hepatic I/R are discussed. Several strategies to protect the liver from I/R injury have been developed in animal models and, some of these, might find their way into clinical practice. We also attempt to highlight the fact that the mechanisms responsible for hepatic I/R injury depend on the experimental model used, and therefore the therapeutic strategies also differ according to the model used. Thus, the choice of model must therefore be adapted to the clinical question being answered.

  2. Biomass thermochemical gasification: Experimental studies and modeling

    Science.gov (United States)

    Kumar, Ajay

    The overall goals of this research were to study the biomass thermochemical gasification using experimental and modeling techniques, and to evaluate the cost of industrial gas production and combined heat and power generation. This dissertation includes an extensive review of progresses in biomass thermochemical gasification. Product gases from biomass gasification can be converted to biopower, biofuels and chemicals. However, for its viable commercial applications, the study summarizes the technical challenges in the gasification and downstream processing of product gas. Corn stover and dried distillers grains with solubles (DDGS), a non-fermentable byproduct of ethanol production, were used as the biomass feedstocks. One of the objectives was to determine selected physical and chemical properties of corn stover related to thermochemical conversion. The parameters of the reaction kinetics for weight loss were obtained. The next objective was to investigate the effects of temperature, steam to biomass ratio and equivalence ratio on gas composition and efficiencies. DDGS gasification was performed on a lab-scale fluidized-bed gasifier with steam and air as fluidizing and oxidizing agents. Increasing the temperature resulted in increases in hydrogen and methane contents and efficiencies. A model was developed to simulate the performance of a lab-scale gasifier using Aspen Plus(TM) software. Mass balance, energy balance and minimization of Gibbs free energy were applied for the gasification to determine the product gas composition. The final objective was to optimize the process by maximizing the net energy efficiency, and to estimate the cost of industrial gas, and combined heat and power (CHP) at a biomass feedrate of 2000 kg/h. The selling price of gas was estimated to be 11.49/GJ for corn stover, and 13.08/GJ for DDGS. For CHP generation, the electrical and net efficiencies were 37 and 86%, respectively for corn stover, and 34 and 78%, respectively for DDGS. For

  3. Overlapping demyelinating syndromes and anti-NMDA receptor encephalitis

    Science.gov (United States)

    Titulaer, Maarten J.; Höftberger, Romana; Iizuka, Takahiro; Leypoldt, Frank; McCracken, Lindsey; Cellucci, Tania; Benson, Leslie A.; Shu, Huidy; Irioka, Takashi; Hirano, Makito; Singh, Gagandeep; Calvo, Alvaro Cobo; Kaida, Kenichi; Morales, Pamela S.; Wirtz, Paul W.; Yamamoto, Tomotaka; Reindl, Markus; Rosenfeld, Myrna R.; Graus, Francesc; Saiz, Albert; Dalmau, Josep

    2014-01-01

    Objective To report the clinical, radiological, and immunological association of demyelinating disorders with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. Methods Clinical and radiological analysis of a cohort of 691 patients with anti-NMDAR encephalitis. Determination of antibodies to NMDAR, aquaporin-4 (AQP4) and myelin oligodendrocyte glycoprotein (MOG) was performed using brain immunohistochemistry and cell-based assays. Results Twenty-three of 691 patients with anti-NMDAR encephalitis had prominent MRI and/or clinical features of demyelination. Group 1 included 12 patients in whom anti-NMDAR encephalitis was preceded or followed by independent episodes of NMO-spectrum disorder (5 cases, 4 anti-AQP4-positive), or brainstem or multifocal demyelinating syndromes (7 cases, all anti-MOG-positive). Group 2 included 11 patients in whom anti-NMDAR encephalitis occurred simultaneously with MRI and symptoms compatible with demyelination (5 AQ4-positive, 2 MOG-positive). Group 3 (136 controls) included 50 randomly selected patients with typical anti-NMDAR encephalitis, 56 with NMO, and 30 with multiple sclerosis: NMDAR-antibodies were detected only in the 50 anti-NMDAR patients, MOG-antibodies in 3/50 anti-NMDAR and 1/56 NMO patients, and AQP4-antibodies in 48/56 NMO and 1/50 anti-NMDAR patients (pdemyelinating episodes required more intensive therapy and resulted in more residual deficits. Only 1/23 NMDAR patients with signs of demyelination had ovarian teratoma compared with 18/50 anti-NMDAR controls (p=0.011) Interpretation Patients with anti-NMDAR encephalitis may develop concurrent or separate episodes of demyelinating disorders, and conversely patients with NMO or demyelinating disorders with atypical symptoms (e.g., dyskinesias, psychosis) may have anti-NMDAR encephalitis. PMID:24700511

  4. Perivenous demyelination: association with clinically defined acute disseminated encephalomyelitis and comparison with pathologically confirmed multiple sclerosis.

    Science.gov (United States)

    Young, Nathan P; Weinshenker, Brian G; Parisi, Joseph E; Scheithauer, B; Giannini, C; Roemer, Shanu F; Thomsen, Kristine M; Mandrekar, Jayawant N; Erickson, Bradley J; Lucchinetti, Claudia F

    2010-02-01

    Distinction between acute disseminated encephalomyelitis and acute multiple sclerosis is often clinically difficult. Perivenous demyelination is the pathological hallmark of acute disseminated encephalomyelitis, whereas confluent demyelination is the hallmark of acute multiple sclerosis. We investigated whether perivenous demyelination versus confluent demyelination distinguishes acute disseminated encephalomyelitis from multiple sclerosis. Patients with perivenous demyelination (n = 13; median age 43 years, range 5-67) on brain biopsy and/or autopsy, ascertained retrospectively, were compared with a cohort with confluent demyelination only (n = 91; 84% multiple sclerosis, 16% isolated syndrome at follow-up; median age 39 years, range 10-69). Clinical presentation, course and the International Paediatric Multiple Sclerosis Study Group clinical criteria for acute disseminated encephalomyelitis were assessed in both cohorts. Among the perivenous demyelination cohort, 10 patients had only perivenous demyelination and three also had confluent demyelination. All but one patient with perivenous demyelination only had a monophasic course, whereas two of three with both types had a relapsing course. The perivenous demyelination cohort was more likely than the confluent demyelination cohort to present with encephalopathy (P acute disseminated encephalomyelitis (perivenous demyelination), but misdiagnosed acute disseminated encephalomyelitis among 9% of patients with confluent demyelination and multiple sclerosis diagnosis at last follow-up. Perivenous demyelination is associated with meningoencephalopathic presentations and a monophasic course. Depressed level of consciousness is a more specific clinical criterion for pathologically confirmed acute disseminated encephalomyelitis than encephalopathy, which over-diagnosed acute disseminated encephalomyelitis among multiple sclerosis patients. A distinct pattern of cortical microglial activation without cortical demyelination

  5. PMWS: Experimental model and co-infections

    DEFF Research Database (Denmark)

    Allan, G. M.; McNeilly, F.; Ellis, J

    2004-01-01

    and pneumonia and typical histological lesions include lymphocytic depletion and multinucleated giant cell formation in lymph nodes, degeneration and necrosis of hepatocytes, and multifocal lymphohistocytic interstitial pneumonia. This communication will review the results of experimental infections...

  6. The quality of cortical network function recovery depends on localization and degree of axonal demyelination.

    Science.gov (United States)

    Cerina, Manuela; Narayanan, Venu; Göbel, Kerstin; Bittner, Stefan; Ruck, Tobias; Meuth, Patrick; Herrmann, Alexander M; Stangel, Martin; Gudi, Viktoria; Skripuletz, Thomas; Daldrup, Thiemo; Wiendl, Heinz; Seidenbecher, Thomas; Ehling, Petra; Kleinschnitz, Christoph; Pape, Hans-Christian; Budde, Thomas; Meuth, Sven G

    2017-01-01

    Myelin loss is a severe pathological hallmark common to a number of neurodegenerative diseases, including multiple sclerosis (MS). Demyelination in the central nervous system appears in the form of lesions affecting both white and gray matter structures. The functional consequences of demyelination on neuronal network and brain function are not well understood. Current therapeutic strategies for ameliorating the course of such diseases usually focus on promoting remyelination, but the effectiveness of these approaches strongly depends on the timing in relation to the disease state. In this study, we sought to characterize the time course of sensory and behavioral alterations induced by de- and remyelination to establish a rational for the use of remyelination strategies. By taking advantage of animal models of general and focal demyelination, we tested the consequences of myelin loss on the functionality of the auditory thalamocortical system: a well-studied neuronal network consisting of both white and gray matter regions. We found that general demyelination was associated with a permanent loss of the tonotopic cortical organization in vivo, and the inability to induce tone-frequency-dependent conditioned behaviors, a status persisting after remyelination. Targeted, focal lysolecithin-induced lesions in the white matter fiber tract, but not in the gray matter regions of cortex, were fully reversible at the morphological, functional and behavioral level. These findings indicate that remyelination of white and gray matter lesions have a different functional regeneration potential, with the white matter being able to regain full functionality while cortical gray matter lesions suffer from permanently altered network function. Therefore therapeutic interventions aiming for remyelination have to consider both region- and time-dependent strategies. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Peripheral nerve proteins as potential autoantigens in acute and chronic inflammatory demyelinating polyneuropathies.

    Science.gov (United States)

    Lim, Jia Pei; Devaux, Jérôme; Yuki, Nobuhiro

    2014-10-01

    Guillain-Barré syndrome is classified into acute inflammatory demyelinating polyneuropathy and acute motor axonal neuropathy. Whereas autoantibodies to GM1 or GD1a induce the development of acute motor axonal neuropathy, pathogenic autoantibodies have yet to be identified in acute inflammatory demyelinating polyneuropathy and chronic inflammatory demyelinating polyneuropathy. This review highlights the importance of autoantibodies to peripheral nerve proteins in the physiopathology of acute and chronic inflammatory demyelinating polyneuropathies. Moreover, we listed up other potential antigens, which may become helpful biomarkers for acquired, dysimmune demyelinating neuropathies based on their critical functions during myelination and their implications in hereditary demyelinating neuropathies. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Invivo insulin deficiency as a potential etiology for demyelinating disease.

    Science.gov (United States)

    Gong, Xiaoming; Xie, Zuoping; Zuo, Huancong

    2008-09-01

    Demyelinating disease is pathologically characterized by the death of mature oligodendrocytes that normally synthesize myelin to perform insulating functions. Moreover, demyelinating disease also results in the failure of remyelination process in which oligodendrocyte progenitor cells reactivate and differentiate into new oligodendrocytes. Thus, this disease reflects decreased nerve conduction velocity and eventually dysfunction of the nervous system. A notable fact in the clinic is that demyelination is one of the most common diabetes-induced complications, implying that demyelinating disease may be relevant to insulin deficiency in vivo. However, the explicit pathological relationship between demyelination and diabetes remains unclear. Mainstream theories posit that demyelinating disease is an autoimmune disease arising from abnormal immunological reactions, but this perspective is limited when applied to the clinic. Olig1 is a vital transcription factor involved in oligodendrogenesis and is essential for the survival and maturation of oligodendrocyte progenitor cells. Furthermore, Olig1 is required for the onset of remyelination in adults. In the present study, we serendipitously found by means of protein immunoblot that the expression of nuclear Olig1 was inhibited when mouse oligodendrocyte progenitor cells were cultured in the absence of insulin. Combining this finding with the clinical relevance of demyelination and diabetes, we hypothesize that in vivo insulin deficiency impairs the reactivation and differentiation of oligodendrocyte progenitor cells through downregulation of nuclear Olig1 expression and therefore hinders the remyelination, which is an important process required for functional recovery in demyelinating disease. This hypothesis implies that in vivo insulin deficiency may be a novel etiological cause of demyelinating disease and thus contribute to improved the clinical therapies for remyelination repair. We suggest that sustaining normal

  9. Multifocal Motor Neuropathy, Multifocal Acquired Demyelinating Sensory and Motor Neuropathy and Other Chronic Acquired Demyelinating Polyneuropathy Variants

    Science.gov (United States)

    Barohn, Richard J.; Katz, Jonathan

    2014-01-01

    Chronic acquired demyelinating neuropathies (CADP) are an important group of immune neuromuscular disorders affecting myelin. These are distinct from chronic inflammatory demyelinating polyneuropathy (CIDP). Classically, CIDP is characterized by proximal and distal weakness, large fiber sensory loss, elevated cerebrospinal fluid (CSF) protein content, demyelinating changes nerve conduction studies or nerve biopsy, and response to immunomodulating treatment. In this chapter we discuss CADP with emphasis on multifocal motor neuropathy (MMN), multifocal acquired demyelinating sensory and motor neuropathy (MADSAM), distal acquired demyelinating symmetric (DADS) neuropathy and conclude with less common variants. While each of these entities has distinctive laboratory and electrodiagnostic features that aid in their diagnosis, clinical characteristics are of paramount importance in diagnosing specific conditions and determining the most appropriate therapies. Unlike CIDP, MMN is typically asymmetric and affects only the motor nerve fibers. MMN is a rare disease that presents chronically, over several years of progression affecting the arms are more commonly than the legs. Men are more likely than women to develop MMN. MADSAM should be suspected in patients who have weakness and loss of sensation in primarily one arm or leg which progresses slowly over several months to years. It is important in patient with multifocal demyelinating clinical presentation to distinguish MMN from MADSAM since corticosteroids are not effective in MMN where the mainstay of therapy is intravenous gammaglobulin (IVIg). DADS can be subdivided into DADS-M (associated woth M-protein) and DADS-I which is idioapthic. While DADS-I patients respond somewhat to immunotherapy, DADS-M patients present with distal predominant sensorimotor demyelinating neuropathy phenotype and are notoriously refractory to immunotherapies regardless of antibodies to myelin-associated glycoprotein (MAG). Our knowledge

  10. Diffusion-weighted imaging in acute demyelinating myelopathy

    Energy Technology Data Exchange (ETDEWEB)

    Zecca, Chiara; Cereda, Carlo; Tschuor, Silvia; Staedler, Claudio; Nadarajah, Navarajah; Bassetti, Claudio L.; Gobbi, Claudio [Ospedale Regionale di Lugano, Servizio di Neurologia e Neuroradiologia, Neurocenter of Southern Switzerland, Lugano (Switzerland); Wetzel, Stephan [Swiss Neuro Institute (SNI), Abteilung fuer Neuroradiologie, Hirslanden Klinik Zuerich, Zuerich (Switzerland); Santini, Francesco [University of Basel Hospital, Division of Radiological Physics, Basel (Switzerland)

    2012-06-15

    Diffusion-weighted imaging (DWI) has become a reference MRI technique for the evaluation of neurological disorders. Few publications have investigated the application of DWI for inflammatory demyelinating lesions. The purpose of the study was to describe diffusion-weighted imaging characteristics of acute, spinal demyelinating lesions. Six consecutive patients (two males, four females; aged 28-64 years) with acute spinal cord demyelinating lesions were studied in a prospective case series design from June 2009 to October 2010. We performed magnetic resonance imaging studies from 2 to 14 days from symptom onset on the patients with relapsing remitting multiple sclerosis (n = 3) or clinically isolated syndrome (n = 3). Main outcome measures were diffusion-weighted imaging and apparent diffusion coefficient pattern (ADC) of acute spinal cord demyelinating lesions. All spinal lesions showed a restricted diffusion pattern (DWI+/ADC-) with a 24% median ADC signal decrease. A good correlation between clinical presentation and lesion site was observed. Acute demyelinating spinal cord lesions show a uniform restricted diffusion pattern. Clinicians and neuro-radiologists should be aware that this pattern is not necessarily confirmatory for an ischaemic aetiology. (orig.)

  11. Optic and auditory pathway dysfunction in demyelinating neuropathies.

    Science.gov (United States)

    Knopp, M; Leese, R J; Martin-Lamb, D; Rajabally, Y A

    2014-07-01

    The involvement of optic and auditory pathways has rarely been studied in demyelinating polyneuropathies. We here aimed to study this further in a cohort of patients with acquired and gentic demyelinating neuropathy. We studied eight patients with hereditary neuropathy with liability to pressure palsies (HNPP), six with Charcot-Marie-Tooth disease type 1A (CMT1A), ten with chronic inflammatory demyelinating polyneuropathy (CIDP) and seven with antimyelin-associated glycoprotein (MAG) neuropathy using visual evoked potentials and brainstem auditory evoked potentials. Optic pathway dysfunction was detected in 6/7 anti-MAG neuropathy patients, about half of those with CIDP and HNPP, but only in 1/6 patients with CMT1A. Peripheral auditory nerve dysfunction appeared common in all groups except HNPP. Brainstem involvement was exceptional in all groups. We conclude optic nerve involvement may be frequent in all demyelinating polyneuropathies, particularly anti-MAG neuropathy, except in CMT1A. Peripheral auditory nerves may be spared in HNPP possibly due to absence of local compression. Evidence for central brainstem pathology appeared infrequent in all four studied neuropathies. This study suggests that acquired and genetic demyelinating polyneuropathies may be associated with optic and auditory nerve involvement, which may contribute to neurological disability, and require greater awareness. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Demyelinating disease in SLE: is it multiple sclerosis or lupus?

    Science.gov (United States)

    Magro Checa, César; Cohen, Danielle; Bollen, Eduard L E M; van Buchem, Mark A; Huizinga, Tom W J; Steup-Beekman, Gerda M

    2013-06-01

    Among the 12 systemic lupus erythematosus (SLE)-related central nervous system (CNS) syndromes defined by the American College of Rheumatology (ACR), demyelinating syndrome and myelopathy are two of the less prevalent and more poorly understood ones. One important issue concerning demyelinating disease in SLE is that it can be easily misdiagnosed with other central nervous system demyelinating disorders such as multiple sclerosis (MS). A clinically isolated neurological syndrome can be the presenting feature before other concomitant symptoms of SLE appear or definite MS is diagnosed. Although challenging, some diagnostic tests used in clinical practice and research may help to differentiate between these entities. These tests have improved the understanding of the pathogenesis in these diseases, but some points, such as the role of antiphospholipid antibodies in SLE-associated transverse myelitis, remain unclear and are a matter of ongoing debate. This review discusses clinical, pathophysiological, radiological and therapeutic concepts of demyelinating disease of the CNS in SLE, focussing on its differentiation from MS and its relation with other CNS demyelinating processes, such as transverse myelitis, optic neuritis and neuromyelitis optica. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Diagnosis and treatment of chronic acquired demyelinating polyneuropathies.

    Science.gov (United States)

    Latov, Norman

    2014-08-01

    Chronic neuropathies are operationally classified as primarily demyelinating or axonal, on the basis of electrodiagnostic or pathological criteria. Demyelinating neuropathies are further classified as hereditary or acquired-this distinction is important, because the acquired neuropathies are immune-mediated and, thus, amenable to treatment. The acquired chronic demyelinating neuropathies include chronic inflammatory demyelinating polyneuropathy (CIDP), neuropathy associated with monoclonal IgM antibodies to myelin-associated glycoprotein (MAG; anti-MAG neuropathy), multifocal motor neuropathy (MMN), and POEMS syndrome. They have characteristic--though overlapping--clinical presentations, are mediated by distinct immune mechanisms, and respond to different therapies. CIDP is the default diagnosis if the neuropathy is demyelinating and no other cause is found. Anti-MAG neuropathy is diagnosed on the basis of the presence of anti-MAG antibodies, MMN is characterized by multifocal weakness and motor conduction blocks, and POEMS syndrome is associated with IgG or IgA λ-type monoclonal gammopathy and osteosclerotic myeloma. The correct diagnosis, however, can be difficult to make in patients with atypical or overlapping presentations, or nondefinitive laboratory studies. First-line treatments include intravenous immunoglobulin (IVIg), corticosteroids or plasmapheresis for CIDP; IVIg for MMN; rituximab for anti-MAG neuropathy; and irradiation or chemotherapy for POEMS syndrome. A correct diagnosis is required for choosing the appropriate treatment, with the aim of preventing progressive neuropathy.

  14. Dynamic vehicle model for handling performance using experimental data

    Directory of Open Access Journals (Sweden)

    SangDo Na

    2015-11-01

    Full Text Available An analytical vehicle model is essential for the development of vehicle design and performance. Various vehicle models have different complexities, assumptions and limitations depending on the type of vehicle analysis. An accurate full vehicle model is essential in representing the behaviour of the vehicle in order to estimate vehicle dynamic system performance such as ride comfort and handling. An experimental vehicle model is developed in this article, which employs experimental kinematic and compliance data measured between the wheel and chassis. From these data, a vehicle model, which includes dynamic effects due to vehicle geometry changes, has been developed. The experimental vehicle model was validated using an instrumented experimental vehicle and data such as a step change steering input. This article shows a process to develop and validate an experimental vehicle model to enhance the accuracy of handling performance, which comes from precise suspension model measured by experimental data of a vehicle. The experimental force data obtained from a suspension parameter measuring device are employed for a precise modelling of the steering and handling response. The steering system is modelled by a lumped model, with stiffness coefficients defined and identified by comparing steering stiffness obtained by the measured data. The outputs, specifically the yaw rate and lateral acceleration of the vehicle, are verified by experimental results.

  15. Chronic inflammatory demyelinating polyradiculoneuropathy: from pathology to phenotype

    Science.gov (United States)

    Mathey, Emily K; Park, Susanna B; Hughes, Richard A C; Pollard, John D; Armati, Patricia J; Barnett, Michael H; Taylor, Bruce V; Dyck, P James B; Kiernan, Matthew C; Lin, Cindy S-Y

    2015-01-01

    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an inflammatory neuropathy, classically characterised by a slowly progressive onset and symmetrical, sensorimotor involvement. However, there are many phenotypic variants, suggesting that CIDP may not be a discrete disease entity but rather a spectrum of related conditions. While the abiding theory of CIDP pathogenesis is that cell-mediated and humoral mechanisms act together in an aberrant immune response to cause damage to peripheral nerves, the relative contributions of T cell and autoantibody responses remain largely undefined. In animal models of spontaneous inflammatory neuropathy, T cell responses to defined myelin antigens are responsible. In other human inflammatory neuropathies, there is evidence of antibody responses to Schwann cell, compact myelin or nodal antigens. In this review, the roles of the cellular and humoral immune systems in the pathogenesis of CIDP will be discussed. In time, it is anticipated that delineation of clinical phenotypes and the underlying disease mechanisms might help guide diagnostic and individualised treatment strategies for CIDP. PMID:25677463

  16. Chronic inflammatory demyelinating polyneuropathy associated with primary biliary cirrhosis.

    Science.gov (United States)

    Murata, Ken-ya; Ishiguchi, Hiroshi; Ando, Ryuki; Miwa, Hideto; Kondo, Tomoyoshi

    2013-12-01

    We report a patient with chronic inflammatory demyelinating polyneuropathy associated with primary biliary cirrhosis (PBC). Except for minimal biochemical abnormalities, clinical symptoms of PBC were not observed, and we diagnosed our patient with asymptomatic PBC from the results of a liver biopsy. Although the patient noticed little muscle weakness, an electrophysiological study demonstrated slow conduction velocities and prolonged distal latencies, with definite conduction blocks in the median, ulnar, and tibial nerves. The disturbed sensory pattern was asymmetrical, and sensory nerve action potentials were not evoked. From these observations, we diagnosed this patient with chronic inflammatory demyelinating polyneuropathy. Neuropathy associated with PBC is very rare. We must differentiate demyelinating neuropathy with PBC in patients with asymmetrical sensory dominant neuropathy with high immunoglobulin M titers, and investigate for the presence of anti-mitochondrial antibodies to rule out a complication of asymptomatic PBC. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Multifocal sensory demyelinating neuropathy: Report of a case.

    Science.gov (United States)

    Oh, Shin J

    2017-10-01

    Multifocal sensory demyelinating neuropathy has not been adequately reported in the literature. A 42-year-old man with numbness of the left hand for 3 years and of the right hand for 6 months had a pure multifocal sensory neuropathy involving both hands, most prominently affecting 2-point discrimination, number writing, and object recognition of the left hand. Near-nerve needle sensory and mixed nerve conduction studies were performed on the left ulnar nerve. Studies of the left ulnar nerve documented a demyelinating neuropathy characterized by temporal dispersion and marked decrease in the amplitudes of the sensory and mixed compound nerve potentials in the above-elbow-axilla segment. With intravenous immunoglobulin treatment, there was improvement in his neuropathic condition. In this study I describe a case of multifocal sensory demyelinating neuropathy as a counterpart of multifocal motor neuropathy. Muscle Nerve 56: 825-828, 2017. © 2016 Wiley Periodicals, Inc.

  18. Tumefactive demyelinating lesions during etanercept treatment requiring decompressive hemicraniectomy.

    Science.gov (United States)

    Cereda, C W; Zecca, C; Mazzucchelli, L; Valci, L; Staedler, C; Bassetti, C L; Gobbi, C

    2013-05-01

    Tumor necrosis factor alpha (TNF-α) is a pro-inflammatory and immunoregulatory cytokine involved in the pathogenesis of several autoimmune disorders. Etanercept, a TNF-α antagonist (anti-TNF-α) acting as a soluble TNF-α receptor, has been associated with neurological demyelinating disorders. This paper aims to report an unusual case showing tumefactive central nervous system (CNS) inflammatory demyelination in a patient in the course of TNF -α antagonist therapy, requiring decompressive hemicraniectomy. This report is based on magnetic resonance imaging (MRI) findings and histology. A biopsy confirmed the inflammatory demyelinating nature of the lesions. The clinical presentation is unusual due to the severity of the disease process, requiring decompressive hemicraniotomy with a clinically favorable outcome.

  19. Experimental comparison of models for ultrafast impact ionization is silicon

    DEFF Research Database (Denmark)

    Tarekegne, Abebe Tilahun; Iwaszczuk, Krzysztof; Jepsen, Peter Uhd

    2016-01-01

    We compare experimentally the exponential and quadratic (Keldysh formula) impact ionization models using THz induced impact ionization in silicon. We demonstrate that the exponential model offers the best description of impact ionization process for ultrashort electric filed pulses....

  20. Microglia-induced activation of noncanonical Wnt signaling aggravates neurodegeneration in demyelinating disorders

    NARCIS (Netherlands)

    Shimizu, T. (Takeshi); M.J.M. Smits (Ron); Ikenaka, K. (Kazuhiro)

    2016-01-01

    textabstractOligodendrocytes are myelinating cells of the central nervous system. Multiple sclerosis (MS) is a demyelinating disease characterized by both myelin loss and neuronal degeneration. However, the molecular mechanisms underlying neuronal degeneration in demyelinating disorders are not

  1. White matter changes in paediatric multiple sclerosis and monophasic demyelinating disorders.

    Science.gov (United States)

    Longoni, Giulia; Brown, Robert A; MomayyezSiahkal, Parya; Elliott, Colm; Narayanan, Sridar; Bar-Or, Amit; Marrie, Ruth Ann; Yeh, E Ann; Filippi, Massimo; Banwell, Brenda; Arnold, Douglas L

    2017-05-01

    See Hacohen et al. (doi:10.1093/awx075) for a scientific commentary on this article. Most children who experience an acquired demyelinating syndrome of the central nervous system will have a monophasic disease course, with no further clinical or radiological symptoms. A subset will be diagnosed with multiple sclerosis, a life-long disorder. Using linear mixed effects models we examined longitudinal diffusion properties of normal-appearing white matter in 505 serial scans of 132 paediatric participants with acquired demyelinating syndromes followed for a median of 4.4 years, many from first clinical presentation, and 106 scans of 80 healthy paediatric participants. Fifty-three participants with demyelinating syndromes eventually received a diagnosis of paediatric-onset multiple sclerosis. Diffusion tensor imaging measures properties of water diffusion through tissue, which normally becomes increasingly restricted and anisotropic in the brain during childhood and adolescence, as fibre bundles develop and myelinate. In the healthy paediatric participants, our data demonstrate the expected trajectory of more restricted and anisotropic white matter diffusivity with increasing age. However, in participants with multiple sclerosis, fractional anisotropy decreased and mean diffusivity of non-lesional, normal-appearing white matter progressively increased after clinical presentation, suggesting not only a failure of age-expected white matter development but also a progressive loss of tissue integrity. Surprisingly, patients with monophasic disease failed to show age-expected changes in diffusion parameters in normal-appearing white matter, although they did not show progressive loss of integrity over time. Further analysis demonstrated that participants with monophasic disease experienced different post-onset trajectories in normal-appearing white matter depending on their presenting phenotype: those with acute disseminated encephalomyelitis demonstrated abnormal

  2. The spectrum of post-vaccination inflammatory CNS demyelinating syndromes.

    Science.gov (United States)

    Karussis, Dimitrios; Petrou, Panayiota

    2014-03-01

    A wide variety of inflammatory diseases temporally associated with the administration of various vaccines, has been reported in the literature. A PubMed search from 1979 to 2013 revealed seventy one (71) documented cases. The most commonly reported vaccinations that were associated with CNS demyelinating diseases included influenza (21 cases), human papilloma virus (HPV) (9 cases), hepatitis A or B (8 cases), rabies (5 cases), measles (5 cases), rubella (5 cases), yellow fever (3 cases), anthrax (2 cases),meningococcus (2 cases) and tetanus (2 cases). The vast majority of post-vaccination CNS demyelinating syndromes, are related to influenza vaccination and this could be attributed to the high percentage of the population that received the vaccine during the HI1N1 epidemia from 2009 to 2012. Usually the symptoms of the CNS demyelinating syndrome appear few days following the immunization (mean: 14.2 days) but there are cases where the clinical presentation was delayed (more than 3 weeks or even up to 5 months post-vaccination) (approximately a third of all the reported cases). In terms of the clinical presentation and the affected CNS areas, there is a great diversity among the reported cases of post-vaccination acute demyelinating syndromes. Optic neuritis was the prominent clinical presentation in 38 cases, multifocal disseminated demyelination in 30, myelitis in 24 and encephalitis in 17. Interestingly in a rather high proportion of the patients (and especially following influenza and human papiloma virus vaccination-HPV) the dominant localizations of demyelination were the optic nerves and the myelon, presenting as optic neuritis and myelitis (with or without additional manifestations of ADEM), reminiscent to neuromyelitic optica (or, more generally, the NMO-spectrum of diseases). Seven patients suffered an NMO-like disease following HPV and we had two similar cases in our Center. One patient with post-vaccination ADEM, subsequently developed NMO. Overall, the

  3. Studies on experimental models used for nutritional and biological ...

    African Journals Online (AJOL)

    The anatomical location for a successful implantation in order to reduce complications to the hearest minimum has been suggested . The maintenance of the implanted cannulae for the purpose of keeping the modified experimental model in perfect health is discussed. Key Words: Experimental Models, Nutritional Biological ...

  4. Tumefactive demyelinating lesions: Characteristics of individual lesions, individual patients, or a unique disease entity?

    Science.gov (United States)

    Weinshenker, Brian G

    2015-11-01

    Whether or not recurrent tumefactive demyelinating lesions are a unique form of CNS demyelinating disease or part of the continuum of multiple sclerosis is a question raised by the case report on which this commentary is based. Detailed review and immunopathologic study of biopsy material may not only confirm or refute a diagnosis of demyelinating disease, but potentially uncover unique features that may assist in understanding pathophysiology and nosology of rare cases with recurrent tumefactive demyelination. © The Author(s), 2015.

  5. Improving the physiological realism of experimental models

    NARCIS (Netherlands)

    Vinnakota, Kalyan C.; Cha, Chae Y.; Rorsman, Patrik; Balaban, Robert S.; La Gerche, Andre; Wade-Martins, Richard; Beard, Daniel A.; Jeneson, Jeroen A. L.

    The Virtual Physiological Human (VPH) project aims to develop integrative, explanatory and predictive computational models (C-Models) as numerical investigational tools to study disease, identify and design effective therapies and provide an in silico platform for drug screening. Ultimately, these

  6. Teriflunomide reduces behavioral, electrophysiological, and histopathological deficits in the Dark Agouti rat model of experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Merrill, Jean E; Hanak, Susan; Pu, Su-Fen; Liang, Jinjun; Dang, Chelsea; Iglesias-Bregna, Deborah; Harvey, Brian; Zhu, Bin; McMonagle-Strucko, Kathleen

    2009-01-01

    Teriflunomide is an orally available anti-inflammatory drug that prevents T and B cell proliferation and function by inhibition of dihydroorotate dehydrogenase. It is currently being developed for the treatment of multiple sclerosis (MS). We report here for the first time the anti-inflammatory effects of teriflunomide in the Dark Agouti rat model of experimental autoimmune encephalomyelitis (EAE). Neurological evaluation demonstrated that prophylactic dosing of teriflunomide at 3 and 10 mg/kg delayed disease onset and reduced maximal and cumulative scores. Therapeutic administration of teriflunomide at doses of 3 or 10 mg/kg at disease onset significantly reduced maximal and cumulative disease scores as compared to vehicle treated rats. Dosing teriflunomide at disease remission, at 3 and 10 mg/kg, reduced the cumulative scores for the remaining course of the disease. Teriflunomide at 10 mg/kg significantly reduced inflammation, demyelination, and axonal loss when dosed prophylactically or therapeutically. In electrophysiological somatosensory evoked potential studies, therapeutic administration of teriflunomide, at the onset of disease, prevented both a decrease in waveform amplitude and an increase in the latency to waveform initiation in EAE animals compared to vehicle. Therapeutic dosing with teriflunomide at disease remission prevented a decrease in evoked potential amplitude, prevented an increase in latency, and enhanced recovery time within the CNS.

  7. Therapeutic testosterone administration preserves excitatory synaptic transmission in the hippocampus during autoimmune demyelinating disease.

    Science.gov (United States)

    Ziehn, Marina O; Avedisian, Andrea A; Dervin, Shannon M; Umeda, Elizabeth A; O'Dell, Thomas J; Voskuhl, Rhonda R

    2012-09-05

    Over 50% of multiple sclerosis (MS) patients experience cognitive deficits, and hippocampal-dependent memory impairment has been reported in >30% of these patients. While postmortem pathology studies and in vivo magnetic resonance imaging demonstrate that the hippocampus is targeted in MS, the neuropathology underlying hippocampal dysfunction remains unknown. Furthermore, there are no treatments available to date to effectively prevent neurodegeneration and associated cognitive dysfunction in MS. We have recently demonstrated that the hippocampus is also targeted in experimental autoimmune encephalomyelitis (EAE), the most widely used animal model of MS. The objective of this study was to assess whether a candidate treatment (testosterone) could prevent hippocampal synaptic dysfunction and underlying pathology when administered in either a preventative or a therapeutic (postdisease induction) manner. Electrophysiological studies revealed impairments in basal excitatory synaptic transmission that involved both AMPA receptor-mediated changes in synaptic currents, and faster decay rates of NMDA receptor-mediated currents in mice with EAE. Neuropathology revealed atrophy of the pyramidal and dendritic layers of hippocampal CA1, decreased presynaptic (Synapsin-1) and postsynaptic (postsynaptic density 95; PSD-95) staining, diffuse demyelination, and microglial activation. Testosterone treatment administered either before or after disease induction restores excitatory synaptic transmission as well as presynaptic and postsynaptic protein levels within the hippocampus. Furthermore, cross-modality correlations demonstrate that fluctuations in EPSPs are significantly correlated to changes in postsynaptic protein levels and suggest that PSD-95 is a neuropathological substrate to impaired synaptic transmission in the hippocampus during EAE. This is the first report demonstrating that testosterone is a viable therapeutic treatment option that can restore both hippocampal

  8. Experimental Diabetes Mellitus in Different Animal Models

    Directory of Open Access Journals (Sweden)

    Amin Al-awar

    2016-01-01

    Full Text Available Animal models have historically played a critical role in the exploration and characterization of disease pathophysiology and target identification and in the evaluation of novel therapeutic agents and treatments in vivo. Diabetes mellitus disease, commonly known as diabetes, is a group of metabolic disorders characterized by high blood glucose levels for a prolonged time. To avoid late complications of diabetes and related costs, primary prevention and early treatment are therefore necessary. Due to its chronic symptoms, new treatment strategies need to be developed, because of the limited effectiveness of the current therapies. We overviewed the pathophysiological features of diabetes in relation to its complications in type 1 and type 2 mice along with rat models, including Zucker Diabetic Fatty (ZDF rats, BB rats, LEW 1AR1/-iddm rats, Goto-Kakizaki rats, chemically induced diabetic models, and Nonobese Diabetic mouse, and Akita mice model. The advantages and disadvantages that these models comprise were also addressed in this review. This paper briefly reviews the wide pathophysiological and molecular mechanisms associated with type 1 and type 2 diabetes, particularly focusing on the challenges associated with the evaluation and predictive validation of these models as ideal animal models for preclinical assessments and discovering new drugs and therapeutic agents for translational application in humans.

  9. Experimental model to induce obesity in rats

    National Research Council Canada - National Science Library

    Vinicius Von Diemen; Eduardo Neubarth Trindade; Manoel Roberto Maciel Trindade

    2006-01-01

    .... Obesity can be induced in animals by neuroendocrine, dietary or genetic changes. The most widely used models to induce obesity in rats are a lesion of the ventromedial hypothalamic nucleus (VMH...

  10. Optimization of experimental human leukemia models (review

    Directory of Open Access Journals (Sweden)

    D. D. Pankov

    2012-01-01

    Full Text Available Actual problem of assessing immunotherapy prospects including antigenpecific cell therapy using animal models was covered in this review.Describe the various groups of currently existing animal models and methods of their creating – from different immunodeficient mice to severalvariants of tumor cells engraftment in them. The review addresses the possibility of tumor stem cells studying using mouse models for the leukemia treatment with adoptive cell therapy including WT1. Also issues of human leukemia cells migration and proliferation in a mice withdifferent immunodeficiency degree are discussed. To assess the potential immunotherapy efficacy comparison of immunodeficient mouse model with clinical situation in oncology patients after chemotherapy is proposed.

  11. Experimental model of arteriovenous malformation in vitro using biological grafts

    Directory of Open Access Journals (Sweden)

    Sandu Aurelia Mihaela

    2015-06-01

    Full Text Available Introduction: Brain arteriovenous malformations (AVMs represent a serious health problem all around the world. Experimental models help to better understand the pathophysiology of these lesions. Experiment: We performed an experimental model of AVM using biological grafts, arteries and veins harvested from chicken wings at the elbow joint. We used 14 vessels and we performed 20 end-to-end anastomoses to create a nidus with a single feeding artery and a single draining vein. The system was irrigated with colored solution. The experiment was done according with law in force regarding experimental research activity. Conclusions: Experimental models allow us to understand the hemodynamics and predict the outcome of brain AVMs in humans. This experimental model is a useful tool in understanding the hemodynamic properties of brain AVMs. It is very useful in vascular anastomosis training

  12. An experimental comparison of modelling techniques for speaker ...

    Indian Academy of Sciences (India)

    Most of the existing modelling techniques for the speaker recognition task make an implicit assumption of sufficient data for speaker modelling and hence may lead to poor modelling under limited data condition. The present work gives an experimental evaluation of the modelling techniques like Crisp Vector Quantization ...

  13. Innate immune CD11b+Gr-1+ cells, suppressor cells, affect the immune response during Theiler's virus-induced demyelinating disease.

    Science.gov (United States)

    Bowen, Jenna L; Olson, Julie K

    2009-12-01

    Multiple sclerosis is a demyelinating disease associated with an inflammatory immune response in the CNS. Theiler's murine encephalomyelitis virus (TMEV)-induced demyelinating disease is a relevant mouse model for the study of multiple sclerosis. TMEV infection of susceptible mice leads to a persistent virus infection of the CNS which contributes to development of demyelinating disease. We have previously shown that the innate immune response can affect the development and progression of demyelinating disease. In the current studies, we determined that the predominant infiltrating cells during the innate immune response are CD11b(+)Ly6C(+) cells. CD11b(+)Ly6C(+) cells are immature myeloid cells that have exited the bone marrow without maturing and have been shown to suppress CD4(+) and CD8(+) T cell responses. Therefore, we wanted to determine what role these cells play in development and progression of demyelinating disease. TMEV-infected mice depleted of CD11b(+)Ly6C(+) cells during the innate immune response developed a reduced demyelinating disease which was associated with a decreased myelin-specific CD4(+) T cell response and a decreased inflammatory immune response in the CNS. TMEV-infected mice depleted of CD11b(+)Ly6C(+) cells had increased virus-specific CD4(+) and CD8(+) T cell responses during early virus infection associated with increased expression of IFN-gamma and IL-17 and decreased expression of IL-10 in the CNS. These results suggest that CD11b(+)Ly6C(+) cells which infiltrate into the CNS during the innate immune response are myeloid-derived suppressor cells that suppress virus-specific T cell responses and contribute to the development of demyelinating disease.

  14. Hysteretic behavior of a belt tensioner: modeling and experimental investigation

    OpenAIRE

    Michon, Guilhem; Manin, Lionel; Dufour, Regis

    2005-01-01

    In this paper we describe the modeling of the hysteretic behavior of belt tensioners. An initial experimental device is composed only of the tensioner by using forcing frequencies, preloads and deflection amplitudes. It permits the identification of the parameters of the restoring force model used. Comparison of the measured and predicted force deflection loops of the tensioner subjected to large deflections permits preliminary validation of the model.The second experimental device consists o...

  15. Spatial and temporal profiles of growth factor expression during CNS demyelination reveal the dynamics of repair priming.

    Directory of Open Access Journals (Sweden)

    Viktoria Gudi

    Full Text Available Demyelination is the cause of disability in various neurological disorders. It is therefore crucial to understand the molecular regulation of oligodendrocytes, the myelin forming cells in the CNS. Growth factors are known to be essential for the development and maintenance of oligodendrocytes and are involved in the regulation of glial responses in various pathological conditions. We employed the well established murine cuprizone model of toxic demyelination to analyze the expression of 13 growth factors in the CNS during de- and remyelination. The temporal mRNA expression profile during demyelination and the subsequent remyelination were analyzed separately in the corpus callosum and cerebral cortex using laser microdissection and real-time PCR techniques. During demyelination a similar pattern of growth factor mRNA expression was observed in both areas with a strong up-regulation of NRG1 and GDNF and a slight increase of CNTF in the first week of cuprizone treatment. HGF, FGF-2, LIF, IGF-I, and TGF-ß1 were up-regulated mainly during peak demyelination. In contrast, during remyelination there were regional differences in growth factor mRNA expression levels. GDNF, CNTF, HGF, FGF-2, and BDNF were elevated in the corpus callosum but not in the cortex, suggesting tissue differences in the molecular regulation of remyelination in the white and grey matter. To clarify the cellular source we isolated microglia from the cuprizone lesions. GDNF, IGF-1, and FGF mRNA were detected in the microglial fraction with a temporal pattern corresponding to that from whole tissue PCR. In addition, immunohistochemical analysis revealed IGF-1 protein expression also in the reactive astrocytes. CNTF was located in astrocytes. This study identified seven different temporal expression patterns for growth factors in white and grey matter and demonstrated the importance of early tissue priming and exact orchestration of different steps during callosal and cortical de

  16. CAMFAK syndrome: a demyelinating inherited disease similar to Cockayne syndrome.

    Science.gov (United States)

    Talwar, D; Smith, S A

    1989-10-01

    CAMFAK syndrome is an inherited disease characterized by congenital cataracts, microcephaly, failure to thrive, and kyphoscoliosis with onset in early infancy. Its pathogenesis has not been clearly defined. We report on a patient with this syndrome and present evidence that it is a neurologic disease characterized by peripheral and central demyelination similar to that seen in Cockayne syndrome.

  17. Intravenous immunoglobulin treatment in chronic inflammatory demyelinating polyneuropathy

    NARCIS (Netherlands)

    P.A. van Doorn (Pieter)

    1990-01-01

    textabstractPatients with a chronic inflammatory demyelinating polyneuropathy (CIDP) may respond to treatment with corticosteroids and to plasmapheresis, which was demonstrated in controlled clinical studies. In an uncontrolled study it was found that 13/17 CIDP patients had a rapid and

  18. Coexisting neuronal autoantibodies among children with demyelinating syndromes.

    Science.gov (United States)

    Kıztanır, Hikmet; Bektaş, Gonca; Yıldız, Edibe Pembegül; Uzunhan, Tuğçe Aksu; Tatlı, Burak; Aydınlı, Nur; Çalışkan, Mine; Özmen, Meral

    2017-03-01

    To determine the incidence and clinical relevance of neuronal autoantibodies in children with demyelinating syndromes. We conducted a prospective study including 31 consecutive children with demyelinating syndromes. Four patients with N-Methyl-D-aspartate receptor (NMDAR) encephalitis, 32 patients with Guillain-Barre syndrome, 13 children with benign childhood epilepsy, and 28 healthy children were used as controls. Prior to initiating immunomodulatory therapy, serum samples were tested for antibodies against NMDAR, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) 1, AMPAR2, leucine-rich glioma-activated protein 1, contactin-associated protein 2, gamma-aminobutyric acid B receptors, paraneoplastic ma antigen 2 (PNMA2/Ta), Yo, Ri, Hu, CV2, amphiphysin, and aquaporin-4 by indirect immunofluorescence assays. Three anti-neuronal antibodies were detected; NMDAR antibody in one with multiple sclerosis, PNMA2/Ta antibody in one with multiple sclerosis, and Yo antibody in one with clinically isolated syndrome. The positivity rate of neuronal autoantibodies in demyelinating syndrome was 10%. All seropositive patients were found to be negative for tumor screening. None of these patients exhibited symptoms of encephalitis. Children with demyelinating syndromes without symptoms of encephalitis can be positive for anti-neuronal antibodies. Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  19. Does Campylobacter jejuni infection elicit "demyelinating" Guillain-Barre syndrome?

    Science.gov (United States)

    Kuwabara, S; Ogawara, K; Misawa, S; Koga, M; Mori, M; Hiraga, A; Kanesaka, T; Hattori, T; Yuki, N

    2004-08-10

    Campylobacter jejuni enteritis is the most common antecedent infection in Guillain-Barré syndrome (GBS). C. jejuni-related GBS is usually acute motor axonal neuropathy (AMAN), but previous reports described many cases of the demyelinating subtype of GBS (acute inflammatory demyelinating polyneuropathy [AIDP]) after C. jejuni infection. To investigate whether C. jejuni infection elicits AIDP. In 159 consecutive patients with GBS, antibodies against C. jejuni were measured using ELISA. Antecedent C. jejuni infection was determined by the strict criteria of positive C. jejuni serology and a history of a diarrheal illness within the previous 3 weeks. Electrodiagnostic studies were performed weekly for the first 4 weeks, and sequential findings were analyzed. There was evidence of recent C. jejuni infection in 22 (14%) patients. By electrodiagnostic criteria, these patients were classified with AMAN (n = 16; 73%) or AIDP (n = 5; 23%) or as unclassified (n = 1) in the first studies. The five C. jejuni-positive patients with the AIDP pattern showed prolonged motor distal latencies in two or more nerves and had their rapid normalization within 2 weeks, eventually all showing the AMAN pattern. In contrast, patients with cytomegalovirus- or Epstein-Barr virus-related AIDP (n = 13) showed progressive increases in distal latencies in the 8 weeks after onset. Patients with C. jejuni-related Guillain-Barré syndrome can show transient slowing of nerve conduction, mimicking demyelination, but C. jejuni infection does not appear to elicit acute inflammatory demyelinating polyneuropathy.

  20. Involvement of morbilliviruses in the pathogenesis of demyelinating disease

    NARCIS (Netherlands)

    Sips, G. J.; Chesik, D.; Glazenburg, L.; Wilschut, J.; De Keyser, J.; Wilczak, N.

    2007-01-01

    Two members of the morbillivirus genus of the family Paramyxoviridae, canine distemper virus (CDV) and measles virus (MV), are well-known for their ability to cause a chronic demyelinating disease of the CNS in their natural hosts, dogs and humans, respectively. Both viruses have been studied for

  1. Acquired demyelinating disorders of central nervous system: A pediatric cohort

    Directory of Open Access Journals (Sweden)

    Sheffali Gulati

    2015-01-01

    Full Text Available Objective : This is a retrospective chart review of consecutive children with acquired demyelinating disorders presenting to a north Indian tertiary care hospital over 4 years. The aim of this review is to describe all the patients (with single event as well as those with recurrences with detailed description of those who recurred. Materials and Methods: Overall 35 cases were reviewed and their clinical presentations, diagnosis, management, and follow-up are being presented. Results : Out of 35 cases, 24 did not show any recurrences (seven acute disseminated encephalomyelitis (ADEM and 17 clinically isolated syndromes. Amongst the 11 patients with recurrent demyelination, majority were multiple sclerosis (8/11, 72.7% followed by neuromyelitis optica (NMO; 2/11, and multiphasic ADEM (1/11. The median disease duration and follow-up since onset for those with recurrent episodes is 4 years (2.5-4.5 years. Steroids caused significant improvement in acute episodes of demyelination. However, recurrent demyelinating disorders like multiple sclerosis and NMO required long-term immunomodulation. Azathioprine currently is the most favored long-term immunomodulator used in NMO. Interferon-β and glatiramer acetate are currently recommended for multiple sclerosis. However, azathioprine may be a suitable alternative in a resource-limited setting. Conclusion : The consensus definitions for these groups of disorders need further validation in the pediatric age group. Studies with larger population size are required to characterize features that predict future recurrences.

  2. Acute Inflammatory Demyelination: MRI Prognostic Factors for Relapse

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-09-01

    Full Text Available Initial MRI factors predictive of a second attack and disability following a first episode of acute CNS inflammatory demyelination in a cohort of 116 children seen between 1990 and 2002 were studied at the Hopital Cochin-Saint-Vincent de Paul, Paris; Hopital Bicetre, Lille; Hopital Neurologique, Lyon, France; and McGill University, Montreal, Canada.

  3. Familial Hemophagocytic Lymphohistiocytosis Type 3 with Demyelinating CNS Disease

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2009-02-01

    Full Text Available A case of familial hemophagocytic lymphohistiocytosis type 3 (FHLH3 presenting in a 3-year-old boy with fulminant demyelinating neurological disease is reported by researchers at Kravis Children’s Hospital at Mount Sinai Medical Center, New York.

  4. Experimental Measurement, Analysis and Modelling of Dependency ...

    African Journals Online (AJOL)

    We propose a direct method of measurement of the total emissivity of opaque samples on a range of temperature around the ambient one. The method rests on the modulation of the temperature of the sample and the infra-red signal processing resulting from the surface of the sample we model the total emissivity obtained ...

  5. Early loss of oligodendrocytes in human and experimental neuromyelitis optica lesions.

    Science.gov (United States)

    Wrzos, Claudia; Winkler, Anne; Metz, Imke; Kayser, Dieter M; Thal, Dietmar R; Wegner, Christiane; Brück, Wolfgang; Nessler, Stefan; Bennett, Jeffrey L; Stadelmann, Christine

    2014-04-01

    Neuromyelitis optica (NMO) is a chronic, mostly relapsing inflammatory demyelinating disease of the CNS characterized by serum anti-aquaporin 4 (AQP4) antibodies in the majority of patients. Anti-AQP4 antibodies derived from NMO patients target and deplete astrocytes in experimental models when co-injected with complement. However, the time course and mechanisms of oligodendrocyte loss and demyelination and the fate of oligodendrocyte precursor cells (OPC) have not been examined in detail. Also, no studies regarding astrocyte repopulation of experimental NMO lesions have been reported. We utilized two rat models using either systemic transfer or focal intracerebral injection of recombinant human anti-AQP4 antibodies to generate NMO-like lesions. Time-course experiments were performed to examine oligodendroglial and astroglial damage and repair. In addition, oligodendrocyte pathology was studied in early human NMO lesions. Apart from early complement-mediated astrocyte destruction, we observed a prominent, very early loss of oligodendrocytes and oligodendrocyte precursor cells (OPCs) as well as a delayed loss of myelin. Astrocyte repopulation of focal NMO lesions was already substantial after 1 week. Olig2-positive OPCs reappeared before NogoA-positive, mature oligodendrocytes. Thus, using two experimental models that closely mimic the human disease, our study demonstrates that oligodendrocyte and OPC loss is an extremely early feature in the formation of human and experimental NMO lesions and leads to subsequent, delayed demyelination, highlighting an important difference in the pathogenesis of MS and NMO.

  6. New experimental model for training in videosurgery Novo modelo experimental para treinamento em videocirurgia

    Directory of Open Access Journals (Sweden)

    Danilo Malta Batista

    2012-10-01

    Full Text Available PURPOSE: To develop a new experimental model of lower cost for training in videosurgery. METHODS: This project was performed at the Nucleus of Experimental Surgery of the Bahiana School of Medicine and Public Health, based on previous models described in the literature and under the supervision of the full professor of Operative Technique and Experimental Surgery II. It was made a model cube-shaped, made of wood, with holes distributed in various locations, rubber stoppers for the holes and lined externally with carpet, and internally with laminate. RESULTS: The new experimental model is of low cost and reproduces quite faithfully several videosurgical procedures. CONCLUSION: Medical schools interested in the subject may adopt the new model for training in videosurgery without the need of high costs for making and using these models.OBJETIVO: Desenvolver um novo modelo experimental de baixo custo para treinamento em videocirurgia MÉTODOS: Este projeto foi conduzido no Núcleo de Cirurgia Experimental da Escola Bahiana de Medicina e Saúde Pública, baseado em modelos prévios descritos na literatura e sob a supervisão do professor titular de Técnica Operatória e Cirurgia Experimental II. Foi feito um modelo em formato de cubo, de madeira, com furos distribuídos em vários locais, tampas de borracha para os orifícios e forrado externamente com carpete e internamente com laminado. RESULTADOS: O novo modelo experimental desenvolvido é de baixo custo e reproduz de forma bastante fiel diversos procedimentos videocirúrgicos. CONCLUSÃO: Faculdades médicas interessadas no tema poderão adotar o novo modelo para o treinamento em videocirurgia sem que sejam necessários gastos elevados para a confecção e o uso desses modelos.

  7. Different experimental approaches in modelling cataractogenesis

    Science.gov (United States)

    Kyselova, Zuzana

    2010-01-01

    Cataract, the opacification of eye lens, is the leading cause of blindness worldwide. At present, the only remedy is surgical removal of the cataractous lens and substitution with a lens made of synthetic polymers. However, besides significant costs of operation and possible complications, an artificial lens just does not have the overall optical qualities of a normal one. Hence it remains a significant public health problem, and biochemical solutions or pharmacological interventions that will maintain the transparency of the lens are highly required. Naturally, there is a persistent demand for suitable biological models. The ocular lens would appear to be an ideal organ for maintaining culture conditions because of lacking blood vessels and nerves. The lens in vivo obtains its nutrients and eliminates waste products via diffusion with the surrounding fluids. Lens opacification observed in vivo can be mimicked in vitro by addition of the cataractogenic agent sodium selenite (Na2SeO3) to the culture medium. Moreover, since an overdose of sodium selenite induces also cataract in young rats, it became an extremely rapid and convenient model of nuclear cataract in vivo. The main focus of this review will be on selenium (Se) and its salt sodium selenite, their toxicological characteristics and safety data in relevance of modelling cataractogenesis, either under in vivo or in vitro conditions. The studies revealing the mechanisms of lens opacification induced by selenite are highlighted, the representatives from screening for potential anti-cataract agents are listed. PMID:21217865

  8. Experimentally testing the standard cosmological model

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, D.N. (Chicago Univ., IL (USA) Fermi National Accelerator Lab., Batavia, IL (USA))

    1990-11-01

    The standard model of cosmology, the big bang, is now being tested and confirmed to remarkable accuracy. Recent high precision measurements relate to the microwave background; and big bang nucleosynthesis. This paper focuses on the latter since that relates more directly to high energy experiments. In particular, the recent LEP (and SLC) results on the number of neutrinos are discussed as a positive laboratory test of the standard cosmology scenario. Discussion is presented on the improved light element observational data as well as the improved neutron lifetime data. alternate nucleosynthesis scenarios of decaying matter or of quark-hadron induced inhomogeneities are discussed. It is shown that when these scenarios are made to fit the observed abundances accurately, the resulting conclusions on the baryonic density relative to the critical density, {Omega}{sub b}, remain approximately the same as in the standard homogeneous case, thus, adding to the robustness of the standard model conclusion that {Omega}{sub b} {approximately} 0.06. This latter point is the deriving force behind the need for non-baryonic dark matter (assuming {Omega}{sub total} = 1) and the need for dark baryonic matter, since {Omega}{sub visible} < {Omega}{sub b}. Recent accelerator constraints on non-baryonic matter are discussed, showing that any massive cold dark matter candidate must now have a mass M{sub x} {approx gt} 20 GeV and an interaction weaker than the Z{sup 0} coupling to a neutrino. It is also noted that recent hints regarding the solar neutrino experiments coupled with the see-saw model for {nu}-masses may imply that the {nu}{sub {tau}} is a good hot dark matter candidate. 73 refs., 5 figs.

  9. Tesla coil theoretical model and experimental verification

    OpenAIRE

    Voitkans, Janis; Voitkans, Arnis

    2014-01-01

    Abstract – In this paper a theoretical model of a Tesla coil operation is proposed. Tesla coil is described as a long line with distributed parameters in a single-wired format, where the line voltage is measured against electrically neutral space. It is shown that equivalent two-wired scheme can be found for a single-wired scheme and already known long line theory can be applied to a Tesla coil. Formulas for calculation of voltage in a Tesla coil by coordinate and calculation of resonance fre...

  10. Mathematical Models and the Experimental Analysis of Behavior

    Science.gov (United States)

    Mazur, James E.

    2006-01-01

    The use of mathematical models in the experimental analysis of behavior has increased over the years, and they offer several advantages. Mathematical models require theorists to be precise and unambiguous, often allowing comparisons of competing theories that sound similar when stated in words. Sometimes different mathematical models may make…

  11. The effect of Cordia platythyrsa on various experimental models of ...

    African Journals Online (AJOL)

    The effect of Cordia platythyrsa on various experimental models of pain and carrageenan induced inflammation. Benedicta N Nkeh-Chungag, Eugene J Ndebia, Joseph T Mbafor, Lonwabo A Dotwana, OO Oyedeji, Jehu E Iputo ...

  12. Microplasticity of MMC. Experimental results and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Maire, E. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France)); Lormand, G. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France)); Gobin, P.F. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France)); Fougeres, R. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France))

    1993-11-01

    The microplastic behavior of several MMC is investigated by means of tension and compression tests. This behavior is assymetric : the proportional limit is higher in tension than in compression but the work hardening rate is higher in compression. These differences are analysed in terms of maxium of the Tresca's shear stress at the interface (proportional limit) and of the emission of dislocation loops during the cooling (work hardening rate). On another hand, a model is proposed to calculate the value of the yield stress, describing the composite as a material composed of three phases : inclusion, unaffected matrix and matrix surrounding the inclusion having a gradient in the density of the thermally induced dilocations. (orig.).

  13. Intracranial Demyelinating Pseudotumor: A Case Report and Review of the Literature.

    Science.gov (United States)

    Ning, Xianbin; Zhao, Changfu; Wang, Caiqin; Zhang, Duo; Luo, Qi

    2017-01-01

    Demyelinating pseudotumor is a rare inflammatory demyelinating disease of the central nervous system (CNS) that has a similar clinical presentation and computed tomography (CT) and magnetic resonance imaging (MRI) imaging findings as brain tumors or abscesses. Unlike brain tumors, demyelinating pseudotumors respond well to steroid hormones. There are only a few reported cases of intracranial demyelinating pseudotumors in the literature. In this case report, we present the diagnosis and treatment of demyelinating pseudotumor in a patient whose condition was initially misdiagnosed as an astrocytoma. Based on the literature and our case, we formulated an outline for the differential diagnosis of demyelinating pseudotumor and astrocytoma. A timely and correct diagnosis of demyelinating pseudotumor would avoid blind surgery, radiotherapy and chemotherapy, which are used to treat brain tumors.

  14. Exogenous schwann cells migrate, remyelinate and promote clinical recovery in experimental auto-immune encephalomyelitis.

    Directory of Open Access Journals (Sweden)

    Violetta Zujovic

    Full Text Available Schwann cell (SC transplantation is currently being discussed as a strategy that may promote functional recovery in patients with multiple sclerosis (MS and other inflammatory demyelinating diseases of the central nervous system (CNS. However this assumes they will not only survive but also remyelinate demyelinated axons in the chronically inflamed CNS. To address this question we investigated the fate of transplanted SCs in myelin oligodendrocyte glycoprotein (MOG-induced experimental autoimmune encephalomyelitis (EAE in the Dark Agouti rat; an animal model that reproduces the complex inflammatory demyelinating immunopathology of MS. We now report that SCs expressing green fluorescent protein (GFP-SCs allografted after disease onset not only survive but also migrate to remyelinate lesions in the inflamed CNS. GFP-SCs were detected more frequently in the parenchyma after direct injection into the spinal cord, than via intra-thecal delivery into the cerebrospinal fluid. In both cases the transplanted cells intermingled with astrocytes in demyelinated lesions, aligned with axons and by twenty one days post transplantation had formed Pzero protein immunoreactive internodes. Strikingly, GFP-SCs transplantation was associated with marked decrease in clinical disease severity in terms of mortality; all GFP-SCs transplanted animals survived whilst 80% of controls died within 40 days of disease.

  15. Exogenous Schwann Cells Migrate, Remyelinate and Promote Clinical Recovery in Experimental Auto-Immune Encephalomyelitis

    Science.gov (United States)

    Zujovic, Violetta; Doucerain, Cédric; Hidalgo, Antoine; Bachelin, Corinne; Lachapelle, François; Weissert, Robert; Stadelmann, Christine; Linington, Chris; Evercooren, Anne Baron-Van

    2012-01-01

    Schwann cell (SC) transplantation is currently being discussed as a strategy that may promote functional recovery in patients with multiple sclerosis (MS) and other inflammatory demyelinating diseases of the central nervous system (CNS). However this assumes they will not only survive but also remyelinate demyelinated axons in the chronically inflamed CNS. To address this question we investigated the fate of transplanted SCs in myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE) in the Dark Agouti rat; an animal model that reproduces the complex inflammatory demyelinating immunopathology of MS. We now report that SCs expressing green fluorescent protein (GFP-SCs) allografted after disease onset not only survive but also migrate to remyelinate lesions in the inflamed CNS. GFP-SCs were detected more frequently in the parenchyma after direct injection into the spinal cord, than via intra-thecal delivery into the cerebrospinal fluid. In both cases the transplanted cells intermingled with astrocytes in demyelinated lesions, aligned with axons and by twenty one days post transplantation had formed Pzero protein immunoreactive internodes. Strikingly, GFP-SCs transplantation was associated with marked decrease in clinical disease severity in terms of mortality; all GFP-SCs transplanted animals survived whilst 80% of controls died within 40 days of disease. PMID:22984406

  16. Experimental investigation of a flapping wing model

    Energy Technology Data Exchange (ETDEWEB)

    Hubel, Tatjana Y.; Tropea, Cameron [Technische Universitaet Darmstadt, Fachgebiet Stroemungslehre und Aerodynamik, Darmstadt (Germany)

    2009-05-15

    The main objective of this research study was to investigate the aerodynamic forces of an avian flapping wing model system. The model size and the flow conditions were chosen to approximate the flight of a goose. Direct force measurements, using a three-component balance, and PIV flow field measurements parallel and perpendicular to the oncoming flow, were performed in a wind tunnel at Reynolds numbers between 28,000 and 141,000 (3-15 m/s), throughout a range of reduced frequencies between 0.04 and 0.20. The appropriateness of quasi-steady assumptions used to compare 2D, time-averaged particle image velocimetry (PIV) measurements in the wake with direct force measurements was evaluated. The vertical force coefficient for flapping wings was typically significantly higher than the maximum coefficient of the fixed wing, implying the influence of unsteady effects, such as delayed stall, even at low reduced frequencies. This puts the validity of the quasi-steady assumption into question. The (local) change in circulation over the wing beat cycle and the circulation distribution along the wingspan were obtained from the measurements in the tip and transverse vortex planes. Flow separation could be observed in the distribution of the circulation, and while the circulation derived from the wake measurements failed to agree exactly with the absolute value of the circulation, the change in circulation over the wing beat cycle was in excellent agreement for low and moderate reduced frequencies. The comparison between the PIV measurements in the two perpendicular planes and the direct force balance measurements, show that within certain limitations the wake visualization is a powerful tool to gain insight into force generation and the flow behavior on flapping wings over the wing beat cycle. (orig.)

  17. Statistical approach for uncertainty quantification of experimental modal model parameters

    DEFF Research Database (Denmark)

    Luczak, M.; Peeters, B.; Kahsin, M.

    2014-01-01

    . This paper aims at a systematic approach for uncertainty quantification of the parameters of the modal models estimated from experimentally obtained data. Statistical analysis of modal parameters is implemented to derive an assessment of the entire modal model uncertainty measure. Investigated structures...... estimates obtained from vibration experiments. Modal testing results are influenced by numerous factors introducing uncertainty to the measurement results. Different experimental techniques applied to the same test item or testing numerous nominally identical specimens yields different test results...

  18. In silico simulations of experimental protocols for cardiac modeling.

    Science.gov (United States)

    Carro, Jesus; Rodriguez, Jose Felix; Pueyo, Esther

    2014-01-01

    A mathematical model of the AP involves the sum of different transmembrane ionic currents and the balance of intracellular ionic concentrations. To each ionic current corresponds an equation involving several effects. There are a number of model parameters that must be identified using specific experimental protocols in which the effects are considered as independent. However, when the model complexity grows, the interaction between effects becomes increasingly important. Therefore, model parameters identified considering the different effects as independent might be misleading. In this work, a novel methodology consisting in performing in silico simulations of the experimental protocol and then comparing experimental and simulated outcomes is proposed for parameter model identification and validation. The potential of the methodology is demonstrated by validating voltage-dependent L-type calcium current (ICaL) inactivation in recently proposed human ventricular AP models with different formulations. Our results show large differences between ICaL inactivation as calculated from the model equation and ICaL inactivation from the in silico simulations due to the interaction between effects and/or to the experimental protocol. Our results suggest that, when proposing any new model formulation, consistency between such formulation and the corresponding experimental data that is aimed at being reproduced needs to be first verified considering all involved factors.

  19. Quetiapine, an atypical antipsychotic, is protective against autoimmune-mediated demyelination by inhibiting effector T cell proliferation.

    Directory of Open Access Journals (Sweden)

    Feng Mei

    Full Text Available Quetiapine (Que, a commonly used atypical antipsychotic drug (APD, can prevent myelin from breakdown without immune attack. Multiple sclerosis (MS, an autoimmune reactive inflammation demyelinating disease, is triggered by activated myelin-specific T lymphocytes (T cells. In this study, we investigated the potential efficacy of Que as an immune-modulating therapeutic agent for experimental autoimmune encephalomyelitis (EAE, a mouse model for MS. Que treatment was initiated on the onset of MOG(35-55 peptide induced EAE mice and the efficacy of Que on modulating the immune response was determined by Flow Cytometry through analyzing CD4(+/CD8(+ populations and the proliferation of effector T cells (CD4(+CD25(- in peripheral immune organs. Our results show that Que dramatically attenuates the severity of EAE symptoms. Que treatment decreases the extent of CD4(+/CD8(+ T cell infiltration into the spinal cord and suppresses local glial activation, thereby diminishing the loss of mature oligodendrocytes and myelin breakdown in the spinal cord of EAE mice. Our results further demonstrate that Que treatment decreases the CD4(+/CD8(+ T cell populations in lymph nodes and spleens of EAE mice and inhibits either MOG(35-55 or anti-CD3 induced proliferation as well as IL-2 production of effector T cells (CD4(+CD25(- isolated from EAE mice spleen. Together, these findings suggest that Que displays an immune-modulating role during the course of EAE, and thus may be a promising candidate for treatment of MS.

  20. Selective accumulation of pro-inflammatory T cells in the intestine contributes to the resistance to autoimmune demyelinating disease.

    Science.gov (United States)

    Berer, Kerstin; Boziki, Marina; Krishnamoorthy, Gurumoorthy

    2014-01-01

    Myelin-specific, pro-inflammatory TH17 cells are widely regarded as the drivers of experimental autoimmune encephalomyelitis (EAE), an animal model for Multiple sclerosis (MS). The factors, responsible for the generation and maintenance of TH17 cells as well as their participation in the pathogenic cascade leading to the demyelinating disease, have been studied extensively. However, how these harmful autoreactive cells are controlled in vivo remains unclear. By comparing TCR transgenic mice on a disease susceptible and a disease resistant genetic background, we show here that pathogenic TH17 cells are sequestered within the intestine of spontaneous EAE resistant B10.S mice. Disease resistant B10.S mice harbored higher frequencies of TH17 cells in the intestine compared to EAE susceptible SJL/J mice. Moreover, transferred TH17 cells selectively migrated to intestinal lymphoid organs of B10.S mice. The sequestration of TH17 cells in the gut was partially dependent on the gut homing receptor α4β7-mediated adhesion to the intestine. Administration of α4β7 blocking-antibodies increased the peripheral availability of TH17 cells, resulting in increased EAE severity after immunization in B10.S mice. Together, these results support the concept that the intestine is a check-point for controlling pathogenic, organ-specific T cells.

  1. The use of Alloxan and Streptozotocin in Experimental Diabetes Models

    Directory of Open Access Journals (Sweden)

    Zehra Kurçer

    2012-06-01

    Full Text Available Diabetes is a chronic metabolic disease which leads to several acute and chronic complications, morbidity and mortality, and decreased lifespan and quality of life. Therefore, in research studies that aim to enlighten the pathogenesis of diabetes and investigate possible treatment strategies, experimental animal models of diabetes provide many advantages to the investigator. Models of diabetes obtained by chemical induction, diet, surgical manipulations or combination thereof and also new genetically modified animal models are some of the experimental models. Alloxan and streptozotocin (STZ, which are toxic glucose analogues that preferentially accumulate in pancreatic beta cells, are widely used toxic agents to induce experimental diabetes in animals. This review gives an overview on the use of alloxan and STZ to induce chemical diabetes models with reference to their mechanisms, utilizable doses, advantages and disadvantages in diabetes research. Turk Jem 2012; 16: 34-40

  2. Methylcobalamin promotes the differentiation of Schwann cells and remyelination in lysophosphatidylcholine-induced demyelination of the rat sciatic nerve

    Directory of Open Access Journals (Sweden)

    Shunsuke eNishimoto

    2015-08-01

    Full Text Available Schwann cells (SCs are constituents of the peripheral nervous system. The differentiation of SCs in injured peripheral nerves is critical for regeneration after injury. Methylcobalamin (MeCbl is a vitamin B12 analog that is necessary for the maintenance of the peripheral nervous system. In this study, we estimated the effect of MeCbl on SCs. We showed that MeCbl downregulated the activity of Erk1/2 and promoted the expression of the myelin basic protein in SCs. In a dorsal root ganglion neuron–SC coculture system, myelination was promoted by MeCbl. In a focal demyelination rat model, MeCbl promoted remyelination and motor and sensory functional regeneration. MeCbl promoted the in vitro differentiation of SCs and in vivo myelination in a rat demyelination model and may be a novel therapy for several types of nervous disorders.

  3. Inducible Expression of CXCL1 within the Central Nervous System Amplifies Viral-Induced Demyelination.

    Science.gov (United States)

    Marro, Brett S; Grist, Jonathan J; Lane, Thomas E

    2016-02-15

    The functional role of the ELR(+) chemokine CXCL1 in host defense and disease following infection of the CNS with the neurotropic JHM strain of mouse hepatitis virus (JHMV) was examined. Mice in which expression of CXCL1 is under the control of a tetracycline-inducible promoter active within glial fibrillary acidic protein-positive cells were generated and this allowed for selectively increasing CNS expression of CXCL1 in response to JHMV infection and evaluating the effects on neuroinflammation, control of viral replication, and demyelination. Inducible expression of CNS-derived CXCL1 resulted in increased levels of CXCL1 protein within the serum, brain, and spinal cord that correlated with increased frequency of Ly6G(+)CD11b(+) neutrophils present within the CNS. Elevated levels of CXCL1 did not influence the generation of virus-specific T cells, and there was no difference in control of JHMV replication compared with control mice, indicating that T cell infiltration into the CNS is CXCL1-independent. Sustained CXCL1 expression within the CNS resulted in increased mortality that correlated with elevated neutrophil infiltration, diminished numbers of mature oligodendrocytes, and an increase in the severity of demyelination. Neutrophil ablation in CXCL1-transgenic mice reduced the severity of demyelination in mice, arguing for a role for these cells in white matter damage. Collectively, these findings illustrate that sustained CXCL1 expression amplifies the severity of white matter damage and that neutrophils can contribute to this process in a model of viral-induced neurologic disease. Copyright © 2016 by The American Association of Immunologists, Inc.

  4. Mechanisms of immunotherapeutic intervention by anti-CD40L (CD154) antibody in an animal model of multiple sclerosis

    NARCIS (Netherlands)

    Howard, L.M.; Miga, A.J.; Vanderlugt, C.L.; Dal Canto, M.C.; Laman, J.D.; Noelle, R.J.; Miller, S.D.

    1999-01-01

    Relapsing experimental autoimmune encephalomyelitis (R-EAE) in the SJL mouse is a Th1-mediated autoimmune demyelinating disease model for human multiple sclerosis and is characterized by infiltration of the central nervous system (CNS) by Th1 cells and macrophages. Disease relapses are mediated by T

  5. Chronic restraint stress during early Theiler’s virus infection exacerbates the subsequent demyelinating disease in SJL mice: II. CNS disease severity

    Science.gov (United States)

    Young, Erin E.; Sieve, Amy N.; Vichaya, Elisabeth G.; Carcoba, Luis M.; Young, Colin R.; Ambrus, Andrew; Storts, Ralph; Welsh, C. Jane R.; Meagher, Mary W.

    2010-01-01

    Theiler’s murine encephalomyelitis virus (TMEV) infection is a well-characterized model of multiple sclerosis (MS). Previous research has shown that chronic restraint stress (RS) during early TMEV infection exacerbates behavioral signs of disease. The present data suggest RS-induced increases in CNS inflammation, demyelination, and axonal degeneration may underlie this exacerbation. In addition, we report that males exhibit greater CNS inflammation and higher numbers of demyelinating lesions while females show greater susceptibility to RS-induced exacerbation. These findings indicate RS during early TMEV infection increases CNS lesion formation during the late phase and suggest the effects of RS are sex-dependent. PMID:20167380

  6. Design and Implementation of an Experimental Segway Model

    Science.gov (United States)

    Younis, Wael; Abdelati, Mohammed

    2009-03-01

    The segway is the first transportation product to stand, balance, and move in the same way we do. It is a truly 21st-century idea. The aim of this research is to study the theory behind building segway vehicles based on the stabilization of an inverted pendulum. An experimental model has been designed and implemented through this study. The model has been tested for its balance by running a Proportional Derivative (PD) algorithm on a microprocessor chip. The model has been identified in order to serve as an educational experimental platform for segways.

  7. Experimental and modeling studies of mass transfer in ...

    African Journals Online (AJOL)

    Gaining a better understanding of mass transfer problems in encapsulated cell systems and in tissue engineering requires both experimental investigations and mathematical modelling. Specific mass transfer studies are reviewed including oxygen transfer in immobilised animal cell culture systems, modelling of ...

  8. Distal acquired demyelinating symmetric (DADS) neuropathy associated with colorectal adenocarcinoma.

    Science.gov (United States)

    Ayyappan, Sujith; Day, Timothy; Kiers, Lynette

    2015-06-01

    Paraneoplastic neuropathies are well recognized as a remote effect of cancer, and subacute sensory neuronopathy is a recognized syndrome. Demyelinating neuropathies are relatively rare. Distal acquired demyelinating symmetric (DADS) neuropathy associated with lymphoproliferative disease has been reported previously. We present the association of DADS neuropathy with solid tumor. We report the clinical presentation, electrophysiology, and progress of DADS neuropathy in a patient later found to have colorectal adenocarcinoma. A patient presented with subacute onset of symmetric distal sensory and motor symptoms. Electrophysiology was typical of DADS neuropathy. Anti-MAG antibodies were initially positive at low titer, and indirect immunofluorescence analysis for anti-nuclear antibodies revealed autoantibodies to centromere nuclear protein-F (CENP-F). There was clinical and electrophysiologic resolution after tumor resection. This case describes the presentation of DADS neuropathy as a paraneoplastic syndrome in a patient later found to have colorectal adenocarcinoma. © 2014 Wiley Periodicals, Inc.

  9. Osmotic demyelination syndrome with a dysequilibrium syndrome: reversible MRI findings

    Energy Technology Data Exchange (ETDEWEB)

    Agildere, A.M.; Coskun, M.; Boyvat, F. [Baskent University Medical School Hospital, Radiology Department, Ankara (Turkey); Benli, S. [Baskent University Medical School Hospital, Neurology Department, Ankara (Turkey); Erten, Y.; Oezdemir, N. [Baskent University Medical School Hospital, Nephrology Department, Ankara (Turkey)

    1998-04-01

    Neurological disorders may be seen in end-stage renal disease patients due to uraemia or to complications of dialysis. A dysequilibrium syndrome may be seen, usually soon after or towards the end of haemodialysis. This group of patients has no particular findings on MRI. On the other hand, the osmotic demyelination syndrome has definitive MRI findings, not to date reported with the dysequilibrium syndrome. We report a patient with end-stage renal disease and the dysequilibrium syndrome who showed findings of osmotic demyelination on MRI. The patient had a convulsion after a first haemodialysis, with quadriparesis and hyperactive deep tendon reflexes and bilateral Babinski signs. The upper motor neurone signs lasted for a week. Meanwhile, he was also dysarthric and had dysphagia. He recovered neurologically without any residuum following appropriate treatment and there was improvement on MRI. (orig.) With 3 figs., 11 refs.

  10. Isolated paroxysmal dysarthria caused by a single demyelinating midbrain lesion.

    Science.gov (United States)

    Codeluppi, Luca; Bigliardi, Guido; Chiari, Annalisa; Meletti, Stefano

    2013-10-16

    Paroxysmal dysarthria is an unusual condition characterised by brief episodes of dysarthria with the sudden onset and frequent recurrence. It has been mainly reported in multiple sclerosis and an association with midbrain lesions has been claimed; however, most of the reported patients had multiple brain alterations so it was difficult to associate this symptom with a specific lesion site. We illustrate the cases of two patients with an isolated demyelinating midbrain lesion presenting paroxysmal dysarthria as the only symptom; both participants had oligoclonal bands in the cerebrospinal fluid and an unremarkable follow-up. Both patients had benefit from carbamazepine treatment, similarly to previously reported cases. Our report confirms that a demyelinating midbrain lesion is sufficient to provoke paroxysmal dysarthria. It is noteworthy that an erroneous diagnosis of psychogenic disorders was initially made in both cases, highlighting the importance not to underestimate isolated paroxysmal symptoms in clinical practice.

  11. Spinal cord demyelination combined with hyperhomocysteinemia: a case report

    Directory of Open Access Journals (Sweden)

    Hao MM

    2014-11-01

    Full Text Available Meimei Hao, Yan Zhang, Shuangxing Hou, Yanling Chen, Ming Shi, Gang Zhao, Yanchun Deng Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi’an, People’s Republic of China Abstract: Hyperhomocysteinemia (HHcy has been recognized as an independent risk factor for atherosclerotic vascular disease. Here we report a patient who suffered from spinal cord demyelination combined with HHcy. The patient was admitted to our hospital with a diagnosis of acute myelitis. However, hormone therapy was ineffective. Further investigations revealed that he had HHcy and a homozygous mutation of the gene encoding methylenetetrahydrofolate reductase (MTHFR c.677C>T, which is a key enzyme involved in homocysteine metabolism. In view of these findings, we treated the patient with B vitamins and his symptoms gradually improved. Spinal magnetic resonance imaging performed 3 months after onset showed near recovery of the lesion. To our knowledge, similar reports are rare. Keywords: demyelination, hyperhomocysteinemia, homocysteine, methylenetetrahydrofolate reductase, methylation

  12. An update on the management of chronic inflammatory demyelinating polyneuropathy

    Science.gov (United States)

    2012-01-01

    Chronic inflammatory demyelinating polyneuropathy (CIDP) is an immune mediated disorder of the peripheral nervous system with clinical features that include weakness, sensory loss, imbalance, pain and impaired ambulation which may lead to substantial disability. This review highlights current treatment strategies for CIDP, how best to utilize proven therapies such as intravenous immunoglobulin, oral prednisone, pulse dexamethasone, and plasma exchange, and when and how to use alternative immunosuppressive agents when first-line therapies are ineffective or poorly tolerated. PMID:23139706

  13. Epidemiology of chronic inflammatory demyelinating polyneuropathy abroad and in Russia

    Directory of Open Access Journals (Sweden)

    T. E. Popova

    2015-01-01

    Full Text Available Current article provides an overview of the results of epidemiological studies of chronic inflammatory demyelinating polyneuropathy (CIDP in Russia and abroad. It is shown that the prevalence of CIDP is different in countries, due to the use of different diagnostic criteria. It should be noted that the reliability of epidemiological prevalence and incidence is affected by difficulties of diagnosis of atypical forms of the disease.

  14. Cerebrospinal fluid analysis in the context of CNS demyelinating diseases

    Directory of Open Access Journals (Sweden)

    Sandro Luiz de Andrade Matas

    2013-09-01

    Full Text Available The central nervous system demyelinating diseases are a group of disorders with different etiologies, characterized by inflammatory lesions that are associated with loss of myelin and eventually axonal damage. In this group the most studied ones are multiple sclerosis (MS, neuromyelitis optic (NMO and acute disseminated encephalomyelitis (ADEM. The cerebrospinal fluid is essential to differentiate between these different syndromes and to define multiple sclerosis, helping to assess the probability of Clinical Isolated Syndrome turn into multiple sclerosis.

  15. Using an experimental model for the study of therapeutic touch.

    Science.gov (United States)

    dos Santos, Daniella Soares; Marta, Ilda Estéfani Ribeiro; Cárnio, Evelin Capellari; de Quadros, Andreza Urba; Cunha, Thiago Mattar; de Carvalho, Emilia Campos

    2013-02-01

    to verify whether the Paw Edema Model can be used in investigations about the effects of Therapeutic Touch on inflammation by measuring the variables pain, edema and neutrophil migration. this is a pilot and experimental study, involving ten male mice of the same genetic strain and divided into experimental and control group, submitted to the chemical induction of local inflammation in the right back paw. The experimental group received a daily administration of Therapeutic Touch for 15 minutes during three days. the data showed statistically significant differences in the nociceptive threshold and in the paw circumference of the animals from the experimental group on the second day of the experiment. the experiment model involving animals can contribute to study the effects of Therapeutic Touch on inflammation, and adjustments are suggested in the treatment duration, number of sessions and experiment duration.

  16. Linking Experimental Characterization and Computational Modeling in Microstructural Evolution

    Energy Technology Data Exchange (ETDEWEB)

    Demirel, Melik Cumhar [Univ. of Pittsburgh, PA (United States)

    2002-06-01

    It is known that by controlling microstructural development, desirable properties of materials can be achieved. The main objective of our research is to understand and control interface dominated material properties, and finally, to verify experimental results with computer simulations. In order to accomplish this objective, we studied the grain growth in detail with experimental techniques and computational simulations. We obtained 5170-grain data from an Aluminum-film (120μm thick) with a columnar grain structure from the Electron Backscattered Diffraction (EBSD) measurements. Experimentally obtained starting microstructure and grain boundary properties are input for the three-dimensional grain growth simulation. In the computational model, minimization of the interface energy is the driving force for the grain boundary motion. The computed evolved microstructure is compared with the final experimental microstructure, after annealing at 550 ºC. Two different measures were introduced as methods of comparing experimental and computed microstructures. Modeling with anisotropic mobility explains a significant amount of mismatch between experiment and isotropic modeling. We have shown that isotropic modeling has very little predictive value. Microstructural evolution in columnar Aluminum foils can be correctly modeled with anisotropic parameters. We observed a strong similarity between grain growth experiments and anisotropic three-dimensional simulations.

  17. Development of a fault test experimental facility model using Matlab

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Iraci Martinez; Moraes, Davi Almeida, E-mail: martinez@ipen.br, E-mail: dmoraes@dk8.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    The Fault Test Experimental Facility was developed to simulate a PWR nuclear power plant and is instrumented with temperature, level and pressure sensors. The Fault Test Experimental Facility can be operated to generate normal and fault data, and these failures can be added initially small, and their magnitude being increasing gradually. This work presents the Fault Test Experimental Facility model developed using the Matlab GUIDE (Graphical User Interface Development Environment) toolbox that consists of a set of functions designed to create interfaces in an easy and fast way. The system model is based on the mass and energy inventory balance equations. Physical as well as operational aspects are taken into consideration. The interface layout looks like a process flowchart and the user can set the input variables. Besides the normal operation conditions, there is the possibility to choose a faulty variable from a list. The program also allows the user to set the noise level for the input variables. Using the model, data were generated for different operational conditions, both under normal and fault conditions with different noise levels added to the input variables. Data generated by the model will be compared with Fault Test Experimental Facility data. The Fault Test Experimental Facility theoretical model results will be used for the development of a Monitoring and Fault Detection System. (author)

  18. Linking Experimental Characterization and Computational Modeling in Microstructural Evolution

    Energy Technology Data Exchange (ETDEWEB)

    Demirel, Melik Cumhur [Univ. of California, Berkeley, CA (United States)

    2002-06-01

    It is known that by controlling microstructural development, desirable properties of materials can be achieved. The main objective of our research is to understand and control interface dominated material properties, and finally, to verify experimental results with computer simulations. In order to accomplish this objective, we studied the grain growth in detail with experimental techniques and computational simulations. We obtained 5170-grain data from an Aluminum-film (120μm thick) with a columnar grain structure from the Electron Backscattered Diffraction (EBSD) measurements. Experimentally obtained starting microstructure and grain boundary properties are input for the three-dimensional grain growth simulation. In the computational model, minimization of the interface energy is the driving force for the grain boundary motion. The computed evolved microstructure is compared with the final experimental microstructure, after annealing at 550 ºC. Two different measures were introduced as methods of comparing experimental and computed microstructures. Modeling with anisotropic mobility explains a significant amount of mismatch between experiment and isotropic modeling. We have shown that isotropic modeling has very little predictive value. Microstructural evolution in columnar Aluminum foils can be correctly modeled with anisotropic parameters. We observed a strong similarity

  19. Clinical analysis of five cases of demyelinating pseudotumor

    Directory of Open Access Journals (Sweden)

    Fu-rong GU

    2017-03-01

    Full Text Available Objective To study the clinical manifestations, imaging and pathological features, treatment and prognosis of 5 patients diagnosed as demyelinating pseudotumor (DPT by pathology. Methods The data of clinical features, radiological and histological examination of 5 patients with DPT were retrospectively analyzed, and relevant literatures were reviewed.  Results All patients were male. Main symptoms included limb weakness in 3 cases, dizziness and impaired memory in 2 cases, seizures in one case. Head MRI examination revealed space-occupying lesions with hypointense signal on T1WI, hyperintense signal on T2WI and FLAIR. Enhanced MRI showed obvious enhancement of lesions (open-ring enhancement in 3 cases. The lesion were totally (4 cases or partially (one case removed, and postoperative histological examination showed inflammatory demyelination. One case died after twice relapse, and others had favorable prognosis.  Conclusions DPT is an inflammatory demyelination with mass effect. It should be differentiated from central nervous system tumors in order to avoid unnecessary resection or radiotherapy. DOI: 10.3969/j.issn.1672-6731.2017.03.010

  20. Systematic reviews of treatment for inflammatory demyelinating neuropathy*

    Science.gov (United States)

    Hughes, RAC

    2002-01-01

    This review describes the progress made in preparing Cochrane systematic reviews of randomized controlled trials for Guillain–Barré syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), multifocal motor neuropathy (MMN) and the demyelinating neuropathies associated with paraproteins. The discovery of antibodies against myelin andaxolemmal glycolipids and proteins has not yet replaced the clinicopathological classificationon which treatment trials have been based. Systematic reviews have endorsed the equivalence of plasma exchange (PE) and intravenous immunoglobulin (IVIg) and the lack of efficacy of steroids in GBS. Systematic reviews have also endorsed the value of steroids, PE and IVIg in CIDP butrandomized controlled trials have only shown benefit from IVIg in MMN. There is a paucity of evidence concerning the efficacy of treatments in paraproteinaemic demyelinating neuropathy apartment from small trials showing short-term benefit from PE or IVIg. There is a lack of good quality controlled trials of immunosuppressive agents in any of these conditions. As the numberof treatment trials increases, Cochrane systematic reviews will be an increasingly valuable resource for summarizing the evidence from randomised controlled trials on which to base clinical practice. They already demonstrate major deficiencies in the existing evidence base. PMID:12090400

  1. Chronic inflammatory demyelinating polyradiculoneuropathy and anesthesia: a case series.

    Science.gov (United States)

    Mortenson, Andrew R; Sprung, Juraj; Watson, James C; Dyck, P James B; Weingarten, Toby N

    2017-09-21

    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an acquired autoimmune demyelinating polyneuropathy characterized by symmetrical diffuse weakness that also can rarely affect bulbar and respiratory muscles. The study objective was to describe perioperative outcomes of patients with CIDP who received general anesthesia. This retrospective observational study evaluated patients with active (diagnosed or treated within the previous year) CIDP who underwent general anesthesia at our institution between January 1, 2010, and December 31, 2015. Medical records were reviewed for perioperative outcomes with emphasis on respiratory complications or unexpected reactions to muscle relaxants. Seventeen patients with CIDP underwent general anesthesia, of whom 16 had muscle weakness. Succinylcholine was used in 5 cases (29.4%) and nondepolarizing muscle relaxants in 11 cases (64.7%). Two patients required postoperative mechanical ventilation; one was critically ill and the other had open heart surgery. One patient had aspiration on the second postoperative day and required endotracheal intubation and mechanical ventilation for 3 days. Three patients had worsening CIDP symptoms: 1 acutely after surgery; 1 several months later; and 1 who died in the hospital. The patient who died underwent lengthy abdominal exploration, had acute worsening of neurologic symptoms, and died after 46 days of malnutrition. Anesthetic concerns of patients with CIDP include frailty, bulbar dysfunction, and the effects of immunosuppressive therapy. Although our patients tolerated neuromuscular drugs, substantial theoretical concerns with these medications in patients with demyelinating neuropathies preclude safety in this population without further study.

  2. Experimental-analytical method of technological processes modeling in education

    OpenAIRE

    Efremov German I.; Geller Julia A.

    2016-01-01

    The article considers general modeling techniques used in the study in education at different stages. The classification of different types of models and main stages of the simulation are considered. It is shown that in the course “Process of simulation” for technical areas of the Universities required the category of “Experimental-analytical simulation method”. For example, a new textbook for bachelors “Modeling of chemical-technological processes” shows that the section facilitates the comp...

  3. Experimental Validation of a Dynamic Model for Lightweight Robots

    Directory of Open Access Journals (Sweden)

    Alessandro Gasparetto

    2013-03-01

    Full Text Available Nowadays, one of the main topics in robotics research is dynamic performance improvement by means of a lightening of the overall system structure. The effective motion and control of these lightweight robotic systems occurs with the use of suitable motion planning and control process. In order to do so, model-based approaches can be adopted by exploiting accurate dynamic models that take into account the inertial and elastic terms that are usually neglected in a heavy rigid link configuration. In this paper, an effective method for modelling spatial lightweight industrial robots based on an Equivalent Rigid Link System approach is considered from an experimental validation perspective. A dynamic simulator implementing the formulation is used and an experimental test-bench is set-up. Experimental tests are carried out with a benchmark L-shape mechanism.

  4. A systematic review of animal models for experimental neuroma.

    Science.gov (United States)

    Toia, Francesca; Giesen, Thomas; Giovanoli, Pietro; Calcagni, Maurizio

    2015-10-01

    Peripheral neuromas can result in an unbearable neuropathic pain and functional impairment. Their treatment is still challenging, and their optimal management is to be defined. Experimental research still plays a major role, but - although numerous neuroma models have been proposed on different animals - there is still no single model recognised as being the reference. Several models show advantages over the others in specific aspects of neuroma physiopathology, prevention or treatment, making it unlikely that a single model could be of reference. A reproducible and standardised model of peripheral neuroma would allow better comparison of results from different studies. We present a systematic review of the literature on experimental in vivo models, analysing advantages and disadvantages, specific features and indications, with the goal of providing suggestions to help their standardisation. Published models greatly differ in the animal and the nerve employed, the mechanisms of nerve injury and the evaluation methods. Specific experimental models exist for terminal neuromas and neuromas in continuity (NIC). The rat is the most widely employed animal, the rabbit being the second most popular model. NIC models are more actively researched, but it is more difficult to generate such studies in a reproducible manner. Nerve transection is considered the best method to cause terminal neuromas, whereas partial transection is the best method to cause NIC. Traditional histomorphology is the historical gold-standard evaluation method, but immunolabelling, reverse transcriptase-polymerase chain reaction (RT-PCR) and proteomics are gaining increasing popularity. Computerised gait analysis is the gold standard for motor-recovery evaluation, whereas mechanical testing of allodynia and hyperalgesia reproducibly assesses sensory recovery. This review summarises current knowledge on experimental neuroma models, and it provides a useful tool for defining experimental protocols

  5. Experimental modeling of injectivity loss; Modelagem experimental da perda de injetividade

    Energy Technology Data Exchange (ETDEWEB)

    Bonato, Adriano Jose do Amaral Mello; Silva, Pedro Glauto de Farias e; Gomes, Vanessa Limeira Azevedo; Santos, Adriano dos [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2012-07-01

    Produced water reinjection, suspended particles are retained in the porous media causing formation damage and injectivity decline. In general the retention of the particles occurs near the side of injection, this fact occurs in most cases, due to the size exclusion. The modeling of filtration and the consequent formation damage is essential to the project management of water injection in oil reservoirs. Thus, mathematical models are studied to better predict the distribution of particles throughout the porous media and determine the parameters of adjustment to injectivity decline. Among these models, there is the classic model which consists in determining these parameters (coefficient of filtration and formation damage). The methodology used in modeling is given from the equations the mass conservation, kinetic particle retention, the modified Darcy equation and the function formation damage. This study aimed to improve experimental modeling, including development of software for acquisition and processing of experimental data, considering the variable number of pressure measurements along the sample. The software was developed using the Labview 2011 platform and allows the determination of relevant parameters to predict injectivity loss in water injection wells. Furthermore, based on the traditional model of filtration in porous media (including depth filtration and formation of the external plaster), the software was applied to predict injectivity loss in addition to the properties of the grout. Finally, the classical models for transporting suspensions and damage to the formation were observed. (author)

  6. Contact Modelling in Resistance Welding, Part II: Experimental Validation

    DEFF Research Database (Denmark)

    Song, Quanfeng; Zhang, Wenqi; Bay, Niels

    2006-01-01

    Contact algorithms in resistance welding presented in the previous paper are experimentally validated in the present paper. In order to verify the mechanical contact algorithm, two types of experiments, i.e. sandwich upsetting of circular, cylindrical specimens and compression tests of discs...... with a solid ring projection towards a flat ring, are carried out at room temperature. The complete algorithm, involving not only the mechanical model but also the thermal and electrical models, is validated by projection welding experiments. The experimental results are in satisfactory agreement...... with the simulation prediction, showing the validity of the algorithm....

  7. A Mutation in PMP2 Causes Dominant Demyelinating Charcot-Marie-Tooth Neuropathy.

    Directory of Open Access Journals (Sweden)

    Young Bin Hong

    2016-02-01

    Full Text Available Charcot-Marie-Tooth disease (CMT is a heterogeneous group of peripheral neuropathies with diverse genetic causes. In this study, we identified p.I43N mutation in PMP2 from a family exhibiting autosomal dominant demyelinating CMT neuropathy by whole exome sequencing and characterized the clinical features. The age at onset was the first to second decades and muscle atrophy started in the distal portion of the leg. Predominant fatty replacement in the anterior and lateral compartment was similar to that in CMT1A caused by PMP22 duplication. Sural nerve biopsy showed onion bulbs and degenerating fibers with various myelin abnormalities. The relevance of PMP2 mutation as a genetic cause of dominant CMT1 was assessed using transgenic mouse models. Transgenic mice expressing wild type or mutant (p.I43N PMP2 exhibited abnormal motor function. Electrophysiological data revealed that both mice had reduced motor nerve conduction velocities (MNCV. Electron microscopy revealed that demyelinating fibers and internodal lengths were shortened in both transgenic mice. These data imply that overexpression of wild type as well as mutant PMP2 also causes the CMT1 phenotype, which has been documented in the PMP22. This report might expand the genetic and clinical features of CMT and a further mechanism study will enhance our understanding of PMP2-associated peripheral neuropathy.

  8. Team Modelling: Review of Experimental Scenarios and Computational Models

    Science.gov (United States)

    2006-09-01

    designed to be) Yes Yes No Yes (Model individuals, or sub-teams - groups of individuals.) 19 C3TRACE* (Command, Control, and Communicatio ...radar sensors, satellites, c2 structures, jammers, communicatio ns networks and devices, and fire support) Depends (EADSIM normally models at

  9. IL-17 receptor signaling and T helper 17-mediated autoimmune demyelinating disease.

    Science.gov (United States)

    Zepp, Jarod; Wu, Ling; Li, Xiaoxia

    2011-05-01

    Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS). Experimental autoimmune encephalomyelitis (EAE) is widely used to dissect molecular mechanisms of MS and to develop new therapeutic strategies. The T helper 17 (Th17) subset of CD4 T cells plays a crucial role in the development of EAE. IL-17, a cytokine produced by Th17 cells, participates in EAE pathogenesis through induction of inflammatory gene expression in target cells. Recent work has shown that Act1, a U-box E3 ubiquitin ligase, is recruited to IL-17 receptor (IL-17R) upon IL-17 stimulation and is required for IL-17-mediated signaling. Here, we review the molecular and cellular mechanisms by which IL-17 and Act1-mediated signaling contribute to EAE. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Instrumental and ethical aspects of experimental research with animal models

    Directory of Open Access Journals (Sweden)

    Mirian Watanabe

    2014-02-01

    Full Text Available Experimental animal models offer possibilities of physiology knowledge, pathogenesis of disease and action of drugs that are directly related to quality nursing care. This integrative review describes the current state of the instrumental and ethical aspects of experimental research with animal models, including the main recommendations of ethics committees that focus on animal welfare and raises questions about the impact of their findings in nursing care. Data show that, in Brazil, the progress in ethics for the use of animals for scientific purposes was consolidated with Law No. 11.794/2008 establishing ethical procedures, attending health, genetic and experimental parameters. The application of ethics in handling of animals for scientific and educational purposes and obtaining consistent and quality data brings unquestionable contributions to the nurse, as they offer subsidies to relate pathophysiological mechanisms and the clinical aspect on the patient.

  11. Modeling and experimentation of a positioning system of SMA wires

    Science.gov (United States)

    Lei, KinFong; Yam, Yeung

    2000-06-01

    This work reports two modeling and control attempts performed on a positioning system comprising of linking SMA wires and an overlooking video system for on-line measurements. The first attempt takes the model by Ikuta and identifies experimentally the parameters of the SMA wire. The identified single wire model is then extended to a system of two SMA wires joining together at their tips, based upon which open loop position control of the linkage is then conducted. The approach, however, becomes too complicated when more SMA wires are involved. The second attempt utilizes a neuro-fuzzy based approach for positioning control of a linkage point joining together four SMA wires. The second approach involves four ANFIS neuro-networks with hybrid learning algorithm trained to model the currents to the SMA wires as functions of present and target positions of the linkage point. Experimentation for both the two-wires and four-wires system yield quite satisfactory performance.

  12. Recruitment of endogenous CNS stem cells for regeneration in demyelinating disease.

    Science.gov (United States)

    Murphy, Natalia A; Franklin, Robin J M

    2017-01-01

    Demyelinating diseases, such as multiple sclerosis (MS), are responsible for a significant portion of the neurological disability burden worldwide, especially in young adults. Demyelination can be followed by a spontaneous regenerative process called remyelination, in which new myelin sheaths are restored to denuded axons. However, in chronic demyelinating disease such as MS, this process becomes progressively less efficient. This chapter reviews the biology of remyelination and the rationale and strategies by which it can be enhanced therapeutically in acquired demyelinating disease. © 2017 Elsevier B.V. All rights reserved.

  13. Experimental bounds on collapse models from gravitational wave detectors

    Science.gov (United States)

    Carlesso, Matteo; Bassi, Angelo; Falferi, Paolo; Vinante, Andrea

    2016-12-01

    Wave function collapse models postulate a fundamental breakdown of the quantum superposition principle at the macroscale. Therefore, experimental tests of collapse models are also fundamental tests of quantum mechanics. Here, we compute the upper bounds on the collapse parameters, which can be inferred by the gravitational wave detectors LIGO, LISA Pathfinder, and AURIGA. We consider the most widely used collapse model, the continuous spontaneous localization (CSL) model. We show that these experiments exclude a huge portion of the CSL parameter space, the strongest bound being set by the recently launched space mission LISA Pathfinder. We also rule out a proposal for quantum-gravity-induced decoherence.

  14. Experimental model in rat for sentinel node biopsy

    Directory of Open Access Journals (Sweden)

    Oliveira Filho Renato Santos de

    2003-01-01

    Full Text Available Although sentinel node procedure has been used world wide, there are many aspects to be defined and better standardized. This study address if the experimental model in rats is appropriate for sentinel node biopsy. In this model, the lymph nodes are showed by lymphoscintigraphy, they are dyed by patent blue and identified by intraoperative gamma probe detection. It isn?t necessary to use magnification for the procedure. The model demonstrated that sentinel node biopsy in rats is feasible. So, besides allowing researches in this field, the model is useful for training and diffusing this technique.

  15. Effects of prophylactic and therapeutic teriflunomide in transcranial magnetic stimulation-induced motor-evoked potentials in the dark agouti rat model of experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Iglesias-Bregna, Deborah; Hanak, Susan; Ji, Zhongqi; Petty, Margaret; Liu, Li; Zhang, Donghui; McMonagle-Strucko, Kathleen

    2013-10-01

    Teriflunomide is a once-daily oral immunomodulatory agent recently approved in the United States for the treatment of relapsing multiple sclerosis (RMS). This study investigated neurophysiological deficits in descending spinal cord motor tracts during experimental autoimmune encephalomyelitis (EAE; a model of multiple sclerosis) and the functional effectiveness of prophylactic or therapeutic teriflunomide treatment in preventing the debilitating paralysis observed in this model. Relapsing-remitting EAE was induced in Dark Agouti rats using rat spinal cord homogenate. Animals were treated with oral teriflunomide (10 mg/kg daily) prophylactically, therapeutically, or with vehicle (control). Transcranial magnetic motor-evoked potentials were measured throughout the disease to provide quantitative assessment of the neurophysiological status of descending motor tracts. Axonal damage was quantified histologically by silver staining. Both prophylactic and therapeutic teriflunomide treatment significantly reduced maximum EAE disease scores (P teriflunomide treatment regimens prevented a delay in wave-form latency and a decrease in wave-form amplitude compared with that observed in vehicle-treated animals. A significant reduction in axonal loss was observed with both teriflunomide treatment regimens compared with vehicle (P teriflunomide can prevent the deficits observed in this animal model in descending spinal cord motor tracts. The mechanism behind reduced axonal loss and improved motor function may be primarily the reduced inflammation and consequent demyelination observed in these animals through the known effects of teriflunomide on impairing proliferation of stimulated T cells. These findings may have significant implications for patients with RMS.

  16. Experimental Analysis and Model Validation of an Opaque Ventilated Facade

    DEFF Research Database (Denmark)

    López, F. Peci; Jensen, Rasmus Lund; Heiselberg, Per

    2012-01-01

    Natural ventilation is a convenient way of reducing energy consumption in buildings. In this study an experimental module of an opaque ventilated façade (OVF) was built and tested for assessing its potential of supplying free ventilation and air preheating for the building. A numerical model was ...

  17. Experimental model of capsular contracture in silicone implants

    Directory of Open Access Journals (Sweden)

    Bastos Érika Malheiros

    2003-01-01

    Full Text Available The breast implant procedure is one of the most performed into Plastic Surgery and the contracture that occurs the capsule formed around the breast implants one of most frequent complication. We describe here one experimental model of capsule contracture in rats.

  18. Sciara as an experimental model for studies on the evolutionary ...

    Indian Academy of Sciences (India)

    Sciara as an experimental model for studies on the evolutionary relationships between the zygotic, maternal and environmental primary signals for sexual development. Lucas Sánchez. Review Article Volume ... Lucas Sánchez1. Centro de Investigaciones Biol´ogicas (C. S. I. C.), Ramiro de Maeztu 9, 28040 Madrid, Spain ...

  19. Novel sensors for food inspection modelling, fabrication and experimentation

    CERN Document Server

    Abdul Rahman, Mohd Syaifudin; Yu, Pak-Lam

    2014-01-01

    This book addresses presents recent developments of novel planar interdigital sensors for food inspection. It covers the fundamentals of sensors, their design, modelling and simulations, fabrications, characterizations, experimental investigations and analyses. This book will be useful for the engineers and researchers especially higher undergraduate, postgraduate students as well as practitioners working on the development of Electromagnetic Sensors.

  20. numerical and numerical and experimental modeling of the static

    African Journals Online (AJOL)

    eobe

    recommendation for subsequent experiments and analysis of these types of structural elements. In this paper a report of numerical and experimental modeling of the static response of thin-walled reinforced concrete box girder bridges is given. The work is executed to verify the validity of a software developed by the authors ...

  1. An Interactive Multimedia Based Instruction in Experimental Modelling

    DEFF Research Database (Denmark)

    Knudsen, Morten; Nielsen, J.N.; Østergaard, J.

    1997-01-01

    A CD-ROM based interactive multimedia instruction in experimental modelling for Danish Engineering School teachers is described. The content is based on a new sensitivity approach for direct estimation of physical parameters in linear and nonlinear dynamic systems. The presentation is inspired...

  2. Pruning Chinese trees : an experimental and modelling approach

    NARCIS (Netherlands)

    Zeng, Bo

    2001-01-01

    Pruning of trees, in which some branches are removed from the lower crown of a tree, has been extensively used in China in silvicultural management for many purposes. With an experimental and modelling approach, the effects of pruning on tree growth and on the harvest of plant material were studied.

  3. [Establishment and evaluation of experimental sepsis mouse model].

    Science.gov (United States)

    Wang, Li-Yan; Xu, Ruo-Nan; Han, Gen-Cheng; Wang, Ren-Xi; Chen, Guo-Jiang; Xiao, He; Hou, Chun-Mei; Shen, Bei-Fen; Li, Yan

    2010-06-01

    After treating with chemotherapy or immunosuppressant, malignant diseases of hematopoietic system such as leukemia, malignant lymphoma and aplastic anemia usually induced severe infection such as sepsis. Sepsis which is hard to be diagnosed causes high death rate. This study was purposed to establish an experimental sepsis mouse model so as to provide a basis for pathogenesis and intervention study. A classic caecal ligation and puncture (CLP) was used to establish experimental sepsis model. ELISA was used to detect levels of C5a, IL-6, TNFalpha, and IFN-gamma. Flow Cytometry was applied to measure apoptosis of lymphocytes in thymus and mesentery. The pathologic changes of thymus and spleen were confirmed by HE staining. The results showed that almost 70%-80% mice died at 72 hours after CLP. Only approximate 20% animal survived during finite time, mice in CLP group had significant weight lose. Meanwhile large release of different inflammatory mediators which are related with sepsis (C5a, IL-6, TNF-alpha, and IFN-gamma) was observed after CLP. Apoptosis of lymphocytes in thymus and mesentery lymphonodus was enhanced markedly after CLP. Significantly pathologic injury was also observed in thymus and spleen. It is concluded that a mouse model of experimental sepsis was successfully established by caecal ligation and puncture which can well mimic the clinical symptom of sepsis. The experimental sepsis mouse model provides an excellent tool for exploring the pathogenesis and intervention ways for sepsis accompanied with complicated malignant hematological diseases in vivo.

  4. Systematic integration of experimental data and models in systems biology

    Directory of Open Access Journals (Sweden)

    Simeonidis Evangelos

    2010-11-01

    Full Text Available Abstract Background The behaviour of biological systems can be deduced from their mathematical models. However, multiple sources of data in diverse forms are required in the construction of a model in order to define its components and their biochemical reactions, and corresponding parameters. Automating the assembly and use of systems biology models is dependent upon data integration processes involving the interoperation of data and analytical resources. Results Taverna workflows have been developed for the automated assembly of quantitative parameterised metabolic networks in the Systems Biology Markup Language (SBML. A SBML model is built in a systematic fashion by the workflows which starts with the construction of a qualitative network using data from a MIRIAM-compliant genome-scale model of yeast metabolism. This is followed by parameterisation of the SBML model with experimental data from two repositories, the SABIO-RK enzyme kinetics database and a database of quantitative experimental results. The models are then calibrated and simulated in workflows that call out to COPASIWS, the web service interface to the COPASI software application for analysing biochemical networks. These systems biology workflows were evaluated for their ability to construct a parameterised model of yeast glycolysis. Conclusions Distributed information about metabolic reactions that have been described to MIRIAM standards enables the automated assembly of quantitative systems biology models of metabolic networks based on user-defined criteria. Such data integration processes can be implemented as Taverna workflows to provide a rapid overview of the components and their relationships within a biochemical system.

  5. Theories linguistiques, modeles informatiques, experimentation psycholinguistique (Linguistic Theories, Information-Processing Models, Psycholinguistic Experimentation)

    Science.gov (United States)

    Dubois, Daniele

    1975-01-01

    Delineates and elaborates upon the underlying psychological postulates in linguistic and information-processing models, and shows the interdependence of psycholinguistics and linguistic analysis. (Text is in French.) (DB)

  6. Optimization of Regression Models of Experimental Data Using Confirmation Points

    Science.gov (United States)

    Ulbrich, N.

    2010-01-01

    A new search metric is discussed that may be used to better assess the predictive capability of different math term combinations during the optimization of a regression model of experimental data. The new search metric can be determined for each tested math term combination if the given experimental data set is split into two subsets. The first subset consists of data points that are only used to determine the coefficients of the regression model. The second subset consists of confirmation points that are exclusively used to test the regression model. The new search metric value is assigned after comparing two values that describe the quality of the fit of each subset. The first value is the standard deviation of the PRESS residuals of the data points. The second value is the standard deviation of the response residuals of the confirmation points. The greater of the two values is used as the new search metric value. This choice guarantees that both standard deviations are always less or equal to the value that is used during the optimization. Experimental data from the calibration of a wind tunnel strain-gage balance is used to illustrate the application of the new search metric. The new search metric ultimately generates an optimized regression model that was already tested at regression model independent confirmation points before it is ever used to predict an unknown response from a set of regressors.

  7. Thermal conductivity of microporous layers: Analytical modeling and experimental validation

    Science.gov (United States)

    Andisheh-Tadbir, Mehdi; Kjeang, Erik; Bahrami, Majid

    2015-11-01

    A new compact relationship is developed for the thermal conductivity of the microporous layer (MPL) used in polymer electrolyte fuel cells as a function of pore size distribution, porosity, and compression pressure. The proposed model is successfully validated against experimental data obtained from a transient plane source thermal constants analyzer. The thermal conductivities of carbon paper samples with and without MPL were measured as a function of load (1-6 bars) and the MPL thermal conductivity was found between 0.13 and 0.17 W m-1 K-1. The proposed analytical model predicts the experimental thermal conductivities within 5%. A correlation generated from the analytical model was used in a multi objective genetic algorithm to predict the pore size distribution and porosity for an MPL with optimized thermal conductivity and mass diffusivity. The results suggest that an optimized MPL, in terms of heat and mass transfer coefficients, has an average pore size of 122 nm and 63% porosity.

  8. A systematic review of prion therapeutics in experimental models.

    Science.gov (United States)

    Trevitt, Clare R; Collinge, John

    2006-09-01

    Prion diseases are transmissible, invariably fatal, neurodegenerative diseases which include Creutzfeldt-Jakob disease (CJD) in humans and bovine spongiform encephalopathy and scrapie in animals. A large number of putative treatments have been studied in experimental models over the past 30 years, with at best modest disease-modifying effects. The arrival of variant CJD in the UK in the 1990s has intensified the search for effective therapeutic agents, using an increasing number of animal, cellular and in vitro models with some recent promising proof of principle studies. Here, for the first time, we present a comprehensive systematic, rather than selective, review of published data on experimental approaches to prion therapeutics to provide a scientific resource for informing future therapeutics research, both in laboratory models and in clinical studies.

  9. Experimental validation of the multiphase extended Leblond's model

    Science.gov (United States)

    Weisz-Patrault, Daniel

    2017-10-01

    Transformation induced plasticity is a crucial contribution of the simulation of several forming processes involving phase transitions under mechanical loads, resulting in large irreversible strain even though the applied stress is under the yield stress. One of the most elegant and widely used models is based on analytic homogenization procedures and has been proposed by Leblond et al. [1-4]. Very recently, a simple extension of the Leblond's model has been developed by Weisz-Patrault [8]. Several product phases are taken into account and several assumptions are relaxed in order to extend the applicability of the model. The present contribution compares experimental tests with numerical computations, in order to discuss the validity of the developed theory. Thus, experimental results extracted from the existing literature are analyzed. Results show a good agreement between measurements and theoretical computations.

  10. Regression Model Optimization for the Analysis of Experimental Data

    Science.gov (United States)

    Ulbrich, N.

    2009-01-01

    A candidate math model search algorithm was developed at Ames Research Center that determines a recommended math model for the multivariate regression analysis of experimental data. The search algorithm is applicable to classical regression analysis problems as well as wind tunnel strain gage balance calibration analysis applications. The algorithm compares the predictive capability of different regression models using the standard deviation of the PRESS residuals of the responses as a search metric. This search metric is minimized during the search. Singular value decomposition is used during the search to reject math models that lead to a singular solution of the regression analysis problem. Two threshold dependent constraints are also applied. The first constraint rejects math models with insignificant terms. The second constraint rejects math models with near-linear dependencies between terms. The math term hierarchy rule may also be applied as an optional constraint during or after the candidate math model search. The final term selection of the recommended math model depends on the regressor and response values of the data set, the user s function class combination choice, the user s constraint selections, and the result of the search metric minimization. A frequently used regression analysis example from the literature is used to illustrate the application of the search algorithm to experimental data.

  11. Creatine Enhances Mitochondrial-Mediated Oligodendrocyte Survival After Demyelinating Injury.

    Science.gov (United States)

    Chamberlain, Kelly A; Chapey, Kristen S; Nanescu, Sonia E; Huang, Jeffrey K

    2017-02-08

    Chronic oligodendrocyte loss, which occurs in the demyelinating disorder multiple sclerosis (MS), contributes to axonal dysfunction and neurodegeneration. Current therapies are able to reduce MS severity, but do not prevent transition into the progressive phase of the disease, which is characterized by chronic neurodegeneration. Therefore, pharmacological compounds that promote oligodendrocyte survival could be beneficial for neuroprotection in MS. Here, we investigated the role of creatine, an organic acid involved in adenosine triphosphate (ATP) buffering, in oligodendrocyte function. We found that creatine increased mitochondrial ATP production directly in oligodendrocyte lineage cell cultures and exerted robust protection on oligodendrocytes by preventing cell death in both naive and lipopolysaccharide-treated mixed glia. Moreover, lysolecithin-mediated demyelination in mice deficient in the creatine-synthesizing enzyme guanidinoacetate-methyltransferase (Gamt) did not affect oligodendrocyte precursor cell recruitment, but resulted in exacerbated apoptosis of regenerated oligodendrocytes in central nervous system (CNS) lesions. Remarkably, creatine administration into Gamt-deficient and wild-type mice with demyelinating injury reduced oligodendrocyte apoptosis, thereby increasing oligodendrocyte density and myelin basic protein staining in CNS lesions. We found that creatine did not affect the recruitment of macrophages/microglia into lesions, suggesting that creatine affects oligodendrocyte survival independently of inflammation. Together, our results demonstrate a novel function for creatine in promoting oligodendrocyte viability during CNS remyelination.SIGNIFICANCE STATEMENT We report that creatine enhances oligodendrocyte mitochondrial function and protects against caspase-dependent oligodendrocyte apoptosis during CNS remyelination. This work has important implications for the development of therapeutic targets for diseases characterized by

  12. The dilemma of diabetes in chronic inflammatory demyelinating polyneuropathy

    Science.gov (United States)

    Bril, Vera; Blanchette, Christopher M.; Noone, Joshua M.; Runken, M. Chris; Gelinas, Deborah; Russell, James W.

    2017-01-01

    Purpose We reviewed the literature on chronic inflammatory demyelinating polyneuropathy (CIDP) in diabetes mellitus (DM) and explored real-world data on the prevalence and treatment of CIDP within DM. Methods: A literature search of Scopus was performed for the terms chronic inflammatory demyelinating polyradiculoneuropathy, chronic inflammatory demyelinating polyneuropathy, CIDP, and prevalence, incidence, epidemiology, or diabetes; peripheral neuropathy and prevalence or diabetes. We also searched through the reference lists of the resulting publications for additional findings that may have been missed. Additional publications on guidelines for the diagnosis of CIDP and diabetic neuropathy were also included. A descriptive analysis of the 2009–2013 PharMetrics Plus™ Database was performed to estimate the prevalence and treatment of CIDP within the DM population. Results There is an increasing body of literature suggesting that the prevalence of CIDP tends to be higher in diabetic patients, especially in those of older age. Our real-world data seem to support published findings from the literature. For the total cohort (N = 101,321,694), the percent prevalence of CIDP (n = 8,173) was 0.008%; DM (n = 4,026,740) was 4%. The percent prevalence of CIDP without DM (n = 5,986) was 0.006%; CIDP with DM (n = 2,187) was 9-fold higher at 0.054%. For patients >50 years old, there was a significantly higher percentage of CIDP with DM than CIDP without DM. Approximately 50% of CIDP patients were treated with IVIg, 23%–24% with steroids, 1%–2% with PE, and 20%–23% received no treatment. Conclusions In addition to the growing evidence of higher prevalence of CIDP in DM, our findings reinforce the need for heightened awareness of the association of CIDP and DM. PMID:27389526

  13. Citation classics in central nervous system inflammatory demyelinating disease.

    Science.gov (United States)

    Kim, Jee-Eun; Park, Kang M; Kim, Yerim; Yoon, Dae Y; Bae, Jong S

    2017-06-01

    To identify and analyze the characteristics of the most influential articles about central nervous system (CNS) inflammatory demyelinating disease. The Institute for Scientific Information (ISI) Web of Science database and the 2014 Journal Citation Reports Science Edition were used to retrieve the top 100 cited articles on CNS inflammatory demyelinating disease. The citation numbers, journals, years of publication, authorships, article types, subjects and main issues were analyzed. For neuromyelitis optica (NMO), articles that were cited more than 100 times were regarded as a citation classic and described separately. The top 100 cited articles were published between 1972 and 2011 in 13 journals. The highest number of articles (n = 24) was published in Brain, followed by The New England Journal of Medicine (n = 21). The average number of citations was 664 (range 330-3,897), and 64% of the articles were from the United States and the United Kingdom. The majority of the top 100 cited articles were related to multiple sclerosis (n = 87), and only a few articles reported on other topics such as NMO (n = 9), acute disseminated encephalomyelitis (n = 2) and optic neuritis (n = 2). Among the top 100 cited articles, 77% were original articles. Forty-one citation classics were found for NMO. Our study provides a historical perspective on the research progress on CNS inflammatory demyelinating disease and may serve as a guide for important advances and trends in the field for associated researchers.

  14. Dynamic Modeling of Wind Turbine Gearboxes and Experimental Validation

    DEFF Research Database (Denmark)

    Pedersen, Rune

    is presented. The model takes into account the effects of load and applied grinding corrections. The results are verified by comparing to simulated and experimental results reported in the existing literature. Using gear data loosely based on a 1 MW wind turbine gearbox, the gear mesh stiffness is expanded...... analysis in relation to gear dynamics. A multibody model of two complete 2.3MWwind turbine gearboxes mounted back-to-back in a test rig is built. The mean values of the proposed gear mesh stiffnesses are included. The model is validated by comparing with calculated and measured eigenfrequencies and mode...

  15. Experimental validation of a Bayesian model of visual acuity.

    LENUS (Irish Health Repository)

    Dalimier, Eugénie

    2009-01-01

    Based on standard procedures used in optometry clinics, we compare measurements of visual acuity for 10 subjects (11 eyes tested) in the presence of natural ocular aberrations and different degrees of induced defocus, with the predictions given by a Bayesian model customized with aberrometric data of the eye. The absolute predictions of the model, without any adjustment, show good agreement with the experimental data, in terms of correlation and absolute error. The efficiency of the model is discussed in comparison with image quality metrics and other customized visual process models. An analysis of the importance and customization of each stage of the model is also given; it stresses the potential high predictive power from precise modeling of ocular and neural transfer functions.

  16. Endogenous opioid antagonism in physiological experimental pain models

    DEFF Research Database (Denmark)

    Werner, Mads U; Pereira, Manuel P; Andersen, Lars Peter H

    2015-01-01

    Opioid antagonists are pharmacological tools applied as an indirect measure to detect activation of the endogenous opioid system (EOS) in experimental pain models. The objective of this systematic review was to examine the effect of mu-opioid-receptor (MOR) antagonists in placebo-controlled, double...... hyperalgesia models (6 studies), 'pain' models (25 studies), summation models (2 studies), nociceptive reflex models (3 studies) and miscellaneous models (2 studies). A consistent reversal of analgesia by a MOR-antagonist was demonstrated in 10 of the 25 ITP-studies, including stress-induced analgesia and r......TMS. In the remaining 14 conditioning modulation studies either absence of effects or ambiguous effects by MOR-antagonists, were observed. In the STP-studies, no effect of the opioid-blockade could be demonstrated in 5 out of 6 secondary hyperalgesia studies. The direction of MOR-antagonist dependent effects upon pain...

  17. Experimental-analytical method of technological processes modeling in education

    Directory of Open Access Journals (Sweden)

    Efremov German I.

    2016-01-01

    Full Text Available The article considers general modeling techniques used in the study in education at different stages. The classification of different types of models and main stages of the simulation are considered. It is shown that in the course “Process of simulation” for technical areas of the Universities required the category of “Experimental-analytical simulation method”. For example, a new textbook for bachelors “Modeling of chemical-technological processes” shows that the section facilitates the compilation of process models in general; gives the possibility of studying the process at different levels; describes the nonlinear properties of the simulation objects, and to obtain refined adjustment of the model according to the experiment. The use of models of high accuracy can improve the quality of education.

  18. Experimental Evaluation of Equivalent-Fluid Models for Melamine Foam

    Science.gov (United States)

    Allen, Albert R.; Schiller, Noah H.

    2016-01-01

    Melamine foam is a soft porous material commonly used in noise control applications. Many models exist to represent porous materials at various levels of fidelity. This work focuses on rigid frame equivalent fluid models, which represent the foam as a fluid with a complex speed of sound and density. There are several empirical models available to determine these frequency dependent parameters based on an estimate of the material flow resistivity. Alternatively, these properties can be experimentally educed using an impedance tube setup. Since vibroacoustic models are generally sensitive to these properties, this paper assesses the accuracy of several empirical models relative to impedance tube measurements collected with melamine foam samples. Diffuse field sound absorption measurements collected using large test articles in a laboratory are also compared with absorption predictions determined using model-based and measured foam properties. Melamine foam slabs of various thicknesses are considered.

  19. Secondary retinitis pigmentosa and cerebral demyelination in Lyme borreliosis.

    Science.gov (United States)

    Karma, A; Pirttilä, T A; Viljanen, M K; Lähde, Y E; Raitta, C M

    1993-01-01

    A 15-year-old girl developed retinitis pigmentosa-like fundus changes in the left eye and optic neuropathy in the right eye as well as cerebral demyelination as a result of late Lyme borreliosis (LB). The diagnosis was confirmed by polymerase chain reaction, which detected a Borrelia burgdorferi specific segment of a gene coding for 41 kD endoflagellin, both in the vitreous and the cerebrospinal fluid. The diagnosis was delayed because testing for Borrelia antibodies in serum and cerebrospinal fluid yielded negative results. However, later on, another laboratory reported the antibodies of the patient's pretreatment serum to be positive for LB. Images PMID:8435413

  20. Conventional and advanced magnetic resonance imaging in tumefactive demyelination

    Energy Technology Data Exchange (ETDEWEB)

    Saini, Jitender; Chatterjee, Somenath; Thomas, Bejoy; Kesavadas, Chandrasekharan (Dept. of Imaging Sciences and Interventional Radiology, Sree Chitra Thirunal Inst. for Medical Sciences and Technology, Trivandrum (India)), email: chandkesav@yahoo.com

    2011-12-15

    Background. Tumefactive demyelination (TD) is a relatively uncommon entity which mimics other focal intracranial lesions. Conventional radiological findings in tumefactive demyelination have been well described. However, DTI and MRS findings in TD have not been studied in detail. Purpose. To evaluate the usefulness of conventional magnetic resonance imaging (MRI), multivoxel 1H spectroscopy (MRS) and diffusion tensor imaging (DTI) in diagnosis and follow-up of TD of the brain. Material and Methods. Clinical and imaging findings of 18 patients were reviewed. MR imaging data which included conventional imaging as well as MRS and DTI were reviewed. At TE 135ms MRS various metabolite ratios were calculated at different depths of the demyelinating lesions. At TE 30 ms, glutamate-glutamine (GLX-2.1-2.5 ppm) was compared in the lesion to the contralateral normal side. DTI data were available for 15 patients and Dav (mean diffusivity) and trace values were recorded from central and peripheral layers of the index lesion. Histopathological (9 patients) and therapeutic response (9 patients) on follow-up imaging were taken as the diagnostic criterion. In addition, the follow-up MRI scans available were also reviewed. Results. Characteristic peripheral 'broken ring' type of contrast enhancement was noted in 12 cases. Two or three concentric distinct zones were noted on imaging with distinct metabolic and structural signature in most cases. On TE 135ms, the central part showed variable Choline (Cho) and significantly low N-Acetyl Aspartate (NAA). DTI demonstrated high Dav and very low trace value in this zone. The intermediate area showed higher Cho and lower NAA compared to contralateral normal side. The outermost layer, which corresponded to the contrast enhancing areas on MRI, showed high Cho, lower NAA, and restricted diffusion on DTI. The GLX increase was noted in tumefactive lesions. Lactate was observed in all patients and it appeared higher at the center

  1. Autoantibodies against vinculin in patients with chronic inflammatory demyelinating polyneuropathy.

    Science.gov (United States)

    Beppu, Minako; Sawai, Setsu; Satoh, Mamoru; Mori, Masahiro; Kazami, Takahiro; Misawa, Sonoko; Shibuya, Kazumoto; Ishibashi, Masumi; Sogawa, Kazuyuki; Kado, Sayaka; Kodera, Yoshio; Nomura, Fumio; Kuwabara, Satoshi

    2015-10-15

    To identify the target molecules of chronic inflammatory demyelinating polyneuropathy (CIDP), we used proteomic-based approach in the extracted proteins from porcine cauda equina. Two of 31 CIDP patients had markedly elevated serum autoantibodies against vinculin, a cell adhesion protein. Both of the patients with anti-vinculin antibodies had similar clinical manifestation, which are compatible with those of "typical" CIDP. Immunocytochemistry showed that vinculin was stained at the myelin sheath of the sciatic nerves by serum samples. Our results suggest that vinculin is a possible immunological target molecule in a subpopulation of typical CIDP patients. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Antineuroinflammatory and neurotrophic effects of CNTF and C16 peptide in an acute experimental autoimmune encephalomyelitis rat model

    Directory of Open Access Journals (Sweden)

    Marong eFang

    2013-12-01

    Full Text Available Experimentalallergic encephalomyelitis (EAE is an animal model for inflammatory demyelinating autoimmune disease, i.e., multiple sclerosis (MS. In the present study, we investigated the antineuroinflammatory/neuroprotective effects of C16, an ανβ3 integrin-binding peptide, and recombinant rat ciliary neurotrophic factor (CNTF, a cytokine that was originally identified as a survival factor for neurons, in an acute rodent EAE model. In this model, C16 peptide was injected intravenously every day for 2 weeks, and CNTF was delivered into the cerebral ventricles with Alzet miniosmotic pumps. Disease severity was assessed weekly using a scale ranging from 0 to 5. Multiple histological and molecular biological assays were employed to assess inflammation, axonal loss, neuronal apoptosis, white matter demyelination, and gliosis in the brain and spinal cord of different groups. Our results showed that the EAE induced rats revealed a significant increase in inflammatory cells infiltration, while C16 treatment could inhibit the infiltration of leukocytes and macrophages down to 2/3-1/3 of vehicle treated EAE control (P<0.05. The delayed onset of disease, reduced clinical score (P<0.01 in peak stage and more rapid recovery also were achieved in C16 treated group. Besides impairing inflammation, CNTF treatment also exerted direct neuroprotective effects, decreasing demyelination and axon loss score (P<0.05 Vs vehicle treated EAE control, and reducing the neuronal death from 40%-50% to 10%-20% (P<0.05. Both treatments suppressed the expression of cytokine tumor necrosis factor-α and interferon-when compared with the vehicle control (P<0.05. Combined treatment with C16 and CNTF produced more obvious functional recovery and neuroprotective effects than individually treatment (P<0.05. These results suggested that combination treatment with C16 and CNTF, which target different neuroprotection pathways, may be an effective therapeutic alternative to

  3. Transvaginal ultrasound ovarian diathermy: sheep as an experimental model

    Directory of Open Access Journals (Sweden)

    Pimentel Anita M

    2012-01-01

    Full Text Available Abstract Background Some techniques of transvaginal ovarian drilling have been previously described. Nevertheless a monopolar transvaginal ovarian cauterization, that use the expertise and safety of transvaginal puncture for oocyte captation seems to be an easier and feasible approach. The aim of this study was to develop a minimally invasive ovarian cauterization technique under transvaginal ultrasound control, and to evaluate the safety of the transvaginal ovarian monopolar cauterization, female sheep at reproductive age were used as an experimental model. Findings An experimental study was performed in a university research center. Seventeen female sheep (15 Corriedale e 2 Suffolk in reproductive age were submitted to transvaginal ovarian cauterization with a monopolar Valleylab Force 2 electrocautery. Macroscopic and microscopic lesions were assessed. Ovarian size were 1.31 cm2 ± 0,43 (Corriedale and 3.41 cm2 ± 0,64 (Suffolk. From 30 ovaries from Corriedale sheep punctured, only 3 were cauterized, presenting macroscopic and typical microscopic lesion. In the Suffolk sheep group, only one ovary was cauterized. No lesion could be found in the needle path. Conclusions This is the first experimental animal model described for ovarian cauterization needle guided by transvaginal ultrasound. The sheep does not seem to be the ideal animal model to study this technique. Another animal model, whose ovaries are better identified by transvaginal ultrasound should be sought for this technique, theoretically less invasive, before it could be offered safely to women with polycystic ovary syndrome.

  4. Numerical modeling of experimental human fibrous cap delamination.

    Science.gov (United States)

    Leng, Xiaochang; Davis, Lindsey A; Deng, Xiaomin; Sutton, Michael A; Lessner, Susan M

    2016-06-01

    Fibrous cap delamination is a critical process during the rupture of atherosclerotic plaque, which often leads to severe life-threatening clinical consequences such as myocardial infarction or stroke. In this study a finite element modeling and simulation approach is presented that enables the study of fibrous cap delamination experiments for the purpose of understanding the fibrous cap delamination process. A cohesive zone model (CZM) approach is applied to simulate delamination of the fibrous cap from the underlying plaque tissue. A viscoelastic anisotropic (VA) model for the bulk arterial material behavior is extended from existing studies so that the hysteresis phenomenon observed in the fibrous cap delamination experiments can be captured. A finite element model is developed for the fibrous cap delamination experiments, in which arterial layers (including the fibrous cap and the underlying plaque tissue) are represented by solid elements based on the VA model and the fibrous cap-underlying plaque tissue interface is characterized by interfacial CZM elements. In the CZM, the delamination process is governed by an exponential traction-separation law which utilizes critical energy release rates obtained directly from the fibrous cap delamination experiments. A set of VA model parameter values and CZM parameter values is determined based on values suggested in the literature and through matching simulation predictions of the load vs. load-point displacement curve with one set of experimental measurements. Using this set of parameter values, simulation predictions for other sets of experimental measurements are obtained and good agreement between simulation predictions and experimental measurements is observed. Results of this study demonstrate the applicability of the viscoelastic anisotropic model and the CZM approach for the simulation of diseased arterial tissue failure processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Target Soil Impact Verification: Experimental Testing and Kayenta Constitutive Modeling.

    Energy Technology Data Exchange (ETDEWEB)

    Broome, Scott Thomas [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Flint, Gregory Mark [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Dewers, Thomas [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Newell, Pania [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    This report details experimental testing and constitutive modeling of sandy soil deformation under quasi - static conditions. This is driven by the need to understand constitutive response of soil to target/component behavior upon impact . An experimental and constitutive modeling program was followed to determine elastic - plastic properties and a compressional failure envelope of dry soil . One hydrostatic, one unconfined compressive stress (UCS), nine axisymmetric compression (ACS) , and one uniaxial strain (US) test were conducted at room temperature . Elastic moduli, assuming isotropy, are determined from unload/reload loops and final unloading for all tests pre - failure and increase monotonically with mean stress. Very little modulus degradation was discernable from elastic results even when exposed to mean stresses above 200 MPa . The failure envelope and initial yield surface were determined from peak stresses and observed onset of plastic yielding from all test results. Soil elasto - plastic behavior is described using the Brannon et al. (2009) Kayenta constitutive model. As a validation exercise, the ACS - parameterized Kayenta model is used to predict response of the soil material under uniaxial strain loading. The resulting parameterized and validated Kayenta model is of high quality and suitable for modeling sandy soil deformation under a range of conditions, including that for impact prediction.

  6. Experimental Damage Identification of a Model Reticulated Shell

    Directory of Open Access Journals (Sweden)

    Jing Xu

    2017-04-01

    Full Text Available The damage identification of a reticulated shell is a challenging task, facing various difficulties, such as the large number of degrees of freedom (DOFs, the phenomenon of modal localization and transition, and low modeling accuracy. Based on structural vibration responses, the damage identification of a reticulated shell was studied. At first, the auto-regressive (AR time series model was established based on the acceleration responses of the reticulated shell. According to the changes in the coefficients of the AR model between the damaged conditions and the undamaged condition, the damage of the reticulated shell can be detected. In addition, the damage sensitive factors were determined based on the coefficients of the AR model. With the damage sensitive factors as the inputs and the damage positions as the outputs, back-propagation neural networks (BPNNs were then established and were trained using the Levenberg–Marquardt algorithm (L–M algorithm. The locations of the damages can be predicted by the back-propagation neural networks. At last, according to the experimental scheme of single-point excitation and multi-point responses, the impact experiments on a K6 shell model with a scale of 1/10 were conducted. The experimental results verified the efficiency of the proposed damage identification method based on the AR time series model and back-propagation neural networks. The proposed damage identification method can ensure the safety of the practical engineering to some extent.

  7. Biomechanics of epithelial cell islands analyzed by modeling and experimentation

    CERN Document Server

    Coburn, Luke; Noppe, Adrian; Caldwell, Benjamin J; Moussa, Elliott; Yap, Chloe; Priya, Rashmi; Lobaskin, Vladimir; Roberts, Anthony P; Yap, Alpha S; Neufeld, Zoltan; Gomez, Guillermo A

    2016-01-01

    We generated a new computational approach to analyze the biomechanics of epithelial cell islands that combines both vertex and contact-inhibition-of-locomotion models to include both cell-cell and cell-substrate adhesion. Examination of the distribution of cell protrusions (adhesion to the substrate) in the model predicted high order profiles of cell organization that agree with those previously seen experimentally. Cells acquired an asymmetric distribution of protrusions (and traction forces) that decreased when moving from the edge to the island center. Our in silico analysis also showed that tension on cell-cell junctions (and monolayer stress) is not homogeneous across the island. Instead it is higher at the island center and scales up with island size, which we confirmed experimentally using laser ablation assays and immunofluorescence. Moreover, our approach has the minimal elements necessary to reproduce mechanical crosstalk between both cell-cell and cell substrate adhesion systems. We found that an i...

  8. Numerical modeling of nitrogen oxide emission and experimental verification

    Directory of Open Access Journals (Sweden)

    Szecowka Lech

    2003-12-01

    Full Text Available The results of nitrogen reduction in combustion process with application of primary method are presented in paper. The reduction of NOx emission, by the recirculation of combustion gasses, staging of fuel and of air was investigated, and than the reduction of NOx emission by simultaneous usage of the mentioned above primary method with pulsatory disturbances.The investigations contain numerical modeling of NOx reduction and experimental verification of obtained numerical calculation results.

  9. Epidural blood patch: A study on an experimental model

    OpenAIRE

    S K Sengupta

    2013-01-01

    Aim: Epidural blood patch has been used to treat spinal headache with varying success. An experimental model was designed to ascertain whether an epidural blood patch can be used to seal the needle puncture sites in dural repair. Materials and Methods: Bovine dura was secured to the lower end of an open-ended calibrated plastic cylinder. Multiple interrupted stitches were applied over a 02 cm length of the dura without any incision. The cylinder was filled with colored saline gradually with t...

  10. Demyelinating disorders secondary to TNF-inhibitor therapy for the treatment of psoriasis: A review.

    Science.gov (United States)

    Zhu, Tian Hao; Nakamura, Mio; Abrouk, Michael; Farahnik, Benjamin; Koo, John; Bhutani, Tina

    2016-10-01

    Tumor necrosis factor-α inhibitors (TNFi) are the most widely used systemic treatments for patients with psoriasis and psoriatic arthritis. There currently exists a U.S. Food and Drug Administration issued warning label on all TNFi for "rare cases of new onset or exacerbation of central nervous system demyelinating disorders." The aim of this review was to update the incidence of TNFi-induced demyelinating diseases. Pubmed database was searched for safety data regarding demyelinating disease secondary to TNFi therapy prescribed for psoriasis. In clinical trials: 6990 patients had received treatment with etanercept with one reported case of multiple sclerosis; 5204 patients were treated with adalimumab with no cases identified and 2322 patients were treated with infliximab with one case of demyelinating polyneuropathy. Outside of clinical trials: 19 individual cases of demyelinating disorders from TNFi treatment have been reported. Although there is potential for TNF blockade to lead to demyelination of the central and peripheral nervous systems, the results of the present review suggest that demyelinating diseases associated with TNFi are extremely rare. TNFi are not recommended for use in patients with a personal history of demyelinating disease. However, with clinical vigilance and individualized treatment regimen, TNFi may be safe for use in other patients.

  11. Imaging and clinical properties of inflammatory demyelinating pseudotumor in the spinal cord.

    Science.gov (United States)

    Wang, Ying; Wang, Min; Liang, Hui; Yu, Quntao; Yan, Zhihui; Kong, Min

    2013-09-15

    Inflammatory demyelinating pseudotumor usually occurs in the brain and rarely occurs in the spinal cord. On imaging, inflammatory demyelinating pseudotumor appears very similar to intramedullary tumors such as gliomas. It is often misdiagnosed as intramedullary tumor and surgically resected. In view of this, the clinical and magnetic resonance imaging manifestations and the pathological fea-tures of 36 cases of inflammatory demyelinating pseudotumor in the spinal cord were retrospec-tively analyzed and summarized. Most of these cases suffered from acute or subacute onset and exhibited a sensorimotor disorder. Among them, six cases were misdiagnosed as having intra-dullary gliomas, and inflammatory demyelinating pseudotumor was only identified and pathologi-cally confirmed after surgical resection. Lesions in the cervical and thoracic spinal cord were com-mon. Magnetic resonance imaging revealed edema and space-occupying lesions to varying grees at the cervical-thoracic junction, with a predominant feature of non-closed rosette-like forcement (open-loop sign). Pathological examination showed perivascular cuffing of predominantly dense lymphocytes, and demyelination was observed in six of the misdiagnosed cases. These re-sults suggest that tumor-like inflammatory demyelinating disease in the spinal cord is a kind of special demyelinating disease that can be categorized as inflammatory pseudotumor. These solitary lesions are easily confused with intramedullary neoplasms. Patchy or non-closed reinforcement (open-ring sign) on magnetic resonance imaging is the predominant property of inflammatory myelinating pseudotumor, and inflammatory cell infiltration and demyelination are additional pa-logical properties.

  12. Acquired Demyelinating Syndromes: Focus on Neuromyelitis Optica and childhood-onset Multiple Sclerosis

    NARCIS (Netherlands)

    E.D. van Pelt - Gravesteijn (Daniëlle)

    2016-01-01

    markdownabstractAcquired demyelinating syndromes (ADS) cover a broad spectrum of central nervous system (CNS) inflammatory demyelinating syndromes, of which multiple sclerosis (MS) is the most common subtype. This thesis focuses on two relatively rare clinical subtypes of ADS: neuromyelitis optica

  13. Pathophysiology of immune-mediated demyelinating neuropathies--Part II: Neurology.

    Science.gov (United States)

    Franssen, Hessel; Straver, Dirk C G

    2014-01-01

    In the second part of this review we deal with the clinical aspects of immune-mediated demyelinating neuropathies. We describe the relationship between pathophysiology and symptoms and discuss the pathophysiology of specific disease entities, including Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy, anti-myelin-associated glycoprotein neuropathy, and POEMS syndrome. Copyright © 2013 Wiley Periodicals, Inc.

  14. Inflammatory demyelinating polyneuropathy in a kidney transplant patient with cytomegalovirus infection

    NARCIS (Netherlands)

    de Maar, E. F.; Kas-Deelen, DM; de Jager, AEJ; The, T. Hauw; Tegzess, Adam M.; van Son, WJ

    Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare disease with a prevalence of approximately 1/100 000 in the general population [1]. The pathogenesis of the demyelination is thought to be immune mediated but the mechanism is uncertain [2]. Antecedent infections are reported in 35%

  15. Dysregulation of ErbB Receptor Trafficking and Signaling in Demyelinating Charcot-Marie-Tooth Disease.

    Science.gov (United States)

    Lee, Samuel M; Chin, Lih-Shen; Li, Lian

    2017-01-01

    Charcot-Marie-Tooth (CMT) disease is the most common inherited peripheral neuropathy with the majority of cases involving demyelination of peripheral nerves. The pathogenic mechanisms of demyelinating CMT remain unclear, and no effective therapy currently exists for this disease. The discovery that mutations in different genes can cause a similar phenotype of demyelinating peripheral neuropathy raises the possibility that there may be convergent mechanisms leading to demyelinating CMT pathogenesis. Increasing evidence indicates that ErbB receptor-mediated signaling plays a major role in the control of Schwann cell-axon communication and myelination in the peripheral nervous system. Recent studies reveal that several demyelinating CMT-linked proteins are novel regulators of endocytic trafficking and/or phosphoinositide metabolism that may affect ErbB receptor signaling. Emerging data have begun to suggest that dysregulation of ErbB receptor trafficking and signaling in Schwann cells may represent a common pathogenic mechanism in multiple subtypes of demyelinating CMT. In this review, we focus on the roles of ErbB receptor trafficking and signaling in regulation of peripheral nerve myelination and discuss the emerging evidence supporting the potential involvement of altered ErbB receptor trafficking and signaling in demyelinating CMT pathogenesis and the possibility of modulating these trafficking and signaling processes for treating demyelinating peripheral neuropathy.

  16. Experimental model of heterotopic ossification in Wistar rats

    Energy Technology Data Exchange (ETDEWEB)

    Zotz, T.G.G. [Escola Politécnica, Programa de Pós-Graduação em Tecnologia em Saúde, Pontifícia Universidade Católica do Paraná, Curitiba, PR (Brazil); Paula, J.B. de [Médico,Doutor em Engenharia Biomédica, Curitiba, PR (Brazil); Moser, A.D.L. [Escola Politécnica, Programa de Pós-Graduação em Tecnologia em Saúde, Pontifícia Universidade Católica do Paraná, Curitiba, PR (Brazil)

    2012-04-05

    Heterotopic ossification (HO) is a metaplastic biological process in which there is newly formed bone in soft tissues adjacent to large joints, resulting in joint mobility deficit. In order to determine which treatment techniques are more appropriate for such condition, experimental models of induced heterotopic bone formation have been proposed using heterologous demineralized bone matrix implants and bone morphogenetic protein and other tissues. The objective of the present experimental study was to identify a reliable protocol to induce HO in Wistar rats, based on autologous bone marrow (BM) implantation, comparing 3 different BM volumes and based on literature evidence of this HO induction model in larger laboratory animals. Twelve male Wistar albino rats weighing 350/390 g were used. The animals were anesthetized for blood sampling before HO induction in order to quantify serum alkaline phosphatase (ALP). HO was induced by BM implantation in both quadriceps muscles of these animals, experimental group (EG). Thirty-five days after the induction, another blood sample was collected for ALP determination. The results showed a weight gain in the EG and no significant difference in ALP levels when comparing the periods before and after induction. Qualitative histological analysis confirmed the occurrence of heterotopic ossification in all 12 EG rats. In conclusion, the HO induction model was effective when 0.35 mL autologous BM was applied to the quadriceps of Wistar rats.

  17. Amplified energy harvester from footsteps: design, modeling, and experimental analysis

    Science.gov (United States)

    Wang, Ya; Chen, Wusi; Guzman, Plinio; Zuo, Lei

    2014-04-01

    This paper presents the design, modeling and experimental analysis of an amplified footstep energy harvester. With the unique design of amplified piezoelectric stack harvester the kinetic energy generated by footsteps can be effectively captured and converted into usable DC power that could potentially be used to power many electric devices, such as smart phones, sensors, monitoring cameras, etc. This doormat-like energy harvester can be used in crowded places such as train stations, malls, concerts, airport escalator/elevator/stairs entrances, or anywhere large group of people walk. The harvested energy provides an alternative renewable green power to replace power requirement from grids, which run on highly polluting and global-warming-inducing fossil fuels. In this paper, two modeling approaches are compared to calculate power output. The first method is derived from the single degree of freedom (SDOF) constitutive equations, and then a correction factor is applied onto the resulting electromechanically coupled equations of motion. The second approach is to derive the coupled equations of motion with Hamilton's principle and the constitutive equations, and then formulate it with the finite element method (FEM). Experimental testing results are presented to validate modeling approaches. Simulation results from both approaches agree very well with experimental results where percentage errors are 2.09% for FEM and 4.31% for SDOF.

  18. Experimental model of cutaneous radiation injury in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Meirelles, Rafael Panisi de Campos [Universidade Federal de Sao Paulo (EPM/UNIFESP), SP (Brazil). Escola Paulista de Medicina; Hochman, Bernardo [Universidade Federal de Sao Paulo (EPM/UNIFESP), SP (Brazil). Escola Paulista de Medicina. Dept. de Cirurgia; Helene Junior, Americo; Fraga, Murillo Francisco Pires [Faculdade de Ciencias Medicas da Santa Casa de Sao Paulo (FCMSCSP), SP (Brazil). Dept. de Cirurgia. Divisao de Cirurgia Plastica; Lellis, Rute [Faculdade de Ciencias Medicas da Santa Casa de Sao Paulo (FCMSCSP), SP (Brazil). Divisao de Patologia; Ferreira, Lydia Masako, E-mail: rpcmeirelles@yahoo.com.br, E-mail: lydia.dcir@epm.br [Universidade Federal de Sao Paulo (EPM/UNIFESP), SP (Brazil). Escola Paulista de Mediciana. Divisao de Cirugia Plastica

    2013-07-01

    Purpose: to describe an experimental model of cutaneous radiation injury in rabbits. Methods: on this study eight six-month-old New Zealand male rabbits, with an average weight of 2.5kg were used. They were distributed in four groups (n=2 per group). The control group did not receive radiotherapy and the others received one radiotherapy session of 2000, 3000 and 4500 cGy, respectively. Photographic analysis and histopathological evaluation of the irradiated areas were carried out. Results: after 30 days, the animals from the control group had all their hair grown. In spite of that, the animals from group 2000 cGy had a 60-day alopecia and from group 3000 cGy, a 90-day alopecia. After the 30th day, the 3000cGy group demonstrated 90-day cutaneous radiation injuries, graded 3 and 4. One of the animals from group 4500 cGy died on the 7th day with visceral necrosis. The other from the same group had total skin necrosis. A progressive reduction of glands and blood vessels count and an increase on collagen deposition was observed. Conclusion: The proposed experimental model is reproducible. This study suggests that the dosage 4500cGy is excessive and the 3000 cGy is the most effective for this experimental model of cutaneous radiation injury in rabbits. (author)

  19. Ionospheric topside models compared with experimental electron density profiles

    Directory of Open Access Journals (Sweden)

    S. M. Radicella

    2005-06-01

    Full Text Available Recently an increasing number of topside electron density profiles has been made available to the scientific community on the Internet. These data are important for ionospheric modeling purposes, since the experimental information on the electron density above the ionosphere maximum of ionization is very scarce. The present work compares NeQuick and IRI models with the topside electron density profiles available in the databases of the ISIS2, IK19 and Cosmos 1809 satellites. Experimental electron content from the F2 peak up to satellite height and electron densities at fixed heights above the peak have been compared under a wide range of different conditions. The analysis performed points out the behavior of the models and the improvements needed to be assessed to have a better reproduction of the experimental results. NeQuick topside is a modified Epstein layer, with thickness parameter determined by an empirical relation. It appears that its performance is strongly affected by this parameter, indicating the need for improvements of its formulation. IRI topside is based on Booker's approach to consider two parts with constant height gradients. It appears that this formulation leads to an overestimation of the electron density in the upper part of the profiles, and overestimation of TEC.

  20. Acute-onset chronic inflammatory demyelinating polyneuropathy: An electrodiagnostic study.

    Science.gov (United States)

    Anadani, Mohammad; Katirji, Bashar

    2015-11-01

    Acute-onset chronic inflammatory demyelinating polyneuropathy (A-CIDP) is an increasingly recognized CIDP subtype. Differentiating A-CIDP from Guillain-Barré syndrome (GBS) is challenging but important, because there are different treatment outcomes. We report 3 patients with A-CIDP who were initially diagnosed with severe GBS but were later confirmed to have CIDP based on their clinical course and electrodiagnostic (EDx) studies. We also report on the long-term treatment of these patients and review the literature on EDx studies in this syndrome. Three patients were initially diagnosed with GBS and responded to treatment. However, all 3 had arrest in improvement or deterioration during their rehabilitation phases. EDx studies showed prominent demyelinating changes many months after the initial presentation. All responded very well to immunotherapy. Although several features may suggest the diagnosis of A-CIDP at initial presentation, close follow-up of GBS patients during the recovery phase is also needed for accurate diagnosis. EDx studies may distinguish patients with A-CIDP from GBS patients. © 2015 Wiley Periodicals, Inc.

  1. Neuro-oncology dilemma: Tumour or tumefactive demyelinating lesion.

    Science.gov (United States)

    Abdoli, Mohammad; Freedman, Mark S

    2015-11-01

    Tumefactive demyelinating lesions (TDLs) are not an uncommon manifestation of demyelinating disease but can pose diagnostic challenges in patients without a pre-existing diagnosis of multiple sclerosis (MS) as well as in known MS patients. Brain tumours can also arise in MS patients and can be seen in chronic MS patients as co-morbidities. Delayed diagnosis or unnecessary intervention or treatment will affect the ultimate prognosis of these patients. In this article, we will review some typical cases illustrating the dilemma and review the information that helps to differentiate the two conditions. The intention is not to present an extensive differential diagnosis of both entities, but to examine some typical examples when the decision arises to decide between the two. We take a somewhat different approach, by presenting the cases in "real time", allowing the readers to consider in their own minds which diagnosis they favour, discussing in detail some of the pertinent literature, then revealing later the actual diagnosis. We would urge readers to consider re-visiting their first thoughts about each case after reading the discussion, before reading the follow-up of each case. The overall objective is to highlight the real possibility of being forced to decide between these two entities in clinical practise, present a reasonable approach to help differentiate them and especially to focus on the possibility of TDLs in order to avoid unnecessary biopsy. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Primary demyelinating disease simulating infiltrating glioma on CT

    Energy Technology Data Exchange (ETDEWEB)

    Nakasu, Yoko; Suda, Kinya; Handa, Jyoji; Hazama, Fumitada (Shiga Univ. of Medical Science, Otsu (Japan))

    1982-12-01

    Demyelinating diseases of the brain may show mass effects and/or contrast enhancement on CT scans, simulating the appearance of infiltrating glioma. A 36-year-old male, had suffered from gait disturbance and convulsive attacks involving the right lower limb since the age of 30. He had gradually developed character changes and urine incontinence. Six months prior to admission he experienced several attacks of generalized convulsions. On admission, he showed a mild hemiparesis, bilateral Babinski signs, and ataxic gait. He was disoriented and had memory disturbance and moria. CT scan showed low density areas in the bilateral frontal lobes Fand corpus callosum associated with a mild mass effect. Contrast study revealed irregular enhancement along the edge of the low density area and another small enhancing lesion in the left temporal lobe. This CT finding was interpreted as that of ''butterfly'' glioma. Craniotomy and right frontal lobectomy were performed. Histological study, however, demonstrated demyelination in the white matter associated with perivascular proliferation of lymphocytes. The final diagnosis was the 'transitional sclerosis' of Poser.

  3. Clinical trials in CIDP and chronic autoimmune demyelinating polyneuropathies.

    Science.gov (United States)

    Dalakas, Marinos C

    2012-05-01

    The main chronic autoimmune neuropathies include chronic inflammatory demyelinating polyneuropathy (CIDP), multifocal motor neuropathy (MMN), and anti-myelin-associated glycoprotein (MAG) demyelinating neuropathy. On the basis of randomized controlled studies, corticosteroids, intravenous immunoglobulin (IVIg), and plasmapheresis provide short-term benefits in CIDP. MMN responds only to IVIg. Because in MMN and CIDP, IVIg infusions are required every 3-6 weeks to sustain benefits or long-term remissions, there is a need for "IVIg-sparing" agents. In CIDP, immunosuppressive drugs, such as azathioprine, cyclosporine, methotrexate, mycophenolate, and cyclophosphamide, are used, but controlled trials have not shown that they are effective. Controlled trials have also not shown benefit to any agents in anti-MAG neuropathy. However, clinicians use many immunosuppressive drugs in both settings, but all have potentially serious side effects and are only effective in some patients. Thus, there is a need for new therapies in the inflammatory and paraproteinemic neuropathies. New agents targeting T cells, B cells, and transmigration and transduction molecules are discussed as potential treatment options for new trials. The need for biomarkers that predict therapeutic responses or identify patients with active disease is emphasized, and the search for better scoring tools that capture meaningful changes after response to therapies is highlighted. © 2012 Peripheral Nerve Society.

  4. [Demyelinating disease and vaccination of the human papillomavirus].

    Science.gov (United States)

    Álvarez-Soria, M Josefa; Hernández-González, Amalia; Carrasco-García de León, Sira; del Real-Francia, M Ángeles; Gallardo-Alcañiz, M José; López-Gómez, José L

    2011-04-16

    Primary prevention by prophylactic vaccination against the major cause of cervical cancer, the carcinogenic human papillomavirus (HPV) types 16 and 18, is now available worldwide. Postlicensure adverse neurological effects have been described. The studies realized after the license are descriptive and limited by the difficulty to obtain the information, despite most of the statistical indexes show that the adverse effects by the vaccine of the HPV are not upper compared with other vaccines, the substimation must be considered. We describe the cases of four young women that developed demyelinating disease after the vaccination of the HPV, with a rank of time between the administration of the dose and the development of the clinical of seven days to a month, with similar symptoms with the successive doses. We have described six episodes coinciding after the vaccination. Have been described seizures, autoimmune disorders such as Guillain-Barre syndrome, transverse myelitis, or motor neuron disease, probably adverse effects following immunization by HPV vaccine. So we suggest that vaccine may trigger an immunological mechanism leading to demyelinating events, perhaps in predisposed young.

  5. CFD modeling of pharmaceutical isolators with experimental verification of airflow.

    Science.gov (United States)

    Nayan, N; Akay, H U; Walsh, M R; Bell, W V; Troyer, G L; Dukes, R E; Mohan, P

    2007-01-01

    Computational fluid dynamics (CFD) models have been developed to predict the airflow in a transfer isolator using a commercial CFD code. In order to assess the ability of the CFD approach in predicting the flow inside an isolator, hot wire anemometry measurements and a novel experimental flow visualization technique consisting of helium-filled glycerin bubbles were used. The results obtained have been shown to agree well with the experiments and show that CFD can be used to model barrier systems and isolators with practical fidelity. This indicates that CFD can and should be used to support the design, testing, and operation of barrier systems and isolators.

  6. Contact drying: a review of experimental and mechanistic modeling approaches.

    Science.gov (United States)

    Sahni, Ekneet Kaur; Chaudhuri, Bodhisattwa

    2012-09-15

    Drying is one of the most complex unit operations with simultaneous heat and mass transfer. The contact drying process is also not well understood as several physical phenomena occur concurrently. This paper reviews current experimental and modeling approaches employed towards a better understanding of the contact drying operation. Additionally, an overview of some fundamental aspects relating to contact drying is provided. A brief discussion of some model extensions such as incorporation of noncontact forces, interstitial fluids and attrition rate is also presented. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Reactivity to Novel Autoantigens in Patients with Coexisting Central Nervous System Demyelinating Disease and Autoimmune Thyroid Disease

    OpenAIRE

    Greer, Judith M; Broadley, Simon; Pender, Michael P

    2017-01-01

    Several lines of evidence suggest a definite and unique link between CNS demyelinating diseases and autoimmune thyroid disease (AITD). The aim of the current study was to systematically compare the clinical and laboratory features of patients with coexistent AITD and CNS demyelinating disease with those of patients with just CNS demyelinating disease. Forty-four patients with coexisting CNS demyelinating disease and AITD were identified and their clinical and radiological features were record...

  8. Pneumatic Adaptive Absorber: Mathematical Modelling with Experimental Verification

    Directory of Open Access Journals (Sweden)

    Grzegorz Mikułowski

    2016-01-01

    Full Text Available Many of mechanical energy absorbers utilized in engineering structures are hydraulic dampers, since they are simple and highly efficient and have favourable volume to load capacity ratio. However, there exist fields of applications where a threat of toxic contamination with the hydraulic fluid contents must be avoided, for example, food or pharmacy industries. A solution here can be a Pneumatic Adaptive Absorber (PAA, which is characterized by a high dissipation efficiency and an inactive medium. In order to properly analyse the characteristics of a PAA, an adequate mathematical model is required. This paper proposes a concept for mathematical modelling of a PAA with experimental verification. The PAA is considered as a piston-cylinder device with a controllable valve incorporated inside the piston. The objective of this paper is to describe a thermodynamic model of a double chamber cylinder with gas migration between the inner volumes of the device. The specific situation considered here is that the process cannot be defined as polytropic, characterized by constant in time thermodynamic coefficients. Instead, the coefficients of the proposed model are updated during the analysis. The results of the experimental research reveal that the proposed mathematical model is able to accurately reflect the physical behaviour of the fabricated demonstrator of the shock absorber.

  9. Iron and copper in progressive demyelination--New lessons from Skogholt's disease.

    Science.gov (United States)

    Aspli, Klaus Thanke; Flaten, Trond Peder; Roos, Per M; Holmøy, Trygve; Skogholt, Jon H; Aaseth, Jan

    2015-01-01

    The pathophysiological mechanisms of progressive demyelinating disorders including multiple sclerosis are incompletely understood. Increasing evidence indicates a role for trace metals in the progression of several neurodegenerative disorders. The study of Skogholt disease, a recently discovered demyelinating disease affecting both the central and peripheral nervous system, might shed some light on the mechanisms underlying demyelination. Cerebrospinal fluid iron and copper concentrations are about four times higher in Skogholt patients than in controls. The transit into cerebrospinal fluid of these elements from blood probably occurs in protein bound form. We hypothesize that exchangeable fractions of iron and copper are further transferred from cerebrospinal fluid into myelin, thereby contributing to the pathogenesis of demyelination. Free or weakly bound iron and copper ions may exert their toxic action on myelin by catalyzing production of oxygen radicals. Similarities to demyelinating processes in multiple sclerosis and other myelinopathies are discussed. Copyright © 2014 Elsevier GmbH. All rights reserved.

  10. Autoantibodies to tetraspanins (CD9, CD81 and CD82) in demyelinating diseases.

    Science.gov (United States)

    Miyaji, Kazuki; Paul, Friedemann; Shahrizaila, Nortina; Umapathi, Thirugnanam; Yuki, Nobuhiro

    2016-02-15

    Tetraspanin family proteins, CD9, CD81 and CD82 are expressed in the oligodendrocytes and Schwann cells. We investigated autoantibodies to tetraspanin proteins in patients with demyelinating diseases. Sera were collected from 119 multiple sclerosis patients, 19 neuromyelitis optica, 42 acute inflammatory demyelinating polyneuropathy, 23 chronic inflammatory demyelinating polyneuropathy and 13 acute motor axonal neuropathy as well as 55 healthy controls. Few multiple sclerosis and acute inflammatory demyelinating polyneuropathy patients had autoantibodies that were weakly reactive to CD9 or CD81 but the significance is unclear. It is unlikely that these autoantibodies are pathogenic or serve as potential biomarkers in demyelinating diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Childhood chronic inflammatory demyelinating polyneuropathy: an overview of 10 cases in the modern era.

    Science.gov (United States)

    Ware, Tyson L; Kornberg, Andrew J; Rodriguez-Casero, M Victoria; Ryan, Monique M

    2014-01-01

    Chronic inflammatory demyelinating polyneuropathy is a rare condition in children. In this article, we report our experience in the management of 10 cases of childhood chronic inflammatory demyelinating polyneuropathy in a single center, in the era of contrast-enhanced magnetic resonance imaging (MRI), genetic microarray, and chronic inflammatory demyelinating polyneuropathy disease activity status. Robust neurophysiologic abnormalities were present in all cases and both MRI and lumbar puncture were useful adjuncts in diagnosis. Genetic microarray is a simple technique useful in excluding the most common hereditary demyelinating neuropathy. Intravenous immunoglobulin was an effective first-line therapy in most cases, with refractory cases responding to corticosteroids and rituximab. We found the chronic inflammatory demyelinating polyneuropathy disease activity status useful for assessing outcome at final follow-up, whereas the modified Rankin score was better for assessing peak motor disability.

  12. A case of chronic inflammatory demyelinating polyneuropathy presented with unilateral ptosis.

    Science.gov (United States)

    Izadi, Sadegh; Karamimagham, Sina; Poursadeghfard, Maryam

    2014-01-01

    Chronic Inflammatory Demyelinating Polyneuropathy is an autoimmune disease with progressive and relapsing courses. The main clinical presentations are diffuse deep tendon hyporeflexia or areflexia and symmetric proximal-distal muscles weakness. Myasthenia gravis is also an immune mediated disease with fluctuating ocular and bulbar symptoms and sometimes weakness. Although both myasthenia gravis and chronic inflammatory demyelinating polyneuropathy are immune mediated disorders, clinical presentations are obviously different in the two diseases. Herein, we will report a case of chronic inflammatory demyelinating polyneuropathy who presented with isolated unilateral ptosis. Initially, the patient was managed as ocular type of myasthenia gravis, but after progression to general limb weakness and areflexia, the diagnosis of chronic inflammatory demyelinating polyneuropathy was made. Although unilateral ptosis is a typical feature of myasthenia gravis, it may be seen as the first presentation of chronic inflammatory demyelinating polyneuropathy as well which mimics myasthenia gravis disease.

  13. Fibroblast growth factor signaling in oligodendrocyte-lineage cells facilitates recovery of chronically demyelinated lesions but is redundant in acute lesions.

    Science.gov (United States)

    Furusho, Miki; Roulois, Aude J; Franklin, Robin J M; Bansal, Rashmi

    2015-10-01

    Remyelination is a potent regenerative process in demyelinating diseases, such as multiple sclerosis, the effective therapeutic promotion of which will fill an unmet clinical need. The development of proregenerative therapies requires the identification of key regulatory targets that are likely to be involved in the integration of multiple signaling mechanisms. Fibroblast growth factor (FGF) signaling system, which comprises multiple ligands and receptors, potentially provides one such target. Since the FGF/FGF receptor (FGFR) interactions are complex and regulate multiple diverse functions of oligodendrocyte lineage cells, it is difficult to predict their overall therapeutic potential in the regeneration of oligodendrocytes and myelin. Therefore, to assess the integrated effects of FGFR signaling on this process, we simultaneously inactivated both FGFR1 and FGFR2 in oligodendrocytes and their precursors using two Cre-driver mouse lines. Acute and chronic cuprizone-induced or lysolecithin-induced demyelination was established in Fgfr1/Fgfr2 double knockout mice (dKO). We found that in the acute cuprizone model, there was normal differentiation of oligodendrocytes and recovery of myelin in the corpus callosum of both control and dKO mice. Similarly, in the spinal cord, lysolecithin-induced demyelinated lesions regenerated similarly in the dKO and control mice. In contrast, in the chronic cuprizone model, fewer differentiated oligodendrocytes and less efficient myelin recovery were observed in the dKO compared to control mice. These data suggest that while cell-autonomous FGF signaling is redundant during recovery of acute demyelinated lesions, it facilitates regenerative processes in chronic demyelination. Thus, FGF-based therapies have potential value in stimulating oligodendrocyte and myelin regeneration in late-stage disease. © 2015 Wiley Periodicals, Inc.

  14. A new formulation of cannabidiol in cream shows therapeutic effects in a mouse model of experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Giacoppo, Sabrina; Galuppo, Maria; Pollastro, Federica; Grassi, Gianpaolo; Bramanti, Placido; Mazzon, Emanuela

    2015-10-21

    The present study was designed to investigate the efficacy of a new formulation of alone, purified cannabidiol (CBD) (>98 %), the main non-psychotropic cannabinoid of Cannabis sativa, as a topical treatment in an experimental model of autoimmune encephalomyelitis (EAE), the most commonly used model for multiple sclerosis (MS). Particularly, we evaluated whether administration of a topical 1 % CBD-cream, given at the time of symptomatic disease onset, could affect the EAE progression and if this treatment could also recover paralysis of hind limbs, qualifying topical-CBD for the symptomatic treatment of MS. In order to have a preparation of 1 % of CBD-cream, pure CBD have been solubilized in propylene glycoland basic dense cream O/A. EAE was induced by immunization with myelin oligodendroglial glycoprotein peptide (MOG35-55) in C57BL/6 mice. After EAE onset, mice were allocated into several experimental groups (Naïve, EAE, EAE-1 % CBD-cream, EAE-vehicle cream, CTRL-1 % CBD-cream, CTRL-vehicle cream). Mice were observed daily for signs of EAE and weight loss. At the sacrifice of the animals, which occurred at the 28(th) day from EAE-induction, spinal cord and spleen tissues were collected in order to perform histological evaluation, immunohistochemistry and western blotting analysis. Achieved results surprisingly show that daily treatment with topical 1 % CBD-cream may exert neuroprotective effects against EAE, diminishing clinical disease score (mean of 5.0 in EAE mice vs 1.5 in EAE + CBD-cream), by recovering of paralysis of hind limbs and by ameliorating histological score typical of disease (lymphocytic infiltration and demyelination) in spinal cord tissues. Also, 1 % CBD-cream is able to counteract the EAE-induced damage reducing release of CD4 and CD8α T cells (spleen tissue localization was quantified about 10,69 % and 35,96 % of positive staining respectively in EAE mice) and expression of the main pro-inflammatory cytokines as well as several other

  15. Experimental models in vaccine research: malaria and leishmaniasis

    Directory of Open Access Journals (Sweden)

    C. Teixeira

    2013-02-01

    Full Text Available Animal models have a long history of being useful tools, not only to test and select vaccines, but also to help understand the elaborate details of the immune response that follows infection. Different models have been extensively used to investigate putative immunological correlates of protection against parasitic diseases that are important to reach a successful vaccine. The greatest challenge has been the improvement and adaptation of these models to reflect the reality of human disease and the screening of vaccine candidates capable of overcoming the challenge of natural transmission. This review will discuss the advantages and challenges of using experimental animal models for vaccine development and how the knowledge achieved can be extrapolated to human disease by looking into two important parasitic diseases: malaria and leishmaniasis.

  16. Experimental models in vaccine research: malaria and leishmaniasis.

    Science.gov (United States)

    Teixeira, C; Gomes, R

    2013-02-01

    Animal models have a long history of being useful tools, not only to test and select vaccines, but also to help understand the elaborate details of the immune response that follows infection. Different models have been extensively used to investigate putative immunological correlates of protection against parasitic diseases that are important to reach a successful vaccine. The greatest challenge has been the improvement and adaptation of these models to reflect the reality of human disease and the screening of vaccine candidates capable of overcoming the challenge of natural transmission. This review will discuss the advantages and challenges of using experimental animal models for vaccine development and how the knowledge achieved can be extrapolated to human disease by looking into two important parasitic diseases: malaria and leishmaniasis.

  17. Neuroantigen-specific autoregulatory CD8+ T cells inhibit autoimmune demyelination through modulation of dendritic cell function.

    Directory of Open Access Journals (Sweden)

    Venkatesh P Kashi

    Full Text Available Experimental autoimmune encephalomyelitis (EAE is a well-established murine model of multiple sclerosis, an immune-mediated demyelinating disorder of the central nervous system (CNS. We have previously shown that CNS-specific CD8+ T cells (CNS-CD8+ ameliorate EAE, at least in part through modulation of CNS-specific CD4+ T cell responses. In this study, we show that CNS-CD8+ also modulate the function of CD11c+ dendritic cells (DC, but not other APCs such as CD11b+ monocytes or B220+ B cells. DC from mice receiving either myelin oligodendrocyte glycoprotein-specific CD8+ (MOG-CD8+ or proteolipid protein-specific CD8+ (PLP-CD8+ T cells were rendered inefficient in priming T cell responses from naïve CD4+ T cells (OT-II or supporting recall responses from CNS-specific CD4+ T cells. CNS-CD8+ did not alter DC subset distribution or MHC class II and CD86 expression, suggesting that DC maturation was not affected. However, the cytokine profile of DC from CNS-CD8+ recipients showed lower IL-12 and higher IL-10 production. These functions were not modulated in the absence of immunization with CD8-cognate antigen, suggesting an antigen-specific mechanism likely requiring CNS-CD8-DC interaction. Interestingly, blockade of IL-10 in vitro rescued CD4+ proliferation and in vivo expression of IL-10 was necessary for the suppression of EAE by MOG-CD8+. These studies demonstrate a complex interplay between CNS-specific CD8+ T cells, DC and pathogenic CD4+ T cells, with important implications for therapeutic interventions in this disease.

  18. Experimental model of cultured keratinocytes Modelo experimental de cultura de queratinócitos

    Directory of Open Access Journals (Sweden)

    Alfredo Gragnani

    2003-01-01

    Full Text Available The bioengineering research is essential in the development of ideal combination of biomaterials and cultured cells to produce the permanent wound coverage. The experimental model of cultured keratinocytes presents all steps of the culture, since the isolation of the keratinocytes, preparation of the human acellular dermis, preparation of the composite skin graft and their elevation to the air-liquid interface. The research in cultured keratinocytes model advances in two main ways: 1. optimization of the methods in vitro to the skin cells culture and proliferation and 2. developing biomaterials that present similar skin properties.A pesquisa em bioengenharia é primordial no desenvolvimento da combinação ideal de biomateriais e células cultivadas para produzir a cobertura definitiva das lesões. O modelo experimental da cultura de queratinócitos apresenta toda as etapas do cultivo, desde o isolamento dos queratinócitos, preparação da derme acelular humana, do enxerto composto e da sua elevação à interface ar-líquido. A pesquisa em modelo de cultura de queratinócitos desenvolve-se em duas vias principais: 1. otimização dos métodos in vitro para cultivo e proliferação de células da pele e 2. desenvolvimento de biomateriais que mimetizem as propriedades da pele.

  19. DMFC anode polarization: Experimental analysis and model validation

    Energy Technology Data Exchange (ETDEWEB)

    Casalegno, A.; Marchesi, R. [Dipartimento di Energetica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

    2008-01-03

    Anode two-phase flow has an important influence on DMFC performance and methanol crossover. In order to elucidate two-phase flow influence on anode performance, in this work, anode polarization is investigated combining experimental and modelling approach. A systematic experimental analysis of operating conditions influence on anode polarization is presented. Hysteresis due to operating condition is observed; experimental results suggest that it arises from methanol accumulation and has to be considered in evaluating DMFC performances and measurements reproducibility. A model of DMFC anode polarization is presented and utilised as tool to investigate anode two-phase flow. The proposed analysis permits one to produce a confident interpretation of the main involved phenomena. In particular, it confirms that methanol electro-oxidation kinetics is weakly dependent on methanol concentration and that methanol transport in gas phase produces an important contribution in anode feeding. Moreover, it emphasises the possibility to optimise anode flow rate in order to improve DMFC performance and reduce methanol crossover. (author)

  20. Of mice and men: modelling post-stroke depression experimentally

    Science.gov (United States)

    Kronenberg, G; Gertz, K; Heinz, A; Endres, M

    2014-01-01

    At least one-third of stroke survivors suffer from depression. The development of comorbid depression after stroke is clinically highly significant because post-stroke depression is associated with increased mortality, slows recovery and leads to worse functional outcomes. Here, we review the evidence that post-stroke depression can be effectively modelled in experimental rodents via a variety of approaches. This opens an exciting new window onto the neurobiology of depression and permits probing potential underlying mechanisms such as disturbed cellular plasticity, neuroendocrine dysregulation, neuroinflammation, and neurodegeneration in a novel context. From the point of view of translational stroke research, extending the scope of experimental investigations beyond the study of short-term end points and, in particular, acute lesion size, may help improve the relevance of preclinical results to human disease. Furthermore, accumulating evidence from both clinical and experimental studies offers the tantalizing prospect of 5-hydroxytryptaminergic antidepressants as the first pharmacological therapy for stroke that would be available during the subacute and chronic phases of recovery. Interdisciplinary neuropsychiatric research will be called on to dissect the mechanisms underpinning the beneficial effects of antidepressants on stroke recovery. Linked Articles This article is part of a themed section on Animal Models in Psychiatry Research. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-20 PMID:24838087

  1. Analytical modeling and experimental characterization of chemotaxis in Serratia marcescens

    Science.gov (United States)

    Zhuang, Jiang; Wei, Guopeng; Wright Carlsen, Rika; Edwards, Matthew R.; Marculescu, Radu; Bogdan, Paul; Sitti, Metin

    2014-05-01

    This paper presents a modeling and experimental framework to characterize the chemotaxis of Serratia marcescens (S. marcescens) relying on two-dimensional and three-dimensional tracking of individual bacteria. Previous studies mainly characterized bacterial chemotaxis based on population density analysis. Instead, this study focuses on single-cell tracking and measuring the chemotactic drift velocity VC from the biased tumble rate of individual bacteria on exposure to a concentration gradient of l-aspartate. The chemotactic response of S. marcescens is quantified over a range of concentration gradients (10-3 to 5 mM/mm) and average concentrations (0.5×10-3 to 2.5 mM). Through the analysis of a large number of bacterial swimming trajectories, the tumble rate is found to have a significant bias with respect to the swimming direction. We also verify the relative gradient sensing mechanism in the chemotaxis of S. marcescens by measuring the change of VC with the average concentration and the gradient. The applied full pathway model with fitted parameters matches the experimental data. Finally, we show that our measurements based on individual bacteria lead to the determination of the motility coefficient μ (7.25×10-6 cm2/s) of a population. The experimental characterization and simulation results for the chemotaxis of this bacterial species contribute towards using S. marcescens in chemically controlled biohybrid systems.

  2. An experimental and modeling study of diethyl carbonate oxidation

    KAUST Repository

    Nakamura, Hisashi

    2015-04-01

    Diethyl carbonate (DEC) is an attractive biofuel that can be used to displace petroleum-derived diesel fuel, thereby reducing CO2 and particulate emissions from diesel engines. A better understanding of DEC combustion characteristics is needed to facilitate its use in internal combustion engines. Toward this goal, ignition delay times for DEC were measured at conditions relevant to internal combustion engines using a rapid compression machine (RCM) and a shock tube. The experimental conditions investigated covered a wide range of temperatures (660-1300K), a pressure of 30bar, and equivalence ratios of 0.5, 1.0 and 2.0 in air. To provide further understanding of the intermediates formed in DEC oxidation, species concentrations were measured in a jet-stirred reactor at 10atm over a temperature range of 500-1200K and at equivalence ratios of 0.5, 1.0 and 2.0. These experimental measurements were used to aid the development and validation of a chemical kinetic model for DEC.The experimental results for ignition in the RCM showed near negative temperature coefficient (NTC) behavior. Six-membered alkylperoxy radical (RO˙2) isomerizations are conventionally thought to initiate low-temperature branching reactions responsible for NTC behavior, but DEC has no such possible 6- and 7-membered ring isomerizations. However, its molecular structure allows for 5-, 8- and 9-membered ring RO˙2 isomerizations. To provide accurate rate constants for these ring structures, ab initio computations for RO˙2⇌Q˙OOH isomerization reactions were performed. These new RO˙2 isomerization rate constants have been implemented in a chemical kinetic model for DEC oxidation. The model simulations have been compared with ignition delay times measured in the RCM near the NTC region. Results of the simulation were also compared with experimental results for ignition in the high-temperature region and for species concentrations in the jet-stirred reactor. Chemical kinetic insights into the

  3. Experimental validation of Swy-2 clay standard's PHREEQC model

    Science.gov (United States)

    Szabó, Zsuzsanna; Hegyfalvi, Csaba; Freiler, Ágnes; Udvardi, Beatrix; Kónya, Péter; Székely, Edit; Falus, György

    2017-04-01

    One of the challenges of the present century is to limit the greenhouse gas emissions for the mitigation of climate change which is possible for example by a transitional technology, CCS (Carbon Capture and Storage) and, among others, by the increase of nuclear proportion in the energy mix. Clay minerals are considered to be responsible for the low permeability and sealing capacity of caprocks sealing off stored CO2 and they are also the main constituents of bentonite in high level radioactive waste disposal facilities. The understanding of clay behaviour in these deep geological environments is possible through laboratory batch experiments of well-known standards and coupled geochemical models. Such experimentally validated models are scarce even though they allow deriving more precise long-term predictions of mineral reactions and rock and bentonite degradation underground and, therefore, ensuring the safety of the above technologies and increase their public acceptance. This ongoing work aims to create a kinetic geochemical model of Na-montmorillonite standard Swy-2 in the widely used PHREEQC code, supported by solution and mineral composition results from batch experiments. Several four days experiments have been carried out in 1:35 rock:water ratio at atmospheric conditions, and with inert and CO2 supercritical phase at 100 bar and 80 ⁰C relevant for the potential Hungarian CO2 reservoir complex. Solution samples have been taken during and after experiments and their compositions were measured by ICP-OES. The treated solid phase has been analysed by XRD and ATR-FTIR and compared to in-parallel measured references (dried Swy-2). Kinetic geochemical modelling of the experimental conditions has been performed by PHREEQC version 3 using equations and kinetic rate parameters from the USGS report of Palandri and Kharaka (2004). The visualization of experimental and numerous modelling results has been automatized by R. Experiments and models show very fast

  4. Experimental validation of solid rocket motor damping models

    Science.gov (United States)

    Riso, Cristina; Fransen, Sebastiaan; Mastroddi, Franco; Coppotelli, Giuliano; Trequattrini, Francesco; De Vivo, Alessio

    2017-12-01

    In design and certification of spacecraft, payload/launcher coupled load analyses are performed to simulate the satellite dynamic environment. To obtain accurate predictions, the system damping properties must be properly taken into account in the finite element model used for coupled load analysis. This is typically done using a structural damping characterization in the frequency domain, which is not applicable in the time domain. Therefore, the structural damping matrix of the system must be converted into an equivalent viscous damping matrix when a transient coupled load analysis is performed. This paper focuses on the validation of equivalent viscous damping methods for dynamically condensed finite element models via correlation with experimental data for a realistic structure representative of a slender launch vehicle with solid rocket motors. A second scope of the paper is to investigate how to conveniently choose a single combination of Young's modulus and structural damping coefficient—complex Young's modulus—to approximate the viscoelastic behavior of a solid propellant material in the frequency band of interest for coupled load analysis. A scaled-down test article inspired to the Z9-ignition Vega launcher configuration is designed, manufactured, and experimentally tested to obtain data for validation of the equivalent viscous damping methods. The Z9-like component of the test article is filled with a viscoelastic material representative of the Z9 solid propellant that is also preliminarily tested to investigate the dependency of the complex Young's modulus on the excitation frequency and provide data for the test article finite element model. Experimental results from seismic and shock tests performed on the test configuration are correlated with numerical results from frequency and time domain analyses carried out on its dynamically condensed finite element model to assess the applicability of different equivalent viscous damping methods to describe

  5. Experimental limits from ATLAS on Standard Model Higgs production.

    CERN Multimedia

    ATLAS, collaboration

    2012-01-01

    Experimental limits from ATLAS on Standard Model Higgs production in the mass range 110-600 GeV. The solid curve reflects the observed experimental limits for the production of a Higgs of each possible mass value (horizontal axis). The region for which the solid curve dips below the horizontal line at the value of 1 is excluded with a 95% confidence level (CL). The dashed curve shows the expected limit in the absence of the Higgs boson, based on simulations. The green and yellow bands correspond (respectively) to 68%, and 95% confidence level regions from the expected limits. Higgs masses in the narrow range 123-130 GeV are the only masses not excluded at 95% CL

  6. Experimentally supported mathematical modeling of continuous baking processes

    DEFF Research Database (Denmark)

    Stenby Andresen, Mette

    The scope of the PhD project was to increase knowledge on the process-to-product interactions in continuous tunnel ovens. The work has focused on five main objectives. These objectives cover development of new experimental equipment for pilot plant baking experiments, mathematical modeling of heat...... and mass transfer in a butter cookie product, and evaluation of quality assessment methods. The pilot plant oven is a special batch oven designed to emulate continuous convection tunnel oven baking. The design, construction, and validation of the oven has been part of the project and is described...... in this thesis. The oven was successfully validated against a 10 m tunnel oven. Besides the ability to emulate the baking conditions in a tunnel oven, the new batch oven is designed and constructed for experimental research work. In the design options to follow the product continuously (especially weight...

  7. Continuum damage modeling through theoretical and experimental pressure limit formulas

    Directory of Open Access Journals (Sweden)

    Fatima Majid

    2018-01-01

    Full Text Available In this paper, we developed a mathematical modeling to represent the damage of thermoplastic pipes. On the one hand, we adapted the theories of the rupture pressure to fit the High Density Polyethylene (HDPE case. Indeed, the theories for calculating the rupture pressure are multiple, designed originally for steels and alloys. For polymer materials, we have found that these theories can be adapted using a coefficient related to the nature of the studied material. The HDPE is characterized by two important values of pressure, deduced from the ductile form of the internal pressures evolution until burst. For this reason, we have designed an alpha coefficient taking into account these two pressures and giving a good approximation of the evolution of the experimental burst pressures through the theoretically corrected ones, using Faupel㒒s pressure formula. Then, we can deduce the evolution of the theoretical damage using the calculated pressures. On the other hand, two other mathematical models were undertaken. The first one has given rise to an adaptive model referring to an expression of the pressure as a function of the life fraction, the characteristic pressures and the critical life fraction. The second model represents a continuum damage model incorporating the pressure equations as a function of the life fraction and based on the burst pressure�s static damage model. These models represent important tools for industrials to assess the failure of thermoplastic pipes and proceed quick checks

  8. Short note: the experimental geopotential model XGM2016

    Science.gov (United States)

    Pail, R.; Fecher, T.; Barnes, D.; Factor, J. F.; Holmes, S. A.; Gruber, T.; Zingerle, P.

    2017-10-01

    As a precursor study for the upcoming combined Earth Gravitational Model 2020 (EGM2020), the Experimental Gravity Field Model XGM2016, parameterized as a spherical harmonic series up to degree and order 719, is computed. XGM2016 shares the same combination methodology as its predecessor model GOCO05c (Fecher et al. in Surv Geophys 38(3): 571-590, 2017. doi: 10.1007/s10712-016-9406-y). The main difference between these models is that XGM2016 is supported by an improved terrestrial data set of 15^' × 15^' gravity anomaly area-means provided by the United States National Geospatial-Intelligence Agency (NGA), resulting in significant upgrades compared to existing combined gravity field models, especially in continental areas such as South America, Africa, parts of Asia, and Antarctica. A combination strategy of relative regional weighting provides for improved performance in near-coastal ocean regions, including regions where the altimetric data are mostly unchanged from previous models. Comparing cumulative height anomalies, from both EGM2008 and XGM2016 at degree/order 719, yields differences of 26 cm in Africa and 40 cm in South America. These differences result from including additional information of satellite data, as well as from the improved ground data in these regions. XGM2016 also yields a smoother Mean Dynamic Topography with significantly reduced artifacts, which indicates an improved modeling of the ocean areas.

  9. Experimental validation of mathematical model for small air compressor

    Directory of Open Access Journals (Sweden)

    Tuhovčák Ján

    2017-01-01

    Full Text Available Development process of reciprocating compressors can be simplified by using simulation tools. Modelling of a compressor requires a trade-off between computational effort and accuracy of desired results. This paper presents experimental validation of the simulation tool, which can be used to predict compressor behaviour under different working conditions. The mathematical model provides fast results with very good accuracy, however the model must be calibrated for a certain type of compressor. Small air compressor was used to validate an in-house simulation tool, which is based on mass and energy conservation in a control volume. The simulation tool calculates pressure and temperature history inside the cylinder, valve characteristics, mass flow and heat losses during the cycle of the compressor. A test bench for the compressor consisted of pressure sensors on both discharge and suction side, temperature sensor on discharge side and flow meter with calorimetric principle sensor.

  10. A two-Higgs-doublet model facing experimental hints

    Directory of Open Access Journals (Sweden)

    Crivellin Andreas

    2016-01-01

    Full Text Available Physics beyond the Standard Model has so far eluded our experimental probes. Nevertheless, a number of interesting anomalies have accumulated that can be taken as hints towards new physics: BaBar, Belle, and LHCb have found deviations of approximately 3:8σ in B → Dτν and B → D*τν; the anomalous magnetic moment of the muon differs by about 3σ from the theoretic prediction; the branching ratio for τ → μνν is about 2σ above the Standard Model expectation; and CMS and ATLAS found hints for a non-zero decay rate of h → μτ at 2.6σ. Here we consider these processes within a lepton-specific two-Higgs doublet model with additional non-standard Yukawa couplings and show how (and which of these excesses can be accommodated.

  11. Comparison of mixed layer models predictions with experimental data

    Energy Technology Data Exchange (ETDEWEB)

    Faggian, P.; Riva, G.M. [CISE Spa, Divisione Ambiente, Segrate (Italy); Brusasca, G. [ENEL Spa, CRAM, Milano (Italy)

    1997-10-01

    The temporal evolution of the PBL vertical structure for a North Italian rural site, situated within relatively large agricultural fields and almost flat terrain, has been investigated during the period 22-28 June 1993 by experimental and modellistic point of view. In particular, the results about a sunny day (June 22) and a cloudy day (June 25) are presented in this paper. Three schemes to estimate mixing layer depth have been compared, i.e. Holzworth (1967), Carson (1973) and Gryning-Batchvarova models (1990), which use standard meteorological observations. To estimate their degree of accuracy, model outputs were analyzed considering radio-sounding meteorological profiles and stability atmospheric classification criteria. Besides, the mixed layer depths prediction were compared with the estimated values obtained by a simple box model, whose input requires hourly measures of air concentrations and ground flux of {sup 222}Rn. (LN)

  12. Evaluation of Algebraic Reynolds Stress Model Assumptions Using Experimental Data

    Science.gov (United States)

    Jyoti, B.; Ewing, D.; Matovic, D.

    1996-11-01

    The accuracy of Rodi's ASM assumption is examined by evaluating the terms in Reynolds stress transport equation and their modelled counterparts. The basic model assumption: Dτ_ij/Dt + partial T_ijl/partial xl = (τ_ij/k )(Dk/Dt + partial Tl /partial xl ) (Rodi( Rodi W., ZAMM.), 56, pp. 219-221, 1976.), can also be broken into two stronger assumptions: Da_ij/Dt = 0 and (2) partial T_ijl/partial xl = (τ_ij/k )(partial Tl /partial xl ) (e.g. Taulbee( Taulbee D. B., Phys. of Fluids), 4(11), pp. 2555-2561, 1992.). Fu et al( Fu S., Huang P.G., Launder B.E. & Leschziner M.A., J. Fluid Eng.), 110(2), pp. 216-221., 1988 examined the accuracy of Rodi's assumption using the results of RSM calculation of axisymmetric jets. Since the RSM results did not accurately predict the experimental results either, it may be useful to examine the basic ASM model assumptions using experimental data. The database of Hussein, Capp and George( Hussein H., Capp S. & George W., J.F.M.), 258, pp.31-75., 1994. is sufficiently detailed to evaluate the terms of Reynolds stress transport equations individually, thus allowing both Rodi's and the stronger assumptions to be tested. For this flow assumption (1) is well satisfied for all the components (including \\overlineuv); however, assumption (2) does not seem as well satisfied.

  13. Neuroinflammatory targets and treatments for epilepsy validated in experimental models.

    Science.gov (United States)

    Aronica, Eleonora; Bauer, Sebastian; Bozzi, Yuri; Caleo, Matteo; Dingledine, Raymond; Gorter, Jan A; Henshall, David C; Kaufer, Daniela; Koh, Sookyong; Löscher, Wolfgang; Louboutin, Jean-Pierre; Mishto, Michele; Norwood, Braxton A; Palma, Eleonora; Poulter, Michael O; Terrone, Gaetano; Vezzani, Annamaria; Kaminski, Rafal M

    2017-07-01

    A large body of evidence that has accumulated over the past decade strongly supports the role of inflammation in the pathophysiology of human epilepsy. Specific inflammatory molecules and pathways have been identified that influence various pathologic outcomes in different experimental models of epilepsy. Most importantly, the same inflammatory pathways have also been found in surgically resected brain tissue from patients with treatment-resistant epilepsy. New antiseizure therapies may be derived from these novel potential targets. An essential and crucial question is whether targeting these molecules and pathways may result in anti-ictogenesis, antiepileptogenesis, and/or disease-modification effects. Therefore, preclinical testing in models mimicking relevant aspects of epileptogenesis is needed to guide integrated experimental and clinical trial designs. We discuss the most recent preclinical proof-of-concept studies validating a number of therapeutic approaches against inflammatory mechanisms in animal models that could represent novel avenues for drug development in epilepsy. Finally, we suggest future directions to accelerate preclinical to clinical translation of these recent discoveries. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

  14. Hepatoprotective activity of Musa paradisiaca on experimental animal models.

    Science.gov (United States)

    Nirmala, M; Girija, K; Lakshman, K; Divya, T

    2012-01-01

    To investigate the hepatoprotective activity of stem of Musa paradisiaca (M. paradisiaca) in CCl4 and paracetamol induced hepatotoxicity models in rats. Hepatoprotective activity of alcoholic and aqueous extracts of stem of M. paradisiaca was demonstrated by using two experimentally induced hepatotoxicity models. Administration of hepatotoxins (CCl4 and paracetamol) showed significant biochemical and histological deteriorations in the liver of experimental animals. Pretreatment with alcoholic extract (500 mg/kg), more significantly and to a lesser extent the alcoholic extract (250 mg/kg) and aqueous extract (500 mg/kg), reduced the elevated levels of the serum enzymes like serum glutamic-oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), alkaline phosphatase (ALP) and bilirubin levels and alcoholic and aqueous extracts reversed the hepatic damage towards the normal, which further evidenced the hepatoprotective activity of stem of M. paradisiaca. The alcoholic extract at doses of 250 and 500 mg/kg, p.o. and aqueous extract at a dose of 500 mg/kg, p.o. of stem of M. paradisiaca have significant effect on the liver of CCl4 and paracetamol induced hepatotoxicity animal models.

  15. A comprehensive experimental and modeling study of 2-methylbutanol combustion

    KAUST Repository

    Park, Sungwoo

    2015-05-01

    2-Methylbutanol (2-methyl-1-butanol) is one of several next-generation biofuels that can be used as an alternative fuel or blending component for combustion engines. This paper presents new experimental data for 2-methylbutanol, including ignition delay times in a high-pressure shock tube and premixed laminar flame speeds in a constant volume combustion vessel. Shock tube ignition delay times were measured for 2-methylbutanol/air mixtures at three equivalence ratios, temperatures ranging from 750 to 1250. K, and at nominal pressures near 20 and 40. bar. Laminar flame speed data were obtained using the spherically propagating premixed flame configuration at pressures of 1, 2, and 5. bar. A detailed chemical kinetic model for 2-methylbutanol oxidation was developed including high- and low-temperature chemistry based on previous modeling studies on butanol and pentanol isomers. The proposed model was tested against new and existing experimental data at pressures of 1-40. atm, temperatures of 740-1636. K, equivalence ratios of 0.25-2.0. Reaction path and sensitivity analyses were conducted for identifying key reactions at various combustion conditions, and to obtain better understanding of the combustion characteristics of larger alcohols.

  16. Model reduction for experimental thermal characterization of a holding furnace

    Science.gov (United States)

    Loussouarn, Thomas; Maillet, Denis; Remy, Benjamin; Dan, Diane

    2017-09-01

    Vacuum holding induction furnaces are used for the manufacturing of turbine blades by loss wax foundry process. The control of solidification parameters is a key factor for the manufacturing of these parts. The definition of the structure of a reduced heat transfer model with experimental identification through an estimation of its parameters is required here. Internal sensors outputs, together with this model, can be used for assessing the thermal state of the furnace through an inverse approach, for a better control. Here, an axisymmetric furnace and its load have been numerically modelled using FlexPDE, a finite elements code. The internal induction heat source as well as the transient radiative transfer inside the furnace are calculated through this detailed model. A reduced lumped body model has been constructed to represent the numerical furnace. The model reduction and the estimation of the parameters of the lumped body have been made using a Levenberg-Marquardt least squares minimization algorithm, using two synthetic temperature signals with a further validation test.

  17. Experimental models of sepsis and septic shock: an overview

    Directory of Open Access Journals (Sweden)

    Garrido Alejandra G.

    2004-01-01

    Full Text Available Sepsis remains a major cause of morbidity and mortality in surgical patients and trauma victims, mainly due to sepsis-induced multiple organ dysfunction. In contrast to preclinical studies, most clinical trials of promising new treatment strategies for sepsis have fails to demonstrate efficacy. Although many reasons could account for this discrepancy, the misinterpretation of preclinical data obtained from experimental studies, and especially the use of animal models that do not adequately mimic human sepsis may have been contributing factors. In this review, the benefits and limitations of various animal models of sepsis are discussed to clarify the extend to which findings are relevant to human sepsis, particularly with respect to the subsequent design and execution of clinical trials. Such models include intravascular infusion of endotoxin or live bacteria, bacterial peritonitis, cecal ligation and perforation, soft tissue infection, pneumonia or meningitis models, using different animal species including rats, mice, rabbits, dogs, pigs, sheep and nonhuman primates. Despite several limitations, animal models remain essential in the development of all new therapies for sepsis and septic shock, because they provide fundamental information about the pharmacokinetics, toxicity, and mechanism of drug action that cannot be duplicated by other methods. New therapeutic agents should be studies in infection models, even after the initiation of the septic process. Furthermore, debility conditions need to be reproduced to avoid the exclusive use of healthy animals, which often do not represent the human septic patient.

  18. The TIM-3 pathway ameliorates Theiler's murine encephalomyelitis virus-induced demyelinating disease.

    Science.gov (United States)

    Kaneyama, Tomoki; Tomiki, Hiroki; Tsugane, Sayaka; Inaba, Yuji; Ichikawa, Motoki; Akiba, Hisaya; Yagita, Hideo; Kim, Byung S; Koh, Chang-Sung

    2014-07-01

    Infection by Theiler's murine encephalomyelitis virus (TMEV) in the central nervous system (CNS) induces an immune-mediated demyelinating disease in susceptible mouse strains and serves as a relevant infection model for human multiple sclerosis. T-cell immunoglobulin and mucin domain-3 (TIM-3) has been demonstrated to play a crucial role in the maintenance of peripheral tolerance. In this study, we examined the regulatory role of the TIM-3 pathway in the development of TMEV-induced demyelinating disease (TMEV-IDD). The expression of TIM-3 was increased at both protein and mRNA levels in the spinal cords of mice with TMEV-IDD compared with naive controls. In addition, by utilizing a blocking mAb, we demonstrate that TIM-3 negatively regulates TMEV-specific ex vivo production of IFN-γ and IL-10 by CD4(+) T cells and IFN-γ by CD8(+) T cells from the CNS of mice with TMEV-IDD at 36 days post-infection (dpi). In vivo blockade of TIM-3 by using the anti-TIM-3 mAb resulted in significant exacerbation of the development of TMEV-IDD both clinically and histologically. The number of infiltrating mononuclear cells in the CNS was also increased in mice administered with anti-TIM-3 mAb both at the induction phase (10 dpi) and at the effector phase (36 dpi). Flow cytometric analysis of intracellular cytokines revealed that the number of CD4(+) T cells producing TNF, IL-4, IL-10 and IL-17 was significantly increased at the effector phase in the CNS of anti-TIM-3 mAb-treated mice. These results suggest that the TIM-3 pathway plays a critical role in the regulation of TMEV-IDD. © The Japanese Society for Immunology. 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. CFD Modeling and Experimental Validation of a Solar Still

    Directory of Open Access Journals (Sweden)

    Mahmood Tahir

    2017-01-01

    Full Text Available Earth is the densest planet of the solar system with total area of 510.072 million square Km. Over 71.68% of this area is covered with water leaving a scant area of 28.32% for human to inhabit. The fresh water accounts for only 2.5% of the total volume and the rest is the brackish water. Presently, the world is facing chief problem of lack of potable water. This issue can be addressed by converting brackish water into potable through a solar distillation process and solar still is specially assigned for this purpose. Efficiency of a solar still explicitly depends on its design parameters, such as wall material, chamber depth, width and slope of the zcondensing surface. This study was aimed at investigating the solar still parameters using CFD modeling and experimental validation. The simulation data of ANSYS-FLUENT was compared with actual experimental data. A close agreement among the simulated and experimental results was seen in the presented work. It reveals that ANSYS-FLUENT is a potent tool to analyse the efficiency of the new designs of the solar distillation systems.

  20. Experimental model for creation of carotid artery aneurysms in dogs

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Hyun; Han, Moon Hee; Yu, In Kyu; Lee, Sang Hyun; Chang, Kee Hyun [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    1996-11-01

    To describe the detailed technique for producing experimental carotid aneurysms in dogs and the success rate, cause of failure and remedy, based on our experience. Fourteen male dogs weighing 12-15kg were anesthetized with inhalation of 1-2% halothane and 50% nitrous oxide. Each surgical procedure was performed under sterile condition with the aid of an operating microscope. A paramidline incision 7-8cm in length was made parallel to and medial to the external jugular vein in the dog's neck. The external jugular vein was harvested as a 1cm vein pouch by ligation and division of the proximal and distal ends. The ipsilateral common carotid artery was exposed and clamped at both ends by a vascular clamp. A 5-mm long elliptical arteriotomy was made at the mid portion of the artery, and then end to side anastomosis between the artery and vein sac was performed by using interrupted 7-0 monofilament prolene sutures. Carotid arteriography or Doppler sonography was performed 1-6 weeks after aneurysm construction. Twenty experimental aneurysms were constructed, and 17 aneurysms were patent on follow up study, but one dog with two aneurysms died from hemorrhagic pneumonia 17 days after surgery. The overall patency rate was 75%. We demonstrated the feasibility of creating experimental aneurysm models in the dog and expect that the technique presented will help to avoid failure in the construction of aneurysms.

  1. Plasma transferred arc welding—modeling and experimental optimization

    Science.gov (United States)

    Wilden, J.; Bergmann, J. P.; Frank, H.

    2006-12-01

    Plasma transferred arc (PTA) welded coatings are used to improve surface properties of mechanical parts. Advantages are the high reliability of the process and the low dilution of substrate and coating material. Processing of surfaces by PTA welding is restricted at the time to flat horizontal position. Furthermore, industry is interested in the development of strategies for coating with PTA in constraint position as complex three-dimensional (3D) parts could be then easily processed as well. Under commercial aspects, the process design can be optimized to increase process efficiency and to reduce heat input during the welding process. Process optimization involves the determination of guidelines for PTA welding in constraint positions as well. Modeling the process gives an alternative to reduce the experimental effort to optimize the welding process. Results of simulation studies of the PTA welding process are given in the present work. It will be shown that coating conditions can be optimized by varying plasma gas flow, heat input and heat flow, process speed, or powder injection with regard to welding in constraint positions. The defined controlling of the PTA welding allows modification of process management with less experimental effort and to develop coating strategies for processing in different positions. In experimental investigations, the developed coating strategies are confirmed by producing PTA coatings in constraint position as well as complex 3D parts.

  2. Chronic inflammatory demyelinating polyneuropathy associated with diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Farzad Fatehi

    2013-01-01

    Full Text Available Various forms of neuropathy are seen diabetic patients; chronic inflammatory demyelinating polyneuropathy (CIDP seems not to be infrequent neuropathy in patients suffering from diabetes and it seems to be more common than in the general population; on the contrary, some authorities do not support pathogenetic association between diabetes mellitus (DM and CIDP. Also, there are some controversies on the subject of CIDP treatment in diabetic patients. Some studies showed that patients with CIDP-DM considerably had recovered following treatment with immunotherapeutic modalities like (Intravenous immunoglobulin IVIG and conversely, some else have argued against the prescription of IVIG in this group and recommend treatment with corticosteroids and provided that resistant, rituximab may be beneficial. The main limitation in most studies is the inadequate number of cases and as a result, problematic decision making in treatment. This article represents an inclusive review of diabetic CIDP presentation and treatment.

  3. CHRONIC INFLAMMATORY DEMYELINATING POLYNEUROPATHY IN CHILDREN: DIAGNOSIS AND TREATMENT

    Directory of Open Access Journals (Sweden)

    А.L. Kurenkov

    2014-01-01

    Full Text Available Chronic inflammatory demyelinating polyneuropathy (CIDP in children is a rare autoimmune disease of the peripheral nervous system. The article analyzes current international diagnostic criteria and clinical presentation features of the disease in childhood. The article discusses general principles of CIDP treatment and focuses on the pathogenetic therapies: intravenous immunotherapy using a standard human immunoglobulin (IVIG with the content of IgG > 95%, prescription of large doses of glucocorticoids and plasmapheresis. It analyzes the recommendations for prioritizing the use of different types of treatment when initiating the therapy and describes the main drug prescription protocols and recommended doses. Two clinical cases of CIDP in children are described. It is shown that the use of adequate doses of IVIG, glucocorticoids and long-term maintenance treatment can completely reverse the symptoms of peripheral lesion, prevent repeated exacerbations of the disease and significantly improve the quality of life.

  4. Subcutaneous immunoglobulin preserves muscle strength in chronic inflammatory demyelinating polyneuropathy

    DEFF Research Database (Denmark)

    Markvardsen, L H; Harbo, T; Sindrup, S H

    2014-01-01

    BACKGROUND AND PURPOSE: Subcutaneous immunoglobulin (SCIG) is superior to placebo treatment for maintenance of muscle strength during 12 weeks in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). The present study evaluated whether SCIG preserves muscle strength for 1 year...... evaluated after 3, 6 and 12 months. Primary end-points were changes in muscle strength evaluated by isokinetic dynamometry in four affected muscle groups and a composite score of muscle performance and function tests, including Medical Research Council (MRC) score, grip strength, 40-m walking test (40-MWT...... remained unchanged. CONCLUSION: SCIG preserves muscle strength and functional ability in patients with CIDP who previously responded to IVIG. SCIG should be considered as an alternative in long-term treatment of CIDP patients....

  5. Solitary osteosclerotic plasmacytoma: association with demyelinating polyneuropathy and amyloid deposition

    Energy Technology Data Exchange (ETDEWEB)

    Voss, S.D.; Hall, F.M. [Dept. of Radiology, Beth Israel Deaconess Medical Center, Boston, MA (United States); Harvard Medical School, Boston, MA (United States); Murphey, M.D. [Dept. of Radiologic Pathology, Armed Forces Institute of Pathology, Washington, DC (United States); Dept. of Radiology and Nuclear Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD (United States); Department of Radiology, University of Maryland School of Medicine, Baltimore, Maryland (United States)

    2001-09-01

    A 51-year-old man presented with a 1-year history of polyneuropathy necessitating the use of a wheelchair. Initial diagnosis was idiopathic chronic inflammatory demyelinating polyneuropathy (CIDP) and associated monoclonal gammopathy. Investigations for multiple myeloma, including bone marrow aspiration and biopsy, were negative. What was initially felt to be an incidental osteosclerotic focus noted on the radiographic bone survey was eventually shown to be a solitary osteosclereotic plasmacytoma with associated amyloid. This dramatically altered treatment. This case emphasizes the importance of including osteosclerotic plasmacytoma in the differential diagnosis of a focal sclerotic bone lesion in the clinical setting of polyneuropathy. These lesions are less likely to progress to multiple myeloma than lytic plasma cell neoplasms, and the presence of polyneuropathy often results in earlier diagnosis and treatment with enhanced prospect of cure. The finding of amyloid deposition within the osteosclerotic lesion may be of prognostic importance. (orig.)

  6. A 17 year-old girl with a demyelinating disease requiring mechanical ventilation: a case report

    Directory of Open Access Journals (Sweden)

    Katsenos Chrysostomos

    2013-01-01

    Full Text Available Abstract Background Demyelinating diseases cause destruction of the myelin sheath, while axons are relatively spared. Pathologically, demyelination can be the result of an inflammatory process, viral infection, acquired metabolic derangement and ischemic insult. Three diseases that can cause inflammatory demyelination of the CNS are: Multiple sclerosis (MS, Acute disseminated encephalomyelitis (ADEM and Acute hemorrhagic leucoencephalitis. Differentiation is not always easy and there is considerable overlaping. Data about adults with acute demyelination requiring ICU admission is limited. Case presentation A 17 year old Greek female was hospitalised in the ICU because of acute respiratory failure requiring mechanical ventilation. She had a history of febrile disease one month before, acute onset of paraplegia, diplopia, progressive arm weakness and dyspnea. Her consciousness was not impaired. A demyelinating central nervous system (CNS disease, possibly post infectious encephalomyelitis (ADEM was the underlying condition. The MRI of the brain disclosed diffused expanded cerebral lesions involving the optic nerve, basal ganglia cerebellum, pons and medulla oblongata. There was also extended involvement of the cervical and thoracic part of the spinal cord. CSF leukocyte count was elevated with lymphocyte predominance. The patient required mechanical ventilation for two months. Then she was transferred to a rehabilitation centre. Three years later she remains paraplegic. Since then she has not suffered any other demyelination attack. Conclusions Demyelinating diseases can cause acute respiratory failure when the spinal cord is affected. Severe forms of these diseases, making necessary ICU admission, is less frequently reported. Intensivists should be aware of the features of these rare diseases.

  7. A 17 year-old girl with a demyelinating disease requiring mechanical ventilation: a case report.

    Science.gov (United States)

    Katsenos, Chrysostomos; Androulaki, Despoina; Lyra, Stavroula; Tsoutsouras, Theodoros; Mandragos, Costas

    2013-01-18

    Demyelinating diseases cause destruction of the myelin sheath, while axons are relatively spared. Pathologically, demyelination can be the result of an inflammatory process, viral infection, acquired metabolic derangement and ischemic insult. Three diseases that can cause inflammatory demyelination of the CNS are: Multiple sclerosis (MS), Acute disseminated encephalomyelitis (ADEM) and Acute hemorrhagic leucoencephalitis. Differentiation is not always easy and there is considerable overlaping. Data about adults with acute demyelination requiring ICU admission is limited. A 17 year old Greek female was hospitalised in the ICU because of acute respiratory failure requiring mechanical ventilation. She had a history of febrile disease one month before, acute onset of paraplegia, diplopia, progressive arm weakness and dyspnea. Her consciousness was not impaired. A demyelinating central nervous system (CNS) disease, possibly post infectious encephalomyelitis (ADEM) was the underlying condition. The MRI of the brain disclosed diffused expanded cerebral lesions involving the optic nerve, basal ganglia cerebellum, pons and medulla oblongata. There was also extended involvement of the cervical and thoracic part of the spinal cord. CSF leukocyte count was elevated with lymphocyte predominance. The patient required mechanical ventilation for two months. Then she was transferred to a rehabilitation centre. Three years later she remains paraplegic. Since then she has not suffered any other demyelination attack. Demyelinating diseases can cause acute respiratory failure when the spinal cord is affected. Severe forms of these diseases, making necessary ICU admission, is less frequently reported. Intensivists should be aware of the features of these rare diseases.

  8. Clinical and magnetic resonance imaging (MRI) distinctions between tumefactive demyelination and brain tumors in children.

    Science.gov (United States)

    Yiu, Eppie M; Laughlin, Suzanne; Verhey, Leonard H; Banwell, Brenda L

    2014-05-01

    Tumefactive demyelinating lesions can be difficult to distinguish from tumors. Clinical and magnetic resonance imaging features of children with tumefactive demyelination and supratentorial brain tumors were compared. Patients were identified through a 23-site national demyelinating disease study, and from a single-site neuroradiology database. For inclusion, lesions met at least 1 of 3 criteria: maximal cross-sectional diameter >20 mm, local or global cerebral mass effect, or presence of perilesional edema. Thirty-one children with tumefactive demyelination (5 with solitary lesions) were identified: 27 of 189 (14.3%) from the demyelinating disease study and 4 from the database. Thirty-three children with tumors were identified. Children with tumefactive demyelination were more likely to have an abnormal neurologic examination and polyfocal neurologic deficits compared to children with tumors. Tumefactive demyelination was distinguished from tumor by the presence of multiple lesions, absence of cortical involvement, and decrease in lesion size or detection of new lesions on serial imaging.

  9. An efficient approach to bioconversion kinetic model generation based on automated microscale experimentation integrated with model driven experimental design

    DEFF Research Database (Denmark)

    Chen, B. H.; Micheletti, M.; Baganz, F.

    2009-01-01

    design. It incorporates a model driven approach to the experimental design that minimises the number of experiments to be performed, while still generating accurate values of kinetic parameters. The approach has been illustrated with the transketolase mediated asymmetric synthesis of L......Reliable models of enzyme kinetics are required for the effective design of bioconversion processes. Kinetic expressions of the enzyme-catalysed reaction rate however, are frequently complex and establishing accurate values of kinetic parameters normally requires a large number of experiments....... These can be both time consuming and expensive when working with the types of non-natural chiral intermediates important in pharmaceutical syntheses. This paper presents ail automated microscale approach to the rapid and cost effective generation of reliable kinetic models useful for bioconversion process...

  10. A DIDATIC EXPERIENCE IN BIOCHEMISTRY LABWORKS: THEORETICALVERSUS EXPERIMENTAL MODEL

    Directory of Open Access Journals (Sweden)

    B.C Rossi-Rodrigues

    2008-05-01

    Full Text Available Biochemistry labworks are fundamental to both the instrumentation and  for  the  establishment of important concepts. The labworks of Basic  Biochemistry  (BB280 for Biology students at UNICAMP have gone through several  improvements. The labworks are  now  structured  from simple  activities to more complex ones, and aimed  to  the student’s  autonomy  development  in the experiments planning and execution  over  the teaching  semester. The first practical activity is on buffer systems, and   it is based  on  the confrontation of a theoretical model with the  lab experiments results.  First of all, the students  simulate  a Titration  in  a computational environment, where students lay a theoretical model from their knowledge. In the theoretical model the buffer parameters are set according to the teacher instructions, and the experiment conditions are also set and tested.  The simulation results are used for planning  the experiment and to compare with the experimental ones.  After having the simulations concluded and having the experiment planned the students  perform  the  in lab  Titration with the parameters established in the simulation. The results obtained by students are presented in a report. We analyzed the reports from 76 BB280’s students in 2007(night class and day class. The students identified as the main causes of the discrepancy between theoretical and experimental data: 1 experimental errors, related to the lack of technical skill 2 limitation of equipment used 3 unexpected behavior of the substances  used. In addition to the theoretical content related to  labwork, the confrontation between the  simulation and experimentation provided the students with ability  to identify the main aspects of which can influence the quality of the data obtained.

  11. Astrocyte regulation of sleep circuits: experimental and modeling perspectives

    Directory of Open Access Journals (Sweden)

    Tommaso eFellin

    2012-08-01

    Full Text Available Integrated within neural circuits, astrocytes have recently been shown to modulate brain rhythms thought to mediate sleep function. Experimental evidence suggests that local impact of astrocytes on single synapses translates into global modulation of neuronal networks and behavior. We discuss these findings in the context of current conceptual models of sleep generation and function, each of which have historically focused on neural mechanisms. We highlight the implications and the challenges introduced by these results from a conceptual and computational perspective. We further provide modeling directions on how these data might extend our knowledge of astrocytic properties and sleep function. Given our evolving understanding of how local cellular activities during sleep lead to functional outcomes for the brain, further mechanistic and theoretical understanding of astrocytic contribution to these dynamics will undoubtedly be of great basic and translational benefit.

  12. An experimental and modeling study of n-octanol combustion

    KAUST Repository

    Cai, Liming

    2015-01-01

    This study presents the first investigation on the combustion chemistry of n-octanol, a long chain alcohol. Ignition delay times were determined experimentally in a high-pressure shock tube, and stable species concentration profiles were obtained in a jet stirred reactor for a range of initial conditions. A detailed kinetic model was developed to describe the oxidation of n-octanol at both low and high temperatures, and the model shows good agreement with the present dataset. The fuel\\'s combustion characteristics are compared to those of n-alkanes and to short chain alcohols to illustrate the effects of the hydroxyl moiety and the carbon chain length on important combustion properties. Finally, the results are discussed in detail. © 2014 The Combustion Institute.

  13. Experimental studies and modeling on concentration polarization in forward osmosis.

    Science.gov (United States)

    Qin, Jian-Jun; Chen, Sijie; Oo, Maung Htun; Kekre, Kiran A; Cornelissen, Emile R; Ruiken, Chris J

    2010-01-01

    Concentration polarization (CP) is an important issue in forward osmosis (FO) processes and it is believed that the coupled effect of dilutive internal CP (DICP) and concentrative external CP (CECP) limits FO flux. The objective of this study was to distinguish individual contribution of different types of DICP and CECP via modeling and to validate it by pilot studies. The influence of DICP/CECP on FO flux has been investigated in this study. The CP model presented in this work was derived from a previous study and evaluated by bench-scale FO experiments. Experiments were conducted with drinking water as the feed and NaCl/MgSO(4) as draw solutions at different concentrations and velocities. Modeling results indicated that DICP contributed to a flux reduction by 99.9% for 0.5 M NaCl as a draw solution although the flow pattern of both feed and draw solutions was turbulent. DICP could be improved via selection of the draw solution. The modeling results were well fit with the experimental data. It was concluded that the model could be used for selection of the draw solution and prediction of water flux under similar situation. A draw solution with greater diffusion coefficient or a thinner substrate of an asymmetric FO membrane resulted in a higher flux.

  14. Immunology and Homeopathy. 3. Experimental Studies on Animal Models

    Directory of Open Access Journals (Sweden)

    Paolo Bellavite

    2006-01-01

    Full Text Available A search of the literature and the experiments carried out by the authors of this review show that there are a number of animal models where the effect of homeopathic dilutions or the principles of homeopathic medicine have been tested. The results relate to the immunostimulation by ultralow doses of antigens, the immunological models of the ‘simile’, the regulation of acute or chronic inflammatory processes and the use of homeopathic medicines in farming. The models utilized by different research groups are extremely etherogeneous and differ as the test medicines, the dilutions and the outcomes are concerned. Some experimental lines, particularly those utilizing mice models of immunomodulation and anti-inflammatory effects of homeopathic complex formulations, give support to a real effect of homeopathic high dilutions in animals, but often these data are of preliminary nature and have not been independently replicated. The evidence emerging from animal models is supporting the traditional ‘simile’ rule, according to which ultralow doses of compounds, that in high doses are pathogenic, may have paradoxically a protective or curative effect. Despite a few encouraging observational studies, the effectiveness of the homeopathic prevention or therapy of infections in veterinary medicine is not sufficiently supported by randomized and controlled trials.

  15. Maternal hypothyroidism: An overview of current experimental models.

    Science.gov (United States)

    Ghanbari, Mahboubeh; Ghasemi, Asghar

    2017-10-15

    Maternal hypothyroidism (MH) is the most common cause of transient congenital hypothyroidism. Different animal models are used for assessing developmental effects of MH in offspring. The severity and status of hypothyroidism in animal models must be a reflection of the actual conditions in humans. To obtain comparable results with different clinical conditions, which lead to MH in humans, several factors have been suggested for researchers to consider before designing the experimental models. Regarding development of fetal body systems during pregnancy, interference at different times provides different results and the appropriate time for induction of hypothyroidism should be selected based on accurate time of development of the system under assessment. Other factors that should be taken into consideration include, physiological and biochemical differences between humans and other species, thyroid hormone-independent effects of anti-thyroid drugs, circadian rhythms in TSH secretion, sex differences, physical and psychological stress. This review addresses essential guidelines for selecting and managing the optimal animal model for MH as well as discussing the pros and cons of currently used models. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Antioxidant Capacity: Experimental Determination by EPR Spectroscopy and Mathematical Modeling.

    Science.gov (United States)

    Polak, Justyna; Bartoszek, Mariola; Chorążewski, Mirosław

    2015-07-22

    A new method of determining antioxidant capacity based on a mathematical model is presented in this paper. The model was fitted to 1000 data points of electron paramagnetic resonance (EPR) spectroscopy measurements of various food product samples such as tea, wine, juice, and herbs with Trolox equivalent antioxidant capacity (TEAC) values from 20 to 2000 μmol TE/100 mL. The proposed mathematical equation allows for a determination of TEAC of food products based on a single EPR spectroscopy measurement. The model was tested on the basis of 80 EPR spectroscopy measurements of herbs, tea, coffee, and juice samples. The proposed model works for both strong and weak antioxidants (TEAC values from 21 to 2347 μmol TE/100 mL). The determination coefficient between TEAC values obtained experimentally and TEAC values calculated with proposed mathematical equation was found to be R(2) = 0.98. Therefore, the proposed new method of TEAC determination based on a mathematical model is a good alternative to the standard EPR method due to its being fast, accurate, inexpensive, and simple to perform.

  17. An experimental methodology for a fuzzy set preference model

    Science.gov (United States)

    Turksen, I. B.; Willson, Ian A.

    1992-01-01

    models and vague linguistic preferences has greatly limited the usefulness and predictive validity of existing preference models. A fuzzy set preference model that uses linguistic variables and a fully interactive implementation should be able to simultaneously address these issues and substantially improve the accuracy of demand estimates. The parallel implementation of crisp and fuzzy conjoint models using identical data not only validates the fuzzy set model but also provides an opportunity to assess the impact of fuzzy set definitions and individual attribute choices implemented in the interactive methodology developed in this research. The generalized experimental tools needed for conjoint models can also be applied to many other types of intelligent systems.

  18. Contaminant plume configuration and movement: an experimental model

    Science.gov (United States)

    Alencoao, A.; Reis, A.; Pereira, M. G.; Liberato, M. L. R.; Caramelo, L.; Amraoui, M.; Amorim, V.

    2009-04-01

    The relevance of Science and Technology in our daily routines makes it compulsory to educate citizens who have both scientific literacy and scientific knowledge. These will allow them to be intervening citizens in a constantly changing society. Thus, physical and natural sciences are included in school curricula, both in primary and secondary education, with the fundamental aim of developing in the students the skills, attitudes and knowledge needed for the understanding of the planet Earth and its real problems. On the other hand, teaching in Geosciences is more and more based on practical methodologies which use didactic material, sustaining teachers' pedagogical practices and facilitating students' learning tasks suggested on the syllabus defined for each school level. Themes related to exploring the different components of the Hydrological Cycle and themes related to natural environment protection and preservation, namely water resources and soil contamination by industrial and urban sewage are examples of subject matters included on the Portuguese syllabus. These topics motivated the conception and construction of experimental models for the study of the propagation of pollutants on a porous medium. The experimental models allow inducing a horizontal flux of water though different kinds of permeable substances (e.g. sand, silt), with contamination spots on its surface. These experimental activities facilitate the student to understand the flow path of contaminating substances on the saturated zone and to observe the contaminant plume configuration and movement. The activities are explored in a teaching and learning process perspective where the student builds its own knowledge through real question- problem based learning which relate Science, Technology and Society. These activities have been developed in the framework of project ‘Water in the Environment' (CV/PVI/0854) of the POCTI Program (Programa Operacional "Ciência, Tecnologia, Inovação") financed

  19. Taenia solium: Development of an Experimental Model of Porcine Neurocysticercosis.

    Science.gov (United States)

    Fleury, Agnès; Trejo, Armando; Cisneros, Humberto; García-Navarrete, Roberto; Villalobos, Nelly; Hernández, Marisela; Villeda Hernández, Juana; Hernández, Beatriz; Rosas, Gabriela; Bobes, Raul J; de Aluja, Aline S; Sciutto, Edda; Fragoso, Gladis

    2015-01-01

    Human neurocysticercosis (NC) is caused by the establishment of Taenia solium larvae in the central nervous system. NC is a severe disease still affecting the population in developing countries of Latin America, Asia, and Africa. While great improvements have been made on NC diagnosis, treatment, and prevention, the management of patients affected by extraparenchymal parasites remains a challenge. The development of a T. solium NC experimental model in pigs that will allow the evaluation of new therapeutic alternatives is herein presented. Activated oncospheres (either 500 or 1000) were surgically implanted in the cerebral subarachnoid space of piglets. The clinical status and the level of serum antibodies in the animals were evaluated for a 4-month period after implantation. The animals were sacrificed, cysticerci were counted during necropsy, and both the macroscopic and microscopic characteristics of cysts were described. Based on the number of established cysticerci, infection efficiency ranged from 3.6% (1000 oncospheres) to 5.4% (500 oncospheres). Most parasites were caseous or calcified (38/63, 60.3%) and were surrounded by an exacerbated inflammatory response with lymphocyte infiltration and increased inflammatory markers. The infection elicited specific antibodies but no neurological signs. This novel experimental model of NC provides a useful tool to evaluate new cysticidal and anti-inflammatory approaches and it should improve the management of severe NC patients, refractory to the current treatments.

  20. Experimental Model of Intervertebral Disk Mediated Postoperative Epidural Fibrosis.

    Science.gov (United States)

    Larionov, Sergey N; Sorokovikov, V A; Erdyneyev, K C; Lepekhova, S A; Goldberg, O A

    2016-07-01

    Postoperative epidural fibrosis (EF) after lumbar discectomy is the most common and at the same time controversial issue. The etiology and pathogenesis creates a lot of discussion and selection of methods of treatment and prevention continues. LIV laminectomy with dura mater (DM) exposition was done in 24 rats, and then, 0.3 ml of elements of suspension of autologous intervertebral disk was implicated on DM. As autologous intervertebral disk, we used the intervertebral disk from amputated tail. In all the animals, incisions were closed with 3/0 Vicryl. EF was examined. Fibroblast cell density was calculated in each field at ×40 magnification: Grade 1 - fewer than 100 fibroblasts in each field; Grade 2 - 100-150 fibroblasts in each field; Grade 3 - more than 150 fibroblasts in each field. Based on histological results, we confirmed our model of experiment. On the 30th day of evaluation, there were significant histological evidences of postoperative epidural adhesions in experimental animals, which included the obliteration of epidural space, the presence of adhesions in the dura and nerve roots, the restructuring of the yellow ligament, bone sclerosis, excessive appearance of fibrous tissue around the autologous intervertebral disk tissue that applied on the DM. In our work, we describe a new experimental model, where the elements of autologous intervertebral disk play the role of inflammation trigger, which cause postoperative scar and EF.

  1. Experimental Investigation and Theoretical Modeling of Nanosilica Activity in Concrete

    Directory of Open Access Journals (Sweden)

    Han-Seung Lee

    2014-01-01

    Full Text Available This paper presents experimental investigations and theoretical modeling of the hydration reaction of nanosilica blended concrete with different water-to-binder ratios and different nanosilica replacement ratios. The developments of chemically bound water contents, calcium hydroxide contents, and compressive strength of Portland cement control specimens and nanosilica blended specimens were measured at different ages: 1 day, 3 days, 7 days, 14 days, and 28 days. Due to the pozzolanic reaction of nanosilica, the contents of calcium hydroxide in nanosilica blended pastes are considerably lower than those in the control specimens. Compared with the control specimens, the extent of compressive strength enhancement in the nanosilica blended specimens is much higher at early ages. Additionally, a blended cement hydration model that considers both the hydration reaction of cement and the pozzolanic reaction of nanosilica is proposed. The properties of nanosilica blended concrete during hardening were evaluated using the degree of hydration of cement and the reaction degree of nanosilica. The calculated chemically bound water contents, calcium hydroxide contents, and compressive strength were generally consistent with the experimental results.

  2. NADPH Oxidase-Related Pathophysiology in Experimental Models of Stroke

    Directory of Open Access Journals (Sweden)

    Hiroshi Yao

    2017-10-01

    Full Text Available Several experimental studies have indicated that nicotinamide adenine dinucleotide phosphate (NADPH oxidases (Nox exert detrimental effects on ischemic brain tissue; Nox-knockout mice generally exhibit resistance to damage due to experimental stroke following middle cerebral artery occlusion (MCAO. Furthermore, our previous MCAO study indicated that infarct size and blood-brain barrier breakdown are enhanced in mice with pericyte-specific overexpression of Nox4, relative to levels observed in controls. However, it remains unclear whether Nox affects the stroke outcome directly by increasing oxidative stress at the site of ischemia, or indirectly by modifying physiological variables such as blood pressure or cerebral blood flow (CBF. Because of technical problems in the measurement of physiological variables and CBF, it is often difficult to address this issue in mouse models due to their small body size; in our previous study, we examined the effects of Nox activity on focal ischemic injury in a novel congenic rat strain: stroke-prone spontaneously hypertensive rats with loss-of-function in Nox. In this review, we summarize the current literature regarding the role of Nox in focal ischemic injury and discuss critical issues that should be considered when investigating Nox-related pathophysiology in animal models of stroke.

  3. Experimental model of distraction osteogenesis in edentulous rats

    Directory of Open Access Journals (Sweden)

    Maria Montserrat Pujadas Bigi

    2011-06-01

    Full Text Available Distraction osteogenesis (DO is a surgical technique producing bone lengthening by distraction of the fracture callus. Although a large number of experimental studies on the events associated with DO of craniofacial skeleton have been reported, the few employing rat mandibular bone DO used complicated designs and produced a small volume of newly formed bone. Thus, this study aims to present an original experimental model of mandibular DO in edentulous rats that produces a sufficient quantity and quality of intramembranous bone. Eight male Wistar rats, weighing 75 g, underwent extraction of lower molars. With rats weighing 350 g, right mandibular osteotomy was performed and the distraction device was placed. The distraction device was custom made using micro-implants, expansion screws, and acrylic resin. Study protocol: latency: 6 days, distraction: ¼ turn (0.175 mm once a day during 6 d, consolidation: 28 d after distraction phase, sacrifice. DO-treated and contralateral hemimandibles were dissected and compared macroscopically and using radiographic studies. Histological sections were obtained and stained with H&E. A distraction gap filled with newly formed and mature bone tissue was obtained. This model of mandibular DO proved useful to obtain adequate quantity and quality of bone to study bone regeneration.

  4. Sparse linear models: Variational approximate inference and Bayesian experimental design

    Energy Technology Data Exchange (ETDEWEB)

    Seeger, Matthias W [Saarland University and Max Planck Institute for Informatics, Campus E1.4, 66123 Saarbruecken (Germany)

    2009-12-01

    A wide range of problems such as signal reconstruction, denoising, source separation, feature selection, and graphical model search are addressed today by posterior maximization for linear models with sparsity-favouring prior distributions. The Bayesian posterior contains useful information far beyond its mode, which can be used to drive methods for sampling optimization (active learning), feature relevance ranking, or hyperparameter estimation, if only this representation of uncertainty can be approximated in a tractable manner. In this paper, we review recent results for variational sparse inference, and show that they share underlying computational primitives. We discuss how sampling optimization can be implemented as sequential Bayesian experimental design. While there has been tremendous recent activity to develop sparse estimation, little attendance has been given to sparse approximate inference. In this paper, we argue that many problems in practice, such as compressive sensing for real-world image reconstruction, are served much better by proper uncertainty approximations than by ever more aggressive sparse estimation algorithms. Moreover, since some variational inference methods have been given strong convex optimization characterizations recently, theoretical analysis may become possible, promising new insights into nonlinear experimental design.

  5. Glial cell-derived neurotrophic factor alleviates sepsis-induced neuromuscular dysfunction by decreasing the expression of γ- and α7-nicotinic acetylcholine receptors in an experimental rat model of neuromyopathy.

    Science.gov (United States)

    Wang, Xin; Min, Su; Xie, Fei; Yang, Jun; Li, Liang; Chen, Jingyuan

    2018-02-05

    Sepsis-induced neuromuscular dysfunction results from up-regulation of the expression of γ- and α7-nicotinic acetylcholine receptors (nAChR). Although glial cell derived neurotrophic factor (GDNF) has been implicated in repairing and supporting neurons, little is known about the effects of GDNF on demyelination of nerves in sepsis. In this study, we tested the hypothesis that GDNF could alleviate sepsis-induced neuromuscular dysfunction by decreasing the expression of γ- and α7-nAChR in an experimental rat model of neuromyopathy. Rats were randomly divided into a sham group and a sepsis group. Levels of inflammatory factors, muscle function, and nicotinic acetylcholine receptors were tested in rats after cecal ligation and puncture (CLP). At 24 h after CLP, GDNF was injected around the sciatic nerve of sepsis rats, cytokines were detected by enzyme-linked immunosorbent assay (ELISA), and immunofluorescence staining was used to detect the expression of nAChRs. GDNF and its downstream effector (Erk1/2 and GFR-α), neuregulin-1 (NRG-1) and γ- and α7-nAChR were measured using Western blot analysis. The expression of GDNF reached a minimum at 24 h after CLP. Compared with the sham group, the release of cytokines and the expression of γ- and α7-nAChR were significantly increased in the sepsis group. The administration of GDNF significantly alleviated sepsis-induced neuromuscular dysfunction, as well as reducing the expression of γ- and α7-nAChR. In addition, the expression of Erk1/2, GFR-α, NRG-1 were significantly increased after GDNF treatment. GDNF administration may improve patient outcomes by reducing the demyelination of nerves and the expression of γ- and α7-nAChR. Copyright © 2018. Published by Elsevier Inc.

  6. Partial demyelination of cat spinal cord after x-irradiation and surgical interference

    Energy Technology Data Exchange (ETDEWEB)

    Blakemore, W.F.

    1978-09-01

    Following 4000 rad of x-irradiation and transplantation of sciatic nerve over the dorsal columns, extensive partial demyelination occurred in some animals. This dose of radiation inhibits remyelination so this phenomenon could be studied knowing that remyelination was absent. Partial demyelination was characterized by translocation of myelin to form large myelin ovoids which remained associated with the remaining thinned myelin sheath; nodal widening, involvement of one paranode only, transition from thin to thick myelin along an internode, enlargement and disorientated oligodendrocyte tongues were also features of this change. It is concluded that partial demyelination results when oligodendrocytes have to function in a sub-optimal environment.

  7. Application of Iterative Robust Model-based Optimal Experimental Design for the Calibration of Biocatalytic Models

    DEFF Research Database (Denmark)

    Van Daele, Timothy; Gernaey, Krist V.; Ringborg, Rolf Hoffmeyer

    2017-01-01

    The aim of model calibration is to estimate unique parameter values from available experimental data, here applied to a biocatalytic process. The traditional approach of first gathering data followed by performing a model calibration is inefficient, since the information gathered during...... experimentation is not actively used to optimise the experimental design. By applying an iterative robust model-based optimal experimental design, the limited amount of data collected is used to design additional informative experiments. The algorithm is used here to calibrate the initial reaction rate of an ω......-transaminase catalysed reaction in a more accurate way. The parameter confidence region estimated from the Fisher Information Matrix is compared with the likelihood confidence region, which is a more accurate, but also a computationally more expensive method. As a result, an important deviation between both approaches...

  8. Integral Reactor Containment Condensation Model and Experimental Validation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qiao [Oregon State Univ., Corvallis, OR (United States); Corradini, Michael [Univ. of Wisconsin, Madison, WI (United States)

    2016-05-02

    This NEUP funded project, NEUP 12-3630, is for experimental, numerical and analytical studies on high-pressure steam condensation phenomena in a steel containment vessel connected to a water cooling tank, carried out at Oregon State University (OrSU) and the University of Wisconsin at Madison (UW-Madison). In the three years of investigation duration, following the original proposal, the planned tasks have been completed: (1) Performed a scaling study for the full pressure test facility applicable to the reference design for the condensation heat transfer process during design basis accidents (DBAs), modified the existing test facility to route the steady-state secondary steam flow into the high pressure containment for controllable condensation tests, and extended the operations at negative gage pressure conditions (OrSU). (2) Conducted a series of DBA and quasi-steady experiments using the full pressure test facility to provide a reliable high pressure condensation database (OrSU). (3) Analyzed experimental data and evaluated condensation model for the experimental conditions, and predicted the prototypic containment performance under accidental conditions (UW-Madison). A film flow model was developed for the scaling analysis, and the results suggest that the 1/3 scaled test facility covers large portion of laminar film flow, leading to a lower average heat transfer coefficient comparing to the prototypic value. Although it is conservative in reactor safety analysis, the significant reduction of heat transfer coefficient (50%) could under estimate the prototypic condensation heat transfer rate, resulting in inaccurate prediction of the decay heat removal capability. Further investigation is thus needed to quantify the scaling distortion for safety analysis code validation. Experimental investigations were performed in the existing MASLWR test facility at OrST with minor modifications. A total of 13 containment condensation tests were conducted for pressure

  9. Toxin-Induced Experimental Models of Learning and Memory Impairment.

    Science.gov (United States)

    More, Sandeep Vasant; Kumar, Hemant; Cho, Duk-Yeon; Yun, Yo-Sep; Choi, Dong-Kug

    2016-09-01

    Animal models for learning and memory have significantly contributed to novel strategies for drug development and hence are an imperative part in the assessment of therapeutics. Learning and memory involve different stages including acquisition, consolidation, and retrieval and each stage can be characterized using specific toxin. Recent studies have postulated the molecular basis of these processes and have also demonstrated many signaling molecules that are involved in several stages of memory. Most insights into learning and memory impairment and to develop a novel compound stems from the investigations performed in experimental models, especially those produced by neurotoxins models. Several toxins have been utilized based on their mechanism of action for learning and memory impairment such as scopolamine, streptozotocin, quinolinic acid, and domoic acid. Further, some toxins like 6-hydroxy dopamine (6-OHDA), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and amyloid-β are known to cause specific learning and memory impairment which imitate the disease pathology of Parkinson's disease dementia and Alzheimer's disease dementia. Apart from these toxins, several other toxins come under a miscellaneous category like an environmental pollutant, snake venoms, botulinum, and lipopolysaccharide. This review will focus on the various classes of neurotoxin models for learning and memory impairment with their specific mechanism of action that could assist the process of drug discovery and development for dementia and cognitive disorders.

  10. Toxin-Induced Experimental Models of Learning and Memory Impairment

    Directory of Open Access Journals (Sweden)

    Sandeep Vasant More

    2016-09-01

    Full Text Available Animal models for learning and memory have significantly contributed to novel strategies for drug development and hence are an imperative part in the assessment of therapeutics. Learning and memory involve different stages including acquisition, consolidation, and retrieval and each stage can be characterized using specific toxin. Recent studies have postulated the molecular basis of these processes and have also demonstrated many signaling molecules that are involved in several stages of memory. Most insights into learning and memory impairment and to develop a novel compound stems from the investigations performed in experimental models, especially those produced by neurotoxins models. Several toxins have been utilized based on their mechanism of action for learning and memory impairment such as scopolamine, streptozotocin, quinolinic acid, and domoic acid. Further, some toxins like 6-hydroxy dopamine (6-OHDA, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP and amyloid-β are known to cause specific learning and memory impairment which imitate the disease pathology of Parkinson’s disease dementia and Alzheimer’s disease dementia. Apart from these toxins, several other toxins come under a miscellaneous category like an environmental pollutant, snake venoms, botulinum, and lipopolysaccharide. This review will focus on the various classes of neurotoxin models for learning and memory impairment with their specific mechanism of action that could assist the process of drug discovery and development for dementia and cognitive disorders.

  11. Mass spectrometry analysis of hepcidin peptides in experimental mouse models.

    Science.gov (United States)

    Tjalsma, Harold; Laarakkers, Coby M M; van Swelm, Rachel P L; Theurl, Milan; Theurl, Igor; Kemna, Erwin H; van der Burgt, Yuri E M; Venselaar, Hanka; Dutilh, Bas E; Russel, Frans G M; Weiss, Günter; Masereeuw, Rosalinde; Fleming, Robert E; Swinkels, Dorine W

    2011-03-08

    The mouse is a valuable model for unravelling the role of hepcidin in iron homeostasis, however, such studies still report hepcidin mRNA levels as a surrogate marker for bioactive hepcidin in its pivotal function to block ferroportin-mediated iron transport. Here, we aimed to assess bioactive mouse Hepcidin-1 (Hep-1) and its paralogue Hepcidin-2 (Hep-2) at the peptide level. To this purpose, Fourier transform ion cyclotron resonance (FTICR) and tandem-MS was used for hepcidin identification, after which a time-of-flight (TOF) MS-based methodology was exploited to routinely determine Hep-1 and -2 levels in mouse serum and urine. This method was biologically validated by hepcidin assessment in: i) 3 mouse strains (C57Bl/6; DBA/2 and BABL/c) upon stimulation with intravenous iron and LPS, ii) homozygous Hfe knock out, homozygous transferrin receptor 2 (Y245X) mutated mice and double affected mice, and iii) mice treated with a sublethal hepatotoxic dose of paracetamol. The results showed that detection of Hep-1 was restricted to serum, whereas Hep-2 and its presumed isoforms were predominantly present in urine. Elevations in serum Hep-1 and urine Hep-2 upon intravenous iron or LPS were only moderate and varied considerably between mouse strains. Serum Hep-1 was decreased in all three hemochromatosis models, being lowest in the double affected mice. Serum Hep-1 levels correlated with liver hepcidin-1 gene expression, while acute liver damage by paracetamol depleted Hep-1 from serum. Furthermore, serum Hep-1 appeared to be an excellent indicator of splenic iron accumulation. In conclusion, Hep-1 and Hep-2 peptide responses in experimental mouse agree with the known biology of hepcidin mRNA regulators, and their measurement can now be implemented in experimental mouse models to provide novel insights in post-transcriptional regulation, hepcidin function, and kinetics.

  12. Mass spectrometry analysis of hepcidin peptides in experimental mouse models.

    Directory of Open Access Journals (Sweden)

    Harold Tjalsma

    Full Text Available The mouse is a valuable model for unravelling the role of hepcidin in iron homeostasis, however, such studies still report hepcidin mRNA levels as a surrogate marker for bioactive hepcidin in its pivotal function to block ferroportin-mediated iron transport. Here, we aimed to assess bioactive mouse Hepcidin-1 (Hep-1 and its paralogue Hepcidin-2 (Hep-2 at the peptide level. To this purpose, Fourier transform ion cyclotron resonance (FTICR and tandem-MS was used for hepcidin identification, after which a time-of-flight (TOF MS-based methodology was exploited to routinely determine Hep-1 and -2 levels in mouse serum and urine. This method was biologically validated by hepcidin assessment in: i 3 mouse strains (C57Bl/6; DBA/2 and BABL/c upon stimulation with intravenous iron and LPS, ii homozygous Hfe knock out, homozygous transferrin receptor 2 (Y245X mutated mice and double affected mice, and iii mice treated with a sublethal hepatotoxic dose of paracetamol. The results showed that detection of Hep-1 was restricted to serum, whereas Hep-2 and its presumed isoforms were predominantly present in urine. Elevations in serum Hep-1 and urine Hep-2 upon intravenous iron or LPS were only moderate and varied considerably between mouse strains. Serum Hep-1 was decreased in all three hemochromatosis models, being lowest in the double affected mice. Serum Hep-1 levels correlated with liver hepcidin-1 gene expression, while acute liver damage by paracetamol depleted Hep-1 from serum. Furthermore, serum Hep-1 appeared to be an excellent indicator of splenic iron accumulation. In conclusion, Hep-1 and Hep-2 peptide responses in experimental mouse agree with the known biology of hepcidin mRNA regulators, and their measurement can now be implemented in experimental mouse models to provide novel insights in post-transcriptional regulation, hepcidin function, and kinetics.

  13. Mass Spectrometry Analysis of Hepcidin Peptides in Experimental Mouse Models

    Science.gov (United States)

    van Swelm, Rachel P. L.; Theurl, Milan; Theurl, Igor; Kemna, Erwin H.; van der Burgt, Yuri E. M.; Venselaar, Hanka; Dutilh, Bas E.; Russel, Frans G. M.; Weiss, Günter; Masereeuw, Rosalinde; Fleming, Robert E.; Swinkels, Dorine W.

    2011-01-01

    The mouse is a valuable model for unravelling the role of hepcidin in iron homeostasis, however, such studies still report hepcidin mRNA levels as a surrogate marker for bioactive hepcidin in its pivotal function to block ferroportin-mediated iron transport. Here, we aimed to assess bioactive mouse Hepcidin-1 (Hep-1) and its paralogue Hepcidin-2 (Hep-2) at the peptide level. To this purpose, fourier transform ion cyclotron resonance (FTICR) and tandem-MS was used for hepcidin identification, after which a time-of-flight (TOF) MS-based methodology was exploited to routinely determine Hep-1 and -2 levels in mouse serum and urine. This method was biologically validated by hepcidin assessment in: i) 3 mouse strains (C57Bl/6; DBA/2 and BABL/c) upon stimulation with intravenous iron and LPS, ii) homozygous Hfe knock out, homozygous transferrin receptor 2 (Y245X) mutated mice and double affected mice, and iii) mice treated with a sublethal hepatotoxic dose of paracetamol. The results showed that detection of Hep-1 was restricted to serum, whereas Hep-2 and its presumed isoforms were predominantly present in urine. Elevations in serum Hep-1 and urine Hep-2 upon intravenous iron or LPS were only moderate and varied considerably between mouse strains. Serum Hep-1 was decreased in all three hemochromatosis models, being lowest in the double affected mice. Serum Hep-1 levels correlated with liver hepcidin-1 gene expression, while acute liver damage by paracetamol depleted Hep-1 from serum. Furthermore, serum Hep-1 appeared to be an excellent indicator of splenic iron accumulation. In conclusion, Hep-1 and Hep-2 peptide responses in experimental mouse agree with the known biology of hepcidin mRNA regulators, and their measurement can now be implemented in experimental mouse models to provide novel insights in post-transcriptional regulation, hepcidin function, and kinetics. PMID:21408141

  14. Predicting subsurface uranium transport: Mechanistic modeling constrained by experimental data

    Science.gov (United States)

    Ottman, Michael; Schenkeveld, Walter D. C.; Kraemer, Stephan

    2017-04-01

    Depleted uranium (DU) munitions and their widespread use throughout conflict zones around the world pose a persistent health threat to the inhabitants of those areas long after the conclusion of active combat. However, little emphasis has been put on developing a comprehensive, quantitative tool for use in remediation and hazard avoidance planning in a wide range of environments. In this context, we report experimental data on U interaction with soils and sediments. Here, we strive to improve existing risk assessment modeling paradigms by incorporating a variety of experimental data into a mechanistic U transport model for subsurface environments. 20 different soils and sediments from a variety of environments were chosen to represent a range of geochemical parameters that are relevant to U transport. The parameters included pH, organic matter content, CaCO3, Fe content and speciation, and clay content. pH ranged from 3 to 10, organic matter content from 6 to 120 g kg-1, CaCO3 from 0 to 700 g kg-1, amorphous Fe content from 0.3 to 6 g kg-1 and clay content from 4 to 580 g kg-1. Sorption experiments were then performed, and linear isotherms were constructed. Sorption experiment results show that among separate sets of sediments and soils, there is an inverse correlation between both soil pH and CaCO¬3 concentration relative to U sorptive affinity. The geological materials with the highest and lowest sorptive affinities for U differed in CaCO3 and organic matter concentrations, as well as clay content and pH. In a further step, we are testing if transport behavior in saturated porous media can be predicted based on adsorption isotherms and generic geochemical parameters, and comparing these modeling predictions with the results from column experiments. The comparison of these two data sets will examine if U transport can be effectively predicted from reactive transport modeling that incorporates the generic geochemical parameters. This work will serve to show

  15. Evaluation of two experimental models of hepatic encephalopathy in rats

    Directory of Open Access Journals (Sweden)

    L.M. García-Moreno

    2005-01-01

    Full Text Available The serious neuropsychological repercussions of hepatic encephalopathy have led to the creation of several experimental models in order to better understand the pathogenesis of the disease. In the present investigation, two possible causes of hepatic encephalopathy, cholestasis and portal hypertension, were chosen to study the behavioral impairments caused by the disease using an object recognition task. This working memory test is based on a paradigm of spontaneous delayed non-matching to sample and was performed 60 days after surgery. Male Wistar rats (225-250 g were divided into three groups: two experimental groups, microsurgical cholestasis (N = 20 and extrahepatic portal hypertension (N = 20, and a control group (N = 20. A mild alteration of the recognition memory occurred in rats with cholestasis compared to control rats and portal hypertensive rats. The latter group showed the poorest performance on the basis of the behavioral indexes tested. In particular, only the control group spent significantly more time exploring novel objects compared to familiar ones (P < 0.001. In addition, the portal hypertension group spent the shortest time exploring both the novel and familiar objects (P < 0.001. These results suggest that the existence of portosystemic collateral circulation per se may be responsible for subclinical encephalopathy.

  16. Tesla Coil Theoretical Model and its Experimental Verification

    Directory of Open Access Journals (Sweden)

    Voitkans Janis

    2014-12-01

    Full Text Available In this paper a theoretical model of Tesla coil operation is proposed. Tesla coil is described as a long line with distributed parameters in a single-wire form, where the line voltage is measured across electrically neutral space. By applying the principle of equivalence of single-wire and two-wire schemes an equivalent two-wire scheme can be found for a single-wire scheme and the already known long line theory can be applied to the Tesla coil. A new method of multiple reflections is developed to characterize a signal in a long line. Formulas for calculation of voltage in Tesla coil by coordinate and calculation of resonance frequencies are proposed. The theoretical calculations are verified experimentally. Resonance frequencies of Tesla coil are measured and voltage standing wave characteristics are obtained for different output capacities in the single-wire mode. Wave resistance and phase coefficient of Tesla coil is obtained. Experimental measurements show good compliance with the proposed theory. The formulas obtained in this paper are also usable for a regular two-wire long line with distributed parameters.

  17. Modelling concentration-analgesia relationships for morphine to evaluate experimental pain models

    DEFF Research Database (Denmark)

    Sverrisdóttir, Eva; Foster, David John Richard; Upton, Richard Neil

    2015-01-01

    -blind, placebo-controlled, crossover study, 39 healthy volunteers received an oral dose of 30 mg morphine hydrochloride or placebo. Non-linear mixed effects modelling was used to describe the plasma concentrations of morphine and metabolites, and the analgesic effect of morphine on experimental pain in skin......The aim of this study was to develop population pharmacokinetic-pharmacodynamic models for morphine in experimental pain induced by skin heat and muscle pressure, and to evaluate the experimental pain models with regard to assessment of morphine pharmacodynamics. In a randomized, double...... and muscle. Baseline pain metrics varied between individuals and occasions, and were described with interindividual and interoccasion variability. Placebo-response did not change with time. For both pain metrics, morphine effect was proportional to baseline pain and was described with a linear model...

  18. A molecular machine biosensor: construction, predictive models and experimental studies.

    Science.gov (United States)

    Moradi-Monfared, Sahar; Krishnamurthy, Vikram; Cornell, Bruce

    2012-04-15

    This paper describes the construction, operation and predictive modeling of a molecular machine, functioning as a high sensitivity biosensor. Embedded gramicidin A (gA) ionchannels in a self-assembled tethered lipid bilayer act as biological switches in response to target molecules and provide a signal amplification mechanism that results in high sensitivity molecular detection. The biosensor can be used as a rapid and sensitive point of care diagnostic device in different media such as human serum, plasma and whole blood without the need for pre and post processing steps required in an enzyme-linked immunosorbent assay. The electrical reader of the device provides the added advantage of objective measurement. Novel ideas in the construction of the molecular machine, including fabrication of biochip arrays, and experimental studies of its ability to detect analyte molecules over a wide range of concentrations are presented. Remarkably, despite the complexity of the device, it is shown that the response can be predicted by modeling the analyte fluid flow and surface chemical reactions. The derived predictive models for the sensing dynamics also facilitate determining important variables in the design of a molecular machine such as the ion channel lifetime and diffusion dynamics within the bilayer lipid membrane as well as the bio-molecular interaction rate constants. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Thermal infrared spectroscopy and modeling of experimentally shocked basalts

    Science.gov (United States)

    Johnson, J. R.; Staid, M.I.; Kraft, M.D.

    2007-01-01

    New measurements of thermal infrared emission spectra (250-1400 cm-1; ???7-40 ??m) of experimentally shocked basalt and basaltic andesite (17-56 GPa) exhibit changes in spectral features with increasing pressure consistent with changes in the structure of plagioclase feldspars. Major spectral absorptions in unshocked rocks between 350-700 cm-1 (due to Si-O-Si octahedral bending vibrations) and between 1000-1250 cm-1 (due to Si-O antisymmetric stretch motions of the silica tetrahedra) transform at pressures >20-25 GPa to two broad spectral features centered near 950-1050 and 400-450 cm-1. Linear deconvolution models using spectral libraries composed of common mineral and glass spectra replicate the spectra of shocked basalt relatively well up to shock pressures of 20-25 GPa, above which model errors increase substantially, coincident with the onset of diaplectic glass formation in plagioclase. Inclusion of shocked feldspar spectra in the libraries improves fits for more highly shocked basalt. However, deconvolution models of the basaltic andesite select shocked feldspar end-members even for unshocked samples, likely caused by the higher primary glass content in the basaltic andesite sample.

  20. Experimental rat models of chronic allograft nephropathy: a review

    Directory of Open Access Journals (Sweden)

    Shrestha B

    2014-07-01

    Full Text Available Badri Shrestha, John HaylorSheffield Kidney Institute, Sheffield Teaching Hospitals NHS Trust, Sheffield, UKAbstract: Chronic allograft nephropathy (CAN is the leading cause of late allograft loss after renal transplantation (RT, which continues to remain an unresolved problem. A rat model of CAN was first described in 1969 by White et al. Although the rat model of RT can be technically challenging, it is attractive because the pathogenesis of CAN is similar to that following human RT and the pathological features of CAN develop within months as compared with years in human RT. The rat model of RT is considered as a useful investigational tool in the field of experimental transplantation research. We have reviewed the literature on studies of rat RT reporting the donor and recipient strain combinations that have investigated resultant survival and histological outcomes. Several different combinations of inbred and outbred rat combinations have been reported to investigate the multiple aspects of transplantation, including acute rejection, cellular and humoral rejection mechanisms and their treatments, CAN, and potential targets for its prevention.Keywords: interventions, therapy, late allograft loss, renal transplantation

  1. Standardised Models for Inducing Experimental Peritoneal Adhesions in Female Rats

    Directory of Open Access Journals (Sweden)

    Bernhard Kraemer

    2014-01-01

    Full Text Available Animal models for adhesion induction are heterogeneous and often poorly described. We compare and discuss different models to induce peritoneal adhesions in a randomized, experimental in vivo animal study with 72 female Wistar rats. Six different standardized techniques for peritoneal trauma were used: brushing of peritoneal sidewall and uterine horns (group 1, brushing of parietal peritoneum only (group 2, sharp excision of parietal peritoneum closed with interrupted sutures (group 3, ischemic buttons by grasping the parietal peritoneum and ligating the base with Vicryl suture (group 4, bipolar electrocoagulation of the peritoneum (group 5, and traumatisation by electrocoagulation followed by closure of the resulting peritoneal defect using Vicryl sutures (group 6. Upon second look, there were significant differences in the adhesion incidence between the groups (P<0.01. Analysis of the fraction of adhesions showed that groups 2 (0% and 5 (4% were significantly less than the other groups (P<0.01. Furthermore, group 6 (69% was significantly higher than group 1 (48% (P<0.05 and group 4 (47% (P<0.05. There was no difference between group 3 (60% and group 6 (P=0.2. From a clinical viewpoint, comparison of different electrocoagulation modes and pharmaceutical adhesion barriers is possible with standardised models.

  2. Optimization of Experimental Model Parameter Identification for Energy Storage Systems

    Directory of Open Access Journals (Sweden)

    Rosario Morello

    2013-09-01

    Full Text Available The smart grid approach is envisioned to take advantage of all available modern technologies in transforming the current power system to provide benefits to all stakeholders in the fields of efficient energy utilisation and of wide integration of renewable sources. Energy storage systems could help to solve some issues that stem from renewable energy usage in terms of stabilizing the intermittent energy production, power quality and power peak mitigation. With the integration of energy storage systems into the smart grids, their accurate modeling becomes a necessity, in order to gain robust real-time control on the network, in terms of stability and energy supply forecasting. In this framework, this paper proposes a procedure to identify the values of the battery model parameters in order to best fit experimental data and integrate it, along with models of energy sources and electrical loads, in a complete framework which represents a real time smart grid management system. The proposed method is based on a hybrid optimisation technique, which makes combined use of a stochastic and a deterministic algorithm, with low computational burden and can therefore be repeated over time in order to account for parameter variations due to the battery’s age and usage.

  3. Models of Investor Forecasting Behavior — Experimental Evidence

    Directory of Open Access Journals (Sweden)

    Federico Bonetto

    2017-12-01

    Full Text Available Different forecasting behaviors affect investors’ trading decisions and lead to qualitatively different asset price trajectories. It has been shown in the literature that the weights that investors place on observed asset price changes when forecasting future price changes, and the nature of their confidence when price changes are forecast, determine whether price bubbles, price crashes, and unpredictable price cycles occur. In this paper, we report the results of behavioral experiments involving multiple investors who participated in a market for a virtual asset. Our goal is to study investors’ forecast formation. We conducted three experimental sessions with different participants in each session. We fit different models of forecast formation to the observed data. There is strong evidence that the investors forecast future prices by extrapolating past price changes, even when they know the fundamental value of the asset exactly and the extrapolated forecasts differ significantly from the fundamental value. The rational expectations hypothesis seems inconsistent with the observed forecasts. The forecasting models of all participants that best fit the observed forecasting data were of the type that cause price bubbles and cycles in dynamical systems models, and price bubbles and cycles ended up occurring in all three sessions.

  4. Experimental and numerical investigation of a simplified exhaust model

    Directory of Open Access Journals (Sweden)

    Balázs Vehovszky

    2016-10-01

    Full Text Available A simplified experimental equipment was built to investigate heat radiation and free convection around hot exhaust pipe. Temperatures were measured on the surface of the pipe as like as on heat insulating and -reflecting aluminum shield. Special care was taken to the temperature measuring method: result proved that inappropriate fixing of measuring thermocouples lead to an error of up to 30 % in the temperature-increase values. A detailed 1D numerical model was set up and parametrized so as to the calculation results can be fitted to measured temperature values. In this way thermal properties of the surfaces – as emissivities, absorption coefficients and convective heat transfer coefficients – were determined for temperature sweeps and stationary state cases. The used methods are to be further improved for real automotive parts and higher temperatures.

  5. Modeling the constitutive response of tantalum across experimental platforms

    Science.gov (United States)

    Barton, Nathan; Austin, Ryan; Brown, Justin; Marinak, Marty; Park, Hye-Sook; Prisbrey, Shon

    2017-06-01

    Given the complexities of the mechanics related to strength and the wide range of conditions of interest, it is useful to make comparisons across experimental platforms and across computational methods where possible. Modeling results will be presented from one such cross-platform study; including results from plate impact, ramp compression, and Rayleigh-Taylor instability growth experiments. Observables from strength experiments at more extreme conditions are influenced by a variety of material response characteristics, not just by the material's resistance to plastic deformation. Results include sensitivities to some of these other aspects, such as equation of state and shear modulus formulations. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 (LLNL-ABS-724459).

  6. Experimental human pneumococcal carriage models for vaccine research.

    Science.gov (United States)

    Ferreira, Daniela M; Jambo, Kondwani C; Gordon, Stephen B

    2011-09-01

    Pneumococcal conjugate vaccines have had unprecedented success in controlling vaccine-type invasive pneumococcal disease. As serotype replacement and the complexity of designing vaccines to multiple capsular polysaccharides ultimately pose a threat to these vaccines, the development of alternative protein vaccines is important. Protein vaccines offer the promise of extended serotype coverage, reduced cost, and improved protection against otitis media and pneumococcal pneumonia. As placebo-controlled trials are not currently ethically justifiable, human pneumococcal challenge models using prevention of carriage as a test endpoint offer an attractive link between preclinical studies and clinical efficacy trials. Experimental human pneumococcal carriage studies offer a means of describing mechanisms of protection against carriage and a clinical tool to choose between vaccine candidates. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Practical application of stereological kidney methods in experimental animal models

    Directory of Open Access Journals (Sweden)

    María Teresa Fernández García

    2017-01-01

    Full Text Available The kidneys are vital organs responsible for excretion, fluid and electrolyte balance and hormone production. The nephrons are the kidney's functional and structural units. The number, size and distribution of the nephron components contain relevant information on renal function. Stereology is a branch of morphometry that applies mathematical principles to obtain three-dimensional information from serial, parallel and equidistant two-dimensional microscopic sections. Because of the complexity of stereological studies and the lack of scientific literature on the subject, the aim of this paper is to clearly explain, through animal models, the basic concepts of stereology and how to calculate the main kidney stereological parameters that can be applied in future experimental studies.

  8. Dietary whey supplementation in experimental models of wound healing.

    Science.gov (United States)

    Velioglu Ogünç, A; Manukyan, M; Cingi, A; Eksioglu-Demiralp, E; Ozdemir Aktan, A; Süha Yalçin, A

    2008-03-01

    Whey is a dairy product containing milk serum proteins with diverse biological effects. In this study, the effect of dietary whey supplementation on wound healing was investigated. Rats were fed a standard or whey-supplemented diet for three weeks. Wound healing parameters, glutathione, and lipid peroxide levels were determined three days after the application of two different models of wound healing, i.e. laparotomy and colonic anastomosis. Dietary whey supplementation significantly increased glutathione levels and suppressed lipid peroxidation after experimental laparotomy and colonic anastomosis. Bursting pressures, hydroxyproline, and cytokine levels were not changed. Our results show that dietary whey supplementation increases glutathione synthesis and cellular antioxidant defense. Long-term effects of whey feeding on wound healing remains to be investigated.

  9. Calcium Intervention Ameliorates Experimental Model of Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Dariush Haghmorad

    2014-05-01

    Full Text Available Objective: Multiple sclerosis (MS is the most common inflammatory disease of the CNS. Experimental autoimmune encephalomyelitis (EAE is a widely used model for MS. In the present research, our aim was to test the therapeutic efficacy of Calcium (Ca in an experimental model of MS. Methods: In this study the experiment was done on C57BL/6 mice. EAE was induced using 200 μg of the MOG35-55 peptide emulsified in CFA and injected subcutaneously on day 0 over two flank areas. In addition, 250 ng of pertussis toxin was injected on days 0 and 2. In the treatment group, 30 mg/kg Ca was administered intraperitoneally four times at regular 48 hour intervals. The mice were sacrificed 21 days after EAE induction and blood samples were taken from their hearts. The brains of mice were removed for histological analysis and their isolated splenocytes were cultured. Results: Our results showed that treatment with Ca caused a significant reduction in the severity of the EAE. Histological analysis indicated that there was no plaque in brain sections of Ca treated group of mice whereas 4 ± 1 plaques were detected in brain sections of controls. The density of mononuclear infiltration in the CNS of Ca treated mice was lower than in controls. The serum level of Nitric Oxide in the treatment group was lower than in the control group but was not significant. Moreover, the levels of IFN-γ in cell culture supernatant of splenocytes in treated mice were significantly lower than in the control group. Conclusion: The data indicates that Ca intervention can effectively attenuate EAE progression.

  10. CT and MRI 'ring sign' may be due to demyelination: diagnostic pitfall.

    LENUS (Irish Health Repository)

    Kamel, M H

    2012-02-03

    We report a case of acute demyelinating encephalomyelitis (ADEM) in which both CT and MRI showed multiple ring-enhancing lesions suggestive of abscesses or brain tumour. This is a relatively rare phenomenon.

  11. Clinical and Pharmacological Aspects of Inflammatory Demyelinating Diseases in Childhood: An Update

    Science.gov (United States)

    Spalice, Alberto; Parisi, Pasquale; Papetti, Laura; Nicita, Francesco; Ursitti, Fabiana; Del Balzo, Francesca; Properzi, Enrico; Verrotti, Alberto; Ruggieri, Martino; Iannetti, Paola

    2010-01-01

    Inflammatory demyelinating diseases comprise a spectrum of disorders affecting the myelin of the central and peripheral nervous system. These diseases can usually be differentiated on the basis of clinical, radiological, laboratory and pathological findings. Recent studies have contributed to current awareness that inflammatory demyelinating diseases are not restricted to the adult age group, but are more common in pediatric age than previously believed. Some of pediatric inflammatory demyelinating diseases carry an unfavorable long-term prognosis but appropriate treatments can improve the outcome. The possibility of physical and cognitive disability resulting from these diseases, highlights the urgent need for therapeutic strategies for neurorehabilitation, neuroregeneration, and neurorepair. This review discusses characteristics of primary demyelinating diseases more frequently observed in childhood, focusing on epidemiology, clinical aspects and treatments. PMID:21119885

  12. Experimental and modelling evidence of shortening heat in cardiac muscle.

    Science.gov (United States)

    Tran, Kenneth; Han, June-Chiew; Crampin, Edmund John; Taberner, Andrew James; Loiselle, Denis Scott

    2017-10-01

    Heat associated with muscle shortening has been repeatedly demonstrated in skeletal muscle, but its existence in cardiac muscle remains contentious after five decades of study. By iterating between experiments and computational modelling, we show compelling evidence for the existence of shortening heat in cardiac muscle and reveal, mechanistically, the source of this excess heat. Our results clarify a long-standing uncertainty in the field of cardiac muscle energetics. We provide a revised partitioning of cardiac muscle energy expenditure to include this newly revealed thermal component. When a muscle shortens against an afterload, the heat that it liberates is greater than that produced by the same muscle contracting isometrically at the same level of force. This excess heat is defined as 'shortening heat', and has been repeatedly demonstrated in skeletal muscle but not in cardiac muscle. Given the micro-structural similarities between these two muscle types, and since we imagine that shortening heat is the thermal accompaniment of cross-bridge cycling, we have re-examined this issue. Using our flow-through microcalorimeter, we measured force and heat generated by isolated rat trabeculae undergoing isometric contractions at different muscle lengths and work-loop (shortening) contractions at different afterloads. We simulated these experimental protocols using a thermodynamically constrained model of cross-bridge cycling and probed the mechanisms underpinning shortening heat. Predictions generated by the model were subsequently validated by a further set of experiments. Both our experimental and modelling results show convincing evidence for the existence of shortening heat in cardiac muscle. Its magnitude is inversely related to the afterload or, equivalently, directly related to the extent of shortening. Computational simulations reveal that the heat of shortening arises from the cycling of cross-bridges, and that the rate of ATP hydrolysis is more sensitive to

  13. Experimental model of severe acute pancreatitis in rabbits Modelo experimental de pancreatite aguda grave em coelhos

    Directory of Open Access Journals (Sweden)

    Alberto Goldenberg

    2007-10-01

    Full Text Available PURPOSE: To develop an experimental model of severe acute pancreatitis in rabbits through a pancreatic ductal injection of sodium taurocholate. METHODS: Twenty-four albino rabbits of the New Zealand lineage were distributed into four groups of six animals (A, B, C and S. The rabbits of three experimental groups (A, B and C were submitted to a laparatomy and received a pancreatic ductal injection of 1ml/kg sodium taurocholate 5%. Also, they were submitted to further laparatomies after 4h, 8h and 12h, respectively. The control group (S was subdivided into two groups of three animals: in subgroup S1 only the pancreatic duct catheterization was performed whereas in subgroup S2 the pancreatic duct catheterization as well as an injection of 1ml/kg physiologic solution 0.9% were carried out. After 12 hours, the rabbits were evaluated. In the re-intervention, blood was collected to determine the amylasemia and a pancreatectomy was carried out to investigate interstitial infiltration, steatonecrosis and necrosis of the organ, using an optical microscope. RESULTS: There was an elevation of amylase in all groups thus proving the existence of acute pancreatitis. The size of the interlobular septum increased progressively with a greater variation between group S1 (0.13 and group C (0. 53 (p=0.035. While all the animals in group A exhibited focal cellular necrosis, it was more intense in the rabbits of group B and culminated with a high proportion of severe pancreatic necrosis in group C animals. The difference in the intensity of cellular necrosis showed statistic significance (p=0.001. CONCLUSION: The proposed experimental model demonstrated its reproducibility and effectiveness in producing severe acute pancreatitis in rabbits.OBJETIVO: Desenvolver modelo experimental de pancreatite aguda grave em coelhos por meio da injeção de taurocolato de sódio no ducto pancreático. MÉTODOS: Vinte e quatro coelhos albinos da linhagem Nova Zelândia foram distribu

  14. Association between demyelinating disease and autoimmune rheumatic disease in a pediatric population

    OpenAIRE

    Amorim,Ana Luiza M.; Cabral, Nadia C.; Osaku, Fabiane M.; Claudio A. Len; Oliveira, Enedina M.L.; Terreri, Maria Teresa

    2016-01-01

    ABSTRACT Introduction: Multiple sclerosis (MS) and neuromyelitis optica (NMO) are demyelinating diseases of the central nervous system. Autoimmunity in patients with demyelinating disease and in their families has been broadly investigated and discussed. Recent studies show a higher incidence of rheumatic autoimmune diseases among adult patients with MS or NMO and their families, but there are no studies in the pediatric population. Objective: To evaluate an association of MS and NMO with a...

  15. Characteristics of an explosive blast-induced brain injury in an experimental model.

    Science.gov (United States)

    de Lanerolle, Nihal C; Bandak, Faris; Kang, Dewey; Li, Alexander Y; Du, Fu; Swauger, Peter; Parks, Steven; Ling, Geoffrey; Kim, Jung H

    2011-11-01

    Mild traumatic brain injury resulting from exposure to an explosive blast is associated with significant neurobehavioral outcomes in soldiers. Little is known about the neuropathologic consequences of such an insult to the human brain. This study is an attempt to understand the effects of an explosive blast in a large animal gyrencephalic brain blast injury model. Anesthetized Yorkshire swine were exposed to measured explosive blast levels in 3 operationally relevant scenarios: simulated free field (blast tube), high-mobility multipurpose wheeled vehicle surrogate, and building (4-walled structure). Histologic changes in exposed animals up to 2 weeks after blast were compared to a group of naive and sham controls. The overall pathologic changes in all 3 blast scenarios were limited, with very little neuronal injury, fiber tract demyelination, or intracranial hemorrhage observed. However, there were 2 distinct neuropathologic changes observed: increased astrocyte activation and proliferation and periventricular axonal injury detected with β-amyloid precursor protein immunohistochemistry. We postulate that the increased astrogliosis observed may have a longer-term potential for the exacerbation of brain injury and that the pattern of periventricular axonal injury may be related to a potential for cognitive and mood disorders.

  16. Health-care use before a first demyelinating event suggestive of a multiple sclerosis prodrome: a matched cohort study.

    Science.gov (United States)

    Wijnands, José M A; Kingwell, Elaine; Zhu, Feng; Zhao, Yinshan; Högg, Tanja; Stadnyk, Karen; Ekuma, Okechukwu; Lu, Xinya; Evans, Charity; Fisk, John D; Marrie, Ruth Ann; Tremlett, Helen

    2017-06-01

    Degenerative processes in neurodegenerative diseases can start years before clinical manifestation. We aimed to establish whether a multiple sclerosis prodromal period exists by examining patterns of health-care use before a first demyelinating event. In this matched cohort study, we used data from linked health administrative and clinical databases from four Canadian provinces (British Columbia, Saskatchewan, Manitoba, and Nova Scotia) to compare hospital, physician, and prescription use data from people with multiple sclerosis and matched general population controls in the 5 years before the first demyelinating disease claim (health administrative index date) or clinically reported symptom onset (clinical index date). Rate ratios (RRs) were estimated using negative binomial regression and combined across provinces using random effect models. The primary outcome was all-cause use of health care during each of the 5 years before the health administrative or clinical index date. The health administrative cohort included 14 428 multiple sclerosis cases and 72 059 matched controls for whom data were available between April, 1984, and April, 2014. Annual health-care use increased steadily between 5 years and 1 year before the first demyelinating disease claim in people with multiple sclerosis compared with controls (from RR 1·26 [95% CI 1·16-1·36] to 1·78 [1·50-2·10] for hospital admissions; from 1·24 [1·16-1·32] to 1·88 [1·72-2·07] for physician claims; and from 1·23 [1·06-1·41] to 1·49 [1·41-1·59] for prescriptions, assessed as drug classes). Similar patterns for physician claims and prescriptions were observed in the cohort with available clinical symptom onset (3202 individuals with multiple sclerosis and 16 006 controls), although the differences in use in each of the 5 years mostly did not reach statistical significance. More frequent use of health care in patients with multiple sclerosis than in controls in the 5 years before a first

  17. Experimental model for Porphyromonas gingivalis infection in animals.

    Science.gov (United States)

    Eke, P I; Rotimi, V O; Laughon, B E

    1996-03-01

    A virulence model suitable for studying the dynamics of Porphyromonas gingivalis infection, including the pathogenicity of P. gingivalis in experimentally induced infections of multiple organs was developed using mouse and hamster. Virulence of P. gingivalis strains was expressed contrastingly in subcutaneous (sc) infection in the Murine abscess model (MAM) and the Hamsters abscess model (HAM). Subcutaneous infection in the MAM was characterized by a gravity abscess, spreading from the primary site of inoculation downwards, frequently erupting as a secondary lesion. In contract, s.c. P. gingivalis infection in HAM was characterized as a palpable localized abscess at the primary site of inoculation. When the Semi-Solid Agar (SSA) was added to the mono-culture of P. gingivalis, reproducibility of infection in both models was enhanced. P. gingivalis culture supplemented with haemin, or combined with oral Actinomyces viscosus had its virulence overtly enhanced and often fatal in the MAM. Menadione, Eh reducing agents and mixture with the Streptococcus or A. neaslundii did not potentiate virulence in either mode. Transtracheal challenge of the lungs of hamster with P. gingivalis initiated an early pneumonitis and later sequelae of necrosis and abscess formation. Also, abscess was induced by direct inoculation of P. gingivalis in the muscles, liver and testes, but did not induce intra-abdominal abscesses. In conclusion, the HAM applied with the SSA procedure caused a localized P. gingivalis tissue infection with practical advantages for quantitative and qualitative studies of P. gingivalis infections. This study also demonstrates the pathogenic potential of P. gingivalis by reproducing similar infections in multiple anatomical sites.

  18. Microbial dormancy improves development and experimental validation of ecosystem model.

    Science.gov (United States)

    Wang, Gangsheng; Jagadamma, Sindhu; Mayes, Melanie A; Schadt, Christopher W; Steinweg, J Megan; Gu, Lianhong; Post, Wilfred M

    2015-01-01

    Climate feedbacks from soils can result from environmental change followed by response of plant and microbial communities, and/or associated changes in nutrient cycling. Explicit consideration of microbial life-history traits and functions may be necessary to predict climate feedbacks owing to changes in the physiology and community composition of microbes and their associated effect on carbon cycling. Here we developed the microbial enzyme-mediated decomposition (MEND) model by incorporating microbial dormancy and the ability to track multiple isotopes of carbon. We tested two versions of MEND, that is, MEND with dormancy (MEND) and MEND without dormancy (MEND_wod), against long-term (270 days) carbon decomposition data from laboratory incubations of four soils with isotopically labeled substrates. MEND_wod adequately fitted multiple observations (total C-CO2 and (14)C-CO2 respiration, and dissolved organic carbon), but at the cost of significantly underestimating the total microbial biomass. MEND improved estimates of microbial biomass by 20-71% over MEND_wod. We also quantified uncertainties in parameters and model simulations using the Critical Objective Function Index method, which is based on a global stochastic optimization algorithm, as well as model complexity and observational data availability. Together our model extrapolations of the incubation study show that long-term soil incubations with experimental data for multiple carbon pools are conducive to estimate both decomposition and microbial parameters. These efforts should provide essential support to future field- and global-scale simulations, and enable more confident predictions of feedbacks between environmental change and carbon cycling.

  19. An experimental model of vitreous motion induced by eye rotations.

    Science.gov (United States)

    Bonfiglio, Andrea; Lagazzo, Alberto; Repetto, Rodolfo; Stocchino, Alessandro

    2015-01-01

    During eye rotations the vitreous humour moves with respect to the eye globe. This relative motion has been suggested to possibly have an important role in inducing degradation of the gel structure, which might lead to vitreous liquefaction and/or posterior vitreous detachment. Aim of the present work is to study the characteristics of vitreous motion induced by eye rotations. We use an experimental setup, consisting of a Perspex model of the vitreous chamber that, for simplicity, is taken to have a spherical shape. The model is filled with an artificial vitreous humour, prepared as a solution of agar powder and hyaluronic acid sodium salt in deionised water, which has viscoelastic mechanical properties similar to those of the real vitreous. The model rotates about an axis passing through the centre of the sphere and velocity measurements are taken on the equatorial plane orthogonal to the axis of rotation, using an optical technique. The results show that fluid viscoelasticity has a strong influence on flow characteristics. In particular, at certain frequencies of oscillation of the eye model, fluid motion can be resonantly excited. This means that fluid velocity within the domain can be significantly larger than that of the wall. The frequencies for which resonant excitation occurs are within the range of possible eye rotations frequencies. Therefore, the present results suggest that resonant excitation of vitreous motion is likely to occur in practice. This, in turn, implies that eye rotations produce large stresses on the retina and within the vitreous that may contribute to the disruption of the vitreous gel structure. The present results also have implications for the choice of the ideal properties for vitreous substitute fluids.

  20. Tumefactive demyelinating lesions as a first clinical event: Clinical, imaging, and follow-up observations.

    Science.gov (United States)

    Jeong, In Hye; Kim, Su-Hyun; Hyun, Jae-Won; Joung, AeRan; Cho, Hyo-Jin; Kim, Ho Jin

    2015-11-15

    Tumefactive demyelinating lesions (TDLs) are associated with a variety of demyelinating diseases in the central nervous system (CNS). However, there are no current guidelines describing how to classify and treat patients with this rare phenotype. Thus, the present study aimed to determine the long-term evolution and disease course of patients initially presenting with TDLs and to describe their clinical and radiographic characteristics. From the National Cancer Center registry of inflammatory diseases of the CNS, 31 patients initially presenting with TDLs with follow-up for at least 12 months were enrolled and their demographic, clinical, and radiographic characteristics were evaluated. The median follow-up duration was 37.6 months, during which time 11 patients were diagnosed with neuromyelitis optica spectrum disorder (NMOSD), seven with multiple sclerosis (MS), and 11 remained idiopathic; six did not experience any further clinical events (isolated demyelinating syndrome), and five patients experienced recurrent demyelinating events that were not consistent with either MS or NMOSD. Of the remaining two patients, one was diagnosed with hyperthyroidism-associated demyelination and one with tacrolimus-induced demyelination. The majority of TDLs evolve into MS or NMOSD. However, despite extensive diagnostic work-ups and long-term follow-ups, the etiology of TDLs was unknown for some patients. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. The topograpy of demyelination and neurodegeneration in the multiple sclerosis brain

    Science.gov (United States)

    Haider, Lukas; Hametner, Simon; Höftberger, Romana; Bagnato, Francesca; Grabner, Günther; Trattnig, Siegfried; Pfeifenbring, Sabine; Brück, Wolfgang

    2016-01-01

    Multiple sclerosis is a chronic inflammatory disease with primary demyelination and neurodegeneration in the central nervous system. In our study we analysed demyelination and neurodegeneration in a large series of multiple sclerosis brains and provide a map that displays the frequency of different brain areas to be affected by these processes. Demyelination in the cerebral cortex was related to inflammatory infiltrates in the meninges, which was pronounced in invaginations of the brain surface (sulci) and possibly promoted by low flow of the cerebrospinal fluid in these areas. Focal demyelinated lesions in the white matter occurred at sites with high venous density and additionally accumulated in watershed areas of low arterial blood supply. Two different patterns of neurodegeneration in the cortex were identified: oxidative injury of cortical neurons and retrograde neurodegeneration due to axonal injury in the white matter. While oxidative injury was related to the inflammatory process in the meninges and pronounced in actively demyelinating cortical lesions, retrograde degeneration was mainly related to demyelinated lesions and axonal loss in the white matter. Our data show that accumulation of lesions and neurodegeneration in the multiple sclerosis brain does not affect all brain regions equally and provides the pathological basis for the selection of brain areas for monitoring regional injury and atrophy development in future magnetic resonance imaging studies. PMID:26912645

  2. Experimental Investigation and Modeling of Copper Smelting Slags

    Science.gov (United States)

    Starodub, Konstantin; Kuminova, Yaroslava; Dinsdale, Alan; Cheverikin, Vladimir; Filichkina, Vera; Saynazarov, Abdukahhar; Khvan, Alexandra; Kondratiev, Alex

    2016-10-01

    Effective extraction of copper from sulfide ores requires careful operation of a copper smelter, which in turn depends very much on chemistry of the feed and resulted slag and matte. For example, chemical composition of copper smelting slags has to be in a certain range to ensure that their properties are within specific limits. Disobeying these rules may lead to complications in smelting operation, poor quality of the copper products, and premature shutdown of the copper smelter. In the present paper the microstructure and phase composition of slags from the Almalyk copper flash smelter were investigated experimentally and then modeled thermodynamically to evaluate potential ways of improvement and optimization of the copper smelting process and its products. The slag samples were taken at different stages of the copper smelting process: on slag tapping, after slag transportation to a deposition site, and at the site. Experimental investigation included the XRD, XRF, and SEM techniques, which were also confirmed by the traditional wet chemistry analysis. Thermodynamic modeling was carried out using thermochemical software package MTDATA, which enables thermodynamic and physical properties of the matte, slag, and gas phases to be calculated in a wide range of temperatures, pressures, and chemical compositions. In addition, slag viscosities and corresponding matte settling rates were estimated using the modified Urbain and Utigard-Warczok models, and the Hadamard-Rybczynski equation, respectively. It was found that the copper content in the slags may vary significantly depending on the location of slag sampling. Cu was found to be present as sulfide particles, almost no Cu was found to be dissolved in the slag. Analysis of microstructure and phase composition showed that major phase found in the samples is fayalite, while other phases are complex spinels (based on magnetite), different sulfides, and a glass-like phase. Thermodynamic calculations demonstrated the

  3. Experimental osteonecrosis: development of a model in rodents administered alendronate.

    Science.gov (United States)

    Conte, Nicolau; Spolidorio, Luis Carlos; Andrade, Cleverton Roberto de; Esteves, Jônatas Caldeira; Marcantonio, Elcio

    2016-08-22

    The main objective of this study was to cause bisphosphonate-related osteonecrosis of the jaws to develop in a rodent model. Adult male Holtzman rats were assigned to one of two experimental groups to receive alendronate (AL; 1 mg/kg/week; n = 6) or saline solution (CTL; n = 6). After 60 days of drug therapy, all animals were subjected to first lower molar extraction, and 28 days later, animals were euthanized. All rats treated with alendronate developed osteonecrosis, presenting as ulcers and necrotic bone, associated with a significant infection process, especially at the inter-alveolar septum area and crestal regions. The degree of vascularization, the levels of C-telopeptide cross-linked collagen type I and bone-specific alkaline phosphatase, as well as the bone volume were significantly reduced in these animals. Furthermore, on radiographic analysis, animals treated with alendronate presented evident sclerosis of the lamina dura of the lower first molar alveolar socket associated with decreased radiographic density in this area. These findings indicate that the protocol developed in the present study opens new perspectives and could be a good starting model for future property design.

  4. Experimental osteonecrosis: development of a model in rodents administered alendronate

    Directory of Open Access Journals (Sweden)

    Nicolau CONTE NETO

    Full Text Available Abstract The main objective of this study was to cause bisphosphonate-related osteonecrosis of the jaws to develop in a rodent model. Adult male Holtzman rats were assigned to one of two experimental groups to receive alendronate (AL; 1 mg/kg/week; n = 6 or saline solution (CTL; n = 6. After 60 days of drug therapy, all animals were subjected to first lower molar extraction, and 28 days later, animals were euthanized. All rats treated with alendronate developed osteonecrosis, presenting as ulcers and necrotic bone, associated with a significant infection process, especially at the inter-alveolar septum area and crestal regions. The degree of vascularization, the levels of C-telopeptide cross-linked collagen type I and bone-specific alkaline phosphatase, as well as the bone volume were significantly reduced in these animals. Furthermore, on radiographic analysis, animals treated with alendronate presented evident sclerosis of the lamina dura of the lower first molar alveolar socket associated with decreased radiographic density in this area. These findings indicate that the protocol developed in the present study opens new perspectives and could be a good starting model for future property design.

  5. [Coronary microvascular disease: from experimental models to clinical practice].

    Science.gov (United States)

    Vecoli, Cecilia; Caselli, Chiara; Caruso, Raffaele; Morales, Maria Aurora

    2012-01-01

    Coronary vascular microcirculation plays a major role in the pathogenesis of left ventricular dysfunction as well as in the development of heart failure. Coronary microcirculation includes all the vessels which contribute to provide resistance to coronary flow. It represents the district where coronary circulation blood flow is regulated to ensure that each structural and functional cardiac component receives the proper amount of oxygen and metabolic substrates through the capillary network. Coronary microcirculation is fundamental for myocardial function which largely depends on the ratio between energetic metabolites received from coronary circulation and their utilization by the myocytes. Alterations in coronary microvascular circulation which limit myocardial perfusion can cause repetitive ischemic events leading to left ventricular dysfunction in several ischemic and non ischemic cardiomyopathies as the idiopathic dilated cardiomyopathy. To date, mechanisms underlying microvascular dysfunction are not completely understood and experimental animal models are employed to study alterations which may cause microcirculation impairment. These animals models are unique tools to identify new therapeutic targets, to test new drug therapies for the treatment of left ventricular dysfunction as well as its progression towards overt heart failure.

  6. Experimental studies on power transformer model winding provided with MOVs

    Directory of Open Access Journals (Sweden)

    G.H. Kusumadevi

    2017-05-01

    Full Text Available Surge voltage distribution across a HV transformer winding due to appearance of very fast rise time (rise time of order 1 μs transient voltages is highly non-uniform along the length of the winding for initial time instant of occurrence of surge. In order to achieve nearly uniform initial time instant voltage distribution along the length of the HV winding, investigations have been carried out on transformer model winding. By connecting similar type of metal oxide varistors across sections of HV transformer model winding, it is possible to improve initial time instant surge voltage distribution across length of the HV transformer winding. Transformer windings with α values 5.3, 9.5 and 19 have been analyzed. The experimental studies have been carried out using high speed oscilloscope of good accuracy. The initial time instant voltage distribution across sections of winding with MOV remains nearly uniform along length of the winding. Also results of fault diagnostics carried out with and without connection of MOVs across sections of winding are reported.

  7. Development of Experimental Tissue Models for Blast Injury

    Science.gov (United States)

    Butler, Benjamin; Bo, Chiara; Williams, Alun; Jardine, Andy; Brown, Katherine

    2013-06-01

    There is a pressing need to better understand the relationship between the intensity of a blast wave and the clinical consequences for victims of an explosion. In order to quantitatively study how these factors correlate with one another, blast injury tissue models are being developed. Sections of larynx, trachea and pulmonary tissue were excised from a recently sacrificed pig and maintained on ice prior to testing. The samples were subjected to strain rates of between 0.001 s-1 and 1000 s-1 in the laboratory by using a Split Hopkinson Pressure Bar and quasi-static testing apparatus. During high strain rate testing, samples were housed in a polycarbonate chamber which permitted experimentation on tissue held in fluid. Data were analysed using 1, 2 and 3 wave analysis software in Matlab to yield information about the material properties of both undamaged and damaged tissues. In addition, macroscopic changes in tissue organization were also visualized using histopathological techniques. This work is being extended to cellular and animal models to derive more detailed information about the underlying molecular changes relating to blast-induced damage and repair. The Royal British Legion Centre for Blast Injury Studies.

  8. Effectiveness and safety of iodopovidone in an experimental pleurodesis model

    Directory of Open Access Journals (Sweden)

    Lisete R. Teixeira

    2013-04-01

    Full Text Available OBJECTIVES: Chemical pleurodesis is an important therapeutic tool to control recurrent malignant pleural effusion. Among the various sclerosing agents, iodopovidone is considered effective and safe. However, in a recent study, ocular changes were described after iodopovidone was used in recurrent pneumothorax. The aim of the study was to evaluate the efficacy and morbidity of iodopovidone pleurodesis in an experimental model. METHODS: New Zealand rabbits were submitted to intrapleural injection of iodopovidone at concentrations of 2%, 4% and 10%. Biochemical (lactic dehydrogenase, proteins, triiodothyronine, free thyroxine, urea and creatinine and immunological (Interleukin-8 [IL-8], VEGF and TGFβ parameters were measured in the pleural fluid and blood. After 1, 3, 7, 14 and 28 days, groups of animals were euthanized, and macro- (pleura and microscopic (pleura and retina analyses were performed. RESULTS: An early pleural inflammatory response with low systemic repercussion was observed without corresponding changes in thyroid or renal function. The higher concentrations (4% and 10% correlated with greater initial exudation, and maximum pleural thickening was observed after 28 days. No changes were observed in the retinal pigment epithelium of the rabbits. CONCLUSION: Iodopovidone is considered to be an effective and safe sclerosing agent in this animal model. However, its efficacy, tolerance and safety in humans should be further evaluated.

  9. An experimental model of hemolysis-induced acute pancreatitis

    Directory of Open Access Journals (Sweden)

    Saruc M.

    2003-01-01

    Full Text Available The literature indicates that acute pancreatitis is a complication of massive hemolysis with a prevalence of about 20%. We describe an experimental model of hemolysis-induced acute pancreatitis. Hemolytic anemia was induced in rats by a single ip injection of 60 mg/kg of 20 mg/ml acetylphenylhydrazine (APH in 20% (v/v ethanol on the first experimental day (day 0. One hundred and fifty Wistar albino rats weighing 180-200 g were divided into three groups of 50 animals each: groups 1, 2 and 3 were injected ip with APH, 20% ethanol, and physiological saline, respectively. Ten rats from each group were sacrificed on study days 1, 2, 3, 4 and 5. Serum amylase, lipase levels and pancreatic tissue tumor necrosis factor-alpha (TNF-alpha and platelet-activating factor (PAF contents were determined and a histological examination of the pancreas was performed. No hemolysis or pancreatitis was observed in any of the rats in groups 2 and 3. In group 1, massive hemolysis was observed in 35 (70% of 50 rats, moderate hemolysis in seven (14%, and no hemolysis in eight (16%. Thirty-three of 35 (94.2% rats with massive hemolysis had hyperamylasemia, and 29 of these rats (82.8% had histologically proven pancreatitis. The most severe pancreatitis occurred on day 3, as demonstrated by histology. Tissue TNF-alpha and PAF levels were statistically higher in group 1 than in groups 2 and 3. Acute massive hemolysis induced acute pancreatitis, as indicated by histology, in almost 80% of cases. Hemolysis may induce acute pancreatitis by triggering the release of proinflammatory and immunoregulatory cytokines.

  10. Epidural blood patch: A study on an experimental model