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Sample records for forma axonal aguda

  1. ESTUDIO DE CASO DE LEPTOSPIROSIS AGUDA EN SU FORMA ICTERICA EN UN PERRO FRENCH POODLE

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    V. Velázquez-Ordoñez

    2015-01-01

    En el estudio de caso realizado mediante el examen físico y el estudio patológico de un perro French poodle con ictericia, permitió determinar un cuadro de Leptospirosis canina en su forma ictérica relacionada con la enfermedad de Weil, ocasionada posiblemente por L. icterohaemorrhagiae la cual produce una ictericia de origen hepático. La signología referida en el animal de: ictericia, fiebre, deshidratación severa, dolor lumbar y abdominal, se relacionaron con una enfermedad renal y hepática...

  2. 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...

  3. Hipercalcemia grave como forma de apresentação de leucemia linfoblástica aguda em crianças

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    Andreia Luís Martins

    2015-12-01

    Full Text Available RESUMO A hipercalcemia é um distúrbio metabólico raro em pediatria, potencialmente fatal, apresentando um vasto diagnóstico diferencial, incluindo neoplasias. Relatamos aqui o caso de uma criança de 3 anos, previamente saudável, admitida no serviço de urgência por fadiga, hiporreatividade, febre e claudicação da marcha com 5 dias de evolução, de agravamento progressivo. À observação, apresentava-se inconsciente (escore de coma Glasgow: 8. Laboratorialmente, apresentava hipercalcemia grave (cálcio total 21,39mg/dL, ionizado 2,93mmol/L e anemia microcítica. Iniciou hiper-hidratação e foi transferido para a unidade de cuidados intensivos pediátricos. Instituiu-se hemodiafiltração venovenosa contínua com soluto livre de cálcio, ocorrendo a progressiva normalização da calcemia, com melhoria do estado de consciência. Administrou-se zolendronato. Excluíram-se causas metabólicas, infecciosas e intoxicação. O mielograma permitiu o diagnóstico de leucemia linfoblástica aguda. A hipercalcemia associada à malignidade em pediatria é rara, ocorrendo como forma de apresentação da neoplasia ou na recorrência desta. Em situações com risco de vida iminente, deve se considerar hemodiafiltração venovenosa contínua.

  4. 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

  5. Hepatitis viral aguda

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    Héctor Rubén Hernández Garcés; René F. Espinosa Álvarez

    1998-01-01

    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, ...

  6. DIARREA AGUDA

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    RAÚL ACUÑA M., DR.

    2015-01-01

    En este artículo se enfocará la diarrea aguda del adulto desde una perspectiva clínica, incorporando definiciones básicas de epidemiología, fisiopatología, enfrentamiento clínico, estudio cuando corresponda y tratamiento. Se presentarán nuevas herramientas diagnósticas basadas en biología molecular, de reciente introducción en clínica y que han significado un aporte en casos seleccionados. Además, se enfrentan situaciones especiales como la diarrea del viajero y de los pacientes inmunocomprom...

  7. Respostas cardiovasculares agudas ao exercício de força realizado em três diferentes formas de execução Acute cardiovascular responses to strength exercise in three different execution patterns

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    Walace David Monteiro

    2008-04-01

    Full Text Available A forma de condução do movimento no exercício de força pode afetar as respostas cardiovasculares agudas. O estudo comparou as respostas agudas de freqüência cardíaca (FC, pressão arterial sistólica (PAS e duplo produto (DP durante o exercício extensão de joelhos nas formas unilateral, bilateral e alternada. A amostra foi composta por 10 voluntários com idades entre 23 e 39 anos (28±5 anos. Inicialmente os sujeitos realizaram testes de 10 repetições máximas (RM nas execuções bilateral e unilateral. Em seguida, foram medidas as respostas cardiovasculares nas três formas de execução. Em todos os casos, foram feitas três séries de 10 RM, com 2 min de intervalo entre elas. As medidas para cada forma de execução foram feitas com 24 h de intervalo. Os valores das variáveis observadas, considerando cada série para as formas bilateral, unilateral e alternada foram, respectivamente: FC1=108,6 vs 117,3 vs 110,9; FC2=120,0 vs 130,1 vs 130,0; FC=125,3 vs 137,1 vs 135,2; PAS1=143,8 vs 150,0 vs 144,8; PAS2=155,8 vs 159,6 vs 158,8; PAS3=159,6 vs 166,0 vs 164,8; DP1=15609,8 vs 17873,4 vs 16246,6; DP3=20016,8 vs 23175,2 vs 22572,0. Não foram encontradas diferenças significativas nas respostas de FC, PAS e DP para as distintas formas de execução em cada série isoladamente. A partir da 2ª série os valores absolutos para as respostas de FC e DP foram maiores nas formas unilateral e alternada, em comparação com a execução bilateral (pThe pattern of execution can influence the acute cardiovascular responses during exercise. The study observed the heart rate (HR, systolic blood pressure (SBP, and double product (DP during leg extension executed in three different ways - single-leg (SL, double-leg (DL and alternate (AL. Ten healthy volunteers (28 ± 5 years-old performed three bouts of 10 maximum repetitions of each execution pattern, with a two min interval between sets. The sessions for SL, DL, and AL were held at different days

  8. DIARREA AGUDA

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    RAÚL ACUÑA M., DR.

    2015-09-01

    Full Text Available En este artículo se enfocará la diarrea aguda del adulto desde una perspectiva clínica, incorporando definiciones básicas de epidemiología, fisiopatología, enfrentamiento clínico, estudio cuando corresponda y tratamiento. Se presentarán nuevas herramientas diagnósticas basadas en biología molecular, de reciente introducción en clínica y que han significado un aporte en casos seleccionados. Además, se enfrentan situaciones especiales como la diarrea del viajero y de los pacientes inmunocomprometidos. La diarrea asociada a antibióticos se tratará en un artículo aparte.

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. Meningitis bacteriana aguda

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    D. Rodrigo Blamey, Dr.

    2014-01-01

    La Meningitis Bacteriana Aguda (MBA) de adquisición comunitaria es una enfermedad prevalente en todo el mundo; constituye siempre una emergencia médica y se asocia a una alta morbimortalidad. Su epidemiología es variable y los principales agentes en adultos son S. pneumoniae, N. meningitidis, H. influenzae y L. monocitogenes. En Chile existe un sistema de vigilancia recientemente implementado que permitirá un mejor diagnóstico epidemiológico. Las manifestaciones clínicas clásicas no siempre e...

  16. 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.

  17. Insuficiencia Renal Aguda

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    Domínguez Otero, Ana Isabel

    1986-01-01

    Dadas la graves alteraciones fisiopatológicas producidas por la Insuficiencia Renal Aguda (I.R.A), y siendo ésta una enfermedad en alto porcentaje prevenible, se trata de ilustrar cómo en toda persona en estado crítico una buena observación de la función renal y un adecuado manejo de la alteración primaria, por parte del profesional de enfermería, disminuye los riesgos de desarrollar una insuficiencia renal y los daños que tal síndrome produce.

  18. Segunda contribuição sobre as alterações ultra-estruturais dos hepatócitos na forma aguda (toxêmica da esquistossomose mansoni Second contribution on ultrastructural alterations of acute hepatocyte (toxaemic of schistosomiasis mansoni

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    Pedro Raso

    1981-06-01

    Full Text Available Estudamos as alterações ultra-estruturais dos hepatócitos na forma aguda, toxêmica, da esquistossomose, em cinco pacientes, membros de uma mesma família infectados em idênticas condições em um córrego existente próximo da lagoa de Pampulha, em Belo Horizonte (MG, e não tratados especificamente para a esquistossomose. Este estudo confirma os dados obtidos em trabalho anterior, em sete pacientes infectados no Município de Sabara (MG. Nos cinco casos, as alterações ultra-estruturais foram inespecíficas, pouco acentuadas, embora mais intensas do que as observadas anteriormente, e se caracterizaram sobretudo pelas modificações das organelas citoplasmáticas, explicando o freqüente encontro de células claras a microscopia óptica. A identificação de alguns granulomas a microscopia eletrônica permitiu verificar que estes mostram, no exstudato, granulócitos eosinófilos, macrófagos, plasmócitos, células epitelióides e mastócitos. Entre as células havia material amorfo e finos feixes de colágeno.In this paper the authors discuss the ultrastructural changes of liver cells in the acute toxaemic form of schistosomiasis mansoni in five member of the same family who got the infection in identical conditions in an endemic area located near the Pampulha Lake, in Belo Horizonte (MG and that did not receive specific treatment for schistosomiasis. This study confirms the data obtained and documented in a prior communication in seven patients infected in Sabará (MG. In the five cases the ultrastructural changes were also non-specific, although more intense than observed previuosly and were characterized mainly by alteration of the cytoplasmic organelles that could explain the common feature of clear cells by light microscopy. The results of the observation of some granulomas in ultrathin sections have demonstrated eosinophils, macrophages, plasma cells, epithelioid cells and mast cells. Among these cells there were also ground

  19. Meningitis bacteriana aguda

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    D. Rodrigo Blamey, Dr.

    2014-05-01

    Full Text Available La Meningitis Bacteriana Aguda (MBA de adquisición comunitaria es una enfermedad prevalente en todo el mundo; constituye siempre una emergencia médica y se asocia a una alta morbimortalidad. Su epidemiología es variable y los principales agentes en adultos son S. pneumoniae, N. meningitidis, H. influenzae y L. monocitogenes. En Chile existe un sistema de vigilancia recientemente implementado que permitirá un mejor diagnóstico epidemiológico. Las manifestaciones clínicas clásicas no siempre están presentes principalmente en adultos mayores. El diagnóstico requiere del estudio de líquido cefalorraquídeo, y las técnicas de biología molecular han significado un aporte relevante en los últimos años. El tratamiento antibiótico debe ser instaurado rápidamente para mejorar el pronóstico, mientras que la terapia coadyuvante con corticoides en adultos tiene sólo beneficios en etiología neumocócica. Se requieren mejores estrategias de prevención frente a una entidad que no ha cambiado su mortalidad a pesar del progreso de la medicina moderna.

  20. PANCREATITIS AGUDA EN EL EMBARAZO: A PROPÓSITO DE UN CASO CLÍNICO

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    Sanhueza R,Pablo; Yaksic B,Nicole; Chahuán I,Karina; Corvalán A,Jaime

    2004-01-01

    Se describe el caso clínico de un embarazo complicado con pancreatitis aguda, destacándose la importancia del diagnóstico correcto y las opciones terapéuticas en pacientes embarazadas. Paciente primigesta de 35 semanas con sospecha clínica de pancreatitis aguda y confirmación mediante amilasemia de 2.236 U/L y lipasemia de 1.930 U/L, es tratada en forma conservadora. Al cuarto día de hospitalización se realiza operación cesárea por sufrimiento fetal. Evoluciona en buenas condiciones y es dada...

  1. 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.

  2. PREVALENCIA DE PANCREATITIS AGUDA EN EL EMBARAZO

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    Ríos-Cruz,Daniel; Valerio-Ureña,Joaquín; Santiago-Pérez,Fátima

    2015-01-01

    Objetivo: Determinar la prevalencia y características de la pancreatitis aguda durante el embarazo en el Hospital de Alta Especialidad de Veracruz, México. Material y Métodos: Se realizó un estudio retrospectivo, descriptivo de todas las pacientes embarazadas diagnosticadas con pancreatitis agudas de enero tratadas en este Hospital. Resultados: Se revisaron 4.478 expedientes de mujeres gestantes, de las cuales 6 presentaron pancreatitis aguda durante su embarazo, esto corresponde a una de cad...

  3. Estratégias para atenuação e manutenção do desempenho de atletas expostos de forma aguda a ambientes hipobáricos: uma revisão bibliográfica = Performance maintenance strategies of athletes exposed to hypobaric environments: a literature review

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    Lara, Bernardo Amarante de

    2013-01-01

    Full Text Available A exposição aguda à altitude ainda é um grande desafio para atletas de diferentes modalidades, pois promove importantes alterações fisiológicas no corpo humano. O objetivo desta revisão foi buscar estratégias de atenuação ou tratamentos dos efeitos da exposição aguda à altitude em situações de exercício. Quarenta e um artigos foram incluídos, através de busca a bases de dados. Os demais artigos que complementam essa revisão referem-se à leitura das referências dos artigos base. Dentre as estratégias mais utilizadas estão a aclimatação, o suporte de O2, injeção de Eritropoietina e a nutrição. Um estudo utilizou-se da Pressão Positiva Contínua nas Vias Aéreas (CPAP para tratamento de edema de pulmão de alta altitude, apresentando resultados promissores. Novos estudos visando à manutenção e à atenuação do desempenho esportivo em altitude devem ser realizados

  4. Acute nutritional axonal neuropathy.

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    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.

  5. Colecistitis aguda por Streptococcus constellatus

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    M Sandra Gómez-Canosa

    2016-03-01

    Full Text Available Presentamos el caso de una paciente de edad avanzada y significativa comorbilidad que se diagnosticó de colecistitis aguda por Streptococcus constellatus. El drenaje de la vesícula biliar por colecistostomía percutánea, asociado a penicilinas, ha conseguido una evolución favorable. We report the case of a patient of advanced age and significant comorbidity diagnosed acute cholecystitis by Streptococcus constellatus. Gallbladder drainage by percutaneous cholecystostomy associated with penicillins has achieved a favorable outcome.

  6. 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.

  7. Classificação de gravidade na pancreatite aguda

    Directory of Open Access Journals (Sweden)

    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.

  8. 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.

  9. Incidencia de las intoxicaciones agudas

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    María Luisa González Valiente

    1999-02-01

    Full Text Available Se realiza un estudio de tipo descriptivo longitudinal y prospectivo para conocer la incidencia de intoxicaciones agudas y sus principales características, y para valorar indicadores de morbimortalidad con vistas a proponer medidas para el control y la prevención de esta enfermedad. El universo lo constituyó la totalidad de la población del territorio (Marianao, de donde se obtuvo una muestra representativa probabilística con el método combinado (estratificado y conglomerado. El riesgo de intoxicaciones agudas fue de 363,1 casos por 100 000 habitantes, cifra muy superior a la del país, según notificación del Sistema Estadístico de las Enfermedades de Declaración Obligatoria. El sexo femenino duplicó el riesgo en relación con el masculino. En las edades pediátricas el riesgo es muy superior al del adulto, ubicándose la mayor frecuencia de casos entre los 5 y los 9 años, mientras que en los adultos la mayor incidencia está entre los más jóvenes (15 a 24 años. Predominó el riesgo de accidentes en general, pero en las mujeres la supremacía se presentó en la causa voluntaria. Los agentes causales más frecuentes de las intoxicaciones agudas fueron los medicamentos, y entre éstos, los psicofármacosA descriptive, longitudinal and prospective study was conducted to know the incidence of acute poisonings and their main characteristics, and to assess the morbimortality indicators to propose measures for the control and prevention of this disease. The universe was composed of all the people living in the territory of Marianao. A probabilistic representative sample was obtained by the combined method (stratified and conglomerate. The risk of acute poisonings was 363.1 cases per 100 000 inhabitants, a much higher figure compared with that of the country, according to the report of the Statistical System of Diseases of Compulsory Declaration. Females doubled the risk in comparison with males. The risk at pediatric ages was much more

  10. 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.

  11. Fase aguda da esquistossomose mansoni

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    Edward Tonelli

    1972-10-01

    Full Text Available O A. faz um estudo panorâmico sobre a fase aguda da esquistossomose mansoni, abordando o quadro clínico e seu diagnóstico, os exames subsidiários, o diagnóstico diferencial, a terapêutica e os aspectos evolutivos. As manifestações clinicas dos períodos de incubação, de estado e de supressão são abordados. O diagnóstico da fase aguda é baseado em dado epidemiológico, 110 exame fisico e em exames subsidiários. O dado epidemiológico. em geral, é positivo, com menção a banho infectante, comumente 30 a 40 dias antes do início do quadro clínico e ao exame físico, encontramos hipertermia (38 - 4G°C, prostração, micropoliadenia hepatomegalia dolorosa em 95%, dos casos e esplenomegalia em 70% dos casos. Os exames prioritários para o diagnóstico são o exame parasiiológico de fezes seriado, que é positivo para ovos viáveis de S. mansoni e o leucograma seriado, que, geralmente, acusa leucocitose com eosinofilia. Em caso de dúvida ou para complementação diagnostica, podemos recorrer à endoscovia retal, ao oograma e á biópsia hepática. A endoscopia acusa, comumente, mucosa hiperêmica, edemaciada, friável, granulosa, com pontos hemorrágicos e o exame colhido por punção biópsia revela, entre outros achados, granulomas na fase necrótica-exsudativa. O diagnóstico diferencial deve ser feito com as seguintes entidades clínicas: gastroenterites. febre tifóide, disenteria bacilar, amebíase aguda, salmonelose septicêrnica prolongada, devendo, ainda, figurar a tuberculose miliar, abdome agudo, a G.N.D.A., a mononucleose infecciosa, a leptospirose, a hepatite e as poaneurites. A terapeutica é baseada nos cuidados gerais, na córticoterapia e na terapêutica específica. Observamos regressão dramática do quadro toxinfeccioso. nas primeiras 24 a 48 horas com a córticoterapia (prednisona que tem duração aproximada de 7 a 10 dias. A terapêutica específica (derivado nitrotiazolico = ambilhar e derivado hidroximet

  12. PANCREATITIS AGUDA PUERPERAL TRAS CESÁREA

    OpenAIRE

    Díaz M,Virginia; Moral P,José María; Zapardiel G,Ignacio; Bartolomé V,Alicia; Barbosa R,José Luís; García M,Pedro

    2008-01-01

    La pancreatitis aguda es una complicación poco frecuente en el embarazo, pero que presenta una gran morbimortalidad, siendo su prevalencia mayor en el tercer trimestre y puerperio inmediato. Presentamos un caso de pancreatitis aguda post cesárea en una paciente sin antecedentes, a cuyo diagnóstico se llegó por el apoyo de pruebas diagnósticas de imagen. El tratamiento fue llevado por un equipo multidisciplinario que logró la remisión completa de la enfermedad.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. Formas obstrutivas da neurocisticercose ventricular

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    Sylvio de Vergueiro Forjaz

    1961-03-01

    Full Text Available A incidência da cisticercose cerebral entre os consulentes orientados para o Ambulatório de Neurologia da Faculdade de Medicina de Ribeirão Prêto é muito alta. Trata-se de moléstia que, pela gravidade de seus sintomas, pela facilidade de infestação e pela precariedade dos recursos terapêuticos, representa um probiema individual e social grave nesta região. Muitos aspectos da moléstia já foram esclarecidos, sendo grande a contribuição de autores brasileiros. Certas feições da moléstia, porém, ainda comportam maiores estudos. É nosso objetivo oferecer uma contribuição ao estudo das formas intraventriculares de neurocisticercose. Relatamos as observações de 4 pacientes com queixas de hipertensão intracraniana periódica e com achados liquóricos e radiológicos compatíveis com a suspeita de cisticercose cerebral. Exames subsidiários (pneumencefalografia ou ventriculografia mostraram que em dois dêstes pacientes havia bloqueio do aqueduto de Sylvius (casos 3 e 4 e que, nos outros dois, havia exclusão de um ventrículo lateral por bloqueio do buraco de Monro (caso 1 e da confluência dos cornos temporal e occipital (caso 2. Nos dois casos em que havia bloqueio na parte alta do aqueduto de Sylvius os pacientes acusavam dificuldade no olhar vertical (síndrome de Parinaud. O tratamento cirúrgico permitiu desfazer o bloqueio em 3 casos (casos 2, 3 e 4; no caso 1 as punções feitas após a intervenção cirúrgica parecem ter agido benèficamente no sentido de restabelecer o trânsito do liqüido cefalorraquidiano. Excluindo um paciente (caso 2 que faleceu em caquexia 3 meses após a operação e no qual o exame necroscópico mostrou lesões pregressas imputáveis apenas à hipertensão aguda sem lesões cisticercóticas, os outros casos evoluíram para a cura.

  19. 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

  20. Soporte nutricional en la insuficiencia renal aguda

    OpenAIRE

    Cristina Olivos, O.

    2010-01-01

    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 ac...

  1. Soporte nutricional en la insuficiencia renal aguda

    Directory of Open Access Journals (Sweden)

    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.

  2. 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.

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

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    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. CSPGs inhibit axon branching by impairing mitochondria-dependent regulation of actin dynamics and axonal translation.

    Science.gov (United States)

    Sainath, Rajiv; Ketschek, Andrea; Grandi, Leah; Gallo, Gianluca

    2017-04-01

    Chondroitin sulfate proteoglycans (CSPGs) inhibit the formation of axon collateral branches. The regulation of the axonal cytoskeleton and mitochondria are important components of the mechanism of branching. Actin-dependent axonal plasticity, reflected in the dynamics of axonal actin patches and filopodia, is greatest along segments of the axon populated by mitochondria. It is reported that CSPGs partially depolarize the membrane potential of axonal mitochondria, which impairs the dynamics of the axonal actin cytoskeleton and decreases the formation and duration of axonal filopodia, the first steps in the mechanism of branching. The effects of CSPGs on actin cytoskeletal dynamics are specific to axon segments populated by mitochondria. In contrast, CSPGs do not affect the microtubule content of axons, or the localization of microtubules into axonal filopodia, a required step in the mechanism of branch formation. It is also reported that CSPGs decrease the mitochondria-dependent axonal translation of cortactin, an actin associated protein involved in branching. Finally, the inhibitory effects of CSPGs on axon branching, actin cytoskeletal dynamics and the axonal translation of cortactin are reversed by culturing neurons with acetyl-l-carnitine, which promotes mitochondrial respiration. Collectively these data indicate that CSPGs impair mitochondrial function in axons, an effect which contributes to the inhibition of axon branching. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 419-437, 2017. © 2016 Wiley Periodicals, Inc.

  6. The axonal cytoskeleton : from organization to function

    NARCIS (Netherlands)

    Kevenaar, Josta T|info:eu-repo/dai/nl/338771042; Hoogenraad, Casper C|info:eu-repo/dai/nl/227263502

    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

  7. Necrosectomía laparoscópica en pancreatitis aguda

    Directory of Open Access Journals (Sweden)

    Andrés Fernández Gómez

    Full Text Available Introducción: la pancreatitis aguda, a pesar de los avances recientes, es aún un problema para la cirugía actual. Su forma necrotizante constituye la forma más temida con una mortalidad estimada del 50% de los casos operados, y hasta el 100% de los no operados. Un número significativo de afectados de pancreatitis necrotizante requerirá cirugía, siendo la necrosectomía por laparotomía la forma fundamental del manejo, sin embargo, nuevas modalidades de cirugía mínimamente invasivas han sido incorporadas al tratamiento. El abordaje laparoscópico constituye una de estas modalidades con las consiguientes ventajas que supone el método en la ulterior evolución del paciente y su rápida recuperación, siendo también una de las rutas menos empleadas y evaluadas fundamentalmente por los requerimientos técnicos, personal entrenado y condiciones del paciente que se necesitan. Caso clínico: se trató de un paciente con diagnóstico clínico y tomográfico de pancreatitis aguda necrotizante, intervenido quirúrgicamente a las tres semanas de su ingreso por la presencia de un absceso pancreático y ulteriormente por necrosis extensa infectada. Se logra una evolución satisfactoria siendo egresado sin complicaciones. Conclusiones: el abordaje laparoscópico de estos pacientes es posible siempre que existan las condiciones técnicas disponibles, el personal entrenado, y las condiciones del paciente lo permitan. Esto significaría muchas ventajas para los mismos, con resultados superiores a la vía convencional incluyendo la posibilidad de una marcada reducción de la alta tasa de morbilidad y mortalidad aún presentes en la cirugía de la pancreatitis aguda complicada.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Bronquiolite Aguda: Actualização de Conceitos Terapêuticos e Profilácticos

    OpenAIRE

    Pequito, Margarida; Branco, Ana Sofia; Pereira, Luísa; Barreto, Celeste; Lito, Luís; Bandeira, Teresa

    2014-01-01

    A bronquiolite aguda é frequente abaixo dos 2 anos de idade. Apesar da inexistência de vacinação ou de terapêuticas específicas com comprovada eficácia, novas formas de profilaxia surgiram nos últimos anos cuja prescrição deverá ser baseada em dados epidemiológicos e conhecimento de grupos de risco.Com o objectivo de avaliar grupos de risco e agentes responsáveis por bronquiolite com necessidade de internamento e comparar a terapêutica efectuada com as actuais recomendações da literatura, efe...

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

    OpenAIRE

    Marcelo J. Melero; Sergio G. Sarquis; César Biancolini; Natalio Baredes; Roberto Villa

    2007-01-01

    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 e...

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Intoxicación aguda por plaguicidas en edades pediátricas. Guatemala, 2011

    Directory of Open Access Journals (Sweden)

    Mario Enrique Pla Acevedo

    2015-11-01

    Full Text Available Se realizó un estudio descriptivo retrospectivo de la Intoxicación Aguda por plaguicidas en edades pediátricas en Guatemala, que abarcó el  período de enero hasta diciembre del 2011. La muestra estuvo comprendida por 457 pacientes en edades pediátricas. Se analizaron las variables: edad y sexo, actividad que realizaba en el momento de la intoxicación, tipo de plaguicida, severidad, utilización de equipos de protección y lugar de asistencia médica. Las variables para el análisis de los indicadores fueron obtenidas por el Centro Nacional de Epidemiología. Como resultados fundamentales se observó que la Intoxicación Aguda por plaguicidas afectó principalmente al grupo de edades entre 17 y 19 años. El sexo masculino fue el más perjudicado, el mayor porciento de afectados, según causa, fue accidente de trabajo, con un 68% del total de casos; el tipo de plaguicida más utilizado que provocó intoxicación fue el paraquat; predominó la forma severa en los que no usaron medios de protección y el  lugar de atención médica y de notificación correspondió al hospital.

  14. 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

  15. Epidemiología de la injuria renal aguda y enfermedad renal crónica en la unidad de cuidados intensivos

    Directory of Open Access Journals (Sweden)

    Darwin Tejera

    2017-11-01

    Full Text Available RESUMEN Objetivo: Describir la epidemiología de la injuria renal aguda, la relación con la enfermedad renal crónica y los factores asociados a su incidencia. Métodos: Estudio de cohorte y seguimiento en una unidad de terapia intensiva de Montevideo - Uruguay. Se incluyeron pacientes ingresados entre noviembre 2014 a octubre 2015, mayores de 15 años con dos mediciones de creatinina sérica. Se excluyeron pacientes con menos de 48 horas de internación o fallecidos en ese tiempo y portadores de enfermedad renal crónica en hemodiálisis o diálisis peritoneal. No hubo intervenciones. La injuria renal aguda se definió según criterios Acute Kidney Injury Disease Improving Global Outcomes y la enfermedad renal crónica según Cronic Kidney Disease Work Group. Resultados: Se incluyeron 401 pacientes, sexo masculino 56,6%, mediana de edad 68 (rango intercuartílico - RIC 51 - 79 años. El diagnóstico al ingreso fue sepsis grave 36,3%, neurocrítico 16,3%, politrauma 15,2% y otros 32,2%. La incidencia de injuria renal aguda fue de 50,1%. El 14,1% eran portadores de enfermedad renal crónica. La incidencia de injuria renal aguda séptica fue de 75,3%. La mortalidad en los pacientes con o sin injuria renal aguda fue de 41,8 y 14% respectivamente (p < 0,001. En el análisis multivariado las variables de mayor significación para la injuria renal aguda fueron enfermedad renal crónica (odds ratio - OR 5,39 IC95% 2,04 - 14,29 p = 0,001, shock (OR 3,94 IC95% 1,72 - 9,07 p = 0,001 y sepsis grave (OR 7,79 IC 95% 2,02 - 29,97 p = 0,003. Conclusión: La incidencia de injuria renal aguda es elevada principalmente en pacientes sépticos. La enfermedad renal crónica se asoció de forma independiente al desarrollo de injuria renal aguda.

  16. Diagnóstico laboratorial das leucemias linfóides agudas

    OpenAIRE

    Farias Mariela Granero; Castro Simone Martins de

    2004-01-01

    A leucemia linfóide aguda (LLA) é a forma mais comum de câncer na infância, compreendendo 70% dos casos; em adultos a incidência é de apenas 20%. A abordagem inicial do diagnóstico consiste no exame citomorfológico do sangue periférico e da medula óssea. O estudo imunofenotípico eleva para 99% o percentual de casos corretamente classificados, permitindo identificar a linhagem celular (T ou B) e os diferentes estágios de maturação da célula. Aproximadamente 20% dos casos são de origem de célul...

  17. 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 b...

  18. Cell intrinsic control of axon regeneration

    Science.gov (United States)

    Mar, Fernando M; Bonni, Azad; Sousa, Mónica M

    2014-01-01

    Although neurons execute a cell intrinsic program of axonal growth during development, following the establishment of connections, the developmental growth capacity declines. Besides environmental challenges, this switch largely accounts for the failure of adult central nervous system (CNS) axons to regenerate. Here, we discuss the cell intrinsic control of axon regeneration, including not only the regulation of transcriptional and epigenetic mechanisms, but also the modulation of local protein translation, retrograde and anterograde axonal transport, and microtubule dynamics. We further explore the causes underlying the failure of CNS neurons to mount a vigorous regenerative response, and the paradigms demonstrating the activation of cell intrinsic axon growth programs. Finally, we present potential mechanisms to support axon regeneration, as these may represent future therapeutic approaches to promote recovery following CNS injury and disease. PMID:24531721

  19. Sorting of Dendritic and Axonal Vesicles at the Pre-axonal Exclusion Zone

    Directory of Open Access Journals (Sweden)

    Ginny G. Farías

    2015-11-01

    Full Text Available Polarized sorting of newly synthesized proteins to the somatodendritic and axonal domains of neurons occurs by selective incorporation into distinct populations of vesicular transport carriers. An unresolved issue is how the vesicles themselves are sorted to their corresponding neuronal domains. Previous studies concluded that the axon initial segment (AIS is an actin-based filter that selectively prevents passage of somatodendritic vesicles into the axon. We find, however, that most somatodendritic vesicles fail to enter the axon at a more proximal region in the axon hillock, herein referred to as the pre-axonal exclusion zone (PAEZ. Forced coupling of a somatodendritic cargo protein to an axonally directed kinesin is sufficient to drive transport of whole somatodendritic vesicles through the PAEZ toward the distal axon. Based on these findings, we propose that polarized sorting of transport vesicles occurs at the PAEZ and depends on the ability of the vesicles to acquire an appropriately directed microtubule motor.

  20. Esofagitis necrotizante aguda: Una entidad inusual

    Directory of Open Access Journals (Sweden)

    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.

  1. Radial glia phagocytose axonal debris from degenerating overextending axons in the developing olfactory bulb.

    Science.gov (United States)

    Amaya, Daniel A; Wegner, Michael; Stolt, C Claus; Chehrehasa, Fatemeh; Ekberg, Jenny A K; St John, James A

    2015-02-01

    Axon targeting during the development of the olfactory system is not always accurate, and numerous axons overextend past the target layer into the deeper layers of the olfactory bulb. To date, the fate of the mis-targeted axons has not been determined. We hypothesized that following overextension, the axons degenerate, and cells within the deeper layers of the olfactory bulb phagocytose the axonal debris. We utilized a line of transgenic mice that expresses ZsGreen fluorescent protein in primary olfactory axons. We found that overextending axons closely followed the filaments of radial glia present in the olfactory bulb during embryonic development. Following overextension into deeper layers of the olfactory bulb, axons degenerated and radial glia responded by phagocytosing the resulting debris. We used in vitro analysis to confirm that the radial glia had phagocytosed debris from olfactory axons. We also investigated whether the fate of overextending axons was altered when the development of the olfactory bulb was perturbed. In mice that lacked Sox10, a transcription factor essential for normal olfactory bulb development, we observed a disruption to the morphology and positioning of radial glia and an accumulation of olfactory axon debris within the bulb. Our results demonstrate that during early development of the olfactory system, radial glia play an important role in removing overextended axons from the deeper layers of the olfactory bulb. © 2014 Wiley Periodicals, Inc.

  2. 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.

  3. AxonSeg: Open Source Software for Axon and Myelin Segmentation and Morphometric Analysis.

    Science.gov (United States)

    Zaimi, Aldo; Duval, Tanguy; Gasecka, Alicja; Côté, Daniel; Stikov, Nikola; Cohen-Adad, Julien

    2016-01-01

    Segmenting axon and myelin from microscopic images is relevant for studying the peripheral and central nervous system and for validating new MRI techniques that aim at quantifying tissue microstructure. While several software packages have been proposed, their interface is sometimes limited and/or they are designed to work with a specific modality (e.g., scanning electron microscopy (SEM) only). Here we introduce AxonSeg, which allows to perform automatic axon and myelin segmentation on histology images, and to extract relevant morphometric information, such as axon diameter distribution, axon density and the myelin g-ratio. AxonSeg includes a simple and intuitive MATLAB-based graphical user interface (GUI) and can easily be adapted to a variety of imaging modalities. The main steps of AxonSeg consist of: (i) image pre-processing; (ii) pre-segmentation of axons over a cropped image and discriminant analysis (DA) to select the best parameters based on axon shape and intensity information; (iii) automatic axon and myelin segmentation over the full image; and (iv) atlas-based statistics to extract morphometric information. Segmentation results from standard optical microscopy (OM), SEM and coherent anti-Stokes Raman scattering (CARS) microscopy are presented, along with validation against manual segmentations. Being fully-automatic after a quick manual intervention on a cropped image, we believe AxonSeg will be useful to researchers interested in large throughput histology. AxonSeg is open source and freely available at: https://github.com/neuropoly/axonseg.

  4. Regulating Axonal Responses to Injury: The Intersection between Signaling Pathways Involved in Axon Myelination and The Inhibition of Axon Regeneration

    Science.gov (United States)

    Rao, Sudheendra N. R.; Pearse, Damien D.

    2016-01-01

    Following spinal cord injury (SCI), a multitude of intrinsic and extrinsic factors adversely affect the gene programs that govern the expression of regeneration-associated genes (RAGs) and the production of a diversity of extracellular matrix molecules (ECM). Insufficient RAG expression in the injured neuron and the presence of inhibitory ECM at the lesion, leads to structural alterations in the axon that perturb the growth machinery, or form an extraneous barrier to axonal regeneration, respectively. Here, the role of myelin, both intact and debris, in antagonizing axon regeneration has been the focus of numerous investigations. These studies have employed antagonizing antibodies and knockout animals to examine how the growth cone of the re-growing axon responds to the presence of myelin and myelin-associated inhibitors (MAIs) within the lesion environment and caudal spinal cord. However, less attention has been placed on how the myelination of the axon after SCI, whether by endogenous glia or exogenously implanted glia, may alter axon regeneration. Here, we examine the intersection between intracellular signaling pathways in neurons and glia that are involved in axon myelination and axon growth, to provide greater insight into how interrogating this complex network of molecular interactions may lead to new therapeutics targeting SCI. PMID:27375427

  5. Axonal interferon responses and alphaherpesvirus neuroinvasion

    Science.gov (United States)

    Song, Ren

    Infection by alphaherpesviruses, including herpes simplex virus (HSV) and pseudorabies virus (PRV), typically begins at a peripheral epithelial surface and continues into the peripheral nervous system (PNS) that innervates this tissue. Inflammatory responses are induced at the infected peripheral site prior to viral invasion of the PNS. PNS neurons are highly polarized cells with long axonal processes that connect to distant targets. When the peripheral tissue is first infected, only the innervating axons are exposed to this inflammatory milieu, which include type I interferon (e.g. IFNbeta) and type II interferon (i.e. IFNgamma). IFNbeta can be produced by all types of cells, while IFNgamma is secreted by some specific types of immune cells. And both types of IFN induce antiviral responses in surrounding cells that express the IFN receptors. The fundamental question is how do PNS neurons respond to the inflammatory milieu experienced only by their axons. Axons must act as potential front-line barriers to prevent PNS infection and damage. Using compartmented cultures that physically separate neuron axons from cell bodies, I found that pretreating isolated axons with IFNbeta or IFNgamma significantly diminished the number of HSV-1 and PRV particles moving from axons to the cell bodies in an IFN receptor-dependent manner. Furthermore, I found the responses in axons are activated differentially by the two types of IFNs. The response to IFNbeta is a rapid, axon-only response, while the response to IFNgamma involves long distance signaling to the PNS cell body. For example, exposing axons to IFNbeta induced STAT1 phosphorylation (p-STAT1) only in axons, while exposure of axons to IFNgamma induced p-STAT1 accumulation in distant cell body nuclei. Blocking transcription in cell bodies eliminated IFNgamma-, but not IFNbeta-mediated antiviral effects. Proteomic analysis of IFNbeta- or IFNgamma-treated axons identified several differentially regulated proteins. Therefore

  6. Torsional Behavior of Axonal Microtubule Bundles

    Science.gov (United States)

    Lazarus, Carole; Soheilypour, Mohammad; Mofrad, Mohammad R.K.

    2015-01-01

    Axonal microtubule (MT) bundles crosslinked by microtubule-associated protein (MAP) tau are responsible for vital biological functions such as maintaining mechanical integrity and shape of the axon as well as facilitating axonal transport. Breaking and twisting of MTs have been previously observed in damaged undulated axons. Such breaking and twisting of MTs is suggested to cause axonal swellings that lead to axonal degeneration, which is known as “diffuse axonal injury”. In particular, overstretching and torsion of axons can potentially damage the axonal cytoskeleton. Following our previous studies on mechanical response of axonal MT bundles under uniaxial tension and compression, this work seeks to characterize the mechanical behavior of MT bundles under pure torsion as well as a combination of torsional and tensile loads using a coarse-grained computational model. In the case of pure torsion, a competition between MAP tau tensile and MT bending energies is observed. After three turns, a transition occurs in the mechanical behavior of the bundle that is characterized by its diameter shrinkage. Furthermore, crosslink spacing is shown to considerably influence the mechanical response, with larger MAP tau spacing resulting in a higher rate of turns. Therefore, MAP tau crosslinking of MT filaments protects the bundle from excessive deformation. Simultaneous application of torsion and tension on MT bundles is shown to accelerate bundle failure, compared to pure tension experiments. MAP tau proteins fail in clusters of 10–100 elements located at the discontinuities or the ends of MT filaments. This failure occurs in a stepwise fashion, implying gradual accumulation of elastic tensile energy in crosslinks followed by rupture. Failure of large groups of interconnecting MAP tau proteins leads to detachment of MT filaments from the bundle near discontinuities. This study highlights the importance of torsional loading in axonal damage after traumatic brain injury

  7. IMP2 axonal localization, RNA interactome, and function in the development of axon trajectories

    DEFF Research Database (Denmark)

    Preitner, Nicolas; Quan, Jie; Li, Xinmin

    2016-01-01

    RNA-based regulatory mechanisms play important roles in the development and plasticity of neural circuits and neurological disease. Developing axons provide a model well suited to the study of RNA-based regulation, and contain specific subsets of mRNAsthat are locally translated and have roles...... to strong defects in commissural axon trajectories at the midline intermediate target. These results reveal a highly distinctive axonal enrichment of IMP2, show that it interacts with a network of axon guidance-related mRNAs, and reveal that it is required for normal axon pathfinding during vertebrate...

  8. Squid Giant Axons Synthesize NF Proteins.

    Science.gov (United States)

    Crispino, Marianna; Chun, Jong Tai; Giuditta, Antonio

    2018-04-01

    Squid giant axon has been an excellent model system for studying fundamental topics in neurobiology such as neuronal signaling. It has been also useful in addressing the questions of local protein synthesis in the axons. Incubation of isolated squid giant axons with [ 35 S]methionine followed by immunoprecipitation with a rabbit antibody against all squid neurofilament (NF) proteins demonstrates the local synthesis of a major 180 kDa NF protein and of several NF proteins of lower molecular weights. Their identification as NF proteins is based on their absence in the preimmune precipitates. Immunoprecipitates washed with more stringent buffers confirmed these results. Our data are at variance with a recent study based on the same experimental procedure that failed to visualize the local synthesis of NF proteins by the giant axon and thereby suggested their exclusive derivation from nerve cell bodies (as reported by Gainer et al. in Cell Mol Neurobiol 37:475-486, 2017). By reviewing the pertinent literature, we confute the claims that mRNA translation is absent in mature axons because of a putative translation block and that most proteins of mature axons are synthesized in the surrounding glial cells. Given the intrinsic axonal capacity to synthesize proteins, we stress the glial derivation of axonal and presynaptic RNAs and the related proposal that these neuronal domains are endowed with largely independent gene expression systems (as reported by Giuditta et al. in Physiol Rev 88:515-555, 2008).

  9. 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.

  10. Pancreatitis aguda debido a intususcepción gastroduodenal

    OpenAIRE

    Salazar Alarcón, Jorge Luis; Arones Collantes, Ricardo Alfredo; León Estrella, Miguel Ángel; Peña Peña, Carlos Saúl

    2016-01-01

    Introducción: Los pólipos gástricos adenomatosos son poco frecuentes y generalmente se encuentran en el examen endoscópico de rutina. La intususcepción gastroduodenal es una com- plicación poco frecuente de los pólipos gástricos y ha sido raramente descrita como una causa de pancreatitis aguda. Caso clínico: Presentamos el caso de un varón de 68 anos ̃ el cual ingresa de urgencia con dolor abdominal, náuseas y vómitos catalogados en un inicio como pancreatitis aguda de eti...

  11. Tratamiento fisioterápico en la bronquiolitis aguda infantil

    OpenAIRE

    Calonge García, Paula

    2016-01-01

    Introducción: La bronquiolitis aguda infantil es una de las principales causas de morbimortalidad en los niños cuya máxima incidencia está aumentando mucho en los últimos años generando así multitud de costes socioeconómicos. Objetivo: Realizar una revisión bibliográfica sobre las principales técnicas que se utilizan en fisioterapia respiratoria para conocer su evidencia y efectividad en los lactantes con bronquiolitis aguda infantil. Metodología: Se utilizaron las bases de datos MEDLIN...

  12. 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.

  13. Lesiones periapicales agudas en pacientes adultos

    Directory of Open Access Journals (Sweden)

    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. Necrose tubular aguda e anemia grave após uso intermitente de rifampicina

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    Eduardo Santos

    2013-03-01

    Full Text Available A rifampicina (RFP pode ser administrada diariamente ou num esquema intermitente. Quando é administrada de forma intermitente pode produzir reações imuno-alérgicas graves. Apresentamos o caso clínico de um pa-ciente que, após tratamento com RFP de forma intermitente para uma infeção por Mycobacterium intracellulare, desenvolveu quadro de necrose tubular aguda, anemia, prolongamento dos tempos de coagulação e citó-lise hepática ligeira. Após suspensão do fármaco houve recuperação em 24h das alterações da coagulação e da citólise hepática, tendo tido no entanto necessidade de hemodiálise por persistência de anúria e uremia, e transfusão de concentrados de eritrócitos pela gravidade da anemia. Teve alta com recuperação de todas as disfunções.

  15. The Genetics of Axon Guidance and Axon Regeneration in Caenorhabditis elegans

    Science.gov (United States)

    Chisholm, Andrew D.; Hutter, Harald; Jin, Yishi; Wadsworth, William G.

    2016-01-01

    The correct wiring of neuronal circuits depends on outgrowth and guidance of neuronal processes during development. In the past two decades, great progress has been made in understanding the molecular basis of axon outgrowth and guidance. Genetic analysis in Caenorhabditis elegans has played a key role in elucidating conserved pathways regulating axon guidance, including Netrin signaling, the slit Slit/Robo pathway, Wnt signaling, and others. Axon guidance factors were first identified by screens for mutations affecting animal behavior, and by direct visual screens for axon guidance defects. Genetic analysis of these pathways has revealed the complex and combinatorial nature of guidance cues, and has delineated how cues guide growth cones via receptor activity and cytoskeletal rearrangement. Several axon guidance pathways also affect directed migrations of non-neuronal cells in C. elegans, with implications for normal and pathological cell migrations in situations such as tumor metastasis. The small number of neurons and highly stereotyped axonal architecture of the C. elegans nervous system allow analysis of axon guidance at the level of single identified axons, and permit in vivo tests of prevailing models of axon guidance. C. elegans axons also have a robust capacity to undergo regenerative regrowth after precise laser injury (axotomy). Although such axon regrowth shares some similarities with developmental axon outgrowth, screens for regrowth mutants have revealed regeneration-specific pathways and factors that were not identified in developmental screens. Several areas remain poorly understood, including how major axon tracts are formed in the embryo, and the function of axon regeneration in the natural environment. PMID:28114100

  16. 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.

  17. 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.

  18. Forma e performance

    Directory of Open Access Journals (Sweden)

    Patricia Elizabeth Easterling

    2014-09-01

    Full Text Available Este artigo propõe uma revisão da tragédia grega, chamando a atenção para a necessidade de se abandonar o modelo evolutivo tradicional e entendê-las como essencialmente uma forma performática, em que o texto atende às necessidades de palco, e, em um esforço imaginativo, se ler as peças a partir, também, de seus elementos dêiticos e meta-narrativos, operação ilustrada através de uma análise de Medeia e As Troianas. Tradução: Ricardo Pinto de Souza(publicado originalmente em The Cambridge COmpanion to Greek TragedyAbstract: This paper proposes a revision of the Greek Tragedy calling for the need of leave behind the traditional evolutive model and emphasize the performatic nature of Greek Tragedy. Tragedy is an art-form in which text must re-spond to stage and performatic needs and, as consequence, demands from its reader an imaginative effort to consider its deictic and meta-narrative elements of essence to its understanding.Keywords: Greek Tragedy; Deixis; Performance; Medea; The Trojan Women Patricia Elizabeth Easterling é fellow da Academia Britânica para Humanidades e Ciências Sociais e do Newham College, primeira mulher em 450 anos a receber a prestigiosa cátedra de Professor Régio de Grego da Universidade de Cambridge (de 1994 até sua aposentadoria, em 2001, especialista na obra de Sófocles e organizadora de The Cambridge History of Classical Literature (com E. J. Kenney e The Cambridge Companion to Greek Tragedy. Livros: Sophocles: Trachiniae, Cambridge, 1982; Greek Religion and Society, ed. com J. V. Muir, 1984; The Cambridge History of Classical Literature, ed. com E. J. Kenney, 1994; The Cambridge Companion to Greek Tragedy, ed. , 1997; Greek and Roman Actors: Aspects of an Ancient Profession, ed. com Edith Hall, 2002. Ricardo Pinto de Souza é professor de Teoria Literária na Faculdade de Letras da UFRJ, onde leciona também no Programa de Pós-Graduação em Ciência da Literatura. Coordena o Laborat

  19. 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.

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

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    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.

  1. Developmental downregulation of LIS1 expression limits axonal extension and allows axon pruning

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    Kanako Kumamoto

    2017-07-01

    Full Text Available The robust axonal growth and regenerative capacities of young neurons decrease substantially with age. This developmental downregulation of axonal growth may facilitate axonal pruning and neural circuit formation but limits functional recovery following nerve damage. While external factors influencing axonal growth have been extensively investigated, relatively little is known about the intrinsic molecular changes underlying the age-dependent reduction in regeneration capacity. We report that developmental downregulation of LIS1 is responsible for the decreased axonal extension capacity of mature dorsal root ganglion (DRG neurons. In contrast, exogenous LIS1 expression or endogenous LIS1 augmentation by calpain inhibition restored axonal extension capacity in mature DRG neurons and facilitated regeneration of the damaged sciatic nerve. The insulator protein CTCF suppressed LIS1 expression in mature DRG neurons, and this reduction resulted in excessive accumulation of phosphoactivated GSK-3β at the axon tip, causing failure of the axonal extension. Conversely, sustained LIS1 expression inhibited developmental axon pruning in the mammillary body. Thus, LIS1 regulation may coordinate the balance between axonal growth and pruning during maturation of neuronal circuits.

  2. 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.

  3. Insuficiencia renal aguda (IRA) en unidades de cuidados intensivos

    OpenAIRE

    Malinar, L. M.; Ciappa, J. M.; Auil, J. F.; Maltas, S.; Aran, M. N.; Ferrigno, J. A.; Dall'Aglio Palermo, L.

    2010-01-01

    La Injuria Renal Aguda es reconocida por su impacto en la evolución de los pacientes admitidos en Unidades de cuidados Intensivos. La amplia variedad de definiciones utilizadas en los diversos estudios es responsable de las diferencias en los reportes de incidencia y de Mortalidad asociada.

  4. 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.

  5. Fisiopatología de los trastornos hidroelectrolíticos y del equilibrio ácido-base, en la diarrea aguda coleriforme.

    OpenAIRE

    Cieza Zevallos, Javier

    2013-01-01

    El cólera es una enfermedad aguda que resulta de la colonización del intestino delgado por el vibrio cólera cuya patogenicidad se debe básicamente a la producción de toxina colérica y diarrea secretoria (1). Ya en los escritos de Susruta, Hipócrates y Galeno, se reconocen cuadros de diarrea y vómitos que causan la muerte. Sin embargo, existe duda desde cuando el cólera fue descrito por primera vez en su forma epidémica (2).

  6. Registro Alemán de la Disección Aguda de Aorta Tipo A (GERAADA

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    Ernst Weigang

    2009-07-01

    Full Text Available La disección aguda de aorta tipo A es una enfermedad grave de obligado tratamiento quirúrgico. El tratamiento quirúrgico tiene morbimortalidad elevada. No hay acuerdo general acerca de la mejor forma de tratamiento. Para obtener información que permita definir las mejores estrategias operatorias y de manejo global, el Grupo de Trabajo de Cirugía de la Aorta y Cirugía Vascular Intervencionista de la Sociedad Alemana de Cirugía Torácica y Cardiovascular (GSTCVS creó el Registro Alemán de la Disección Aguda Tipo A (GERAADA. Desde 2006, 44 centros han incluido 1.610 casos, con información completa en 1.558. La mortalidad a 30 días ha sido del 16% y la tasa de accidentes neurológicos del 10%. Tras la experiencia inicial con el registro, se desea desarrollar un Registro Europeo de las Enfermedades de la Aorta (European Registry for aortic Diseases [EuRADa] bajo los auspicios del vascular domain de la european association for Cardiothoracic Surgery (EACTS.

  7. 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...

  8. Genetics Home Reference: giant axonal neuropathy

    Science.gov (United States)

    ... connect the brain and spinal cord (central nervous system) to muscles and to sensory cells that detect sensations such as touch, pain, heat, and sound. However, axons in the central nervous system are affected as well. The signs and symptoms ...

  9. 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

  10. 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.

  11. 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: Neurosciences (including psychophysiology Impact factor: 4.431, year: 2016

  12. 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

  13. Axonal cleaved caspase-3 regulates axon targeting and morphogenesis in the developing auditory brainstem

    Directory of Open Access Journals (Sweden)

    Sarah E Rotschafer

    2016-10-01

    Full Text Available Caspase-3 is a cysteine protease that is most commonly associated with cell death. Recent studies have shown additional roles in mediating cell differentiation, cell proliferation, and development of cell morphology. We investigated the role of caspase-3 in the development of chick auditory brainstem nuclei during embryogenesis. Immunofluorescence from embryonic days E6-13 revealed that the temporal expression of cleaved caspase-3 follows the ascending anatomical pathway. Expression is first seen in the auditory portion of VIIIth nerve including central axonal regions projecting to nucleus magnocellularis (NM, then later in NM axons projecting to nucleus laminaris (NL, and subsequently in NL dendrites. To examine the function of cleaved caspase-3 in chick auditory brainstem development, we blocked caspase-3 cleavage in developing chick embryos with the caspase-3 inhibitor Z-DEVD-FMK from E6 to E9, then examined NM and NL morphology and NM axonal targeting on E10. NL lamination in treated embryos was disorganized and the neuropil around NL contained a significant number of glial cells normally excluded from this region. Additionally, NM axons projected into inappropriate portions of NL in Z-DEVD-FMK treated embyros. We found that the presence of misrouted axons was associated with more severe NL disorganization. The effects of axonal caspase-3 inhibition on both NL morphogenesis and NM axon targeting suggest that these developmental processes are coordinated, likely through communication between axons and their targets.

  14. Aspectos nutricionais na lesão renal aguda

    OpenAIRE

    Berbel,Marina Nogueira; Pinto,Milene Peron Rodrigues; Ponce,Daniela; Balbi,André Luís

    2011-01-01

    A avaliação nutricional é ferramenta indispensável para a monitoração e acompanhamento clínico do paciente com lesão renal aguda (LRA). A perda aguda da função renal interfere no metabolismo de todos os macronutrientes, propiciando situações pró-inflamatórias, pró-oxidativas e de hipercatabolismo. As principais alterações nutricionais no paciente com LRA são hipercatabolismo, hiperglicemia e hipertrigliceridemia, que, somadas às contribuições da doença de base, complicações e necessidade de t...

  15. Bronquiolite Aguda: O que Mudou nos Últimos Anos?

    OpenAIRE

    Coelho, Joana Malveiro Castelhanito Lourenço; Almeida, Marta; Martins, Teresa; Nunes, Filipa; Pinto, Margarida; Azeredo, Paula

    2015-01-01

    Introdução: A bronquiolite aguda é uma doença respiratória infecciosa aguda, muito contagiosa, frequente em crianças com idade inferior a dois anos. Existe uma enorme variabilidade na utilização de exames complementares de diagnóstico e na abordagem terapêutica. O objectivo deste estudo foi caracterizar a população de crianças com bronquiolite internadas na enfermaria de um hospital secundário em relação ao pedido de exames complementares de diagnóstico, tratamento e evolução. Métodos: Anális...

  16. Insuficiência renal aguda associada à leptospirose

    Directory of Open Access Journals (Sweden)

    Elizabeth De Francesco Daher

    2010-12-01

    Full Text Available A leptospirose é a zoonose mais importante do mundo. Os pacientes são tipicamente homens jovens. Vários fatores estão envolvidos na insuficiência renal aguda (IRA na leptospirose, incluindo ação nefrotóxica direta da leptospira, hiperbilirrubinemia, rabdomiólise e hipovolemia. Os principais achados histológicos são nefrite intersticial aguda e necrose tubular aguda. A IRA na leptospirose é geralmente não oligúrica e hipocalêmica. Alterações da função tubular precedem a queda na taxa de filtração glomerular, o que poderia explicar a alta frequência de hipocalemia. O tratamento antibiótico é eficaz nas fases precoces e tardias e/ou graves. Para pacientes críticos com IRA na leptospirose, as seguintes condutas são recomendadas: hemodiálise precoce e diária; baixa infusão de volume (devido ao risco de hemorragia pulmonar, e estratégias de proteção pulmonar. A mortalidade na IRA associada à leptospirose está em torno de 22%.

  17. 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

  18. 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.

  19. 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.

  20. Enfoque del paciente con intoxicación aguda por plaguicidas organosfoforados

    Directory of Open Access Journals (Sweden)

    Carlos Mauricio Hurtado Clavijo

    2005-10-01

    Full Text Available Un gran número de insecticidas organofosforados se usan en todo el mundo a diario. Las intoxicaciones ocurren generalmente de forma accidental por exposición laboral, o intencional, con fines suicidas. Los organofosforados producen sus efectos tóxicos a través de la inhibición de la acetilcolinesterasa, la enzima responsable de la hidrólisis del neurotransmisor acetilcolina, produciendo ácido acético y colina, productos químicamente inertes. La unión entre los organofosforados y la acetilcolina es una unión irreversible espontáneamente, sin embargo, puede ser reversible con el uso de antídotos específico llamados oximas. La administración temprana de pralidoxima es crucial y muy útil si se inicia en las primeras seis horas luego de la intoxicación aguda. La atropina produce un beneficio clínico dramático para los síntomas muscarínicos del síndrome colinérgico. Pueden ocurrir complicaciones importantes en los pacientes por intoxicación con organofosforados, como hipotensión, arritmias cardíacas fatales, síndrome intermedio, distres respiratorio, neumonía y aún disfunción cerebral severa.

  1. Porfiria aguda intermitente: estudo anátomo-patológico de um caso

    Directory of Open Access Journals (Sweden)

    José Antonio Levy

    1958-06-01

    Full Text Available Após considerações preliminares sôbre as moléstias decorrentes de alterações do metabolismo das porfirinas e que se traduzem clinicamente por alterações cutâneas, digestivas, neurológicas e psíquicas, é apresentado o caso de uma paciente portadora de forma aguda de porfiria. Trata-se de paciente com 29 anos de idade, com antecedentes de dores nos membros e cólicas abdominais, que apresentou bruscamente quadro de paralisia motora dos quatro membros e de alguns nervos cranianos. O teste de Watson e Schwartz revelou a presença de porfobilinogênio na urina, o que firmou o diagnóstico. Após um ano de internação, durante o qual a moléstia evoluiu por surtos, a paciente faleceu, tendo o exame anátomo-patológico do sistema nervoso revelado alterações degenerativas das células motoras das pontas anteriores da medula e de núcleos motores do tronco encefálico.

  2. Nuevas Formas de Precariedad Laboral

    OpenAIRE

    Zubiri-Rey, Jon Bernat

    2008-01-01

    En este artículo trataremos de recoger brevemente algunas conceptualizaciones sobre la precariedad laboral que son necesarias para aproximarse a estos fenómenos complejos. Seguidamente trataremos de presentar esquemáticamente algunas herramientas que pueden ser utlizadas para medir las Nuevas Formas de Precariedad Laboral, tarea ineludible para que una critica social y sindical trasformadora sea posible.

  3. 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...

  4. The effect of myelinating Schwann cells on axons.

    Science.gov (United States)

    Martini, R

    2001-04-01

    Myelinating Schwann cells control the number of neurofilaments and elevate the phosphorylation state of neurofilaments in the axon, eventually leading to the typical large axon caliber. Conversely, absence of myelin leads to lower amounts of neurofilaments, reduced phosphorylation levels, and smaller axon diameters. In addition, myelinating Schwann cells mediate the spacing of Na(+) channel clusters during development of the node of Ranvier. When axons are associated with mutant Schwann cells in inherited neuropathies, their calibers are reduced and their neurofilaments are less phosphorylated and more closely spaced. Also, axonal transport is reduced and axons degenerate at the distal ends of long nerves. Myelin-associated glycoprotein may mediate some aspects of Schwann cell-axon communication, but much remains to be learned about the molecular bases of Schwann cell-axon communication. Copyright 2001 John Wiley & Sons, Inc.

  5. Modeling molecular mechanisms in the axon

    Science.gov (United States)

    de Rooij, R.; Miller, K.E.; Kuhl, E.

    2016-01-01

    Axons are living systems that display highly dynamic changes in stiffness, viscosity, and internal stress. However, the mechanistic origin of these phenomenological properties remains elusive. Here we establish a computational mechanics model that interprets cellular-level characteristics as emergent properties from molecular-level events. We create an axon model of discrete microtubules, which are connected to neighboring microtubules via discrete crosslinking mechanisms that obey a set of simple rules. We explore two types of mechanisms: passive and active crosslinking. Our passive and active simulations suggest that the stiffness and viscosity of the axon increase linearly with the crosslink density, and that both are highly sensitive to the crosslink detachment and reattachment times. Our model explains how active crosslinking with dynein motors generates internal stresses and actively drives axon elongation. We anticipate that our model will allow us to probe a wide variety of molecular phenomena–both in isolation and in interaction–to explore emergent cellular-level features under physiological and pathological conditions. PMID:28603326

  6. 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

  7. Ataxia cerebelar aguda na criança

    Directory of Open Access Journals (Sweden)

    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.

  8. Isquemia aguda de miembros inferiores secundaria a ergortismo

    OpenAIRE

    Franco J. Vallejo, MD; Juan F. Gómez, MD; Natalia Tamayo, MD

    2011-01-01

    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 vasod...

  9. Insuficiencia renal aguda inducida por mordedura de serpiente Bothrops

    Directory of Open Access Journals (Sweden)

    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.

  10. Otite Média Aguda no Pequeno Lactente

    OpenAIRE

    Rodrigues, V; Maia, R; Pedrosa, C; Brito, MJ; Cordeiro Ferreira, G

    2011-01-01

    Introdução: A otite média aguda (OMA) é uma patologia comum na infância mas rara abaixo dos 3 meses de idade Objectivos: Caracterizar a OMA e avaliar eventuais factores de risco no pequeno lactente. Métodos: Estudo descritivo, de 2005 a 2009 em lactentes com menos de três meses, internados por OMA. Analisaram-se idade, sexo, factores de risco (FR) comorbilidades, clínica, terapêutica e evolução. A avaliação de factores de risco foi realizada com grupo de controlo emparelh...

  11. Pancreatitis Aguda como consecuencia del uso de Orlistat

    OpenAIRE

    Claudia Mariela Cruz Copa; Mariela Delgadillo Céspedes; Juan Pablo Delgadillo López; Dr. Gonzalo Torres Ortiz

    2011-01-01

    La pancreatitis aguda es un proceso inflamatorio del páncreas desencadenada por la auto digestión ante la activaciónde sus pro fermentos, tiene un manejo urgente ya que pone en peligro la vida del paciente. El recienteingreso de Orlistat, un fármaco inhibidor de la lipasa gástrica y pancreática para tratar la obesidad, a través de suventa creciente sin receta se ha estado traduciendo en una mayor frecuencia de eventos adversos sobre todogastrointestinales (diarrea grasa, esteatorrea, incontin...

  12. 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.

  13. Mitochondria Localize to Injured Axons to Support Regeneration.

    Science.gov (United States)

    Han, Sung Min; Baig, Huma S; Hammarlund, Marc

    2016-12-21

    Axon regeneration is essential to restore the nervous system after axon injury. However, the neuronal cell biology that underlies axon regeneration is incompletely understood. Here we use in vivo, single-neuron analysis to investigate the relationship between nerve injury, mitochondrial localization, and axon regeneration. Mitochondria translocate into injured axons so that average mitochondria density increases after injury. Moreover, single-neuron analysis reveals that axons that fail to increase mitochondria have poor regeneration. Experimental alterations to axonal mitochondrial distribution or mitochondrial respiratory chain function result in corresponding changes to regeneration outcomes. Axonal mitochondria are specifically required for growth-cone migration, identifying a key energy challenge for injured neurons. Finally, mitochondrial localization to the axon after injury is regulated in part by dual-leucine zipper kinase 1 (DLK-1), a conserved regulator of axon regeneration. These data identify regulation of axonal mitochondria as a new cell-biological mechanism that helps determine the regenerative response of injured neurons. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Diffuse Axonal Injury and Oxidative Stress: A Comprehensive Review

    Directory of Open Access Journals (Sweden)

    Alessandro Frati

    2017-12-01

    Full Text Available Traumatic brain injury (TBI is one of the world’s leading causes of morbidity and mortality among young individuals. TBI applies powerful rotational and translational forces to the brain parenchyma, which results in a traumatic diffuse axonal injury (DAI responsible for brain swelling and neuronal death. Following TBI, axonal degeneration has been identified as a progressive process that starts with disrupted axonal transport causing axonal swelling, followed by secondary axonal disconnection and Wallerian degeneration. These modifications in the axonal cytoskeleton interrupt the axoplasmic transport mechanisms, causing the gradual gathering of transport products so as to generate axonal swellings and modifications in neuronal homeostasis. Oxidative stress with consequent impairment of endogenous antioxidant defense mechanisms plays a significant role in the secondary events leading to neuronal death. Studies support the role of an altered axonal calcium homeostasis as a mechanism in the secondary damage of axon, and suggest that calcium channel blocker can alleviate the secondary damage, as well as other mechanisms implied in the secondary injury, and could be targeted as a candidate for therapeutic approaches. Reactive oxygen species (ROS-mediated axonal degeneration is mainly caused by extracellular Ca2+. Increases in the defense mechanisms through the use of exogenous antioxidants may be neuroprotective, particularly if they are given within the neuroprotective time window. A promising potential therapeutic target for DAI is to directly address mitochondria-related injury or to modulate energetic axonal energy failure.

  15. Diffuse Axonal Injury and Oxidative Stress: A Comprehensive Review.

    Science.gov (United States)

    Frati, Alessandro; Cerretani, Daniela; Fiaschi, Anna Ida; Frati, Paola; Gatto, Vittorio; La Russa, Raffaele; Pesce, Alessandro; Pinchi, Enrica; Santurro, Alessandro; Fraschetti, Flavia; Fineschi, Vittorio

    2017-12-02

    Traumatic brain injury (TBI) is one of the world's leading causes of morbidity and mortality among young individuals. TBI applies powerful rotational and translational forces to the brain parenchyma, which results in a traumatic diffuse axonal injury (DAI) responsible for brain swelling and neuronal death. Following TBI, axonal degeneration has been identified as a progressive process that starts with disrupted axonal transport causing axonal swelling, followed by secondary axonal disconnection and Wallerian degeneration. These modifications in the axonal cytoskeleton interrupt the axoplasmic transport mechanisms, causing the gradual gathering of transport products so as to generate axonal swellings and modifications in neuronal homeostasis. Oxidative stress with consequent impairment of endogenous antioxidant defense mechanisms plays a significant role in the secondary events leading to neuronal death. Studies support the role of an altered axonal calcium homeostasis as a mechanism in the secondary damage of axon, and suggest that calcium channel blocker can alleviate the secondary damage, as well as other mechanisms implied in the secondary injury, and could be targeted as a candidate for therapeutic approaches. Reactive oxygen species (ROS)-mediated axonal degeneration is mainly caused by extracellular Ca 2+ . Increases in the defense mechanisms through the use of exogenous antioxidants may be neuroprotective, particularly if they are given within the neuroprotective time window. A promising potential therapeutic target for DAI is to directly address mitochondria-related injury or to modulate energetic axonal energy failure.

  16. 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.

  17. Oclusión arterial aguda asociada a hidatidosis diseminada

    Directory of Open Access Journals (Sweden)

    Jose Somocurcio

    Full Text Available Hidatidosis o equinococosis son términos usados para denominar a la infestación zoonótica causada por los estadios adulto y larvario (metacéstode del céstode del género Equinococcus (familia tenidae. El término hidatidosis debe ser aplicado a la infestación por el metacéstode mientras que el de equinococosis a los estadios larvario y adulto. En el Perú existe una alta prevalencia de esta infección siendo el hígado y pulmón los órganos más afectados. Existen factores tanto del agente infeccioso como del hospedero que contribuyen a esta infección, donde el componente inmunológico del hospedero es un punto importante tanto en la infección como en la diseminación. En el presente artículo se reporta un caso de oclusión arterial aguda asociada a hidatidosis diseminada en un paciente de 54 años de edad, natural y procedente de Huancavelica, de inicio súbito con un cuadro de obstrucción arterial aguda; que no mejoró luego de la cirugía con fallecimiento a las 48 horas de la presentación

  18. Axon degeneration: make the Schwann cell great again

    Directory of Open Access Journals (Sweden)

    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.

  19. 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.

  20. 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...... at ankle distal to axotomy were monitored by 'threshold-tracking'. The plantar compound muscle action potentials (CMAPs) were recorded under anesthesia in three animal models: 8-week-old wild-type mice, 8-week-old slow Wallerian degeneration mutant mice and 3-year-old cats. We found that the progressive...... decrease in CMAP following crush injury was associated with slowing of conduction and marked abnormalities in excitability: increased peak threshold deviations during both depolarizing and hyperpolarizing threshold electrotonus, enhanced superexcitability during the recovery cycle and increased rheobase...

  1. B-RAF kinase drives developmental axon growth and promotes axon regeneration in the injured mature CNS

    Science.gov (United States)

    O’Donovan, Kevin J.; Ma, Kaijie; Guo, Hengchang; Wang, Chen; Sun, Fang; Han, Seung Baek; Kim, Hyukmin; Wong, Jamie K.; Charron, Jean; Zou, Hongyan; Son, Young-Jin; He, Zhigang

    2014-01-01

    Activation of intrinsic growth programs that promote developmental axon growth may also facilitate axon regeneration in injured adult neurons. Here, we demonstrate that conditional activation of B-RAF kinase alone in mouse embryonic neurons is sufficient to drive the growth of long-range peripheral sensory axon projections in vivo in the absence of upstream neurotrophin signaling. We further show that activated B-RAF signaling enables robust regenerative growth of sensory axons into the spinal cord after a dorsal root crush as well as substantial axon regrowth in the crush-lesioned optic nerve. Finally, the combination of B-RAF gain-of-function and PTEN loss-of-function promotes optic nerve axon extension beyond what would be predicted for a simple additive effect. We conclude that cell-intrinsic RAF signaling is a crucial pathway promoting developmental and regenerative axon growth in the peripheral and central nervous systems. PMID:24733831

  2. Sensory axonal dysfunction in cervical radiculopathy.

    Science.gov (United States)

    Sung, Jia-Ying; Tani, Jowy; Hung, Kuo-Sheng; Lui, Tai-Ngar; Lin, Cindy Shin-Yi

    2015-06-01

    The aim of this study was to evaluate changes in sensory axonal excitability in the distal nerve in patients with cervical radiculopathy. The patients were classified by the findings of cervical MRI into two subgroups: 22 patients with C6/7 root compression and 25 patients with cervical cord and root compression above/at C6/7. Patients were investigated using conventional nerve conduction studies (NCS) and nerve excitability testing. Sensory nerve excitability testing was undertaken with stimulation at the wrist and recording from digit II (dermatome C6/7). The results were compared with healthy controls. Both preoperative and postoperative tests were performed if the patient underwent surgery. Sensory axonal excitability was significantly different in both cohorts compared with healthy controls, including prolonged strength-duration time constant, reduced S2 accommodation, increased threshold electrotonus hyperpolarisation (TEh (90-100 ms)), and increased superexcitability. The changes in these excitability indices are compatible with axonal membrane hyperpolarisation. In five patients who underwent surgery, the postoperative sensory excitability was tested after 1 week, and showed significant changes in TE (TEh (90-100 ms) and TEh slope, pcervical radiculopathy. These findings suggest that the hyperpolarised pattern might be due to Na(+)-K(+) ATPase overactivation induced by proximal ischaemia, or could reflect the remyelinating process. Distal sensory axons were hyperpolarised even though there were no changes in NCS, suggesting that nerve excitability testing may be more sensitive to clinical symptoms than NCS in patients with cervical radiculopathy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  3. Unidirectional ephaptic stimulation between two myelinated axons.

    Science.gov (United States)

    Capllonch-Juan, Miguel; Kolbl, Florian; Sepulveda, Francisco

    2017-07-01

    Providing realistic sensory feedback for prosthetic devices strongly relies on an accurate modelling of machine-nerve interfaces. Models of these interfaces in the peripheral nervous system usually neglect the effects that ephaptic coupling can have on the selectivity of stimulating electrodes. In this contribution, we study the ephaptic stimulation between myelinated axons and show its relation with the separation between fibers and the conductivity of the medium that surrounds them.

  4. Multifunctional Silk Nerve Guides for Axon Outgrowth

    Science.gov (United States)

    Tupaj, Marie C.

    Peripheral nerve regeneration is a critical issue as 2.8% of trauma patients present with this type of injury, estimating a total of 200,000 nerve repair procedures yearly in the United States. While the peripheral nervous system exhibits slow regeneration, at a rate of 0.5 mm -- 9 mm/day following trauma, this regenerative ability is only possible under certain conditions. Clinical repairs have changed slightly in the last 30 years and standard methods of treatment include suturing damaged nerve ends, allografting, and autografting, with the autograft the gold standard of these approaches. Unfortunately, the use of autografts requires a second surgery and there is a shortage of nerves available for grafting. Allografts are a second option however allografts have lower success rates and are accompanied by the need of immunosuppressant drugs. Recently there has been a focus on developing nerve guides as an "off the shelf" approach. Although some natural and synthetic guidance channels have been approved by the FDA, these nerve guides are unfunctionalized and repair only short gaps, less than 3 cm in length. The goal of this project was to identify strategies for functionalizing peripheral nerve conduits for the outgrowth of neuron axons in vitro . To accomplish this, two strategies (bioelectrical and biophysical) were indentified for increasing axon outgrowth and promoting axon guidance. Bioelectrical strategies exploited electrical stimulation for increasing neurite outgrowth. Biophysical strategies tested a range of surface topographies for axon guidance. Novel methods were developed for integrating electrical and biophysical strategies into silk films in 2D. Finally, a functionalized nerve conduit system was developed that integrated all strategies for the purpose of attaching, elongating, and guiding nervous tissue in vitro. Future directions of this work include silk conduit translation into a rat sciatic nerve model in vivo for the purpose of repairing long

  5. Papel del estrés oxidativo y del tejido adiposo en la pancreatitis aguda experimental

    OpenAIRE

    Pérez Garrido, Salvador

    2013-01-01

    La pancreatitis aguda es un proceso inflamatorio agudo del páncreas con afectación variable de otros tejidos y sistemas orgánicos alejados. La incidencia de la pancreatitis aguda en la Unión Europea y Estados Unidos varía de 5 a 30 casos/100.000/año (Ellis y cols., 2009). La mortalidad en pacientes con pancreatitis aguda es alrededor del 5%, pero este porcentaje aumenta al 17-20% en pacientes con pancreatitis necrotizante (Pandol y cols., 2007). La participación del estrés oxidativo en la ...

  6. Synaptic Democracy and Vesicular Transport in Axons

    Science.gov (United States)

    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".

  7. Esofagitis necrotizante aguda: Una patología poco conocida Acute esophageal necrosis: An underdiagnosed disease

    Directory of Open Access Journals (Sweden)

    L. Julián Gómez

    2008-11-01

    Full Text Available La esofagitis necrotizante aguda (ENA es una rara entidad cuya etiología es desconocida, siendo el mecanismo patogénico multifactorial, participando fundamentalmente el compromiso isquémico, la malnutrición y la obstrucción del tracto digestivo alto. Los hallazgos endoscópicos muestran una coloración negruzca de la mucosa esofágica con transición brusca a nivel de la unión esofagogástrica. El pronóstico depende de las enfermedades de base. Se revisan los casos de ENA, excluyendo los secundarios a caústicos, recogidos de forma retrospectiva durante los últimos 2 años. Se analizan los factores de riesgo, la presentación clínica, los hallazgos endoscópicos, la histología, el tratamiento y la evolución. En nuestro departamento, se han diagnosticado 7 casos de ENA en 6.003 gastroscopias realizadas en el periodo de estudio, representando así la ENA el 0,11% de la exploraciones.Acute esophageal necrosis is a rare disorder, and its etiology is unknown, the mechanism of damage being usually multifactorial and secondary to ischemic compromise, acute gastric outlet obstruction, and malnutrition. Endoscopic findings show circumferential black discoloration of the distal esophagus with proximal extension ending sharply at the gastroesophageal junction, which is the most common presentation. Prognosis depends on comorbid illnesses. In this study we analyze all cases reported in a retrospective analysis over a 2-year period to define risk factors, clinical presentation, endoscopic features, histological appearance, treatment and outcome. Our department has recorded 7 cases from 6,003 endoscopies performed in the last 2 years. The finding of a "black esophagus" represented 0.11% of cases.

  8. Complicaciones agudas del síndrome nefrótico

    Directory of Open Access Journals (Sweden)

    Sandalio Durán Álvarez

    1999-12-01

    Full Text Available Se hace una breve revisión de las complicaciones del síndrome nefrótico que se presentan a veces en forma súbita e inesperada y que pueden poner en riesgo la vida del paciente. Las infecciones son las complicaciones más frecuentes y se destaca la peritonitis primaria como la primera causa. Se analizan las infecciones que se pueden presentar en los pacientes "inmunosuprimidos". Se revisan las complicaciones tromboembólicas y se destaca la importancia de los traumatismos como precipitantes de las trombosis arteriales y el alto riesgo para la vida o el miembro afectado. Se hace un análisis de la hipovolemia que tienen algunos pacientes y las crisis de "shock hipovolémico" que pueden ocurrir. Por último se plantea una complicación infrecuente pero grave, la insuficiencia renal aguda idiopática reversible y los mecanismos que tratan de explicar esta complicación. De todas las complicaciones se hace un breve análisis de su manejo profiláctico y terapéutico.We briefly reviewed the nephrotic syndrome complications that sometimes emerge suddenly and unexpectedly and that may put the patient's life at risk. Infections are the most common complications mainly caused by primary peritonitis. We analized infections that may occur in inmunosuppresed patients and reviewed the thromboembolic complications; we also underlined the importance of trauma as precipitating factors of arterial thrombosis and the implied high risk for life or affected member. We similarly made an analysis of hypovolemia in some patients and the hypovolemic shock that might occur. Finally, we present an unfrequent but serious complication, i.e, acute reversible idiopathic renal failure and the likely mechanisms explainig this complication. The prophylactic and therapeutical management of all the described complications are briefly analyzed.

  9. Axonal branching patterns of nucleus accumbens neurons in the rat.

    Science.gov (United States)

    Tripathi, Anushree; Prensa, Lucía; Cebrián, Carolina; Mengual, Elisa

    2010-11-15

    The patterns of axonal collateralization of nucleus accumbens (Acb) projection neurons were investigated in the rat by means of single-axon tracing techniques using the anterograde tracer biotinylated dextran amine. Seventy-three axons were fully traced, originating from either the core (AcbC) or shell (AcbSh) compartment, as assessed by differential calbindin D28k-immunoreactivity. Axons from AcbC and AcbSh showed a substantial segregation in their targets; target areas were either exclusively or preferentially innervated from AcbC or AcbSh. Axon collaterals in the subthalamic nucleus were found at higher than expected frequencies; moreover, these originated exclusively in the dorsal AcbC. Intercompartmental collaterals were observed from ventral AcbC axons into AcbSh, and likewise, interconnections at pallidal and mesencephalic levels were also observed, although mostly from AcbC axons toward AcbSh targets, possibly supporting crosstalk between the two subcircuits at several levels. Cell somata giving rise to short-range accumbal axons, projecting to the ventral pallidum (VP), were spatially intermingled with others, giving rise to long-range axons that innervated VP and more caudal targets. This anatomical organization parallels that of the dorsal striatum and provides the basis for possible dual direct and indirect actions from a single axon on either individual or small sets of neurons. Copyright © 2010 Wiley-Liss, Inc.

  10. Rol de la colangio pancreatografía retrógrada endoscópica en pacientes con pancreatitis aguda biliar leve y vesícula in situ

    OpenAIRE

    ANSELMI M,MARIO; GEMMATO P,ANA MARÍA

    2011-01-01

    Objetivo: Analizar en forma prospectiva los resultados de la Colangio Pancreatografía Retrógrada Endoscópica (CPRE) y eventual manejo endoscópico en pacientes portadores de pancreatitis aguda biliar (PAB) leve con vesícula in situ. Material y Método: Se estudiaron 90 pacientes consecutivos con PAB leve y vesícula in situ. La edad promedio fue de 49,5 ± 18,6 años (78,9% mujeres y 21,1% hombres). Del total, 49 pacientes (54,4%) presentaron ictericia y 12 (13,3%) colangitis. Resultados: La CPRE ...

  11. Ingestão aguda de cafeína reduz a glicemia sanguínea antes e após o exercício físico agudo em ratos diabéticos

    OpenAIRE

    Silva, Luiz Augusto Da; Pereira, Ricardo Aparecido; Túrmina, Janaína Angela; Kerppers, Ivo Ilvan; Altimari, Leandro Ricardo; Malfatti, Carlos Ricardo Maneck

    2014-01-01

    OBJETIVO: O presente estudo verificou os efeitos da suplementação com cafeína associada ao exercício físico agudo sobre a resposta glicêmica em ratos diabéticos. MÉTODOS: Foram utilizados 32 animais, com 60 dias de idade, e 238±3 g de peso, divididos em quatro grupos: controle, controle cafeína, diabetes e diabetes/cafeína. O modelo de diabetes foi induzido pela administração intraperitoneal de 60 mg/kg de estreptozotocina. De forma aguda, os animais receberam 6 mg de cafeína ou salina par...

  12. Axonal and Transynaptic Spread of Prions

    Science.gov (United States)

    Shearin, Harold

    2014-01-01

    ABSTRACT Natural transmission of prion diseases depends upon the spread of prions from the nervous system to excretory or secretory tissues, but the mechanism of prion transport in axons and into peripheral tissue is unresolved. Here, we examined the temporal and spatial movement of prions from the brain stem along cranial nerves into skeletal muscle as a model of axonal transport and transynaptic spread. The disease-specific isoform of the prion protein, PrPSc, was observed in nerve fibers of the tongue approximately 2 weeks prior to PrPSc deposition in skeletal muscle. Initially, PrPSc deposits had a small punctate pattern on the edge of muscle cells that colocalized with synaptophysin, a marker for the neuromuscular junction (NMJ), in >50% of the cells. At later time points PrPSc was widely distributed in muscle cells, but PrPSc deposition at the NMJ, suggesting additional prion replication and dissemination within muscle cells. In contrast to the NMJ, PrPSc was not associated with synaptophysin in nerve fibers but was found to colocalize with LAMP-1 and cathepsin D during early stages of axonal spread. We propose that PrPSc-bound endosomes can lead to membrane recycling in which PrPSc is directed to the synapse, where it either moves across the NMJ into the postsynaptic muscle cell or induces PrPSc formation on muscle cells across the NMJ. IMPORTANCE Prion diseases are transmissible and fatal neurodegenerative diseases in which prion dissemination to excretory or secretory tissues is necessary for natural disease transmission. Despite the importance of this pathway, the cellular mechanism of prion transport in axons and into peripheral tissue is unresolved. This study demonstrates anterograde spread of prions within nerve fibers prior to infection of peripheral synapses (i.e., neuromuscular junction) and infection of peripheral tissues (i.e., muscle cells). Within nerve fibers prions were associated with the endosomal-lysosomal pathway prior to entry into

  13. Esquistossomose aguda autóctone de foco na cidade do Rio de Janeiro: estudo de 22 casos

    Directory of Open Access Journals (Sweden)

    J. Rodrigues Coura

    1970-12-01

    Full Text Available Os autores descrevem a ocorrência de um verdadeiro "surto" da forma aguda da esquistossomose mansoni em um foco cujas características da espécie vetora, seus índices de infecção, a natureza e o local da exposição nada faziam supor esta possibilidade. Foram estudados 22 pacientes (14 crianças e 8 adultos com a forma aguda da esquistossomose contraída em banho nas Furnas da Tifuca, no Rio de Janeiro, no período de 9 a 22 de março de 1970. Todos os pacientes eram de côr branca e de bom nível social e foram infectados em banho único, ocasional, durante piquenique nesse logradouro. As manifestações clínicas foram severas em 7 casos, moderados em outros 7 e discretos cm 8, caracterizando-se por febre em 17 casos, hepatomegalia em 14, tosse seca em I3,astenia em 13, diarréia em 12, emagrecimento em 11 casos, colicas abdominais em 9, espienomegalia em 9, cefalèia em 7 casos e nauseas e vômitos em 3. O hemogrcima mostrou leucocitose e eosinofilia na grande maioria, dos casos e na eletroforese das proteínas séricas houve uma baixa da albumina, aumento das gíobulinas alfa 2 e gama em alguns casos. As transaminases estavam normais em todos. O período ds incubação medio foi de 5 semanas. Após fazerem uma revisão sumária dos focos de esquistossomose no Estado da Guanabara, estudam a dinâmica da transmissão neste foco , recente camitendo a transmissão a distância do foco por carreamento das cercarías ou de seu hapedeiro intermediário pela água.

  14. 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.

  15. Nefrite Intersticial Aguda Após Exposição a Losartan

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    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.

  16. 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.

  17. Regulation and dysregulation of axon infrastructure by myelinating glia.

    Science.gov (United States)

    Pan, Simon; Chan, Jonah R

    2017-12-04

    Axon loss and neurodegeneration constitute clinically debilitating sequelae in demyelinating diseases such as multiple sclerosis, but the underlying mechanisms of secondary degeneration are not well understood. Myelinating glia play a fundamental role in promoting the maturation of the axon cytoskeleton, regulating axon trafficking parameters, and imposing architectural rearrangements such as the nodes of Ranvier and their associated molecular domains. In the setting of demyelination, these changes may be reversed or persist as maladaptive features, leading to axon degeneration. In this review, we consider recent insights into axon-glial interactions during development and disease to propose that disruption of the cytoskeleton, nodal architecture, and other components of axon infrastructure is a potential mediator of pathophysiological damage after demyelination. © 2017 Pan and Chan.

  18. Active polysomes in the axoplasm of the squid giant axon.

    Science.gov (United States)

    Giuditta, A; Menichini, E; Perrone Capano, C; Langella, M; Martin, R; Castigli, E; Kaplan, B B

    1991-01-01

    Axons and axon terminals are widely believed to lack the capacity to synthesize proteins, relying instead on the delivery of proteins made in the perikaryon. In agreement with this view, axoplasmic proteins synthesized by the isolated giant axon of the squid are believed to derive entirely from periaxonal glial cells. However, squid axoplasm is known to contain the requisite components of an extra-mitochondrial protein synthetic system, including protein factors, tRNAs, rRNAs, and a heterogeneous family of mRNAs. Hence, the giant axon could, in principle, maintain an endogenous protein synthetic capacity. Here, we report that the squid giant axon also contains active polysomes and mRNA, which hybridizes to a riboprobe encoding murine neurofilament protein. Taken together, these findings provide direct evidence that proteins (including the putative neuron-specific neurofilament protein) are also synthesized de novo in the axonal compartment.

  19. Regeneración axonal posterior a lesiones traumáticas de médula espinal: papel crítico de galectina-1

    OpenAIRE

    Quintá, Héctor Ramiro; Pasquini, Juana Maria; Rabinovich, Gabriel Adrian; Pasquini, Laura Andrea

    2016-01-01

    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 rev...

  20. INSUFICIÊNCIA RENAL AGUDA DEVIDO À RABDOMIÓLISE

    OpenAIRE

    Guilherme Gomide CABRAL; Leticia Mattar MONICE; Lorena Rocha Dias MACHADO; Luana Modesto Lopes CALDEIRA; Lucas Roquim SILVA; Hudson Araújo COUTO

    2015-01-01

    Atividades físicas são importantes para a saúde de qualquer individuo, porém, quando realizadas em condições inapropriadas, baseando-se em exercícios muito violentos, pode ocorrer rabdomiólise, sendo uma de suas consequências, a insuficiência renal aguda (IRA). Os dois principais fatores que predispõem à IRA por rabdomiólise são: a hipovolemia secundária ao sequestro de volume da musculatura acometida e a presença de urina ácida. A rabdomiólise caracteriza-se pela lesão da musculatura estriad...

  1. 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

  2. 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.

  3. Toxidade aguda de rutina e bixina de Bixa orellana

    OpenAIRE

    Lima, Leonardo R.P.; Oliveira, Tania Toledo de; Nagem, Tanus Jorge; Pinto, Aloisio da Silva; Lima, Ednaldo Queiroga de; Silva, José F.

    2003-01-01

    As substâncias rutina e bixina foram escolhidas para estudo uma vez que nosso laboratório de pesquisas busca efeitos farmacológicos de flavonóides e corantes naturais em várias plantas brasileiras. Foram avaliadas a toxidade aguda de bixina e rutina na dose diária de 0,01 mol/Kg em coelhos hiperlipidêmicos induzidos por colesterol a 0,5% e ácido cólico a 0,1%, durante vinte e oito dias, após os quais foram dosadas uréia, creatinina, ácido úrico, proteínas totais, cálcio, transaminase glutâ...

  4. Comportamiento de la enfermedad diarreica aguda en Guatemala

    Directory of Open Access Journals (Sweden)

    Mario Enrique Plá Acevedo

    2015-12-01

    Full Text Available Se realizó un estudio descriptivo de corte transversal, con el objetivo de conocer el comportamiento de la Enfermedad Diarreica Aguda (EDA en Tierra Blanca, Departamento Petén, Guatemala; en el período comprendido de enero a diciembre del año 2011. El universo de estudio lo formaron todos los individuos que fueron evaluados en el puesto de salud de Tierra Blanca con diagnóstico clínico de EDA. La muestra estuvo constituida por 529 pacientes. Se trabajó con el Sistema de Información Gerencial en Salud 18 (SIGSA, las fichas de salud individual de cada paciente, así como una entrevista estructurada que se le aplicó a los mismos, previo consentimiento informado; información con la cual se obtuvieron las variables relacionadas con los aspectos socio-demográficos, epidemiológicos y clínicos. Los meses donde más casos se reportaron fueron entre mayo y septiembre, coincidiendo esto con los meses de lluvias. Las edades más frecuentes fueron de uno a diez años y el sexo que predominó fue el masculino. El 40,3% consumían agua procedente de chorro intradomiciliario; las infecciones respiratorias agudas fueron las patologías que con más frecuencia se asociaron a las EDA y el 88,1% recibió tratamiento con sales de rehidratación oral.

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

    OpenAIRE

    White, Robin; Krämer-Albers, Eva-Maria

    2014-01-01

    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 specialized glial cells which ensheath axons with a lipid-rich insulating membrane. Myelination is a multi-step process initiated by axon-glia recognition triggering glial polarization followed by targeted myelin membrane expansion and compaction. Thereby, a myelin sheath of complex subdomain structure is...

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

    OpenAIRE

    Eder A. Hernández-Ruiz; Jaime A. Castrillón-Estrada; Juan G. Acosta-Vélez; David F. Castrillón-Estrada

    2008-01-01

    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...

  7. Insuficiência renal aguda e febre prolongada – um caso de nefrite intersticial aguda induzida por fármacos

    OpenAIRE

    Melo, Cláudia; Santos Silva, Rita; Tomé, Soraia; Carvalho, Sónia; Teixeira, Paulo

    2013-01-01

    A nefrite intersticial aguda (NIA) é uma causa de insuficiência renal aguda em idade pediátrica. A etiologia medicamentosa é a mais frequente e o tratamento primário da NIA consiste na eliminação do agente etiológico suspeito. Descreve-se o caso de uma adolescente, de 15 anos, com uma síndrome febril com 24 dias de evolução, acompanhado de exantema maculopapular e insuficiência renal aguda (IRA). Após exclusão de etiologias mais frequentes, foi diagnosticada NIA induzida por fármacos e após d...

  8. 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

  9. Concepts for regulation of axon integrity by enwrapping glia

    Directory of Open Access Journals (Sweden)

    Bogdan eBeirowski

    2013-12-01

    Full Text Available Long axons and their enwrapping glia (Schwann cells and oligodendrocytes form a unique compound structure that serves as conduit for transport of electric and chemical information in the nervous system. The peculiar cytoarchitecture over an enormous length as well as its substantial energetic requirements make this conduit particularly susceptible to detrimental alterations. Degeneration of long axons independent of neuronal cell bodies is observed comparatively early in a range of neurodegenerative conditions as a consequence of abnormalities in Schwann cells and oligodendrocytes. This leads to the most relevant disease symptoms and highlights the critical role that these glia have for axon integrity, but the underlying mechanisms remain elusive. The quest to understand why and how axons degenerate is now a crucial frontier in disease-oriented research. This challenge is most likely to lead to significant progress if the inextricable link between axons and their flanking glia in pathological situations is recognized. In this review I compile recent advances in our understanding of the molecular programs governing axon degeneration, and mechanisms of enwrapping glia’s non-cell autonomous impact on axon-integrity. A particular focus is placed on emerging evidence suggesting that enwrapping glia nurture long axons by virtue of their intimate association, release of trophic substances, and neurometabolic coupling. The correction of defects in these functions has the potential to stabilize axons in a variety of neuronal diseases in the peripheral and central nervous system.

  10. Axonal branching patterns of ventral pallidal neurons in the rat.

    Science.gov (United States)

    Tripathi, Anushree; Prensa, Lucía; Mengual, Elisa

    2013-09-01

    The ventral pallidum (VP) is a key component of the cortico-basal ganglia circuits that process motivational and emotional information, and also a crucial site for reward. Although the main targets of the two VP compartments, medial (VPm) and lateral (VPl) have already been established, the collateralization patterns of individual axons have not previously been investigated. Here we have fully traced eighty-four axons from VPm, VPl and the rostral extension of VP into the olfactory tubercle (VPr), using the anterograde tracer biotinylated dextran amine in the rat. Thirty to fifty percent of axons originating from VPm and VPr collateralized in the mediodorsal thalamic nucleus and lateral habenula, indicating a close association between the ventral basal ganglia-thalamo-cortical loop and the reward network at the single axon level. Additional collateralization of these axons in diverse components of the extended amygdala and corticopetal system supports a multisystem integration that may take place at the basal forebrain. Remarkably, we did not find evidence for a sharp segregation in the targets of axons arising from the two VP compartments, as VPl axons frequently collateralized in the caudal lateral hypothalamus and ventral tegmental area, the well-known targets of VPm, while VPm axons, in turn, also collateralized in typical VPl targets such as the subthalamic nucleus, substantia nigra pars compacta and reticulata, and retrorubral field. Nevertheless, VPl and VPm displayed collateralization patterns that paralleled those of dorsal pallidal components, confirming at the single axon level the parallel organization of functionally different basal ganglia loops.

  11. Differences in excitability properties of FDI and ADM motor axons.

    Science.gov (United States)

    Bae, Jong Seok; Sawai, Setsu; Misawa, Sonoko; Kanai, Kazuaki; Isose, Sagiri; Kuwabara, Satoshi

    2009-03-01

    The first dorsal interosseous (FDI) and abductor digiti minimi (ADM) muscles are innervated by the same ulnar nerve, but studies have shown that the former is much more severely affected in amyotrophic lateral sclerosis. In this study, threshold tracking was used to investigate whether membrane properties differ between FDI and ADM motor axons. In 12 normal subjects, compound muscle action potentials were recorded from FDI and ADM after ulnar nerve stimulation at the wrist. The strength-duration time constant was significantly longer in the FDI axons than in the ADM axons, and latent addition studies showed greater threshold changes at the conditioning-test stimulus of 0.2 ms in FDI than in ADM axons. These findings suggest that nodal persistent sodium conductances are more prominent in FDI axons than in ADM axons, and therefore excitability is physiologically higher in FDI axons. Even in the same nerve at the same sites, membrane properties of FDI and ADM motor axons differ significantly, and thus their axonal/neuronal responses to disease may also differ.

  12. Paracoccidioidomicose aguda/subaguda disseminada. Primeiro caso no Rio Grande do Sul Acute/subacute disseminated paracoccidioidomycosis. First case in Rio Grande do Sul State, Brazil

    Directory of Open Access Journals (Sweden)

    Soraya Malafaia Colares

    1998-12-01

    Full Text Available É relatado o primeiro caso autóctone de paracoccidioidomicose disseminada aguda/subaguda ocorrido em criança no Rio Grande do Sul. A doença iniciou com adenomegalias superficiais generalizadas, seis meses antes da internação hospitalar. O diagnóstico foi feito através de biópsia de gânglio cervical. É comentado o espectro de formas clínicas da micose observado nesse Estado.The first autochthonous case of acute/subacute disseminated paracoccidioidomycosis observed in a child in Rio Grande do Sul (Brazil is reported. The disease started with widespread superficial lymphadenopathy six months before the patient was admitted to the hospital. The diagnosis was made through a cervical lymph node biopsy. The spectrum of the clinical forms of the mycosis observed in this State is commented upon.

  13. ExpressÃo da L-Selectina e do CD44 nas leucemias linfÃides agudas em crianÃas e dolescentes.

    OpenAIRE

    Daniel Willian Lustosa de Sousa

    2009-01-01

    IntroduÃÃo â AlteraÃÃes na expressÃo ou funÃÃo das molÃculas de adesÃo (MA) nas cÃlulas leucÃmicas podem contribuir para a evoluÃÃo e no comportamento biolÃgico das leucemias agudas. A expressÃo aumentada nas LLAs parece relacionar-se aos mecanismos de disseminaÃÃo extramedular dos linfoblastos, infiltraÃÃo do SNC e formaÃÃo de massas tumorais. Objetivos â Analisar a expressÃo da L-selectina e do CD44 nas LLAs em crianÃas e adolescentes. Avaliar os fatores prognÃsticos (idade, sexo, leucom...

  14. 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

  15. Una nueva forma de conflicto

    Directory of Open Access Journals (Sweden)

    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.

  16. 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.

  17. Apendicitis aguda: incidencia y factores asociados. Hospital Nacional “Dos de Mayo” Lima, Perú 2009

    OpenAIRE

    Gamero, Marco; Barreda, Jorge; Hinostroza, Gerardo

    2011-01-01

     OBJETIVODeterminar la incidencia de la apendicitis aguda y sus factores asociados en el Hospital Nacional “Dos de Mayo”.MATERIAL Y MÉTODOEs un estudio observacional, descriptivo, transversal y retrospectivo. Las variables fueron: edad, sexo, tipo de apendicitis aguda, tipo de cirugía, apendicitis aguda complicada y no complicada, tipo de sutura de herida, tratamiento del muñón apendicular y drenaje en apendicitis agudaSe revisaron los Reportes Operatorios en los libros de Emergencia del cita...

  18. Age-related changes in axonal transport.

    Science.gov (United States)

    Frolkis, V V; Tanin, S A; Gorban, Y N

    1997-01-01

    In rats the rate of axonal transport (AT) or radiolabeled material decreased in the ventral roots of the spinal cord and the vagal and hypoglossal nerves with aging. A maximum AT deceleration in old age was observed in the vagus. The uncoupling of oxidative phosphorylation, inhibition of glycolysis and hypoxia induced a greater AT deceleration in old rats as compared to adults. Small doses of sodium fluoride accelerated AT, and this correlated with a rise in cAMP levels in ventral roots. High doses of sodium fluoride decelerated AT more markedly in old rats. It was shown that anabolic hormones (sex steroids and thyroxine) accelerated AT in both adult and old rats, whereas insulin induced a rise in AT rate in only adults. The catabolic steroid, hydrocortisone decelerated AT. In old rats castration diminished AT, while thyroidectomy had no effect. It was also shown that hydrocortisone and testosterone were transported along axons, reached fibers of the skeletal muscles, and hyperpolarized the plasma membrane. In old age the latent period was extended. Following 73 to 74 days of irradiation, AT slowed down in all the nerves studied in both adult and old rats. Following irradiation hormonal effects on AT changed, for example, the stimulatory effect of estradiol became weak, especially in old rats. Changes in AT could be an important mechanism of disordering the growth of neurons and innervated cells in old age.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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

  1. Protein-synthesizing machinery in the axon compartment.

    Science.gov (United States)

    Koenig, E; Giuditta, A

    1999-03-01

    Contrary to the prevailing view that the axon lacks the capacity to synthesize proteins, a substantial body of evidence points to the existence of a metabolically active endogenous translational machinery. The machinery appears to be largely localized in the cortical zone of the axon, where, in vertebrate axons, it is distributed longitudinally as intermittent, discrete domains, called periaxoplasmic plaques. Studies, based on translation assays and probes of RNA transcripts in axon models such as the squid giant axon and selected vertebrate axons, provide evidence of locally synthesized proteins, most of which appear to be constituents of the slow axoplasmic transport rate groups. Metabolic and molecular biological findings are consistent with the view that the synthesis of proteins undergoing local turnover in the axonal compartment of macroneurons depends on the activity of an endogenous translational machinery. The documented presence of a metabolically active machinery in presynaptic terminals of squid photoreceptor neurons is also described. Finally, potential sources of axoplasmic RNAs comprising the machinery, which may include the ensheathing cell of the axon, as well as the cognate cell body, are also discussed.

  2. Wnts guide longitudinal axon tracts in the brain

    NARCIS (Netherlands)

    Prasad, A.A.

    2011-01-01

    The human brain contains more than 10 billion neurons that form over 10 trillion connections. The establishment of these connections during development requires axons to extend through the extracellular environment to their synaptic targets. This process of axon guidance is mediated by molecular

  3. Treatment of acute experimental schistosomiasis Tratamento da esquistossomose aguda experimental

    Directory of Open Access Journals (Sweden)

    Zilton A. Andrade

    1989-12-01

    Full Text Available A model of acute schistosomiasis of the mouse was used to observe whether curative treatment would be followed by an enhancement of the hepatic and splenic lesions, as a consequence of the massive destruction of worms and eggs within the portal system. Mice infected with 50 cercariae of Schistosoma mansoni were treated with both oxamniquine and praziquantel on the 50th day of infection and submitted to a sequential histologic examination from the 2nd to the 45th day after treatment. Although severe focal lesions due to dead and disintegranting worms were present in the livers of the treated animals, no aggravation of the general changes (reative hepatitis and splenitis, or periovular granulomas was seen in comparison with a control non-treated group. Of 50 animals treated during the acute phase of schistosomiasis only one died espontaneously, while 16 ou of 30 infected controls died before the end of the experiment. The present investigation indicates that curative treatment during the acute phase of schistosomiasis does not enhance previous lesions at first and results in progressive disappearance of the lesions starting six days following chemotherapy.Foi utilizado um modelo de esquistossomose aguda do camundongo para testar se o tratamentop curativo da parasitose nesta fase poderia produzir uma exacerbação das lesões hepáticas e esplênicas, em virtude da destruição maciça de vermes e ovos nointerior do sistema porta. Camundongos infectados com 50 cercárias do Schistosoma mansoni foram tratados no 50º dia da infecção por uma combinação de oxamniquine e praziquantel e submetidos a exames histopatológicos seqüenciados desde o 2º até o 45º dia após o tratamento. Muito embora tenham sido encontrados lesões focais intensas causadas por vermes mortos no interior do fígado, não foi encontrada qualquer evidência de agravamento das lesões gerais (hepatite reacional e esplenite, ou nos granulomas periovulares quando se fez

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

    Directory of Open Access Journals (Sweden)

    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.

  5. 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.

  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. Insuficiencia renal aguda obstructiva: Estudio de 42 pacientes

    Directory of Open Access Journals (Sweden)

    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

  8. UN CAMBIO EN LOS PARADIGMAS DE LA INSUFICIENCIA RENAL AGUDA

    Directory of Open Access Journals (Sweden)

    Juan Daniel Ordóñez

    2016-04-01

    Full Text Available

    Entre los años 2007 y 2009, varios estudios epidemiológicos sobre la Insuficiencia Renal Aguda (IRA, mostraron que la enfermedad tiene características clínicas y pronóstico distinto y más severo que los considerados previamente. Otras investigaciones, realizadas entre los años 2010 y 2014, confirmaron y extendieron esos hallazgos. Tomados en conjunto y con la perspectiva de los estudios posteriores, el resultado de los iniciales ha cambiado los paradigmas de la In- suficiencia Renal Aguda y el manejo de los pacientes. Los estudios más recientes sugieren que el pronóstico de la enfermedad puede estar mejorando, posiblemente como consecuencia del mejor manejo de la enfermedad. El autor fue coinvestigador y dirigió una de las tres entidades que participaron en los estudios originales.

    A CHANGE IN THE PARADIGMS OF THE ACUTE RENAL FAILURE

    ABSTRACT

    Between the years of 2007 and 2009 several epidemiologic studies on Acute Renal Failure showed that the disease has clinical features and prognosis different from the predominating beliefs at the time. Rather than having a benign prognosis after recovery, Acute Renal Failure has a high mortality and a guarded prognosis, with frequent development of progressive chro- nic Kidney Disease and the need for maintenance hemodialysis after apparent recovery. The recommendation was made that these patients be closely followed by a nehrologist after leaving the Hospital. Several other studies between 2010 and 2014 confirmed and extended these findings. Taken as a whole, and with the added information of later publications, these studies have changed the paradigm of Acute Renal failure and the management of patients with that disease. The most recent studies suggest that the disease prognosis may be improving, in part at least as a consequence of the better and more insightful management of the disease. The author was a co-investigator and directed one

  9. Recomendaciones para el manejo de la faringoamigdalitis aguda del adulto

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    Josep M. Cots

    2015-10-01

    Full Text Available La faringoamigdalitis aguda (FAA en el adulto es una de las enfermedades infecciosas más comunes en la consulta del médico de familia. La etiología más frecuente es viral. Dentro de la etiología bacteriana, el principal agente responsable es Streptococcus pyogenes o estreptococo β-hemolítico del grupo A (EBHGA, causante del 5-30% de los casos. En el manejo diagnóstico, las escalas de valoración clínica para predecir la posible etiología bacteriana, son una buena ayuda para seleccionar a qué pacientes se deben practicar las técnicas de detección rápida de antígeno estreptocócico. Es conocido que, en general, sin estas técnicas se tiende al sobrediagnóstico de FAA estreptocócica, con la consiguiente prescripción innecesaria de antibióticos, muchas veces de amplio espectro. Así, con el manejo de las escalas y la técnica de diagnóstico rápido, elaboramos los algoritmos de manejo de la FAA. Los objetivos del tratamiento son acelerar la resolución de los síntomas, reducir el tiempo de contagio y prevenir las complicaciones supurativas locales y no supurativas. Los antibióticos de elección para el tratamiento de la FAA estreptocócica son penicilina y amoxicilina. La asociación de amoxicilina y clavulánico no está indicada en el tratamiento inicial en la infección aguda. Los macrólidos tampoco son un tratamiento de primera elección; su uso debe reservarse para pacientes con alergia a la penicilina. Es importante en nuestro país adecuar tanto el diagnóstico de la FAA bacteriana y la prescripción de antibióticos a la evidencia científica disponible. La implantación de protocolos de actuación en las farmacias comunitarias puede ser de utilidad para identificar y cribar los casos que no requieran tratamiento antibiótico.

  10. Plasticity of the Axon Initial Segment

    DEFF Research Database (Denmark)

    Petersen, Anders Victor; Cotel, Florence; Perrier, Jean François

    2017-01-01

    undergo important modifications during development. The development of the AIS is governed by intrinsic mechanisms. In addition, surrounding neuronal networks modify its maturation. As a result, neurons get tuned to particular physiological functions. Neuronal activity also influences the morphology......The axon initial segment (AIS) is a key neuronal compartment because it is responsible for action potential initiation. The local density of Na+ channels, the biophysical properties of K+ channels, as well as the length and diameter of the AIS determine the spiking of neurons. These parameters...... of the mature AIS. When excitatory neurons are hyperactive, their AIS undergo structural changes that decrease their excitability and thereby maintain the activity within a given range. These slow homeostatic regulatory mechanisms occur on a time scale of hours or days. In contrast, the activation...

  11. Prolyl Isomerase Pin1 Regulates Axon Guidance by Stabilizing CRMP2A Selectively in Distal Axons

    Czech Academy of Sciences Publication Activity Database

    Balaštík, Martin; Zhou, X.Z.; Alberich-Jorda, Meritxell; Weissová, Romana; Žiak, Jakub; Pazyra-Murphy, M.F.; Cosker, K.E.; Machoňová, Olga; Kozmiková, Iryna; Chen, CH.; Pastorino, L.; Asara, J.M.; Cole, A.; Sutherland, C.; Segal, R. A.; Lu, K.P.

    2015-01-01

    Roč. 13, č. 4 (2015), s. 812-828 ISSN 2211-1247 R&D Projects: GA MŠk(CZ) LK11213; GA MŠk LK21307; GA ČR GA15-03796S; GA MŠk LO1419 Institutional support: RVO:68378050 Keywords : Pin1 * axon guidance * Semaphorin 3A Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 7.870, year: 2015

  12. 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

  13. Efeito da hipertermia na pancreatite aguda grave experimental

    Directory of Open Access Journals (Sweden)

    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.

  14. Uso de la jalea de aloe en la cervicitis aguda

    Directory of Open Access Journals (Sweden)

    Miguel Lugones Botell

    1999-04-01

    Full Text Available Se realiza un ensayo clínico a doble ciegas en un grupo de pacientes con cervicitis aguda, las cuales fueron atendidas en los policlínicos "Jorge Ruíz Ramírez" y "26 de Julio", del municipio Playa. Se analizaron diferentes síntomas y signos así como la respuesta al tratamiento con curas de aloe. Se concluye que el aloe es efectivo en el tratamiento de esta entidad y que se incrementan sus resultados favorables cuando se asocia con ácido lácticoA double-blind clinical trial was conducted in a group of patients with acute cervicitis that received attention at the"Jorge Ruiz Ramírez" and"26 de Julio" polyclinics, in the municipality of Playa. Different symptoms and signs as well as the response to aloe cures were analyzed. It was concluded that aloe is effective to treat this disease and that its favorable results increase when it is associated with lactic acid

  15. Pericarditis aguda: diagnóstico electrocardiográfico

    Directory of Open Access Journals (Sweden)

    Abraham enrique Katime Zúñiga

    2014-06-01

    Full Text Available La pericarditis es un proceso inflamatorio del pericardio, por lo general relacionado con procesos virales respiratorios o gastrointestinales; esta entidad es una de las principales causas de dolor torácico en el servicio de urgencias. El médico debe estar familiarizado con las manifestaciones clínicas y el flujograma diagnóstico. El diagnóstico de la pericarditis usualmente es clínico, los estudios paraclínicos evidencian inflamación sistémica (leucocitosis, aumento de la VSG y PCR. Las enzimas cardíacas (CPK MB – Troponinas se encuentran elevadas en casos de compromiso miocárdico asociado (Miopericarditis. El ecocardiograma revela derrame pericárdico, y el electrocardiograma se caracteriza por elevación difusa del segmento ST. En este artículo revisaremos los principales cambios electrocardiográficos relacionados a la pericarditis aguda y sus complicaciones. (Duazary 2009-II 159-164

  16. 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.

  17. Respostas cardiopulmonares agudas ao exercício com kettlebell

    Directory of Open Access Journals (Sweden)

    Flor Fusi

    Full Text Available Resumo Com o objetivo de comparar o consumo de oxigênio (VO2 e a frequência cardíaca (FC alcançados nos exercício swing e clean com kettlebell (KB, em relação ao máximo e ao limiar anaeróbio ventilatório (LAV, foram avaliadas 12 mulheres treinadas em KB (idade 31 ± 7; %G 21 ± 7; VO2máx. 43,5 ± 6,8; FCmáx. 183 ± 7. Foram feitos o teste cardiopulmonar em esteira ergométrica (TCPE e dois testes de cinco minutos com KB. Não houve diferença significativa entre swing e clean para qualquer das variáveis. O VO2 atingiu valores acima do encontrado no LAV do TCPE, tanto para o swing quanto para o clean, 75% e 77% do VO2máx.(ml.kg–1.min–1 e 93% e 95% da FCmáx (bpm, respectivamente. Os resultados sugerem uma exigência aguda do sistema aeróbio suficiente para possíveis adaptações cardiovasculares em resposta aos exercícios com KB.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Axonal Regulation of Central Nervous System Myelination: Structure and Function.

    Science.gov (United States)

    Klingseisen, Anna; Lyons, David A

    2018-02-01

    Approximately half of the human brain consists of myelinated axons. Central nervous system (CNS) myelin is made by oligodendrocytes and is essential for nervous system formation, health, and function. Once thought simply as a static insulator that facilitated rapid impulse conduction, myelin is now known to be made and remodeled in to adult life. Oligodendrocytes have a remarkable capacity to differentiate by default, but many aspects of their development can be influenced by axons. However, how axons and oligodendrocytes interact and cooperate to regulate myelination in the CNS remains unclear. Here, we review recent advances in our understanding of how such interactions generate the complexity of myelination known to exist in vivo. We highlight intriguing results that indicate that the cross-sectional size of an axon alone may regulate myelination to a surprising degree. We also review new studies, which have highlighted diversity in the myelination of axons of different neuronal subtypes and circuits, and structure-function relationships, which suggest that myelinated axons can be exquisitely fine-tuned to mediate precise conduction needs. We also discuss recent advances in our understanding of how neuronal activity regulates CNS myelination, and aim to provide an integrated overview of how axon-oligodendrocyte interactions sculpt neuronal circuit structure and function.

  2. Regeneration of axons in the mouse retina after injury.

    Science.gov (United States)

    McConnell, P; Berry, M

    1982-01-01

    It is generally accepted that most axons in the mammalian CNS show only transient growth in response to injury, and numerous hypotheses have been advanced to account for this phenomenon. Detailed knowledge of the time-course and extent of this so-called 'abortive regeneration' is, however, surprisingly lacking. The retina of the adult albino mouse provides a convenient system in which to quantify the response of central axons to injury, since the retina can be prepared as a whole mount, allowing silver-impregnated axons to be followed along their entire course. Using this experimental model, sprouting of injured axons was observed as early as 14 h post lesion (hpl) with rapid growth (20 micrometers/day on average) continuing until 10 dpl. Thereafter, a decline in the overall growth rate was observed, presumably regenerated sprouts began to degenerate. However, not all axons showed this abortive response: numerous unfasciculated axons continued in random growth until at least 100 dpl. One possible interpretation of these results is that the concept of abortive regeneration of injured axons is untenable in regions of the CNS which are lacking in myelin.

  3. Axonal and presynaptic RNAs are locally transcribed in glial cells.

    Science.gov (United States)

    Giuditta, Antonio; Chun, Jong Tai; Eyman, Maria; Cefaliello, Carolina; Bruno, Anna Paola; Crispino, Marianna

    2007-01-01

    In the last few years, the long-standing opinion that axonal and presynaptic proteins are exclusively derived from the neuron cell body has been substantially modified by the demonstration that active systems of protein synthesis are present in axons and nerve terminals. These observations have raised the issue of the cellular origin of the involved RNAs, which has been generally attributed to the neuron soma. However, data gathered in a number of model systems indicated that axonal RNAs are synthesized in the surrounding glial cells. More recent experiments on the perfused squid giant axon have definitively proved that axoplasmic RNAs are transcribed in periaxonal glia. Their delivery to the axon occurs by a modulatory mechanism based on the release of neurotransmitters from the stimulated axon and on their binding to glial receptors. In additional experiments on squid optic lobe synaptosomes, presynaptic RNA has been also shown to be synthesized locally, presumably in nearby glia. Together with a wealth of literature data, these observations indicate that axons and nerve terminals are endowed with a local system of gene expression that supports the maintenance and plasticity of these neuronal domains.

  4. Propagation of action potentials in inhomogeneous axon regions.

    Science.gov (United States)

    Ramón, F; Joyner, R W; Moore, J W

    1975-04-01

    Described are studies of propagation of action potentials through inhomogenous axon regions through experiments performed on squid giant axons and by computer simulations. The initial speed of propagation of the action potential is dependent upon the stimulus waveform. For a rectangular pulse of current, the action potential travel initally at a high speed that declines over the distance, reaching a constant speed of propagation at about 1-5 resting length constants; this distance depends on the stimulus strength. additional experiments studied the effects of changing the axon diameter and of introducing a temperature step. It was found that the propagated action potential suffers profound modification in shape and velocity as it reaches the region of transition. In both cases, it was possible to obtain reflected action potentials. A region of increased effective diameter was produced experimentally in the squid giant axon by insertion of an axial wire as usually employed in voltage clamps. It was found that the action potential, at the axial wire tip region, undergoes shape changes similar to those obtained tn simulations of a region of increased diameter as in a junction with the axon and soma in motor neurons. It is conducluded that the gaint axon can be used to reproduce simple electrical behaviors in other structures.-Ramón, F., R. W. Joyner and J.W. Moore. Propagation of action potentials in inhomogeneous axon regions.

  5. 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.

  6. Mitotic motors coregulate microtubule patterns in axons and dendrites.

    Science.gov (United States)

    Lin, Shen; Liu, Mei; Mozgova, Olga I; Yu, Wenqian; Baas, Peter W

    2012-10-03

    Microtubules are nearly uniformly oriented in the axons of vertebrate neurons but are non-uniformly oriented in their dendrites. Studies to date suggest a scenario for establishing these microtubule patterns whereby microtubules are transported into the axon and nascent dendrites with plus-ends-leading, and then additional microtubules of the opposite orientation are transported into the developing dendrites. Here, we used contemporary tools to confirm that depletion of kinesin-6 (also called CHO1/MKLP1 or kif23) from rat sympathetic neurons causes a reduction in the appearance of minus-end-distal microtubules in developing dendrites, which in turn causes them to assume an axon-like morphology. Interestingly, we observed a similar phenomenon when we depleted kinesin-12 (also called kif15 or HKLP2). Both motors are best known for their participation in mitosis in other cell types, and both are enriched in the cell body and dendrites of neurons. Unlike kinesin-12, which is present throughout the neuron, kinesin-6 is barely detectable in the axon. Accordingly, depletion of kinesin-6, unlike depletion of kinesin-12, has no effect on axonal branching or navigation. Interestingly, depletion of either motor results in faster growing axons with greater numbers of mobile microtubules. Based on these observations, we posit a model whereby these two motors generate forces that attenuate the transport of microtubules with plus-ends-leading from the cell body into the axon. Some of these microtubules are not only prevented from moving into the axon but are driven with minus-ends-leading into developing dendrites. In this manner, these so-called "mitotic" motors coregulate the microtubule patterns of axons and dendrites.

  7. Nefronía lobar aguda en un niño: reporte de caso

    Directory of Open Access Journals (Sweden)

    Angie Vanessa Vergara Espitia

    2015-04-01

    Full Text Available La nefronía lobar aguda o nefritis aguda focal es una entidad poco frecuente en los niños. Se trata de una infección renal con presentación clínica variada e inusual. Su diagnóstico se realiza a través de la tomografía axial computarizada (TAC, que actualmente es considerada como la prueba más sensible y especifica. Una terapia antibiótica adecuada, según el germen aislado, es la clave de un tratamiento exitoso que evite la progresión a absceso renal. Se presenta el caso de un paciente pediátrico que cursó con fiebre de origen prolongado y fue diagnosticado con nefronía lobar aguda después de varios días de estudio intrahospitalario.

  8. 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

  9. 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

  10. Mobilização precoce na fase aguda da trombose venosa profunda de membros inferiores

    OpenAIRE

    Penha,Geane de Souza; Damiano,Ana Paula; Carvalho,Tales de; Lain,Vinícius; Serafim,João Daniel

    2009-01-01

    O tratamento convencional da trombose venosa profunda na fase aguda consiste em restrição ao leito. Porém, estudos recentes contestam essa abordagem terapêutica, enfatizando que a mobilização precoce propicia resultados clínicos favoráveis. O objetivo deste estudo foi pesquisar em literatura científica, principalmente ensaios clínicos controlados, sobre a mobilização precoce de pacientes portadores de trombose venosa profunda de membros inferiores na fase aguda. Utilizou-se como estratégia de...

  11. Nuevas perspectivas en el tratamiento de la diarrea aguda del lactante: racecadotrilo

    OpenAIRE

    Maldonado Lozano, Jos??

    2006-01-01

    El prop??sito del presente trabajo es realizar una puesta al d??a del tratamiento de la diarrea aguda del lactante, as?? como evaluar la efi cacia del racecadotrilo, un nuevo f??rmaco antisecretor intestinal, en el tratamiento de la diarrea aguda. Se revisan los datos disponibles en la bibliograf??a referentes al tratamiento de rehidrataci??n y realimentaci??n y sobre racecadotrilo, en este ??ltimo caso tanto en experimentaci??n animal como sobre el tratamiento de adultos y ni??os...

  12. Esofagitis necrotizante aguda en paciente inestable Acute necrotizing esophagitis in an unstable patient

    OpenAIRE

    M. Rodrigo; B.E. Gorraiz; C. Merino; J. Eguaras; J.M. Elizalde; W. Soler

    2009-01-01

    La esofagitis necrotizante aguda o esófago negro es una afección rara, conocida en la literatura médica desde 1990. Aunque su mecanismo no es del todo conocido, el compromiso isquémico parece ser el factor fisiopatológico fundamental. Cuando la esofagitis necrotizante aguda es un hallazgo en el estudio endoscópico de hemorragia digestiva alta, sin desestabilización hemodinámica, el pronóstico es bueno. Presentamos un caso en el que el diagnóstico de esófago negro fue un mero hallazgo endoscóp...

  13. Plan de cuidados en una paciente con insuficiencia renal aguda. Caso Clínico

    OpenAIRE

    Delgado-Hito, Pilar; Romero García, Marta

    1999-01-01

    La Insuficiencia Renal Aguda puede definirse como una reducción o cese brusco de la función renal. Debido a la importancia del riñón en el mantenimiento del medio extracelular, la disminución aguda de la función renal afectará muchos, en realidad, la mayoría de los sistemas orgánicos. Los síntomas de presentación, curso clínico y complicaciones son manifestaciones de estos...

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

    OpenAIRE

    Raidel González Rodríguez; Juan Cardentey García

    2015-01-01

    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 mue...

  15. 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

  16. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  18. Bronquiolite aguda, uma revisão atualizada

    Directory of Open Access Journals (Sweden)

    Werther Brunow de Carvalho

    Full Text Available A bronquiolite aguda (BA é um diagnóstico freqüente de internação hospitalar em pediatria, ocasionada principalmente pelo vírus sincicial respiratório (VSR. Ocorre epidemicamente nos meses de outono e inverno. Algumas populações de crianças (recém-nascidos pré-termo, cardiopatia congênita, doença pulmonar crônica, imunocomprometidos, desnutridos, entre outros apresentam maior risco de morbidade e mortalidade. Os vírus multiplicam-se nas células epiteliais ciliadas, e a inflamação e os debris celulares ocasionam obstrução da via aérea, hiperinsuflação, atelectasia localizada, chiado e alterações das trocas gasosas. Não existem evidências definitivas em relação aos tratamentos utilizados para esta doença. O tratamento inclui a utilização de oxigênio, hidratação, beta-2 agonistas por via inalatória, epinefrina racêmica, DNase recombinante, fisioterapia respiratória, entre outros. Medidas profiláticas: administração de anticorpos monoclonais (palivizumab. A maioria das crianças com BA, independentemente da gravidade da doença, recuperam-se sem seqüelas. O curso natural desta doença, habitualmente, varia entre sete a dez dias, mas algumas crianças permanecem doentes por semanas.

  19. Intoxicación aguda por hidrato de hidracina

    Directory of Open Access Journals (Sweden)

    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.

  20. Axon diameter mapping in crossing fibers with diffusion MRI

    DEFF Research Database (Denmark)

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

    2011-01-01

    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......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...... orientation assumption is a reasonable one. However, fiber crossings and other complex configurations are widespread in the brain. In such areas, the existing techniques will fail to provide useful axon diameter indices for any of the individual fiber populations. We propose a novel crossing fiber tissue...

  1. 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...

  2. 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...

  3. The nigrostriatal pathway: axonal collateralization and compartmental specificity.

    Science.gov (United States)

    Prensa, L; Giménez-Amaya, J M; Parent, A; Bernácer, J; Cebrián, C

    2009-01-01

    This paper reviews two of the major features of the nigrostriatal pathway, its axonal collateralization, and compartmental specificity, as revealed by single-axon labeling experiments in rodents and immunocytological analysis of human postmortem tissue. The dorsal and ventral tiers of the substantia nigra pars compacta harbor various types of neurons the axons of which branch not only within the striatum but also in other major components of the basal ganglia. Furthermore, some nigrostriatal axons send collaterals both to thalamus and to brainstem pedunculopontine tegmental nucleus. In humans, the compartmental specificity of the nigrostriatal pathway is revealed by the fact that the matrix compartment is densely innervated by dopaminergic fibers, whereas the striosomes display different densities of dopaminergic terminals depending on their location within the striatum. The nigral neurons most severely affected in Parkinson's disease are the ventral tier cells that project to the matrix and form deep clusters in the substantia nigra pars reticulata.

  4. Syndecan Promotes Axon Regeneration by Stabilizing Growth Cone Migration

    Directory of Open Access Journals (Sweden)

    Tyson J. Edwards

    2014-07-01

    Full Text Available Growth cones facilitate the repair of nervous system damage by providing the driving force for axon regeneration. Using single-neuron laser axotomy and in vivo time-lapse imaging, we show that syndecan, a heparan sulfate (HS proteoglycan, is required for growth cone function during axon regeneration in C. elegans. In the absence of syndecan, regenerating growth cones form but are unstable and collapse, decreasing the effective growth rate and impeding regrowth to target cells. We provide evidence that syndecan has two distinct functions during axon regeneration: (1 a canonical function in axon guidance that requires expression outside the nervous system and depends on HS chains and (2 an intrinsic function in growth cone stabilization that is mediated by the syndecan core protein, independently of HS. Thus, syndecan is a regulator of a critical choke point in nervous system repair.

  5. Differential compartmentalization of mRNAs in squid giant axon.

    Science.gov (United States)

    Chun, J T; Gioio, A E; Crispino, M; Giuditta, A; Kaplan, B B

    1996-11-01

    Previously, we reported that the squid giant axon contains a heterogeneous population of mRNAs that includes beta-actin, beta-tubulin, kinesin, neurofilament proteins, and enolase. To define the absolute levels and relative distribution of these mRNAs, we have used competitive reverse transcription-PCR to quantify the levels of five mRNAs present in the giant axon and giant fiber lobe (GFL), the location of the parental cell soma. In the GFL, the number of transcripts for these mRNAs varied over a fourfold range, with beta-tubulin being the most abundant mRNA species (1.25 x 10(9) molecules per GFL). Based on transcript number, the rank order of mRNA levels in the GFL was beta-tubulin > beta-actin > kinesin > enolase > microtubule-associated protein (MAP) H1. In contrast, kinesin mRNA was most abundant in the axon (4.1 x 10(7) molecules per axon) with individual mRNA levels varying 15-fold. The rank order of mRNA levels in the axon was kinesin > beta-tubulin > MAP H1 > beta-actin > enolase. The relative abundance of the mRNA species in the axon did not correlate with the size of the transcript, nor was it directly related to their corresponding levels in the GFL. Taken together, these findings confirm that significant amounts of mRNA are present in the giant axon and suggest that specific mRNAs are differentially transported into the axonal domain.

  6. 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.

  7. 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.

  8. Modality-specific axonal regeneration: toward selective regenerative neural interfaces.

    Science.gov (United States)

    Lotfi, Parisa; Garde, Kshitija; Chouhan, Amit K; Bengali, Ebrahim; Romero-Ortega, Mario I

    2011-01-01

    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 sub-modality 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 threefold in the NT-3 channels. These results were confirmed using a 3D "Y"-shaped in vitro assay showing that the arm containing NGF was able to entice a fivefold 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 toward 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.

  9. Análisis de la mortalidad por leucemia aguda pediátrica en el Instituto Nacional de Cancerología

    Directory of Open Access Journals (Sweden)

    Anyul Milena Vera

    2012-03-01

    Full Text Available Introducción. La mortalidad por leucemia aguda pediátrica es un indicador trazador del acceso yefectividad de la atención en salud; su análisis permite identificar los factores involucrados en elproceso de la enfermedad que pueden influir en la condición final de los niños. Objetivo. Describir la experiencia operativa y los resultados obtenidos en los comités de análisisinstitucional de la mortalidad por leucemia aguda pediátrica. Materiales y métodos. Se hizo un análisis descriptivo de las muertes por leucemia linfoide o mieloideaguda ocurridas en niños menores de 15 años en el Instituto Nacional de Cancerología, 2008-2010.Se llevó a cabo el análisis de “evitabilidad” (sic. con el modelo de las tres demoras propuesto porThaddeus y Maine. Resultados. Se analizaron 24 defunciones. El 87,5 % fueron a causa de leucemia linfoide aguda. Lamediana de edad fue de 10,5 años. Se encontró que la demora 3 (obtener el tratamiento adecuadoy oportuno ocurrió en el 83 % de los casos analizados y que los traslados durante el tratamiento fuela limitación más común (66,7 %. El 83,3 % de las muertes se consideraron no evitables dadas lascondiciones clínicas de la enfermedad. Conclusiones. Es la primera experiencia en el análisis de mortalidad por un evento crónico enla población pediátrica del Instituto Nacional de Cancerología y en el país. Aunque las demorasidentificadas no condicionaron de forma directa la mortalidad, sí constituyen la base para estableceracciones de mejoría que influyan en la calidad de la atención de los niños con cáncer.   doi: http://dx.doi.org/10.7705/biomedica.v32i3.691

  10. MR imaging of a diffuse axonal injury

    International Nuclear Information System (INIS)

    Inoue, Yukiya; Okamoto, Hisayo; Mitsushima, Minoru; Hori, Tomokatsu; Sasaki, Mamoru; Teraoka, Akira.

    1989-01-01

    Six patients who had been diagnosed as having so-called a 'Diffuse Axonal Injury (DAI)' were examined by means of Magnetic Resonance Imaging (Yokogawa Resona 0.5T and Shimadzu SMT 50A). MRI revealed clear evidence of injured white matter in these patients, while X-ray CT scanning could not demonstrate such lesions definitely. The patients consisted of three adults and three adolescents. They had been injured by traffic accidents or falls. Every patient had lost consciousness immediately, and their coma had continued for at least two weeks after the trauma. X-ray CT scanning demonstrated no complicated lesion, such as intracranial hematoma or brain edema, resulting in increased intracranial pressure and cerebral herniation. In all of the patients, injuries of the deep white matter (corpus callosum, upper pons, or internal capsule, for example) were clearly found by T 2 -weighted imaging. Because these lesions had characteristic features in their localation, as has been described by Adams et al. these patients were diagnosed as having DAI. Also, it was interesting that the focal neurological deficits of these patients correlated well with the local injuries of the white matter. The three young patients recovered to various degrees, but the three adults passed into a vegetative state. The prognosis of the patients seemed to be determined by their age. Because the clinical diagnosis of DAI is controversial, the use of MRI will help in its clinical diagnosis and analysis. (author)

  11. 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

  12. MR imaging of a diffuse axonal injury

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Yukiya; Okamoto, Hisayo; Mitsushima, Minoru; Hori, Tomokatsu (Tottori Univ., Yonago (Japan). School of Medicine); Sasaki, Mamoru; Teraoka, Akira

    1989-04-01

    Six patients who had been diagnosed as having so-called a 'Diffuse Axonal Injury (DAI)' were examined by means of Magnetic Resonance Imaging (Yokogawa Resona 0.5T and Shimadzu SMT 50A). MRI revealed clear evidence of injured white matter in these patients, while X-ray CT scanning could not demonstrate such lesions definitely. The patients consisted of three adults and three adolescents. They had been injured by traffic accidents or falls. Every patient had lost consciousness immediately, and their coma had continued for at least two weeks after the trauma. X-ray CT scanning demonstrated no complicated lesion, such as intracranial hematoma or brain edema, resulting in increased intracranial pressure and cerebral herniation. In all of the patients, injuries of the deep white matter (corpus callosum, upper pons, or internal capsule, for example) were clearly found by T{sub 2}-weighted imaging. Because these lesions had characteristic features in their localation, as has been described by Adams et al. these patients were diagnosed as having DAI. Also, it was interesting that the focal neurological deficits of these patients correlated well with the local injuries of the white matter. The three young patients recovered to various degrees, but the three adults passed into a vegetative state. The prognosis of the patients seemed to be determined by their age. Because the clinical diagnosis of DAI is controversial, the use of MRI will help in its clinical diagnosis and analysis. (author).

  13. 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.

  14. 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.

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    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. 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

    to represent large-diameter axons that have failed to myelinate. Conditional neuregulin-1 ablation resulted in a reduced sensitivity to noxious mechanical stimuli. These findings emphasize the importance of neuregulin-1 in mediating the signaling between axons and both myelinating and nonmyelinating Schwann...... cells required for normal sensory function. Sensory neuronal survival and axonal maintenance, however, are not dependent on axon-derived neuregulin-1 signaling in adulthood Udgivelsesdato: 2009/6/17...

  18. 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.

  19. Síndrome de Guillain-Barré associada a pancreatite aguda: relato de caso

    OpenAIRE

    GRZESIUK,ANDERSON KUNTZ; SANTOS,LUIZ AUGUSTO DOS

    1999-01-01

    Relatamos um caso clínico de síndrome de Guillain-Barré associada a pancreatite aguda, e realizamos revisão na literatura sobre complicações clínicas relacionadas à síndrome de Guillain- Barré. Sugerimos estarem os eventos clínicos relacionados imunologicamente.

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

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    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

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

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    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

  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. Fisiopatología de la diarrea aguda

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    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

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

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    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

  5. Pneumonia Aguda da Comunidade na Criança — Decisão Terapêutica

    OpenAIRE

    Quintas, Sofia; Boto, Ana; Pereira, Luísa; Barreto, Celeste; Lito, Luís; Bandeira, Teresa

    2014-01-01

    A etiologia da pneumonia aguda da comunidade na criança fica por determinar em 20 a 50% dos episódios. Com o objectivo de identificar elementos clínicos, laboratoriais ou radiológicos relevantes para a decisão terapêutica em crianças com pneumonia aguda, realizámos um estudo retrospectivo de 310 casos de pneumonia aguda adquirida na comunidade internados na Unidade de Pneumologia Pediátrica (U.P.P.) entre Janeiro 1996 e Dezembro 2000. A população estudada foi dividida em dois grupos, em funçã...

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

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    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.

  7. 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.

  8. Molecular Disorganization of Axons Adjacent to Human Cortical Microinfarcts

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    Hamza Coban

    2017-08-01

    Full Text Available Cortical microinfarcts (CMIs are microscopically identified wedge-shaped ischemic lesions that occur at or near the cortical surface and result from occlusion of penetrating arterioles. These microscopic lesions can be observed with high-resolution magnetic resonance imaging in aging brains and in patients with cerebrovascular disease. Recent studies have suggested that strategically located microinfarcts strongly correlate with cognitive deficits, which can contribute to Alzheimer’s disease as well as other forms of dementia. We have recently shown that the molecular organization of axons into functional microdomains is altered in areas adjacent to white matter lacunar and microinfarcts, creating a peri-infarct penumbral injury in surviving axons. Whether similar changes in nodal, adjacent paranodal, and proximal axon initial segment molecular organization occur in the cortex adjacent to human CMIs is not known. Paraffin-embedded sections of autopsy brain tissue from five patients with CMIs were immunofluorescently labeled for nodal and paranodal markers including beta-IV spectrin, ankyrin-G, and contactin-associated protein. High magnification images from the peri-infarct cortical tissue were generated using confocal microscopy. In surviving cortical tissue adjacent to microinfarcts, we observed a dramatic loss of axon initial segments, suggesting that neuronal firing capacity in adjacent cortical tissue is likely compromised. The number of identifiable nodal/paranodal complexes in surviving cortical tissue is reduced adjacent to microinfarcts, while the average paranodal length is increased indicating a breakdown of axoglial contact. This axonal microdomain disorganization occurs in the relative absence of changes in the structural integrity of myelinated axons as measured by myelin basic protein and neurofilament staining. These findings indicate that the molecular organization of surviving axons adjacent to human CMIs is abnormal

  9. 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

  10. Myelinated sensory and alpha motor axon regeneration in peripheral nerve neuromas

    Science.gov (United States)

    Macias, M. Y.; Lehman, C. T.; Sanger, J. R.; Riley, D. A.

    1998-01-01

    Histochemical staining for carbonic anhydrase and cholinesterase (CE) activities was used to analyze sensory and motor axon regeneration, respectively, during neuroma formation in transected and tube-encapsulated peripheral nerves. Median-ulnar and sciatic nerves in the rodent model permitted testing whether a 4 cm greater distance of the motor neuron soma from axotomy site or intrinsic differences between motor and sensory neurons influenced regeneration and neuroma formation 10, 30, and 90 days later. Ventral root radiculotomy confirmed that CE-stained axons were 97% alpha motor axons. Distance significantly delayed axon regeneration. When distance was negligible, sensory axons grew out sooner than motor axons, but motor axons regenerated to a greater quantity. These results indicate regeneration differences between axon subtypes and suggest more extensive branching of motor axons within the neuroma. Thus, both distance from injury site to soma and inherent motor and sensory differences should be considered in peripheral nerve repair strategies.

  11. La estructura de las formas libres

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    Azagra, D.

    2012-06-01

    Full Text Available The current situation, characterised by an impressive advance of conceptual, design and construction techniques, together with an establishment of a digital culture, has led to the architectural development of the so called free-forms. This paper evaluates the diverse development of different types of free-forms, and the role of the structure in each case. Four conceptual approaches are considered to tackle the design of free-forms as a function of both the process of generation and the influence of the structure in its development: sculptural forms, forms of concurrent structural adaptation, forms of structural algorithmic generation, and parametric forms. Starting from this analysis, four issues are presented for discussion: the process of development of free-foms, the design approach considering the multiplicity of factors in current projects, the response and relevance of the structure in free-form architecture, and finally, the potential of digital architecture and the role of the structure in its development.

    La situación actual, caracterizada por un impresionante avance de las técnicas de diseño, proyecto y construcción, y por el establecimiento de una cultura digital, ha propiciado el desarrollo arquitectónico de formas que podríamos calificar como libres. El artículo valora el diverso desarrollo de estas formas libres, y el papel de la estructura en dicho proceso. Se consideran para ello cuatro planteamientos con los que afrontar el desarrollo de estas formas libres, en función de su proceso de generación y de la influencia de la estructura: formas escultóricas, formas de conjunción estructural, formas de generación estructural o algorítmica, y formas paramétricas. A partir de este análisis se proponen cuatro puntos de discusión: el proceso de desarrollo de las formas libres; cómo afrontar la multiplicidad de factores actuales; la respuesta y relevancia de la estructura; y el potencial de la arquitectura

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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)

  17. Fast and reliable identification of axons, axon initial segments and dendrites with local field potential recording

    DEFF Research Database (Denmark)

    Petersen, Anders V.; Johansen, Emil O.; Perrier, Jean-Francois

    2015-01-01

    The axon initial segment (AIS) is an essential neuronal compartment. It is usually where action potentials are initiated. Recent studies demonstrated that the AIS is a plastic structure that can be regulated by neuronal activity and by the activation of metabotropic receptors. Studying the AIS...... in live tissue can be difficult because its identification is not always reliable. Here we provide a new technique allowing a fast and reliable identification of the AIS in live brain slice preparations. By simultaneous recording of extracellular local field potentials and whole-cell patch-clamp recording...... of neurons, we can detect sinks caused by inward currents flowing across the membrane. We determine the location of the AIS by comparing the timing of these events with the action potential. We demonstrate that this method allows the unequivocal identification of the AIS of different types of neurons from...

  18. Fast and reliable identification of axons, axon initial segments and dendrites with local field potential recording

    Directory of Open Access Journals (Sweden)

    Anders Victor ePetersen

    2015-10-01

    Full Text Available The axon initial segment (AIS is an essential neuronal compartment. It is usually where action potentials are initiated. Recent studies demonstrated that the AIS is a plastic structure that can be regulated by neuronal activity and by the activation of metabotropic receptors. Studying the AIS in live tissue can be difficult because its identification is not always reliable. Here we provide a new technique allowing a fast and reliable identification of the AIS in live brain slice preparations. By simultaneous recoding of extracellular local field potentials and whole-cell patch-clamp recording of neurons, we can detect sinks caused by inward currents flowing across the membrane. We determine the location of the AIS by comparing the timing of these events with the action potential. We demonstrate that this method allows the unequivocal identification of the AIS of different types of neurons from the brain.

  19. Contrastes de Forma: Contrastes de ilusiones (I)

    OpenAIRE

    Salvador González, José María

    1986-01-01

    Primera parte del análisis crítico de los principales movimientos artísticos representados en la Exposición Contrastes de Forma, organizada por varios museos de Nueva York en el Museo de Arte Contemporáneo de Caracas.

  20. 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

  1. Nível de NT-proBNP em pacientes com síndrome coronariana aguda sem supradesnivelamento do segmento ST

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    Luiz Ricardo A. Castro

    2011-12-01

    Full Text Available FUNDAMENTO: A síndrome coronariana aguda (SCA sem supradesnivelamento do segmento ST (SCASEST está associada ao supradesnivelamento do peptídeo natriurético tipo B (BNP e aos marcadores de necrose miocárdica, embora se desconheça a correlação dessa síndrome ao escore de trombólise no infarto do miocárdio (TIMI e à função ventricular esquerda. OBJETIVO: Avaliar a correlação entre os níveis do fragmento N-terminal do peptídeo natriurético tipo B (NT-proBNP e os marcadores de necrose miocárdica (creatinofosfoquinase fração músculo-cérebro CK-MB e troponina I, bem como entre o escore de risco TIMI e a fração de ejeção do ventrículo esquerdo (FEVE nos pacientes com síndrome coronariana aguda sem supradesnivelamento do segmento ST. MÉTODOS: Oitenta e sete pacientes com síndrome coronariana aguda sem supradesnivelamento do segmento ST foram divididos em dois grupos: 37 (42,5% com angina instável e 50 (57,5% com infarto agudo do miocárdio sem supradesnivelamento do segmento ST (IAMSSST. RESULTADOS: A fração de ejeção do ventrículo esquerdo superior a 40% foi encontrada em 86,2% do total da amostra. Os níveis séricos de NT-proBNP foram maiores em pacientes com infarto do miocárdio sem supradesnivelamento do segmento ST, em comparação àqueles com angina instável (p<0,001. O aumento dos níveis de NT-proBNP foi associado ao aumento de troponina I (rs=0,425, p<0,001, pico de CK-MB (rs=0,458, p<0,001 e FEVE (rs=-0,345, p=0,002, não havendo correlação com o escore de risco TIMI (rs=0,082, p=0,44. Na análise multivariada, a fração de ejeção do ventrículo esquerdo e a troponina I correlacionaram-se de forma independente aos níveis de NT-proBNP (p=0,017 e p=0,002, respectivamente. CONCLUSÃO: O aumento dos níveis de NT-proBNP em pacientes com síndrome coronariana aguda sem supradesnivelamento do segmento ST não está relacionado exclusivamente à redução da fração de ejeção do ventrículo esquerdo

  2. 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

  3. 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.

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

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    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.

  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. Early-onset acute transverse myelitis following hepatitis B vaccination and respiratory infection: case report Mielite transversa aguda de início precoce precedida de vacinação para hepatite B e infecção viral respiratória: relato de caso

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Fonseca

    2003-06-01

    Full Text Available Acute transverse myelitis is an acute inflammatory process of the spinal cord and it is a rare clinical syndrome in childhood. In this paper, we report a case of 3 years-old boy who developed acute onset tetraparesia following a viral respiratory infecction and hepatitis B vaccination. Magnetic resonance imaging of the spinal cord disclosed signal-intensity abnormalities from C4 to C3. A diagnosis of acute transverse myelitis was made and the patient was treated with IV methylprednisolone and IV immunoglobulin. The child had a fair outcome despite of the very acute course of the disease and the presence of a cervical sensory level which usually harbor a poor prognosis.A mielite transversa aguda é processo inflamatório agudo da medula espinhal de ocorrência rara na infância. Neste artigo, reportamos o caso de um menino de 3 anos que desenvolveu tetraparesia aguda precedida de infecção viral respiratória e pós-vacinação para Hepatite B. A imagem pela Ressonância Magnética da medula espinhal revelou anormalidade de aumento de sinal em C4-T3. Após o diagnóstico da mielite transversa aguda, o paciente foi tratado com metilprednisolona e imunoglobulina. Embora a doença tenha se apresentado de forma aguda e acompanhada de nível sensitivo, o que usualmente levaria a um prognóstico sombrio, a criança evoluiu favoravelmente.

  7. Axoplasmic RNA species synthesized in the isolated squid giant axon.

    Science.gov (United States)

    Rapallino, M V; Cupello, A; Giuditta, A

    1988-07-01

    Isolated squid stellate nerves and giant fiber lobes were incubated for 8 hr in Millipore filtered sea water containing [3H]uridine. The electrophoretic patterns of radioactive RNA purified from the axoplasm of the giant axon and from the giant fiber lobe (cell bodies of the giant axon) demonstrated the presence of RNA species with mobilities corresponding to tRNA and rRNA. The presence of labeled rRNAs was confirmed by the behavior of the large rRNA component (31S) which, in the squid, readily dissociates into its two constituent moyeties (17S and 20S). Comparable results were obtained with the axonal sheath and the stellate nerve. In all the electrophoretic patterns, additional species of radioactive RNA migrated between the 4S and the 20S markers, i.e. with mobilities corresponding to presumptive mRNAs. Chromatographic analysis of the purified RNAs on oligo(dT)cellulose indicated the presence of labeled poly(A)+ RNA in all tissue samples. Radioactive poly(A)+ RNA represented approximately 1% of the total labeled RNA in the axoplasm, axonal sheath and stellate nerve, but more than 2% in the giant fiber lobe. The labeled poly(A)+ RNAs of the giant fibre lobe showed a prevalence of larger species in comparison to the axonal sheath and stellate nerve. In conclusion, the axoplasmic RNAs synthesized by the isolated squid giant axon appear to include all the major classes of axoplasmic RNAs, that is rRNA, tRNA and mRNA.

  8. 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.

  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. 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.

  11. 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.

  12. 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

  13. Estado oxidante e antioxidante de crianças com bronquiolite aguda

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    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.

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

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    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.

  15. IFNgamma enhances microglial reactions to hippocampal axonal degeneration

    DEFF Research Database (Denmark)

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

    2000-01-01

    Glial reactivity is implicated in CNS repair and regenerative responses. Microglia, the cells responding earliest to axonal injury, produce tumor necrosis factor-alpha (TNFalpha), a cytokine with both cytopathic and neuroprotective effects. We have studied activation of hippocampal microglia...... 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...

  16. Selective rab11 transport and the intrinsic regenerative ability of CNS axons.

    Science.gov (United States)

    Koseki, Hiroaki; Donegá, Matteo; Lam, Brian Yh; Petrova, Veselina; van Erp, Susan; Yeo, Giles Sh; Kwok, Jessica Cf; Ffrench-Constant, Charles; Eva, Richard; Fawcett, James W

    2017-08-08

    Neurons lose intrinsic axon regenerative ability with maturation, but the mechanism remains unclear. Using an in-vitro laser axotomy model, we show a progressive decline in the ability of cut CNS axons to form a new growth cone and then elongate. Failure of regeneration was associated with increased retraction after axotomy. Transportation into axons becomes selective with maturation; we hypothesized that selective exclusion of molecules needed for growth may contribute to regeneration decline. With neuronal maturity rab11 vesicles (which carry many molecules involved in axon growth) became selectively targeted to the somatodendritic compartment and excluded from axons by predominant retrograde transport However, on overexpression rab11 was mistrafficked into proximal axons, and these axons showed less retraction and enhanced regeneration after axotomy. These results suggest that the decline of intrinsic axon regenerative ability is associated with selective exclusion of key molecules, and that manipulation of transport can enhance regeneration.

  17. Forma de crecimiento en Leptochloa Chloridiformis (Poaceae

    Directory of Open Access Journals (Sweden)

    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

  18. Diagnóstico laboratorial das leucemias mielóides agudas

    OpenAIRE

    Silva,Graziele C. da; Pilger,Diogo A.; Castro,Simone M. de; Wagner,Sandrine C.

    2006-01-01

    As leucemias agudas caracterizam-se pela proliferação clonal e pelo bloqueio maturativo das células hematopoéticas, com substituição difusa da medula óssea por células neoplásicas. A leucemia mielóide aguda (LMA) é um grupo heterogêneo de doenças clonais do tecido hematopoético, que acomete predominantemente idosos acima de 60 anos de idade. A LMA apresenta oito subtipos distintos morfologicamente: LMA M0 a M7. Os métodos diagnósticos para identificação da LMA e classificação dos subtipos são...

  19. Hepatitis virales agudas en un hospital de adultos, de 1992 a 2001

    OpenAIRE

    José Acuña; Elizabeth Umaña; Mauricio Saldarriaga; Jorge Mora; Fernando Brenes; Alfredo Martén

    2003-01-01

    Justificación y objetivos: Debido al cambio de la distribución etiológica de las hepatitis virales agudas, percibido en la práctica clínica diaria en el ámbito nacional y confirmado en otros países, se hizo evidente la necesidad de realizar un análisis casuístico de las infecciones virales hepáticas agudas en nuestro país. Se puso enfasis en el virus productor de hepatitis Acuya presentación clínica es más severa en adultos en comparación con los niños. Métodos: Se registraron todos los casos...

  20. Insuficiência renal aguda em pacientes com Síndrome Hellp

    OpenAIRE

    Sílvia Maria Dorigoni

    2001-01-01

    A síndrome HELLP ocorre em gestantes ou puérperas e é caracterizada pelo surgimento de hemólise, elevação de enzimas hepáticas e plaquetopenia. Desenvolve-se em aproximadamente 10% das gestantes com pré-eclampsia, sendo mais freqüente entre a 22a e 36a semanas de gestação. Insuficiência renal aguda é uma complicação freqüente e grave nessas pacientes. O objetivo deste estudo foi avaliar, em pacientes com síndrome HELLP, a prevalência de insuficiência renal aguda e estudar fatores a ela associ...

  1. Axon diameter and intra-axonal volume fraction of the corticospinal tract in idiopathic normal pressure hydrocephalus measured by q-space imaging.

    Directory of Open Access Journals (Sweden)

    Kouhei Kamiya

    Full Text Available PURPOSE: Previous studies suggest that compression and stretching of the corticospinal tract (CST potentially cause treatable gait disturbance in patients with idiopathic normal pressure hydrocephalus (iNPH. Measurement of axon diameter with diffusion MRI has recently been used to investigate microstructural alterations in neurological diseases. In this study, we investigated alterations in the axon diameter and intra-axonal fraction of the CST in iNPH by q-space imaging (QSI analysis. METHODS: Nineteen patients with iNPH and 10 age-matched controls were recruited. QSI data were obtained with a 3-T system by using a single-shot echo planar imaging sequence with the diffusion gradient applied parallel to the antero-posterior axis. By using a two-component low-q fit model, the root mean square displacements of intra-axonal space ( =  axon diameter and intra-axonal volume fraction of the CST were calculated at the levels of the internal capsule and body of the lateral ventricle, respectively. RESULTS: Wilcoxon's rank-sum test revealed a significant increase in CST intra-axonal volume fraction at the paraventricular level in patients (p<0.001, whereas no significant difference was observed in the axon diameter. At the level of the internal capsule, neither axon diameter nor intra-axonal volume fraction differed significantly between the two groups. CONCLUSION: Our results suggest that in patients with iNPH, the CST does not undergo irreversible axonal damage but is rather compressed and/or stretched owing to pressure from the enlarged ventricle. These analyses of axon diameter and intra-axonal fraction yield insights into microstructural alterations of the CST in iNPH.

  2. Las formas del recuerdo. La memoria colectiva

    Directory of Open Access Journals (Sweden)

    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. Lesiones asociadas a una toxoplasmosis aguda en perdices rojas (alectoris rufa) infectadas experimentalmente

    OpenAIRE

    Martínez-Carrasco Pleite, Carlos; Bernabé Salazar, Antonio; Ortiz Sánchez, Juana; Alonso de Vega, Francisco

    2006-01-01

    En el presente trabajo se describen las lesiones asociadas a una toxoplasmosis aguda en perdices rojas (Alectoris rufa) infectadas experimentalmente con ooquistes de Toxoplasma gondii. Para ello, treinta perdices rojas de cinco meses de edad fueron infectadas por vía oral con ooquistes de la cepa OV-51/95 de T. gondii. Las aves fueron distribuidas en cinco lotes, que recibieron unas dosis infectantes de 10, 50, 100, 1000 y 10000 ooquistes, respectivamente. Sólo dos aves, inocu...

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

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    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

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    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.

  11. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  13. Diagnóstico laboratorial das leucemias linfóides agudas In vitro diagnosis of acute lymphoid leukemias

    Directory of Open Access Journals (Sweden)

    Mariela Granero Farias

    2004-04-01

    Full Text Available A leucemia linfóide aguda (LLA é a forma mais comum de câncer na infância, compreendendo 70% dos casos; em adultos a incidência é de apenas 20%. A abordagem inicial do diagnóstico consiste no exame citomorfológico do sangue periférico e da medula óssea. O estudo imunofenotípico eleva para 99% o percentual de casos corretamente classificados, permitindo identificar a linhagem celular (T ou B e os diferentes estágios de maturação da célula. Aproximadamente 20% dos casos são de origem de célula T; 75%, precursores de célula B; e 5%, de célula B madura. As técnicas citogenéticas têm contribuído de maneira fundamental para a compreensão da biologia molecular e do tratamento da LLA. As anormalidades cromossômicas, quando associadas ao painel de imunofenotipagem, constituem o parâmetro mais importante para a classificação das leucemias, e, juntamente com outros fatores clínicos e laboratoriais, possibilitam a estratificação dos pacientes em diferentes grupos de risco, tendo importância fundamental para determinar o prognóstico e estabelecer o tratamento adequado. O objetivo deste trabalho é fazer uma revisão bibliográfica dos métodos laboratoriais através dos critérios morfológicos, citoquímicos, imunológicos, citogenéticos e de genética molecular, que são úteis para a classificação e o diagnóstico das leucemias linfóides agudas.Acute lymphoid leukemia (ALL is the commonest type of cancer in childhood, representing 70% of cases. In adults its incidence is 20% only. The initial diagnosis approach consists of a peripheral blood and bone marrow cytomorphological examination. The rate of correctly classified cases is increased up to 99% through immunophenotypic study, which allows to identify the cell line (T or B and the different stages of cell maturation. Nearly 20% derive from T cells, 75% from B-cell precursors and 5% from mature B-cells. The cytogenetic techniques have markedly contributed to the

  14. 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)

  15. Quantifying mechanical force in axonal growth and guidance

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    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.

  16. Model of fasciculation and sorting in mixed populations of axons

    Czech Academy of Sciences Publication Activity Database

    Chaudhuri, D.; Borowski, P.; Zápotocký, Martin

    2011-01-01

    Roč. 84, č. 2 (2011), e021908 ISSN 1539-3755 R&D Projects: GA MŠk(CZ) LC554 Institutional research plan: CEZ:AV0Z50110509 Keywords : axon guidance * neurogenesis * mathematical model Subject RIV: FH - Neurology Impact factor: 2.255, year: 2011

  17. Axonal dynamics of excitatory and inhibitory neurons in somatosensory cortex.

    Directory of Open Access Journals (Sweden)

    Sally A Marik

    2010-06-01

    Full Text Available Cortical topography can be remapped as a consequence of sensory deprivation, suggesting that cortical circuits are continually modified by experience. To see the effect of altered sensory experience on specific components of cortical circuits, we imaged neurons, labeled with a genetically modified adeno-associated virus, in the intact mouse somatosensory cortex before and after whisker plucking. Following whisker plucking we observed massive and rapid reorganization of the axons of both excitatory and inhibitory neurons, accompanied by a transient increase in bouton density. For horizontally projecting axons of excitatory neurons there was a net increase in axonal projections from the non-deprived whisker barrel columns into the deprived barrel columns. The axon collaterals of inhibitory neurons located in the deprived whisker barrel columns retracted in the vicinity of their somata and sprouted long-range projections beyond their normal reach towards the non-deprived whisker barrel columns. These results suggest that alterations in the balance of excitation and inhibition in deprived and non-deprived barrel columns underlie the topographic remapping associated with sensory deprivation.

  18. Acute Motor Axonal Neuropathy in Association with Hepatitis E

    Directory of Open Access Journals (Sweden)

    Araz Al-Saffar

    2018-02-01

    Full Text Available Guillain–Barré syndrome (GBS is an acute peripheral neuropathy that develops as a result of post-infectious immune-mediated nerve injury. It can be classified into classic and variant GBS. Acute motor axonal neuropathy (AMAN is a subtype of GBS with the key clinical features of pure motor weakness, areflexia, absence of sensory symptoms, and lack of neurophysiologic evidence of demyelination. We reported a case of acute motor axonal neuropathy in association with hepatitis E infection. A young woman was referred to us after a period of nausea, fever, and diarrhea. She had unexplained muscle weakness at admission and has been diagnosed with acute hepatitis E infection. A rigorous clinical neurological assessment revealed bilateral symmetrical weakness, which affects the lower limbs more than the upper limbs, with no evidence of sensory involvement. Neurophysiological measurements indicated acute axonal injury without clues to demyelination. A diagnosis of acute motor axonal neuropathy subtype has been made, to which she only received supportive therapy. The symptoms resolved spontaneously and full recovery of motor function was attained after 35 days of weakness onset with complete normalization of neurophysiologic parameters.

  19. 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.

  20. IFNgamma enhances microglial reactions to hippocampal axonal degeneration

    DEFF Research Database (Denmark)

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

    2000-01-01

    Glial reactivity is implicated in CNS repair and regenerative responses. Microglia, the cells responding earliest to axonal injury, produce tumor necrosis factor-alpha (TNFalpha), a cytokine with both cytopathic and neuroprotective effects. We have studied activation of hippocampal microglia to p...

  1. 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.

  2. Intoxicaciones agudas con plaguicidas: costos humanos y económicos

    Directory of Open Access Journals (Sweden)

    Jaime E. García

    Full Text Available El uso de los plaguicidas ha producido grandes beneficios agrícolas y, a la vez, graves problemas de salud pública que requieren solución. En algunos estudios de los años ochenta y noventa se informa que anualmente se registran entre medio millón y millón y medio de casos de intoxicación aguda por plaguicidas con un número correspondiente de defunciones que oscila de 3000 a 28000. Este trabajo tuvo como objetivo destacar la incidencia de las intoxicaciones agudas por plaguicidas y los costos sociales y económicos atribuibles a estas en diferentes lugares del mundo. Se presentan datos relacionados con la importancia económica de la industria de los plaguicidas y se describe la situación de las intoxicaciones agudas por exposición a plaguicidas y por consumo de alimentos contaminados con ellos. Estos datos revelan que las intoxicaciones por plaguicidas son más frecuentes en los países en desarrollo que en los países industrializados, pese a que su consumo general es menor en los primeros. También se estiman los costos económicos relacionados con las intoxicaciones causadas por estas sustancias y se examinan, por último, algunos aspectos adicionales de la situación descrita, con hincapié en la necesidad de reducir el uso de los plaguicidas.

  3. Hipercalcemia grave como forma de apresentação de leucemia linfoblástica aguda em crianças

    OpenAIRE

    Martins, Andreia Luís; Moniz, Marta; Nunes, Pedro Sampaio; Abadesso, Clara; Loureiro, Helena Cristina; Duarte, Ximo; Almeida, Helena Isabel

    2015-01-01

    RESUMO A hipercalcemia é um distúrbio metabólico raro em pediatria, potencialmente fatal, apresentando um vasto diagnóstico diferencial, incluindo neoplasias. Relatamos aqui o caso de uma criança de 3 anos, previamente saudável, admitida no serviço de urgência por fadiga, hiporreatividade, febre e claudicação da marcha com 5 dias de evolução, de agravamento progressivo. À observação, apresentava-se inconsciente (escore de coma Glasgow: 8). Laboratorialmente, apresentava hipercalcemia grave (c...

  4. Genetic Deletion of the Transcriptional Repressor NFIL3 Enhances Axon Growth In Vitro but Not Axonal Repair In Vivo

    NARCIS (Netherlands)

    van der Kallen, Loek R; Eggers, Ruben; Ehlert, Erich M; Verhaagen, J.; Smit, August B; van Kesteren, Ronald E

    2015-01-01

    Axonal regeneration after injury requires the coordinated expression of genes in injured neurons. We previously showed that either reducing expression or blocking function of the transcriptional repressor NFIL3 activates transcription of regeneration-associated genes Arg1 and Gap43 and strongly

  5. 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 injur...

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

    Directory of Open Access Journals (Sweden)

    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

  7. Adult onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) and Nasu-Hakola disease: lesion staging and dynamic changes of axons and microglial subsets.

    Science.gov (United States)

    Oyanagi, Kiyomitsu; Kinoshita, Michiaki; Suzuki-Kouyama, Emi; Inoue, Teruhiko; Nakahara, Asa; Tokiwai, Mika; Arai, Nobutaka; Satoh, Jun-Ichi; Aoki, Naoya; Jinnai, Kenji; Yazawa, Ikuru; Arai, Kimihito; Ishihara, Kenji; Kawamura, Mitsuru; Ishizawa, Keisuke; Hasegawa, Kazuko; Yagisita, Saburo; Amano, Naoji; Yoshida, Kunihiro; Terada, Seishi; Yoshida, Mari; Akiyama, Haruhiko; Mitsuyama, Yoshio; Ikeda, Shu-Ichi

    2017-11-01

    The brains of 10 Japanese patients with adult onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) encompassing hereditary diffuse leukoencephalopathy with axonal spheroids (HDLS) and pigmentary orthochromatic leukodystrophy (POLD) and eight Japanese patients with Nasu-Hakola disease (N-HD) and five age-matched Japanese controls were examined neuropathologically with special reference to lesion staging and dynamic changes of microglial subsets. In both diseases, the pathognomonic neuropathological features included spherically swollen axons (spheroids and globules), axon loss and changes of microglia in the white matter. In ALSP, four lesion stages based on the degree of axon loss were discernible: Stage I, patchy axon loss in the cerebral white matter without atrophy; Stage II, large patchy areas of axon loss with slight atrophy of the cerebral white matter and slight dilatation of the lateral ventricles; Stage III, extensive axon loss in the cerebral white matter and dilatation of the lateral and third ventricles without remarkable axon loss in the brainstem and cerebellum; Stage IV, devastated cerebral white matter with marked dilatation of the ventricles and axon loss in the brainstem and/or cerebellum. Internal capsule and pontine base were relatively well preserved in the N-HD, even at Stage IV, and the swollen axons were larger with a higher density in the ALSP. Microglial cells immunopositive for CD68, CD163 or CD204 were far more obvious in ALSP, than in N-HD, and the shape and density of the cells changed in each stage. With progression of the stage, clinical symptoms became worse to apathetic state, and epilepsy was frequently observed in patients at Stages III and IV in both diseases. From these findings, it is concluded that (i) shape, density and subsets of microglia change dynamically along the passage of stages and (ii) increase of IBA-1-, CD68-, CD163- and CD204-immunopositive cells precedes loss of axons in ALSP. © 2016

  8. 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%

  9. 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.

  10. 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

  11. Acute pancreatitis associated with acute viral hepatitis: case report and review of literature Pancreatite aguda associada com hepatite A aguda: relato de caso e revisão da literatura

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    Danilo Bora Moleta

    2009-12-01

    Full Text Available This case report, along with the review presented, describes a patient diagnosed with acute viral hepatitis, who developed a framework of intense abdominal pain and laboratorial alterations compatible with acute pancreatitis. The association of acute pancreatitis complicating fulminant and non-fulminant acute hepatitis virus (AHV has been reported and several mechanisms have been proposed for this complication, but so far none is clearly involved. As acute hepatitis is a common disease, it is important to stimulate the development of other studies in order to determine local incidence and profile of patients presenting this association in our environment.Este relato de caso, junto com a revisão de literatura, descreve um paciente com diagnóstico de hepatite viral aguda, que desenvolveu quadro de dor abdominal intensa e alterações laboratoriais compatíveis com pancreatite aguda. Casos de pancreatite aguda complicando hepatites virais agudas fulminantes e não fulminantes tem sido esporadicamente relatados e vários mecanismos são propostos para explicar esta complicação, no entanto sua causa ainda se mantém desconhecida. Como a hepatite aguda é doença comum, é importante estimular o desenvolvimento de mais estudos na América Latina que visem determinar a incidência local e o perfil dos pacientes que apresentam esta complicação.

  12. 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

  13. 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

  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. Creativos, Precarios, y Nuevas Formas de Interculturalidad

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    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.

  16. 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

  17. Pharmacogenetic stimulation of neuronal activity increases myelination in an axon-specific manner.

    Science.gov (United States)

    Mitew, Stanislaw; Gobius, Ilan; Fenlon, Laura R; McDougall, Stuart J; Hawkes, David; Xing, Yao Lulu; Bujalka, Helena; Gundlach, Andrew L; Richards, Linda J; Kilpatrick, Trevor J; Merson, Tobias D; Emery, Ben

    2018-01-22

    Mounting evidence suggests that neuronal activity influences myelination, potentially allowing for experience-driven modulation of neural circuitry. The degree to which neuronal activity is capable of regulating myelination at the individual axon level is unclear. Here we demonstrate that stimulation of somatosensory axons in the mouse brain increases proliferation and differentiation of oligodendrocyte progenitor cells (OPCs) within the underlying white matter. Stimulated axons display an increased probability of being myelinated compared to neighboring non-stimulated axons, in addition to being ensheathed with thicker myelin. Conversely, attenuating neuronal firing reduces axonal myelination in a selective activity-dependent manner. Our findings reveal that the process of selecting axons for myelination is strongly influenced by the relative activity of individual axons within a population. These observed cellular changes are consistent with the emerging concept that adaptive myelination is a key mechanism for the fine-tuning of neuronal circuitry in the mammalian CNS.

  18. Effect of vesicle traps on traffic jam formation in fast axonal transport.

    Science.gov (United States)

    Kuznetsov, A V

    2010-08-01

    The purpose of this paper is to develop a model for simulation of the formation of organelle traps in fast axonal transport. Such traps may form in the regions of microtubule polar mismatching. Depending on the orientation of microtubules pointing toward the trap region, these traps can accumulate either plus-end or minus-end oriented vesicles. The model predicts that the maximum concentrations of organelles occur at the boundaries of the trap regions; the overall concentration of organelles in the axon with traps is greatly increased compared to that in a healthy axon, which is expected to contribute to mechanical damages of the axon. The organelle traps induce hindrance to organelle transport down the axon; the total organelle flux down the axon with traps is found to be significantly reduced compared to that in a healthy axon. Copyright 2010 Elsevier Inc. All rights reserved.

  19. Efficient retrograde transport of pseudorabies virus within neurons requires local protein synthesis in axons.

    Science.gov (United States)

    Koyuncu, Orkide O; Perlman, David H; Enquist, Lynn W

    2013-01-16

    After replicating in epithelial cells, alphaherpesviruses such as pseudorabies virus (PRV) invade axons of peripheral nervous system neurons and undergo retrograde transport toward the distant cell bodies. Although several viral proteins engage molecular motors to facilitate transport, the initial steps and neuronal responses to infection are poorly understood. Using compartmented neuron cultures to physically separate axon infection from cell bodies, we found that PRV infection induces local protein synthesis in axons, including proteins involved in cytoskeletal remodeling, intracellular trafficking, signaling, and metabolism. This rapid translation of axonal mRNAs is required for efficient PRV retrograde transport and infection of cell bodies. Furthermore, induction of axonal damage, which also induces local protein synthesis, prior to infection reduces virion trafficking, suggesting that host damage signals and virus particles compete for retrograde transport. Thus, similar to axonal damage, virus infection induces local protein translation in axons, and viruses likely exploit this response for invasion. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Retinal ganglion cells: Energetics, compartmentation, axonal transport, cytoskeletons and vulnerability.

    Science.gov (United States)

    Yu, Dao-Yi; Cringle, Stephen J; Balaratnasingam, Chandrakumar; Morgan, William H; Yu, Paula K; Su, Er-Ning

    2013-09-01

    Retinal ganglion cells (RGCs) are specialized projection neurons that relay an immense amount of visual information from the retina to the brain. RGC signal inputs are collected by dendrites and output is distributed from the cell body via very thin (0.5-1 μm) and long (∼50 mm) axons. The RGC cell body is larger than other retinal neurons, but is still only a very small fraction (one ten thousandths) of the length and total surface area of the axon. The total distance traversed by RGCs extends from the retina, starting from synapses with bipolar and amacrine cells, to the brain, to synapses with neurons in the lateral geniculate nucleus. This review will focus on the energy demands of RGCs and the relevant tissues that surround them. RGC survival and function unexceptionally depends upon free energy, predominantly adenosine triphosphate (ATP). RGC energy metabolism is vastly different when compared to that of the photoreceptors. Each subcellular component of the RGC is remarkably different in terms of structure, function and extracellular environment. The energy demands and distribution of each component are also distinct as evidenced by the uneven distribution of mitochondria and ATP within the RGC - signifying the presence of intracellular energy gradients. In this review we will describe RGCs as having four subcellular components, (1) Dendrites, (2) Cell body, (3) Non-myelinated axon, including intraocular and optic nerve head portions, and (4) Myelinated axon, including the intra-orbital and intracranial portions. We will also describe how RGCs integrate information from each subcellular component in order achieve intracellular homeostatic stability as well as respond to perturbations in the extracellular environment. The possible cellular mechanisms such as axonal transport and axonal cytoskeleton proteins that are involved in maintaining RGC energy homeostasis during normal and disease conditions will also be discussed in depth. The emphasis of this

  1. 17 CFR 210.8-05 - Pro forma financial information.

    Science.gov (United States)

    2010-04-01

    ... Statements of Smaller Reporting Companies § 210.8-05 Pro forma financial information. (a) Pro forma 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...

  2. 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

  3. Squid Giant Axon Contains Neurofilament Protein mRNA but does not Synthesize Neurofilament Proteins.

    Science.gov (United States)

    Gainer, Harold; House, Shirley; Kim, Dong Sun; Chin, Hemin; Pant, Harish C

    2017-04-01

    When isolated squid giant axons are incubated in radioactive amino acids, abundant newly synthesized proteins are found in the axoplasm. These proteins are translated in the adaxonal Schwann cells and subsequently transferred into the giant axon. The question as to whether any de novo protein synthesis occurs in the giant axon itself is difficult to resolve because the small contribution of the proteins possibly synthesized intra-axonally is not easily distinguished from the large amounts of the proteins being supplied from the Schwann cells. In this paper, we reexamine this issue by studying the synthesis of endogenous neurofilament (NF) proteins in the axon. Our laboratory previously showed that NF mRNA and protein are present in the squid giant axon, but not in the surrounding adaxonal glia. Therefore, if the isolated squid axon could be shown to contain newly synthesized NF protein de novo, it could not arise from the adaxonal glia. The results of experiments in this paper show that abundant 3H-labeled NF protein is synthesized in the squid giant fiber lobe containing the giant axon's neuronal cell bodies, but despite the presence of NF mRNA in the giant axon no labeled NF protein is detected in the giant axon. This lends support to the glia-axon protein transfer hypothesis which posits that the squid giant axon obtains newly synthesized protein by Schwann cell transfer and not through intra-axonal protein synthesis, and further suggests that the NF mRNA in the axon is in a translationally repressed state.

  4. Neocortical axon arbors trade-off material and conduction delay conservation.

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    Julian M L Budd

    2010-03-01

    Full Text Available The brain contains a complex network of axons rapidly communicating information between billions of synaptically connected neurons. The morphology of individual axons, therefore, defines the course of information flow within the brain. More than a century ago, Ramón y Cajal proposed that conservation laws to save material (wire length and limit conduction delay regulate the design of individual axon arbors in cerebral cortex. Yet the spatial and temporal communication costs of single neocortical axons remain undefined. Here, using reconstructions of in vivo labelled excitatory spiny cell and inhibitory basket cell intracortical axons combined with a variety of graph optimization algorithms, we empirically investigated Cajal's conservation laws in cerebral cortex for whole three-dimensional (3D axon arbors, to our knowledge the first study of its kind. We found intracortical axons were significantly longer than optimal. The temporal cost of cortical axons was also suboptimal though far superior to wire-minimized arbors. We discovered that cortical axon branching appears to promote a low temporal dispersion of axonal latencies and a tight relationship between cortical distance and axonal latency. In addition, inhibitory basket cell axonal latencies may occur within a much narrower temporal window than excitatory spiny cell axons, which may help boost signal detection. Thus, to optimize neuronal network communication we find that a modest excess of axonal wire is traded-off to enhance arbor temporal economy and precision. Our results offer insight into the principles of brain organization and communication in and development of grey matter, where temporal precision is a crucial prerequisite for coincidence detection, synchronization and rapid network oscillations.

  5. 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.

  6. A resposta metabólica ao trauma cranioencefálico é autolimitada? Análise das proteínas de fase aguda e glicemia

    Directory of Open Access Journals (Sweden)

    SCHELP ARTHUR O.

    1998-01-01

    Full Text Available Nos últimos anos tem havido referências à limitação da resposta metabólica nas duas primeiras semanas após trauma cranioencefálico (TCE. Foi feita proposta de estudo a partir de experimento clínico em pacientes com trauma encefálico grave, que foram avaliados por volta de 7 dias após a lesão (M1. A segunda avaliação ocorreu 4 dias após (M2, e a terceira 3 a 4 dias após (M3. Em um período de 2 anos, foram selecionados 28 pacientes do sexo masculino, com trauma encefálico grave, escala de gravidade de Glasgow entre 4 e 6. Dentre os 28 pacientes, 6 completaram o estudo proposto. Os pacientes foram acompanhados clinicamente durante toda a fase do experimento. Em cada um dos momentos de análise, foram feitas análises da excreção nitrogenada e proteínas de fase aguda. Da mesma forma foram feitas determinações da glicemia plasmática, N-amínico e triglicerídeos. Os resultados do estudo demonstraram não haver modificações no balanço nitrogenado, normalização da proteína-C-reativa e redução relativa da glicemia ao final do experimento. Os autores tecem considerações sobre os possíveis mecanismos envolvidos na modulação da resposta metabólica e concluem que o hipermetabolismo, a basear-se na análise da glicemia e das proteínas de fase aguda, não persiste além do 13° dia do período de recuperação pós-trauma. São feitas sugestões de estudos futuros que possam elucidar os mecanismos envolvidos na normalização do hipercatabolismo e hipermetabolismo observados nas duas primeiras semanas após TCE.

  7. 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

  8. Factores de riesgo de las infecciones respiratorias agudas en pacientes menores de un año Risk factors of acute respiratory infections in patient younger one year

    Directory of Open Access Journals (Sweden)

    Adealvys Corcho Quintero

    2010-12-01

    Full Text Available El comportamiento de las infecciones respiratorias agudas es similar en los países desarrollados y en los subdesarrollados. Constituyen la primera causa de muerte por enfermedad infecciosa en los países desarrollados, y en Cuba se ubica entre las 10 primeras causas de muerte. Bajo un diseño de estudio de corte transversal, se detallan en este artículo los factores de riesgo asociados a estas infecciones en los pacientes menores de un año del Consejo Popular No. 2, perteneciente al Policlínico "Flores Betancourt", en Caimito, durante el año 2007. De los 67 niños estudiados fueron 54 los que enfermaron. Las infecciones respiratorias agudas altas no complicadas, fueron la forma de presentación más frecuente. Los factores que predominaron en los pacientes expuestos fueron: la lactancia mixta y artificial, la contaminación ambiental, la inmunización regular y/o deficiente, el bajo peso al nacer, la asistencia a instituciones infantiles, las edades maternas de 20 a 24 años de edad, y el nivel escolar materno de preuniversitario concluido.The behavior of acute respiratory infections is similar in developed countries and in those underdeveloped being the first cause of death from infectious disease in the developed ones and in Cuba it is place among the 10 first causes of death. In present cross-sectional study design are detailed the risk factors associated with these infections in patients younger one year from the No. 2 Popular Council from the "Flores Betancourt" Polyclinic in Caimito municipality over 2007. From the study children 54 become ill. The non-complicated high acute respiratory infections were the more frequent. The factors prevailing in exposed patients were: mixed and artificial breastfeeding, the environmental contamination, the regular and/or poor immunization, the low birth weight, attendance to children institutions, mother aged 20 to 24 and the mother pre-university level concluded.

  9. Coevolution of axon guidance molecule Slit and its receptor Robo.

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    Qi Yu

    Full Text Available Coevolution is important for the maintenance of the interaction between a ligand and its receptor during evolution. The interaction between axon guidance molecule Slit and its receptor Robo is critical for the axon repulsion in neural tissues, which is evolutionarily conserved from planarians to humans. However, the mechanism of coevolution between Slit and Robo remains unclear. In this study, we found that coordinated amino acid changes took place at interacting sites of Slit and Robo by comparing the amino acids at these sites among different organisms. In addition, the high level correlation between evolutionary rate of Slit and Robo was identified in vertebrates. Furthermore, the sites under positive selection of slit and robo were detected in the same lineage such as mosquito and teleost. Overall, our results provide evidence for the coevolution between Slit and Robo.

  10. Activated retinal glia mediated axon regeneration in experimental glaucoma.

    Science.gov (United States)

    Lorber, Barbara; Guidi, Alessandra; Fawcett, James W; Martin, Keith R

    2012-01-01

    Glaucoma, a leading cause of blindness, is a neurodegenerative disease characterized by progressive loss of retinal ganglion cell axons in the optic nerve and their cell bodies in the retina. Reactive retinal glial changes have been observed in glaucoma but the role of such glial changes in the pathogenesis of the condition remains unclear. In the present study we found that retinal ganglion cells in an experimental animal model of glaucoma have an increased axon regenerative potential. Regeneration of adult rat retinal ganglion cell axons after optic nerve crush was significantly increased in vivo when combined with intraocular pressure-induced experimental glaucoma. This enhanced axon regeneration response was correlated with a significant increase in activation of glial fibrillary acidic protein+retinal glia. Using a dissociated retinal ganglion cell culture model we showed that reducing the number of activated retinal glia with a glial specific toxin, α-Aminoadipic acid, significantly reduced the growth potential of retinal ganglion cells from glaucomatous rat eyes, suggesting that activated retinal glia mediate, at least in part, the growth promoting effect. This was shown to be mediated by both membrane-bound and soluble glial-derived factors. Neurotrophin and ciliary neurotrophic/leukemia inhibitory factor blockers did not affect the regenerative potential, excluding these growth factors as principal mediators of the enhanced growth response occurring in glaucomatous retinal cultures. These observations are the first to reveal that retinal ganglion cells from glaucomatous rat eyes have an enhanced regenerative capacity. Furthermore, our results suggest that activated retinal glia mediate at least part of this response. Further work to understand and enhance the regeneration-promoting effect of activated retinal glia is required to determine if this approach could be useful as part of a therapeutic strategy to encourage optic nerve regeneration in glaucoma

  11. [Craniocerebral trauma: magnetic resonance imaging of diffuse axonal injury].

    Science.gov (United States)

    Mallouhi, A

    2014-09-01

    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.

  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...... lesions in rodents and that the fibers remain several months after injury. The findings of tyrosine hydroxylase- and serotonin-immunoreactivity in the axons suggest that descending central fibers contribute to this endogenous repair of ischemic spinal cord injury....

  13. 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.

  14. 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.

  15. Two stable steady states in the Hodgkin-Huxley axons

    OpenAIRE

    Aihara, K.; Matsumoto, G.

    1983-01-01

    Two stable steady states were found in the numerical solution of the Hodgkin-Huxley equations for the intact squid axon bathed in potassium-rich sea water with an externally applied inward current. Under the conditions the two stable steady-states exist, the Hodgkin-Huxley equations have a complex bifurcation structure including, in addition to the two stable steady-states, a stable limit cycle, two unstable equilibrium points, and one asymptotically stable equilibrium point. It was also conc...

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

    OpenAIRE

    CHEBLI,Júlio Maria Fonseca; FERRARI Jr.,Ângelo Paulo; SILVA,Maria Regina Regis; BORGES,Durval Rosa; ATALLAH,Álvaro Nagib; NEVES,Manoel Martins das

    2000-01-01

    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 c...

  17. 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

  18. Inner membrane fusion mediates spatial distribution of axonal mitochondria

    Science.gov (United States)

    Yu, Yiyi; Lee, Hao-Chih; Chen, Kuan-Chieh; Suhan, Joseph; Qiu, Minhua; Ba, Qinle; Yang, Ge

    2016-01-01

    In eukaryotic cells, mitochondria form a dynamic interconnected network to respond to changing needs at different subcellular locations. A fundamental yet unanswered question regarding this network is whether, and if so how, local fusion and fission of individual mitochondria affect their global distribution. To address this question, we developed high-resolution computational image analysis techniques to examine the relations between mitochondrial fusion/fission and spatial distribution within the axon of Drosophila larval neurons. We found that stationary and moving mitochondria underwent fusion and fission regularly but followed different spatial distribution patterns and exhibited different morphology. Disruption of inner membrane fusion by knockdown of dOpa1, Drosophila Optic Atrophy 1, not only increased the spatial density of stationary and moving mitochondria but also changed their spatial distributions and morphology differentially. Knockdown of dOpa1 also impaired axonal transport of mitochondria. But the changed spatial distributions of mitochondria resulted primarily from disruption of inner membrane fusion because knockdown of Milton, a mitochondrial kinesin-1 adapter, caused similar transport velocity impairment but different spatial distributions. Together, our data reveals that stationary mitochondria within the axon interconnect with moving mitochondria through fusion and fission and that local inner membrane fusion between individual mitochondria mediates their global distribution. PMID:26742817

  19. Dendritic and Axonal Wiring Optimization of Cortical GABAergic Interneurons.

    Science.gov (United States)

    Anton-Sanchez, Laura; Bielza, Concha; Benavides-Piccione, Ruth; DeFelipe, Javier; Larrañaga, Pedro

    2016-10-01

    The way in which a neuronal tree expands plays an important role in its functional and computational characteristics. We aimed to study the existence of an optimal neuronal design for different types of cortical GABAergic neurons. To do this, we hypothesized that both the axonal and dendritic trees of individual neurons optimize brain connectivity in terms of wiring length. We took the branching points of real three-dimensional neuronal reconstructions of the axonal and dendritic trees of different types of cortical interneurons and searched for the minimal wiring arborization structure that respects the branching points. We compared the minimal wiring arborization with real axonal and dendritic trees. We tested this optimization problem using a new approach based on graph theory and evolutionary computation techniques. We concluded that neuronal wiring is near-optimal in most of the tested neurons, although the wiring length of dendritic trees is generally nearer to the optimum. Therefore, wiring economy is related to the way in which neuronal arborizations grow irrespective of the marked differences in the morphology of the examined interneurons.

  20. Axonal Actin Transport Driven By Metastable Actin Filaments

    Science.gov (United States)

    Chakrabarty, Nilaj; Ganguly, Archan; Roy, Subhojit; Jung, Peter

    Actin is one of the key constituents of the neuronal cytoskeleton and is responsible for driving important cellular processes like axon elongation. Axonal actin is synthesized in the cell body and transported at rates of 0.25 - 3 mm/day, as shown by in-vivo pulse-chase radiolabelling studies. However, the underlying transport mechanisms are unknown. Recent experiments in cultured neurons have revealed a dynamic network of metastable actin filaments (actin trails). Actin trails seem to originate from focal actin hotspots which colocalize with stationary endosomes. Interestingly, the number of actin trails extending anterogradely is higher than the ones extending retrogradely. We hypothesize that the bulk axonal transport of actin originates from this directional asymmetry of the number of actin trails. To test this, we constructed a computational model of actin trail growth and simulated the pulse-chase experiment. In our model, local, metastable trails, which grow with their barbed ends anchored to the hotspots, drive the bulk anterograde transport. Our results indicate that the observed bias of the nucleation probabilities and the elongation rate of actin trails are sufficient to drive the bulk transport of actin at rates that agree with in-vivo pulse chase experiments.

  1. 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.

  2. 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

  3. A metamorfose das formas em Tatiana Blass

    Directory of Open Access Journals (Sweden)

    Viviane Baschirotto

    2015-06-01

    Full Text Available Este artigo é uma pequena parte da dissertação de mestrado defendida em 2015 que se ocupou de pensar o gesto artístico da artista visual brasileira Tatiana Blass. Cada artista possui um gesto que carrega consigo, que se encontra como uma persistência e recorrência em sua produção e sempre retorna. Um dos gestos da artista se encontra na metamorfose das formas com os usos distintos de meios e materiais. Utilizando principalmente os conceitos de arquidesenho de Yves Alain Bois e acontecimento de Gilles Deleuze, o artigo se propõe a refletir sobre a plausibilidade do gesto da metamorfose em suas obras tridimensionais que se encontram entre escultura, performance e instalação.

  4. NUEVAS FORMAS ORGANIZACIONALES EN LA GOBERNABILIDAD TRANSNACIONAL

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    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.

  5. 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

  6. Intra-axonal protein synthesis - a new target for neural repair?

    Directory of Open Access Journals (Sweden)

    Jeffery L Twiss

    2016-01-01

    Full Text Available Although initially argued to be a feature of immature neurons with incomplete polarization, there is clear evidence that neurons in the peripheral nervous system retain the capacity for intra-axonal protein synthesis well into adulthood. This localized protein synthesis has been shown to contribute to injury signaling and axon regeneration in peripheral nerves. Recent works point to potential for protein synthesis in axons of the vertebrate central nervous system. mRNAs and protein synthesis machinery have now been documented in lamprey, mouse, and rat spinal cord axons. Intra-axonal protein synthesis appears to be activated in adult vertebrate spinal cord axons when they are regeneration-competent. Rat spinal cord axons regenerating into a peripheral nerve graft contain mRNAs and markers of activated translational machinery. Indeed, levels of some growth-associated mRNAs in these spinal cord axons are comparable to the regenerating sciatic nerve. Markers of active translation tend to decrease when these axons stop growing, but can be reactivated by a second axotomy. These emerging observations raise the possibility that mRNA transport into and translation within axons could be targeted to facilitate regeneration in both the peripheral and central nervous systems.

  7. 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

  8. Manejo asistencial inicial del paciente politraumatizado con sospecha de lesión medular cervical aguda

    OpenAIRE

    Bartolomé Bercial, Leticia; Fernández Silberia, Gemma

    2017-01-01

    Trabajo fin de grado en Enfermería Introducción: los traumatismos constituyen un 12% de la carga mundial de enfermedad, siendo, en el paciente politraumatizado, mayoritariamente frecuentes a nivel cervical (38%), y asociados en muchos casos a una lesión medular aguda. Se estima que entorno al 25% de los daños existentes en pacientes con lesión medular pueden ocurrir o verse aumentados durante el manejo prehospitalario. Por ello, el objetivo de este trabajo es analizar a...

  9. 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.

  10. Estudio de la recurrencia de la pancreatitis aguda litiàsica

    OpenAIRE

    Romaguera Monzonís, Andreu

    2012-01-01

    OBJETIVOS La pancreatitis aguda litiásica (PAL) es una enfermedad con tendencia a recurrir. La colecistectomía precoz (durante el mismo ingreso o antes de las dos semanas) o en determinados casos la CREP están recomendadas en la mayoría de guías clínicas, para evitar la recurrencia. Pero, el porcentaje de recurrencia y el intervalo de aparición de la misma no se conocen con exactitud. Nuestros objetivos son: 1) Determinar el porcentaje de recurrencia en nuestro entorno tras un primer episodio...

  11. Manejo de la pancreatitis aguda litiásica en la embarazada

    OpenAIRE

    Camila Andrea Fernandez; Jorge Carvajal; Fernando Crovari E; Claudio Vera; José Poblete L

    2017-01-01

    La pancreatitis aguda (PA) es una patología poco frecuente durante el embarazo, siendo la colelitiasis una de sus principales etiologías y Chile uno de los países con más altas prevalencias de colelitiasis en el mundo. Esta patología clásicamente ha reportado altas tasas de mortalidad materno-fetal, así como también riesgo de morbilidad fetal. Sin embargo, gracias a los avances en terapia de soporte y mejoras en unidades de neonatología, en la actualidad el pronóstico con un adecuado tratamie...

  12. Síndrome de Guillain-Barré associada a pancreatite aguda: relato de caso

    OpenAIRE

    GRZESIUK, ANDERSON KUNTZ; SANTOS, LUIZ AUGUSTO DOS

    1999-01-01

    Relatamos um caso clínico de síndrome de Guillain-Barré associada a pancreatite aguda, e realizamos revisão na literatura sobre complicações clínicas relacionadas à síndrome de Guillain- Barré. Sugerimos estarem os eventos clínicos relacionados imunologicamente. We report a clinical case of Guillain-Barré syndrome associated with acute pancreatitis, and perform a review in literature about clinical complications related to Guillain-Barré syndrome. We suggest the possibility of being the ev...

  13. Diarrea aguda en trasplantes renales y reno-pancreáticos

    OpenAIRE

    Alberto A Carena; Santiago Boughen; María Inés Gagliardi; Mariana Galante

    2015-01-01

    La diarrea es una complicación frecuente y potencialmente grave del trasplante renal. Se describen aquí, en un estudio de corte transversal, las características epidemiológicas y microbiológicas de la diarrea aguda y persistente en pacientes internados con trasplante renal o reno-páncreas. Se incluyeron 52 pacientes internados en un hospital de la Ciudad de Buenos Aires, 42 (80.8%) habían recibido un trasplante renal y 10 (19.2%) reno-páncreas. La diarrea fue el motivo de ingreso en 34 casos ...

  14. Insuficiência renal aguda por picada de abelhas: relato de casos

    OpenAIRE

    Daher,Elizabeth De Francesco; Oliveira,Rodrigo Alves de; Silva,Leila Silveira Vieira da; Silva,Emanuel Maurício Bezerra e; Morais,Talita Peixoto de

    2009-01-01

    Rabdomiólise é uma síndrome caracterizada por injúria muscular, mais freqüentemente decorrente de esmagamento e traumas musculares. No entanto, a rabdomiólise pode ter também causas não traumáticas, como por exemplo, picadas de abelhas africanizadas. Descrevemos dois casos de rabdomiólise que apresentaram insuficiência renal aguda dialítica após várias picadas de abelhas.

  15. Leucemia linfoblástica aguda infantil: una aproximación genómica

    OpenAIRE

    Jiménez-Morales, Silvia; Hidalgo-Miranda, Alfredo; Ramírez-Bello, Julián

    2017-01-01

    En paralelo al proyecto de la secuenciación del genoma humano, se han desarrollado varias plataformas tecnológicas que están permitiendo ganar conocimiento sobre la estructura del genoma de las entidades humanas, así como evaluar su utilidad en el abordaje clínico del paciente. En la leucemia linfoblástica aguda (LLA), el cáncer infantil más común, las herramientas genómicas prometen ser útiles para detectar a los pacientes con alto riesgo de recaída, ya sea al diagnóstico o durante el tratam...

  16. Isquemia aguda de miembros inferiores secundaria a ergortismo Acute ischemia of lower limbs secondary to ergotism

    OpenAIRE

    Franco J Vallejo; Juan F Gómez; Natalia Tamayo

    2011-01-01

    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 vasod...

  17. Estudio retrospectivo de la epiglotitis aguda en Cantabria en el periodo 1992-2015

    Directory of Open Access Journals (Sweden)

    Natalia CASTAÑEDA-CURTO

    2018-03-01

    Full Text Available Introducción y objetivo: La epiglotitis aguda es una inflamación de la epiglotis y estructuras adyacentes rápidamente progresiva que puede producir obstrucción severa de la vía aérea. Objetivo: conocer las características clínico-epidemiológicas de las epiglotitis aguda en Cantabria. Método Estudio retrospectivo descriptivo de los pacientes diagnosticados de epiglotitis aguda desde enero de 1992 a abril de 2015 en la Comunidad Autónoma de Cantabria (España. Resultados: Cincuenta pacientes fueron incluidos en el estudio, con edades comprendidas entre 1 y 80 años, de los cuales cuarenta eran varones y diez eran mujeres. Sólo uno de ellos se trataba de un paciente pediátrico. Se diagnosticaron 2,7 casos por año, con una incidencia de 0,5 casos por 100000 habitantes y año. Dos pacientes tenían síndrome de Down. El síntoma principal de presentación fue odinofagia (88% seguido de disnea (56% y alteración en la voz (52%. Nueve pacientes requirieron ingreso en cuidados Intensivos. Cuatro pacientes precisaron intubación orotraqueal; a cinco se les realizó una traqueotomía de urgencia. Siete pacientes presentaron complicaciones graves, uno de ellos con secuelas neurológicas severas. Ninguno de ellos murió a consecuencia de la epiglotitis. Conclusiones: La epiglotitis aguda es una patología poco frecuente pero grave y que, por tanto, precisa un tratamiento precoz para evitar complicaciones. Objetivamos una práctica desaparición de la epiglotitis en pacientes pediátricos en nuestro medio, lo que se explica por la introducción en el calendario vacunal de la inmunización contra el Haemophilus Influenzae.

  18. Roturas agudas do tendão de aquiles: tratamento conservador versus cirúrgico

    OpenAIRE

    Cunha, Ana Catarina Martins da

    2015-01-01

    Trabalho final de mestrado integrado em Medicina (Ortopedia), apresentado à Faculdade de Medicina da Universidade de Coimbra. Introdução: O tendão de Aquiles, apesar do seu tamanho e robustez, é a estrutura tendinosa que mais frequentemente sofre rotura. A rotura aguda afeta sobretudo indivíduos do sexo masculino de meia idade, ocorrendo geralmente durante a prática desportiva. Apesar do diagnóstico desta patologia ser bastante acessível, uma vez que a história clínica associada ao exame f...

  19. Líneas de Beau secundarias a enfermedad aguda en una mujer anciana

    Directory of Open Access Journals (Sweden)

    José Mauricio Ocampo

    2013-12-01

    Full Text Available Las líneas de Beau fueron descritas por primera vez en 1846 por Justin Honore Simon Beau. Beau observó que estas líneas se presentaban semanas después del padecimiento de enfermedades febriles agudas. También encontró que el crecimiento normal de las uñas y el cabello se afecta, y estos hallazgos se convierten en indicadores de exposición previa a un evento agudo.   doi: http://dx.doi.org/10.7705/biomedica.v33i4.1430

  20. Utilidad de la Tomografía Computada helicoidal en la diverticulitis aguda

    OpenAIRE

    Sebastián Atilio Rossini; Rubén F. González Villaveirán; Salvador Merola

    2009-01-01

    Objetivo: Evaluar la utilidad de la tomografía computada helicoidal (TCH) en el diagnóstico y manejo terapéutico de la diverticulitis aguda. Materiales y métodos: Estudio de cohorte retrospectivo realizado sobre un periodo de 6 meses que incluyó a 100 pacientes con sospecha clínica de diverticulitis. Se efectuó TCH con contraste oral y endovenoso, salvo contraindicación. Los estudios se correlacionaron con la respuesta terapéutica y el seguimiento clínico y con cirugía e histopatología cuando...

  1. 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 ...

  2. Perfil epidemiológico de internamentos por intoxicação aguda nos HUC: 2000-2007

    OpenAIRE

    Silva, Pedro Alexandre Gonçalves da

    2009-01-01

    As intoxicações agudas são um problema muito relevante de Saúde Pública e que, no entanto, continua pouco explorado, principalmente em Portugal, onde não existem estatísticas oficiais acerca deste tema. A literatura internacional afirma que nos países desenvolvidos as intoxicações agudas são sobretudo medicamentosas e nos países em desenvolvimento devem-se maioritariamente a pesticidas responsáveis por numerosas mortes e graves sequelas. Os objectivos do estudo foram estudar de que form...

  3. Niveles de trombopoyetina en humor acuoso de pacientes con uveítis anterior aguda no infecciosa

    OpenAIRE

    Mondejar Garcia, José Juan

    2015-01-01

    Niveles de trombopoyetina en humor acuoso de pacientes con uveítis anterior aguda no infecciosa Introducción: Las uveítis anteriores agudas no infecciosas (UAANI) son idiopáticas, aunque ligadas a estímulos ambientales y genéticos. Están relacionadas con la respuesta inmune innata y adaptativa. Han sido aisladas citoquinas y factores de crecimiento celular (PEDF y VEGF) en el ojo y el suero de pacientes con uveítis. Los factores de crecimiento (FC) controlan el crecimiento y la diferencia...

  4. 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.

  5. 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

  6. Identificación molecular de Escherichia coli enterotoxigénica en niños con infecciones diarreicas agudas mediante la Reacción en Cadena de la Polimerasa

    Directory of Open Access Journals (Sweden)

    Marx Peña Hidalgo

    2014-12-01

    Full Text Available Las infecciones diarreicas agudas (IDAs son problemas comunes en niños menores de 5 años en nuestro país y la Región Loreto. Sin embargo, se desconocen los agentes microbiológicos causales de estas infecciones. Para cubrir estos vacíos en el conocimiento, el objetivo de esta investigación fue realizar la identificación molecular de Escherichia coli enterotoxigénica (ECET en niños con infecciones diarreicas agudas mediante la Reacción en Cadena de la Polimerasa (PCR. Se colectaron 188 muestras diarreicas de niños menores de cinco años de siete Centros de Salud de Iquitos. A partir de estas se aislaron cepas de E. coli, se extrajo el ADN y amplificó regiones de los genes que codifican las enterotoxinas lábil al calor (LT y estable al calor (ST. De los 188 casos con IDAs se ha encontrado que ~83% son atribuibles a infecciones por cepas de E. coli y de estas ~18% fueron identificadas molecularmente como ECET por presentar el gen LT (19 o el gen ST (9. En conclusión, la mayoría de las IDAs en niños < 5 años de Iquitos están asociadas con cepas de E. coli. Una fracción importante de estas cepas han sido identificadas molecularmente (mediante PCR y demostrado que pertenecen al patotipo ECET. Asimismo, se ha evidenciado que las cepas ECET portadoras del gen LT predominan con respecto a las que tienen el gen ST y no se ha encontrado cepas ECET que porten de forma simultánea ambos genes.

  7. Identificación molecular de Escherichia coli enterotoxigénica en niños con infecciones diarreicas agudas mediante la Reacción en Cadena de la Polimerasa

    Directory of Open Access Journals (Sweden)

    Marx Peña-Hidalgo

    2015-01-01

    Full Text Available Las infecciones diarreicas agudas (IDAs son problemas comunes en niños menores de 5 años en nuestro país y la Región Loreto. Sin embargo, se desconocen los agentes microbiológicos causales de estas infecciones. Para cubrir estos vacíos en el conocimiento, el objetivo de esta investigación fue realizar la identificación molecular de Escherichia coli enterotoxigénica (ECET en niños con infecciones diarreicas agudas mediante la Reacción en Cadena de la Polimerasa (PCR. Se colectaron 188 muestras diarreicas de niños menores de cinco años de siete Centros de Salud de Iquitos. A partir de estas se aislaron cepas de E. coli, se extrajo el ADN y amplificó regiones de los genes que codifican las enterotoxinas lábil al calor (LT y estable al calor (ST. De los 188 casos con IDAs se ha encontrado que ~83% son atribuibles a infecciones por cepas de E. coli y de estas ~18% fueron identificadas molecularmente como ECET por presentar el gen LT (19 o el gen ST (9. En conclusión, la mayoría de las IDAs en niños < 5 años de Iquitos están asociadas con cepas de E. coli. Una fracción importante de estas cepas han sido identificadas molecularmente (mediante PCR y demostrado que pertenecen al patotipo ECET. Asimismo, se ha evidenciado que las cepas ECET portadoras del gen LT predominan con respecto a las que tienen el gen ST y no se ha encontrado cepas ECET que porten de forma simultánea ambos genes.

  8. 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

    of neuroprotective therapies. Energy depletion due to mitochondrial dysfunction has been postulated as an important step in the damage of axons. This prompted us to study the effects of acute inflammation and oxidative stress on the morphology, transport, and function of mitochondria in axons. METHODS: Mouse......BACKGROUND: In brain inflammatory diseases, axonal damage is one of the most critical steps in the cascade that leads to permanent disability. Thus, identifying the initial events triggered by inflammation or oxidative stress that provoke axonal damage is critical for the development...... in axons, increasing the proportion of stationary mitochondria in axons after LPS challenge. Indeed, the two challenges used produced different effects: inflammation mostly reducing retrograde transport and oxidative stress slightly enhancing retrograde transportation. CONCLUSIONS: Neuroinflammation...

  9. Segregation of Axial Motor and Sensory Pathways via Heterotypic Trans-Axonal Signaling

    Science.gov (United States)

    Gallarda, Benjamin W.; Bonanomi, Dario; Müller, Daniel; Brown, Arthur; Alaynick, William A.; Andrews, Shane E.; Lemke, Greg; Pfaff, Samuel L.; Marquardt, Till

    2011-01-01

    Execution of motor behaviors relies on circuitries effectively integrating immediate sensory feedback to efferent pathways controlling muscle activity. It remains unclear how, during neuromuscular circuit assembly, sensory and motor projections become incorporated into tightly coordinated, yet functionally separate pathways. We report that, within axial nerves, establishment of discrete afferent and efferent pathways depends on coordinate signaling between coextending sensory and motor projections. These heterotypic axon-axon interactions require motor axonal EphA3/EphA4 receptor tyrosine kinases activated by cognate sensory axonal ephrin-A ligands. Genetic elimination of trans-axonal ephrin-A → EphA signaling in mice triggers drastic motor-sensory miswiring, culminating in functional efferents within proximal afferent pathways. Effective assembly of a key circuit underlying motor behaviors thus critically depends on trans-axonal signaling interactions resolving motor and sensory projections into discrete pathways. PMID:18403711

  10. 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.

  11. 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

    restores sensory functions. In this study, we elucidate mechanisms underlying stem cell-mediated ingrowth of sensory axons after dorsal root avulsion (DRA). We show that human spinal cord neural stem/progenitor cells (hscNSPC), and also, mesoporous silica particles loaded with growth factor mimetics (Meso......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......MIM prevented stem cell migration, “bridges” were not formed, and sensory axons failed to enter the spinal cord. MesoMIM applied alone supported sensory axons ingrowth, but without affecting glial scar formation. In vitro, the presence of MesoMIM significantly impaired migration of hscNSPC without affecting...

  12. Inter-axonal interaction defines tiled presynaptic innervation in C. elegans

    OpenAIRE

    Mizumoto, Kota; Shen, Kang

    2013-01-01

    Cellular interactions between neighboring axons are essential for global topographic map formation. Here we show that axonal interactions also precisely instruct the location of synapses. Motoneurons form en passant synapses in Caenorhabditis elegans. While axons from the same neuron class significantly overlap, each neuron innervates a unique and tiled segment of the muscle field by restricting its synapses to a distinct subaxonal domain—a phenomenon we term “synaptic tiling”. Using DA8 and ...

  13. 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

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Manejo de la pancreatitis aguda litiásica en la embarazada

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    Camila Andrea Fernandez

    2017-09-01

    Full Text Available La pancreatitis aguda (PA es una patología poco frecuente durante el embarazo, siendo la colelitiasis una de sus principales etiologías y Chile uno de los países con más altas prevalencias de colelitiasis en el mundo. Esta patología clásicamente ha reportado altas tasas de mortalidad materno-fetal, así como también riesgo de morbilidad fetal. Sin embargo, gracias a los avances en terapia de soporte y mejoras en unidades de neonatología, en la actualidad el pronóstico con un adecuado tratamiento es alentador. Nos parece imperativo tener protocolos adecuados de toma de decisión en la embarazada con pancreatitis aguda, puesto que, a pesar de ser una patología de baja prevalencia, un correcto enfrentamiento puede mejorar el resultado materno-fetal. El presente trabajo propone una guía de manejo clínico interdisciplinario de la embarazada con pancreatitis y aporta una revisión actual sobre este tema.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Infeção por Chlamydia pneumoniae e Hepatite Aguda

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    Ana R. Ramos

    2017-12-01

    Full Text Available A Chlamydia pneumoniae é uma espécie associada sobretudo a infeções da via aérea respiratória, e pouco descrita e muito raramente associada a Hepatite Aguda.1 Apresenta-se um caso de uma mulher de 86 que recorreu ao Serviço de Urgência por quadro de epigastralgias, associadas a náuseas e vómitos pós prandiais. Ao exame objetivo: subfebril e o abdómen globoso, com timpanismo difuso e doloroso à palpação profunda do epigastro e hipocôndrio direito. Do estudo complementar realizado apresentava parâmetros inflamatórios aumentados, uma citocolestase hepática, sem insuficiência hepática, com ecografia abdominal apenas com ectasia da via biliar principal; e excluiu-se causa tóxica, isquémica e imunológica, marcadores víricos negativos; serologias negativas, excepto a serologia da Chlamydia pneumoniae, IgM e IgG positivos. Quadro compatível com uma hepatite colestática aguda sem evidência de infeção respiratória prévia ou concomitante. Os autores apresentam este caso clínico dada a raridade desta correlação, mesmo após exclusão de todas as outras causas.

  19. Ribosomes and polyribosomes are present in the squid giant axon: an immunocytochemical study.

    Science.gov (United States)

    Sotelo, J R; Kun, A; Benech, J C; Giuditta, A; Morillas, J; Benech, C R

    1999-05-01

    Ribosomes and polyribosomes were detected by immuno-electron microscopy in the giant axon and small axons of the squid using a polyclonal antibody against rat brain ribosomes. The ribosomal fraction used as antigen was purified by ultracentrifugation on a sucrose density gradient and shown to contain ribosomal RNAs and native ribosomes. The polyclonal antibody raised in rabbits reacted with at least ten proteins on immunoblots of purified rat brain ribosomes as well as with a set of multiple ribosomal proteins prepared from the squid giant fiber lobe. Immunoreactions were performed on cryostat sections of the stellate nerve cut at a distance of more than 3 cm from the stellate ganglion, using pre-embedding techniques. Ribosomes and polyribosomes were identified within the giant axon and small axons using electron microscopic methods, following binding of peroxidase-conjugated anti-rabbit IgG secondary antibody. Polysomes were more frequently localized in peripheral axoplasm, including the cortical layer of the giant axon, and were generally associated with unidentified cytoskeletal filaments or with dense matrix material. The immunochemical demonstration of ribosomes and polyribosomes in the giant axon and small axons of the squid confirms similar observations in the squid and the goldfish obtained with the method of electron spectroscopic imaging, and strongly supports the view that a local system of protein synthesis is present in axons. The immunochemical method here described offers an alternative tool for the selective identification of ribosomes, and is likely to prove of value in the analyses of other axonal systems.

  20. 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...

  1. Forced notch signaling inhibits commissural axon outgrowth in the developing chick central nerve system.

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    Ming Shi

    Full Text Available BACKGROUND: A collection of in vitro evidence has demonstrated that Notch signaling plays a key role in the growth of neurites in differentiated neurons. However, the effects of Notch signaling on axon outgrowth in an in vivo condition remain largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: In this study, the neural tubes of HH10-11 chick embryos were in ovo electroporated with various Notch transgenes of activating or inhibiting Notch signaling, and then their effects on commissural axon outgrowth across the floor plate midline in the chick developing central nerve system were investigated. Our results showed that forced expression of Notch intracellular domain, constitutively active form of RBPJ, or full-length Hes1 in the rostral hindbrain, diencephalon and spinal cord at stage HH10-11 significantly inhibited commissural axon outgrowth. On the other hand, inhibition of Notch signaling by ectopically expressing a dominant-negative form of RBPJ promoted commissural axonal growth along the circumferential axis. Further results revealed that these Notch signaling-mediated axon outgrowth defects may be not due to the alteration of axon guidance since commissural axon marker TAG1 was present in the axons in floor plate midline, and also not result from the changes in cell fate determination of commissural neurons since the expression of postmitotic neuron marker Tuj1 and specific commissural markers TAG1 and Pax7 was unchanged. CONCLUSIONS/SIGNIFICANCE: We first used an in vivo system to provide evidence that forced Notch signaling negatively regulates commissural axon outgrowth.

  2. Alterations in the Local Axonal Environment Influence Target Reinnervation and Neuronal Survival after Postnatal Axotomy

    National Research Council Canada - National Science Library

    Dainer, Hugh M

    2000-01-01

    Following peripheral nerve injury in adult animals, Schwann cells (SC) proliferate and provide guidance in the local axonal environment by generating the infrastructure along which regenerating nerves grow...

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

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    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.

  4. The 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

    2018-02-21

    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 non-inflammatory 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. Since 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.

  5. Segregation of ipsilateral retinal ganglion cell axons at the optic chiasm requires the Shh receptor Boc.

    Science.gov (United States)

    Fabre, Pierre J; Shimogori, Tomomi; Charron, Frédéric

    2010-01-06

    The pattern of contralaterally and ipsilaterally projecting retinal ganglion cell (RGC) axons at the optic chiasm is essential for the establishment of binocular vision. Contralateral axons cross the chiasm midline as they progress from the optic nerve to the optic tract. In contrast, ipsilateral axons deviate from the chiasm and continue in the ipsilateral optic tract, avoiding the chiasm midline. The molecular mechanism underlying this phenomenon is not completely understood. Here we show that the Sonic Hedgehog (Shh) receptor Boc is enriched in ipsilateral RGCs of the developing retina. Together with the presence of Shh at the midline, this complementary expression pattern led us to hypothesize that Shh might repel ipsilateral RGC axons at the chiasm. Consistent with this hypothesis, we found that only Boc-positive RGC axons retract in vitro in response to Shh and that this response is lost in Boc mutant RGCs. In vivo, we show that Boc is required for the normal segregation of ipsilateral axons at the optic chiasm and, conversely, that Boc expression in contralateral RGCs prevents their axons from crossing the optic chiasm. Together, these results suggest that Shh repels ipsilateral RGC axons at the optic chiasm via its receptor Boc. This work identifies a novel molecular pathway required for the segregation of axons at the optic chiasm.

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

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    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

  7. Sinusite invasiva por Aspergillus flavus : relato de um caso associado a leucemia aguda bifenotípica

    OpenAIRE

    Xavier, Melissa Orzechowski; Oliveira, Flávio de Mattos; Almeida, Valdir de; Prolla, Gabriel; Severo, Luiz Carlos

    2009-01-01

    Here we report a case of invasive pansinusitis with proptosis of the right eye caused by Aspergillus flavus in an immunocompromised patient with acute biphenotypic leukemia without aggressive therapy response.Descreve-se um caso de pansinusite invasiva com proptose do globo ocular direito causado por Aspergillus flavus em um paciente imunossuprimido com leucemia aguda bifenotípica sem resposta a terapia agressiva.

  8. 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

  9. CONOCIMIENTOS Y PRÁCTICAS DE INFECCIONES RESPIRATORIAS Y ENFERMEDADES DIARREICAS AGUDAS EN MADRES DE UNA COMUNIDAD DE PIURA, PERÚ

    Directory of Open Access Journals (Sweden)

    Mario J. Valladares Garrido

    2016-07-01

    Full Text Available Objetivo: Determinar conocimientos y prácticas frente a enfermedades diarreicas agudas (IRAS y las infecciones respiratorias agudas (EDAS antes y después de una intervención educativa. Material y Métodos: Se realizó un estudio de intervención en un centro de salud de Piura aplicando un cuestionario a 60 madres, el cual estuvo constituido por 40 preguntas y dividido en 4 secciones: datos sociodemográficos maternos y del niño, signos de alarma y prácticas de IRAS y EDAS, y conocimiento sobre IRAS. Resultados: De 60 madres participantes del estudio, la mayoría presentó un deficiente conocimiento sobre IRAS (75%. Los signos de alarma menos reconocidos antes de la intervención fueron la presencia de sangre en deposiciones (11,7%, beber mal o no poder beber (13,3% y tiraje subcostal (8,3% y silbido de pecho (15%. Los signos más reconocidos post intervención fueron respiración rápida (86,7%, diarreas acuosas (88,3% y ojos hundidos (83,3%. Conclusión: Se presentó poco reconocimiento de los signos de alarma de IRAS y EDAS en las madres antes de la intervención educativa. Palabras clave: conocimientos, prácticas, infecciones respiratorias agudas, enfermedades diarreicas agudas. (DeCS

  10. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Injúria renal aguda e hipertensão intra-abdominal em paciente queimado em terapia intensiva

    Directory of Open Access Journals (Sweden)

    Thalita Bento Talizin

    2018-03-01

    Full Text Available RESUMO Objetivo: Avaliar a frequência de hipertensão intra-abdominal no paciente grande queimado e sua associação com a ocorrência de injúria renal aguda. Métodos: Estudo de coorte prospectivo, com população de pacientes queimados internados nos leitos de unidade de terapia intensiva especializada. Realizada amostragem de conveniência de pacientes adultos internados no período de 1º de agosto de 2015 a 31 de outubro de 2016. Foram coletados dados clínicos e da queimadura, além de medidas seriadas da pressão intra-abdominal. O nível de significância utilizado foi de 5%. Resultados: Foram analisados 46 pacientes. Evoluíram com hipertensão intra-abdominal 38 pacientes (82,6%. A mediana da maior pressão intra-abdominal foi 15,0mmHg (intervalo interquartílico: 12,0 - 19,0. Desenvolveram injúria renal aguda 32 (69,9% pacientes. A mediana do tempo para desenvolvimento de injúria renal aguda foi de 3 dias (intervalo interquartílico: 1 - 7. A análise individual de fatores de risco para injúria renal aguda apontou associação com hipertensão intra-abdominal (p = 0,041, uso de glicopeptídeos (p = 0,001, uso de vasopressor (p = 0,001 e uso de ventilação mecânica (p = 0,006. Foi evidenciada associação de injúria renal aguda com maior mortalidade em 30 dias (log-rank, p = 0,009. Conclusão: Ocorreu hipertensão intra-abdominal em grande parte dos pacientes estudados, predominantemente nos graus I e II. Os fatores de risco identificados para ocorrência de injúria renal aguda foram hipertensão intra-abdominal, uso de glicopeptídeos, vasopressor e ventilação mecânica. Injúria renal aguda esteve associada à maior mortalidade em 30 dias.

  13. Estudio de seguimiento a cinco años de la psicosis aguda: evolución diagnóstica y adaptación psicosocial

    OpenAIRE

    A Pedrós Roselló; José María Tenías Burillo

    2012-01-01

    Introducción: existe un grupo de psicosis agudas que presenta un pronóstico más favorable. Sin embargo, algunas de estas psicosis pueden evolucionar hacia enfermedades crónicas psicóticas o afectivas. El objetivo de este trabajo es el estudio de la evolución diagnóstica y pronóstico en psicosis aguda. Método. Estudio observacional durante cinco años de una muestra poblacional de pacientes con psicosis aguda. Resultados: a los cinco años el 73,2% de los 41 pacientes analizados recibe un diagnó...

  14. Forma nervosa da artrite-encefalite caprina

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    Karla Moraes Rocha Guedes

    2013-12-01

    Full Text Available São descritos dois casos de caprinos, fêmeas, mestiços da raça Saanen de dois meses de idade com sinais clínicos de paresia de membros posteriores, incoordenação, dificuldade respiratória e caquexia, que foram submetidos à eutanásia, devido ao prognóstico desfavorável. Na necropsia, observou-se congestão do sistema nervoso central (SNC e consolidação pulmonar nos dois caprinos. Microscopicamente, as alterações foram caracterizadas por leucoencefalomielite linfoplasmocítica multifocal, com vacuolização do neurópilo e esferoides axonais, leptomeningite, pneumonia intersticial não supurativa no caprino A e broncopneumonia bacteriana no caprino B. O exame de imuno-histoquímica (IHQ foi positivo para o vírus da artrite-encefalite caprina em fragmento de tálamo. A prova de imunodifusão em gel de ágar (IDGA foi realizada em vinte animais do rebanho de origem e dezesseis animais foram positivos. O diagnóstico da forma nervosa da infecção pelo vírus da artrite-encefalite caprina (CAEV foi baseado no quadro clínico-patológico, IHQ e IDGA. Esta apresentação clínica da CAE pode ser pouco comum no Brasil, mas deve ser considerada em caso de doenças neurológicas em pequenos ruminantes.

  15. Incidência e fatores de risco de diarréia e infecções respiratórias agudas em comunidades urbanas de Pernambuco, Brasil

    Directory of Open Access Journals (Sweden)

    Vázquez M. Luisa

    1999-01-01

    Full Text Available Em estudo de intervenção educativa sobre diarréia e infecções respiratórias agudas (IRA nos Municípios de Olinda e Recife, realizaram-se duas pesquisas domiciliares em uma amostra de famílias, com pelo menos uma criança abaixo de cinco anos, em abril-maio de 1992 e 1994. Foram estudadas 5.436 crianças. A incidência anual corrigida (IAC de diarréia foi de 2,7 episódios por criança/ano, com uma incidência de 10,2% nas duas semanas prévias ao inquérito, estável para 1992 e 1994. Os fatores associados de forma constante a um maior risco de diarréia foram a idade da criança abaixo de dois anos, ausência de saneamento básico e de eletrodomésticos no domicílio. IAC de IRA foi de 9,5 episódios por criança/ano. A incidência de IRA foi de 41,0% em 1992 e de 32,6% em 1994, sendo a maioria de vias respiratórias altas (75,9%. Só o fator baixa idade mostrou associação com o maior risco de IRA. Os resultados indicam a importância que ambas patologias ainda têm na saúde das crianças menores de cinco anos, e, no caso da diarréia, a necessidade urgente de ampliar a cobertura dos serviços básicos visando ao impacto na redução da incidência.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Relationship of acute axonal damage, Wallerian degeneration, and clinical disability in multiple sclerosis.

    Science.gov (United States)

    Singh, Shailender; Dallenga, Tobias; Winkler, Anne; Roemer, Shanu; Maruschak, Brigitte; Siebert, Heike; Brück, Wolfgang; Stadelmann, Christine

    2017-03-17

    Axonal damage and loss substantially contribute to the incremental accumulation of clinical disability in progressive multiple sclerosis. Here, we assessed the amount of Wallerian degeneration in brain tissue of multiple sclerosis patients in relation to demyelinating lesion activity and asked whether a transient blockade of Wallerian degeneration decreases axonal loss and clinical disability in a mouse model of inflammatory demyelination. Wallerian degeneration and acute axonal damage were determined immunohistochemically in the periplaque white matter of multiple sclerosis patients with early actively demyelinating lesions, chronic active lesions, and inactive lesions. Furthermore, we studied the effects of Wallerian degeneration blockage on clinical severity, inflammatory pathology, acute axonal damage, and long-term axonal loss in experimental autoimmune encephalomyelitis using Wallerian degeneration slow (Wld S ) mutant mice. The highest numbers of axons undergoing Wallerian degeneration were found in the perilesional white matter of multiple sclerosis patients early in the disease course and with actively demyelinating lesions. Furthermore, Wallerian degeneration was more abundant in patients harboring chronic active as compared to chronic inactive lesions. No co-localization of neuropeptide Y-Y1 receptor, a bona fide immunohistochemical marker of Wallerian degeneration, with amyloid precursor protein, frequently used as an indicator of acute axonal transport disturbance, was observed in human and mouse tissue, indicating distinct axon-degenerative processes. Experimentally, a delay of Wallerian degeneration, as observed in Wld S mice, did not result in a reduction of clinical disability or acute axonal damage in experimental autoimmune encephalomyelitis, further supporting that acute axonal damage as reflected by axonal transport disturbances does not share common molecular mechanisms with Wallerian degeneration. Furthermore, delaying Wallerian degeneration

  18. Gogo receptor contributes to retinotopic map formation and prevents R1-6 photoreceptor axon bundling.

    Directory of Open Access Journals (Sweden)

    Irina Hein

    Full Text Available BACKGROUND: Topographic maps form the basis of neural processing in sensory systems of both vertebrate and invertebrate species. In the Drosophila visual system, neighboring R1-R6 photoreceptor axons innervate adjacent positions in the first optic ganglion, the lamina, and thereby represent visual space as a continuous map in the brain. The mechanisms responsible for the establishment of retinotopic maps remain incompletely understood. RESULTS: Here, we show that the receptor Golden goal (Gogo is required for R axon lamina targeting and cartridge elongation in a partially redundant fashion with local guidance cues provided by neighboring axons. Loss of function of Gogo in large clones of R axons results in aberrant R1-R6 fascicle spacing. Gogo affects target cartridge selection only indirectly as a consequence of the disordered lamina map. Interestingly, small clones of gogo deficient R axons perfectly integrate into a proper retinotopic map suggesting that surrounding R axons of the same or neighboring fascicles provide complementary spatial guidance. Using single photoreceptor type rescue, we show that Gogo expression exclusively in R8 cells is sufficient to mediate targeting of all photoreceptor types in the lamina. Upon lamina targeting and cartridge selection, R axons elongate within their individual cartridges. Interestingly, here Gogo prevents bundling of extending R1-6 axons. CONCLUSION: Taken together, we propose that Gogo contributes to retinotopic map formation in the Drosophila lamina by controlling the distribution of R1-R6 axon fascicles. In a later developmental step, the regular position of R1-R6 axons along the lamina plexus is crucial for target cartridge selection. During cartridge elongation, Gogo allows R1-R6 axons to extend centrally in the lamina cartridge.

  19. N-cadherin regulates primary motor axon growth and branching during zebrafish embryonic development.

    Science.gov (United States)

    Brusés, Juan L

    2011-06-15

    N-cadherin is a classical type I cadherin that contributes to the formation of neural circuits by regulating growth cone migration and the formation of synaptic contacts. This study analyzed the role of N-cadherin in primary motor axons growth during development of the zebrafish (Danio rerio) embryo. After exiting the spinal cord, primary motor axons migrate ventrally through a common pathway and form the first neuromuscular junction with the muscle pioneer cells located at the horizontal myoseptum, which serves as a choice point for cell-type-specific pathway selection. Analysis of N-cadherin mutants (cdh2(hi3644Tg) ) and embryos injected with N-cadherin antisense morpholinos showed primary motor axons extending aberrant axonal branches at the choice point in ∼40% of the somitic hemisegments and an ∼150% increase in the number of branches per axon length within the ventral myotome. Analysis of individual axons trajectories showed that the caudal (CaP) and rostral (RoP) motor neurons axons formed aberrant branches at the choice point that abnormally extended in the rostrocaudal axis and ventrally to the horizontal myoseptum. Expression of a dominant-interfering N-cadherin cytoplasmic domain in primary motor neurons caused some axons to stall abnormally at the horizontal myoseptum and to impair their migration into the ventral myotome. However, in N-cadherin-depleted embryos, the majority of primary motor axons innervated their appropriate myotomal territories, indicating that N-cadherin regulates motor axon growth and branching without severely affecting the mechanisms that control axonal target selection. Copyright © 2011 Wiley-Liss, Inc.

  20. 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

  1. 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.

  2. Imaging findings in diffuse axonal injury after closed head trauma

    Energy Technology Data Exchange (ETDEWEB)

    Parizel, P.M.; Oezsarlak, Oe.; Goethem, J.W. van; Hauwe, L. van den; Schepper, A.M. de [Department of Radiology, Universitair Ziekenhuis Antwerpen (University of Antwerp), Edegem (Belgium); Dillen, C.; Cosyns, P. [Department of Psychiatry, Universitair Ziekenhuis Antwerpen (University of Antwerp), Edegem (Belgium); Verlooy, J. [Department of Neurosurgery, Universitair Ziekenhuis Antwerpen (University of Antwerp), Edegem (Belgium)

    1998-07-01

    Even in patients with closed head trauma, brain parenchyma can be severely injured due to disruption of axonal fibers by shearing forces during acceleration, deceleration, and rotation of the head. In this article we review the spectrum of imaging findings in patients with diffuse axonal injuries (DAI) after closed head trauma. Knowledge of the location and imaging characteristics of DAI is important to radiologists for detection and diagnosis. Common locations of DAI include: cerebral hemispheric gray-white matter interface and subcortical white matter, body and splenium of corpus callosum, basal ganglia, dorsolateral aspect of brainstem, and cerebellum. In the acute phase, CT may show punctate hemorrhages. The true extent of brain involvement is better appreciated with MR imaging, because both hemorrhagic and non-hemorrhagic lesions (gliotic scars) can be detected. The MR appearance of DAI lesions depends on several factors, including age of injury, presence of hemorrhage or blood-breakdown products (e. g., hemosiderin), and type of sequence used. Technical aspects in MR imaging of these patients are discussed. Non-hemorrhagic lesions can be detected with fluid attenuated inversion recovery (FLAIR), proton-density-, or T2-weighted images, whereas gradient echo sequences with long TE increase the visibility of old hemorrhagic lesions. (orig.) With 12 figs., 12 refs.

  3. Rapid signaling in distinct dopaminergic axons during locomotion and reward

    Science.gov (United States)

    Howe, MW; Dombeck, DA

    2016-01-01

    Summary Dopaminergic projections from the midbrain to striatum are critical for motor control, as their degeneration in Parkinson’s disease results in profound movement deficits. Paradoxically, most recording methods report rapid phasic dopamine signaling (~100ms bursts) to unpredicted rewards, with little evidence for movement-related signaling. The leading model posits that phasic signaling in striatum targeting dopamine neurons drive reward-based learning, while slow variations in firing (tens of seconds to minutes) in these same neurons bias animals towards or away from movement. However, despite widespread acceptance of this model, current methods have provided little evidence to support or refute it. Here, using new optical recording methods, we report the discovery of rapid phasic signaling in striatum-targeting dopaminergic axons that was associated with, and capable of triggering, locomotion in mice. Axons expressing these signals were largely distinct from those signaling during unexpected rewards. These results suggest that dopaminergic neuromodulation can differentially impact motor control and reward learning with sub-second precision and suggest that both precise signal timing and neuronal subtype are important parameters to consider in the treatment of dopamine-related disorders. PMID:27398617

  4. Forma(s) de governo nas reduções guaranis

    OpenAIRE

    Caten, Odécio Ten

    2001-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Jurídicas Análise histórico-crítica, sob o viés da interdisciplinaridade, com enfoque na Ciência Política e no Direito, das trinta reduções guaranis que prosperaram (dentre as 54 fundadas) em solo hispano-americano nos séculos XVII-XVIII. Uma diversidade de formas de governo foram atribuídas pela bibliografia a essas reduções: Estado Jesuítico Independente, Teocracia, Utopia, Socialismo, Comunismo, Repúblic...

  5. Intoxicaciones agudas con plaguicidas: costos humanos y económicos

    Directory of Open Access Journals (Sweden)

    Jaime E. García

    1998-12-01

    Full Text Available El uso de los plaguicidas ha producido grandes beneficios agrícolas y, a la vez, graves problemas de salud pública que requieren solución. En algunos estudios de los años ochenta y noventa se informa que anualmente se registran entre medio millón y millón y medio de casos de intoxicación aguda por plaguicidas con un número correspondiente de defunciones que oscila de 3000 a 28000. Este trabajo tuvo como objetivo destacar la incidencia de las intoxicaciones agudas por plaguicidas y los costos sociales y económicos atribuibles a estas en diferentes lugares del mundo. Se presentan datos relacionados con la importancia económica de la industria de los plaguicidas y se describe la situación de las intoxicaciones agudas por exposición a plaguicidas y por consumo de alimentos contaminados con ellos. Estos datos revelan que las intoxicaciones por plaguicidas son más frecuentes en los países en desarrollo que en los países industrializados, pese a que su consumo general es menor en los primeros. También se estiman los costos económicos relacionados con las intoxicaciones causadas por estas sustancias y se examinan, por último, algunos aspectos adicionales de la situación descrita, con hincapié en la necesidad de reducir el uso de los plaguicidas.The use of pesticides has produced great agricultural benefits and, at the same time, serious public health problems that need to be solved. According to studies performed in the 1980s and 1990s, every year about half a million to one and a half million cases of acute pesticide poisoning are notified, together with 3000 to 28000 deaths. The purpose of this study was to draw attention to the incidence of acute pesticide poisoning and to the social and economic costs that are attributable to pesticides in different parts of the world. We present data on the economic importance of the pesticide industry and describe the situation of acute poisonings from exposure to pesticides and consumption of

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

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    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. 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.

  8. The role of mitochondria in axonal degeneration and tissue repair in MS

    NARCIS (Netherlands)

    van Horssen, J.; Witte, M.E.; Ciccarelli, O.

    2012-01-01

    Axonal injury is a key feature of multiple sclerosis (MS) pathology and is currently seen as the main correlate for permanent clinical disability. Although little is known about the pathogenetic mechanisms that drive axonal damage and loss, there is accumulating evidence highlighting the central

  9. 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.

  10. The progeroid gene BubR1 regulates axon myelination and motor function

    NARCIS (Netherlands)

    Choi, C.I.; Yoo, K.H.; Hussaini, S.M.; Jeon, B.T.; Welby, J.; Gan, H.; Scarisbrick, I.A.; Zhang, Z.; Baker, D.J.; Deursen, J.M.A. van; Rodriguez, M.; Jang, M.H.

    2016-01-01

    Myelination, the process by which oligodendrocytes form the myelin sheath around axons, is key to axonal signal transduction and related motor function in the central nervous system (CNS). Aging is characterized by degenerative changes in the myelin sheath, although the molecular underpinnings of

  11. 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.

  12. Axonal and presynaptic protein synthesis: new insights into the biology of the neuron

    NARCIS (Netherlands)

    Giuditta, A.; Kaplan, B.B.; van Minnen, J.; Alvarez, J.; Koenig, E.

    2002-01-01

    The presence of a local mRNA translation system in axons and terminals was proposed almost 40 years ago. Over the ensuing period, an impressive body of evidence has grown to support this proposal - yet the nerve cell body is still considered to be the only source of axonal and presynaptic proteins.

  13. 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.

  14. 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.

  15. Schwann Cell and Axon: An Interlaced Unit-From Action Potential to Phenotype Expression.

    Science.gov (United States)

    Court, Felipe A; Alvarez, Jaime

    2016-01-01

    Here we propose a model of a peripheral axon with a great deal of autonomy from its cell body-the autonomous axon-but with a substantial dependence on its ensheathing Schwann cell (SC), the axon-SC unit. We review evidence in several fields and show that (i) axons can extend sprouts and grow without the concurrence of the cell body, but regulated by SCs; (ii) axons synthesize their proteins assisted by SCs that supply them with ribosomes and, probably, with mRNAs by way of exosomes; (iii) the molecular organization of the axoplasm, i.e., its phenotype, is regulated by the SC, as illustrated by the axonal microtubular content, which is down-regulated by the SC; and (iv) the axon has a program for self-destruction that is boosted by the SC. The main novelty of this model axon-SC unit is that it breaks with the notion that all proteins of the nerve cell are specified by its own nucleus. The notion of a collaborative specification of the axoplasm by more than one nucleus, which we present here, opens a new dimension in the understanding of the nervous system in health and disease and is also a frame of reference to understand other tissues or cell associations.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Organophosphate-Related Alterations in Myelin and Axonal Transport in the Living Mammalian Brain

    Science.gov (United States)

    2014-10-01

    510. Duncan JE, Goldstein LS. 2006. The Genetics of Axonal Transport and Axonal Transport Disorders PLoS Genet . 2(9): e124. 25 Duysen EG, Li...Gitajn L, Rea W, Yang Y, Stein EA.2007. Cocaine -induced brain activation detected by dynamic manganese-enhanced magnetic resonance imaging (MEMRI

  18. Misdirection and guidance of regenerating axons after experimental nerve injury and repair

    NARCIS (Netherlands)

    de Ruiter, Godard C W; Spinner, Robert J; Verhaagen, J.; Malessy, Martijn J A

    Misdirection of regenerating axons is one of the factors that can explain the limited results often found after nerve injury and repair. In the repair of mixed nerves innervating different distal targets (skin and muscle), misdirection may, for example, lead to motor axons projecting toward skin,

  19. Misdirection and guidance of regenerating axons after experimental nerve injury and repair A review

    NARCIS (Netherlands)

    Ruiter, G.C.W.; Spinner, R.J.; Verhaagen, J.; Malessay, M.J.A.

    2014-01-01

    Misdirection of regenerating axons is one of the factors that can explain the limited results often found after nerve injury and repair. In the repair of mixed nerves innervating different distal targets (skin and muscle), misdirection may, for example, lead to motor axons projecting toward skin,

  20. Misdirection and guidance of regenerating motor axons after experimental nerve injury and repair

    NARCIS (Netherlands)

    Ruiter, Godard de

    2013-01-01

    Misdirection of regenerating motor axons is one of the factors that can explain the disappointing recovery of function often observed after nerve injury and repair. In the first part of this thesis we quantified misdirection of motor axon regeneration after different types of nerve injury and repair

  1. Frizzled3 controls axonal polarity and intermediate target entry during striatal pathway development

    NARCIS (Netherlands)

    Morello, Francesca; Prasad, Asheeta A.; Rehberg, Kati; Baptista Vieira de Sá, Renata; Antón-Bolaños, Noelia; Leyva-Diaz, Eduardo; Adolfs, Youri; Tissir, Fadel; López-Bendito, Guillermina; Pasterkamp, R. Jeroen

    2015-01-01

    The striatum is a large brain nucleus with an important role in the control of movement and emotions.Mediumspiny neurons (MSNs) are striatal output neurons forming prominent descending axon tracts that target different brain nuclei. However, how MSN axon tracts in the forebrain develop remains

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Axonal remodeling in the corticospinal tract after stroke: how does rehabilitative training modulate it?

    Directory of Open Access Journals (Sweden)

    Naohiko Okabe

    2017-01-01

    Full Text Available Stroke causes long-term disability, and rehabilitative training is commonly used to improve the consecutive functional recovery. Following brain damage, surviving neurons undergo morphological alterations to reconstruct the remaining neural network. In the motor system, such neural network remodeling is observed as a motor map reorganization. Because of its significant correlation with functional recovery, motor map reorganization has been regarded as a key phenomenon for functional recovery after stroke. Although the mechanism underlying motor map reorganization remains unclear, increasing evidence has shown a critical role for axonal remodeling in the corticospinal tract. In this study, we review previous studies investigating axonal remodeling in the corticospinal tract after stroke and discuss which mechanisms may underlie the stimulatory effect of rehabilitative training. Axonal remodeling in the corticospinal tract can be classified into three types based on the location and the original targets of corticospinal neurons, and it seems that all the surviving corticospinal neurons in both ipsilesional and contralesional hemisphere can participate in axonal remodeling and motor map reorganization. Through axonal remodeling, corticospinal neurons alter their output selectivity from a single to multiple areas to compensate for the lost function. The remodeling of the corticospinal axon is influenced by the extent of tissue destruction and promoted by various therapeutic interventions, including rehabilitative training. Although the precise molecular mechanism underlying rehabilitation-promoted axonal remodeling remains elusive, previous data suggest that rehabilitative training promotes axonal remodeling by upregulating growth-promoting and downregulating growth-inhibiting signals.

  4. Neurobiology of axonal transport defects in motor neuron diseases: Opportunities for translational research?

    Science.gov (United States)

    De Vos, Kurt J; Hafezparast, Majid

    2017-09-01

    Intracellular trafficking of cargoes is an essential process to maintain the structure and function of all mammalian cell types, but especially of neurons because of their extreme axon/dendrite polarisation. Axonal transport mediates the movement of cargoes such as proteins, mRNA, lipids, membrane-bound vesicles and organelles that are mostly synthesised in the cell body and in doing so is responsible for their correct spatiotemporal distribution in the axon, for example at specialised sites such as nodes of Ranvier and synaptic terminals. In addition, axonal transport maintains the essential long-distance communication between the cell body and synaptic terminals that allows neurons to react to their surroundings via trafficking of for example signalling endosomes. Axonal transport defects are a common observation in a variety of neurodegenerative diseases, and mutations in components of the axonal transport machinery have unequivocally shown that impaired axonal transport can cause neurodegeneration (reviewed in El-Kadi et al., 2007, De Vos et al., 2008; Millecamps and Julien, 2013). Here we review our current understanding of axonal transport defects and the role they play in motor neuron diseases (MNDs) with a specific focus on the most common form of MND, amyotrophic lateral sclerosis (ALS). Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  5. 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

    Neuregulin-1 has a key role in mediating signaling between axons and Schwann cells during development. A limitation to studying its role in adulthood is the embryonic lethality of global Nrg1 gene deletion. We used the Cre-loxP system to generate transgenic mice in which neuregulin-1 is condition......Neuregulin-1 has a key role in mediating signaling between axons and Schwann cells during development. A limitation to studying its role in adulthood is the embryonic lethality of global Nrg1 gene deletion. We used the Cre-loxP system to generate transgenic mice in which neuregulin-1...... is conditionally ablated in the majority of small-diameter and a proportion of large-diameter sensory neurons that have axons conducting in the C- and Adelta-fiber range, respectively. Sensory neuron-specific neuregulin-1 ablation resulted in abnormally large Remak bundles with axons clustered in "polyaxonal...... cells required for normal sensory function. Sensory neuronal survival and axonal maintenance, however, are not dependent on axon-derived neuregulin-1 signaling in adulthood Udgivelsesdato: 2009/6/17...

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

    Directory of Open Access Journals (Sweden)

    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.

  7. JMJD-1.2/PHF8 controls axon guidance by regulating Hedgehog-like signaling

    DEFF Research Database (Denmark)

    Riveiro, Alba; Mariani, Luca; Malmberg, Kim Emily

    2017-01-01

    Components of the KDM7 family of histone demethylases are implicated in neuronal development and one member, PHF8, is often found to be mutated in cases of X-linked mental retardation. However, how PHF8 regulates neurodevelopmental processes and contributes to the disease is still largely unknown...... the axonal defects. Deficiency of either wrt-8 or grl-16, or reduced expression of homologs of genes promoting Hedgehog signaling, restores correct axon guidance in jmjd-1.2 mutants. Genetic and overexpression data indicate that Hedgehog-related genes act on axon guidance through actin remodelers. Thus, our...... study highlights a novel function of jmjd-1.2 in axon guidance that might be relevant for the onset of X-linked mental retardation and provides compelling evidence of a conserved function of the Hedgehog pathway in C. elegans axon migration....

  8. Lost in the jungle: new hurdles for optic nerve axon regeneration.

    Science.gov (United States)

    Pernet, Vincent; Schwab, Martin E

    2014-07-01

    The poor regenerative capacity of injured central nervous system (CNS) axons leads to permanent neurological deficits after brain, spinal cord, or optic nerve lesions. In the optic nerve, recent studies showed that stimulation of the cytokine or mammalian target of rapamycin (mTOR) signaling pathways potently enhances sprouting and regeneration of injured retinal ganglion cell axons in adult mice, but does not allow the majority of axons to reach their main cerebral targets. New analyses have revealed axon navigation defects in the optic nerve and at the optic chiasm under conditions of strong growth stimulation. We propose that a balanced growth stimulatory treatment will have to be combined with guidance factors and suppression of local growth inhibitory factors to obtain the full regeneration of long CNS axonal tracts. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Regulation of axon guidance by compartmentalized nonsense-mediated mRNA decay

    DEFF Research Database (Denmark)

    Colak, Dilek; Ji, Sheng-Jian; Porse, Bo T

    2013-01-01

    Growth cones enable axons to navigate toward their targets by responding to extracellular signaling molecules. Growth-cone responses are mediated in part by the local translation of axonal messenger RNAs (mRNAs). However, the mechanisms that regulate local translation are poorly understood. Here we...... show that Robo3.2, a receptor for the Slit family of guidance cues, is synthesized locally within axons of commissural neurons. Robo3.2 translation is induced by floor-plate-derived signals as axons cross the spinal cord midline. Robo3.2 is also a predicted target of the nonsense-mediated mRNA decay.......2 expression. These data show that local translation is regulated by mRNA stability and that NMD acts locally to influence axonal pathfinding....

  10. PACSIN1, a Tau-interacting protein, regulates axonal elongation and branching by facilitating microtubule instability.

    Science.gov (United States)

    Liu, Yingying; Lv, Kaosheng; Li, Zenglong; Yu, Albert C H; Chen, Jianguo; Teng, Junlin

    2012-11-16

    Tau is a major member of the neuronal microtubule-associated proteins. It promotes tubulin assembly and stabilizes axonal microtubules. Previous studies have demonstrated that Tau forms cross-bridges between microtubules, with some particles located on cross-bridges, suggesting that some proteins interact with Tau and might be involved in regulating Tau-related microtubule dynamics. This study reports that PACSIN1 interacts with Tau in axon. PACSIN1 blockade results in impaired axonal elongation and a higher number of primary axonal branches in mouse dorsal root ganglia neurons, which is induced by increasing the binding ability of Tau to microtubules. In PACSIN1-blocked dorsal root ganglia neurons, a greater amount of Tau is inclined to accumulate in the central domain of growth cones, and it promotes the stability of the microtubule network. Taken together, these results suggest that PACSIN1 is an important Tau binding partner in regulating microtubule dynamics and forming axonal plasticity.

  11. 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....

  12. Pancreatite aguda em cães: casos clínicos

    OpenAIRE

    Peito, Filipa Margarida de Melo Cordeiro Pires

    2016-01-01

    Dissertação de Mestrado Integrado em Medicina Veterinária A pancreatite aguda é uma doença bastante frequente no cão (retirei o resto da frase). Apesar disso, vários aspetos desta doença continuam desconhecidos, nomeadamente alguns relacionados com a sua etiologia e fisiopatologia. A sua apresentação clínica é muito inespecífica e o diagnóstico é difícil. O tratamento é distinto para cada apresentação clínica e o prognóstico é muito variável. Assim, o objetivo deste trabalho foi o de conso...

  13. Modificaciones del electrocardiograma en el curso de la anoxemia aguda en el perro

    Directory of Open Access Journals (Sweden)

    León Binet

    1937-05-01

    Full Text Available La experiencia nos ha mostrado que en el curso de la anoxemia aguda la muerte puede sobrevenir por paro cardíaco primitivo. Estos hechos nos han inducido a profundizar el estudio del corazón por el método electrocardiográfico, en perros sometidos a la prueba de la anoxemia. Lo mismo que en nuestras investigaciones anteriores, la anoxemia se ha llevado a cabo en perros cloralosados, haciéndolos inspirar por medio de la válvula de Tissot, una mezcla de aire y de nitrógeno, pobre en oxígeno, a la presión de 760 m m Hg. De 22 animales cuyos trazados han sido obtenidos en las tres derivaciones, merecen citarse los siguientes casos: I. Anoxemia acentuada pero no mortal. II. Casos de anoxemia avanzada con aparición de apnea en algunos minutos. III. Retorno al aire normal.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Mutações de PTEN nas leucemias linfóides agudas T

    OpenAIRE

    Patricia Yoshioka Jotta

    2012-01-01

    Resumo: A leucemia linfóide aguda (LLA) é o câncer mais frequente na infância, e destas, 15% são do tipo T (LLA-T). A hiperativação da via PI3K/Akt tem sido amplamente descrita em tumores e em linhagens celulares de LLA-T. PTEN é o principal regulador negativo dessa via e frequentemente encontra-se inativado em cânceres humanos. Com frequência, pacientes com LLA-T apresentam mutações ativadoras de NOTCH1. NOTCH1 pode regular transcricionalmente PTEN, contudo ainda não está claro como as mutaç...

  16. Hepatite aguda colestática pelo propiltiouracil: relato de caso

    Directory of Open Access Journals (Sweden)

    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.

  17. INSUFICIENCIA RENAL AGUDA EN EL ANCIANO. CONSIDERACIONES ACERCA DE SU VALORACIÓN Y TRATAMIENTO.

    OpenAIRE

    Musso CG

    2005-01-01

    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 inter...

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

    Directory of Open Access Journals (Sweden)

    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.

  19. 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...

  20. 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...

  1. Encefalopatia necrotizante aguda: paciente com evolução recidivante e letal

    OpenAIRE

    Casella,Erasmo B.; Nudelman,Victor; Felix,Marcelo M.; Amaro Jr.,Edson; Handfas,Benjamin; Radvany,João; Stape,Adalberto; Troster,Eduardo

    2007-01-01

    A encefalopatia necrotizante aguda foi descrita inicialmente em crianças japonesas e se caracteriza por rápida evolução e lesões simétricas no tronco encefálico, cerebelo e especialmente nos tálamos. Avaliamos uma menina de 7 meses de idade, que apresentou dois episódios de depressão da consciência de rápida instalação e paresias, sem alterações metabólicas. Houve uma rápida melhora na primeira crise, porém o segundo episódio foi fulminante, tendo evoluído para estado de morte encefálica em d...

  2. Guía práctica clínica. Hemorragia digestiva aguda

    Directory of Open Access Journals (Sweden)

    Oscar Páez Rodríguez

    2006-01-01

    Full Text Available Este artículo es una propuesta de abordaje, tanto clínico como terapéutico, de los pacientes que consultan a urgencias por presentar un cuadro de hemorragia digestiva aguda. Señala las prioridades en la atención de estos enfermos, enfatiza el papel de la clínica en su evaluación y ofrece una secuencia lógica de las intervenciones médicas. Muestra cómo la atención inicial del paciente, que es la de mayor impacto, la puede realizar exitosamente el médico general bien entrenado.

  3. Miocardite aguda

    Directory of Open Access Journals (Sweden)

    Felipe Homem Valle

    2013-10-01

    Full Text Available Homem de 27 anos, previamente hígido, veio ao Hospital de Clínicas de Porto Alegre com dor torácica iniciada há 7 dias. A dor se caracterizava por pressão no dorso, irradiada para região anterior do tórax, sem associação com outros sintomas, fatores de alívio ou agravamento. Ausência de febre, tosse ou outras queixas. Ao exame físico, não foram detectadas alterações. Eletrocardiograma (figura 1 apresentou inversão de onda T em D2, D3 e AVF. Foi realizada dosagem de marcador de necrose miocárdica – troponina I – que demonstrou valor inicial de 5.7ng/mL (referência para lesão miocárdica >0,04ng/mL, com redução para 1.7ng/mL, após 24 horas de internação. Foi realizado ecocardiograma que demonstrou coração normal.

  4. Toxicidad aguda y crónica del lindano sobre Ceriodaphnia cornuta (Cladocera: Daphniidae

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    Jorgelina Juárez

    2011-05-01

    Full Text Available El lindano es un plaguicida organoclorado cuya toxicidad produce efectos nocivos en la salud humana y la biota. El objetivo de este estudio fue evaluar la toxicidad aguda y crónica del lindano sobre el microcrustáceo Ceriodaphnia cornuta. Para las pruebas agudas se empleó un diseño estático, usando 10 neonatos ≤ 24 horas de edad para el control y para cada concentración de lindano (5, 10, 15, 20 y 25 mg/L. Se realizaron tres réplicas de cada tratamiento. Se controló la inmovilización de los individuos a las 48 hs y se calcularon los valores de CL50. Los bioensayos crónicos consistieron en un diseño semi-estático, utilizando 10 neonatos menores de 24 horas de edad (uno por recipiente para el control y para cada concentración subletal del tóxico (0,1; 0,15; 0,2; 0,25 y 0,3 mg/L. Se evaluaron los efectos sobre la supervivencia y reproducción durante 21 días. El valor obtenido de CL50 48 horas fue de 5,293 ± 0,7 mg/L. Los parámetros reproductivos (neonatos por hembra, tamaño de la camada e índice de incremento natural disminuyeron al aumentar la concentración del tóxico evaluado, mientras que el inicio de la madurez sexual se retrasó, demostrando la sensibilidad de los organismos prueba al lindano.

  5. Controvérsias no manejo farmacológico da asma aguda infantil

    Directory of Open Access Journals (Sweden)

    Amantéa Sérgio Luís

    2002-01-01

    Full Text Available Objetivos: apresentar uma revisão acerca de questões controversas, relativas ao manejo farmacológico utilizado nos pacientes pediátricos portadores de asma aguda. Fontes dos dados: foram utilizadas informações de artigos publicados em revistas científicas nacionais e internacionais, selecionadas das bases de dados Lilacs e Medline. Síntese dos dados: o artigo foi estruturado em tópicos, apresentando aspectos consensuais no tratamento farmacológico da asma infantil. Questões relacionadas à utilização de inaladores dosimetrados versus nebulizadores, o papel das drogas ß2-adrenérgicas utilizadas pela via endovenosa, bem como das metilxantinas e do sulfato de magnésio, são abordados de maneira crítica. Conclusões: os ß2-agonistas administrados pela via inalatória, associados aos coricosteróides, permanecem o tratamento de eleição para episódios agudos de asma na população pediátrica. Tanto os nebulizadores quanto os inaladores dosimetrados, acoplados a espaçadores, são efetivos para alívio dos sintomas agudos. Pacientes refratários ao tratamento convencional, que evoluem para quadros de asma aguda grave, devem ter considerada a utilização de drogas ß2-agonistas pela via endovenosa, desde que adequadamente monitorizados. Quanto às metilxantinas e ao sulfato de magnésio, devem ser considerados alternativas secundárias para pacientes selecionados.

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Activity-dependent myelination of parvalbumin interneurons mediated by axonal morphological plasticity.

    Science.gov (United States)

    Stedehouder, J; Brizee, D; Shpak, G; Kushner, S A

    2018-03-05

    Axonal myelination of neocortical pyramidal neurons is dynamically modulated by neuronal activity. Recent studies have shown that a substantial proportion of neocortical myelin content is contributed by fast-spiking, parvalbumin (PV)-positive interneurons. However, it remains unknown whether the myelination of PV + interneurons is also modulated by intrinsic activity. Here, we utilized cell-type specific Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) in adult male and female mice to activate a sparse population of medial prefrontal cortex PV + interneurons. Using single-cell axonal reconstructions, we find that DREADD-stimulated PV + interneurons exhibit a nearly two-fold increase in total length of myelination, predominantly mediated by a parallel increase of axonal arborization and number of internodes. In contrast, the distribution of axonal inter-branch segment distance and myelin internode length were not significantly altered. Topographical analysis revealed that myelination of DREADD-stimulated cells extended to higher axonal branch orders, while retaining a similar inter-branch distance threshold for myelination. Together, our results demonstrate that chemogenetically-induced neuronal activity increases the myelination of neocortical PV + interneurons mediated at least in part by an elaboration of their axonal morphology. SIGNIFICANCE STATEMENT Myelination is the wrapping of an axon in order to optimize conduction velocity in an energy-efficient manner. Previous studies have shown that myelination of neocortical pyramidal neurons is experience and activity-dependent. We now show that activity-dependent myelin plasticity in the adult neocortex extends to parvalbumin-expressing fast-spiking interneurons. Specifically, chemogenetic stimulation of parvalbumin interneurons in the medial prefrontal cortex significantly enhanced axonal myelination, which was paralleled by an increase in axonal arborization. This suggests that activity

  9. Axon Counts Yield Multiple Options for Triceps Fascicular Nerve to Axillary Nerve Transfer.

    Science.gov (United States)

    Khair, M Michael; Schreiber, Joseph J; Rosenblatt, Lauren; Byun, David J; Lee, Steve K; Wolfe, Scott W

    2016-11-01

    To evaluate the relative axonal match between potential donor and recipient nerves, so that maximal reinnervation potential may be reached with the least chance of donor site morbidity. In 10 fresh-frozen cadaveric specimens, the main trunk and anterior, posterior, sensory and teres minor branches of the axillary nerve were identified, as were the radial nerve branches to the long, medial, and lateral heads of the triceps. The swing distances of the triceps fascicular nerve branches and the axillary nerve branches relative to the inferior border of the teres major muscle were recorded. Histomorphological analysis and axon counts were performed on sections of each branch. The median number of axons in the main axillary trunk was 7,887, with 4,052, 1,242, and 1,161 axons in the anterior, posterior, and teres minor branches, respectively. All specimens had a single long head triceps branch (median, 2,302 axons), a range of 1 to 3 branches to the medial head of the triceps (composite axon count, 2,198 axons), and 1 to 3 branches to the lateral head of the triceps (composite average, 1,462 axons). The medial and lateral head branches had sufficient swing distance to reach the anterior branch of the axillary nerve in all 10 specimens, with only 4 specimens having adequate long head branch swing distances. It is anatomically feasible to transfer multiple branches of the radial nerve supplying the medial, lateral, and sometimes, long head of the triceps to all branches of the axillary nerve in an attempt to reinnervate the deltoid and teres minor muscles. Understanding the axon counts of the different possible transfer combinations will improve operative flexibility and enable peripheral nerve surgeons to reinnervate for both abduction and external rotation with the highest donor/recipient axon count ratios. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  10. 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

  11. Atividade elétrica cerebral do rato com lesões da formação reticular mesencefálica

    Directory of Open Access Journals (Sweden)

    Walter C. Pereira

    1970-09-01

    Full Text Available No presente estudo foram utilizados 73 ratos em preparações agudas e crônicas, nas quais lesamos a formação reticular mesencefálica com corrente contínua (3,5 a 4,0 mA durante 5 a 10 segundos. O eletródio ativo era implantado estereotàxicamente segundo as coordenadas de König e Klippel. As lesões eram feitas parcial ou totalmente, uni ou bilateralmente, e em todos os animais procedeu-se ao controle histológico das áreas lesadas, usando-se o método de Weil. O registro da atividade elétrica cortical foi feito com polígrafo Beckman de 4 canais, utilizando-se derivações bipolares curtas (1mm com eletródios esféricos de platina. As experiências permitiram as seguintes conclusões: 1 — As características eletrofisiológicas dos fusos que ocorrem após lesões da formação reticular mesencefálica são muito semelhantes às dos fusos espontâneos e barbitúricos, inclusive quanto à projeção cortical. Quanto à duração dos potenciais que os constituem, contudo, notamos que a faixa de variação era mais centuada (20 a 80 ms, o que pode ser atribuído à maior complexidade dos potenciais do cérebro isolado, possivelmente pela falta de ação cronadora da formação reticular sobre o sistema sincronizador talâmico. 2 — Os mecanismos envolvidos na gênese dos fusos do sono barbitúrico ou espontâneo e os do cérebro isolado são, pelo menos em parte, dependentes do bloqueio da formação reticular mesencefálica. 3 — A formação reticular mesencefálica ativa preferencialmente o hemisfério cerebral homolateral; o contingente cruzado talvez seja mobilizado somente quando estímulos alertantes intensos atingem o tegmento mesencefálico. 4 — Além da formação reticular mesencefálica deve haver outros mecanismos ativadores corticais, visto que, em preparações agudas de cérebro isolado, observamos: a surtos de curta duração de atividade dessincronizada; b oscilações freqüentes do ECoG durante o registro

  12. 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.

  13. A macroscopic model of traffic jams in axons.

    Science.gov (United States)

    Kuznetsov, A V; Avramenko, A A

    2009-04-01

    The purpose of this paper is to develop a minimal macroscopic model capable of explaining the formation of traffic jams in fast axonal transport. The model accounts for the decrease of the number density of positively (and negatively) oriented microtubules near the location of the traffic jam due to formation of microtubule swirls; the model also accounts for the reduction of the effective velocity of organelle transport in the traffic jam region due to organelles falling off microtubule tracks more often in the swirl region. The model is based on molecular-motor-assisted transport equations and the hydrodynamic model of traffic jams in highway traffic. Parametric analyses of the model's predictions for various values of viscosity of the traffic flow, variance of the velocity distribution, diffusivity of microtubule-bound and free organelles, rate constants for binding to and detachment from microtubules, relaxation time, and average motor velocities of the retrograde and anterograde transport, are carried out.

  14. 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.

  15. The axonal guidance receptor neogenin promotes acute inflammation.

    Directory of Open Access Journals (Sweden)

    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.

  16. Video Object Tracking in Neural Axons with Fluorescence Microscopy Images

    Directory of Open Access Journals (Sweden)

    Liang Yuan

    2014-01-01

    tracking. In this paper, we describe two automated tracking methods for analyzing neurofilament movement based on two different techniques: constrained particle filtering and tracking-by-detection. First, we introduce the constrained particle filtering approach. In this approach, the orientation and position of a particle are constrained by the axon’s shape such that fewer particles are necessary for tracking neurofilament movement than object tracking techniques based on generic particle filtering. Secondly, a tracking-by-detection approach to neurofilament tracking is presented. For this approach, the axon is decomposed into blocks, and the blocks encompassing the moving neurofilaments are detected by graph labeling using Markov random field. Finally, we compare two tracking methods by performing tracking experiments on real time-lapse image sequences of neurofilament movement, and the experimental results show that both methods demonstrate good performance in comparison with the existing approaches, and the tracking accuracy of the tracing-by-detection approach is slightly better between the two.

  17. Ephexin1 Is Required for Eph-Mediated Limb Trajectory of Spinal Motor Axons.

    Science.gov (United States)

    Chang, Chih-Ju; Chang, Ming-Yuan; Chou, Szu-Yi; Huang, Chi-Chen; Chuang, Jian-Ying; Hsu, Tsung-I; Chang, Hsing-Fang; Wu, Yi-Hsin; Wu, Chung-Che; Morales, Daniel; Kania, Artur; Kao, Tzu-Jen

    2018-02-21

    The precise assembly of a functional nervous system relies on the guided migration of axonal growth cones, which is made possible by signals transmitted to the cytoskeleton by cell surface-expressed guidance receptors. We investigated the function of ephexin1, a Rho guanine nucleotide exchange factor, as an essential growth-cone guidance intermediary in the context of spinal lateral motor column (LMC) motor axon trajectory selection in the limb mesenchyme. Using in situ mRNA detection, we first show that ephexin1 is expressed in LMC neurons of chick and mouse embryos at the time of spinal motor axon extension into the limb. Ephexin1 loss of function and gain of function using in ovo electroporation in chick LMC neurons, of either sex, perturbed LMC axon trajectory selection, demonstrating an essential role of ephexin1 in motor axon guidance. In addition, ephexin1 loss in mice of either sex led to LMC axon trajectory selection errors. We also show that ephexin1 knockdown attenuates the growth preference of LMC neurites against ephrins in vitro and Eph receptor-mediated retargeting of LMC axons in vivo , suggesting that ephexin1 is required in Eph-mediated LMC motor axon guidance. Finally, both ephexin1 knockdown and ectopic expression of nonphosphorylatable ephexin1 mutant attenuated the retargeting of LMC axons caused by Src overexpression, implicating ephexin1 as an Src target in Eph signal relay in this context. In summary, our findings demonstrate that ephexin1 is essential for motor axon guidance and suggest an important role in relaying ephrin:Eph signals that mediate motor axon trajectory selection. SIGNIFICANCE STATEMENT The proper development of functioning neural circuits requires precise nerve connections among neurons or between neurons and their muscle targets. The Eph tyrosine kinase receptors expressed in neurons are important in many contexts during neural-circuit formation, such as axon outgrowth, axon guidance, and synaptic formation, and have been

  18. 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

  19. 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

  20. Multichannel activity propagation across an engineered axon network

    Science.gov (United States)

    Chen, H. Isaac; Wolf, John A.; Smith, Douglas H.

    2017-04-01

    Objective. Although substantial progress has been made in mapping the connections of the brain, less is known about how this organization translates into brain function. In particular, the massive interconnectivity of the brain has made it difficult to specifically examine data transmission between two nodes of the connectome, a central component of the ‘neural code.’ Here, we investigated the propagation of multiple streams of asynchronous neuronal activity across an isolated in vitro ‘connectome unit.’ Approach. We used the novel technique of axon stretch growth to create a model of a long-range cortico-cortical network, a modular system consisting of paired nodes of cortical neurons connected by axon tracts. Using optical stimulation and multi-electrode array recording techniques, we explored how input patterns are represented by cortical networks, how these representations shift as they are transmitted between cortical nodes and perturbed by external conditions, and how well the downstream node distinguishes different patterns. Main results. Stimulus representations included direct, synaptic, and multiplexed responses that grew in complexity as the distance between the stimulation source and recorded neuron increased. These representations collapsed into patterns with lower information content at higher stimulation frequencies. With internodal activity propagation, a hierarchy of network pathways, including latent circuits, was revealed using glutamatergic blockade. As stimulus channels were added, divergent, non-linear effects were observed in local versus distant network layers. Pairwise difference analysis of neuronal responses suggested that neuronal ensembles generally outperformed individual cells in discriminating input patterns. Significance. Our data illuminate the complexity of spiking activity propagation in cortical networks in vitro, which is characterized by the transformation of an input into myriad outputs over several network layers

  1. Formação continuada na escola

    OpenAIRE

    Yamamoto, Carolina

    2008-01-01

    A presente pesquisa trata da formação continuada no cotidiano escolar, a partir das ações desenvolvidas no horário de trabalho pedagógico coletivo (HTPC), com o objetivo de investigar em que medida os professores e membros da equipe de gestão consideram a escola como importante locus de formação continuada. Para a realização desta investigação foi feito um levantamento bibliográfico, para fundamentar as concepções de formação continuada; uma pesquisa documental, para conhecer os conceitos ado...

  2. 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.

    2017-01-01

    Key points 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. Abstract 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

  3. 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

  4. O papel da fisioterapia respiratória na bronquiolite viral aguda = Role of chest physiotherapy in acute viral bronchiolitis

    Directory of Open Access Journals (Sweden)

    Luisi, Fernanda

    2008-01-01

    Conclusões: mesmo que não existem evidências diretas, a fisioterapia respiratória tem sido utilizada na bronquiolite aguda com objetivo de desobstrução, higiene brônquica, prevenção de atelectasias e recrutamento alveolar, podendo contribuir para diminuição da resistência das vias aéreas, promover melhor ventilação-perfusão e diminuir o trabalho ventilatório pela remoção do excesso de muco. São necessários estudos clínicos randomizados, controlados e cegados, que avaliem as técnicas mais modernas, para que se possa definir o papel da fisioterapia respiratória no tratamento da bronquiolite viral aguda

  5. Stimulation of nicotinamide adenine dinucleotide biosynthetic pathways delays axonal degeneration after axotomy.

    Science.gov (United States)

    Sasaki, Yo; Araki, Toshiyuki; Milbrandt, Jeffrey

    2006-08-16

    Axonal degeneration occurs in many neurodegenerative diseases and after traumatic injury and is a self-destructive program independent from programmed cell death. Previous studies demonstrated that overexpression of nicotinamide mononucleotide adenylyltransferase 1 (Nmnat1) or exogenous application of nicotinamide adenine dinucleotide (NAD) can protect axons of cultured dorsal root ganglion (DRG) neurons from degeneration caused by mechanical or neurotoxic injury. In mammalian cells, NAD can be synthesized from multiple precursors, including tryptophan, nicotinic acid, nicotinamide, and nicotinamide riboside (NmR), via multiple enzymatic steps. To determine whether other components of these NAD biosynthetic pathways are capable of delaying axonal degeneration, we overexpressed each of the enzymes involved in each pathway and/or exogenously administered their respective substrates in DRG cultures and assessed their capacity to protect axons after axotomy. Among the enzymes tested, Nmnat1 had the strongest protective effects, whereas nicotinamide phosphoribosyl transferase and nicotinic acid phosphoribosyl transferase showed moderate protective activity in the presence of their substrates. Strong axonal protection was also provided by Nmnat3, which is predominantly located in mitochondria, and an Nmnat1 mutant localized to the cytoplasm, indicating that the subcellular location of NAD production is not crucial for protective activity. In addition, we showed that exogenous application of the NAD precursors that are the substrates of these enzymes, including nicotinic acid mononucleotide, nicotinamide mononucleotide, and NmR, can also delay axonal degeneration. These results indicate that stimulation of NAD biosynthetic pathways via a variety of interventions may be useful in preventing or delaying axonal degeneration.

  6. Glia initiate brain assembly through non-canonical Chimaerin/Furin axon guidance in C. elegans

    Science.gov (United States)

    Rapti, Georgia; Li, Chang; Shan, Alan; Lu, Yun; Shaham, Shai

    2017-01-01

    Brain assembly is hypothesized to begin when pioneer axons extend over non-neuronal cells, forming tracts guiding follower axons. Yet pioneer-neuron identities, their guidance substrates, and their interactions, are not well understood. Here, using time-lapse embryonic imaging, genetics, protein-interaction, and functional studies, we uncover the early events of C. elegans brain assembly. We demonstrate that C. elegans glia are key for assembly initiation, guiding pioneer and follower axons using distinct signals. Pioneer sublateral neurons, with unique growth properties, anatomy, and innervation, cooperate with glia to mediate follower-axon guidance. We further identify a CHIN-1/Chimaerin-KPC-1/Furin double mutant that severely disrupts assembly. CHIN-1/Chimaerin and KPC-1/Furin function non-canonically in glia and pioneer neurons for guidance-cue trafficking. We exploit this bottleneck to define roles for glial Netrin and Semaphorin in pioneer- and follower-axon guidance, respectively, and for glial and pioneer-neuron Flamingo/CELSR in follower-axon navigation. Altogether, our studies reveal previously-unknown glial roles in pioneer-axon guidance, suggesting conserved brain-assembly principles. PMID:28846083

  7. Expression of plasminogen activator inhibitor-1 by olfactory ensheathing glia promotes axonal regeneration.

    Science.gov (United States)

    Simón, Diana; Martín-Bermejo, Maria Jesús; Gallego-Hernández, Maria Teresa; Pastrana, Erika; García-Escudero, Vega; García-Gómez, Ana; Lim, Filip; Díaz-Nido, Javier; Avila, Jesús; Moreno-Flores, Maria Teresa

    2011-10-01

    Olfactory ensheathing glia (OEG) cells are known to facilitate repair following axotomy of adult neurons, although the molecular mechanisms involved are not fully understood. We previously identified plasminogen activator inhibitor-1 (PAI-1), proteinase-activated receptor-1 (PAR-1), and thrombomodulin (TM) as candidates to regulate rat OEG-dependent axonal regeneration. In this study, we have validated the involvement of these proteins in promoting axonal regeneration by immortalized human OEGs. We studied the effect of silencing these proteins in OEGs on their capacity to promote the regeneration of severed adult retinal ganglion cells (RGCs) axons. Our results support the role of glial PAI-1 as a downstream effector of PAR-1 in promoting axon regeneration. In contrast, we found that TM inhibits OEG induced-axonal regeneration. We also assessed the signaling pathways downstream of PAR-1 that might modulate PAI-1 expression, observing that specifically inhibiting Gα(i), Rho kinase, or PLC and PKC downregulated the expression of PAI-1 in OEGs, with a concomitant reduction in OEG-dependent axon regeneration in adult RGCs. Our findings support an important role for the thrombin system in regulating adult axonal regeneration by OEGs. Copyright © 2011 Wiley-Liss, Inc.

  8. 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.

  9. 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.

  10. Modeling the mechanics of axonal fiber tracts using the embedded finite element method.

    Science.gov (United States)

    Garimella, Harsha T; Kraft, Reuben H

    2017-05-01

    A subject-specific human head finite element model with embedded axonal fiber tractography obtained from diffusion tensor imaging was developed. The axonal fiber tractography finite element model was coupled with the volumetric elements in the head model using the embedded element method. This technique enables the calculation of axonal strains and real-time tracking of the mechanical response of the axonal fiber tracts. The coupled model was then verified using pressure and relative displacement-based (between skull and brain) experimental studies and was employed to analyze a head impact, demonstrating the applicability of this method in studying axonal injury. Following this, a comparison study of different injury criteria was performed. This model was used to determine the influence of impact direction on the extent of the axonal injury. The results suggested that the lateral impact loading is more dangerous compared to loading in the sagittal plane, a finding in agreement with previous studies. Through this analysis, we demonstrated the viability of the embedded element method as an alternative numerical approach for studying axonal injury in patient-specific human head models. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Impaired JIP3-dependent axonal lysosome transport promotes amyloid plaque pathology.

    Science.gov (United States)

    Gowrishankar, Swetha; Wu, Yumei; Ferguson, Shawn M

    2017-10-02

    Lysosomes robustly accumulate within axonal swellings at Alzheimer's disease (AD) amyloid plaques. However, the underlying mechanisms and disease relevance of such lysosome accumulations are not well understood. Motivated by these problems, we identified JNK-interacting protein 3 (JIP3) as an important regulator of axonal lysosome transport and maturation. JIP3 knockout mouse neuron primary cultures accumulate lysosomes within focal axonal swellings that resemble the dystrophic axons at amyloid plaques. These swellings contain high levels of amyloid precursor protein processing enzymes (BACE1 and presenilin 2) and are accompanied by elevated Aβ peptide levels. The in vivo importance of the JIP3-dependent regulation of axonal lysosomes was revealed by the worsening of the amyloid plaque pathology arising from JIP3 haploinsufficiency in a mouse model of AD. These results establish the critical role of JIP3-dependent axonal lysosome transport in regulating amyloidogenic amyloid precursor protein processing and support a model wherein Aβ production is amplified by plaque-induced axonal lysosome transport defects. © 2017 Gowrishankar et al.

  12. Characterizing Semaphorin-Mediated Effects on Sensory and Motor Axon Pathfinding and Connectivity During Embryonic Development.

    Science.gov (United States)

    Huettl, Rosa Eva; Huber, Andrea B

    2017-01-01

    How are precise connectivity to peripheral targets and corresponding sensory-motor networks established during developmental innervation of the vertebrate extremities? The formation of functional sensory-motor circuits requires highly appropriate temporal and spatial regulation of axon growth which is achieved through the combination of different molecular mechanisms such as communication between heterotypic fiber systems, axon-environment, or axon-glia interactions that ensure proper fasciculation and accurate pathfinding to distal targets. Family members of the class 3 semaphorins and their cognate receptors, the neuropilins, were shown to govern various events during wiring of central and peripheral circuits, with mice lacking Sema3-Npn signaling showing deficits in timing of growth, selective fasciculation, guidance fidelity, and coupling of sensory axon growth to motor axons at developmental time points. Given the accuracy with which these processes have to interact in a stepwise manner, deficiency of the smallest cog in the wheel may impact severely on the faithful establishment and functionality of peripheral circuitries, ultimately leading to behavioral impairments or even cause the death of the animal. Reliable quantitative analyses of sensory-motor fasciculation, extension, and guidance of axons to their cognate target muscles and the skin during development, but also assessment of physiological and behavioral consequences at adult age, are therefore a necessity to extend our understanding of the molecular mechanisms of peripheral circuit formation. In this chapter we provide a detailed methodology to characterize class 3 semaphorin-mediated effects on peripheral sensory and motor axon pathfinding and connectivity during embryonic development.

  13. Non-nuclear Pool of Splicing Factor SFPQ Regulates Axonal Transcripts Required for Normal Motor Development.

    Science.gov (United States)

    Thomas-Jinu, Swapna; Gordon, Patricia M; Fielding, Triona; Taylor, Richard; Smith, Bradley N; Snowden, Victoria; Blanc, Eric; Vance, Caroline; Topp, Simon; Wong, Chun-Hao; Bielen, Holger; Williams, Kelly L; McCann, Emily P; Nicholson, Garth A; Pan-Vazquez, Alejandro; Fox, Archa H; Bond, Charles S; Talbot, William S; Blair, Ian P; Shaw, Christopher E; Houart, Corinne

    2017-04-19

    Recent progress revealed the complexity of RNA processing and its association to human disorders. Here, we unveil a new facet of this complexity. Complete loss of function of the ubiquitous splicing factor SFPQ affects zebrafish motoneuron differentiation cell autonomously. In addition to its nuclear localization, the protein unexpectedly localizes to motor axons. The cytosolic version of SFPQ abolishes motor axonal defects, rescuing key transcripts, and restores motility in the paralyzed sfpq null mutants, indicating a non-nuclear processing role in motor axons. Novel variants affecting the conserved coiled-coil domain, so far exclusively found in fALS exomes, specifically affect the ability of SFPQ to localize in axons. They broadly rescue morphology and motility in the zebrafish mutant, but alter motor axon morphology, demonstrating functional requirement for axonal SFPQ. Altogether, we uncover the axonal function of the splicing factor SFPQ in motor development and highlight the importance of the coiled-coil domain in this process. VIDEO ABSTRACT. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  14. 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.

  15. GDF10 Is a Signal for Axonal Sprouting and Functional Recovery after Stroke

    Science.gov (United States)

    Li, S; Nie, EH; Yin, Y; Benowitz, LI; Tung, S; Vinters, HV; Bahjat, FR; Stenzel-Poore, MP; Kawaguchi, R; Coppola, G; Carmichael, ST

    2016-01-01

    Stroke produces a limited process of neural repair. Axonal sprouting in cortex adjacent to the infarct is part of this recovery process, but the signal that initiates axonal sprouting is not known. Growth and Differentiation Factor 10 (GDF10) is induced in peri-infarct neurons in mouse, non-human primate and human. GDF10 promotes axonal outgrowth in vitro in mouse, rat and human neurons through TGFβRI/II signaling. Using pharmacogenetic gain and loss of function studies, GDF10 produces axonal sprouting and enhanced functional recovery after stroke; knocking down GDF10 blocks axonal sprouting and reduces recovery. RNA-seq from peri-infarct cortical neurons indicates that GDF10 downregulates PTEN and upregulates PI3 kinase signaling and induces specific axonal guidance molecules. Unsupervised genome-wide association analysis of the GDF10 transcriptome shows that it is not related to neurodevelopment but may partially overlap with other CNS injury patterns. GDF10 is a stroke-induced signal for axonal sprouting and functional recovery. PMID:26502261

  16. 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

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    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

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

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    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

  18. Óxido nítrico (NO inalado na lesão pulmonar aguda: Resultados de um estudo europeu multicêntrico

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    S. Lundin

    2000-01-01

    ãorespondedores, isto é, cujo PaO2 não subta após a inalação de NO fez apenas terapêutica convencional. O NOi foi instituido na dose eficaz mats batxa por um período de 30 dias ou até que se verificasse a recuperação da IRA No grupo controlo era possivel iniciar NOi se se verificasse IRA severa. Em todos os doentes foram monitorizados parâmetres de segurança e resultados clínicos. Dos 268 doentes incluídos. foram constituidos três grupos – Grupo I (n=98, respondedores submetidos a NOi e terapêutica convencional. – Grupo II (n=87, respondedores submetidos a terapêutica convcncional (controlo – Grupo III (n=88 não respondedores submetidos a terapêutica convencional. A taxa de recuperação da IRA não foi estatistiçamente diferente entre o grupo NOi (61% e o grupo controlo (54%; p >0 2 A progressão para IRA severa foi menor no grupo NOi (2,2% que no grupo controlo (10,3%; p0,2 para grupo NOi e de 45% no grupo de nao respondedores. A frequência de complicações foi maior no grupo NOi. Os autores concluem que a melhoria da oxigenação pelo NOi não se repercutiu na recuperação da IRA, não tendo igualmente alterado a mortalidade, embora diminuísse a progressão para IRA severa. COMENTÁRIO: Como já anteriormente provado em numerosos estudos fisiológicos, o óxido nítrico inalado leva a uma vasodilatação pulmonar selectiva, com diminuição das resistências vasculares pulmonares, diminuição da pressão arterial pulmonar e melhoria da oxigenação. Estes efeitos, que se verificam de forma aguda, levaram à utilização clínica do óxido nítrico inalado em situações de insuficiência respiratória aguda acompanhada de hipoxémia refractária a outras medidas terapêuticas, como é frequentemente o caso na lesão pulmonar aguda/SDRA. No entaoto, está por provar o beneficio desta modalidade sobre a taxa de rem

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

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    Jason E Duncan

    Full Text Available 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.

  20. 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

  1. 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.

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

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    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

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

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    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

  4. 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.

  5. Complicações orbitárias da rinossinusite aguda: uma nova classificação Orbital complications of acute rhinosinusitis: a new classification

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    Antonio Augusto Velasco e Cruz

    2007-10-01

    Full Text Available A rinossinusite é uma doença potencialmente grave, e pode apresentar sérias complicações. As orbitárias são as mais freqüentes, graças às peculiaridades anatômicas desta região, podendo levar à morte em 5% dos casos. Os sintomas variam desde sinais flogísticos periorbitários até proptose do globo ocular, oftalmoplegia e amaurose. OBJETIVOS: Proposição de uma nova classificação para as complicações orbitárias das rinossinusites agudas. MATERIAL E MÉTODO: Revisão de TC e prontuários de 83 pacientes atendidos no Hospital das Clínicas da FMRP-USP, entre os anos de 1995 a 2005, com rinossinusites agudas complicadas. RESULTADOS: Após a revisão das TC e história clínica, foram identificadas em sessenta e seis pacientes, três tipos de complicações orbitárias: celulite orbitária (46,9%, abscesso subperiosteal (40,9% e abscesso orbitário (12,1%. Dezessete foram considerados como infecções palpebrais, ficando excluídos da nova classificação. CONCLUSÃO: As classificações das complicações orbitárias existentes na atualidade, como a de Chandler, não levam em conta os parâmetros anatômicos da órbita e tornaram-se obsoletas com o advento da TC. Este estudo propõe uma classificação mais concisa e objetiva que ajude a guiar a conduta terapêutica de forma mais linear.Rhinosinusitis is a severe sickness and may have serious complications. Orbital complications happen more often, due to anatomical particularities and are lethal in 5% of patients. They vary from inflammatory signs to proptosis, loss of ocular motility and blindness. AIM: We propose a new classification of acute rhinosinusitis complications. METHODS: A review of 83 patients with CT scan and clinical reports. Patients were evaluated at HCFMRP-USP between 1995 and 2005 and were diagnosed with complicated rhinosinusitis. RESULTS: In sixty-six patients, were identified three types of orbital complications: orbital cellulitis (46. 9%, subperiosteal

  6. 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

  7. 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

  8. Extracellular matrix molecules play diverse roles in the growth and guidance of central nervous system axons

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    M.A. Pires-Neto

    1999-05-01

    Full Text Available Axon growth and guidance represent complex biological processes in which probably intervene diverse sets of molecular cues that allow for the appropriate wiring of the central nervous system (CNS. The extracellular matrix (ECM represents a major contributor of molecular signals either diffusible or membrane-bound that may regulate different stages of neural development. Some of the brain ECM molecules form tridimensional structures (tunnels and boundaries that appear during time- and space-regulated events, possibly playing relevant roles in the control of axon elongation and pathfinding. This short review focuses mainly on the recognized roles played by proteoglycans, laminin, fibronectin and tenascin in axonal development during ontogenesis.

  9. Axonal and presynaptic protein synthesis: new insights into the biology of the neuron.

    Science.gov (United States)

    Giuditta, Antonio; Kaplan, Barry B; van Minnen, Jan; Alvarez, Jaime; Koenig, Edward

    2002-08-01

    The presence of a local mRNA translation system in axons and terminals was proposed almost 40 years ago. Over the ensuing period, an impressive body of evidence has grown to support this proposal -- yet the nerve cell body is still considered to be the only source of axonal and presynaptic proteins. To dispel this lingering neglect, we now present the wealth of recent observations bearing on this central idea, and consider their impact on our understanding of the biology of the neuron. We demonstrate that extrasomatic translation sites, which are now well recognized in dendrites, are also present in axonal and presynaptic compartments.

  10. 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

  11. 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...

  12. 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.

  13. An Atypical SCF-like Ubiquitin Ligase Complex Promotes Wallerian Degeneration through Regulation of Axonal Nmnat2

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    Yuya Yamagishi

    2016-10-01

    Full Text Available Axon degeneration is a tightly regulated, self-destructive program that is a critical feature of many neurodegenerative diseases, but the molecular mechanisms regulating this program remain poorly understood. Here, we identify S-phase kinase-associated protein 1A (Skp1a, a core component of a Skp/Cullin/F-box (SCF-type E3 ubiquitin ligase complex, as a critical regulator of axon degeneration after injury in mammalian neurons. Depletion of Skp1a prolongs survival of injured axons in vitro and in the optic nerve in vivo. We demonstrate that Skp1a regulates the protein level of the nicotinamide adenine dinucleotide (NAD+ synthesizing enzyme nicotinamide mononucleotide adenylyltransferase 2 (Nmnat2 in axons. Loss of axonal Nmnat2 contributes to a local ATP deficit that triggers axon degeneration. Knockdown of Skp1a elevates basal levels of axonal Nmnat2, thereby delaying axon degeneration through prolonged maintenance of axonal ATP. Consistent with Skp1a functioning through regulation of Nmnat2, Skp1a knockdown fails to protect axons from Nmnat2 knockdown. These results illuminate the molecular mechanism underlying Skp1a-dependent axonal destruction.

  14. Guidance of Drosophila Mushroom Body Axons Depends upon DRL-Wnt Receptor Cleavage in the Brain Dorsomedial Lineage Precursors

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    Elodie Reynaud

    2015-05-01

    Full Text Available In vivo axon pathfinding mechanisms in the neuron-dense brain remain relatively poorly characterized. We study the Drosophila mushroom body (MB axons, whose α and β branches connect to different brain areas. We show that the Ryk family WNT5 receptor, DRL (derailed, which is expressed in the dorsomedial lineages, brain structure precursors adjacent to the MBs, is required for MB α branch axon guidance. DRL acts to capture and present WNT5 to MB axons rather than transduce a WNT5 signal. DRL’s ectodomain must be cleaved and shed to guide α axons. DRL-2, another Ryk, is expressed within MB axons and functions as a repulsive WNT5 signaling receptor. Finally, our biochemical data support the existence of a ternary complex composed of the cleaved DRL ectodomain, WNT5, and DRL-2. Thus, the interaction of MB-extrinsic and -intrinsic Ryks via their common ligand acts to guide MB α axons.

  15. Sorting of cargos between axons and dendrites: modelling of differences in cargo transport in these two types of neurites.

    Science.gov (United States)

    Kuznetsov, A V

    2014-05-01

    Explaining how intracellular cargos are sorted between axons and dendrites is important for a mechanistic understanding of what happens in many neurodegenerative disorders. A simple model of cargo sorting relies on differences in microtubule (MT) orientation between axons and dendrites: in mammalian neurons all MTs in axons have their plus ends directed outward while in proximal regions of dendrites the MT polarity is mixed. It can therefore be assumed that cargos that need to be driven into axons associate with kinesin motors while cargos that need to be driven into dendrites associate with dynein motors. This paper develops equations of cargo transport in axons and dendrites based on the above assumptions. Propagation of a pulse of radiolabelled cargos entering an axon and dendrite is simulated. The model equations are solved utilising the Laplace transform method. Differences in cargo transport between axons and dendrites are discussed.

  16. 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

  17. Propriedades físicoquímicas e avaliação da toxicidade aguda do extrato etanólico padronizado a 70% das folhas de Mikania glomerata (Asteraceae

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    L.C.L.R. Santana

    2013-01-01

    Full Text Available Mikania glomerata (Asteraceae é bastante utilizada na medicina popular devido às suas ações broncodilatadora, antiasmática, expectorante e antitussígena. O objetivo do presente estudo foi determinar propriedades físicoquímicas do pó obtido a partir das folhas de M. glomerata, bem como avaliar a toxicidade em camundongos após tratamento agudo com doses repetidas do extrato etanólico padronizado a 70% preparado durante 30 dias consecutivos. No estudo das propriedades físicoquímicas fez-se a determinação da densidade bruta e de compactação, do teor de cinzas totais, do teor de umidade e da granulometria. De acordo com os resultados obtidos o pó pode ser usado na formulação de uma forma farmacêutica sólida, uma vez que suas propriedades físico-químicas são compatíveis com o desenvolvimento desse tipo de formulação. Na segunda parte do estudo foi determinada a dose letal 50% (DL50 em camundongos, e na análise morfológica macroscópica dos principais órgãos e avaliada a toxicidade aguda com doses repetidas em parâmetros bioquímicos e hematológicos de camundongos. Os resultados sugerem que o extrato etanólico padronizado a 70% pode ser usado de forma segura, uma vez que apresentou um valor para a DL50 (~3000 mg kg-1 que pode ser classificado na categoria nociva, e não produziu nenhuma alteração morfológica nos principais órgãos e em parâmetros bioquímicos e hematológicos de camundongos.

  18. Estudo das propriedades físico-químicas e avaliação da toxicidade aguda do extrato etanólico das folhas de Mikania glomerata Sprengel

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    L.C.L.R. Santana

    2014-01-01

    Full Text Available A Mikania glomerata é uma planta pertencente à família Asteraceae que é bastante utilizada na medicina popular devido às suas ações broncodilatadora, antiasmática, expectorante e antitussígena. O objetivo do presente estudo foi determinar as propriedades físico-químicas do pó obtido a partir das folhas de M. glomerata, bem como, avaliar a toxicidade em camundongos após tratamento agudo com doses repetidas do extrato etanólico padronizado preparado a partir das folhas dessa espécie. Durante o estudo das propriedades físico-químicas do pó obtido a partir das folhas de M. glomerata foram feitas as determinações da densidade bruta e de compactação, do teor de cinzas totais, do teor de umidade, e da granulometria. De acordo com os resultados obtidos podemos sugerir que o pó pode ser usado na formulação de uma forma farmacêutica sólida. Na segunda parte do estudo foi determinada a Dose Letal 50% (DL50, bem como, realizada a análise morfológica macroscópica e avaliados a toxicidade aguda com doses repetidas e os parâmetros bioquímicos e hematológicos de camundongos. De acordo com os dados obtidos na segunda parte deste estudo podemos sugerir que o extrato etanólico pode ser usado de forma segura em humanos, uma vez que apresentou valor de DL50 de aproximadamente 3000 mg Kg-1, bem como, não produziu nenhuma alteração morfológica nos principais órgãos, e nem provocou alterações nos parâmetros bioquímicos e hematológicos de camundongos.

  19. Uso de jarabes antitusivos y otros medicamentos en las infecciones respiratorias agudas

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    María Eulalia Prieto Herrera

    2000-01-01

    Full Text Available Se realizó un estudio de intervención para la aplicación del protocolo de tratamiento estándar de casos de infecciones respiratorias agudas y el uso de jarabes antitusivos y otros medicamentos, propuesto por la Organización Panamericana de la Salud/Organización Mundial de la Salud, en el Policlínico Comunitario Este de Camagüey durante el año 1998. El universo de estudio fueron los 252 niños menores de 5 años con diagnóstico de infección respiratoria aguda. El registro de pacientes atendidos y la historia clínica individual constituyeron la fuente primaria de datos. Los resultados más relevantes fueron que después de la intervención disminuyó el uso de jarabes antitusivos (44,04 %, así como los casos tratados ambulatoriamente (37,6 %. Se concluyó que existió predominio del sexo masculino y del grupo de edades de 1 a 2 años; los medicamentos más utilizados fueron los expectorantes y mucolíticos en el catarro común, observándose una disminución después de la intervención.An intervention study for the application of the standard treatment protocol for acute respiratory infections and the use of antitussive syrups and other medication was made after being proposed by the Pan-American Health Organization/World Health Organization, at the Eastern Community Hospital of Camagüey in the year 1998. The study material was constituted by the 252 children under 5 years of age with diagnosis of acute respiratory infection. The record of patients treated and their individual medical history were the primary data sources. The most relevant outcomes being that after intervention the use of antitussive syrups decreased (44.04%, as well as the ambulatory cases (37.6 %. It was concluded that there was a prevalence of male sex and the age group of 1-2 years old. The most frequently used medication were expectorants and mucolytic medication in common catarrh, a decrease being noticed after intervention.

  20. 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.

  1. SINDROME INTERMEDIO: UN PATRÓN TÍPICO DE INSUFICIENCIA RENAL AGUDA EN EL ANCIANO

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    Algranati L

    2004-01-01

    Full Text Available Acute renal failure is a frequent entity in the elderly. This is due on one hand to the structural and physiological changes of the aged kidney, and on the other hand to the exposure of this population to polypharmacy and their reduced capability to metabolize drugs. In the present report we present a case of a seventy year-old woman who developed acute renal failure secondary to severe dehydration with a clinical and laboratory pattern of intermediate syndrome: laboratory results compatible with parenchymal renal insufficiency (elevated urinary sodium, plasma urea and creatinine, but with a positive response to hydration. The main characteristics of the aged kidney that predispose to the development of an intermediate syndrome are: the vascular dysautonomy and reduced capability of sodium and water reabsorption. The intermediate syndrome is a typical pattern of pre-renal insufficiency in the elderly. RESUMEN: La insuficiencia renal aguda es frecuente en el anciano. Esto se debe por un lado a los cambios estructurales y funcionales propios del riñón senil, y por otro a la gran exposición que esta población tiene a la polifarmacia, y su reducida capacidad para metabolizar los medicamentos. En este reporte presentamos el caso de una mujer de 70 años que desarrolló una insuficiencia renal aguda secundaria a severa deshidratación, mostrando un patrón clínico y de laboratorio propio de un sindrome intermedio: laboratorios compatibles con una insuficiencia renal parenquimatosa (sodio urinario, uremia y creatininemia elevadas, pero con una respuesta favorable a la hidratación. Las principales características del riñón senil que predisponen al desarrollo del sindrome intermedio: son la disautonomía vascular y la reducida capacidad en la recuperación de sodio y agua El sindrome intermedio es un patrón típico de insuficiencia prerrenal en el anciano.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. Myosin-V Induces Cargo Immobilization and Clustering at the Axon Initial Segment

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    Anne F. J. Janssen

    2017-08-01

    Full Text Available The selective transport of different cargoes into axons and dendrites underlies the polarized organization of the neuron. Although it has become clear that the combined activity of different motors determines the destination and selectivity of transport, little is known about the mechanistic details of motor cooperation. For example, the exact role of myosin-V in opposing microtubule-based axon entries has remained unclear. Here we use two orthogonal chemically-induced heterodimerization systems to independently recruit different motors to cargoes. We find that recruiting myosin-V to kinesin-propelled cargoes at approximately equal numbers is sufficient to stall motility. Kinesin-driven cargoes entering the axon were arrested in the axon initial segment (AIS upon myosin-V recruitment and accumulated in distinct actin-rich hotspots. Importantly, unlike proposed previously, myosin-V did not return these cargoes to the cell body, suggesting that additional mechanism are required to establish cargo retrieval from the AIS.

  8. Islet Coordinately Regulates Motor Axon Guidance and Dendrite Targeting through the Frazzled/DCC Receptor

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    Celine Santiago

    2017-02-01

    Full Text Available Motor neuron axon targeting in the periphery is correlated with the positions of motor neuron inputs in the CNS, but how these processes are coordinated to form a myotopic map remains poorly understood. We show that the LIM homeodomain factor Islet (Isl controls targeting of both axons and dendrites in Drosophila motor neurons through regulation of the Frazzled (Fra/DCC receptor. Isl is required for fra expression in ventrally projecting motor neurons, and isl and fra mutants have similar axon guidance defects. Single-cell labeling indicates that isl and fra are also required for dendrite targeting in a subset of motor neurons. Finally, overexpression of Fra rescues axon and dendrite targeting defects in isl mutants. These results indicate that Fra acts downstream of Isl in both the periphery and the CNS, demonstrating how a single regulatory relationship is used in multiple cellular compartments to coordinate neural circuit wiring.

  9. Molecular and Cellular Mechanisms of Axonal Regeneration After Spinal Cord Injury*

    Science.gov (United States)

    van Niekerk, Erna A.; Tuszynski, Mark H.; Lu, Paul; Dulin, Jennifer N.

    2016-01-01

    Following axotomy, a complex temporal and spatial coordination of molecular events enables regeneration of the peripheral nerve. In contrast, multiple intrinsic and extrinsic factors contribute to the general failure of axonal regeneration in the central nervous system. In this review, we examine the current understanding of differences in protein expression and post-translational modifications, activation of signaling networks, and environmental cues that may underlie the divergent regenerative capacity of central and peripheral axons. We also highlight key experimental strategies to enhance axonal regeneration via modulation of intraneuronal signaling networks and the extracellular milieu. Finally, we explore potential applications of proteomics to fill gaps in the current understanding of molecular mechanisms underlying regeneration, and to provide insight into the development of more effective approaches to promote axonal regeneration following injury to the nervous system. PMID:26695766

  10. Molecular and Cellular Mechanisms of Axonal Regeneration After Spinal Cord Injury.

    Science.gov (United States)

    van Niekerk, Erna A; Tuszynski, Mark H; Lu, Paul; Dulin, Jennifer N

    2016-02-01

    Following axotomy, a complex temporal and spatial coordination of molecular events enables regeneration of the peripheral nerve. In contrast, multiple intrinsic and extrinsic factors contribute to the general failure of axonal regeneration in the central nervous system. In this review, we examine the current understanding of differences in protein expression and post-translational modifications, activation of signaling networks, and environmental cues that may underlie the divergent regenerative capacity of central and peripheral axons. We also highlight key experimental strategies to enhance axonal regeneration via modulation of intraneuronal signaling networks and the extracellular milieu. Finally, we explore potential applications of proteomics to fill gaps in the current understanding of molecular mechanisms underlying regeneration, and to provide insight into the development of more effective approaches to promote axonal regeneration following injury to the nervous system. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Vertebrate Fidgetin Restrains Axonal Growth by Severing Labile Domains of Microtubules

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    Lanfranco Leo

    2015-09-01

    Full Text Available Individual microtubules (MTs in the axon consist of a stable domain that is highly acetylated and a labile domain that is not. Traditional MT-severing proteins preferentially cut the MT in the stable domain. In Drosophila, fidgetin behaves in this fashion, with targeted knockdown resulting in neurons with a higher fraction of acetylated (stable MT mass in their axons. Conversely, in a fidgetin knockout mouse, the fraction of MT mass that is acetylated is lower than in the control animal. When fidgetin is depleted from cultured rodent neurons, there is a 62% increase in axonal MT mass, all of which is labile. Concomitantly, there are more minor processes and a longer axon. Together with experimental data showing that vertebrate fidgetin targets unacetylated tubulin, these results indicate that vertebrate fidgetin (unlike its fly ortholog regulates neuronal development by tamping back the expansion of the labile domains of MTs.

  12. Progress of Research on Diffuse Axonal Injury after Traumatic Brain Injury

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    Junwei Ma

    2016-01-01

    Full Text Available The current work reviews the concept, pathological mechanism, and process of diagnosing of DAI. The pathological mechanism underlying DAI is complicated, including axonal breakage caused by axonal retraction balls, discontinued protein transport along the axonal axis, calcium influx, and calpain-mediated hydrolysis of structural protein, degradation of axonal cytoskeleton network, the changes of transport proteins such as amyloid precursor protein, and changes of glia cells. Based on the above pathological mechanism, the diagnosis of DAI is usually made using methods such as CT, traditional and new MRI, biochemical markers, and neuropsychological assessment. This review provides a basis in literature for further investigation and discusses the pathological mechanism. It may also facilitate improvement of the accuracy of diagnosis for DAI, which may come to play a critical role in breaking through the bottleneck of the clinical treatment of DAI and improving the survival and quality of life of patients through clear understanding of pathological mechanisms and accurate diagnosis.

  13. Lithium Enhances Axonal Regeneration in Peripheral Nerve by Inhibiting Glycogen Synthase Kinase 3β Activation

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    Huanxing Su

    2014-01-01

    Full Text Available Brachial plexus injury often involves traumatic root avulsion resulting in permanent paralysis of the innervated muscles. The lack of sufficient regeneration from spinal motoneurons to the peripheral nerve (PN is considered to be one of the major causes of the unsatisfactory outcome of various surgical interventions for repair of the devastating injury. The present study was undertaken to investigate potential inhibitory signals which influence axonal regeneration after root avulsion injury. The results of the study showed that root avulsion triggered GSK-3β activation in the injured motoneurons and remaining axons in the ventral funiculus. Systemic application of a clinical dose of lithium suppressed activated GSK-3β in the lesioned spinal cord to the normal level and induced extensive axonal regeneration into replanted ventral roots. Our study suggests that GSK-3β activity is involved in negative regulation for axonal elongation and regeneration and lithium, the specific GSK-3β inhibitor, enhances motoneuron regeneration from CNS to PNS.

  14. Phosphatidylserine improves axonal transport by inhibition of HDAC and has potential in treatment of neurodegenerative diseases

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    Shiran Naftelberg

    2017-01-01

    Full Text Available Familial dysautonomia (FD is a rare children neurodegenerative disease caused due to a point mutation in the IKBKAP gene that results in decreased IKK complex-associated protein (IKAP protein production. The disease affects mostly the dorsal root ganglion (DRG and the sympathetic ganglion. Recently, we found that the molecular mechanisms underlying neurodegeneration in FD patients are defects in axonal transport of nerve growth factors and microtubule stability in the DRG. Neurons are highly polarized cells with very long axons. In order to survive and maintain proper function, neurons depend on transport of proteins and other cellular components from the neuronal body along the axons. We further demonstrated that IKAP is necessary for axon maintenance and showed that phosphatidylserine acts as an HDAC6 inhibitor to rescue neuronal function in FD cells. In this review, we will highlight our latest research findings.

  15. 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 in...

  16. Tormenta simpática paroxística siguiendo a injuria Axonal difusa Paroxysmal sympathetic storm after diffuse axonal head injury

    OpenAIRE

    Pablo Young; Barbara C. Finn; Debora Pellegrini; Elias D. Soloaga; Julio E. Bruetman

    2006-01-01

    El término tormenta simpática paroxística se utiliza como sinónimo de alteraciones episódicas de la temperatura corporal, la presión arterial, la frecuencia respiratoria y cardíaca, el tamaño pupilar y el nivel de conciencia, que coinciden con hiperhidrosis, salivación excesiva y postura extensora. Esto siempre en el contexto de una injuria axonal difusa grave que sigue a un traumatismo encéfalo-craneano (TEC) grave. Presentamos dos pacientes jóvenes con injuria axonal difusa secundaria a TEC...

  17. Chondroitin sulfate proteoglycans negatively regulate the positioning of mitochondria and endoplasmic reticulum to distal axons.

    Science.gov (United States)

    Sainath, Rajiv; Armijo-Weingart, Lorena; Ketscheck, Andrea; Xu, Zhuxuan; Li, Shuxin; Gallo, Gianluca

    2017-12-01

    Chondroitin sulfate proteoglycans (CSPGs) are components of the extracellular matrix that inhibit the extension and regeneration of axons. However, the underlying mechanism of action remains poorly understood. Mitochondria and endoplasmic reticulum (ER) are functionally inter-linked organelles important to axon development and maintenance. We report that CSPGs impair the targeting of mitochondria and ER to the growth cones of chicken embryonic sensory axons. The effect of CSPGs on the targeting of mitochondria is blocked by inhibition of the LAR receptor for CSPGs. The regulation of the targeting of mitochondria and ER to the growth cone by CSPGs is due to attenuation of PI3K signaling, which is known to be downstream of LAR receptor activation. Dynactin is a required component of the dynein motor complex that drives the normally occurring retrograde evacuation of mitochondria from growth cones. CSPGs elevate the levels of p150 Glu dynactin found in distal axons, and inhibition of the interaction of dynactin with dynein increased axon lengths on CSPGs. CSPGs decreased the membrane potential of mitochondria, and pharmacological inhibition of mitochondria respiration at the growth cone independent of manipulation of mitochondria positioning impaired axon extension. Combined inhibition of dynactin and potentiation of mitochondria respiration further increased axon lengths on CSPGs relative to inhibition of dynactin alone. These data reveal that the regulation of the localization of mitochondria and ER to growth cones is a previously unappreciated aspect of the effects of CSPGs on embryonic axons. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 77: 1351-1370, 2017. © 2017 Wiley Periodicals, Inc.

  18. Selective axonal growth of embryonic hippocampal neurons according to topographic features of various sizes and shapes

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    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

  19. 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.

  20. Activation of ganglion cells and axon bundles using epiretinal electrical stimulation.

    Science.gov (United States)

    Grosberg, Lauren E; Ganesan, Karthik; Goetz, Georges A; Madugula, Sasidhar S; Bhaskhar, Nandita; Fan, Victoria; Li, Peter; Hottowy, Pawel; Dabrowski, Wladyslaw; Sher, Alexander; Litke, Alan M; Mitra, Subhasish; Chichilnisky, E J

    2017-09-01

    Epiretinal prostheses for treating blindness activate axon bundles, causing large, arc-shaped visual percepts that limit the quality of artificial vision. Improving the function of epiretinal prostheses therefore requires understanding and avoiding axon bundle activation. This study introduces a method to detect axon bundle activation on the basis of its electrical signature and uses the method to test whether epiretinal stimulation can directly elicit spikes in individual retinal ganglion cells without activating nearby axon bundles. Combined electrical stimulation and recording from isolated primate retina were performed using a custom multielectrode system (512 electrodes, 10-μm diameter, 60-μm pitch). Axon bundle signals were identified by their bidirectional propagation, speed, and increasing amplitude as a function of stimulation current. The threshold for bundle activation varied across electrodes and retinas, and was in the same range as the threshold for activating retinal ganglion cells near their somas. In the peripheral retina, 45% of electrodes that activated individual ganglion cells (17% of all electrodes) did so without activating bundles. This permitted selective activation of 21% of recorded ganglion cells (7% of expected ganglion cells) over the array. In one recording in the central retina, 75% of electrodes that activated individual ganglion cells (16% of all electrodes) did so without activating bundles. The ability to selectively activate a subset of retinal ganglion cells without axon bundles suggests a possible novel architecture for future epiretinal prostheses. NEW & NOTEWORTHY Large-scale multielectrode recording and stimulation were used to test how selectively retinal ganglion cells can be electrically activated without activating axon bundles. A novel method was developed to identify axon activation on the basis of its unique electrical signature and was used to find that a subset of ganglion cells can be activated at single