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Sample records for forma axonal aguda

  1. Forma atípica de tireoidite supurativa aguda em paciente pediátrico: relato de caso

    OpenAIRE

    Torres, Maria Rosineide dos S.; Medeiros, Carla C. M.; Nóbrega Neto, Sebastião Horácio; Souza, Lincoln S.; Rodrigues, Mônica L. C.; Silva, Maria Nelice M.; Maior, Lyzandra de H. C. S.; Avelino, Márcia C.; Mourão, Germana T. F.

    2008-01-01

    A tireoidite aguda é uma doença rara. Na infância associa-se principalmente a anormalidades congênitas com acometimento do lobo esquerdo. Na ausência de tireoidopatia preexistente, a função tireoidiana geralmente está normal. Relatamos um caso de uma menina, 6 anos de idade, com tumoração associada a sinais flogísticos na região cervical anterior há 15 dias acompanhada de leucocitose com desvio à esquerda, VSH e TSH elevados. Não havia história prévia de tireoidopatia. A ultra-sonografia da r...

  2. Respostas cardiovasculares agudas na extensão do joelho realizada em diferentes formas de execução Respuestas cardiovasculares agudas a la extensión de rodilla realizada en diferentes formas de ejecución Acute cardiovascular responses on knee extension at different performance modes

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    Marcos Doederlein Polito

    2004-06-01

    Full Text Available O objetivo do estudo foi verificar as pressões arteriais sistólica (PAS e diastólica (PAD, freqüência cardíaca (FC e duplo-produto (DP durante e após a extensão do joelho realizada de forma uni e bilateral até a exaustão. Dezoito indivíduos - seis homens e 12 mulheres - (33 ± 11 anos; 63,5 ± 11,4kg; 168,6 ± 7,1cm, voluntários, saudáveis e experientes no treinamento de força realizaram três séries de 12 repetições máximas da extensão do joelho, realizadas de forma uni (UN e bilateral (BI. A pressão arterial foi medida pelo método auscultatório ao final de cada série e durante 20 minutos após o exercício, com intervalos de cinco minutos. A ANOVA de duas entradas com medidas repetidas mostrou que a variação percentual em relação ao repouso (D% da PAS foi significativamente maior na 3ª série (UN = 31,7 ± 11,9%; BI = 38,5 ± 10,9% que na 1ª (UN = 19,5 ± 12,5%; BI = 26,0 ± 10,2%. Quanto à PAD, o D% foi maior na 3ª série (UN = 48,5 ± 13,9%; BI = 51,4 ± 13,3% que na 1ª (UN = 30,5 ± 13,0%; BI = 34,9 ± 16,0% e na 2ª (UN = 40,9 ± 15,4%; BI = 47,3 ± 12,9%. Não foram observadas diferenças para FC e DP, assim como entre os modos de execução. Após o exercício, não foram identificadas diferenças entre todas as variáveis observadas. Aparentemente, a forma de execução da extensão unilateral do joelho não repercutiria sobre as respostas cardiovasculares agudas, durante ou após o exercício. Contudo, a execução bilateral mostrou tendência a elevar os valores de PAS e DP em relação à execução unilateral, o que deve ser considerado na prescrição para pessoas que necessitem de cuidados especiais.El objetivo de este estudio fué verificar las presiones arterial sistólica (PAS e diastólica (PAD, frecuencia cardíaca (FC y producto doble (DP durante y después de la extensión de rodilla realizada de forma uni y bilateral hasta el agotamiento. Dieciocho individuos - seis hombres y 12 mujeres

  3. Apendicitis Aguda

    OpenAIRE

    Jorge Fallas González

    2012-01-01

    La apendicitis aguda, descrita desde 1886, es la emergencia quirúrgica más común. Tiene su mayor incidencia durante la adultez joven y su menor incidencia en niños y adultos mayores. Su diagnóstico se basa en una historia clínica completa, un examen físico bien orientado y en una adecuada interpretación de los exámenes de laboratorio y gabinete. A pesar de ser una entidad de resolución quirúrgica, su tratamiento engloba diferentes aspectos médicosAcute appendicitis, described since 1886, is t...

  4. Hepatitis viral aguda

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    Héctor Rubén Hernández Garcés

    1998-10-01

    Full Text Available Se realizó una revisión bibliográfica de las hepatitis virales agudas sobre aspectos vinculados a su etiología. Se tuvieron en cuenta además algunos datos epidemiológicos, las formas clínicas más importantes, los exámenes complementarios con especial énfasis en los marcadores virales y el diagnóstico positivoA bibliographical review of acute viral hepatitis was made taking into account those aspects connected with its etiology. Some epidemiological markers, the most important clinical forms, and the complementary examinations with special emphasis on the viral markers and the positive diagnosis were also considered

  5. Leucemia congénita aguda

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    Nilvia Esther González García

    2011-06-01

    Full Text Available La leucemia aguda durante el período neonatal es poco frecuente de evolución rápida y pronóstico sombrío. Sus características clínicas y biológicas difieren de las encontradas en niños de mayor edad, y su inicio se caracteriza por afectación cutánea, hepatoesplenomegalia, hiperleucocitosis e infiltración del sistema nervioso central. Se han observado pacientes con formas tanto mieloides como linfoides, pero la leucemia mieloide aguda parece predominar en esta etapa de la vida. Se presenta el caso de un paciente con leucemia congénita clasificada morfológicamente, con aparición de manifestaciones clínicas de enfermedad hematológica desde el nacimiento y diagnóstico de leucemia linfoblástica aguda congénita.

  6. Ataxias agudas en la infancia

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    Yaline Betancourt Fursow

    2013-09-01

    Full Text Available La ataxia cerebelosa aguda infantil (ACAI es la forma más frecuente de complicación neurológica por el virus de la varicela.Descritas dentro del grupo de las cerebelitis agudas. Los objetivos de este estudio fueron: evaluar la presentación clínica, manejo y seguimiento de niños hospitalizados con ACAI en un hospital pediátrico terciario donde la inmunización para varicela no está disponible (parte I y describir los diagnósticos diferenciales de la cerebelitis aguda (parte II. Estudiamos 95 pacientes. Los criterios diagnósticos de ataxia aguda se basaron en: pérdida aguda de la coordinación o dificultad para la marcha con o sin nistagmo asociado y duración menor de 48 horas, en un niño previamente sano. Estos criterios se cumplían en todos los casos valorados, excepto en las ataxias secundarias a ingesta de tóxicos, en los que la duración debía ser menor de 24 horas para su inclusión en el estudio. Se registraron los datos en una historia clínica pediátrica y neurológica. Entre los pacientes inmunosuprimidos la incidencia mayor fue la complicación por varicela. La mayoría de los pacientes fueron varones. El rango de edad fue la preescolar, 5 años . El intervalo entre la presentación del rash y el ingreso fue de 1 a 3 días. El estudio de LCR se practicó en 59.5% de los casos. La TAC y la resonancia magnética cerebral (RM presentaron edema en el 33.3%. El aciclovir endovenoso fue utilizado en 23 pacientes; pero no hubo diferencias significativas en las manifestaciones clínicas y seguimiento entre tratados y no tratados. La ataxia fue la primera manifestación clínica. La estadía hospitalaria fue de 4 días (rango: 2-11 días.

  7. Estudo comparativo, prospectivo e randomizado do resultado de duas formas de tratamento clínico das lesões ligamentares primárias agudas e graves do tornozelo

    OpenAIRE

    Marcelo Pires Prado

    2013-01-01

    Objetivo: Este trabalho tem como objetivo a avaliação dos resultados funcionais, e da incidência da instabilidade articular mecânica, resultantes do tratamento clínico das lesões ligamentares primárias, agudas e graves do tornozelo (associada a instabilidade articular). Esta lesão é extremamente frequente e acomete indivíduos jovens, economicamente e fisicamente ativos, causando prejuízos pessoais e econômicos importantes. Existe dificuldade no adequado diagnóstico e heterogeneidade na escolh...

  8. Pneumonia aguda fibrinosa e organizante

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    Cláudia Santos

    2010-07-01

    Full Text Available Resumo: O padrão histológico de Pneumonia Aguda Fibrinosa e Organizante (AFOP – Acute Fibrinous And Organizing Pneumonia, descrito por Beasley em 2002, caracteriza-se pela existência de fibrina intra-alveolar sob a forma de bolas de fibrina e pneumonia organizativa difusa. A apresentação clínica desta doença intersticial pulmonar pode ser aguda ou subaguda, diferindo no entanto dos outros padrões histológicos habitualmente associados a lesão pulmonar aguda – Lesão Alveolar Difusa (DAD, Pneumonia Organizativa (OP e Pneumonia Eosinofílica (EP.A propósito deste tema, os autores fazem uma revisão da literatura e descrevem o caso clínico de um doente de 44 anos, com aspectos imagiológicos e evolução pouco habituais. Abstract: The histologic pattern of Acute Fibrinous and Organizing Pneumonia (AFOP, described by Beasley in 2002, is characterized by the existence of intra alveolar fibrin in the form of fibrin “balls” and diffuse organizing pneumonia. Presenting symptoms of this interstitial pulmonary disease can be acute or subacute. However, it differs from the well-recognized histologic patterns of acute pulmonary lesion – Diffuse Alveolar Damage (DAD, Organizing Pneumonia (OP and Eosinophilic Pneumonia (EP.The authors carry out a review of the literature concerning this topic and describe the clinical case of a 44-year-old patient with unusual imaging features and outcome. Palavras-chave: AFOP, bolas de fibrina, pneumonia organizativa, Key-word: AFOP, fibrin balls, organizing pneumonia

  9. Notas sobre apendicitis aguda

    OpenAIRE

    Méndez S., Martín

    2011-01-01

    Hacer un buen diagnóstico, tener el valor de la responsabilidad operando precozmente los enfermos, en los cuales después de minucioso examen se cree o se tiene certeza de una apendicitis aguda, es uno de los méritos de todo buen cirujano. Sin duda tendrá que luchar contra todo, la familia, el enfermo y los allegados; pero si triunfa y vence logrará éxitos y salvará vidas. Parece fácil diagnosticar unaapendicitis aguda y sin embargo, es necesario decirlo claro, nada hay tan complicado y en oca...

  10. Resultados do tratamento da pancreatite aguda grave

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    Franz Robert Apodaca-Torrez

    Full Text Available OBJETIVO: Avaliar os resultados do Protocolo de Atendimento de pacientes com diagnóstico de pancreatite aguda grave. MÉTODOS: Foram analisados, consecutivamente, a partir de janeiro de 2002, idade, sexo, etiologia, tempo de internação, tipo de tratamento e mortalidade de 37 pacientes portadores de pancreatite aguda grave. RESULTADOS: A idade dos pacientes variou de 20 a 88 anos (média de 50 anos; 27% foram do sexo feminino e 73% do masculino. O tempo médio global de internação foi 47 dias. Treze pacientes foram tratados cirurgicamente; a média de operações realizadas foi duas por paciente. Ocorreram seis óbitos dentre os pacientes submetidos ao tratamento cirúrgico (46% e dois óbitos no grupo submetido somente ao tratamento clínico (8,3%. A mortalidade global foi 21% CONCLUSÃO: Após a modificação na forma de abordagem dos pacientes com pancreatite aguda grave, houve diminuição da mortalidade e uma tendência para a conduta expectante.

  11. Insuficiencia respiratoria aguda

    OpenAIRE

    Gutiérrez Muñoz, Fernando R.

    2010-01-01

    La función respiratoria básica es el intercambio gaseoso de oxígeno y dióxido carbono; lo que implica un perfecto equilibrio y control entre los componentes del sistema respiratorio. a insuficiencia respiratoria aguda (IRA) es la incapacidad del sistema respiratorio de cumplir su función básica, que es el intercambio gaseoso de oxígeno y dióxido de carbono. Basic respiratory function is gas exchange of oxygen and carbon dioxide, which implies a perfect balance and control between the compo...

  12. Notas sobre apendicitis aguda

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    Martín Méndez S.

    1933-04-01

    apendicitis aguda y sin embargo, es necesario decirlo claro, nada hay tan complicado y en ocasiones tan oscuro. Sin duda, a medida que los conocimientos clínicos se extienden, se va iluminando el campo, antes inexplorado, de la cirugía apendicular, y hoy día casi todos los médicos y cirujanos tienen un criterio científico muy bien formado para lograr hacer un buen diagnóstico y aconsejar o llevar a cabo una intervención quirúrgica.

  13. Gingivitis ulceronecrosante aguda

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    Eduardo de la Teja-Ángeles

    2015-11-01

    Full Text Available La gingivitis ulcerativa necrosante, conocida por sus siglas en inglés como GUN (anteriormente se le conocía como enfermedad de Vincent o “boca de trinchera” por afectar a soldados en guerra, es una enfermedad poco frecuente.1-6 Se caracteriza por ser una infección aguda y dolorosa en la que las encías sangran, hay necrosis de las papilas interdentales y ataque al estado general.

  14. Abdomen agudo ocasionado por apendicitis aguda de probable origen tuberculoso. Informe de un caso

    OpenAIRE

    Montiel-Jarquín, Álvaro José; Alvarado-Ortega, Iván; Romero-Figueroa, María del Socorro; Rodríguez-Pérez, Fabiola; Rodríguez-Lima, Felipe; Loria-Castellanos, Jorge

    2017-01-01

    RESUMEN Antecedentes: la apendicitis aguda tuberculosa es una enfermedad rara, constituye de 0,001 % a 0,01 % de las formas clínicas de tuberculosis. Se presenta un caso de apendicitis aguda probablemente tuberculosa como causa de abdomen agudo quirúrgico. Caso clínico: hombre de 29 años con cuadro de dolor abdominal leve a moderado que se intensificó y localizó en el hemiabdomen derecho, claudicación, febrícula, vómito, mal estado general, leucocitosis de 11 300/µL y neutrofilia de 91 %....

  15. Algunas observaciones sobre la apendicitis aguda en los niños

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    Luis Piñeros Suárez

    1940-03-01

    Full Text Available La apendicitis aguda en los niños, presenta actitudes particulares que diferencian de la apendicitis aguda del adulto y que vienen a formar grupos clínicos casi exclusivamente de la infancia. De una manera general, las formas más graves, las formas fulminantes de la apendicitis aguda se encuentran especialmente en la infancia y en estas formas graves llama poderosamente la atención, la falta de relación entre los signos clínicos observados y la importancia de las lesiones encontradas en el apéndice y el peritoneo, pues en los niños con signos de intensidad media y sin que se hayan presentado los síntomas que en el adulto caracterizan las formas graves de apendicitis, podemos encontrar en las operaciones practicadas en las primeras 24 a 36 horas, peritonitis generalizadas, formas de apendicitis gangrenosas, que no son frecuentes en el adulto y mucho menos en un lapso de tiempo tan corto.

  16. Transmissão da doença de Chagas por transplante renal: ocorrência da forma aguda da doença em dois receptores de um mesmo doador Transmission of Chagas' disease through transplantede kidney: occurrence of the acute form of the disease in two recipients from the same donor

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    A.S. Ferraz

    1993-10-01

    Full Text Available São apresentados dois casos de doença de Chagas aguda, adquiridos através de transplante de rins originários de um mesmo doador. O presente relato confirma a transmissão da doença de Chagas a partir do transplante renal e reforça a necessidade de exclusão de doadores renais infectados pelo Trypanosoma cruzi.Two cases of acute Chagas' disease acquired after renal transplantation are reported. The two patients received the kidney from the same donor. The present paper confirms this form of transmission of Chagas' disease and reinforces the need to exclude kidney donors with Trypanosoma cruzi infection.

  17. Leucemia congénita aguda Acute congenital leukemia

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    Nilvia Esther González García

    2011-06-01

    Full Text Available La leucemia aguda durante el período neonatal es poco frecuente de evolución rápida y pronóstico sombrío. Sus características clínicas y biológicas difieren de las encontradas en niños de mayor edad, y su inicio se caracteriza por afectación cutánea, hepatoesplenomegalia, hiperleucocitosis e infiltración del sistema nervioso central. Se han observado pacientes con formas tanto mieloides como linfoides, pero la leucemia mieloide aguda parece predominar en esta etapa de la vida. Se presenta el caso de un paciente con leucemia congénita clasificada morfológicamente, con aparición de manifestaciones clínicas de enfermedad hematológica desde el nacimiento y diagnóstico de leucemia linfoblástica aguda congénita.Acute leukemia during neonatal period is not frequent, of a fast course and gloomy prognosis. Its clinical and biological features differ of that present in older children and it onset is characterized by cutaneous affection, hepatosplenomegaly, hyperleukocytosis and infiltration of central nervous system (CNS. There are patients presenting with myeloid and lymphoid types, but the acute leukemia seems to predominate in this stage of life. This is the case of a patient with acute leukemia morphologically classified, with appearance of clinical manifestations of hematologic disease from birth and a diagnosis of congenital acute lymphoblastic leukemia.

  18. Classificação de gravidade na pancreatite aguda

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    Tercio De Campos

    Full Text Available De acordo com a Classificação de Atlanta a pancreatite aguda pode ser dividida, baseado em sua severidade, em uma forma leve ou grave. Uma série de aspectos têm sido discutidos nos últimos anos, tais como, quantas categorias de gravidade devem ser consideradas; se o doente com falência orgânica é igual ao doente com necrose infectada; qual o papel da falência orgânica transitória; e como avaliar a falência orgânica. A reunião de revista"Telemedicina Baseada em Evidência - Cirurgia do Trauma e Emergência" (TBE-CiTE realizou uma avaliação crítica de artigos relacionados a este tema, considerando três artigos recentes que delinearam duas grandes revisões publicadas nos últimos meses. Estes artigos sugerem a classificação de gravidade em três ou quatro categorias, ao invés de pancreatite aguda leve ou grave, além de discutir qual o melhor escore para avaliar a falência orgânica. As seguintes recomendações foram propostas: (1 A pancreatite aguda deve ser classificada em quatro categorias: leve, moderada, grave e crítica, o que permite uma melhor determinação das características dos doentes; (2 Avaliação de falência orgânica com um escore de gravidade, preferencialmente algum que avalie diretamente cada falência orgânica, tais como o SOFA e o MODS (Marshall. O SOFA parece ter maior acurácia, mas o MODS tem melhor aplicabilidade devido à facilidade de uso.

  19. O mosaico patogênico da pancreatite aguda grave

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    Márcio Cavalcante Carneiro

    Full Text Available A pancreatite aguda tem sido alvo de grandes discussões que vão desde o entendimento de sua fisiopatologia até a investigação de novas modalidades terapêuticas. Reconhece-se que a necrose pancreática e a falência orgânica múltipla - mormente associadas à infecção - representam os principais fatores determinantes da evolução para o óbito, mas, apesar dos grandes avanços em seu estudo, a doença permanece como um desafio para o clínico e o cirurgião. Deste modo, um melhor conhecimento dos mecanismos envolvidos em sua fisiopatologia pode ser a chave para um tratamento mais eficaz, principalmente em relação às formas graves, cuja letalidade ainda encontra-se substancialmente elevada. Baseado nestas considerações, o presente trabalho tem por objetivo a revisão bibliográfica da fisiopatologia, dos fatores patogênicos envolvidos na história natural da pancreatite aguda grave e dos eventos associados à síndrome da resposta inflamatória sistêmica e à sepse, esboçando-se assim o mosaico patogênico desta importante condição.

  20. Respostas cardiovasculares agudas em ambiente virtualmente simulado pelo Nintendo Wii

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    Renato Aparecido de Souza

    2013-01-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2013v15n1p60 Recentemente, tem sido verificada a utilização do Nintendo Wii no contexto da saúde. O objetivo do presente estudo foi analisar as respostas cardiovasculares agudas monitoradas por meio do comportamento da frequência cardíaca, pressão arterial sistólica, pressão arterial diastólica e duplo produto, em ambiente virtualmente simulado pelo console Nintendo Wii. A amostra foi composta por 18 universitários saudáveis, com média de idade de 22,07 ± 1,34 anos. As variáveis foram observadas com uso de deltas (valor final - inicial após 25 arremessos de basquetebol em duas situações experimentais: (I com o voluntário sentado e, (II com o voluntário saltando verticalmente. Os resultados sugerem que a prática de atividade física em ambiente virtual emulado pelo Nintendo Wii é capaz de alterar as respostas cardiovasculares agudas, especialmente, quando realizada em associação a saltos verticais. Assim, os resultados sustentam a viabilidade do uso do Nintendo Wii em programas de treinamento e favorecem sua indicação de forma mais segura.

  1. Axonal GABAA receptors.

    Science.gov (United States)

    Trigo, Federico F; Marty, Alain; Stell, Brandon M

    2008-09-01

    Type A GABA receptors (GABA(A)Rs) are well established as the main inhibitory receptors in the mature mammalian forebrain. In recent years, evidence has accumulated showing that GABA(A)Rs are prevalent not only in the somatodendritic compartment of CNS neurons, but also in their axonal compartment. Evidence for axonal GABA(A)Rs includes new immunohistochemical and immunogold data: direct recording from single axonal terminals; and effects of local applications of GABA(A)R modulators on action potential generation, on axonal calcium signalling, and on neurotransmitter release. Strikingly, whereas presynaptic GABA(A)Rs have long been considered inhibitory, the new studies in the mammalian brain mostly indicate an excitatory action. Depending on the neuron that is under study, axonal GABA(A)Rs can be activated by ambient GABA, by GABA spillover, or by an autocrine action, to increase either action potential firing and/or transmitter release. In certain neurons, the excitatory effects of axonal GABA(A)Rs persist into adulthood. Altogether, axonal GABA(A)Rs appear as potent neuronal modulators of the mammalian CNS.

  2. Acute nutritional axonal neuropathy.

    Science.gov (United States)

    Hamel, Johanna; Logigian, Eric L

    2018-01-01

    This study describes clinical, laboratory, and electrodiagnostic features of a severe acute axonal polyneuropathy common to patients with acute nutritional deficiency in the setting of alcoholism, bariatric surgery (BS), or anorexia. Retrospective analysis of clinical, electrodiagnostic, and laboratory data of patients with acute axonal neuropathy. Thirteen patients were identified with a severe, painful, sensory or sensorimotor axonal polyneuropathy that developed over 2-12 weeks with sensory ataxia, areflexia, variable muscle weakness, poor nutritional status, and weight loss, often with prolonged vomiting and normal cerebrospinal fluid protein. Vitamin B6 was low in half and thiamine was low in all patients when obtained before supplementation. Patients improved with weight gain and vitamin supplementation, with motor greater than sensory recovery. We suggest that acute or subacute axonal neuropathy in patients with weight loss or vomiting associated with alcohol abuse, BS, or dietary deficiency is one syndrome, caused by micronutrient deficiencies. Muscle Nerve 57: 33-39, 2018. © 2017 Wiley Periodicals, Inc.

  3. Axons take a dive

    Science.gov (United States)

    Tong, Cheuk Ka; Cebrián-Silla, Arantxa; Paredes, Mercedes F; Huang, Eric J; García-Verdugo, Jose Manuel; Alvarez-Buylla, Arturo

    2015-01-01

    In the walls of the lateral ventricles of the adult mammalian brain, neural stem cells (NSCs) and ependymal (E1) cells share the apical surface of the ventricular–subventricular zone (V–SVZ). In a recent article, we show that supraependymal serotonergic (5HT) axons originating from the raphe nuclei in mice form an extensive plexus on the walls of the lateral ventricles where they contact E1 cells and NSCs. Here we further characterize the contacts between 5HT supraependymal axons and E1 cells in mice, and show that suprependymal axons tightly associated to E1 cells are also present in the walls of the human lateral ventricles. These observations raise interesting questions about the function of supraependymal axons in the regulation of E1 cells. PMID:26413556

  4. Electrophysiology of Axonal Constrictions

    Science.gov (United States)

    Johnson, Christopher; Jung, Peter; Brown, Anthony

    2013-03-01

    Axons of myelinated neurons are constricted at the nodes of Ranvier, where they are directly exposed to the extracellular space and where the vast majority of the ion channels are located. These constrictions are generated by local regulation of the kinetics of neurofilaments the most important cytoskeletal elements of the axon. In this paper we discuss how this shape affects the electrophysiological function of the neuron. Specifically, although the nodes are short (about 1 μm) in comparison to the distance between nodes (hundreds of μm) they have a substantial influence on the conduction velocity of neurons. We show through computational modeling that nodal constrictions (all other features such as numbers of ion channels left constant) reduce the required fiber diameter for a given target conduction velocity by up to 50% in comparison to an unconstricted axon. We further show that the predicted optimal fiber morphologies closely match reported fiber morphologies. Supported by The National Science Foundation (IOS 1146789)

  5. Pancreatitis aguda grave asociada a gangrena vesicular

    OpenAIRE

    Arroyo-Sánchez, Abel S; Aguirre-Mejía, Rosa Y; Echenique-Martínez, Sergio E

    2014-01-01

    Se presenta el caso un paciente diabético que desarrolló un cuadro de pancreatitis aguda grave asociada a gangrena vesicular, en el que se evaluó la aplicabilidad de los criterios de clasificación y manejo de la hoja de ruta para pancreatitis aguda, así mismo se proponen algunos tópicos que pudieran ser investigados a futuro We present a diabetic patient who developed severe acute pancreatitis associated to gallbladder gangrene, in this case we assessed the applicability of classification ...

  6. Glia to axon RNA transfer.

    Science.gov (United States)

    Sotelo, José Roberto; Canclini, Lucía; Kun, Alejandra; Sotelo-Silveira, José Roberto; Calliari, Aldo; Cal, Karina; Bresque, Mariana; Dipaolo, Andrés; Farias, Joaquina; Mercer, John A

    2014-03-01

    The existence of RNA in axons has been a matter of dispute for decades. Evidence for RNA and ribosomes has now accumulated to a point at which it is difficult to question, much of the disputes turned to the origin of these axonal RNAs. In this review, we focus on studies addressing the origin of axonal RNAs and ribosomes. The neuronal soma as the source of most axonal RNAs has been demonstrated and is indisputable. However, the surrounding glial cells may be a supplemental source of axonal RNAs, a matter scarcely investigated in the literature. Here, we review the few papers that have demonstrated that glial-to-axon RNA transfer is not only feasible, but likely. We describe this process in both invertebrate axons and vertebrate axons. Schwann cell to axon ribosomes transfer was conclusively demonstrated (Court et al. [2008]: J. Neurosci 28:11024-11029; Court et al. [2011]: Glia 59:1529-1539). However, mRNA transfer still remains to be demonstrated in a conclusive way. The intercellular transport of mRNA has interesting implications, particularly with respect to the integration of glial and axonal function. This evolving field is likely to impact our understanding of the cell biology of the axon in both normal and pathological conditions. Most importantly, if the synthesis of proteins in the axon can be controlled by interacting glia, the possibilities for clinical interventions in injury and neurodegeneration are greatly increased. Copyright © 2013 Wiley Periodicals, Inc.

  7. Pneumonia aguda fibrinosa e organizante

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    C. Damas

    2006-09-01

    Full Text Available Resumo: A designação acute fibrinous and organizing pneumonia (AFOP foi proposta por Beasley et al para os casos em que as características histopatológicas das lesões não se enquadravam em outras situações clínicas (agu-das ou subagudas conhecidas. A presença de fibrina intra alveolar e de pneumonia organizativa, com distribuição difusa, é a principal alteração histológica associada a esta entidade.Os autores descrevem o caso de um doente do sexo masculino, com o diagnóstico de AFOP, por bióp-sia pulmonar cirúrgica. O doente teve uma apresentação subaguda, apresentando por queixas principais tosse, dor torácica e febre. TAC torácica mostrou infiltrados bilaterais, difusos. Após início de corticoterapia sistémica e ciclofosfamida, o doente apresentou melhoria clínica significativa. Ao elaborar este caso, os autores esperam acrescentar mais alguns dados sobre esta nova entidade.Rev Port Pneumol 2006; XII (5: 615-620 Abstract: The term Acute Fibrinous and Organizing Pneumonia (AFOP has been proposed by Beasley et al for cases that not fit into the histopathologic criteria of the recognized entities described as acute or subacute clinical presentations. The presence of intra-alveolar fibrin in the form of fibrin ‘balls’ and organizing pneumonia with patchy distribution are the main histological features of this entity. We describe the case of a male patient with the diagnostic of AFOP made by surgical lung biopsy. He had a subacute presentation of symptoms consisting of productive cough, chest pain and fever. Bilateral infiltrates with patchy and diffuse distribution were the predominant features in his chest HRCT scan. The patient had a good clinical course after a treatment with prednisone and cyclophosphamide. Our hope in reporting this case study is to add some more data to the discussion of this new entity.Rev Port Pneumol 2006; XII (5: 615-620 Palavras

  8. Sarcoidosis aguda: Variante de Síndrome de Löfgren sin eritema nodoso

    OpenAIRE

    Pérez, Gerardo; Facal, Jorge

    2014-01-01

    El síndrome de Löfgren, es una variante aguda de la sarcoidosis, que se caracteriza por fiebre, eritema nodoso, adenomegalias hiliares pulmonares y artritis. En general, tiene un curso benigno y autolimitado, que contrasta con las formas crónicas que requieren uso de corticoides y tienen tendencia a la recidiva. Se describe aquí el caso clínico de un paciente joven, de sexo masculino, con artritis pero sin eritema nodoso, lo que dificultó el planteo diagnóstico de síndrome de Löfgren. Se real...

  9. Signal propagation along the axon.

    Science.gov (United States)

    Rama, Sylvain; Zbili, Mickaël; Debanne, Dominique

    2018-03-08

    Axons link distant brain regions and are usually considered as simple transmission cables in which reliable propagation occurs once an action potential has been generated. Safe propagation of action potentials relies on specific ion channel expression at strategic points of the axon such as nodes of Ranvier or axonal branch points. However, while action potentials are generally considered as the quantum of neuronal information, their signaling is not entirely digital. In fact, both their shape and their conduction speed have been shown to be modulated by activity, leading to regulations of synaptic latency and synaptic strength. We report here newly identified mechanisms of (1) safe spike propagation along the axon, (2) compartmentalization of action potential shape in the axon, (3) analog modulation of spike-evoked synaptic transmission and (4) alteration in conduction time after persistent regulation of axon morphology in central neurons. We discuss the contribution of these regulations in information processing. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. VIH: Infeccion aguda, pesquisa y manejo

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    Cortés S. Esteban, Dr.

    2014-05-01

    Si bien existe una relativa facilidad para realizar el diagnóstico de un paciente con la infección crónica por VIH, existe por otro lado una relativa dificultad para realizar el diagnóstico de la infección aguda en etapas tempranas de la infección. Esta situación es de importancia desde el punto de vista de la Salud Pública por cuanto en la infección aguda es cuando se producen las viremias más elevadas y por tanto la mayor facilidad para que el sujeto sea infectante y disemine la infección viral.

  11. Bases moleculares de las leucemias agudas

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    G. Martínez Antuña

    2006-04-01

    Full Text Available El gran desarrollo de la biología molecular en los últimos años ha contribuido a un importante avance en los conocimientos relacionados con las bases moleculares de las leucemias agudas (LA. Ademas de profundizar en la biología de estas enfermedades y conocer las bases moleculares, ha renido también gran impacto en mejorar el resultado de los tratamientos y disminuir la toxicidad de las terapias.

  12. Otomastoidite Aguda em Criança

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    João Araújo

    2017-09-01

    Full Text Available Criança de 2 anos, sexo masculino, diagnóstico de otite média aguda bilateral, medicada inicialmente com amoxicilina + clavulanato 90 mg/kg/dia desde há 7 dias, internada por agravamento do quadro à esquerda, com edema e eritema retroauricular, apagamento do sulco retroauricular [...] Recebido: 07/09/2015 · Aceite: 7/01/2016

  13. Comportamiento de la otitis media aguda

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    Gladys Fuentes Fernández

    Full Text Available Introducción: la otitis media aguda es una complicación de las infecciones respiratorias agudas altas, frecuente en los niños menores de 5 años. Objetivos: caracterizar su comportamiento, según edad y sexo, e identificar algunos factores de riesgo en este grupo de edad. Métodos: se realizó un estudio descriptivo retrospectivo de 554 niños ingresados en el hospital Pediátrico de Centro Habana con el diagnóstico de otitis media aguda, durante los años 2006-2010. Los datos se recogieron de las historias clínicas. Resultados: la otitis media aguda fue más frecuente en el sexo masculino (58,7 % y en los menores de 1 año (53,1 %. El antecedente de bajo peso (33,9 % y la prematuridad (27,5 %, la asistencia a círculos infantiles (43,5 % y el hábito de fumar de los padres (58,4 %, además del antecedente de ingresos hospitalarios por otitis media en el mes previo a la aparición del episodio actual (59,0 %, constituyeron los principales factores de riesgo en el presente estudio. Conclusiones: la otitis media es una causa frecuente de ingresos hospitalarios, y se identifican como principales factores de riesgo la asistencia a círculos infantiles y el tabaquismo de algunos de los padres.

  14. Otitis media aguda: nuevo enfoque terapéutico

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    Ileana Alvarez Lam

    2004-03-01

    Full Text Available La otitis media aguda continúa siendo una de las enfermedades infecciosas más frecuentes en la infancia. Se hace una revisión del tema haciendo énfasis en la conducta terapéutica actual luego del surgimiento de complejos mecanismos de resistencia bacteriana creados por los microorganismos causantes de la enfermedad. Como toda enfermedad infecciosa las esperanzas están cifradas en el surgimiento de una vacuna que impacte de forma positiva en nuestra población infantil. En tal sentido se hace una reflexión sobre el uso de la vacuna antineumocócica de 7 valencias (Prevnar y su repercusión sobre esta enfermedad.Acute otitis media is still one of the most common infectious diseases among children. A review of the topic is made giving emphasis to the present therapeutic conduct after the appearance of complex mechanisms of bacterial resistance created by the microorganisms causing the disease. As in every infectious disease, we place our hopes on the emergence of a vaccine with a positive impact on our infantile population. In this sense, a reflection is made on the use of the heptavalent antipneumococcic vaccine (Prevnar and its repercussion on this disease.

  15. Infarto esplénico secundario a pancreatitis aguda Splenic infarction secondary to acute pancreatitis

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    J. J. Arenal Vera

    2008-05-01

    Full Text Available Fundamento y objetivo: la estrecha relación anatómica del páncreas con los vasos esplénicos y el bazo es responsable de complicaciones esplénicas en el curso de la pancreatitis aguda. El objetivo es presentar dos casos clínicos de pancreatitis aguda grave que sufrieron infarto esplénico como complicación de la enfermedad pancreática. Pacientes, participantes: en un periodo de tres meses, dos pacientes fueron diagnosticados de infarto esplénico secundario a pancreatitis aguda. En ambos casos el diagnóstico y seguimiento evolutivo del infarto esplénico se hizo a través de tomografía axial computerizada. Resultados: en el primer paciente, las imágenes muestran de forma inequívoca la afectación de la arteria esplénica por el proceso inflamatorio pancreático. En el segundo, no se pudo demostrar afectación de los vasos esplénicos, por lo que la única posible explicación etiológica es un incremento de coagulabilidad intravascular. Conclusiones: sería recomendable añadir las complicaciones esplénicas al conjunto de complicaciones graves extrapancreáticas de la pancreatitis aguda. La tomografía axial computerizada es de gran utilidad para la detección y seguimiento de las complicaciones esplénicas de la pancreatitis aguda.Background and objective: the close anatomic relationship of the pancreas with the splenic vessels and the spleen is responsible for splenic complications in the course of acute pancreatitis. Our objective was to report two cases of severe acute pancreatitis complicated by splenic infarction. Patients: in a three-month period of time two patients were diagnosed with splenic infarction secondary to acute pancreatitis. In both cases splenic infarction diagnosis and follow-up were carried out using computed tomography. Results: in the first case images clearly showed a narrowing of the splenic artery due to the inflammatory pancreatic condition. In the second case no involvement of the splenic vessels could

  16. The genetics of axonal transport and axonal transport disorders.

    Directory of Open Access Journals (Sweden)

    Jason E Duncan

    2006-09-01

    Full Text Available Neurons are specialized cells with a complex architecture that includes elaborate dendritic branches and a long, narrow axon that extends from the cell body to the synaptic terminal. The organized transport of essential biological materials throughout the neuron is required to support its growth, function, and viability. In this review, we focus on insights that have emerged from the genetic analysis of long-distance axonal transport between the cell body and the synaptic terminal. We also discuss recent genetic evidence that supports the hypothesis that disruptions in axonal transport may cause or dramatically contribute to neurodegenerative diseases.

  17. Soporte nutricional en la insuficiencia renal aguda

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    O. Cristina Olivos, Dra.

    2010-07-01

    Full Text Available La insuficiencia renal aguda (IRA se presenta frecuentemente en distintas condiciones clínicas y es especialmente frecuente en unidades de cuidados intensivos. La presencia de IRA se considera como un factor de riesgo independiente de morbilidad y mortalidad hospitalaria. De ahí la importancia de evaluar los diversos factores determinantes de su evolución, entre los que cuenta la desnutrición calórico-proteica. El propósito de esta revisión es analizar la literatura más relevante hasta la actualidad en este tema.

  18. Intoxicaciones agudas en pediatría

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    Yalena Prado Vizcaíno

    2011-12-01

    Full Text Available Introducción: las intoxicaciones han sido en los últimos años una importante causa de aumento de la morbilidad y mortalidad en edades pediátricas. Objetivo: determinar el comportamiento clínico de las intoxicaciones agudas en la etapa de enero de 2005 a diciembre de 2009 en el Hospital Pediátrico "William Soler". Métodos: el estudio se realizó en el Hospital "William Soler". Se revisaron las historias clínicas, los registros de intoxicaciones agudas y las tarjetas de codificación de egresos hospitalarios por intoxicaciones de los pacientes llegados al hospital en esta etapa. Resultados: se recibieron en el hospital 886 pacientes. El grupo de mayor frecuencia de intoxicaciones fue el de 1 a 5 años, con predominio del sexo masculino, aunque sin diferencias significativas con respecto al sexo femenino. Las intoxicaciones más frecuentes fueron por medicamentos, fundamentalmente psicofármacos y antibióticos, seguido por alimentos y por productos químicos del hogar. El 30,2 % de los casos fueron ingresados. Conclusiones: estos resultados nos hacen pensar en la necesidad de estar alertas y crear acciones encaminadas a proteger o evitar las intoxicaciones en edades tan vulnerables.

  19. INSUFICIENCIA RENAL AGUDA CON UREMIA NORMAL EN PACIENTE MONO-RENO SECUNDARIA A PIELONEFRITIS AGUDA

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    Musso CG

    2006-03-01

    Full Text Available RESUMEN:La insuficiencia renal aguda es un sindrome que característicamente cursa con niveles plasmáticos elevados de urea y creatinina. Sin embargo, hay situaciones clínicas en las cuales este sindrome puede cursar con un incremento de la creatininemia sin presentar elevación de la uremia.En este reporte presentamos un caso clínico de una insuficiencia renal aguda con uremia normal secundaria a una pielonefritis aguda en un paciente con riñón único. El paciente presentaba una elevada excreción fraccional de urea lo cual podía explicar su uremia normal pese a estar cursando una caída del filtrado gomerular. Dicha excreción de urea elevada fue interpretada como secundaria a una diabetes insipida nefrogénica y una alteración en el recirculado intra-renal de la urea ambos producto de la pielonefritis aguda. Concluimos que la pielonefritis aguda en un paciente mono-reno puede presentarse con un patrón de insuficiencia renal aguda con uremia normal. SUMMARYAcute renal failure is a syndrome that usually runs with an increase in creatinine and urea plasma levels. However, there are clinical situations in which this syndrome may run with an increase in plasma creatinine keeping normal the urea one.In this report we present a case of acute renal failure with normal plasma urea level secondary to an acute pyelonephritis in a single kidney patient. The patient had an increased fractional excretion of urea which could explain the normal plasma urea levels found despite of his reduced glomerular filtration. This increased urea excretion state was interpreted as a consequence of the nephrogenic diabetes insipidus and alteration of the intra-renal urea reciclying process that the acute pyelonephritis induced. In conclusion: Acute pyelonephritis in a single kidney patient can appear as a pattern of acute renal failure with normal plasma urea levels.

  20. INSUFICIENCIA RENAL AGUDA CON UREMIA NORMAL EN PACIENTE MONO-RENO SECUNDARIA A PIELONEFRITIS AGUDA

    Directory of Open Access Journals (Sweden)

    Musso CG

    2007-04-01

    Full Text Available RESUMENLa insuficiencia renal aguda es un sindrome que característicamente cursa con niveles plasmáticos elevados de urea y creatinina. Sin embargo, hay situaciones clínicas en las cuales este sindrome puede cursar con un incremento de la creatininemia sin presentar elevación de la uremia. En este reporte presentamos un caso clínico de una insuficiencia renal aguda con uremia normal secundaria a una pielonefritis aguda en un paciente con riñón único. El paciente presentaba una elevada excreción fraccional de urea lo cual podía explicar su uremia normal pese a estar cursando una caída del filtrado gomerular. Dicha excreción de urea elevada fue interpretada como secundaria a una diabetes insipida nefrogénica y una alteración en el recirculado intra-renal de la urea ambos producto de la pielonefritis aguda. Concluimos que la pielonefritis aguda en un paciente mono-reno puede presentarse con un patrón de insuficiencia renal aguda con uremia normal.SUMMARYAcute renal failure is a syndrome that usually runs with an increase in creatinine and urea plasma levels. However, there are clinical situations in which this syndrome may run with an increase in plasma creatinine keeping normal the urea one. In this report we present a case of acute renal failure with normal plasma urea level secondary to an acute pyelonephritis in a single kidney patient. The patient had an increased fractional excretion of urea which could explain the normal plasma urea levels found despite of his reduced glomerular filtration. This increased urea excretion state was interpreted as a consequence of the nephrogenic diabetes insipidus and alteration of the intra-renal urea reciclying process that the acute pyelonephritis induced. In conclusion: Acute pyelonephritis in a single kidney patient can appear as a pattern of acute renal failure with normal plasma urea levels.

  1. Miocardite na forma aguda da doença de Chagas

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    Eitel Duarte

    1948-12-01

    Full Text Available The autopsy of a case of CHAGAS'S disease or American tryponosomiasis (a girl, 5 years old, dead in the 22nd day of illness is reported. The anatomic diagnosis was a follows: Acute diffuse chagasic nyocarditis. Chagasic encephalitis. Chagasic lymphadenitis of the right posterior auricular node. Tuberculosis of the bronchial and pulmonary nodes. Chronic passive hyperemia and atelectasia of the lungs. Chronic passive congestion and hemorrhages of the spleen. Serous hepatitis. Parotiditis. Edema of the right eyelids. Bilateral hydrothorax. Hydropericardium. Hydroperitoneum. The morphology of Schizotrypanum cruzi in the myocardium is considered. Besides agglomerates with typical small oval or round intracellular bodies, pre-flagellate and flagellate organisms, others are found in which the great amount of parasites and marked pressure exerted by them against each other render very difficult their identification; sometimes the similitude of such agglamerates to Toxoplasma is striking (Fig. 1 and 1 A. In such a case, the structure of the blepharoplast (Fig. 1 and IA, usually preserved, is profitable and allows the identification of the pre-flagellate and flagellate forms of Schizotrypanum cruzi. Most of the small sensitive nerves in the epicardium shows mononuclear infiltration of the perineurium (perineuritis, Figs. 12-14. Microscopically there is extensive Zenker's degeneration (Figs. 6-8 and parasitism of the heart muscle fibers, marked cellular infiltration of the interstitial connective tissue, which are found in the ordinary musculature of every chamber of the heart (Figs. 10-11 as well as in Tawara's node (Fig. 9, main bundle (Fig. 2 and right (Fig. 4 and left (Fig. 5 septal divisions of the bundle of His, and perineuritis. Those anatomic changes are associated to an abnormal electrocardiogram presenting some similitude to that of an anemic infarct of the anterior wall of the heart and which will be discussed elsewhere (unpublished paper by Dias, Nobrega & Laranja.

  2. Insuficiencia renal aguda con necrosis tubular aguda secundaria a picadura masiva de abejas

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    Gustavo A. Aroca - Martínez

    2006-01-01

    Full Text Available Leñador de 46 años consulta al servicio de nefrología, de la Clínica Renal de la Costa en Barranquilla, con episodio de insuficiencia renal aguda 48 horas después de haber sufrido múltiples picaduras por abejas africanizadas. Durante su estancia hospitalaria presentó incremento de enzimas musculares (AST LDH, y de pruebas de función renal, motivo por el cual fue dializado en varias ocasiones. Con mejoría total, se decide egresar y manejar ambulatoriamente. Se concluye que el caso se trata de una insuficiencia renal por necrosis tubular aguda por rabdomiolisis debida a la picadura múltiple de abejas africanizadas.

  3. Forma y esfuerzos estructurales

    OpenAIRE

    Cervera Bravo, Jaime

    2002-01-01

    El objetivo del texto es analizar el comportamiento estructural desde la perspectiva de la forma de la estructura, determinando los parámetros de forma especialmente relevantes. Esto permitirá comprender los medios --las herramientas de transformación formal-- que pueden emplearse para recorrer un amplio abanico tipológico, con especial énfasis en los tipos de cubierta, como si de un continuo se tratase. En este continuo el comportamiento global será idéntico en todas las estructuras, po...

  4. Mielopatia transversa em adulto portador de leucemia aguda linfoblástica: relato de caso

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    Brito José Correia de Farias

    2001-01-01

    Full Text Available Relatamos um caso de mielopatia transversa aguda em paciente masculino de 31 anos de idade, branco, portador de leucemia aguda linfoblástica, subtipo L3 (LLA-L3. Esta é uma forma grave de leucemia e compromete mais crianças em relação aos adultos. Menos de 1% dos pacientes leucêmicos apresentam complicações espinais. No paciente em estudo, a sintomatologia instalou-se de modo abrupto e com as seguintes características: dores nas costas, paraplegia crural flácida e perda das funções sensitivas e vegetativas abaixo do segmento afetado. O diagnóstico etiológico foi estabelecido após a realização dos seguintes exames: hemograma, mielograma, análise do líquido cefalorraqueano e ressonância magnética de coluna dorsal. Foi instituído tratamento específico, que não interferiu com a evolução fatal da doença.

  5. Suscetibilidade genética na lesão pulmonar aguda e síndrome da angústia respiratória aguda Genetic susceptibility in acute lung injury and acute respiratory distress syndrome

    Directory of Open Access Journals (Sweden)

    Fernando Suparregui Dias

    2009-12-01

    Full Text Available A lesão pulmonar aguda e sua forma mais grave, a síndrome da angústia respiratória aguda, são o denominador comum de várias doenças que podem provocar uma inflamação exagerada nos pulmões. Nos últimos anos, essa variabilidade tem sido atribuída, pelo menos em parte, a fatores genéticos. O presente estudo tem por objetivos revisar o papel dos principais genes envolvidos na suscetibilidade, morbidade e mortalidade na lesão pulmonar aguda e na síndrome da angústia respiratória aguda. Através de pesquisa nas bases de dados PubMed e LiLACS, empregando-se os unitermos lesão pulmonar aguda, síndrome da angústia respiratória aguda e síndrome da angústia respiratória do adulto em combinação com polimorfismos genéticos, foram selecionados 69 artigos, dos quais 38 foram incluídos nesta revisão. Foram também considerados artigos relevantes extraídos das referências bibliográficas nos artigos selecionados das bases de dados. Os polimorfismos genéticos são variantes gênicas presentes em pelo menos 1% da população. A presença destas variantes genéticas pode influenciar a expressão de mediadores da resposta inflamatória, afetando diretamente a suscetibilidade à lesão pulmonar aguda, a intensidade da inflamação no parênquima pulmonar, a evolução e o desfecho destes pacientes. Estudos de associação com grandes populações e passíveis de reprodução permitirão de modo definitivo a inclusão da genômica no arsenal diagnóstico, prognóstico e terapêutico de pacientes com lesão pulmonar aguda/síndrome da angústia respiratória agudaAcute lung injury and its most severe presentation, acute respiratory distress syndrome, are a common denominator for several diseases which can lead to exaggerated lung inflammation. In the last years this variability has been ascribed, at least partially, to genetic issues. This study aims to review the role of the main genes involved in acute lung injury and acute respiratory

  6. Falla cardíaca aguda

    OpenAIRE

    Sénior Sánchez, Juan Manuel; Gándara Ricardo, Jairo Alfonso

    2015-01-01

    Se presenta el caso clínico de una mujer de 26 años de edad, que acudió al Hospital Universitario San Vicente Fundación (Medellín) con síntomas y signos de falla cardíaca aguda y diagnóstico previo de falla cardíaca crónica con fracción de expulsión disminuida, de origen no claro, tromboembolismo pulmonar y ataque cerebrovascular isquémico, sin modulación neurohormonal óptima. Ingresó a la institución con hallazgos clínicos de sobrecarga hídrica y baja perfusión tisular, con requerimiento de ...

  7. Coréia aguda na gravidez

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    Walter C. Pereira

    1967-12-01

    Full Text Available São apresentados doze casos de coréia aguda observados entre 150.000 gestantes (1/12.500. A maioria dos surtos ocorreu no segundo trimestre da primeira gravidez. A duração média dos sintomas foi de três meses, não tendo sido registrado caso algum de óbito materno. Todos os partos foram espontâneos e normais. Houve apenas um óbito fetal conseqüente a choque hemorrágico. São tecidas considerações a propósito dos aspectos clínico, laboratorial e prognóstico da coréia gravídica, sendo focalizado mais pormenorizadamente o problema fisiopatogênico dessa afecção.

  8. Axon density and axon orientation dispersion in children born preterm

    NARCIS (Netherlands)

    Kelly, Claire E.; Thompson, Deanne K.; Chen, Jian; Leemans, Alexander; Adamson, Christopher L.; Inder, Terrie E.; Cheong, Jeanie L Y; Doyle, Lex W.; Anderson, Peter J.

    2016-01-01

    Background Very preterm birth (VPT, <32 weeks' gestation) is associated with altered white matter fractional anisotropy (FA), the biological basis of which is uncertain but may relate to changes in axon density and/or dispersion, which can be measured using Neurite Orientation Dispersion and Density

  9. Optofluidic control of axonal guidance

    Science.gov (United States)

    Gu, Ling; Ordonez, Simon; Black, Bryan; Mohanty, Samarendra K.

    2013-03-01

    Significant efforts are being made for control on axonal guidance due to its importance in nerve regeneration and in the formation of functional neuronal circuitry in-vitro. These include several physical (topographic modification, optical force, and electric field), chemical (surface functionalization cues) and hybrid (electro-chemical, photochemical etc) methods. Here, we report comparison of the effect of linear flow versus microfluidic flow produced by an opticallydriven micromotor in guiding retinal ganglion axons. A circularly polarized laser tweezers was used to hold, position and spin birefringent calcite particle near growth cone, which in turn resulted in microfluidic flow. The flow rate and resulting shear-force on axons could be controlled by a varying the power of the laser tweezers beam. The calcite particles were placed separately in one chamber and single particle was transported through microfluidic channel to another chamber containing the retina explant. In presence of flow, the turning of axons was found to strongly correlate with the direction of flow. Turning angle as high as 90° was achieved. Optofluidic-manipulation can be applied to other types of mammalian neurons and also can be extended to stimulate mechano-sensing neurons.

  10. The axonal cytoskeleton : from organization to function

    NARCIS (Netherlands)

    Kevenaar, Josta T; Hoogenraad, Casper C

    The axon is the single long fiber that extends from the neuron and transmits electrical signals away from the cell body. The neuronal cytoskeleton, composed of microtubules (MTs), actin filaments and neurofilaments, is not only required for axon formation and axonal transport but also provides the

  11. Slowing of axonal regeneration is correlated with increased axonal viscosity during aging

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    Heidemann Steven R

    2010-10-01

    Full Text Available Abstract Background As we age, the speed of axonal regeneration declines. At the biophysical level, why this occurs is not well understood. Results To investigate we first measured the rate of axonal elongation of sensory neurons cultured from neonatal and adult rats. We found that neonatal axons grew 40% faster than adult axons (11.5 µm/hour vs. 8.2 µm/hour. To determine how the mechanical properties of axons change during maturation, we used force calibrated towing needles to measure the viscosity (stiffness and strength of substrate adhesion of neonatal and adult sensory axons. We found no significant difference in the strength of adhesions, but did find that adult axons were 3 times intrinsically stiffer than neonatal axons. Conclusions Taken together, our results suggest decreasing axonal stiffness may be part of an effective strategy to accelerate the regeneration of axons in the adult peripheral nervous system.

  12. Esofagitis necrotizante aguda: Una entidad inusual

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    Silvana E. Pramparo

    2010-12-01

    Full Text Available La esofagitis necrotizante aguda (ENA, también denominada esófago negro, es una rara enfermedad poco descripta en la literatura médica. Describimos el caso de un hombre de 80 años, con hemorragia digestiva alta quien desarrolló un esófago negro luego de un episodio de hipotensión. La necrosis fue confirmada histológicamente. Los pacientes se presentan con hematemesis y melena en más del 70% de los casos. Los hallazgos endoscópicos muestran una coloración negruzca de la mucosa esofágica. El diagnóstico se realiza con endoscopia y confirmación histológica. La mortalidad es alta (más del 50% aunque relacionada a las enfermedades de base del paciente. Por último, podemos decir que la sospecha es muy importante en el diagnóstico de ENA, particularmente en pacientes ancianos con enfermedades asociadas y evidencia de hemorragia digestiva alta. En este trabajo describimos las características clínicas, endoscópicas e histopatológicas de un paciente con ENA.

  13. Lesiones periapicales agudas en pacientes adultos

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    María Elena Fernández Collazo

    2012-06-01

    Full Text Available Se realizó un estudio analítico de corte transversal en el área de salud del Policlínico "27 de Noviembre" del municipio Marianao, La Habana, en el periodo correspondiente de enero a diciembre de 2009. Se incluyeron todos los pacientes que acudieron al servicio de urgencia y que presentaron lesiones periapicales agudas. Se recogió información de las variables edad, sexo, grupo dentario, causa de la enfermedad, características clínicas e higiene bucal. Esta última se clasificó en las categorías eficiente y deficiente según el índice simplificado de higiene bucal. Se utilizó el X² para estimar la relación entre las variables, y la comparación de proporciones para contrastar la hipótesis de que existieran diferencias entre las lesiones periapicales para las categorías de las variables grupo dentario, causa de la enfermedad y características clínicas. Se encontró un predominio del absceso periapical agudo en un 84,7 % del grupo de edad de 35 a 59 años y del sexo masculino, aunque no se encontraron diferencias significativas para estas variables, ni en los grupos dentarios con respecto a la enfermedad. La higiene bucal resultó estar relacionada con las lesiones periapicales. Se encontraron diferencias significativas en las lesiones periapicales respecto a todas las causas estudiadas, con excepción de las enfermedades periodontales. Respecto a las características clínicas hubo significación en cuanto al aumento de volumen del fondo del surco vestibular y la movilidad dentaria.

  14. Primeras experiencias con drenaje biliar percutáneo de urgencia en la colangitis aguda

    Directory of Open Access Journals (Sweden)

    José Luis González González

    Full Text Available Introducción: la obstrucción biliar es motivo frecuente de morbilidad en los pacientes con metástasis hepáticas, adenopatías periportales y cáncer hepatobiliopancreático. La colangitis aguda es la complicación más temida, debido a su mortalidad. En este trabajo se presentan los primeros abordajes percutáneos realizados por cirujanos del Hospital Clínicoquirúrgico "Hermanos Ameijeiras" como herramienta para el tratamiento urgente de esta entidad. Objetivo: caracterizar el drenaje percutáneo transparietohepático de urgencia en pacientes con colangitis aguda e ictericia obstructiva. Métodos: se realizó un estudio descriptivo, prospectivo y aplicado con 30 pacientes atendidos de esta forma en dicha institución entre enero de 2008 y diciembre de 2010. Resultados: el diagnóstico etiológico preponderante fue el de tumor maligno de la cabeza del páncreas. La localización baja de la lesión duplicó a la localización alta. La mejoría clínica de la ictericia se evidenció en la mayoría de los pacientes después de una semana tras el procedimiento: el drenaje percutáneo constituyó el método definitivo en el 73,3 % de los pacientes. Las edades medias para los distintos diagnósticos etiológicos exhibieron diferencias estadísticamente significativas. No hubo complicaciones ni mortalidad relacionadas con el procedimiento. Conclusiones: el drenaje biliar percutáneo guiado por ultrasonido es una herramienta útil y segura para el tratamiento de urgencia de la colangitis aguda. Es un método que pueden realizar los cirujanos generales con entrenamiento adecuado y específico, y tiene asociadas pocas complicaciones.

  15. Mielitis aguda necrotizante en un paciente con Sida Acute necrotizing myelitis in an AIDS patient

    Directory of Open Access Journals (Sweden)

    M. Corti

    2003-04-01

    Full Text Available Como consecuencia de la infección por el virus de la inmunodeficiencia humana tipo-1 (HIV-1, otros patógenos como citomegalovirus (CMV y herpes simple tipo 1-2 (HSV 1-2 pueden comprometer tanto el sistema nervioso central como el periférico. Estos agentes pueden involucrar también a la médula espinal y causar una mielitis aguda necrotizante. Esta complicación ocurre por lo general en pacientes con enfermedad HIV/sida avanzada y marcada inmunodeficiencia, con recuentos de linfocitos T CD4+ de menos de 50 cél/µL. El cuadro clínico, los cambios en el LCR y las neuroimágenes generan una importante sospecha diagnóstica. Es fundamental el inicio precoz de la terapia antiviral específica. Se presenta un paciente con enfermedad avanzada debida al HIV-1 y mielitis aguda necrotizante por CMV y HSV bajo la forma clínica de síndrome de la cola de caballo.In the setting of HIV infection, cytomegalovirus (CMV and herpes simplex virus type 1-2 (HSV 1-2 can affect both the central and peripheral nervous systems. These agents can involve the spinal cord and produce a necrotizing transverse myelitis. This usually occurs in AIDS patients with severe immunodeficiency: CD4 + lymphocyte counts typically are less than 50 cell/µL. The clinical presentation, CSF and imaging studies can provide a high level of suspicion diagnosis. Prompt initiation of antiviral specific drugs is essential. We report a patient with an acute necrotizing myelitis (cauda equina syndrome secondary to CMV and HSV infections.

  16. Nutritional support in patients with severe acute pancreatitis Soporte nutricional en pacientes con pancreatitis aguda grave

    Directory of Open Access Journals (Sweden)

    Mónica Marcela Peláez Hernández

    2007-04-01

    Full Text Available Severe acute pancreatitis is associated with a systemic inflammatory response leading to a hypermetabolic, hypercatabolic condition; for those reasons, patients suffering from this disease require an excellent artificial nutritional support in order to maintain the structural integrity and the function of vital organs with minimal pancreatic secretion. Total parenteral nutrition has been the standard practice in the treatment of patients with severe acute pancreatitis because of the favorable outcomes of early nutritional support while avoiding pancreatic stimulation; however, recent evidence suggests there are potentially greater benefits with enteral as compared with parenteral nutrition, including fewer septic and metabolic complications and lesser costs. That is why present guidelines for the management of acute pancreatitis recommend that enteral instead of parenteral nutrition be used in patients with severe acute pancreatitis. La pancreatitis aguda, especialmente en su forma grave, está asociada con una respuesta inflamatoria sistémica que lleva a un estado de hipermetabolismo e hipercatabolismo, en el que se requiere un excelente soporte nutricional que permita mantener la integridad estructural y la función de los órganos vitales con un estímulo mínimo de la secreción pancreática. La nutrición parenteral total era el soporte de elección, que permitía obtener todos los beneficios de la nutrición temprana sin estimular la secreción pancreática; pero la evidencia actual muestra mayores beneficios con la nutrición enteral, porque se asocia con menos complicaciones infecciosas y metabólicas y con disminución en los costos. Por ello las guías actuales de tratamiento de la pancreatitis aguda grave recomiendan como primera elección el soporte nutricional enteral.

  17. Elucidation of axonal transport by radioautography

    International Nuclear Information System (INIS)

    Droz, Bernard.

    1979-01-01

    Radioautography permits to distinguish various pathways within the axons: the axoplasm which includes soluble enzymes and constituents of the cytoskeleton moving with slow axoplasmic flow; the mitochondria which are conveyed as organelles; the smooth endoplasmic reticulum which ensures the fast axonal transport of membrane constituents delivered to axolemma, synaptic vesicles, presynaptic membranes or mitochondria. Furthermore radioautography makes it possible to visualize intercellular exchanges of molecules between axon and glia

  18. Motor axon excitability during Wallerian degeneration

    DEFF Research Database (Denmark)

    Moldovan, Mihai; Alvarez, Susana; Krarup, Christian

    2008-01-01

    Axonal loss and degeneration are major factors in determining long-term outcome in patients with peripheral nerve disorders or injury. Following loss of axonal continuity, the isolated nerve stump distal to the lesion undergoes Wallerian degeneration in several phases. In the initial 'latent' phase......, action potential propagation and structural integrity of the distal segment are maintained. The aim of this study was to investigate in vivo the changes in membrane function of motor axons during the 'latent' phase of Wallerian degeneration. Multiple indices of axonal excitability of the tibial nerve...

  19. Axonal regeneration in zebrafish spinal cord

    Science.gov (United States)

    Hui, Subhra Prakash

    2018-01-01

    Abstract In the present review we discuss two interrelated events—axonal damage and repair—known to occur after spinal cord injury (SCI) in the zebrafish. Adult zebrafish are capable of regenerating axonal tracts and can restore full functionality after SCI. Unlike fish, axon regeneration in the adult mammalian central nervous system is extremely limited. As a consequence of an injury there is very little repair of disengaged axons and therefore functional deficit persists after SCI in adult mammals. In contrast, peripheral nervous system axons readily regenerate following injury and hence allow functional recovery both in mammals and fish. A better mechanistic understanding of these three scenarios could provide a more comprehensive insight into the success or failure of axonal regeneration after SCI. This review summarizes the present understanding of the cellular and molecular basis of axonal regeneration, in both the peripheral nervous system and the central nervous system, and large scale gene expression analysis is used to focus on different events during regeneration. The discovery and identification of genes involved in zebrafish spinal cord regeneration and subsequent functional experimentation will provide more insight into the endogenous mechanism of myelination and remyelination. Furthermore, precise knowledge of the mechanism underlying the extraordinary axonal regeneration process in zebrafish will also allow us to unravel the potential therapeutic strategies to be implemented for enhancing regrowth and remyelination of axons in mammals. PMID:29721326

  20. Action Potential Dynamics in Fine Axons Probed with an Axonally Targeted Optical Voltage Sensor.

    Science.gov (United States)

    Ma, Yihe; Bayguinov, Peter O; Jackson, Meyer B

    2017-01-01

    The complex and malleable conduction properties of axons determine how action potentials propagate through extensive axonal arbors to reach synaptic terminals. The excitability of axonal membranes plays a major role in neural circuit function, but because most axons are too thin for conventional electrical recording, their properties remain largely unexplored. To overcome this obstacle, we used a genetically encoded hybrid voltage sensor (hVOS) harboring an axonal targeting motif. Expressing this probe in transgenic mice enabled us to monitor voltage changes optically in two populations of axons in hippocampal slices, the large axons of dentate granule cells (mossy fibers) in the stratum lucidum of the CA3 region and the much finer axons of hilar mossy cells in the inner molecular layer of the dentate gyrus. Action potentials propagated with distinct velocities in each type of axon. Repetitive firing broadened action potentials in both populations, but at an intermediate frequency the degree of broadening differed. Repetitive firing also attenuated action potential amplitudes in both mossy cell and granule cell axons. These results indicate that the features of use-dependent action potential broadening, and possible failure, observed previously in large nerve terminals also appear in much finer unmyelinated axons. Subtle differences in the frequency dependences could influence the propagation of activity through different pathways to excite different populations of neurons. The axonally targeted hVOS probe used here opens up the diverse repertoire of neuronal processes to detailed biophysical study.

  1. Differential effects of myostatin deficiency on motor and sensory axons.

    Science.gov (United States)

    Jones, Maria R; Villalón, Eric; Northcutt, Adam J; Calcutt, Nigel A; Garcia, Michael L

    2017-12-01

    Deletion of myostatin in mice (MSTN -/- ) alters structural properties of peripheral axons. However, properties like axon diameter and myelin thickness were analyzed in mixed nerves, so it is unclear whether loss of myostatin affects motor, sensory, or both types of axons. Using the MSTN -/- mouse model, we analyzed the effects of increasing the number of muscle fibers on axon diameter, myelin thickness, and internode length in motor and sensory axons. Axon diameter and myelin thickness were increased in motor axons of MSTN -/- mice without affecting internode length or axon number. The number of sensory axons was increased without affecting their structural properties. These results suggest that motor and sensory axons establish structural properties by independent mechanisms. Moreover, in motor axons, instructive cues from the neuromuscular junction may play a role in co-regulating axon diameter and myelin thickness, whereas internode length is established independently. Muscle Nerve 56: E100-E107, 2017. © 2017 Wiley Periodicals, Inc.

  2. Ascending Midbrain Dopaminergic Axons Require Descending GAD65 Axon Fascicles for Normal Pathfinding

    Directory of Open Access Journals (Sweden)

    Claudia Marcela Garcia-Peña

    2014-06-01

    Full Text Available The Nigrostriatal pathway (NSP is formed by dopaminergic axons that project from the ventral midbrain to the dorsolateral striatum as part of the medial forebrain bundle. Previous studies have implicated chemotropic proteins in the formation of the NSP during development but little is known of the role of substrate-anchored signals in this process. We observed in mouse and rat embryos that midbrain dopaminergic axons ascend in close apposition to descending GAD65-positive axon bundles throughout their trajectory to the striatum. To test whether such interaction is important for dopaminergic axon pathfinding, we analyzed transgenic mouse embryos in which the GAD65 axon bundle was reduced by the conditional expression of the diphtheria toxin. In these embryos we observed dopaminergic misprojection into the hypothalamic region and abnormal projection in the striatum. In addition, analysis of Robo1/2 and Slit1/2 knockout embryos revealed that the previously described dopaminergic misprojection in these embryos is accompanied by severe alterations in the GAD65 axon scaffold. Additional studies with cultured dopaminergic neurons and whole embryos suggest that NCAM and Robo proteins are involved in the interaction of GAD65 and dopaminergic axons. These results indicate that the fasciculation between descending GAD65 axon bundles and ascending dopaminergic axons is required for the stereotypical NSP formation during brain development and that known guidance cues may determine this projection indirectly by instructing the pathfinding of the axons that are part of the GAD65 axon scaffold.

  3. Axon-Axon Interactions Regulate Topographic Optic Tract Sorting via CYFIP2-Dependent WAVE Complex Function.

    Science.gov (United States)

    Cioni, Jean-Michel; Wong, Hovy Ho-Wai; Bressan, Dario; Kodama, Lay; Harris, William A; Holt, Christine E

    2018-03-07

    The axons of retinal ganglion cells (RGCs) are topographically sorted before they arrive at the optic tectum. This pre-target sorting, typical of axon tracts throughout the brain, is poorly understood. Here, we show that cytoplasmic FMR1-interacting proteins (CYFIPs) fulfill non-redundant functions in RGCs, with CYFIP1 mediating axon growth and CYFIP2 specifically involved in axon sorting. We find that CYFIP2 mediates homotypic and heterotypic contact-triggered fasciculation and repulsion responses between dorsal and ventral axons. CYFIP2 associates with transporting ribonucleoprotein particles in axons and regulates translation. Axon-axon contact stimulates CYFIP2 to move into growth cones where it joins the actin nucleating WAVE regulatory complex (WRC) in the periphery and regulates actin remodeling and filopodial dynamics. CYFIP2's function in axon sorting is mediated by its binding to the WRC but not its translational regulation. Together, these findings uncover CYFIP2 as a key regulatory link between axon-axon interactions, filopodial dynamics, and optic tract sorting. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Las nuevas formas de racismo

    OpenAIRE

    Gutiérrez López-Dóriga, Cristina

    2012-01-01

    El racismo tal y como lo conocíamos ha disminuido considerablemente ya que ha debido adaptarse a las nuevas exigencias sociales. Esta adaptación ha creado una nueva forma de expresión de este fenómeno, más larvada pero igual de dañina que las anteriores formas manifiestas. Y aunque las bases que sustentan esta nueva forma de racismo dependen de la historia cultural del lugar, siendo así diferentes en Europa y Estados Unidos, ambas aluden a los mismos procesos que crean y mantienen la desigual...

  5. Pro Forma Registration of Companies

    DEFF Research Database (Denmark)

    Werlauff, Erik

    2010-01-01

    The article analyses the view taken by Community law on companies' pro forma registration in another EU or EEA country. Community law recognises pro forma registration under company law, i.e. a brass plate is sufficient, whereas it does not recognise pro forma registration under tax law, i.......e. a brass plate is not sufficient. The article provides reasons for the differential treatment of the two contexts and clarifies the difference on the basis of the Hubbard criterion, in which it was ruled that the effectiveness of Community law cannot vary according to the various branches of national law....

  6. Dynamics of mitochondrial transport in axons

    Directory of Open Access Journals (Sweden)

    Robert Francis Niescier

    2016-05-01

    Full Text Available The polarized structure and long neurites of neurons pose a unique challenge for proper mitochondrial distribution. It is widely accepted that mitochondria move from the cell body to axon ends and vice versa; however, we have found that mitochondria originating from the axon ends moving in the retrograde direction never reach to the cell body, and only a limited number of mitochondria moving in the anterograde direction from the cell body arrive at the axon ends of mouse hippocampal neurons. Furthermore, we have derived a mathematical formula using the Fokker-Planck equation to characterize features of mitochondrial transport, and the equation could determine altered mitochondrial transport in axons overexpressing parkin. Our analysis will provide new insights into the dynamics of mitochondrial transport in axons of normal and unhealthy neurons.

  7. Meninges-derived cues control axon guidance.

    Science.gov (United States)

    Suter, Tracey A C S; DeLoughery, Zachary J; Jaworski, Alexander

    2017-10-01

    The axons of developing neurons travel long distances along stereotyped pathways under the direction of extracellular cues sensed by the axonal growth cone. Guidance cues are either secreted proteins that diffuse freely or bind the extracellular matrix, or membrane-anchored proteins. Different populations of axons express distinct sets of receptors for guidance cues, which results in differential responses to specific ligands. The full repertoire of axon guidance cues and receptors and the identity of the tissues producing these cues remain to be elucidated. The meninges are connective tissue layers enveloping the vertebrate brain and spinal cord that serve to protect the central nervous system (CNS). The meninges also instruct nervous system development by regulating the generation and migration of neural progenitors, but it has not been determined whether they help guide axons to their targets. Here, we investigate a possible role for the meninges in neuronal wiring. Using mouse neural tissue explants, we show that developing spinal cord meninges produce secreted attractive and repulsive cues that can guide multiple types of axons in vitro. We find that motor and sensory neurons, which project axons across the CNS-peripheral nervous system (PNS) boundary, are attracted by meninges. Conversely, axons of both ipsi- and contralaterally projecting dorsal spinal cord interneurons are repelled by meninges. The responses of these axonal populations to the meninges are consistent with their trajectories relative to meninges in vivo, suggesting that meningeal guidance factors contribute to nervous system wiring and control which axons are able to traverse the CNS-PNS boundary. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Daño pulmonar agudo relacionado con la transfusión (Trali y Bartonelosis aguda

    Directory of Open Access Journals (Sweden)

    Douglas López de Guimaraes

    2006-07-01

    Full Text Available Se presenta el caso de un varón de 22 años procedente de la periferia de la ciudad de Huaraz, Perú, que acude al Hospital "Victor Ramos Guardia" de Huaraz con un tiempo de enfermedad de 14 días, febril, pálido e ictérico, en el frotis de sangre periférica se encuentran formas bacilares de Bartonella bacilliformis en 99% de la lámina; se inicia tratamiento antibiótico con ceftriaxona y ciprofloxacino. Al día siguiente se le indica transfusión de dos paquetes globulares (puesto que tenía 6,2 g/dL de Hb, dos horas después presenta dolor toráxico, tos seca exigente, vómitos, dificultad respiratoria y cianosis, en la auscultación se encuentran roncantes y crepitantes, la radiografía de tórax muestra infiltrado alveolar difuso a predominio derecho. Es trasladado a la UCI donde recibe oxígeno con máscara de reservorio, dopamina, corticoides y se inicia el monitoreo hemodinámico; responde en forma satisfactoria, sale de alta con frotis negativo a Bartonella bacilliformis. Es el primer caso de daño pulmonar agudo relacionado con la transfusión (TRALI asociado con Bartonelosis aguda con cuadro clínico - radiológico y evolución compatible, es importante distinguir entre la complicación pulmonar debido a la sepsis grave por Bartonelosis aguda, que puede producir un cuadro clínico similar y el TRALI.

  9. Miopia aguda induzida por topiramato: relato de dois casos

    Directory of Open Access Journals (Sweden)

    Kathy Dadam Sgrott

    2011-06-01

    Full Text Available RESUMO A miopia aguda pode ser desencadeada pelo uso de medicações sistêmicas, dentre elas, o anticonvulsivante topiramato. Este trabalho descreve dois casos de pacientes jovens com quadro agudo bilateral de miopia induzida por terapia com topiramato para controle de síndrome depressiva, fazendo relação com casos semelhantes descritos na literatura e revisão bibliográfica pertinente.

  10. Serie de 8 casos de parotiditis supurada aguda neonatal

    Directory of Open Access Journals (Sweden)

    Manuel Díaz Álvarez

    Full Text Available La parotiditis supurada aguda es una infección poco frecuente en la práctica del pediatra y neonatólogo. El objetivo es mostrar nuestra experiencia en la atención de serie de casos con parotiditis supurada aguda en el período neonatal, y describir sus características de presentación. Se presentan los hallazgos clínicos en 8 pacientes con parotiditis supurativa neonatal, quienes estuvieron ingresados en el Servicio de Neonatología del Hospital Pediátrico Universitario "Juan Manuel Márquez", durante el período de 22 años (desde el año 1992 hasta el año 2013, y se contrasta con los reportes publicados en la literatura internacional. Las características de presentación de la parotiditis aguda supurada de nuestros casos concuerdan con la literatura revisada en muchos aspectos, y se demuestra que es, además, una infección poco frecuente en el período neonatal. Es la primera publicación sobre esta entidad en neonatos en Cuba, y la mayor serie de casos en el ámbito latinoamericano.

  11. Dynamics of target recognition by interstitial axon branching along developing cortical axons.

    Science.gov (United States)

    Bastmeyer, M; O'Leary, D D

    1996-02-15

    Corticospinal axons innervate their midbrain, hindbrain, and spinal targets by extending collateral branches interstitially along their length. To establish that the axon shaft rather than the axonal growth cone is responsible for target recognition in this system, and to characterize the dynamics of interstitial branch formation, we have studied this process in an in vivo-like setting using slice cultures from neonatal mice containing the entire pathway of corticospinal axons. Corticospinal axons labeled with the dye 1,1'-dioctodecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (or Dil) were imaged using time-lapse video microscopy of their pathway overlying the basilar pons, their major hindbrain target. The axon shaft millimeters behind the growth cone exhibits several dynamic behaviors, including the de novo formation of varicosities and filopodia-like extensions, and a behavior that we term "pulsation," which is characterized by a variable thickening and thining of short segments of the axon. An individual axon can have multiple sites of branching activity, with many of the branches being transient. These dynamic behaviors occur along the portion of the axon shaft overlying the basilar pons, but not just caudal to it. Once the collaterals extend into the pontine neuropil, they branch further in the neuropil, while the parent axon becomes quiescent. Thus, the branching activity is spatially restricted to specific portions of the axon, as well as temporally restricted to a relatively brief time window. These findings provide definitive evidence that collateral branches form de novo along corticospinal axons and establish that the process of target recognition in this system is a property of the axon shaft rather than the leading growth cone.

  12. OTITIS MEDIA AGUDA. DIAGNÓSTICO Y MANEJO PRÁCTICO

    Directory of Open Access Journals (Sweden)

    Dr. Francisco J. Krause

    2016-11-01

    Full Text Available La otitis media aguda es una patología infecciosa del oído medio muy frecuente. El diagnóstico es clínico, por lo que es fundamental un acucioso examen físico y una neumootoscopía para evaluar la movilidad timpánica. Hay dos tendencias respecto al manejo, tratamiento antibiótico inmediato u observación estricta (dependiendo de las características del paciente y del cuadro clínico. Los gérmenes más frecuentes son los virus, Neumococo, Haemophilus influenza y Moraxella catarrhalis. La prevalencia de cada uno de ellos varía según región geográfica y según la presencia de vacunación. La resistencia a antibióticos ha ido en aumento en estos años, pero aún puede considerarse sensible a amoxicilina por lo que se recomienda su uso como primera línea. En el caso de fracaso a tratamiento pueden utilizarse asociaciones con B-lactámicos y/o cefalosporinas, dejando en forma excepcional clindamicina o quinolonas. Aquellos niños con OMA recurrente requerirán evaluación por especialidad para mayor estudio y tratamiento.

  13. Leucemias agudas en ancianos de la provincia de Santiago de Cuba

    Directory of Open Access Journals (Sweden)

    Lidia Clara Suárez Beyríes

    2015-04-01

    Full Text Available Se realizó un estudio descriptivo y retrospectivo de 64 pacientes mayores de 60 años con leucemia aguda, atendidos en el Servicio de Hematología del Hospital General Docente "Dr. Juan Bruno Zayas Alfonso" de Santiago de Cuba, durante el quinquenio 2006-2011, para determinar las principales características clínicas y hematológicas en el momento del diagnóstico, así como la supervivencia global de los afectados, aunque los tratamientos administrados no tenían criterio curativo. La edad promedio de los ancianos fue de 70 años, en un rango etario de 60 a 90; en tanto, la variedad no linfoblástica representó 98,4 %, y todos los pacientes presentaron anemia y trombocitopenia como alteraciones hematológicas, con incremento en los requerimientos transfusionales. De igual forma, la presencia de blastos en la sangre periférica se demostró en 50 % y la hiperleucocitosis en 59,4 %, mientras las principales causas de muerte estuvieron relacionadas con la hemorragia cerebral y la progresión de la enfermedad con la infiltración multiorgánica, lo cual condujo a una supervivencia muy corta de los integrantes de la serie

  14. Cargo distributions differentiate pathological axonal transport impairments.

    Science.gov (United States)

    Mitchell, Cassie S; Lee, Robert H

    2012-05-07

    Axonal transport is an essential process in neurons, analogous to shipping goods, by which energetic and cellular building supplies are carried downstream (anterogradely) and wastes are carried upstream (retrogradely) by molecular motors, which act as cargo porters. Impairments in axonal transport have been linked to devastating and often lethal neurodegenerative diseases, such as Amyotrophic Lateral Sclerosis, Huntington's, and Alzheimer's. Axonal transport impairment types include a decrease in available motors for cargo transport (motor depletion), the presence of defective or non-functional motors (motor dilution), and the presence of increased or larger cargos (protein aggregation). An impediment to potential treatment identification has been the inability to determine what type(s) of axonal transport impairment candidates that could be present in a given disease. In this study, we utilize a computational model and common axonal transport experimental metrics to reveal the axonal transport impairment general characteristics or "signatures" that result from three general defect types of motor depletion, motor dilution, and protein aggregation. Our results not only provide a means to discern these general impairments types, they also reveal key dynamic and emergent features of axonal transport, which potentially underlie multiple impairment types. The identified characteristics, as well as the analytical method, can be used to help elucidate the axonal transport impairments observed in experimental and clinical data. For example, using the model-predicted defect signatures, we identify the defect candidates, which are most likely to be responsible for the axonal transport impairments in the G93A SOD1 mouse model of ALS. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Axonal inclusions in the crab Hemigrapsus nudus.

    Science.gov (United States)

    Smith, R S

    1978-10-01

    Light microscopic examination of living giant axons from the walking legs of Hemigrapsus nudus revealed intra-axonal inclusions which were usually several tens of micrometers long and about 5 micron wide. The inclusions were filled with small light-scattering particles. The inclusions were shown, by thin section electron microscopy, to be composed largely 68% by volume) of mitochondria. Each inclusion was surrounded by membrane bounded spaces which are presumed to represent a part of the smooth endoplasmic reticulum. Similar inclusions were not found in the leg axons of a variety of other decapod crustaceans.

  16. Intoxicación aguda por cocaína en un lactante no asociada a lactancia materna: A propósito de un caso clínico

    OpenAIRE

    Decia1, Mónica; Pan, Melina; Telechea, Héctor; Laborde, Amalia; Menchaca, Amanda

    2015-01-01

    La intoxicación aguda por cocaína es infrecuente en lactantes y niños. Las formas más frecuentes de presentación clínica son las convulsiones tónico-clónicas en apirexia, alteraciones motoras y la excitación psicomotriz. Se presenta el caso de un lactante de 1 mes que ingresó a la Unidad de Cuidados Intensivos de Niños del Centro Hospitalario Pereira Rossell por una intoxicación aguda por cocaína. El cuadro clínico consistió en manifestaciones secundarias a un estado hiperadrenérgico generali...

  17. Drug therapy for chronic idiopathic axonal polyneuropathy

    NARCIS (Netherlands)

    Vrancken, A. F. J. E.; van Schaik, I. N.; Hughes, R. A. C.; Notermans, N. C.

    2004-01-01

    BACKGROUND: Chronic idiopathic axonal polyneuropathy is an insidiously progressive sensory or sensorimotor polyneuropathy that affects elderly people. Although severe disability or handicap does not occur, it reduces quality of life. OBJECTIVES: To assess whether drug therapy for chronic idiopathic

  18. Modeling of axonal endoplasmic reticulum network by spastic paraplegia proteins.

    Science.gov (United States)

    Yalçın, Belgin; Zhao, Lu; Stofanko, Martin; O'Sullivan, Niamh C; Kang, Zi Han; Roost, Annika; Thomas, Matthew R; Zaessinger, Sophie; Blard, Olivier; Patto, Alex L; Sohail, Anood; Baena, Valentina; Terasaki, Mark; O'Kane, Cahir J

    2017-07-25

    Axons contain a smooth tubular endoplasmic reticulum (ER) network that is thought to be continuous with ER throughout the neuron; the mechanisms that form this axonal network are unknown. Mutations affecting reticulon or REEP proteins, with intramembrane hairpin domains that model ER membranes, cause an axon degenerative disease, hereditary spastic paraplegia (HSP). We show that Drosophila axons have a dynamic axonal ER network, which these proteins help to model. Loss of HSP hairpin proteins causes ER sheet expansion, partial loss of ER from distal motor axons, and occasional discontinuities in axonal ER. Ultrastructural analysis reveals an extensive ER network in axons, which shows larger and fewer tubules in larvae that lack reticulon and REEP proteins, consistent with loss of membrane curvature. Therefore HSP hairpin-containing proteins are required for shaping and continuity of axonal ER, thus suggesting roles for ER modeling in axon maintenance and function.

  19. Pancreatitis Aguda en Pediatría

    Directory of Open Access Journals (Sweden)

    Jaime Forero Gómez

    1992-03-01

    Full Text Available

    Pancreatitis es el término utilizado para describir una inflamación del páncreas, cuya evolución clínica puede variar de síntomas crónicos leves durante años a deterioro rápido, progresivo y mortal en un lapso de pocas horas a días.(l

    A diferencia de lo informado en la población adulta, la frecuencia de este padecimiento en edades Pediátricas no se conoce con precisión. Excluyendo a la pancreatitis causada por traumatismo abdominal, se presenta con una frecuencia cinco veces mayor en mujeres.(2

    Por la localización del páncreas en la cavidad abdominal, es difícil efectuar una valoración clínica adecuada. Cuando el órgano se inflama, el proceso se manifiesta de diferentes maneras; en múltiples ocasiones en forma totalmente atípica, lo que origina que con frecuencia se diagnostique sólo en estudios post-mortem (2,3.

    Frey y Redo confirman el diagnóstico por autopsia en 77% de sus casos. En lo concerniente a pancreatitis secundaria por medicamentos, Buntay y colaboradores (2 consideran la posibilidad de que no se diagnostique en vida en e133% de los casos; estos mismos autores, cuando se trata de pancreatitis por traumatismo abdominal, afirman que no se diagnostica en 25% de los casos. Consideramos conveniente, tomando en cuenta los factores anteriores, realizar una revisión del tema con el propósito de actualizar conocimientos y llamar la atención del Médico en general acerca de la importancia de este diagnóstico en los casos de dolor abdominal y de etiología desconocida, pues el diagnóstico oportuno ofrece un pronóstico con menor riesgo de complicaciones y muerte...

  20. Con-nectin axons and dendrites.

    Science.gov (United States)

    Beaudoin, Gerard M J

    2006-07-03

    Unlike adherens junctions, synapses are asymmetric connections, usually between axons and dendrites, that rely on various cell adhesion molecules for structural stability and function. Two cell types of adhesion molecules found at adherens junctions, cadherins and nectins, are thought to mediate homophilic interaction between neighboring cells. In this issue, Togashi et al. (see p. 141) demonstrate that the differential localization of two heterophilic interacting nectins mediates the selective attraction of axons and dendrites in cooperation with cadherins.

  1. Ataxia cerebelar aguda na criança

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    Valeriana Moura Ribeiro

    1968-03-01

    Full Text Available São relatados os casos de 6 crianças com ataxia cerebelar aguda. Admitem os autores a presença de um fator etiológico de caráter viral comum a todos êles, discutindo os mecanismos patogênicos com base nos casos da literatura. A evolução foi favorável em todos os pacientes, com regressão completa da sintomatologia, dentro do período de 6 a 60 dias.

  2. Insuficiencia renal aguda inducida por mordedura de serpiente Bothrops

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    Gustavo A. Aroca Martínez

    2014-01-01

    Full Text Available Mujer de 58 años de edad, remitida a urgencias por presentar cuadro clínico de insuficiencia renal aguda (IRA secundaria a mordedura de serpiente (Bothrops Atrox. Ingresa hipotensa con elevación de azoados e hiperkalemia, ecografía renal dentro de parámetros normales. Se maneja terapia dialítica con lo cual presenta mejoría clínica. En este reporte se detallan aspectos del diagnóstico, manejo clínico y posibles mecanismos fisiopatológicos que explican el daño renal.

  3. EFA6 regulates selective polarised transport and axon regeneration from the axon initial segment

    Czech Academy of Sciences Publication Activity Database

    Eva, R.; Koseki, H.; Kanamarlapudi, V.; Fawcett, James

    2017-01-01

    Roč. 130, č. 21 (2017), s. 3663-3675 ISSN 0021-9533 Institutional support: RVO:68378041 Keywords : axon regeneration * axon transport * neuronal polarisation Subject RIV: FH - Neurology OBOR OECD: Neuroscience s (including psychophysiology Impact factor: 4.431, year: 2016

  4. Axon initial segment Kv1 channels control axonal action potential waveform and synaptic efficacy

    NARCIS (Netherlands)

    Kole, Maarten H. P.; Letzkus, Johannes J.; Stuart, Greg J.

    2007-01-01

    Action potentials are binary signals that transmit information via their rate and temporal pattern. In this context, the axon is thought of as a transmission line, devoid of a role in neuronal computation. Here, we show a highly localized role of axonal Kv1 potassium channels in shaping the action

  5. O papel da avaliação inicial simplificada no prognóstico da pancreatite aguda

    Directory of Open Access Journals (Sweden)

    Márcio Cavalcante Carneiro

    Full Text Available OBJETIVO: Correlacionar a avaliação clínico-laboratorial inicial simplificada com a gravidade da pancreatite aguda e a presença de necrose. MÉTODO: Foi realizado um estudo retrospectivo dos pacientes com diagnóstico final de PA internados no Hospital Universitário Clementino Fraga Filho - UFRJ entre janeiro de 1990 e agosto de 2002. Foi considerado apenas o primeiro episódio de cada paciente. Os dados obtidos foram submetidos a análise estatística. Foram estudados 164 pacientes onde a idade média foi de 43,7 anos. RESULTADOS: A etiologia biliar foi a mais freqüente com 43,9% dos casos. A incidência de necrose foi de 21,3% e a mortalidade global de 23,2%. Observamos que a ausência de taquicardia na admissão estava associada à forma branda da doença, e que os níveis plasmáticos de uréia e creatinina elevados na admissão estão associados à forma grave da doença, e a hiperglicemia (121mg/dl à necrose pancreática. CONCLUSÕES: A avaliação inicial simplificada ainda tem espaço, embora que limitado, no acompanhamento do paciente com PA.

  6. Increased mitochondrial content in remyelinated axons: implications for multiple sclerosis

    Science.gov (United States)

    Zambonin, Jessica L.; Zhao, Chao; Ohno, Nobuhiko; Campbell, Graham R.; Engeham, Sarah; Ziabreva, Iryna; Schwarz, Nadine; Lee, Sok Ee; Frischer, Josa M.; Turnbull, Doug M.; Trapp, Bruce D.; Lassmann, Hans; Franklin, Robin J. M.

    2011-01-01

    Mitochondrial content within axons increases following demyelination in the central nervous system, presumably as a response to the changes in energy needs of axons imposed by redistribution of sodium channels. Myelin sheaths can be restored in demyelinated axons and remyelination in some multiple sclerosis lesions is extensive, while in others it is incomplete or absent. The effects of remyelination on axonal mitochondrial content in multiple sclerosis, particularly whether remyelination completely reverses the mitochondrial changes that follow demyelination, are currently unknown. In this study, we analysed axonal mitochondria within demyelinated, remyelinated and myelinated axons in post-mortem tissue from patients with multiple sclerosis and controls, as well as in experimental models of demyelination and remyelination, in vivo and in vitro. Immunofluorescent labelling of mitochondria (porin, a voltage-dependent anion channel expressed on all mitochondria) and axons (neurofilament), and ultrastructural imaging showed that in both multiple sclerosis and experimental demyelination, mitochondrial content within remyelinated axons was significantly less than in acutely and chronically demyelinated axons but more numerous than in myelinated axons. The greater mitochondrial content within remyelinated, compared with myelinated, axons was due to an increase in density of porin elements whereas increase in size accounted for the change observed in demyelinated axons. The increase in mitochondrial content in remyelinated axons was associated with an increase in mitochondrial respiratory chain complex IV activity. In vitro studies showed a significant increase in the number of stationary mitochondria in remyelinated compared with myelinated and demyelinated axons. The number of mobile mitochondria in remyelinated axons did not significantly differ from myelinated axons, although significantly greater than in demyelinated axons. Our neuropathological data and findings in

  7. Epigenetic regulation of axon and dendrite growth

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    Ephraim F Trakhtenberg

    2012-03-01

    Full Text Available Neuroregenerative therapies for central nervous system (CNS injury, neurodegenerative disease, or stroke require axons of damaged neurons to grow and reinnervate their targets. However, mature mammalian CNS neurons do not regenerate their axons, limiting recovery in these diseases (Yiu and He, 2006. CNS’ regenerative failure may be attributable to the development of an inhibitory CNS environment by glial-associated inhibitory molecules (Yiu and He, 2006, and by various cell-autonomous factors (Sun and He, 2010. Intrinsic axon growth ability also declines developmentally (Li et al., 1995; Goldberg et al., 2002; Bouslama-Oueghlani et al., 2003; Blackmore and Letourneau, 2006 and is dependent on transcription (Moore et al., 2009. Although neurons’ intrinsic capacity for axon growth may depend in part on the panoply of expressed transcription factors (Moore and Goldberg, 2011, epigenetic factors such as the accessibility of DNA and organization of chromatin are required for downstream genes to be transcribed. Thus a potential approach to overcoming regenerative failure focuses on the epigenetic mechanisms regulating regenerative gene expression in the CNS. Here we review molecular mechanisms regulating the epigenetic state of DNA through chromatin modifications, their implications for regulating axon and dendrite growth, and important new directions for this field of study.

  8. Guidance of retinal axons in mammals.

    Science.gov (United States)

    Herrera, Eloísa; Erskine, Lynda; Morenilla-Palao, Cruz

    2017-11-26

    In order to navigate through the surrounding environment many mammals, including humans, primarily rely on vision. The eye, composed of the choroid, sclera, retinal pigmented epithelium, cornea, lens, iris and retina, is the structure that receives the light and converts it into electrical impulses. The retina contains six major types of neurons involving in receiving and modifying visual information and passing it onto higher visual processing centres in the brain. Visual information is relayed to the brain via the axons of retinal ganglion cells (RGCs), a projection known as the optic pathway. The proper formation of this pathway during development is essential for normal vision in the adult individual. Along this pathway there are several points where visual axons face 'choices' in their direction of growth. Understanding how these choices are made has advanced significantly our knowledge of axon guidance mechanisms. Thus, the development of the visual pathway has served as an extremely useful model to reveal general principles of axon pathfinding throughout the nervous system. However, due to its particularities, some cellular and molecular mechanisms are specific for the visual circuit. Here we review both general and specific mechanisms involved in the guidance of mammalian RGC axons when they are traveling from the retina to the brain to establish precise and stereotyped connections that will sustain vision. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Forma urbana tradicional e modernista:

    Directory of Open Access Journals (Sweden)

    Dr. Arq. Antônio Tarcìsio da Luz Reis

    2014-12-01

    Full Text Available O objetivo deste artigo é refletir sobre algumas das implicações da forma urbana tradicional e da forma urbana modernista, para o uso e estética dos espaços ur banos, tais como a existência de conexões visuais e funcionais entre as edifca- ções e os espaços abertos públicos e o uso dado aos pavimentos térreos. Na "for ma urbana tradicional" as edifcações possuem portas frontais e janelas voltadas para as ruas públicas, enquanto na "forma urbana modernista" as edifcações ten dem a ter portas e janelas distantes das vias públicas e/ou voltadas para espaços abertos internos ao quarteirão, sem distinção entre portas e janelas frontais e pos teriores. Assim, exemplos de cidades em diferentes países são utilizados para as comparações e reflexões envolvendo estes aspectos. As principais consequências destas análises reforçam a necessidade de um melhor entendimento em relação às implicações da forma urbana para o uso e a estética dos espaços urbanos. Adi cionalmente, destaca–se a importância da existência de conexões visuais e fun cionais entre os térreos das edifcações e os espaços abertos públicos para a vi talidade, segurança e aparência dos espaços urbanos.

  10. Sumário de atualização da II Diretriz Brasileira de Insuficiência Cardíaca Aguda 2009/2011

    Directory of Open Access Journals (Sweden)

    Marcelo Westerlund Montera

    2012-05-01

    Full Text Available Nos últimos dois anos, observamos diversas modificações na abordagem diagnóstica e terapêutica dos pacientes com Insuficiência Cardíaca aguda (IC aguda, o que nos motivou quanto à necessidade da realização de um sumário de atualização da II Diretriz Brasileira de Insuficiência Cardíaca Aguda de 2009. Na avaliação diagnóstica, o fluxograma diagnóstico foi simplificado e foi fortalecido o papel da avaliação clínica e ecocardiograma. Na avaliação clínico-hemodinâmica admissional, o ecocardiograma hemodinâmico ganhou destaque no auxilio da definição dessa condição no paciente com IC aguda na sala de emergência. Na avaliação prognóstica, os biomarcadores tiveram seu papel mais bem estabelecido, e a síndrome cardiorrenal teve seus critérios e valor prognóstico mais bem definidos. Os fluxogramas de abordagem terapêutica foram revistos, tornando-se mais simples e objetivos. Dentre os avanços na terapêutica medicamentosa destacam-se a segurança e a importância da manutenção ou introdução dos betabloqueadores na terapêutica admissional. A anticoagulação, de acordo com as novas evidências, ganha um espectro maior de indicações. O edema agudo de pulmão tem bem estabelecido os seus modelos hemodinâmicos de apresentação com suas distintas formas de abordagens terapêuticas, com novos níveis de indicação e evidência. No tratamento cirúrgico da IC aguda, a revascularização miocárdica, a abordagem das lesões mecânicas e o transplante cardíaco foram revistos e atualizados. Este sumário de atualização fortalece a II Diretriz Brasileira de Insuficiência Cardíaca Aguda por mantê-la atualizada e rejuvenescida. Todos os clínicos cardiologistas que lidam com pacientes com IC aguda encontrarão na diretriz e em seu sumário de atualização importantes instrumentos no auxílio da prática clínica para o melhor diagnóstico e tratamento de seus pacientes.

  11. Carambola como causa de lesão renal aguda

    Directory of Open Access Journals (Sweden)

    Karilla Lany Scaranello

    2014-04-01

    Full Text Available A carambola pertence à família das Oxalidáceas, espécie Averrhoa carambola. É rica em sais minerais, vitaminas A, C, complexo B e ácido oxálico. Estudos recentes demonstram que a toxicidade da fruta difere entre os indivíduos e pode ser explicada pelas respostas biológicas individuais como idade, quantidade da ingestão, neurotoxinas em cada tipo de fruta. Adicionalmente, a nefrotoxicidade causada pela fruta é dose dependente, podendo levar ao desenvolvimento de lesão renal aguda pela deposição de cristais de oxalato de cálcio intratubular, assim como por lesão direta das células epiteliais tubulares, levando à apoptose das mesmas. Relatamos o caso de uma paciente que, após a ingestão do suco da fruta e fruta in natura, desenvolveu lesão renal aguda, necessitando de terapia dialítica, evoluindo com desfecho favorável e recuperação da função renal.

  12. Escala de Alvarado como herramienta diagnóstica para apendicitis aguda

    Directory of Open Access Journals (Sweden)

    Iván Pimienta Concepción

    2017-06-01

    Full Text Available Introducción: La apendicitis aguda es la enfermedad intrabdominal más frecuente tratada de urgencia. Resulta de interés la utilización de la Escala de Alvarado en el diagnóstico de esta patología por su contribución a la disminución de apendicectomías negativas. Objetivo: Determinar la validez de la Escala de Alvarado como herramienta diagnóstica para apendicitis aguda en pacientes atendidos en el Servicio de Cirugía General del Hospital IESS Ambato. Métodos: Se realizó una investigación observacional, descriptiva y transversal en pacientes hospitalizados con cuadro de dolor abdominal y sospecha de apendicitis aguda, valorados en el Servicio de Cirugía General en el Hospital General IESS Ambato en el período junio 2015 a noviembre del año 2015. Resultados: De acuerdo al resultado histopatológico predominó la apendicitis aguda supurada con (n=83, 54.9%; seguida de apendicitis aguda gangrenosa (n=35, 23.2%; apendicitis aguda precoz (n=15, 9.9%; mientras que el resultado normal y apendicitis aguda gangrenosa perforada se encontraron con los mismos valores (n=9, 5.9%. Conclusiones: Existió un puntaje elevado de la Escala de Alvarado para el diagnóstico de apendicitis aguda según la severidad de los hallazgos descritos en el resultado histopatológico posterior a la apendicectomía. El resultado histopatológico de mayor frecuencia fue la apendicitis aguda supurada, con un riesgo medio en la Escala de Alvarado, la cual es más sensible en periodos de gravedad.

  13. Creatine pretreatment protects cortical axons from energy depletion in vitro

    Science.gov (United States)

    Shen, Hua; Goldberg, Mark P.

    2012-01-01

    Creatine is a natural nitrogenous guanidino compound involved in bioenergy metabolism. Although creatine has been shown to protect neurons of the central nervous system (CNS) from experimental hypoxia/ischemia, it remains unclear if creatine may also protect CNS axons, and if the potential axonal protection depends on glial cells. To evaluate the direct impact of creatine on CNS axons, cortical axons were cultured in a separate compartment from their somas and proximal neurites using a modified two-compartment culture device. Axons in the axon compartment were subjected to acute energy depletion, an in vitro model of white matter ischemia, by exposure to 6 mM sodium azide for 30 min in the absence of glucose and pyruvate. Energy depletion reduced axonal ATP by 65%, depolarized axonal resting potential, and damaged 75% of axons. Application of creatine (10 mM) to both compartments of the culture at 24 h prior to energy depletion significantly reduced axonal damage by 50%. In line with the role of creatine in the bioenergy metabolism, this application also alleviated the axonal ATP loss and depolarization. Inhibition of axonal depolarization by blocking sodium influx with tetrodotoxin also effectively reduced the axonal damage caused by energy depletion. Further study revealed that the creatine effect was independent of glial cells, as axonal protection was sustained even when creatine was applied only to the axon compartment (free from somas and glial cells) for as little as 2 h. In contrast, application of creatine after energy depletion did not protect axons. The data provide the first evidence that creatine pretreatment may directly protect CNS axons from energy deficiency. PMID:22521466

  14. Efectividad de la acupuntura en la crisis aguda de asma bronquial

    Directory of Open Access Journals (Sweden)

    María Teresa Paz Rodríguez

    2014-10-01

    Full Text Available Introducción: el asma bronquial es una enfermedad respiratoria con significativa prevalencia y una de las principales causas de ingreso hospitalario y la acupuntura una forma terapéutica de la Medicina Tradicional y Natural con múltiples indicaciones, dentro de ellas esta afección. Objetivo: determinar la evolución de los pacientes asmáticos persistentes moderados de ambos sexos antes y después del tratamiento con acupuntura en el servicio de urgencia en el Hospital General Docente Abel Santamaría Cuadrado de Pinar del Río. Material y método: se realizó un estudio de intervención, prospectivo, longitudinal, utilizando la acupuntura como modalidad terapéutica de la Medicina Tradicional China en pacientes que acudieron al cuerpo de guardia de Medicina Interna del Hospital General Docente "Abel Santamaría Cuadrado" de Pinar del Rio, en el período comprendido entre octubre-diciembre del 2013. El universo lo integraron todos los pacientes que acudieron a la consulta con crisis aguda de asma bronquial (223 y la muestra, 83 pacientes clasificados como asmáticos persistentes moderados utilizándose acupuntura en los puntos pulmón 7, vaso concepción 17 y vejiga 13 al grupo de estudio (41 pacientes y 42 con tratamiento convencional. Resultados: al tratar estos pacientes se ha evidenciado que el 78,4% de ellos mejoró por la aplicación de este método milenario. Ninguno presentó complicaciones y sólo 11 pacientes no mejoraron. Conclusiones: los pacientes respondieron de igual forma al tratamiento sin distinción de edad y sexo, demostrando este método ser eficiente, de fácil aplicación con aparición de menos reacciones adversas y además, económico.

  15. [Severe, subacute axonal polyneuropathy due to hypophosphatemia].

    NARCIS (Netherlands)

    Eijk, J.J.J. van; Abdo, W.F.; Deurwaarder, E. den; Zwarts, M.J.; Warrenburg, B.P.C. van de

    2010-01-01

    A 46-year-old man receiving tube feeding because of anorexia and weight loss developed progressive neurological symptoms initially resembling Guillain-Barre syndrome. Eventually axonal neuropathy due to severe hypophosphatemia was diagnosed. Hypophosphatemia can be caused by the so-called refeeding

  16. Macrophages Promote Axon Regeneration with Concurrent Neurotoxicity

    NARCIS (Netherlands)

    Gensel, J.C.; Nakamura, S.; Guan, Z.; Rooijen, van N.; Ankeny, D.P.; Popovich, P.G.

    2009-01-01

    Activated macrophages can promote regeneration of CNS axons. However, macrophages also release factors that kill neurons. These opposing functions are likely induced simultaneously but are rarely considered together in the same experimental preparation. A goal of this study was to unequivocally

  17. Drug therapy for chronic idiopathic axonal polyneuropathy

    NARCIS (Netherlands)

    Warendorf, Janna; Vrancken, Alexander F.J.E.; van Schaik, Ivo N.; Hughes, Richard A.C.; Notermans, Nicolette C.

    2017-01-01

    Background: Chronic idiopathic axonal polyneuropathy (CIAP) is an insidiously progressive sensory or sensorimotor polyneuropathy that affects elderly people. Although severe disability or handicap does not occur, CIAP reduces quality of life. CIAP is diagnosed in 10% to 25% of people referred for

  18. Drug therapy for chronic idiopathic axonal polyneuropathy

    NARCIS (Netherlands)

    Warendorf, Janna; Vrancken, Alexander F. J. E.; van Schaik, Ivo N.; Hughes, Richard A. C.; Notermans, Nicolette C.

    2017-01-01

    Chronic idiopathic axonal polyneuropathy (CIAP) is an insidiously progressive sensory or sensorimotor polyneuropathy that affects elderly people. Although severe disability or handicap does not occur, CIAP reduces quality of life. CIAP is diagnosed in 10% to 25% of people referred for evaluation of

  19. Nefrite Intersticial Aguda Após Exposição a Losartan

    Directory of Open Access Journals (Sweden)

    Letícia Schwerz Weinert

    2007-07-01

    Full Text Available Nefrite intersticial aguda é uma causa comum de perda aguda de função renal. Exposição a drogas é o fator desencadeante mais freqüentemente relatado, porém auto-imunidade e infecções também estão associadas. Os inibidores da enzima de conversão da angiotensina têm sido relatados como possíveis agentes, porém não há relato na literatura de nefrite intersticial com uso de losartan. Descrevemos então, o caso de perda aguda de função renal após exposição a losartan, em paciente com dano renal prévio por nefropatia diabética, cuja biópsia renal diagnosticou nefrite intersticial aguda.

  20. Calcio sérico total y calcio corregido como predictores de severidad en pancreatitis aguda

    Directory of Open Access Journals (Sweden)

    A.A. Gutiérrez-Jiménez

    2014-01-01

    Conclusiones: El CT y CCA tomados en las primeras 24 h son útiles como predictores de severidad en pancreatitis aguda, con valores de S y predictivos comparables o superiores a los de las escalas pronósticas tradicionales.

  1. Formas estructurales de fuerza constante

    Directory of Open Access Journals (Sweden)

    Zalewski, Waclaw

    1963-05-01

    Full Text Available The author seeks to prove the need to obtain the most essential form in the various types of structures by applying a number of rational principles, of which the constant stress principle is one of the most decisive. The structural form should be a logical consequence of all its functional circumstances, and this requires a clear understanding of the general behaviour of each part of the structure, and also of the main stresses which operate on it, considered as a unitary whole. To complete his theoretical argument, the author gives some examples, in the design of which the criterion of constant stress has been adopted. The author considers the various aspects which are involved in obtaining a structural design that satisfies given functional and aesthetic requirements. In doing so he refers to his personal experience within Poland, and infers technical principles of general validity which should determine the rational design of the form, as an integrated aspect of the structural pattern. The projects which illustrate this paper are Polish designs of undoubted constructive significance, in which the principle of constant stress has been applied. Finally the author condenses his whole theory in a simple and straightforward practical formula, which should be followed if a truly rational form is to be achieved: the constancy of stress in the various structural elements.El autor se esfuerza en mostrar la necesidad de llegar a la forma real en las distintas estructuras siguiendo una serie de principios racionales, entre los que domina el criterio de la fuerza constante. La forma ha de ser una consecuencia lógica en todos sus aspectos, y esto exige un claro conocimiento del comportamiento general de cada una de las partes de la estructura, y de los esfuerzos generales que dominan en la misma al considerarla como un todo. Para completar la exposición de orden teórico, el autor presenta algunos ejemplos en cuyo proyecto se ha seguido el criterio de

  2. Embolectomía en una embolia pulmonar aguda masiva

    Directory of Open Access Journals (Sweden)

    Manuel Carnero Alcázar

    2007-07-01

    Full Text Available Presentamos el caso de un varón de 57 años que, en el seno de un meningioma microcítico, padece una tromboembolia pulmonar masiva aguda con inestabilidad hemodinámica. Dado el riesgo de hemorragia por el tumor craneal, se contraindica la terapia fibrinolítica y se procede a practicar embolectomía pulmonar. Ésta se realiza bajo anestesia general, con canulación convencional y bajo hipotermia moderada. Se extrae émbolo en el tronco de la arteria pulmonar y con catéter de Fogarty se extraen émbolos en ramas lobares y segmentarias. Discutimos la asociación de enfermedad tromboembólica con determinadas neoplasias y el tratamiento de la tromboembolia pulmonar

  3. Epidemia de infección respiratoria aguda observaciones hospitalarias

    OpenAIRE

    Chavarría Milanés, José Fernando; Mata, Leonardo; Mohs Villalta, Edgar; Ramírez, Giselle; Lizano, Lucía

    1985-01-01

    artículo -- Universidad de Costa Rica. Instituto de Investigaciones en Salud, 1985 Se describe la clínica, tratamiento y complicaciones de 81 niños lactantes con infección respiratoria aguda. Los niños provenían del cantón central de San José y fueron admitidos en el Hospital Nacional de Niños del 10 de noviembre al 15 de diciembre de 1983. Se encontró un 57% de varones y un 43% de mujeres; los más afectados fueron los niños menores de 3 meses. Más de la mitad de los niños egresó con el di...

  4. Acidosis láctica severa y leucemia aguda

    Directory of Open Access Journals (Sweden)

    David Loja

    2004-03-01

    Full Text Available Reportamos el caso de una paciente de 27 años de edad con leucemia linfoblástica aguda, quien presentó acidosis láctica severa como complicación metabólica. Ella acudió con desnutrición severa, anemia marcada y síndrome consuntivo. No había compromiso del sistema reticuloendotelial y un mielograma inicial fue normal. Estos factores retardaron el diagnóstico y obligaron a ampliar el diagnóstico diferencial. La sospecha de neoplasia hematológica asociada a acidosis láctica sin causa aparente permitió reevaluar el caso con un nuevo mielograma y establecer el diagnóstico.

  5. Isquemia aguda de miembros inferiores secundaria a ergortismo

    Directory of Open Access Journals (Sweden)

    Franco J. Vallejo, MD

    2011-11-01

    Full Text Available Paciente de género femenino, de 21 años de edad, quien ingresó por dolor progresivo e intenso en miembros inferiores, y refirió antecedente reciente de ingestión de derivados del ergot. Al examen físico se observó ausencia de pulsos en ambos miembros inferiores. Por angiotomografia se documentó disminución severa, generalizada y bilateral, del calibre de los vasos arteriales de miembros inferiores. Se diagnosticó isquemia arterial aguda secundaria a ergotismo y se inició tratamiento con vasodilatadores y calcio-antagonistas, que resolvió los síntomas en su totalidad.

  6. Comunicação e educação nas consultas de crianças com infecções respiratórias agudas

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    Ana Paula Alves de Carvalho

    2011-08-01

    Full Text Available Este estudo objetivou identificar as orientações de cuidado à criança com infecções respiratórias agudas (IRA e descrever o processo de comunicação entre profissionais e mães na consulta. Os dados foram coletados em Unidades Básicas de Saúde, em entrevistas e observação de consultas de enfermeiras e médicos a crianças com IRA. Os resultados mostram orientações variáveis e incompletas entre os profissionais, predominantemente prescritivas e centradas na doença, principalmente no tratamento medicamentoso. A comunicação é centrada no profissional, o que não favorece um processo educativo emancipatório. Conclui-se a necessidade de incluir esses conteúdos na formação inicial e permanente dos profissionais.

  7. Two Modes of the Axonal Interferon Response Limit Alphaherpesvirus Neuroinvasion

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    Ren Song

    2016-02-01

    Full Text Available Infection by alphaherpesviruses, including herpes simplex virus (HSV and pseudorabies virus (PRV, typically begins at epithelial surfaces and continues into the peripheral nervous system (PNS. Inflammatory responses are induced at the infected peripheral site prior to invasion of the PNS. When the peripheral tissue is first infected, only the innervating axons are exposed to this inflammatory milieu, which includes the interferons (IFNs. The fundamental question is how do PNS cell bodies respond to these distant, potentially damaging events experienced by axons. Using compartmented cultures that physically separate neuron axons from cell bodies, we found that pretreating isolated axons with beta interferon (IFN-β or gamma interferon (IFN-γ significantly diminished the number of herpes simplex virus 1 (HSV-1 and PRV particles moving in axons toward the cell bodies in a receptor-dependent manner. Exposing axons to IFN-β induced STAT1 phosphorylation (p-STAT1 only in axons, while exposure of axons to IFN-γ induced p-STAT1 accumulation in distant cell body nuclei. Blocking transcription in cell bodies eliminated antiviral effects induced by IFN-γ, but not those induced by IFN-β. Proteomic analysis of IFN-β- or IFN-γ-treated axons identified several differentially regulated proteins. Therefore, unlike treatment with IFN-γ, IFN-β induces a noncanonical, local antiviral response in axons. The activation of a local IFN response in axons represents a new paradigm for cytokine control of neuroinvasion.

  8. Axon degeneration: make the Schwann cell great again

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    Keit Men Wong

    2017-01-01

    Full Text Available Axonal degeneration is a pivotal feature of many neurodegenerative conditions and substantially accounts for neurological morbidity. A widely used experimental model to study the mechanisms of axonal degeneration is Wallerian degeneration (WD, which occurs after acute axonal injury. In the peripheral nervous system (PNS, WD is characterized by swift dismantling and clearance of injured axons with their myelin sheaths. This is a prerequisite for successful axonal regeneration. In the central nervous system (CNS, WD is much slower, which significantly contributes to failed axonal regeneration. Although it is well-documented that Schwann cells (SCs have a critical role in the regenerative potential of the PNS, to date we have only scarce knowledge as to how SCs 'sense' axonal injury and immediately respond to it. In this regard, it remains unknown as to whether SCs play the role of a passive bystander or an active director during the execution of the highly orchestrated disintegration program of axons. Older reports, together with more recent studies, suggest that SCs mount dynamic injury responses minutes after axonal injury, long before axonal breakdown occurs. The swift SC response to axonal injury could play either a pro-degenerative role, or alternatively a supportive role, to the integrity of distressed axons that have not yet committed to degenerate. Indeed, supporting the latter concept, recent findings in a chronic PNS neurodegeneration model indicate that deactivation of a key molecule promoting SC injury responses exacerbates axonal loss. If this holds true in a broader spectrum of conditions, it may provide the grounds for the development of new glia-centric therapeutic approaches to counteract axonal loss.

  9. Necrose pancreática delimitada e outros conceitos atuais na avaliação radiológica da pancreatite aguda

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    Elen Freitas de Cerqueira Cunha

    2014-06-01

    Full Text Available A pancreatite aguda é uma condição inflamatória causada por ativação intracelular e extravasamento inapropriado de enzimas proteolíticas que determinam destruição do parênquima pancreático e dos tecidos peripancreáticos. Consiste em uma condição clínica bastante frequente, identificando-se duas formas principais de apresentação: a forma edematosa, menos intensa, e a forma necrosante, a forma grave da doença que acomete uma proporção significativa dos pacientes. A avaliação radiológica, sobretudo por tomografia computadorizada, tem papel fundamental na definição da conduta nos casos graves, sobretudo no que diz respeito à caracterização das complicações locais, que têm implicação prognóstica, e na determinação do tipo de abordagem terapêutica. Novos conceitos incluem a subdivisão da pancreatite necrosante nas formas de necrose do parênquima pancreático concomitante com necrose dos tecidos peripancreáticos ou necrose restrita aos tecidos peripancreáticos. Além disso, houve sistematização dos termos: acúmulos líquidos agudos peripancreáticos, pseudocisto, alterações pós-necróticas pancreáticas/peripancreáticas e necrose pancreática delimitada. Tal conhecimento é de extrema relevância no sentido de uniformizar a linguagem entre os especialistas envolvidos no diagnóstico e tratamento desses pacientes.

  10. Uma nova forma de Coffea

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    C. A. Krug

    1950-01-01

    Full Text Available Nos extensos trabalhos de melhoramento do cafeeiro, há 18 anos em realização na Subdivisão de Genética do Instituto Agronômico, tem-se dedicado especial atenção à espécie C. arabica L., pelo fato de todos os nossos cafèzais pertencerem a esta espécie que, sem dúvida, fornece o produto de melhor qualidade. Nas regiões de terras extremamente cansadas, um dos principais fatôres levados em consideração no melhoramento é a rusticidade, caráter êsse, entretanto, encontrado de preferência em outras espécies, tais como o C. canephora e C. Dewevrei, cujos cafés são de má qualidade. A hibridação interespecífica, que poderia reunir em uma só planta caraterísticos de rusticidade e boa qualidade de bebida, tem o inconveniente de dar origem a plantas triplóides, que são estéreis. Daí se deduz que a obtenção artificial de formas que combinassem êsses caraterísticos constitui problema, cuja solução é extremamente demorada. No presente trabalho, apresentam-se os caracteres de uma nova forma de Coffea, encontrada em cafèzal da Fazenda Itaporã, em Terra Roxa, município de Viradouro, que, com algumas ressalvas, oferece a desejada combinação de caracteres. Trata-se, provàvelmente, de um híbrido espontâneo entre C. arabica e C. Dewevrei, com 2n = 44 cromosômios, extremamente rústico e produtivo, cujas sementes fornecem uma bebida que pode ser classificada como boa. Apenas apresenta, como principal defeito, uma auto-esterilidade quase completa. Os seus caraterísticos botânicos são descritos em detalhe. Devido ao seu porte elevado, ramos abundantes e folhas grandes e coriáceas, esse cafeeiro se assemelha ao C. Dewevrei. Os frutos são oval-elípticos, de um vermelho bem escuro quando maduros, e as sementes oblongas, constatan-do-se elevada percentagem do tipo "moca" e "chocha". Quanto à constituição citológica, as pesquisas conduziram à hipótese de este cafeeiro possuir 22 cromosômios de C. arabica e 22 (n

  11. Axonal excitability properties in amyotrophic lateral sclerosis.

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    Vucic, Steve; Kiernan, Matthew C

    2006-07-01

    To investigate axolemmal ion channel function in patients diagnosed with sporadic amyotrophic lateral sclerosis (ALS). A recently described threshold tracking protocol was implemented to measure multiple indices of axonal excitability in 26 ALS patients by stimulating the median motor nerve at the wrist. The excitability indices studied included: stimulus-response curve (SR); strength-duration time constant (tauSD); current/threshold relationship; threshold electrotonus to a 100 ms polarizing current; and recovery curves to a supramaximal stimulus. Compound muscle action potential (CMAP) amplitudes were significantly reduced in ALS patients (ALS, 2.84+/-1.17 mV; controls, 8.27+/-1.09 mV, P<0.0005) and the SR curves for both 0.2 and 1 ms pulse widths were shifted in a hyperpolarized direction. Threshold electrotonus revealed a greater threshold change to both depolarizing and hyperpolarizing conditioning stimuli, similar to the 'fanned out' appearance that occurs with membrane hyperpolarization. The tauSD was significantly increased in ALS patients (ALS, 0.50+/-0.03 ms; controls, 0.42+/-0.02 ms, P<0.05). The recovery cycle of excitability following a conditioning supramaximal stimulus revealed increased superexcitability in ALS patients (ALS, 29.63+/-1.25%; controls, 25.11+/-1.01%, P<0.01). Threshold tracking studies revealed changes indicative of widespread dysfunction in axonal ion channel conduction, including increased persistent Na+ channel conduction, and abnormalities of fast paranodal K+ and internodal slow K+ channel function, in ALS patients. An increase in persistent Na+ conductances coupled with reduction in K+ currents would predispose axons of ALS patients to generation of fasciculations and cramps. Axonal excitability studies may provide insight into mechanisms responsible for motor neuron loss in ALS.

  12. Pielonefritis enfisematosa aguda bilateral: Un desafío terapéutico Acute bilateral emphysematous pyelonephritis: A therapeutic challenge

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    Marcelo J. Melero

    2007-06-01

    Full Text Available La pielonefritis enfisematosa es una forma poco común de infección renal, caracterizada por la presencia de bacterias coliformes productoras de gas que afecta preferentemente a los pacientes diabéticos. Comunicamos el caso de una mujer diabética de 57 años de edad que ingresó en el hospital por un shock séptico, signos de pielonefritis enfisematosa aguda bilateral y cetoacidosis diabética. En los cultivos de las muestras de orina y sangre desarrolló Escherichia coli. La paciente fue tratada exitosamente con antibióticos de amplio espectro por un tiempo prolongado, control diabético y medidas de sostén solamente. No fue necesario el drenaje con catéteres o la nefrectomía para superar esta situación potencialmente letal.Emphysematous pyelonephritis is a rare form of kidney infection characterized by the presence of gas-forming coliform bacteria which affects more frequently diabetic subjects. We report the case of a 57-years-old diabetic woman, who was admitted in septic shock, signs of acute bilateral emphysematous pyelonephritis, and diabetic ketoacidosis. Both blood and urine cultures yielded Escherichia coli. The patient was successfully treated using long-term broad-spectrum antibiotics, diabetic control and supportive measures alone. Catheter drainage and nephrectomy were not necessary to overcome this life threatening situation.

  13. Synaptic Democracy and Vesicular Transport in Axons

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    Bressloff, Paul C.; Levien, Ethan

    2015-04-01

    Synaptic democracy concerns the general problem of how regions of an axon or dendrite far from the cell body (soma) of a neuron can play an effective role in neuronal function. For example, stimulated synapses far from the soma are unlikely to influence the firing of a neuron unless some sort of active dendritic processing occurs. Analogously, the motor-driven transport of newly synthesized proteins from the soma to presynaptic targets along the axon tends to favor the delivery of resources to proximal synapses. Both of these phenomena reflect fundamental limitations of transport processes based on a localized source. In this Letter, we show that a more democratic distribution of proteins along an axon can be achieved by making the transport process less efficient. This involves two components: bidirectional or "stop-and-go" motor transport (which can be modeled in terms of advection-diffusion), and reversible interactions between motor-cargo complexes and synaptic targets. Both of these features have recently been observed experimentally. Our model suggests that, just as in human societies, there needs to be a balance between "efficiency" and "equality".

  14. Retinoic acid signaling in axonal regeneration

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    Radhika ePuttagunta

    2012-01-01

    Full Text Available Following an acute central nervous system injury, axonal regeneration and functional recovery are extremely limited. This is due to an extrinsic inhibitory growth environment and the lack of intrinsic growth competence. Retinoic acid (RA signaling, essential in developmental dorsoventral patterning and specification of spinal motor neurons, has been shown through its receptor, the transcription factor RA receptor β2 (RARß2, to induce axonal regeneration following spinal cord injury (SCI. Recently, it has been shown that in dorsal root ganglia neurons, cAMP levels were greatly increased by lentiviral RARβ2 expression and contributed to neurite outgrowth. Moreover, RARβ agonists, in cerebellar granule neurons and in the brain in vivo, induced phosphoinositide 3-kinase dependent phosphorylation of AKT that was involved in RARβ-dependent neurite outgrowth. More recently, RA-RARß pathways were shown to directly transcriptionally repress a member of the inhibitory Nogo receptor complex, Lingo-1, under an axonal growth inhibitory environment in vitro as well as following spinal injury in vivo. This perspective focuses on these newly discovered molecular mechanisms and future directions in the field.

  15. Candidiasis hepatoesplénica en un paciente con leucemia mieloide aguda Hepatosplenic candidiasis in acute myeloid leukemia

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    A. Larregina

    2004-03-01

    Full Text Available La candidiasis diseminada crónica, principalmente en su variedad hepatoesplénica, es una de las formas clínicas más características de infección invasora por Candida en pacientes hematológicos. Se presenta el caso clínico de un varón de 31 años, con leucemia mieloide aguda (LMA M2, internado en el Servicio de Clínica Médica del hospital, que luego del tratamiento quimioterápico de inducción y consolidación presentó neutropenia febril leve. La candidiasis hepatoesplénica fue diagnosticada por tomografía axial computada (TAC y biopsia hepática. El enfermo fue tratado con anfotericina B, seguida de la forma liposomal hasta completar los 4 g. Se le dió el alta en espera de transplante de médula ósea. En este paciente se demostró que la sospecha temprana de candidiasis hepatoesplénica ayudó en la elección de un método de diagnóstico precoz y a su correcto tratamiento.Chronic diseminated candidiasis - mainly its hepatosplenic form- is one of the most characteristic invasive infection due to Candida in haematological patients. A case is presented of a 31 year old man admitted to the Clinical Department with acute mieloid leukosis M2, showing febrile neutropenia after induction and consolidation chemotherapy. Hepatoesplenic candidiasis was diagnosed and confirmed by computered axial tomography (CAT and hepatic biopsy; amphotericin B followed by liposome encapsuled amphotericin B up to complete a total dose of 4 g was used for treatment. The patient was discharged waiting for bone marrow transplantation. Early suspicion of hepatosplenic candidiasis helps to select a rapid diagnosis method and an effective treatment.

  16. Una nueva forma de conflicto

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    SALUSTIANO DEL CAMPO

    2002-01-01

    Full Text Available Con el ataque del 11 de septiembre al World Trade Center, el siglo XXI ha empezado con una nueva forma de conflicto y un realineamiento global. Samuel P. Huntington (1993 describió esto como un choque de civilizaciones entre el islam y occidente, pero se argumenta que esto es una simplificación. Otros factores a tener en cuenta son la coexistencia de las sociedades modernas y postmodernas, la desigual distribución de la riqueza, los conflictos internacionales insolubles de larga duración y la condición del islam en diferentes países. Se discute el impacto de la futura diseminación de la tecnología de la información en la resolución de algunas de estas diferencias. Recientemente se han desmantelado anteriores redes internacionales e instituciones. Coexisten redes legales e ilegales de negocios y organizaciones. En el caso de las redes terroristas, es muy complicado identifcarlas, atacarlas y desactivarlas. En el proceso de combatir al terrorismo no deberían sacrificarse los derechos fundamentales democráticos.

  17. Insuficiencia renal aguda obstructiva: Estudio de 42 pacientes

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    Isabel Caravia Pubillones

    1997-04-01

    Full Text Available Se revisaron las historias clínicas de 42 pacientes ingresados en el Servicio de Cuidados Intensivos del Instituto de Nefrología con el diagnóstico de insuficiencia renal aguda obstructiva (IRAO, con 1 ó 2 riñones funcionantes. Los pacientes estudiados estaban entre la 5ta y la 7ma década de la vida, con una mayor incidencia en el sexo masculino. La causa más frecuente de IRAO fue la litiasis renal (47,62 %, seguida por las enfermedades tumorales que infiltraban los uréteres (28,57 %. Se empleó tratamiento médico en 9 pacientes y el resto (33 fueron sometidos a tratamiento quirúrgico. Las principales complicaciones fueron sépticas con un franco predominio de las infecciones del tractus urinario (38,5 %. Hubo 3 fallecidos, 2 de ellos por complicaciones cardiovasculares. Del total de insuficiencias renales agudas que se atendieron en nuestro Centro, el 10,6 % correspondió a IRAO. La efectividad del tratamiento quirúrgico empleado fue del 94,4 % de curación en los pacientes atendidosMedical records of 42 patients admitted to the Intensive Care Unit of the Institute of Nephrology diagnosed as having acute obstructive renal failure with 1 or 2 kidneys functioning, were revised. Patients studied ware at the 5th and 7th decade of life with a greater incidence in males. The most frequent cause of acute obstructive renal failure was renal lithiasis (47.62 %, followed by tumor diseases which were infiltrating the ureters (28.57 %. Medical treatment was employed in 9 patients and the remaining (33 were submitted to surgical treatment. The main complications were septic with predominance of urinary tract infections (38.5 %. Three patients died, 2 of them as a result of cardiovascular complications. Of the total number of cases presenting with acute renal failure and treated in our center, 10.6 % had an acute obstructive renal failure. The effectiveness of the surgical treatment performed was 94.4 % of healing in patients treated for this

  18. Dependence of regenerated sensory axons on continuous neurotrophin-3 delivery.

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    Hou, Shaoping; Nicholson, LaShae; van Niekerk, Erna; Motsch, Melanie; Blesch, Armin

    2012-09-19

    Previous studies have shown that injured dorsal column sensory axons extend across a spinal cord lesion site if axons are guided by a gradient of neurotrophin-3 (NT-3) rostral to the lesion. Here we examined whether continuous NT-3 delivery is necessary to sustain regenerated axons in the injured spinal cord. Using tetracycline-regulated (tet-off) lentiviral gene delivery, NT-3 expression was tightly controlled by doxycycline administration. To examine axon growth responses to regulated NT-3 expression, adult rats underwent a C3 dorsal funiculus lesion. The lesion site was filled with bone marrow stromal cells, tet-off-NT-3 virus was injected rostral to the lesion site, and the intrinsic growth capacity of sensory neurons was activated by a conditioning lesion. When NT-3 gene expression was turned on, cholera toxin β-subunit-labeled sensory axons regenerated into and beyond the lesion/graft site. Surprisingly, the number of regenerated axons significantly declined when NT-3 expression was turned off, whereas continued NT-3 expression sustained regenerated axons. Quantification of axon numbers beyond the lesion demonstrated a significant decline of axon growth in animals with transient NT-3 expression, only some axons that had regenerated over longer distance were sustained. Regenerated axons were located in white matter and did not form axodendritic synapses but expressed presynaptic markers when closely associated with NG2-labeled cells. A decline in axon density was also observed within cellular grafts after NT-3 expression was turned off possibly via reduction in L1 and laminin expression in Schwann cells. Thus, multiple mechanisms underlie the inability of transient NT-3 expression to fully sustain regenerated sensory axons.

  19. Formation of longitudinal axon pathways in Caenorhabditis elegans.

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    Hutter, Harald

    2017-11-18

    The small number of neurons and the simple architecture of the Caenorhabditis elegans (C. elegans) nervous system enables researchers to study axonal pathfinding at the level of individually identified axons. Axons in C. elegans extend predominantly along one of the two major body axes, the anterior-posterior axis and the dorso-ventral axis. This review will focus on axon navigation along the anterior-posterior axis, leading to the establishment of the longitudinal axon tracts, with a focus on the largest longitudinal axon tract, the ventral nerve cord (VNC). In the VNC, axons grow out in a stereotypic order, with early outgrowing axons (pioneers) playing an important role in guiding later outgrowing (follower) axons. Genetic screens have identified a number of genes specifically affecting the formation of longitudinal axon tracts. These genes include secreted proteins, putative receptors and adhesion molecules, as well as intracellular proteins regulating the cell's response to guidance cues. In contrast to dorso-ventral navigation, no major general guidance cues required for the establishment of longitudinal pathways have been identified so far. The limited penetrance of defects found in many mutants affecting longitudinal navigation suggests that guidance cues act redundantly in this process. The majority of the axon guidance genes identified in C. elegans are evolutionary conserved, i.e. have homologs in other animals, including vertebrates. For a number of these genes, a role in axon guidance has not been described outside C. elegans. Taken together, studies in C. elegans contribute to a fundamental understanding of the molecular basis of axonal navigation that can be extended to other animals, including vertebrates and probably humans as well. Copyright © 2017. Published by Elsevier Ltd.

  20. Linfonodo pulmonar na paracoccidioidomicose aguda infantil (relato de um caso

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    Evanil Pires de Campos

    1992-09-01

    Full Text Available Observou-se a evolução de um linfonodo pulmonar na paracoccidioidomicose (PCM aguda infantil. Doente, masculino, 6 anos, branco, natural de Curitiba (PR, procedente de Guaratinguetá (SP, que há 3 meses desenvolveu quadro gripal, febre diária, bimodal, prolongada, precedida de calafrio, acompanhada de sudorese inodora, cefaléia frontal e anorexia. Diagnosticado e tratado como pneumonia por cinco dias, sem melhora do quadro. Há 2 meses, apresentou dor óssea nos braços e articulações do pé, com edema inflamatório e emagrecimento de 6 kg em 3 meses. Exame físico revelou: peso 20 kg; estatura 120 cm; P. A. 90/60 mmHg; facies atípica, hipoativo, palidez cutâneo-mucosa (+ +, hipotrofia muscular, adenopatiageneralizada, sopro sistólico suave em foco aórtico acessório e hepatesplenomegalia. Imunodifusão com exoantígeno glicoprotéico 43 kdpositiva (1/32. A biópsia de gânglio revelou Paracoccidioides brasiliensis. A radiologia demonstrou na primeira consulta, discreto infiltrado intersticial bilateral com linfoadenomegaliapara-hilar que desaparecu em 30 dias. Observou- se, ainda, massa tumoral mediastínica superior, hiperplasia do sistema fagocítico mononuclear e lesões osteolíticas nos 60 dias iniciais da evolução.

  1. Efeito da hipertermia na pancreatite aguda grave experimental

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    Maurício Gustavo Ieri Yamanari

    Full Text Available OBJETIVO: O objetivo deste estudo é avaliar os efeitos da hipertermia na pancreatite aguda (PA grave experimental induzida por ácido taurocólico. MÉTODO: A PA grave foi induzida pela injeção retrógrada de ácido taurocólico a 2,5% ou 5% no ducto pancreático principal. Após a indução, os animais foram colocados numa gaiola contendo duas lâmpadas de 100 W. A temperatura corporal foi aumentada para 39,5ºC e mantida neste nível por 45 minutos. Foram estudados taxa de mortalidade em 72 horas, permeabilidade vascular no pâncreas, porcentagem de água no tecido pancreático, amilase sérica, histologia (edema, necrose acinar e infiltrado inflamatório e níveis séricos de IL-6 e IL-10. RESULTADOS: Não houve alteração em nenhum dos parâmetros avaliados. CONCLUSÃO: Não há benefício da hipertermia na PA grave experimental induzida por ácido taurocólico.

  2. Meningoencefalite na fase aguda do sarampo : relato de seis casos

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    EL-FAR FABIANE

    2000-01-01

    Full Text Available Apresentamos 6 casos de meningoencefalite aguda por sarampo, diagnosticados durante epidemia na cidade de São Paulo, em 1997. Os prontuários dos 6 pacientes foram analisados retrospectivamente. O diagnóstico de meningoencefalite baseou-se nas alterações clínicas e liquóricas, e foi confirmado por sorologia específica. Dos 467 pacientes com sarampo atendidos no Instituto de Infectologia Emílio Ribas nesse período, estes 6 evoluíram com alterações neurológicas e liquóricas durante a fase exantemática, sendo a sonolência e rigidez de nuca os achados mais frequentes. Os pacientes tinham entre 2 meses e 28 anos de idade. O exame do líquor mostrou pleocitose em todos. Não houve correlação entre a severidade do quadro clínico e liquórico com a evolução. Em 4 casos foi necessária internação na unidade de terapia intensiva; destes, 2 foram intubados. Apenas 2 pacientes apresentaram alterações na tomografia computadorizada de crânio. Todos tiveram boa evolução, sem sequelas.

  3. Can injured adult CNS axons regenerate by recapitulating development?

    Science.gov (United States)

    Hilton, Brett J; Bradke, Frank

    2017-10-01

    In the adult mammalian central nervous system (CNS), neurons typically fail to regenerate their axons after injury. During development, by contrast, neurons extend axons effectively. A variety of intracellular mechanisms mediate this difference, including changes in gene expression, the ability to form a growth cone, differences in mitochondrial function/axonal transport and the efficacy of synaptic transmission. In turn, these intracellular processes are linked to extracellular differences between the developing and adult CNS. During development, the extracellular environment directs axon growth and circuit formation. In adulthood, by contrast, extracellular factors, such as myelin and the extracellular matrix, restrict axon growth. Here, we discuss whether the reactivation of developmental processes can elicit axon regeneration in the injured CNS. © 2017. Published by The Company of Biologists Ltd.

  4. Sindrome confusional agudo por abstinencia aguda de nicotina Delirium due to acute nicotine withdrawal

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    Manuel Klein

    2002-08-01

    Full Text Available El síndrome confusional agudo (SCA o delirium en pacientes hospitalizados es un problema frecuente y grave. Se caracteriza por síntomas de comienzo agudo y curso fluctuante con inatención, pensamiento desorganizado, y con distintos niveles de alteración de la conciencia.En la bibliografía consultada, el SCA como manifestación de un síndrome de abstinencia aguda nicotínica fue descripto en solo ocho casos. Presentamos el caso de un tabaquista grave que, internado por una reagudización de su enfermedad pulmonar obstructiva crónica (EPOC, presentó un cuadro de SCA al tercer día de abstinencia tabacal, cediendo los síntomas tras la administración de un parche de nicotina. Lo descripto sugiere que en pacientes internados que presentan SCA y agitación, con fuertes antecedentes de tabaquismo, un simple ensayo con un parche de nicotina puede ofrecer en pocas horas una notable respuesta terapéutica y a su vez un test confirmatorio. El reconocimiento del SCA como forma de presentación de la abstinencia nicotínica permitirá identificar casos habitualmente complejos en los que se podrá implementar una sencilla y eficaz alternativa terapéutica.Delirium or acute confusional state among hospitalized patients is a frequent and serious problem. It is characterized by acute onset symptoms, fluctuating course, impaired attention, unorganized thinking, and altered level of conciousness. Delirium, as a manifestation of acute nicotine withdrawal syndrome has been reported in the reviewed literature only in eight cases. We report the case of a heavy smoker admitted because of a reagudization of his chronic obstructive pulmonary disease. At the third day of nicotine abstinence, he developed delirium with a rapid improvement of his symptoms after treatment with a transdermal nicotine patch. This description suggests that in hospitalized heavy smokers who develop delirium with agitation, a simple trial with a nicotine patch can offer a dramatic

  5. Study of acute hepatotoxicity of Equisetum arvense L. in rats Estudo da hepatotoxicidade aguda da Equisetum arvense L. em ratos

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    Nilo César do Vale Baracho

    2009-12-01

    Full Text Available PURPOSE: To evaluate the acute hepatotoxicity of Equisentum arvense L. in rats. METHODS: Fifty Wistar rats were used, these being divided in four groups, one being the control (receiving only water and the other groups receiving graded doses of Equisentum arvense L. (30, 50, and 100mg/kg respectively for 14 days. Blood samples were obtained to determine TGO, TGP, FA, DHL and GT-gamma activities. After that, hepatic tissue samples were collected for the anatomopathologic analysis. RESULTS: The anatomopathologic exam of the hepatic tissue showed organ with preserved lobular structure. In the same way, there was no significant change in the seric activities of the hepatic enzymes when compared to control group. CONCLUSION: The oral treatment with graded doses of Equisentum arvense L. was not able to produce hepatic changes. Further studies are necessary to evaluate the chronic hepatotoxicity of Equisentum arvense L. in rats.OBJETIVO: Investigar a hepatotoxicidade aguda da Equisetum arvense L. em ratos. MÉTODOS: foram utilizados 50 ratos Wistar, os quais foram divididos em quatro grupos, sendo um controle (recebendo apenas água e os outros grupos recebendo doses crescentes de cavalinha (30, 50 e 100mg/Kg, respectivamente por 14 dias. Foram coletadas amostras de sangue para determinação da atividade sérica de TGO, TGP, FA, DHL e gama-GT. Em seguida, foram obtidas amostras de tecido hepático para análise anatomopatológica. RESULTADOS: O exame anatomopatológico de tecido hepático demonstrou órgão com estrutura lobular preservada. Da mesma forma, não houve alteração significativa na atividade sérica das enzimas hepáticas, quando comparado ao grupo controle. CONCLUSÃO: O tratamento com doses crescentes de Equisetum arvense L., não induziu hepatotoxicidade aguda em ratos. Novos estudos são necessários para avaliar a hepatoxicidade crônica de Equisetum arvense L. em ratos.

  6. Schwann Cell Glycogen Selectively Supports Myelinated Axon Function

    Science.gov (United States)

    Brown, Angus M; Evans, Richard D; Black, Joel; Ransom, Bruce R

    2012-01-01

    Objectives Interruption of energy supply to peripheral axons is a cause of axon loss. We determined if glycogen was present in mammalian peripheral nerve, and if it supported axon conduction during aglycemia. Methods We used biochemical assay and electron microscopy to determine the presence of glycogen, and electrophysiology to monitor axon function. Results Glycogen was present in sciatic nerve, its concentration varying directly with ambient [glucose]. Electron microscopy detected glycogen granules primarily in myelinating Schwann cell cytoplasm and these diminished after exposure to aglycemia. During aglycemia, conduction failure in large myelinated axons (A fibers) mirrored the time-course of glycogen loss. Latency to CAP failure was directly related to nerve glycogen content at aglycemia onset. Glycogen did not benefit the function of slow-conducting, small diameter unmyelinated axons (C fibers) during aglycemia. Blocking glycogen breakdown pharmacologically accelerated CAP failure during aglycemia in A fibers, but not in C fibers. Lactate was as effective as glucose in supporting sciatic nerve function, and was continuously released into the extracellular space in the presence of glucose and fell rapidly during aglycemia. Interpretation Our findings indicated that glycogen is present in peripheral nerve, primarily in myelinating Schwann cells, and exclusively supports large diameter, myelinated axon conduction during aglycemia. Available evidence suggests that peripheral nerve glycogen breaks down during aglycemia and is passed, probably as lactate, to myelinated axons to support function. Unmyelinated axons are not protected by glycogen and are more vulnerable to dysfunction during periods of hypoglycemia. PMID:23034913

  7. Axonal regeneration and development of de novo axons from distal dendrites of adult feline commissural interneurons after a proximal axotomy

    DEFF Research Database (Denmark)

    Fenrich, Keith K; Skelton, Nicole; MacDermid, Victoria E

    2007-01-01

    Following proximal axotomy, several types of neurons sprout de novo axons from distal dendrites. These processes may represent a means of forming new circuits following spinal cord injury. However, it is not know whether mammalian spinal interneurons, axotomized as a result of a spinal cord injury......, develop de novo axons. Our goal was to determine whether spinal commissural interneurons (CINs), axotomized by 3-4-mm midsagittal transection at C3, form de novo axons from distal dendrites. All experiments were performed on adult cats. CINs in C3 were stained with extracellular injections of Neurobiotin...... at 4-5 weeks post injury. The somata of axotomized CINs were identified by the presence of immunoreactivity for the axonal growth-associated protein-43 (GAP-43). Nearly half of the CINs had de novo axons that emerged from distal dendrites. These axons lacked immunoreactivity for the dendritic protein...

  8. Cannabinoid receptor CB2 modulates axon guidance

    DEFF Research Database (Denmark)

    Duff, Gabriel; Argaw, Anteneh; Cecyre, Bruno

    2013-01-01

    on axon guidance. These effects are specific to CB2R since no changes were observed in mice where the gene coding for this receptor was altered (cnr2 (-/-)). The CB2R induced morphological changes observed at the growth cone are PKA dependent and require the presence of the netrin-1 receptor, Deleted...... CB2R's implication in retinothalamic development. Overall, this study demonstrates that the contribution of endocannabinoids to brain development is not solely mediated by CB1R, but also involves CB2R....

  9. Tratamiento de la leucemia mieloide aguda del niño en Cuba Treatment of children acute myeloid leukemia in Cuba

    Directory of Open Access Journals (Sweden)

    Andrea Menéndez Veitía

    2013-06-01

    Full Text Available Introducción: la leucemia mieloide aguda representa alrededor del 20 % de las leucemias agudas de la niñez con una respuesta al tratamiento y supervivencia menores que la leucemia linfoide aguda. Objetivo: describir los resultados obtenidos con el tratamiento de la leucemia mieloide aguda del niño en algunos centros de Cuba en el período 2000-2008. Métodos: se trataron 46 pacientes con leucemia mieloide aguda, se excluyeron los casos con leucemia promielocítica, diagnosticados a partir del año 2000 en las provincias occidentales, Sancti Spíritus y Villa Clara. Se aplicaron dos esquemas de tratamiento tipo BFM en dos períodos: en el primero (2000 -2003 se incluyeron 27 enfermos y en el segundo (2004-2008, 19. La diferencia fundamental entre los dos períodos consistió en la consolidación que en la segunda etapa fue de ciclos más intensos y cortos. Resultados: predominó el sexo masculino (n = 32 y la mediana de edad fue de 9 años. La remisión inicial fue del 71 % en la primera etapa y 89 % en la segunda. La supervivencia libre de eventos (SLE en todos los pacientes fue del 40 % a los 5 años y la supervivencia global (SV fue del 44 % en igual período. En la SLE en las dos etapas se encontraron diferencias significativas siendo mayor en la segunda. En los años comprendidos entre el 2000 y el 2003 la SV a los 5 años fue del 31 %, mientras que entre 2004 y 2008 fue del 63 %. No se empleó el trasplante de células progenitoras hematopoyéticas de forma sistemática. Conclusiones: estos resultados muestran un nivel comparable a los alcanzados a internacionalmente, lo que representa un importante logro del Sistema Nacional de Salud de Cuba.Introduction. acute myeloid leukemia represents about 20 % of all leukemias in childhood with results and survival smaller than in acute lymphoid leukemia. Objectives: to describe the results obtained with the treatment of acute myeloid leukemia in children in some Cuban centers in from 2000 to 2008

  10. Complicaciones de la apendicectomía por apendicitis aguda Complications of the appendicectomy due to acute appendicitis

    Directory of Open Access Journals (Sweden)

    Zenén Rodríguez Fernández

    2010-06-01

    Full Text Available INTRODUCCIÓN. La apendicectomía por apendicitis aguda es la operación de urgencia más común en los servicios quirúrgicos, pero no está exenta de complicaciones condicionadas por factores poco conocidos, cuya determinación podría disminuir la morbilidad y mortalidad por esta causa. Fue objetivo de esta investigación identificar algunos factores relacionados con la aparición de complicaciones en los pacientes apendicectomizados por apendicitis aguda. MÉTODOS. Se realizó un estudio descriptivo, observacional y prospectivo de 560 pacientes apendicectomizados, con diagnóstico histopatológico de apendicitis aguda, egresados del Servicio de Cirugía General del Hospital Provincial Docente «Saturnino Lora» de Santiago de Cuba durante el 2006. RESULTADOS. El 21,6 % de la serie sufrió algún tipo de complicación, principalmente la infección del sitio operatorio. Las complicaciones aumentaron en relación con la edad y se presentaron más frecuentemente en los pacientes con enfermedades asociadas, estado físico más precario, mayor tiempo de evolución preoperatoria, así como en las formas histopatológicas más avanzadas de la afección (en las que se incluyen los 4 pacientes fallecidos. La aparición de tales complicaciones puede ser causa de reintervenciones y de aumento de la estadía hospitalaria. CONCLUSIONES. El diagnóstico precoz de la enfermedad y la apendicectomía inmediata con una técnica quirúrgica adecuada previenen la aparición de complicaciones posquirúrgicas y determinan el éxito del único tratamiento eficaz contra la afección más común que causa el abdomen agudo, cuyo pronóstico depende en gran medida y entre otros factores, del tiempo de evolución preoperatoria y de la fase en que se encuentre el proceso morboso al realizar la intervención.INTRODUCTION. Appendicectomy due to acute appendicitis is the commonest urgency operation in surgical services but it is not exempt from complications conditions by

  11. Lúpus eritematoso sistêmico e pancreatite aguda: relato de dois casos

    OpenAIRE

    Azevedo, Ana Beatriz Cordeiro de; Brito, Fabiano Almeida; Santos, Flávia Patrícia Sena Teixeira; Ferreira, Gilda Aparecida; Carvalho, Marco Antônio Parreiras de

    2003-01-01

    A pancreatite aguda é uma manifestação incomum do lúpus eritematoso sistêmico (LES) e a freqüência desta associação não é conhecida. Contudo, a pancreatite aguda é um diagnóstico diferencial importante na avaliação da dor abdominal em pacientes com LES. Os pacientes, normalmente, apresentam dor de intensidade variável, algumas vezes simulando abdome agudo. Vários fatores têm sido implicados na patogênese desta condição, tais como fenômenos autoimunes, vasculite, anticorpos antifosfolípides e ...

  12. Pengungkapan Pro Forma, Mendukung atau Menyesatkan Investor?

    Directory of Open Access Journals (Sweden)

    Yohanis Rura

    2010-12-01

    Full Text Available Pro forma is originated from Latin. It contains different meaning depends on which discipline it is used. In accounting, pro forma disclosure is used to show effect of important transaction which occurs after the end of periods, or which occurs during period but not fully reflected in historical cost financial statement of a firm. Pro forma disclosure has the objective to support (but might mislead investor in decision making focused on particular influence of important transaction. Company with low GAAP profit information; less profitable company and has higher level of debt but more liquid, whose P-E ratio and market to book is higher than other companies in the industry; has the tendency to do pro forma disclosure. Pro forma disclosure has been supported by several theories such as: efficient market theory, catering theory, agency theory, signaling theory, and stakeholder theory. However, there are problems in reporting pro forma figures. There is no standard to it. Therefore, information on pro forma disclosure might also mislead less sophisticated investor.

  13. Injúria renal aguda: um alerta global

    Directory of Open Access Journals (Sweden)

    Philip Kam Tao Li

    2013-03-01

    Full Text Available A Injúria Renal Aguda (IRA é cada vez mais prevalente nos países desenvolvidos e nos em desenvolvimento, e está associada com morbidade e mortalidade severas. A maioria das causas da IRA pode ser evitada por meio de intervenções em nível individual, comunitário, regional e intra-hospitalar. Medidas efetivas devem incluir, em toda a comunidade, os esforços para aumentar a consciência dos efeitos devastadores do IRA e fornecer orientações sobre as estratégias de prevenção, bem como o reconhecimento e tratamento precoces. Os esforços devem ser focados em minimizar as causas de IRA, aumentando a consciência da importância de medidas seriadas de creatinina sérica em pacientes de alto risco para IRA, e documentar o volume de urina em pessoas gravemente doentes para obtenção de diagnóstico precoce; até o momento, não há ainda um papel definitivo para outros biomarcadores. Há a necessidade de protocolos para sistematizar a conduta em condições de IRA pré-renal e em infecções específicas. Dados mais precisos sobre a verdadeira incidência e o impacto clínico da IRA ajudarão a melhor conhecer a importância desta doença, a aumentar o conhecimento de IRA por parte dos governantes, dos médicos em geral e de outros profissionais de saúde para ajudar na prevenção da doença. A prevenção é a chave para evitar a pesado ônus de mortalidade e morbidade associada com IRA.

  14. Intoxicación aguda por hidrato de hidracina

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    Santiago Nogué Xarau

    2008-06-01

    Full Text Available Se aporta un caso de exposición aguda, debido a un vertido accidental de unos 25 litros de hidrato de hidracina, que el trabajador estuvo recogiendo sin ningún tipo de equipo de protección individual. El trabajador presentó alteraciones bucales, cutáneas y dolores abdominales difusos. De las pruebas complementarias únicamente se detectó un aumento de la bilirrubina total con predominio de la indirecta. Se le separó de la exposición, se le administró un tratamiento sintomático y en un periodo de un mes se recuperó íntegramente. Se comenta los principales casos de intoxicación por hidracina descritos en la literatura médica y se enfatiza en las medidas preventivas que se deben tomar para evitar casos como éste.We report a case of poisoning by acute exposure to hydrazine hydrate in a worker clearing up an accidental spillage of about 25 litres of the product who had no type of individual protective equipment. The patient presented buccal and cutaneous involvement and diffuse abdominal pain. Complementary tests were unremarkable except for an increase in total bilirubin with a predominance of indirect bilirubin. The patient was removed from the occupational exposure, symptomatic treatment was administered and the patient recovered completely after one month. We review the main reported cases of hydrazine poisoning and emphasize the preventive measures that should be taken to avoid this type of poisoning.

  15. Dacriocistitis aguda neonatal (1996-2005 Acute neonatal dacryocystitis

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    Zoila del S López Díaz

    2006-12-01

    Full Text Available Se realizó un estudio longitudinal y retrospectivo en diez años (1996-2005, de todos los neonatos cuyo motivo de ingreso en nuestra Unidad de Cuidados Intensivos Neonatales fue ser portadores de dacriocistitis aguda. Se obtuvo los siguientes resultados: incidencia 0,04 c/ 100 ingresos. Predominio: edades entre 7-27días (sepsis tardía, sexo femenino 66,6 %, nacidos de embarazos a término y con buen peso al nacer 100 %. Etiología no precisada 83,3 %. Tratamiento utilizado: antibioticoterapia (penicilina + gentacina, 4 pacientes, 66,6 %, (unasyn, 1 paciente, 16,6 %, (amoxicilina + unasyn + gentamicina, 1 paciente, 16,6 %; uso de inmunoglobulina humana en 2 pacientes. Complicaciones: celulitis facial y periorbitaria 66,6 %; absceso periorbitario 33,3 %; fiebre (33,3 % y obstrucción nasal 16,6 %. Evolución satisfactoria con seguimiento por Oftalmología después del egreso hospitalario, en 100 % de los casosA retrospective longitudinal study of all neonates admitted to our Intensive Care Unit because they suffered from acute dacryocystitis was performed for 10 years (1996-2005. The results were as follows: incidence rate of 0,04 per 100 admissions; prevalence: 7-27d age groups (late sepsis, females with 66,6%; neonates born to term pregnancies and with good birthweight in 100%. Inaccurate etiology in 83,3 %. Treatment: antibiotic therapy (penicilline + gentamycin in 4 paients, 66,6%, (unasyn, one patient, 16,6 %, (amoxycillin + unasyn +gentamycin, 1 patient, 16.6 %. Use of human immunoglobulin in 2 patients. Complications: facial and periorbital cellulitis, 66,6%; periorbital abscess 33,3 %; fever (33,3 % and nasal obstruction (16,6 %. Satisfactory recovery with ophtalmological follow-up after discharge from hospital in 100 % of cases

  16. Intoxicação aguda por cobre em ovinos

    Directory of Open Access Journals (Sweden)

    Marcele Bettim Bandinelli

    2013-10-01

    Full Text Available Descrevem-se casos de intoxicação aguda por cobre em ovinos da raça Santa Inês, numa propriedade rural, no Rio Grande do Sul. Três ovelhas recém-paridas, que consumiam ração formulada para bovinos, ingeriram, avidamente, sal mineral comercial para bovinos e apresentaram doença clínica e morte, uma semana após a introdução do sal. Os animais desenvolveram anorexia, permaneceram em decúbito lateral, o qual evoluiu para esternal e apresentaram fasciculação e rigidez muscular generalizada, antes de morrerem. À necropsia de um desses animais, as principais alterações foram hepatomegalia moderada e acentuação do padrão lobular hepático, além de erosões e ulcerações multifocais aleatórias na mucosa abomasal. Na avaliação histológica do fígado, havia necrose hepatocelular centrolobular acentuada e difusa, tumefação de hepatócitos, predominantemente, na região periportal, além de pequena quantidade de células de Kupffer com pigmento granular citoplasmático. O diagnóstico baseou-se na história clínica, nos achados de necropsia e histopatológicos e confirmou-se pelas altas concentrações de cobre detectadas no tecido hepático e nas amostras de ração e sal mineral.

  17. Uso de antimicrobianos en la enfermedad diarreica aguda

    Directory of Open Access Journals (Sweden)

    Enrique A. González Corona

    1996-04-01

    Full Text Available Se realizó un estudio sobre el estado actual del uso de antimicrobianos en el Servicio de Enfermedades Diarreicas Agudas del Hospital Infantil Docente Sur de Santiago de Cuba, durante el período comprendido entre marzo y agosto de 1992. El universo estuvo integrado por 427 pacientes ingresados, de los cuales sólo 13,1 % requirió el empleo de estos medicamentos: 9,4 % por infección enteral y 3,7 % por extraenteral bacteriana. Más de la tercera parte de los afectados curaron con alimentación continuada y rehidratación, en su mayoría oral, y fueron las diarreas persistentes y disentéricas las que más frecuentemente condicionaron su administración. El criterio clínico fue determinante en su indicación.A study was carried out on the current state of the use of microbicidals in the Acute Diarrhea Service of the Southern Educational Children's Hospital at Santiago de Cuba, during the period between March and August 1992. The universe was integrated by 427 inpatients, of which only the 13,1 % required the use of these drugs: 9,4 % due to enteral infection, and 3,7 % due to bacterial extraenteral infection. More than the third part of the patients healed with continuous feeding and rehydration, mostly oral, and the persistent and dysenteric diarrheas conditioned most frequently its administration. The clinical criterion was determining in its indication.

  18. Problemas identificados en el manejo de la enfermedad diarreica aguda

    Directory of Open Access Journals (Sweden)

    Carlos Coronel Carbajal

    2000-08-01

    Full Text Available Se realizó un estudio retrospectivo de corte transversal en el Hospital "Armando E. Cardoso", en el período de 1 año (Mayo 98-Febrero 99. Este estudio consistió en encuestar a 256 madres de niños con diarreas agudas con el objetivo de identificar las costumbres inapropiadas que aún persisten en el manejo ambulatorio de las enfermedades diarreicas. Al concluir el estudio se pudo apreciar cómo en el 56,3 % de los pacientes hubo mal manejo alimentario, además solo el 12,1 % de las madres buscaron orientación médica en las primeras 24 horas. En este estudio se pudo conocer que el 100 % de las madres saben que las soluciones de rehidratación oral (SRO forman parte del tratamiento de la EDA, pero solo el 42 % conoce que previenen la deshidratación, además solo un 25 % conoce de otros líquidos que reemplazan el uso de las soluciones de rehidratación oralA cross-sectional study was conducted at the "Armando E. Cardoso" Hospital from May, 1998, to February,1999. 256 mothers of children with acute diarrhea were surveyed in order to identify the inappropiate costums that still exist in the ambulatory management of diarrheal diseases. A poor food management was observed in 56.3% of the patients and only 12.1% of the mothers looked for medical advice during the first 24 hours. It was possible to know through this study that 100% of the mothers know that oral rehydration solutions (ORS are part of the treatment of ADD, but only 42% know that the drug also prevents dehydration. Just 25% know about other fluids that replace the use of oral rehydration solutions

  19. Death Receptor 6 Promotes Wallerian Degeneration in Peripheral Axons.

    Science.gov (United States)

    Gamage, Kanchana K; Cheng, Irene; Park, Rachel E; Karim, Mardeen S; Edamura, Kazusa; Hughes, Christopher; Spano, Anthony J; Erisir, Alev; Deppmann, Christopher D

    2017-03-20

    Axon degeneration during development is required to sculpt a functional nervous system and is also a hallmark of pathological insult, such as injury [1, 2]. Despite similar morphological characteristics, very little overlap in molecular mechanisms has been reported between pathological and developmental degeneration [3-5]. In the peripheral nervous system (PNS), developmental axon pruning relies on receptor-mediated extrinsic degeneration mechanisms to determine which axons are maintained or degenerated [5-7]. Receptors have not been implicated in Wallerian axon degeneration; instead, axon autonomous, intrinsic mechanisms are thought to be the primary driver for this type of axon disintegration [8-10]. Here we survey the role of neuronally expressed, paralogous tumor necrosis factor receptor super family (TNFRSF) members in Wallerian degeneration. We find that an orphan receptor, death receptor 6 (DR6), is required to drive axon degeneration after axotomy in sympathetic and sensory neurons cultured in microfluidic devices. We sought to validate these in vitro findings in vivo using a transected sciatic nerve model. Consistent with the in vitro findings, DR6 -/- animals displayed preserved axons up to 4 weeks after injury. In contrast to phenotypes observed in Wld s and Sarm1 -/- mice, preserved axons in DR6 -/- animals display profound myelin remodeling. This indicates that deterioration of axons and myelin after axotomy are mechanistically distinct processes. Finally, we find that JNK signaling after injury requires DR6, suggesting a link between this novel extrinsic pathway and the axon autonomous, intrinsic pathways that have become established for Wallerian degeneration. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Axon guidance molecules in vascular patterning.

    Science.gov (United States)

    Adams, Ralf H; Eichmann, Anne

    2010-05-01

    Endothelial cells (ECs) form extensive, highly branched and hierarchically organized tubular networks in vertebrates to ensure the proper distribution of molecular and cellular cargo in the vertebrate body. The growth of this vascular system during development, tissue repair or in disease conditions involves the sprouting, migration and proliferation of endothelial cells in a process termed angiogenesis. Surprisingly, specialized ECs, so-called tip cells, which lead and guide endothelial sprouts, share many feature with another guidance structure, the axonal growth cone. Tip cells are motile, invasive and extend numerous filopodial protrusions sensing growth factors, extracellular matrix and other attractive or repulsive cues in their tissue environment. Axonal growth cones and endothelial tip cells also respond to signals belonging to the same molecular families, such as Slits and Roundabouts, Netrins and UNC5 receptors, Semaphorins, Plexins and Neuropilins, and Eph receptors and ephrin ligands. Here we summarize fundamental principles of angiogenic growth, the selection and function of tip cells and the underlying regulation by guidance cues, the Notch pathway and vascular endothelial growth factor signaling.

  1. Parallel simulation of axon growth in the nervous system

    NARCIS (Netherlands)

    J. Wensch; B.P. Sommeijer (Ben)

    2002-01-01

    textabstractIn this paper we discuss a model from neurobiology, which describes theoutgrowth of axons from neurons in the nervous system. The model combines ordinary differential equations, defining the movement of the axons, with parabolic partial differential equations. The parabolic equations

  2. A dam for retrograde axonal degeneration in multiple sclerosis?

    NARCIS (Netherlands)

    Balk, L.J.; Twisk, J.W.R.; Steenwijk, M.D.; Daams, M.; Tewarie, P.; Killestein, J.; Uitdehaag, B.M.J.; Polman, C.H.; Petzold, A.F.S.

    2014-01-01

    Objective: Trans-synaptic axonal degeneration is a mechanism by which neurodegeneration can spread from a sick to a healthy neuron in the central nervous system. This study investigated to what extent trans-synaptic axonal degeneration takes place within the visual pathway in multiple sclerosis

  3. Is action potential threshold lowest in the axon?

    NARCIS (Netherlands)

    Kole, Maarten H. P.; Stuart, Greg J.

    2008-01-01

    Action potential threshold is thought to be lowest in the axon, but when measured using conventional techniques, we found that action potential voltage threshold of rat cortical pyramidal neurons was higher in the axon than at other neuronal locations. In contrast, both current threshold and voltage

  4. SnoN facilitates axonal regeneration after spinal cord injury.

    Directory of Open Access Journals (Sweden)

    Jiun L Do

    Full Text Available Adult CNS neurons exhibit a reduced capacity for growth compared to developing neurons, due in part to downregulation of growth-associated genes as development is completed. We tested the hypothesis that SnoN, an embryonically regulated transcription factor that specifies growth of the axonal compartment, can enhance growth in injured adult neurons. In vitro, SnoN overexpression in dissociated adult DRG neuronal cultures significantly enhanced neurite outgrowth. Moreover, TGF-β1, a negative regulator of SnoN, inhibited neurite outgrowth, and SnoN over-expression overcame this inhibition. We then examined whether SnoN influenced axonal regeneration in vivo: indeed, expression of a mutant form of SnoN resistant to degradation significantly enhanced axonal regeneration following cervical spinal cord injury, despite peri-lesional upregulation of TGF-β1. Thus, a developmental mechanism that specifies extension of the axonal compartment also promotes axonal regeneration after adult CNS injury.

  5. Internodal function in normal and regenerated mammalian axons

    DEFF Research Database (Denmark)

    Moldovan, M; Krarup, C

    2007-01-01

    AIM: Following Wallerian degeneration, peripheral myelinated axons have the ability to regenerate and, given a proper pathway, establish functional connections with targets. In spite of this capacity, the clinical outcome of nerve regeneration remains unsatisfactory. Early studies have found...... that regenerated internodes remain persistently short though this abnormality did not seem to influence recovery in conduction. It remains unclear to which extent abnormalities in axonal function itself may contribute to the poor outcome of nerve regeneration. METHODS: We review experimental evidence indicating...... that internodes play an active role in axonal function. RESULTS: By investigating internodal contribution to axonal excitability we have found evidence that axonal function may be permanently compromised in regenerated nerves. Furthermore, we illustrate that internodal function is also abnormal in regenerated...

  6. Motor Axonal Regeneration After Partial and Complete Spinal Cord Transection

    Science.gov (United States)

    Lu, Paul; Blesch, Armin; Graham, Lori; Wang, Yaozhi; Samara, Ramsey; Banos, Karla; Haringer, Verena; Havton, Leif; Weishaupt, Nina; Bennett, David; Fouad, Karim; Tuszynski, Mark H.

    2012-01-01

    We subjected rats to either partial mid-cervical or complete upper thoracic spinal cord transections and examined whether combinatorial treatments support motor axonal regeneration into and beyond the lesion. Subjects received cAMP injections into brainstem reticular motor neurons to stimulate their endogenous growth state, bone marrow stromal cell grafts in lesion sites to provide permissive matrices for axonal growth, and brain-derived neurotrophic factor (BDNF) gradients beyond the lesion to stimulate distal growth of motor axons. Findings were compared to several control groups. Combinatorial treatment generated motor axon regeneration beyond both C5 hemisection and complete transection sites. Yet despite formation of synapses with neurons below the lesion, motor outcomes worsened after partial cervical lesions and spasticity worsened after complete transection. These findings highlight the complexity of spinal cord repair, and the need for additional control and shaping of axonal regeneration. PMID:22699902

  7. Axon diameter mapping in crossing fibers with diffusion MRI

    DEFF Research Database (Denmark)

    Zhang, Hui; Dyrby, Tim B; Alexander, Daniel C

    2011-01-01

    This paper proposes a technique for a previously unaddressed problem, namely, mapping axon diameter in crossing fiber regions, using diffusion MRI. Direct measurement of tissue microstructure of this kind using diffusion MRI offers a new class of biomarkers that give more specific information about...... tissue than measures derived from diffusion tensor imaging. Most existing techniques for axon diameter mapping assume a single axon orientation in the tissue model, which limits their application to only the most coherently oriented brain white matter, such as the corpus callosum, where the single...... model to enable axon diameter mapping in voxels with crossing fibers. We show in simulation that the technique can provide robust axon diameter estimates in a two-fiber crossing with the crossing angle as small as 45 degrees. Using ex vivo imaging data, we further demonstrate the feasibility...

  8. Axonal loss in the multiple sclerosis spinal cord revisited.

    Science.gov (United States)

    Petrova, Natalia; Carassiti, Daniele; Altmann, Daniel R; Baker, David; Schmierer, Klaus

    2018-05-01

    Preventing chronic disease deterioration is an unmet need in people with multiple sclerosis, where axonal loss is considered a key substrate of disability. Clinically, chronic multiple sclerosis often presents as progressive myelopathy. Spinal cord cross-sectional area (CSA) assessed using MRI predicts increasing disability and has, by inference, been proposed as an indirect index of axonal degeneration. However, the association between CSA and axonal loss, and their correlation with demyelination, have never been systematically investigated using human post mortem tissue. We extensively sampled spinal cords of seven women and six men with multiple sclerosis (mean disease duration= 29 years) and five healthy controls to quantify axonal density and its association with demyelination and CSA. 396 tissue blocks were embedded in paraffin and immuno-stained for myelin basic protein and phosphorylated neurofilaments. Measurements included total CSA, areas of (i) lateral cortico-spinal tracts, (ii) gray matter, (iii) white matter, (iv) demyelination, and the number of axons within the lateral cortico-spinal tracts. Linear mixed models were used to analyze relationships. In multiple sclerosis CSA reduction at cervical, thoracic and lumbar levels ranged between 19 and 24% with white (19-24%) and gray (17-21%) matter atrophy contributing equally across levels. Axonal density in multiple sclerosis was lower by 57-62% across all levels and affected all fibers regardless of diameter. Demyelination affected 24-48% of the gray matter, most extensively at the thoracic level, and 11-13% of the white matter, with no significant differences across levels. Disease duration was associated with reduced axonal density, however not with any area index. Significant association was detected between focal demyelination and decreased axonal density. In conclusion, over nearly 30 years multiple sclerosis reduces axonal density by 60% throughout the spinal cord. Spinal cord cross sectional area

  9. Pneumonia eosinofílica aguda com evolução para síndroma de dificuldade respiratória aguda: caso clínico

    OpenAIRE

    J.P.F. Baptista; P.C. Casanova; J.P.A. Sousa; P.J. Martins; A. Simões; V. Fernandes; J. Souto; J.J. Costa; A. Rebelo; L. Carvalho; J. Pimentel

    2004-01-01

    RESUMO: Os autores apresentam um caso de pneumonia eosinofílica aguda (PEA) associada a síndroma de dificuldade respiratória aguda grave num adolescente previamente saudável, medicado com nitrofurantoína. A PEA deve ser incluída no diagnóstico diferencial da pneumonia adquirida na comunidade, bem como na lista das patologias causadoras de síndroma de dificuldade respiratória aguda, e o seu diagnóstico deve ser sugerido pela presença de alveolite eosinofílica no líquido de lavagem broncoalveol...

  10. 4S RNA is transported axonally in normal and regenerating axons of the sciatic nerves of rats

    Energy Technology Data Exchange (ETDEWEB)

    Lindquist, T D; Ingoglia, N A; Gould, R M [Departments of Physiology and Neuroscience, New Jersey Medical School, Newark, NJ, USA

    1982-12-28

    Experiments were designed to determine if following injection of (/sup 3/H)uridine into the lumbar spinal cord of the rat, (/sup 3/H)RNA could be demonstrated within axons of the sciatic nerve, and if 4S RNA is the predominant predominant RNA species present in these axons.

  11. Intoxicaciones agudas graves en un servicio de medicina intensiva durante doce años

    Directory of Open Access Journals (Sweden)

    César Palazón Sánchez

    2000-01-01

    Full Text Available Conocer 12 epidemiología de las u~tux~- aciones agudas graves en un servicio de medicina intensiva y evaluar el pronóstico de la PCR y mortalidad asociada a los distintos tóxicos.

  12. Efectividad de la magnetoterapia como tratamiento en pacientes con lumbalgia aguda

    Directory of Open Access Journals (Sweden)

    Raidel González Rodríguez

    2015-05-01

    Full Text Available Son numerosos los pacientes aquejados de algias vertebrales, tanto lumbares como dorsales y cervicales. Se realizó esta investigación con el objetivo de determinar la efectividad de la magnetoterapia como tratamiento en la lumbalgia aguda, en pacientes atendidos en el policlínico universitario “Raúl Sánchez” de la provincia de Pinar del Río, Cuba. Se realizó un estudio descriptivo, prospectivo, de corte transversal en pacientes con lumbalgia aguda, pertenecientes a dicha área de salud. La muestra quedó conformada por 68 pacientes de ambos sexos con lumbalgia aguda, diagnosticados clínicamente y mayores de 17 años de edad. En la investigación predominó el sexo femenino (67,6 % y el rango de edad estuvo entre 40 y 49 años. El esfuerzo físico fue el principal factor desencadenante (47,1 %. Con el tratamiento de la magnetoterapia aplicado a los pacientes se redujeron los estadios del dolor. La mayoría de los pacientes presentaron una respuesta clínica excelente y mejoraron los síntomas entre los siete y diez días (61,8 %. No se reportaron efectos adversos. La magnetoterapia resultó efectiva en el tratamiento de pacientes aquejados de lumbalgia aguda

  13. Incidencia de la enfermedad diarreica aguda en menores de cinco años

    Directory of Open Access Journals (Sweden)

    Mayelín Ávila Labrada

    2015-05-01

    Full Text Available La enfermedad diarreica aguda es motivo frecuente de consulta pediátrica, representando un problema grave de salud pública. Los agentes infecciosos son causa frecuente de diarrea aguda. Se realizó un estudio descriptivo, retrospectivo sobre la prevalencia de la enfermedad diarreica aguda en menores de cinco años, atendidos en la clínica “Simón Bolívar” en la ciudad de Mariara del municipio Diego Ibarra, Carabobo, Venezuela; en el periodo comprendido entre enero de 2008 y diciembre de 2012, lo cual ofreció información de cinco años completos. La prevalencia de la enfermedad diarreica aguda disminuyó significativamente en el intervalo 2009-2011, sin embargo, se caracterizó por tener la mayor prevalencia en los años extremos, 2012 y 2008, por ese orden. Los varones y los del grupo de uno a cuatro años fueron los que más incidieron en cada uno de los años estudiados

  14. Fisiopatología de la diarrea aguda

    Directory of Open Access Journals (Sweden)

    Raúl L. Riverón Corteguera

    1999-06-01

    Full Text Available Es un artículo de revisión de los aspectos importantes de la fisiopatología de la diarrea. Se hace una descripción de la fisiopatología intestinal que incluye la anatomía del intestino y de su superficie de absorción y la estructura funcional de la mucosa intestinal. La fisiopatología normal de los líquidos intestinales. Mecanismo de absorción del agua y los electrólitos. Absorción de sodio por difusión electrogénica, unido al ion cloro, intercambio con el ion hidrógeno y unido a sustancias orgánicas como glucosa, aminoácidos y algunos oligopéptidos; secreción intestinal de agua y electrólitos. Control intracelular de la secreción. Mediadores y moduladores extracelulares del transporte intestinal. Factores que aumentan la absorción y reducen la secreción. Factores que estimulan la secreción y reducen la absorción Mecanismo fisiopatológico de la diarrea. Clasificación de la diarrea infecciosa aguda: acuosa secretoria y osmótica; diarrea con sangre invasiva y no invasiva.This a review of some important aspects of the physiopathology of diarrhea. A description is made of the intestinal physiopathology, including the anatomy of the intestine and of its surface of absorption, as well as the functional structure of the intestinal mucosa: the normal physiopathology of the intestinal fluids; the mechanism of absorption of water and electrolites; the absorption of sodium by electrogenic difussion, joined to the chloride ion; the interchange with the hydrogen ion and attached to organic substances, such as glucose, aminoacids and some oligopeptides; the intestinal secretion of water and electrolites; the intracellular control of secretion, the extracellular mediators and modulators of intestinal transport; the factors that increase absorption and reduce secretion; the factors that stimulate secretion and absorption; and the physiopathological mechanism of diarrhea. The classification of acute infectious diarrhea in aqueous

  15. Linfonodo pulmonar na paracoccidioidomicose aguda infantil (relato de um caso

    Directory of Open Access Journals (Sweden)

    Evanil Pires de Campos

    1992-09-01

    Full Text Available Observou-se a evolução de um linfonodo pulmonar na paracoccidioidomicose (PCM aguda infantil. Doente, masculino, 6 anos, branco, natural de Curitiba (PR, procedente de Guaratinguetá (SP, que há 3 meses desenvolveu quadro gripal, febre diária, bimodal, prolongada, precedida de calafrio, acompanhada de sudorese inodora, cefaléia frontal e anorexia. Diagnosticado e tratado como pneumonia por cinco dias, sem melhora do quadro. Há 2 meses, apresentou dor óssea nos braços e articulações do pé, com edema inflamatório e emagrecimento de 6 kg em 3 meses. Exame físico revelou: peso 20 kg; estatura 120 cm; P. A. 90/60 mmHg; facies atípica, hipoativo, palidez cutâneo-mucosa (+ +, hipotrofia muscular, adenopatiageneralizada, sopro sistólico suave em foco aórtico acessório e hepatesplenomegalia. Imunodifusão com exoantígeno glicoprotéico 43 kdpositiva (1/32. A biópsia de gânglio revelou Paracoccidioides brasiliensis. A radiologia demonstrou na primeira consulta, discreto infiltrado intersticial bilateral com linfoadenomegaliapara-hilar que desaparecu em 30 dias. Observou- se, ainda, massa tumoral mediastínica superior, hiperplasia do sistema fagocítico mononuclear e lesões osteolíticas nos 60 dias iniciais da evolução.The primary complex like Ghon was observed in a child's clinical roentgenographic study. C.S., white, male, 6 years old, was born in Curitiba (PR, Brazil and living in Guaratingueta (SP, Brazil, developed "common cold", bimodal diary fever, chills, shake and sweats. Dyspnea, cough with general fymphadenopathy. Foot and right shoulder artralgies. Six months ago visited a cave, equitation practice, dog and cat contacts and notransfusion, frontal sweats, fever (38.4°C. T.A. was 8/6, tachicardia in generalizated fymphadenopathy. Cardiopulmonary system was normal, mesogastric tumoral mass, hepatesplenomegaly and no ascitis. Bone marrow with eosinophilia; nodule demonstred presence of P. brasiliensis; hypoalbuminemia

  16. Dermatose Neutrofílica Febril Aguda: A propósito de um caso clínico.

    Directory of Open Access Journals (Sweden)

    Edite Marques Mendes

    2017-12-01

    Full Text Available Introdução: O síndrome de Sweet ou dermatose neutrofílica febril aguda, é uma patologia inflamatória incomum caracterizada pelo aparecimento abrupto de lesões cutâneas dolorosas, tipo nódulos, placas ou pápulas eritematosas e edematosas. Febre e leucocitose podem acompanhar as lesões cutâneas, com frequente envolvimento ocular ou de outros órgãos. Pode estar associado a infecção, malignidade ou exposição a fármacos. O tratamento de primeira linha são os glucocorticóides. Caso Clínico: Homem de 65 anos. Recorreu ao serviço de urgência por tosse produtiva e dor torácica. Teve alta com o diagnóstico de traqueobronquite aguda e medicado com amoxicilina e acido clavulânico. Regressou 3 dias depois por aparecimento de lesões cutâneas não pruriginosas e dolorosas. Sem febre. Ao exame objectivo apresentava diversas lesões cutâneas: placas, pápulas e vesiculas, eritematosas, de forma ovóide (as maiores de 2cm, algumas confluentes. Distribuídas pela zona occipital, pescoço, tórax e pelas extremidades superiores, com raras lesões no abdómen e membros inferiores. Apresentava também pigmentação vermelho-violacea periorbital. Analiticamente com leucocitose (14.3908/mm3, com neutrofilia (90%, elevação da proteina C reactiva (25,5mg/dL e da velocidade de sedimentação (80mm. Internado por suspeita de síndrome de Sweet, para estudo etiológico e controlo de sintomas. Electroforese proteínas normal. Resultado histológico da biópsia de pele revelou infiltrado inflamatório neutrofílico difuso cutâneo compatíveis com síndrome de Sweet. Iniciou tratamento com prednisolona 20 mg, com melhoria 72h após o início de corticoterapia. Diagnóstico final: Síndrome de Sweet Clássico/Idiopático. Conclusão: Os autores pretendem descrever um síndrome incomum, muitas vezes no contexto de infecções ou exposição a fármacos. No entanto, salienta-se a associação frequente com patologia neoplásica, pelo que se deve

  17. Axon tension regulates fasciculation/defasciculation through the control of axon shaft zippering

    Czech Academy of Sciences Publication Activity Database

    Šmít, Daniel; Fouquet, C.; Pincet, F.; Zápotocký, Martin; Trembleau, A.

    2017-01-01

    Roč. 6, Apr 19 (2017), č. článku e19907. ISSN 2050-084X R&D Projects: GA ČR(CZ) GA14-16755S; GA MŠk(CZ) 7AMB12FR002 Institutional support: RVO:67985823 Keywords : biophysics * cell adhesion * coarsening * developmental biology * mathematical model * mechanical tension * axon guidance Subject RIV: BO - Biophysics OBOR OECD: Biophysics Impact factor: 7.725, year: 2016

  18. Neuron Morphology Influences Axon Initial Segment Plasticity.

    Science.gov (United States)

    Gulledge, Allan T; Bravo, Jaime J

    2016-01-01

    In most vertebrate neurons, action potentials are initiated in the axon initial segment (AIS), a specialized region of the axon containing a high density of voltage-gated sodium and potassium channels. It has recently been proposed that neurons use plasticity of AIS length and/or location to regulate their intrinsic excitability. Here we quantify the impact of neuron morphology on AIS plasticity using computational models of simplified and realistic somatodendritic morphologies. In small neurons (e.g., dentate granule neurons), excitability was highest when the AIS was of intermediate length and located adjacent to the soma. Conversely, neurons having larger dendritic trees (e.g., pyramidal neurons) were most excitable when the AIS was longer and/or located away from the soma. For any given somatodendritic morphology, increasing dendritic membrane capacitance and/or conductance favored a longer and more distally located AIS. Overall, changes to AIS length, with corresponding changes in total sodium conductance, were far more effective in regulating neuron excitability than were changes in AIS location, while dendritic capacitance had a larger impact on AIS performance than did dendritic conductance. The somatodendritic influence on AIS performance reflects modest soma-to-AIS voltage attenuation combined with neuron size-dependent changes in AIS input resistance, effective membrane time constant, and isolation from somatodendritic capacitance. We conclude that the impact of AIS plasticity on neuron excitability will depend largely on somatodendritic morphology, and that, in some neurons, a shorter or more distally located AIS may promote, rather than limit, action potential generation.

  19. Formas asociativas: Una aproximación a las formas asociativas en el Reino Unido.

    Directory of Open Access Journals (Sweden)

    David Ricardo Sotomonte Mujica

    2004-01-01

    Full Text Available Este escrito se encuentra destinado a proporcionar al lector un acercamiento a las formas asociativas más importantes y utilizadas previstas dentro de la legislación del Reino Unido de La Gran Bretaña para la actividad empresarial. De igual forma es una guía para los estudiantes y profesionales del derecho, encaminada a facilitar la comprensión de las formas asociativas existentes en el sistema del common law.

  20. Hemograma e proteínas de fase aguda de bezerros sadios do nascimento aos 30 dias de idade

    Directory of Open Access Journals (Sweden)

    Thaís G. Rocha

    2013-12-01

    Full Text Available O conhecimento da dinâmica das alterações nos parâmetros hematológicos e na cinética das proteínas de fase aguda em animais saudáveis nas primeiras semanas de vida é essencial para a interpretação correta dessas avaliações em situações de morbidez e para diferenciar animais sadios e enfermos de forma confiável. Com o intuito de avaliar a cinética desses parâmetros no primeiro mês de vida de bezerros de corte sadios, filhos de vacas primíparas ou pluríparas, amostras de sangue foram coletadas antes da ingestão de colostro e 1, 2, 7, 15 e 30 dias após o nascimento. Os parâmetros eritrocitários foram influenciados pelo número de partos das vacas e o leucograma mostrou alterações características de influência do cortisol fetal liberado por ocasião do nascimento. O teor sérico de proteína total aumentou significativamente após a ingestão do colostro. As concentrações de ceruloplasmina, haptoglobina e proteínas de pesos moleculares 33 kDa e 23 kDa aumentaram significativamente no primeiro dia de vida, seja pela resposta ao nascimento ou pela ingestão do colostro, enquanto os teores de transferrina, albumina e α1-glicoproteína ácida mantiveram-se relativamente estáveis nos primeiros dias de vida, aumentando gradualmente até os 30 dias de idade.

  1. Comparação do corticoide inalatório e oral no tratamento da disfonia aguda Use of inhaled versus oral steroids for acute dysphonia

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    Andréa Moreira Veiga de Souza

    2013-04-01

    Full Text Available A disfonia aguda é um quadro comum na prática clínica. Seu tratamento, principalmente em adultos, não é bem definido na literatura. O corticoide é o tratamento medicamentoso mais recomendado. Os estudos existentes, entretanto, não são suficientes para a determinação da superioridade entre diferentes corticoides e a melhor forma de administração. OBJETIVO: Este estudo clínico prospectivo teve como objetivo comparar o efeito do corticoide inalatório na forma de pó seco com o efeito do corticoide oral, no tratamento da disfonia aguda. MÉTODO: Foram avaliados 32 pacientes adultos, divididos em dois grupos de 16 pacientes para cada um dos tratamentos, antes e após sete dias do uso da medicação. Os pacientes foram submetidos à videolaringosocpia e avaliação perceptiva e acústica da voz. RESULTADOS: O tratamento inalatório e oral reduziram significativamente a hiperemia, o edema e melhorou o movimento muco-ondulatório; entretanto, a redução do edema foi estatisticamente mais significativa (p = 0,012 nos pacientes tratados com a forma inalatória. A comparação dos valores da análise perceptiva auditiva e das medidas acústicas após tratamento entre os grupos, entretanto, não apresentou significância estatística. CONCLUSÃO: Houve melhora significativa da laringite aguda nas avaliações realizadas, em todos os pacientes estudados, com os dois tratamentos. O tratamento com corticoide inalatório foi significativamente mais efetivo na redução do edema.Acute dysphonia is a frequent condition in clinical practice. Its treatment, especially in adults, is not well established in the literature. Steroids are the most recommended drug treatment. However, the existing studies are not enough to establish superiority among the different steroids and the best route of administration. OBJECTIVE: This prospective clinical study aimed at comparing the effect of inhaling steroids as a dry powder with the effect of oral steroids to

  2. Pro forma: impact on communication skills?

    Science.gov (United States)

    Morris, Marie; Donohoe, Gary; Hennessy, Martina; O Ciardha, Caoilte

    2013-10-01

    A doctor performs 160 000-300 000 interviews during a lifetime career, thus making the medical interview the most common procedure in clinical medicine. It is reported that 60-80 per cent of diagnosis is based on history taking, yet there is little published data advising on the best method for medical students to initially attain and further refine these core skills during their medical degree. Medical students interviewed two patients: using an open interview first, based on the Calgary-Cambridge approach, and then using a structured pro forma. The students' medical data were assessed by a senior lecturer, and their communication skills were assessed by a behavioural scientist and by the patients. An exact Wilcoxon paired signed rank test was conducted to determine whether there was a difference between the open interview and pro forma methods for history taking and communication skills. The test yielded p-values of 0.0017 and 0.069, respectively, with the pro forma method providing a statistically significantly higher history-taking score and communication score than the open interview method. Subjectively, patients reported the pro forma method as being preferable. Medical students in the early years of training benefit from a structured history-taking pro forma to assist them gather an accurate data set without compromising their interpersonal and communication skills. © 2013 John Wiley & Sons Ltd.

  3. Axonal Membranes and Their Domains: Assembly and Function of the Axon Initial Segment and Node of Ranvier

    Directory of Open Access Journals (Sweden)

    Andrew D. Nelson

    2017-05-01

    Full Text Available Neurons are highly specialized cells of the nervous system that receive, process and transmit electrical signals critical for normal brain function. Here, we review the intricate organization of axonal membrane domains that facilitate rapid action potential conduction underlying communication between complex neuronal circuits. Two critical excitable domains of vertebrate axons are the axon initial segment (AIS and the nodes of Ranvier, which are characterized by the high concentrations of voltage-gated ion channels, cell adhesion molecules and specialized cytoskeletal networks. The AIS is located at the proximal region of the axon and serves as the site of action potential initiation, while nodes of Ranvier, gaps between adjacent myelin sheaths, allow rapid propagation of the action potential through saltatory conduction. The AIS and nodes of Ranvier are assembled by ankyrins, spectrins and their associated binding partners through the clustering of membrane proteins and connection to the underlying cytoskeleton network. Although the AIS and nodes of Ranvier share similar protein composition, their mechanisms of assembly are strikingly different. Here we will cover the mechanisms of formation and maintenance of these axonal excitable membrane domains, specifically highlighting the similarities and differences between them. We will also discuss recent advances in super resolution fluorescence imaging which have elucidated the arrangement of the submembranous axonal cytoskeleton revealing a surprising structural organization necessary to maintain axonal organization and function. Finally, human mutations in axonal domain components have been associated with a growing number of neurological disorders including severe cognitive dysfunction, epilepsy, autism, neurodegenerative diseases and psychiatric disorders. Overall, this review highlights the assembly, maintenance and function of axonal excitable domains, particularly the AIS and nodes of

  4. Npn-1 contributes to axon-axon interactions that differentially control sensory and motor innervation of the limb.

    Directory of Open Access Journals (Sweden)

    Rosa-Eva Huettl

    2011-02-01

    Full Text Available The initiation, execution, and completion of complex locomotor behaviors are depending on precisely integrated neural circuitries consisting of motor pathways that activate muscles in the extremities and sensory afferents that deliver feedback to motoneurons. These projections form in tight temporal and spatial vicinities during development, yet the molecular mechanisms and cues coordinating these processes are not well understood. Using cell-type specific ablation of the axon guidance receptor Neuropilin-1 (Npn-1 in spinal motoneurons or in sensory neurons in the dorsal root ganglia (DRG, we have explored the contribution of this signaling pathway to correct innervation of the limb. We show that Npn-1 controls the fasciculation of both projections and mediates inter-axonal communication. Removal of Npn-1 from sensory neurons results in defasciculation of sensory axons and, surprisingly, also of motor axons. In addition, the tight coupling between these two heterotypic axonal populations is lifted with sensory fibers now leading the spinal nerve projection. These findings are corroborated by partial genetic elimination of sensory neurons, which causes defasciculation of motor projections to the limb. Deletion of Npn-1 from motoneurons leads to severe defasciculation of motor axons in the distal limb and dorsal-ventral pathfinding errors, while outgrowth and fasciculation of sensory trajectories into the limb remain unaffected. Genetic elimination of motoneurons, however, revealed that sensory axons need only minimal scaffolding by motor axons to establish their projections in the distal limb. Thus, motor and sensory axons are mutually dependent on each other for the generation of their trajectories and interact in part through Npn-1-mediated fasciculation before and within the plexus region of the limbs.

  5. Nuevas formas organizacionales en la gobernabilidad transnacional

    OpenAIRE

    Vargas Hernández, José Gpe.

    2008-01-01

    El objetivo de este trabajo es analizar las transformaciones que están teniendo las formas organizacionales para adaptarse a los requerimientos de una gobernabilidad transnacional que de respuesta a los cambios del medio ambiente creado por los procesos de globalización económica. A partir de un análisis de los elementos sobresalientes de las estructuras en las organizaciones, se determinan las tendencias en las nuevas formas organizacionales considerando las variables de un medio ambiente ca...

  6. La forma en el proyecto urbano moderno

    OpenAIRE

    Ordóñez Alvarado, Wilson Paúl

    2011-01-01

    La forma en el proyecto urbano moderno nos introduce al análisis de la supercuadra de Brasilia, la misma que es considerada como el módulo base del planteamiento urbano de vivienda masiva en la modernidad. Se plantea la idea de una correspondencia existente entre la forma moderna expresada en el diseño y el planeamiento urbano, conceptos y pensamiento con los que el arquitecto Lucio Costa procedió a desarrollar el plan piloto con el que se concibió la nueva capital. Se presenta además un brev...

  7. Formação por ciclos

    OpenAIRE

    Nedbajluk,Lidia

    2006-01-01

    Artigo desenvolvido a partir dos estudos de Mestrado na Universidade Federal do Paraná, na linha de pesquisa Currículo, Conhecimento e Saberes nas Práticas Escolares, investigando a Formação por Ciclos. Analisa a diversidade de termos utilizados como complemento ao termo ciclos no ensino fundamental (Ciclos de Aprendizagem; Escola em Ciclos; Ensino em Ciclos; Ciclos de Desenvolvimento; Ciclos de Formação; Ciclo de Estudos) e esclarece a inadequação do uso dos mesmos indistintamente. Considera...

  8. Histoplasmose pulmonar aguda no Rio Grande do Sul Acute pulmonary histoplasmosis in the State of Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Gisela Unis

    2005-02-01

    Full Text Available INTRODUÇÃO: A histoplasmose pulmonar aguda depende da inalação de uma grande quantidade de propágulos fúngicos por um paciente hígido. O tempo de exposição determina a gravidade da doença. Uma epidemia é influenciada por fatores que afetam o crescimento e a transmissão do Histoplasma capsulatum var. capsulatum na natureza. OBJETIVO: Identificar os aspectos epidemiológicos e clínico-laboratoriais dos pacientes com histoplasmose pulmonar aguda no Rio Grande do Sul e compará-los com as microepidemias relatadas no Brasil. MÉTODO: Foram revisados 212 prontuários clínicos de pacientes com histoplasmose dos arquivos do Laboratório de Micologia do Complexo Hospitalar Santa Casa de Porto Alegre (RS num período de 25 anos (1977-2002. Foram identificados e incluídos no estudo os casos de histoplasmose pulmonar aguda com cultivo positivo e/ou achado histopatológico compatível. As microepidemias foram diagnosticadas com a comprovação de um caso ou evidência soromicológica com história clínica compatível. Foram revisadas as microepidemias publicadas no Brasil. RESULTADOS: Dezoito de um total de 212 pacientes (8,5% foram incluídos no trabalho. A idade variou de 8 a 63 anos (média de 35,4; mediana de 34,5, e 67% eram do sexo masculino. A história epidemiológica foi sugestiva em 11 pacientes (61%. O tipo primário de histoplasmose pulmonar aguda foi o mais freqüente (17; 95%. Houve predomínio de casos isolados. CONCLUSÃO: O reconhecimento de casos isolados e a presença de microepidemias demonstram a abundância do H. capsulatum no solo, e juntamente com a ocorrência de todas as formas da doença, confirmam o Rio Grande do Sul como hiperendêmico para histoplasmose.BACKGROUND: Acute pulmonary histoplasmosis is a respiratory infection occurring when an otherwise healthy individual inhales a large quantity of fungal propagules. Length of exposure determines disease severity. An epidemic is influenced by factors affecting the

  9. Detección molecular de las translocaciones más comunes en Leucemia aguda mediante RT-PCR

    Directory of Open Access Journals (Sweden)

    L. García

    2001-07-01

    Full Text Available Evaluar la incidencia de las translocaciones t(4;11, t(1;19, t(9;22 y t(12;21 en leucemia linfoide aguda (LLA y t(15;17, t(8;21 e Inv.(16 en leucemia mieloide aguda (LMA. Correlacionar los resultados obtenidos con el diagnóstico morfológico y citogenético.

  10. Proteína C reactiva e gravidade da bronquiolite aguda

    Directory of Open Access Journals (Sweden)

    S. Costa

    2009-01-01

    Full Text Available Resumo: O diagnóstico de bronquiolite aguda é essencialmente clínico. A utilidade de exames laboratoriais, em particular do doseamento da proteína C reactiva (PCR, não está bem estabelecida.O objectivo deste trabalho foi avaliar a relação entre o valor da PCR e os marcadores indirectos de gravidade em doentes com diagnóstico de bronquiolite.Foram incluídos no estudo todos os doentes admitidos no Serviço de Pediatria do HSJ durante o ano de 2006 e que tiveram como diagnóstico principal bronquiolite, tendo sido feita uma revisão retrospectiva do processo clínico desses doentes.Foram incluídos 176 doentes com idades compreendidas entre zero e 36 meses (mediana de 4 meses; 63,1% eram do sexo masculino. O doseamento da PCR tinha sido efectuado em 94,3% dos doentes, com valores compreendidos entre zero e 256 mg/L e com mediana de 11 mg/L.O valor da PCR, na população estudada, apresentou uma relação estatisticamente significativa com a admissão em unidade de cuidados intensivos (UCI (p=0,008, a duração do internamento hospitalar (p=0,025 e a necessidade de oxigenoterapia (p=0,022.Desta forma, este trabalho coloca a hipótese de o valor de PCR poder ser um marcador de gravidade e ter significado prognóstico em doentes com bronquiolite. Mais estudos são necessários para validar estes resultados e esclarecer se existe uma relação real entre as variáveis estudadas ou se esta é produzida pelo efeito confundidor de outras infecções.Rev Port Pneumol 2009; XV (1: 55-65 Abstract: A diagnosis of bronchiolitis is made clinically and the use of supportive laboratory examinations, including the quantification of C reactive protein (CRP, is not well established.The aim of this study was to evaluate the correlation between CRP value and indirect markers of disease severity in patients with bronchiolitis.This study included the patients diagnosed with bronchiolitis admitted to the Pediatrics Department of S. João Hospital in 2006. A

  11. Neurotrophin Signaling via Long-Distance Axonal Transport

    Science.gov (United States)

    Chowdary, Praveen D.; Che, Dung L.; Cui, Bianxiao

    2012-05-01

    Neurotrophins are a family of target-derived growth factors that support survival, development, and maintenance of innervating neurons. Owing to the unique architecture of neurons, neurotrophins that act locally on the axonal terminals must convey their signals across the entire axon for subsequent regulation of gene transcription in the cell nucleus. This long-distance retrograde signaling, a motor-driven process that can take hours or days, has been a subject of intense interest. In the last decade, live-cell imaging with high sensitivity has significantly increased our capability to track the transport of neurotrophins, their receptors, and subsequent signals in real time. This review summarizes recent research progress in understanding neurotrophin-receptor interactions at the axonal terminal and their transport dynamics along the axon. We emphasize high-resolution studies at the single-molecule level and also discuss recent technical advances in the field.

  12. Spontaneous axonal regeneration in rodent spinal cord after ischemic injury

    DEFF Research Database (Denmark)

    von Euler, Mia; Janson, A M; Larsen, Jytte Overgaard

    2002-01-01

    cells, while other fibers were unmyelinated. Immunohistochemistry demonstrated that some of the regenerated fibers were tyrosine hydroxylase- or serotonin-immunoreactive, indicating a central origin. These findings suggest that there is a considerable amount of spontaneous regeneration after spinal cord......Here we present evidence for spontaneous and long-lasting regeneration of CNS axons after spinal cord lesions in adult rats. The length of 200 kD neurofilament (NF)-immunolabeled axons was estimated after photochemically induced ischemic spinal cord lesions using a stereological tool. The total...... length of all NF-immunolabeled axons within the lesion cavities was increased 6- to 10-fold at 5, 10, and 15 wk post-lesion compared with 1 wk post-surgery. In ultrastructural studies we found the putatively regenerating axons within the lesion to be associated either with oligodendrocytes or Schwann...

  13. Fiber Optic Detection of Action Potentials in Axons

    National Research Council Canada - National Science Library

    Smela, Elisabeth

    2006-01-01

    In prior exploratory research, we had designed a fiber optic sensor utilizing a long period Bragg grating for the purpose of detecting action potentials in axons optically, through a change in index...

  14. Esofagitis necrosante aguda: análisis retrospectivo Acute esophageal necrosis: a retrospective case series

    Directory of Open Access Journals (Sweden)

    R. Ramos

    2008-09-01

    Full Text Available Introducción: la esofagitis necrosante aguda es una entidad rara. Se reconoce por el aspecto negro difuso del esófago a la endoscopia. Su incidencia e patogénesis se desconoce. Pacientes y métodos: se analizaron retrospectivamente 11 pacientes con esofagitis necrosante aguda desde el punto de vista de los datos clínicos, de laboratorio y endoscopicos en 2 años. Resultados: se analizaron las endoscopias realizadas a 3.976 pacientes, observándose esofagitis necrosante aguda en 11 pacientes. El estado nutricional era malo en 6 pacientes. La resolución completa de la esofagitis se observó en cuatro pacientes. Durante el seguimiento se observó una estenosis en un paciente y un nuevo episodio de esofagitis necrosante aguda en otro paciente. Siete pacientes fallecieron, pero esta elevada mortalidad parece deberse a las enfermedades de base y no es atribuible a las lesiones de la esofagitis necrosante. Conclusiones: la incidencia de esofagitis necrosante aguda en nuestra serie fue 0,28%. La esofagitis necrosante aguda tiene una elevada mortalidad.Background: acute esophageal necrosis has been considered a rare event. It is defined as the presence of diffuse dark pigmentation of the esophagus on upper endoscopy. Its incidence has not yet been established. The pathogenesis remains unknown. Patients and methods: a retrospective analysis of clinical, laboratory, endoscopic, and histological data, and of the clinical course of 11 patients with acute necrotizing esophagitis was carried out over a 2-year period. Results: among 3,976 patients who underwent upper endoscopy, 11 (0.28% with acute esophageal necrosis were identified. Nutritional status was poor for 6 patients. Complete resolution of acute esophageal necrosis without further recurrence was observed in 4. One stricture appeared during follow-up and other patient developed new-onset acute esophageal necrosis. Seven patients died, but no death was directly related to acute esophageal necrosis

  15. Estado oxidante e antioxidante de crianças com bronquiolite aguda

    Directory of Open Access Journals (Sweden)

    Rusen Dundaroz

    2013-08-01

    Full Text Available OBJETIVO: O estresse oxidativo demonstrou contribuir para a patogênese de doenças pulmonares inflamatórias agudas e crônicas. Nosso objetivo foi avaliar o estado oxidante/antioxidante de crianças com bronquiolite aguda por meio de mensuração da capacidade antioxidante total do plasma, estado oxidante total e índice de estresse oxidativo. MÉTODOS: As crianças com bronquiolite aguda encaminhadas para o Departamento de Emergência Pediátrica do hospital universitário entre janeiro e abril 2012 foram comparadas a controles saudáveis de mesma idade. Os pacientes com bronquiolite aguda tiveram essa doença classificada como leve e moderada. O estado oxidante e antioxidante foi avaliado pela mensuração da capacidade antioxidante total do plasma, estado oxidante total e índice de estresse oxidativo. RESULTADOS: Foram incluídas 31 crianças com bronquiolite aguda com idade de três meses a dois anos e 37 crianças saudáveis. O estado oxidante total (EOT foi maior em pacientes com bronquiolite aguda do que no grupo de controle (5,16±1,99 µmol H2O2 em comparação a 3,78±1,78 µmol H2O2 [p = 0,004]. A capacidade antioxidante total (CAT foi significativamente menor em crianças com bronquiolite que no grupo de controle (2,51±0,37 µmol Trolox equivalente/L em comparação a 2,75±0,39 µmol Trolox Eqv/L (p = 0,013. Os pacientes com bronquiolite moderada apresentaram níveis de EOT mais elevados que os com bronquiolite leve e os do grupo de controle (p = 0,03, p < 0,001. Os pacientes com bronquiolite moderada apresentaram níveis de IEO mais elevados que os do grupo de controle (p = 0,015. O nível de saturação de oxigênio de pacientes com bronquiolite foi inversamente correlacionado ao nível de EOT (r = -0,476, p < 0,05. CONCLUSÃO: O equilíbrio entre os sistemas oxidante e antioxidante é interrompido em crianças com bronquiolite moderada, indicando que o fator de estresse poderá ter um papel na patogênese da doença.

  16. Regeneración axonal posterior a lesiones traumáticas de médula espinal: Papel crítico de galectina-1

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    Héctor R Quintá

    2014-08-01

    Full Text Available Al producirse una lesión de médula espinal (LME, un sinnúmero de proteínas inhibidoras de la regeneración axonal ocupan el sitio de lesión en forma secuencial. La primer proteína en llegar al mismo se conoce como semaforina 3A (Sema3A, siendo además una de las más potentes por su acción de inhibir la regeneración axonal. A nivel mecanístico la unión de esta proteína al complejo-receptor neuronal neuropilin-1 (NRP-1/PlexinA4 evita que se produzca regeneración axonal. En este trabajo de revisión se discutirá la acción de galectin-1 (Gal-1, una proteína endógena de unión a glicanos, que selectivamente se une al complejo-receptor NRP-1/PlexinA4 de las neuronas lesionadas a través de un mecanismo dependiente de interacciones lectina-glicano, interrumpiendo la señalización generada por Sema3A y permitiendo de esta manera la regeneración axonal y recuperación locomotora luego de producirse la LME. Mientras ambas formas de Gal-1 (monomérica y dimérica contribuyen a la inactivación de la microglia, solo la forma dimérica de Gal-1 es capaz de unirse al complejo-receptor NRP-1/PlexinA4 y promover regeneración axonal. Por lo tanto, Gal-1 dimérica produce recuperación de las lesiones espinales interfiriendo en la señalización de Sema3A a través de la unión al complejo-receptor NRP-1/PlexinA4, sugiriendo el uso de esta lectina en su forma dimérica para el tratamiento de pacientes con LME.

  17. Functional characterization and axonal transport of quantum dot labeled BDNF

    OpenAIRE

    Xie, Wenjun; Zhang, Kai; Cui, Bianxiao

    2012-01-01

    Brain derived neurotrophic factor (BDNF) plays a key role in the growth, development and maintenance of the central and peripheral nervous systems. Exogenous BDNF activates its membrane receptors at the axon terminal, and subsequently sends regulation signals to the cell body. To understand how BDNF signal propagates in neurons, it is important to follow the trafficking of BDNF after it is internalized at the axon terminal. Here we labeled BDNF with bright, photostable quantum dot (QD-BDNF) a...

  18. Modality-Specific Axonal Regeneration: Towards selective regenerative neural interfaces

    Directory of Open Access Journals (Sweden)

    Parisa eLotfi

    2011-10-01

    Full Text Available Regenerative peripheral nerve interfaces have been proposed as viable alternatives for the natural control of robotic prosthetic devices. However, sensory and motor axons at the neural interface are of mixed submodality types, which difficult the specific recording from motor axons and the eliciting of precise sensory modalities through selective stimulation. Here we evaluated the possibility of using type-specific neurotrophins to preferentially entice the regeneration of defined axonal populations from transected peripheral nerves into separate compartments. Segregation of mixed sensory fibers from dorsal root ganglion neurons was evaluated in vitro by compartmentalized diffusion delivery of nerve growth factor (NGF and neurotrophin-3 (NT-3, to preferentially entice the growth of TrkA+ nociceptive and TrkC+ proprioceptive subsets of sensory neurons, respectively. The average axon length in the NGF channel increased 2.5 fold compared to that in saline or NT-3, whereas the number of branches increased 3 fold in the NT-3 channels. These results were confirmed using a 3-D Y-shaped in vitro assay showing that the arm containing NGF was able to entice a 5-fold increase in axonal length of unbranched fibers. To address if such segregation can be enticed in vivo, a Y-shaped tubing was used to allow regeneration of the transected adult rat sciatic nerve into separate compartments filled with either NFG or NT-3. A significant increase in the number of CGRP+ pain fibers were attracted towards the sural nerve, while N-52+ large diameter axons were observed in the tibial and NT-3 compartments. This study demonstrates the guided enrichment of sensory axons in specific regenerative chambers, and supports the notion that neurotrophic factors can be used to segregate sensory and perhaps motor axons in separate peripheral interfaces.

  19. Self-amplifying autocrine actions of BDNF in axon development

    OpenAIRE

    Cheng, Pei-Lin; Song, Ai-Hong; Wong, Yu-Hui; Wang, Sheng; Zhang, Xiang; Poo, Mu-Ming

    2011-01-01

    A critical step in neuronal development is the formation of axon/dendrite polarity, a process involving symmetry breaking in the newborn neuron. Local self-amplifying processes could enhance and stabilize the initial asymmetry in the distribution of axon/dendrite determinants, but the identity of these processes remains elusive. We here report that BDNF, a secreted neurotrophin essential for the survival and differentiation of many neuronal populations, serves as a self-amplifying autocrine f...

  20. Fcγ receptor-mediated inflammation inhibits axon regeneration.

    Directory of Open Access Journals (Sweden)

    Gang Zhang

    Full Text Available Anti-glycan/ganglioside antibodies are the most common immune effectors found in patients with Guillain-Barré Syndrome, which is a peripheral autoimmune neuropathy. We previously reported that disease-relevant anti-glycan autoantibodies inhibited axon regeneration, which echo the clinical association of these antibodies and poor recovery in Guillain-Barré Syndrome. However, the specific molecular and cellular elements involved in this antibody-mediated inhibition of axon regeneration are not previously defined. This study examined the role of Fcγ receptors and macrophages in the antibody-mediated inhibition of axon regeneration. A well characterized antibody passive transfer sciatic nerve crush and transplant models were used to study the anti-ganglioside antibody-mediated inhibition of axon regeneration in wild type and various mutant and transgenic mice with altered expression of specific Fcγ receptors and macrophage/microglia populations. Outcome measures included behavior, electrophysiology, morphometry, immunocytochemistry, quantitative real-time PCR, and western blotting. We demonstrate that the presence of autoantibodies, directed against neuronal/axonal cell surface gangliosides, in the injured mammalian peripheral nerves switch the proregenerative inflammatory environment to growth inhibitory milieu by engaging specific activating Fcγ receptors on recruited monocyte-derived macrophages to cause severe inhibition of axon regeneration. Our data demonstrate that the antibody orchestrated Fcγ receptor-mediated switch in inflammation is one mechanism underlying inhibition of axon regeneration. These findings have clinical implications for nerve repair and recovery in antibody-mediated immune neuropathies. Our results add to the complexity of axon regeneration in injured peripheral and central nervous systems as adverse effects of B cells and autoantibodies on neural injury and repair are increasingly recognized.

  1. Dendrosomatic Sonic Hedgehog Signaling in Hippocampal Neurons Regulates Axon Elongation

    Science.gov (United States)

    Petralia, Ronald S.; Ott, Carolyn; Wang, Ya-Xian; Lippincott-Schwartz, Jennifer; Mattson, Mark P.

    2015-01-01

    The presence of Sonic Hedgehog (Shh) and its signaling components in the neurons of the hippocampus raises a question about what role the Shh signaling pathway may play in these neurons. We show here that activation of the Shh signaling pathway stimulates axon elongation in rat hippocampal neurons. This Shh-induced effect depends on the pathway transducer Smoothened (Smo) and the transcription factor Gli1. The axon itself does not respond directly to Shh; instead, the Shh signal transduction originates from the somatodendritic region of the neurons and occurs in neurons with and without detectable primary cilia. Upon Shh stimulation, Smo localization to dendrites increases significantly. Shh pathway activation results in increased levels of profilin1 (Pfn1), an actin-binding protein. Mutations in Pfn1's actin-binding sites or reduction of Pfn1 eliminate the Shh-induced axon elongation. These findings indicate that Shh can regulate axon growth, which may be critical for development of hippocampal neurons. SIGNIFICANCE STATEMENT Although numerous signaling mechanisms have been identified that act directly on axons to regulate their outgrowth, it is not known whether signals transduced in dendrites may also affect axon outgrowth. We describe here a transcellular signaling pathway in embryonic hippocampal neurons in which activation of Sonic Hedgehog (Shh) receptors in dendrites stimulates axon growth. The pathway involves the dendritic-membrane-associated Shh signal transducer Smoothened (Smo) and the transcription factor Gli, which induces the expression of the gene encoding the actin-binding protein profilin 1. Our findings suggest scenarios in which stimulation of Shh in dendrites results in accelerated outgrowth of the axon, which therefore reaches its presumptive postsynaptic target cell more quickly. By this mechanism, Shh may play critical roles in the development of hippocampal neuronal circuits. PMID:26658865

  2. Kinematics of turnaround and retrograde axonal transport

    International Nuclear Information System (INIS)

    Snyder, R.E.

    1986-01-01

    Rapid axonal transport of a pulse of 35 S-methionine-labelled material was studied in vitro in the sensory neurons of amphibian sciatic nerve using a position-sensitive detector. For 10 nerves studied at 23.0 +/- 0.2 degrees C it was found that a pulse moved in the anterograde direction characterized by front edge, peak, and trailing edge transport rates of (mm/d) 180.8 +/- 2.2 (+/- SEM), 176.6 +/- 2.3, and 153.7 +/- 3.0, respectively. Following its arrival at a distal ligature, a smaller pulse was observed to move in the retrograde direction characterized by front edge and peak transport rates of 158.0 +/- 7.3 and 110.3 +/- 3.5, respectively, indicating that retrograde transport proceeds at a rate of 0.88 +/- 0.04 that of anterograde. The retrograde pulse was observed to disperse at a rate greater than the anterograde. Reversal of radiolabel at the distal ligature began 1.49 +/- 0.15 h following arrival of the first radiolabel. Considerable variation was seen between preparations in the way radiolabel accumulated in the end (ligature) regions of the nerve. Although a retrograde pulse was seen in all preparations, in 7 of 10 preparations there was no evidence of this pulse accumulating within less than 2-3 mm of a proximal ligature; however, accumulation was observed within less than 5 mm in all preparations

  3. Developmental time windows for axon growth influence neuronal network topology.

    Science.gov (United States)

    Lim, Sol; Kaiser, Marcus

    2015-04-01

    Early brain connectivity development consists of multiple stages: birth of neurons, their migration and the subsequent growth of axons and dendrites. Each stage occurs within a certain period of time depending on types of neurons and cortical layers. Forming synapses between neurons either by growing axons starting at similar times for all neurons (much-overlapped time windows) or at different time points (less-overlapped) may affect the topological and spatial properties of neuronal networks. Here, we explore the extreme cases of axon formation during early development, either starting at the same time for all neurons (parallel, i.e., maximally overlapped time windows) or occurring for each neuron separately one neuron after another (serial, i.e., no overlaps in time windows). For both cases, the number of potential and established synapses remained comparable. Topological and spatial properties, however, differed: Neurons that started axon growth early on in serial growth achieved higher out-degrees, higher local efficiency and longer axon lengths while neurons demonstrated more homogeneous connectivity patterns for parallel growth. Second, connection probability decreased more rapidly with distance between neurons for parallel growth than for serial growth. Third, bidirectional connections were more numerous for parallel growth. Finally, we tested our predictions with C. elegans data. Together, this indicates that time windows for axon growth influence the topological and spatial properties of neuronal networks opening up the possibility to a posteriori estimate developmental mechanisms based on network properties of a developed network.

  4. Parametric Probability Distribution Functions for Axon Diameters of Corpus Callosum

    Directory of Open Access Journals (Sweden)

    Farshid eSepehrband

    2016-05-01

    Full Text Available Axon diameter is an important neuroanatomical characteristic of the nervous system that alters in the course of neurological disorders such as multiple sclerosis. Axon diameters vary, even within a fiber bundle, and are not normally distributed. An accurate distribution function is therefore beneficial, either to describe axon diameters that are obtained from a direct measurement technique (e.g., microscopy, or to infer them indirectly (e.g., using diffusion-weighted MRI. The gamma distribution is a common choice for this purpose (particularly for the inferential approach because it resembles the distribution profile of measured axon diameters which has been consistently shown to be non-negative and right-skewed. In this study we compared a wide range of parametric probability distribution functions against empirical data obtained from electron microscopy images. We observed that the gamma distribution fails to accurately describe the main characteristics of the axon diameter distribution, such as location and scale of the mode and the profile of distribution tails. We also found that the generalized extreme value distribution consistently fitted the measured distribution better than other distribution functions. This suggests that there may be distinct subpopulations of axons in the corpus callosum, each with their own distribution profiles. In addition, we observed that several other distributions outperformed the gamma distribution, yet had the same number of unknown parameters; these were the inverse Gaussian, log normal, log logistic and Birnbaum-Saunders distributions.

  5. Axon-glia interaction and membrane traffic in myelin formation

    Directory of Open Access Journals (Sweden)

    Robin eWhite

    2014-01-01

    Full Text Available In vertebrate nervous systems myelination of neuronal axons has evolved to increase conduction velocity of electrical impulses with minimal space and energy requirements. Myelin is formed by specialised glial cells which ensheath axons with a lipid-rich insulating membrane. Myelination is a multi-step process initiated by axon-glia recognition triggering glial polarisation followed by targeted myelin membrane expansion and compaction. Thereby, a myelin sheath of complex subdomain structure is established. Continuous communication between neurons and glial cells is essential for myelin maintenance and axonal integrity. A diverse group of diseases, from multiple sclerosis to schizophrenia, have been linked to malfunction of myelinating cells reflecting the physiological importance of the axon-glial unit. This review describes the mechanisms of axonal signal integration by oligodendrocytes emphasising the central role of the Src-family kinase Fyn during CNS myelination. Furthermore, we discuss myelin membrane trafficking with particular focus on endocytic recycling and the control of PLP (proteolipid protein transport by SNARE proteins. Finally, PLP mistrafficking is considered in the context of myelin diseases.

  6. Cerebelite aguda causada por vírus Epstein-Barr: relato de caso

    Directory of Open Access Journals (Sweden)

    Teive Hélio A.G.

    2001-01-01

    Full Text Available A cerebelite aguda pode ocorrer em associação a infecção pelo vírus da varicela-zoster, enterovirus, caxumba, micoplasma e outros agentes infecciosos. A cerebelite aguda é uma complicação rara da infecção pelo vírus Epstein-Barr (EBV. Relatamos o caso de uma mulher de 21 anos com história de 12 dias de evolução com náuseas, vômitos, ataxia de marcha e membros, tremor cefálico e de membros, opsoclono, mioclonias e rash cutâneo. Sorologia para EBV foi positiva. A infecção pelo EBV, com complicações neurológicas, pode não se apresentar com os sinais e sintomas clássicos da mononucleose infeciosa.

  7. Nutrição na pancreatite aguda : monografia : Nutrition in acute pancreatitis

    OpenAIRE

    Oliveira, Joana da Silva

    2009-01-01

    Resumo da tese:A pancreatite aguda (PA) é uma doença inflamatória aguda do pâncreas de etiologia multifactorial e pode ter atingimento local (PA ligeira a moderada) ou sistémico (PA grave). A magnitude da lesão pancreática, a presença e extensão da necrose e de infecção determinam o grau de gravidade. Prever a gravidade é fundamental para direccionar antecipadamente a terapêutica médica e nutricional. Na sua maioria, os episódios de PA são ligeiros a moderados, de resolução espontânea, enquan...

  8. Formas duradouras e formas emergentes de trabalho precário entre os jornalistas brasileiros

    Directory of Open Access Journals (Sweden)

    Jeferson Bertolini

    2015-08-01

    Full Text Available Este artigo busca dimensionar o conceito de trabalho precário entre os jornalistas brasileiros. O texto indica que a categoria sempre esteve exposta a formas precárias de trabalho, mas que o problema se agravou nos últimos 10 anos, com as tecnologias digitais: elas redefiniram o perfil do profissional e reordenaram o modelo de negócio das empresas do setor. O manuscrito, baseado em levantamento bibliográfico e experiência de campo, lista oito formas duradouras e oito formas emergentes de trabalho precário no jornalismo.

  9. Axonal Conduction Delays, Brain State, and Corticogeniculate Communication.

    Science.gov (United States)

    Stoelzel, Carl R; Bereshpolova, Yulia; Alonso, Jose-Manuel; Swadlow, Harvey A

    2017-06-28

    Thalamocortical conduction times are short, but layer 6 corticothalamic axons display an enormous range of conduction times, some exceeding 40-50 ms. Here, we investigate (1) how axonal conduction times of corticogeniculate (CG) neurons are related to the visual information conveyed to the thalamus, and (2) how alert versus nonalert awake brain states affect visual processing across the spectrum of CG conduction times. In awake female Dutch-Belted rabbits, we found 58% of CG neurons to be visually responsive, and 42% to be unresponsive. All responsive CG neurons had simple, orientation-selective receptive fields, and generated sustained responses to stationary stimuli. CG axonal conduction times were strongly related to modulated firing rates (F1 values) generated by drifting grating stimuli, and their associated interspike interval distributions, suggesting a continuum of visual responsiveness spanning the spectrum of axonal conduction times. CG conduction times were also significantly related to visual response latency, contrast sensitivity (C-50 values), directional selectivity, and optimal stimulus velocity. Increasing alertness did not cause visually unresponsive CG neurons to become responsive and did not change the response linearity (F1/F0 ratios) of visually responsive CG neurons. However, for visually responsive CG neurons, increased alertness nearly doubled the modulated response amplitude to optimal visual stimulation (F1 values), significantly shortened response latency, and dramatically increased response reliability. These effects of alertness were uniform across the broad spectrum of CG axonal conduction times. SIGNIFICANCE STATEMENT Corticothalamic neurons of layer 6 send a dense feedback projection to thalamic nuclei that provide input to sensory neocortex. While sensory information reaches the cortex after brief thalamocortical axonal delays, corticothalamic axons can exhibit conduction delays of <2 ms to 40-50 ms. Here, in the corticogeniculate

  10. Dor aguda no joelho do paciente idoso Acute knee pain in elderly patients

    Directory of Open Access Journals (Sweden)

    Gilberto Luís Camanho

    2008-09-01

    Full Text Available A dor aguda no joelho de pacientes idosos é freqüente, sendo caracterizada por seu aparecimento súbito, sem causa aparente, com exame radiográfico dentro dos padrões da normalidade, na maioria dos casos. A etiologia da dor aguda no joelho é decorrente de insuficiência das estruturas, e seu quadro clínico difere completamente daquele determinado pela osteoartrose, sendo sempre unilateral e ocorre na grande maioria em pacientes do sexo feminino, após a quinta década de vida, e na região medial do joelho (local de maior carga. Com o propósito de analisar as possíveis etiologias para a dor aguda do joelho de pacientes acima de 60 anos de idade, suas características e tratamento, os autores discutem as etiologias relacionadas à dor aguda: lesão meniscal, fratura por fadiga e osteonecrose idiopática.Acute knee pain in elderly patients is not uncommon, and is characterized by a sudden onset, no apparent cause, and by normal radiographic findings in most cases. The etiology of acute knee pain is the result of insufficient structures, and clinical symptoms are totally different from the symptoms seen in osteoarthrosis. This acute pain in the knee is always unilateral and in the medial region of the knee joint (site with the heaviest load, predominantly in females after the fifth decade of live. In order to consider the possible etiologies for acute knee joint pain in patients older than 60 years, its characteristics and treatment, the authors discuss etiologies related to acute pain: lesion of the meniscus, stress fracture, and idiopathic osteonecrosis.

  11. Perfiles clínicos y hemodinámicos en pacientes con falla cardiaca aguda

    Directory of Open Access Journals (Sweden)

    Luis Eduardo Calderón

    2017-09-01

    Conclusiones: la falla cardíaca aguda descompensada es el perfil de presentación clínica más común en nuestra población con dos tercios del total de casos. El perfil hemodinámico más frecuente fue el “caliente y húmedo” (Stevenson B, resultados que concuerdan con lo observado en estudios locales y registros internacionales.

  12. Primeiro consenso brasileiro do tratamento da fase aguda do acidente vascular cerebral

    Directory of Open Access Journals (Sweden)

    2001-01-01

    Full Text Available Este texto apresenta a síntese das conclusões do Iº Consenso Brasileiro do Tratamento da Fase Aguda do Acidente Vascular Cerebral (AVC. Tratou-se de reunião patrocinada e coordenada pela Sociedade Brasileira de Doenças Cerebrovasculares, com neurologistas especializados nas doenças cerebrovasculares, que analisaram os principais itens da conduta dos AVC.

  13. Relación entre las infecciones respiratorias agudas altas y el asma bronquial

    Directory of Open Access Journals (Sweden)

    Verónica Soler Fonseca

    Full Text Available Introducción: la infección respiratoria es la enfermedad más frecuente en los seres humanos, pues es responsable de la mitad de todas las enfermedades agudas. En Cuba al igual que en el resto del mundo, el asma bronquial constituye un importante problema de salud con incidencia relevante en los niños. Se señala que las infecciones virales están involucradas en la patogénesis del asma, sobre todo en el paciente pediátrico. Objetivo: identificar la influencia de las Infecciones Respiratorias Agudas Altas en la aparición y exacerbación de las crisis de asma bronquial. Métodos: se realizó un estudio descriptivo, transversal y prospectivo de los pacientes ingresados con asma bronquial en el servicio de enfermedades respiratorias del Hospital Pediátrico Docente de San Miguel del Padrón, durante todo el año 2008. Resultados: el tiempo de evolución de la IRAA más frecuente que desencadenó la crisis de asma bronquial fue de más de 7 días, con un 54,8 %. Un total de 188 pacientes presentaron rinofaringitis aguda catarral relacionada con la aparición de la crisis de asma bronquial, lo que representó el 82,4 % del total de la muestra. Conclusiones: predominó el grupo de 1 a 4 años con manifestaciones respiratorias altas de posible etiología viral sin diferencias apreciables en relación con el sexo. La mayoría de los pacientes que participaron en el estudio presentaron IRAA de etiología viral (Rinofaringitis, que precedieron la aparición y exacerbación de las crisis agudas de asma bronquial.

  14. Sertralina e pancreatite aguda: relato de caso Sertraline and acute pancreatitis: a case-report

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    André Malbergier

    2004-03-01

    Full Text Available A pancreatite aguda é uma patologia grave e com considerável morbidade e mortalidade. Vários fatores são apontados como possíveis causas de pancreatite aguda. Neste relato, será apresentado um caso de pancreatite aguda com possível associação causal com um inibidor seletivo de recaptura de serotonina: sertralina. Após um mês de tratamento com sertralina, uma paciente do sexo feminino, 55 anos, desenvolveu forte dor abdominal e elevação da amilase sérica. Após internação e retirada da sertralina, seus sintomas remitiram e os níveis de amilase voltaram ao normal. Pela potencial gravidade do quadro e pelo amplo uso desta medicação, tal associação deve ser lembrada em investigações de casos de pancreatite aguda.Acute pancreatitis is a severe disease with considerable morbidity and mortality. Many risk factors are causally related to acute pancreatitis. In this report, a case of acute pancreatitis with possible causal relationship with the use of a selective serotonin reuptake inhibitor, sertraline, will be discussed. After one month of treatment with sertraline, a female patient, 55 years-old, developed a severe abdominal pain and showed a serum amylase elevation. She was admitted to the hospital and the use of sertraline was interrupted. After that, the symptoms remitted and the serum amylase level returned to normal. Because of the potential severity of this disease and the widespread use of sertraline, this association should be reminded when investigating possible causes for acute pancreatitis.

  15. Necessidades básicas das esposas de pacientes infartados na fase aguda do tratamento

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    Edna Ikumi Umebayashi Takahashi

    1990-12-01

    Full Text Available Trata-se de um estudo exploratório que teve por finalidade as necessidades básicas das esposas de pacientes infartados, na fase aguda do tratamento. Foi utlizado como referencial para análise os conceitos de Nacessidades Básicas de MASLOW. Os resultados permitiram identificar como principais necessidades afetadas das esposas: segurança, amor e gregária, estima.

  16. NECESSIDADES BÁSICAS DAS ESPOSAS DE PACIENTES INFARTADOS, NA FASE AGUDA DO TRATAMENTO

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    Edna Ikumi Umebayashi Takahashi

    Full Text Available Trata-se de um estudo exploratório que teve por finalidade identificar as necessidades básicas das esposas de pacientes infartados, na fase aguda do tratamento. Foi utilizado como referencial para análise os conceitos de Necessidades Básicas de Maslow. Os resultados permitiram identificar como principais necessidades afetadas das esposas: segurança, amor e gregária, estima.

  17. Necessidades básicas das esposas de pacientes infartados na fase aguda do tratamento

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    Edna Ikumi Umebayashi Takahashi

    Full Text Available Trata-se de um estudo exploratório que teve por finalidade as necessidades básicas das esposas de pacientes infartados, na fase aguda do tratamento. Foi utlizado como referencial para análise os conceitos de Nacessidades Básicas de MASLOW. Os resultados permitiram identificar como principais necessidades afetadas das esposas: segurança, amor e gregária, estima.

  18. Consideraciones actuales sobre el diagnóstico de la apendicitis aguda: Current criteria Diagnosis of acute appendicitis:

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    Zenén Rodríguez Fernández

    2009-09-01

    Full Text Available INTRODUCCIÓN. El objetivo de la presente investigación fue identificar algunos aspectos relacionados con el diagnóstico preoperatorio de la apendicitis aguda, según variables seleccionadas, así como establecer comparaciones con los hallazgos de otros autores. MÉTODOS. Se realizó un estudio observacional, descriptivo y prospectivo de 560 pacientes operados y dados de alta con el diagnóstico histopatológico de apendicitis aguda. Los pacientes fueron atendidos en el Servicio de Cirugía General del Hospital Provincial Docente «Saturnino Lora» de Santiago de Cuba, durante el 2006. RESULTADOS. Entre los resultados más importantes sobresalieron el predominio de los varones jóvenes con mediana de edad de 25,5 años y la preponderancia del diagnóstico clínico. La mediana del tiempo de evolución preoperatoria fue mayor en los hombres y predominaron las variedades gangrenosa y perforada, aunque la primacía correspondió a la apendicitis supurada. En los fallecidos se detectaron las formas histopatológicas más graves, y estos fueron ancianos con manifestaciones clínicas atípicas de la enfermedad. CONCLUSIONES. El método clínico continúa teniendo una importancia capital, pues a través de él se puede diagnosticar precozmente esta urgencia tan común y reducir el tiempo de evolución preoperatoria, cuya prolongación es causa de morbilidad y mortalidad innecesarias.INTRODUCTION: The aim of present paper was to identify some features related to preoperative diagnosis of acute appendicitis, according the selected variables, as well as to establish comparisons with findings from other authors. METHODS: We made a prospective, descriptive and observational study of 560 patients operated on and discharged with the histopathology diagnosis of acute appendicitis. Patients were seen in General Surgery Service of the "Saturnino Lora" Teaching Provincial Hospital of Santiago de Cuba during year 2006. RESULTS: Among the more significant results

  19. Wnt5a regulates midbrain dopaminergic axon growth and guidance.

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    Brette D Blakely

    2011-03-01

    Full Text Available During development, precise temporal and spatial gradients are responsible for guiding axons to their appropriate targets. Within the developing ventral midbrain (VM the cues that guide dopaminergic (DA axons to their forebrain targets remain to be fully elucidated. Wnts are morphogens that have been identified as axon guidance molecules. Several Wnts are expressed in the VM where they regulate the birth of DA neurons. Here, we describe that a precise temporo-spatial expression of Wnt5a accompanies the development of nigrostriatal projections by VM DA neurons. In mice at E11.5, Wnt5a is expressed in the VM where it was found to promote DA neurite and axonal growth in VM primary cultures. By E14.5, when DA axons are approaching their striatal target, Wnt5a causes DA neurite retraction in primary cultures. Co-culture of VM explants with Wnt5a-overexpressing cell aggregates revealed that Wnt5a is capable of repelling DA neurites. Antagonism experiments revealed that the effects of Wnt5a are mediated by the Frizzled receptors and by the small GTPase, Rac1 (a component of the non-canonical Wnt planar cell polarity pathway. Moreover, the effects were specific as they could be blocked by Wnt5a antibody, sFRPs and RYK-Fc. The importance of Wnt5a in DA axon morphogenesis was further verified in Wnt5a-/- mice, where fasciculation of the medial forebrain bundle (MFB as well as the density of DA neurites in the MFB and striatal terminals were disrupted. Thus, our results identify a novel role of Wnt5a in DA axon growth and guidance.

  20. Modelling in vivo action potential propagation along a giant axon.

    Science.gov (United States)

    George, Stuart; Foster, Jamie M; Richardson, Giles

    2015-01-01

    A partial differential equation model for the three-dimensional current flow in an excitable, unmyelinated axon is considered. Where the axon radius is significantly below a critical value R(crit) (that depends upon intra- and extra-cellular conductivity and ion channel conductance) the resistance of the intracellular space is significantly higher than that of the extracellular space, such that the potential outside the axon is uniformly small whilst the intracellular potential is approximated by the transmembrane potential. In turn, since the current flow is predominantly axial, it can be shown that the transmembrane potential is approximated by a solution to the one-dimensional cable equation. It is noted that the radius of the squid giant axon, investigated by (Hodgkin and Huxley 1952e), lies close to R(crit). This motivates us to apply the three-dimensional model to the squid giant axon and compare the results thus found to those obtained using the cable equation. In the context of the in vitro experiments conducted in (Hodgkin and Huxley 1952e) we find only a small difference between the wave profiles determined using these two different approaches and little difference between the speeds of action potential propagation predicted. This suggests that the cable equation approximation is accurate in this scenario. However when applied to the it in vivo setting, in which the conductivity of the surrounding tissue is considerably lower than that of the axoplasm, there are marked differences in both wave profile and speed of action potential propagation calculated using the two approaches. In particular, the cable equation significantly over predicts the increase in the velocity of propagation as axon radius increases. The consequences of these results are discussed in terms of the evolutionary costs associated with increasing the speed of action potential propagation by increasing axon radius.

  1. Forma de crecimiento en Leptochloa Chloridiformis (Poaceae

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    Mariel G. Perreta

    2000-01-01

    Full Text Available Perreta, M. G., Tivano, J. C. & Vegetti, A. C. 2000. Forma de crecimiento en Leptochloachloridiformis (Poaceae. Darwiniana 38(3-4: 219-226.El objetivo de este trabajo fue analizar la forma de crecimiento de Leptochloa chloridiformis (Hack.Parodi. En esta especie perenne la ramificación ocurre principalmente a través de yemas axilarespresentes en la zona de innovación. Este sistema de ramificación genera una planta cespitosa, en la cual lasconexiones entre unidades estructurales son rizomas cortos. Dependiendo de su posición estas conexio-nes muestran diferentes tendencias en relación a la desarticulación estructural. En algunas plantas seobservó ramificación en la zona de entrenudos largos posiblemente debido a cambios ambientalesrelacionados con las distintas estaciones

  2. Las formas del recuerdo. La memoria colectiva

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    Jorge Mendoza García

    2004-11-01

    Full Text Available La memoria tiene una estructura narrativa. Sus contenidos, formas y maneras de expresión así lo ponen de manifiesto. Retomando planteamientos de los fundadores de la perspectiva de la memoria colectiva, Halbwachs, Blondel, Bartlett y Vygotsky, y reflexionando desde los postulados de Bruner, el presente trabajo argumenta que la memoria, incluso la denominada individual, se construye sobre la base de narraciones que constituyen formas de discursos y modos de organizar experiencias, por ejemplo las pasadas, que son culturalmente dotados de significado, y que para ser inteligibles a la persona, grupo, sociedad o colectividad a quien se presentan hay que expresarla en relatos lógicos que muestren la verosimilitud de lo que se está recordando o relatando. Ciertamente, en la vida cotidiana encontramos cantidad de narraciones sobre las experiencias colectivas, encontramos ?narradores de historias?, y como ocurre en la literatura no sólo vale lo que se cuenta sino cómo se cuenta. Así como hay convenciones de ideas sobre la realidad, las hay también para las narrativas: existen modelos narrativos que hacen más verosímil una narración que otra. Tales narraciones dotan de sentido al mundo. Las narraciones, asimismo, devienen marcos sociales de la memoria, como el tiempo y espacio de los que habló Halbwachs, la modalidad narrativa es un marco, una manera de enmarcar la experiencia, y lo que no se estructura de forma narrativa se pierde de la memoria. A esos marcos Bartlett los denomin esquemas, que son delineados por instituciones, costumbres y grupos, que dictan cómo hay que presentar los eventos pasados, es decir, cómo hay que narrarlos, y en tanto relatos, éstos dan forma a las realidades que crean y eso opera para las experiencias pasadas que el grupo guarda.

  3. Tratamiento quirúrgico de las colecciones agudas y crónicas del pericardio

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    Orestes Noel Mederos Curbelo

    Full Text Available Introducción: las colecciones agudas o crónicas del pericardio con frecuencia producen una compresión del corazón que en los casos crónicos conlleva invalidez y, en los agudos, peligro de muerte por taponamiento cardíaco. Objetivo: caracterizar a los pacientes intervenidos quirúrgicamente en el Hospital Universitario "Comandante Manuel Fajardo" entre 1995 y 2012 a causa de colecciones pericárdicas. Métodos: se realizó un estudio descriptivo transversal con los pacientes atendidos quirúrgicamente en dicha institución por colecciones del pericardio. Constituyeron el universo 24 pacientes: 22 con colecciones agudas y 2 con colecciones crónicas. Resultados: la causa más frecuente de los derrames agudos fue la pericarditis aguda idiopática (25 %. Las colecciones crónicas fueron por pericarditis fibrosa de causa idiopática en el 100 % de los enfermos. La intervención realizada fue la resección del pericardio y el drenaje de las colecciones agudas mediante toracotomía izquierda o por vía preperitoneal subxifoidea. En las colecciones de origen maligno se realizó la resección pericárdica con fines paliativos y, en los derrames por lesión traumática del corazón, la sutura de este órgano fue el tratamiento quirúrgico empleado en todos los casos. En las pericarditis constrictivas, la pericardiectomía radical fue el tratamiento empleado en el 100 % de los casos. Conclusiones: el tratamiento quirúrgico en las colecciones agudas y crónicas del pericardio permite drenar el contenido por una ventana pericárdica obtenida por toracoscopia o por vía preperitoneal subxifoidea, mientras que la toracotomía izquierda es útil en las emergencias. En los derrames crónicos con fibrosis y síntomas de insuficiencia cardíaca, la pericardiectomía radical mediante esternotomía media ofrece los mejores resultados.

  4. Intoxicaciones agudas graves en un servicio de medicina intensiva durante doce años

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    Palazón Sánchez C

    2000-01-01

    Full Text Available Fundamento: Conocer la epidemiología de las intoxicaciones agudas graves en un servicio de medicina intensiva y evaluar el pronóstico de la PCR y mortalidad asociada a los distintos tóxicos Métodos: Estudio retrospectivo realizado en el servicio de medicina intensiva polivalente de 10 camas, ubicado en un Hospital General de adultos. Período de estudio 12 años. Revisión de las historias clínicas de las personas ingresadas en el servicio de medicina intensiva por intoxicaciones agudas graves. Se recogieron datos demográficos, existencia de PCR al ingreso, necesidad de VM, complicaciones de las intoxicaciones agudas graves y mortalidad de la serie. Se realizó un análisis global y por año de estudio. El tratamiento estadístico de los datos se realizó con el paquete SPSS mediante la "t" de Student o la "chi" cuadrado, considerando valores significativos si p<0,05 Resultados: Se han incluido 233 sujetos, de los que 130 fueron varones. La estancia media fue de 4 días. El 63% de los pacientes fueron menores de 40 años (p<0,05. La intoxicación más frecuente fue la medicamentosa debida a un solo producto (72%. La supervivencia tras la PCR fue del 40% (4/10. La mortalidad global se situó en el 5,6% (n=13, habiendo precisado el 92% de los sujetos que posteriormente murieron, VM en algún momento de su ingreso en la unidad de cuidados intensivos. Conclusiones: En nuestro medio, la intoxicación más frecuente es la medicamentosa. La mortalidad se muestra dependiente del carácter de voluntariedad, pero independiente del tipo de tóxico (medicamentoso o no. La PCR asociada a las intoxicaciones agudas graves tiene, en nuestra serie, un mejor pronostico que la asociada a otras patologías. La VM asociada a las intoxicaciones agudas graves tiene una mortalidad baja (15,7%

  5. Intoxicação experimental aguda por Senecio brasiliensis em ovinos e indução de resistência à intoxicação

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    Fabiane B. Grecco

    2012-09-01

    Full Text Available Ovinos são mais resistentes à intoxicação por Senecio spp. que bovinos e equinos. Para determinar se essa resistência é induzida pela ingestão de pequenas e repetidas doses da planta e se essa resistência é duradoura, foram realizados três experimentos com folhas e talos verdes de Senecio brasilienses. Para determinar a dose mínima que causa intoxicação aguda (experimento 1, foram administradas doses únicas de 60, 80, 90, 100 e 100g/kg de peso corporal (pc a cinco ovinos, respectivamente. Os animais que receberam 60 e 80 g/kg de pc de S. brasiliensis não adoeceram, porém o ovino que recebeu 80g/kg de pc apresentava fibrose e megalocitose discretas nas biópsias realizadas aos 90, 120 e 150 dias do término da administração da planta. Os ovinos que receberam 90 e 100g/kg de pc apresentaram anorexia, prostração, movimentos de pedalagem, dor abdominal e morte 12-48 horas após o aparecimento dos sinais clínicos. Na necropsia havia ascite, petéquias disseminadas e acentuação do padrão lobular hepático. Histologicamente havia necrose hemorrágica centro-lobular. No Experimento 2 a dose capaz de causar a intoxicação aguda foi fracionada e administrada em duas, cinco e 10 doses diárias para 3 ovinos, respectivamente. A dose tóxica fracionada não provocou sinais clínicos de intoxicação em nenhum dos ovinos, porém havia fibrose periportal e megalocitose moderadas nas biopsias realizadas aos 60 dias do término da administração da planta, as quais não evoluíram. O ovino que recebeu a dose fracionada em 10 administrações não apresentou lesões histológicas nas biópsias. Para determinar se os ovinos tornam-se resistentes à forma aguda da intoxicação (experimento 3, foram administradas doses diárias de 15g/kg de pc por 30 dias e 30g/kg de pc por 10 dias a quatro ovinos. No dia seguinte à última administração dois ovinos receberam a dose única de 100g/kg de pc de S. brasiliensis, mas não adoeceram nem

  6. Cortical Interneuron Subtypes Vary in Their Axonal Action Potential Properties.

    Science.gov (United States)

    Casale, Amanda E; Foust, Amanda J; Bal, Thierry; McCormick, David A

    2015-11-25

    The role of interneurons in cortical microcircuits is strongly influenced by their passive and active electrical properties. Although different types of interneurons exhibit unique electrophysiological properties recorded at the soma, it is not yet clear whether these differences are also manifested in other neuronal compartments. To address this question, we have used voltage-sensitive dye to image the propagation of action potentials into the fine collaterals of axons and dendrites in two of the largest cortical interneuron subtypes in the mouse: fast-spiking interneurons, which are typically basket or chandelier neurons; and somatostatin containing interneurons, which are typically regular spiking Martinotti cells. We found that fast-spiking and somatostatin-expressing interneurons differed in their electrophysiological characteristics along their entire dendrosomatoaxonal extent. The action potentials generated in the somata and axons, including axon collaterals, of somatostatin-expressing interneurons are significantly broader than those generated in the same compartments of fast-spiking inhibitory interneurons. In addition, action potentials back-propagated into the dendrites of somatostatin-expressing interneurons much more readily than fast-spiking interneurons. Pharmacological investigations suggested that axonal action potential repolarization in both cell types depends critically upon Kv1 channels, whereas the axonal and somatic action potentials of somatostatin-expressing interneurons also depend on BK Ca(2+)-activated K(+) channels. These results indicate that the two broad classes of interneurons studied here have expressly different subcellular physiological properties, allowing them to perform unique computational roles in cortical circuit operations. Neurons in the cerebral cortex are of two major types: excitatory and inhibitory. The proper balance of excitation and inhibition in the brain is critical for its operation. Neurons contain three main

  7. Tratamento cirúrgico postergado da pancreatite aguda biliar

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    Rodrigo Altenfelder Silva

    Full Text Available A análise do tratamento cirúrgico de doentes portadores de pancreatite biliar mostra a existência de controvérsias em relação à oportunidade da intervenção, principalmente se deve ser precoce ou postergada. Do mesmo modo, a possibilidade do emprego de procedimentos endoscópicos no pré, intra ou pós-operatório e o advento da videolaparoscopia, trouxeram novos aspectos à discussão. Não existe consenso sobre a escolha da melhor conduta. Em função disso, analisamos retrospectivamente os resultados imediatos de 107 doentes portadores de forma leve de pancreatite, todos com menos de três sinais de gravidade, segundo o critério de estratificação proposto por Ranson, e que foram submetidos ao tratamento cirúrgico postergado na mesma internação, no período de janeiro de 1988 a maio de 1999, tanto por via convencional como por via laparoscópica. Desses, 80 doentes (75% eram do sexo feminino, 90% da raça branca e a média de idade foi de 46 anos. Os doentes foram operados em média após 9,5 dias de internação e receberam alta hospitalar após 2,9 dias, o que resultou numa permanência hospitalar média de 12,6 dias. A colangiografia intra-operatória foi realizada em 102 casos (96% e a colangiografia endoscópica pré-operatória em 24 doentes (22,4%. Os resultados mostraram incidência de coledocolitíase em 25 casos (23%, taxa de morbidade de 12% e mortalidade nula. Dos 107 casos estudados, 64 (60% foram operados pela via de acesso convencional e 43 (40% pela via laparoscópica. A comparação dos resultados entre as vias de acesso empregadas mostrou diferença estatística significante em relação ao intervalo de tempo pós-operatório, que foi menor nos doentes submetidos à via de acesso laparoscópica. Concluímos, assim, que o tratamento cirúrgico postergado de doentes portadores de pancreatite biliar na forma leve apresenta baixas morbidade e mortalidade e pode ser feito tanto pela via convencional como pela via

  8. Mechanistic logic underlying the axonal transport of cytosolic proteins

    Science.gov (United States)

    Scott, David A.; Das, Utpal; Tang, Yong; Roy, Subhojit

    2011-01-01

    Proteins vital to presynaptic function are synthesized in the neuronal perikarya and delivered into synapses via two modes of axonal transport. While membrane-anchoring proteins are conveyed in fast axonal transport via motor-driven vesicles, cytosolic proteins travel in slow axonal transport; via mechanisms that are poorly understood. We found that in cultured axons, populations of cytosolic proteins tagged to photoactivable-GFP (PA-GFP) move with a slow motor-dependent anterograde bias; distinct from vesicular-trafficking or diffusion of untagged PA-GFP. The overall bias is likely generated by an intricate particle-kinetics involving transient assembly and short-range vectorial spurts. In-vivo biochemical studies reveal that cytosolic proteins are organized into higher-order structures within axon-enriched fractions that are largely segregated from vesicles. Data-driven biophysical modeling best predicts a scenario where soluble molecules dynamically assemble into mobile supra-molecular structures. We propose a model where cytosolic proteins are transported by dynamically assembling into multi-protein complexes that are directly/indirectly conveyed by motors. PMID:21555071

  9. Protein Prenylation Constitutes an Endogenous Brake on Axonal Growth

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    Hai Li

    2016-07-01

    Full Text Available Suboptimal axonal regeneration contributes to the consequences of nervous system trauma and neurodegenerative disease, but the intrinsic mechanisms that regulate axon growth remain unclear. We screened 50,400 small molecules for their ability to promote axon outgrowth on inhibitory substrata. The most potent hits were the statins, which stimulated growth of all mouse- and human-patient-derived neurons tested, both in vitro and in vivo, as did combined inhibition of the protein prenylation enzymes farnesyltransferase (PFT and geranylgeranyl transferase I (PGGT-1. Compensatory sprouting of motor axons may delay clinical onset of amyotrophic lateral sclerosis (ALS. Accordingly, elevated levels of PGGT1B, which would be predicted to reduce sprouting, were found in motor neurons of early- versus late-onset ALS patients postmortem. The mevalonate-prenylation pathway therefore constitutes an endogenous brake on axonal growth, and its inhibition provides a potential therapeutic approach to accelerate neuronal regeneration in humans.

  10. Mechanisms of Distal Axonal Degeneration in Peripheral Neuropathies

    Science.gov (United States)

    Cashman, Christopher R.; Höke, Ahmet

    2015-01-01

    Peripheral neuropathy is a common complication of a variety of diseases and treatments, including diabetes, cancer chemotherapy, and infectious causes (HIV, hepatitis C, and Campylobacter jejuni). Despite the fundamental difference between these insults, peripheral neuropathy develops as a combination of just six primary mechanisms: altered metabolism, covalent modification, altered organelle function and reactive oxygen species formation, altered intracellular and inflammatory signaling, slowed axonal transport, and altered ion channel dynamics and expression. All of these pathways converge to lead to axon dysfunction and symptoms of neuropathy. The detailed mechanisms of axon degeneration itself have begun to be elucidated with studies of animal models with altered degeneration kinetics, including the slowed Wallerian degeneration (Wlds) and Sarmknockout animal models. These studies have shown axonal degeneration to occur througha programmed pathway of injury signaling and cytoskeletal degradation. Insights into the common disease insults that converge on the axonal degeneration pathway promise to facilitate the development of therapeutics that may be effective against other mechanisms of neurodegeneration. PMID:25617478

  11. Calpain Inhibition Reduces Axolemmal Leakage in Traumatic Axonal Injury

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    János Sándor

    2009-12-01

    Full Text Available Calcium-induced, calpain-mediated proteolysis (CMSP has recently been implicated to the pathogenesis of diffuse (traumatic axonal injury (TAI. Some studies suggested that subaxolemmal CMSP may contribute to axolemmal permeability (AP alterations observed in TAI. Seeking direct evidence for this premise we investigated whether subaxolemmal CMSP may contribute to axolemmal permeability alterations (APA and pre-injury calpain-inhibition could reduce AP in a rat model of TAI. Horseradish peroxidase (HRP, a tracer that accumulates in axons with APA was administered one hour prior to injury into the lateral ventricle; 30 min preinjury a single tail vein bolus injection of 30 mg/kg MDL-28170 (a calpain inhibitor or its vehicle was applied in Wistar rats exposed to impact acceleration brain injury. Histological detection of traumatically injured axonal segments accumulating HRP and statistical analysis revealed that pre-injury administration of the calpain inhibitor MDL-28170 significantly reduced the average length of HRP-labeled axonal segments. The axono-protective effect of pre-injury calpain inhibition recently demonstrated with classical immunohistochemical markers of TAI was further corroborated in this experiment; significant reduction of the length of labeled axons in the drug-treated rats implicate CMSP in the progression of altered AP in TAI.

  12. Subtypes of GABAergic neurons project axons in the neocortex

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    Shigeyoshi Higo

    2009-11-01

    Full Text Available γ-aminobutyric acid (GABAergic neurons in the neocortex have been regarded as interneurons and speculated to modulate the activity of neurons locally. Recently, however, several experiments revealed that neuronal nitric oxide synthase (nNOS-positive GABAergic neurons project cortico-cortically with long axons. In this study, we illustrate Golgi-like images of the nNOS-positive GABAergic neurons using a nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d reaction and follow the emanating axon branches in cat brain sections. These axon branches projected cortico-cortically with other non-labeled arcuate fibers, contra-laterally via the corpus callosum and anterior commissure. The labeled fibers were not limited to the neocortex but found also in the fimbria of the hippocampus. In order to have additional information on these GABAergic neuron projections, we investigated green fluorescent protein (GFP-labeled GABAergic neurons in GAD67-Cre knock-in / GFP Cre-reporter mice. GFP-labeled axons emanate densely, especially in the fimbria, a small number in the anterior commissure, and very sparsely in the corpus callosum. These two different approaches confirm that not only nNOS-positive GABAergic neurons but also other subtypes of GABAergic neurons project long axons in the cerebral cortex and are in a position to be involved in information processing.

  13. Characterization of patients with head trauma and traumatic axonal injury

    International Nuclear Information System (INIS)

    Mosquera Betancourt, Dra.C. Gretel; Van Duc, Dr. Hanh; Casares Delgado, Dr. Jorge Alejandro; Hernández González, Dr. Erick Héctor

    2016-01-01

    Background: traumatic axonal injury is characterized by multifocal lesions, consequences of primary, secondary and tertiary damage which is able to cause varying degrees of disability. Objective: to characterize patients with traumatic axonal injury. Methods: a cross-sectional analytical study was conducted from January 2014 to December 2015. The target population was composed of 35 patients over age 18 whose diagnosis was traumatic axonal injury type I and IV of the Marshall computed tomographic (CT) classification. With the data collected from medical records revisions and direct observation, a database was created in SPSS for its processing through univariate and multivariate techniques. Results: male patients between 18 and 30 years old without bad habits prevailed. Most of the patients survived and death was associated with the presence of severe traumatic axonal injury, Marshall computed tomographic (CT) classification degree III, complications and presence of trauma in thorax, abdomen and cervical spine. Conclusions: diagnosis of traumatic axonal injury is based on the clinical radiological correlation based on images from tomography and it is confirmed by Magnetic resonance imaging (MRI). Histological study shows injuries that are not demonstrated in the most advanced radiological studies. Its prevention is the most fundamental base in medical assistance, followed by neurocritical attention oriented by neuromonitoring. (author)

  14. Highly effective photonic cue for repulsive axonal guidance.

    Directory of Open Access Journals (Sweden)

    Bryan J Black

    Full Text Available In vivo nerve repair requires not only the ability to regenerate damaged axons, but most importantly, the ability to guide developing or regenerating axons along paths that will result in functional connections. Furthermore, basic studies in neuroscience and neuro-electronic interface design require the ability to construct in vitro neural circuitry. Both these applications require the development of a noninvasive, highly effective tool for axonal growth-cone guidance. To date, a myriad of technologies have been introduced based on chemical, electrical, mechanical, and hybrid approaches (such as electro-chemical, optofluidic flow and photo-chemical methods. These methods are either lacking in desired spatial and temporal selectivity or require the introduction of invasive external factors. Within the last fifteen years however, several attractive guidance cues have been developed using purely light based cues to achieve axonal guidance. Here, we report a novel, purely optical repulsive guidance technique that uses low power, near infrared light, and demonstrates the guidance of primary goldfish retinal ganglion cell axons through turns of up to 120 degrees and over distances of ∼90 µm.

  15. Functional complexity of the axonal growth cone: a proteomic analysis.

    Directory of Open Access Journals (Sweden)

    Adriana Estrada-Bernal

    Full Text Available The growth cone, the tip of the emerging neurite, plays a crucial role in establishing the wiring of the developing nervous system. We performed an extensive proteomic analysis of axonal growth cones isolated from the brains of fetal Sprague-Dawley rats. Approximately 2000 proteins were identified at ≥ 99% confidence level. Using informatics, including functional annotation cluster and KEGG pathway analysis, we found great diversity of proteins involved in axonal pathfinding, cytoskeletal remodeling, vesicular traffic and carbohydrate metabolism, as expected. We also found a large and complex array of proteins involved in translation, protein folding, posttranslational processing, and proteasome/ubiquitination-dependent degradation. Immunofluorescence studies performed on hippocampal neurons in culture confirmed the presence in the axonal growth cone of proteins representative of these processes. These analyses also provide evidence for rough endoplasmic reticulum and reveal a reticular structure equipped with Golgi-like functions in the axonal growth cone. Furthermore, Western blot revealed the growth cone enrichment, relative to fetal brain homogenate, of some of the proteins involved in protein synthesis, folding and catabolism. Our study provides a resource for further research and amplifies the relatively recently developed concept that the axonal growth cone is equipped with proteins capable of performing a highly diverse range of functions.

  16. Effect of hyperthermia on experimental acute pancreatitis Efeito da hipertermia na pancreatite aguda experimental

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    José Luiz Jesus de Almeida

    2006-12-01

    Full Text Available BACKGROUD: Recent studies indicate that hyperthermia can change inflammatory mechanisms and protect experimental animals from deleterious effects of secretagogue-induced acute pancreatitis AIM: To evaluate the effects of hyperthermia post-treatment on cerulein-induced acute pancreatitis in rats METHODS: Twenty animals were divided in two groups: group I (n = 10, rats with cerulein-induced acute pancreatitis undergone hyperthermia, and group II (n = 10, animals with cerulein-induced acute pancreatitis that were kept normothermic. In all groups, amylase serum levels, histologic damage, vascular permeability and pancreatic water content were assessed. Acute pancreatitis was induced by administration of two cerulein injections (20 mcg/kg. A single dose of Evans' blue dye was administered along with the second dose of cerulein. All animals also received a subcutaneous injection of saline solution. After this process, animals undergone hyperthermia were heated in a cage with two 100 W lamps. Body temperature was increased to 39.5ºC and maintained at that level for 45 minutes. Normothermia rats were kept at room temperature in a second cage RESULTS: Control animals had typical edema, serum amylase activity and morphologic changes of this acute pancreatitis model. Hyperthermia post-treatment ameliorated the pancreatic edema, whereas the histologic damage and the serum amylase level remained unchanged CONCLUSIONS: The findings suggest a beneficial effect of the thermal stress on inflammatory edema in experimental acute pancreatitis.RACIONAL: Estudos recentes indicam que a hipertermia pode modificar mecanismos inflamatórios e proteger animais experimentais dos efeitos deletérios da pancreatite aguda induzida por secretagogos OBJETIVO: Avaliar a eficácia da hipertermia como tratamento da pancreatite aguda induzida por ceruleína em ratos MÉTODOS: Vinte animais foram divididos em dois grupos: grupo I (n = 10, ratos com pancreatite aguda induzida por

  17. Axonal transport and axon sprouting in the adult rat dentate gyrus: an autoradiographic study

    International Nuclear Information System (INIS)

    Goldowitz, D.; Cotman, C.W.

    1980-01-01

    In response to an entorhinal lesion, the commissural and associational afferents to the dentate gyrus have been shown to expand beyond their normal terminal zone into the area denervated by the entorhinal lesion. The present study has investigated the axonal transport of [ 3 H]-labeled proteins in the commissural and associational projections following an entorhinal lesion. Injections of [ 3 H]proline, [ 3 H]leucine or [ 3 H)fucose were given in the vicinity of the commissural and associational cells of origin before, immediately subsequent to, or at 5 to 15 days after the entorhinal lesion. The disposition of previously- or newly-synthesized proteins was examined in the commissural and associational terminal field at different times after an entorhinal lesion by light-microscopic autoradiography. (author)

  18. Axonal transport and axon sprouting in the adult rat dentate gyrus: an autoradiographic study

    Energy Technology Data Exchange (ETDEWEB)

    Goldowitz, D; Cotman, C W [California Univ., Irvine (USA)

    1980-12-01

    In response to an entorhinal lesion, the commissural and associational afferents to the dentate gyrus have been shown to expand beyond their normal terminal zone into the area denervated by the entorhinal lesion. The present study has investigated the axonal transport of (/sup 3/H)-labeled proteins in the commissural and associational projections following an entorhinal lesion. Injections of (/sup 3/H)proline, (/sup 3/H)leucine or (/sup 3/H)fucose were given in the vicinity of the commissural and associational cells of origin before, immediately subsequent to, or at 5 to 15 days after the entorhinal lesion. The disposition of previously- or newly-synthesized proteins was examined in the commissural and associational terminal field at different times after an entorhinal lesion by light-microscopic autoradiography.

  19. Localization of mRNA in vertebrate axonal compartments by in situ hybridization.

    Science.gov (United States)

    Sotelo-Silveira, José Roberto; Calliari, Aldo; Kun, Alejandra; Elizondo, Victoria; Canclini, Lucía; Sotelo, José Roberto

    2011-01-01

    The conclusive demonstration of RNA in vertebrate axons by in situ hybridization (ISH) has been elusive. We review the most important reasons for difficulties, including low concentration of axonal RNAs, localization in specific cortical domains, and the need to isolate axons. We demonstrate the importance of axon micro-dissection to obtain a whole mount perspective of mRNA distribution in the axonal territory. We describe a protocol to perform fluorescent ISH in isolated axons and guidelines for the preservation of structural and molecular integrity of cortical RNA-containing domains (e.g., Periaxoplasmic Ribosomal Plaques, or PARPs) in isolated axoplasm.

  20. Microcristais biliares na pancreatite aguda idiopática: indício para etiologia biliar oculta subjacente

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    CHEBLI Júlio Maria Fonseca

    2000-01-01

    Full Text Available As principais causas de inflamação pancreática no mundo são a litíase biliar e o alcoolismo crônico. Admite-se que 10 a 30% das pancreatites agudas sejam idiopáticas. Sugere-se que parte destas são causadas por microlitíase ou barro biliar, identificados pela presença de microcristais no sedimento biliar. Neste estudo, realizou-se análise microscópica da bile obtida por colangiopancreatografia endoscópica, em pacientes com pancreatite aguda idiopática, pancreatite aguda biliar e pancreatite crônica alcoólica - 20 em cada grupo. Pacientes com pancreatite aguda idiopática e microcristais na bile foram submetidos a colecistectomia. Naqueles inaptos à cirurgia efetuou-se esfincterotomia endoscópica ou tratamento com ácido ursodesoxicólico. Pacientes com pancreatite aguda idiopática sem cristais não receberam tratamento específico. A prevalência de microcristais biliares em pacientes com pancreatite aguda idiopática (75% e pancreatite aguda biliar (90% foi significativamente maior que naqueles com pancreatite crônica alcoólica (15%. A detecção de microcristais apresentou sensibilidade de 90%, especificidade de 85%, valor preditivo positivo de 85,7%, valor preditivo negativo de 89,4% e acurácia de 87,5% em identificar pancreatite de origem biliar. Nos pacientes com pancreatite aguda idiopática recurrente, cursando com microcristais, houve redução significante dos episódios de pancreatite após tratamento específico. No seguimento deste grupo durante 23,3 meses, recidiva ocorreu apenas naqueles que apresentavam "fator biliar persistente" (coledocolitíase ou microcristais. Todos os pacientes com pancreatite aguda idiopática submetidos a colecistectomia apresentavam colecistite crônica, e microlitíase foi observada em um paciente. No seguimento ultra-sonográfico, colelitíase foi detectada em um dos casos. No subgrupo de cinco pacientes com pancreatite aguda idiopática sem microcristais houve uma recidiva. Estudo

  1. Perilesional edema in radiation necrosis reflects axonal degeneration

    International Nuclear Information System (INIS)

    Perez-Torres, Carlos J; Yuan, Liya; Schmidt, Robert E; Rich, Keith M; Ackerman, Joseph JH; Garbow, Joel R

    2015-01-01

    Recently, we characterized a Gamma Knife® radiation necrosis mouse model with various magnetic resonance imaging (MRI) protocols to identify biomarkers useful in differentiation from tumors. Though the irradiation was focal to one hemisphere, a contralateral injury was observed that appeared to be localized in the white matter only. Interestingly, this injury was identifiable in T2-weighted images, apparent diffusion coefficient (ADC), and magnetization transfer ratio (MTR) maps, but not on post-contrast T1-weighted images. This observation of edema independent of vascular changes is akin to the perilesional edema seen in clinical radiation necrosis. The pathology underlying the observed white-matter MRI changes was explored by performing immunohistochemistry for healthy axons and myelin. The presence of both healthy axons and myelin was reduced in the contralateral white-matter lesion. Based on our immunohistochemical findings, the contralateral white-matter injury is most likely due to axonal degeneration

  2. The nano-architecture of the axonal cytoskeleton.

    Science.gov (United States)

    Leterrier, Christophe; Dubey, Pankaj; Roy, Subhojit

    2017-12-01

    The corporeal beauty of the neuronal cytoskeleton has captured the imagination of generations of scientists. One of the easiest cellular structures to visualize by light microscopy, its existence has been known for well over 100 years, yet we have only recently begun to fully appreciate its intricacy and diversity. Recent studies combining new probes with super-resolution microscopy and live imaging have revealed surprising details about the axonal cytoskeleton and, in particular, have discovered previously unknown actin-based structures. Along with traditional electron microscopy, these newer techniques offer a nanoscale view of the axonal cytoskeleton, which is important for our understanding of neuronal form and function, and lay the foundation for future studies. In this Review, we summarize existing concepts in the field and highlight contemporary discoveries that have fundamentally altered our perception of the axonal cytoskeleton.

  3. Chondroitin-4-sulfation negatively regulates axonal guidance and growth

    Science.gov (United States)

    Wang, Hang; Katagiri, Yasuhiro; McCann, Thomas E.; Unsworth, Edward; Goldsmith, Paul; Yu, Zu-Xi; Tan, Fei; Santiago, Lizzie; Mills, Edward M.; Wang, Yu; Symes, Aviva J.; Geller, Herbert M.

    2008-01-01

    Summary Glycosaminoglycan (GAG) side chains endow extracellular matrix proteoglycans with diversity and complexity based upon the length, composition, and charge distribution of the polysaccharide chain. Using cultured primary neurons, we show that specific sulfation in the GAG chains of chondroitin sulfate (CS) mediates neuronal guidance cues and axonal growth inhibition. Chondroitin-4-sulfate (CS-A), but not chondroitin-6-sulfate (CS-C), exhibits a strong negative guidance cue to mouse cerebellar granule neurons. Enzymatic and gene-based manipulations of 4-sulfation in the GAG side chains alter their ability to direct growing axons. Furthermore, 4-sulfated CS GAG chains are rapidly and significantly increased in regions that do not support axonal regeneration proximal to spinal cord lesions in mice. Thus, our findings provide the evidence showing that specific sulfation along the carbohydrate backbone carries instructions to regulate neuronal function. PMID:18768934

  4. Growing axons analysis by using Granulometric Size Distribution

    International Nuclear Information System (INIS)

    Gonzalez, Mariela A; Ballarin, Virginia L; Rapacioli, Melina; CelIn, A R; Sanchez, V; Flores, V

    2011-01-01

    Neurite growth (neuritogenesis) in vitro is a common methodology in the field of developmental neurobiology. Morphological analyses of growing neurites are usually difficult because their thinness and low contrast usually prevent to observe clearly their shape, number, length and spatial orientation. This paper presents the use of the granulometric size distribution in order to automatically obtain information about the shape, size and spatial orientation of growing axons in tissue cultures. The results here presented show that the granulometric size distribution results in a very useful morphological tool since it allows the automatic detection of growing axons and the precise characterization of a relevant parameter indicative of the axonal growth spatial orientation such as the quantification of the angle of deviation of the growing direction. The developed algorithms automatically quantify this orientation by facilitating the analysis of these images, which is important given the large number of images that need to be processed for this type of study.

  5. The axon-protective WLD(S) protein partially rescues mitochondrial respiration and glycolysis after axonal injury.

    Science.gov (United States)

    Godzik, Katharina; Coleman, Michael P

    2015-04-01

    The axon-protective Wallerian degeneration slow (WLD(S)) protein can ameliorate the decline in axonal ATP levels after neurite transection. Here, we tested the hypothesis that this effect is associated with maintenance of mitochondrial respiration and/or glycolysis. We used isolated neurites of superior cervical ganglion (SCG) cultures in the Seahorse XF-24 Metabolic Flux Analyser to determine mitochondrial respiration and glycolysis under different conditions. We observed that both mitochondrial respiration and glycolysis declined significantly during the latent phase of Wallerian degeneration. WLD(S) partially reduced the decline both in glycolysis and in mitochondrial respiration. In addition, we found that depleting NAD levels in uncut cultures led to changes in mitochondrial respiration and glycolysis similar to those rescued by WLD(S) after cut, suggesting that the maintenance of NAD levels in Wld(S) neurites after axonal injury at least partially underlies the maintenance of ATP levels. However, by using another axon-protective mutation (Sarm1(-/-)), we could demonstrate that rescue of basal ECAR (and hence probably glycolysis) rather than basal OCR (mitochondrial respiration) may be part of the protective phenotype to delay Wallerian degeneration. These findings open new routes to study glycolysis and the connection between NAD and ATP levels in axon degeneration, which may help to eventually develop therapeutic strategies to treat neurodegenerative diseases.

  6. Factores de riesgo para infección respiratoria aguda baja grave en Bogotá, 2001.

    Directory of Open Access Journals (Sweden)

    María Belén Jaimes

    2003-09-01

    Full Text Available La gravedad de la infección respiratoria aguda (IRA es mayor en países en desarrollo, sobre todo entre grupos social y económicamente pobres. Las neumonías virales son las más comunes, especialmente en niños. Con el fin de medir algunos factores asociados con formas graves de infección respiratoria baja realizamos un estudio de casos y controles prospectivo y de base hospitalaria en Bogotá entre noviembre de 2000 y agosto de 2001. Los casos fueron niños entre 2 meses y 5 años que llenaban los criterios de la OMS para IRA grave o muy grave. Los controles eran niños con IRA en el mismo rango de edad, que consultaban al mismo hospital y que no presentaban tirajes. Se estudiaron 638 niños entre los 2 meses y los 5 años de edad (277 casos y 361 controles. Los factores más importantes fueron: vivienda en préstamo (OR=2,7; IC95%: 1,06-7,07, compartir la cama (OR=1,88; IC95%: 1,0-3,7, más de 9 personas en la misma casa (OR=1,82; IC95%: 1,0-3,51 y fumadores en la vivienda (OR=1,4; IC95%: 1,0-2,05. Se tomaron 114 muestras nasofaríngeas (niños con 3 días de haber iniciado síntomas y se obtuvieron virus en 98 de ellas, y se identificó el virus sincitial respiratorio en 41,8%, virus influenza A en 3,1% y virus influenza B en 1%. El 100% de los aislamientos positivos para influenza A y B fueron enviados al CDC en Atlanta, donde fueron clasificados como influenza A/PANAMA/2007/99-like e influenza B/SICHUAN/379/99-like, respectivamente.

  7. Surto de aflatoxicose aguda em cães no município de Pelotas/RS

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    Karina Guterres

    Full Text Available RESUMO: As aflatoxinas pertencem ao grupo das micotoxinas e são substâncias sintetizadas durante a multiplicação de fungos que podem contaminar alimentos e rações animais, produzindo efeitos agudos ou crônicos naqueles que os consomem. Os cães são sensíveis aos efeitos tóxicos das aflatoxinas, havendo dificuldades de diagnóstico definitivo desta doença devido a fatores, como a inespecificidade dos sinais clínicos e o custo elevado da análise da presença de toxinas na alimentação. Desta forma, o objetivo deste artigo foi relatar um surto de aflatoxicose em dezoito caninos, no município de Pelotas - RS, no qual apenas um canino não veio a óbito, após a ingestão de quirelas de milho e arroz contaminadas. O diagnóstico definitivo de aflatoxicose aguda foi obtido através dos dados da anamnese, exames complementares, resultados de necropsia e histopatologia, além de análise da presença de toxinas na alimentação dos animais. Na necropsia observou-se degeneração e necrose hepática severa e na análise das amostras de alimento foi constatada a presença de aflatoxinas B1, B2, G1 e G2, em um somatório de 898,2μg/kg na quirela de milho e de 409,86μg/kg na de arroz. Assim sendo, medidas de conscientização acerca do controle e prevenção das micotoxicoses devem ser tomadas, salientando os possíveis danos à saúde dos animais. Além disto, métodos de identificação de micotoxinas, devem ser implementados na rotina hospitalar, incluindo a análise da ração oferecida, visto que a aflatoxicose, muitas vezes é subestimada.

  8. Otite externa difusa aguda: um estudo prospectivo no verão do Rio de Janeiro Acute diffuse external otitis: a prospective study in Rio de Janeiro's summer

    Directory of Open Access Journals (Sweden)

    Ricardo R. Figueiredo

    2004-04-01

    Full Text Available A Otite Externa Aguda é uma doença extremamente comum em países tropicais, especialmente no verão. Vários fatores predisponentes são identificáveis e o quadro clínico pode ser bastante variado, principalmente com relação à intensidade da otalgia. OBJETIVO: Avaliar, através de um estudo prospectivo no maior hospital de Emergências do Rio de Janeiro, a incidência e as características da otite externa no período de verão. FORMA DE ESTUDO: Estudo clínico com coorte transversal. MATERIAL E MÉTODO: 391 pacientes com otite externa atendidos no Serviço de ORL do Hospital Souza Aguiar foram avaliados em uma série de parâmetros clínicos e de tratamento, incluindo análise de possíveis fatores predisponentes. RESULTADOS: Os principais sintomas referidos foram otalgia, otorréia discreta e plenitude auricular. Os principais fatores predisponentes foram banho de mar e piscina e uso de cotonetes. CONCLUSÃO: A otite externa aguda é uma doença extremamente comum em países tropicais, especialmente no verão. A possível contaminação da água de praias e piscinas, embora descartada por vários autores como fatores predisponentes, pode ter alguma influência na sua patogênese.The acute external otitis is a very common disease in tropical countries, especially in summer. There are many predisposing factors and clinical features may vary, particularly the pain's severity. AIM: Evaluate, with a prospective study in Rio de Janeiro's largest Urgencies Hospital, the incidence and characteristics of the acute external otitis in summer. STUDY DESIGN: Clinical study with transversal cohort. MATERIAL AND METH: 391 patients with acute external otitis in Souza Aguiar Hospital were evaluated in several clinical and treatment parameters, including predisposing factors analysis. RESULTS Pain, moderate ear discharge and sensation of "full ear" were the most common complaints. Sea and pool baths and the use of ear sticks were the most common

  9. Uncovering sensory axonal dysfunction in asymptomatic type 2 diabetic neuropathy.

    Directory of Open Access Journals (Sweden)

    Jia-Ying Sung

    Full Text Available This study investigated sensory and motor nerve excitability properties to elucidate the development of diabetic neuropathy. A total of 109 type 2 diabetes patients were recruited, and 106 were analyzed. According to neuropathy severity, patients were categorized into G0, G1, and G2+3 groups using the total neuropathy score-reduced (TNSr. Patients in the G0 group were asymptomatic and had a TNSr score of 0. Sensory and motor nerve excitability data from diabetic patients were compared with data from 33 healthy controls. Clinical assessment, nerve conduction studies, and sensory and motor nerve excitability testing data were analyzed to determine axonal dysfunction in diabetic neuropathy. In the G0 group, sensory excitability testing revealed increased stimulus for the 50% sensory nerve action potential (P<0.05, shortened strength-duration time constant (P<0.01, increased superexcitability (P<0.01, decreased subexcitability (P<0.05, decreased accommodation to depolarizing current (P<0.01, and a trend of decreased accommodation to hyperpolarizing current in threshold electrotonus. All the changes progressed into G1 (TNSr 1-8 and G2+3 (TNSr 9-24 groups. In contrast, motor excitability only had significantly increased stimulus for the 50% compound motor nerve action potential (P<0.01 in the G0 group. This study revealed that the development of axonal dysfunction in sensory axons occurred prior to and in a different fashion from motor axons. Additionally, sensory nerve excitability tests can detect axonal dysfunction even in asymptomatic patients. These insights further our understanding of diabetic neuropathy and enable the early detection of sensory axonal abnormalities, which may provide a basis for neuroprotective therapeutic approaches.

  10. Pannexin 1 Modulates Axonal Growth in Mouse Peripheral Nerves

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    Steven M. Horton

    2017-11-01

    Full Text Available The pannexin family of channels consists of three members—pannexin-1 (Panx1, pannexin-2 (Panx2, and pannexin-3 (Panx3 that enable the exchange of metabolites and signaling molecules between intracellular and extracellular compartments. Pannexin-mediated release of intracellular ATP into the extracellular space has been tied to a number of cellular activities, primarily through the activity of type P2 purinergic receptors. Previous work indicates that the opening of Panx1 channels and activation of purinergic receptors by extracellular ATP may cause inflammation and apoptosis. In the CNS (central nervous system and PNS (peripheral nervous system, coupled pannexin, and P2 functions have been linked to peripheral sensitization (pain pathways. Purinergic pathways are also essential for other critical processes in the PNS, including myelination and neurite outgrowth. However, whether such pathways are pannexin-dependent remains to be determined. In this study, we use a Panx1 knockout mouse model and pharmacological inhibitors of the Panx1 and the ATP-mediated signaling pathway to fill gaps in our understanding of Panx1 localization in peripheral nerves, roles for Panx1 in axonal outgrowth and myelination, and neurite extension. Our data show that Panx1 is localized to axonal, myelin, and vascular compartments of the peripheral nerves. Knockout of Panx1 gene significantly increased axonal caliber in vivo and axonal growth rate in cultured dorsal root ganglia (DRG neurons. Furthermore, genetic knockout of Panx1 or inhibition of components of purinergic signaling, by treatment with probenecid and apyrase, resulted in denser axonal outgrowth from cultured DRG explants compared to untreated wild-types. Our findings suggest that Panx1 regulates axonal growth in the peripheral nervous system.

  11. Motoneuron axon pathfinding errors in zebrafish: Differential effects related to concentration and timing of nicotine exposure

    International Nuclear Information System (INIS)

    Menelaou, Evdokia; Paul, Latoya T.; Perera, Surangi N.; Svoboda, Kurt R.

    2015-01-01

    Nicotine exposure during embryonic stages of development can affect many neurodevelopmental processes. In the developing zebrafish, exposure to nicotine was reported to cause axonal pathfinding errors in the later born secondary motoneurons (SMNs). These alterations in SMN axon morphology coincided with muscle degeneration at high nicotine concentrations (15–30 μM). Previous work showed that the paralytic mutant zebrafish known as sofa potato exhibited nicotine-induced effects onto SMN axons at these high concentrations but in the absence of any muscle deficits, indicating that pathfinding errors could occur independent of muscle effects. In this study, we used varying concentrations of nicotine at different developmental windows of exposure to specifically isolate its effects onto subpopulations of motoneuron axons. We found that nicotine exposure can affect SMN axon morphology in a dose-dependent manner. At low concentrations of nicotine, SMN axons exhibited pathfinding errors, in the absence of any nicotine-induced muscle abnormalities. Moreover, the nicotine exposure paradigms used affected the 3 subpopulations of SMN axons differently, but the dorsal projecting SMN axons were primarily affected. We then identified morphologically distinct pathfinding errors that best described the nicotine-induced effects on dorsal projecting SMN axons. To test whether SMN pathfinding was potentially influenced by alterations in the early born primary motoneuron (PMN), we performed dual labeling studies, where both PMN and SMN axons were simultaneously labeled with antibodies. We show that only a subset of the SMN axon pathfinding errors coincided with abnormal PMN axonal targeting in nicotine-exposed zebrafish. We conclude that nicotine exposure can exert differential effects depending on the levels of nicotine and developmental exposure window. - Highlights: • Embryonic nicotine exposure can specifically affect secondary motoneuron axons in a dose-dependent manner.

  12. Motoneuron axon pathfinding errors in zebrafish: Differential effects related to concentration and timing of nicotine exposure

    Energy Technology Data Exchange (ETDEWEB)

    Menelaou, Evdokia; Paul, Latoya T. [Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803 (United States); Perera, Surangi N. [Joseph J. Zilber School of Public Health, University of Wisconsin — Milwaukee, Milwaukee, WI 53205 (United States); Svoboda, Kurt R., E-mail: svobodak@uwm.edu [Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803 (United States); Joseph J. Zilber School of Public Health, University of Wisconsin — Milwaukee, Milwaukee, WI 53205 (United States)

    2015-04-01

    Nicotine exposure during embryonic stages of development can affect many neurodevelopmental processes. In the developing zebrafish, exposure to nicotine was reported to cause axonal pathfinding errors in the later born secondary motoneurons (SMNs). These alterations in SMN axon morphology coincided with muscle degeneration at high nicotine concentrations (15–30 μM). Previous work showed that the paralytic mutant zebrafish known as sofa potato exhibited nicotine-induced effects onto SMN axons at these high concentrations but in the absence of any muscle deficits, indicating that pathfinding errors could occur independent of muscle effects. In this study, we used varying concentrations of nicotine at different developmental windows of exposure to specifically isolate its effects onto subpopulations of motoneuron axons. We found that nicotine exposure can affect SMN axon morphology in a dose-dependent manner. At low concentrations of nicotine, SMN axons exhibited pathfinding errors, in the absence of any nicotine-induced muscle abnormalities. Moreover, the nicotine exposure paradigms used affected the 3 subpopulations of SMN axons differently, but the dorsal projecting SMN axons were primarily affected. We then identified morphologically distinct pathfinding errors that best described the nicotine-induced effects on dorsal projecting SMN axons. To test whether SMN pathfinding was potentially influenced by alterations in the early born primary motoneuron (PMN), we performed dual labeling studies, where both PMN and SMN axons were simultaneously labeled with antibodies. We show that only a subset of the SMN axon pathfinding errors coincided with abnormal PMN axonal targeting in nicotine-exposed zebrafish. We conclude that nicotine exposure can exert differential effects depending on the levels of nicotine and developmental exposure window. - Highlights: • Embryonic nicotine exposure can specifically affect secondary motoneuron axons in a dose-dependent manner.

  13. Creativos, Precarios, y Nuevas Formas de Interculturalidad

    Directory of Open Access Journals (Sweden)

    Néstor García Canclini

    2016-05-01

    Full Text Available Quiero proponer explorar la fertilidad de un enfoque antropológico queconsiste en mirar como conversaciones los signos de lo que cuesta entender en elmundo contemporáneo. Con ese fin voy a contarles dos investigaciones en las quebuscamos cambiar algunas preguntas habituales sobre los comportamientos de losjóvenes creativos y sobre lo que hacemos hoy en las nuevas formas de leer, en papel y en pantallas. Ambos estudios surgieron del descontento con las fotos y los relatos que nos daban la sociología y la economía acerca de los jóvenes y la lectura.

  14. The utility of Pro Forma Income Statements.

    Science.gov (United States)

    Reiboldt, Max; Reiboldt, John

    2002-01-01

    Recent headlines surrounding the financial demise of the nation's seventh largest company, Enron, and its subsequent entanglements with its accounting and consulting firm, Arthur Andersen, have placed a cloud of suspicion upon many reasonable business practices that otherwise are considered standard procedure. The proforma income statement is one of those practices. An oft-used tool in financial management, pro formas play a useful role for projecting financial performance based on predictable forecasts or assumptions. Regardless of the current scrutiny, there is still a valid use for accurately prepared statements.

  15. Nuevas formas organizacionales en la gobernabilidad transnacional

    Directory of Open Access Journals (Sweden)

    José Gpe. Vargas Hernández

    Full Text Available El objetivo de este trabajo es analizar las transformaciones que están teniendo las formas organizacionales para adaptarse a los requerimientos de una gobernabilidad transnacional que de respuesta a los cambios del medio ambiente creado por los procesos de globalización económica. A partir de un análisis de los elementos sobresalientes de las estructuras en las organizaciones, se determinan las tendencias en las nuevas formas organizacionales considerando las variables de un medio ambiente caracterizado por altos niveles de absorción de incertidumbre, complejidad de sistemas involucrados, flexibilidad de estructuras, comportamientos y procesos, interdependencia e interacciones de agentes económicos y actores políticos y sociales, incremento de la velocidad, cambios de poder y desmembramiento de fenómenos organizacionales. Finalmente, se hace una elaboración de las implicaciones del diseño organizacional e institucional bajo los diferentes modelos desde los enfoques del neoliberalismo, el intergubernamentalismo y las redes de gestión. A partir de este análisis se concluye con una delimitación de los principales retos.

  16. Comportamento da síndrome coronariana aguda: resultados de um registro brasileiro

    Directory of Open Access Journals (Sweden)

    Leopoldo Soares Piegas

    2013-06-01

    Full Text Available FUNDAMENTO: O Brasil carece de registros multicêntricos publicados de síndrome coronariana aguda. OBJETIVO: O Registro Brasileiro de Síndrome Coronariana Aguda é um estudo multicêntrico nacional com objetivo de apresentar dados representativos das características clínicas, e manejo e evolução hospitalares dessa síndrome. MÉTODOS: Participaram 23 hospitais de 14 cidades. Foram elegíveis pacientes que se apresentaram com suspeita de síndrome coronariana aguda nas primeiras 24 horas, com quadro clínico sugestivo, associado a alterações eletrocardiográficas compatíveis e/ou marcadores de necrose. O seguimento foi realizado até o óbito ou a alta hospitalar. RESULTADOS: Entre os anos de 2003 e 2008, foram incluídos 2.693 pacientes com diagnóstico de síndrome coronariana aguda, sendo 864 (32,1% mulheres. O diagnóstico final foi de angina instável para 1.141 (42,4% pacientes, com mortalidade de 3,06% deles; de infarto agudo do miocárdio sem supradesnível de ST para 529 (19,6% pacientes, com mortalidade de 6,8% deles; e de infarto agudo do miocárdio com supradesnível de ST para 950 (35,3% pacientes, com mortalidade de 8,1% deles; tiveram diagnóstico não confirmado 73 (2,7% pacientes, com mortalidade de 1,36% deles. A mortalidade global foi de 5,53%. O modelo de regressão logística múltipla identificou o gênero feminino (OR=1,45, o diabetes melito (OR=1,59, o índice de massa corporal (OR=1,27 e a intervenção coronariana percutânea (OR=0,70 como fatores de risco de óbito, para demografia e intervenções. Um modelo para óbito por complicações maiores identificou choque cardiogênico/Edema Agudo de Pulmão (OR=4,57, reinfarto (OR=3,48, acidente vascular cerebral (OR=21,56, sangramento grave (OR=3,33, parada cardiorrespiratória (OR=40,27 e classe funcional de Killip (OR=3,37. CONCLUSÃO: Os dados do Registro Brasileiro de Síndrome Coronariana Aguda não diferem de outros coletados fora do país. Seus achados poder

  17. Studies of axon-glial cell interactions and periaxonal K+ homeostasis--II. The effect of axonal stimulation, cholinergic agents and transport inhibitors on the resistance in series with the axon membrane.

    Science.gov (United States)

    Hassan, S; Lieberman, E M

    1988-06-01

    The small electrical resistance in series with the axon membrane is generally modeled as the intercellular pathway for current flow through the periaxonal glial (Schwann cell) sheath. The series resistance of the medial giant axon of the crayfish, Procambarus clarkii, was found to vary with conditions known to affect the electrical properties of the periaxonal glia. Series resistance was estimated from computer analysed voltage waveforms generated by axial wire-constant current and space clamp techniques. The average series resistance for all axons was 6.2 +/- 0.5 omega cm2 (n = 128). Values ranged between 1 and 30 omega cm2. The series resistance of axons with low resting membrane resistance (less than 1500 omega cm2) increased an average of 30% when stimulated for 45 s to 7 min (50 Hz) whereas the series resistance of high membrane resistance (greater than 1500 omega cm2) axons decreased an average of 10%. Carbachol (10(-7) M) caused the series resistance of low membrane resistance axons to decrease during stimulation but had no effect on high membrane resistance axons. d-Tubocurare (10(-8) M) caused the series resistance of high membrane resistance axons to increase during stimulation but had no effect on low membrane resistance axons. Bumetanide, a Na-K-Cl cotransport inhibitor and low [K+]o, prevented the stimulation-induced increase in series resistance of low membrane resistance axons but had no effect on the high membrane resistance axons. The results suggest that the series resistance of axons varies in response to the activity of the glial K+ uptake mechanisms stimulated by the appearance of K+ in the periaxonal space during action potential generation.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. La lactancia materna y su influencia en el comportamiento de las infecciones respiratorias agudas The breastfeeding and its influence on the behavior of acute respiratory infections

    Directory of Open Access Journals (Sweden)

    Tatiana de la Vega Paitková

    2010-09-01

    Full Text Available INTRODUCCIÓN: la lactancia materna es reconocida como el mejor inductor de la maduración inmunológica de la etapa posnatal. La leche materna provee una nutrición completa para cualquier bebé desde el nacimiento hasta los 6 meses de vida. MÉTODOS: se estudiaron 80 transicionales, pertenecientes al Grupo Básico de Trabajo No. 2 del Policlínico "Ana Betancourt", con el objetivo de identificar la frecuencia y variedad de las infecciones respiratorias agudas en relación con el tipo de lactancia recibida. Para la recolección de los datos se consideró la información reflejada en las consultas de puericultura realizadas, durante el primer año de vida, contempladas en las historias clínicas pediátricas (revisión documental. RESULTADOS: predominaron los niños lactados (83 %, aunque de estos, solo el 25 % se alimentó de forma exclusiva. La lactancia mixta, aunque mayoritaria (58 %, predomina por debajo del cuarto mes de vida y el 17 % de los casos fue lactado de manera artificial. Las infecciones respiratorias agudas fueron más frecuentes en niños que recibieron poco tiempo de lactancia mixta (19 %, así como en los que se alimentaron de modo artificial (14 %, con predominio en ellos de la mayor parte de las otitis medias y la totalidad de las neumonías. Solo en 3 de estos pacientes fue necesaria la hospitalización, y la evolución en todos los casos fue satisfactoria. CONCLUSIONES: predominó la variedad mixta de lactancia materna. Se comprobó una alta morbilidad por infecciones respiratorias agudas en los transicionales estudiados. Mientras más breve es el período de lactancia materna, mayor es el riesgo de infección y la severidad de estas. Las dos terceras partes de la otitis media y la totalidad de las neumonías ocurren en casos con lactancia materna mixta breve o artificial.INTRODUCCIÓN: breastfeeding is recognized as the better inductor of the immunologic maturation of postnatal stage. Mother milk provides a complete

  19. TOXICIDAD AGUDA DE Aleurites moluccana POR VIA ORAL EN RATAS SPRAGUE-DAWLEY

    Directory of Open Access Journals (Sweden)

    Laura Rocío Orellana-Cuéllar

    2014-12-01

    Full Text Available Objetivo: Determinar la toxicidad aguda por Aleurites moluccana por administración oral en ratas Sprague-Dawley. Metodología: Estudio experimental realizado en el Instituto de Patología de la Facultad de Medicina-UNMSM. Se usaron treinta ratas Sprague-Dawley, hembras y machos, de 6 semanas de edad. Se formaron aleatoriamente tres grupos de diez ratas: grupo A1, recibió 8,2 mg/Kg de peso de A. moluccana; grupo  A2, recibió 2000 mg/Kg de peso de A. moluccana; grupo control, recibió agua ad libitum. Se evaluaron los signos clínicos de toxicidad, los pesos, variables bioquímicas y las características histopatológicas de hígado, riñón, corazón, intestino, bazo y gónadas. Se consideró significativo un p0,05. Los grupos  A1 y A2 presentaron signos clínicos de toxicidad y la muerte de tres ratas; células hepáticas binucleadas y regenerativas en el hígado; y hemorragia glomerular en el riñón. Conclusiones: Las variables clínicas e histopatológicas en hígado y riñón demostraron que la Aleurites moluccana produce toxicidad aguda, las variables bioquímicas no demostraron este efecto. Palabras Claves: Aleurites moluccana, Toxicidad aguda, Ratas Sprague-Dawley.

  20. Síndrome coronariana aguda em paciente jovem com sintomas atípicos

    Directory of Open Access Journals (Sweden)

    Gustavo Daher

    2012-08-01

    Full Text Available O diagnóstico da dor torácica aguda no setor de emergência pode ser difícil e desafiador, incluindo diversos diagnósticos diferenciais, dentre eles: causas benignas a causas potencialmente fatais. O diagnóstico na maioria das vezesé estabelecido através do quadro clínico e de exames complementares como: marcadores de necrose miocárdica, eletrocardiograma e radiografia de tórax.A angiotomografia coronariana tem sido utilizada nos casos de dor torácica aguda com baixa ou intermediária probabilidade de síndrome coronariana aguda, permitindo sua exclusão e conseqüente alta precoce dos pacientes. Apresentamosrelato de caso de uma paciente jovem com dor precordial atípica e marcadores de necrose miocárdica discretamente elevados. Considerando-se a epidemiologia e o quadro clínico da paciente, foi feita hipótese diagnóstica inicial de miocardite. A angiotomografia cardíaca com pesquisa de realce tardiofoi solicitada. Apesar do escore de cálcio ter sido zero, foi diagnosticada lesão estenosante grave no terço médio da artéria coronária descendente anterior com realce tardio na parede anterior do ventrículo esquerdo, compatível comnecrose miocárdica. A paciente foi submetida a cateterismo com angioplastia da lesão.

  1. Pancreatitis aguda por hipertrigliceridemia severa: reporte de caso y revisión de la literatura

    OpenAIRE

    Herrera Del Águila, Dwight Denis; Garavito Rentería, Jorge; Linarez Medina, Karen; Lizarzaburu Rodríguez, Víctor

    2015-01-01

    La pancreatitis aguda por hipertrigliceridemia se presenta en aproximadamente 1-4 % de los casos, es la tercera causa de pancreatitis luego de la etiología biliar y alcohólica. La hipertrigliceridemia puede ser producida por causas primarias asociadas a trastornos genéticos en el metabolismo de los lípidos, y por casusas secundarias. Se presenta el caso de un paciente varón de 32 años de edad, natural de Huancayo, con antecedentes de diabetes mellitus tipo 2, dislipidemia mixta severa con hip...

  2. Inmunofenotipos aberrantes en leucemias agudas en una población hospitalaria de Buenos Aires

    Directory of Open Access Journals (Sweden)

    Viviana Novoa

    2013-02-01

    Full Text Available La citometría de flujo multiparamétrica es el método de elección para la caracterización inmunofenotípica de las células hematopoyéticas clonales presentes en los distintos procesos leucémicos agudos. El objetivo fue analizar la expresión de antígenos de membrana y evaluar la presencia de fenotipos aberrantes en los blastos de pacientes con diagnóstico de leucemia aguda, que permiten el monitoreo de la respuesta al tratamiento. Se revisaron los inmunofenotipos de 364 muestras de pacientes adultos derivadas a nuestro laboratorio en un período de 7 años. El inmunofenotipo se realizó por citometría de flujo con un amplio panel de anticuerpos monoclonales con el que se evaluó la expresión de antígenos de linaje linfoide, mieloide y también antígenos de maduración. De las 364 muestras estudiadas, 60.2% presentaron un fenotipo compatible con leucemia mieloide aguda (LMA, 28.8% con leucemia linfoblástica B (LLA-B, 6.6% con leucemia linfoblástica T (LLA-T y 4.4% con leucemias agudas poco frecuentes. La presencia de fenotipos aberrantes se observó en 89% de los casos, los fenotipos aberrantes identificados fueron: 1 infidelidad de linaje: LMA (54%, LLA-B (40%, LLA-T (29%; 2 ausencia de expresión antigénica: LMA (21%, LLA-B (35%, LLA-T (70%; 3 alteración de la expresión antigénica: LMA (67%, LLA-B (66%, LLA-T (84%; 4 asincronismo madurativo: LMA (26%, LLA-B (37% y 5 fenotipo ectópico: LLA-T 96%. El análisis por citometría de flujo multiparamétrica de las leucemias agudas permitió la identificación de fenotipos aberrantes en la mayoría de nuestros pacientes, que son de utilidad para el monitoreo de la respuesta al tratamiento.

  3. Infecciones respiratorias agudas en los niños. Posibles medidas de control

    OpenAIRE

    Mohs Villalta, Edgar

    1985-01-01

    Artículo científico -- Universidad de Costa Rica. Instituto de Investigaciones en Salud, 1985 Las infecciones respiratorias agudas que representan el 50% aproximadamente, de los casos de enfermedades que deben notificarse a las autoridades y de las consultas pediátricas de pacientes ambulatorios en los países en desarrollo, son también una de las principales causas de las enfermedades contraídas en los hospitales y de mortalidad por enfermedades nosocomiales. En 1982, por *mph:), fueron la...

  4. El problema Patogénico de las Pancreatitis Agudas. Lesiones producidas por la Etionina.

    OpenAIRE

    Pera Blanco-Morales, Cristóbal

    2016-01-01

    Cuando en el año 1952 realizamos una extensa revisión del problema de la necrosis aguda del páncreas, conveníamos en que eran tres las razones que justifican el gran interés que el estudio de esta afección conserva en la actualidad: a) Las dudas existentes acerca de su etiología y patogénesis. b) La extraordinaria gravedad del proceso que conduce a la muerte en una elevada proporción de casos. c) La incertidumbre sobre cua...

  5. PARTO PRETÉRMINO Y SUFRIMIENTO FETAL SECUNDARIOS A PERITONITIS POR APENDICITIS AGUDA PERFORADA

    OpenAIRE

    Hidalgo M,Juan José; Molina P,Marta; Varo GM,Begoña; Rivas R,Salvador; Bernabeu A,José Ramón; Perales M,Alfredo

    2009-01-01

    La apendicitis aguda es la urgencia quirúrgica no obstétrica más frecuente durante el embarazo. Se ha asociado a parto pretérmino y a morbimortalidad fetal y materna, especialmente cuando se complica con peritonitis. Los cambios anatómicos, fisiológicos y bioquímicos que se producen durante la gestación pueden alterar los síntomas y signos típicos asociados a la apendicitis. Esto puede retrasar el diagnóstico y dar lugar a un aumento de la morbimortalidad materna y fetal. Presentamos el caso ...

  6. Efecto de la restitución temprana de la nutrición oral en la pancreatitis aguda leve

    OpenAIRE

    Vega Sandoval, Carlos Andres; Isaza Restrepo, Andres; Moscoso Daza, Alejandro

    2010-01-01

    Aunque el manejo nutricional de los pacientes con Pancreatitis Aguda Severa ha sido bien establecido por la evidencia disponible, el inicio de la vía oral en Pancreatitis Leve no ha sido igualmente estudiado. El objetivo de este estudio es evaluar el efecto del inicio temprano de la nutrición por vía oral en estos pacientes. Métodos: Realizamos un descriptivo serie de comparación de casos en los cuales comparamos la evolución y resultados del manejo de los pacientes con pancreatitis aguda ant...

  7. Aspectos disautonômicos da porfiria aguda intermitente: a propósito de seis casos

    Directory of Open Access Journals (Sweden)

    Charles P. Tilbery

    1979-06-01

    Full Text Available Foram estudados seis casos de porfiria aguda intermitente, sendo enfocados os aspectos disautonômicos apresentados durante a longa permanência hospitalar dos doentes (média de 64 dias. Foram observados taquicardia sinusal e hipertensão arterial (4 casos, parada cardíaca (3 casos e depressão respiratória (5 casos. Os autores tecem comentários a propósito da fisiopatologia destas alterações e chamam a atenção sobre o prognóstico sombrio da porfiria aguda intermitente.

  8. Quantifying mechanical force in axonal growth and guidance

    Directory of Open Access Journals (Sweden)

    Ahmad Ibrahim Mahmoud Athamneh

    2015-09-01

    Full Text Available Mechanical force plays a fundamental role in neuronal development, physiology, and regeneration. In particular, research has shown that force is involved in growth cone-mediated axonal growth and guidance as well as stretch-induced elongation when an organism increases in size after forming initial synaptic connections. However, much of the details about the exact role of force in these fundamental processes remain unknown. In this review, we highlight (1 standing questions concerning the role of mechanical force in axonal growth and guidance and (2 different experimental techniques used to quantify forces in axons and growth cones. We believe that satisfying answers to these questions will require quantitative information about the relationship between elongation, forces, cytoskeletal dynamics, axonal transport, signaling, substrate adhesion, and stiffness contributing to directional growth advance. Furthermore, we address why a wide range of force values have been reported in the literature, and what these values mean in the context of neuronal mechanics. We hope that this review will provide a guide for those interested in studying the role of force in development and regeneration of neuronal networks.

  9. Investigation on the mechanism of peripheral axonal injury in glaucoma

    Directory of Open Access Journals (Sweden)

    Jun- Hong Zhao

    2013-05-01

    Full Text Available AIM: To compare the angles of longitudinal section of sclera around optic nerve heads and the never fiber layer changes in healthy adults and patients with glaucoma, and to investigate the mechanism of peripheral retinal axonal injury, with the combined knowledge of biomechanics. METHODS: The optical nerves and their peripheral tissue specimen in the 12 eyes from health adult donators and 12 eyes from glaucoma patient donators were dyed by Glees' method to compare the angles of longitudinal section of sclera around optic nerve heads(through optic nerve center, and to observe the anatomical features of the peripheral retinal axons. RESULTS: The mean angle of longitudinal section of sclera around optic nerve in healthy adults was 73.3°, while that in patients with absolute glaucoma was 75.6°. The difference showed no significance(t=1.44, P>0.05. There was a sharp bend in the course of peripheral optical fiber in healthy adults. However, the optic nerve fiber disappeared completely in patients with glaucoma end stage. CONCLUSION: The angle between the medial edge and leading edge of sclera(around optic nerve headsis an acute angle. The optical fiber in glaucoma end stage disappeared completely. The phenomenon may be related to high intraocular pressure, the sclera shape, the shear modulus of sclera and axons, and “axonal bending-injury” mechanism.

  10. RGM is a repulsive guidance molecule for retinal axons

    DEFF Research Database (Denmark)

    Monnier, Philippe P; Sierra, Ana; Macchi, Paolo

    2002-01-01

    with known guidance cues, and its messenger RNA is distributed in a gradient with increasing concentration from the anterior to posterior pole of the embryonic tectum. Recombinant RGM at low nanomolar concentration induces collapse of temporal but not of nasal growth cones and guides temporal retinal axons...

  11. IFNgamma enhances microglial reactions to hippocampal axonal degeneration

    DEFF Research Database (Denmark)

    Jensen, M B; Hegelund, I V; Lomholt, N D

    2000-01-01

    periods. Message for the immune cytokine interferon-gamma (IFNgamma) was undetectable, and glial reactivity to axonal lesions occurred as normal in IFNgamma-deficient mice. Microglial responses to lesion-induced neuronal injury were markedly enhanced in myelin basic protein promoter-driven transgenic mice...

  12. Multiple sclerosis and anterograde axonal degeneration study by magnetic resonance

    International Nuclear Information System (INIS)

    Martinez Pardo, P.; Capdevila Cirera, A.; Sanz Marin, P.M.; Gili Planas, J.

    1993-01-01

    Multiple sclerosis (MS) is a disease of the central nervous system that affects specifically the myelin. Its diagnosis by imaging techniques is, since the development of magnetic resonance (MR), relatively simple, and its occasional association with anterograde axonal degeneration (WD) has been reported. In both disorders, there is a lengthening of the T1 and T2 relaxation times. In the present report, 76 patients with MS with less than 4 plaques in the typical periventricular position were studied retrospectively, resulting in a rate of association with anterograde axonal degeneration of 8%. We consider that in spite of their same behavior in MR,MS and WD, with moreover represent completely different pathologies, are perfectly differential by MR. The S-E images with longer repetition and echo times in the axial and coronal planes have proved to be those most sensitive for this differentiation. Given that MS is specific pathology of then myelin, the axonal damages in delayed until several plaques adjacent to an axon affect it. We consider that this, added to the restriction of our study group (less than 4 plaques), is the cause of the pow percentage of the MS-WD association in our study. (Author)

  13. Chronic severe axonal polyneuropathy associated with hyperthyroidism and multivitamin deficiency.

    Science.gov (United States)

    Sugie, Kazuma; Umehara, Fujio; Kataoka, Hiroshi; Kumazawa, Aya; Ueno, Satoshi

    2012-01-01

    Hyperthyroidism is often associated with various neuromuscular disorders, most commonly proximal myopathy. Peripheral nerve involvement in hyperthyroidism is very uncommon and has rarely been reported. We describe a 29-year-old woman with untreated hyperthyroidism who presented with chronic severe axonal sensory-motor polyneuropathy. Peripheral nerve involvement developed together with other symptoms of hyperthyroidism 2 years before presentation. She also had anorexia nervosa for the past 6 months, resulting in multivitamin deficiency. Electrophysiological and pathological findings as well as clinical manifestations confirmed the diagnosis of severe axonal polyneuropathy. Anorexia nervosa has been considered a manifestation of untreated hyperthyroidism. We considered hyperthyroidism to be an important causal factor in the polyneuropathy in our patient, although peripheral nerve involvement in hyperthyroidism is rare. To our knowledge, this is the first documented case of chronic severe axonal polyneuropathy ascribed to both hyperthyroidism and multivitamin deficiency. Our findings strongly suggest that not only multivitamin deficiency, but also hyperthyroidism can cause axonal polyneuropathy, thus expanding the clinical spectrum of hyperthyroidism.

  14. Impaired Mitochondrial Dynamics Underlie Axonal Defects in Hereditary Spastic Paraplegias.

    Science.gov (United States)

    Denton, Kyle; Mou, Yongchao; Xu, Chong-Chong; Shah, Dhruvi; Chang, Jaerak; Blackstone, Craig; Li, Xue-Jun

    2018-05-02

    Mechanisms by which long corticospinal axons degenerate in hereditary spastic paraplegia (HSP) are largely unknown. Here, we have generated induced pluripotent stem cells (iPSCs) from patients with two autosomal recessive forms of HSP, SPG15 and SPG48, which are caused by mutations in the ZFYVE26 and AP5Z1 genes encoding proteins in the same complex, the spastizin and AP5Z1 proteins, respectively. In patient iPSC-derived telencephalic glutamatergic and midbrain dopaminergic neurons, neurite number, length and branching are significantly reduced, recapitulating disease-specific phenotypes. We analyzed mitochondrial morphology and noted a significant reduction in both mitochondrial length and their densities within axons of these HSP neurons. Mitochondrial membrane potential was also decreased, confirming functional mitochondrial defects. Notably, mdivi-1, an inhibitor of the mitochondrial fission GTPase DRP1, rescues mitochondrial morphology defects and suppresses the impairment in neurite outgrowth and late-onset apoptosis in HSP neurons. Furthermore, knockdown of these HSP genes causes similar axonal defects, also mitigated by treatment with mdivi-1. Finally, neurite outgrowth defects in SPG15 and SPG48 cortical neurons can be rescued by knocking down DRP1 directly. Thus, abnormal mitochondrial morphology caused by an imbalance of mitochondrial fission and fusion underlies specific axonal defects and serves as a potential therapeutic target for SPG15 and SPG48.

  15. Botulinum toxin's axonal transport from periphery to the spinal cord.

    Science.gov (United States)

    Matak, Ivica; Riederer, Peter; Lacković, Zdravko

    2012-07-01

    Axonal transport of enzymatically active botulinum toxin A (BTX-A) from periphery to the CNS has been described in facial and trigeminal nerve, leading to cleavage of synaptosomal-associated protein 25 (SNAP-25) in central nuclei. Aim of present study was to examine the existence of axonal transport of peripherally applied BTX-A to spinal cord via sciatic nerve. We employed BTX-A-cleaved SNAP-25 immunohistochemistry of lumbar spinal cord after intramuscular and subcutaneous hind limb injections, and intraneural BTX-A sciatic nerve injections. Truncated SNAP-25 in ipsilateral spinal cord ventral horns and dorsal horns appeared after single peripheral BTX-A administrations, even at low intramuscular dose applied (5 U/kg). Cleaved SNAP-25 appearance in the spinal cord after BTX-A injection into the sciatic nerve was prevented by proximal intrasciatic injection of colchicine (5 mM, 2 μl). Cleaved SNAP-25 in ventral horn, using choline-acetyltransferase (ChAT) double labeling, was localized within cholinergic neurons. These results extend the recent findings on BTX-A retrograde axonal transport in facial and trigeminal nerve. Appearance of truncated SNAP-25 in spinal cord following low-dose peripheral BTX-A suggest that the axonal transport of BTX-A occurs commonly following peripheral application. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Computed tomography in diagnosis of diffuse axonal injury

    International Nuclear Information System (INIS)

    Iwadate, Yasuo; Ono, Juniti; Okimura, Yoshitaka; Suda, Sumio; Isobe, Katsumi; Yamaura, Akira.

    1990-01-01

    Diffuse axonal injury (DAI) has been described in instances of prolonged traumatic coma on the basis of the neuropathological findings, but the same findings are also found in patients with cerebral concussion. Experimental studies confirm that the quality of survivors following trauma is directly proportional to the amount of primarily injured-axon. When the injured axon lies in a widespread area of the brain, outcome for the patient is always poor. In a series of 260 severely head-injured patients, based on their poor outcome, 69 (27%) were diagnosed as DAI. Because of their relatively good outcome, eighty-two patients (32%) were classified into non-DAI group. The predominant CT finding of DAI patients was intraparenchymal deep-seated hemorrhagic lesion. This was observed in 28 patients (41%). Normal CT was also observed in 11 patients (16%). On the other hand, 8 of the non-DAI group (10%) manifested deep-seated lesions. Diffuse cerebral swelling (DCS) appeared in both groups in the same incidence. Subarachnoid hematoma in the perimesencephalic cistern (SAH (PMC)) and intraventricular hematoma (IVH) were observed in 64% of the DAI group, and in 23% of the non-DAI group. The available evidence indicates that various types of hematoma seen in the deep-seated structures of the brain do not have an absolute diagnostic value, but the frequency of hematoma is thought to increase in proportion to the amount of injured-axon. (author)

  17. Unravelling the incidence and etiology of chronic idiopathic axonal polyneuropathy

    NARCIS (Netherlands)

    Visser, N.A.

    2016-01-01

    Chronic idiopathic axonal polyneuropathy (CIAP) is a sensory or sensorimotor polyneuropathy that has a slowly progressive course without severe disability. CIAP is diagnosed in a significant proportion of patients with polyneuropathy, but precise figures on the incidence of polyneuropathy and CIAP

  18. Differential Axonal Projection of Mitral and Tufted Cells in the Mouse Main Olfactory System

    Directory of Open Access Journals (Sweden)

    Shin Nagayama

    2010-09-01

    Full Text Available In the past decade, much has been elucidated regarding the functional organization of the axonal connection of olfactory sensory neurons to olfactory bulb (OB glomeruli. However, the manner in which projection neurons of the OB process odorant input and send this information to higher brain centers remains unclear. Here, we report long-range, large-scale tracing of the axonal projection patterns of OB neurons using two-photon microscopy. Tracer injection into a single glomerulus demonstrated widely distributed mitral/tufted cell axonal projections on the lateroventral surface of the mouse brain, including the anterior/posterior piriform cortex (PC and olfactory tubercle (OT. We noted two distinct groups of labeled axons: PC-orienting axons and OT-orienting axons. Each group occupied distinct parts of the lateral olfactory tract. PC-orienting axons projected axon collaterals to a wide area of the PC but only a few collaterals to the OT. OT-orienting axons densely projected axon collaterals primarily to the anterolateral OT (alOT. Different colored dye injections into the superficial and deep portions of the OB external plexiform layer revealed that the PC-orienting axon populations originated in presumed mitral cells and the OT-orienting axons in presumed tufted cells. These data suggest that although mitral and tufted cells receive similar odor signals from a shared glomerulus, they process the odor information in different ways and send their output to different higher brain centers via the PC and alOT.

  19. NUEVAS FORMAS ORGANIZACIONALES EN LA GOBERNABILIDAD TRANSNACIONAL

    Directory of Open Access Journals (Sweden)

    José Guadalupe Vargas Hernández

    2004-07-01

    Full Text Available El objetivo de este trabajo es analizar las transformaciones que están teniendo las formas organizacionales para adaptarse a los requerimientos de una gobernabilidad transnacional que dé respuesta a los cambios del medio ambiente creado por los procesos de globalización económica. Se tienen en consideración las variables de un medio ambiente caracterizado por altos niveles de absorción de incertidumbre, complejidad de sistemas, flexibilidad de estructuras, comportamientos y procesos, interdependencia e interacciones de agentes económicos y actores políticos y sociales, incremento de la velocidad, cambios de poder y desmembramiento de fenómenos organizacionales. Finalmente, se describen las implicaciones del diseño organizacional e institucional bajo los diferentes modelos desde los enfoques del neoliberalismo, el intergubernamentalismo y las redes de gestión.

  20. Reação de fase aguda e sua relação com o desempenho de cavalos em competição de longa distância

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    L.A. Amaral

    2015-04-01

    Full Text Available O exercício físico é um dos estímulos fisiológicos mais estressantes que um animal pode sofrer e, dependendo de sua intensidade, sugere-se que possa gerar uma reação mediada por proteínas de fase aguda (PFA. O objetivo deste estudo foi caracterizar a reação de fase aguda e sua relação com o desempenho de cavalos submetidos a uma competição de longa distância. O experimento foi desenvolvido durante a Marcha de Resistência anual promovida pela Associação Brasileira de Criadores de Cavalos Crioulos (ABCCC, composta por um percurso de 750km percorrido durante 15 dias. Foram avaliados 23 equinos, os quais foram divididos em dois grupos, sendo o grupo 1 composto pelos 10 primeiros colocados na competição e o grupo 2 formado pelos 13 animais que concluíram a competição em colocações inferiores ou foram desclassificados antes de terminar a prova. Efetuaram-se coletas sanguíneas em repouso (dia 0 e no último dia de competição, e foi realizado o teste de eletroforese em gel de poliacrilamida contendo dodecil sulfato de sódio (SDS-PAGE para identificar as proteínas (albumina, haptoglobina, ceruloplasmina, transferrina, imunoglobulina G, imunoglobulina A, glicoproteína ácida e proteína de peso molecular de 23kDa. Os resultados demonstraram que o exercício físico imposto influenciou de forma significativa (P<0,0001 as concentrações séricas de haptoglobina, ceruloplasmina, imunoglobulina A, glicoproteína ácida e proteína de peso molecular de 23kDa. Quando comparados os resultados dos grupos estudados, observou-se que a concentração de haptoglobina após a competição foi superior no grupo de animais com baixo desempenho (grupo 2. Conclui-se que a competição de longa duração é capaz de gerar reação de fase aguda e que o monitoramento da concentração de haptoglobina pode ser um sinalizador de processo inflamatório e baixo desempenho.

  1. Interleucina-18 (IL-18 y otros parámetros inmunológicos como marcadores de gravedad en la pancreatitis aguda Interleukin 18 (IL-18 and other immunological parameters as markers of severity in acute pancreatitis

    Directory of Open Access Journals (Sweden)

    M. A. Martín

    2008-12-01

    Full Text Available Objetivo: se trata de comparar prospectivamente el comportamiento durante la primera semana del ingreso de los niveles de interleucina-18 (IL-18, y otros parámetros inmunológicos entre pacientes con pancreatitis aguda con y sin criterios de gravedad, así como entre pacientes con y sin desarrollo ulterior de seudoquiste. Pacientes y métodos: se compararon en 36 pacientes con pancreatitis aguda los resultados de sTNF-RI, IL-1Ra, IL-6 e IL-18 los días 1, 2, 3 y 7 desde el ingreso entre pancretitis leve, grave y un grupo control (13 pacientes con cólico biliar simple, así como entre pacientes con o sin seudoquiste. Resultados: al comparar pancreatitis leve con grave, IL-18 fue significativamente superior sólo el primer día en las pancreatitis graves y los otros parámetros a partir del segundo día de forma mantenida. También en pacientes que desarrollaron seudoquiste, IL-18 estuvo significativamente elevada el primer día. Conclusiones: IL-18 resultó el marcador más precoz de complicaciones y gravedad de la pancreatitis aguda a nivel sistémico y local (seudoquiste.Objective: our aim was to prospectively compare the behavior of interleukin 18 (IL-18 levels and other immunological parameters during the first week of hospitalization between acute pancreatitis patients with and without severity criteria, as well as between patients with and without late pseudocyst development. Patients and methods: in 36 patients with acute pancreatitis we compared sTNF-RI, IL-1Ra, IL-6, and IL-18 levels at days 1, 2, 3 and 7 after hospitalization between mild pancreatitis, severe pancreatitis, and a "control" group (13 patients with uncomplicated biliary colic, as well as between patients with and without pseudocyst. Results: on comparing mild to severe pancreatitis, IL-18 was significantly higher only the first day in severe pancreatitis, while the other parameters were steadily higher after the second day. In patients developing pseudocyst, IL-18 was

  2. The Woodlands: Una forma diferente de gobernar

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    Raquel Insa-Ciriza

    2010-06-01

    Full Text Available The Woodlands (Texas es uno de los mejores ejemplos de éxito de los partenariados público-privados entre el Departamento de Urbanismo y Vivienda Americano (Department of Housing and Urban Development, US - HUD y la empresa privada. The Woodlands, que fue creada como una «Nueva Ciudad» por la compañía Mitchell Energy & Development Corporation, ha ido creciendo y creando una masa crítica de residentes, trabajadores, su propio sentido de comunidad y lo más importante, su propia forma de gobierno. Es el único caso en Estados Unidos de ciudad gobernada por asociaciones privadas. Estas asociaciones, representadas por un Consejo de Administración, proveen la mayoría de los servicios públicos a los ciudadanos. En este artículo se muestra lo que llamo «complicidad ciudadana» basada en lo que el Nuevo Servicio Público define como gobierno basado en la comunidad. Ellos no están reinventando ninguna clase de gobierno, lo que están haciendo es crear una nueva forma de gobierno en la que los ciudadanos prefieren tomar el mando que servir. El estudio del caso que muestro nos ayuda a entender cómo una mayor participación de los ciudadanos en las tareas de la administración local puede hacer disminuir visiblemente el poder del promotor en el desarrollo de una Nueva Ciudad. Esta complicidad ciudadana se traduce en términos de implicación de los miembros de la comunidad en el crecimiento y en el Gobierno de la ciudad

  3. Oligodendrocyte Development in the Absence of Their Target Axons In Vivo.

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    Rafael Almeida

    Full Text Available Oligodendrocytes form myelin around axons of the central nervous system, enabling saltatory conduction. Recent work has established that axons can regulate certain aspects of oligodendrocyte development and myelination, yet remarkably oligodendrocytes in culture retain the ability to differentiate in the absence of axons and elaborate myelin sheaths around synthetic axon-like substrates. It remains unclear the extent to which the life-course of oligodendrocytes requires the presence of, or signals derived from axons in vivo. In particular, it is unclear whether the specific axons fated for myelination regulate the oligodendrocyte population in a living organism, and if so, which precise steps of oligodendrocyte-cell lineage progression are regulated by target axons. Here, we use live-imaging of zebrafish larvae carrying transgenic reporters that label oligodendrocyte-lineage cells to investigate which aspects of oligodendrocyte development, from specification to differentiation, are affected when we manipulate the target axonal environment. To drastically reduce the number of axons targeted for myelination, we use a previously identified kinesin-binding protein (kbp mutant, in which the first myelinated axons in the spinal cord, reticulospinal axons, do not fully grow in length, creating a region in the posterior spinal cord where most initial targets for myelination are absent. We find that a 73% reduction of reticulospinal axon surface in the posterior spinal cord of kbp mutants results in a 27% reduction in the number of oligodendrocytes. By time-lapse analysis of transgenic OPC reporters, we find that the reduction in oligodendrocyte number is explained by a reduction in OPC proliferation and survival. Interestingly, OPC specification and migration are unaltered in the near absence of normal axonal targets. Finally, we find that timely differentiation of OPCs into oligodendrocytes does not depend at all on the presence of target axons

  4. Time course of ongoing activity during neuritis and following axonal transport disruption.

    Science.gov (United States)

    Satkeviciute, Ieva; Goodwin, George; Bove, Geoffrey M; Dilley, Andrew

    2018-05-01

    Local nerve inflammation (neuritis) leads to ongoing activity and axonal mechanical sensitivity (AMS) along intact nociceptor axons and disrupts axonal transport. This phenomenon forms the most feasible cause of radiating pain, such as sciatica. We have previously shown that axonal transport disruption without inflammation or degeneration also leads to AMS but does not cause ongoing activity at the time point when AMS occurs, despite causing cutaneous hypersensitivity. However, there have been no systematic studies of ongoing activity during neuritis or noninflammatory axonal transport disruption. In this study, we present the time course of ongoing activity from primary sensory neurons following neuritis and vinblastine-induced axonal transport disruption. Whereas 24% of C/slow Aδ-fiber neurons had ongoing activity during neuritis, few (disruption of axonal transport without inflammation does not lead to ongoing activity in sensory neurons, including nociceptors, but does cause a rapid and transient development of AMS. Because it is proposed that AMS underlies mechanically induced radiating pain, and a transient disruption of axonal transport (as previously reported) leads to transient AMS, it follows that processes that disrupt axonal transport, such as neuritis, must persist to maintain AMS and the associated symptoms. NEW & NOTEWORTHY Many patients with radiating pain lack signs of nerve injury on clinical examination but may have neuritis, which disrupts axonal transport. We have shown that axonal transport disruption does not induce ongoing activity in primary sensory neurons but does cause transient axonal mechanical sensitivity. The present data complete a profile of key axonal sensitivities following axonal transport disruption. Collectively, this profile supports that an active peripheral process is necessary for maintained axonal sensitivities.

  5. Particularidades del síndrome de dificultad respiratoria aguda en edades pediátricas

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    Valentín Santiago Rodríguez Moya

    Full Text Available Desde las primeras descripciones del síndrome de dificultad respiratoria aguda los pediatras intensivistas reconocieron que posee particularidades que la hacen diferente en la población pediátrica. El objetivo de este trabajo es divulgar la definición específica en el modelo infantil, aunque existen similitudes en la fisiopatología del síndrome de dificultad respiratoria en adultos y niños. Se revisaron los conceptos vigentes sobre el síndrome de dificultad respiratoria aguda desde su descripción, a través de los diferentes consensos (desde el de 1994 hasta el de 2015 y se señalaron las recomendaciones en el tratamiento y seguimiento de esta entidad. Los tópicos que se trataron fueron: concepto; prevalencia y epidemiología; fisiopatología, severidad y enfermedades asociadas; soporte ventilatorio; tratamientos secundarios específicos sobre el pulmón; tratamientos concomitantes; monitoreo general y pulmonar; soporte ventilatorio no invasivo; terapia extracorpórea y el seguimiento a largo plazo. Las recomendaciones propuestas en la última conferencia de consenso para el tratamiento del síndrome de dificultad respiratoria en edades pediátricas permiten optimizar el tratamiento e identificar necesidades futuras de investigación del tema.

  6. Retinopatia de Purtscher-like e pancreatite aguda Purtscher-like retinopathy and acute pancreatitis

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    Kelly Fernandes de Paula Rodrigues

    2008-04-01

    Full Text Available Retinopatia de Purtscher-like é uma baixa súbita da visão associada à imagem de múltiplas áreas branco-amareladas (manchas algodonosas e hemorragias no pólo posterior de ambos os olhos. O exato mecanismo da injúria ainda não é claro, mas provavelmente seria de natureza embólica.Tem sido descrita em uma variedade de condições, incluindo pancreatite aguda, síndrome de embolia gordurosa, insuficiência renal, nascimento (parto e pós-parto, desordens do tecido conectivo, entre outras. Serão relatados três casos de pancreatite aguda confirmada pelos exames laboratoriais e história clínica, associadas a alterações no exame do fundo de olho, compatíveis com esta retinopatia.Purtscher-like retinopathy is acute loss of vision associated image of the multiple areas of retinal whitening and hemorrhage in the posterior pole of both eyes. The exact mechanism of injury remains unclear, current evidence suggests that it is embolic in nature. In a variety of conditions are been described including acute pancreatitis, fat embolism syndrome, renal failure, childbirth, and connective tissue disorders. Will are related three cases of the acute pancreatitis which was confirmed by complementary laboratory studies and clinical history, associated from exam of the fundus of the eye, similar is this retinopathy.

  7. An αII Spectrin-Based Cytoskeleton Protects Large-Diameter Myelinated Axons from Degeneration.

    Science.gov (United States)

    Huang, Claire Yu-Mei; Zhang, Chuansheng; Zollinger, Daniel R; Leterrier, Christophe; Rasband, Matthew N

    2017-11-22

    Axons must withstand mechanical forces, including tension, torsion, and compression. Spectrins and actin form a periodic cytoskeleton proposed to protect axons against these forces. However, because spectrins also participate in assembly of axon initial segments (AISs) and nodes of Ranvier, it is difficult to uncouple their roles in maintaining axon integrity from their functions at AIS and nodes. To overcome this problem and to determine the importance of spectrin cytoskeletons for axon integrity, we generated mice with αII spectrin-deficient peripheral sensory neurons. The axons of these neurons are very long and exposed to the mechanical forces associated with limb movement; most lack an AIS, and some are unmyelinated and have no nodes. We analyzed αII spectrin-deficient mice of both sexes and found that, in myelinated axons, αII spectrin forms a periodic cytoskeleton with βIV and βII spectrin at nodes of Ranvier and paranodes, respectively, but that loss of αII spectrin disrupts this organization. Avil-cre;Sptan1 f/f mice have reduced numbers of nodes, disrupted paranodal junctions, and mislocalized Kv1 K + channels. We show that the density of nodal βIV spectrin is constant among axons, but the density of nodal αII spectrin increases with axon diameter. Remarkably, Avil-cre;Sptan1 f/f mice have intact nociception and small-diameter axons, but severe ataxia due to preferential degeneration of large-diameter myelinated axons. Our results suggest that nodal αII spectrin helps resist the mechanical forces experienced by large-diameter axons, and that αII spectrin-dependent cytoskeletons are also required for assembly of nodes of Ranvier. SIGNIFICANCE STATEMENT A periodic axonal cytoskeleton consisting of actin and spectrin has been proposed to help axons resist the mechanical forces to which they are exposed (e.g., compression, torsion, and stretch). However, until now, no vertebrate animal model has tested the requirement of the spectrin cytoskeleton in

  8. Environmental Subconcussive Injury, Axonal Injury, and Chronic Traumatic Encephalopathy

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    Wendy A. Morley

    2018-03-01

    Full Text Available Brain injury occurs in two phases: the initial injury itself and a secondary cascade of precise immune-based neurochemical events. The secondary phase is typically functional in nature and characterized by delayed axonal injury with more axonal disconnections occurring than in the initial phase. Axonal injury occurs across the spectrum of disease severity, with subconcussive injury, especially when repetitive, now considered capable of producing significant neurological damage consistent with axonal injury seen in clinically evident concussion, despite no observable symptoms. This review is the first to introduce the concept of environmental subconcussive injury (ESCI and sets out how secondary brain damage from ESCI once past the juncture of microglial activation appears to follow the same neuron-damaging pathway as secondary brain damage from conventional brain injury. The immune response associated with ESCI is strikingly similar to that mounted after conventional concussion. Specifically, microglial activation is followed closely by glutamate and calcium flux, excitotoxicity, reactive oxygen species and reactive nitrogen species (RNS generation, lipid peroxidation, and mitochondrial dysfunction and energy crisis. ESCI damage also occurs in two phases, with the primary damage coming from microbiome injury (due to microbiome-altering events and secondary damage (axonal injury from progressive secondary neurochemical events. The concept of ESCI and the underlying mechanisms have profound implications for the understanding of chronic traumatic encephalopathy (CTE etiology because it has previously been suggested that repetitive axonal injury may be the primary CTE pathogenesis in susceptible individuals and it is best correlated with lifetime brain trauma load. Taken together, it appears that susceptibility to brain injury and downstream neurodegenerative diseases, such as CTE, can be conceptualized as a continuum of brain resilience. At one end

  9. Lesao óssea em leucemias agudas linfoblásticas tipo T e TIPO nao T / nao B

    OpenAIRE

    Martins, Fernando Lopes

    2013-01-01

    Resumo: O AUTOR APRESENTA OS RESULTADOS DO ESTUDO RADIOLÓGICO DE ESQUELETO DE 61 PACIENTES PORTADORES DE LEUCEMIA AGUDA LINFOBLÁSTICA, CORRELACIONANDO A PRESENÇA OU NÃO DE Lesões ÓSSEAS COM A CLASSIFICAÇÃO IMUNOLÓGICA DE LAL TIPO T E TIPO não T / não B

  10. Acute appendicitis in an incarcerated crural hernia: analysis of our experience Apendicitis aguda en una hernia crural incarcerada: análisis de nuestra experiencia

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    P. Priego

    2005-10-01

    de apendicitis aguda y 372 de hernia crural incarcerada. Del total, se van a estudiar 6 casos de hernia crural incarcerada en cuyo interior se encuentra el apéndice vermiforme, analizándose de forma retrospectiva los siguientes parámetros: edad, sexo, antecedentes personales, clínica de presentación, pruebas diagnósticas preoperatorias, técnica quirúrgica empleada, días de estancia hospitalaria y evolución. Resultados: todos los pacientes eran mujeres con una media de edad de 78,83 años. En todos ellos la clínica de presentación corresponde a dolor y tumoración en región inguinocrural derecha, de intensidad y duración variables. No se observan signos clínicos, analíticos y radiológicos que nos ayuden a realizar un diagnóstico preoperatorio del cuadro. En la mayor parte de las ocasiones se utiliza anestesia general y la vía de abordaje fue la crural. En todos los casos se realiza la apendicectomía a través del saco herniario, confirmándose la existencia de apendicitis aguda en 4 de ellos (66,67%. En 3 casos (50% se utiliza material protésico, observándose un caso de infección de herida quirúrgica y en los otros 3 casos se sutura el orifico herniario con puntos sueltos de prolene. Conclusión: la presencia del apéndice en una hernia crural incarcerada es una entidad poco frecuente de mujeres de edad avanzada y difícil de diagnosticar de forma preoperatoria. El tratamiento es la apendicectomía y herniorrafia. El uso de material protésico es controvertido.

  11. A growing field: The regulation of axonal regeneration by Wnt signaling.

    Science.gov (United States)

    Garcia, Armando L; Udeh, Adanna; Kalahasty, Karthik; Hackam, Abigail S

    2018-01-01

    The canonical Wnt/β-catenin pathway is a highly conserved signaling cascade that plays critical roles during embryogenesis. Wnt ligands regulate axonal extension, growth cone guidance and synaptogenesis throughout the developing central nervous system (CNS). Recently, studies in mammalian and fish model systems have demonstrated that Wnt/β-catenin signaling also promotes axonal regeneration in the adult optic nerve and spinal cord after injury, raising the possibility that Wnt could be developed as a therapeutic strategy. In this review, we summarize experimental evidence that reveals novel roles for Wnt signaling in the injured CNS, and discuss possible mechanisms by which Wnt ligands could overcome molecular barriers inhibiting axonal growth to promote regeneration. A central challenge in the neuroscience field is developing therapeutic strategies that induce robust axonal regeneration. Although adult axons have the capacity to respond to axonal guidance molecules after injury, there are several major obstacles for axonal growth, including extensive neuronal death, glial scars at the injury site, and lack of axonal guidance signals. Research in rodents demonstrated that activation of Wnt/β-catenin signaling in retinal neurons and radial glia induced neuronal survival and axonal growth, but that activation within reactive glia at the injury site promoted proliferation and glial scar formation. Studies in zebrafish spinal cord injury models confirm an axonal regenerative role for Wnt/β-catenin signaling and identified the cell types responsible. Additionally, in vitro and in vivo studies demonstrated that Wnt induces axonal and neurite growth through transcription-dependent effects of its central mediator β-catenin, potentially by inducing regeneration-promoting genes. Canonical Wnt signaling may also function through transcription-independent interactions of β-catenin with cytoskeletal elements, which could stabilize growing axons and control growth cone

  12. Use of self-complementary adeno-associated virus serotype 2 as a tracer for labeling axons: implications for axon regeneration.

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    Yingpeng Liu

    Full Text Available Various types of tracers are available for use in axon regeneration, but they require an extra operational tracer injection, time-consuming immunohistochemical analysis and cause non-specific labeling. Considerable efforts over the past years have explored other methodologies, especially the use of viral vectors, to investigate axon regeneration after injury. Recent studies have demonstrated that self-complementary Adeno-Associated Virus (scAAV induced a high transduction efficiency and faster expression of transgenes. Here, we describe for the first time the use of scAAV2-GFP to label long-projection axons in the corticospinal tract (CST, rubrospinal tract (RST and the central axons of dorsal root ganglion (DRG in the normal and lesioned animal models. We found that scAAV2-GFP could efficiently transduce neurons in the sensorimotor cortex, red nucleus and DRG. Strong GFP expression could be transported anterogradely along the axon to label the numerous axon fibers from CST, RST and central axons of DRG separately. Comparison of the scAAV2 vector with single-stranded (ss AAV2 vector in co-labeled sections showed that the scAAV2 vector induced a faster and stronger transgene expression than the ssAAV2 vector in DRG neurons and their axons. In both spinal cord lesion and dorsal root crush injury models, scAAV-GFP could efficiently label the lesioned and regenerated axons around the lesion cavity and the dorsal root entry zone (DREZ respectively. Further, scAAV2-GFP vector could be combined with traditional tracer to specifically label sensory and motor axons after spinal cord lesion. Thus, we show that using scAAV2-GFP as a tracer is a more effective and efficient way to study axon regeneration following injury.

  13. Insuficiencia renal aguda en pacientes de la Unidad de Cuidados Intensivos, Hospital Regional de Cuilapa, Santa Rosa, Guatemala

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    Ronald J. Ajcalon

    2017-03-01

    Full Text Available La insuficiencia renal aguda, es una condición común en la Unidad de Cuidados Intensivos de Adultos (UCIA y probablemente una consecuencia de la enfermedad crítica que se asocia a resultados clínicos adversos, altos costos y una mortalidad de más del 50%, sobre todo si se requiere tratamiento de reemplazo renal. El objetivo fue determinar la incidencia de insuficiencia renal aguda en pacientes ingresados a la UCIA. El estudio fue prospectivo, longitudinal, observacional, en 101 pacientes ingresados en la UCIA del Hospital Regional de Cuilapa. Se diagnosticaron 101 pacientes durante el periodo de estudio con insuficiencia renal aguda represento el 27.4% del total de pacientes internados (368 en el servicio en un año. La incidencia de mortalidad en pacientes que requieren terapia de reemplazo renal y se encuentran en ventilación mecánica es del 100%. Del total de pacientes estudiados, según la escala Akin, se encontró que el 49.5% de los pacientes correspondían a grado II, aunque el grado I también fue frecuente (29%, y que el 22 % de los pacientes correspondían a grado III. La patología que mayormente se asoció al desarrollo de insuficiencia renal aguda fue sepsis grave con un 31%, seguido de pacientes sometidos a cirugía mayor e hipovolemia con el 21 y 18% respectivamente. Se halló una incidencia aumentada de insuficiencia renal aguda comparado con estadísticas internacionales, cuya etiología fue mayormente causada por procesos sépticos.

  14. The Woodlands: Una forma diferente de gobernar

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    Raquel Insa-Ciriza

    2010-01-01

    Unidos de ciudad gobernada por asociaciones privadas. Estas asociaciones, representadas por un Consejo de Administración, proveen la mayoría de los servicios públicos a los ciudadanos. En este artículo se muestra lo que llamo «complicidad ciudadana» basada en lo que el Nuevo Servicio Público define como gobierno basado en la comunidad. Ellos no están reinventando ninguna clase de gobierno, lo que están haciendo es crear una nueva forma de gobierno en la que los ciudadanos prefieren tomar el mando que servir. El estudio del caso que muestro nos ayuda a entender cómo una mayor participación de los ciudadanos en las tareas de la administración local puede hacer disminuir visiblemente el poder del promotor en el desarrollo de una Nueva Ciudad. Esta complicidad ciudadana se traduce en términos de implicación de los miembros de la comunidad en el crecimiento y en el Gobierno de la ciudad. Clasificación JEL: H1, H11, H70.

  15. Antiretroviral Therapy-Associated Acute Motor and Sensory Axonal Neuropathy

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    Kimberly N. Capers

    2011-01-01

    Full Text Available Guillain-Barré syndrome (GBS has been reported in HIV-infected patients in association with the immune reconstitution syndrome whose symptoms can be mimicked by highly active antiretroviral therapy (HAART-mediated mitochondrial toxicity. We report a case of a 17-year-old, HIV-infected patient on HAART with a normal CD4 count and undetectable viral load, presenting with acute lower extremity weakness associated with lactatemia. Electromyography/nerve conduction studies revealed absent sensory potentials and decreased compound muscle action potentials, consistent with a diagnosis of acute motor and sensory axonal neuropathy. Lactatemia resolved following cessation of HAART; however, neurological deficits minimally improved over several months in spite of immune modulatory therapy. This case highlights the potential association between HAART, mitochondrial toxicity and acute axonal neuropathies in HIV-infected patients, distinct from the immune reconstitution syndrome.

  16. Craniocerebral trauma. Magnetic resonance imaging of diffuse axonal injury

    International Nuclear Information System (INIS)

    Mallouhi, A.

    2014-01-01

    Acceleration-deceleration rotational brain trauma is a common cause of disability or death in young adults and often leads to a focal destruction of axons. The resulting pathology, axonal shear injury is referred to as diffuse axonal injury (DAI). The DAI-associated lesions occur bilaterally, are widely dispersed and have been observed in the surface and deep white matter. They are found near to and far from the impact site. When DAI is clinically suspected, magnetic resonance imaging (MRI) is the method of choice for further clarification, especially in patients where cranial computed tomography (CT) is inconspicuous. To investigate the presence of DAI after traumatic brain injury (TBI), a multimodal MRI approach is applied including the common structural and also functional imaging sequences. For structural MRI, fluid-attenuated inversion recovery (FLAIR) weighted and susceptibility contrast imaging (SWI) are the sequences mainly used. The SWI technique is extremely sensitive to blood breakdown products, which appear as small signal voids at three locations, at the gray-white interface, in the corpus callosum and in the brain stem. Functional MRI comprises a group of constantly developing techniques that have great potential in optimal evaluation of the white matter in patients after craniocerebral trauma. These imaging techniques allow the visualization of changes associated with shear injuries, such as functional impairment of axons and decreased blood flow and abnormal metabolic activity of the brain parts affected. The multimodal MRI approach in patients with DAI results in a more detailed and differentiated representation of the underlying pathophysiological changes of the injured nerve tracts and helps to improve the diagnostic and prognostic accuracy of MRI. When DAI is suspected multimodal MRI should be performed as soon as possible after craniocerebral injury. (orig.) [de

  17. Polyethylene glycol restores axonal conduction after corpus callosum transection

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    Ravinder Bamba

    2017-01-01

    Full Text Available Polyethylene glycol (PEG has been shown to restore axonal continuity after peripheral nerve transection in animal models. We hypothesized that PEG can also restore axonal continuity in the central nervous system. In this current experiment, coronal sectioning of the brains of Sprague-Dawley rats was performed after animal sacrifice. 3Brain high-resolution microelectrode arrays (MEA were used to measure mean firing rate (MFR and peak amplitude across the corpus callosum of the ex-vivo brain slices. The corpus callosum was subsequently transected and repeated measurements were performed. The cut ends of the corpus callosum were still apposite at this time. A PEG solution was applied to the injury site and repeated measurements were performed. MEA measurements showed that PEG was capable of restoring electrophysiology signaling after transection of central nerves. Before injury, the average MFRs at the ipsilateral, midline, and contralateral corpus callosum were 0.76, 0.66, and 0.65 spikes/second, respectively, and the average peak amplitudes were 69.79, 58.68, and 49.60 μV, respectively. After injury, the average MFRs were 0.71, 0.14, and 0.25 spikes/second, respectively and peak amplitudes were 52.11, 8.98, and 16.09 μV, respectively. After application of PEG, there were spikes in MFR and peak amplitude at the injury site and contralaterally. The average MFRs were 0.75, 0.55, and 0.47 spikes/second at the ipsilateral, midline, and contralateral corpus callosum, respectively and peak amplitudes were 59.44, 45.33, 40.02 μV, respectively. There were statistically differences in the average MFRs and peak amplitudes between the midline and non-midline corpus callosum groups (P < 0.01, P < 0.05. These findings suggest that PEG restores axonal conduction between severed central nerves, potentially representing axonal fusion.

  18. Polyethylene glycol restores axonal conduction after corpus callosum transection.

    Science.gov (United States)

    Bamba, Ravinder; Riley, D Colton; Boyer, Richard B; Pollins, Alonda C; Shack, R Bruce; Thayer, Wesley P

    2017-05-01

    Polyethylene glycol (PEG) has been shown to restore axonal continuity after peripheral nerve transection in animal models. We hypothesized that PEG can also restore axonal continuity in the central nervous system. In this current experiment, coronal sectioning of the brains of Sprague-Dawley rats was performed after animal sacrifice. 3Brain high-resolution microelectrode arrays (MEA) were used to measure mean firing rate (MFR) and peak amplitude across the corpus callosum of the ex-vivo brain slices. The corpus callosum was subsequently transected and repeated measurements were performed. The cut ends of the corpus callosum were still apposite at this time. A PEG solution was applied to the injury site and repeated measurements were performed. MEA measurements showed that PEG was capable of restoring electrophysiology signaling after transection of central nerves. Before injury, the average MFRs at the ipsilateral, midline, and contralateral corpus callosum were 0.76, 0.66, and 0.65 spikes/second, respectively, and the average peak amplitudes were 69.79, 58.68, and 49.60 μV, respectively. After injury, the average MFRs were 0.71, 0.14, and 0.25 spikes/second, respectively and peak amplitudes were 52.11, 8.98, and 16.09 μV, respectively. After application of PEG, there were spikes in MFR and peak amplitude at the injury site and contralaterally. The average MFRs were 0.75, 0.55, and 0.47 spikes/second at the ipsilateral, midline, and contralateral corpus callosum, respectively and peak amplitudes were 59.44, 45.33, 40.02 μV, respectively. There were statistically differences in the average MFRs and peak amplitudes between the midline and non-midline corpus callosum groups ( P < 0.01, P < 0.05). These findings suggest that PEG restores axonal conduction between severed central nerves, potentially representing axonal fusion.

  19. Prediction of Functional Outcome in Axonal Guillain-Barre Syndrome.

    Science.gov (United States)

    Sung, Eun Jung; Kim, Dae Yul; Chang, Min Cheol; Ko, Eun Jae

    2016-06-01

    To identify the factors that could predict the functional outcome in patients with the axonal type of Guillain-Barre syndrome (GBS). Two hundred and two GBS patients admitted to our university hospital between 2003 and 2014 were reviewed retrospectively. We defined a good outcome as being "able to walk independently at 1 month after onset" and a poor outcome as being "unable to walk independently at 1 month after onset". We evaluated the factors that differed between the good and poor outcome groups. Twenty-four patients were classified into the acute motor axonal neuropathy type. There was a statistically significant difference between the good and poor outcome groups in terms of the GBS disability score at admission, and GBS disability score and Medical Research Council sum score at 1 month after admission. In an electrophysiologic analysis, the good outcome group showed greater amplitude of median, ulnar, deep peroneal, and posterior tibial nerve compound muscle action potentials (CMAP) and greater amplitude of median, ulnar, and superficial peroneal sensory nerve action potentials (SNAP) than the poor outcome group. A lower GBS disability score at admission, high amplitude of median, ulnar, deep peroneal, and posterior tibial CMAPs, and high amplitude of median, ulnar, and superficial peroneal SNAPs were associated with being able to walk at 1 month in patients with axonal GBS.

  20. Axonal Control of the Adult Neural Stem Cell Niche

    Science.gov (United States)

    Tong, Cheuk Ka; Chen, Jiadong; Cebrián-Silla, Arantxa; Mirzadeh, Zaman; Obernier, Kirsten; Guinto, Cristina D.; Tecott, Laurence H.; García-Verdugo, Jose Manuel; Kriegstein, Arnold; Alvarez-Buylla, Arturo

    2014-01-01

    SUMMARY The ventricular-subventricular zone (V-SVZ) is an extensive germinal niche containing neural stem cells (NSC) in the walls of the lateral ventricles of the adult brain. How the adult brain’s neural activity influences the behavior of adult NSCs remains largely unknown. We show that serotonergic (5HT) axons originating from a small group of neurons in the raphe form an extensive plexus on most of the ventricular walls. Electron microscopy revealed intimate contacts between 5HT axons and NSCs (B1) or ependymal cells (E1) and these cells were labeled by a transsynaptic viral tracer injected into the raphe. B1 cells express the 5HT receptors 2C and 5A. Electrophysiology showed that activation of these receptors in B1 cells induced small inward currents. Intraventricular infusion of 5HT2C agonist or antagonist increased or decreased V-SVZ proliferation, respectively. These results indicate that supraependymal 5HT axons directly interact with NSCs to regulate neurogenesis via 5HT2C. PMID:24561083

  1. Vesicular glutamate release from central axons contributes to myelin damage.

    Science.gov (United States)

    Doyle, Sean; Hansen, Daniel Bloch; Vella, Jasmine; Bond, Peter; Harper, Glenn; Zammit, Christian; Valentino, Mario; Fern, Robert

    2018-03-12

    The axon myelin sheath is prone to injury associated with N-methyl-D-aspartate (NMDA)-type glutamate receptor activation but the source of glutamate in this context is unknown. Myelin damage results in permanent action potential loss and severe functional deficit in the white matter of the CNS, for example in ischemic stroke. Here, we show that in rats and mice, ischemic conditions trigger activation of myelinic NMDA receptors incorporating GluN2C/D subunits following release of axonal vesicular glutamate into the peri-axonal space under the myelin sheath. Glial sources of glutamate such as reverse transport did not contribute significantly to this phenomenon. We demonstrate selective myelin uptake and retention of a GluN2C/D NMDA receptor negative allosteric modulator that shields myelin from ischemic injury. The findings potentially support a rational approach toward a low-impact prophylactic therapy to protect patients at risk of stroke and other forms of excitotoxic injury.

  2. Retinal glia promote dorsal root ganglion axon regeneration.

    Directory of Open Access Journals (Sweden)

    Barbara Lorber

    Full Text Available Axon regeneration in the adult central nervous system (CNS is limited by several factors including a lack of neurotrophic support. Recent studies have shown that glia from the adult rat CNS, specifically retinal astrocytes and Müller glia, can promote regeneration of retinal ganglion cell axons. In the present study we investigated whether retinal glia also exert a growth promoting effect outside the visual system. We found that retinal glial conditioned medium significantly enhanced neurite growth and branching of adult rat dorsal root ganglion neurons (DRG in culture. Furthermore, transplantation of retinal glia significantly enhanced regeneration of DRG axons past the dorsal root entry zone after root crush in adult rats. To identify the factors that mediate the growth promoting effects of retinal glia, mass spectrometric analysis of retinal glial conditioned medium was performed. Apolipoprotein E and secreted protein acidic and rich in cysteine (SPARC were found to be present in high abundance, a finding further confirmed by western blotting. Inhibition of Apolipoprotein E and SPARC significantly reduced the neuritogenic effects of retinal glial conditioned medium on DRG in culture, suggesting that Apolipoprotein E and SPARC are the major mediators of this regenerative response.

  3. Internalization and Axonal Transport of the HIV Glycoprotein gp120

    Science.gov (United States)

    Berth, Sarah; Caicedo, Hector Hugo; Sarma, Tulika; Morfini, Gerardo

    2015-01-01

    The HIV glycoprotein gp120, a neurotoxic HIV glycoprotein that is overproduced and shed by HIV-infected macrophages, is associated with neurological complications of HIV such as distal sensory polyneuropathy, but interactions of gp120 in the peripheral nervous system remain to be characterized. Here, we demonstrate internalization of extracellular gp120 in a manner partially independent of binding to its coreceptor CXCR4 by F11 neuroblastoma cells and cultured dorsal root ganglion neurons. Immunocytochemical and pharmacological experiments indicate that gp120 does not undergo trafficking through the endolysosomal pathway. Instead, gp120 is mainly internalized through lipid rafts in a cholesterol-dependent manner, with a minor fraction being internalized by fluid phase pinocytosis. Experiments using compartmentalized microfluidic chambers further indicate that, after internalization, endocytosed gp120 selectively undergoes retrograde but not anterograde axonal transport from axons to neuronal cell bodies. Collectively, these studies illuminate mechanisms of gp120 internalization and axonal transport in peripheral nervous system neurons, providing a novel framework for mechanisms for gp120 neurotoxicity. PMID:25636314

  4. Pathophysiologic insights into motor axonal function in Kennedy disease.

    Science.gov (United States)

    Vucic, Steve; Kiernan, Matthew C

    2007-11-06

    Kennedy disease (KD), or spinobulbomuscular atrophy, is a slowly progressive inherited neurodegenerative disorder, marked by prominent fasciculations that typically precede the development of other symptoms. Although the genetic basis of KD relates to triplet (CAG) repeat expansion in the androgen receptor (AR) gene on the X chromosome, the mechanisms underlying the clinical presentation in KD have yet to be established. Consequently, the present study applied axonal excitability techniques to investigate the pathophysiologic mechanisms associated with KD. Peripheral nerve excitability studies were undertaken in 7 patients with KD with compound muscle action potentials (CMAP) recorded from the right abductor pollicis brevis. Strength-duration time constant (KD 0.54 +/- 0.03 msec; controls, 0.41 +/- 0.02 msec, p TEd [90 to 100 msec], 50.75 +/- 1.98%; controls TEd [90 to 100 msec], 45.67 +/- 0.67%, p < 0.01) and hyperpolarizing (KD TEh [90 to 100 msec], 128.5 +/- 6.9%; controls TEh [90 to 100 msec], 120.5 +/- 2.4%) conditioning pulses. Measurements of refractoriness, superexcitability, and late subexcitability changed appropriately for axonal hyperpolarization, perhaps reflecting the effects of increased ectopic activity. In total, the increase in the strength-duration time constant may be the primary event, occurring early in course of the disease, contributing to the development of axonal hyperexcitability in Kennedy disease, and thereby to the generation of fasciculations, a characteristic hallmark of the disease.

  5. Caracterización inmunofenotípica de pacientes con leucemia mieloide aguda

    Directory of Open Access Journals (Sweden)

    Daily Pino Blanco

    Full Text Available Introducción: la leucemia mieloide aguda incluye un grupo heterogéneo de neoplasias caracterizadas por una expansión clonal de mieloblastos, cuya clasificación involucra varios criterios, incluidos los inmunológicos. Objetivo: caracterizar el inmunofenotipo de los pacientes con leucemia mieloide aguda evaluados en el Instituto de Hematología e Inmunología. Métodos: se realizó un estudio descriptivo transversal de los pacientes diagnosticados con este tipo de leucemia, cuyas muestras de sangre fueron procesadas en el Departamento de Inmunología en el período 2008-2012. Se usó un ultramicrométodo inmunocitoquímico que utiliza un panel de anticuerpos monoclonales específicos de antígenos mieloides y linfoides. Las variables analizadas fueron: edad, sexo, subtipo de leucemia y expresión de marcadores inmunológicos, cuyas asociaciones fueron analizadas con los estadígrafos Chi-cuadrado y coeficiente de correlación de Spearman. Resultados: se estudiaron 58 pacientes, 28 del sexo femenino y 30 del masculino. El grupo de edad predominante fue de 0 a 9 años con una mediana de 26 años. El subtipo M4 resultó el más frecuente (30,4 %. Los subtipos M4 y M7 predominaron en niños, mientras que el M0, predominó en adultos, con diferencias estadísticamente significativas (p d»0,05. La combinación de los antígenos panmieloides CD13 y CD33 se presentó en el 91 % de los enfermos. Las combinaciones de CD13/CD33, CD14/CD15, CD33/CD14 y CD33/CD15 mostraron correlación significativa. En el 20,6 % de los pacientes evaluados, fueron detectados, además, antígenos linfoides. No se encontraron diferencias significativas en cuanto al sexo y la edad. El antígeno CD7 fue el más expresado, seguido de los antígenos: CD3, CD20, CD22 y CD79, en igual proporción. Conclusiones: el inmunofenotipaje celular demostró ser un procedimiento útil para confirmar el diagnóstico morfológico y clínico de la leucemia mieloide aguda.

  6. Leucemia linfoblástica aguda em lactentes: 20 anos de experiência

    Directory of Open Access Journals (Sweden)

    Amanda Ibagy

    2013-02-01

    Full Text Available OBJETIVO: Analisar pacientes com menos de dois anos de idade com leucemia linfoblástica aguda atendidos no período de 1990 a 2010, em um centro de referência estadual. MÉTODOS: Estudo clínico, epidemiológico, transversal, descritivo e observacional. Pacientes incluídos tinham menos de dois anos de idade, com leucemia linfoblástica aguda, tratados no período de 1990 a 2010 na unidade de oncologia pediátrica de um centro de referência estadual, totalizando 41 casos. RESULTADOS: Todos os pacientes eram Caucasianos e 60,9% eram do sexo feminino. Com relação à idade, 24,38% tinham menos de seis meses, 17,07% tinham entre seis meses e um ano e 58,53% mais do que um ano de idade. A idade de seis meses foi estatisticamente significante para o desfecho de óbito. Os sinais e sintomas predominantes foram febre, hematomas e petéquias. Uma contagem de leucócitos superior a 100.000 foi observada em 34,14% dos casos; hemoglobina inferior a 11 em 95,13% e contagem de plaquetas inferior a 100.000, em 75,61% dos casos. Infiltração do sistema nervoso central estava presente em 12,91% dos pacientes. Em relação à linhagem, a linhagem B predominou (73%, mas a linhagem de células T foi estatisticamente significativa para o óbito. Trinta e nove por cento dos pacientes tiveram recorrência da doença. Em relação ao estado vital, 70,73% dos pacientes morreram, sendo choque séptico a principal causa. CONCLUSÕES: leucemia linfoblástica aguda em crianças tem uma alta taxa de mortalidade, principalmente em crianças menores de um ano e linhagem derivada de células T.

  7. In vivo imaging reveals mitophagy independence in the maintenance of axonal mitochondria during normal aging.

    Science.gov (United States)

    Cao, Xu; Wang, Haiqiong; Wang, Zhao; Wang, Qingyao; Zhang, Shuang; Deng, Yuanping; Fang, Yanshan

    2017-10-01

    Mitophagy is thought to be a critical mitochondrial quality control mechanism in neurons and has been extensively studied in neurological disorders such as Parkinson's disease. However, little is known about how mitochondria are maintained in the lengthy neuronal axons in the context of physiological aging. Here, we utilized the unique Drosophila wing nerve model and in vivo imaging to rigorously profile changes in axonal mitochondria during aging. We revealed that mitochondria became fragmented and accumulated in aged axons. However, lack of Pink1 or Parkin did not lead to the accumulation of axonal mitochondria or axonal degeneration. Further, unlike in in vitro cultured neurons, we found that mitophagy rarely occurred in intact axons in vivo, even in aged animals. Furthermore, blocking overall mitophagy by knockdown of the core autophagy genes Atg12 or Atg17 had little effect on the turnover of axonal mitochondria or axonal integrity, suggesting that mitophagy is not required for axonal maintenance; this is regardless of whether the mitophagy is PINK1-Parkin dependent or independent. In contrast, downregulation of mitochondrial fission-fusion genes caused age-dependent axonal degeneration. Moreover, Opa1 expression in the fly head was significantly decreased with age, which may underlie the accumulation of fragmented mitochondria in aged axons. Finally, we showed that adult-onset, neuronal downregulation of the fission-fusion, but not mitophagy genes, dramatically accelerated features of aging. We propose that axonal mitochondria are maintained independently of mitophagy and that mitophagy-independent mechanisms such as fission-fusion may be central to the maintenance of axonal mitochondria and neural integrity during normal aging. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  8. Sodium Channel β2 Subunits Prevent Action Potential Propagation Failures at Axonal Branch Points.

    Science.gov (United States)

    Cho, In Ha; Panzera, Lauren C; Chin, Morven; Hoppa, Michael B

    2017-09-27

    Neurotransmitter release depends on voltage-gated Na + channels (Na v s) to propagate an action potential (AP) successfully from the axon hillock to a synaptic terminal. Unmyelinated sections of axon are very diverse structures encompassing branch points and numerous presynaptic terminals with undefined molecular partners of Na + channels. Using optical recordings of Ca 2+ and membrane voltage, we demonstrate here that Na + channel β2 subunits (Na v β2s) are required to prevent AP propagation failures across the axonal arborization of cultured rat hippocampal neurons (mixed male and female). When Na v β2 expression was reduced, we identified two specific phenotypes: (1) membrane excitability and AP-evoked Ca 2+ entry were impaired at synapses and (2) AP propagation was severely compromised with >40% of axonal branches no longer responding to AP-stimulation. We went on to show that a great deal of electrical signaling heterogeneity exists in AP waveforms across the axonal arborization independent of axon morphology. Therefore, Na v β2 is a critical regulator of axonal excitability and synaptic function in unmyelinated axons. SIGNIFICANCE STATEMENT Voltage-gated Ca 2+ channels are fulcrums of neurotransmission that convert electrical inputs into chemical outputs in the form of vesicle fusion at synaptic terminals. However, the role of the electrical signal, the presynaptic action potential (AP), in modulating synaptic transmission is less clear. What is the fidelity of a propagating AP waveform in the axon and what molecules shape it throughout the axonal arborization? Our work identifies several new features of AP propagation in unmyelinated axons: (1) branches of a single axonal arborization have variable AP waveforms independent of morphology, (2) Na + channel β2 subunits modulate AP-evoked Ca 2+ -influx, and (3) β2 subunits maintain successful AP propagation across the axonal arbor. These findings are relevant to understanding the flow of excitation in the

  9. Dynamic Changes of Neuroskeletal Proteins in DRGs Underlie Impaired Axonal Maturation and Progressive Axonal Degeneration in Type 1 Diabetes

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    Hideki Kamiya

    2009-01-01

    Full Text Available We investigated mechanisms underlying progressive axonal dysfunction and structural deficits in type 1 BB/Wor-rats from 1 week to 10 month diabetes duration. Motor and sensory conduction velocities were decreased after 4 and 6 weeks of diabetes and declined further over the remaining 9 months. Myelinated sural nerve fibers showed progressive deficits in fiber numbers and sizes. Structural deficits in unmyelinated axonal size were evident at 2 month and deficits in number were present at 4 mo. These changes were preceded by decreased availability of insulin, C-peptide and IGF-1 and decreased expression of neurofilaments and β-III-tubulin. Upregulation of phosphorylating stress kinases like Cdk5, p-GSK-3β, and p42/44 resulted in increased phosphorylation of neurofilaments. Increasing activity of p-GSK-3β correlated with increasing phosphorylation of NFH, whereas decreasing Cdk5 correlated with diminishing phosphorylation of NFM. The data suggest that impaired neurotrophic support results in sequentially impaired synthesis and postranslational modifications of neuroskeletal proteins, resulting in progressive deficits in axonal function, maturation and size.

  10. Hemiplejía aguda infantil asociada a infección por enterovirus

    OpenAIRE

    Muñoz, Erika; Caramuta, Luciana; Frenkel, Susana; Cáceres, Lidia

    2005-01-01

    El ictus isquémico en la infancia es una entidad infrecuente, en el 50% de los casos no existe una causa identificable. Sin embargo, con el advenimiento de nuevas técnicas diagnósticas se han podido conocer más afecciones causales. Presentamos el caso de una paciente de 9 años con hemiplejía aguda izquierda, con estudios de neuroimágenes poco significativos y en la cual el análisis del líquido cefalorraquídeo por método de reacción en cadena de polimerasa (PCR) para ARN viral, fue positivo pa...

  11. Diagnósticos de enfermagem em adultos com leucemia mielóide aguda

    OpenAIRE

    Souza, Luccas Melo de; Gorini, Maria Isabel Pinto Coelho

    2006-01-01

    Trata-se de um estudo de casos, que objetivou identificar os Diagnósticos de Enfermagem (DE) de pacientes adultos com Leucemia Mielóide Aguda, a fim de fornecer subsídios à Sistematização da Assistência de Enfermagem. Utilizaram-se as técnicas de entrevista e observação, além da aplicação do Processo de Enfermagem. Durantes os três meses da coleta de dados, outros DEs foram encontrados através de novas buscas nos prontuários dos 6 pacientes. Os 32 DEs encontrados foram agrupados conforme a Te...

  12. Toxicidade aguda do extrato aquoso de folhas de Erythrina velutina em animais experimentais

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    Ariadne Conceição Santos Craveiro

    Full Text Available Este trabalho teve como objetivo a avaliação da toxicidade aguda do extrato aquoso de folhas de Erythrina velutina, espécie vegetal muito usada na medicina popular principalmente como tranqüilizante. O protocolo experimental utilizado seguiu o Guia para a Realização de Estudos de Toxicidade Pré-clínica de Fitoterápicos da Agência Nacional de Vigilância Sanitária (Anvisa, 2004. Ratos Wistar adultos foram tratados por via oral com a dose limite de 5 g/kg do extrato e observados por 14 dias consecutivos. Nenhum animal veio a óbito e nenhum sinal de toxicidade foi detectado nas observações comportamentais ou nas autópsias, indicando uma razoável atoxicidade do extrato.

  13. Ataxia cerebelar aguda na criança Acute cerebellar ataxia in children

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    Valeriana Moura Ribeiro

    1968-03-01

    Full Text Available São relatados os casos de 6 crianças com ataxia cerebelar aguda. Admitem os autores a presença de um fator etiológico de caráter viral comum a todos êles, discutindo os mecanismos patogênicos com base nos casos da literatura. A evolução foi favorável em todos os pacientes, com regressão completa da sintomatologia, dentro do período de 6 a 60 dias.Clinical observations of 6 children with acute cerebellar ataxia and respective laboratorial data are reported. Considerations are made in order to support the hypothesis of involving virus. The evolution of the disorder was a nonfatal one and the patients regained normal cerebellar function within a period of 6 to 60 days.

  14. Hepatite aguda colestática pelo propiltiouracil: relato de caso

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    PAROLIN Mônica Beatriz

    2000-01-01

    Full Text Available Propiltiouracil é uma droga amplamente utilizada no tratamento do hipertiroidismo. A hepatotoxicidade é um dos efeitos colaterais mais raros e também mais graves associados a ela. Relata-se um caso de hepatite aguda colestática que acomete um jovem de 15 anos em uso de propiltiouracil para tratamento de hipertiroidismo. Causas virais, metabólicas e autoimunes foram excluídas e a biopsia hepática revelou achados histopatológicos sugestivos de hepatite colestática induzida por droga. Com a suspensão da droga, houve remissão dos sintomas e normalização progressiva das provas de função hepática. Raramente, os pacientes em uso de propiltiouracil podem desenvolver injúria hepática grave.

  15. Leucemia Linfoblástica Aguda Caso clínico

    OpenAIRE

    Jiménez Navarro, Nuria

    2017-01-01

    El cáncer es una de las segundas causas de muerte de nuestra población considerándose también la segunda causa de muerte entre los 0-14 años de edad. Es una enfermedad multifactorial que consigue deteriorar al paciente tanto física como psíquicamente. La leucemia linfoblástica aguda es el cáncer más relevante en niños, constituyendo el 80% de los casos. Está localizado en las células sanguíneas, normalmente en los glóbulos blancos, de la médula ósea, afectando a la función inmunológica. Debid...

  16. Diabetes Mellitus en el servicio de urgencias: manejo de las complicaciones agudas en adultos

    Directory of Open Access Journals (Sweden)

    Eder A. Hernández-Ruiz

    2008-01-01

    Full Text Available La Diabetes Mellitus (DM es una enfermedad de alta prevalencia, reconocida como un problema de salud pública, debido a sus altas tasas de morbilidad y mortalidad asociadas. Diferentes estudios han documentado que la falta de adherencia al tratamiento, constituye uno de los principales factores desencadenantes para las descompensaciones agudas en el paciente diabético. Dentro del espectro de dichas alteraciones se encuentran las crisis hiperglicémicas agudas, las cuales se han dicotomizado en dos entidades clínicas: la Cetoacidosis Diabética (CAD y el Estado Hiperglicémico Hiperosmolar (EHH, que constituyen complicaciones metabólicas potencialmente fatales en el corto plazo y de las cuales pueden encontrarse cuadros superpuestos. Se han establecido criterios diagnósticos específicos buscando realizar un diagnóstico diferencial acertado, que permita un tratamiento idóneo; sin embargo, las tasas de morbilidad y mortalidad siguen siendo considerables. Por su parte, la Hipoglicemia también constituye una emergencia médica que, de no ser tratada oportunamente, puede ocasionar daño neurológico permanente e incluso la muerte. De lo anterior se deduce la importancia de que existan guías claras de manejo de estas alteraciones en todos los centros y servicios donde se preste atención médica de urgencias. Se siguen realizando investigaciones en busca de nuevas estrategias diagnósticas y terapéuticas que permitan un manejo más integral de la DM y sus complicaciones, en aras de mejorar la calidad de vida de los pacientes.

  17. Factores de riesgo de infecciones respiratorias agudas en menores de 5 años

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    María Eulalia Prieto Herrera

    2000-01-01

    Full Text Available Se realizó un estudio analítico, retrospectivo de casos y controles, pareado 1:1 para conocer algunos factores de riesgo de infecciones respiratorias agudas en menores de 5 años del reparto La Yaba, pertenecientes al policlínico Este de Camagüey, durante el año 1996. El universo fueron 90 niños que padecieron infecciones respiratorias agudas durante este período. La fuente de obtención de datos fue la historia clínica familiar e individual. El registro primario fue la encuesta con las variables: lactancia materna, desnutrición, enfermedades asociadas, fumador pasivo, hacinamiento. Se concluyó que la lactancia materna inadecuada (RR 12, 152, la desnutrición (RR 2, 278, la enfermedad parasitaria (RR 1, 643, el fumador pasivo (RR, 536 y el hacinamiento (RR 2, 719 se comportaron como factores de riesgo.An analytic retrospective case-control study was performed, matched 1:1, with the aim of getting to know the risk factors for acute respiratory diseases in children under 5 years of age from La Yaba neighborhood belonging to the health area of the eastern policlinics of Camaguey, during the year 1996. The study material was made up of 90 children that suffered from acute respiratory diseases during that period. The data source was the individual and family medical histories. The primary record was a survey including the following variables: breast feeding, malnutrition, associated diseases, passive smoking, overcrowding. It was concluded that inadequate breast feeding (RR 12, 152, malnutrition (RR 2, 278, parasitic disease (RR 1, 643, passive smoking (RR, 536 and overcrowding (RR 2, 719 behaved as risk factors.

  18. Crisis aguda de Asma Bronquial. Diagnóstico y tratamiento estandarizado

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    Anelia de la Caridad Rojas-Pérez

    2013-01-01

    Full Text Available Se realizó un estudio prospectivo de intervención en 150 pacientes con diagnóstico de Asma Bronquial que acudieron con crisis aguda al Servicio de Urgencias del Hospital Pediátrico de Holguín, de Enero del 2009 hasta Diciembre del 2010; para evaluar la evolución de los mismos después de la aplicación de Guías de Buenas Prácticas. Se aplicó tratamiento a los pacientes según lo establecido, observando su respuesta. Predominó el grupo de 4 a 8 años del sexo masculino, el 52 % de los pacientes presentaron crisis ligeras, buena respuesta al uso de broncodilatadores en aerosol, se aplicó la Prednisona por vía oral en la mayoría de los casos que lo requirieron, el 68,7 % realizó tratamiento domiciliario con respuestas controladas y solo en el 31,3 % se decidió ingreso hospitalario lo que permitió arribar a la siguiente conclusión: Con la aplicación de Guías de Buenas Prácticas Clínicas par a el manejo de la exacerbación aguda del Asma Bronquial se logró una clasificación adecuada de la severidad de la misma, buena respuesta a los tratamientos utilizados y disminución de los ingresos hospitalarios.

  19. Clio pyramidata Linnaeus, 1767 forma convexa (Boas, 1886) (Mollusca, Pteropoda)

    NARCIS (Netherlands)

    Spoel, van der S.

    1973-01-01

    The pelagic fauna of the Red Sea shows special variation induced by its isolated character (Van der Spoel, 1971). Clio pyramidata from the Red Sea is usually incorrectly referred to as the tropical forma lanceolata (Lesueur, 1813) or the typical forma pyramidata Linnaeus, 1767. Some large samples

  20. Proteína C reactiva e gravidade da bronquiolite aguda C Reactive protein and disease severity in bronchiolitis

    Directory of Open Access Journals (Sweden)

    S Costa

    2009-01-01

    Full Text Available O diagnóstico de bronquiolite aguda é essencialmente clínico. A utilidade de exames laboratoriais, em particular do doseamento da proteína C reactiva (PCR, não está bem estabelecida. O objectivo deste trabalho foi avaliar a relação entre o valor da PCR e os marcadores indirectos de gravidade em doentes com diagnóstico de bronquiolite. Foram incluídos no estudo todos os doentes admitidos no Serviço de Pediatria do HSJ durante o ano de 2006 e que tiveram como diagnóstico principal bronquiolite, tendo sido feita uma revisão retrospectiva do processo clínico desses doentes. Foram incluídos 176 doentes com idades compreendidas entre zero e 36 meses (mediana de 4 meses; 63,1% eram do sexo masculino. O doseamento da PCR tinha sido efectuado em 94,3% dos doentes, com valores compreendidos entre zero e 256mg/L e com mediana de 11 mg/L. O valor da PCR, na população estudada, apresentou uma relação estatisticamente significativa com a admissão em unidade de cuidados intensivos (UCI (p=0,008, a duração do internamento hospitalar (p=0,025 e a necessidade de oxigenoterapia (p=0,022. Desta forma, este trabalho coloca a hipótese de o valor de PCR poder ser um marcador de gravidade e ter significado prognóstico em doentes com bronquiolite. Mais estudos são necessários para validar estes resultados e esclarecer se existe uma relação real entre as variáveis estudadas ou se esta é produzida pelo efeito confundidor de outras infecções.A diagnosis of bronchiolitis is made clinically and the use of supportive laboratory examinations, including the quantification of C reactive protein (CRP, is not well established. The aim of this study was to evaluate the correlation between CRP value and indirect markers of disease severity in patients with bronchiolitis. This study included the patients diagnosed with bronchiolitis admitted to the Pediatrics Department of S. João Hospital in 2006. A retrospective review was made through analysing

  1. Axonal Spheroid Accumulation In the Brainstem and Spinal Cord of A Young Angus Cow with Ataxia.

    Science.gov (United States)

    Hanshaw, D M; Finnie, J W; Manavis, J; Kessell, A E

    2015-08-01

    An 18-month-old Angus cow presented with rapidly developing ataxia and subsequently died. The finding of large numbers of axonal spheroids in brainstem nuclei and spinal cord grey matter, bilaterally symmetrical in distribution, was consistent with a histopathological diagnosis of neuroaxonal dystrophy (NAD). Most of the axonal swellings were immunopositive to amyloid precursor protein, suggesting that interruption to axonal flow was important in their genesis. The topographical distribution of axonal spheroids in the brain and spinal cord in this bovine case closely resembled that found in the ovine neurodegenerative disorder termed NAD, in which axonal swellings are the major pathological feature. This appears to be the first reported case of this type of NAD in cattle. The aetiology of the spheroidal aggregations in this case was not determined. There was no evidence from the case history or neuropathology to indicate whether the axonal spheroids in this case involved an acquired or heritable aetiology. © 2015 Australian Veterinary Association.

  2. Role of calpains in the injury-induced dysfunction and degeneration of the mammalian axon.

    Science.gov (United States)

    Ma, Marek

    2013-12-01

    Axonal injury and degeneration, whether primary or secondary, contribute to the morbidity and mortality seen in many acquired and inherited central nervous system (CNS) and peripheral nervous system (PNS) disorders, such as traumatic brain injury, spinal cord injury, cerebral ischemia, neurodegenerative diseases, and peripheral neuropathies. The calpain family of proteases has been mechanistically linked to the dysfunction and degeneration of axons. While the direct mechanisms by which transection, mechanical strain, ischemia, or complement activation trigger intra-axonal calpain activity are likely different, the downstream effects of unregulated calpain activity may be similar in seemingly disparate diseases. In this review, a brief examination of axonal structure is followed by a focused overview of the calpain family. Finally, the mechanisms by which calpains may disrupt the axonal cytoskeleton, transport, and specialized domains (axon initial segment, nodes, and terminals) are discussed. © 2013.

  3. A Combinatorial Approach to Induce Sensory Axon Regeneration into the Dorsal Root Avulsed Spinal Cord

    DEFF Research Database (Denmark)

    Hoeber, Jan; Konig, Niclas; Trolle, Carl

    2017-01-01

    Spinal root injuries result in newly formed glial scar formation, which prevents regeneration of sensory axons causing permanent sensory loss. Previous studies showed that delivery of trophic factors or implantation of human neural progenitor cells supports sensory axon regeneration and partly......MIM), supported sensory axon regeneration. However, when hscNSPC and MesoMIM were combined, sensory axon regeneration failed. Morphological and tracing analysis showed that sensory axons grow through the newly established glial scar along “bridges” formed by migrating stem cells. Coimplantation of Meso...... their level of differentiation. Our data show that (1) the ability of stem cells to migrate into the spinal cord and organize cellular “bridges” in the newly formed interface is crucial for successful sensory axon regeneration, (2) trophic factor mimetics delivered by mesoporous silica may be a convenient...

  4. REGENERATIVE GROWTH OF CORTICOSPINAL TRACT AXONS VIA THE VENTRAL COLUMN AFTER SPINAL CORD INJURY IN MICE

    OpenAIRE

    Steward, Oswald; Zheng, Binhai; Tessier-Lavigne, Marc; Hofstadter, Maura; Sharp, Kelli; Yee, Kelly Matsudaira

    2008-01-01

    Studies that have assessed regeneration of corticospinal tract (CST) axons in mice following genetic modifications or other treatments have tacitly assumed that there is little if any regeneration of CST axons in normal mice in the absence of some intervention. Here, we document a previously unrecognized capability for regenerative growth of CST axons in normal mice that involves growth past the lesion via the ventral column. Mice received dorsal hemisection injuries at thoracic level 6–7, wh...

  5. Defective Ca2+ channel clustering in axon terminals disturbs excitability in motoneurons in spinal muscular atrophy

    OpenAIRE

    Jablonka, Sibylle; Beck, Marcus; Lechner, Barbara Dorothea; Mayer, Christine; Sendtner, Michael

    2007-01-01

    Proximal spinal muscular atrophy (SMA) is a motoneuron disease for which there is currently no effective treatment. In animal models of SMA, spinal motoneurons exhibit reduced axon elongation and growth cone size. These defects correlate with reduced β-actin messenger RNA and protein levels in distal axons. We show that survival motoneuron gene (Smn)–deficient motoneurons exhibit severe defects in clustering Cav2.2 channels in axonal growth cones. These defects also correlate with a reduced f...

  6. Oligodendroglial MCT1 and Metabolic Support of Axons in Multiple Sclerosis

    Science.gov (United States)

    2015-10-01

    AWARD NUMBER: W81XWH-14-1-0524 TITLE:Oligodendroglial MCT1 and Metabolic Support of Axons in Multiple Sclerosis PRINCIPAL INVESTIGATOR: Jeffrey D...29 Sep 2015 4. TITLE AND SUBTITLE Oligodendroglial MCT1 and Metabolic Support of Axons in Multiple Sclerosis 5a. CONTRACT NUMBER W81XWH-14-1-0524...MCT1 in injured oligodendroglia of multiple sclerosis patients contributes to axon neurodegeneration and that increasing MCT1 will be protective in the

  7. 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.

  8. N-Propionylmannosamine stimulates axonal elongation in a murine model of sciatic nerve injury

    Directory of Open Access Journals (Sweden)

    Christian Witzel

    2015-01-01

    Full Text Available Increasing evidence indicates that sialic acid plays an important role during nerve regeneration. Sialic acids can be modified in vitro as well as in vivo using metabolic oligosaccharide engineering of the N-acyl side chain. N-Propionylmannosamine (ManNProp increases neurite outgrowth and accelerates the reestablishment of functional synapses in vitro. We investigated the influence of systemic ManNProp application using a specific in vivo mouse model. Using mice expressing axonal fluorescent proteins, we quantified the extension of regenerating axons, the number of regenerating axons, the number of arborising axons and the number of branches per axon 5 days after injury. Sciatic nerves from non-expressing mice were grafted into those expressing yellow fluorescent protein. We began a twice-daily intraperitoneal application of either peracetylated ManNProp (200 mg/kg or saline solution 5 days before injury, and continued it until nerve harvest (5 days after transection. ManNProp significantly increased the mean distance of axonal regeneration (2.49 mm vs. 1.53 mm; P < 0.005 and the number of arborizing axons (21% vs. 16% P = 0.008 5 days after sciatic nerve grafting. ManNProp did not affect the number of regenerating axons or the number of branches per arborizing axon. The biochemical glycoengineering of the N-acyl side chain of sialic acid might be a promising approach for improving peripheral nerve regeneration.

  9. The Molecular and Cellular Mechanisms of Axon Guidance in Mossy Fiber Sprouting

    Directory of Open Access Journals (Sweden)

    Ryuta Koyama

    2018-05-01

    Full Text Available The question of whether mossy fiber sprouting is epileptogenic has not been resolved; both sprouting-induced recurrent excitatory and inhibitory circuit hypotheses have been experimentally (but not fully supported. Therefore, whether mossy fiber sprouting is a potential therapeutic target for epilepsy remains under debate. Moreover, the axon guidance mechanisms of mossy fiber sprouting have attracted the interest of neuroscientists. Sprouting of mossy fibers exhibits several uncommon axonal growth features in the basically non-plastic adult brain. For example, robust branching of axonal collaterals arises from pre-existing primary mossy fiber axons. Understanding the branching mechanisms in adulthood may contribute to axonal regeneration therapies in neuroregenerative medicine in which robust axonal re-growth is essential. Additionally, because granule cells are produced throughout life in the neurogenic dentate gyrus, it is interesting to examine whether the mossy fibers of newly generated granule cells follow the pre-existing trajectories of sprouted mossy fibers in the epileptic brain. Understanding these axon guidance mechanisms may contribute to neuron transplantation therapies, for which the incorporation of transplanted neurons into pre-existing neural circuits is essential. Thus, clarifying the axon guidance mechanisms of mossy fiber sprouting could lead to an understanding of central nervous system (CNS network reorganization and plasticity. Here, we review the molecular and cellular mechanisms of axon guidance in mossy fiber sprouting by discussing mainly in vitro studies.

  10. NMNAT1 inhibits axon degeneration via blockade of SARM1-mediated NAD+ depletion

    Science.gov (United States)

    Sasaki, Yo; Nakagawa, Takashi; Mao, Xianrong; DiAntonio, Aaron; Milbrandt, Jeffrey

    2016-01-01

    Overexpression of the NAD+ biosynthetic enzyme NMNAT1 leads to preservation of injured axons. While increased NAD+ or decreased NMN levels are thought to be critical to this process, the mechanism(s) of this axon protection remain obscure. Using steady-state and flux analysis of NAD+ metabolites in healthy and injured mouse dorsal root ganglion axons, we find that rather than altering NAD+ synthesis, NMNAT1 instead blocks the injury-induced, SARM1-dependent NAD+ consumption that is central to axon degeneration. DOI: http://dx.doi.org/10.7554/eLife.19749.001 PMID:27735788

  11. GSK3 controls axon growth via CLASP-mediated regulation of growth cone microtubules

    Science.gov (United States)

    Hur, Eun-Mi; Saijilafu; Lee, Byoung Dae; Kim, Seong-Jin; Xu, Wen-Lin; Zhou, Feng-Quan

    2011-01-01

    Suppression of glycogen synthase kinase 3 (GSK3) activity in neurons yields pleiotropic outcomes, causing both axon growth promotion and inhibition. Previous studies have suggested that specific GSK3 substrates, such as adenomatous polyposis coli (APC) and collapsin response mediator protein 2 (CRMP2), support axon growth by regulating the stability of axonal microtubules (MTs), but the substrate(s) and mechanisms conveying axon growth inhibition remain elusive. Here we show that CLIP (cytoplasmic linker protein)-associated protein (CLASP), originally identified as a MT plus end-binding protein, displays both plus end-binding and lattice-binding activities in nerve growth cones, and reveal that the two MT-binding activities regulate axon growth in an opposing manner: The lattice-binding activity mediates axon growth inhibition induced by suppression of GSK3 activity via preventing MT protrusion into the growth cone periphery, whereas the plus end-binding property supports axon extension via stabilizing the growing ends of axonal MTs. We propose a model in which CLASP transduces GSK3 activity levels to differentially control axon growth by coordinating the stability and configuration of growth cone MTs. PMID:21937714

  12. Regulation of Axonal Midline Guidance by Prolyl 4-Hydroxylation in Caenorhabditis elegans

    DEFF Research Database (Denmark)

    Torpe, Nanna; Pocock, Roger David John

    2014-01-01

    , little is known of its importance in the control of axon guidance. In a screen of prolyl 4-hydroxylase (P4H) mutants, we found that genetic removal of a specific P4H subunit, DPY-18, causes dramatic defects in C. elegans neuroanatomy. In dpy-18 mutant animals, the axons of specific ventral nerve cord......Neuronal wiring during development requires that the growth cones of axons and dendrites are correctly guided to their appropriate targets. As in other animals, axon growth cones in Caenorhabditis elegans integrate information in their extracellular environment via interactions among transiently...

  13. Biomarker evidence of axonal injury in neuroasymptomatic HIV-1 patients.

    Directory of Open Access Journals (Sweden)

    Jan Jessen Krut

    Full Text Available Prevalence of neurocognitive impairment in HIV-1 infected patients is reported to be high. Whether this is a result of active HIV-related neurodegeneration is unclear. We examined axonal injury in HIV-1 patients by measuring the light subunit of neurofilament protein (NFL in CSF with a novel, sensitive method.With a cross-sectional design, CSF concentrations of neurofilament protein light (NFL (marker of neuronal injury, neopterin (intrathecal immunoactivation and CSF/Plasma albumin ratio (blood-brain barrier integrity were analyzed on CSF from 252 HIV-infected patients, subdivided into untreated neuroasymptomatics (n = 200, HIV-associated dementia (HAD (n = 14 and on combinations antiretroviral treatment (cART (n = 85, and healthy controls (n = 204. 46 HIV-infected patients were included in both treated and untreated groups, but sampled at different timepoints. Furthermore, 78 neuroasymptomatic patients were analyzed before and after treatment initiation.While HAD patients had the highest NFL concentrations, elevated CSF NFL was also found in 33% of untreated neuroasymptomatic patients, mainly in those with blood CD4+ cell counts below 250 cells/μL. CSF NFL concentrations in the untreated neuroasymptomatics and treated groups were equivalent to controls 18.5 and 3.9 years older, respectively. Neopterin correlated with NFL levels in untreated groups while the albumin ratio correlated with NFL in both untreated and treated groups.Increased CSF NFL indicates ongoing axonal injury in many neuroasymptomatic patients. Treatment decreases NFL, but treated patients retain higher levels than controls, indicating either continued virus-related injury or an aging-like effect of HIV infection. NFL correlates with neopterin and albumin ratio, suggesting an association between axonal injury, neuroinflammation and blood-brain barrier permeability. NFL appears to be a sensitive biomarker of subclinical and clinical brain injury in HIV and warrants further

  14. Axon-Schwann cell interaction in the squid nerve fibre.

    Science.gov (United States)

    Villegas, J

    1972-09-01

    The electrical properties of Schwann cells and the effects of neuronal impulses on their membrane potential have been studied in the giant nerve fibre of the squid.1. The behaviour of the Schwann cell membrane to current injection into the cell was ohmic. No impulse-like responses were observed with displacements of 35 mV in the membrane potential. The resistance of the Schwann cell membrane was found to be approximately 10(3) Omega cm(2).2. A long-lasting hyperpolarization is observed in the Schwann cells following the conduction of impulse trains by the axon. Whereas the propagation of a single impulse had little effect, prolonged stimulation of the fibre at 250 impulses/sec was followed by a hyperpolarization of the Schwann cell that gradually declined over a period of several minutes.3. The prolonged effects of nerve impulse trains on the Schwann cell were similar to those produced by depolarizing current pulses applied to the axon by the voltage-clamp technique. Thus, a series of depolarizing pulses in the axon was followed by a long-lasting hyperpolarization of the Schwann cells. In contrast, the application of a series of hyperpolarizing 100 mV pulses at a frequency of 1/sec had no apparent effects.4. Changes in the external potassium concentration did not reproduce the long-lasting effects of nerve excitation.5. The hyperpolarizing effects of impulse trains were abolished by the incubation of the nerve fibre in a sea-water solution containing trypsin.6. These findings are discussed in relation to the possible mechanisms that might be responsible for the long-lasting hyperpolarizations of the Schwann cells.

  15. Excitability properties of motor axons in adults with cerebral palsy

    Directory of Open Access Journals (Sweden)

    Cliff S. Klein

    2015-06-01

    Full Text Available Cerebral Palsy (CP is a permanent disorder caused by a lesion to the developing brain that significantly impairs motor function. The neurophysiological mechanisms underlying motor impairment are not well understood. Specifically, few have addressed whether motoneuron or peripheral axon properties are altered in CP, even though disruption of descending inputs to the spinal cord may cause them to change. In the present study, we have compared nerve excitability properties in seven adults with CP and fourteen healthy controls using threshold tracking techniques by stimulating the median nerve at the wrist and recording the compound muscle action potential (CMAP over the abductor pollicis brevis. The excitability properties in the CP subjects were found to be abnormal. Early and late depolarizing and hyperpolarizing threshold electrotonus was significantly larger (i.e., fanning out, and resting current-threshold (I/V slope was smaller, in CP compared to control. In addition resting threshold and rheobase tended to be larger in CP. According to a modeling analysis of the data, an increase in leakage current under or through the myelin sheath, i.e., the Barrett-Barrett conductance (GBB, combined with a slight hyperpolarization of the resting membrane potential, best explained the group differences in excitability properties. There was a trend for those with greater impairment in gross motor function to have more abnormal axon properties. The findings indicate plasticity of motor axon properties far removed from the site of the lesion. We suspect that this plasticity is caused by disruption of descending inputs to the motoneurons at an early age around the time of their injury.

  16. Mechanisms of hyperpolarization in regenerated mature motor axons in cat

    DEFF Research Database (Denmark)

    Moldovan, Mihai; Krarup, Christian

    2004-01-01

    We found persistent abnormalities in the recovery of membrane excitability in long-term regenerated motor nerve fibres in the cat as indicated in the companion paper. These abnormalities could partly be explained by membrane hyperpolarization. To further investigate this possibility, we compared...... the changes in excitability in control nerves and long-term regenerated cat nerves (3-5 years after tibial nerve crush) during manoeuvres known to alter axonal membrane Na(+)-K(+) pump function: polarization, cooling to 20 degrees C, reperfusion after 10 min ischaemia, and up to 60 s of repetitive stimulation...

  17. Conservative approach versus urgent appendectomy in surgical management of acute appendicitis with abscess or phlegmon Resultados del tratamiento conservador inicial y de la cirugía urgente en la apendicitis aguda evolucionada

    Directory of Open Access Journals (Sweden)

    J. M. Aranda-Narváez

    2010-11-01

    Full Text Available Background: Surgical management of acute appendicitis with appendiceal abscess or phlegmon remains controversial. We studied the results of initial conservative treatment (antibiotics and percutaneous drainage if necessary, with or without interval appendectomy compared with immediate surgery. Methods: We undertook an observational, retrospective cohort study of patients with a clinical and radiological diagnosis of acute appendicitis with an abscess or phlegmon, treated in our hospital between January 1997 and March 2009. Patients younger than 14, with severe sepsis or with diffuse peritonitis were excluded. A study group of 15 patients with acute appendicitis complicated with an abscess or phlegmon underwent conservative treatment. A control group was composed of the other patients, who all underwent urgent appendectomy, matched for age and later randomized 1:1. The infectious risk stratification was established with the National Nosocomial Infections Surveillance System (NNIS index. Dependent variables were hospital stay and surgical site infection. Analysis was with SPSS, with p Introducción: Existe controversia acerca del tratamiento idóneo de la apendicitis aguda evolucionada en forma de absceso o flemón. Realizamos un estudio para la evaluación de resultados del tratamiento conservador inicial (antibiótico y drenaje percutáneo si se precisa, con/sin apendicectomía diferida y del tratamiento quirúrgico urgente. Método: Estudio observacional analítico de cohortes retrospectivas. Criterios de inclusión: pacientes con diagnóstico clínico y radiológico de apendicitis aguda evolucionada en forma de absceso o flemón, tratados en nuestro hospital entre enero 1997 y marzo 2009, excluyendo pacientes pediátricos, con sepsis grave o peritonitis difusa. En 15 pacientes con apendicitis complicada con absceso o flemón (cohorte de estudio se indicó tratamiento conservador inicial. El grupo control se obtuvo del resto de pacientes (en

  18. Intoxicação experimental aguda por samambaia (Pteridium aquilinum em bovinos Experimental acute poisoning by bracken fern (Pteridium aquilinum in cattle

    Directory of Open Access Journals (Sweden)

    Bruno L. Anjos

    2009-09-01

    conflitantes, não permitindo concluir se a coagulação intravascular disseminada tem participação na patogênese das hemorragias nessa intoxicação. A citopatologia e histopatologia da medula óssea dos quatro bovinos intoxicados revelaram acentuada diminuição no número de células hematopoéticas das três linhagens medulares, caracterizando insuficiência medular por aplasia; conclui-se que apenas eventos da hemostasia primária devidos a trombocitopenia são responsáveis pelas hemorragias. Na hemocultura de três dos bovinos intoxicados houve crescimento de Klebsiella oxytoca, Staphylococcus hyicus e Staphylococcus aureus, indicando que a septicemia, facilitada pela neutropenia, pode ter participação na causa da morte de bovinos na intoxicação aguda pela ingestão de P. aquilinum. Aspectos adicionais de interesse na reprodução da intoxicação aguda por samambaia em bovinos deste relato incluem o desenvolvimento de hematúria na doença aguda e a apresentação da chamada forma laríngea da doença.This experiment was design to address the following points in relation to the acute poisoning by bracken fern (Pteridium aquilinum in cattle: 1 the severity of the thrombocytopenia in different stages of the intoxication and its relationship to possible deficits in the secondary hemostasis, 2 the relationship between neutropenia and the morphological signs of septicemia occasionally found at necropsy, and 3 the mechanism of anemia and its relationship with blood loss, medium life of erythrocytes and the progress of the disease. The fresh green upper parts of P. aquilinum were fed to four mixed breed calves with average age of 18 months and weights ranging from 190 to 215 kg. A calf of similar age and weight was kept together with the other four under the same conditions, except for the ingestion of P. aquilinum. The four fern-fed calves died with typical features of acute bracken fern poisoning after being fed with the plant for 53-58 days daily doses of 8.0, 8

  19. NGAL urinária em pacientes sem e com lesão renal aguda em unidade de terapia intensiva

    Directory of Open Access Journals (Sweden)

    Mirian Watanabe

    2014-12-01

    Full Text Available Objetivo: Avaliar a eficácia diagnóstica e prognóstica da lipocalina associada à gelatinase neutrofílica urinária em pacientes de unidade de terapia intensiva. Métodos: Estudo do tipo coorte, prospectivo, longitudinal desenvolvido em uma unidade de terapia intensiva clínica especializada em cardiologia. Os pacientes foram estratificados segundo os grupos sem e com lesão renal aguda, acompanhados a partir das primeiras 24 horas de internação até a alta hospitalar ou óbito. A creatinina sérica, o fluxo urinário e a lipocalina associada à gelatinase neutrofílica urinária foram coletadas em dois períodos: 24 horas e 48 horas de admissão. Resultados: Foram avaliados 83 pacientes clínicos da unidade de terapia intensiva, com predomínio do gênero masculino (57,8%. Os pacientes foram agrupados em sem lesão renal aguda (N=18, com lesão renal aguda (N=28 ou com lesão renal aguda grave (N=37. Entre os pacientes com lesão renal aguda e lesão renal aguda grave, foram prevalentes os portadores de doenças crônicas, em uso de ventilação mecânica e em terapia de substituição renal, além daqueles com maiores taxas de permanência na unidade de terapia intensiva e hospitalar, e maior mortalidade. O grupo com lesão renal aguda não apresentou alteração significativa da creatinina sérica nas primeiras 24 horas na unidade de terapia intensiva, apesar dos níveis elevados de lipocalina associada à gelatinase neutrofilica urinária demonstrados nos grupos com lesão renal aguda e lesão renal aguda grave (p<0,001. Níveis elevados de lipocalina associada à gelatinase neutrofílica urinária na amostra foram associados ao óbito. Conclusão: A elevação nos níveis de lipocalina associada à gelatinase neutrofílica urinária antecede as variações da creatinina sérica em pacientes com lesão renal aguda e pode ser associada ao óbito.

  20. Budesonida inalatória em crianças com asma aguda Nebulized budesonide to treat acute asthma in children

    Directory of Open Access Journals (Sweden)

    Geórgia K. M. Milani

    2004-04-01

    Full Text Available OBJETIVO: Avaliar a eficácia de budesonida na forma de suspensão, em dose única para inalação, como tratamento adjunto ao b2 inalatório, comparada com dose única de prednisona por via oral, em pacientes com crise aguda de asma. MÉTODO: Estudo prospectivo, randômico, paralelo, duplo-cego, duplo-placebo. Foram selecionadas 49 crianças, com idade entre 2 e 7 anos, em crise aguda de asma, que, após inalação com salbutamol (0,15 mg/kg, foram divididas em três grupos. O grupo I foi tratado com placebo via oral e inalatório; o grupo II, com prednisona via oral (1 mg/kg e placebo inalatório; e o grupo III, budesonida inalatória (2 mg e placebo via oral. As avaliações foram realizadas pela aplicação de um escore clínico e medida da saturação transcutânea da hemoglobina, seqüencialmente até 72 horas. Caso o escore clínico fosse igual ou superior ao da avaliação inicial, e a saturação inferior à primeira avaliação, a inalação com b2 adrenérgico era repetida. RESULTADOS: A melhora do escore clínico foi progressiva a partir de 30 minutos, e não houve diferença significativa nos três grupos estudados. Ocorreu aumento significativo da saturação da hemoglobina em relação ao valor inicial, com 2 horas no grupo prednisona, 4 horas no grupo budesonida e 24 horas no grupo placebo. CONCLUSÃO: O número de inalações com broncodilatador foi semelhante nos três grupos, com uma média de 2,9 no grupo placebo; 2,7 no grupo prednisona; e 2,5 no grupo budesonida. Em geral, as drogas estudadas foram bem toleradas, com efeitos colaterais semelhantes ao placebo. A administração de dose única de budesonida inalatória associada ao salbutamol, na crise moderada de asma, promoveu melhora clínica comparável à da prednisona oral. A recuperação da saturação transcutânea da hemoglobina foi mais rápida com prednisona.OBJECTIVE: To investigate the efficacy of a single dose of inhaled budesonide as compared to oral

  1. Síndromes coronarianas agudas: tratamento e estratificação de risco Acute coronary syndromes: treatment and risk stratification

    Directory of Open Access Journals (Sweden)

    Antonio Eduardo Pereira Pesaro

    2008-06-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: As síndromes coronarianas agudas são resultado da ruptura de uma placa coronariana instável, complicada pela formação de trombo intraluminal, embolização e graus variáveis de obstrução coronária. Pacientes com oclusão total de uma artéria coronária apresentam infarto agudo do miocárdio (IAM com supradesnivelamento do segmento ST. Uma oclusão parcial do vaso pode resultar em IAM sem supradesnivelamento do segmento ST ou angina instável. As manifestações clínicas e as alterações eletrocardiográficas são componentes fundamentais para identificação dos pacientes portadores destas síndromes. A triagem rápida e eficaz desses pacientes, quanto à presença ou não do supradesnivelamento do segmento ST, é fundamental para a determinação da estratégia terapêutica a ser empregada. O objetivo deste estudo foi realizar uma revisão da literatura sobre as evidências atuais e as recomendações para avaliação e tratamento das síndromes coronarianas agudas. CONTEÚDO: Revisão da literatura, utilizando as bases eletrônicas de dados MedLine e LILACS, no período de janeiro de 1990 a setembro de 2007. CONCLUSÕES: A reperfusão da artéria responsável pelo infarto é a etapa fundamental no tratamento de pacientes com infarto agudo do miocárdio com supradesnivelamento do segmento ST. A terapia trombolítica ou a intervenção coronariana percutânea são duas opções terapêuticas bem estabelecidas na literatura. Pacientes portadores de IAM sem supradesnivelamento do segmento ST ou angina instável necessitam de estratificação de risco precoce. Pacientes de alto risco devem ser submetidos à estratégia invasiva precoce, que consiste na realização do cateterismo cardíaco nas primeiras 24-48 horas do início dos sintomas.BACKGROUND AND OBJECTIVES: Acute coronary syndromes result from a disruption of a vulnerable coronary plaque complicated by intraluminal thrombus formation, embolisation, and

  2. Leucemia linfóide aguda: uma doença curável Acute lymphoblastic leukemia: a curable disease

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    Francisco Pedrosa

    2002-04-01

    Full Text Available RESUMO: Leucemia linfóide Aguda (LLA, é o tipo mais comum de câncer infantil, constituindo cerca de um terço de todas as neoplasias malignas da criança. A incidência de LLA em crianças nos Estados Unidos é aproximadamente de 3,4 casos por 100.000 crianças menores de 15 anos de idade. Até a metade do século passado, as leucemias eram consideras universalmene, uma doença fatal. O desenvolvimento de combinações terapêuticas, utilizando diversas drogas citotóxicas com ou sem transplante de medula óssea, tem aumentado o percentual de cura da criança portadora de Leucemia linfóide Aguda em mais de 80%. Anualmente cerca de 1.500 crianças com LLA, nos Estados Unidos, estão sendo curadas. Contudo, dos 75.000 novos casos de LLA, que são diagnosticados anualmente em todo o mundo, cerca de 60.000 (80% não têm acesso a essas modernas formas de tratamento e são, portanto excluídos desse processo de cura. O desafio de tornar a LLA uma doença curável começa a ser vencido com o relato de taxas de sobrevida maior que 50% para crianças tratadas em países com recursos limitados. Em El salvador, Bonilla, conseguiu aumentar a taxa de sobrevida de crianças com LLA de 5% para 50%. No Recife, Pernambuco, Brasil, Pedrosa evoluiu de uma taxa de 29% nos anos 80, para 75% na era atual.ABSTRACT: Acute lymphoblastic leukemia (ALL is the most common type of cancer in children, accoun-ting for one third of all malignant neoplasias affecting them. ALL incidences in children in the United States are of approximately 3,4 cases per 100.000 children under fifteen years old. Up to the middle of last century leukemia was universally considered a fatal di-sease. The development of therapeutic combinations through the use of various cytotoxic drugs with or without bone marrow transplantation has increased cure percentages of children with ALL in over 80%. Annually around 1.500 children with ALL in the Uni-ted States are being cured. Nevertheless, of the

  3. Appendicular pseudodiverticula and acute appendicitis: Our 12-year experience Pseudodivertículos apendiculares y apendicitis aguda: Nuestra experiencia en 12 años

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    María del Carmen Manzanares-Campillo

    2011-11-01

    histología de los mismos, comparando los resultados con la literatura precedente. Resultados: la incidencia de enfermedad diverticular en nuestro medio fue de 13 casos (0,8% de 1634 apendicectomías realizadas por apendicitis aguda. En 8 pacientes se halló diverticulitis (61,5% y en 5 diverticulosis (38,5%. La perforación apendicular fue más frecuente en los pacientes con enfermedad diverticular (53,8% que en su ausencia (31,1%. Conclusiones: la enfermedad diverticular complicada en el apéndice vermiforme en pacientes de edad adulta puede originar una clínica insidiosa y recurrente, que dificulta el diagnóstico preoperatorio certero. El mayor riesgo de perforación apendicular relacionado con su presencia sitúa a la apendicectomía como el tratamiento de elección, incluso de forma profiláctica cuando su hallazgo intraoperatorio sea incidental.

  4. Fatores preditivos de coledocolitíase em doentes com pancreatite aguda biliar Predictors of choledocholithiasis in patients sustaining acute biliary pancreatitis

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    José Gustavo Parreira

    2004-12-01

    Full Text Available OBJETIVO: Avaliar o papel da fosfatase alcalina (FA, gama glutamiltransferase (gamaGT e ultra-sonografia (US como fatores preditivos de coledocolitíase em doentes com pancreatite aguda biliar (PAB. MÉTODOS: Os dados foram coletados prospectivamente durante um período de 31 meses. Quarenta doentes foram incluídos, sendo 30 mulheres, com média etária de 49 + 16 anos. Foram registrados os dados de todos os doentes com pancreatite aguda biliar. Aqueles doentes ictéricos e com a forma grave da doença foram excluídos. As dosagens de FA e GGT, assim como a US, eram realizadas na admissão e 48 horas antes da cirurgia. Todos os pacientes foram submetidos à colangiografia intra-operatória (CIO ou à colangiografia retrógrada endoscópica (CPRE pré-operatória, que era definida baseada na probabilidade de coledocolitíase. Com o intuito de identificar os indicadores de coledocolitíase, as variáveis foram comparadas entre os pacientes com ou sem coledocolitíase. Os testes t de Student, Qui-quadrado e Fisher foram empregados para a análise estatística, considerando-se pBACKGROUND: To assess the role of alkaline phosphatase (AP, gamil-glutamyltransferase (gammaGT and abdominal ultrasound (US as predictors of choledocholithiasis in patients sustaining acute biliary pancreatitis. METHODS: Data was prospectively collected during a period of 31 months. Forty patients were included, 30 were female and the mean age was 49 + 16. All patients sustaining acute biliary pancreatitis were enrolled. Patients with clinical jaundice and severe pancreatitis were excluded. Serum content of AP and gGT as well as US were assessed at admission and 48 hours before cholecistectomy. All patients underwent intra-operative cholangiography (IOC or pre-operative endoscopic retrograde cholangiography (ERCP, which was indicated based on the odds of choledocholithiasis. In order to identify the predictors of choledocholithiasis, variables were compared between patients

  5. Asma aguda em adultos na sala de emergência: o manejo clínico na primeira hora

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    DALCIN PAULO DE TARSO ROTH

    2000-01-01

    Full Text Available Asma é doença com alta prevalência em nosso meio e ao redor do mundo. Embora novas opções terapêuticas tenham sido recentemente desenvolvidas, parece haver aumento mundial na sua morbidade e mortalidade. Em muitas instituições, as exacerbações asmáticas ainda constituem emergência médica muito comum. As evidências têm demonstrado que a primeira hora no manejo da asma aguda na sala de emergência concentra decisões cruciais que podem determinar o desfecho desta situação clínica. Nesta revisão não-sistemática, os autores enfocaram a primeira hora da avaliação e tratamento do paciente com asma aguda na sala de emergência, descrevendo uma estratégia apropriada para o seu manejo. São consideradas as seguintes etapas: diagnóstico, avaliação da gravidade, tratamento farmacológico, avaliação das complicações e decisão sobre onde se realizará o tratamento adicional. Espera-se que estas recomendações contribuam para que o médico clínico tome a decisão apropriada na primeira hora do manejo da asma aguda.

  6. Plexin A3 and turnout regulate motor axonal branch morphogenesis in zebrafish.

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    Rajiv Sainath

    Full Text Available During embryogenesis motor axons navigate to their target muscles, where individual motor axons develop complex branch morphologies. The mechanisms that control axonal branching morphogenesis have been studied intensively, yet it still remains unclear when branches begin to form or how branch locations are determined. Live cell imaging of individual zebrafish motor axons reveals that the first axonal branches are generated at the ventral extent of the myotome via bifurcation of the growth cone. Subsequent branches are generated by collateral branching restricted to their synaptic target field along the distal portion of the axon. This precisely timed and spatially restricted branching process is disrupted in turnout mutants we identified in a forward genetic screen. Molecular genetic mapping positioned the turnout mutation within a 300 kb region encompassing eight annotated genes, however sequence analysis of all eight open reading frames failed to unambiguously identify the turnout mutation. Chimeric analysis and single cell labeling reveal that turnout function is required cell non-autonomously for intraspinal motor axon guidance and peripheral branch formation. turnout mutant motor axons form the first branch on time via growth cone bifurcation, but unlike wild-type they form collateral branches precociously, when the growth cone is still navigating towards the ventral myotome. These precocious collateral branches emerge along the proximal region of the axon shaft typically devoid of branches, and they develop into stable, permanent branches. Furthermore, we find that null mutants of the guidance receptor plexin A3 display identical motor axon branching defects, and time lapse analysis reveals that precocious branch formation in turnout and plexin A3 mutants is due to increased stability of otherwise short-lived axonal protrusions. Thus, plexin A3 dependent intrinsic and turnout dependent extrinsic mechanisms suppress collateral branch

  7. Neuron-to-neuron transmission of α-synuclein fibrils through axonal transport

    Science.gov (United States)

    Freundt, Eric C.; Maynard, Nate; Clancy, Eileen K.; Roy, Shyamali; Bousset, Luc; Sourigues, Yannick; Covert, Markus; Melki, Ronald; Kirkegaard, Karla; Brahic, Michel

    2012-01-01

    Objective The lesions of Parkinson's disease spread through the brain in a characteristic pattern that corresponds to axonal projections. Previous observations suggest that misfolded α-synuclein could behave as a prion, moving from neuron to neuron and causing endogenous α-synuclein to misfold. Here, we characterized and quantified the axonal transport of α-synuclein fibrils and showed that fibrils could be transferred from axons to second-order neurons following anterograde transport. Methods We grew primary cortical mouse neurons in microfluidic devices to separate soma from axonal projections in fluidically isolated microenvironments. We used live-cell imaging and immunofluorescence to characterize the transport of fluorescent α-synuclein fibrils and their transfer to second-order neurons. Results Fibrillar α-synuclein was internalized by primary neurons and transported in axons with kinetics consistent with slow component-b of axonal transport (fast axonal transport with saltatory movement). Fibrillar α-synuclein was readily observed in the cell bodies of second-order neurons following anterograde axonal transport. Axon-to-soma transfer appeared not to require synaptic contacts. Interpretation These results support the hypothesis that the progression of Parkinson's disease can be caused by neuron-to-neuron spread of α-synuclein aggregates and that the anatomical pattern of progression of lesions between axonally connected areas results from the axonal transport of such aggregates. That the transfer did not appear to be transsynaptic gives hope that α-synuclein fibrils could be intercepted by drugs during the extra-cellular phase of their journey. PMID:23109146

  8. Pancreatic cancer genomes reveal aberrations in axon guidance pathway genes.

    Science.gov (United States)

    Biankin, Andrew V; Waddell, Nicola; Kassahn, Karin S; Gingras, Marie-Claude; Muthuswamy, Lakshmi B; Johns, Amber L; Miller, David K; Wilson, Peter J; Patch, Ann-Marie; Wu, Jianmin; Chang, David K; Cowley, Mark J; Gardiner, Brooke B; Song, Sarah; Harliwong, Ivon; Idrisoglu, Senel; Nourse, Craig; Nourbakhsh, Ehsan; Manning, Suzanne; Wani, Shivangi; Gongora, Milena; Pajic, Marina; Scarlett, Christopher J; Gill, Anthony J; Pinho, Andreia V; Rooman, Ilse; Anderson, Matthew; Holmes, Oliver; Leonard, Conrad; Taylor, Darrin; Wood, Scott; Xu, Qinying; Nones, Katia; Fink, J Lynn; Christ, Angelika; Bruxner, Tim; Cloonan, Nicole; Kolle, Gabriel; Newell, Felicity; Pinese, Mark; Mead, R Scott; Humphris, Jeremy L; Kaplan, Warren; Jones, Marc D; Colvin, Emily K; Nagrial, Adnan M; Humphrey, Emily S; Chou, Angela; Chin, Venessa T; Chantrill, Lorraine A; Mawson, Amanda; Samra, Jaswinder S; Kench, James G; Lovell, Jessica A; Daly, Roger J; Merrett, Neil D; Toon, Christopher; Epari, Krishna; Nguyen, Nam Q; Barbour, Andrew; Zeps, Nikolajs; Kakkar, Nipun; Zhao, Fengmei; Wu, Yuan Qing; Wang, Min; Muzny, Donna M; Fisher, William E; Brunicardi, F Charles; Hodges, Sally E; Reid, Jeffrey G; Drummond, Jennifer; Chang, Kyle; Han, Yi; Lewis, Lora R; Dinh, Huyen; Buhay, Christian J; Beck, Timothy; Timms, Lee; Sam, Michelle; Begley, Kimberly; Brown, Andrew; Pai, Deepa; Panchal, Ami; Buchner, Nicholas; De Borja, Richard; Denroche, Robert E; Yung, Christina K; Serra, Stefano; Onetto, Nicole; Mukhopadhyay, Debabrata; Tsao, Ming-Sound; Shaw, Patricia A; Petersen, Gloria M; Gallinger, Steven; Hruban, Ralph H; Maitra, Anirban; Iacobuzio-Donahue, Christine A; Schulick, Richard D; Wolfgang, Christopher L; Morgan, Richard A; Lawlor, Rita T; Capelli, Paola; Corbo, Vincenzo; Scardoni, Maria; Tortora, Giampaolo; Tempero, Margaret A; Mann, Karen M; Jenkins, Nancy A; Perez-Mancera, Pedro A; Adams, David J; Largaespada, David A; Wessels, Lodewyk F A; Rust, Alistair G; Stein, Lincoln D; Tuveson, David A; Copeland, Neal G; Musgrove, Elizabeth A; Scarpa, Aldo; Eshleman, James R; Hudson, Thomas J; Sutherland, Robert L; Wheeler, David A; Pearson, John V; McPherson, John D; Gibbs, Richard A; Grimmond, Sean M

    2012-11-15

    Pancreatic cancer is a highly lethal malignancy with few effective therapies. We performed exome sequencing and copy number analysis to define genomic aberrations in a prospectively accrued clinical cohort (n = 142) of early (stage I and II) sporadic pancreatic ductal adenocarcinoma. Detailed analysis of 99 informative tumours identified substantial heterogeneity with 2,016 non-silent mutations and 1,628 copy-number variations. We define 16 significantly mutated genes, reaffirming known mutations (KRAS, TP53, CDKN2A, SMAD4, MLL3, TGFBR2, ARID1A and SF3B1), and uncover novel mutated genes including additional genes involved in chromatin modification (EPC1 and ARID2), DNA damage repair (ATM) and other mechanisms (ZIM2, MAP2K4, NALCN, SLC16A4 and MAGEA6). Integrative analysis with in vitro functional data and animal models provided supportive evidence for potential roles for these genetic aberrations in carcinogenesis. Pathway-based analysis of recurrently mutated genes recapitulated clustering in core signalling pathways in pancreatic ductal adenocarcinoma, and identified new mutated genes in each pathway. We also identified frequent and diverse somatic aberrations in genes described traditionally as embryonic regulators of axon guidance, particularly SLIT/ROBO signalling, which was also evident in murine Sleeping Beauty transposon-mediated somatic mutagenesis models of pancreatic cancer, providing further supportive evidence for the potential involvement of axon guidance genes in pancreatic carcinogenesis.

  9. Nociceptive DRG neurons express muscle lim protein upon axonal injury.

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    Levin, Evgeny; Andreadaki, Anastasia; Gobrecht, Philipp; Bosse, Frank; Fischer, Dietmar

    2017-04-04

    Muscle lim protein (MLP) has long been regarded as a cytosolic and nuclear muscular protein. Here, we show that MLP is also expressed in a subpopulation of adult rat dorsal root ganglia (DRG) neurons in response to axonal injury, while the protein was not detectable in naïve cells. Detailed immunohistochemical analysis of L4/L5 DRG revealed ~3% of MLP-positive neurons 2 days after complete sciatic nerve crush and maximum ~10% after 4-14 days. Similarly, in mixed cultures from cervical, thoracic, lumbar and sacral DRG ~6% of neurons were MLP-positive after 2 days and maximal 17% after 3 days. In both, histological sections and cell cultures, the protein was detected in the cytosol and axons of small diameter cells, while the nucleus remained devoid. Moreover, the vast majority could not be assigned to any of the well characterized canonical DRG subpopulations at 7 days after nerve injury. However, further analysis in cell culture revealed that the largest population of MLP expressing cells originated from non-peptidergic IB4-positive nociceptive neurons, which lose their ability to bind the lectin upon axotomy. Thus, MLP is mostly expressed in a subset of axotomized nociceptive neurons and can be used as a novel marker for this population of cells.

  10. Profiling biomarkers of traumatic axonal injury: From mouse to man.

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    Manivannan, Susruta; Makwana, Milan; Ahmed, Aminul Islam; Zaben, Malik

    2018-05-18

    Traumatic brain injury (TBI) poses a major public health problem on a global scale. Its burden results from high mortality and significant morbidity in survivors. This stems, in part, from an ongoing inadequacy in diagnostic and prognostic indicators despite significant technological advances. Traumatic axonal injury (TAI) is a key driver of the ongoing pathological process following TBI, causing chronic neurological deficits and disability. The science underpinning biomarkers of TAI has been a subject of many reviews in recent literature. However, in this review we provide a comprehensive account of biomarkers from animal models to clinical studies, bridging the gap between experimental science and clinical medicine. We have discussed pathogenesis, temporal kinetics, relationships to neuro-imaging, and, most importantly, clinical applicability in order to provide a holistic perspective of how this could improve TBI diagnosis and predict clinical outcome in a real-life setting. We conclude that early and reliable identification of axonal injury post-TBI with the help of body fluid biomarkers could enhance current care of TBI patients by (i) increasing speed and accuracy of diagnosis, (ii) providing invaluable prognostic information, (iii) allow efficient allocation of rehabilitation services, and (iv) provide potential therapeutic targets. The optimal model for assessing TAI is likely to involve multiple components, including several blood biomarkers and neuro-imaging modalities, at different time points. Copyright © 2018. Published by Elsevier B.V.

  11. Uso de la antibioticoterapia perioperatoria en la apendicitis aguda: Use of perioperative antibiotic therapy Acute appendicitis:

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    Gimel Sosa Martín

    2009-09-01

    Full Text Available INTRODUCCIÓN. La apendicitis aguda es la afección que más frecuentemente requiere intervención quirúrgica de urgencia. El uso de profilaxis antimicrobiana disminuye la incidencia de sepsis de la herida quirúrgica y mejora la relación riesgo-beneficio y costo-beneficio de la operación. El presente estudio buscó diseñar e implantar un protocolo terapéutico para el uso de antimicrobianos, según estadio de la apendicitis aguda, para uso en centros de atención secundaria. MÉTODOS. Se realizó un estudio prospectivo de indicación-prescripción con elementos de consecuencias prácticas y un grupo de intervención. Se seleccionaron de manera aleatoria 215 pacientes con diagnóstico de apendicitis aguda, atendidos entre diciembre del 2002 y diciembre del 2006. Se establecieron dos grupos, uno de control y uno experimental. Se instauró un protocolo de profilaxis aplicado al grupo experimental, basado en textos de referencia y adecuado al contexto socioeconómico cubano. RESULTADOS. Se aplicó el protocolo de profilaxis a 105 pacientes. La incidencia de sepsis fue del 8,5 %, significativamente menor a la del grupo control (24,5 %. El costo fue igualmente menor en el grupo experimental. CONCLUSIONES. El uso racional de la terapéutica antimicrobiana para la profilaxis de la infección de la herida quirúrgica mejora la relación riesgo-beneficio y costo-beneficio del procedimiento quirúrgico y la calidad de la atención médica.INTRODUCTION: Acute appendicitis if the affection that more frequent requires of an emergence surgical intervention. Use of antimicrobial prophylaxis decreases sepsis incidence of surgical wound, and to improve the risk-benefit and the cost-benefit relation of surgery. Present study tried to design and to creates a therapeutical protocol for use of antimicrobials, according to acute appendicitis stage to use in secondary care centers. METHODS: We made a prospective study of prescription-indication with the elements

  12. Professional training Formação profissional

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    Vera Lúcia Lemos Basto Echenique

    1990-08-01

    Full Text Available This paper presents a disucssion about the professional training of qualified human resources and the role of the university in this kind of preparation considering the present developement reality.O testo apresenta uma discussão sobre a formação profissional, o preparo de mão-de-obra qualificada e o papel da universidade frente a essa formação, considerando a realidade desenvolvida atual.

  13. Exacerbação aguda da fibrose pulmonar idiopática

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    Natália Melo

    2009-03-01

    Full Text Available Resumo: Alguns doentes com fibrose pulmonar idiopática (FPI apresentam durante a sua evolução fases de agravamento clínico sem causa conhecida, designadas como “exacerbação aguda” ou “fase acelerada” da doença (EA. Caracterizam-se pelo agravamento marcado da dispneia, hipoxemia e pelo aparecimento de novas opacidades pulmonares ou pelo agravamento das já existentes no estudo imagiológico. Os achados histológicos típicos são o dano alveolar difuso (DAD sobreposto a alterações de pneumonia intersticial usual (UIP. Esta entidade clínica associa-se a uma mortalidade elevada, não havendo até ao momento nenhuma terapêutica de comprovada eficácia.Os autores descrevem os casos clínicos de cinco doentes que apresentaram alterações clínicas, funcionais e radiológicas sugestivas de EA-FPI, assim como o tratamento efectuado e a evolução observada, enquadrando-os na discussão das características normalmente apresentadas por esta entidade. Abstract: Some patients with Idiopathic Pulmonary Fibrosis (IPF have disease accelerated deterioration without identifiable cause referred as “acute exacerbation” or “accelerated stage”. It is characterized by severe worsening of dyspnea, hypoxemia and new or progressive opacities on imaging studies. The typical histological findings are diffuse alveolar damage in addition to the features of usual interstitial pneumonia pattern. Mortality in this clinical entity is very high and no efficacious therapeutic have been described.The authors describe the clinical, functional and radiological features, treatment and evolution of five patients with IPF acute exacerbation. A discussion will be carry out concerning the IPF acute exacerbation usual features comparing with the alterations noticed in those patients. Palavras-chave: Fibrose pulmonar idiopática, exacerbação aguda, Key words: Idiopathic

  14. Nuevo enfoque de la interpretación del dolor en una pulpitis aguda

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    Andrés O Pérez Ruiz

    2000-04-01

    Full Text Available El dolor es probablemente el principal motivo de consulta en las urgencias estomatológicas y es precisamente el dolor de la pulpitis aguda el que comentamos en este trabajo. El dolor pulpar en sí mismo es similar al dolor que resulta por inflamación de los órganos viscerales y, por lo tanto, podrían ser inadecuados los intentos de explicarlos por comparación con los nociceptores de estructuras somáticas. Se propone analizar el comportamiento del dolor como consecuencia de una pulpitis aguda, con un nuevo enfoque, asimilándolo como el dolor proveniente de estructuras viscerales con manifestaciones dolorosas alejadas del sitio o zona dañada y en el propio diente en que el tejido ha sido injuriado y evoluciona rápidamente hacia la necrosis. Establecemos una analogía entre el dolor visceral como el generado de la pulpa y el del tipo somático profundo como el correspondiente a la afectación periapical por rápida evolución de la inflamación hacia la necrosis.Pain is probably the chief complaint in dental emergencies and this paper deals precisely with the pain caused by acute pulpitis. The pulpar pain itself is similar to the one resulting from inflammation of the visceral organs and, therefore, the attempts to explain these pains by comparing them with the nociceptors of somatic structures may be inappropiate. It is our objective to analyze the behaviour of pain caused by acute pulpitis with a new approach, assimilating it as the pain from visceral structures with painful manifestations far from the damaged site or zone and it is the own tooth whose tissue has been affected and evolves rapidly to necrosis.We establish an analogy between the visceral pain as the one generated by the pulpa and that of deep somatic type as the corresponding to the periapical affection by the fast evolution of inflammation to necrosis.

  15. Prevención de las infecciones respiratorias agudas: Presente y futuro

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    Roberto Razón Behar

    2003-12-01

    Full Text Available Las infecciones respiratorias agudas (IRA, son las causas más frecuentes de morbilidad en el mundo y de elevada mortalidad particularmente en los países en desarrollo. Los virus son los agentes etiológicos más frecuentes. Los virus influenza a y b, y el virus sincitial respiratorio (VSR son los más importantes por la severidad de la enfermedad y por la alta transmisibilidad. Las bacterias, principalmente el Streptococcus pneumoniae (neumococo, y el Haemophilus influenzae tipo B (Hib, son las causas más frecuentes de neumonías adquiridas en la comunidad. Las estrategias generales en la prevención y en el tratamiento se basan en: evaluar sistemáticamente los conocimientos existentes acerca de las IRA, divulgarlos y aplicarlos, desarrollar una guía nacional para las indicaciones de los antibióticos, aplicar las vacunas existentes: DPT, triple viral (SRP, anti-Hi, incrementar la inmunización contra el neumococo y los virus influenza, particularmente en grupos de riesgo y desarrollar y evaluar nuevas vacunas contra el VSR, Haemophilus influenzae no serotipificables, Bordetella pertussis y otros agentes infecciosos que afectan el aparato respiratorio. Se realiza una revisión de nuevos agentes y drogas antivirales, así como del desarrollo presente y futuro de las inmunizaciones contra los principales virus y bacterias, que causan infecciones respiratorias agudas.Acute respiratory infections (ARI are the most frequent cause of morbidity and of the high mortality in the world, particularly in the developing countries. The viruses are the most common etiological agents.The influenza a and b viruses and the syncytial respiratory virus (SRV are the most important due to the severity of the disease and to their high transmissibility. The bacteria, mainly Streptococcus pneumoniae (Pneumococcus, and Haemophilus influenzae type B (Hib, are the most frequent cause of pneumonias acquired in the community. The general strategies in the prevention and

  16. Efeitos hemodinâmicos da sobrecarga ventricular direita aguda experimental

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    Flávio Brito Filho

    2011-04-01

    Full Text Available FUNDAMENTO: A sobrecarga ventricular direita aguda está associada a situações clínicas de elevada morbimortalidade, tais como: ressecções pulmonares extensas, tromboembolismo pulmonar, transplante pulmonar e edema pulmonar das altitudes. Alguns pontos de sua fisiopatologia permanecem obscuros. OBJETIVO: Avaliar os efeitos hemodinâmicos da sobrecarga ventricular direita aguda experimental em suínos. MÉTODOS: A sobrecarga ventricular direita foi induzida pela oclusão das artérias pulmonares através de ligaduras. Vinte porcos foram utilizados no estudo, sendo alocados em 04 grupos: um controle, não submetido à oclusão vascular pulmonar, e três de sobrecarga ventricular direita submetidos à oclusão das seguintes artérias pulmonares: SVD1 (artéria pulmonar esquerda; SVD2 (artéria pulmonar esquerda e do lobo inferior direito e SVD3 (artéria pulmonar esquerda, do lobo inferior direito e do lobo mediastinal, obstruindo a vasculatura pulmonar em 42, 76 e 82,0% respectivamente. Variáveis de hemodinâmica foram medidas a cada 15 minutos durante a uma hora do estudo. Na análise estatística, foram utilizados ajustes de modelos lineares mistos com estrutura de variâncias e covariâncias. RESULTADOS: Nas comparações intergrupais, houve aumento significativo da frequência cardíaca (p = 0,004, pressão arterial pulmonar média (p = 0,001 e pressão capilar pulmonar (p < 0,0001. Houve redução significativa da pressão arterial média (p = 0,01 e do índice sistólico (p = 0,002. Não houve diferença significativa no índice cardíaco (p = 0,94. CONCLUSÃO: Apesar da intensa sobrecarga ventricular direita promovida pela obstrução de 82,0% da vasculatura pulmonar e pelo aumento significativo da pressão arterial pulmonar não houve disfunção cardiovascular severa e/ou choque circulatório no período estudado.

  17. Micronutrientes: una opción en el tratamiento de las enfermedades diarreicas agudas

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    Carlos Coronel Carbajal

    2000-12-01

    Full Text Available Se realizó un estudio longitudinal y prospectivo a 126 pacientes que ingresaron al Servicio de Diarreas Agudas del Hospital General Docente "Armando Enrique Cardoso", en el período comprendido entre junio de 1998 y enero de 1999. A 71 pacientes se les ofrecieron microelementos (vitamina A, sulfato de zinc y fumarato ferroso con el objetivo de conocer los beneficios de los microelementos en la enfermedad diarreica aguda. Al concluir el estudio se pudo comprobar que el grupo de pacientes suplementados tuvo una estadía más corta y la duración del episodio fue menor. Además se halló que en estos pacientes el número de deposiciones es menor, así como la afectación nutricional. También se comprobó cómo la recuperación nutricional es mucho más rápida, así como la recuperación del apetito. Se pudo mostrar cómo la consistencia de las deposiciones al tercer día de tratamiento, en el grupo que recibió micronutrientes, mejoró.A longitudinal and prospective study was conducted among 126 patients that were admitted in the Service of Acute Diarrheas of "Armando Enrique Cardoso" General Teaching Hospital between June, 1998, and January, 1999. 71 patients were administered microelements (vitamin A, zinc sulfate and ferrous fumarate in order to know their benefits in the acute diarrheal disease. On concluding the study, it was proved that the length of stay and the episode were shorter in the group of supplemented patients. It was also observed that the number of defecations as well as the nutritional affectation were lower in these patients and that the nutritional recovery and the recuperation of appetite were faster. The consistency of the defecations improved on the third day of treatment in the group that received micronutrients.

  18. Respuesta del sistema antioxidante en varones sanos, frente a hiperglicemia aguda inducida

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    Raquel Oré

    2009-09-01

    Full Text Available Objetivo: determinar la respuesta del sistema antioxidante en varones sanos, frente a la hiperglicemia aguda inducida. Diseño: estudio prospectivo, descriptivo, longitudinal, experimental. Lugar: Instituto Nacional de Biología Andina, Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú. Material biológico: Sangre y suero de sujetos aparentemente sanos. Intervenciones: A 13 sujetos adultos clínicamente sanos, entre 20 y 41años, después de 10 horas de ayuno, se administró glucosa vía endovenosa, mediante el método de clamp hiperglicémico, a 125 mg/dL por encima del valor basal, durante 120 minutos. Se realizó mediciones de la glicemia a 0, 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110 y 120 minutos. Se tomó la muestra sanguínea con anticoagulante EDTA y otra de sangre total, para obtención de suero, para las pruebas bioquímicas a los 0, 60 y 120 minutos. Principales medidas de resultados: Modificaciones de la glicemia y lipoperoxidación en suero, glutatión y actividad superóxido dismutasa en glóbulos rojos lisados e índices de estrés oxidativo. Resultados: El nivel de glucosa durante el clamp hiperglicémico, luego de alcanzar el ‘equilibrio’, fue 197±17,58 mg/dL. La lipoperoxidación aumentó de 2,54 + 0,51 a 2,90 + 0,58 umol/L, de 0 a 60 minutos, y a 2,66 + 0,55 umol/L a los 120 minutos. El glutatión se redujo en 8,10% a la hora, aumentando 7,08% a los 120 minutos. La actividad superóxido dismutasa se elevó 0,54% a los 60 minutos y 5,66% a los 120 minutos, sobre el basal. Los índices de valoración del estrés oxidativo tuvieron correlación r Pearson positiva, en nivel alto a muy alto. Conclusiones: la hiperglicemia aguda inducida hasta 2 horas elevó el estrés oxidativo, promoviendo generación de defensa antioxidante, con síntesis de glutatión reducido de novo y mayor actividad de la superóxido dismutasa.

  19. Caracterización epidemiológica de la descompensación aguda del asma bronquial

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    Yanin Arteaga Prado

    2013-08-01

    Full Text Available Introducción: el asma bronquial tiene una compleja fisiopatología que involucra la presencia en el paciente de factores genéticos de atopia, mecanismos inmunológicos disfuncionales. Objetivo: caracterizar la asociación de diversos aspectos epidemiológicos con la aparición de descompensaciones agudas del asma bronquial. Material y método: se realizó un estudio descriptivo y transversal a 118 pacientes del área de dos consultorios médicos del Policlínico Universitario "Hermanos Cruz" de la Ciudad de Pinar del Río durante el primer trimestre del 2012. Se comparó el grupo de pacientes que presentaron descompensaciones de la enfermedad con el grupo de pacientes que no se descompensó. Se aplicó un cuestionario para explorar las variables de interés. Para verificar la asociación entre variables se utilizó el estadígrafo ji cuadrado para un valor de significación estadística á=0.05. Resultados: las descompensaciones agudas fueron casi dos veces más frecuentes en el sexo femenino. De manera muy significativa (Z=3,26 p<0,01 una tercera parte de los asmáticos de su enfermedad; las amas de casa y los estudiantes fueron los más afectados. Solo el 38,1 % de los asmáticos tuvo un adecuado seguimiento por un especialista (clínico, pediatra, alergólogo o inmunólogo y de estos solo el 11,1 % presentaron descompensaciones agudas, en tanto se descompensó un 39,7 % de los que no tienen seguimiento especializado. Conclusiones: la degradación de las condiciones de la vivienda favoreció la aparición de descompensaciones agudas del asma. En tres cuartas partes de las casas había animales domésticos, existiendo una fuerte asociación entre esta condición y la aparición de descompensaciones agudas del paciente asmático.

  20. Incidencia y factores de riesgo para adquirir diarrea aguda en una comunidad rural de la selva peruana

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    César Henríquez Camacho

    2002-04-01

    Full Text Available Objetivo: Determinar la incidencia y factores de riesgo para adquirir diarrea aguda en una comunidad rural localizada en la selva del departamento de San Martín, Perú. Material y métodos: Una cohorte de 119 personas fue seleccionada al azar entre la población de 446 habitantes y seguida diariamente por un mes entre enero y febrero de 1999, buscando casos de diarrea aguda, definida como tres ó más cámaras de deposiciones al día por no más de 3 días. Un estudio caso control pareado fue diseñado para determinar los factores de riesgo para adquirir diarrea. Resultados: Fueron observados 18 casos de diarrea aguda; la incidencia fue 15.1 casos por 100 personas-mes (IC 95%: 9.45-23.12. La edad media de los casos fue de 10.7 años (rango: 1-34 años y 66% de los casos fueron niños menores de 10 años de edad. Los factores de riesgo para adquirir diarrea fueron: consumo de alimentos crudos, RR: 2.2 (IC 95%: 1.12-4.33, consumo de alimentos no lavados, RR: 4.47 (IC 95%: 1.56-12.82, falta de lavado de manos antes de alimentarse, RR: 9.61 (95% IC: 1.44-64.16, consumo de agua no hervida, RR: 4.52 (IC 95%: 1.23-16.65 y alimentación fuera de casa, RR: 2.2 (IC 95%: 1.51-3.20. La diferencia en el número promedio (DE de personas que vivían por casa entre casos y controles fue de 4.38 (1.03 vs. 3.22 (0.54, p=0.0003, respectivamente. No hubo diferencia en el tiempo de residencia en la comunidad entre casos y controles, media de 5.61 ( 5.04 años vs. 8.83 (9.79, p=0.5747. Conclusiones: Diarrea aguda es un problema de salud pública en la selva de San Martín. Hacinamiento, carencia de saneamiento y pobres prácticas higiénicas son los responsables para adquirir diarrea aguda en esta comunidad de bajo nivel socioeconómico. Campañas educativas y mejora en las condiciones sanitarias son claramente necesarias para superar este problema.

  1. Formas cocoides de Helicobacter pylori: viables o degenerativas

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    Felipe Cava

    2003-06-01

    Full Text Available De los trabajos presentados acerca de las formas cocoides de Helicobacter pylori se deduce una controversia mucho mayor que la resultante del mero estudio clínico de este microorganismo. Parece claro que existe una conversión tanto in vivo como in vitro de las formas espirales a las formas cocoides inducida por varios motivos, como cultivos prolongados, estrés físico y químico, y agentes antimicrobianos. En esta revisión repasamos los puntos de vista que han dividido a investigadores de esta área en dos grupos bien definidos: Los que consideran a estas formas cocoides como un producto no viable de degeneración celular y los que piensan que estas formas son estructuras viables,durmientes o de resistencia frente a condiciones ambientales adversas. Esta discrepancia conlleva a que interrogantes sobre la relación entre la transmisión de la enfermedad y estas formas cocoides permanezcan sin respuesta todavía.

  2. Bridging the gap: axonal fusion drives rapid functional recovery of the nervous system

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    Jean-Sébastien Teoh

    2018-01-01

    Full Text Available Injuries to the central or peripheral nervous system frequently cause long-term disabilities because damaged neurons are unable to efficiently self-repair. This inherent deficiency necessitates the need for new treatment options aimed at restoring lost function to patients. Compared to humans, a number of species possess far greater regenerative capabilities, and can therefore provide important insights into how our own nervous systems can be repaired. In particular, several invertebrate species have been shown to rapidly initiate regeneration post-injury, allowing separated axon segments to re-join. This process, known as axonal fusion, represents a highly efficient repair mechanism as a regrowing axon needs to only bridge the site of damage and fuse with its separated counterpart in order to re-establish its original structure. Our recent findings in the nematode Caenorhabditis elegans have expanded the promise of axonal fusion by demonstrating that it can restore complete function to damaged neurons. Moreover, we revealed the importance of injury-induced changes in the composition of the axonal membrane for mediating axonal fusion, and discovered that the level of axonal fusion can be enhanced by promoting a neuron's intrinsic growth potential. A complete understanding of the molecular mechanisms controlling axonal fusion may permit similar approaches to be applied in a clinical setting.

  3. Noninvasive Detection and Differentiation of Axonal Injury/Loss, Demyelination, and Inflammation

    Science.gov (United States)

    2014-10-01

    phosphorylated neurofilament primary antibody (SMI-31; 1:1000, Covance , US) to stain non-injured axons, and in rabbit anti-myelin basic protein (MBP) primary...neurofilament antibody (SMI- 31; 1:1000, Covance , US) to stain non-injured axons or with rabbit anti-myelin basic protein (MBP) antibody (1:1000, Sigma Inc

  4. MuSC is involved in regulating axonal fasciculation of mouse primary vestibular afferents.

    Science.gov (United States)

    Kawauchi, Daisuke; Kobayashi, Hiroaki; Sekine-Aizawa, Yoko; Fujita, Shinobu C; Murakami, Fujio

    2003-10-01

    Regulation of axonal fasciculation plays an important role in the precise patterning of neural circuits. Selective fasciculation contributes to the sorting of different types of axons and prevents the misrouting of axons. However, axons must defasciculate once they reach the target area. To study the regulation of fasciculation, we focused on the primary vestibulo-cerebellar afferents (PVAs), which show a dramatic change from fasciculated axon bundles to defasciculated individual axons at their target region, the cerebellar primordium. To understand how fasciculation and defasciculation are regulated in this system, we investigated the roles of murine SC1-related protein (MuSC), a molecule belonging to the immunoglobulin superfamily. We show: (i) by comparing 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (Dil) labelling and anti-MuSC immunohistochemistry, that downregulation of MuSC in PVAs during development is concomitant with the defasciculation of PVA axons; (ii) in a binding assay with cells expressing MuSC, that MuSC has cell-adhesive activity via a homophilic binding mechanism, and this activity is increased by multimerization; and (iii) that MuSC also displays neurite outgrowth-promoting activity in vestibular ganglion cultures. These findings suggest that MuSC is involved in axonal fasciculation and its downregulation may help to initiate the defasciculation of PVAs.

  5. Interaction between the soma and the axon terminal of horizontal cells in carp retina

    NARCIS (Netherlands)

    Kamermans, M.; van Dijk, B. W.; Spekreijse, H.

    1990-01-01

    In teleost retina, the receptive fields of horizontal cell axon terminals have a larger space constant than the receptive fields of the horizontal cell somata. Generally this difference in receptive field size is attributed to the cell coupling which is assumed to be stronger in the horizontal axon

  6. Axon-somatic back-propagation in detailed models of spinal alpha motoneurons

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    Pietro eBalbi

    2015-02-01

    Full Text Available Antidromic action potentials following distal stimulation of motor axons occasionally fail to invade the soma of alpha motoneurons in spinal cord, due to their passing through regions of high non-uniformity.Morphologically detailed conductance-based models of cat spinal alpha motoneurons have been developed, with the aim to reproduce and clarify some aspects of the electrophysiological behavior of the antidromic axon-somatic spike propagation. Fourteen 3D morphologically detailed somata and dendrites of cat spinal alpha motoneurons have been imported from an open-access web-based database of neuronal morphologies, NeuroMorpho.org, and instantiated in neurocomputational models. An axon hillock, an axonal initial segment and a myelinated axon are added to each model.By sweeping the diameter of the axonal initial segment (AIS and the axon hillock, as well as the maximal conductances of sodium channels at the AIS and at the soma, the developed models are able to show the relationships between different geometric and electrophysiological configurations and the voltage attenuation of the antidromically travelling wave.In particular, a greater than usually admitted sodium conductance at AIS is necessary and sufficient to overcome the dramatic voltage attenuation occurring during antidromic spike propagation both at the myelinated axon-AIS and at the AIS-soma transitions.

  7. Structure and Function of an Actin-Based Filter in the Proximal Axon

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    Varuzhan Balasanyan

    2017-12-01

    Full Text Available Summary: The essential organization of microtubules within neurons has been described; however, less is known about how neuronal actin is arranged and the functional implications of its arrangement. Here, we describe, in live cells, an actin-based structure in the proximal axon that selectively prevents some proteins from entering the axon while allowing the passage of others. Concentrated patches of actin in proximal axons are present shortly after axonal specification in rat and zebrafish neurons imaged live, and they mark positions where anterogradely traveling vesicles carrying dendritic proteins halt and reverse. Patches colocalize with the ARP2/3 complex, and when ARP2/3-mediated nucleation is blocked, a dendritic protein mislocalizes to the axon. Patches are highly dynamic, with few persisting longer than 30 min. In neurons in culture and in vivo, actin appears to form a contiguous, semipermeable barrier, despite its apparently sparse distribution, preventing axonal localization of constitutively active myosin Va but not myosin VI. : Balasanyan et al. find dynamic patches of actin in proximal axons of live neurons, mature and newly differentiated, in culture and in vivo. Patches contribute to a filter that sequesters some proteins within the somatodendritic domain while allowing others to pass into the axon, leading to polarized localization of proteins.

  8. N-docosahexaenoylethanolamine regulates Hedgehog signaling and promotes growth of cortical axons

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    Giorgi Kharebava

    2015-12-01

    Full Text Available Axonogenesis, a process for the establishment of neuron connectivity, is central to brain function. The role of metabolites derived from docosahexaenoic acid (DHA, 22:6n-3 that is specifically enriched in the brain, has not been addressed in axon development. In this study, we tested if synaptamide (N-docosahexaenoylethanolamine, an endogenous metabolite of DHA, affects axon growth in cultured cortical neurons. We found that synaptamide increased the average axon length, inhibited GLI family zinc finger 1 (GLI1 transcription and sonic hedgehog (Shh target gene expression while inducing cAMP elevation. Similar effects were produced by cyclopamine, a regulator of the Shh pathway. Conversely, Shh antagonized elevation of cAMP and blocked synaptamide-mediated increase in axon length. Activation of Shh pathway by a smoothened (SMO agonist (SAG or overexpression of SMO did not inhibit axon growth mediated by synaptamide or cyclopamine. Instead, adenylate cyclase inhibitor SQ22536 abolished synaptamide-mediated axon growth indicating requirement of cAMP elevation for this process. Our findings establish that synaptamide promotes axon growth while Shh antagonizes synaptamide-mediated cAMP elevation and axon growth by a SMO-independent, non-canonical pathway.

  9. A high mitochondrial transport rate characterizes CNS neurons with high axonal regeneration capacity.

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    Romain Cartoni

    Full Text Available Improving axonal transport in the injured and diseased central nervous system has been proposed as a promising strategy to improve neuronal repair. However, the contribution of each cargo to the repair mechanism is unknown. DRG neurons globally increase axonal transport during regeneration. Because the transport of specific cargos after axonal insult has not been examined systematically in a model of enhanced regenerative capacity, it is unknown whether the transport of all cargos would be modulated equally in injured central nervous system neurons. Here, using a microfluidic culture system we compared neurons co-deleted for PTEN and SOCS3, an established model of high axonal regeneration capacity, to control neurons. We measured the axonal transport of three cargos (mitochondria, synaptic vesicles and late endosomes in regenerating axons and found that the transport of mitochondria, but not the other cargos, was increased in PTEN/SOCS3 co-deleted axons relative to controls. The results reported here suggest a pivotal role for this organelle during axonal regeneration.

  10. In silico modeling of axonal reconnection within a discrete fiber tract after spinal cord injury.

    Science.gov (United States)

    Woolfe, Franco; Waxman, Stephen G; Hains, Bryan C

    2007-02-01

    Following spinal cord injury (SCI), descending axons that carry motor commands from the brain to the spinal cord are injured or transected, producing chronic motor dysfunction and paralysis. Reconnection of these axons is a major prerequisite for restoration of function after SCI. Thus far, only modest gains in motor function have been achieved experimentally or in the clinic after SCI, identifying the practical limitations of current treatment approaches. In this paper, we use an ordinary differential equation (ODE) to simulate the relative and synergistic contributions of several experimentally-established biological factors related to inhibition or promotion of axonal repair and restoration of function after SCI. The factors were mathematically modeled by the ODE. The results of our simulation show that in a model system, many factors influenced the achievability of axonal reconnection. Certain factors more strongly affected axonal reconnection in isolation, and some factors interacted in a synergistic fashion to produce further improvements in axonal reconnection. Our data suggest that mathematical modeling may be useful in evaluating the complex interactions of discrete therapeutic factors not possible in experimental preparations, and highlight the benefit of a combinatorial therapeutic approach focused on promoting axonal sprouting, attraction of cut ends, and removal of growth inhibition for achieving axonal reconnection. Predictions of this simulation may be of utility in guiding future experiments aimed at restoring function after SCI.

  11. A developmental timing switch promotes axon outgrowth independent of known guidance receptors.

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    Katherine Olsson-Carter

    2010-08-01

    Full Text Available To form functional neuronal connections, axon outgrowth and guidance must be tightly regulated across space as well as time. While a number of genes and pathways have been shown to control spatial features of axon development, very little is known about the in vivo mechanisms that direct the timing of axon initiation and elongation. The Caenorhabditis elegans hermaphrodite specific motor neurons (HSNs extend a single axon ventrally and then anteriorly during the L4 larval stage. Here we show the lin-4 microRNA promotes HSN axon initiation after cell cycle withdrawal. Axons fail to form in lin-4 mutants, while they grow prematurely in lin-4-overexpressing animals. lin-4 is required to down-regulate two inhibitors of HSN differentiation--the transcriptional regulator LIN-14 and the "stemness" factor LIN-28--and it likely does so through a cell-autonomous mechanism. This developmental switch depends neither on the UNC-40/DCC and SAX-3/Robo receptors nor on the direction of axon growth, demonstrating that it acts independently of ventral guidance signals to control the timing of HSN axon elongation.

  12. Modeling of the axon membrane skeleton structure and implications for its mechanical properties.

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    Yihao Zhang

    2017-02-01

    Full Text Available Super-resolution microscopy recently revealed that, unlike the soma and dendrites, the axon membrane skeleton is structured as a series of actin rings connected by spectrin filaments that are held under tension. Currently, the structure-function relationship of the axonal structure is unclear. Here, we used atomic force microscopy (AFM to show that the stiffness of the axon plasma membrane is significantly higher than the stiffnesses of dendrites and somata. To examine whether the structure of the axon plasma membrane determines its overall stiffness, we introduced a coarse-grain molecular dynamics model of the axon membrane skeleton that reproduces the structure identified by super-resolution microscopy. Our proposed computational model accurately simulates the median value of the Young's modulus of the axon plasma membrane determined by atomic force microscopy. It also predicts that because the spectrin filaments are under entropic tension, the thermal random motion of the voltage-gated sodium channels (Nav, which are bound to ankyrin particles, a critical axonal protein, is reduced compared to the thermal motion when spectrin filaments are held at equilibrium. Lastly, our model predicts that because spectrin filaments are under tension, any axonal injuries that lacerate spectrin filaments will likely lead to a permanent disruption of the membrane skeleton due to the inability of spectrin filaments to spontaneously form their initial under-tension configuration.

  13. Modeling of the axon membrane skeleton structure and implications for its mechanical properties.

    Science.gov (United States)

    Zhang, Yihao; Abiraman, Krithika; Li, He; Pierce, David M; Tzingounis, Anastasios V; Lykotrafitis, George

    2017-02-01

    Super-resolution microscopy recently revealed that, unlike the soma and dendrites, the axon membrane skeleton is structured as a series of actin rings connected by spectrin filaments that are held under tension. Currently, the structure-function relationship of the axonal structure is unclear. Here, we used atomic force microscopy (AFM) to show that the stiffness of the axon plasma membrane is significantly higher than the stiffnesses of dendrites and somata. To examine whether the structure of the axon plasma membrane determines its overall stiffness, we introduced a coarse-grain molecular dynamics model of the axon membrane skeleton that reproduces the structure identified by super-resolution microscopy. Our proposed computational model accurately simulates the median value of the Young's modulus of the axon plasma membrane determined by atomic force microscopy. It also predicts that because the spectrin filaments are under entropic tension, the thermal random motion of the voltage-gated sodium channels (Nav), which are bound to ankyrin particles, a critical axonal protein, is reduced compared to the thermal motion when spectrin filaments are held at equilibrium. Lastly, our model predicts that because spectrin filaments are under tension, any axonal injuries that lacerate spectrin filaments will likely lead to a permanent disruption of the membrane skeleton due to the inability of spectrin filaments to spontaneously form their initial under-tension configuration.

  14. Blast overpressure induced axonal injury changes in rat brainstem and spinal cord

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    Srinivasu Kallakuri

    2015-01-01

    Full Text Available Introduction: Blast induced neurotrauma has been the signature wound in returning soldiers from the ongoing wars in Iraq and Afghanistan. Of importance is understanding the pathomechansim(s of blast overpressure (OP induced axonal injury. Although several recent animal models of blast injury indicate the neuronal and axonal injury in various brain regions, animal studies related to axonal injury in the white matter (WM tracts of cervical spinal cord are limited. Objective: The purpose of this study was to assess the extent of axonal injury in WM tracts of cervical spinal cord in male Sprague Dawley rats subjected to a single insult of blast OP. Materials and Methods: Sagittal brainstem sections and horizontal cervical spinal cord sections from blast and sham animals were stained by neurofilament light (NF-L chain and beta amyloid precursor protein immunocytochemistry and observed for axonal injury changes. Results: Observations from this preliminary study demonstrate axonal injury changes in the form of prominent swellings, retraction bulbs, and putative signs of membrane disruptions in the brainstem and cervical spinal cord WM tracts of rats subjected to blast OP. Conclusions: Prominent axonal injury changes following the blast OP exposure in brainstem and cervical spinal WM tracts underscores the need for careful evaluation of blast induced injury changes and associated symptoms. NF-L immunocytochemistry can be considered as an additional tool to assess the blast OP induced axonal injury.

  15. The Kinesin Adaptor Calsyntenin-1 Organizes Microtubule Polarity and Regulates Dynamics during Sensory Axon Arbor Development

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    Mary C. Halloran

    2017-04-01

    Full Text Available Axon growth and branching, and development of neuronal polarity are critically dependent on proper organization and dynamics of the microtubule (MT cytoskeleton. MTs must organize with correct polarity for delivery of diverse cargos to appropriate subcellular locations, yet the molecular mechanisms regulating MT polarity remain poorly understood. Moreover, how an actively branching axon reorganizes MTs to direct their plus ends distally at branch points is unknown. We used high-speed, in vivo imaging of polymerizing MT plus ends to characterize MT dynamics in developing sensory axon arbors in zebrafish embryos. We find that axonal MTs are highly dynamic throughout development, and that the peripheral and central axons of sensory neurons show differences in MT behaviors. Furthermore, we show that Calsyntenin-1 (Clstn-1, a kinesin adaptor required for sensory axon branching, also regulates MT polarity in developing axon arbors. In wild type neurons the vast majority of MTs are directed in the correct plus-end-distal orientation from early stages of development. Loss of Clstn-1 causes an increase in MTs polymerizing in the retrograde direction. These misoriented MTs most often are found near growth cones and branch points, suggesting Clstn-1 is particularly important for organizing MT polarity at these locations. Together, our results suggest that Clstn-1, in addition to regulating kinesin-mediated cargo transport, also organizes the underlying MT highway during axon arbor development.

  16. Integration of shallow gradients of Shh and Netrin-1 guides commissural axons.

    Science.gov (United States)

    Sloan, Tyler F W; Qasaimeh, Mohammad A; Juncker, David; Yam, Patricia T; Charron, Frédéric

    2015-03-01

    During nervous system development, gradients of Sonic Hedgehog (Shh) and Netrin-1 attract growth cones of commissural axons toward the floor plate of the embryonic spinal cord. Mice defective for either Shh or Netrin-1 signaling have commissural axon guidance defects, suggesting that both Shh and Netrin-1 are required for correct axon guidance. However, how Shh and Netrin-1 collaborate to guide axons is not known. We first quantified the steepness of the Shh gradient in the spinal cord and found that it is mostly very shallow. We then developed an in vitro microfluidic guidance assay to simulate these shallow gradients. We found that axons of dissociated commissural neurons respond to steep but not shallow gradients of Shh or Netrin-1. However, when we presented axons with combined Shh and Netrin-1 gradients, they had heightened sensitivity to the guidance cues, turning in response to shallower gradients that were unable to guide axons when only one cue was present. Furthermore, these shallow gradients polarized growth cone Src-family kinase (SFK) activity only when Shh and Netrin-1 were combined, indicating that SFKs can integrate the two guidance cues. Together, our results indicate that Shh and Netrin-1 synergize to enable growth cones to sense shallow gradients in regions of the spinal cord where the steepness of a single guidance cue is insufficient to guide axons, and we identify a novel type of synergy that occurs when the steepness (and not the concentration) of a guidance cue is limiting.

  17. Brief electrical stimulation accelerates axon regeneration in the peripheral nervous system and promotes sensory axon regeneration in the central nervous system.

    Science.gov (United States)

    Gordon, Tessa; Udina, Esther; Verge, Valerie M K; de Chaves, Elena I Posse

    2009-10-01

    Injured peripheral but not central nerves regenerate their axons but functional recovery is often poor. We demonstrate that prolonged periods of axon separation from targets and Schwann cell denervation eliminate regenerative capacity in the peripheral nervous system (PNS). A substantial delay of 4 weeks for all regenerating axons to cross a site of repair of sectioned nerve contributes to the long period of separation. Findings that 1h 20Hz bipolar electrical stimulation accelerates axon outgrowth across the repair site and the downstream reinnervation of denervated muscles in rats and human patients, provides a new and exciting method to improve functional recovery after nerve injuries. Drugs that elevate neuronal cAMP and activate PKA promote axon outgrowth in vivo and in vitro, mimicking the electrical stimulation effect. Rapid expression of neurotrophic factors and their receptors and then of growth associated proteins thereafter via cAMP, is the likely mechanism by which electrical stimulation accelerates axon outgrowth from the site of injury in both peripheral and central nervous systems.

  18. Transfer of vesicles from Schwann cell to axon: a novel mechanism of communication in the peripheral nervous system

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    María Alejandra eLopez-Verrilli

    2012-06-01

    Full Text Available Schwann cells (SCs are the glial component of the peripheral nervous system, with essential roles during development and maintenance of axons, as well as during regenerative processes after nerve injury. SCs increase conduction velocities by myelinating axons, regulate synaptic activity at presynaptic nerve terminals and are a source of trophic factors to neurons. Thus, development and maintenance of peripheral nerves are crucially dependent on local signalling between SCs and axons. In addition to the classic mechanisms of intercellular signalling, the possibility of communication through secreted vesicles has been poorly explored to date. Interesting recent findings suggest the occurrence of lateral transfer mediated by vesicles from glial cells to axons that could have important roles in axonal growth and axonal regeneration. Here, we review the role of vesicular transfer from SCs to axons and propose the benefits of this means in supporting neuronal and axonal maintenance and regeneration after nerve damage.

  19. The disruption of mitochondrial axonal transport is an early event in neuroinflammation

    DEFF Research Database (Denmark)

    Errea, Oihana; Moreno, Beatriz; Gonzalez-Franquesa, Alba

    2015-01-01

    in the cerebellar slice cultures was analyzed through high-resolution respirometry assays and quantification of adenosine triphosphate (ATP) production. RESULTS: Both conditions promoted an increase in the size and complexity of axonal mitochondria evident in electron microscopy images, suggesting a compensatory...... acutely impairs axonal mitochondrial transportation, which would promote an inappropriate delivery of energy throughout axons and, by this way, contribute to axonal damage. Thus, preserving axonal mitochondrial transport might represent a promising avenue to exploit as a therapeutic target...... response. Such compensation was reflected at the tissue level as increased respiratory activity of complexes I and IV and as a transient increase in ATP production in response to acute inflammation. Notably, time-lapse microscopy indicated that mitochondrial transport (mean velocity) was severely impaired...

  20. Golgi bypass for local delivery of axonal proteins, fact or fiction?

    Science.gov (United States)

    González, Carolina; Cornejo, Víctor Hugo; Couve, Andrés

    2018-04-06

    Although translation of cytosolic proteins is well described in axons, much less is known about the synthesis, processing and trafficking of transmembrane and secreted proteins. A canonical rough endoplasmic reticulum or a stacked Golgi apparatus has not been detected in axons, generating doubts about the functionality of a local route. However, axons contain mRNAs for membrane and secreted proteins, translation factors, ribosomal components, smooth endoplasmic reticulum and post-endoplasmic reticulum elements that may contribute to local biosynthesis and plasma membrane delivery. Here we consider the evidence supporting a local secretory system in axons. We discuss exocytic elements and examples of autonomous axonal trafficking that impact development and maintenance. We also examine whether unconventional post-endoplasmic reticulum pathways may replace the canonical Golgi apparatus. Copyright © 2018. Published by Elsevier Ltd.

  1. Nuclear-Encoded Mitochondrial mRNAs: A Powerful Force in Axonal Growth and Development.

    Science.gov (United States)

    Gale, Jenna R; Aschrafi, Armaz; Gioio, Anthony E; Kaplan, Barry B

    2018-04-01

    Axons, their growth cones, and synaptic nerve terminals are neuronal subcompartments that have high energetic needs. As such, they are enriched in mitochondria, which supply the ATP necessary to meet these demands. To date, a heterogeneous population of nuclear-encoded mitochondrial mRNAs has been identified in distal axons and growth cones. Accumulating evidence suggests that the local translation of these mRNAs is required for mitochondrial maintenance and axonal viability. Here, we review evidence that suggests a critical role for axonal translation of nuclear-encoded mitochondrial mRNAs in axonal growth and development. Additionally, we explore the role that site-specific translation at the mitochondria itself may play in this process. Finally, we briefly review the clinical implications of dysregulation of local translation of mitochondrial-related mRNAs in neurodevelopmental disorders.

  2. Intra-axonal Synthesis of SNAP25 Is Required for the Formation of Presynaptic Terminals

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    Andreia F.R. Batista

    2017-09-01

    Full Text Available Localized protein synthesis is a mechanism for developing axons to react acutely and in a spatially restricted manner to extracellular signals. As such, it is important for many aspects of axonal development, but its role in the formation of presynapses remains poorly understood. We found that the induced assembly of presynaptic terminals required local protein synthesis. Newly synthesized proteins were detectable at nascent presynapses within 15 min of inducing synapse formation in isolated axons. The transcript for the t-SNARE protein SNAP25, which is required for the fusion of synaptic vesicles with the plasma membrane, was recruited to presynaptic sites and locally translated. Inhibition of intra-axonal SNAP25 synthesis affected the clustering of SNAP25 and other presynaptic proteins and interfered with the release of synaptic vesicles from presynaptic sites. This study reveals a critical role for the axonal synthesis of SNAP25 in the assembly of presynaptic terminals.

  3. BmRobo2/3 is required for axon guidance in the silkworm Bombyx mori.

    Science.gov (United States)

    Li, Xiao-Tong; Yu, Qi; Zhou, Qi-Sheng; Zhao, Xiao; Liu, Zhao-Yang; Cui, Wei-Zheng; Liu, Qing-Xin

    2016-02-15

    Axon guidance is critical for proper wiring of the nervous system. During the neural development, the axon guidance molecules play a key role and direct axons to choose the correct way to reach the target. Robo, as the receptor of axon guidance molecule Slit, is evolutionarily conserved from planarians to humans. However, the function of Robo in the silkworm, Bombyx mori, remained unknown. In this study, we cloned robo2/3 from B. mori (Bmrobo2/3), a homologue of robo2/3 in Tribolium castaneum. Moreover, BmRobo2/3 was localized in the neuropil, and RNAi-mediated knockdown of Bmrobo2/3 resulted in the longitudinal connectives forming closer to the midline. These data demonstrate that BmRobo2/3 is required for axon guidance in the silkworm. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Axonal sprouting regulates myelin basic protein gene expression in denervated mouse hippocampus

    DEFF Research Database (Denmark)

    Jensen, M B; Poulsen, F R; Finsen, B

    2000-01-01

    to 35 days after transection of the entorhino-hippocampal perforant path axonal projection. In situ hybridization analysis showed that anterograde axonal and terminal degeneration lead to upregulated oligodendrocyte MBP mRNA expression starting between day 2 and day 4, in (1) the deep part of stratum...... axonal and terminal degeneration, myelin degenerative changes, microglial activation and axotomi-induced axonal sprouting. Oligodendrocyte MBP mRNA expression reached maximum in both these areas at day 7. MBP gene transcription remained constant in stratum radiatum, stratum pyramidale and stratum oriens...... of CA1, areas that were unaffected by perforant path transection. These results provide strong evidence that oligodendrocyte MBP gene expression can be regulated by axonal sprouting independently of microglial activation in the injured adult CNS....

  5. Dorsal column sensory axons degenerate due to impaired microvascular perfusion after spinal cord injury in rats

    Science.gov (United States)

    Muradov, Johongir M.; Ewan, Eric E.; Hagg, Theo

    2013-01-01

    The mechanisms contributing to axon loss after spinal cord injury (SCI) are largely unknown but may involve microvascular loss as we have previously suggested. Here, we used a mild contusive injury (120 kdyn IH impactor) at T9 in rats focusing on ascending primary sensory dorsal column axons, anterogradely traced from the sciatic nerves. The injury caused a rapid and progressive loss of dorsal column microvasculature and oligodendrocytes at the injury site and penumbra and a ~70% loss of the sensory axons, by 24 hours. To model the microvascular loss, focal ischemia of the T9 dorsal columns was achieved via phototoxic activation of intravenously injected rose bengal. This caused an ~53% loss of sensory axons and an ~80% loss of dorsal column oligodendrocytes by 24 hours. Axon loss correlated with the extent and axial length of microvessel and oligodendrocyte loss along the dorsal column. To determine if oligodendrocyte loss contributes to axon loss, the glial toxin ethidium bromide (EB; 0.3 µg/µl) was microinjected into the T9 dorsal columns, and resulted in an ~88% loss of dorsal column oligodendrocytes and an ~56% loss of sensory axons after 72 hours. EB also caused an ~72% loss of microvessels. Lower concentrations of EB resulted in less axon, oligodendrocyte and microvessel loss, which were highly correlated (R2 = 0.81). These data suggest that focal spinal cord ischemia causes both oligodendrocyte and axon degeneration, which are perhaps linked. Importantly, they highlight the need of limiting the penumbral spread of ischemia and oligodendrocyte loss after SCI in order to protect axons. PMID:23978615

  6. Delineating neurotrophin-3 dependent signaling pathways underlying sympathetic axon growth along intermediate targets.

    Science.gov (United States)

    Keeler, Austin B; Suo, Dong; Park, Juyeon; Deppmann, Christopher D

    2017-07-01

    Postganglionic sympathetic neurons detect vascular derived neurotrophin 3 (NT3) via the axonally expressed receptor tyrosine kinase, TrkA, to promote chemo-attraction along intermediate targets. Once axons arrive to their final target, a structurally related neurotrophic factor, nerve growth factor (NGF), also acts through TrkA to promote final target innervation. Does TrkA signal differently at these different locales? We previously found that Coronin-1 is upregulated in sympathetic neurons upon exposure to NGF, thereby endowing the NGF-TrkA complex with new signaling capabilities (i.e. calcium signaling), which dampens axon growth and branching. Based on the notion that axons do not express functional levels of Coronin-1 prior to final target innervation, we developed an in vitro model for axon growth and branching along intermediate targets using Coro1a -/- neurons grown in NT3. We found that, similar to NGF-TrkA, NT3-TrkA is capable of inducing MAPK and PI3K in the presence or absence of Coronin-1. However, unlike NGF, NT3 does not induce calcium release from intracellular stores. Using a combination of pharmacology, knockout neurons and in vitro functional assays, we suggest that the NT3-TrkA complex uses Ras/MAPK and/or PI3K-AKT signaling to induce axon growth and inhibit axon branching along intermediate targets. However, in the presence of Coronin-1, these signaling pathways lose their ability to impact NT3 dependent axon growth or branching. This is consistent with a role for Coronin-1 as a molecular switch for axon behavior and suggests that Coronin-1 suppresses NT3 dependent axon behavior. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Insuficiência renal aguda em paciente tratada com ATRA e anfotericina B: relato de caso

    Directory of Open Access Journals (Sweden)

    Gelcimar Moresco

    2011-06-01

    Full Text Available O presente relato apresenta o caso clínico de uma paciente com leucemia promie-locítica aguda tratada com ácido todo-transretinoico (ATRA, que apresentou suspeita de síndrome do ácido transreti-noico (síndrome de ATRA. Com a ocor-rência de leucopenia febril inespecífica, foram associados ao tratamento antimi-crobianos e antifúngicos. A diminuição da função renal, observada inicialmente, contribuiu para a suspeita de síndrome de ATRA, que foi agravada pelos antifúngi-cos. Assim, o uso de ATRA foi suspenso, mas somente 8 dias depois foi caracteriza-da pneumonia e descartada a hipótese de síndrome de ATRA. Nesse contexto, foi discutida a nefrotoxicidade do ATRA e a potencialização desse efeito adverso pelo uso de antifúngicos nefrotóxicos, em par-ticular da anfotericina B, assim como a im-portância do diagnóstico diferencial entre síndrome de ATRA e doença infecciosa.

  8. Subtipos moleculares de PML/RARα en pacientes con leucemia promielocítica aguda

    Directory of Open Access Journals (Sweden)

    María del Carmen Castro-Mujica

    2013-03-01

    Full Text Available El objetivo fue describir la frecuencia de los subtipos moleculares de PML/RARα en pacientes con leucemia promielocítica aguda (LPA y su distribución según grupo de riesgo de recaída y citomorfología. Se realizó una serie de casos que incluyó a cincuenta pacientes registrados en el Instituto Nacional de Enfermedades Neoplásicas (INEN, durante el periodo 2010-2012, con diagnóstico molecular de LPA PML/RARα y subtipos bcr1, bcr2 y bcr3 por reacción en cadena de la polimerasa con transcriptasa reversa (RT-PCR. El subtipo bcr1 fue el más frecuente (62%. Los pacientes con riesgo de recaída intermedio y morfología hipergranular fueron, en su mayoría, bcr1 (70% y todos los que poseían riesgo de recaída alto y morfología hipogranular fueron bcr3. Se concluye que en la población estudiada hay un predomino del subtipo bcr1 y que existen diferencias en la distribución de los subtipos bcr1 y bcr3 según el grupo de riesgo de recaída y citomorfología

  9. Consumo alimentar e estresse em pacientes com síndrome coronariana aguda

    Directory of Open Access Journals (Sweden)

    Evelise Helena Fadini Reis Brunori

    2015-10-01

    Full Text Available RESUMOObjetivo:Avaliar se o consumo alimentar de pacientes com síndrome coronariana aguda (SCA segue as recomendações nacionais e internacionais e se existe relação com níveis de estresseMétodo:Estudo transversal com 150 pacientes com SCA que foram entrevistados utilizando-se os Questionários de Frequência Alimentar e Escala de Estresse Percebido-10.Resultados:Consumo diário acima das recomendações: colesterol (92%, fi bras (42,7% e proteínas (68%; consumo abaixo das recomendações: potássio (88% e carboidratos (68,7%; consumo conforme recomendações: sódio (53,3% e lípides (53,3%. A maioria (54% com consumo alimentar inadequado era estressada ou altamente estressada. Houve associação estatisticamente signifi cante entre menor nível de estresse e maior consumo de fibras.Conclusão:Em pacientes com SCA, o consumo alimentar esteve fora do recomendado pelas diretrizes e o menor consumo de fibras ocorre concomitantemente com maior estresse. Esforços educativos podem instrumentalizar os pacientes na adequação do consumo alimentar e no controle do estresse.

  10. Toxicidad aguda de las hojas de Xanthium spinosum en ratones BALB/C

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    Arturo Silvero-Isidre

    2016-01-01

    Full Text Available Las hojas de la planta Xanthium spinosum se utilizan culturalmente en Paraguay por sus propiedades medicinales. Se evaluó la toxicidad aguda del extracto de hojas maduras; para el estudio se seleccionaron 35 ratones BALB/C machos que fueron distribuidos en 7 grupos, 6 de ensayo y 1 de control. El extracto fue preparado en concentraciones de 6 y 9% (g/dL; se administró la solución 6% a tres grupos y la solución 9% a los otros tres grupos, con dosis entre 200 y 1000 mg/kg. Al final de 14 días de observación, se extrajeron muestras de sangre para estudios laboratoriales de urea y transaminasas, además de órganos para estudios anatomopatológicos. Se determinaron aumentos en los niveles de GOT y urea en comparación al grupo control. Se concluye que el consumo del extracto de hojas maduras de Xanthium spinosum puede causar daño hepático.

  11. Actuación de enfermería en la leucemia mieloide aguda.

    Directory of Open Access Journals (Sweden)

    Melchor Pino, Pilar

    2012-08-01

    Full Text Available La leucemia mieloide aguda (LMA es una proliferación neoplásica de células inmaduras de estirpe mieloide que se produce por una alteración en el crecimiento y diferenciación de las células hematopoyéticas.En este trabajo se presenta un caso clínico sobre un paciente de 37 años diagnosticado de LMA. Se hace una valoración de las necesidades básicas siguiendo el modelo de Virginia Henderson al ingreso del paciente, mediante una entrevista dirigida y la obtención de datos mediante la observación.El objetivo general es elaborar un plan individualizado de cuidados a dicho paciente, mediante la aplicación del Proceso Enfermero y la utilización de la taxonomía NANDA-NOC-NIC que nos permitirá aplicar unos cuidados de calidad a este paciente.Cuando el paciente abandone el hospital, la enfermera le entregará un informe de alta, que asegurará la continuidad de sus cuidados.

  12. Reacciones adversas e interacciones medicamentosas en el tratamiento de las enfermedades respiratorias agudas

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    Oneyda Clapé Laffita

    2000-12-01

    Full Text Available Como continuación de los estudios de farmacovigilancia en la Unidad de Cuidados Intensivos e Intermedios del Hospital Provincial Docente Clinicoquirúrgico "Saturnino Lora", se evaluaron las reacciones adversas e interacciones medicamentosas detectadas en el tratamiento de las enfermedades respiratorias agudas, para lo cual se aplicó el método de vigilancia intensiva del paciente hospitalizado, a fin de validar los datos obtenidos farmacológica y estadísticamente. Se encontraron 96 reacciones adversas y 47 interacciones medicamentosas, valores estos que fueron relacionados con aspectos clínicos y demográficos. Los posibles riesgos quedaron atenuados por las medidas propuestas en cada plan terapéutico y la orientación farmacológica al enfermo.As part of the pharmacovigilance studies conducted at the Intensive and Intermediate Care Unit of the "Saturnino Lora" Provincial Clinical and Surgical Teaching Hospital, the adverse reactions and drug interactions detected in the treatment of acute respiratory diseases were evaluated. The method of intensive surveillance of the hospitalized patient was used to validate the data obtained from the pharmacological and statistical point of view. 96 adverse reactions and 47 drug interactions were found. These values were related to clinical and demographic aspects. The possible risks were attenuated by the measures proposed in each therapeutic plan and the pharmacological advice given to the patient.

  13. Reversible Axonal Dystrophy by Calcium Modulation in Frataxin-Deficient Sensory Neurons of YG8R Mice

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    Belén Mollá

    2017-08-01

    Full Text Available Friedreich’s ataxia (FRDA is a peripheral neuropathy involving a loss of proprioceptive sensory neurons. Studies of biopsies from patients suggest that axonal dysfunction precedes the death of proprioceptive neurons in a dying-back process. We observed that the deficiency of frataxin in sensory neurons of dorsal root ganglia (DRG of the YG8R mouse model causes the formation of axonal spheroids which retain dysfunctional mitochondria, shows alterations in the cytoskeleton and it produces impairment of axonal transport and autophagic flux. The homogenous distribution of axonal spheroids along the neurites supports the existence of continues focal damages. This lead us to propose for FRDA a model of distal axonopathy based on axonal focal damages. In addition, we observed the involvement of oxidative stress and dyshomeostasis of calcium in axonal spheroid formation generating axonal injury as a primary cause of pathophysiology. Axonal spheroids may be a consequence of calcium imbalance, thus we propose the quenching or removal extracellular Ca2+ to prevent spheroids formation. In our neuronal model, treatments with BAPTA and o-phenanthroline reverted the axonal dystrophy and the mitochondrial dysmorphic parameters. These results support the hypothesis that axonal pathology is reversible in FRDA by pharmacological manipulation of intracellular Ca2+ with Ca2+ chelators or metalloprotease inhibitors, preventing Ca2+-mediated axonal injury. Thus, the modulation of Ca2+ levels may be a relevant therapeutic target to develop early axonal protection and prevent dying-back neurodegeneration.

  14. Extrinsic and intrinsic regulation of axon regeneration at a crossroads.

    Science.gov (United States)

    Kaplan, Andrew; Ong Tone, Stephan; Fournier, Alyson E

    2015-01-01

    Repair of the injured spinal cord is a major challenge in medicine. The limited intrinsic regenerative response mounted by adult central nervous system (CNS) neurons is further hampered by astrogliosis, myelin debris and scar tissue that characterize the damaged CNS. Improved axon regeneration and recovery can be elicited by targeting extrinsic factors as well as by boosting neuron-intrinsic growth regulators. Our knowledge of the molecular basis of intrinsic and extrinsic regulators of regeneration has expanded rapidly, resulting in promising new targets to promote repair. Intriguingly certain neuron-intrinsic growth regulators are emerging as promising targets to both stimulate growth and relieve extrinsic inhibition of regeneration. This crossroads between the intrinsic and extrinsic aspects of spinal cord injury is a promising target for effective therapies for this unmet need.

  15. The cholinergic ligand binding material of axonal membranes

    International Nuclear Information System (INIS)

    Mautner, H.G.; Coronado, R.; Jumblatt, J.E.

    1986-01-01

    Choline acetyltransferase and acetylcholinesterase, the enzymes responsible for the synthesis and hydrolysis of ACh, are present in nerve fibers. In crustacean peripheral nerves, release of ACh from cut nerve fibers has been demonstrated. Previously closed membrane vesicles have been prepared from lobster walking leg nerve plasma membrane and saturable binding of cholinergic agonsist and antagonists to such membranes have been demonstrated. This paper studies this axonal cholinergic binding material, and elucidates its functions. The binding of tritium-nicotine to lobster nerve plasma membranes was antagonized by a series of cholinergic ligands as well as by a series of local anesthetics. This preparation was capable of binding I 125-alpha-bungarotoxin, a ligand widely believed to be a specific label for nicotinic ACh receptor. The labelling of 50 K petide band with tritium-MBTA following disulfide reduction is illustrated

  16. The axonal guidance receptor neogenin promotes acute inflammation.

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    Klemens König

    Full Text Available Neuronal guidance proteins (NGP were originally described in the context of axonal growth and migration. Yet recent work has demonstrated that NGPs also serve as guidance cues for immune competent cells. A crucial target receptor for NGPs during embryonic development is the neogenin receptor, however its role during acute inflammation is unknown. We report here that neogenin is abundantly expressed outside the nervous system and that animals with endogenous repression of neogenin (Neo1(-/- demonstrate attenuated changes of acute inflammation. Studies using functional inhibition of neogenin resulted in a significant attenuation of inflammatory peritonitis. In studies employing bone marrow chimeric animals we found the hematopoietic presence of Neo1(-/- to be responsible for the attenuated inflammatory response. Taken together our studies suggest that the guidance receptor neogenin holds crucial importance for the propagation of an acute inflammatory response and further define mechanisms shared between the nervous and the immune system.

  17. Neurogenetics of slow axonal transport: from cells to animals.

    Science.gov (United States)

    Sadananda, Aparna; Ray, Krishanu

    2012-09-01

    Slow axonal transport is a multivariate phenomenon implicated in several neurodegenerative disorders. Recent reports have unraveled the molecular basis of the transport of certain slow component proteins, such as the neurofilament subunits, tubulin, and certain soluble enzymes such as Ca(2+)/calmodulin-dependent protein kinase IIa (CaM kinase IIa), etc., in tissue cultured neurons. In addition, genetic analyses also implicate microtubule-dependent motors and other housekeeping proteins in this process. However, the biological relevance of this phenomenon is not so well understood. Here, the authors have discussed the possibility of adopting neurogenetic analyses in multiple model organisms to correlate molecular level measurements of the slow transport phenomenon to animal behavior, thus facilitating the investigation of its biological efficacy.

  18. Condiciones ambientales riesgosas para las infecciones respiratorias agudas en escolares de primaria Risky environmental conditions for acute respiratory infections in primary school students

    Directory of Open Access Journals (Sweden)

    Alina Mezquía Valera

    2011-06-01

    Full Text Available Introducción: el deterioro de las condiciones ambientales contribuye de forma importante a los procesos de la enfermedad, porque expone a la población urbana a enfermedades y riesgos muy bien identificados y conocidos. Objetivos: identificar las condiciones ambientales riesgosas en los hogares, las escuelas y sus entornos para la prevalencia de las infecciones respiratorias en educandos, en el curso escolar 2006-2007. Métodos: se realizó un estudio descriptivo transversal en los educandos de 1ro. a 6to. grado del universo de las escuelas primarias del consejo popular Cayo Hueso, del municipio Centro Habana. Se aplicó a las madres un cuestionario con preguntas al respecto, y se realizó la evaluación de las condiciones ambientales de las escuelas y sus entornos, según las orientaciones de guías preelaboradas. Resultados: la prevalencia de infecciones respiratorias agudas fueron obtenidas de los educandos que asisten a las escuelas "Pedro Carbó Serviá", "Salvador Cisneros Betancourt", "Fernández Roig" y "República de Bolivia", y coincidió con que son las que tienen más factores de riesgo del ambiente y/o las que tienen mayores frecuencias de educandos con condiciones ambientales riesgosas de sus hogares, escuelas o entorno.Introduction: deterioration of environmental conditions contributes in a very important way to disease processes because of to expose to urban population to diseases and risks very well identified and well known. Objective: to identify the risky environmental conditions at homes, schools and its surroundings for prevalence of respiratory infections in the students during 2006-1007 courses. Methods: a cross-sectional and descriptive study was conducted in students from 1st to sixth degrees from the universe of primary schools of "Cayo Hueso" popular council of the Centro Habana municipality. In mothers a questionnaire was distributed with related questions and the environmental conditions of schools and its

  19. Determinantes nas intoxicações medicamentosas agudas na zona urbana de um município do Sul do Brasil Causes of acute poisoning with medication in a southern Brazilian city

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    Fabiana Burdini Margonato

    2008-02-01

    Full Text Available As intoxicações medicamentosas no Brasil resultam entre diversos fatores os relacionados a uma frágil política de medicamentos em nosso país. Assim, o objetivo deste estudo foi analisar variáveis sócio-econômicas, tipos de indicação, formas de aquisição e armazenamento de medicamentos das pessoas acometidas por intoxicações medicamentosas agudas não-intencionais. Os dados foram coletados durante visitas domiciliares aos pacientes com registro de intoxicação medicamentosa aguda não-intencional pelo Centro de Controle de Intoxicações de Maringá, Paraná, em 2004. Foram estudadas variáveis relacionadas ao intoxicado, à intoxicação, ao medicamento e armazenamento doméstico de medicamentos. Dentre as 97 intoxicações registradas no período, foram entrevistadas 72 famílias, sendo a maioria de menores de 10 anos (73,6%, sexo masculino (54,2%, estratos econômicos C e D (63,9%. Muitos entrevistados referiram não ter recebido informações sobre o medicamento (76,5%. Houve associação significativa entre pessoas dos estratos econômicos C e D e armazenamento inadequado de medicamentos (p Acute poisoning with medicines in Brazil has various causes, including a deficient national drug policy. The current study thus aimed to analyze socioeconomic variables, prescription characteristics, and forms of purchase or acquisition and storing of medicines by victims of acute unintentional poisoning. The data were collected during home visits to patients with a record of acute unintentional drug poisoning according to the Poison Control Center in Maringá, Paraná State, in 2004. The variables were related to the victim, the poisoning event, the product, and its household storage. For the 97 poisonings recorded during the study period, 72 families were interviewed, with the majority of the victims under 10 years of age (73.6%, males (54.2%, and from lower-income groups (63.9%. Many interviewees reported not having received information

  20. Is rhabdomyolysis an additional factor in the pathogenesis of acute renal failure in leptospirosis? É a rabdomiólise um fator adicional na patogônese da insuficiencia renal aguda na leptospirose?

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    Reinaldo Martinelli

    1994-04-01

    Full Text Available Leptospirosis is an important cause of acute renal failure in our environment. Although several mechanisms are implicated, the role of rhabdomyolysis in the pathogenesis of acute renal failure in leptospirosis has not been analysed. Sixteen patients with the diagnosis of leptospiroses consecutively admitted to the hospital were prospectively studied. The disease was characterized by sudden onset in all patients and, at admission, jaundice, conjunctival suffusion and myalgias. Mild to moderate proteinuria with unremarkable urinary sediment was recorded in 37.5% of the patients and abnormal levels of urea creatinine were found in 87.5% and 74.0%, respectively. Increased levels of aminotranspherase were documented in all 12 and CPK in all 10 patients studied. Serum myoglobin levels greater than 120µg/l recorded in 56.2%. A correlation between myoglobin and renal failure or severity of disease, however, could not be established.Leptospirose é uma importante causa de insuficiência renal aguda, em nosso ambiente. Embora vários sejam os mecanismos implicados, o papel da rabdomiólise na patogênese da insuficiência renal aguda na leptospirose ainda não foi analisado. Com esse objetivo, 16 pacientes com o diagnóstico da forma icterohemorrágica da leptospirose consecutivamente admitidos no Hospital Couto Maia, Salvador, Bahia, foram prospectivamente estudados. A doença foi caracterizada por início súbito e, à admissão, ictericia, sufusões hemorrágicas conjuntivais e mialgias. Proteinúria de intensidade média a moderada com sedimento urinário inexpressivo foi observada em 37,5% dos pacientes e níveis séricos elevados de uréia e creatinina em 78,5% e 74,0%, respectivamente. Níveis aumentados de aminotransferase foram documentados em todos os 12 e de CPK em todos os 10 pacientes avaliados para essas enzimas. Níveis séricos maiores que 120µg/l foram observados em 56,2% dos pacientes. Não foram encontradas correlações, entretanto

  1. Neuron Morphology Influences Axon Initial Segment Plasticity123

    Science.gov (United States)

    2016-01-01

    In most vertebrate neurons, action potentials are initiated in the axon initial segment (AIS), a specialized region of the axon containing a high density of voltage-gated sodium and potassium channels. It has recently been proposed that neurons use plasticity of AIS length and/or location to regulate their intrinsic excitability. Here we quantify the impact of neuron morphology on AIS plasticity using computational models of simplified and realistic somatodendritic morphologies. In small neurons (e.g., dentate granule neurons), excitability was highest when the AIS was of intermediate length and located adjacent to the soma. Conversely, neurons having larger dendritic trees (e.g., pyramidal neurons) were most excitable when the AIS was longer and/or located away from the soma. For any given somatodendritic morphology, increasing dendritic membrane capacitance and/or conductance favored a longer and more distally located AIS. Overall, changes to AIS length, with corresponding changes in total sodium conductance, were far more effective in regulating neuron excitability than were changes in AIS location, while dendritic capacitance had a larger impact on AIS performance than did dendritic conductance. The somatodendritic influence on AIS performance reflects modest soma-to-AIS voltage attenuation combined with neuron size-dependent changes in AIS input resistance, effective membrane time constant, and isolation from somatodendritic capacitance. We conclude that the impact of AIS plasticity on neuron excitability will depend largely on somatodendritic morphology, and that, in some neurons, a shorter or more distally located AIS may promote, rather than limit, action potential generation. PMID:27022619

  2. Dynein is the motor for retrograde axonal transport of organelles

    International Nuclear Information System (INIS)

    Schnapp, B.J.; Reese, T.S.

    1989-01-01

    Vesicular organelles in axons of nerve cells are transported along microtubules either toward their plus ends (fast anterograde transport) or toward their minus ends (retrograde transport). Two microtubule-based motors were previously identified by examining plastic beads induced to move along microtubules by cytosol fractions from the squid giant axon: (i) an anterograde motor, kinesin, and (ii) a retrograde motor, which is characterized here. The retrograde motor, a cytosolic protein previously termed HMW1, was purified from optic lobes and extruded axoplasm by nucleotide-dependent microtubule affinity and release; microtubule gliding was used as the assay of motor activity. The following properties of the retrograde motor suggest that it is cytoplasmic dynein: (i) sedimentation at 20-22 S with a heavy chain of Mr greater than 200,000 that coelectrophoreses with the alpha and beta subunits of axonemal dynein, (ii) cleavage by UV irradiation in the presence of ATP and vanadate, and (iii) a molecular structure resembling two-headed dynein from axonemes. Furthermore, bead movement toward the minus end of microtubules was blocked when axoplasmic supernatants were treated with UV/vanadate. Treatment of axoplasmic supernatant with UV/vanadate also blocks the retrograde movement of purified organelles in vitro without changing the number of anterograde moving organelles, indicating that dynein interacts specifically with a subgroup of organelles programmed to move toward the cell body. However, purified optic lobe dynein, like purified kinesin, does not by itself promote the movement of purified organelles along microtubules, suggesting that additional axoplasmic factors are necessary for retrograde as well as anterograde transport

  3. Diffuse axonal injury at ultra-high field MRI.

    Directory of Open Access Journals (Sweden)

    Christoph Moenninghoff

    Full Text Available Diffuse axonal injury (DAI is a specific type of traumatic brain injury caused by shearing forces leading to widespread tearing of axons and small vessels. Traumatic microbleeds (TMBs are regarded as a radiological marker for DAI. This study aims to compare DAI-associated TMBs at 3 Tesla (T and 7 T susceptibility weighted imaging (SWI to evaluate possible diagnostic benefits of ultra-high field (UHF MRI.10 study participants (4 male, 6 female, age range 20-74 years with known DAI were included. All MR exams were performed with a 3 T MR system (Magnetom Skyra and a 7 T MR research system (Magnetom 7 T, Siemens AG, Healthcare Sector, Erlangen, Germany each in combination with a 32-channel-receive coil. The average time interval between trauma and imaging was 22 months. Location and count of TMBs were independently evaluated by two neuroradiologists on 3 T and 7 T SWI images with similar and additionally increased spatial resolution at 7 T. Inter- and intraobserver reliability was assessed using the interclass correlation coefficient (ICC. Count and diameter of TMB were evaluated with Wilcoxon signed rank test.Susceptibility weighted imaging revealed a total of 485 TMBs (range 1-190, median 25 at 3 T, 584 TMBs (plus 20%, range 1-262, median 30.5 at 7 T with similar spatial resolution, and 684 TMBs (plus 41%, range 1-288, median 39.5 at 7 T with 10-times higher spatial resolution. Hemorrhagic DAI appeared significantly larger at 7 T compared to 3 T (p = 0.005. Inter- and intraobserver correlation regarding the counted TMB was high and almost equal 3 T and 7 T.7 T SWI improves the depiction of small hemorrhagic DAI compared to 3 T and may be supplementary to lower field strengths for diagnostic in inconclusive or medicolegal cases.

  4. Axonal transport of proteoglycans to the goldfish optic tectum

    International Nuclear Information System (INIS)

    Ripellino, J.A.; Elam, J.S.

    1988-01-01

    The study addressed the question of whether 35 SO 4 labeled molecules that have been delivered to the goldfish optic nerve terminals by rapid axonal transport include soluble proteoglycans. For analysis, tectal homogenates were subfractionated into a soluble fraction (soluble after centrifugation at 105,000 g), a lysis fraction (soluble after treatment with hypotonic buffer followed by centrifugation at 105,000 g) and a final 105,000 g pellet fraction. The soluble fraction contained 25.7% of incorporated radioactivity and upon DEAE chromatography was resolved into a fraction of sulfated glycoproteins eluting at 0-0.32 M NaCl and containing 39.5% of total soluble label and a fraction eluting at 0.32-0.60 M NaCl containing 53.9% of soluble label. This latter fraction was included on columns of Sepharose CL-6B with or without 4 M guanidine and after pronase digestion was found to have 51% of its radioactivity contained in the glycosaminoglycans (GAGs) heparan sulfate and chondroitin (4 or 6) sulfate in the ratio of 70% to 30%. Mobility of both intact proteoglycans and constituent GAGs on Sepharose CL-6B indicated a size distribution that is smaller than has been observed for proteoglycans and GAGs from cultured neuronal cell lines. Similar analysis of lysis fraction, containing 11.5% of incorporated 35 SO 4 , showed a mixture of heparan sulfate and chondroitin sulfate containing proteoglycans, apparent free heparan sulfate and few, if any, sulfated glycoproteins. Overall, the results support the hypothesis that soluble proteoglycans are among the molecules axonally transported in the visual system

  5. Live Imaging of Calcium Dynamics during Axon Degeneration Reveals Two Functionally Distinct Phases of Calcium Influx

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    Yamagishi, Yuya; Tessier-Lavigne, Marc

    2015-01-01

    Calcium is a key regulator of axon degeneration caused by trauma and disease, but its specific spatial and temporal dynamics in injured axons remain unclear. To clarify the function of calcium in axon degeneration, we observed calcium dynamics in single injured neurons in live zebrafish larvae and tested the temporal requirement for calcium in zebrafish neurons and cultured mouse DRG neurons. Using laser axotomy to induce Wallerian degeneration (WD) in zebrafish peripheral sensory axons, we monitored calcium dynamics from injury to fragmentation, revealing two stereotyped phases of axonal calcium influx. First, axotomy triggered a transient local calcium wave originating at the injury site. This initial calcium wave only disrupted mitochondria near the injury site and was not altered by expression of the protective WD slow (WldS) protein. Inducing multiple waves with additional axotomies did not change the kinetics of degeneration. In contrast, a second phase of calcium influx occurring minutes before fragmentation spread as a wave throughout the axon, entered mitochondria, and was abolished by WldS expression. In live zebrafish, chelating calcium after the first wave, but before the second wave, delayed the progress of fragmentation. In cultured DRG neurons, chelating calcium early in the process of WD did not alter degeneration, but chelating calcium late in WD delayed fragmentation. We propose that a terminal calcium wave is a key instructive component of the axon degeneration program. SIGNIFICANCE STATEMENT Axon degeneration resulting from trauma or neurodegenerative disease can cause devastating deficits in neural function. Understanding the molecular and cellular events that execute axon degeneration is essential for developing treatments to address these conditions. Calcium is known to contribute to axon degeneration, but its temporal requirements in this process have been unclear. Live calcium imaging in severed zebrafish neurons and temporally controlled

  6. Compensatory axon sprouting for very slow axonal die-back in a transgenic model of spinal muscular atrophy type III.

    Science.gov (United States)

    Udina, Esther; Putman, Charles T; Harris, Luke R; Tyreman, Neil; Cook, Victoria E; Gordon, Tessa

    2017-03-01

    Smn +/- transgenic mouse is a model of the mildest form of spinal muscular atrophy. Although there is a loss of spinal motoneurons in 11-month-old animals, muscular force is maintained. This maintained muscular force is mediated by reinnervation of the denervated fibres by surviving motoneurons. The spinal motoneurons in these animals do not show an increased susceptibility to death after nerve injury and they retain their regenerative capacity. We conclude that the hypothesized immaturity of the neuromuscular system in this model cannot explain the loss of motoneurons by systematic die-back. Spinal muscular atrophy (SMA) is a common autosomal recessive disorder in humans and is the leading genetic cause of infantile death. Patients lack the SMN1 gene with the severity of the disease depending on the number of copies of the highly homologous SMN2 gene. Although motoneuron death in the Smn +/- transgenic mouse model of the mildest form of SMA, SMA type III, has been reported, we have used retrograde tracing of sciatic and femoral motoneurons in the hindlimb with recording of muscle and motor unit isometric forces to count the number of motoneurons with intact neuromuscular connections. Thereby, we investigated whether incomplete maturation of the neuromuscular system induced by survival motoneuron protein (SMN) defects is responsible for die-back of axons relative to survival of motoneurons. First, a reduction of ∼30% of backlabelled motoneurons began relatively late, at 11 months of age, with a significant loss of 19% at 7 months. Motor axon die-back was affirmed by motor unit number estimation. Loss of functional motor units was fully compensated by axonal sprouting to retain normal contractile force in four hindlimb muscles (three fast-twitch and one slow-twitch) innervated by branches of the sciatic nerve. Second, our evaluation of whether axotomy of motoneurons in the adult Smn +/- transgenic mouse increases their susceptibility to cell death demonstrated

  7. Formas clínicas de los aneurismas arteriales intracraneanos

    Directory of Open Access Journals (Sweden)

    Alejandro H. Schroeder

    1952-06-01

    Full Text Available Los autores exponen las modalidades clínicas que presentan los aneurismas arteriales intracraneanos, baseando su clasificación en experiencia propia que es de 30 casos, y exponen 9 casos típicos que describen clínica y arteriográficamente, relatando el método quirúrgico utilizado. El diagnóstico del aneurisma arterial y la localización del mismo se hace siempre de manera precisa por la arteriografía, método que tiene un mínimo de riezgo (los autores han hecho 400 arteriografías sin accidente grave. Los autores consideran la clasificación propucsta como previa que, a medida que se amplie la experiencia, habrá que modificar o completar. La clasificación empleada es la que va a continuación: 1 formas de hemorragias meningeas; 2 formas con parálisis de los músculos oculares extrínsecos; 3 formas pseudo-tumorales; 4 formas pseudo-encefa-líticas; 5 formas con epilepsia clinicamente esencial.

  8. Hindsight regulates photoreceptor axon targeting through transcriptional control of jitterbug/Filamin and multiple genes involved in axon guidance in Drosophila.

    Science.gov (United States)

    Oliva, Carlos; Molina-Fernandez, Claudia; Maureira, Miguel; Candia, Noemi; López, Estefanía; Hassan, Bassem; Aerts, Stein; Cánovas, José; Olguín, Patricio; Sierralta, Jimena

    2015-09-01

    During axon targeting, a stereotyped pattern of connectivity is achieved by the integration of intrinsic genetic programs and the response to extrinsic long and short-range directional cues. How this coordination occurs is the subject of intense study. Transcription factors play a central role due to their ability to regulate the expression of multiple genes required to sense and respond to these cues during development. Here we show that the transcription factor HNT regulates layer-specific photoreceptor axon targeting in Drosophila through transcriptional control of jbug/Filamin and multiple genes involved in axon guidance and cytoskeleton organization.Using a microarray analysis we identified 235 genes whose expression levels were changed by HNT overexpression in the eye primordia. We analyzed nine candidate genes involved in cytoskeleton regulation and axon guidance, six of which displayed significantly altered gene expression levels in hnt mutant retinas. Functional analysis confirmed the role of OTK/PTK7 in photoreceptor axon targeting and uncovered Tiggrin, an integrin ligand, and Jbug/Filamin, a conserved actin- binding protein, as new factors that participate of photoreceptor axon targeting. Moreover, we provided in silico and molecular evidence that supports jbug/Filamin as a direct transcriptional target of HNT and that HNT acts partially through Jbug/Filamin in vivo to regulate axon guidance. Our work broadens the understanding of how HNT regulates the coordinated expression of a group of genes to achieve the correct connectivity pattern in the Drosophila visual system. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 75: 1018-1032, 2015. © 2015 Wiley Periodicals, Inc.

  9. Glia-axon interactions and the regulation of the extracellular K+ in the peripheral nerve.

    Science.gov (United States)

    Jirounek, P; Robert, A; Kindler, E; Blazek, T

    1998-01-01

    Changes in membrane potential of both axons and Schwann cells were measured simultaneously during electrical activity and during the period of recovery in the rabbit vagus nerve by the use of the sucrose-gap apparatus. During low-frequency stimulation (0.5-1 Hz) the preparation developed a ouabain-sensitive hyperpolarization. This hyperpolarization increased when the inwardly rectifying K+ channels in Schwann cells were blocked with Ba2+, indicating that the hyperpolarization was generated by the electrogenic glial Na(+)-K+ pump. During trains at higher frequencies (15 Hz), the preparation depolarized, but after cessation of the stimulation it developed a posttetanic hyperpolarization (PTH). The PTH was also ouabain-sensitive and was strongly enhanced by Cs+ which is known to block the hyperpolarization-activated inward current (Ih) in axons but not in glial cells. These results show that the PTH reflects mainly the axonal electrogenic pump. Our results indicate that during activity the K+ released from the firing axons is removed from the extracellular space by Schwann cells and that after cessation of the stimulation the K+ surplus returns from Schwann cells back to axons. Both the glial and axonal K+ uptake is mediated by successive activation of the glial and axonal Na(+)-K+ pump. The nature of the signalling mechanisms that control the pumping rates of the respective pumps remain unknown.

  10. Characterization of axon formation in the embryonic stem cell-derived motoneuron.

    Science.gov (United States)

    Pan, Hung-Chuan; Wu, Ya-Ting; Shen, Shih-Cheng; Wang, Chi-Chung; Tsai, Ming-Shiun; Cheng, Fu-Chou; Lin, Shinn-Zong; Chen, Ching-Wen; Liu, Ching-San; Su, Hong-Lin

    2011-01-01

    The developing neural cell must form a highly organized architecture to properly receive and transmit nerve signals. Neural formation from embryonic stem (ES) cells provides a novel system for studying axonogenesis, which are orchestrated by polarity-regulating molecules. Here the ES-derived motoneurons, identified by HB9 promoter-driven green fluorescent protein (GFP) expression, showed characteristics of motoneuron-specific gene expression. In the majority of motoneurons, one of the bilateral neurites developed into an axon that featured with axonal markers, including Tau1, vesicle acetylcholine transporter, and synaptophysin. Interestingly, one third of the motoneurons developed bi-axonal processes but no multiple axonal GFP cell was found. The neuronal polarity-regulating proteins, including the phosphorylated AKT and ERK, were compartmentalized into both of the bilateral axonal tips. Importantly, this aberrant axon morphology was still present after the engraftment of GFP(+) neurons into the spinal cord, suggesting that even a mature neural environment fails to provide a proper niche to guide normal axon formation. These findings underscore the necessity for evaluating the morphogenesis and functionality of neurons before the clinical trials using ES or somatic stem cells.

  11. Target-Derived Neurotrophins Coordinate Transcription and Transport of Bclw to Prevent Axonal Degeneration

    Science.gov (United States)

    Cosker, Katharina E.; Pazyra-Murphy, Maria F.; Fenstermacher, Sara J.

    2013-01-01

    Establishment of neuronal circuitry depends on both formation and refinement of neural connections. During this process, target-derived neurotrophins regulate both transcription and translation to enable selective axon survival or elimination. However, it is not known whether retrograde signaling pathways that control transcription are coordinated with neurotrophin-regulated actions that transpire in the axon. Here we report that target-derived neurotrophins coordinate transcription of the antiapoptotic gene bclw with transport of bclw mRNA to the axon, and thereby prevent axonal degeneration in rat and mouse sensory neurons. We show that neurotrophin stimulation of nerve terminals elicits new bclw transcripts that are immediately transported to the axons and translated into protein. Bclw interacts with Bax and suppresses the caspase6 apoptotic cascade that fosters axonal degeneration. The scope of bclw regulation at the levels of transcription, transport, and translation provides a mechanism whereby sustained neurotrophin stimulation can be integrated over time, so that axonal survival is restricted to neurons connected within a stable circuit. PMID:23516285

  12. A Communication Theoretical Modeling of Axonal Propagation in Hippocampal Pyramidal Neurons.

    Science.gov (United States)

    Ramezani, Hamideh; Akan, Ozgur B

    2017-06-01

    Understanding the fundamentals of communication among neurons, known as neuro-spike communication, leads to reach bio-inspired nanoscale communication paradigms. In this paper, we focus on a part of neuro-spike communication, known as axonal transmission, and propose a realistic model for it. The shape of the spike during axonal transmission varies according to previously applied stimulations to the neuron, and these variations affect the amount of information communicated between neurons. Hence, to reach an accurate model for neuro-spike communication, the memory of axon and its effect on the axonal transmission should be considered, which are not studied in the existing literature. In this paper, we extract the important factors on the memory of axon and define memory states based on these factors. We also describe the transition among these states and the properties of axonal transmission in each of them. Finally, we demonstrate that the proposed model can follow changes in the axonal functionality properly by simulating the proposed model and reporting the root mean square error between simulation results and experimental data.

  13. Microtubule-targeting drugs rescue axonal swellings in cortical neurons from spastin knockout mice

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    Coralie Fassier

    2013-01-01

    Mutations in SPG4, encoding the microtubule-severing protein spastin, are responsible for the most frequent form of hereditary spastic paraplegia (HSP, a heterogeneous group of genetic diseases characterized by degeneration of the corticospinal tracts. We previously reported that mice harboring a deletion in Spg4, generating a premature stop codon, develop progressive axonal degeneration characterized by focal axonal swellings associated with impaired axonal transport. To further characterize the molecular and cellular mechanisms underlying this mutant phenotype, we have assessed microtubule dynamics and axonal transport in primary cultures of cortical neurons from spastin-mutant mice. We show an early and marked impairment of microtubule dynamics all along the axons of spastin-deficient cortical neurons, which is likely to be responsible for the occurrence of axonal swellings and cargo stalling. Our analysis also reveals that a modulation of microtubule dynamics by microtubule-targeting drugs rescues the mutant phenotype of cortical neurons. Together, these results contribute to a better understanding of the pathogenesis of SPG4-linked HSP and ascertain the influence of microtubule-targeted drugs on the early axonal phenotype in a mouse model of the disease.

  14. Optogenetically enhanced axon regeneration: motor versus sensory neuron-specific stimulation.

    Science.gov (United States)

    Ward, Patricia J; Clanton, Scott L; English, Arthur W

    2018-02-01

    Brief neuronal activation in injured peripheral nerves is both necessary and sufficient to enhance motor axon regeneration, and this effect is specific to the activated motoneurons. It is less clear whether sensory neurons respond in a similar manner to neuronal activation following peripheral axotomy. Further, it is unknown to what extent enhancement of axon regeneration with increased neuronal activity relies on a reflexive interaction within the spinal circuitry. We used mouse genetics and optical tools to evaluate the precision and selectivity of system-specific neuronal activation to enhance axon regeneration in a mixed nerve. We evaluated sensory and motor axon regeneration in two different mouse models expressing the light-sensitive cation channel, channelrhodopsin (ChR2). We selectively activated either sensory or motor axons using light stimulation combined with transection and repair of the sciatic nerve. Regardless of genotype, the number of ChR2-positive neurons whose axons had regenerated successfully was greater following system-specific optical treatment, with no effect on the number of ChR2-negative neurons (whether motor or sensory neurons). We conclude that acute system-specific neuronal activation is sufficient to enhance both motor and sensory axon regeneration. This regeneration-enhancing effect is likely cell autonomous. © 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  15. The Drosophila HEM-2/NAP1 homolog KETTE controls axonal pathfinding and cytoskeletal organization.

    Science.gov (United States)

    Hummel, T; Leifker, K; Klämbt, C

    2000-04-01

    In Drosophila, the correct formation of the segmental commissures depends on neuron-glial interactions at the midline. The VUM midline neurons extend axons along which glial cells migrate in between anterior and posterior commissures. Here, we show that the gene kette is required for the normal projection of the VUM axons and subsequently disrupts glial migration. Axonal projection defects are also found for many other moto- and interneurons. In addition, kette affects the cell morphology of mesodermal and epidermal derivatives, which show an abnormal actin cytoskeleton. The KETTE protein is homologous to the transmembrane protein HEM-2/NAP1 evolutionary conserved from worms to vertebrates. In vitro analysis has shown a specific interaction of the vertebrate HEM-2/NAP1 with the SH2-SH3 adapter protein NCK and the small GTPase RAC1, which both have been implicated in regulating cytoskeleton organization and axonal growth. Hypomorphic kette mutations lead to axonal defects similar to mutations in the Drosophila NCK homolog dreadlocks. Furthermore, we show that kette and dock mutants genetically interact. NCK is thought to interact with the small G proteins RAC1 and CDC42, which play a role in axonal growth. In line with these observations, a kette phenocopy can be obtained following directed expression of mutant DCDC42 or DRAC1 in the CNS midline. In addition, the kette mutant phenotype can be partially rescued by expression of an activated DRAC1 transgene. Our data suggest an important role of the HEM-2 protein in cytoskeletal organization during axonal pathfinding.

  16. The Influence of Glutamate on Axonal Compound Action Potential In Vitro.

    Science.gov (United States)

    Abouelela, Ahmed; Wieraszko, Andrzej

    2016-01-01

    Background  Our previous experiments demonstrated modulation of the amplitude of the axonal compound action potential (CAP) by electrical stimulation. To verify assumption that glutamate released from axons could be involved in this phenomenon, the modification of the axonal CAP induced by glutamate was investigated. Objectives  The major objective of this research is to verify the hypothesis that axonal activity would trigger the release of glutamate, which in turn would interact with specific axonal receptors modifying the amplitude of the action potential. Methods  Segments of the sciatic nerve were exposed to exogenous glutamate in vitro, and CAP was recorded before and after glutamate application. In some experiments, the release of radioactive glutamate analog from the sciatic nerve exposed to exogenous glutamate was also evaluated. Results  The glutamate-induced increase in CAP was blocked by different glutamate receptor antagonists. The effect of glutamate was not observed in Ca-free medium, and was blocked by antagonists of calcium channels. Exogenous glutamate, applied to the segments of sciatic nerve, induced the release of radioactive glutamate analog, demonstrating glutamate-induced glutamate release. Immunohistochemical examination revealed that axolemma contains components necessary for glutamatergic neurotransmission. Conclusion  The proteins of the axonal membrane can under the influence of electrical stimulation or exogenous glutamate change membrane permeability and ionic conductance, leading to a change in the amplitude of CAP. We suggest that increased axonal activity leads to the release of glutamate that results in changes in the amplitude of CAPs.

  17. Formas de integración de las empresas

    Directory of Open Access Journals (Sweden)

    Juan David Piñeros

    2007-10-01

    Full Text Available Este artículo presenta las diferentes formas de integración en las empresas como referencia para el estudio de los nuevos tipos de organizaciones económicas. Se ofrecen algunas razones que determinan la organización de las empresas recurriendo a los conceptos de la empresa de Coase, los costos de transacción, economías de escala y subaditividad de costos. Igualmente, se describen las distintas formas de integración como son la Integración Vertical, la Integración Horizontal y el Conglomerado analizando sus distintas formas de realización, y algunos aspectos económicos que guían a su adopción en las empresas

  18. The Microtubule Regulatory Protein Stathmin Is Required to Maintain the Integrity of Axonal Microtubules in Drosophila

    Science.gov (United States)

    Duncan, Jason E.; Lytle, Nikki K.; Zuniga, Alfredo; Goldstein, Lawrence S. B.

    2013-01-01

    Axonal transport, a form of long-distance, bi-directional intracellular transport that occurs between the cell body and synaptic terminal, is critical in maintaining the function and viability of neurons. We have identified a requirement for the stathmin (stai) gene in the maintenance of axonal microtubules and regulation of axonal transport in Drosophila . The stai gene encodes a cytosolic phosphoprotein that regulates microtubule dynamics by partitioning tubulin dimers between pools of soluble tubulin and polymerized microtubules, and by directly binding to microtubules and promoting depolymerization. Analysis of stai function in Drosophila , which has a single stai gene, circumvents potential complications with studies performed in vertebrate systems in which mutant phenotypes may be compensated by genetic redundancy of other members of the stai gene family. This has allowed us to identify an essential function for stai in the maintenance of the integrity of axonal microtubules. In addition to the severe disruption in the abundance and architecture of microtubules in the axons of stai mutant Drosophila , we also observe additional neurological phenotypes associated with loss of stai function including a posterior paralysis and tail-flip phenotype in third instar larvae, aberrant accumulation of transported membranous organelles in stai deficient axons, a progressive bang-sensitive response to mechanical stimulation reminiscent of the class of Drosophila mutants used to model human epileptic seizures, and a reduced adult lifespan. Reductions in the levels of Kinesin-1, the primary anterograde motor in axonal transport, enhance these phenotypes. Collectively, our results indicate that stai has an important role in neuronal function, likely through the maintenance of microtubule integrity in the axons of nerves of the peripheral nervous system necessary to support and sustain long-distance axonal transport. PMID:23840848

  19. Schwann cell transplantation improves reticulospinal axon growth and forelimb strength after severe cervical spinal cord contusion.

    Science.gov (United States)

    Schaal, S M; Kitay, B M; Cho, K S; Lo, T P; Barakat, D J; Marcillo, A E; Sanchez, A R; Andrade, C M; Pearse, D D

    2007-01-01

    Schwann cell (SC) implantation alone has been shown to promote the growth of propriospinal and sensory axons, but not long-tract descending axons, after thoracic spinal cord injury (SCI). In the current study, we examined if an axotomy close to the cell body of origin (so as to enhance the intrinsic growth response) could permit supraspinal axons to grow onto SC grafts. Adult female Fischer rats received a severe (C5) cervical contusion (1.1 mm displacement, 3 KDyn). At 1 week postinjury, 2 million SCs ex vivo transduced with lentiviral vector encoding enhanced green fluorescent protein (EGFP) were implanted within media into the injury epicenter; injury-only animals served as controls. Animals were tested weekly using the BBB score for 7 weeks postimplantation and received at end point tests for upper body strength: self-supported forelimb hanging, forearm grip force, and the incline plane. Following behavioral assessment, animals were anterogradely traced bilaterally from the reticular formation using BDA-Texas Red. Stereological quantification revealed a twofold increase in the numbers of preserved NeuN+ neurons rostral and caudal to the injury/graft site in SC implanted animals, corroborating previous reports of their neuroprotective efficacy. Examination of labeled reticulospinal axon growth revealed that while rarely an axon was present within the lesion site of injury-only controls, numerous reticulospinal axons had penetrated the SC implant/lesion milieu. This has not been observed following implantation of SCs alone into the injured thoracic spinal cord. Significant behavioral improvements over injury-only controls in upper limb strength, including an enhanced grip strength (a 296% increase) and an increased self-supported forelimb hanging, accompanied SC-mediated neuroprotection and reticulospinal axon growth. The current study further supports the neuroprotective efficacy of SC implants after SCI and demonstrates that SCs alone are capable of supporting

  20. Molecular Analysis of Sensory Axon Branching Unraveled a cGMP-Dependent Signaling Cascade

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    Alexandre Dumoulin

    2018-04-01

    Full Text Available Axonal branching is a key process in the establishment of circuit connectivity within the nervous system. Molecular-genetic studies have shown that a specific form of axonal branching—the bifurcation of sensory neurons at the transition zone between the peripheral and the central nervous system—is regulated by a cyclic guanosine monophosphate (cGMP-dependent signaling cascade which is composed of C-type natriuretic peptide (CNP, the receptor guanylyl cyclase Npr2, and cGMP-dependent protein kinase Iα (cGKIα. In the absence of any one of these components, neurons in dorsal root ganglia (DRG and cranial sensory ganglia no longer bifurcate, and instead turn in either an ascending or a descending direction. In contrast, collateral axonal branch formation which represents a second type of axonal branch formation is not affected by inactivation of CNP, Npr2, or cGKI. Whereas axon bifurcation was lost in mouse mutants deficient for components of CNP-induced cGMP formation; the absence of the cGMP-degrading enzyme phosphodiesterase 2A had no effect on axon bifurcation. Adult mice that lack sensory axon bifurcation due to the conditional inactivation of Npr2-mediated cGMP signaling in DRG neurons demonstrated an altered shape of sensory axon terminal fields in the spinal cord, indicating that elaborate compensatory mechanisms reorganize neuronal circuits in the absence of bifurcation. On a functional level, these mice showed impaired heat sensation and nociception induced by chemical irritants, whereas responses to cold sensation, mechanical stimulation, and motor coordination are normal. These data point to a critical role of axon bifurcation for the processing of acute pain perception.

  1. Trafficking of cholesterol from cell bodies to distal axons in Niemann Pick C1-deficient neurons.

    Science.gov (United States)

    Karten, Barbara; Vance, Dennis E; Campenot, Robert B; Vance, Jean E

    2003-02-07

    Niemann Pick type C (NPC) disease is a progressive neurodegenerative disorder. In cells lacking functional NPC1 protein, endocytosed cholesterol accumulates in late endosomes/lysosomes. We utilized primary neuronal cultures in which cell bodies and distal axons reside in separate compartments to investigate the requirement of NPC1 protein for transport of cholesterol from cell bodies to distal axons. We have recently observed that in NPC1-deficient neurons compared with wild-type neurons, cholesterol accumulates in cell bodies but is reduced in distal axons (Karten, B., Vance, D. E., Campenot, R. B., and Vance, J. E. (2002) J. Neurochem. 83, 1154-1163). We now show that NPC1 protein is expressed in both cell bodies and distal axons. In NPC1-deficient neurons, cholesterol delivered to cell bodies from low density lipoproteins (LDLs), high density lipoproteins, or cyclodextrin complexes was transported into axons in normal amounts, whereas transport of endogenously synthesized cholesterol was impaired. Inhibition of cholesterol synthesis with pravastatin in wild-type and NPC1-deficient neurons reduced axonal growth. However, LDLs restored a normal rate of growth to wild-type but not NPC1-deficient neurons treated with pravastatin. Thus, although LDL cholesterol is transported into axons of NPC1-deficient neurons, this source of cholesterol does not sustain normal axonal growth. Over the lifespan of NPC1-deficient neurons, these defects in cholesterol transport might be responsible for the observed altered distribution of cholesterol between cell bodies and axons and, consequently, might contribute to the neurological dysfunction in NPC disease.

  2. Molecular Analysis of Sensory Axon Branching Unraveled a cGMP-Dependent Signaling Cascade.

    Science.gov (United States)

    Dumoulin, Alexandre; Ter-Avetisyan, Gohar; Schmidt, Hannes; Rathjen, Fritz G

    2018-04-24

    Axonal branching is a key process in the establishment of circuit connectivity within the nervous system. Molecular-genetic studies have shown that a specific form of axonal branching—the bifurcation of sensory neurons at the transition zone between the peripheral and the central nervous system—is regulated by a cyclic guanosine monophosphate (cGMP)-dependent signaling cascade which is composed of C-type natriuretic peptide (CNP), the receptor guanylyl cyclase Npr2, and cGMP-dependent protein kinase Iα (cGKIα). In the absence of any one of these components, neurons in dorsal root ganglia (DRG) and cranial sensory ganglia no longer bifurcate, and instead turn in either an ascending or a descending direction. In contrast, collateral axonal branch formation which represents a second type of axonal branch formation is not affected by inactivation of CNP, Npr2, or cGKI. Whereas axon bifurcation was lost in mouse mutants deficient for components of CNP-induced cGMP formation; the absence of the cGMP-degrading enzyme phosphodiesterase 2A had no effect on axon bifurcation. Adult mice that lack sensory axon bifurcation due to the conditional inactivation of Npr2-mediated cGMP signaling in DRG neurons demonstrated an altered shape of sensory axon terminal fields in the spinal cord, indicating that elaborate compensatory mechanisms reorganize neuronal circuits in the absence of bifurcation. On a functional level, these mice showed impaired heat sensation and nociception induced by chemical irritants, whereas responses to cold sensation, mechanical stimulation, and motor coordination are normal. These data point to a critical role of axon bifurcation for the processing of acute pain perception.

  3. Aspectos gerais da formação de professores

    Directory of Open Access Journals (Sweden)

    Edson do Carmo Inforsato

    1996-08-01

    Full Text Available Este artigo, ancorado em estudos recentes e antigos, mostra o afastamento dos cursos de formação de professores em relação aos elementos que compõem a prática profissional docente. Favorável a uma aproximação efetiva com o contexto das práticas de sala de aula, o autor defende a idéia de uma formação de professores atrelada aos problemas e necessidades da prática docente no ensino formal de 1º e 2º graus.

  4. Nuevas formas de interactividad en videojuegos: los cascos EEG

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    Aniorte Llanes, Carlos

    2017-01-01

    Los videojuegos actuales cada vez nos ofrecen más formas y más variadas de interaccionar con ellos. La exploración de nuevos medios de interactividad en videojuegos amplia las perspectivas de juego y su aplicación. Por ello, este trabajo propone investigar estas nuevas formas de obtener entradas para la interacción, en concreto, las posibilidades de controlar los juegos mediante las ondas cerebrales. El público de este videojuego se centraría en personas que tienen un estado cognitivo normal,...

  5. Current Opportunities for Clinical Monitoring of Axonal Pathology in Traumatic Brain Injury

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    Parmenion P. Tsitsopoulos

    2017-11-01

    Full Text Available Traumatic brain injury (TBI is a multidimensional and highly complex disease commonly resulting in widespread injury to axons, due to rapid inertial acceleration/deceleration forces transmitted to the brain during impact. Axonal injury leads to brain network dysfunction, significantly contributing to cognitive and functional impairments frequently observed in TBI survivors. Diffuse axonal injury (DAI is a clinical entity suggested by impaired level of consciousness and coma on clinical examination and characterized by widespread injury to the hemispheric white matter tracts, the corpus callosum and the brain stem. The clinical course of DAI is commonly unpredictable and it remains a challenging entity with limited therapeutic options, to date. Although axonal integrity may be disrupted at impact, the majority of axonal pathology evolves over time, resulting from delayed activation of complex intracellular biochemical cascades. Activation of these secondary biochemical pathways may lead to axonal transection, named secondary axotomy, and be responsible for the clinical decline of DAI patients. Advances in the neurocritical care of TBI patients have been achieved by refinements in multimodality monitoring for prevention and early detection of secondary injury factors, which can be applied also to DAI. There is an emerging role for biomarkers in blood, cerebrospinal fluid, and interstitial fluid using microdialysis in the evaluation of axonal injury in TBI. These biomarker studies have assessed various axonal and neuroglial markers as well as inflammatory mediators, such as cytokines and chemokines. Moreover, modern neuroimaging can detect subtle or overt DAI/white matter changes in diffuse TBI patients across all injury severities using magnetic resonance spectroscopy, diffusion tensor imaging, and positron emission tomography. Importantly, serial neuroimaging studies provide evidence for evolving axonal injury. Since axonal injury may be a key

  6. Axonal degeneration stimulates the formation of NG2+ cells and oligodendrocytes in the mouse

    DEFF Research Database (Denmark)

    Nielsen, Helle Hvilsted; Ladeby, Rune; Drøjdahl, Nina

    2006-01-01

    the response of the NG2+ cells to the different components of demyelinating pathology, we investigated the response of adult NG2+ cells to axonal degeneration in the absence of primary myelin or oligodendrocyte pathology. Axonal degeneration was induced in the hippocampal dentate gyrus of adult mice...... by transection of the entorhino-dentate perforant path projection. The acutely induced degeneration of axons and terminals resulted in a prompt response of NG2+ cells, consisting of morphological transformation, cellular proliferation, and upregulation of NG2 expression days 2-3 after surgery. This was followed...

  7. Diffuse axonal injury: detection of changes in anisotropy of water diffusion by diffusion-weighted imaging

    International Nuclear Information System (INIS)

    Chan, J.H.M.; Tsui, E.Y.K.; Yuen, M.K.; Peh, W.C.G.; Fong, D.; Fok, K.F.; Leung, K.M.; Fung, K.K.L.

    2003-01-01

    Myelinated axons of white matter demonstrate prominent directional differences in water diffusion. We performed diffusion-weighted imaging on ten patients with head injury to explore the feasibility of using water diffusion anisotropy for quantitating diffuse axonal injury. We showed significant decrease in diffusion anisotropy indices in areas with or without signal abnormality on T2 and T2*-weighted images. We conclude that the water diffusion anisotropy index a potentially useful, sensitive and quantitative way of diagnosing and assessing patients with diffuse axonal injury. (orig.)

  8. Injuria renal aguda en la sepsis grave Acute kidney injury in severe sepsis

    Directory of Open Access Journals (Sweden)

    Hernán Trimarchi

    2009-06-01

    Full Text Available La sepsis afecta al 40% de los pacientes críticos, siendo su mortalidad de aproximadamente un 30% en el caso de la sepsis grave, y de 75% con injuria renal aguda, la cual sucede en el 20-51% de los casos. Se realizó un estudio prospectivo, observacional, longitudinal, en 80 pacientes sépticos graves en el lapso de 1 año para determinar el desarrollo de injuria renal aguda y su relación con la mortalidad; correlacionar antecedentes clínicos y variaciones del laboratorio con la mortalidad; determinar la tasa de mortalidad de la sepsis grave; relacionar óbito y foco séptico primario; evaluar la predictibilidad de mortalidad según niveles de creatinina de ingreso y sus variaciones finales. Se definieron dos grupos: Obito (n = 25 y No-óbito (n = 55. Analizados según la creatinina de ingreso, 39 tenían valores normales de creatinina (10 óbitos y 41 la presentaban elevada (15 óbitos; según la creatinina de egreso, 48 presentaron creatinina normal y fallecieron 7, mientras que 32 tenían daño renal agudo, de los cuales 18 fallecieron. De los 25 pacientes fallecidos, el 72% presentaron daño renal. De éstos, 7 pacientes vivos y 2 fallecidos requirieron hemodiálisis. El foco primario más frecuente fue el respiratorio (26.4%. El desarrollo de daño renal es un alto predictor de mortalidad en la sepsis, independientemente de los valores iniciales de creatinina. Edad más avanzada, hipertensión arterial, score APACHE más elevado, anemia más grave, hipoalbuminemia, hiperfosfatemia e hiperkalemia se asociaron a mayor mortalidad. La mortalidad global fue 31.3%. La imposibilidad de identificar el foco séptico primario se asoció a mayor mortalidad. El foco respiratorio se relacionó a mayor riesgo de requerir hemodiálisis.Sepsis affects 40% of critically ill patients, with a reported mortality of approximately 30% in severe sepsis, raising to 75% when acute kidney injury ensues, which occurs in about 20-51% of cases. The present study

  9. Neurocisticercose: formas clínicas pouco frequentes. II - formas do ângulo pontocerebelar

    Directory of Open Access Journals (Sweden)

    Horácio M. Canelas

    1962-06-01

    Full Text Available A localização de cisticercos no recesso lateral da cisterna pontina poderá levar à constituição de uma síndrome do ângulo pontocerebelar, simulando eventualmente um neurinoma do acústico. São revistos os casos dessa forma clínica de neurocisticercose descritos na literatura. O problema do diagnóstico diferencial com os tumores (neurinomas do acústico é discutido sob os pontos de vista clínico e radiológico. Os autores apresentam 7 casos de cisticercose do ângulo pontocerebelar. O diagnóstico etiológico foi estabelecido pela positividade da reação de fixação do complemento para cisticercose no liqüido cefalorraqueano em 5 casos e, em 2, pela cirurgia e/ou necropsia. Em todos os pacientes havia sintomas de lesão coclear, bilaterais em 2; lesão vestibular foi comprovada em 4 casos. Em 6 pacientes ocorreram sinais indicativos de lesão unilateral do nervo trigêmeo. Comprometimento do nervo facial foi observado em 4 casos. Existia faringoplegia em 3 casos e estrabismo interno em 2. Em 3 casos não foram observados sinais cerebelares, o que faria com que o diagnóstico propendesse para o de tumor do acústico, não fôssem outras características clínicas e subsidiárias. A síndrome de hipertensão intracraniana era nítida em 5 pacientes. Convulsões ocorreram em 2 casos. A propósito do resultado dos exames radiológicos, os autores salientam que, num dos casos, foi verificada amputação da ponta do rochedo ipsolateral à síndrome do ângulo pontocerebelar; outros comemorativos do caso levaram, porém, a rejeitar a hipótese de tumor (neurinoma do acústico, tendo a cirurgia comprovado o acêrto do diagnóstico clínico.

  10. Leucograma e proteínas de fase aguda de ruminantes domésticos sadios e enfermos

    OpenAIRE

    Simplicio, Kalina Maria de Medeiros Gomes [UNESP

    2011-01-01

    Foi avaliada a importância de proteínas de fase aguda (PFA) como biomarcadores de enfermidades em ruminantes domésticos. Para tal se determinou o proteinograma sérico e leucograma de 15 bovinos sadios e 15 doentes, 15 ovinos sadios e 15 doentes, e 15 caprinos sadios e 15 doentes. Todos foram submetidos a colheitas diárias de sangue durante sete dias, enquanto permaneciam internados no Hospital Veterinário da FCAV-UNESP, Câmpus de Jaboticabal. Em bovinos a haptoglobina teve destaque como bioma...

  11. Guía para la práctica clínica de las enfermedades diarreicas agudas

    OpenAIRE

    Freijoso Santiesteban, Elsie; Cires Pujol, María Miriam; Silva Herrera, Lázaro; Delgado Martínez, Ibis; Riverón Corteguera, Raúl; Ramírez, Margarita

    2003-01-01

    Se presenta una guía para la práctica clínica de las enfermedades diarreicas agudas (EDA), cuyo objetivo principal es el de establecer recomendaciones para el manejo terapéutico de pacientes con EDA. En la misma se abordan las definiciones y causas de las EDA, los objetivos del tratamiento, la evaluación del paciente con diarreas y las características clínico epidemiológicas, así como las consideraciones terapéuticas y tratamientos para las diarreas causadas por diferentes microorganismos.A c...

  12. Infección respiratoria aguda en niños que acuden a un centro de desarrollo infantil

    Directory of Open Access Journals (Sweden)

    Nandí-Lozano Eugenia

    2002-01-01

    Full Text Available Objetivo. Establecer la incidencia de infección respiratoria y los patrones de colonización faríngea en niños que asisten a guarderías. Material y métodos. Se realizó un estudio de cohorte en niños menores de cuatro años de edad, de uno u otro sexo, asistentes a la guardería del Hospital Infantil de México Federico Gómez, de la Ciudad de México, durante abril a octubre de 1999. Se registró la presencia de infección de vías aéreas superiores cada semana, y de colonización cada tres meses, mediante un exudado nasofaríngeo. Se hizo estadística descriptiva de las variables analizadas. Se determinaron tasas de infección respiratoria aguda. Resultados. Se estudiaron 85 niños, 40 del sexo femenino (47% y 45 del sexo masculino (53% durante un total de 9 090 niños/día de seguimiento. Tres niños tenían antecedentes de atopia (3.52%, seis niños antecedentes de asma (7.05%, y 39 eran expuestos a tabaquismo pasivo (45.88%. Se diagnosticaron 246 rinofaringitis (95.3%, nueve otitis media aguda (3.48%, tres bronquiolitis (1.16%, para un total de 258 eventos de infección respiratoria aguda. La tasa de incidencia global fue de 10.35 infecciones por niño/año de observación (IC 95% 8.7-12.0. La incidencia de otitis y bronquiolitis fue de 0.36 y 0.12 eventos por niño/año de observación. Se tomaron cultivos nasofaríngeos con una prevalencia de colonización para S. pneumoniae de 20.4%, H. influenzae no tipificable 13.1% y Moraxella catarrhalis 8.1%. Conclusiones. Los resultados no sólo demuestran una alta prevalencia de colonización debido a cepas invasivas, sino que también revelan una tasa de incidencia de infección respiratoria aguda del doble de lo reportado en estudios de comunidad. Estos resultados ayudan a caracterizar un problema pobremente documentado en nuestro país.

  13. Consenso intersociedades para el manejo de infecciones respiratorias: bronquitis aguda y enfermedad pulmonar obstructiva crónica

    OpenAIRE

    Gustavo Lopardo; Claudia Pensotti; Pablo Scapellato; Oscar Caberlotto; Aníbal Calmaggi; Liliana Clara; Manuel Klein; Gabriel Levy Hara; María J. López Furst; Analía Mykietiuk; Daniel Pryluka; Maria J. Rial; Claudia Vujacich; Diego Yahni

    2013-01-01

    La Sociedad Argentina de Infectología convocó a otras sociedades científicas para elaborar una guía práctica y actualizada para el manejo del tratamiento antibiótico de las bronquitis agudas (BA) y los episodios de reagudización de enfermedad pulmonar obstructiva crónica (EPOC), con el objetivo de promover el uso racional de los recursos diagnósticos y terapéuticos. La BA se caracteriza por la inflamación del árbol bronquial que afecta tanto a adultos como a niños sin enfermedades pulmonares ...

  14. Tratamiento quirúrgico de la diverticulitis aguda en la Comunidad Valenciana. Estudio multicéntrico.

    OpenAIRE

    Salvador Martínez, Antonio

    2015-01-01

    Diverticulitis aguda. Estado actual y controversias Este término representa un espectro de los cambios inflamatorios que van desde una inflamación local subclínica hasta la peritonitis generalizada con perforación libre. Su mecanismo de aparición gira alrededor de una perforación de un divertículo. El antiguo concepto de obstrucción luminal probablemente represente un hecho raro. El aumento de la presión intraluminal o las partículas espesadas de alimentos pueden erosionar la pared d...

  15. Características clínico epidemiologicas de los pacientes con Leucemia Aguda del Servicio de Hematologia del Hospital Almanzor Aguinaga Asenjo

    OpenAIRE

    Polo-Capuñay, Ana María; Universidad de San Martín de Porres; León-Seminario, Carlos Alberto; Universidad de San Martín de Porres; Pérez-Villena, Joan Flaubert; Universidad de San Martín de Porres; Yovera-Merino, Jhonny David; Universidad de San Martín de Porres; Barraza-Chavesta, Omar; Universidad de San Martín de Porres; Torres-Anaya, Victor; Universidad de San Martín de Porres; Diaz-Vélez., Cristian; Universidad de San Martín de Porres

    2014-01-01

    OBJETIVOIdentificar las características clínico-epidemiológicas de los pacientes con leucemia en el área de Hematología del H.A.A.A.MATERIAL Y MÉTODOEstudio retrospectivo, transversal y descriptivo. Se revisaron 55 historias clínicas de pacientes con diagnóstico de Leucemia Aguda, tomadas de la oficina de registro del HNAAA, durante el periodo de Enero 2005 a Marzo 2010.RESULTADOSEn el periodo de estudio, se diagnosticaron 142 casos de Leucemia, 105 (73.94%) correspondieron a Leucemia aguda. De...

  16. Colesterol y triglicéridos como marcadores bioquímicos del estado de la enfermedad del paciente con leucemia linfocítica aguda

    OpenAIRE

    Marco Guzmán; Miguel Sandoval

    2004-01-01

    Objetivo: Determinar la relación de los niveles séricos de colesterol y triglicéridos con el estado de respuesta al tratamiento quimioterápico de inducción de pacientes con leucemia linfocítica aguda. Material y Métodos: La muestra la conforman 25 pacientes de 2 a 18 años de edad, admitidos al Instituto de Enfermedades Neoplásicas con un diagnóstico reciente de leucemia linfocítica aguda; determinándose en ellos sus concentraciones séricas de colesterol total, colesterol-HDL, colesterol-LDL y...

  17. Aféresis en el tratamiento de pancreatitis aguda hipertrigliceridémica: Reporte de caso y revisión de la literatura

    OpenAIRE

    Zaragoza, José J.; Villa, Gianluca; Borbolla-Arizti, Juan Pablo; Salgado-Hernández, Turmalina; Cerón-Díaz, Ulises

    2015-01-01

    La hipertrigliceridemia severa está asociada con varias patologías incluyendo pancreatitis aguda. Las opciones de tratamiento para la pancreatitis aguda hipertrigliceridémica incluyen insulina, glucosa y heparina en infusión, así como muchos tipos de aféresis. Los pacientes se pueden beneficiar del uso temprano de recambio plasmático para reducir los niveles de lípidos en sangre. El tiempo de inicio y el tipo de terapia juegan un papel importante para conseguir los beneficios completos del pr...

  18. Nutrición parenteral total en una paciente gestante con pancreatitis aguda e hipertrigliceridemia por déficit de lipoproteín lipasa

    OpenAIRE

    Contreras-Bolívar, Victoria; González-Molero, Inmaculada; Valdivieso, Pedro; Olveira, Gabriel

    2015-01-01

    Presentamos un caso de pancreatitis aguda severa inducida por hipertrigliceridemia secundaria a déficit de lipoproteín lipasa (LPL) en una paciente gestante con diabetes gestacional, manejada inicialmente con dieta, siendo necesario posteriormente llevar a cabo medidas de soporte nutricional artificial: nutrición parenteral total. El déficit de LPL causa hipertrigliceridemia severa y, frecuentemente, pancreatitis aguda de repetición, situación de difícil manejo y de importante gravedad durant...

  19. Amigdalitis aguda recurrente bacteriana: Estudio prospectivo, comparativo y controlado de sus características clínicas y microbiológicas

    OpenAIRE

    Der M,Carolina; Iñiguez C,Rodrigo; Guzman D,Ana Maria; Jofré P,David; Iñiguez C,Armando; Labarca L,Jaime

    2007-01-01

    Introducción: La amigdalitis aguda recurrente es una patología de frecuente consulta, es una de las indicaciones de amigdalectomía. No se sabe con exactitud el origen de esta patología. Objetivo: Identificar la microbiología y patrones de susceptibilidad de las bacterias en la amigdalitis aguda recurrente bacteriana (AARB) a los antimicrobianos más comúnmente en el medio nacional, usados en su tratamiento. Material y método: Se planificó un estudio prospectivo, controlado y ciego. Se evaluaro...

  20. Glomerulonefritis aguda post-infecciosa asociada a neumonía neumocócica Acute post infectious glomerulonephritis associated to pneumococcal pneumonia

    OpenAIRE

    S. Fernández de Miguel; E. de Goicoechea Manzanares; M. Gaboli; J.M. Sánchez Granados; V. Murga Herrera

    2009-01-01

    Presentamos un niño de 6 años con insuficiencia renal aguda secundaria a glomerulonefritis asociada a neumonía neumocócica. El paciente presentó en primer lugar un síndrome nefrítico con hematuria, proteinuria, oliguria, edemas y deterioro de la función renal, siendo diagnosticado a continuación de neumonía con derrame pleural. La función renal se normalizó tras 72 horas, persistiendo una hipertensión arterial que precisó tratamiento en la fase aguda. El cuadro se resolvió sin secue...

  1. Efecto de los inotrópicos sobre la mortalidad en falla cardiaca aguda. Metaanálisis en red de ensayos clínicos

    OpenAIRE

    Juan M. Sénior; Edison Muñoz; James Díaz

    2017-01-01

    Introducción: en pacientes con falla cardiaca aguda es necesario el uso de inotrópicos para lograr su estabilización. Objetivo: definir cuál de los medicamentos inotrópicos se asocia con menor mortalidad. Metodología: se realizó un metaanálisis en red con la aproximación frecuentista. La búsqueda sistemática incluyó PUBMED, EMBASE, CENTRAL, DARE, Epistemonikos, SieELO, LILACS y OpenGray. Se incluyeron ensayos clínicos con asignación aleatoria en pacientes con falla cardiaca aguda que re...

  2. Apendicitis aguda en el paciente senil: Factores asociados a una mayor morbimortalidad post operatoria

    Directory of Open Access Journals (Sweden)

    Víctor Eduardo Chian Chang

    1996-04-01

    Full Text Available Objetivo: Definir los factores asociados a una mayor morbilidad y mortalidad en pacientes seniles con apendicitis aguda. Material y métodos: Se realizó un estudio retrospectivo con 100 pacientes intervenidos en el Hospital Nacional Arzobispo Loayza, durante el período comprendido entre 1984 a 1994. Resultados: Se asociaron a una mayor frecuencia de complicaciones postoperatorias: edad mayor o igual a 70 años, tiempo de enfermedad mayor de 48 horas, presencia de apendicitis perforada con peritonitis localizada o generalizada (p<0.05. Además la presencia de apendicitis perforada se asoció significativamente a la presencia de absceso residual y/o fístula estercorácea (p=0.027 y la presencia de AA gangrenosa o perforada a mayor frecuencia de infección de herida operatoria (p<0.05. El antecedente de patología cardiovascular previa se asoció a mayor frecuencia de complicaciones cardiovasculares (p<0.05. Se asociaron a mayor mortalidad en AA, pacientes con intervención quirúrgica adicional a la apendicetomía (p=0.016 y presencia de AA perforada (p=0.027. Conclusiones: Los estadios avanzados de AA, así como la presencia de problema cardiovascular al momento del diagnóstico se asociaron con una mayor frecuencia de complicaciones post-operatorias. La presencia de peritonitis se asocia con la mortalidad. (Rev Med Hered 1996; 7: 62-67.

  3. Infecciones respiratorias agudas y factores asociados Acute respiratory infections and associated factors

    Directory of Open Access Journals (Sweden)

    Rogelio León López

    2005-12-01

    Full Text Available Se realizó un estudio descriptivo y retrospectivo con la finalidad de conocer la relación entre las infecciones respiratorias agudas con algunos factores asociados seleccionados en lactantes, durante el trienio 2001-2003, en el área de salud del Policlínico Docente “30 de Noviembre”, del municipio 10 de Octubre. La incidencia de estas enfermedades en el mencionado período fue de 933 x 1 000. Se encontró que la mayoría de los infantes exhibió un adecuado estado inmunológico y nutricional, así como también que no tenían historia de alergia respiratoria. La institucionalización de estos niños no influyó en la aparición de estas enfermedades, y el tratamiento que predominó fue el sintomático.A descriptive and retrospective study was conducted to know the relation between acute respiratory infections and some associated factors selected in infants from the health area of “30 de Noviembre” Teaching Polyclinic, in “10 de Octubre” municipality, between 2001 and 2003. The incidence of these diseases in the above period was 933 x 1000. It was observed that most of the infants had an adequate immunological and nutritional state, and that they did not have any history of respiratory allergy. The institutionalization of these children did not influence on the appearance of these diseases. There was a predominance of the symptomatic treatment.

  4. INSUFICIENCIA RENAL AGUDA EN EL ANCIANO. CONSIDERACIONES ACERCA DE SU VALORACIÓN Y TRATAMIENTO.

    Directory of Open Access Journals (Sweden)

    Musso CG

    2005-02-01

    Full Text Available RESUMEN:La insuficiencia renal aguda (IRA es un trastorno frecuente en los ancianos a raíz de la senescencia renal, la menor metabolización de los fármacos y la mayor exposición a la polifarmacia y enfermedades sistémicas que ellos padecen. Las siguientes son las principales características de la IRA en el anciano: carácter multifactorial, presentación clínica atípica, fragilidad tubular, patrón de síndrome intermedio y poca fiabilidad del examen físico y de los índices urinarios en la interpretación de su etiología. Las medidas de profilaxis y rehidratación siguen siendo los mejores tratamientos de la IRA en el viejo. La biopsia renal y la diálisis tienen el mismo rol tanto en el grupo senil como en el joven.ABSTRACTACUTE RENAL FAILURE IN THE ELDERLY: PEARLS FOR ITS ASSESSMENT AND TREATMENT.Acute renal failure (ARF is a frequent disorder in the elderly, and this phenomenon is due to the senescence process, reduced metabolization of drugs, increased exposure to polypharmacy and systemic diseases of the aged group. The following are the main characteristics of the ARF in the elderly: mulfactorial, atypical presentation, tubular frailty, intermediate syndrome pattern, low reliable physical examination and urinary indeces. Profilaxis and rehydration are the best treatments for ARF in the old population. Renal biopsy and dialysis have the same role in young and old people.

  5. A sepse como causa de lesão renal aguda: modelo experimental

    Directory of Open Access Journals (Sweden)

    Carolina Ferreira Pinto

    2012-10-01

    Full Text Available A sepse associada à falência de múltiplos órgãos como a lesão renal aguda (LRA demonstra alta taxa de mortalidade no paciente crítico. Este estudo investigou a LRA induzida pela sepse em modelo experimental. Foram utilizados ratos da raça Wistar, adultos e machos divididos nos seguintes grupos: Controle - controle cirúrgico e Sepse - indução da sepse pela ligadura e punção do cécon (LPC. Foram avaliados os parâmetros fisiológicos (temperatura retal, pressão arterial média - PAM, glicemia sérica e fluxo urinário; a função renal (clearance de creatinina; o estresse oxidativo (peróxidos urinários e substâncias reativas com ácido tiobarbitúrico - TBARS e realizada a análise histológica renal. O estudo conclui que a LRA induzida pela sepse caracteriza-se por lesão endotelial com disfunção hemodinâmica, liberação de mediadores inflamatórios e geração de espécies reativas de oxigênio (EROs por células tubulares, caracterizando-se como uma associação de vasoconstrição renal de origem hemodinâmica e inflamatória.

  6. Citarabina y reacciones cutáneas en leucemia aguda mieloide

    Directory of Open Access Journals (Sweden)

    Sofía Grille

    2013-12-01

    Full Text Available La citarabina es un antimetabolito utilizado en el tratamiento de las leucemias agudas mieloides (LAM. Esta droga presenta numerosos efectos adversos (mielosupresión, toxicidad en sistema nervioso central, hepática, gastrointestinal, ocular y cutánea. La toxicidad dermatológica es habitualmente descrita como rara, sin embargo existen diferencias en la incidencia comunicada. Se realizó un estudio retrospectivo donde se incluyeron todas las LAM tratadas con quimioterapia que incluía citarabina, entre el 1º de julio 2006 y el 1° de julio 2012. Se incluyeron 46 pacientes con una mediana de edad de 55 años. La incidencia global de reacciones cutáneas fue de 39% (n = 18. La presencia de lesiones cutáneas no se asoció con sexo, edad, antecedentes de atopía, de reacciones medicamentosas, tipo de LAM ni dosis de citarabina utilizada. Las lesiones se observaron entre 2 a 8 días de iniciado el tratamiento. En cuanto al grado lesional, 27.8% presentaron grado 1, 38.9% grado 2 y 33.3% grado 3. No existieron lesiones grado 4 ni muerte vinculada a toxicidad cutánea. En cuanto al tipo de lesiones, 55.6% se presentaban con máculas, 22.2% con pápulas y 22.2% con eritema. Con respecto a la distribución de las lesiones, 52% de los pacientes presentaron una distribución difusa, 39.3% acral y 8.7% a nivel flexural. Las reacciones adversas cutáneas con la administración de citarabina son frecuentes en nuestro medio, en algunos casos con afectación grave. Si bien suelen resolverse espontáneamente, pueden determinar mayor riesgo de infección, así como comprometer la calidad de vida.

  7. Actividad antiulcerosa y toxicidad aguda oral de celulosa microcristalina suspensión al 12 %

    Directory of Open Access Journals (Sweden)

    Pedro Gilberto Barzaga Fernández

    Full Text Available La celulosa microcristalina ha sido usada recientemente en el tratamiento de la gastritis alcalina por reflujo biliar duodenogástrico. Se realizó un estudio toxicológico y se evaluó el efecto antiulceroso de celulosa microcristalina suspensión al 12 % en ratas. La determinación de la toxicidad aguda oral se realizó mediante el ensayo de dosis límite, mediante la administración de una dosis de 2 000 mg/kg a animales de uno y otro sexos. El efecto protector sobre la mucosa gástrica se evaluó sobre lesiones inducidas por taurocolato de sodio y se ensayaron las dosis de 240, 360 y 540 mg/kg de la suspensión. Como resultado en el estudio toxicológico, no se produjo mortalidad para la dosis ensayada, por lo que se clasificó la sustancia como no tóxica. Mientras que las diferentes dosis empleadas para el efecto antiulceroso disminuyeron el número y la intensidad de las lesiones significativamente de manera dosis dependiente. La dosis efectiva media fue de 356,8 mg/kg. Tales hallazgos permiten sugerir que el efecto protector de celulosa microcristalina suspensión al 12 % podría estar dado por una inactivación de los ácidos biliares o por una alteración en la cantidad o composición de la capa de moco que recubre la mucosa gástrica.

  8. Enfermedad diarreica aguda por Escherichia coli patógenas en Colombia

    Science.gov (United States)

    Gómez-Duarte, Oscar G.

    2014-01-01

    Resumen Las cepas de E. coli patógenas intestinales son causas importantes de la enfermedad diarreica aguda (EDA) en niños menores de 5 años en América Latina, África y Asia y están asociadas a alta mortalidad en niños en las comunidades más pobres de África y el Sudeste Asiático. Estudios sobre el papel de las E. coli patógenas intestinales en la EDA infantil en Colombia y otros países de América Latina son limitados debido a la carencia de ensayos para detección de estos patógenos en los laboratorios clínicos de centros de salud. Estudios recientes han reportado la detección de E. coli patógenas intestinales en Colombia, siendo la E. coli enterotoxigénica la cepa más frecuentemente asociada a diarrea en niños menores de 5 años. Otros patógenos detectados en estos pacientes incluyen las E. coli enteroagregativa, enteropatógena, productora de toxina Shiga, y de adherencia difusa. Con base en estudios que reportan la presencia de E. coli productora de toxina Shiga y E. coli enteroagregativa en carnes y vegetales en supermercados, se cree que productos alimentarios contaminados contribuyen a la transmisión de estos patógenos y a la infección del huésped susceptible. Más estudios son necesarios para evaluar los mecanismos de transmisión, el impacto en la epidemiologia de la EDA, y las pautas de manejo y prevención de estos patógenos que afectan la población pediátrica en Colombia. PMID:25491457

  9. Injúria renal aguda: um alerta global Acute kidney injury: a global alert

    Directory of Open Access Journals (Sweden)

    Philip Kam Tao Li

    2013-03-01

    Full Text Available A Injúria Renal Aguda (IRA é cada vez mais prevalente nos países desenvolvidos e nos em desenvolvimento, e está associada com morbidade e mortalidade severas. A maioria das causas da IRA pode ser evitada por meio de intervenções em nível individual, comunitário, regional e intra-hospitalar. Medidas efetivas devem incluir, em toda a comunidade, os esforços para aumentar a consciência dos efeitos devastadores do IRA e fornecer orientações sobre as estratégias de prevenção, bem como o reconhecimento e tratamento precoces. Os esforços devem ser focados em minimizar as causas de IRA, aumentando a consciência da importância de medidas seriadas de creatinina sérica em pacientes de alto risco para IRA, e documentar o volume de urina em pessoas gravemente doentes para obtenção de diagnóstico precoce; até o momento, não há ainda um papel definitivo para outros biomarcadores. Há a necessidade de protocolos para sistematizar a conduta em condições de IRA pré-renal e em infecções específicas. Dados mais precisos sobre a verdadeira incidência e o impacto clínico da IRA ajudarão a melhor conhecer a importância desta doença, a aumentar o conhecimento de IRA por parte dos governantes, dos médicos em geral e de outros profissionais de saúde para ajudar na prevenção da doença. A prevenção é a chave para evitar a pesado ônus de mortalidade e morbidade associada com IRA.

  10. Injuria renal aguda, perfil epidemiológico intrahospitalario y factores asociados al riesgo de muerte

    Directory of Open Access Journals (Sweden)

    Cristian León

    2014-10-01

    Full Text Available La injuria renal aguda (IRA es un evento mórbido de gran impacto en la vida de las personas. La tasa de letalidad de la IRA ha sido un tema relevante y se han estudiado muchos factores relacionados. Objetivos: Determinar el perfil epidemiológico de los pacientes con IRA en un hospital de Lima y los factores asociados a la mortalidad durante el periodo de hospitalización. Material y métodos: Estudio descriptivo, retrospectivo de una cohorte de pacientes incidentes con diagnóstico de IRA. Se calculó la letalidad bruta y la ajustada a tiempo de permanencia hospitalaria. Se usó la regresión multivariante de Cox, así como el mejor modelo para regresión logística binaria asociada a letalidad. Se aceptó una significancia estadística de p<0,05. Resultados: Se identificaron 90 pacientes con IRA en los años 2002, 2003 y 2004 (incidencia de 30, 39 y 21 pacientes/año, respectivamente. Su permanencia hospitalaria fue 13,44 ± 1,66 (promedio±1ES días, la tasa bruta de letalidad 39% y la tasa ajustada 2,89 fallecidos/100 días de hospitalización. Las variables relacionadas al riesgo de muerte en el tiempo fueron el estado de shock, el diagnóstico de sepsis y la disfunción respiratoria al momento de la admisión. Conclusiones: La gravedad clínica como condición al momento de la admisión al centro hospitalario, el estado séptico y la presencia de disfunción respiratoria, fueron los factores que influenciaron en el pronóstico de supervivencia de pacientes con IRA.

  11. Estudo longitudinal do eletrocardiograma na doença de Chagas desde a fase aguda

    Directory of Open Access Journals (Sweden)

    Roberto C. Pedrosa

    1993-09-01

    Full Text Available Vários trabalhos com eletrocardiograma na doença de Chagas têm sido feitos. Alguns referindo-se a grupos selecionados de casos, outros a estudos longitudinais, relatam as características da mortalidade nas diversas fases da doença. Com o objetivo de avaliar o valor do eletrocardiograma como índice de avaliação terapêutica e de seu comportamento na doença de Chagas desde a fase aguda, no presente trabalho, analisou-se evolutivamente o eletrocardiograma de 42 pacientes (18 mulheres e 24 homens procedentes da zona rural do Norte de Minas Gerais; predomínio etário foi nas duas primeiras décadas; todos com comprometimento cardíaco; todos receberam tratamento específico. O acompanhamento dos 42 pacientes foi de 9 anos dos quais 3 pacientes tiveram seguimento de 20 anos. Foram analisados 270 eletrocardiogramas. Nós utilizamos os seguintes critérios para a análise do ECG: código de Minnesota modificado para doença de Chagas; WHO/I. S. F. C. TASK FORCE para condução intraventricular e critérios de Pieretti para área eletricamente inativa. Concluímos que as alterações eletrocardiográficas agravam com a evolução da doença e que o eletrocardiograma não serve de índice de avaliação terapêutica.

  12. Níveis de PCR são maiores em pacientes com síndrome coronariana aguda e supradesnivelamento do segmento ST do que em pacientes sem supradesnivelamento do segmento ST

    Directory of Open Access Journals (Sweden)

    Syed Shahid Habib

    2011-01-01

    Full Text Available FUNDAMENTO: Há grande interesse no uso de proteína C-reativa de alta sensibilidade (PCR-as para avaliação de risco. Altos níveis de PCR-as no início da síndrome coronária aguda (SCA, antes da necrose tecidual, pode ser um marcador substituto para comorbidades cardiovasculares. OBJETIVO: Dessa forma, nosso objetivo foi estudar diferentes medidas de seguimento de níveis de PCR-as em pacientes com SCA e comparar as diferenças entre infarto do miocárdio sem elevação do segmento ST (NSTEMI com pacientes apresentando elevação do segmento ST (STEMI. MÉTODOS: Este é um estudo observacional. Dos 89 pacientes recrutados, 60 apresentavam infarto agudo do miocárdio (IAM. Três níveis seriados de PCR-us, a nível basal na hospitalização antes de 12 horas após inicio dos sintomas, níveis de pico 36-48 horas após hospitalização e níveis de acompanhamento após 4 a 6 semanas foram analisados e comparados entre pacientes com (IAMCSST e sem supradesnivelamento do segmento ST (IAMSSST. RESULTADOS: Pacientes com IAMCSST tinham IMC significantemente mais alta quando comparados com pacientes IAMSSST. Os níveis de creatino quinase fração MB (CK-MB e aspartato aminotransferase (AST eram significantemente mais altos em pacientes com IAMCSST quando comparados com pacientes com IAMSSST (p<0,05. Os níveis de PCR a nível basal e no acompanhamento não diferiram de forma significante entre os dois grupos (p=0,2152 e p=0,4686 respectivamente. Houve uma diferença significante nos níveis de pico de PCR entre os dois grupos. No grupo de pacientes com IAMCSST os níveis foram significantemente mais altos quando comparados aos pacientes com IAMSSST (p=0,0464. CONCLUSÃO: Pacientes com IAMCSST apresentam picos significantemente mais elevados de PCR quando comparados a pacientes IAMSSST. Esses dados sugerem que o processo inflamatório tem um papel independente na patogênese do infarto do miocárdio. Dessa forma, os níveis de PCR podem ajudar na

  13. Nuevas formas de hacer, nuevas formas de ser: las tecnologías digitales como agentes dinamizadores del aprendizaje informal

    OpenAIRE

    López Gil, Mónica María

    2014-01-01

    Entre los cambios sufridos durante los últimos años, destacamos la revolución tecnológica. Es innegable que en la actualidad vivimos una utilización masiva de herramientas electrónicas que han transformado, y siguen transformando, nuestras maneras de comunicarnos, nos entretenemos, usamos nuestro tiempo Suoronta (2003), nos formamos o trabajamos. Siendo así, por tanto, se están demandando nuevas formas de saber y de saber hacer así como se están creando nuevas formas de ser y hacer (Delors, 1...

  14. Effector profiles distinguish formae speciales of Fusarium oxysporum.

    Science.gov (United States)

    van Dam, Peter; Fokkens, Like; Schmidt, Sarah M; Linmans, Jasper H J; Kistler, H Corby; Ma, Li-Jun; Rep, Martijn

    2016-11-01

    Formae speciales (ff.spp.) of the fungus Fusarium oxysporum are often polyphyletic within the species complex, making it impossible to identify them on the basis of conserved genes. However, sequences that determine host-specific pathogenicity may be expected to be similar between strains within the same forma specialis. Whole genome sequencing was performed on strains from five different ff.spp. (cucumerinum, niveum, melonis, radicis-cucumerinum and lycopersici). In each genome, genes for putative effectors were identified based on small size, secretion signal, and vicinity to a "miniature impala" transposable element. The candidate effector genes of all genomes were collected and the presence/absence patterns in each individual genome were clustered. Members of the same forma specialis turned out to group together, with cucurbit-infecting strains forming a supercluster separate from other ff.spp. Moreover, strains from different clonal lineages within the same forma specialis harbour identical effector gene sequences, supporting horizontal transfer of genetic material. These data offer new insight into the genetic basis of host specificity in the F. oxysporum species complex and show that (putative) effectors can be used to predict host specificity in F. oxysporum. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  15. A Pro-Forma approach to Car-Carrier Design

    CSIR Research Space (South Africa)

    Benade, R

    2016-11-01

    Full Text Available In this work a pro-forma approach is developed for assessing truck and centre-axle tag-trailer or 50/50 car-carrier designs in terms of their compliance with the South African Performance-Based Standards (PBS) pilot project requirements. First...

  16. Invariante absolutos en la forma cuadrática ternaria

    OpenAIRE

    Greiff Bravo, Luis de

    2012-01-01

    Antes de analizar los invariantes absolutos en la forma cuadrática ternaria, de tan grande importancia en Geometría analítica, conviene revisar las propiedades principales de la sustitución lineal ortogonal de coordenadas.

  17. 17 CFR 210.8-05 - Pro forma financial information.

    Science.gov (United States)

    2010-04-01

    ... information showing the effects of the acquisition shall be furnished if financial statements of a business... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Pro forma financial information. 210.8-05 Section 210.8-05 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION...

  18. Relação entre forma e vazio, com fantasia e imaginação : o vazio é forma, a forma é vazio : experiências fora e dentro da sala de aula

    OpenAIRE

    Guerra, Manuel Pereira Rodrigues

    2011-01-01

    Este trabalho Cria e Recria a Forma e Vazio com Fantasia e Imaginação,apresentando uma forte ligação entre a Forma e Vazio. Considerando mesmo,que o vazio é forma e a forma é vazio,por outro lado, é no vazio que as formas acontecem. Além das experiências que foram desenvolvidas individualmente, também trabalhei conjuntamente em grupos com os alunos. Este trabalho ajudou a uma boa cooperação entre o professor e os alunos. Estas experiências demonstram, que os pedagogos, os professores devem da...

  19. Correlación de la t(9;22, t(12;21 e hiperdiploidía de ADN con el inmunofenotipo y la tasa de proliferación de células B neoplásicas en niños con leucemia linfoblástica aguda de precursores B

    Directory of Open Access Journals (Sweden)

    Sandra Milena Quijano

    2013-09-01

    Full Text Available Introducción. Del 60 al 80 % de los pacientes con leucemia linfoblástica aguda de precursores B presentan alteraciones genéticas que influyen en el pronóstico de la enfermedad y en la biología del tumor. Objetivo. Analizar distintas alteraciones genéticas en leucemia linfoblástica aguda de precursores B en niños, y su relación con el inmunofenotipo y con la tasa de proliferación, en comparación con precursores B normales. Materiales y métodos. En 44 pacientes se evaluó, por citometría de flujo, el inmunofenotipo, el contenido de ADN y la proliferación, y por RT-PCR, las traslocaciones t(9;22, t(12;21, t(4;11 y t(1;19. Mediante un análisis jerarquizado de conglomerados se identificaron los patrones inmunofenotípicosde expresión asociados a las traslocaciones, tomando como referencia precursores B normales. Resultados. La cuantificación del ADN mostró que el 21 % de los casos de leucemia linfoblástica aguda de precursores B eran hiperdiploides de índice alto y, el 47,7 %, hiperdiploides de índice bajo. La presencia de hiperdiploidía se asoció con mayor proliferación tumoral y con inmunofenotipos aberrantes, que incluyeron expresión anormal de CD10, TdT, CD38 y CD45 y un mayor tamaño de los linfoblastos. La presencia de t(9;22 y t(12;21 discrimina células normales de células tumorales con aberraciones en la expresión de CD19, CD20, CD13, CD33, CD38, CD34 y CD45. Conclusiones. El perfil de aberraciones fenotípicas detectado en conjunto con anormalidades en la proliferación tumoral, se asocia de forma significativa con hiperdiploidiía de ADN y discrimina deforma clara linfoblastos con t(9;22 y t(12;21 de los precursores B normales. La identificación de estos parámetros será de gran utilidad como herramienta para la clasificación y seguimiento de lospacientes.   doi: http://dx.doi.org/10.7705/biomedica.v33i3.1441

  20. Precise Somatotopic Thalamocortical Axon Guidance Depends on LPA-Mediated PRG-2/Radixin Signaling

    DEFF Research Database (Denmark)

    Cheng, Jin; Sahani, Sadhna; Hausrat, Torben Johann

    2016-01-01

    Precise connection of thalamic barreloids with their corresponding cortical barrels is critical for processing of vibrissal sensory information. Here, we show that PRG-2, a phospholipid-interacting molecule, is important for thalamocortical axon guidance. Developing thalamocortical fibers both...

  1. In vivo electrophysiological measurement of the rat ulnar nerve with axonal excitability testing

    DEFF Research Database (Denmark)

    Wild, Brandon M.; Morris, Renée; Moldovan, Mihai

    2018-01-01

    Electrophysiology enables the objective assessment of peripheral nerve function in vivo. Traditional nerve conduction measures such as amplitude and latency detect chronic axon loss and demyelination, respectively. Axonal excitability techniques "by threshold tracking" expand upon these measures...... by providing information regarding the activity of ion channels, pumps and exchangers that relate to acute function and may precede degenerative events. As such, the use of axonal excitability in animal models of neurological disorders may provide a useful in vivo measure to assess novel therapeutic...... interventions. Here we describe an experimental setup for multiple measures of motor axonal excitability techniques in the rat ulnar nerve. The animals are anesthetized with isoflurane and carefully monitored to ensure constant and adequate depth of anesthesia. Body temperature, respiration rate, heart rate...

  2. Axonal plasticity elicits long-term changes in oligodendroglia and myelinated fibers

    DEFF Research Database (Denmark)

    Drøjdahl, Nina; Nielsen, Helle Hvilsted; Gardi, Jonathan E

    2010-01-01

    Axons are linked to induction of myelination during development and to the maintenance of myelin and myelinated tracts in the adult CNS. Currently, it is unknown whether and how axonal plasticity in adult CNS impacts the myelinating cells and their precursors. In this article, we report that newly...... formed axonal sprouts are able to induce a protracted myelination response in adult CNS. We show that newly formed axonal sprouts, induced by lesion of the entorhino-hippocampal perforant pathway, have the ability to induce a myelination response in stratum radiatum and lucidum CA3. The lesion resulted...... in significant recruitment of newly formed myelinating cells, documented by incorporation of the proliferation marker bromodeoxyuridine into chondroitin sulphate NG2 expressing cells in stratum radiatum and lucidum CA3 early after lesion, and the occurrence of a 28% increase in the number of oligodendrocytes...

  3. Organophosphate-Related Alterations in Myelin and Axonal Transport in the Living Mammalian Brain

    Science.gov (United States)

    2014-10-01

    stress, impairments of mitochondrial function, neuroinflammation, altered neurotrophin responses, etc. (reviewed, Soltaninejad and Abdollahi, 2009...Exposure to Chlorpyrifos in Rats: Protracted Effects on Axonal Transport, Neurotrophin Receptors, Cholinergic Markers, and Information Processing

  4. Organophosphate Related Alterations in Myelin and Axonal Transport in the Living Mammalian Brain

    Science.gov (United States)

    2015-10-01

    function, neuroinflammation, al- tered neurotrophin responses, etc. (reviewed, Soltaninejad and Abdollahi, 2009; Banks and Lein, 2012; Terry, 2012). Conflict...JN, Middlemore ML, Williamson LN, et al. Chronic, intermittent exposure to chlorpyrifos in rats: protracted effects on axonal transport, neurotrophin

  5. Effects of X-irradiation on axonal sprouting induced by botulinum toxin

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, S; Duchen, L W [National Hospital, London (UK); Hornsey, S [Hammersmith Hospital, London (UK). M.R.C. Cyclotron Unit

    1982-01-01

    The effect of X-irradiation on axonal sprouting of motor nerves induced by botulinum toxin was examined. Muscles of one leg in the mouse were X-irradiated (15Gy) prior to the injection of a locally paralysing dose of botulinum toxin. It was found that axonal sprouting occurred as expected, but the sprouts remained unmyelinated and many degenerated. Fewer new end-plates were formed, muscles remained more severely atrophied and supersensitive to acetylcholine and recovery of neuromuscular transmission was greatly delayed when compared with the effects of botulinum toxin alone. X-irradiation did not prevent sprouting but, probably by impairing Schwann cell proliferation, altered axon-Schwann cell relationships and prevented the maturation of newly-formed axons and the differentiation of new end-plates.

  6. BORC/kinesin-1 ensemble drives polarized transport of lysosomes into the axon.

    Science.gov (United States)

    Farías, Ginny G; Guardia, Carlos M; De Pace, Raffaella; Britt, Dylan J; Bonifacino, Juan S

    2017-04-04

    The ability of lysosomes to move within the cytoplasm is important for many cellular functions. This ability is particularly critical in neurons, which comprise vast, highly differentiated domains such as the axon and dendrites. The mechanisms that control lysosome movement in these domains, however, remain poorly understood. Here we show that an ensemble of BORC, Arl8, SKIP, and kinesin-1, previously shown to mediate centrifugal transport of lysosomes in nonneuronal cells, specifically drives lysosome transport into the axon, and not the dendrites, in cultured rat hippocampal neurons. This transport is essential for maintenance of axonal growth-cone dynamics and autophagosome turnover. Our findings illustrate how a general mechanism for lysosome dispersal in nonneuronal cells is adapted to drive polarized transport in neurons, and emphasize the importance of this mechanism for critical axonal processes.

  7. BORC/kinesin-1 ensemble drives polarized transport of lysosomes into the axon

    Science.gov (United States)

    Farías, Ginny G.; Guardia, Carlos M.; De Pace, Raffaella; Britt, Dylan J.; Bonifacino, Juan S.

    2017-01-01

    The ability of lysosomes to move within the cytoplasm is important for many cellular functions. This ability is particularly critical in neurons, which comprise vast, highly differentiated domains such as the axon and dendrites. The mechanisms that control lysosome movement in these domains, however, remain poorly understood. Here we show that an ensemble of BORC, Arl8, SKIP, and kinesin-1, previously shown to mediate centrifugal transport of lysosomes in nonneuronal cells, specifically drives lysosome transport into the axon, and not the dendrites, in cultured rat hippocampal neurons. This transport is essential for maintenance of axonal growth-cone dynamics and autophagosome turnover. Our findings illustrate how a general mechanism for lysosome dispersal in nonneuronal cells is adapted to drive polarized transport in neurons, and emphasize the importance of this mechanism for critical axonal processes. PMID:28320970

  8. Sensory axon-derived neuregulin-1 is required for axoglial signaling and normal sensory function but not for long-term axon maintenance

    DEFF Research Database (Denmark)

    Fricker, F.R.; Zhu, N.; Tsantoulas, C.

    2009-01-01

    " pockets. The total number of axons in the sural nerve was unchanged, but a greater proportion was unmyelinated. In addition, we observed large-diameter axons that were in a 1:1 relationship with Schwann cells, surrounded by a basal lamina but not myelinated. There was no evidence of DRG or Schwann cell...... death; the markers of different DRG cell populations and cutaneous innervation were unchanged. These anatomical changes were reflected in a slowing of conduction velocity at the lower end of the A-fiber conduction velocity range and a new population of more rapidly conducting C-fibers that are likely...

  9. Developmental plasticity of ascending spinal axons studies using the North American opossum, Didelphis virginiana.

    Science.gov (United States)

    Terman, J R; Wang, X M; Martin, G F

    1999-01-11

    The objectives of the present study were to determine if axons of all ascending tracts grow through the lesion after transection of the thoracic spinal cord during development in the North American opossum, and if so, whether they reach regions of the brain they normally innervate. Opossum pups were subjected to transection of the mid-thoracic cord at PD5, PD8, PD12, PD20, or PD26 and injections of Fast Blue (FB) into the lower thoracic or upper lumbar cord 30-40 days or 6 months later. In the PD5 transected cases, labeled axons were present in all of the supraspinal areas labeled by comparable injections in unlesioned, age-matched controls. In the experimental cases, however, labeled axons appeared to be fewer in number and in some areas more restricted in location than in the controls. When lesions were made at PD8, labeled axons were present in the brain of animals allowed to survive 30-40 days prior to FB injections but they were not observed in those allowed to survive 6 months. When lesions were made at PD12 or later, labeled axons were never found rostral to the lesion. It appears, therefore, that axons of all ascending spinal pathways grow though the lesion after transection of the thoracic cord in developing opossums and that they innervate appropriate areas of the brain. Interestingly, the critical period for such growth is shorter than that for most descending axons, suggesting that factors which influence loss of developmental plasticity are not the same for all axons.

  10. Adenosine: an activity-dependent axonal signal regulating MAP kinase and proliferation in developing Schwann cells

    OpenAIRE

    Stevens, Beth; Ishibashi, Tomoko; Chen, Jiang-Fan; Fields, R. Douglas

    2004-01-01

    Nonsynaptic release of ATP from electrically stimulated dorsal root gangion (DRG) axons inhibits Schwann cell (SC) proliferation and arrests SC development at the premyelinating stage, but the specific types of purinergic receptor(s) and intracellular signaling pathways involved in this form of neuron–glia communication are not known. Recent research shows that adenosine is a neuron–glial transmitter between axons and myelinating glia of the CNS. The present study investigates the possibility...

  11. Selective axonal growth of embryonic hippocampal neurons according to topographic features of various sizes and shapes

    Directory of Open Access Journals (Sweden)

    Christine E Schmidt

    2010-12-01

    Full Text Available David Y Fozdar1*, Jae Y Lee2*, Christine E Schmidt2–6, Shaochen Chen1,3–5,7,1Departments of Mechanical Engineering, 2Chemical Engineering, 3Biomedical Engineering; 4Center for Nano Molecular Science and Technology; 5Texas Materials Institute; 6Institute of Neuroscience; 7Microelectronics Research Center, The University of Texas at Austin, Austin, TX, USA *Contributed equally to this workPurpose: Understanding how surface features influence the establishment and outgrowth of the axon of developing neurons at the single cell level may aid in designing implantable scaffolds for the regeneration of damaged nerves. Past studies have shown that micropatterned ridge-groove structures not only instigate axon polarization, alignment, and extension, but are also preferred over smooth surfaces and even neurotrophic ligands.Methods: Here, we performed axonal-outgrowth competition assays using a proprietary four-quadrant topography grid to determine the capacity of various micropatterned topographies to act as stimuli sequestering axon extension. Each topography in the grid consisted of an array of microscale (approximately 2 µm or submicroscale (approximately 300 nm holes or lines with variable dimensions. Individual rat embryonic hippocampal cells were positioned either between two juxtaposing topographies or at the borders of individual topographies juxtaposing unpatterned smooth surface, cultured for 24 hours, and analyzed with respect to axonal selection using conventional imaging techniques.Results: Topography was found to influence axon formation and extension relative to smooth surface, and the distance of neurons relative to topography was found to impact whether the topography could serve as an effective cue. Neurons were also found to prefer submicroscale over microscale features and holes over lines for a given feature size.Conclusion: The results suggest that implementing physical cues of various shapes and sizes on nerve guidance conduits

  12. Regional Retinal Ganglion Cell Axon Loss in a Murine Glaucoma Model.

    Science.gov (United States)

    Schaub, Julie A; Kimball, Elizabeth C; Steinhart, Matthew R; Nguyen, Cathy; Pease, Mary E; Oglesby, Ericka N; Jefferys, Joan L; Quigley, Harry A

    2017-05-01

    To determine if retinal ganglion cell (RGC) axon loss in experimental mouse glaucoma is uniform in the optic nerve. Experimental glaucoma was induced for 6 weeks with a microbead injection model in CD1 (n = 78) and C57BL/6 (B6, n = 68) mice. From epoxy-embedded sections of optic nerve 1 to 2 mm posterior to the globe, total nerve area and regional axon density (axons/1600 μm2) were measured in superior, inferior, nasal, and temporal zones. Control eyes of CD1 mice have higher axon density and more total RGCs than control B6 mice eyes. There were no significant differences in control regional axon density in all mice or by strain (all P > 0.2, mixed model). Exposure to elevated IOP caused loss of RGC in both strains. In CD1 mice, axon density declined without significant loss of nerve area, while B6 mice had less density loss, but greater decrease in nerve area. Axon density loss in glaucoma eyes was not significantly greater in any region in either mouse strain (both P > 0.2, mixed model). In moderately damaged CD1 glaucoma eyes, and CD1 eyes with the greatest IOP elevation exposure, density loss differed by region (P = 0.05, P = 0.03, mixed model) with the greatest loss in the temporal and superior regions, while in severely injured B6 nerves superior loss was greater than inferior loss (P = 0.01, mixed model, Bonferroni corrected). There was selectively greater loss of superior and temporal optic nerve axons of RGCs in mouse glaucoma at certain stages of damage. Differences in nerve area change suggest non-RGC responses differ between mouse strains.

  13. Normal axonal ion channel function in large peripheral nerve fibers following chronic ciguatera sensitization.

    Science.gov (United States)

    Vucic, Steve; Kiernan, Matthew C

    2008-03-01

    Although the acute clinical effects of ciguatera poisoning, due to ingestion of ciguatoxin, are mediated by activation of transient Na+ channels, the mechanisms underlying ciguatera sensitization remain undefined. Axonal excitability studies were performed by stimulating the median motor and sensory nerves in two patients with ciguatera sensitization. Excitability parameters were all within normal limits, thereby arguing against dysfunction of axonal membrane ion channels in large-diameter fibers in ciguatera sensitization.

  14. Hydrogels as scaffolds and delivery systems to enhance axonal regeneration after injuries

    Directory of Open Access Journals (Sweden)

    Oscar A. Carballo-Molina

    2015-02-01

    Full Text Available Damage caused to neural tissue by disease or injury frequently produces a discontinuity in the nervous system. Such damage generates diverse alterations that are commonly permanent, due to the limited regeneration capacity of the adult nervous system, particularly the Central Nervous System (CNS. The cellular reaction to noxious stimulus leads to several events such as the formation of glial and fibrous scars, which inhibit axonal regeneration in both the CNS and the Peripheral Nervous System (PNS. Although in the PNS there is some degree of nerve regeneration, it is common that the growing axons reinnervate incorrect areas, causing mismatches. Providing a permissive substrate for axonal regeneration in combination with delivery systems for the release of molecules, which enhances axonal growth, could increase regeneration and the recovery of functions in the CNS or the PNS. Currently, there are no effective vehicles to supply growth factors or cells to the damaged/diseased nervous system. Hydrogels are polymers that are biodegradable, biocompatible and have the capacity to deliver a large range of molecules in situ. The inclusion of cultured neural cells into hydrogels forming three-dimensional structures allows the formation of synapses and neuronal survival. There is also evidence showing that hydrogels constitute an amenable substrate for axonal growth of endogenous or grafted cells, overcoming the presence of axonal regeneration inhibitory molecules, in both the central and peripheral nervous systems. Recent experiments suggest that hydrogels can carry and deliver several proteins relevant for improving neuronal survival and axonal growth. Although the use of hydrogels is appealing, its effectiveness is still a matter of discussion, and more results are needed to achieve consistent recovery using different parameters. This review also discusses areas of opportunity where hydrogels can be applied, in order to promote axonal regeneration of

  15. Axonal Elongation into Peripheral Nervous System ``Bridges'' after Central Nervous System Injury in Adult Rats

    Science.gov (United States)

    David, Samuel; Aguayo, Albert J.

    1981-11-01

    The origin, termination, and length of axonal growth after focal central nervous system injury was examined in adult rats by means of a new experimental model. When peripheral nerve segments were used as ``bridges'' between the medulla and spinal cord, axons from neurons at both these levels grew approximately 30 millimeters. The regenerative potential of these central neurons seems to be expressed when the central nervous system glial environment is changed to that of the peripheral nervous system.

  16. Axon-Sorting Multifunctional Nerve Guides: Accelerating Restoration of Nerve Function

    Science.gov (United States)

    2014-10-01

    factor (singly & in selected combinations) in the organotypic model system for preferential sensory or motor axon extension. Use confocal microscopy to...track axon extension of labeled sensory or motor neurons from spinal cord slices (motor) or dorsal root ganglia ( DRG ) (sensory). 20 Thy1-YFP mice...RESEARCH ACCOMPLISHMENTS: • Established a system of color-coded mixed nerve tracking using GFP and RFP expressing motor and sensory neurons (Figure 1

  17. Wnt Signalling Promotes Actin Dynamics during Axon Remodelling through the Actin-Binding Protein Eps8.

    Directory of Open Access Journals (Sweden)

    Eleanna Stamatakou

    Full Text Available Upon arrival at their synaptic targets, axons slow down their growth and extensively remodel before the assembly of presynaptic boutons. Wnt proteins are target-derived secreted factors that promote axonal remodelling and synaptic assembly. In the developing spinal cord, Wnts secreted by motor neurons promote axonal remodelling of NT-3 responsive dorsal root ganglia neurons. Axon remodelling induced by Wnts is characterised by growth cone pausing and enlargement, processes that depend on the re-organisation of microtubules. However, the contribution of the actin cytoskeleton has remained unexplored. Here, we demonstrate that Wnt3a regulates the actin cytoskeleton by rapidly inducing F-actin accumulation in growth cones from rodent DRG neurons through the scaffold protein Dishevelled-1 (Dvl1 and the serine-threonine kinase Gsk3β. Importantly, these changes in actin cytoskeleton occurs before enlargement of the growth cones is evident. Time-lapse imaging shows that Wnt3a increases lamellar protrusion and filopodia velocity. In addition, pharmacological inhibition of actin assembly demonstrates that Wnt3a increases actin dynamics. Through a yeast-two hybrid screen, we identified the actin-binding protein Eps8 as a direct interactor of Dvl1, a scaffold protein crucial for the Wnt signalling pathway. Gain of function of Eps8 mimics Wnt-mediated axon remodelling, whereas Eps8 silencing blocks the axon remodelling activity of Wnt3a. Importantly, blockade of the Dvl1-Eps8 interaction completely abolishes Wnt3a-mediated axonal remodelling. These findings demonstrate a novel role for Wnt-Dvl1 signalling through Eps8 in the regulation of axonal remodeling.

  18. Independent signaling by Drosophila insulin receptor for axon guidance and growth

    Directory of Open Access Journals (Sweden)

    Caroline Rita Li

    2014-01-01

    Full Text Available The Drosophila insulin receptor (DInR regulates a diverse array of biological processes including growth, axon guidance, and sugar homeostasis. Growth regulation by DInR is mediated by Chico, the Drosophila homolog of vertebrate insulin-receptor-substrate proteins IRS1-4. In contrast, DInR regulation of photoreceptor axon guidance in the developing visual system is mediated by the SH2-SH3 domain adaptor protein Dreadlocks (Dock. In vitro studies by others identified five NPXY motifs, one in the juxtamembrane region and four in the signaling C-terminal tail (C-tail, important for interaction with Chico. Here we used yeast two-hybrid assays to identify regions in the DInR C-tail that interact with Dock. These Dock-binding sites were in separate portions of the C-tail from the previously identified Chico-binding sites. To test whether these sites are required for growth or axon guidance in whole animals, a panel of DInR proteins, in which the putative Chico and Dock interaction sites had been mutated individually or in combination, were tested for their ability to rescue viability, growth, and axon guidance defects of dinr mutant flies. Sites required for viability were identified. Unexpectedly, mutation of both putative Dock binding sites, either individually or in combination, did not lead to defects in photoreceptor axon guidance. Thus, either sites also required for viability are necessary for DInR function in axon guidance and/or there is redundancy built into the DInR/Dock interaction such that Dock is able to interact with multiple regions of DInR. We also found that simultaneous mutation of all 5 NPXY motifs implicated in Chico interaction drastically decreased growth in both male and female adult flies. Mutation of these 5 NPXY motifs did not affect photoreceptor axon guidance, showing that different sites within DInR control growth and axon guidance.

  19. MRI findings in acute diffuse axonal injured patients

    International Nuclear Information System (INIS)

    Sato, Hidetaka

    2001-01-01

    Diffuse axonal injury (DAI) in the acute stage was clinically evaluated using magnetic resonance imaging (MRI), which is considered superior to computed tomography (CT) in detecting parenchymal brain lesions. MRI was disadvantageous, however, to patients suffering from acute severe head injury because of the long time required to construct imaging and unstable patient vital signs. We conducted MRI safely under a high magnetic field (1.5 tesla) in acute DAI by close observation and with nonmagnetic respirator and electrocardiographic monitoring. MRI was conducted in 95 patients diagnosed with DAI classified into mild (14), moderate (17) and severe (64) DAI by criteria established by Gennarelli (1986). In patients with mild or moderate DAI, CT revealed no lesion in the parenchymal area although MRI detected lesions in every case, mainly in cortical white matter or basal ganglia. In patients with severe DAI, CT revealed parenchymal lesions in 14 although MRI detected further lesions in cortical white matter, basal ganglia, corpus callosum and brainstem in every case. These results correspond well to the experimental model Gennarelli's. This study concluded that MRI was useful in assessing acute DAI patients. (author)

  20. Structural study of Purkinje cell axonal torpedoes in essential tremor.

    Science.gov (United States)

    Louis, Elan D; Yi, Hong; Erickson-Davis, Cordelia; Vonsattel, Jean-Paul G; Faust, Phyllis L

    2009-02-06

    Essential tremor (ET) is one of the most common neurological diseases. A basic understanding of its neuropathology is now emerging. Aside from Purkinje cell loss, a prominent finding is an abundance of torpedoes (rounded swellings of Purkinje cell axons). Such swellings often result from the mis-accumulation of cell constituents. Identifying the basic nature of these accumulations is an important step in understanding the underlying disease process. Torpedoes, only recently identified in ET, have not yet been characterized ultrastructurally. Light and electron microscopy were used to characterize the structural constituents of torpedoes in ET. Formalin-fixed cerebellar cortical tissue from four prospectively collected ET brains was sectioned and immunostained with a monoclonal phosphorylated neurofilament antibody (SMI-31, Covance, Emeryville, CA). Using additional sections from three ET brains, torpedoes were assessed using electron microscopy. Immunoreactivity for phosphorylated neurofilament protein revealed clear labeling of torpedoes in each case. Torpedoes were strongly immunoreactive; in many instances, two or more torpedoes were noted in close proximity to one another. On electron microscopy, torpedoes were packed with randomly arranged 10-12nm neurofilaments. Mitochondria and smooth endoplasmic reticulum were abundant as well, particularly at the periphery of the torpedo. We demonstrated that the torpedoes in ET represent the mis-accumulation of disorganized neurofilaments and other organelles. It is not known where in the pathogenic cascade these accumulations occur (i.e., whether these accumulations are the primary event or a secondary/downstream event) and this deserves further study.

  1. Myelin-associated proteins labelled by slow axonal transport

    International Nuclear Information System (INIS)

    Giorgi, P.P.; DuBois, H.

    1981-01-01

    This paper deals with the problem of protein metabolism and provides evidence that the neuronal contribution to myelin metabolism may be restricted to lipids only. On the other hand this line of research led to the partial characterization of a group of neuronal proteins probably involved in axo-glial interactions subserving the onset of myelination and the structural maintenance of the mature myelin sheath. Intraocular injection of radioactive amino acids allows the study of the anterograde transport of labelled proteins along retinofugal fibres which are well myelinated. Myelin extracted from the optic nerve and tract under these conditions also contains labelled proteins. Three hypotheses are available to explain this phenomenon. To offer an explanation for this phenomenon the work was planned as follows. a) Characterization of the spatio-temporal pattern of labelling of myelin, in order to define the experimental conditions (survival time and region of the optic pathway to be studied) necessary to obtain maximal labelling. b) Characterization (by gel electrophoresis) of the myelin-associated proteins which become labelled by axonal transport, in order to work on a consistent pattern of labelling. c) Investigation of the possible mechanism responsible for the labelling of myelin-associated proteins. (Auth.)

  2. Bridging Physics and Biology Using Resistance and Axons

    Science.gov (United States)

    Dyer, Joshua M.

    2014-11-01

    When teaching physics, it is often difficult to get biology-oriented students to see the relevance of physics.1 A complaint often heard is that biology students are required to take physics for the Medical College Admission Test (MCAT) as part of a "weeding out" process, but that they don't feel like they need physics for biology. Despite this impression held by students, there have been calls for better physics education for future physicians and life scientists.2,3 Research is being performed to improve physics classes and labs by linking topics in biology and physics.4,5 Described here is a laboratory experiment covering the topics of resistance of materials and circuits/Kirchhoff's laws in a biology context with their direct application to neurons, axons, and electrical impulse transmission within animals. This experiment will also demonstrate the mechanism believed to cause multiple sclerosis. The apparatus was designed with low-cost and readily available materials in mind.

  3. EFFECT OF DETERGENT ON ELECTRICAL PROPERTIES OF SQUID AXON MEMBRANE.

    Science.gov (United States)

    KISHIMOTO, U; ADELMAN, W J

    1964-05-01

    The effects of detergents on squid giant axon action and resting potentials as well as membrane conductances in the voltage clamp have been studied. Anionic detergents (sodium lauryl sulfate, 0.1 to 1.0 mM; dimethyl benzene sulfonate, 1 to 20 mM, pH 7.6) cause a temporary increase and a later decrease of action potential height and the value of the resting potential. Cationic detergent (cetyl trimethyl ammonium chloride, 6 x 10(-5)M or more, pH 7.6) generally brings about immediate and irreversible decreases in the action and resting potentials. Non-ionic detergent (tween 80, 0.1 M, pH 7.6) causes a slight reversible reduction of action potential height without affecting the value of the resting potential. Both anionic and cationic detergents generally decrease the sodium and potassium conductances irreversibly. The effect of non-ionic detergent is to decrease the sodium conductance reversibly, leaving the potassium conductance almost unchanged.

  4. Detection of functional homotopy in traumatic axonal injury

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jian; Gao, Lei; Xie, Kai; Zhan, Jie; Luo, Xiaoping; Wang, Huifang; Zhang, Huifang; Zhao, Jing; Zhou, Fuqing; Zeng, Xianjun; He, Laichang; He, Yulin; Gong, Honghan [Nanchang University, Department of Radiology, The First Affiliated Hospital, Nanchang City, Jiangxi (China)

    2017-01-15

    This study aimed to explore the interhemispheric intrinsic connectivity in traumatic axonal injury (TAI) patients. Twenty-one patients with TAI (14 males, seven females; mean age, 38.71 ± 15.25 years) and 22 well-matched healthy controls (16 males, six females; mean age, 38.50 ± 13.82 years) were recruited, and from them we obtained resting-state fMRI data. Interhemispheric coordination was examined using voxel-mirrored homotopic connectivity (VMHC) and seed-based functional connectivity analysis was performed. We observed significantly decreased VMHC in a number of regions in TAI patients, including the prefrontal, temporal, occipital, parietal, and posterior cingulate cortices, thalami and cerebellar posterior lobes. Subsequent seed-based functional connectivity analysis revealed widely disrupted functional connectivity between the regions of local homotopic connectivity deficits and other areas of the brain, particularly the areas subserving the default, salience, integrative, and executive systems. The lower VMHC of the inferior frontal gyrus and basal ganglia, thalamus, and caudate were significant correlated with the Beck Depression Inventory score, Clinical Dementia Rating score, and Mini-Mental State Examination score, respectively. TAI is associated with regionally decreased interhemispheric interactions and extensively disrupted seed-based functional connectivity, generating further evidence of diffuse disconnection being associated with clinical symptoms in TAI patients. (orig.)

  5. Detection of functional homotopy in traumatic axonal injury

    International Nuclear Information System (INIS)

    Li, Jian; Gao, Lei; Xie, Kai; Zhan, Jie; Luo, Xiaoping; Wang, Huifang; Zhang, Huifang; Zhao, Jing; Zhou, Fuqing; Zeng, Xianjun; He, Laichang; He, Yulin; Gong, Honghan

    2017-01-01

    This study aimed to explore the interhemispheric intrinsic connectivity in traumatic axonal injury (TAI) patients. Twenty-one patients with TAI (14 males, seven females; mean age, 38.71 ± 15.25 years) and 22 well-matched healthy controls (16 males, six females; mean age, 38.50 ± 13.82 years) were recruited, and from them we obtained resting-state fMRI data. Interhemispheric coordination was examined using voxel-mirrored homotopic connectivity (VMHC) and seed-based functional connectivity analysis was performed. We observed significantly decreased VMHC in a number of regions in TAI patients, including the prefrontal, temporal, occipital, parietal, and posterior cingulate cortices, thalami and cerebellar posterior lobes. Subsequent seed-based functional connectivity analysis revealed widely disrupted functional connectivity between the regions of local homotopic connectivity deficits and other areas of the brain, particularly the areas subserving the default, salience, integrative, and executive systems. The lower VMHC of the inferior frontal gyrus and basal ganglia, thalamus, and caudate were significant correlated with the Beck Depression Inventory score, Clinical Dementia Rating score, and Mini-Mental State Examination score, respectively. TAI is associated with regionally decreased interhemispheric interactions and extensively disrupted seed-based functional connectivity, generating further evidence of diffuse disconnection being associated with clinical symptoms in TAI patients. (orig.)

  6. O uso do Aloe sp (aloe vera em feridas agudas e crônicas: revisão integrativa

    Directory of Open Access Journals (Sweden)

    Lucélia Terra Chini

    2017-01-01

    Full Text Available Objetivos: buscar evidencias disponibles en la literatura acerca del uso de Aloe sp (sábila en la cicatrización de heridas agudas y crónicas. Materiales y método: se trata de una revisión integradora realizada en las bases de datos LILACS, PubMed y Scopus, en el periodo de febrero a marzo del 2015. La búsqueda resultó en 178 publicaciones. Resultados: siete estudios constituyeron la revisión, los cuales involucraron personas con heridas de cesárea, heridas de episiotomía, quemaduras, área donadora de injerto, heridas posthemorroidectomía y heridas fisuarias anales crónicas. Se evidenció que la sábila promueve la cicatrización de heridas, además de disminuir el dolor en fisuras anales crónicas y quemaduras. Conclusiones: la sábila representa una nueva terapéutica en el tratamiento de heridas; sin embargo, las evidencias disponibles sobre su eficacia y seguridad son ineficientes para legitimar su uso en la cicatrización de heridas agudas y crónicas; por lo tanto, no se pueden generalizar.

  7. Abordaje transumbilical en pacientes pediátricos con sospecha de apendicitis aguda. Un serie de 424 pacientes

    Directory of Open Access Journals (Sweden)

    Luis Augusto Zárate Suárez

    2013-05-01

    Full Text Available Antecedentes: El tratamiento de la apendicitis aguda implica su extirpación; es frecuente la solicitud de cicatrices postquirúrgicas del mejor tamaño posible. Una de las estrategias disponibles es el abordaje transumbilical. Objetivos: Descubrir las características clínicas y los desenlaces operatorios de los pacientes pediátricos en quienes se realiza apendicectomía vía transumbilical. Metodología: Estudio prospectivo de 424 pacientes sucesivos en cuanto a los desenlaces operatorios a corto plazo. Resultados: El tiempo promedio de intervención quirúrgica fue de 22 minutos; 95,8% de los pacientes presentó evolución satisfactoria del postquirúrgico; 1,4% de los pacientes se reintervino para drenar un absceso intracavitario residual y 0,2% presentó infencción de sitio operatorio sin mas complicaciones. Conclusión: El abordaje transumbilical de la apendicitis es una alternativa minimamente invasiva para todos los estados de apendicitis aguda e implica disminución del tiempo de realización, menor estancia del postquirúrgico, menor incidencia de complicaciones y mayor conformidad con los resultados estéticos.

  8. Surto de toxoplasmose aguda transmitida através da ingestão de carne crua de gado ovino

    Directory of Open Access Journals (Sweden)

    Bonametti Ana Maria

    1997-01-01

    Full Text Available Os autores apresentam 17 casos de toxoplasmose aguda sintomática adquirida pela ingestão de carne crua de carneiro, servida em uma festa à qual todos os pacientes compareceram. Em relação ao quadro clínico, o período de incubação da doença variou de 6 a 13 dias (10,9 ± 7,0 e 16 (94,5% pacientes apresentaram febre, cefaléia, mialgia, artralgia e adenomegalia (cervical ou cervical/axilar. Outros sinais clínicos encontrados foram: hepatomegalia em 6 pacientes, esplenomegalia em 4 e exantema em 2. Um paciente apresentou quadro clínico de corioretinite, confirmada através de exame oftalmológico. Todos os pacientes apresentavam títulos séricos de anticorpos específicos (IgG e IgM que evidenciavam fase aguda de toxoplasmose, pela Reação de Imunofluorescência Indireta. Todos os pacientes foram tratados especificamente e houve boa resposta clínica e laboratorial ao tratamento.

  9. Ciencia, tecnología y sociedad: reflexiones sobre el tratamiento antimicrobiano secuencial en la apendicitis aguda complicada

    Directory of Open Access Journals (Sweden)

    José Carlos Bueno Rodríguez

    Full Text Available Actualmente los estudios de Ciencia, Tecnología y Sociedad (CTS constituyen un importante espacio de trabajo en la política pública, la educación y la investigación. La introducción de nuevos procedimientos y tecnologías en la atención médica debe analizarse desde la perspectiva de los estudios de CTS porque requiere de un sustento científico-tecnológico y tiene que cumplir, entre otros, con los requisitos éticos de aplicabilidad a los seres humanos. La utilización secuencial de los antimicrobianos en el tratamiento postoperatorio de la apendicitis aguda complicada en los niños, constituye una modificación de la terapéutica comúnmente empleada en Cuba y en muchas instituciones de salud del mundo. El presente trabajo muestra una reflexión sobre los pilares científicos, tecnológicos y sociales que sustentan la aplicación de un nuevo protocolo de tratamiento con el uso secuencial de los antimicrobianos en los niños con apendicitis aguda complicada.

  10. Diabetes insipidus como manifestação inicial de leucemia mieloide aguda em paciente com monossomia do cromossomo 7

    Directory of Open Access Journals (Sweden)

    Amanda Dias Lima Morais

    2017-04-01

    Full Text Available O diabetes insipidus (DI central é uma síndrome caracterizada pela incapacidade de concentração urinária devido à deficiência do hormônio antidiurético. O envolvimento do sistema nervoso central é frequente nas leucemias, mas a ocorrência de DI é rara e confere pior prognóstico. A patogênese do DI na leucemia não é totalmente conhecida, mas a infiltração do eixo hipotálamo-hipofisário por células leucêmicas parece ser um fator responsável. O presente relato descreve o caso de um paciente que apresentou DI como primeira manifestação de leucemia mieloide aguda e que evoluiu com dificuldades de ajustes do sódio sérico, da poliúria e da reposição volêmica, necessitando de permanência prolongada em unidade de cuidados intensivos. Palavras-chave: diabetes insipidus; leucemia mieloide aguda; monossomia; cromossomo 7.

  11. Epiteliopatía pigmentaria placoide posterior multifocal aguda unilateral. A propósito de un caso

    Directory of Open Access Journals (Sweden)

    Ana Isabel Díaz Zapién

    2016-07-01

    Full Text Available Se presenta el caso de una mujer de 48 años de edad, que inicia su cuadro clínico con disminución súbita de agudeza visual acompañado de la presencia de un escotoma central en ojo derecho unilateral, sin otros síntomas acompañantes, antecedentes personales patológicos negados, 4 semanas después la paciente recupera visión llegando a un 20/20 sin la presencia del escotoma. La epiteliopatía pigmentaria placoide posterior multifocal aguda (EPPPMA es una patología inflamatoria coriorretiniana, que se presenta en adultos jóvenes, sanos, sin predominio por algún género, produciendo alteraciones visuales agudas, con hallazgos fundoscópicos característicos de lesiones placoides blanco-amarillentas a nivel del epitelio pigmentario de la retina. El diagnóstico se basa en los datos clínicos y la evolución complementado con la fluorangiografía, la mayoría de los casos con buen pronóstico visual, con una recuperación de la agudeza visual completa dentro de las primeras 3-6 semanas.

  12. Early development of the circumferential axonal pathway in mouse and chick spinal cord.

    Science.gov (United States)

    Holley, J A

    1982-03-10

    The early development of the circumferential axonal pathway in the brachial and lumbar spinal cord of mouse and chick embryos was studied by scanning and transmission electron microscopy. The cellular processes which comprise this pathway grow in the transverse plane and along the lateral margin of the marginal zone (i.e., circumferentially oriented), as typified by the early embryonic commissural axons. The first formative event observed was in the ventrolateral margin of the primitive spinal cord ventricular zone. Cellular processes were found near the external limiting membrane that appeared to grow a variable distance either dorsally or ventrally. Later in development, presumptive motor column neurons migrated into the ventrolateral region, distal to these early circumferentially oriented processes. Concurrently, other circumferentially oriented perikarya and processes appeared along the dorsolateral margin. Due to their aligned sites of origin and parallel growth, the circumferential processes formed a more or less continuous line or pathway, which in about 10% of the scanned specimens could be followed along the entire lateral margin of the embryonic spinal cord. Several specimens later in development had two sets of aligned circumferential processes in the ventral region. Large numbers of circumferential axons were then found to follow the preformed pathway by fasciculation, after the primitive motor column had become established. Since the earliest circumferential processes appeared to differentiate into axons and were found nearly 24 hours prior to growth of most circumferential axons, their role in guidance as pioneering axons was suggested.

  13. PTEN deletion from adult-generated dentate granule cells disrupts granule cell mossy fiber axon structure.

    Science.gov (United States)

    LaSarge, Candi L; Santos, Victor R; Danzer, Steve C

    2015-03-01

    Dysregulation of the mTOR-signaling pathway is implicated in the development of temporal lobe epilepsy. In mice, deletion of PTEN from hippocampal dentate granule cells leads to mTOR hyperactivation and promotes the rapid onset of spontaneous seizures. The mechanism by which these abnormal cells initiate epileptogenesis, however, is unclear. PTEN-knockout granule cells develop abnormally, exhibiting morphological features indicative of increased excitatory input. If these cells are directly responsible for seizure genesis, it follows that they should also possess increased output. To test this prediction, dentate granule cell axon morphology was quantified in control and PTEN-knockout mice. Unexpectedly, PTEN deletion increased giant mossy fiber bouton spacing along the axon length, suggesting reduced innervation of CA3. Increased width of the mossy fiber axon pathway in stratum lucidum, however, which likely reflects an unusual increase in mossy fiber axon collateralization in this region, offsets the reduction in boutons per axon length. These morphological changes predict a net increase in granule cell innervation of CA3. Increased diameter of axons from PTEN-knockout cells would further enhance granule cell communication with CA3. Altogether, these findings suggest that amplified information flow through the hippocampal circuit contributes to seizure occurrence in the PTEN-knockout mouse model of temporal lobe epilepsy. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Fractional cable equation for general geometry: A model of axons with swellings and anomalous diffusion

    Science.gov (United States)

    López-Sánchez, Erick J.; Romero, Juan M.; Yépez-Martínez, Huitzilin

    2017-09-01

    Different experimental studies have reported anomalous diffusion in brain tissues and notably this anomalous diffusion is expressed through fractional derivatives. Axons are important to understand neurodegenerative diseases such as multiple sclerosis, Alzheimer's disease, and Parkinson's disease. Indeed, abnormal accumulation of proteins and organelles in axons is a hallmark of these diseases. The diffusion in the axons can become anomalous as a result of this abnormality. In this case the voltage propagation in axons is affected. Another hallmark of different neurodegenerative diseases is given by discrete swellings along the axon. In order to model the voltage propagation in axons with anomalous diffusion and swellings, in this paper we propose a fractional cable equation for a general geometry. This generalized equation depends on fractional parameters and geometric quantities such as the curvature and torsion of the cable. For a cable with a constant radius we show that the voltage decreases when the fractional effect increases. In cables with swellings we find that when the fractional effect or the swelling radius increases, the voltage decreases. Similar behavior is obtained when the number of swellings and the fractional effect increase. Moreover, we find that when the radius swelling (or the number of swellings) and the fractional effect increase at the same time, the voltage dramatically decreases.

  15. Vesicular Axonal Transport is Modified In Vivo by Tau Deletion or Overexpression in Drosophila

    Directory of Open Access Journals (Sweden)

    Yasmina Talmat-Amar

    2018-03-01

    Full Text Available Structural microtubule associated protein Tau is found in high amount in axons and is involved in several neurodegenerative diseases. Although many studies have highlighted the toxicity of an excess of Tau in neurons, the in vivo understanding of the endogenous role of Tau in axon morphology and physiology is poor. Indeed, knock-out mice display no strong cytoskeleton or axonal transport phenotype, probably because of some important functional redundancy with other microtubule-associated proteins (MAPs. Here, we took advantage of the model organism Drosophila, which genome contains only one homologue of the Tau/MAP2/MAP4 family to decipher (endogenous Tau functions. We found that Tau depletion leads to a decrease in microtubule number and microtubule density within axons, while Tau excess leads to the opposite phenotypes. Analysis of vesicular transport in tau mutants showed altered mobility of vesicles, but no change in the total amount of putatively mobile vesicles, whereas both aspects were affected when Tau was overexpressed. In conclusion, we show that loss of Tau in tau mutants not only leads to a decrease in axonal microtubule density, but also impairs axonal vesicular transport, albeit to a lesser extent compared to the effects of an excess of Tau.

  16. Drosophila growth cones: a genetically tractable platform for the analysis of axonal growth dynamics.

    Science.gov (United States)

    Sánchez-Soriano, Natalia; Gonçalves-Pimentel, Catarina; Beaven, Robin; Haessler, Ulrike; Ofner-Ziegenfuss, Lisa; Ballestrem, Christoph; Prokop, Andreas

    2010-01-01

    The formation of neuronal networks, during development and regeneration, requires outgrowth of axons along reproducible paths toward their appropriate postsynaptic target cells. Axonal extension occurs at growth cones (GCs) at the tips of axons. GC advance and navigation requires the activity of their cytoskeletal networks, comprising filamentous actin (F-actin) in lamellipodia and filopodia as well as dynamic microtubules (MTs) emanating from bundles of the axonal core. The molecular mechanisms governing these two cytoskeletal networks, their cross-talk, and their response to extracellular signaling cues are only partially understood, hindering our conceptual understanding of how regulated changes in GC behavior are controlled. Here, we introduce Drosophila GCs as a suitable model to address these mechanisms. Morphological and cytoskeletal readouts of Drosophila GCs are similar to those of other models, including mammals, as demonstrated here for MT and F-actin dynamics, axonal growth rates, filopodial structure and motility, organizational principles of MT networks, and subcellular marker localization. Therefore, we expect fundamental insights gained in Drosophila to be translatable into vertebrate biology. The advantage of the Drosophila model over others is its enormous amenability to combinatorial genetics as a powerful strategy to address the complexity of regulatory networks governing axonal growth. Thus, using pharmacological and genetic manipulations, we demonstrate a role of the actin cytoskeleton in a specific form of MT organization (loop formation), known to regulate GC pausing behavior. We demonstrate these events to be mediated by the actin-MT linking factor Short stop, thus identifying an essential molecular player in this context.

  17. DISCO Interacting Protein 2 regulates axonal bifurcation and guidance of Drosophila mushroom body neurons.

    Science.gov (United States)

    Nitta, Yohei; Yamazaki, Daisuke; Sugie, Atsushi; Hiroi, Makoto; Tabata, Tetsuya

    2017-01-15

    Axonal branching is one of the key processes within the enormous complexity of the nervous system to enable a single neuron to send information to multiple targets. However, the molecular mechanisms that control branch formation are poorly understood. In particular, previous studies have rarely addressed the mechanisms underlying axonal bifurcation, in which axons form new branches via splitting of the growth cone. We demonstrate that DISCO Interacting Protein 2 (DIP2) is required for precise axonal bifurcation in Drosophila mushroom body (MB) neurons by suppressing ectopic bifurcation and regulating the guidance of sister axons. We also found that DIP2 localize to the plasma membrane. Domain function analysis revealed that the AMP-synthetase domains of DIP2 are essential for its function, which may involve exerting a catalytic activity that modifies fatty acids. Genetic analysis and subsequent biochemical analysis suggested that DIP2 is involved in the fatty acid metabolization of acyl-CoA. Taken together, our results reveal a function of DIP2 in the developing nervous system and provide a potential functional relationship between fatty acid metabolism and axon morphogenesis. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Wnt3 and Gata4 regulate axon regeneration in adult mouse DRG neurons.

    Science.gov (United States)

    Duan, Run-Shan; Liu, Pei-Pei; Xi, Feng; Wang, Wei-Hua; Tang, Gang-Bin; Wang, Rui-Ying; Saijilafu; Liu, Chang-Mei

    2018-05-05

    Neurons in the adult central nervous system (CNS) have a poor intrinsic axon growth potential after injury, but the underlying mechanisms are largely unknown. Wingless-related mouse mammary tumor virus integration site (WNT) family members regulate neural stem cell proliferation, axon tract and forebrain development in the nervous system. Here we report that Wnt3 is an important modulator of axon regeneration. Downregulation or overexpression of Wnt3 in adult dorsal root ganglion (DRG) neurons enhances or inhibits their axon regeneration ability respectively in vitro and in vivo. Especially, we show that Wnt3 modulates axon regeneration by repressing mRNA translation of the important transcription factor Gata4 via binding to the three prime untranslated region (3'UTR). Downregulation of Gata4 could restore the phenotype exhibited by Wnt3 downregulation in DRG neurons. Taken together, these data indicate that Wnt3 is a key intrinsic regulator of axon growth ability of the nervous system. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Conduction velocity is regulated by sodium channel inactivation in unmyelinated axons innervating the rat cranial meninges.

    Science.gov (United States)

    De Col, Roberto; Messlinger, Karl; Carr, Richard W

    2008-02-15

    Axonal conduction velocity varies according to the level of preceding impulse activity. In unmyelinated axons this typically results in a slowing of conduction velocity and a parallel increase in threshold. It is currently held that Na(+)-K(+)-ATPase-dependent axonal hyperpolarization is responsible for this slowing but this has long been equivocal. We therefore examined conduction velocity changes during repetitive activation of single unmyelinated axons innervating the rat cranial meninges. In direct contradiction to the currently accepted postulate, Na(+)-K(+)-ATPase blockade actually enhanced activity-induced conduction velocity slowing, while the degree of velocity slowing was curtailed in the presence of lidocaine (10-300 microm) and carbamazepine (30-500 microm) but not tetrodotoxin (TTX, 10-80 nm). This suggests that a change in the number of available sodium channels is the most prominent factor responsible for activity-induced changes in conduction velocity in unmyelinated axons. At moderate stimulus frequencies, axonal conduction velocity is determined by an interaction between residual sodium channel inactivation following each impulse and the retrieval of channels from inactivation by a concomitant Na(+)-K(+)-ATPase-mediated hyperpolarization. Since the process is primarily dependent upon sodium channel availability, tracking conduction velocity provides a means of accessing relative changes in the excitability of nociceptive neurons.

  20. p27Kip1 Modulates Axonal Transport by Regulating α-Tubulin Acetyltransferase 1 Stability

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    Giovanni Morelli

    2018-05-01

    Full Text Available Summary: The protein p27Kip1 plays roles that extend beyond cell-cycle regulation during cerebral cortex development, such as the regulation of neuronal migration and neurite branching via signaling pathways that converge on the actin and microtubule cytoskeletons. Microtubule-dependent transport is essential for the maturation of neurons and the establishment of neuronal connectivity though synapse formation and maintenance. Here, we show that p27Kip1 controls the transport of vesicles and organelles along the axon of mice cortical projection neurons in vitro. Moreover, suppression of the p27Kip1 ortholog, dacapo, in Drosophila melanogaster disrupts axonal transport in vivo, leading to the reduction of locomotor activity in third instar larvae and adult flies. At the molecular level, p27Kip1 stabilizes the α-tubulin acetyltransferase 1, thereby promoting the acetylation of microtubules, a post-translational modification required for proper axonal transport. : Morelli et al. report that p27Kip1/Dacapo modulates the acetylation of microtubules in axons via stabilization of ATAT1, the main α-tubulin acetyltransferase. Its conditional loss leads to the reduction of bidirectional axonal transport of vesicles and mitochondria in vitro in mice and in vivo in Drosophila. Keywords: p27Kip1, dacapo, acetylation, axonal transport, ATAT1, alpha-tubulin, HDAC6, Drosophila, mouse, cerebral cortex

  1. Polarized axonal surface expression of neuronal KCNQ potassium channels is regulated by calmodulin interaction with KCNQ2 subunit.

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    John P Cavaretta

    Full Text Available KCNQ potassium channels composed of KCNQ2 and KCNQ3 subunits give rise to the M-current, a slow-activating and non-inactivating voltage-dependent potassium current that limits repetitive firing of action potentials. KCNQ channels are enriched at the surface of axons and axonal initial segments, the sites for action potential generation and modulation. Their enrichment at the axonal surface is impaired by mutations in KCNQ2 carboxy-terminal tail that cause benign familial neonatal convulsion and myokymia, suggesting that their correct surface distribution and density at the axon is crucial for control of neuronal excitability. However, the molecular mechanisms responsible for regulating enrichment of KCNQ channels at the neuronal axon remain elusive. Here, we show that enrichment of KCNQ channels at the axonal surface of dissociated rat hippocampal cultured neurons is regulated by ubiquitous calcium sensor calmodulin. Using immunocytochemistry and the cluster of differentiation 4 (CD4 membrane protein as a trafficking reporter, we demonstrate that fusion of KCNQ2 carboxy-terminal tail is sufficient to target CD4 protein to the axonal surface whereas inhibition of calmodulin binding to KCNQ2 abolishes axonal surface expression of CD4 fusion proteins by retaining them in the endoplasmic reticulum. Disruption of calmodulin binding to KCNQ2 also impairs enrichment of heteromeric KCNQ2/KCNQ3 channels at the axonal surface by blocking their trafficking from the endoplasmic reticulum to the axon. Consistently, hippocampal neuronal excitability is dampened by transient expression of wild-type KCNQ2 but not mutant KCNQ2 deficient in calmodulin binding. Furthermore, coexpression of mutant calmodulin, which can interact with KCNQ2/KCNQ3 channels but not calcium, reduces but does not abolish their enrichment at the axonal surface, suggesting that apo calmodulin but not calcium-bound calmodulin is necessary for their preferential targeting to the axonal

  2. Book review. La forma degli animali. Adolf Portmann

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    Manuel Graziani

    2013-09-01

    Full Text Available Nel 1931 il biologo Adolf Portmann era già talmente noto a livello internazionale per le sue ricerche da guadagnarsi la cattedra in zoologia nell'università della sua città natale, Basilea, all'età di appena 34 anni. All'attività di docente universitario ha sempre affiancato un'originale riflessione sul significato delle scienze della vita, imponendosi come una delle figure chiave nel dibattito tra biologia teoretica, estetica e antropologia filosofica. La forma degli animali, la sua opera più celebre, si pone al confine tra varie discipline e conserva un grande interesse ancora oggi che il dialogo tra estetica e biologia si è fatto nuovamente intenso. Pubblicata nel 1948 e in forma ampliata nel 1960 (da cui deriva questa prima edizione italiana a cura di Pietro Conte l'opera rappresenta il frutto più maturo delle sue ricerche "interdisciplinari".Un saggio che nasce dall'insoddisfazione nei confronti dei paradigmi scientifici consolidati e che ripropone l'idea morfologica in biologia sulla scorta del pensiero di J. W. Goethe il quale affermava che "tutto ciò che è deve anche dar cenno di sé e mostrarsi". Adolf Portmann è un convinto sostenitore che dalla forma si possano dedurne le complessive caratteristiche interne ed esterne degli animali. Secondo questa prospettiva la peculiare fisionomia dell'organismo dipende dalla congiunzione delle sue parti e dalle loro reciproche funzioni. Tuttavia l'autore non vede nello studio della forma l'alternativa al funzionalismo quanto, piuttosto, il suo necessario bilanciamento come dichiara nell'introduzione: "… per giungere alla conoscenza della vita animale di strade ce ne sono molte, e tutte possono contribuire ad arricchire la nostra esperienza. Questo lavoro si occupa della forma degli animali e si propone di mettere in luce la peculiare natura dell'aspetto visibile. Ci sono persone che si dedicano allo studio degli animali, conoscono moltissime specie, hanno imparato centinaia di nomi e

  3. Fístula bilio-duodenal pós colecistite aguda: Relato de caso

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    Marina Araújo Fonte Boa

    2016-12-01

    Full Text Available As fístulas biliares internas espontâneas são comunicações estabelecidas entre qualquer segmento da árvore biliar e dos órgãos abdominais. Elas constituem uma afecção rara apesar de compreender uma complicação da colecistite, patologia freqüente da prática cirúrgica. As fístulas bilioentericas ocorrem em 3-5% dos doentes com colelitíase, sendo 68% destas bilioduodenais. O objetivo desse manuscrito é relatar um caso de fístula bilioduodenal complicada com hemobilia e hemorragia digestiva, descrevendo a conduta adotada. Os dados foram coletados entre dezembro/2015 a abril/2016 através da analise de prontuário fornecido pelo Hospital Universitário Sul Fluminense (HUSF. Trata-se de um paciente masculino, 75 anos, atendido no HUSF-Vassouras/RJ com diagnóstico sindrômico de abdome agudo inflamatório por colecistite aguda, submetido a tratamento conservador para regressão da inflamação peri-colecística, diminuindo assim, o risco de lesões iatrogênicas da árvore biliar em posterior cirurgia. Evoluiu com melena, que foi investigada por endoscopia digestiva alta onde foi observada úlcera de bulbo duodenal com drenagem de secreção purulenta pela sua luz; e tomografia computadorizada de abdome que evidenciou presença de aerobilia indicando presença de fístula bileodigestiva. O tratamento conservador consistiu-se em antibioticoterapia e reposição volêmica, optado devido à remissão do quadro de colecistite após desobstrução pela fístula, devido à hemorragia que cessou espontaneamente e também pelo risco da realização do procedimento cirúrgico em paciente idoso com intensa resposta inflamatória sistêmica. Não é comum na literatura médica a ocorrência de fístulas biliodigestivas com sinais e sintomas hemorrágicos. O quadro clínico geralmente é inespecífico e frequentemente atrasado devido à falta de sinais e sintomas patognomônicos.

  4. Esofagitis necrotizante aguda: Una entidad inusual Acute esophageal necrosis: An unusual entity

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    Silvana E. Pramparo

    2010-12-01

    Full Text Available La esofagitis necrotizante aguda (ENA, también denominada esófago negro, es una rara enfermedad poco descripta en la literatura médica. Describimos el caso de un hombre de 80 años, con hemorragia digestiva alta quien desarrolló un esófago negro luego de un episodio de hipotensión. La necrosis fue confirmada histológicamente. Los pacientes se presentan con hematemesis y melena en más del 70% de los casos. Los hallazgos endoscópicos muestran una coloración negruzca de la mucosa esofágica. El diagnóstico se realiza con endoscopia y confirmación histológica. La mortalidad es alta (más del 50% aunque relacionada a las enfermedades de base del paciente. Por último, podemos decir que la sospecha es muy importante en el diagnóstico de ENA, particularmente en pacientes ancianos con enfermedades asociadas y evidencia de hemorragia digestiva alta. En este trabajo describimos las características clínicas, endoscópicas e histopatológicas de un paciente con ENA.Acute esophageal necrosis (AEN, also designated black esophagus, is a rare disorder that is poorly described in the medical literature. We present the case of an 80 years old man, with upper gastrointestinal bleeding who developed a black esophagus after hypotensive episodes. Necrosis was confirmed histologically. Hematemesis and melena are present in more than 70% of the cases. Endoscopic findings show black discoloration of the distal esophagus with proximal extension ending sharply at the gastroesophageal junction. Diagnosis is reached endoscopically with histological support. Mortality is high (up to 50% even though related to the patient's underlying condition. Finally, we may say that to keep in mind the posibility of AEN is a key factor in its diagnosis, particularly in older patients with associated morbidity and evidence of upper gastrointestinal bleeding. In the present report we describe the clinical, endoscopic and histophatological characteristics of a patient with a

  5. Injúria Renal Aguda no paciente politraumatizado Acute Renal Injury in polytrauma patients

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    Thiago Gomes Romano

    2013-03-01

    Full Text Available A Injúria Renal Aguda (IRA no contexto do paciente politraumatizado ocorre, na maioria das vezes, por uma conjuntura de fatores que passam por eventos correlacionados à ressuscitação volêmica inicial, ao grau de resposta inflamatória sistêmica associada ao trauma, ao uso de contraste iodado para procedimentos diagnósticos, à rabdomiólise e à síndrome compartimental abdominal. Atualmente, passamos por uma fase de uniformização dos critérios diagnósticos da IRA com o Acute Kidney Injury Network (AKIN, sendo a referência mais aceita. Consequentemente, o estudo da IRA no politraumatismo também passa por uma fase de reformulação. Esta revisão da literatura médica visa trazer dados epidemiológicos, fisiológicos e de implicação clínica para o manuseio destes pacientes, bem como expor os riscos do uso indiscriminado de expansores volêmicos e particularidades sobre a instituição de terapia renal substitutiva em indivíduos sob risco de hipertensão intracraniana.Acute Kidney Injury (AKI in trauma is, in most cases, multifactorial. Factors related to the initial ressuscitation protocol, degree of the systemic inflamatory response to trauma, contrast nephropathy in diagnostic procedures, rhabdomyolysis and abdominal compartment syndrome are some of those factors. Nowadays a uniformization in diagnostic criteria for AKI has been proposed by the Acute Kidney Injury Network (AKIN and as a result the incidence of AKI and its impact in outcomes in trauma patients also needs to be reconsider. In this review we aim to approach epidemiologic, physiologic and clinical relevant data in the critical care of patients victims of trauma and also to expose the risks of indiscriminate use of volume expanders and the interaction between renal replacement theraphy and intracranial hypertension.

  6. Intoxicación aguda por inhalación de Acrilato de Etilo, Lima 2002

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    Jeannette Ávila VM

    2005-10-01

    Full Text Available Objetivos: Describir las características clínico-epidemiológicas de los casos de intoxicación aguda por inhalación de acrilato de etilo, ocasionado por el manejo clandestino de un envase con restos de ésta sustancia, en una urbanización del distrito Comas, en Lima, Perú en noviembre del año 2002. Materiales y métodos: Estudio transversal analítico realizado en residentes y población del centro educativo aledaño a la zona del accidente. Se realizó una encuesta a todas las personas expuestas, se consideró como caso la presencia de cefalea, irritación ocular, nauseas, dolor abdominal y prurito intenso en el cuerpo. Se caracterizó el accidente en tiempo, espacio y persona. En el centro educativo se exploraron factores de exposición que favorecieron la presencia de intoxicados. Los datos fueron ingresados en Epi Info v 6.0 y analizados en STATA v.8.0 Resultados: Se encuestó 456 residentes y 326 personas en la escuela. La tasa de ataque general fue 21,9%, 46,9% en la escuela y 4,2% en viviendas. Los síntomas predominantes fueron cefalea 56%, irritación ocular 47%, dolor abdominal 42%. El 23% requirió hospitalización. El permanecer en pisos superiores de la escuela fue un factor de riesgo OR 4,54 (IC95% 2,66-7,84 y en el pabellón A OR 3,82 (IC95% 2,33-6,25. Conclusiones: Los síntomas predominantes fueron cefalea, irritación ocular y dolor abdominal. La cercanía a la zona de exposición del cilindro y la dispersión de los vapores tóxicos influyeron para afectar mayormente a la escuela y a aquellos que ocupaban aulas en pisos superiores y el pabellón A. La legislación peruana debe contemplar el problema del manejo clandestino de residuos peligrosos.

  7. Leucemia linfoblástica aguda (LLA durante a gravidez: um relato de caso

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    Marcelo Gil Cliquet

    2015-10-01

    Full Text Available A incidência de Leucemia Linfoblástica Aguda (LLA associada à gestação é pequena, entretanto, devido à gravidade da doença, é fundamental que o obstetra esteja capacitado a orientar a conduta médica. O tratamento deve ser iniciado logo após o diagnóstico para que não haja prejuízo do prognóstico materno. Quando diagnosticada, sabe-se que haverá prejuízos fetais frente à quimioterapia a ser empregada. O dilema ético criado pela concomitância de neoplasias com a gestação é de difícil manejo. Objetivo: relatar o caso de uma gestante no primeiro trimestre com diagnóstico de LLA. Metodologia: as informações foram obtidas por meio de revisão do prontuário e da literatura. Relato: Relatamos o caso de uma gestante, 30 anos, com dores articulares no joelho e hemograma com pancitopenia. O mielograma e a imunofenotipagem foram compatíveis com Leucemia Linfoblástica B comum, quando a paciente estava com 12 semanas de gestação (ultrassom. A paciente foi informada sobre todos os riscos do tratamento quimioterápico para o feto, bem como os riscos maternos em postergar o tratamento. A partir da discussão entre a paciente, seus familiares e equipe médica, ela decidiu por iniciar o tratamento com protocolo BFM 86 modificado, assinando um termo de consentimento. Durante a Indução 2, foi diagnosticado óbito fetal por ultra-sonografia (21 semanas de gestação. A paciente continuou o tratamento com suporte psicológico e no momento encontra-se em remissão completa, iniciando a fase de consolidação do referido protocolo. Conclusão: Pretendemos alertar sobre a difícil decisão feita por uma paciente grávida com a LLA. Tal escolha deve ser feita com o amparo de toda a equipe médica e familiares dos pacientes, além de ser firmada por meio de um termo de consentimento.

  8. Rinovirus: Frecuencia en niños con infección respiratoria aguda, no internados

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    Débora N. Marcone

    2012-02-01

    Full Text Available Los métodos moleculares para diagnosticar rinovirus humanos (RVH han aumentado la sensibilidad de detección. Esto ha permitido documentar la asociación entre los RVH y las infecciones respiratorias agudas (IRA altas y bajas. La infección por RVH durante la infancia se asoció con posterior desarrollo de asma. Se estudió la frecuencia de RVH en 186 niños menores de 6 años ambulatorios con IRA (alta o baja, durante 2 años consecutivos (1/6/2008 - 31/5/2010. Se correlacionó la presencia de RVH con los antecedentes y características clínico-epidemiológicas. La detección de RVH se realizó con una RT-PCR en tiempo real que amplifica parte de la región 5' no codificante del genoma. Los virus respiratorios clásicos se estudiaron por inmunofluorescencia. En el 61% de los niños se detectó etiología viral. Las frecuencias fueron: RVH 27%, virus sincicial respiratorio (VSR 16%, influenza A y B 9%, parainfluenza 8%, metapneumovirus 7% y adenovirus 0.5%. Se observaron coinfecciones duales en 8 casos, siendo RVH el más frecuente (en 4 de ellos. Los RVH circularon durante todo el período estudiado, con picos en invierno y primavera. No se observaron diferencias clínico-epidemiológicas significativas entre pacientes con o sin RVH, excepto un mayor porcentaje de niños afebriles con RVH. Los RVH fueron los virus más detectados en niños ambulatorios, principalmente en menores de 2 años, los segundos virus asociados a bronquiolitis, luego del VSR, y detectados tres veces más en los niños expuestos a tabaquismo pasivo (OR: 2,91; p = 0.012 que en el resto. Fueron identificados como único agente en el 28% de las bronquiolitis.

  9. Intoxicación aguda por plaguicidas Acute poisoning from pesticides

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    Jaime Jesús Durán-Nah

    2000-02-01

    Full Text Available OBJETIVO: Describir la epidemiología de la intoxicación aguda por plaguicidas (IAP en el Hospital General O'Horán de Mérida, Yucatán, México. MATERIAL Y MÉTODOS: Se revisaron los expedientes de 33 pacientes ³ 13 años, tratados en una unidad de cuidados intensivos (UCI, entre 1994 y 1998. Se recopilaron variables demográficas y clínicas relevantes, y se aplicó estadística descriptiva. RESULTADOS: En la población estudiada predominó el sexo masculino (82% del medio rural (70%, y la edad media fue de 34 ± 15.8 años. El intento de suicidio fue causa frecuente de IAP (79%, y en 33% de los casos la intoxicación se produjo por la utilización de organofosforados. La mortalidad fue de 12%. CONCLUSIONES: La IAP fue baja entre los sujetos del medio rural, por lo que los resultados de este estudio parecen no reflejar la realidad del problema. Es importante añadir que los plaguicidas son utilizados con relativa frecuencia para el intento de suicidio.OBJECTIVE: To describe the epidemiologic pattern of acute pesticide poisoning (APP in a general hospital in Merida, Yucatan, Mexico. MATERIAL AND METHODS: From 1994 to 1998, 33 patients 13 years of age or older with diagnosis of APP were studied. Descriptive statistics were used to analyze information. RESULTS: Males were frequently affected (82%, specially those coming from rural areas (60%. The mean age of the group was 34 ± 15.8 years. In 79% of the cases, pesticides were used to commit suicide and 33% of poisoning cases were due to organophospate pesticides. The mortality rate was 12%. CONCLUSIONS: In this small sample, acute poisoning from pesticides in the agricultural setting may be underestimated, since it was less frequent than in the general population. APP was more commonly used by indigent people to commit suicide.

  10. Progressão de policitemia Vera para leucemia mieloide aguda

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    Marcelo Gil Cliquet

    2016-10-01

    Full Text Available Introdução: A Policitemia Vera (PV é um distúrbio clonal caracterizado pela hiperplasia de células hematopoiéticas, com acúmulo de eritrócitos, leucócitos e plaquetas. A mutação pontual JAK2 V617F parece ser o evento inicial da doença, presente em mais de 95% dos pacientes. Com a evolução da doença, há risco de progressão para leucemia mieloide aguda/ síndrome mielodisplásica (LMA/SMD. A transformação leucêmica pode ser espontânea em razão da idade, estágio da doença, estado imunológico ou associada com a terapia citoredutora, principalmente quando se usa alquilantes. Objetivo: Relatar o caso e um paciente com diagnóstico de PV há 19 anos com evolução para LMA há 8 meses. Métodos: As informações foram obtidas por meio de revisão do prontuário, entrevista com o paciente, registro fotográfico de exames e revisão da literatura. Relato: Paciente masculino, 81 anos, hipertenso, teve diagnóstico de PV em 1997, segundo critérios da OMS. No hemograma, concentração de hemograma(Hb de 18,2 g/dl, Heritrócito de 58,5%, leucócitos(leuc = 18.100/mm3 e plaquetas(plt = 64.800/mm3. Apresentava esplenomegalia a 4cm do rebordo costal esquerdo, fraqueza, cansaço e edema em membros inferiores. Paciente foi tratado com Hydroxiureia. O exame molecular de sangue periférico, em 2013, constatou a presença de mutação JAK2 (Val617Phe. Em Março de 2016, apresentou leuc de 86.400/mm3, plt de 152.000, Hb de 10,4g/dl. A imunofe- notipagem confirmou diagnóstico de LMA e o tratamento com Aracytin 20mg SC por sete dias foi iniciado. O paciente evoluiu com piora do estado geral, fraqueza, e infecção em membro inferior, vindo a falecer. Conclusão: Deve- se lembrar sobre a possibilidade da evolução da PV para LMA, mesmo em pacientes em tratamento por longos períodos em uso de hidroxiureia.

  11. Enfermedades diarreicas agudas en el niño: comportamiento de algunos factores de riesgo

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    Freddie Hernández Cisneros

    2000-01-01

    Full Text Available Se realizó un estudio de casos y controles, pareado 1:1, con el objetivo de conocer el comportamiento de algunos factores de riesgo de las enfermedades diarreicas agudas en el niño, en el Policlínico Comunitario Centro de Camagüey, durante 18 meses de trabajo. El grupo de casos estuvo representado por 89 niños de dicha área de salud egresados con ese diagnóstico, y el grupo control, por la misma cantidad de niños no egresados por ninguna enfermedad y de la misma área de salud. A ambos grupos se les aplicó una encuesta cuyos datos obtenidos se procesaron automatizadamente. Se encontraron como resultados más importantes un 97,67 % de niños menores de 1 año, la higiene doméstica no fue buena en el 80,9 % y la personal mala en el 73,03 %. Hubo destete precoz en el 65,17 % y hacinamiento en el 62,92 %, presentándose en el 45,9 % algún grado de desnutrición y el 37,08 % fueron bajo peso al nacer. El 32,58 % eran madres menores de 20 años y sólo el 15,73 % uso la lactancia materna pura. Se concluyó que todos los factores evaluados se comportaron como factores de riesgo, infiriéndose la importancia de la Educación para la Salud.A case-control study, matched 1:1, was conducted aimed at knowing the behaviour of some risk factors of acute diarrheal diseases in children at the Central Community Polyclinic of Camagüey, during 18 months. The case group was composed of 89 children from that health area that were discharged with that diagnosis, whereas the control group had the same number of children who were sound and lived in the same area. Both groups were surveyed and the data obtained were automatically processed. 97.6 % of the children were under 1, domestic hygiene was not good in 80.9 % and personal hygiene was also bad in 73.03 %. It was observed early weaning in 65.1 % and heaping in 62.92 %. Some degree of malnutrition was found in 15.9 % and 37.08 % were considered as low birth weight. 32.58 % were mothers under 20. Only 15

  12. Estudo longitudinal do eletrocardiograma na doença de Chagas desde a fase aguda

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    Roberto C. Pedrosa

    1993-09-01

    Full Text Available Vários trabalhos com eletrocardiograma na doença de Chagas têm sido feitos. Alguns referindo-se a grupos selecionados de casos, outros a estudos longitudinais, relatam as características da mortalidade nas diversas fases da doença. Com o objetivo de avaliar o valor do eletrocardiograma como índice de avaliação terapêutica e de seu comportamento na doença de Chagas desde a fase aguda, no presente trabalho, analisou-se evolutivamente o eletrocardiograma de 42 pacientes (18 mulheres e 24 homens procedentes da zona rural do Norte de Minas Gerais; predomínio etário foi nas duas primeiras décadas; todos com comprometimento cardíaco; todos receberam tratamento específico. O acompanhamento dos 42 pacientes foi de 9 anos dos quais 3 pacientes tiveram seguimento de 20 anos. Foram analisados 270 eletrocardiogramas. Nós utilizamos os seguintes critérios para a análise do ECG: código de Minnesota modificado para doença de Chagas; WHO/I. S. F. C. TASK FORCE para condução intraventricular e critérios de Pieretti para área eletricamente inativa. Concluímos que as alterações eletrocardiográficas agravam com a evolução da doença e que o eletrocardiograma não serve de índice de avaliação terapêutica.Several studies have been done to analyse the relationship between the characteristics of the electrocardiogram (ECG and mortality in the several stages of the disease, using different methods like multiple case and longitudinal studies. We anatysed the ECGfrom the acute stage up to twenty years of follow-up (±9 years in 42 patients with Chagas ' disease to determine their evolution and it 's value like an indexfor therapeutic evaluation. The 42 patients (18 female, 24 males were originalty from the North of the State of Minas Gerais (Brazil and the initial stage was mainly in the first two decades of age. All bad cardiac involvementand received fiill specific treatment. We utilized the following criteria for the ECG analyses

  13. Manejo de las infecciones respiratorias agudas (IRA en una comunidad kaqchiquel de Guatemala

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    Sáenz de Tejada Sandra

    1997-01-01

    Full Text Available Las infecciones respiratorias agudas (IRA figuran entre las principales causas de morbilidad y mortalidad infantiles en América Latina. En Guatemala, la neumonía es la primera causa de muerte en niños pequeños y ocasiona aproximadamente una tercera parte de las consultas ambulatorias a servicios pediátricos. Una buena proporción de estas muertes se deben a un manejo deficiente, atribuible a la falta de reconocimiento de los primeros signos de neumonía, a la presencia de barreras que impiden una búsqueda inmediata de atención, a la consulta a proveedores inapropiados o a recomendaciones terapéuticas inadecuadas. El propósito de esta breve investigación cualitativa fue estudiar las percepciones y los comportamientos de los habitantes de San Juan Comalapa, comunidad kaqchiquel en el altiplano central de Guatemala, en lo que respecta a las IRA. Se entrevistó a 32 madres en su domicilio con el fin de determinar cómo clasificaban las IRA y qué signos y síntomas las hacían buscar atención inmediata. Los resultados revelaron que las madres sabían reconocer la presencia de respiración rápida, pero no de tiraje respiratorio (dos signos importantes de neumonía. Cuando buscaban atención, solían acudir a médicos u otros proveedores en centros de salud y ocasionalmente en consultorios privados, pero la búsqueda raras veces era oportuna debido a la poca accesibilidad de los servicios y a la subestimación de la gravedad de los síntomas. Esta conducta podría modificarse por medio de una intervención educativa. Al final se hacen recomendaciones orientadas a mejorar la comunicación verbal entre los proveedores de atención de salud y las madres.

  14. Manejo de las infecciones respiratorias agudas (IRA en una comunidad kaqchiquel de Guatemala

    Directory of Open Access Journals (Sweden)

    Sandra Sáenz de Tejada

    1997-04-01

    Full Text Available Las infecciones respiratorias agudas (IRA figuran entre las principales causas de morbilidad y mortalidad infantiles en América Latina. En Guatemala, la neumonía es la primera causa de muerte en niños pequeños y ocasiona aproximadamente una tercera parte de las consultas ambulatorias a servicios pediátricos. Una buena proporción de estas muertes se deben a un manejo deficiente, atribuible a la falta de reconocimiento de los primeros signos de neumonía, a la presencia de barreras que impiden una búsqueda inmediata de atención, a la consulta a proveedores inapropiados o a recomendaciones terapéuticas inadecuadas. El propósito de esta breve investigación cualitativa fue estudiar las percepciones y los comportamientos de los habitantes de San Juan Comalapa, comunidad kaqchiquel en el altiplano central de Guatemala, en lo que respecta a las IRA. Se entrevistó a 32 madres en su domicilio con el fin de determinar cómo clasificaban las IRA y qué signos y síntomas las hacían buscar atención inmediata. Los resultados revelaron que las madres sabían reconocer la presencia de respiración rápida, pero no de tiraje respiratorio (dos signos importantes de neumonía. Cuando buscaban atención, solían acudir a médicos u otros proveedores en centros de salud y ocasionalmente en consultorios privados, pero la búsqueda raras veces era oportuna debido a la poca accesibilidad de los servicios y a la subestimación de la gravedad de los síntomas. Esta conducta podría modificarse por medio de una intervención educativa. Al final se hacen recomendaciones orientadas a mejorar la comunicación verbal entre los proveedores de atención de salud y las madres.

  15. Mortalidad por intoxicaciones agudas producidas con medicamentos: Cuba, 1995-1996

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    María Luisa González Valiente

    2000-04-01

    Full Text Available Se realizó un estudio descriptivo para determinar la incidencia de intoxicaciones agudas fatales medicamentosas en 1995 y 1996, y los principal