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Sample records for capacidad contractil uterina

  1. Myocardial contractility

    Energy Technology Data Exchange (ETDEWEB)

    Comet, M.; Machecourt, J.

    1988-01-01

    The myocardial contractility characterizes the intensity of the activation representing the globality of the processes which lead to the formation of the sites where the strength is generated. Some parameters allowing a quantification of the contractility are measured during the isovolumic phase of the ventricular contraction: they are essentially dP/dt/sub max/, and eventually V/sub max/. For the measurement of these parameters, a pressure detector needs to be introduced into the left ventricle. Other parameters are measured during the systolic ejection phase: they are the ejection fraction, which is easy to measure and is very load dependant, and the maximal elastance. This last parameter is not easy to measure, but seems load independant. With the radioisotopes, it is possible to measure the ejection fraction and the maximal elastance. Contractility measurements are of interest in the study of ischemic cardiopathies and of valvular desease.

  2. Altas capacidades e interdisciplinariedad

    OpenAIRE

    Moreno-García, María José

    2013-01-01

    El presente trabajo fin de grado trata de abordar la importancia de dar una respuesta educativa acorde a las necesidades del alumnado de altas capacidades. Para ello, primeramente, se ha visto necesario definir el término de altas capacidades, analizar sus características, matizar la importancia de su detección temprana, desbancar falsos mitos y conocer la legislación vigente al respecto, para posteriormente elaborar una propuesta de intervención, que se ha llevado a cabo en el Colegio Nelva,...

  3. Symphysis-fundal height curve in the diagnosis of fetal growth deviations Curva de altura uterina por edad de gestación y diagnóstico de desvíos del crecimiento fetal Curva de altura uterina por idade gestacional e diagnóstico de desvios do crescimento fetal

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    Djacyr Magna Cabral Freire

    2010-12-01

    marzo y octubre de 2006, con edad de gestación por encima de 27 semanas. La altura uterina fue medida de acuerdo con técnica recomendada por el Ministerio de la Salud. El patrón-oro fue el peso fetal, estimado por el ultrasonido con base en la curva de referencia brasilera por edad de gestación. Una sub-muestra de 122 casos con pesos neonatales obtenidos hasta siete días después de la estimación del peso fetal, la clasificación de la altura uterina fue comparada con la curva de Lubchenco como estándar-oro. La sensibilidad, la especificidad y los valores predictivos positivo y negativo fueron calculados. Para comparar el desempeño de la sensibilidad entre ambas curvas de altura uterina, se utilizó la prueba chi-cuadrado de McNemar. RESULTADOS: La sensibilidad de la nueva curva para la detección de fetos pequeños para la edad de gestación fue de 51,6%, mientras que la curva del patrón-oro fue significativamente menor (12,5%. En la sub-muestra que tuvo el peso neonatal como estándar-oro, la sensibilidad de la nueva curva de referencia fue de 87,7%, mientras que la del Ministerio de la Salud exhibió 42,9% de sensibilidad para la detección de fetos pequeños para la edad de gestación. CONCLUSIONES: La capacidad diagnóstica de la nueva curva de referencia para detectar fetos pequeños para la edad de gestación fue significativamente mejor que la curva recomendada por el Ministerio de la Salud.OBJETIVO: Validar curva de referência de altura uterina por idade gestacional para o rastreamento de desvios do crescimento fetal e comparar sua performance com a curva-padrão adotada pelo Ministério da Saúde do Brasil. MÉTODOS: Estudo observacional que envolveu 753 gestantes de baixo risco de João Pessoa, PB, entre março e outubro de 2006, com idade gestacional acima de 27 semanas. A altura uterina foi medida de acordo com técnica preconizada pelo Ministério da Saúde. O padrão-ouro foi o peso fetal, estimado pelo ultrassom com base na curva de refer

  4. Fractalkine depresses cardiomyocyte contractility.

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    David Taube

    Full Text Available BACKGROUND: Our laboratory reported that male mice with cardiomyocyte-selective knockout of the prostaglandin E2 EP4 receptor sub-type (EP4 KO exhibit reduced cardiac function. Gene array on left ventricles (LV showed increased fractalkine, a chemokine implicated in heart failure. We therefore hypothesized that fractalkine is regulated by PGE2 and contributes to depressed contractility via alterations in intracellular calcium. METHODS: Fractalkine was measured in LV of 28-32 week old male EP4 KO and wild type controls (WT by ELISA and the effect of PGE2 on fractalkine secretion was measured in cultured neonatal cardiomyocytes and fibroblasts. The effect of fractalkine on contractility and intracellular calcium was determined in Fura-2 AM-loaded, electrical field-paced cardiomyocytes. Cardiomyocytes (AVM from male C57Bl/6 mice were treated with fractalkine and responses measured under basal conditions and after isoproterenol (Iso stimulation. RESULTS: LV fractalkine was increased in EP4 KO mice but surprisingly, PGE2 regulated fractalkine secretion only in fibroblasts. Fractalkine treatment of AVM decreased both the speed of contraction and relaxation under basal conditions and after Iso stimulation. Despite reducing contractility after Iso stimulation, fractalkine increased the Ca(2+ transient amplitude but decreased phosphorylation of cardiac troponin I, suggesting direct effects on the contractile machinery. CONCLUSIONS: Fractalkine depresses myocyte contractility by mechanisms downstream of intracellular calcium.

  5. Active contractility in actomyosin networks

    CERN Document Server

    Wang, Shenshen

    2012-01-01

    Contractile forces are essential for many developmental processes involving cell shape change and tissue deformation. Recent experiments on reconstituted actomyosin networks, the major component of the contractile machinery, have shown that active contractility occurs above a threshold motor concentration and within a window of crosslink concentration. We present a microscopic dynamic model that incorporates two essential aspects of actomyosin self-organization: the asymmetric load response of individual actin filaments and the correlated motor-driven events mimicking myosin-induced filament sliding. Using computer simulations we examine how the concentration and susceptibility of motors contribute to their collective behavior and interplay with the network connectivity to regulate macroscopic contractility. Our model is shown to capture the formation and dynamics of contractile structures and agree with the observed dependence of active contractility on microscopic parameters including the contractility onse...

  6. Tratamento dos Leiomiomas por Embolização das Artérias Uterinas

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    Messina Marcos de Lorenzo

    2001-01-01

    Full Text Available Objetivos: avaliar os resultados da embolização das artérias uterinas (EAU como tratamento do leiomioma uterino. Métodos: foram estudadas 18 mulheres com diagnóstico ultra-sonográfico de leiomioma uterino submetidas à EAU com partículas de álcool polivinílico (PVA. O acesso arterial foi realizado por punção da artéria femoral e a progressão do cateter foi monitorada até atingir seletivamente as artérias uterinas. A avaliação dos resultados foi realizada pelo estudo ultra-sonográfico antes e três meses após o procedimento. Foi realizado controle clínico evolutivo para avaliação das características menstruais e do volume uterino. Resultados: houve insucesso técnico em três casos por dificuldade de cateterização das artérias uterinas. O sangramento e a dismenorréia foram controlados no intervalo de três meses em 86 e 60% das pacientes, respectivamente. A média dos volumes uterinos iniciais foi de 381 cm³ e após 3 meses foi de 263 cm³. Houve redução média de 27,4% no volume uterino três meses após o tratamento. Três pacientes tiveram insuficiência ovariana clínica e laboratorial (20% dos casos. Conclusões: a EAU representa alternativa terapêutica para o tratamento dos leiomiomas uterinos. Em virtude do risco de insuficiência ovariana esse procedimento é reservado para pacientes com mais de 45 anos de idade ou com prole completa.

  7. Capital humano y capacidad humana

    OpenAIRE

    Sen, Amartya Kumar

    2010-01-01

    En este articulo se examinan las relaciones y diferencias entre el concepto de 'capital humano' y el concepto de 'capacidad humana'. El concepto de capital humano es mas limitado puesto que solo concibe las cualidades humanas en su relación con el crecimiento económico mientras que el concepto de capacidades da énfasis a la expansión de libertad humana para vivir el tipo de vida que la gente considera valedera. Cuando se adopta esa visión mas amplia, el proceso de desarrollo no puede verse si...

  8. Structural comparison of contractile nanomachines

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    Sebastian Kube

    2015-05-01

    Full Text Available Contractile molecular machines are a common feature among bacteriophages and prokaryotes. Due to their stability and the large size, contractile-tailed bacteriophages are traditionally investigated by electron microscopic methods. Complemented by crystallographic studies, a molecular model of contraction for the T4 phage was developed. Lately, also related contractile structures like the Photorhabdus virulence cassette-like particles, the R-Type pyocins and the contractile tubule of the bacterial Type VI secretion system have been analyzed by cryo electron microscopy. Photorhabdus virulence cassette particles and R-Type pyocins are toxin complexes reminiscent of bacteriophage tails that are secreted by bacteria to kill their insect host or competing bacteria. In contrast, the Type VI secretion system is an intracellular apparatus for injection of effector proteins into bacterial and eukaryotic cells. Although it shares homology with other contractile systems, the Type VI secretion system is additionally equipped with a recycling function, which makes it suitable for multiple rounds of action. Starting from the 3D reconstructions, we compare these molecular machines structurally and functionally to their viral counterparts and summarize the current knowledge on their respective mode of action.

  9. Uso de nifedipina en el manejo de la hiperestimulación uterina producida por misoprostol.

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    Rodrigo Cifuentes

    2009-11-01

    Full Text Available La medicina basada en la evidencia ha demostrado mediante una serie de estudios, la eficacia clínica de algunos fármacos, como el caso del misoprostol análogo de la prostaglandina E1 utilizado en obstetricia para lograr maduración cervical en inducción de trabajo de parto con cérvix no favorable, con un efecto no deseado en la mayoría de los casos como lo es la hiperestimulación uterina. Se diseñó un estudio clínico prospectivo entre noviembre, 2002 y febrero, 2003 en la Clínica Rafael Uribe Uribe del Instituto de Seguro Social, Cali, donde se incluyeron 29 pacientes con criterio para inducción del trabajo de parto con índice de Bishop no favorable; se les administró 50 mcg de misoprostol por vía vaginal y desarrollaron polisistolia (>5 contracciones en 10 minutos. A estas 29 pacientes se les suministró 20 mg de nifedipina por vía oral en el momento en que apareció la polisistolia y se estableció mediante el registro por monitoría electrónica maternofetal durante 30 minutos la disminución en el número, la duración de las contracciones y la “actividad uterina”.

  10. Transfusão Intra-uterina na Isoimunização Materna pelo Fator Rh

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    Cabral Antonio Carlos Vieira

    2001-01-01

    Full Text Available Objetivos: avaliar os resultados do tratamento intra-útero de fetos anêmicos devido a isoimunização materna pelo fator Rh. Pacientes e Métodos: foram acompanhados 61 fetos submetidos a transfusão intra-uterina seja por via intraperitoneal, intravascular ou combinada. Os casos de fetos hidrópicos corresponderam a 19,7% do total, sendo que nestes a via de tratamento sempre foi a intravascular. Foram realizadas em média 2,7 transfusões por feto, com um total de 163 procedimentos. A indicação para a transfusão se baseou na espectrofotometria do líquido amniótico (método de Liley ou quando a dosagem de hemoglobina em sangue de cordão obtido por cordocentese fosse menor que 10 g/dl. Resultados: em metade dos casos submetidos a transfusão intra-uterina, empregou-se a via intravascular. Em relação aos casos de fetos hidrópicos a sobrevida foi de 46% e nos fetos não-hidrópicos, de 84%. Não ocorreram complicações maternas relacionadas ao procedimento. A idade média da interrupção da gestação foi de 34,8 semanas. Conclusões: apesar da melhora do resultado com a transfusão intra-uterina guiada pelo ultra-som e da cordocentese, a isoimunização materna pelo fator Rh permanece como causa de elevada morbimortalidade perinatal.

  11. Distribuição da altura uterina ao longo da gestação em uma coorte brasileira: comparação com a curva de referência do Centro Latino-Americano de Perinatologia Distribution of uterine height during pregnancy in a Brazilian cohort: comparison with the reference curve of the Centro Latino-Americano de Perinatologia

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    Maria Lúcia Rocha Oppermann

    2006-09-01

    Full Text Available OBJETIVOS: descrever, em gestantes do Estudo Brasileiro do Diabetes Gestacional (EBDG, a distribuição da altura uterina de acordo com a idade gestacional e validar a curva do Centro Latino-Americano de Perinatologia (CLAP, curva de referência para a predição de anormalidades do crescimento fetal. MÉTODOS: o EBDG é uma coorte de 5564 gestantes, com mais de 19 anos, seguidas até e após o parto. Entrevistas e medidas antropométricas padronizadas foram feitas no arrolamento entre a 20ª e a 28ª semana. Os prontuários foram revisados segundo protocolo padronizado, abrangendo os períodos de pré-natal e parto. As análises referem-se a 3539 gestantes com datação da gravidez confirmada por ultra-sonografia. Determinamos as propriedades diagnósticas dos percentis 10 e 90 de altura uterina de ambas as curvas (EBDG e CLAP como indicadores de anormalidade no peso neonatal. RESULTADOS: as medidas de altura uterina no EBDG foram maiores que as do CLAP em todas as semanas de gestação (1 a 4 cm e 2 a 6 cm, respectivamente, nos percentis 10 e 90. O percentil 10 do CLAP identificou como pequenas as medidas uterinas de 0,3 a 1,7% das gestantes brasileiras, ao passo que o percentil 90 classificou como grandes as medidas uterinas de 42 a 57% das brasileiras. A sensibilidade do percentil 10 do CLAP para predizer recém-nascidos pequenos para a idade gestacional variou de 0,8 a 6% e a especificidade do percentil 90 para predizer grandes para a idade gestacional, de 46 a 61%. CONCLUSÕES: a curva de referência do CLAP não reflete o padrão de crescimento uterino das gestantes brasileiras, limitando sua capacidade de identificar anormalidades de crescimento fetal, especialmente a restrição de crescimento.PURPOSE: to describe, in participants of the Brazilian Study of Gestational Diabetes (EBDG, the percentile distribution of uterine height by gestational age and to validate the use of percentiles of the chart derived by the "Centro Latino

  12. Modulatory effects of taurine on jejunal contractility

    OpenAIRE

    Yao, Q Y; Chen, D. P.; D.M. Ye; Y.P. Diao; Lin, Y.

    2014-01-01

    Taurine (2-aminoethanesulfonic acid) is widely distributed in animal tissues and has diverse pharmacological effects. However, the role of taurine in modulating smooth muscle contractility is still controversial. We propose that taurine (5-80 mM) can exert bidirectional modulation on the contractility of isolated rat jejunal segments. Different low and high contractile states were induced in isolated jejunal segments of rats to observe the effects of taurine and the associated mechanisms. Tau...

  13. Frequência de mola hidatiforme em tecidos obtidos por curetagem uterina Frequency of hydatidiform mole in tissue obtained by curettage

    OpenAIRE

    Andressa Biscaro; Sheila Koettker Silveira; Giovani de Figueiredo Locks; Lívia Ribeiro Mileo; João Péricles da Silva Júnior; Péricles Pretto

    2012-01-01

    OBJETIVO: Determinar a frequência de mola hidatiforme em tecidos obtidos por curetagem uterina. MÉTODOS: Estudo transversal, prospectivo e descritivo que incluiu pacientes submetidas à curetagem uterina por diagnóstico de aborto ou mola hidatiforme cujo material obtido foi encaminhado para exame anatomopatológico. Foram excluídas aquelas que não aceitaram participar da pesquisa, recusando-se a assinar o Termo de Consentimento Informado Livre e Esclarecido. Foram analisadas as seguintes variáv...

  14. Factor de crecimiento vascular endotelial total y Doppler de las arterias uterinas en preeclampticas y embarazadas normotensas sanas

    OpenAIRE

    Eduardo Reyna-Villasmil; Jorly Mejia-Montilla; Joel Santos-Bolívar; Duly Torres-Cepeda; Yolimar Navarro-Briceño; Nadia Reyna-Villasmil; Ismael Suarez-Torres

    2014-01-01

    El objetivo de la investigación fue establecer las concentraciones de factor de crecimiento vascular endotelial (VEGF) total en preeclámpticas y embarazadas normotensas, y relacionar los valores de los hallazgos Doppler de las arterias uterinas con las concentraciones plasmáticas. Se seleccionaron 160 sujetos. Se incluyeron 47 preeclámpticas severas (grupo A), 33 preeclámpticas leves (grupo B) y un grupo control con edades similares a los grupos de estudio de 80 embarazadas sanas (grupo C). L...

  15. Capacidade de aprendizagem das empresas familiares

    OpenAIRE

    Fernandes, António B.; Ussmane, Ana Maria

    2012-01-01

    A capacidade de aprender de uma empresa é frequentemente apontada como uma estratégia viável para a sua longevidade. Esta capacidade tem maior impacto nas empresas familiares, dadas as suas particularidades. Assim, pretende-se com o presente trabalho analisar a capacidade de aprender de um conjunto de empresas seleccionadas aleatoriamente. Para tal, após uma revisão da literatura, procede-se a um estudo empírico, com base em dados primários recolhidos de um estudo de casos múltiplos de 22 ...

  16. Modulatory effects of taurine on jejunal contractility

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    Q.Y. Yao

    2014-12-01

    Full Text Available Taurine (2-aminoethanesulfonic acid is widely distributed in animal tissues and has diverse pharmacological effects. However, the role of taurine in modulating smooth muscle contractility is still controversial. We propose that taurine (5-80 mM can exert bidirectional modulation on the contractility of isolated rat jejunal segments. Different low and high contractile states were induced in isolated jejunal segments of rats to observe the effects of taurine and the associated mechanisms. Taurine induced stimulatory effects on the contractility of isolated rat jejunal segments at 3 different low contractile states, and inhibitory effects at 3 different high contractile states. Bidirectional modulation was not observed in the presence of verapamil or tetrodotoxin, suggesting that taurine-induced bidirectional modulation is Ca2+ dependent and requires the presence of the enteric nervous system. The stimulatory effects of taurine on the contractility of isolated jejunal segments was blocked by atropine but not by diphenhydramine or by cimetidine, suggesting that muscarinic-linked activation was involved in the stimulatory effects when isolated jejunal segments were in a low contractile state. The inhibitory effects of taurine on the contractility of isolated jejunal segments were blocked by propranolol and L-NG-nitroarginine but not by phentolamine, suggesting that adrenergic β receptors and a nitric oxide relaxing mechanism were involved when isolated jejunal segments were in high contractile states. No bidirectional effects of taurine on myosin phosphorylation were observed. The contractile states of jejunal segments determine taurine-induced stimulatory or inhibitory effects, which are associated with muscarinic receptors and adrenergic β receptors, and a nitric oxide associated relaxing mechanism.

  17. Modulatory effects of taurine on jejunal contractility

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Q.Y.; Chen, D.P.; Ye, D.M.; Diao, Y.P.; Lin, Y. [Dalian Medical University, Dalian, Liaoning (China)

    2014-10-14

    Taurine (2-aminoethanesulfonic acid) is widely distributed in animal tissues and has diverse pharmacological effects. However, the role of taurine in modulating smooth muscle contractility is still controversial. We propose that taurine (5-80 mM) can exert bidirectional modulation on the contractility of isolated rat jejunal segments. Different low and high contractile states were induced in isolated jejunal segments of rats to observe the effects of taurine and the associated mechanisms. Taurine induced stimulatory effects on the contractility of isolated rat jejunal segments at 3 different low contractile states, and inhibitory effects at 3 different high contractile states. Bidirectional modulation was not observed in the presence of verapamil or tetrodotoxin, suggesting that taurine-induced bidirectional modulation is Ca{sup 2+} dependent and requires the presence of the enteric nervous system. The stimulatory effects of taurine on the contractility of isolated jejunal segments was blocked by atropine but not by diphenhydramine or by cimetidine, suggesting that muscarinic-linked activation was involved in the stimulatory effects when isolated jejunal segments were in a low contractile state. The inhibitory effects of taurine on the contractility of isolated jejunal segments were blocked by propranolol and L-NG-nitroarginine but not by phentolamine, suggesting that adrenergic β receptors and a nitric oxide relaxing mechanism were involved when isolated jejunal segments were in high contractile states. No bidirectional effects of taurine on myosin phosphorylation were observed. The contractile states of jejunal segments determine taurine-induced stimulatory or inhibitory effects, which are associated with muscarinic receptors and adrenergic β receptors, and a nitric oxide associated relaxing mechanism.

  18. Compensatory Hypertrophy of Skeletal Muscle: Contractile Characteristics

    Science.gov (United States)

    Ianuzzo, C. D.; Chen, V.

    1977-01-01

    Describes an experiment using rats that demonstrates contractile characteristics of normal and hypertrophied muscle. Compensatory hypertrophy of the plantaris muscle is induced by surgical removal of the synergistic gastrocnemium muscle. Includes methods for determination of contractile properties of normal and hypertrophied muscle and…

  19. Cellular contractility requires ubiquitin mediated proteolysis.

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    Yuval Cinnamon

    Full Text Available BACKGROUND: Cellular contractility, essential for cell movement and proliferation, is regulated by microtubules, RhoA and actomyosin. The RhoA dependent kinase ROCK ensures the phosphorylation of the regulatory Myosin II Light Chain (MLC Ser19, thereby activating actomyosin contractions. Microtubules are upstream inhibitors of contractility and their depolymerization or depletion cause cells to contract by activating RhoA. How microtubule dynamics regulates RhoA remains, a major missing link in understanding contractility. PRINCIPAL FINDINGS: We observed that contractility is inhibited by microtubules not only, as previously reported, in adherent cells, but also in non-adhering interphase and mitotic cells. Strikingly we observed that contractility requires ubiquitin mediated proteolysis by a Cullin-RING ubiquitin ligase. Inhibition of proteolysis, ubiquitination and neddylation all led to complete cessation of contractility and considerably reduced MLC Ser19 phosphorylation. CONCLUSIONS: Our results imply that cells express a contractility inhibitor that is degraded by ubiquitin mediated proteolysis, either constitutively or in response to microtubule depolymerization. This degradation seems to depend on a Cullin-RING ubiquitin ligase and is required for cellular contractions.

  20. Requirements for disordered actomyosin bundle contractility

    CERN Document Server

    Lenz, Martin

    2011-01-01

    Actomyosin contractility is essential for biological force generation, and is well understood in highly ordered structures such as striated muscle. In vitro experiments have shown that non-sarcomeric bundles comprised only of F-actin and myosin thick filaments can also display contractile behavior, which cannot be described by standard muscle models. Here we investigate the microscopic symmetries underlying this process in large non-sarcomeric bundles with long actin filaments. We prove that contractile behavior requires non-identical motors that generate large enough forces to probe the nonlinear elastic behavior of F-actin. A simple disordered bundle model demonstrates a contraction mechanism based on these assumptions and predicts realistic bundle deformations. Recent experimental observations of F-actin buckling in in vitro contractile bundles support our model.

  1. UTERINE PROLAPSE IN QUEEN AND UTERINE PROLAPSO UTERINO EM GATA E RETROFLEXÃO UTERINA EM CADELA

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    Giuliano Queiroz Mostachio

    2008-10-01

    Full Text Available

    Obstetrical emergencies are problem in veterinary clinics and hospital. So, the aim of this report is to describe the clinical-surgical aspect of one of them, the uterine prolapse. Complete protrusion and retroflexion of uterus had been diagnosed in a queen and female dog, respectively. After the stabilization of the animals and reduction of the prolapses followed by ovary-hysterectomy, one of the animals came to death due to septicemia and hypovolemic shock. Rapid assessment and intensive treatments are required to sustain the life of the animal.

    KEY WORDS: Cat, dog, uterine prolapse, uterine retroflexion.

    Emergências obstétricas, como o prolapso uterino, constituem um problema em clínicas e hospitais veterinários. Neste relato descreve-se o aspecto clínico-cirúrgico do prolapso uterino. Diagnosticaram-se, em uma gata e em uma cadela, protrusão completa e retroflexão uterina, respectivamente. Após a estabilização dos animais e redução dos prolapsos seguidos de ovário-histerectomia, um dos animais veio a óbito, em decorrência de septicemia e choque hipovolêmico. Portanto, a rápida avaliação e tratamentos intensivos são requeridos para assegurar a vida do animal.

     

    PALAVRAS-CHAVES: Cão, gato, prolapso uterino, retroflexão uterina

  2. Estudo da involução uterina por meio da ultra-sonografia (modo-B) em cadelas submetidas a cesariana

    OpenAIRE

    Ferri S.T.S.; Vicente W.R.R.; Toniollo G.H.

    2003-01-01

    Utilizaram-se 15 cadelas gestantes submetidas a cesariana e posteriormente a exames ultra-sonográficos seriados, em modo B (tempo real), para averiguação do diâmetro uterino nos dias 0, 3, 7, 14 e 21 pós-cesariana, com o objetivo de verificar a influência do ato cirúrgico na involução uterina. Os resultados (média e desvio-padrão, em centímetros) registrados para os dias estudados foram, respectivamente: 3,99+0,71; 3,27+0,51; 2,60+0,54; 2,01+0,34; 1,28+0,24. A involução uterina pós-cesariana ...

  3. Rotura Uterina Espontánea en embarazo de segundo trimestre: presentación de un caso y revisión de la literatura

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    Airam Amoroso

    2013-09-01

    Full Text Available La rotura uterina se define como la solución de continuidad de la pared uterina. Es una complicación obstétrica poco frecuente y potencialmente letal para la madre y el feto, que ocurre generalmente durante el segundo o tercer trimestre de gestación, y que está asociada principalmente a la cirugía uterina previa, constituyendo así un desafío médico por su difícil diagnóstico diferencial y controversial manejo. Se presenta el caso de una paciente de 26 años de edad, con rotura espontánea de útero grávido de 18 semanas de gestación y antecedente de cicatriz uterina. Se realiza laparotomía exploradora obteniendo como hallazgo placenta y cordón umbilical unido a feto sin vida en cavidad abdominal, lo que confirma diagnóstico intraoperatorio. Spontaneous Uterine Rupture in Second Trimester of Pregnancy: Case report and Literature review Abstract Uterine rupture is a solution of continuity of the uterine wall. It is an uncommon and potentially lethal obstetric complication, for both mother and fetus, that mainly occurs during the second or third trimester of pregnancy, and that is mainly associated to previous uterine surgery, thus forming a medical challenge for its difficult differential diagnosis and controversial management. We report the case of a 26 years old patient with a spontaneous gravid uterine rupture, 18 weeks of gestation and cesarean scar background. Laparotomy is conducted finding both placenta and umbilical cord attached to no-living fetus in the abdominal cavity, which confirms intraoperative diagnosis.

  4. Estudo da involução uterina por meio da ultra-sonografia (modo-B em cadelas submetidas a cesariana

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    Ferri S.T.S.

    2003-01-01

    Full Text Available Utilizaram-se 15 cadelas gestantes submetidas a cesariana e posteriormente a exames ultra-sonográficos seriados, em modo B (tempo real, para averiguação do diâmetro uterino nos dias 0, 3, 7, 14 e 21 pós-cesariana, com o objetivo de verificar a influência do ato cirúrgico na involução uterina. Os resultados (média e desvio-padrão, em centímetros registrados para os dias estudados foram, respectivamente: 3,99+0,71; 3,27+0,51; 2,60+0,54; 2,01+0,34; 1,28+0,24. A involução uterina pós-cesariana seguiu o mesmo padrão do puerpério do parto normal, assim como as características das imagens ultra-sonográficas. O parto cesariana não influenciou no padrão de involução uterina.

  5. Carcinoma urotelial primario de la trompa uterina, una patología infrecuente: reporte de un caso

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    Stefano Pozzobon-Borregales

    2013-01-01

    Full Text Available El carcinoma primario de la trompa uterina es una patología maligna infrecuente que ocurre entre el 0,1% al 1,8% de todos los tumores malignos del organismo, siendo aun menos frecuente el tipo histológico transicional o urotelial que representa el 10% de los tumores malignos de trompa uterina. Se presentan principalmente entre la 5ta y 7ma décadas de la vida, y clínicamente se manifiesta, en el 18% de los casos, con la triada de masa palpable y/o distensión abdominal, dolor pélvico y metrorragia. Presentamos el caso de una paciente de 44 años de edad quien inicia enfermedad actual en diciembre del 2010, con antecedente de dolor pélvico y sangrado genital continuo. En la resonancia magnética se apreció un lesión ocupante de espacio parauterina derecha, sugestiva de neoplasia maligna de ovario derecho. El reporte del marcador tumoral Ca 125 mostró valores elevados, acompañado de clínica y paraclínica sugestiva enfermedad tumoral maligna. Se decidió realizar laparotomía ginecológica en la que se evidenció tumoración en trompa uterina derecha. El estudio histológico se concluyó como carcinoma con diferenciación uroterial. Posteriormente se realizó cirugía de estadiaje, que incluyó lavado peritoneal, histerectomía total, salpingooforectomía izquierda, omentectomía subcolónica, apendicectomía y linfadenectomía bilateral selectiva. El reporte de biopsia de dichas piezas operatorias resultaron negativas para malignidad. La paciente se encuentra actualmente libre de enfermedad. Dado lo infrecuente de la patología se reporta este caso. Primary Carcinoma of the uterine tube, an unusual malignant pathology: case report Abstract Primary Carcinoma of the uterine tube is an unusual malignant pathology that occurs between the 0,1% and the 1,8% of all malignant tumors, being the urothelial histological type even less frequent, which represents 10% of malignant tumors of the uterine tubes. These tumors usually appear in women

  6. LA CAPACIDAD ACELERATIVA EN EL DEPORTE

    Directory of Open Access Journals (Sweden)

    Isidoro Hornillos Baz

    2010-01-01

    Full Text Available La capacidad acelerativa adquiere una gran relevancia en las disciplinas deportivas que exigen desplazamientos rápidos. Forma parte de la velocidad, como cualidad motora, en su dimensión compleja. Desde una perspectiva bioenergética, la aceleración depende de la potencia del sistema anaeróbico aláctico. Para mejorar esta capacidad será necesario realizar ejercicios a la máxima intensidad, con recuperaciones completas y con una duración no superior a los seis segundos, en general. También desarrollar las técnicas de salida y de carrera. Los principales medios para la mejora de la aceleración son los multisaltos; las cuestas; los arrastres; los ejercicios con cinturones y tobilleras; los lastres en forma de cinturones, tobilleras o carreras con paracaídas; el entrenamiento de fuerza con cargas y los sprints en terreno liso. Pero en algunos deportes colectivos va a ser determinante la resistencia a la aceleración, debido al alto número de carreras de máxima o alta velocidad durante un partido. En estos casos será también necesario desarrollar la capacidad anaeróbica aláctica y la potencia y capacidad lactácida. Asimismo, hay que alcanzar un mínimo nivel de potencia aeróbica, que representa la máxima cantidad de producción de ATP por unidad de tiempo en base a procesos metabólicos de naturaleza aeróbica.

  7. Prolapso de tuba uterina após histerectomia vaginal: relato de caso Fallopian tube prolapse after vaginal hysterectomy: a case report

    Directory of Open Access Journals (Sweden)

    Maurício B. Noviello

    2003-12-01

    Full Text Available O prolapso de tuba uterina é complicação rara após histerectomia, com aproximadamente 80 casos descritos na literatura. A sintomatologia é inespecífica, podendo incluir sangramento genital, dispareunia e dor pélvica crônica. O diagnóstico diferencial deve ser feito com granuloma de cúpula vaginal e carcinoma de vagina. O tratamento deve ser individualizado, podendo ser realizado por via vaginal, abdominal ou laparoscópica. Relatamos o caso de uma paciente, 47 anos, com miomatose uterina, submetida a histerectomia vaginal, evoluindo com prolapso de tuba uterina após 11 meses de pós-operatório. O exame especular evidenciava lesão vegetante, friável e sangrante localizada na cúpula vaginal. Esses achados clínicos sugeriam o diagnóstico de prolapso de tuba uterina. A paciente foi submetida a nova intervenção cirúrgica, com ressecção da tuba uterina por via vaginal. O exame natomopatológico confirmou o diagnóstico e a paciente evoluiu com remissão completa da sintomatologia.Fallopian tube prolapse is a rare complication after hysterectomy, with approximately 80 cases described in the literature. The symptoms are nonspecific including vaginal bleeding, dyspareunia and chronic pelvic pain. The differential diagnosis must be done with granulation tissue of the vaginal cuff and vaginal carcinoma. The treatment should be individualized, and is possible to be done by vaginal, abdominal or laparoscopic approach. We report a case of a 47-year-old woman with myoma who was submitted to a vaginal hysterectomy and evolved with fallopian tube prolapse 11 months after surgery. Specular examination showed a fungating, friable and bleeding lesion at the vaginal cuff. The clinical findings suggested the diagnosis of fallopian tube prolapse. The patient was submitted to a new surgical intervention with resection of the left fallopian tube. The histologic examination confirmed the diagnosis and the patient evolved with complete remission of

  8. Aprendizaje cooperativo con alumnos de altas capacidades

    OpenAIRE

    Herrera Lara, Inmaculada

    2016-01-01

    El presente Trabajo Fin de Grado tiene como finalidad conocer e investigar la intervención educativa que se lleva a cabo con los alumnos de altas capacidades a través del aprendizaje cooperativo. Estos alumnos necesitan de la ayuda y colaboración de los otros para lograr verdaderos procesos de aprendizaje. Sin la colaboración de docentes, padres y demás organismos del centro educativo no sería posible ofrecer una respuesta válida y eficaz a las necesidades que presenta este colectivo. Tal com...

  9. Embolização arterial seletiva em fístula arteriovenosa uterina pós-traumática Selective arterial embolization of uterine post-traumatic arteriovenous fistula

    Directory of Open Access Journals (Sweden)

    Omero Benedicto Poli-Neto

    2004-08-01

    Full Text Available Malformações arteriovenosas uterinas são pouco freqüentes. Os autores relatam um caso de fístula arteriovenosa traumática tratada por embolização seletiva das artérias uterinas, método que tem sido utilizado no controle da hemorragia pós-parto e hemorragia resultante de malignidade pélvica. Uma discussão é apresentada para ressaltar uma conseqüência da perfuração uterina e o controle da hemorragia sem sacrificar a fertilidade.Uterine arteriovenous malformations are uncommon. The authors report a case of traumatic arteriovenous fistula treated by selective uterine arteries embolization. Selective artery embolization has been effectively used to control postpartum hemorrhage and hemorrhage resulting from pelvic malignancy. A discussion on the consequences of uterine perforation and the control of hemorrhage without sacrificing fertility is presented.

  10. Capacidad emulsionante de sueros de soja

    Directory of Open Access Journals (Sweden)

    Jorge Wagner

    2011-05-01

    Full Text Available El objetivo fue analizar la capacidad emulsionante de diferentes sueros de soja como productos integrales. Se ensayaron: suero de soja liofilizado (SSL, suero de soja liofilizado y calentado (SSLC, suero de tofu liofilizado (STL y suero de tofu secado térmicamente (STST. Las emulsiones fueron realizadas a igual nivel de proteína bruta (0,1.1,0% p/v, buffer fosfato 10 mm, ƒ³masico =0,33, Ultraturrax T-25. La estabilidad de las emulsiones (medida a traves del aceite separado decrecio en el orden: SSLC > STST > STL > SSL. Estos resultados se correlacionan con el índice de actividad emulsificante con y sin SDS. Por medidas de BackScattering y difracción láser se observo una reducción del tamaño de partícula en las emulsiones preparadas con sueros calentados (SSLC respecto a SSL y STST respecto a STL. Se observaron diferencias en la capacidad emulsionante de SSLC y STST, atribuidas a las condiciones de calentamiento. Las reacciones de desnaturalización y de formación de agregadosglicosilados en el suero de soja liofilizado y calentado reducirían la formación de floculos en la emulsión, principal mecanismode desestabilización en estas emulsiones.

  11. Spontaneous actin dynamics in contractile rings

    Science.gov (United States)

    Kruse, Karsten; Wollrab, Viktoria; Thiagarajan, Raghavan; Wald, Anne; Riveline, Daniel

    Networks of polymerizing actin filaments are known to be capable to self-organize into a variety of structures. For example, spontaneous actin polymerization waves have been observed in living cells in a number of circumstances, notably, in crawling neutrophils and slime molds. During later stages of cell division, they can also spontaneously form a contractile ring that will eventually cleave the cell into two daughter cells. We present a framework for describing networks of polymerizing actin filaments, where assembly is regulated by various proteins. It can also include the effects of molecular motors. We show that the molecular processes driven by these proteins can generate various structures that have been observed in contractile rings of fission yeast and mammalian cells. We discuss a possible functional role of each of these patterns. The work was supported by Agence Nationale de la Recherche, France, (ANR-10-LABX-0030-INRT) and by Deutsche Forschungsgemeinschaft through SFB1027.

  12. Malformação arteriovenosa uterina após doença trofoblástica gestacional Uterine arteriovenous malformation after gestational trophoblastic disease

    OpenAIRE

    Paulo Belfort; Antônio Braga; Nazaré Serra Freire

    2006-01-01

    OBJETIVO: investigar a presença e resultados de malformações vasculares uterinas (MAVU) após doença trofoblástica gestacional (DTG). MÉTODOS: estudo retrospectivo com inclusão de casos diagnosticados entre 1987 e 2004; 2764 pacientes após DTG foram acompanhadas anualmente com ultra-sonografia transvaginal e Doppler colorido no Centro de Neoplasia Trofoblástica Gestacional da Santa Casa da Misericórdia (Rio de Janeiro, RJ, Brasil). Sete pacientes tiveram diagnóstico final de MAVU baseado em an...

  13. Fatores determinantes da capacidade funcional entre idosos

    Directory of Open Access Journals (Sweden)

    Tereza Etsuko da Costa Rosa

    2003-02-01

    Full Text Available OBJETIVO; Investigar a influência de fatores socioeconômicos e demográficos relativos à saúde, bem como os fatores ligados às atividades sociais e à avaliação subjetiva da saúde sobre a capacidade funcional dos idosos. MÉTODOS: Estudo transversal, integrante de estudo multicêntrico, em amostra representativa do município de São Paulo, realizado em 1989. A capacidade funcional foi avaliada através da escala de atividades da vida diária pessoal e instrumental e investigada como variável dicotômica: ausência de dependência - incapacidade/dificuldade em nenhuma das atividades versus presença de dependência moderada/grave - incapacidade/dificuldade em 4 ou mais atividades. Análise de regressão logística múltipla foi aplicada aos fatores hierarquicamente agrupados. RESULTADOS: As características que se associaram com a dependência moderada/grave foram analfabetismo, ser aposentado, ser pensionista, ser dona de casa, não ser proprietário da moradia, ter mais de 65 anos, ter composição familiar multigeracional, ter sido internado nos últimos 6 meses, ser "caso" no rastreamento de saúde mental, não visitar amigos, ter problemas de visão, ter história de derrame, não visitar parentes e ter avaliação pessimista da saúde ao se comparar com seus pares. CONCLUSÕES: As características identificadas que se associaram à dependência moderada/grave sugerem uma complexa rede causal do declínio da capacidade funcional. Pode-se supor, entretanto, que ações preventivas especificamente voltadas para certos fatores podem propiciar benefícios para o prolongamento do bem estar da população idosa.

  14. A altura uterina é capaz de diagnosticar os desvios do volume de líquido amniótico? Is uterine height able to diagnose amniotic fluid volume deviations?

    Directory of Open Access Journals (Sweden)

    Djacyr Magna Cabral Freire

    2013-02-01

    Full Text Available OBJETIVO: Avaliar o desempenho de uma curva de altura uterina (AU quanto à capacidade de rastrear desvios do volume de líquido amniótico, utilizando uma curva brasileira de índice de líquido amniótico (ILA como padrão-ouro. MÉTODOS: O presente estudo representa um corte transversal no qual foram incluídas 753 gestantes em acompanhamento pré-natal na rede pública de João Pessoa (PB no período de março a outubro de 2006 e que tiveram um exame de ultrassonografia (US de rotina agendado para depois da 26ª semana de idade gestacional. Foram excluídos os casos com diagnóstico de gestação gemelar, óbito fetal intrauterino e malformações fetais maiores. Além de informações sociodemográficas, foram coletados também os valores da AU medida de forma padronizada, os valores do peso fetal estimado, do ILA e a idade gestacional pelo exame de US. A capacidade da curva de AU em predizer os desvios do volume de líquido amniótico foi avaliada tendo uma curva brasileira de ILA em função da idade gestacional como padrão-ouro. Para isso, foram estimados a sensibilidade, especificidade e valores preditivos positivo e negativo para diferentes pontos de corte. RESULTADOS: A medida da AU identificou 10,5% das mulheres como AU baixa e possivelmente associada ao oligoâmnio, e 25,2% como AU alta e possivelmente associada ao polidrâmnio. Utilizando uma curva brasileira de referência para ILA, a AU foi capaz de predizer pobremente a ocorrência de oligoâmnio (sensibilidade variando entre 37 a 28% e de forma razoável a ocorrência de polidrâmnio (sensibilidade variando entre 88 a 69%. CONCLUSÃO: A medida da altura uterina mostrou um desempenho ruim para predizer oligoâmnio e um desempenho razoável para predizer polidrâmnio. Sua utilização para essa finalidade só se justifica, portanto, em situações nas quais o exame ultrassonográfico não esteja fácil e rotineiramente disponível, a fim de ajudar na priorização dos casos que

  15. Cell stiffness, contractile stress and the role of extracellular matrix

    Science.gov (United States)

    An, Steven S.; Kim, Jina; Ahn, Kwangmi; Trepat, Xavier; Drake, Kenneth J.; Kumar, Sarvesh; Ling, Guoyu; Purington, Carolyn; Rangasamy, Tirumalai; Kensler, Thomas W.; Mitzner, Wayne; Fredberg, Jeffrey J.; Biswal, Shyam

    2010-01-01

    Here we have assessed the effects of extracellular matrix (ECM) composition and rigidity on mechanical properties of the human airway smooth muscle (ASM) cell. Cell stiffness and contractile stress showed appreciable changes from the most relaxed state to the most contracted state: we refer to the maximal range of these changes as the cell contractile scope. The contractile scope was least when the cell was adherent upon collagen V, followed by collagen IV, laminin, and collagen I, and greatest for fibronectin. Regardless of ECM composition, upon adherence to increasingly rigid substrates, the ASM cell positively regulated expression of antioxidant genes in the glutathione pathway and heme oxygenase, and disruption of a redox-sensitive transcription factor, nuclear erythroid 2 p45-related factor (Nrf2), culminated in greater contractile scope. These findings provide biophysical evidence that ECM differentially modulates muscle contractility and, for the first time, demonstrate a link between muscle contractility and Nrf2-directed responses. PMID:19327344

  16. Cell stiffness, contractile stress and the role of extracellular matrix

    Energy Technology Data Exchange (ETDEWEB)

    An, Steven S., E-mail: san@jhsph.edu [Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Room E-7616, Baltimore, MD 21205 (United States); Kim, Jina [Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Room E-7616, Baltimore, MD 21205 (United States); Ahn, Kwangmi [Division of Biostatistics, Penn State College of Medicine, Hershey, PA 17033 (United States); Trepat, Xavier [CIBER, Enfermedades Respiratorias, 07110 Bunyola (Spain); Drake, Kenneth J. [Division of Molecular and Integrative Physiological Sciences, Harvard School of Public Health, Boston, MA 02115 (United States); Kumar, Sarvesh; Ling, Guoyu; Purington, Carolyn; Rangasamy, Tirumalai; Kensler, Thomas W.; Mitzner, Wayne [Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Room E-7616, Baltimore, MD 21205 (United States); Fredberg, Jeffrey J. [Division of Molecular and Integrative Physiological Sciences, Harvard School of Public Health, Boston, MA 02115 (United States); Biswal, Shyam [Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Room E-7616, Baltimore, MD 21205 (United States); Division of Pulmonary and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205 (United States)

    2009-05-15

    Here we have assessed the effects of extracellular matrix (ECM) composition and rigidity on mechanical properties of the human airway smooth muscle (ASM) cell. Cell stiffness and contractile stress showed appreciable changes from the most relaxed state to the most contracted state: we refer to the maximal range of these changes as the cell contractile scope. The contractile scope was least when the cell was adherent upon collagen V, followed by collagen IV, laminin, and collagen I, and greatest for fibronectin. Regardless of ECM composition, upon adherence to increasingly rigid substrates, the ASM cell positively regulated expression of antioxidant genes in the glutathione pathway and heme oxygenase, and disruption of a redox-sensitive transcription factor, nuclear erythroid 2 p45-related factor (Nrf2), culminated in greater contractile scope. These findings provide biophysical evidence that ECM differentially modulates muscle contractility and, for the first time, demonstrate a link between muscle contractility and Nrf2-directed responses.

  17. Regulation of tissue morphodynamics: an important role for actomyosin contractility

    Science.gov (United States)

    Siedlik, Michael J.; Nelson, Celeste M.

    2015-01-01

    Forces arising from contractile actomyosin filaments help shape tissue form during morphogenesis. Developmental events that result from actomyosin contractility include tissue elongation, bending, budding, and collective migration. Here, we highlight recent insights into these morphogenetic processes from the perspective of actomyosin contractility as a key regulator. Emphasis is placed on a range of results obtained through live imaging, culture, and computational methods. Combining these approaches in the future has the potential to generate a robust, quantitative understanding of tissue morphodynamics. PMID:25748251

  18. Molecular Model of the Contractile Ring

    CERN Document Server

    Biron, D; Tlusty, Tsvi; Moses, Elisha; 10.1103/PhysRevLett.95.098102

    2010-01-01

    We present a model for the actin contractile ring of adherent animal cells. The model suggests that the actin concentration within the ring and consequently the power that the ring exerts both increase during contraction. We demonstrate the crucial role of actin polymerization and depolymerization throughout cytokinesis, and the dominance of viscous dissipation in the dynamics. The physical origin of two phases in cytokinesis dynamics ("biphasic cytokinesis") follows from a limitation on the actin density. The model is consistent with a wide range of measurements of the midzone of dividing animal cells.

  19. Contractility Dispersion in Long QT Syndrome

    Directory of Open Access Journals (Sweden)

    MH Nikoo

    2009-09-01

    Full Text Available Background: Previous studies, using M mode echocardiography, provided unexpected evidence of a mechanical alteration in patients with long QT syndrome. The aim of this study was to evaluate entire left ventricular (LV wall motion characteristics in patients with long QT syndrome using tissue Doppler imaging. Methods: We enrolled 17 patients with congenital long QT syndrome [11 female and 6 male], aged 21 to 45 years. 10 subjects without cardiac disease were also selected as a control group. Two-dimensional tissue Doppler imaging (TDI recording of the LV was obtained from the basal and mid-segments from apical four-chamber, two-chamber, and long-axis views. ‘Myocardial Contraction Duration’ [MCD] was defined as the time from start of R wave on ECG to end of S wave on TDI. MCD was measured in the six LV wall positions: septal, anteroseptal, lateral, inferior, posterior and anterior positions.Results: LV contractility dispersion was significantly greater in long QT syndrome patients compared to control group [0.051 ± 0.011 vs. 0.016 ± 0.06; P < 0.001]. Conclusion: Our study evaluated left ventricular dispersion of contractility duration in patients with long QT syndrome. This mechanical dispersion may be a reflection of the inhomogeneity of repolarisation in the long QT syndrome.

  20. Contractile Dysfunction in Sarcomeric Hypertrophic Cardiomyopathy.

    Science.gov (United States)

    MacIver, David H; Clark, Andrew L

    2016-09-01

    The pathophysiological mechanisms underlying the clinical phenotype of sarcomeric hypertrophic cardiomyopathy are controversial. The development of cardiac hypertrophy in hypertension and aortic stenosis is usually described as a compensatory mechanism that normalizes wall stress. We suggest that an important abnormality in hypertrophic cardiomyopathy is reduced contractile stress (the force per unit area) generated by myocardial tissue secondary to abnormalities such as cardiomyocyte disarray. In turn, a progressive deterioration in contractile stress provokes worsening hypertrophy and disarray. A maintained or even exaggerated ejection fraction is explained by the increased end-diastolic wall thickness producing augmented thickening. We propose that the nature of the hemodynamic load in an individual with hypertrophic cardiomyopathy could determine its phenotype. Hypertensive patients with hypertrophic cardiomyopathy are more likely to develop exaggerated concentric hypertrophy; athletic individuals an asymmetric pattern; and inactive individuals a more apical hypertrophy. The development of a left ventricular outflow tract gradient and mitral regurgitation may be explained by differential regional strain resulting in mitral annular rotation.

  1. A quantitative analysis of contractility in active cytoskeletal protein networks.

    Science.gov (United States)

    Bendix, Poul M; Koenderink, Gijsje H; Cuvelier, Damien; Dogic, Zvonimir; Koeleman, Bernard N; Brieher, William M; Field, Christine M; Mahadevan, L; Weitz, David A

    2008-04-15

    Cells actively produce contractile forces for a variety of processes including cytokinesis and motility. Contractility is known to rely on myosin II motors which convert chemical energy from ATP hydrolysis into forces on actin filaments. However, the basic physical principles of cell contractility remain poorly understood. We reconstitute contractility in a simplified model system of purified F-actin, muscle myosin II motors, and alpha-actinin cross-linkers. We show that contractility occurs above a threshold motor concentration and within a window of cross-linker concentrations. We also quantify the pore size of the bundled networks and find contractility to occur at a critical distance between the bundles. We propose a simple mechanism of contraction based on myosin filaments pulling neighboring bundles together into an aggregated structure. Observations of this reconstituted system in both bulk and low-dimensional geometries show that the contracting gels pull on and deform their surface with a contractile force of approximately 1 microN, or approximately 100 pN per F-actin bundle. Cytoplasmic extracts contracting in identical environments show a similar behavior and dependence on myosin as the reconstituted system. Our results suggest that cellular contractility can be sensitively regulated by tuning the (local) activity of molecular motors and the cross-linker density and binding affinity. PMID:18192374

  2. Characteristics of deslanoside-induced modulation on jejunal contractility

    Institute of Scientific and Technical Information of China (English)

    Da-Peng Chen; Yong-Jian Xiong; Ze-Yao Tang; Qi-Ying Yao; Dong-Mei Ye; Sha-Sha Liu; Yuan Lin

    2012-01-01

    AIM:TO characterize the dual effects of deslanoside on the contractility of jejunal smooth muscle.METHODS:Eight pairs of different low and high contractile states of isolated jejunal smooth muscle fragment (JSMF) were established.Contractile amplitude of JSMF in different low and high contractile states was selected to determine the effects of deslanoside,and Western blotting analysis was performed to measure the effects of deslanoside on myosin phosphorylation of jejunal smooth muscle.RESULTS:Stimulatory effects on the contractility of JSMF were induced (45.3% ± 4.0% vs 87.0% ± 7.8%,P < 0.01) by deslanoside in 8 low contractile states,and inhibitory effects were induced (180.6% ± 17.8%vs 109.9% ± 10.8%,P < 0.01) on the contractility of JSMF in 8 high contractile states.The effect of deslanoside on the phosphorylation of myosin light chain ofJSMF in low (78.1% ± 4.1% vs 96.0% ± 8.1%,P <0.01) and high contractile state (139.2% ± 8.5% vs 105.5 ± 7.34,P < 0.01) was also bidirectional.Bidirectional regulation (BR) was abolished in the presence of tetrodotoxin.Deslanoside did not affect jejunal contractility pretreated with the Ca2+ channel blocker verapamil or in a Ca2+-free assay condition.The stimulatory effect of deslanoside on JSMF in a low contractile state (low Ca2+ induced) was abolished by atropine.The inhibitory effect of deslanoside on jejunal contractility in a high contractile state (high Ca2+ induced) was blocked by phentolamine,propranolol and L-NG-nitroarginine,respectively.CONCLUSION:Deslanoside-induced BR is Ca2+ dependent and is related to cholinergic and adrenergic systems when JSMF is in low or high contractile states.

  3. Genome sequence of Haloplasma contractile, an unusual contractile bacterium from a deep-sea anoxic brine lake.

    KAUST Repository

    Antunes, Andre

    2011-09-01

    We present the draft genome of Haloplasma contractile, isolated from a deep-sea brine and representing a new order between Firmicutes and Mollicutes. Its complex morphology with contractile protrusions might be strongly influenced by the presence of seven MreB/Mbl homologs, which appears to be the highest copy number ever reported.

  4. Considerations for Contractile Electroactive Materials and Actuators

    Energy Technology Data Exchange (ETDEWEB)

    Lenore Rasmussen, David Schramm, Paul Rasmussen, Kevin Mullaly, Ras Labs, LLC, Intelligent Materials for Prosthetics & Automation, Lewis D. Meixler, Daniel Pearlman and Alice Kirk

    2011-05-23

    Ras Labs produces contractile electroactive polymer (EAP) based materials and actuators that bend, swell, ripple, and contract (new development) with low electric input. In addition, Ras Labs produces EAP materials that quickly contract and expand, repeatedly, by reversing the polarity of the electric input, which can be cycled. This phenomenon was explored using molecular modeling, followed by experimentation. Applied voltage step functions were also investigated. High voltage steps followed by low voltage steps produced a larger contraction followed by a smaller contraction. Actuator control by simply adjusting the electric input is extremely useful for biomimetic applications. Muscles are able to partially contract. If muscles could only completely contract, nobody could hold an egg, for example, without breaking it. A combination of high and low voltage step functions could produce gross motor function and fine manipulation within the same actuator unit. Plasma treated electrodes with various geometries were investigated as a means of providing for more durable actuation.

  5. Considerations For Contractile Electroactive Materials and Actuators

    Energy Technology Data Exchange (ETDEWEB)

    Lenore Rasmussen, Lewis D. Meixler and Charles A. Gentile

    2012-02-29

    Electroactive polymers (EAPs) that bend, swell, ripple (first generation materials), and now contract with low electric input (new development) have been produced. The mechanism of contraction is not well understood. Radionuclide-labeled experiments, molecular modeling, electrolyte experiments, pH experiments, and an ionic concentration experiment were used to determine the chain of events that occur during contraction and, reciprocally, expansion when the polarity is reversed, in these ionic EAPs. Plasma treatment of the electrodes, along with other strategies, allows for the embedded electrodes and the EAP material of the actuator to work and move as a unit, with no detachment, by significantly improving the metal-polymer interface, analogous to nerves and tendons moving with muscles during movement. Challenges involved with prototyping actuation using contractile EAPs are also discussed.

  6. La capacidad desfaunante del extracto de plantas en el rumen

    OpenAIRE

    Alejandro Ley de Coss; Jaime Jorge Martínez Tinajero; Francisco Javier Marroquín Agreda; Carlos Gumaro García Castillo; Oziel Dante Montañez Valdez; Enrique Guerra Medina

    2011-01-01

    El objetivo del presente estudio fue evaluar la capacidad de eliminar protozoarios del rumen con el uso del extracto soluble en agua de las plantas Buddleia cordata, Chenopodium ambrosioides, Datura inoxia, Marrubium vulgare, Mentha piperita y Verbesina perymenioides, las cuales contienen compuestos secundarios con posible efecto tóxico sobre los protozoarios ciliados del rumen. La capacidad desfaunante (CD) del extracto soluble en agua de las plantas se realizó inoculando 0,5 mL de un concen...

  7. EL CAPITAL ESTRUCTURAL Y LA CAPACIDAD INNOVADORA DE LA EMPRESA

    Directory of Open Access Journals (Sweden)

    Santos-Rodrigues, Helena

    2011-09-01

    Full Text Available El entorno empresarial actual presiona a las empresas y a los investigadores para que busquen nuevos factores que permitan alcanzar y mantener sus ventajas competitivas. Entre estos se encuentra cada vez con más importancia el capital intelectual. Un componente representativo de los activos estratégicos de conocimiento, de la propiedad de la empresa, entre otros aspectos, es el capital estructural. Es habitual sospechar que éste afecta a la capacidad innovadora. Sin embargo, es menos conocida la forma en que se produce ese impacto y los aspectos que intervienen. Para investigar esta conexión realizamos una encuesta a 68 empresas que trabajan en el sector de componentes para automoción localizadas en Galicia (Norte de España y el Norte de Portugal. Los resultados muestran, por un lado, que la capacidad innovadora tiene dos dimensiones: la capacidad innovadora de producto - proceso y la capacidad innovadora de gestión; por otro lado, que el capital estructural influye de forma diferenciada en cada tipo de capacidad innovadora. Verificamos que influye directamente en la capacidad innovadora de gestión.

  8. Contractile Changes in the Vasculature After Subchronic Smoking

    DEFF Research Database (Denmark)

    Haanes, Kristian Agmund; Kruse, Lars Schack; Johansson, Helle Wulf;

    2016-01-01

    : Wild type (WT) and SP-D KO mice were exposed to cigarette smoke (CS) or room air for 12 weeks. The pulmonary artery, left anterior descending coronary artery, and basilar artery (BA) were isolated and mounted in wire myographs. Contractile concentration response curves to endothelin-1 and UDP were...... displayed no smoke induced changes, but were surprisingly similar to the CSE WT. CONCLUSION: The contractility to UDP was altered in the brain and heart vasculature of CSE mice. SP-D KO (both control and CSE) and CSE WT had similar changes in contractility compared to control WT. IMPLICATIONS: These results...

  9. Estudo da involução uterina por meio da ultra-sonografia (modo-B) em cadelas submetidas a cesariana Ultrasonographyc study of the postpartum uterine involution in bitches after cesaerean section

    OpenAIRE

    S.T.S. Ferri; W.R.R. Vicente; G.H. Toniollo

    2003-01-01

    Utilizaram-se 15 cadelas gestantes submetidas a cesariana e posteriormente a exames ultra-sonográficos seriados, em modo B (tempo real), para averiguação do diâmetro uterino nos dias 0, 3, 7, 14 e 21 pós-cesariana, com o objetivo de verificar a influência do ato cirúrgico na involução uterina. Os resultados (média e desvio-padrão, em centímetros) registrados para os dias estudados foram, respectivamente: 3,99+0,71; 3,27+0,51; 2,60+0,54; 2,01+0,34; 1,28+0,24. A involução uterina pós-cesariana ...

  10. Dopplervelocimetria das artérias uterinas na predição de complicações em gestações de baixo risco Uterine artery doppler velocimetry for the prediction of complications in low-risk pregnancies

    OpenAIRE

    Fabrício da Silva Costa; Sérgio Pereira da Cunha; Aderson Tadeu Berezowsky

    2005-01-01

    OBJETIVO: determinar a validade da dopplervelocimetria das artérias uterinas na predição de complicações da gestação em população de nulíparas de baixo risco. MÉTODOS: foi conduzido estudo prospectivo que incluiu 45 pacientes primigestas, sem história de doenças crônicas. A dopplervelocimetria das artérias uterinas foi realizada entre 24 e 26 semanas, com determinação do índice de resistência (IR), índice de pulsatilidade (IP), relação S/D e a presença ou ausência de incisura na onda de veloc...

  11. Geometrical Origins of Contractility in Disordered Actomyosin Networks

    Science.gov (United States)

    Lenz, Martin

    2014-10-01

    Movement within eukaryotic cells largely originates from localized forces exerted by myosin motors on scaffolds of actin filaments. Although individual motors locally exert both contractile and extensile forces, large actomyosin structures at the cellular scale are overwhelmingly contractile, suggesting that the scaffold serves to favor contraction over extension. While this mechanism is well understood in highly organized striated muscle, its origin in disordered networks such as the cell cortex is unknown. Here, we develop a mathematical model of the actin scaffold's local two- or three-dimensional mechanics and identify four competing contraction mechanisms. We predict that one mechanism dominates, whereby local deformations of the actin break the balance between contraction and extension. In this mechanism, contractile forces result mostly from motors plucking the filaments transversely rather than buckling them longitudinally. These findings shed light on recent in vitro experiments and provide a new geometrical understanding of contractility in the myriad of disordered actomyosin systems found in vivo.

  12. Genetic fuzzy system predicting contractile reactivity patterns of small arteries

    DEFF Research Database (Denmark)

    Tang, J; Sheykhzade, Majid; Clausen, B F;

    2014-01-01

    strategies. Results show that optimized fuzzy systems (OFSs) predict contractile reactivity of arteries accurately. In addition, OFSs identified significant differences that were undetectable using conventional analysis in the responses of arteries between groups. We concluded that OFSs may be used...

  13. Considerations for Contractile Electroactive Materials and Actuators

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Lenore; Erickson, Carl J.; Meixler, Lewis D.; Ascione, George; Gentile, Charles A.; Tilson, Carl; Bernasek, Stephen L.; Abelev, Esta

    2010-02-19

    Ras Labs produces electroactive polymer (EAP) based materials and actuators that bend, swell, ripple and now contract (new development) with low electric input. This is an important attribute because of the ability of contraction to produce life-like motion. The mechanism of contraction is not well understood. Radionuclide-labeled experiments were conducted to follow the movement of electrolytes and water in these EAPs when activated. Extreme temperature experiments were performed on the contractile EAPs with very favorable results. One of the biggest challenges in developing these actuators, however, is the electrode-EAP interface because of the pronounced movement of the EAP. Plasma treatments of metallic electrodes were investigated in order to improve the attachment of the embedded electrodes to the EAP material. Surface analysis, adhesive testing, and mechanical testing were conducted to test metal surfaces and metal-polymer interfaces. The nitrogen plasma treatment of titanium produced a strong metal-polymer interface; however, oxygen plasma treatment of both stainless steel and titanium produced even stronger metal-polymer interfaces. Plasma treatment of the electrodes allows for the embedded electrodes and the EAP material of the actuator to work and move as a unit, with no detachment, by significantly improving the metal-polymer interface.

  14. Influence of the cardiac myosin hinge region on contractile activity.

    OpenAIRE

    Margossian, S S; Krueger, J W; Sellers, J R; Cuda, G; Caulfield, J B; Norton, P.; Slayter, H. S.

    1991-01-01

    The participation of cardiac myosin hinge in contractility was investigated by in vitro motility and ATPase assays and by measurements of sarcomere shortening. The effect on contractile activity was analyzed using an antibody directed against a 20-amino acid peptide within the hinge region of myosin. This antibody bound specifically at the hinge at a distance of 55 nm from the S1/S2 junction, was specific to human, dog, and rat cardiac myosins, did not crossreact with gizzard or skeletal myos...

  15. Capacidad funcional y salud: orientaciones para cuidar al adulto mayor

    OpenAIRE

    CLARA INÉS GIRALDO M; GLORIA MARÍA FRANCO A

    2008-01-01

    Objetivo: valorar la salud y la capacidad funcional de ancianos con dependencia funcional para el autocuidado, como elementos para orientar el cuidado de enfermería y el cuidado familiar en casa. Metodología: estudio descriptivo transversal en 40 personas de 65 y más años con dependencia funcional, cuidados por familiar, en Envigado Colombia; muestreo por conveniencia. Valoración de la capacidad funcional con el índice de Katz y la escala de Lawton y Brody, ajustados según grupo de Neurocienc...

  16. Capital humano y capacidad humana Human capital and human capacity

    OpenAIRE

    Sen Amartya Kumar

    1998-01-01

    En este articulo se examinan las relaciones y diferencias entre el concepto de 'capital humano' y el concepto de 'capacidad humana'. El concepto de capital humano es mas limitado puesto que solo concibe las cualidades humanas en su relación con el crecimiento económico mientras que el concepto de capacidades da énfasis a la expansión de libertad humana para vivir el tipo de vida que la gente considera valedera. Cuando se adopta esa visión mas amplia, el proceso de desarrollo no puede verse si...

  17. Enriquecimiento curricular para el alumnado con altas capacidades en primaria

    OpenAIRE

    Boldú Caballero, Tomás

    2013-01-01

    La finalidad de este documento es proporcionar al lector, primero, una rápida ojeada a la trayectoria histórica de la atención a las NEE (más concretamente de las altas capacidades); segundo, una conceptualización de las altas capacidades y sus necesidades educativas específicas tomando como punto de referencia algunos de lo más eminentes autores y corrientes psicopedagógicas actuales o del pasado reciente; y por último, facilitar ejemplos prácticos desde la perspectiva del doc...

  18. Myocardial contractile function and intradialytic hypotension.

    Science.gov (United States)

    Owen, Paul J; Priestman, William S; Sigrist, Mhairi K; Lambie, Stewart H; John, Stephen G; Chesterton, Lindsay J; McIntyre, Christopher W

    2009-07-01

    Dialysis-induced hypotension remains a significant problem in hemodialysis (HD) patients. Numerous factors result in dysregulation of blood pressure control and impaired myocardial reserve in response to HD-induced cardiovascular stress. Episodic intradialytic hypotension may be involved in the pathogenesis of evolving myocardial injury. We performed an initial pilot investigation of cardiovascular functional response to pharmacological cardiovascular stress in hypotension-resistant (HR) and hypotension-prone (HP) HD patients. We studied 10 matched chronic HD patients (5 HP, 5 HR). Dobutamine-atropine stress (DAS) was performed on a nondialysis short interval day, with noninvasive pulse-wave analysis using the Finometer to continuously measure hemodynamic variables. Baroreflex sensitivity was assessed at rest and during DAS. Baseline hemodynamic variables were not significantly different. The groups had differing hemodynamic responses to DAS. The Mean arterial pressure was unchanged in the HR group but decreased in HP patients (-13.6 +/- 3.5 mmHg; P<0.001). This was associated with failure to significantly increase cardiac output in the HP group (cf. increase in cardiac output in the HR group of +33.4 +/- 6%; P<0.05), and a reduced response in total peripheral resistance (HP -10.3 +/- 6.8%, HR -22.7 +/- 2.9%, P=NS). Baroreflex sensitivity was not significantly different between groups at baseline or within groups with increasing levels of DAS; however, the mean baroreflex sensitivity was higher in HR cf. HP subjects throughout pharmacological stress (P<0.05). Hypotension-prone patients appear to have an impaired cardiovascular response to DAS. The most significant abnormality is an impaired myocardial contractile reserve. Early identification of these patients would allow utilization of therapeutic strategies to improve intradialytic tolerability, potentially abrogating aggravation of myocardial injury.

  19. Função endotelial, perfusão uterina e fluxo central em gestações complicadas por Pré-Eclampsia

    Directory of Open Access Journals (Sweden)

    Augusto Henriques Fulgêncio Brandão

    2012-10-01

    Full Text Available FUNDAMENTO: A fisiopatologia da Pré-Eclampsia (PE é caracterizada por deficiência no processo de placentação, disfunção endotelial sistêmica e hiperfluxo do Sistema Nervoso Central (SNC. Do ponto de vista clínico, seria interessante determinar a ocorrência desses fenômenos antes do aparecimento das manifestações clínicas da doença, levantando a possibilidade de novos métodos de predição da PE. OBJETIVO: Comparar o processo de placentação, a função endotelial e o hiperfluxo do SNC em gestantes de alto risco para desenvolvimento de PE que posteriormente desenvolveram ou não a síndrome. MÉTODOS: Um total de 74 gestantes foi submetido ao exame de Dilatação Fluxo-Mediada (DFM da artéria braquial, dopplerfluxometria de artérias uterinas e oftálmica para avaliação da função endotelial, processo de placentação e hiperfluxo central, respectivamente. Os exames foram realizados entre 24 e 28 semanas de gestação e as pacientes foram acompanhadas até o puerpério para coleta de dados. RESULTADOS: Quinze pacientes tiveram a gestação complicada pela PE e 59 se mantiveram normotensas até o puerpério. Pacientes que subsequentemente desenvolveram PE apresentaram entre 24 e 28 semanas de gestação, maiores valores no índice de pulsatilidade das artérias uterinas e menores valores de DFM (p < 0,001 e p = 0,001, respectivamente. Entretanto, não houve diferença nos valores obtidos no índice de resistência da artéria oftálmica (p = 0,08. CONCLUSÃO: Os dados obtidos sugerem que a deficiência no processo de placentação e a disfunção endotelial precedem cronologicamente as manifestações clínicas da PE, o que não ocorre com o hiperfluxo do SNC.

  20. DIAGNOSIS AND THERAPEUTIC CONSIDERATIONS OF UTERINE INFECTIONS IN DAIRY CATTLE CONSIDERACIONES DIAGNÓSTICAS Y TERAPÉUTICAS PARA INFECCIONES UTERINAS EN VACAS LECHERAS

    Directory of Open Access Journals (Sweden)

    Risco Carlos

    2009-05-01

    Full Text Available From an animal health-well being, welfare, and performance perspective, the postpartum period is comprised of an early window where acute health and cow survival is an issue with the development of septic metritis. Subsequently, sustained presence of endometritis is likely to be contributing to sub-fertility in lactating dairy cows with an overall herd pregnancy rate of approximately 16%. The challenge is to integrate on commercial dairies preventive medicine programs with reproductive management to improve herd fertility. Cows affected by periparturient disorders such as hypocalcemia, dystocia, and retained fetal membranes are more likely to contract uterine infections than cows that calve normally are. Thus, appropriate management of the transition period is critical in the prevention of uterine infections at the herd level. In addition, a postpartum program to monitor health to provide treatment to cows in the early stages of disease should be implemented.Desde el punto de vista del bienestar animal y de la perspectiva de productividad, el periodo postparto puede estar comprometido por una pequeña ventana durante el postparto temprano, en la cual la salud y supervivencia de las vacas es un problemática, debido a la presentación de metritis séptica. Esta se perpetuán subsecuentemente con la presentación de endometritis, la cual muy posiblemente contribuye con los patrones de sub-fertilidad en vacas lactantes, generando en general bajas tasas de preñez del 16 %. El reto es entonces integrar en las explotaciones comerciales un programa de medicina veterinaria preventiva con el manejo reproductivo, con el fin de mejorar la fertilidad del hato. Se ha descrito que las vacas que sufren problemas durante el periparto tales como hipocalcemia y retención de las membranas fetales son más susceptibles de contraer infecciones uterinas, comparadas con aquellas vacas que tienen un parto normal. Por ello un manejo apropiado del periodo de transici

  1. Modelo computacional para caracterización de células escamosas de citologías cérvico-uterinas

    Directory of Open Access Journals (Sweden)

    Martínez Abaunza Víctor Eduardo

    2005-12-01

    Full Text Available El trabajo se realizó entre el Grupo de Investigación en Ingeniería Biomédica (GIIB y el Grupo de Investigación en Patología Estructural, Funcional y Clínica de la Universidad Industrial de Santander (UIS, junto con la Facultad de Medicina de la Universidad Autónoma de Bucaramanga (UNAB; el objetivo principal es construir un modelo computacional que permita caracterizar las células presentes en una citología cérvico uterina, con el propósito de clasificarlas como normales o displásicas. Las láminas que contenían las muestras celulares las recolectaron los patólogos y se tomaron fotografías digitales por medio de una cámara de video acoplada a un microscopio y conectada a un dispositivo de adquisición. En la segmentación de las imágenes se utilizaron tres algoritmos de binarización que permitieron detectar los núcleos celulares; debido a que estos algoritmos presentaron fallas en la detección del citoplasma, se utilizó binarización manual. La descripción de la textura celular se logró con la distribución del histograma, en cada uno de los planos de color, y en los bordes se emplearon descriptores de Fourier. Se presentan los resultados de la primera fase, implementados en la clasificación e identificación de células normales. En las fases posteriores se aplicará la caracterización de cada uno de los estadios de las células clasificadas inicialmente como displásicas, para lograr discriminar las reactivas de las que realmente tienen cambios de lesión. Palabras clave: tratamiento de imágenes, morfología matemática, citología cérvico uterina, displasia, cáncer de cérvix.

  2. LAS CAPACIDADES TECNOLÓGICAS COMO BASE PARA EL DESARROLLO

    Directory of Open Access Journals (Sweden)

    Álvaro Carbajal Villaplana

    2010-01-01

    Full Text Available En este artículo interesa determinar la estructura lógica del concepto de capacidades tecnológicas para establecer las características y los componentes más relevantes, esto con la intención de proponer una definición filosófica a partir de las ideas de capacidades y funcionamientos de Amartya Sen y del concepto de disposiciones de Gilbert Ryle. Se trata de una ampliación o aplicación de esas nociones a la idea de capacidades tecnológicas con el fin de obtener dicho concepto operativo y apropiado. El estudio se lleva a cabo, porque la noción de capacidades tecnológicas es muy utilizada en diversos textos de economía, administración, tecnología y filosofía, pero sin que se las defina apropiadamente ni se les fundamente filosóficamente. La investigación en la que se sustenta el artículo se realizó en el año 2005 con un enfoque de análisis inscrito en la tradición filosófica analítica.

  3. Mechanisms of impaired gallbladder contractile response in chronic acalculous cholecystitis.

    Science.gov (United States)

    Merg, Anders R; Kalinowski, Scott E; Hinkhouse, Marilyn M; Mitros, Frank A; Ephgrave, Kimberly S; Cullen, Joseph J

    2002-01-01

    The mechanisms involved in the impaired gallbladder contractile response in chronic acalculous cholecystitis are unknown. To determine the mechanisms that may lead to impaired gallbladder emptying in chronic acalculous cholecystitis, gallbladder specimens removed during hepatic resection (controls) and after cholecystectomy for chronic acalculous cholecystitis were attached to force transducers and placed in tissue baths with oxygenated Krebs solution. Electrical field stimulation (EFS) (1 to 10 Hz, 0.1 msec, 70 V) or the contractile agonists, CCK-8 (10(-9) to 10(-5)) or K(+) (80 mmol/L), were placed separately in the tissue baths and changes in tension were determined. Patients with chronic acalculous cholecystitis had a mean gallbladder ejection fraction of 12% +/- 4%. Pathologic examination of all gallbladders removed for chronic acalculous cholecystitis revealed chronic cholecystitis. Spontaneous contractile activity was present in gallbladder strips in 83% of control specimens but only 29% of gallbladder strips from patients with chronic acalculous cholecystitis (P < 0.05 vs. controls). CCK-8 contractions were decreased by 54% and EFS-stimulated contractions were decreased by 50% in the presence of chronic acalculous cholecystitis (P < 0.05 vs. controls). K(+)-induced contractions were similar between control and chronic acalculous cholecystitis gallbladder strips. The impaired gallbladder emptying in chronic acalculous cholecystitis appears to be due to diminished spontaneous contractile activity and decreased contractile responsiveness to both CCK and EFS.

  4. Changes of smooth muscle contractile filaments in small bowel atresia

    Institute of Scientific and Technical Information of China (English)

    Stefan Gfroerer; Henning Fiegel; Priya Ramachandran; Udo Rolle; Roman Metzger

    2012-01-01

    AIM:To investigate morphological changes of intestinal smooth muscle contractile fibres in small bowel atresia patients.METHODS:Resected small bowel specimens from small bowel atresia patients (n =12) were divided into three sections (proximal,atretic and distal).Standard histology hematoxylin-eosin staining and enzyme immunohistochemistry was performed to visualize smooth muscle contractile markers α-smooth muscle actin (SMA) and desmin using conventional paraffin sections of the proximal and distal bowel.Small bowel from agematched patients (n =2) undergoing Meckel's diverticulum resection served as controls.RESULTS:The smooth muscle coat in the proximal bowel of small bowel atresia patients was thickened compared with control tissue,but the distal bowel was unchanged.Expression of smooth muscle contractile fibres SMA and desmin within the proximal bowel was slightly reduced compared with the distal bowel and control tissue.There were no major differences in the architecture of the smooth muscle within the proximal bowel and the distal bowel.The proximal and distal bowel in small bowel atresia patients revealed only minimal differences regarding smooth muscle morphology and the presence of smooth muscle contractile filament markers.CONCLUSION:Changes in smooth muscle contractile filaments do not appear to play a major role in postoperative motility disorders in small bowel atresia.

  5. A Histerossonografia na Avaliação da Cavidade Uterina em Pacientes Menopausadas Sonohysterography in the evaluation of the uterine cavity in postmenopausal women

    Directory of Open Access Journals (Sweden)

    Benito Pio Vitório Ceccato Júnior

    2002-09-01

    Full Text Available Objetivos: avaliar a acuidade diagnóstica da histerossonografia como método de avaliação da cavidade uterina em pacientes menopausadas com cavidade uterina alterada à ultra-sonografia endovaginal convencional. Métodos: este estudo consistiu na avaliação de 99 pacientes menopausadas com cavidade uterina anormal à ultra-sonografia endovaginal convencional, caracterizada por espessura endometrial maior ou igual a 5 mm em pacientes sem terapia de reposição hormonal, ou espessura endometrial maior ou igual a 8 mm em pacientes em terapia de reposição hormonal, com sangramento irregular. Estas pacientes foram submetidas à histerossonografia e após, foram obtidas amostras para avaliação histopatológica por biópsia dirigida por histeroscopia em 92 pacientes, biópsia endometrial em quatro pacientes e histerectomia em três pacientes. Os resultados da histerossonografia foram comparados com os resultados do exame histopatológico, considerado como "padrão-ouro". Resultados: houve oito casos de cavidade uterina normal e 20 casos de atrofia endometrial e a histerossonografia teve altos níveis de especificidade (97,8 e 97,5% e baixa sensibilidade (35 e 25%. Houve altos níveis de sensibilidade (92,3 e 75,0% e especificidade (94,1 e 97,9% em pólipos (65 casos e miomas submucosos (quatro casos. Houve três casos de câncer de endométrio e a histerossonografia teve sensibilidade e especificidade de 100%. Conclusões: a histerossonografia mostrou boa acuidade no diagnóstico de doenças focais (pólipos endometriais e miomas submucosos, com altos níveis de sensibilidade e especificidade. Houve três casos de câncer endometrial, e a histerossonografia diagnosticou corretamente todos eles. Mostrou também ser método acurado para excluir anormalidades endometriais. Entretanto, nos casos de espessamento endometrial difuso, a acuidade é baixa, porque endométrios atróficos ou normais freqüentemente aparecem como tendo espessamento difuso

  6. Cuerpos, capacidades, exigencias funcionales... y otros lechos de Procusto Cuerpos, capacidades, exigencias funcionales... y otros lechos de Procusto

    Directory of Open Access Journals (Sweden)

    Mario Toboso Martín

    2010-03-01

    Full Text Available El denominado modelo social de la discapacidad interpreta ésta como una construcción social, pero no presenta de la misma manera la capacidad. Habitualmente se supone que las capacidades lo son propiamente del cuerpo, mientras que se pasa por alto que llegar a poseer un determinado conjunto de capacidades es un hecho normativamente impuesto por nuestros patrones culturales de vida. Las capacidades que definen este conjunto retratan fielmente las capacidades de lo que aquí denominamos cuerpo normativo. La reflexión en torno al cuerpo, como elemento sociocultural clave, debe cuestionar el esencialismo en la atribución de tales capacidades, notando que el primer paso para caer bajo las miradas médica y capacitista es, precisamente, definir y asumir un conjunto previo de capacidades inherentes atribuibles al cuerpo. Como vía para la deconstrucción del cuerpo normativo nos planteamos poner en práctica una mirada alternativa, que se sitúe lejos de la creencia generalizada en un modo de funcionamiento mayoritario y único, y permita también tener en cuenta los modos minoritarios y menos habituales. La reflexión se convierte así en una cuestión de respeto a la diversidad funcional que, como condición inherente al cuerpo y al ser humano, resulta del reconocimiento de todas las expresiones diferentes de funcionamiento posibles.The so-called social model of disability interprets it as a social construction, but it does not present capability in the same manner. Usually abilities are supposed to be inherent to the body, whereas is overlooked that being able to reach certain set of abilities is an imposed normative fact demanded by our cultural life standards. This set defining abilities reflects accurately the abilities of what we call normative body. The reflection around the body, as a key sociocultural element, must question the essentialism in the attribution of such abilities, remarking that the first step to fall under medical and able

  7. Dietary Nitrate and Skeletal Muscle Contractile Function in Heart Failure.

    Science.gov (United States)

    Coggan, Andrew R; Peterson, Linda R

    2016-08-01

    Heart failure (HF) patients suffer from exercise intolerance that diminishes their ability to perform normal activities of daily living and hence compromises their quality of life. This is due largely to detrimental changes in skeletal muscle mass, structure, metabolism, and function. This includes an impairment of muscle contractile performance, i.e., a decline in the maximal force, speed, and power of muscle shortening. Although numerous mechanisms underlie this reduction in contractility, one contributing factor may be a decrease in nitric oxide (NO) bioavailability. Consistent with this, recent data demonstrate that acute ingestion of NO3 (-)-rich beetroot juice, a source of NO via the NO synthase-independent enterosalivary pathway, markedly increases maximal muscle speed and power in HF patients. This review discusses the role of muscle contractile dysfunction in the exercise intolerance characteristic of HF, and the evidence that dietary NO3 (-) supplementation may represent a novel and simple therapy for this currently underappreciated problem. PMID:27271563

  8. Geometrical origins of contractility in disordered actomyosin networks

    CERN Document Server

    Lenz, Martin

    2014-01-01

    Movement within eukaryotic cells largely originates from localized forces exerted by myosin motors on scaffolds of actin filaments. Although individual motors locally exert both contractile and extensile forces, large actomyosin structures at the cellular scale are overwhelmingly contractile, suggesting that the scaffold serves to favor contraction over extension. While this mechanism is well understood in highly organized striated muscle, its origin in disordered networks such as the cell cortex is unknown. Here we develop a mathematical model of the actin scaffold's local two- or three-dimensional mechanics and identify four competing contraction mechanisms. We predict that one mechanism dominates, whereby local deformations of the actin break the balance between contraction and extension. In this mechanism, contractile forces result mostly from motors plucking the filaments transversely rather than buckling them longitudinally. These findings sheds light on recent $\\textit{in vitro}$ experiments, and provi...

  9. Capacidades intangibles para la competitividad microempresarial en México

    Directory of Open Access Journals (Sweden)

    Noé Fuentes

    2016-01-01

    Full Text Available La competitividad empresarial ha sido objeto de estudio y debate dentro de la literatura económica, estableciendo diferentes factores determinantes para el desarrollo empresarial. En este trabajo, desde el enfoque de la Economía Industrial, la Nueva Economía Industrial y la Teoría de Recursos y Capacidades, se elabora un modelo econométrico de panel con 2 671 microempresas mexicanas a lo largo de cuatro periodos, que detalla la relación de ventajas competitivas de la microempresa con factores externos e internos como la estructura sectorial y los activos tangibles e intangibles de la unidad económica. Los principales resultados encontrados sugieren que la generación de las sinergias adecuadas para el desenvolvimiento del sector productivo de pequeña escala se logra principalmente a partir de las capacidades intangibles.

  10. Cuaderno de Prácticas: Altas Capacidades

    OpenAIRE

    García Fernández, José Manuel; Vicent Juan, Maria; Gonzálvez Macià, Carolina

    2016-01-01

    Este material, centrado en el estudio de las Altas Capacidades, pretende favorecer la adquisición de destrezas en el conocimiento e intervención en el ámbito de la educación especial para conocer de primera mano las diferentes formas que se tienen para actuar e intervenir ante niños con necesidades específicas de apoyo educativo.

  11. Capital humano y capacidad humana Human capital and human capacity

    Directory of Open Access Journals (Sweden)

    Sen Amartya Kumar

    1998-12-01

    Full Text Available En este articulo se examinan las relaciones y diferencias entre el concepto de 'capital humano' y el concepto de 'capacidad humana'. El concepto de capital humano es mas limitado puesto que solo concibe las cualidades humanas en su relación con el crecimiento económico mientras que el concepto de capacidades da énfasis a la expansión de libertad humana para vivir el tipo de vida que la gente considera valedera. Cuando se adopta esa visión mas amplia, el proceso de desarrollo no puede verse simplemente como un incremento del PIB sino como la expansión de la capacidad humana para llevar una vida mas libre y mas digna.In this article the relationships and the differences between the concept of 'human capital' and the concept of 'human capability' are examined. The concept of human capital is more limited since it only conceives human qualities in relation to economic growth, whereas the concept of capabili ties puts emphasis on the expansion of human freedom to live the kind of life that people judge valuable. Whenthis broader vision is adopted, the process of development cannot be seen as simply an increase in the GNP, but rather as the expansion of the human capability to live a more free and worthy life.

  12. Metabolism: flow and contractility of the Langendorff heart

    NARCIS (Netherlands)

    H. Stam (Hans)

    1978-01-01

    textabstractThis thesis reviews current literature and describes experimental studies on the regulation and modification of coronary flow and contractility in isolated rat hearts. In chapter I and introduction is given to the problems of fatty acid toxicity and myocardial function. Coronary flow rat

  13. Myocardial contractile function in survived neonatal piglets after cardiopulmonary bypass

    Directory of Open Access Journals (Sweden)

    Popov Aron-Frederik

    2010-11-01

    Full Text Available Abstract Background Hemodynamic function may be depressed in the early postoperative stages after cardiac surgery. The aim of this study was the analysis of the myocardial contractility in neonates after cardiopulmonary bypass (CPB and mild hypothermia. Methods Three indices of left ventricular myocardial contractile function (dP/dt, (dP/dt/P, and wall thickening were studied up to 6 hours after CPB in neonatal piglets (CPB group; n = 4. The contractility data were analysed and then compared to the data of newborn piglets who also underwent median thoracotomy and instrumentation for the same time intervals but without CPB (non-CPB group; n = 3. Results Left ventricular dP/dtmax and (dP/dtmax/P remained stable in CPB group, while dP/dtmax decreased in non-CPB group 5 hours postoperatively (1761 ± 205 mmHg/s at baseline vs. 1170 ± 205 mmHg/s after 5 h; p max and (dP/dtmax/P there were no statistically significant differences between the two groups. Comparably, although myocardial thickening decreased in the non-CPB group the differences between the two groups were not statistically significant. Conclusions The myocardial contractile function in survived neonatal piglets remained stable 6 hours after cardiopulmonary bypass and mild hypothermia probably due to regional hypercontractility.

  14. Clinical Relationship between Steatocholecystitis and Gallbladder Contractility Measured by Cholescintigraphy

    Directory of Open Access Journals (Sweden)

    Chang Seok Bang

    2015-01-01

    Full Text Available Objective. Contractility of gallbladder is known to be decreased in fatty gallbladder diseases. However, clinical estimation data about this relationship is still lacking. The aim of this study was to investigate the association between steatocholecystitis and contractility of gallbladder. Methods. Patients with cholecystitis (steatocholecystitis versus nonsteatocholecystitis who underwent cholescintigraphy before cholecystectomy were retrospectively evaluated in a single teaching hospital of Korea. The association of steatocholecystitis with contractility of gallbladder, measured by preoperative cholescintigraphy, was assessed by univariable and multivariable analysis. Results. A total of 432 patients were finally enrolled (steatocholecystitis versus nonsteatocholecystitis; 75 versus 357, calculous versus acalculous cholecystitis; 316 versus 116. In the multivariable analysis, age (OR: 0.94, 95% CI: 0.90–0.99, P=0.01 and total serum cholesterol (OR: 1.02, 95% CI: 1.01–1.04, P=0.04 were related to steatocholecystitis in patients with acalculous cholecystitis. Only age (OR: 0.97, 95% CI: 0.94–0.99, P=0.004 was significantly related to steatocholecystitis in patients with calculous cholecystitis. However, ejection fraction of gallbladder reflecting contractility measured by cholescintigraphy was not related to steatocholecystitis irrespective of presence of gallbladder stone in patients with cholecystitis. Conclusion. Ejection fraction of gallbladder measured by cholescintigraphy cannot be used for the detection or confirmation of steatocholecystitis.

  15. Transfusão intra-uterina em fetos afetados pela doença hemolítica perinatal grave: um estudo descritivo Intrauterine transfusion in fetuses affected by severe perinatal hemolytic disease: a descriptive study

    OpenAIRE

    Dorival Antônio Vitorello; Luiz Miguel Mitri Parente; Rodolfo João Ramos; Luís Flávio de Andrade Gonçalves; Cláudia Diniz Baumgarten; Jorge Abi Saab Neto

    1998-01-01

    Objetivo: analisar 54 transfusões intravasculares intra-uterinas (TIVs), ressaltando complicações do procedimento e morbimortalidade perinatal. Material e Métodos: fetos submetidos a TIVs na Clínica Materno-Fetal e Maternidade Carmela Dutra (Florianópolis, SC), entre janeiro de 1992 e agosto de 1997, foram incluídos no estudo. As características das gestantes, dados relativos ao procedimento e ao recém-nascido foram tabulados para análise e apresentados de forma descritiva, utilizando-se perc...

  16. Acurácia da histeroscopia na avaliação da cavidade uterina em pacientes com sangramento uterino pós-menopausa

    Directory of Open Access Journals (Sweden)

    Machado Maria Karenina N.

    2003-01-01

    Full Text Available OBJETIVO: investigar a acurácia da histeroscopia como método de estudo da cavidade uterina de pacientes com sangramento na pós-menopausa. MÉTODO: trata-se de estudo transversal, que consistiu na avaliação de 78 prontuários de pacientes menopausadas com queixa de sangramento, no período de janeiro de 2000 a junho de 2002 no Centro Estadual de Oncologia do Estado da Bahia, submetidas à histeroscopia com biópsia de endométrio. Os achados histeroscópicos foram classificados como benignos (miomas, pólipos, atrofia, normal e suspeitos (espessamento, hiperplasias e câncer e os achados histopatológicos como benignos (miomas, pólipos, atrofia, hiperplasia típica e malignos (hiperplasia atípica e câncer. Os resultados da histeroscopia foram comparados com os exames histopatológicos. RESULTADOS: em relação aos achados suspeitos (espessamento, hiperplasias e câncer, a sensibilidade da histeroscopia foi de 85,7% e a especificidade de 88,7%, quando comparados à histopatologia. O valor preditivo positivo foi de 42,8% e o negativo 98,4%. A razão de probabilidades do teste positivo e a razão de probabilidades do teste negativo foram respectivamente 7,6 e 0,16. A acuidade da histeroscopia foi de 88,4% e o índice kappa 0,5. CONCLUSÃO: a histeroscopia isoladamente não apresentou, no presente estudo, acurácia aceitável, reforçando o conceito de que sua principal vantagem é dirigir a biópsia, devendo sempre estar associada ao diagnóstico histopatológico.

  17. Ensayo de irritabilidad vaginal a un producto natural, obtenido a partir de Rhizophora mangle L. destinado al tratamiento de infecciones uterinas.

    Directory of Open Access Journals (Sweden)

    Félix Agüero, Carlos Bulnes, Reina Durand y Liseth García.

    2005-06-01

    Full Text Available En las últimas décadas, se observa un incremento en la tendencia a obtener productos de origen natural para el tratamiento de afecciones en animales y humanos. Una de las fuentes naturales explotadas en Cuba con este fin es la planta Rhizophora mangle L. conocida comúnmente como Mangle rojo. Sobre los resultados obtenidos en investigaciones previas, nos trazamos como objetivo de nuestro trabajo desarrollar un ensayo para evaluar el potencial irritante de una formulación de Rhizophora mangle L. como medicamento candidato al tratamiento de infecciones uterinas. El ensayo se realizó bajo los procedimientos establecidos en la norma ISO 10993-10. “Biological evaluation of medical devices. Part 10: Test for irritation and sensitization. European Committee for Standarization”. Se cumplieron los principios de las Buenas Prácticas de Laboratorio y los principios éticos para evitar sufrimiento a los animales durante la experimentación. El protocolo de investigación fue aprobado por el Comité Institucional de Ética del CENSA. Como resultado se observó ligera congestión e infiltración leucocitaria. Los índices de irritabilidad fueron de 4.0, 3.1, 2.3 y 0.5, para las concentraciones de 16, 24, 32 y 100 mg/mL, respectivamente. El producto no fue irritante para la mucosa vaginal y se observó una disminución del indicador en la medida que se incrementa la concentración de la formulación.

  18. Capacidade antioxidante de frutas Antioxidant capacity of the fruits

    Directory of Open Access Journals (Sweden)

    Enayde de Almeida Melo

    2008-06-01

    Full Text Available Extratos aquoso e acetônico de 15 frutas foram submetidos a ensaios para investigar a habilidade de seqüestrar o radical estável 1,1-difenil-2-picrilhidrazil (DPPH e a capacidade de inibir a oxidação em sistema modelo β-caroteno/ácido linoléico. Todas as frutas exibiram propriedade antioxidante, entretanto a ação foi diferenciada entre elas. O extrato aquoso da acerola, caju, mamão "Formosa", mamão Havaí, laranja pêra e goiaba foram os mais eficazes (superior a 70%, enquanto que o do abacaxi, laranja cravo, manga rosa, melão espanhol, melão japonês, melão orange flesh e pinha apresentaram ação moderada (60-70% e o da manga espada e melancia exibiram a mais fraca capacidade de seqüestrar o radical DPPH. Os extratos acetônico da acerola, caju, pinha e goiaba exibiram uma forte capacidade de seqüestrar o radical DPPH (superior a 70%. Em sistema modelo β-caroteno/ácido linoléico, o extrato aquoso da pinha e o acetônico da goiaba exibiram moderada capacidade antioxidante (60-70% enquanto que a acerola (extrato aquoso e o mamão formosa (extrato acetônico os menores percentuais. Frente à capacidade antioxidante exibida, as frutas podem ser apontadas como fontes de antioxidantes naturais, destacando-se a acerola, caju, mamão Formosa, mamão Havaí, goiaba, laranja pêra, e a pinha por terem apresentado uma potente capacidade antioxidante.Aqueous and acetone extracts from 15 fruits have been screened for antioxidant activity using DPPH method and ß-carotene/linoleic acid model. All fruits studied showed antioxidant activity, but in different extent. Acerola, cashew-apple, papaya "formosa", papaya "solo", orange and guava showed the higher antioxidant activity (>70% in DPPH method, followed by pineapple, bergamont, mango "rosa", melon "reticulares", melon "inodorus", melon "orange flesh" and sugar-apple aqueous extract (moderate, 60-70% and mango "espada" and watermelon aqueous extract, the lowest activity. Acerola, cashew

  19. Perfil docente para alumnos/as con altas capacidades

    OpenAIRE

    María Leonor Conejeros-Solar; María Paz Gómez-Arizaga; Elizabeth Donoso-Osorio

    2013-01-01

    El presente artículo tiene por objeto determinar un perfil de competencias docentes construido desde la percepción de estudiantes con altas capacidades pertenecientes a un programa universitario para talentos académicos. Se utiliza una metodología cualitativa con una estrategia documental de carácter retrospectivo. Los resultados indican que los estudiantes realizan una evaluación profunda sobre la docencia, incluyendo elementos pedagógicos como flexibilidad, ritmo e integración teoría-prácti...

  20. Proyecto de Historia como respuesta educativa a las altas capacidades

    OpenAIRE

    Miguel Yoldi, Yohanna

    2014-01-01

    Este trabajo presenta una propuesta de intervención en el aula que responde a las necesidades educativas del alumnado con altas capacidades, desde una escuela inclusiva. Para realizarlo, nos hemos basado en dos autores: Roger J. Sternberg y Joseph S. Renzulli, que no sólo definen las características y necesidades educativas de este colectivo, sino que también proponen posibles respuestas que respondan a su forma de aprender. Desde el área de Ciencias Sociales, apostamos por el aprendizaje bas...

  1. Todos iguales, todos diferentes. Altas capacidades en el aula.

    OpenAIRE

    Soloaga Martín, Beatriz

    2012-01-01

    El presente trabajo se centra en el alumnado de altas capacidades y las posibilidades de atención en el marco del modelo de escuela inclusiva. Se comienza explicando las características de estos alumnos, los estereotipos que existen sobre ellos y las disincronías que es frecuente encontrar en su desarrollo. Se sigue la clasificación de varios autores para distinguir entre superdotación y talento viendo las diferencias significativas que existen entre ellos. De forma breve se ha...

  2. Capacidad funcional y salud: orientaciones para cuidar al adulto mayor

    Directory of Open Access Journals (Sweden)

    CLARA INÉS GIRALDO M

    2008-07-01

    Full Text Available Objetivo: valorar la salud y la capacidad funcional de ancianos con dependencia funcional para el autocuidado, como elementos para orientar el cuidado de enfermería y el cuidado familiar en casa. Metodología: estudio descriptivo transversal en 40 personas de 65 y más años con dependencia funcional, cuidados por familiar, en Envigado Colombia; muestreo por conveniencia. Valoración de la capacidad funcional con el índice de Katz y la escala de Lawton y Brody, ajustados según grupo de Neurociencias, Universidad de Antioquia. Hallazgos: población entre 67 y 98 años, edad promedio 84,08 años; 82,5% mujeres. Sistemas orgánicos más afectados: cardiovascular, osteomuscular y neurológico; entre 47,5% y 27,5% de los ancianos los tenían comprometidos. Se identificaron dos comportamientos: los hombres, y las personas de edad más avanzada, con mayores grados de dependencia en las actividades básicas e instrumentales; no se determinó asociación estadística por el pequeño tamaño muestral. Las actividades básicas estaban afectadas así: entre el 67,5% y el 55% de los ancianos requería ayuda; y las actividades instrumentales estuvieron comprometidas: entre el 95% y el 75% de los ancianos son totalmente dependientes en ellas. Conclusiones: Enfermería ha de considerar la valoración de la capacidad funcional articulada al estado de salud integral de los ancianos, para orientar su cuidado y apoyar a los cuida-dores familiares. Esto además previene dependencias de cuidado innecesarias que estarían en contra de las aspiraciones del adulto mayor como individuo autónomo e independiente. Es tarea de profesionales en enfermería capacitar a cuidadores familiares sobre valoración de la capacidad funcional.

  3. Capacidade antioxidante de frutas Antioxidant capacity of the fruits

    OpenAIRE

    Enayde de Almeida Melo; Maria Inês Sucupira Maciel; Vera Lúcia Arroxelas Galvão de Lima; Rosilda Josefa do Nascimento

    2008-01-01

    Extratos aquoso e acetônico de 15 frutas foram submetidos a ensaios para investigar a habilidade de seqüestrar o radical estável 1,1-difenil-2-picrilhidrazil (DPPH) e a capacidade de inibir a oxidação em sistema modelo β-caroteno/ácido linoléico. Todas as frutas exibiram propriedade antioxidante, entretanto a ação foi diferenciada entre elas. O extrato aquoso da acerola, caju, mamão "Formosa", mamão Havaí, laranja pêra e goiaba foram os mais eficazes (superior a 70%), enquanto que o do a...

  4. Implementing cell contractility in filament-based cytoskeletal models.

    Science.gov (United States)

    Fallqvist, B

    2016-02-01

    Cells are known to respond over time to mechanical stimuli, even actively generating force at longer times. In this paper, a microstructural filament-based cytoskeletal network model is extended to incorporate this active response, and a computational study to assess the influence on relaxation behaviour was performed. The incorporation of an active response was achieved by including a strain energy function of contractile activity from the cross-linked actin filaments. A four-state chemical model and strain energy function was adopted, and generalisation to three dimensions and the macroscopic deformation field was performed by integration over the unit sphere. Computational results in MATLAB and ABAQUS/Explicit indicated an active cellular response over various time-scales, dependent on contractile parameters. Important features such as force generation and increasing cell stiffness due to prestress are qualitatively predicted. The work in this paper can easily be extended to encompass other filament-based cytoskeletal models as well. PMID:26899417

  5. Dynamic regulation of β1 subunit trafficking controls vascular contractility

    OpenAIRE

    Leo, M. Dennis; Bannister, John P.; Narayanan, Damodaran; Nair, Anitha; Grubbs, Jordan E.; Gabrick, Kyle S.; Boop, Frederick A.; Jaggar, Jonathan H.

    2014-01-01

    Plasma membrane ion channels composed of pore-forming and auxiliary subunits regulate physiological functions in virtually all cell types. A conventional view is that ion channels assemble with their auxiliary subunits prior to surface trafficking of the multiprotein complex. Arterial myocytes express large-conductance Ca2+-activated potassium (BK) channel α and auxiliary β1 subunits that modulate contractility and blood pressure and flow. The data here show that although most BKα subunits ar...

  6. High-throughput screening for modulators of cellular contractile force

    OpenAIRE

    Park, Chan Young; Zhou, Enhua H; Tambe, Dhananjay; Chen, Bohao; Lavoie, Tera; Dowell, Maria; Simeonov, Anton; Maloney, David J.; Marinkovic, Aleksandar; Tschumperlin, Daniel J.; Burger, Stephanie; Frykenberg, Matthew; Butler, James P.; Stamer, W. Daniel; Johnson, Mark

    2014-01-01

    When cellular contractile forces are central to pathophysiology, these forces comprise a logical target of therapy. Nevertheless, existing high-throughput screens are limited to upstream signaling intermediates with poorly defined relationship to such a physiological endpoint. Using cellular force as the target, here we screened libraries to identify novel drug candidates in the case of human airway smooth muscle cells in the context of asthma, and also in the case of Schlemm's canal endothel...

  7. American Ginseng Acutely Regulates Contractile Function of Rat Heart

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    Mao eJiang

    2014-03-01

    Full Text Available Chronic ginseng treatments have been purported to improve cardiac performance. However reports of acute administration of ginseng on cardiovascular function remain controversial and potential mechanisms are not clear. In this study, we examined effects of acute North American ginseng (Panax quinquefolius administration on rat cardiac contractile function by using electrocardiogram (ECG, non-invasive blood pressure measurement (BP and Langendorff isolated, spontaneously beating, perfused heart measurements (LP. Eight-week old male Sprague Dawley rats (n= 8 per group were gavaged with a single dose of water-soluble American ginseng at 300 mg/kg body weight. Heart rate and blood pressure were measured prior to and at 1 and 24 hr after gavaging (ECG and BP. Additional groups were used for each time point for Langendorff measurements. Heart rate was significantly decreased (ECG: 1 hr: 6 ± 0.2%, 24 hr: 8 ± 0.3%; BP: 1 hr: 8.8 ± 0.2%, 24 hr: 13 ± 0.4% and LP: 1 hr: 22 ± 0.4%, 24 hr: 19 ± 0.4% in rats treated with water-soluble ginseng compared with pre or control measures. An initial marked decrease in left ventricular developed pressure was observed in LP hearts but blood pressure changes were not observed in BP group. A direct inhibitory effect of North American ginseng was observed on cardiac contractile function in LP rats and on fluorescence measurement of intracellular calcium transient in freshly isolated cardiac myocytes when exposed to ginseng (1 µg/ml and 10 µg/ml. Collectively these data present evidence of depressed cardiac contractile function by acute administration of North American ginseng in rat. This acute reduction in cardiac contractile function appears to be intrinsic to the myocardium.

  8. IP3 receptors regulate vascular smooth muscle contractility and hypertension

    Science.gov (United States)

    Lin, Qingsong; Zhao, Guiling; Fang, Xi; Peng, Xiaohong; Tang, Huayuan; Wang, Hong; Jing, Ran; Liu, Jie; Ouyang, Kunfu

    2016-01-01

    Inositol 1, 4, 5-trisphosphate receptor–mediated (IP3R-mediated) calcium (Ca2+) release has been proposed to play an important role in regulating vascular smooth muscle cell (VSMC) contraction for decades. However, whether and how IP3R regulates blood pressure in vivo remains unclear. To address these questions, we have generated a smooth muscle–specific IP3R triple-knockout (smTKO) mouse model using a tamoxifen-inducible system. In this study, the role of IP3R-mediated Ca2+ release in adult VSMCs on aortic vascular contractility and blood pressure was assessed following tamoxifen induction. We demonstrated that deletion of IP3Rs significantly reduced aortic contractile responses to vasoconstrictors, including phenylephrine, U46619, serotonin, and endothelin 1. Deletion of IP3Rs also dramatically reduced the phosphorylation of MLC20 and MYPT1 induced by U46619. Furthermore, although the basal blood pressure of smTKO mice remained similar to that of wild-type controls, the increase in systolic blood pressure upon chronic infusion of angiotensin II was significantly attenuated in smTKO mice. Taken together, our results demonstrate an important role for IP3R-mediated Ca2+ release in VSMCs in regulating vascular contractility and hypertension.

  9. Collective cancer cell invasion induced by coordinated contractile stresses.

    Science.gov (United States)

    Jimenez Valencia, Angela M; Wu, Pei-Hsun; Yogurtcu, Osman N; Rao, Pranay; DiGiacomo, Josh; Godet, Inês; He, Lijuan; Lee, Meng-Horng; Gilkes, Daniele; Sun, Sean X; Wirtz, Denis

    2015-12-22

    The physical underpinnings of fibrosarcoma cell dissemination from a tumor in a surrounding collagen-rich matrix are poorly understood. Here we show that a tumor spheroid embedded in a 3D collagen matrix exerts large contractile forces on the matrix before invasion. Cell invasion is accompanied by complex spatially and temporally dependent patterns of cell migration within and at the surface of the spheroids that are fundamentally different from migratory patterns of individual fibrosarcoma cells homogeneously distributed in the same type of matrix. Cells display a continuous transition from a round morphology at the spheroid core, to highly aligned elongated morphology at the spheroid periphery, which depends on both β1-integrin-based cell-matrix adhesion and myosin II/ROCK-based cell contractility. This isotropic-to-anisotropic transition corresponds to a shift in migration, from a slow and unpolarized movement at the core, to a fast, polarized and persistent one at the periphery. Our results also show that the ensuing collective invasion of fibrosarcoma cells is induced by anisotropic contractile stresses exerted on the surrounding matrix.

  10. Recovery in skeletal muscle contractile function after prolonged hindlimb immobilization

    Science.gov (United States)

    Fitts, R. H.; Brimmer, C. J.

    1985-01-01

    The effect of three-month hindlimb immobilization (IM) in rats on contractile properties of slow-twitch soleus (SOL), fast-twitch extensor digitorum longus, and fast-twitch superficial region of the vastus lateralis were measured after 0, 14, 28, 60, and 90 days of recovery on excized, horizontally suspended muscles stimulated electrically to maximal twitch tension. IM caused decreases in muscle-to-body weight ratios for all muscles, with no complete recovery even after 90 days. The contractile properties of the fast-twitch muscles were less affected by IM than those of the slow-twitch SOL. The SOL isometric twitch duration was shortened, due to reduced contraction and half-relaxation time, both of which returned to control levels after 14 days of recovery. The peak tetanic tension, P(O), g/sq cm,, decreased with IM by 46 percent in the SOL, but recovered by the 28th day. The maximum shortening velocity was not altered by IM in any of the muscles. Thus, normal contractile function could recover after prolonged limb IM.

  11. con la generación de capacidades innovativas

    Directory of Open Access Journals (Sweden)

    Matilde Flores Urbáez

    2005-01-01

    Full Text Available En el presente artículo se destacan los diferentes enfoques teóricos sobre la gerencia del conocimiento en términos de su relación con la generación de capacidades innovativas y el aprendizaje organizacional. Uno de los procesos que ha favorecido el auge de la gerencia del conocimiento es la globalización. Se intenta con el contenido de este artículo comprender, en primer lugar los principios más esenciales de cada uno de los referentes teóricos analizados y en segundo lugar, la relación entre ellos. Se concluye que las empresas inmersas en un entorno cambiante, característico del mundo globalizado, así como los cambios motivados por la misma empresa, han acelerado en ellas la generación y adquisición de nuevos conocimientos y capacidades innovativas para alcanzar posiciones competitivas.

  12. Alterações na gasometria de fetos aloimunizados após procedimento de transfusão intra-uterina

    Directory of Open Access Journals (Sweden)

    Nomura Roseli Mieko Yamamoto

    2003-01-01

    Full Text Available OBJETIVO: este estudo, realizado em gestações com aloimunização pelo fator Rh, tem como objetivo descrever as alterações gasométricas e do equilíbrio ácido-básico fetal antes e após transfusões intra-uterinas (TIU. MÉTODO: no período de junho de 2001 a outubro de 2001, antes e após a TIU em fetos de gestantes aloimunizadas, foram avaliados prospectivamente a gasometria e o equilíbrio ácido-básico no sangue da veia umbilical. As medidas foram realizadas em 8 amostras de sangue de 5 fetos. O sangue fetal foi obtido por cordocentese da veia umbilical antes e após TIU. Os resultados obtidos foram comparados com a expansão volêmica na TIU, a idade gestacional no procedimento, o peso fetal estimado pela ultra-sonografia e as variações da hemoglobina fetal (g/dL. RESULTADOS: em todos os casos foi observada queda nos valores do pH, com redução média de 0,09 (DP=0,02. A hemoglobina fetal apresentou aumento médio de 8,4 g/dL (DP=2,9 g/dL. Foi constatada também variação negativa da pO2 (média = -1,28 mmHg na concentração de HCO3_ (média = _2,25 mEq/l. Houve aumento da pCO2 (média = 3,2 mmHg e redução nos valores do excesso de bases (média = -3,75. CONCLUSÃO: a análise das gasometrias permite concluir que o procedimento de TIU acompanha-se de queda nos valores do pH de sangue de veia umbilical, demonstrando haver acidemia fetal relativa após o procedimento.

  13. Altas capacidades intelectuales. Diagnóstico y seguimiento de una NEE.

    OpenAIRE

    Pérez-i-Martra, Pep

    2013-01-01

    Según la OMS, el 2,3% de la población mundial tiene altas capacidades intelectuales, es decir, en la vida académica de un profesor, éste tendría que descubrir una media de 40 alumnos con capacidades superiores a la media. Saber en qué consisten las altas capacidades y hacer un pre diagnóstico de las mismas será, en muchas ocasiones, trabajo del profesor de secundaria. Pero, ¿tiene éste conocimientos para percatarse de la presencia en clase de un alumno con altas capacidades? ¿Y una vez estudi...

  14. Frequência de mola hidatiforme em tecidos obtidos por curetagem uterina Frequency of hydatidiform mole in tissue obtained by curettage

    Directory of Open Access Journals (Sweden)

    Andressa Biscaro

    2012-06-01

    Full Text Available OBJETIVO: Determinar a frequência de mola hidatiforme em tecidos obtidos por curetagem uterina. MÉTODOS: Estudo transversal, prospectivo e descritivo que incluiu pacientes submetidas à curetagem uterina por diagnóstico de aborto ou mola hidatiforme cujo material obtido foi encaminhado para exame anatomopatológico. Foram excluídas aquelas que não aceitaram participar da pesquisa, recusando-se a assinar o Termo de Consentimento Informado Livre e Esclarecido. Foram analisadas as seguintes variáveis: achados anatomopatológicos, idade, raça/cor, número de gestações e abortos prévios, idade gestacional no momento do diagnóstico, níveis séricos quantitativos da fração beta da gonadotrofina coriônica humana e achados ultrassonográficos. As variáveis foram empregadas para a verificação com o diagnóstico histológico, considerado o padrão-ouro. Os dados foram armazenados e analisados no software Microsoft Excel® e no programa Epi-Info, versão 6.0 (STATCALC e os resultados apresentados como frequência (porcentagem ou média±desvio padrão. Para a associação entre variáveis qualitativas foi usado o teste do χ², e admitiu-se significância estatística quando pPURPOSE: To determine the frequency of hydatiform mole in tissues obtained by curettage. METHODS: A cross-sectional, prospective and descriptive conducted on patients who underwent curretage due to a diagnosis of abortion or hydatiform mole whose material was sent for pathological examination. We excluded women who did not accept to participate and refused to sign the free informed consent form. We studied the following variables: pathological findings, age, race, number of pregnancies and previous abortions, gestational age at diagnosis, quantitative serum beta fraction of human chorionic gonadotropin and ultrasound findings. The data were compared to the to histological diagnosis, considered to be the gold standard. Data were stored and analyzed in Microsoft Excel

  15. Expresi??n de ant??genos HLA clase I e infecci??n por papilomavirus humano tipo 16 en la neoplasia cervical uterina y lesiones precursoras

    OpenAIRE

    Torres Garc??a, Luis Manuel

    1992-01-01

    Sobre una casu??stica de 109 diagn??sticos de diferentes entidades nosologicas de cervix uterino, se determina la presencia de ant??genos hla clase i mediante la t??cnica de la inmunoperoxidasa, encontrando que tanto el epitelio normal como los condilomas y las lesiones intraepiteliales conservan la expresi??n de estos ant??genos, mientras que los tumores invasores pierden esta capacidad en el 15% de los casos, correlacion??ndose con la invasi??n del estroma y un aumento de su malignidad. Se ...

  16. Contractile units in disordered actomyosin bundles arise from F-actin buckling

    CERN Document Server

    Lenz, Martin; Gardel, Margaret L; Dinner, Aaron R

    2012-01-01

    Bundles of filaments and motors are central to contractility in cells. The classic example is striated muscle, where actomyosin contractility is mediated by highly organized sarcomeres which act as fundamental contractile units. However, many contractile bundles in vivo and in vitro lack sarcomeric organization. Here we propose a model for how contractility can arise in actomyosin bundles without sarcomeric organization and validate its predictions with experiments on a reconstituted system. In the model, internal stresses in frustrated arrangements of motors with diverse velocities cause filaments to buckle, leading to overall shortening. We describe the onset of buckling in the presence of stochastic actin-myosin detachment and predict that buckling-induced contraction occurs in an intermediate range of motor densities. We then calculate the size of the "contractile units" associated with this process. Consistent with these results, our reconstituted actomyosin bundles contract at relatively high motor dens...

  17. Embolização uterina para tratamento de miomas sintomáticos: impacto na qualidade de vida Uterine embolization for management of symptomatic fibroids: quality-of-life impact

    Directory of Open Access Journals (Sweden)

    Nestor Kisilevzky

    2007-10-01

    Full Text Available OBJETIVO: Verificar a mudança na qualidade de vida de pacientes portadoras de miomatose uterina sintomática submetidas a tratamento por embolização. MATERIAIS E MÉTODOS: Quarenta mulheres portadoras de miomatose uterina sintomática que foram tratadas com a técnica de embolização responderam a um questionário de qualidade de vida antes e 12 semanas após o procedimento. RESULTADOS: Verificou-se que o escore médio relacionado com a gravidade dos sintomas nas 40 pacientes antes da embolização foi de 62,07 ± 6,34 e se modificou, com significância estatística após o tratamento, quando se verificou escore médio de 20,42 ± 3,81. Da mesma forma, comprovou-se a melhora na qualidade de vida pela modificação dos escores antes e depois do tratamento, o que também apresentou significância estatística, passando de 40,26 ± 2,98 para 85,06 ± 2,57. CONCLUSÃO: A embolização uterina provoca alívio evidente dos sintomas relacionados com a miomatose e proporciona melhora substancial da qualidade de vida das pacientes.OBJECTIVE: To determine the impact on the quality of life in patients with symptomatic uterine fibroids submitted to uterine artery embolization. MATERIALS AND METHODS: Forty patients with symptomatic fibroids submitted to embolization have answered a quality-of-life questionnaire before and 12 weeks after the procedure. RESULTS: Mean score for symptoms severity before the procedure was 62.07 ± 6.34 and decreased with statistical significance to 20.42 ± 3.81 after the procedure. Similarly, scores for quality of life have improved from 40.26 ± 2.98 before the procedure to 85.06 ± 2.57 after the procedure, which again was statistically significant. CONCLUSION: Uterine embolization results in evident symptoms relief and significant improvement in the quality of life of patients with symptomatic fibroids.

  18. Caveolin-3 promotes a vascular smooth muscle contractile phenotype

    Directory of Open Access Journals (Sweden)

    Jorge L. Gutierrez-Pajares

    2015-06-01

    Full Text Available Epidemiological studies have demonstrated the importance of cardiovascular diseases in Western countries. Among the cell types associated with a dysfunctional vasculature, smooth muscle cells are believed to play an essential role in the development of these illnesses. Vascular smooth muscle cells are key regulators of the vascular tone and also have an important function in the development of atherosclerosis and restenosis. While in the normal vasculature contractile smooth muscle cells are predominant, in atherosclerotic vascular lesions, synthetic cells migrate toward the neointima, proliferate, and synthetize extracellular matrix proteins. In the present study, we have examined the role of caveolin-3 in the regulation of smooth muscle cell phenotype. Caveolin-3 is expressed in vivo in normal arterial smooth muscle cells, but its expression appears to be lost in cultured smooth muscle cells. Our data show that caveolin-3 expression in the A7r5 smooth muscle cell line is associated with increased expression of contractility markers such as smooth muscle  actin, smooth muscle myosin heavy chain but decreased expression of the synthetic phenotype markers such as p-Elk and Klf4. Moreover, we also show that caveolin-3 expression can reduce proliferation upon treatment with LDL or PDGF. Finally, we show that caveolin-3-expressing smooth muscle cells are less sensitive to apoptosis than control cells upon treatment with oxidized LDL. Taken together, our data suggest that caveolin-3 can regulate the phenotypic switch between contractile and synthetic smooth muscle cells. A better understanding of the factors regulating caveolin-3 expression and function in this cell type will permit the development of a better comprehension of the factors regulating smooth muscle function in atherosclerosis and restenosis.

  19. A comparison of the contractile properties of myometrium from singleton and twin pregnancies.

    Directory of Open Access Journals (Sweden)

    Peter Turton

    Full Text Available OBJECTIVE: Over half of twin pregnancies in US and UK deliver prematurely but the reasons for this are unclear. The contractility of myometrium from twin pregnancies has not been directly investigated. The objective of this research was to determine if there are differences in the contractile activity and response to oxytocin, between myometrium from singleton and twin pregnancies, across a range of gestational ages. Furthermore, we wished to determine if contractile activity correlates with increasing level of stretch, using neonatal birth weights as a marker of uterine stretch. METHODS: This was an in vitro, laboratory based study of myometrial contractility in women pregnant with one or two babies, using biopsies obtained from non-labouring women undergoing Caesarean section. Spontaneous, oxytocin-stimulated and depolarization induced contractile activity was compared. RESULTS: Direct measurements of myometrial contractility under controlled conditions show that the frequency of contractions and responses to oxytocin are significantly increased in twins compared to singletons. The duration of contraction however was significantly reduced. We find that contractile activity correlates with increasing levels of stretch, using neonatal birth weights as a surrogate for uterine stretch, with response to oxytocin being significantly positively correlated with birth weight. CONCLUSIONS: We have found significant differences in contractile properties between myometrium from singleton and twin pregnancies and that increasing uterine stretch can alter the contractile properties of myometrium. We discuss the implication of these findings to preterm delivery and future studies.

  20. Multiple mechanisms involved in oxytocin-induced modulation of myometrial contractility

    Institute of Scientific and Technical Information of China (English)

    Anatoly SHMYGOL; Joanna GULLAM; Andrew BLANKS; Steven THORNTON

    2006-01-01

    Oxytocin is a small peptide hormone with multiple sites of action in human body.It regulates a large number of reproduction-related processes in all species.Particularly important is its ability to stimulate uterine contractility.This is achieved by multiple mechanisms involving sarcoplasmic reticulum Ca2+ release and sensitization of the contractile apparatus to Ca2+.In this paper,we review the data published by US and other groups on oxytocin-induced modulation of uterine contractility.We conclude that sensitization of contractile apparatus to Ca2+ is the most relevant physiological effect of oxytocin on human myometrium.

  1. Human Engineered Heart Tissue: Analysis of Contractile Force

    OpenAIRE

    Ingra Mannhardt; Kaja Breckwoldt; David Letuffe-Brenière; Sebastian Schaaf; Herbert Schulz; Christiane Neuber; Anika Benzin; Tessa Werner; Alexandra Eder; Thomas Schulze; Birgit Klampe; Torsten Christ; Marc N. Hirt; Norbert Huebner; Alessandra Moretti1

    2016-01-01

    Analyzing contractile force, the most important and best understood function of cardiomyocytes in vivo is not established in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). This study describes the generation of 3D, strip-format, force-generating engineered heart tissues (EHT) from hiPSC-CM and their physiological and pharmacological properties. CM were differentiated from hiPSC by a growth factor-based three-stage protocol. EHTs were generated and analyzed histological...

  2. Human Engineered Heart Tissue: Analysis of Contractile Force

    Directory of Open Access Journals (Sweden)

    Ingra Mannhardt

    2016-07-01

    Full Text Available Analyzing contractile force, the most important and best understood function of cardiomyocytes in vivo is not established in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM. This study describes the generation of 3D, strip-format, force-generating engineered heart tissues (EHT from hiPSC-CM and their physiological and pharmacological properties. CM were differentiated from hiPSC by a growth factor-based three-stage protocol. EHTs were generated and analyzed histologically and functionally. HiPSC-CM in EHTs showed well-developed sarcomeric organization and alignment, and frequent mitochondria. Systematic contractility analysis (26 concentration-response curves reveals that EHTs replicated canonical response to physiological and pharmacological regulators of inotropy, membrane- and calcium-clock mediators of pacemaking, modulators of ion-channel currents, and proarrhythmic compounds with unprecedented precision. The analysis demonstrates a high degree of similarity between hiPSC-CM in EHT format and native human heart tissue, indicating that human EHTs are useful for preclinical drug testing and disease modeling.

  3. Influence of the cardiac myosin hinge region on contractile activity.

    Science.gov (United States)

    Margossian, S S; Krueger, J W; Sellers, J R; Cuda, G; Caulfield, J B; Norton, P; Slayter, H S

    1991-06-01

    The participation of cardiac myosin hinge in contractility was investigated by in vitro motility and ATPase assays and by measurements of sarcomere shortening. The effect on contractile activity was analyzed using an antibody directed against a 20-amino acid peptide within the hinge region of myosin. This antibody bound specifically at the hinge at a distance of 55 nm from the S1/S2 junction, was specific to human, dog, and rat cardiac myosins, did not crossreact with gizzard or skeletal myosin, and had no effect on ATPase activity of purified S1 and myofibrils. However, it completely suppressed the movement of actin filaments in in vitro motility assays and reduced active shortening of sarcomeres of skinned cardiac myocytes by half. Suppression of motion by the anti-hinge antibody may reflect a mechanical constraint imposed by the antibody upon the mobility of the S2 region of myosin. The results suggest that the steps in the mechanochemical energy transduction can be separately influenced through S2.

  4. Human Engineered Heart Tissue: Analysis of Contractile Force.

    Science.gov (United States)

    Mannhardt, Ingra; Breckwoldt, Kaja; Letuffe-Brenière, David; Schaaf, Sebastian; Schulz, Herbert; Neuber, Christiane; Benzin, Anika; Werner, Tessa; Eder, Alexandra; Schulze, Thomas; Klampe, Birgit; Christ, Torsten; Hirt, Marc N; Huebner, Norbert; Moretti, Alessandra; Eschenhagen, Thomas; Hansen, Arne

    2016-07-12

    Analyzing contractile force, the most important and best understood function of cardiomyocytes in vivo is not established in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). This study describes the generation of 3D, strip-format, force-generating engineered heart tissues (EHT) from hiPSC-CM and their physiological and pharmacological properties. CM were differentiated from hiPSC by a growth factor-based three-stage protocol. EHTs were generated and analyzed histologically and functionally. HiPSC-CM in EHTs showed well-developed sarcomeric organization and alignment, and frequent mitochondria. Systematic contractility analysis (26 concentration-response curves) reveals that EHTs replicated canonical response to physiological and pharmacological regulators of inotropy, membrane- and calcium-clock mediators of pacemaking, modulators of ion-channel currents, and proarrhythmic compounds with unprecedented precision. The analysis demonstrates a high degree of similarity between hiPSC-CM in EHT format and native human heart tissue, indicating that human EHTs are useful for preclinical drug testing and disease modeling. PMID:27211213

  5. Resolving the role of actoymyosin contractility in cell microrheology.

    Directory of Open Access Journals (Sweden)

    Christopher M Hale

    Full Text Available Einstein's original description of Brownian motion established a direct relationship between thermally-excited random forces and the transport properties of a submicron particle in a viscous liquid. Recent work based on reconstituted actin filament networks suggests that nonthermal forces driven by the motor protein myosin II can induce large non-equilibrium fluctuations that dominate the motion of particles in cytoskeletal networks. Here, using high-resolution particle tracking, we find that thermal forces, not myosin-induced fluctuating forces, drive the motion of submicron particles embedded in the cytoskeleton of living cells. These results resolve the roles of myosin II and contractile actomyosin structures in the motion of nanoparticles lodged in the cytoplasm, reveal the biphasic mechanical architecture of adherent cells-stiff contractile stress fibers interdigitating in a network at the cell cortex and a soft actin meshwork in the body of the cell, validate the method of particle tracking-microrheology, and reconcile seemingly disparate atomic force microscopy (AFM and particle-tracking microrheology measurements of living cells.

  6. Mechanisms underlying the impaired contractility of diabetic cardiomyopathy

    Institute of Scientific and Technical Information of China (English)

    Marie-Louise; Ward; David; J; Crossman

    2014-01-01

    Cardiac dysfunction is a well-known consequence of diabetes,with sustained hyperglycaemia leading to the development of a cardiomyopathy that is independent of cardiovascular disease or hypertension.Animal models of diabetes are commonly used to study the pathophysiology of diabetic cardiomyopathy,with the hope that increased knowledge will lead ultimately to better therapeutic strategies being developed.At physiological temperature,left ventricular trabeculae isolated from the streptozotocin rat model of type 1 diabetes showed decreased stress and prolonged relaxation,but with no evidence that decreased contractility was a result of altered myocardial Ca2+handling.Although sarcoplasmic reticulum(SR)Ca2+reuptake appeared slower in diabetic trabeculae,it was offset by an increase in actionpotential duration,thereby maintaining SR Ca2+content and favouring increased contraction force.Frequency analysis of t-tubule distribution by confocal imaging of ventricular tissue labeled with wheat germ agglutinin or ryanodine receptor antibodies showed a reduced T-power for diabetic tissue,but the differences were minor in comparison to other models of heart failure.The contractile dysfunction appeared to be the result of disrupted F-actin in conjunction with the increased typeⅠcollagen,with decreased myofilament Ca2+sensitivity contributing to the slowed relaxation.

  7. Effects of lengthening contraction on calcium kinetics and skeletal muscle contractility in humans

    DEFF Research Database (Denmark)

    Nielsen, J S; Madsen, K; Jørgensen, L V;

    2005-01-01

    We have tested the hypothesis that the altered muscle contractility after lengthening contractions (LC) is caused by altered calcium (Ca2+) kinetics.......We have tested the hypothesis that the altered muscle contractility after lengthening contractions (LC) is caused by altered calcium (Ca2+) kinetics....

  8. Contractility of the guinea pig bladder measured in situ and in vitro

    NARCIS (Netherlands)

    J.M. Groen (Jan); R. van Mastrigt (Ron); J.L.H.R. Bosch (Ruud)

    1994-01-01

    textabstractTo study the relative importance of neurogenic factors in detrusor contractility and to relate a total bladder in vitro contractility model to a previously described bladder wall strip model, active intravesical pressure values were compared in situ and in vitro in eight male guinea pigs

  9. Image Processing Techniques for Assessing Contractility in Isolated Neonatal Cardiac Myocytes

    Directory of Open Access Journals (Sweden)

    Carlos Bazan

    2011-01-01

    employed in determining myocyte contractility almost simultaneously with the acquisition of the Ca2+ transient and other correlates of cell contraction. The proposed methodology can be utilized to evaluate changes in contractile behavior resulting from drug intervention, disease models, transgeneity, or other common applications of neonatal cardiocytes.

  10. Transient impairments in single muscle fibre contractile function after prolonged cycling in elite endurance athletes

    DEFF Research Database (Denmark)

    Hvid, L G; Gejl, Kasper Degn; Bech, R D;

    2013-01-01

    Prolonged muscle activity impairs whole-muscle performance and function. However, little is known about the effects of prolonged muscle activity on the contractile function of human single muscle fibres. The purpose of this study was to investigate the effects of prolonged exercise and subsequent...... recovery on the contractile function of single muscle fibres obtained from elite athletes....

  11. Effects of ageing on single muscle fibre contractile function following short-term immobilisation

    DEFF Research Database (Denmark)

    Hvid, Lars G; Ortenblad, Niels; Aagaard, Per;

    2011-01-01

    Very little attention has been given to the combined effects of healthy ageing and short-term disuse on the contractile function of human single muscle fibres. Therefore, the present study investigated the effects of 2 weeks of lower limb cast immobilisation (i.e. disuse) on selected contractile...

  12. Effect of contractile protein alterations on cardiac myofilament function in human heart failure

    NARCIS (Netherlands)

    Narolska, N.A.

    2006-01-01

    The main objective of this thesis was to elucidate the effect of translational and post-translational alterations in contractile proteins occurring during heart failure on contractile function in human cardiac tissue. Isometric force and ATPase activity measurements were performed in skinned human

  13. Capacidade funcional, morbidades e qualidade de vida de idosos

    Directory of Open Access Journals (Sweden)

    Darlene Mara dos Santos Tavares

    2012-01-01

    Full Text Available La investigación tiene como objetivo describir el perfil demográfico, la capacidad funcional y la morbilidad de los ancianos, y verificar la calidad de vida relacionado con el número de incapacidad funcional y la morbilidad. Estudio transversal analítico llevado a cabo con 2.142 personas mayores. Los datos fueron recolectados en el hogar con un instrumento estructurado. El análisis se realizó distribución de frecuencias, F-test de ANOVA y Bonferroni (p<0,05. La mayoría eran mujeres, años, casado, años de escolaridad y los ingresos de un salario mínimo. Predominaron los adultos mayores discapacidades funcionales relacionadas con la movilidad y morbilidad, los problemas de visión más frecuente y la columna vertebral y la hipertensión. Las puntuaciones más altas de calidad de vida para las relaciones sociales y el funcionamiento de los sentidos y el más bajo para su desarrollo físico y la autonomía. El mayor número de incapacidad funcional y la morbilidad asociadas con bajas puntuaciones en la calidad de vida.

  14. Relationships of thigh muscle contractile and non-contractile tissue with function, strength, and age in boys with Duchenne muscular dystrophy.

    Science.gov (United States)

    Akima, Hiroshi; Lott, Donovan; Senesac, Claudia; Deol, Jasjit; Germain, Sean; Arpan, Ishu; Bendixen, Roxanna; Lee Sweeney, H; Walter, Glenn; Vandenborne, Krista

    2012-01-01

    The purpose of this study was to assess the contractile and non-contractile content in thigh muscles of patients with Duchenne muscular dystrophy (DMD) and determine the relationship with functional abilities. Magnetic resonance images of the thigh were acquired in 28 boys with DMD and 10 unaffected boys. Muscle strength, timed functional tests, and the Brookes Lower Extremity scale were also assessed. Non-contractile content in the DMD group was significantly greater than in the control group for six muscles, including rectus femoris, biceps femoris-long head and adductor magnus. Non-contractile content in the total thigh musculature assessed by MRI correlated with the Brookes scale (r(s)=0.75) and supine-up test (r(s)=0.68), as well as other functional measures. An age-related specific torque increase was observed in the control group (r(s)=0.96), but not the DMD (r(s)=0.06). These findings demonstrate that MRI measures of contractile and non-contractile content can provide important information about disease progression in DMD. PMID:21807516

  15. Detecting cardiac contractile activity in the early mouse embryo using multiple modalities

    Directory of Open Access Journals (Sweden)

    Chiann-mun eChen

    2015-01-01

    Full Text Available The heart is one of the first organs to develop during mammalian embryogenesis. In the mouse, it starts to form shortly after gastrulation, and is derived primarily from embryonic mesoderm. The embryonic heart is unique in having to perform a mechanical contractile function while undergoing complex morphogenetic remodelling. Approaches to imaging the morphogenesis and contractile activity of the developing heart are important in understanding not only how this remodelling is controlled but also the origin of congenital heart defects. Here, we describe approaches for visualising contractile activity in the developing mouse embryo, using brightfield time lapse microscopy and confocal microscopy of calcium transients. We describe an algorithm for enhancing this image data and quantifying contractile activity from it. Finally we describe how atomic force microscopy can be used to record contractile activity prior to it being microscopically visible.

  16. Procedures for rat in situ skeletal muscle contractile properties.

    Science.gov (United States)

    MacIntosh, Brian R; Esau, Shane P; Holash, R John; Fletcher, Jared R

    2011-01-01

    There are many circumstances where it is desirable to obtain the contractile response of skeletal muscle under physiological circumstances: normal circulation, intact whole muscle, at body temperature. This includes the study of contractile responses like posttetanic potentiation, staircase and fatigue. Furthermore, the consequences of disease, disuse, injury, training and drug treatment can be of interest. This video demonstrates appropriate procedures to set up and use this valuable muscle preparation. To set up this preparation, the animal must be anesthetized, and the medial gastrocnemius muscle is surgically isolated, with the origin intact. Care must be taken to maintain the blood and nerve supplies. A long section of the sciatic nerve is cleared of connective tissue, and severed proximally. All branches of the distal stump that do not innervate the medial gastrocnemius muscle are severed. The distal nerve stump is inserted into a cuff lined with stainless steel stimulating wires. The calcaneus is severed, leaving a small piece of bone still attached to the Achilles tendon. Sonometric crystals and/or electrodes for electromyography can be inserted. Immobilization by metal probes in the femur and tibia prevents movement of the muscle origin. The Achilles tendon is attached to the force transducer and the loosened skin is pulled up at the sides to form a container that is filled with warmed paraffin oil. The oil distributes heat evenly and minimizes evaporative heat loss. A heat lamp is directed on the muscle, and the muscle and rat are allowed to warm up to 37°C. While it is warming, maximal voltage and optimal length can be determined. These are important initial conditions for any experiment on intact whole muscle. The experiment may include determination of standard contractile properties, like the force-frequency relationship, force-length relationship, and force-velocity relationship. With care in surgical isolation, immobilization of the origin of the

  17. The benefit of enhanced contractility in the infarct borderzone: A virtual experiment.

    Directory of Open Access Journals (Sweden)

    Zhihong eZhang

    2012-04-01

    Full Text Available A. Objectives Contractile function in the normally perfused infarct borderzone (BZ is depressed. However, the impact of reduced BZ contractility on left ventricular (LV pump function is unknown. As a consequence, there have been no therapies specifically designed to improve BZ contractility. We tested the hypothesis that an improvement in borderzone contractility will improve LV pump function.B. Methods From a previously reported study, magnetic resonance (MRI images with non-invasive tags were used to calculate 3D myocardial strain in five sheep 16 weeks after anteroapical myocardial infarction. Animal specific finite element (FE models were created using MRI data and LV pressure obtained at early diastolic filling. Analysis of borderzone function using those FE models has been previously reported. Chamber stiffness, pump function (Starling’s law and stress in the fiber, cross fiber and circumferential directions were calculated. Animal-specific FE models were performed for three cases: a impaired BZ contractility (INJURED; b BZ contractility fully restored (100% BZ IMPROVEMENT; or c BZ contractility partially restored (50% BZ IMPROVEMENT.C. Results 100% BZ IMPROVEMENT and 50% BZ IMPROVEMENT both caused an upward shift in the Starling relationship, resulting in a large (36% and 26% increase in stroke volume at LVPED = 20 mm Hg (8.0 ml, p<0.001. Moreover, there were a leftward shift in the end systolic pressure volume relationship, resulting in a 7% and 5% increase in LVPES at 110 mm Hg (7.7 ml, p<0.005. It showed that even 50% BZ IMPROVEMENT was sufficient to drive much of the calculated increase in function. D. Conclusions. Improved borderzone contractility has a beneficial effect on LV pump function. Partial improvement of borderzone contractility was sufficient to drive much of the calculated increase in function. Therapies specifically designed to improve borderzone contractility should be developed.

  18. La capacidad administrativa del gobierno del Distrito Federal y el cambio climático

    OpenAIRE

    Angélica Rosas Huerta

    2011-01-01

    En este momento existen varios gobiernos centrales y locales que están impulsando acciones orientadas a atender el cambio climático, sin embargo, los resultados pueden ser afectados, entre otros aspectos, por su propia capacidad institucional. En este sentido, el presente artículo busca analizar la capacidad institucional que el gobierno del Distrito Federal (DF) está construyendo para atender el cambio climático, a través de uno de sus componentes, la capacidad administrativa.

  19. Altas Capacidades en Educación Infantil en Guipúzcoa

    OpenAIRE

    Omaetxebarria-Aldarono, Ainara

    2013-01-01

    El trabajo fin de grado que se presenta a continuación aporta información acerca de las altas capacidades en Educación Infantil y su relación con las inteligencias múltiples. Se propone una perspectiva de la realidad actual del tema en el contexto de la provincia de Guipúzcoa. Las altas capacidades se proponen aludiendo a varios aspectos, entre ellos, se define el término, se aportan características de los alumnos con altas capacidades, se señalan alternativas de intervención en las aulas y s...

  20. Qual o melhor período para a realização do doppler das artérias uterinas na predição de complicações da gestação? Which is the best period to perform uterine artery Doppler in the prediction of pregnancy complications?

    OpenAIRE

    Fabrício da Silva Costa; Sérgio Pereira da Cunha; Aderson Tadeu Berezowski

    2006-01-01

    OBJETIVO: Avaliar, prospectivamente, qual o melhor período para a realização do Doppler das artérias uterinas na predição de complicações da gestação. MATERIAIS E MÉTODOS: Foi conduzido estudo prospectivo em 45 pacientes primigestas, sem história de doenças crônicas. O Doppler das artérias uterinas foi realizado entre 18-20, 24-26, 28-30 e 34-36 semanas, com determinação do índice de resistência, índice de pulsatilidade, relação A/B e a presença ou ausência de incisura na onda de velocidade d...

  1. Contractile reaction of isolated frog aorta after X-irradiation

    International Nuclear Information System (INIS)

    The action of X-rays (50 kV, filtered by 0.3 mm Al) on helical strip of frog aorta (rana esculenta) has been investigated. The isolated preparations have a stable basal tone and are radio-sensitive to X-rays which induce reversible, dose-dependent, contractile responses. After repeated irradiational tachyphylaxis appears. The threshold doses are about 250 R at 3 to 6 kR/min, antiadrenergic (phentolamine, propranolol), anticholinergic (atropin), antihistaminic (Neo-Bridal) and serotoninergic (Deseril) drugs have no visible influence on the X-ray induced reaction, i.e. these action mechanisms of the irradiation-induced contraction do not seem probable. Theophylline and cAMP inhibit the X-ray contraction probably non-specifically. Indometacin also inhibits the X-ray contraction: this suggests participation of prostaglandin-mechanism on the contraction of frog aorta after irradiation. (orig.)

  2. High-throughput screening for modulators of cellular contractile force

    CERN Document Server

    Park, Chan Young; Tambe, Dhananjay; Chen, Bohao; Lavoie, Tera; Dowell, Maria; Simeonov, Anton; Maloney, David J; Marinkovic, Aleksandar; Tschumperlin, Daniel J; Burger, Stephanie; Frykenberg, Matthew; Butler, James P; Stamer, W Daniel; Johnson, Mark; Solway, Julian; Fredberg, Jeffrey J; Krishnan, Ramaswamy

    2014-01-01

    When cellular contractile forces are central to pathophysiology, these forces comprise a logical target of therapy. Nevertheless, existing high-throughput screens are limited to upstream signaling intermediates with poorly defined relationship to such a physiological endpoint. Using cellular force as the target, here we screened libraries to identify novel drug candidates in the case of human airway smooth muscle cells in the context of asthma, and also in the case of Schlemm's canal endothelial cells in the context of glaucoma. This approach identified several drug candidates for both asthma and glaucoma. We attained rates of 1000 compounds per screening day, thus establishing a force-based cellular platform for high-throughput drug discovery.

  3. Cardiac contractility, central haemodynamics and blood pressure regulation during semistarvation

    DEFF Research Database (Denmark)

    Stokholm, K H; Breum, L; Astrup, A

    1991-01-01

    pressure (BP) declined. The fall in BP was caused by the reduction in cardiac output as the total peripheral resistance was unchanged. Finally, the decline in total blood volume was not significant. These findings together with a reduction in heart rate indicated that a reduced sympathetic tone via......Eight obese patients were studied before and after 2 weeks of treatment by a very-low-calorie diet (VLCD). Cardiac output and central blood volume (pulmonary blood volume and left atrial volume) were determined by indicator dilution (125I-albumin) and radionuclide angiocardiography (first pass...... and equilibrium technique by [99Tcm]red blood cells). Cardiac output decreased concomitantly with the reduction in oxygen uptake as the calculated systemic arteriovenous difference of oxygen was unaltered. There were no significant decreases in left ventricular contractility indices, i.e. the ejection fraction...

  4. Contractile 5-HT1B receptors in human cerebral arteries

    DEFF Research Database (Denmark)

    Nilsson, T; Longmore, J; Shaw, D;

    1999-01-01

    immunocytochemistry with antibodies selective for human 5-HT1B and human 5-HT1D receptors and also studied the contractile effects of a range of 5-HT receptor agonists and antagonists in HCA. 2 Immunocytochemistry of cerebral arteries showed dense 5-HT1B receptor immunoreactivity (but no 5-HT1D receptor......1 The cerebrovascular receptor(s) that mediates 5-hydroxytryptamine (5-HT)-induced vasoconstriction in human cerebral arteries (HCA)has proven difficult to characterize, yet these are essential in migraine. We have examined 5-HT receptor subtype distribution in cerebral blood vessels by...... immunoreactivity) within the smooth muscle wall of the HCA. The endothelial cell layer was well preserved and weak 5-HT1B receptor immunoreactivity was present. 3 Pharmacological experiments on HCA with intact endothelium showed that 5-carboxamidotryptamine was significantly more potent than alpha-methyl-5-HT, 2...

  5. Electrically contractile polymers augment right ventricular output in the heart.

    Science.gov (United States)

    Ruhparwar, Arjang; Piontek, Patricia; Ungerer, Matthias; Ghodsizad, Ali; Partovi, Sasan; Foroughi, Javad; Szabo, Gabor; Farag, Mina; Karck, Matthias; Spinks, Geoffrey M; Kim, Seon Jeong

    2014-12-01

    Research into the development of artificial heart muscle has been limited to assembly of stem cell-derived cardiomyocytes seeded around a matrix, while nonbiological approaches to tissue engineering have rarely been explored. The aim of the study was to apply electrically contractile polymer-based actuators as cardiomyoplasty for positive inotropic support of the right ventricle. Complex trilayer polypyrrole (PPy) bending polymers for high-speed applications were generated. Bending motion occurred directly as a result of electrochemically driven charging and discharging of the PPy layers. In a rat model (n = 5), strips of polymers (3 × 20 mm) were attached and wrapped around the right ventricle (RV). RV pressure was continuously monitored invasively by direct RV cannulation. Electrical activation occurred simultaneously with either diastole (in order to evaluate the polymer's stand-alone contraction capacity; group 1) or systole (group 2). In group 1, the pressure generation capacity of the polymers was measured by determining the area under the pressure curve (area under curve, AUC). In group 2, the RV pressure AUC was measured in complexes directly preceding those with polymer contraction and compared to RV pressure complexes with simultaneous polymer contraction. In group 1, the AUC generated by polymer contraction was 2768 ± 875 U. In group 2, concomitant polymer contraction significantly increased AUC compared with complexes without polymer support (5987 ± 1334 U vs. 4318 ± 691 U, P ≤ 0.01). Electrically contractile polymers are able to significantly augment right ventricular contraction. This approach may open new perspectives for myocardial tissue engineering, possibly in combination with fetal or embryonic stem cell-derived cardiomyocytes.

  6. Dynamic regulation of β1 subunit trafficking controls vascular contractility

    Science.gov (United States)

    Leo, M. Dennis; Bannister, John P.; Narayanan, Damodaran; Nair, Anitha; Grubbs, Jordan E.; Gabrick, Kyle S.; Boop, Frederick A.; Jaggar, Jonathan H.

    2014-01-01

    Ion channels composed of pore-forming and auxiliary subunits control physiological functions in virtually all cell types. A conventional view is that channels assemble with their auxiliary subunits before anterograde plasma membrane trafficking of the protein complex. Whether the multisubunit composition of surface channels is fixed following protein synthesis or flexible and open to acute and, potentially, rapid modulation to control activity and cellular excitability is unclear. Arterial smooth muscle cells (myocytes) express large-conductance Ca2+-activated potassium (BK) channel α and auxiliary β1 subunits that are functionally significant modulators of arterial contractility. Here, we show that native BKα subunits are primarily (∼95%) plasma membrane-localized in human and rat arterial myocytes. In contrast, only a small fraction (∼10%) of total β1 subunits are located at the cell surface. Immunofluorescence resonance energy transfer microscopy demonstrated that intracellular β1 subunits are stored within Rab11A-postive recycling endosomes. Nitric oxide (NO), acting via cGMP-dependent protein kinase, and cAMP-dependent pathways stimulated rapid (≤1 min) anterograde trafficking of β1 subunit-containing recycling endosomes, which increased surface β1 almost threefold. These β1 subunits associated with surface-resident BKα proteins, elevating channel Ca2+ sensitivity and activity. Our data also show that rapid β1 subunit anterograde trafficking is the primary mechanism by which NO activates myocyte BK channels and induces vasodilation. In summary, we show that rapid β1 subunit surface trafficking controls functional BK channel activity in arterial myocytes and vascular contractility. Conceivably, regulated auxiliary subunit trafficking may control ion channel activity in a wide variety of cell types. PMID:24464482

  7. Nova pipeta para inseminação intra-uterina em suínos New pipette for intrauterine insemination in pigs

    Directory of Open Access Journals (Sweden)

    Gustavo Nogueira Diehl

    2006-02-01

    Full Text Available O objetivo deste trabalho foi avaliar o desempenho reprodutivo de 423 fêmeas suínas de ordem de parto 1 a 9 submetidas à inseminação intra-uterina (IAU, com um novo modelo de pipeta (T1 cuja extremidade não é fixada na cérvix ou uma pipeta de IAU modelo Verona® e que permite a fixação da sua extremidade em espiral na cérvix (T2. Para comparar as duas pipetas, foi considerado o grau de dificuldade para realização das inseminações, o tempo necessário para realizá-las, a presença de sangramento após a inseminação, a presença de refluxo no momento da inseminação, as taxas de retorno ao estro (TR, de prenhez (TPR e de parto ajustada (TPA, além do número de leitões nascidos (NT. As fêmeas de ambos os grupos foram inseminadas com doses de 1 bilhão de espermatozóides, em intervalos de 24 horas. A passagem do cateter de IAU através da cérvix foi possível em 95,9% das fêmeas, sem diferença entre os tratamentos (P>0,05. Em pelo menos uma das inseminações, foi observado sangue no cateter, após a realização da IAU, em 20,6% das fêmeas do T1 e 15,2% das fêmeas do T2 (P=0,14. O tempo médio necessário para realizar a inseminação foi de 2,1 minutos para o T1 e 2,3 minutos para o T2 (P=0,26. O percentual de fêmeas com refluxo de sêmen no momento da inseminação foi maior (P=0,01 no T1 (8,4% em comparação ao T2 (2,9%. Não houve diferença (P>0,05 nas variáveis TR (8,0 e 4,8%, TPR (93,4 e 96,2% e NT (12,4 e 12,7 leitões entre T1 e T2, respectivamente. A TPA do T1 (90,6% apresentou tendência (P=0,07 de ser inferior à do T2 (95,1%. No T1, as fêmeas primíparas apresentaram maior TR e menor TPA em comparação às pluríparas (PThe aim of this work was to evaluate the reproductive performance of 423 sows of 1 to 9 farrowings inseminated with two different intrauterine artificial insemination (IAU pipettes. The first group (T1 was formed by sows inseminated with a new pipette whose extremity was not fixed in the

  8. Malformação arteriovenosa uterina após doença trofoblástica gestacional Uterine arteriovenous malformation after gestational trophoblastic disease

    Directory of Open Access Journals (Sweden)

    Paulo Belfort

    2006-02-01

    Full Text Available OBJETIVO: investigar a presença e resultados de malformações vasculares uterinas (MAVU após doença trofoblástica gestacional (DTG. MÉTODOS: estudo retrospectivo com inclusão de casos diagnosticados entre 1987 e 2004; 2764 pacientes após DTG foram acompanhadas anualmente com ultra-sonografia transvaginal e Doppler colorido no Centro de Neoplasia Trofoblástica Gestacional da Santa Casa da Misericórdia (Rio de Janeiro, RJ, Brasil. Sete pacientes tiveram diagnóstico final de MAVU baseado em análise ultra-sonográfica - índice de pulsatilidade (IP, índice de resistência (IR e velocidade sistólica máxima (VSM - e achados de imagens de ressonância nuclear magnética (RNM. Dosagens negativas de beta-hCG foram decisivas para estabelecer o diagnóstico diferencial com DTG recidivante. RESULTADOS: a incidência de MAVU após DTG foi 0,2% (7/2764. Achados ultra-sonográficos de MAVU: IP médio de 0,44±0,058 (extremos: 0,38-0,52; IR médio de 0,36±0,072 (extremos: 0,29-0,50; VSM média de 64,6±23,99 cm/s (extremos: 37-96. A imagem de RNM revelou útero aumentado, miométrio heterogêneo, espaços vasculares tortuosos e vasos parametriais com ectasia. A apresentação clínica mais comum foi hemorragia transvaginal, presente em 52,7% (4/7 dos casos. Tratamento farmacológico com 150 mg de acetato de medroxiprogesterona foi empregado para controlar a hemorragia, após a estabilização hemodinâmica. Permanecem as pacientes em seguimento, assintomáticas até hoje. Duas pacientes engravidaram com MAVU, com gestações e partos exitosos. CONCLUSÃO: presente sangramento transvaginal em pacientes com beta-hCG negativo e história de DTG, deve-se considerar a possibilidade de MAVU e solicitar avaliação ultra-sonográfica com dopplervelocimetria. O tratamento conservador é a melhor opção na maioria dos casos de MAVU pós-DTG.PURPOSE: to investigate the presence and outcome of uterinevascular malformations (UVAM after gestational

  9. Chronic Contractile Dysfunction without Hypertrophy Does Not Provoke a Compensatory Transcriptional Response in Mouse Hearts.

    Directory of Open Access Journals (Sweden)

    Scot J Matkovich

    Full Text Available Diseased myocardium from humans and experimental animal models shows heightened expression and activity of a specific subtype of phospholipase C (PLC, the splice variant PLCβ1b. Previous studies from our group showed that increasing PLCβ1b expression in adult mouse hearts by viral transduction was sufficient to cause sustained contractile dysfunction of rapid onset, which was maintained indefinitely in the absence of other pathological changes in the myocardium. We hypothesized that impaired contractility alone would be sufficient to induce a compensatory transcriptional response. Unbiased, comprehensive mRNA-sequencing was performed on 6 biological replicates of rAAV6-treated blank, PLCβ1b and PLCβ1a (closely related but inactive splice variant hearts 8 weeks after injection, when reduced contractility was manifest in PLCβ1b hearts without evidence of induced hypertrophy. Expression of PLCβ1b resulted in expression changes in only 9 genes at FDR<0.1 when compared with control and these genes appeared unrelated to contractility. Importantly, PLCβ1a caused similar mild expression changes to PLCβ1b, despite a complete lack of effect of this isoform on cardiac contractility. We conclude that contractile depression caused by PLCβ1b activation is largely independent of changes in the transcriptome, and thus that lowered contractility is not sufficient in itself to provoke measurable transcriptomic alterations. In addition, our data stress the importance of a stringent control group to filter out transcriptional changes unrelated to cardiac function.

  10. CAPACIDAD DE AGENCIA DE AUTOCUIDADO EN LAS PERSONAS ADULTAS QUE PADECEN ARTRITIS REUMATOIDE

    Directory of Open Access Journals (Sweden)

    Viriam Leiva Díaz

    2012-04-01

    Full Text Available El objetivo de la investigación consistió en analizar la capacidad de agencia de autocuidado que poseen laspersonas con diagnóstico de artritis reumatoide, quienes habitan en los cantones de Palmares y San Ramón. Se desarrolló una metodología de investigación cuantitativa de tipo descriptiva transversal. En cuanto a la población participante del estudio, estuvo conformada por 13 personas diagnosticadas con artritis reumatoide; respecto de los instrumentos utilizados para recolectar información, a los colaboradores se les aplicó el instrumento “Escala de apreciación de la capacidad de agencia de autocuidado”, propuesta por Dorothea Orem. Se determinó que los participantes poseen alta capacidad de agencia de autocuidado en las diferentes categorías, ya que únicamente se detectó baja capacidad de agencia de autocuidado en cuanto a interacción social (2 personas, y respecto del consumo insuficiente de alimentos (5 personas. La escala ASA permite a la Enfermera (o determinar la capacidad de agencia de autocuidado, de forma oportuna y eficaz. Además, permitió a las investigadoras observar un panorama general de las necesidades de autocuidado de la población participante y constatar que esta presenta alta capacidad de agencia de autocuidado.

  11. Estudo dopplerfluxométrico das artérias uterinas antes e após inserção do DIU Color doppler flow analysis of the uterine arteries before and after DIU insertion

    Directory of Open Access Journals (Sweden)

    Marco Aurélio Martins de Souza

    2004-06-01

    Full Text Available OBJETIVO: averiguar se ocorrem alterações nos parâmetros da dopplervelocimetria em usuárias do dispositivo intra-uterino (DIU T cobre 380, por meio do estudo das artérias uterinas antes e depois da inserção do DIU em mulheres lactantes e não lactantes. MÉTODOS: ensaio clínico prospectivo, analítico, com 100 pacientes, em que avaliamos à dopplervelocimetria: índice de resistência (IR, índice de pulsatilidade (IP e relação sístole/diástole (SD. As pacientes selecionadas foram submetidas à avaliação pré-inserção do DIU e a novos exames pós-inserção, realizados com 30 dias (um ciclo e com 90 dias (três ciclos. RESULTADOS: os valores obtidos nas artérias uterinas no grupo antes da inserção do DIU foram de 0,9 para o IR, de 2,4 para o IP e de 10,0 para a relação SD. Os valores 30 dias após a inserção do DIU foram de 0,9 para o IR, de 2,5 para o IP e de 10,7 para a relação SD. Após três ciclos aferimos um valor de 0,9 para o IR, de 2,5 para o IP e de 10,7 para a relação SD. A comparação dos resultados obtidos antes e depois da inserção do DIU mostrou valor p de 0,51 para o IR, de 0,37 para o IP e de 0,51 para a relação SD, demonstrando que após a inserção, não houve modificações significativas na dopplervelocimetria. CONCLUSÕES: o uso do DIU T cobre 380 não tem efeito nos índices de dopplervelocimetria das artérias uterinas tanto em pacientes amamentando ou não.OBJECTIVE: to observe if there is any alteration in the Dopplervelocimetry of the uterine arteries of nursing and not nursing women after the insertion of the copper T 380 intrauterine device (IUD. METHODS: prospective, analytical, self-paired clinical assay, with 100 patients in whom we evaluated the color doppler flow: resistance index (RI, pulsative index (PI and systole/diastole (SD ratio. Nursing and not nursing women were assessed before IUD insertion as well as 30 days (one cycle and 90 days (three cycles after the insertion

  12. Contractile responses to ergotamine and dihydroergotamine in the perfused middle cerebral artery of rat

    DEFF Research Database (Denmark)

    Tfelt-Hansen, Peer; Nilsson, Elisabeth; Edvinsson, Lars

    2007-01-01

    mmHg and luminally perfused. All vessels used attained spontaneous contractile tone (34.9+/-1.8% of resting tone) and responded to luminal adenosine triphosphate (ATP) with dilatation (24.1+/-4.0%), which showed functioning endothelium. Luminally added ergotamine or DHE induced maximal contractions...... no significant effect. Using a myograph technique, isolated ring segments of the MCA with intact endothelium were mounted on two metal wires. Neither agonist caused relaxation of resting vessels, however, they both responded by weak contractile responses (26+/-3% of submaximal contractile capacity relative to 60...

  13. Adipose-derived stem cells inhibit the contractile myofibroblast in Dupuytren's disease.

    NARCIS (Netherlands)

    Verhoekx, J.S.; Mudera, V.; Walbeehm, E.T.; Hovius, S.E.

    2013-01-01

    BACKGROUND: In an attempt to provide minimally invasive treatment for Dupuytren's disease, percutaneous disruption of the affected tissue followed by lipografting is being tested. Contractile myofibroblasts drive this fibroproliferative disorder, whereas stem cells have recently been implicated in p

  14. Acidosis-induced p38 MAPK activation and its implication in regulation of cardiac contractility

    Institute of Scientific and Technical Information of China (English)

    Ming ZHENG; Rong HOU; Rui-ping XIAO

    2004-01-01

    AIM: To determine the possible role of pH in mediating activation of p38 mitogen-activated protein kinase (MAPK) and the consequent function of activated p38 MAPK in regulating cardiac contractility. METHODS: Adult rat cardiomyocytes were isolated and cultured. Low pH media was used to induce intracellular acidosis and contraction of single cardiomyocyte was measured. RESULTS: Phosphorylation of p38 MAPK was increased during ischemia, and pHi was decreased. Intracellular acidosis activated p38 MAPK to a similar level as ischemia. Inhibition of p38 MAPK activation by SB203580, a specific inhibitor of p38 MAPK, reversed acidosis-mediated reduction of myocyte contractility. CONCLUSION: In adult rat cardiomyocytes, intracellular acidification activated p38 MAPK and decreased cardiac contractility. Pretreatment of cardiomyocytes with SB203580 completely blocked p38 MAPK activation and partially reversed acidosis-mediated decline of cardiac contractility.

  15. Motor-free actin bundle contractility driven by molecular crowding

    CERN Document Server

    Schnauß, Jörg; Schuldt, Carsten; Schmidt, B U Sebastian; Glaser, Martin; Strehle, Dan; Heussinger, Claus; Käs, Josef A

    2015-01-01

    Modeling approaches of suspended, rod-like particles and recent experimental data have shown that depletion forces display different signatures depending on the orientation of these particles. It has been shown that axial attraction of two rods yields contractile forces of 0.1pN that are independent of the relative axial shift of the two rods. Here, we measured depletion-caused interactions of actin bundles extending the phase space of single pairs of rods to a multi-particle system. In contrast to a filament pair, we found forces up to 3pN . Upon bundle relaxation forces decayed exponentially with a mean decay time of 3.4s . These different dynamics are explained within the frame of a mathematical model by taking pairwise interactions to a multi-filament scale. The macromolecular content employed for our experiments is well below the crowding of cells. Thus, we propose that arising forces can contribute to biological force generation without the need to convert chemical energy into mechanical work.

  16. Phospholemman deficiency in postinfarct hearts: enhanced contractility but increased mortality.

    Science.gov (United States)

    Mirza, M Ayoub; Lane, Susan; Yang, Zequan; Karaoli, Themis; Akosah, Kwame; Hossack, John; McDuffie, Marcia; Wang, JuFang; Zhang, Xue-Qian; Song, Jianliang; Cheung, Joseph Y; Tucker, Amy L

    2012-06-01

    Phospholemman (PLM) regulates [Na(+) ](i), [Ca(2+)](i) and contractility through its interactions with Na(+)-K(+)-ATPase (NKA) and Na(+) /Ca(2+) exchanger (NCX1) in the heart. Both expression and phosphorylation of PLM are altered after myocardial infarction (MI) and heart failure. We tested the hypothesis that absence of PLM regulation of NKA and NCX1 in PLM-knockout (KO) mice is detrimental. Three weeks after MI, wild-type (WT) and PLM-KO hearts were similarly hypertrophied. PLM expression was lower but fractional phosphorylation was higher in WT-MI compared to WT-sham hearts. Left ventricular ejection fraction was severely depressed in WT-MI but significantly less depressed in PLM-KO-MI hearts despite similar infarct sizes. Compared with WT-sham myocytes, the abnormal [Ca(2+) ], transient and contraction amplitudes observed in WT-MI myocytes were ameliorated by genetic absence of PLM. In addition, NCX1 current was depressed in WT-MI but not in PLM-KO-MI myocytes. Despite improved myocardial and myocyte performance, PLM-KO mice demonstrated reduced survival after MI. Our findings indicate that alterations in PLM expression and phosphorylation are important adaptations post-MI, and that complete absence of PLM regulation of NKA and NCX1 is detrimental in post-MI animals.

  17. Contractile Force of Human Extraocular Muscle: A Theoretical Analysis

    Science.gov (United States)

    Guo, Hongmei; Gao, Zhipeng; Chen, Weiyi

    2016-01-01

    Aim. The length-contractile force relationships of six human extraocular muscles (EOMs) in primary innervations should be determined during eye movement modeling and surgery of clinical EOMs. This study aims to investigate these relationships. Method. The proposal is based on the assumption that six EOMs have similar constitutive relationships, with the eye suspended in the primary position. The constitutive relationships of EOMs are obtained by optimizing from previous experimental data and the theory of mechanical equilibrium using traditional model. Further, simulate the existing experiment of resistance force, and then compare the simulated results with the existing experimental results. Finally, the mechanical constitutive relationships of EOMs are obtained. Results. The results show that the simulated resistance forces from the other four EOMs except for the horizontal recti well agree with previous experimental results. Conclusion. The mechanical constitutive relationships of six EOMs in primary innervations are obtained, and the rationality of the constitutive relationships is verified. Whereafter, the active stress-strain relationships of the six EOMs in the primary innervations are obtained. The research results can improve the eye movement model to predict the surgical amounts of EOMs before EOM surgery more precisely. PMID:27087774

  18. Considerations for Contractile Electroactive Polymeric Materials and Actuators

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Lenore; Erickson, Carl J.; Meixler, Lewis D.; Ascione, George; Gentile, Charles A.; Tilson, Charles; Bernasek, Stephen L.; Abelev, Esta

    2009-06-16

    Ras Labs produces electroactive polymer (EAP) based materials and actuators that bend, swell, ripple and now contract (new development) with low electric input. This is an important attribute because of the ability of contraction to produce life-like motion. The mechanism of contraction is not well understood. Radionuclide-labeled experiments were conducted to follow the movement of electrolytes and water in these EAPs when activated. Extreme temperature experiments were performed on the contractile EAPs with very favorable results. One of the biggest challenges in developing these actuators, however, is the electrode-EAP interface because of the pronounced movement of the EAP. Plasma treatments of metallic electrodes were investigated in order to improve the attachment of the embedded electrodes to the EAP material. Surface analysis, adhesive testing, and mechanical testing were conducted to test metal surfaces and metal-polymer interfaces. The nitrogen plasma treatment of titanium produced a strong metal-polymer interface; however, oxygen plasma treatment of both stainless steel and titanium produced even stronger metal-polymer interfaces. Plasma treatment of the electrodes allows for the embedded electrodes and the EAP material of the actuator to work and move as a unit, with no detachment, by significantly improving the metal-polymer interface.

  19. Considerations for Contractile Electroactive Polymeric Materials and Actuators

    International Nuclear Information System (INIS)

    Ras Labs produces electroactive polymer (EAP) based materials and actuators that bend, swell, ripple and now contract (new development) with low electric input. This is an important attribute because of the ability of contraction to produce life-like motion. The mechanism of contraction is not well understood. Radionuclide-labeled experiments were conducted to follow the movement of electrolytes and water in these EAPs when activated. Extreme temperature experiments were performed on the contractile EAPs with very favorable results. One of the biggest challenges in developing these actuators, however, is the electrode-EAP interface because of the pronounced movement of the EAP. Plasma treatments of metallic electrodes were investigated in order to improve the attachment of the embedded electrodes to the EAP material. Surface analysis, adhesive testing, and mechanical testing were conducted to test metal surfaces and metal-polymer interfaces. The nitrogen plasma treatment of titanium produced a strong metal-polymer interface; however, oxygen plasma treatment of both stainless steel and titanium produced even stronger metal-polymer interfaces. Plasma treatment of the electrodes allows for the embedded electrodes and the EAP material of the actuator to work and move as a unit, with no detachment, by significantly improving the metal-polymer interface

  20. Contractile apparatus dysfunction early in thepathophysiology of diabetic cardiomyopathy

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Diabetes mellitus significantly increases the risk ofcardiovascular disease and heart failure in patients.Independent of hypertension and coronary arterydisease, diabetes is associated with a specific cardiomyopathy,known as diabetic cardiomyopathy (DCM).Four decades of research in experimental animalmodels and advances in clinical imaging techniquessuggest that DCM is a progressive disease, beginningearly after the onset of type 1 and type 2 diabetes,ahead of left ventricular remodeling and overt diastolicdysfunction. Although the molecular pathogenesis ofearly DCM still remains largely unclear, activation ofprotein kinase C appears to be central in driving theoxidative stress dependent and independent pathwaysin the development of contractile dysfunction. Multiplesubcellular alterations to the cardiomyocyte are nowbeing highlighted as critical events in the early changesto the rate of force development, relaxation and stabilityunder pathophysiological stresses. These changes includeperturbed calcium handling, suppressed activity ofaerobic energy producing enzymes, altered transcriptionaland posttranslational modification of membrane andsarcomeric cytoskeletal proteins, reduced actin-myosincross-bridge cycling and dynamics, and changed myofilamentcalcium sensitivity. In this review, we will presentand discuss novel aspects of the molecular pathogenesisof early DCM, with a special focus on the sarcomericcontractile apparatus.

  1. A comparative study of contractility of the heart ventricle in some ectothermic vertebrates

    OpenAIRE

    Sergey Kharin; Dmitry Shmakov

    2009-01-01

    The purpose of this study was to analyze contractility of the heart ventricle in selected reptilian and amphibian species having the same ventricular excitation pattern. Systolic time intervals and indices of contractility of the heart ventricle were measured in anaesthetized frogs, snakes, and tortoises by use of polycardiography. The electromechanical delay was significantly shorter in tortoises compared with the other two species. The isovolumetric contraction time in frogs was approximate...

  2. A comparative study of contractility of the heart ventricle in some ectothermic vertebrates

    Directory of Open Access Journals (Sweden)

    Sergey Kharin

    2009-07-01

    Full Text Available The purpose of this study was to analyze contractility of the heart ventricle in selected reptilian and amphibian species having the same ventricular excitation pattern. Systolic time intervals and indices of contractility of the heart ventricle were measured in anaesthetized frogs, snakes, and tortoises by use of polycardiography. The electromechanical delay was significantly shorter in tortoises compared with the other two species. The isovolumetric contraction time in frogs was approximately twofold longer than in reptiles. The pre-ejection period was the longest in frogs and the shortest in tortoises, whereas snakes were intermediate. The ejection time was slightly longer in tortoises compared with the other two species. The greatest isovolumetric contraction index and the smallest myocardial tension index corresponded to the frog and tortoise heart ventricle, respectively. The intrasystolic index in tortoises was significantly greater than in frogs, whereas quite similar to that in snakes. The frog ventricle had lower contractility compared with the reptilian one. Although ventricular contractility tended to be lower in snakes compared with tortoises, this difference was not statistically significant. Possible causes for these differences are discussed. We suppose a large variety in ventricular contractility among amphibian and reptilian species having the same ventricular activation pattern. This variety may be conditioned by heart anatomy, intracardiac shunting, lifestyles, and habitats. It can only be hypothesized that on the average, ventricular contractility is higher in reptiles compared with amphibians and in chelonians compared with snakes.

  3. Chronic Contractile Dysfunction without Hypertrophy Does Not Provoke a Compensatory Transcriptional Response in Mouse Hearts.

    Science.gov (United States)

    Matkovich, Scot J; Grubb, David R; McMullen, Julie R; Woodcock, Elizabeth A

    2016-01-01

    Diseased myocardium from humans and experimental animal models shows heightened expression and activity of a specific subtype of phospholipase C (PLC), the splice variant PLCβ1b. Previous studies from our group showed that increasing PLCβ1b expression in adult mouse hearts by viral transduction was sufficient to cause sustained contractile dysfunction of rapid onset, which was maintained indefinitely in the absence of other pathological changes in the myocardium. We hypothesized that impaired contractility alone would be sufficient to induce a compensatory transcriptional response. Unbiased, comprehensive mRNA-sequencing was performed on 6 biological replicates of rAAV6-treated blank, PLCβ1b and PLCβ1a (closely related but inactive splice variant) hearts 8 weeks after injection, when reduced contractility was manifest in PLCβ1b hearts without evidence of induced hypertrophy. Expression of PLCβ1b resulted in expression changes in only 9 genes at FDRcaused similar mild expression changes to PLCβ1b, despite a complete lack of effect of this isoform on cardiac contractility. We conclude that contractile depression caused by PLCβ1b activation is largely independent of changes in the transcriptome, and thus that lowered contractility is not sufficient in itself to provoke measurable transcriptomic alterations. In addition, our data stress the importance of a stringent control group to filter out transcriptional changes unrelated to cardiac function. PMID:27359099

  4. Reliability of contractile properties of the knee extensor muscles in individuals with post-polio syndrome.

    Directory of Open Access Journals (Sweden)

    Eric L Voorn

    Full Text Available To assess the reliability of contractile properties of the knee extensor muscles in 23 individuals with post-polio syndrome (PPS and 18 age-matched healthy individuals.Contractile properties of the knee extensors were assessed from repeated electrically evoked contractions on 2 separate days, with the use of a fixed dynamometer. Reliability was determined for fatigue resistance, rate of torque development (MRTD, and early and late relaxation time (RT50 and RT25, using the intraclass correlation coefficient (ICC and standard error of measurement (SEM, expressed as % of the mean.In both groups, reliability for fatigue resistance was good, with high ICCs (>0.90 and small SEM values (PPS: 7.1%, healthy individuals: 7.0%. Reliability for contractile speed indices varied, with the best values found for RT50 (ICCs>0.82, SEM values <2.8%. We found no systematic differences between test and retest occasions, except for RT50 in healthy subjects (p = 0.016.In PPS and healthy individuals, the reliability of fatigue resistance, as obtained from electrically evoked contractions is high. The reliability of contractile speed is only moderate, except for RT50 in PPS, demonstrating high reliability.This was the first study to examine the reliability of electrically evoked contractile properties in individuals with PPS. Our results demonstrate its potential to study mechanisms underlying muscle fatigue in PPS and to evaluate changes in contractile properties over time in response to interventions or from natural course.

  5. Menthol inhibits detrusor contractility independently of TRPM8 activation.

    Directory of Open Access Journals (Sweden)

    Antonio Celso Saragossa Ramos-Filho

    Full Text Available Agonists such as icilin and menthol can activate the cool temperature-sensitive ion channel TRPM8. However, biological responses to menthol may occur independently of TRPM8 activation. In the rodent urinary bladder, menthol facilitates the micturition reflex but inhibits muscarinic contractions of the detrusor smooth muscle. The site(s of TRPM8 expression in the bladder are controversial. In this study we investigated the regulation of bladder contractility in vitro by menthol. Bladder strips from wild type and TRPM8 knockout male mice (25-30 g were dissected free and mounted in organ baths. Isometric contractions to carbachol (1 nM-30 µM, CaCl2 (1 µM to 100 mM and electrical field stimulation (EFS; 8, 16, 32 Hz were measured. Strips from both groups contracted similarly in response to both carbachol and EFS. Menthol (300 µM or nifedipine (1 µM inhibited carbachol and EFS-induced contractions in both wild type and TRPM8 knockout bladder strips. Incubation with the sodium channel blocker tetrodotoxin (1 µM, replacement of extracellular sodium with the impermeant cation N-Methyl-D-Glucamine, incubation with a cocktail of potassium channel inhibitors (100 nM charybdotoxin, 1 µM apamin, 10 µM glibenclamide and 1 µM tetraethylammonium or removal of the urothelium did not affect the inhibitory actions of menthol. Contraction to CaCl2 was markedly inhibited by either menthol or nifedipine. In cultured bladder smooth muscle cells, menthol or nifedipine abrogated the carbachol or KCl-induced increases in [Ca2+]i. Intravesical administration of menthol increased voiding frequency while decreasing peak voiding pressure. We conclude that menthol inhibits muscarinic bladder contractions through blockade of L-type calcium channels, independently of TRPM8 activation.

  6. Procesos de automatización cognitiva en alumnado con altas capacidades intelectuales

    Directory of Open Access Journals (Sweden)

    Juan Montero-Linares

    2013-05-01

    Full Text Available Proponemos desde el enfoque del procesamiento de la información, el estudio de características cognitivas que faciliten la identificación de las altas capacidades. A tal fin, elaboramos una tarea de habilidad de segmentación silábica que, a partir del modelo propuesto por Baddeley sobre la memoria de trabajo y la distinción entre procesos automáticos y controlados, nos permitiese comprobar las diferencias en cuanto a la capacidad de automatización de la información y si los indicadores propuestos en la misma, tenían suficiente poder clasificatorio o predictivo en la identificación de la alta capacidad intelectual. Participaron 480 niños y niñas de primero a cuarto de Educación Primaria. Se clasificaron, en función de su CI, en dos grupos: alumnado de altas capacidades y alumnado de capacidades medias. Se les administró una batería de pruebas entre las que se encontraba el test de habilidad de segmentación silábica, lo que permitió realizar su estandarización. Los resultados mostraron que los alumnos con CI superior a 130 fueron capaces de automatizar la segmentación de forma más eficiente que los de inteligencia media. La medición de los procesos automáticos a través del test de habilidad de segmentación silábica, permitió diferenciar a los participantes de altas capacidades de los que no lo eran.

  7. Efeito do sulfato de magnésio sobre o índice de pulsatilidade das artérias uterinas, umbilical e cerebral média fetal de acordo com a persistência da incisura protodiastólica da artéria uterina na pré-eclâmpsia grave Effect of magnesium sulfate on pulsatility index of uterine, umbilical and fetal middle cerebral arteries according to the persistence of bilateral diastolic notch of uterine arteries in patients with severe preeclampsia

    Directory of Open Access Journals (Sweden)

    Alex Sandro Rolland Souza

    2009-02-01

    Full Text Available OBJETIVO: avaliar o efeito do sulfato de magnésio sobre o índice de pulsatilidade (IP das artérias uterinas, umbilicais e cerebral média fetal, de acordo com a persistência ou não da incisura protodiastólica bilateral das artérias uterinas na pré-eclâmpsia grave. MÉTODOS: foi desenvolvido um estudo do tipo coorte, incluindo 40 gestantes com pré-eclâmpsia grave, das quais 23 apresentavam incisura protodiastólica bilateral e 17, incisura ausente/unilateral. As pacientes foram submetidas a doplervelocimetria antes e depois de 20 minutos da administração intravenosa de 6 g do sulfato de magnésio. O exame foi realizado com a paciente em posição semi-Fowler, obtendo-se os sonogramas durante a inatividade fetal, em períodos de apneia e ausência de contrações uterinas. Todos os exames foram realizados por dois pesquisadores, considerando a média como resultado final. A comparação dos IP antes e depois do sulfato de magnésio em cada grupo foi realizada pelo teste de Wilcoxon. A diferença das duas medidas (antes e depois do sulfato de magnésio foi comparada entre os grupos (incisura bilateral e incisura ausente/unilateral utilizando-se o teste de Mann-Whitney. RESULTADOS: houve um aumento significativo da frequência cardíaca materna e uma diminuição da pressão arterial materna e da mediana dos IP das duas artérias uterinas e da artéria cerebral média fetal depois da utilização do sulfato de magnésio em ambos os grupos. Houve redução significativa do IP da artéria uterina esquerda e da artéria umbilical apenas no grupo com incisura protodiastólica unilateral/ausente. No entanto, não foram encontradas diferenças significativas em relação ao IP da artéria uterina direita e relação umbilical/cerebral antes e depois do sulfato de magnésio em cada grupo. Não se encontrou diferença entre os grupos, antes e depois do sulfato de magnésio, para nenhum dos desfechos estudados. CONCLUSÕES: após a administra

  8. Capacidad funcional y salud: orientaciones para cuidar al adulto mayor1

    OpenAIRE

    GIRALDO M, CLARA INÉS

    2010-01-01

    Objetivo: valorar la salud y la capacidad funcional de ancianos con dependencia funcional para el autocuidado, como elementos para orientar el cuidado de enfermería y el cuidado familiar en casa. Metodología: estudio descriptivo transversal en 40 personas de 65 y más años con dependencia funcional, cuidados por familiar, en Envigado Colombia; muestreo por conveniencia. Valoración de la capacidad funcional con el índice de Katz y la escala de Lawton y Brody, ajustados según grupo de Neuro...

  9. El mejoramiento de la capacidad para aprender a través de la lectura

    Directory of Open Access Journals (Sweden)

    Armando Morles

    1997-12-01

    Full Text Available El presente estudio discute la importancia de la instrucción en la capacidad para aprender el contenido de textos escritos. Al inicio se define el aprendizaje a través de la lectura para luego continuar con la identificación de los factores que condicionan este aprendizaje. Luego se suministra lineamientos para mejorar esa capacidad. Finalmente se aportan ideas acerca de cómo conducir el entrenamiento de los estudiantes, incluyendo las modalidades y su ubicación dentro del contexto educativo.

  10. Capacidad de adsorción de sulfato de un suelo forestal mediterráneo.

    OpenAIRE

    Quilchano, Consuelo; Gallardo, Juan F.

    2001-01-01

    En el presente estudio se ha evaluado la capacidad de adsorción de sulfato en un suelo forestal con vegetación mediterránea. El objetivo del trabajo es conocer la capacidad de adsorción de sulfato en cada uno de los horizontes del suelo, ya que se trata de un proceso responsable de la retención de este nutriente esencial (S) en el ecosistema, impidiendo su pérdida por lavado. La lixiviación de sulfato, además de reducir la fertilidad del suelo y generar problemas de contaminación en los ecosi...

  11. ALTAS CAPACIDADES: COMPARATIVA ENTRE EL MODELO ESPAÑOL Y BRITÁNICO

    OpenAIRE

    Rodríguez-Vázquez, María

    2012-01-01

    El presente trabajo de investigación exploratoria reflexiona sobre el concepto de alumno con altas capacidades y propone una comparación legislativa entre el modelo de atención a los alumnos con altas capacidades británico y español y cómo ese modelo afecta al sistema educativo general, ya que aunque tienen puntos en común entre ambos países, pero se trata dos formas de enfocar completamente distintas. Además también pretende recoger información sobre iniciativas y proyectos que reflejen l...

  12. Altas capacidades: Proyecto educativo para el aula de Educación Primaria

    OpenAIRE

    López-Presedo, Iria Flavia

    2015-01-01

    El presente TFG tiene como principal finalidad dar una respuesta educativa, eminentemente práctica, al alumnado de altas capacidades dentro del grupo-clase. En primer lugar, se han revisado las teorías de varios autores sobre las altas capacidades, los métodos de detección e intervención con este tipo de alumnado y, finalmente, se ha elaborado un proyecto en forma de programa de enriquecimiento curricular. Este proyecto se inscribe dentro de la Teoría de las inteligencias múltiples de Gard...

  13. Altas capacidades intelectuales : investigación y propuesta desde las inteligencias múltiples

    OpenAIRE

    Pulido Vinuesa, Salomé

    2015-01-01

    El presente trabajo trata sobre las altas capacidades, investigando sobre ello acerca de su historia y evolución, los diversos tipos existentes, sus características, su identificación, su evaluación, sus metodologías, entre otros. Además, se ha realizado un resumen de cómo es tratada esta necesidad educativa por las leyes, antiguas y en vigor. De igual modo, se trata la educación inclusiva, ya que es un tema que afecta a alumnos/as con altas capacidades. El programa de intervención en rel...

  14. Procesos de automatización cognitiva en alumnado con altas capacidades intelectuales

    OpenAIRE

    Juan Montero-Linares; José I. Navarro-Guzmán; Manuel Aguilar-Villagrán

    2013-01-01

    Proponemos desde el enfoque del procesamiento de la información, el estudio de características cognitivas que faciliten la identificación de las altas capacidades. A tal fin, elaboramos una tarea de habilidad de segmentación silábica que, a partir del modelo propuesto por Baddeley sobre la memoria de trabajo y la distinción entre procesos automáticos y controlados, nos permitiese comprobar las diferencias en cuanto a la capacidad de automatización de la información y si los indicadores propue...

  15. El alumnado con altas capacidades intelectuales: programas de intervención.

    OpenAIRE

    González Arranz, Raquel

    2015-01-01

    El presente Trabajo de Fin de Grado se centra en alumnos considerados de Educación Especial, concretamente en aquellos que poseen Altas Capacidades Intelectuales y las posibilidades de respuesta educativa que se les puede ofrecer dentro del modelo de aula ordinaria. En la primera parte, se afronta el estudio de alumnos con altas capacidades intelectuales en educación primaria. Los temas que se tratan son: conceptualización y definiciones, fundamentación teórica de alumnos con altas capaci...

  16. La autopercepción de las capacidades : origen social y elecciones educativas

    OpenAIRE

    Torrents Vilà, Dani

    2016-01-01

    Este texto analiza el efecto del origen social de los estudiantes en la autopercepción de sus capacidades, una vez controladas las capacidades objetivas. La autopercepción está evaluada en dos dimensiones: la autoubicación especular y las expectativas de resultados. Se trata de una muestra de 1782 estudiantes de 4º de ESO, derivada de ISCY Project . Mediante el análisis bivariado y trivariado de tablas de contingencia y comparación de proporciones, se ha observado un ligero sobreoptimismo de ...

  17. Capacidad de carga de las playas en el Litoral Catalán

    OpenAIRE

    García Guinduláin, Alejandro

    2005-01-01

    En la presente tesina se desarrolla el concepto de capacidad de carga recreativa. Se establecen las variables más relevantes y se evalúa el estado actual de las playas del litoral catalán y su evolución en las últimas décadas en función del tipo de playa y de su localización. Finalmente se presenta un modelo de clasificación de las playas en función de su capacidad de carga recreativa.

  18. Índices de resistência e pulsatilidade das artérias uterinas no primeiro e segundo trimestres de gestações normais Uterine arteries resistance and pulsatility indices at the first and second trimesters of normal pregnancies

    Directory of Open Access Journals (Sweden)

    Antonio Gadelha da Costa

    2010-06-01

    Full Text Available OBJETIVO: Determinar os índices de resistência (IR e pulsatilidade (IP nas artérias uterinas durante o primeiro e segundo trimestres de gestação. MATERIAIS E MÉTODOS: Realizamos estudo prospectivo longitudinal em 44 mulheres normais, da 8ª a 12ª e na 22ª semanas de gestação. A dopplervelocimetria foi realizada em ambas as artérias uterinas por meio do IR e do IP. Utilizamos volume de amostra de 1 a 2 mm, filtro de 50 a 70 Hz e ângulo de insonação abaixo de 60°. RESULTADOS: O IR e o IP da artéria uterina no primeiro trimestre foram maiores da 8ª a 12ª do que na 22ª semana de gestação. O IR e o IP da artéria uterina, no primeiro trimestre, com incisura foram de 0,83 ± 0,07 e 2,32 ± 0,79, e sem incisura, de 0,71 ± 0,16 e 1,61 ± 0,78, respectivamente. No segundo trimestre, o IR e o IP da artéria uterina com incisura foram de 0,59 ± 0,09 e 1,03 ± 0,32, e sem incisura, de 0,44 ± 0,09 e 0,63 ± 0,19, respectivamente. CONCLUSÃO: Estabelecemos os valores de referência do IR e do IP das artérias uterinas de gestantes normais no primeiro e segundo trimestres de gestação.OBJECTIVE: To determine uterine artery resistance index (RI and pulsatility index (PI during the first and second trimesters of pregnancy. MATERIALS AND METHODS: The authors developed a prospective longitudinal study with 44 healthy women at their 8th-12th and 22nd gestational weeks. Doppler velocimetry was utilized for evaluating RI and PI of both uterine arteries, with a sample volume of 1 to 2 mm, a 50-70 Hz filter, and an insonation angle < 60°. RESULTS: At 8th-12th gestational weeks, the uterine artery RI and PI were higher than at the 22nd gestational week. At the first trimester uterine artery RI and PI were, respectively, 0.83 ± 0.07 and 2.32 ± 0.79 with a notch, and 0.71 ± 0.16 and 1.61 ± 0.78, without a notch. At the second trimester, uterine artery RI and PI were, respectively, 0.59 ± 0.09 and 1.03 ± 0.32 with a notch, and 0.44 ± 0

  19. Loss of cortactin causes endothelial barrier dysfunction via disturbed adrenomedullin secretion and actomyosin contractility.

    Science.gov (United States)

    García Ponce, Alexander; Citalán Madrid, Alí F; Vargas Robles, Hilda; Chánez Paredes, Sandra; Nava, Porfirio; Betanzos, Abigail; Zarbock, Alexander; Rottner, Klemens; Vestweber, Dietmar; Schnoor, Michael

    2016-01-01

    Changes in vascular permeability occur during inflammation and the actin cytoskeleton plays a crucial role in regulating endothelial cell contacts and permeability. We demonstrated recently that the actin-binding protein cortactin regulates vascular permeability via Rap1. However, it is unknown if the actin cytoskeleton contributes to increased vascular permeability without cortactin. As we consistently observed more actin fibres in cortactin-depleted endothelial cells, we hypothesised that cortactin depletion results in increased stress fibre contractility and endothelial barrier destabilisation. Analysing the contractile machinery, we found increased ROCK1 protein levels in cortactin-depleted endothelium. Concomitantly, myosin light chain phosphorylation was increased while cofilin, mDia and ERM were unaffected. Secretion of the barrier-stabilising hormone adrenomedullin, which activates Rap1 and counteracts actomyosin contractility, was reduced in plasma from cortactin-deficient mice and in supernatants of cortactin-depleted endothelium. Importantly, adrenomedullin administration and ROCK1 inhibition reduced actomyosin contractility and rescued the effect on permeability provoked by cortactin deficiency in vitro and in vivo. Our data suggest a new role for cortactin in controlling actomyosin contractility with consequences for endothelial barrier integrity. PMID:27357373

  20. THE IMPROVEMENT OF INFARCTED MYOCARDIAL CONTRACTILE FORCE AFTER AUTOLOGOUS SKELETAL MUSCLE SATELLITE CELL IMPLANTATION

    Institute of Scientific and Technical Information of China (English)

    钟竑; 朱洪生; 张臻

    2002-01-01

    Objective To study the improvement of infarcted myocardial contractile force after autologous skeletal muscle satellite cell implantation via intracoronary arterial perfusion. Methods Skeletal muscle cells were harvested from gluteus max of adult mongrel dogs and the cells were cultured and expanded before being labeled with DAPI (4, 6-diamidino-2-phenylindone). The labeled cells were then implanted into the acute myocardial infarct site via the ligated left anterior descending (LAD) coronary artery. Specimens were taken at 2nd, 4th, 8th week after myoblast implantation for histologic and contractile force evaluation, respectively. Results The satellite cells with fluorescence had been observed in the infarct site and also in papi-llary muscle with consistent oriented direction of host myocardium. A portion of the implanted cells had differen-tiated into muscle fibers. Two weeks after implantation, the myocardial contractile force showed no significant difference between the cell implant group and control group. At 4 and 8 week, the contractile force in the cell implant group was better than that in control group. Conclusion The skeletal muscle satellite cells, implanted into infarct myocardium by intracoronary arterial perfusion, could disseminate through the entire infarcted zone with myocardial regeneration and improve the contractile function of the infarcted myocardium.

  1. Sperm concentration on the intrauterine artificial insemination in swine Concentrações espermáticas na inseminação artificial intra-uterina suína

    Directory of Open Access Journals (Sweden)

    Joana Miller

    2009-12-01

    Full Text Available The aim of this work was to evaluate the efficiency of the intrauterine insemination (IUI in swine, considering the conception rate, farrowing rate, litter size (alive born pigs. For the IUI, the females had been insemination at 24 and 48 hours after the estrus detection, and the inseminating doses of 500 million, 1 billion, 1.5 billion and 2 billion spermatozoa in 20 mL extender had been used. The procedure of catheter insertion through the cervical canal was successfully performed in 97.9% of the females. The conception rate was 6.3% in the IUI. The farrowing rate in IUI was 87.2% but the farrowing rate was 100% for the sperm concentration of 500 million. Regarding the number of born pigs and alive born pigs observed in females inseminated with IUI, no significant difference was observed (p > 0.05. The concentration of 500 x 10(6 spermatozoa in 20 mL extender in the intrauterine insemination resulted in an optimal reproductive performance.Conduziu-se este estudo, com o objetivo de avaliar a eficiência da inseminação intra-uterina (IIU em suínos, considerando as taxas de retorno ao estro, aborto, parto, além do tamanho da leitegada (número de leitões nascidos e nascidos vivos. Na IIU, as fêmeas foram inseminadas nos tempos de 24 e 48 horas após a detecção do estro, utilizando-se as concentrações de 500 milhões, 1 bilhão, 1,5 bilhão e 2 bilhões de espermatozóides, em 20mL de diluente. A passagem do cateter de IIU através da cérvix foi possível em 97,9% das fêmeas. Foi realizado diagnóstico de retorno ao estro a partir do 18º dia e diagnóstico de gestação por ultrassonografia transcutânea entre o 28º e 30º dias após a inseminação. A taxa de retorno ao estro foi de 6,3% na IIU. A taxa de parto na IIU foi de 87,2%, sendo a taxa de parto para a concentração de 500 milhões de 100%. Com relação ao número de leitões nascidos totais e nascidos vivos, não houve diferenças, entre as diferentes concentra

  2. Capacidad antioxidante y contenido de polifenoles de 21 extractos de plantas medicinales argentinas

    OpenAIRE

    Tournier, H.; Fioravanti, D.; Dade, Martín; Schinella, Guillermo

    2010-01-01

    En este trabajo se evaluó la capacidad antioxidante total (CAT) y el contenido de fenoles totales (FT) y flavonoides (FV) de 21 extractos acuosos obtenidos de plantas nativas del valle de Traslasierra, Córdoba que son ampliamente utilizadas por poblaciones rurales y urbanas de nuestro país.

  3. La evaluación psicopedagógica del alumnado con altas capacidades

    OpenAIRE

    Grau Rubio, Claudia

    2012-01-01

    Se describen los instrumentos de evaluación psicopedagógica aplicables al alumnado con altas capacidades. Instrumentos referidos al alumno, al contexto escolar, a las variables socio-familiares y la determinación de las necesidades educativas especiales.

  4. La capacidad y el bienestar subjetivo como dimensiones de estudio de la calidad de vida

    Directory of Open Access Journals (Sweden)

    Beatriz Yasuko Arita Watanabe

    2005-01-01

    Full Text Available La Calidad de vida es trabajada científicamente como un constructo muy amplio que abarca diversos significados pero en lo general apunta a la búsqueda de la explicación de la buena vida, aquella que se disfruta, que satisface al que la vive y que le produce estados de felicidad. De allí que sea la persona, desde su percepción, la que evalúe su propia vida, sus capacidades y, en el propio contexto, desarrolle mecanismos de búsqueda del bienestar personal. El Plan de Naciones Unidas para el Desarrollo (PNUD, al hablar de desarrollo humano utiliza un índice combinado que considera niveles de ingreso y educación así como la esperanza de vida de la población. Son medidas objetivas de capacidad centradas en la búsqueda de mejoría de las condiciones de vida de las personas. En México, sus planteamientos son retomados por la Secretaría de Desarrollo Social (Sedesol en su programa “Oportunidades” haciendo referencia a la capacidad de las personas. Este programa no alcanza a definir indicadores que permitan trabajar el estudio de la apreciación de la vida, respecto a las capacidades percibidas y la evaluación del resultado de vida. El objetivo de la presente investigación va dirigido a integrar el estudio de los indicadores objetivos y subjetivos de la capacidad junto con los indicadores del bienestar subjetivo (satisfacción por la vida y felicidad sentida, para considerar a la capacidad y al bienestar subjetivo como dimensiones de explicación de la calidad de vida. La medición de los niveles de ingreso y educación junto con escalas de capacidad para enfrentar la vida y de bienestar subjetivo es utilizada para correr un análisis factorial exploratorio en una muestra representativa de la población adulta de la Zona Urbana de Culiacán, México.

  5. LA CAPACIDAD Y EL BIENESTAR SUBJETIVO COMO DIMENSIONES DE ESTUDIO DE LA CALIDAD DE VIDA

    Directory of Open Access Journals (Sweden)

    Beatriz Yasuko Arita Watanabe

    2005-06-01

    Full Text Available La Calidad de vida es trabajada científicamente como un constructo muy amplio que abarca diversos significados pero en lo general apunta a la búsqueda de la explicación de la buena vida, aquella que se disfruta, que satisface al que la vive y que le produce estados de felicidad. De allí que sea la persona, desde su percepción, la que evalúe su propia vida, sus capacidades y, en el propio contexto, desarrolle mecanismos de búsqueda del bienestar personal. El Plan de Naciones Unidas para el Desarrollo (PNUD, al hablar de desarrollo humano utiliza un índice combinado que considera niveles de ingreso y educación así como la esperanza de vida de la población. Son medidas objetivas de capacidad centradas en la búsqueda de mejoría de las condiciones de vida de las personas. En México, sus planteamientos son retomados por la Secretaría de Desarrollo Social (Sedesol en su programa “Oportunidades†haciendo referencia a la capacidad de las personas. Este programa no alcanza a definir indicadores que permitan trabajar el estudio de la apreciación de la vida, respecto a las capacidades percibidas y la evaluación del resultado de vida. El objetivo de la presente investigación va dirigido a integrar el estudio de los indicadores objetivos y subjetivos de la capacidad junto con los indicadores del bienestar subjetivo (satisfacción por la vida y felicidad sentida, para considerar a la capacidad y al bienestar subjetivo como dimensiones de explicación de la calidad de vida. La medición de los niveles de ingreso y educación junto con escalas de capacidad para enfrentar la vida y de bienestar subjetivo es utilizada para correr un análisis factorial exploratorio en una muestra representativa de la población adulta de la Zona Urbana de Culiacán, México. Palabras clave: Calidad

  6. Desempenho reprodutivo de fêmeas suínas submetidas à inseminação artificial intra-uterina ou à tradicional Reproductive performance of sows submitted to intrauterine or tradicional artificial insemination

    Directory of Open Access Journals (Sweden)

    Paulo Eduardo Bennemann

    2007-12-01

    Full Text Available Foram utilizadas 298 fêmeas pluríparas Camborough 22® distribuídas em dois tratamentos: T1 (n=154, inseminação intra-uterina (IAU com dose inseminante (DI contendo 0,5 bilhão de espermatozóides em volume total de 20ml; e T2 (n=144, inseminação tradicional (IAT, com DI contendo 3,0 bilhões de espermatozóides em volume total de 90ml. Foi possível a realização da IAU em 98,1% das fêmeas. A presença de sangue na extremidade do cateter ou espiral da pipeta de IAU foi observada em 8,4% das fêmeas. As taxas de prenhez (TPr e de parto ajustada não diferiram (P>0,05 entre a IAU e IAT. O tamanho da leitegada (TL diferiu entre os tratamentos (PA total of 298 Camborough 22® sows was distributed in two treatments: T1 (n=154: intrauterine insemination (IUI with 0.5 billion sperms in 20ml total volume; T2 (n=144: traditional insemination (TAI with 3.0 billion sperms in 90ml total volume. It was possible to perform the IUI in 98.1% of sows. It was observed presence of blood on the catheter tip or pipete in 8.4% of IUI sows. The pregnancy (PR and adjusted farrowing rates did not differ (P>0.05 among treatments. Litter size (LS differ among treatments (P<0.05, being observed a reduction of 0.8 piglet in IUI. The blood presence in the IUI did not affect the PR significantly, but resulted in a reduction of 2.6 piglets per litter.

  7. Mechanobiological induction of long-range contractility by diffusing biomolecules and size scaling in cell assemblies.

    Science.gov (United States)

    Dasbiswas, K; Alster, E; Safran, S A

    2016-01-01

    Mechanobiological studies of cell assemblies have generally focused on cells that are, in principle, identical. Here we predict theoretically the effect on cells in culture of locally introduced biochemical signals that diffuse and locally induce cytoskeletal contractility which is initially small. In steady-state, both the concentration profile of the signaling molecule as well as the contractility profile of the cell assembly are inhomogeneous, with a characteristic length that can be of the order of the system size. The long-range nature of this state originates in the elastic interactions of contractile cells (similar to long-range "macroscopic modes" in non-living elastic inclusions) and the non-linear diffusion of the signaling molecules, here termed mechanogens. We suggest model experiments on cell assemblies on substrates that can test the theory as a prelude to its applicability in embryo development where spatial gradients of morphogens initiate cellular development. PMID:27283037

  8. Mechanobiological induction of long-range contractility by diffusing biomolecules and size scaling in cell assemblies

    Science.gov (United States)

    Dasbiswas, K.; Alster, E.; Safran, S. A.

    2016-06-01

    Mechanobiological studies of cell assemblies have generally focused on cells that are, in principle, identical. Here we predict theoretically the effect on cells in culture of locally introduced biochemical signals that diffuse and locally induce cytoskeletal contractility which is initially small. In steady-state, both the concentration profile of the signaling molecule as well as the contractility profile of the cell assembly are inhomogeneous, with a characteristic length that can be of the order of the system size. The long-range nature of this state originates in the elastic interactions of contractile cells (similar to long-range “macroscopic modes” in non-living elastic inclusions) and the non-linear diffusion of the signaling molecules, here termed mechanogens. We suggest model experiments on cell assemblies on substrates that can test the theory as a prelude to its applicability in embryo development where spatial gradients of morphogens initiate cellular development.

  9. Myocardial ischemia-reperfusion induces upregulation of contractile endothelin ETB receptor in rat coronary arteries

    DEFF Research Database (Denmark)

    Skovsted, Gry Freja; Sheykhzade, Majid; Trautner, Simon;

    2011-01-01

    are situated in the vascular smooth muscle cells mediating vasoconstriction. This study aims to examine whether heart ischemia-reperfusion leads to upregulation of contractile ETB receptors in the smooth muscle layer of the coronary arteries and to investigate the signaling pathways involved in the putative...... ETB receptor upregulation. Methods and Results Thirteen Sprague-Dawley male rats (body weight 260-410 g) were anaesthetized with Hypnorm-Midazolam and subjected to 15 min occlusion of left anterior descending coronary artery (LAD) followed by 22 h of reperfusion. The contractile response...... of contractile ETB receptors in the vascular smooth muscle cells in coronary arteries in the post-ischemic area. This study suggests that the upregulation of the ETB receptors depends on a transcriptional upregulation and involves the MEK/ERK type of MAPK....

  10. Study of myogenic spontaneous contractile activities in the detrusor instability rats

    Institute of Scientific and Technical Information of China (English)

    JIANG Hai-hong; WEN Qian-jun; SONG Bo

    2006-01-01

    Objective: To explore a myogenic basis of the spontaneous contractions on the rat bladder smooth muscle strip in a detrusor instability (DI) model in vitro, and to study a nerve blocker's cocktail affecting the spontaneous contractions as well as electrical stimulated contractile response. Methods: DI model rats were made by partial bladder outlet obstruction (BOO) and confirmed by the filling cystometry. Detrusor strip was dissected from fresh bladder, fixed for an isometric tension trial. The contractions were recorded during electrical stimulation or exposure to some agents. Results: The cocktail diminished the nerve-mediated contractile response effectively in DI preparation. DI's spontaneous contractions remained during the presence of the cocktail with a significant change in its contractile amplitude. Conclusion: With the local nerve-concerned factors abolishment by the cocktail, the DI bladder preparations still have the spontaneous contractions, indicating a myogenic basis from themselves.

  11. Transforming growth factor-beta 1 specifically induce proteins involved in the myofibroblast contractile apparatus

    DEFF Research Database (Denmark)

    Malmström, Johan; Lindberg, Henrik Have; Lindberg, Claes;

    2004-01-01

    pattern changes that were identified by mass spectrometry and represent specific induction of several members of the contractile apparatus such as calgizzarin, cofilin, and profilin. These proteins have not previously been shown to be regulated by TGF-beta(1), and the functional role of these proteins...... is to participate in the depolymerization and stabilization of the microfilaments. These results show that TGF-beta(1) induces not only alpha-SMA but a whole set of actin-associated proteins that may contribute to the increased contractile properties of the myofibroblast. These proteins accompany the induced...... expression of alpha-SMA and may participate in the formation of stress fibers, cell contractility, and cell spreading characterizing the myofibroblasts phenotype....

  12. Efecto, en un modelo murino, de dos polisacáridos sulfatados sobre la producción de citoquinas por células NK uterinas y de sangre periférica

    Directory of Open Access Journals (Sweden)

    Angela Patricia Cadavid Jaramillo

    2000-02-01

    Full Text Available

    Las células asesinas naturales (NK uterinas son una subpoblación diferente a las de sangre periférica, expresan los marcadores CD56bright y CD16- y constituyen los linfocitos más abundantes de la decidua humana (70%. Estas células juegan un papel protagónico en el aloreconocimiento del feto, en el control de la invasión del trofoblasto y promueven el crecimiento de la unidad fetoplacentaria mediante la producción del factor estimulante de colonias de granulocitos y macrófagos y del factor estimulante de colonias de monocitos (CSF-1. En los ratones transgénicos Tg2978 deficientes en células NK se presenta una reducción de hasta un 66% en su viabilidad intrauterina y una disminución del 45% en el tamaño placentario señalando la estrecha relación de estas células con la biología de la reproducción.

    De otro lado existen pruebas directas e indirectas de que las células NK podrían ser responsables en algunos casos de falla del embarazo. Diversos tratamientos para el aborto recurrente espontáneo (ARE regulan negativamente el número y la actividad de las células NK como los glicosaminoglicanes sulfatados, y en especial la heparina, que bloquean in vitro su actividad lítica, tal como lo ha demostrado nuestro grupo. En estudios  clínicos de pacientes con ARE de causa inmunológica se observa un efecto benéfico de la combinación heparina-aspirina con o sin inmunizaciones con linfocitos, por lo cual se propone como una posible terapia de esta alteración. Se ha visto además que otro polisacárido sulfatado, el fucoidan, estimula la producción del factor de crecimiento hepático y

  13. Dopplervelocimetria das artérias uterinas na predição de complicações em gestações de baixo risco Uterine artery doppler velocimetry for the prediction of complications in low-risk pregnancies

    Directory of Open Access Journals (Sweden)

    Fabrício da Silva Costa

    2005-06-01

    Full Text Available OBJETIVO: determinar a validade da dopplervelocimetria das artérias uterinas na predição de complicações da gestação em população de nulíparas de baixo risco. MÉTODOS: foi conduzido estudo prospectivo que incluiu 45 pacientes primigestas, sem história de doenças crônicas. A dopplervelocimetria das artérias uterinas foi realizada entre 24 e 26 semanas, com determinação do índice de resistência (IR, índice de pulsatilidade (IP, relação S/D e a presença ou ausência de incisura na onda de velocidade de fluxo. Na análise estatística foi utilizado o teste de Mann-Whitney para amostras não paramétricas e o teste exato de Fisher foi utilizado na avaliação dos parâmentros qualitativos. RESULTADOS: complicações da gravidez foram observadas em 12 pacientes, com quatro casos de pré-eclâmpsia, um caso de recém-nascido pequeno para a idade gestacional (PIG, um caso de PIG e parto pré-termo (PPT, três casos de PPT, um caso de centralização fetal e dois casos de mecônio espesso no líquido amniótico no momento da resolução da gestação. Notamos que o IR (mediana 0,56 x 0,68, IP (mediana 0,98 x 1,29 e a relação S/D (mediana 2,2 x 2,9 estavam mais elevados no exame realizado entre a 24 e a 26ª semana nas pacientes que apresentaram qualquer complicação da gestação e não mostrou diferença nos casos de pré-eclâmpsia ou PIG. A presença de incisura bilateral apresentou sensibilidade de 100 e 90%, especificidade de 60,6 e 62,5%, valor preditivo positivo (VPP de 29,4 e 42,9%, valor preditivo negativo (VPN de 100 e 95,2% para a detecção de pré-eclâmpsia ou PIG e qualquer complicação da gestação, respectivamente. A dopplervelocimetria alterada apresentou sensibilidade de 83,3 e 83,3%, especificidade de 69,7 e 69,7%, VPP de 33,3 e 50,0%, VPN de 95,8 e 92,0% para a detecção de pré-eclâmpsia ou PIG e qualquer complicação da gestação, respectivamente. CONCLUSÃO: índices de alta impedância e a presen

  14. EFFECTS OF DESENSITIZATION AND REBOUND TO ADENOSINE ON ACTION POTENTIAL AND CONTRACTILITY IN ATRIAL CELLS IN GUINEA-PIGS

    Institute of Scientific and Technical Information of China (English)

    张凤杰; 臧伟进; 于晓江; 胡浩; 张春虹; 孙强; 吕军

    2002-01-01

    Objective To investigate the effects of desensitization and rebound to adenosine(Ado) on action potential duration(APD) and contractility in guinea-pig atrial cells. Methods Electrical activity was recorded using standard intracellular microelectrode technique and contractility was recorded using. We studied the effects of adenosine on the action potential and desensitization of contractility and rebound of contractility. Results The results showed that action potential duration were shortened by 1,10,100μmol*L-1Ado, the ratio of shortened APD was (9.58±1.40)%,(13.80±2.26)%,(24.80±3.19)%, respectively. 1μmol*L-1Ado had no desensitization (P>0.05), but the time of desensitization of 10μmol*L-1 Ado and 100μmol*L-1 Ado was 1 minute(P<0.05) and 5 minutes(P<0.05), respectively. The desensitization of contractility of 10*!μmol*L-1 Ado was obvious in atrial cells, the decrease of contractility of 10*!μmol*L-1 Ado was obvious in atrial cells, the decrease of contractility was changed from (31.4±16.04)%(2 minutes) to (50.60±15.87)% (4 minutes), compared with control. After washing out Ado, contractility was shown to rebound, the ratio of increase of contractility by 1,10,100μmol*L-1 Ado was (12.38±7.50)%,(19.00±8.14)% and (27.60±13.44)%, respectively. Conclusion Ado can abbreviate APD in atrial cells. The desensitization of Ado on APD is characterized by concentration-dependent and time-dependent in atrial cells, and the desensitization of contractility of Ado is obvious and contractility was shown to rebound after washing out Ado.

  15. TEOR DE FENÓLICOS TOTAIS E CAPACIDADE ANTIOXIDANTE DE POLPAS CONGELADAS DE FRUTAS

    Directory of Open Access Journals (Sweden)

    E. A. MELO

    2008-12-01

    Full Text Available

    Polpas congeladas de frutas comercializadas na Cidade do Recife-PE foram submetidas à determinação do teor de fenólicos totais e da capacidade de seqüestrar o radical 1,1-difenil-2-picrilhidrazil (DPPH. Todas as polpas de frutas exibiram quantidades relevantes de polifenóis, no entanto, as de acerola, caju e ciriguela exibiram os mais elevados teores destes constituintes. As polpas de acerola, caju, ciriguela, goiaba, manga, pitanga e uva, diluídas em água, exibiram forte capacidade de seqüestro do radical DPPH (>70%, estatisticamente semelhante à do BHT e do ácido ascórbico. As polpas de cajá e graviola apresentaram moderada ação (50–70%, enquanto que as de tangerina e de abacaxi exibiram a menor ação, integrando, juntamente com a de maracujá, o grupo das polpas com fraca capacidade antioxidante (<50%. O extrato metanólico, obtido a partir dos resíduos resultantes da fi ltração das polpas diluídas em água, de todas as polpas, exceto a de uva e de cajá, cujo extrato aquoso exibiu forte capacidade de seqüestro, também apresentou forte ação antioxidante, estatisticamente semelhante à capacidade antioxidante do BHT e ácido ascórbico. Com base nos resultados obtidos, as polpas congeladas de frutas podem ser vistas com uma importante fonte de antioxidante dietético.

  16. Relação familiar da pessoa idosa com comprometimento da capacidade funcional

    Directory of Open Access Journals (Sweden)

    Luana Araújo dos Reis

    2015-01-01

    Full Text Available Objetivo: comprender la relación familiar de la persona adulta con comprometimiento de la capacidad funcional. Materiales y mé - todos: estudio exploratorio y descriptivo de abordaje cualitativo, fundamentado en el método de la historia oral, realizado con 15 adultos mayores asistidos por una unidad de salud de la familia, residentes con familiares y que presentaban comprometimiento de la capacidad funcional. Se recolectaron los datos en el período de marzo y abril del 2012, por medio de entrevistas en profundidad. Las categorías temáticas fueron: buena relación familiar, cambios en la relación familiar, sintiéndose un estorbo para la familia, sintiéndose abandonado por la familia. Resultado: el estudio ha revelado que las personas mayores con comprometimiento de la capacidad funcional vivencian sentimientos diversos que van desde la alegría porque son respetadas y tienen sus necesidades atendidas, hasta la tristeza y revuelta, por la adaptación negativa de la familia y el abandono de los hijos. Conclusión: la relación familiar de la persona mayor pasa por reajustes luego del comprometimiento de la capacidad funcional, lo que repercute significativamente en la dinámica de las relaciones. Desde esta comprensión, los profesionales de salud, sobre todo de enfermería, deben reconocer los retos a los que la familia afronta, orientarla y capacitarla para la atención a las demandas de cuidado presentadas por la persona mayor con comprometimiento de la capacidad funcional, y favorecer la realización del cuidado sin que esto desgaste las relaciones.

  17. Madurez de las capacidades de innovación en empresas colombianas

    Directory of Open Access Journals (Sweden)

    José Enrique Arias Pérez

    2014-01-01

    Full Text Available En la ciudad de Medellín (Colombia, se encuentran ubicadas algunas de las grandes empresas del país líderes en investigación, desarrollo e innovación; sin embargo, a la fecha son pocos los estudios realizados en función de las capacidades de innovación subyacentes a los buenos resultados en el desarrollo de nuevos y mejorados productos. El objetivo del articulo es determinar la madurez de las capacidades de innovación de cinco de estas empresas. Para ello, se utilizo el modele teórico de Essmann y Du Preez (2009, el cual se compone de tres dimensiones: constructo capacidad de innovación, escala de madurez, y constructo organizacional. En cuanto ala metodología, se construyo un índice de capacidad de innovación, y se calcularon los rangos de los tres niveles de madurez, usando el análisis clúster (Jung et ai, 2009; ello permitió clasificar a las empresas objeto de estudio. En cuanto a los resultados, se encontró que la totalidad de las empresas se encuentran en el nivel de madurez formalizado y predecible. En conclusión, si bien se han identificado e implementado las mejores practicas asociadas a cada capacidad de innovación, no se ha logrado que los individuos se apropien y hagan uso de manera sistemática de las mismas.

  18. Stimulation of the cardiopulmonary baroreflex enhances ventricular contractility in awake dogs: a mathematical analysis study.

    Science.gov (United States)

    Sala-Mercado, Javier A; Moslehpour, Mohsen; Hammond, Robert L; Ichinose, Masashi; Chen, Xiaoxiao; Evan, Sell; O'Leary, Donal S; Mukkamala, Ramakrishna

    2014-08-15

    The cardiopulmonary baroreflex responds to an increase in central venous pressure (CVP) by decreasing total peripheral resistance and increasing heart rate (HR) in dogs. However, the direction of ventricular contractility change is not well understood. The aim was to elucidate the cardiopulmonary baroreflex control of ventricular contractility during normal physiological conditions via a mathematical analysis. Spontaneous beat-to-beat fluctuations in maximal ventricular elastance (Emax), which is perhaps the best available index of ventricular contractility, CVP, arterial blood pressure (ABP), and HR were measured from awake dogs at rest before and after β-adrenergic receptor blockade. An autoregressive exogenous input model was employed to jointly identify the three causal transfer functions relating beat-to-beat fluctuations in CVP to Emax (CVP → Emax), which characterizes the cardiopulmonary baroreflex control of ventricular contractility, ABP to Emax, which characterizes the arterial baroreflex control of ventricular contractility, and HR to Emax, which characterizes the force-frequency relation. The CVP → Emax transfer function showed a static gain of 0.037 ± 0.010 ml(-1) (different from zero; P < 0.05) and an overall time constant of 3.2 ± 1.2 s. Hence, Emax would increase and reach steady state in ∼16 s in response to a step increase in CVP, without any change to ABP or HR, due to the cardiopulmonary baroreflex. Following β-adrenergic receptor blockade, the CVP → Emax transfer function showed a static gain of 0.0007 ± 0.0113 ml(-1) (different from control; P < 0.10). Hence, Emax would change little in steady state in response to a step increase in CVP. Stimulation of the cardiopulmonary baroreflex increases ventricular contractility through β-adrenergic receptor system mediation.

  19. The Effects of Histamine H3 Receptors on Contractile Responses on Rat Gastric Fundus

    Directory of Open Access Journals (Sweden)

    Aşkın Hekimoğlu

    2006-01-01

    Full Text Available The aim of this study is to determine the effects of histamine receptors on the gastrointestinal system smooth muscle contractions and the role of histamine H3 receptors on these effects. İsolated rat gastric fundus preparations were hanged on isolated organ bath and histamine receptor agonist and anthagonists were added to the bath solution and the electrical field stimulation-induced contractile responses were evaluated. In our study groups after blocking one of the histamine receptors H1, H2,H3; contractile responses were observed. Then, other two receptors were blocked one by one or combination of them to observe the changes on the contractile responses given to the electrical stimulation .To blocke histamine receptors pyrilamine (10-6м as H1 receptor blocker, famotidine (10-6м as H2 receptor blocker and thioperamide (10-5м as H3 receptor blocker and various combination of them were used. All groups were treated with H3 receptor anthagonist thioperamide (10-5м and agonist (R-α-methylhistamine (RMHA on 10-8, 10-7, 10-6 ve 10-5 molar concentrations cumulatively to observe its mediator effects on contractile responses. We suggested that (R-α-methylhistamine mediates the inhibition on the contractile effects of rat gastric fundus. This conclusion was supported by these findings: a the selective agonists (RMHA caused a dumping of the contractile effect of acetylcholine; b the effect of (RMHA was prevented by the selective H3 receptor antagonist thioperamide.

  20. Actions of genistein on contractile response of smooth muscle isolated from guinea pig gallbladder

    Institute of Scientific and Technical Information of China (English)

    Ya-Li Luo; Ya-Li Wang; Neng-Lian Li; Tian-Zhen Zheng; Li Zhang; Ya-Li She; Shu-Ming Hu

    2009-01-01

    BACKGROUND: Defective contractile motility of the gallbladder is an important factor for gallstone formation. Estrogen might increase the risk of gallstones and cholecystitis, and estradiol inhibits the contractile activity of isolated strips of guinea pig gallbladder. The potential risks associated with hormone replacement therapy (HRT) include symptomatic gallstones. Phytoestrogen have been used to treat menopause syndromes by replacing traditional estrogen. This experiment aimed to determine the effects of the phytoestrogen genistein on the contractile response of smooth muscle strips isolated from guinea pig gallbladder and its possible mechanism of action. METHODS: Guinea pigs were sacriifced to remove the whole gallbladder. Two or three smooth muscle strips were cut longitudinally. Each strip was suspended in a tissue chamber containing Krebs solution. After 2 hours of equilibration, contractile response indexes were recorded. Different concentrations of genistein were added to the chamber and the contractile responses were measured. Each antagonist was added 2 minutes before genistein to study possible mechanisms. The effect of genistein on calcium-dependent contraction curves and biphasic contraction in calcium-free Krebs solution were measured. RESULTS: Genistein decreased the resting tension dose-dependently, and reduced the mean contractile amplitude and frequency in gallbladder strips. Ranitidine partly inhibited the effect of genistein, but methylene blue, Nω-nitro-L-arginine, and propranolol hydrochloride did not inlfuence this action. Genistein had no signiifcant effects on calcium-dependent contraction. Genistein reduced the ifrst contraction induced by acetylcholine chloride, but did not affect the second contraction caused by CaCl2. CONCLUSIONS: Genistein relaxed smooth muscle isolated from the gallbladder of guinea pigs and this might contribute to the formation of gallstones. The inhibitory action might be related to H2 receptors and

  1. Accessory left atrial diverticulae: contractile properties depicted with 64-slice cine-cardiac CT.

    LENUS (Irish Health Repository)

    Killeen, Ronan P

    2012-02-01

    To assess the contractility of accessory left atrial appendages (LAAs) using multiphasic cardiac CT. We retrospectively analyzed the presence, location, size and contractile properties of accessory LAAs using multiphasic cardiac 64-slice CT in 102 consecutive patients (63 males, 39 females, mean age 57). Multiplanar reformats were used to create image planes in axial oblique, sagittal oblique and coronal oblique planes. For all appendages with an orifice diameter >or= 10 mm, axial and sagittal diameters and appendage volumes were recorded in atrial diastole and systole. Regression analysis was performed to assess which imaging appearances best predicted accessory appendage contractility. Twenty-three (23%) patients demonstrated an accessory LAA, all identified along the anterior LA wall. Dimensions for axial oblique (AOD) and sagittal oblique (SOD) diameters and sagittal oblique length (SOL) were 6.3-19, 3.4-20 and 5-21 mm, respectively. All appendages (>or=10 mm) demonstrated significant contraction during atrial systole (greatest diameter reduction was AOD [3.8 mm, 27%]). Significant correlations were noted between AOD-contraction and AOD (R = 0.57, P < 0.05) and SOD-contraction and AOD, SOD and SOL (R = 0.6, P < 0.05). Mean diverticulum volume in atrial diastole was 468.4 +\\/- 493 mm(3) and in systole was 171.2 +\\/- 122 mm(3), indicating a mean change in volume of 297.2 +\\/- 390 mm(3), P < 0.0001. Stepwise multiple regression analysis revealed SOL to be the strongest independent predictor of appendage contractility (R(2) = 0.86, P < 0.0001) followed by SOD (R(2) = 0.91, P < 0.0001). Accessory LAAs show significant contractile properties on cardiac CT. Those accessory LAAs with a large sagittal height or depth should be evaluated for contractile properties, and if present should be examined for ectopic activity during electrophysiological studies.

  2. Effect of a crude sulfated polysaccharide from Halymenia floresia (Rhodophyta) on gastrointestinal smooth muscle contractility

    OpenAIRE

    José Ronaldo Vasconcelos Graça; Mirna Marques Bezerra; Vilma Lima; José Ariévilo Gurgel Rodrigues; Diego Levi Silveira Monteiro; Ana Luíza Gomes Quinderé; Rodrigo César das Neves Amorim; Regina Célia Monteiro de Paula; Norma Maria Barros Benevides

    2011-01-01

    The aim of this work was to study the effect of Halymenia floresia (Hf) on duodenum contractility, and on experimental protocols of gastric compliance (GC) in rats. Fraction Hf2s exhibited a concentration-dependent myocontractile effect (EC50 12.48 µg/ml), and an inhibitory effect after consecutive washing. The contractile response promoted by Hf2s in the duodenum strips was completely inhibited by verapamil, and the effects were prevented in the presence of Ca2+-free medium. The pretreatment...

  3. Validation of an in vitro contractility assay using canine ventricular myocytes

    International Nuclear Information System (INIS)

    Measurement of cardiac contractility is a logical part of pre-clinical safety assessment in a drug discovery project, particularly if a risk has been identified or is suspected based on the primary- or non-target pharmacology. However, there are limited validated assays available that can be used to screen several compounds in order to identify and eliminate inotropic liability from a chemical series. We have therefore sought to develop an in vitro model with sufficient throughput for this purpose. Dog ventricular myocytes were isolated using a collagenase perfusion technique and placed in a perfused recording chamber on the stage of a microscope at ∼ 36 °C. Myocytes were stimulated to contract at a pacing frequency of 1 Hz and a digital, cell geometry measurement system (IonOptix™) was used to measure sarcomere shortening in single myocytes. After perfusion with vehicle (0.1% DMSO), concentration–effect curves were constructed for each compound in 4–30 myocytes taken from 1 or 2 dog hearts. The validation test-set was 22 negative and 8 positive inotropes, and 21 inactive compounds, as defined by their effect in dog, cynolomolgous monkey or humans. By comparing the outcome of the assay to the known in vivo contractility effects, the assay sensitivity was 81%, specificity was 75%, and accuracy was 78%. With a throughput of 6–8 compounds/week from 1 cell isolation, this assay may be of value to drug discovery projects to screen for direct contractility effects and, if a hazard is identified, help identify inactive compounds. -- Highlights: ► Cardiac contractility is an important physiological function of the heart. ► Assessment of contractility is a logical part of pre-clinical drug safety testing. ► There are limited validated assays that predict effects of compounds on contractility. ► Using dog myocytes, we have developed an in vitro cardiac contractility assay. ► The assay predicted the in vivo contractility with a good level of accuracy.

  4. Appearance of contractile endothelin-B receptors in rat mesenteric arterial segments following organ culture

    DEFF Research Database (Denmark)

    Adner, M; Geary, G G; Edvinsson, L

    1998-01-01

    contraction. The maximum contractile response to S6c was not altered in segments cultured with foetal calf serum or in buffer solution, but was reduced to about 20% of the control value when cultured in glucose-free buffer solution. The contraction to S6c was abolished in segments placed in cold (4 degrees C......) buffer solution. Removal of the endothelium had no effect on the S6c-induced contractions. Arteries cultured at isometric tension (at 2 mN) for 1 day achieved the same contractile response for ETB agonists as resting segments. Pressurized arteries (60 mmHg) did not constrict to S6c when mounted...

  5. Real-Time Visualization and Quantification of Contractile Ring Proteins in Single Living Cells.

    Science.gov (United States)

    Davidson, Reshma; Liu, Yajun; Gerien, Kenneth S; Wu, Jian-Qiu

    2016-01-01

    Single-cell microscopy provides a powerful tool to visualize cellular and subcellular processes in wild-type and mutant cells by observing fluorescently tagged proteins. Here, we describe three simple methods to visualize fission yeast cells: gelatin slides, coverslip-bottom dishes, and tetrad fluorescence microscopy. These imaging methods and data analysis using free software make it possible to quantify protein localization, dynamics, and concentration with high spatial and temporal resolution. In fission yeast, the actomyosin contractile ring is essential for cytokinesis. We use the visualization and quantification of contractile ring proteins as an example to demonstrate how to use these methods.

  6. Influence of muscle temperature on the contractile properties of the quadriceps muscle in humans with spinal cord injury

    NARCIS (Netherlands)

    Gerrits, H L; de Haan, A; Hopman, M T; van der Woude, L H; Sargeant, A J

    2000-01-01

    Low muscle temperature in paralysed muscles of individuals with spinal cord injury may affect the contractile properties of these muscles. The present study was therefore undertaken to assess the effects of increased muscle temperature on the isometric contractile properties of electrically stimulat

  7. Influence of bladder outlet obstruction and detrusor contractility on residual urine in patients with benign prostatic hyperplasia

    Institute of Scientific and Technical Information of China (English)

    张鹏; 武治津; 高居忠

    2003-01-01

    Objective To study the relationship between the degree of bladder outlet obstruction (BOO), detrusor contractility and residual urine in patients suffering from benign prostatic hyperplasia (BPH).Methods In 181 patients with BPH, degree of BOO, detrusor contractility, residual urine caculated from cathetering combined with the difference between the filling and the voiding were recorded and analysized statistically using urodynamic technique.Results Residual urine increased when the detusor contractility was weakened (F=12.134, P=0.001). In patients wih severe BOO, there was no significant difference in residual urine (F=2.386, P=0.071).Conclusions Increased residual urine is mainly resulted from decreased detrusor contractility. BOO has no significant influence on residual urine. Some patients with normal or weakened detrusor contractility may have more residual urine

  8. Indicadores antropométricos de estado nutricional como preditores de capacidade em idosos

    Directory of Open Access Journals (Sweden)

    Kleyton Trindade Santos

    2014-06-01

    Full Text Available INTRODUÇÃO: Trata-se de estudo seccional que analisou dados de pesquisa epidemiológica de base populacional e domiciliar conduzida em um município do nordeste do Brasil. OBJETIVO: Identificar os indicadores antropométricos de estado nutricional que apresentam melhor capacidade preditiva de capacidade funcional em idosos. MÉTODOS: A população foi constituída por 316 idosos que foram avaliados por meio de questionário contendo informações sociodemográficas, atividade física e condições de saúde, seguido de avaliação antropométrica. A capacidade funcional foi avaliada por meio das escalas de Katz e de Lawton e Brody para atividades básicas e instrumentais da vida diária, respectivamente. Foram utilizados como indicadores de estado nutricional, o índice de massa corporal, a área muscular do braço e o perímetro da panturrilha. Estimou-se modelos simples e múltiplos de regressão logística multinomial, tendo a capacidade funcional como variável dependente e os indicadores antropométricos como variáveis de interesse. RESULTADOS: Participaram do estudo 173 mulheres (54,7% e 143 homens (45,3%. Os resultados da regressão múltipla mostraram que o perímetro da panturrilha foi o único preditor de capacidade funcional em mulheres (≤ P25: OR = 5,77, p = 0,028, para dependência nas atividades instrumentais, enquanto que nos homens o índice de massa corporal foi o único indicador associado (baixo peso: OR = 11,36, p = 0,006; sobrepeso: OR = 22,06, p = 0,002; para dependência nas atividades básicas e instrumentais. CONCLUSÃO: Os resultados permitem concluir que os indicadores antropométricos preditores de capacidade funcional em idosos variam de acordo com o sexo, com o perímetro da panturrilha sendo mais adequada às mulheres e o índice de massa corporal aos homens.

  9. A massa gorda de risco afeta a capacidade aeróbia de jovens adolescentes

    Directory of Open Access Journals (Sweden)

    Luís Massuça

    2013-12-01

    Full Text Available OBJETIVO: Estudar o comportamento do sexo e os efeitos da idade e da massa gorda sobre a capacidade aeróbia de jovens adolescentes. MÉTODOS: Os 621 estudantes do ensino secundário participantes no estudo (14 aos 17 anos; feminino: n = 329, idade, 15,84 ± 0,92 anos; masculino: n = 292, idade, 15,82 ± 0,87 anos foram avaliados em duas categorias: morfologia (altura, peso e % massa gorda - %MG e aptidão física (capacidade aeróbia. As medições antropométricas foram realizadas de acordo com o protocolo descrito por Marfell-Jones e a %MG foi calculada por bioimpedância. A avaliação da capacidade aeróbia foi realizada com o teste aeróbio de corrida - PACER, e VO2máx relativo foi calculado utilizando a equação de Léger. Os resultados das avaliações foram classificados de acordo com os valores normativos das tabelas de referência da bateria de testes FITNESSGRAM® As técnicas estatísticas utilizadas foram: 1 cálculo de frequências; 2 teste t de Student para amostras independentes; e 3 ANOVA two-way seguida do teste post-hoc HSD de Bonferroni. RESULTADOS: 1 existem diferenças significativas entre sexos no que se refere à %MG e ao VO2máx; 2 durante a adolescência, o VO2máx estabiliza nos rapazes e sofre um declínio nas moças; 3 independentemente do sexo, a classe de %MG e a idade cronológica têm um efeito significativo sobre a capacidade aeróbia; e 4 em jovens adolescentes, com %MG de risco, a redução da %MG para níveis saudáveis parece resultar na melhoria da capacidade aeróbia. CONCLUSÃO: O impacto da %MG na capacidade aeróbia, reforça a importância da educação física escolar na promoção da saúde cardiovascular.

  10. Reproducibility of contractile properties of the human paralysed and non-paralysed quadriceps muscle.

    NARCIS (Netherlands)

    Gerrits, H.L.; Hopman, M.T.E.; Sargeant, A.J.; Haan, A. de

    2001-01-01

    This study assessed the reproducibility of electrically evoked, isometric quadriceps contractile properties in eight people with spinal cord injury (SCI) and eight able-bodied (AB) individuals. Over all, the pooled coefficients of variation (CVps) in the SCI group were significantly lower (ranging f

  11. Influence of Contractility on Myocardial Ultrasonic Integrated Backscatter and Cyclic Variation in Integrated Backscatter

    Institute of Scientific and Technical Information of China (English)

    毕小军; 邓又斌; 潘敏; 杨好意; 向慧娟; 常青; 黎春雷

    2002-01-01

    Summary: To evaluate the effects of left ventricular contractility on the changes of average image intensity (AII) of the myocardial integrated backscatter (IB) and cyclic variation in IB (CVIB), 7 adult mongrel dogs were studied. The magnitude of AII and CVIB were measured from myocardial IB carves before and after dobutamine or propranolol infusion. Dobutamine or propranolol did not affect the magnitude of AII (13.8±0. 7 vs 14.7±0. 5, P>0. 05 or 14.3±0.5 vs 14.2±0. 4, P>0. 05). However, dobutamine produced a significant increase in the magnitude of CVIB (6.8±0.3 vs 9.5 ± 0. 6, P<0. 001) and propranolol induced significant decrease in the magnitude of CVIB (7.1±0. 2 vs 5.2±0. 3, P<0. 001). The changes of the magnitude of AII and CVIB in the myocardium have been demonstrated to reflect different myocardial physiological and pathological changes respectively. The alteration of contractility did not affect the magnitude of AII but induced significant change in CVIB. The increase of left ventricular contractility resulted in a significant rise of the magnitude of CVIB and the decrease of left ventricular contractility resulted in a significant fall of the magnitude of CVIB.

  12. Protective Effect of Capsicum Frutescens on Contractile Reactivity of Streptozotocin-Diabetic Rats

    Directory of Open Access Journals (Sweden)

    F. Roghani-Dehkordi

    2005-07-01

    Full Text Available Introduction & Objective : Considering the higher incidence of atherosclerosis and cardiovascular disorders in diabetes mellitus, this study was conducted to evaluate the effect of oral one-month administration of red pepper (Capsicum frutescens on the contractile reactivity of isolated aorta in diabetic rats. Materials & Methods : For this purpose, male Wistar rats(n=32 were randomly divided into control, pepper-treated control, diabetic, and pepper-treated diabetic groups. For induction of diabetes, streptozotcin (STZ was intraperitoneally administered (60 mg/Kg. Pepper-treated groups received pepper mixed with standard pelleted food at a weight ratio of 1/15. After one month, contractile reactivity of aortic rings to KCl and noreadrenaline was determined using isolated tissue setup. Results : Serum glucose level showed a significant increase in diabetic group at 2nd and 4th weeks (P<0.001, while this increase was less marked in pepper-treated diabetic group at the 2nd week (P<0.05. In addition, the latter group showed a lower contraction to KCl (P<0.05 and noreadrenaline (P<0.05 as compared to diabetic group. Meanwhile, there was no significant difference between control and pepper-treated control groups regarding contractile reactivity. Conclusion : It can be concluded that oral administration of pepper for one month could attenuate the contractile responsiveness of the vascular system and may prevent the development of hypertension in diabetic rats.

  13. Studies of membrane fluidity and heart contractile force in Trypanosoma cruzi infected mice

    Directory of Open Access Journals (Sweden)

    Julio E Enders

    2004-11-01

    Full Text Available In Chagas disease serious cardiac dysfunction can appear. We specifically studied the cardiac function by evaluating: ventricle contractile force and norepinephrine response, affinity and density of beta-adrenergic receptors, dynamic properties of myocardial membranes, and electrocardiography. Albino swiss mice (n = 250 were infected with 55 trypomastigotes, Tulahuen strain and studied at 35, 75, and 180 days post-infection, that correspond to the acute, indeterminate, and chronic phase respectively. Cardiac beta-adrenergic receptors' affinity, myocardial contractility, and norepinephrine response progressively decreased from the acute to the chronic phase of the disease (p < 0.01. The density (expressed as fmol/mg.prot of the receptors was similar to non-infected mice (71.96 ± 0.36 in both the acute (78.24 ± 1.67 and indeterminate phases (77.28 ± 0.91, but lower in the chronic disease (53.32 ± 0.71. Electrocardiographic abnormalities began in the acute phase and were found in 65% of the infected-mice during the indeterminate and chronic phases. Membrane contents of triglycerides, cholesterol, and anisotropy were similar in all groups. A quadratic correlation between the affinity to beta-adrenergic receptors and cardiac contractile force was obtained. In conclusion the changes in cardiac beta-adrenergic receptors suggests a correlation between the modified beta-adrenergic receptors affinity and the cardiac contractile force.

  14. Redundant mechanisms recruit actin into the contractile ring in silkworm spermatocytes.

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2008-09-01

    Full Text Available Cytokinesis is powered by the contraction of actomyosin filaments within the newly assembled contractile ring. Microtubules are a spindle component that is essential for the induction of cytokinesis. This induction could use central spindle and/or astral microtubules to stimulate cortical contraction around the spindle equator (equatorial stimulation. Alternatively, or in addition, induction could rely on astral microtubules to relax the polar cortex (polar relaxation. To investigate the relationship between microtubules, cortical stiffness, and contractile ring assembly, we used different configurations of microtubules to manipulate the distribution of actin in living silkworm spermatocytes. Mechanically repositioned, noninterdigitating microtubules can induce redistribution of actin at any region of the cortex by locally excluding cortical actin filaments. This cortical flow of actin promotes regional relaxation while increasing tension elsewhere (normally at the equatorial cortex. In contrast, repositioned interdigitating microtubule bundles use a novel mechanism to induce local stimulation of contractility anywhere within the cortex; at the antiparallel plus ends of central spindle microtubules, actin aggregates are rapidly assembled de novo and transported laterally to the equatorial cortex. Relaxation depends on microtubule dynamics but not on RhoA activity, whereas stimulation depends on RhoA activity but is largely independent of microtubule dynamics. We conclude that polar relaxation and equatorial stimulation mechanisms redundantly supply actin for contractile ring assembly, thus increasing the fidelity of cleavage.

  15. Effects of C-type natriuretic peptide on rat cardiac contractility

    OpenAIRE

    Brusq, Jean-Marie; Mayoux, Eric; Guigui, Laurent; Kirilovsky, Jorge

    1999-01-01

    Natriuretic peptide receptors have been found in different heart preparations. However, the role of natriuretic peptides in the regulation of cardiac contractility remains largely elusive and was, therefore, studied here.The rate of relaxation of electrically stimulated, isolated rat papillary muscles was enhanced (114.4±1.4%, P

  16. Cellular contractility and extracellular matrix stiffness regulate matrix metalloproteinase activity in pancreatic cancer cells.

    Science.gov (United States)

    Haage, Amanda; Schneider, Ian C

    2014-08-01

    The pathogenesis of cancer is often driven by local invasion and metastasis. Recently, mechanical properties of the tumor microenvironment have been identified as potent regulators of invasion and metastasis, while matrix metalloproteinases (MMPs) are classically known as significant enhancers of cancer cell migration and invasion. Here we have been able to sensitively measure MMP activity changes in response to specific extracellular matrix (ECM) environments and cell contractility states. Cells of a pancreatic cancer cell line, Panc-1, up-regulate MMP activities between 3- and 10-fold with increased cell contractility. Conversely, they down-regulate MMP activities when contractility is blocked to levels seen with pan-MMP activity inhibitors. Similar, albeit attenuated, responses are seen in other pancreatic cancer cell lines, BxPC-3 and AsPC-1. In addition, MMP activity was modulated by substrate stiffness, collagen gel concentration, and the degree of collagen cross-linking, when cells were plated on collagen gels ranging from 0.5 to 5 mg/ml that span the physiological range of substrate stiffness (50-2000 Pa). Panc-1 cells showed enhanced MMP activity on stiffer substrates, whereas BxPC-3 and AsPC-1 cells showed diminished MMP activity. In addition, eliminating heparan sulfate proteoglycans using heparinase completely abrogated the mechanical induction of MMP activity. These results demonstrate the first functional link between MMP activity, contractility, and ECM stiffness and provide an explanation as to why stiffer environments result in enhanced cell migration and invasion.

  17. Mitochondria-targeted antioxidant preserves contractile properties and mitochondrial function of skeletal muscle in aged rats.

    Science.gov (United States)

    Javadov, Sabzali; Jang, Sehwan; Rodriguez-Reyes, Natividad; Rodriguez-Zayas, Ana E; Soto Hernandez, Jessica; Krainz, Tanja; Wipf, Peter; Frontera, Walter

    2015-11-24

    Mitochondrial dysfunction plays a central role in the pathogenesis of sarcopenia associated with a loss of mass and activity of skeletal muscle. In addition to energy deprivation, increased mitochondrial ROS damage proteins and lipids in aged skeletal muscle. Therefore, prevention of mitochondrial ROS is important for potential therapeutic strategies to delay sarcopenia. This study elucidates the pharmacological efficiency of the new developed mitochondria-targeted ROS and electron scavenger, XJB-5-131 (XJB) to restore muscle contractility and mitochondrial function in aged skeletal muscle. Male adult (5-month old) and aged (29-month old) Fischer Brown Norway (F344/BN) rats were treated with XJB for four weeks and contractile properties of single skeletal muscle fibres and activity of mitochondrial ETC complexes were determined at the end of the treatment period. XJB-treated old rats showed higher muscle contractility associated with prevention of protein oxidation in both muscle homogenate and mitochondria compared with untreated counterparts. XJB-treated animals demonstrated a high activity of the respiratory complexes I, III, and IV with no changes in citrate synthase activity. These data demonstrate that mitochondrial ROS play a causal role in muscle weakness, and that a ROS scavenger specifically targeted to mitochondria can reverse age-related alterations of mitochondrial function and improve contractile properties in skeletal muscle.

  18. Effect of pinaverium bromide on stress-induced colonic smooth muscle contractility disorder in rats

    OpenAIRE

    Dai, Yun; Liu, Jian-Xiang; Li, Jun-Xia; Xu, Yun-Feng

    2003-01-01

    AIM: To investigate the effect of pinaverium bromide, a L-type calcium channel blocker with selectivity for the gastrointestinal tract on contractile activity of colonic circular smooth muscle in normal or cold-restraint stressed rats and its possible mechanism.

  19. Impaired pulmonary artery contractile responses in a rat model of microgravity: role of nitric oxide

    Science.gov (United States)

    Nyhan, Daniel; Kim, Soonyul; Dunbar, Stacey; Li, Dechun; Shoukas, Artin; Berkowitz, Dan E.

    2002-01-01

    Vascular contractile hyporesponsiveness is an important mechanism underlying orthostatic intolerance after microgravity. Baroreceptor reflexes can modulate both pulmonary resistance and capacitance function and thus cardiac output. We hypothesized, therefore, that pulmonary vasoreactivity is impaired in the hindlimb-unweighted (HLU) rat model of microgravity. Pulmonary artery (PA) contractile responses to phenylephrine (PE) and U-46619 (U4) were significantly decreased in the PAs from HLU vs. control (C) animals. N(G)-nitro-L-arginine methyl ester (10(-5) M) enhanced the contractile responses in the PA rings from both C and HLU animals and completely abolished the differential responses to PE and U4 in HLU vs. C animals. Vasorelaxant responses to ACh were significantly enhanced in PA rings from HLU rats compared with C. Moreover, vasorelaxant responses to sodium nitroprusside were also significantly enhanced. Endothelial nitric oxide synthase (eNOS) and soluble guanlyl cyclase expression were significantly enhanced in PA and lung tissue from HLU rats. In marked contrast, the expression of inducible nitric oxide synthase was unchanged in lung tissue. These data support the hypothesis that vascular contractile responsiveness is attenuated in PAs from HLU rats and that this hyporesponsiveness is due at least in part to increased nitric oxide synthase activity resulting from enhanced eNOS expression. These findings may have important implications for blood volume distribution and attenuated stroke volume responses to orthostatic stress after microgravity exposure.

  20. Hydrogen ion changes and contractile behavior in the perfused rat heart

    NARCIS (Netherlands)

    Cingolani, H.E.; Maas, A.H.J.; Zimmerman, A.N.E.; Meijler, F.L.

    1975-01-01

    The effect of acid-base alterations was analyzed using isolated rat hearts perfused at constant coronary perfusion pressure, and stimulated to contract at constant rate. The amount of shortening in the major axis and its derivative were measured to assess myocardial contractility. Both the 'respirat

  1. Contractile properties of the quadriceps muscle in individuals with spinal cord injury

    NARCIS (Netherlands)

    Gerrits, H L; De Haan, A; Hopman, M T; van Der Woude, L H; Jones, D A; Sargeant, A J

    1999-01-01

    Selected contractile properties and fatigability of the quadriceps muscle were studied in seven spinal cord-injured (SCI) and 13 able-bodied control (control) individuals. The SCI muscles demonstrated faster rates of contraction and relaxation than did control muscles and extremely large force oscil

  2. A device for rapid and quantitative measurement of cardiac myocyte contractility

    Science.gov (United States)

    Gaitas, Angelo; Malhotra, Ricky; Li, Tao; Herron, Todd; Jalife, José

    2015-03-01

    Cardiac contractility is the hallmark of cardiac function and is a predictor of healthy or diseased cardiac muscle. Despite advancements over the last two decades, the techniques and tools available to cardiovascular scientists are limited in their utility to accurately and reliably measure the amplitude and frequency of cardiomyocyte contractions. Isometric force measurements in the past have entailed cumbersome attachment of isolated and permeabilized cardiomyocytes to a force transducer followed by measurements of sarcomere lengths under conditions of submaximal and maximal Ca2+ activation. These techniques have the inherent disadvantages of being labor intensive and costly. We have engineered a micro-machined cantilever sensor with an embedded deflection-sensing element that, in preliminary experiments, has demonstrated to reliably measure cardiac cell contractions in real-time. Here, we describe this new bioengineering tool with applicability in the cardiovascular research field to effectively and reliably measure cardiac cell contractility in a quantitative manner. We measured contractility in both primary neonatal rat heart cardiomyocyte monolayers that demonstrated a beat frequency of 3 Hz as well as human embryonic stem cell-derived cardiomyocytes with a contractile frequency of about 1 Hz. We also employed the β-adrenergic agonist isoproterenol (100 nmol l-1) and observed that our cantilever demonstrated high sensitivity in detecting subtle changes in both chronotropic and inotropic responses of monolayers. This report describes the utility of our micro-device in both basic cardiovascular research as well as in small molecule drug discovery to monitor cardiac cell contractions.

  3. Contractile speed and fatigue of adductor pollicis muscle in multiple sclerosis

    NARCIS (Netherlands)

    de Ruiter, C J; Jongen, P J; van der Woude, L H; de Haan, A

    2001-01-01

    The purpose of the study was to investigate differences in contractile speed, force, and fatigability of the adductor pollicis muscle between 12 patients with multiple sclerosis (MS) and 8 sedentary control subjects matched for age and gender. There were no differences between the patients with MS a

  4. Consecutive bouts of diverse contractile activity alter acute responses in human skeletal muscle

    DEFF Research Database (Denmark)

    Coffey, Vernon G; Pilegaard, Henriette; Garnham, Andrew P;

    2009-01-01

    -activated receptor gamma coactivator-1alpha mRNA did not reveal an order effect. We conclude that acute responses to diverse bouts of contractile activity are modified by the exercise order. Moreover, undertaking divergent exercise in close proximity influences the acute molecular profile and likely exacerbates...

  5. Four days of muscle disuse impairs single fiber contractile function in young and old healthy men

    DEFF Research Database (Denmark)

    Hvid, Lars G; Suetta, Charlotte; Aagaard, Per;

    2013-01-01

    The purpose of the study was to investigate the effects of 4days of disuse (knee brace) on contractile function of isolated vastus lateralis fibers (n=486) from 11 young (24.3±0.9yrs) and 11 old (67.2±1.0yrs) healthy men having comparable levels of physical activity. Prior to disuse single fiber...

  6. Prolonged ischemic heart disease and coronary artery bypass - relation to contractile reserve

    DEFF Research Database (Denmark)

    Kofoed, Klaus F; Bangsgaard, Regitze; Carstensen, Steen;

    2002-01-01

    OBJECTIVE: A major effect of coronary artery bypass grafting (CABG) in patients with ischemic heart disease and impaired left ventricular (LV) contractile function is believed to be an improvement in LV function due to recovery of dysfunctional, but viable myocardium. However, recent studies have...

  7. In vivo visualization and quantification of collecting lymphatic vessel contractility using near-infrared imaging

    Science.gov (United States)

    Chong, Chloé; Scholkmann, Felix; Bachmann, Samia B.; Luciani, Paola; Leroux, Jean-Christophe; Detmar, Michael; Proulx, Steven T.

    2016-01-01

    Techniques to image lymphatic vessel function in either animal models or in the clinic are limited. In particular, imaging methods that can provide robust outcome measures for collecting lymphatic vessel function are sorely needed. In this study, we aimed to develop a method to visualize and quantify collecting lymphatic vessel function in mice, and to establish an in vivo system for evaluation of contractile agonists and antagonists using near-infrared fluorescence imaging. The flank collecting lymphatic vessel in mice was exposed using a surgical technique and a near-infrared tracer was infused into the inguinal lymph node. Collecting lymphatic vessel contractility and valve function could be easily visualized after the infusion. A diameter tracking method was established and the diameter of the vessel was found to closely correlate to near-infrared fluorescence signal. Phasic contractility measures of frequency and amplitude were established using an automated algorithm. The methods were validated by tracking the vessel response to topical application of a contractile agonist, prostaglandin F2α, and by demonstrating the potential of the technique for non-invasive evaluation of modifiers of lymphatic function. These new methods will enable high-resolution imaging and quantification of collecting lymphatic vessel function in animal models and may have future clinical applications. PMID:26960708

  8. Dietary exposure to ergot alkaloids decreases contractility of bovine mesenteric vasculature.

    Science.gov (United States)

    Egert, A M; Kim, D H; Schrick, F N; Harmon, D L; Klotz, J L

    2014-04-01

    Ergot alkaloids are hypothesized to cause vasoconstriction in the midgut, and prior exposure may affect the vasoactivity of these compounds. The objectives of this study were to profile vasoactivity of ergot alkaloids in bovine mesenteric artery (MA) and vein (MV) and determine if previous exposure to endophyte-infected tall fescue seed affected vasoactivity of ergocryptine (ERP), ergotamine (ERT), ergocristine (ERS), ergocornine (ERO), ergonovine (ERN), lysergic acid (LSA), ergovaline-containing tall fescue seed extract (EXT), and 5-hydroxytryptamine (5HT; serotonin). Ruminally cannulated Angus steers (n = 12; BW = 547 ± 31 kg) were paired by weight and randomly assigned to 6 blocks. Steers were ruminally dosed daily with 1 kg of either endophyte-infected (E+; 4.45 mg ergovaline/kg DM) or endophyte-free (E-; 0 mg ergovaline/kg DM) tall fescue seed for 21 d before slaughter. Branches of MA and MV supporting the cranial portion of the ileum were collected after slaughter on d 22, placed in a modified Krebs-Henseleit buffer on ice, cleaned, sectioned, and mounted in a multimyograph chamber. Contractile response was normalized to a maximum KCl response. Inner diameter (P = 0.04) and outer diameter (P = 0.02) of MA were smaller for E+ steers than E- steers. Maximum contractile responses to 120 mM KCl were not different between seed treatments in MA (P = 0.33; E-: 2.67 ± 0.43 g; E+: 3.33 ± 0.43 g) or MV (P = 0.26; E-: 2.01 ± 0.18 g; E+: 1.81 ± 0.18 g). Steers receiving E+ had a smaller (P < 0.01) MA contractile response than E- steers to ERP, ERT, ERS, ERO, ERN, EXT, and 5HT. Steers receiving E+ had a smaller (P < 0.05) MV contractile response than E- steers to ERP, ERT, ERS, ERN, EXT, and 5HT. Lysergic acid failed to induce a contractile response in MA and MV. The contractile response in MA and MV of E- steers produced by 5HT was very large. The EXT was the most potent (P < 0.05) agonist in MV and MA of E+ steers. These data showed that ergot alkaloids were

  9. Associação entre a Incisura Diastólica das Artérias Uterinas e a Histologia do Leito Placentário em Grávidas com Pré-eclâmpsia Association between Diastolic Notch of Uterine Artery and the Histology of the Placental Bed in Pregnant Women with Preeclampsia

    Directory of Open Access Journals (Sweden)

    Regina Amélia Lopes Pessoa de Aguiar

    2001-08-01

    Full Text Available Objetivo: avaliar a associação entre a presença da incisura diastólica nas artérias uterinas maternas e as alterações histopatológicas dos vasos útero-placentários. Métodos: estudo transversal incluindo 144 pacientes com gestação única interrompida por via abdominal entre a 27ª e a 41ª semana. Destas, 84 gestações estavam associadas à pré-eclâmpsia e 60 não apresentaram intercorrências clínicas. Neste grupo realizou-se dopplerfluxometria de ambas as artérias uterinas e biópsia do leito placentário. Resultados: das 144 pacientes, 88 (61% tiveram o fragmento da biópsia considerado representativo do leito placentário. A incisura diastólica estava presente em 40 (70% dos casos de alterações fisiológicas inadequadas e ausente em 28 (90% dos casos de alterações fisiológicas presentes (p=0,05. A dopplerfluxometria apresentou sensibilidade de 70%, especificidade de 90% e valores preditivos positivo e negativo de 44 e 97%, respectivamente. A associação entre a presença de incisura diastólica bilateral das artérias uterinas e arteriopatia decidual também foi significativa (dos 25 casos de arteriopatia decidual a incisura estava presente em 24, p=0,05. A sensibilidade da dopplerfluxometria foi de 96%, especificidade de 70% e valores preditivos positivo e negativo de 26 e 99%, respectivamente, ao passo que para a arteriolosclerose a dopplerfluxometria apresentou sensibilidade de 80%, especificidade de 55% e valores preditivos positivo e negativo de 17 e 96%, respectivamente. Conclusões: a incisura diastólica nas artérias uterinas maternas é indicador seguro de vasculopatia no leito placentário. A adequada invasão trofoblástica do leito placentário, revelada por histologia típica de alterações fisiológicas, resulta na ausência de incisura diastólica bilateral das artérias uterinas maternas.Purpose: to evaluate the association between the presence of diastolic notch in the maternal uterine arteries, and

  10. CAPACIDADES TECNOLÓGICAS EN LOS PAÍSES MIEMBROS Y ASOCIADOS DEL MERCOSUR

    Directory of Open Access Journals (Sweden)

    Caterina Clemenza

    2016-05-01

    Full Text Available Este estudio tiene por objeto analizar el perfil de las capacidades Tecnológicas de los Países Miembros y Asociados del Mercado Común del Sur. La investigación es de carácter descriptivo, utilizando técnicas de análisis multivariante para el examen de los datos. Los resultados evidenciaron la existencia de dos grupos de países con gran diferencia, sustentadas en los niveles de inversión que realizan para incrementar el gasto, en actividades científico-tecnológica y de I+D, con limitaciones para armonizar las políticas de públicas, que promueva efectivamente el desarrollo y la acumulación de capacidades tecnológicas, conducentes al progreso económico nacional.

  11. Capacidad de carga de las anclas de plataformas petroleras. // Load capacity of oil platforms anchors.

    Directory of Open Access Journals (Sweden)

    J. García de la Figal Costales

    2001-07-01

    Full Text Available Se determina la capacidad de carga de las anclas de solicitación vertical, empleadas en la fijación de las plataformasperforadoras de petróleo de aguas profundas. Para ello, se desarrollan varios modelos del proceso de retención del ancla enel fango del fondo marino por medio del método de los Elementos Finitos. Se analizan con ellos, la influencia de variosparámetros en la capacidad de carga.Palabras claves: ancla, petróleo, elementos finitos, plataformas petroleras._________________________________________________________________________________AbstractThe load capacity of anchors for vertical fixation used as petroleum perforators platforms on deep waters are determined.Several models of retention process of the anchor are developed by means of Finite Elements Method and the influence ofseveral parameters in the load capacity are analized.Key words: anchors, petroleum, Finite Elements Method (FEM.

  12. Avaliação da capacidade na rede ferroviária portuguesa

    OpenAIRE

    Ferreira, Ricardo José Teixeira

    2014-01-01

    Tendo em conta a escassez de combustíveis fósseis e o aumento do custo destes, torna-se importante o estudo e desenvolvimento de alternativas ao transporte rodoviário. O transporte ferroviário surge, assim, como uma possível opção. Esta dissertação apresenta os diferentes tipos de capacidade de uma rede ferroviária, os fatores que a influenciam e métodos de obtenção da mesma. Em relação aos métodos de obtenção da capacidade, esta dissertação foca-se especialmente no método UIC 406, que é s...

  13. Método para valorar la concentración y la capacidad antioxidante del ácido úrico

    OpenAIRE

    Campos, Carlos; Guzmán, Rodrigo; López Fernández, María Encarnación; Casado Moragón, Ángela

    2010-01-01

    La presente invención se refiere a un método para valorar la concentración y la capacidad antioxidante del ácido úrico en muestras ya sean biológicas, en muestras procedentes de la industria alimentaria, en cosméticos ... Además mediante la presente invención se permite determinar la capacidad antioxidante sin la contribución del ácido úrico y la capacidad antioxidante total de una muestra.

  14. Determinantes de la capacidad de innovación en PYMES regionales Determinants of innovativeness in regional SMES

    OpenAIRE

    Carlos Maria Fernández-Jardón

    2013-01-01

    DOI: 10.5902/198346597689La capacidad de innovación es una competencia distintiva que permite innovar y, en consecuencia, potencia la competitividad, especialmente en las pequeñas y medianas empresas (PYME). Dicha capacidad se ve condicionada por factores internos y externos. Este artículo analiza como combina la empresa dichos factores para mejorar la capacidad de innovación. Por un lado, la empresa genera una competencia distintiva denominada gestión de los recursos humanos y tecnológicos a...

  15. Avaliação da capacidade funcional e pulmonar em pacientes pediátricos transplantados renais

    OpenAIRE

    Renata Salatti Ferrari; Camila Wohlgemuth Schaan; Karina Cerutti; Juliana Mendes; Clotilde Druck Garcia; Mariane Borba Monteiro; Janice Luisa Lukrafka

    2013-01-01

    INTRODUÇÃO: Pacientes pediátricos submetidos a transplante renal podem apresentar alterações na função pulmonar, bem como na capacidade funcional para o exercício. OBJETIVO: Avaliar a capacidade funcional e capacidade pulmonar de crianças e adolescentes submetidas a transplante renal. MÉTODO: Foram avaliadas crianças e adolescentes com idade entre 6 e 18 anos em acompanhamento no ambulatório de Nefrologia do Hospital da Criança Santo Antônio, Santa Casa de Porto Alegre-RS, Brasil, no período ...

  16. Estudio de la integración visuomotora en niños con altas capacidades intelectuales

    OpenAIRE

    Gaona Bosque, Sara

    2011-01-01

    A lo largo de los años diversos autores han tratado de demostrar que los niños superdotados -actualmente denominados como niños con “altas capacidades intelectuales”- además de tener una mayor capacidad intelectual destacan también por poseer otras habilidades superiores, como por ejemplo, mayor desarrollo cognitivo, mayor capacidad creativa, niveles superiores de percepción, etc. En el presente estudio tratamos de determinar si también poseen una mejor integración visuomotora. Entendiendo la...

  17. Antecedentes estratégicos de la capacidad de innovación empresarial y sus efectos en los resultados

    OpenAIRE

    Fidel Criado, Pilar

    2016-01-01

    La presente tesis doctoral propone un modelo teórico sobre los antecedentes estratégicos que influyen en la capacidad de innovación de la empresa y su relación con los resultados empresariales. El modelo se construye desde una aproximación integradora de teorías y enfoques que une la teoría de recursos y capacidades y su extensión al enfoque de las capacidades dinámicas y el enfoque basado en el conocimiento, el enfoque al marketing, la teoría del aprendizaje organizacional y la Lógica Domina...

  18. Predicting changes in cardiac myocyte contractility during early drug discovery with in vitro assays

    Energy Technology Data Exchange (ETDEWEB)

    Morton, M.J., E-mail: michael.morton@astrazeneca.com [Discovery Sciences, AstraZeneca, Macclesfield, Cheshire SK10 4TG (United Kingdom); Armstrong, D.; Abi Gerges, N. [Drug Safety and Metabolism, AstraZeneca, Macclesfield, Cheshire SK10 4TG (United Kingdom); Bridgland-Taylor, M. [Discovery Sciences, AstraZeneca, Macclesfield, Cheshire SK10 4TG (United Kingdom); Pollard, C.E.; Bowes, J.; Valentin, J.-P. [Drug Safety and Metabolism, AstraZeneca, Macclesfield, Cheshire SK10 4TG (United Kingdom)

    2014-09-01

    Cardiovascular-related adverse drug effects are a major concern for the pharmaceutical industry. Activity of an investigational drug at the L-type calcium channel could manifest in a number of ways, including changes in cardiac contractility. The aim of this study was to define which of the two assay technologies – radioligand-binding or automated electrophysiology – was most predictive of contractility effects in an in vitro myocyte contractility assay. The activity of reference and proprietary compounds at the L-type calcium channel was measured by radioligand-binding assays, conventional patch-clamp, automated electrophysiology, and by measurement of contractility in canine isolated cardiac myocytes. Activity in the radioligand-binding assay at the L-type Ca channel phenylalkylamine binding site was most predictive of an inotropic effect in the canine cardiac myocyte assay. The sensitivity was 73%, specificity 83% and predictivity 78%. The radioligand-binding assay may be run at a single test concentration and potency estimated. The least predictive assay was automated electrophysiology which showed a significant bias when compared with other assay formats. Given the importance of the L-type calcium channel, not just in cardiac function, but also in other organ systems, a screening strategy emerges whereby single concentration ligand-binding can be performed early in the discovery process with sufficient predictivity, throughput and turnaround time to influence chemical design and address a significant safety-related liability, at relatively low cost. - Highlights: • The L-type calcium channel is a significant safety liability during drug discovery. • Radioligand-binding to the L-type calcium channel can be measured in vitro. • The assay can be run at a single test concentration as part of a screening cascade. • This measurement is highly predictive of changes in cardiac myocyte contractility.

  19. Predicting changes in cardiac myocyte contractility during early drug discovery with in vitro assays

    International Nuclear Information System (INIS)

    Cardiovascular-related adverse drug effects are a major concern for the pharmaceutical industry. Activity of an investigational drug at the L-type calcium channel could manifest in a number of ways, including changes in cardiac contractility. The aim of this study was to define which of the two assay technologies – radioligand-binding or automated electrophysiology – was most predictive of contractility effects in an in vitro myocyte contractility assay. The activity of reference and proprietary compounds at the L-type calcium channel was measured by radioligand-binding assays, conventional patch-clamp, automated electrophysiology, and by measurement of contractility in canine isolated cardiac myocytes. Activity in the radioligand-binding assay at the L-type Ca channel phenylalkylamine binding site was most predictive of an inotropic effect in the canine cardiac myocyte assay. The sensitivity was 73%, specificity 83% and predictivity 78%. The radioligand-binding assay may be run at a single test concentration and potency estimated. The least predictive assay was automated electrophysiology which showed a significant bias when compared with other assay formats. Given the importance of the L-type calcium channel, not just in cardiac function, but also in other organ systems, a screening strategy emerges whereby single concentration ligand-binding can be performed early in the discovery process with sufficient predictivity, throughput and turnaround time to influence chemical design and address a significant safety-related liability, at relatively low cost. - Highlights: • The L-type calcium channel is a significant safety liability during drug discovery. • Radioligand-binding to the L-type calcium channel can be measured in vitro. • The assay can be run at a single test concentration as part of a screening cascade. • This measurement is highly predictive of changes in cardiac myocyte contractility

  20. Cardiac-Specific Knockout of ETA Receptor Mitigates Paraquat-Induced Cardiac Contractile Dysfunction.

    Science.gov (United States)

    Wang, Jiaxing; Lu, Songhe; Zheng, Qijun; Hu, Nan; Yu, Wenjun; Li, Na; Liu, Min; Gao, Beilei; Zhang, Guoyong; Zhang, Yingmei; Wang, Haichang

    2016-07-01

    Paraquat (1,1'-dim ethyl-4-4'-bipyridinium dichloride), a highly toxic quaternary ammonium herbicide widely used in agriculture, exerts potent toxic prooxidant effects resulting in multi-organ failure including the lung and heart although the underlying mechanism remains elusive. Recent evidence suggests possible involvement of endothelin system in paraquat-induced acute lung injury. This study was designed to examine the role of endothelin receptor A (ETA) in paraquat-induced cardiac contractile and mitochondrial injury. Wild-type (WT) and cardiac-specific ETA receptor knockout mice were challenged to paraquat (45 mg/kg, i.p.) for 48 h prior to the assessment of echocardiographic, cardiomyocyte contractile and intracellular Ca(2+) properties, as well as apoptosis and mitochondrial damage. Levels of the mitochondrial proteins for biogenesis and oxidative phosphorylation including UCP2, HSP90 and PGC1α were evaluated. Our results revealed that paraquat elicited cardiac enlargement, mechanical anomalies including compromised echocardiographic parameters (elevated left ventricular end-systolic and end-diastolic diameters as well as reduced factional shortening), suppressed cardiomyocyte contractile function, intracellular Ca(2+) handling, overt apoptosis and mitochondrial damage. ETA receptor knockout itself failed to affect myocardial function, apoptosis, mitochondrial integrity and mitochondrial protein expression. However, ETA receptor knockout ablated or significantly attenuated paraquat-induced cardiac contractile and intracellular Ca(2+) defect, apoptosis and mitochondrial damage. Taken together, these findings revealed that endothelin system in particular the ETA receptor may be involved in paraquat-induced toxic myocardial contractile anomalies possibly related to apoptosis and mitochondrial damage. PMID:26089164

  1. Short-Chain Fatty Acid Propionate Alleviates Akt2 Knockout-Induced Myocardial Contractile Dysfunction

    Directory of Open Access Journals (Sweden)

    Linlin Li

    2012-01-01

    Full Text Available Background and Aims. Dysregulation of Akt has been implicated in diseases such as cancer and diabetes, although little is known about the role of Akt deficiency on cardiomyocyte contractile function. This study was designed to examine the effect of Akt2 knockout-induced cardiomyocyte contractile response and the effect of dietary supplementation of short-chain fatty acid propionate on Akt2 knockout-induced cardiac dysfunction, if any. Methods and Results. Adult male wild-type (WT and Akt2 knockout mice were treated with propionate (0.3 g/kg, p.o. or vehicle for 7 days. Oral glucose tolerance test (OGTT was performed. Cardiomyocyte contractile function and mitochondrial membrane potential were assessed. Expression of insulin-signaling molecules Akt, PTEN, GSK3β, and eNOS receptors for short-chain fatty acids GPR41, and GPR43 as well as protein phosphatase PP2AA, PP2AB, PP2C were evaluated using Western blot analysis. Our results revealed that Akt2 knockout led to overt glucose intolerance, compromised cardiomyocyte contractile function (reduced peak shortening and maximal velocity of shortening/relengthening as well as prolonged relengthening, loss of mitochondrial membrane potential, decreased GPR41 and elevated GPR43 expression, all of which, with the exception of glucose intolerance and elevated GPR43 level, were significantly attenuated by propionate. Neither Akt2 knockout nor propionate affected the expression of protein phosphatases, eNOS, pan, and phosphorylated PTEN and GSK3β. Conclusions. Taken together, these data depicted that Akt2 knockout may elicit cardiomyocyte contractile and mitochondrial defects and a beneficial role of propionate or short-chain fatty acids against Akt2 deficiency-induced cardiac anomalies.

  2. Mechanism underlying the reversal of contractility dysfunction in experimental colitis by cyclooxygenase-2 inhibition.

    Science.gov (United States)

    Khan, I; Oriowo, M A

    2006-03-01

    Inflammatory bowel diseases are associated with reduced colonic contractility and induction of cyclooxygenase-2. In this study a possible role of cyclooxygenase-2 in and the underlying mechanism of the reduced contractility were investigated in experimental colitis. The effects of meloxicam, a cyclooxygenase-2 selective inhibitor were examined on colonic contractility and MAP kinase p38 and ERK(1/2) expression. Colitis was induced in Sprague-Dawley male rats by intra-colonic instillation of trinitrobenzenesulphonic acid (TNBS; 40 mg/rat in 50 ethanol). The animals were divided into three groups. Group 1 (n=9) received meloxicam (3 mg/kg-day) gavage 1 h before and 1 day (Group 2) after induction of colitis. Group 3 (n=9) received phosphate buffered saline (PBS) in a similar manner and served as colitic control. The non colitic control animals received meloxicam in a similar manner. The animals were sacrificed after 5 days of treatment, colon was cleaned with PBS and colonic smooth muscle was obtained which was used in this study. Meloxicam treatment given 1 h before or 1 day after administration of colitis restored the reduced colonic contractility without affecting the sensitivity to carbachol. The levels of colonic smooth muscle IL-1beta mRNA, PGE(2), ERK(1/2), p38, malondialdehyde, myeloperoxidase activity and colonic mass were increased, whereas the body weight was decreased due to TNBS. The changes except colonic muscle mass and p38 expression were reversed by meloxicam treatment. These findings indicate that restoration of reduced colonic contractility by meloxicam is mediated by ERK(1/2), and that ERK(1/2) may serve as an important anti inflammatory target for treatment of colitis. PMID:16835710

  3. ¿Contribuyen las asignaturas de finanzas al desarrollo de la capacidad gerencial del administrador?

    Directory of Open Access Journals (Sweden)

    Luis M. Prada B.

    1996-12-01

    Full Text Available En este artículo el autor presenta los resultados de un trabajo de investigación sobre el aporte de las asignaturas de finanzas al desarrollo de capacidades gerenciales de innovación, liderazgo, comunicación e integridad ética, entre estudiantes de la carrera de Administración en la Universidad Nacional de Colombia. La investigación se realizó de dos maneras: una teórica, consistente en verificar que los programas de esas asignaturas mencionaran de manera explícita en los objetivos, contenidos, metodologías y formas de evaluación, la intención de propiciar el desarrollo de dichas capacidades. La otra, práctica, consistente en conocer la opinión de los estudiantes sobre el aporte real que hicieron esas asignaturas a su desarrollo personal y profesional, con respecto a las mencionadas capacidades. Según los estudiantes, los programas de las cuatro asignaturas obligatorias de finanzas no integran, ni en su enunciado, ni en su desarrollo, principios y estrategias educativas, elementos que promuevan el desarrollo de las mencionadas características gerenciales.

  4. Uso público y capacidad de carga perceptual en espacios naturales protegidos

    Directory of Open Access Journals (Sweden)

    Felipe Leco Berrocal

    2013-01-01

    Full Text Available Este trabajo muestra algunos de los resultados de la investigación realizada en el Proyecto «Las áreas de uso público en la Reserva de la Biosfera de Monfragüe. Accesibilidad y capacidad de carga» (Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica 2004-2007. Orden MAM/321/207. Expte. 024/SGTB/2007/4.1. En líneas generales, se presenta un estudio de las principales áreas de uso público desde la perspectiva de la capacidad de carga, ya que dichas áreas polarizan por regla general los flujos de usuarios, las inversiones y son el eje principal sobre el que descansa la afluencia de usuarios al Parque, por ello es necesario evaluar no sólo la capacidad de carga sino también la intensidad de su uso.

  5. Las capacidades tecnológicas para la innovación en empresas de manufactura

    Directory of Open Access Journals (Sweden)

    Arturo García Velázquez

    2016-02-01

    Full Text Available Las capacidades tecnológicas son habilidades requeridas para un uso efectivo del conocimiento tecnológico. Permiten que las empresas de manufactura puedan innovar, un requisito básico para competir de manera efectiva en los mercados. El objetivo de este trabajo de investigación fue analizar los factores que relacionan las capacidades tecnológicas con la innovación. Para ello se hizo un análisis de la literatura, considerando los aportes de múltiples autores relevantes. Se contrastaron, además, argumentos existentes sobre empresas en economías maduras con algunos que consideran la realidad de organizaciones en economías emergentes. Se encontró que las capacidades tecnológicas son un factor determinante de innovación, pero que estas varían, en particular, en función del nivel de desarrollo de los países.

  6. Trabalhadores da CEASA: fatores associados à fadiga e capacidade para o trabalho

    Directory of Open Access Journals (Sweden)

    Valéria Aparecida Masson

    2015-06-01

    Full Text Available RESUMOObjetivo:avaliar características sociodemográficas, estilo de vida e condições de saúde relacionadas à fadiga e à capacidade para o trabalho.Método:estudo transversal com 90 trabalhadores da Central de Abastecimento de Campinas, com dados coletados em 2011. Foram utilizados três questionários: Fadiga; Índice de Capacidade para o Trabalho e Sociodemográfico.Resultados:na análise de regressão univariada as variáveis associadas a capacidade para o trabalho foram: escolaridade, uso de medicamentos, estresse, dor nos últimos seis meses e dor na última semana. Na análise de regressão univariada as variáveis associadas à fadiga foram: escolaridade, estresse, sonolência, dor nos últimos seis meses, dor na última semana e problemas de saúde.Conclusão:existe necessidade de implantação de programas de promoção da saúde entre estes trabalhadores.

  7. Distribuição dos depósitos de glicogênio durante a odontogênese intra-uterina em Calomys callosus = Distribution of glycogen storage during odontogenesis in fetal development in Calomys callosus

    Directory of Open Access Journals (Sweden)

    Vieira, Andreia Espíndola

    2006-01-01

    Full Text Available As células animais estocam carboidratos na forma de glicogênio como fonte de energia. Esses depósitos ocorrem amplamente nos tecidos embrionários para disponibilização rápida de energia, principalmente durante a diferenciação e o desenvolvimento das células. O presente trabalho avaliou a distribuição de depósitos de glicogênio durante a odontogênese intra-uterina em Calomys callosus utilizando fetos com 12 a 20 dias, sendo 5 fetos de cada dia. As cabeças dos fetos foram removidas e fixadas em formaldeído 10% em PBS. Os espécimes foram processados para inclusão em glicol metacrilato (Leica Historesin, sendo aqueles com mais de 15 dias previamente descalcificados em EDTA. Para cada dia de desenvolvimento obteve-se cortes semi-seriados com 3 μm de espessura. As lâminas foram divididas em 2 grupos, sendo um grupo submetido à reação P. A. S. e o outro submetido à amilase salivar e em seguida à reação P. A. S. (grupo controle. Ao microscópio de luz foi observada, nas fases iniciais da odontogênese (12-15 dias, reação P. A. S. mais evidente nas células ectomesenquimais e aos 16-17 dias a reação predominou na região do folículo dental. Aos 18-19 dias a reação intensificou-se no retículo estrelado e aos 20 dias nas células do epitélio interno e na papila dental. De acordo com a metodologia empregada e com os resultados obtidos, concluímos que ocorre variação dos depósitos de glicogênio nas diferentes regiões do germe dental ao longo da odontogênese e que o Calomys callosus representa um modelo biológico para estudos da odontogênese.

  8. Desempenho reprodutivo de fêmeas suínas inseminadas pela técnica intra-uterina ou tradicional Reproductive performance of swine females inseminated by intrauterine or traditional technique

    Directory of Open Access Journals (Sweden)

    Djane Dallanora

    2004-08-01

    Full Text Available O desempenho reprodutivo de fêmeas suínas foi avaliado com o objetivo de comparar duas técnicas de inseminação. Foram inseminadas, em delineamento inteiramente casualizado, 608 fêmeas com ordem de parto de dois a quatro, em dois tratamentos: inseminação intra-uterina com 1,5 bilhão de espermatozóides em 60 mL e inseminação tradicional, com 3 bilhões em 90 mL. Foi possível introduzir o cateter intra-uterino em 97,4% das fêmeas e houve sangramento em 9,5%, as quais apresentaram retorno ao estro superior (pThe reproductive performance of sows was evaluated aiming at the comparison of two insemination techniques. In a completely randomized design, 608 females of 2-4 parities were inseminated in two treatments: intrauterine with 1.5x10(9 spermatozoa/60 mL or traditional insemination with 3x10(9 spermatozoa/90 mL. It was possible to insert the intrauterine catheter in 97.4% of females and bleeding was observed in 9.5%, which had a higher probability to repeat estrus (p<0.05. The percentage of semen backflow volume, during two hours after insemination, was significantly higher (p<0.05 in intrauterine insemination than traditional, whereas sperm backflow percentage was similar. The sperm backflow percentage did not influence the farrowing rate and the litter size. There was no difference in the return to estrus rate (3.6%; 4.3%, pregnancy rate at 21 days post-insemination (99.5%; 97.2%, adjusted farrowing rate (94.9%; 94.3% and average litter size (11.6; 11.8 piglets between treatments, respectively. The intrauterine insemination ensures a reproductive performance similar to traditional, but with a lower sperm number.

  9. Embolização das artérias uterinas com partículas de PVA-PVAC esférico como preparo para posterior ressecção cirúrgica de miomas

    Directory of Open Access Journals (Sweden)

    Juraci Ghiaroni

    2013-10-01

    Full Text Available OBJETIVO: avaliar a utilização de uma nova partícula de polivinil álcool e polivinil acetato (PVA-PVAc esférica, para embolização das artérias uterinas, em pacientes portadoras de mioma, com indicação cirúrgica. MÉTODOS: doze pacientes foram submetidas à embolização de miomas uterinos com partículas de PVA-PVAc. Três a nove meses depois, realizou-se uma laparotomia com miomectomia. Analisaram-se os seguintes parâmetros: volume do útero e do maior mioma; concentrações do hormônio folículo estimulante e de hemoglobina; sangramento menstrual (número de dias e de absorventes utilizados, sinais e sintomas antes do tratamento, após a embolização e após a miomectomia. RESULTADOS: a média de idade foi 37 anos e a média do volume uterino, previamente ao tratamento, de 939,3cc. Três anos após a embolização, observou-se diminuição do volume uterino (p=0,0005. Houve melhora na concentração de hemoglobina (p= 0,0004, com elevação após a embolização, sem variação subsequente à miomectomia. Não ocorreu variação significante do hormônio folículo estimulante, (p=0,17. Não foi constatado nenhum caso de falência ovariana, mas uma das pacientes apresentou atrofia de endométrio. Duas pacientes engravidaram, com bons indicadores obstétricos. Quanto aos sinais e sintomas, houve melhora após a embolização, que se manteve após a miomectomia. CONCLUSÃO: a embolização arterial com partículas de PVA-PVAc esférico mostrou-se promissora no preparo para uma intervenção cirúrgica com retirada dos miomas, pois, associou-se à redução do volume uterino, à diminuição do sangramento operatório e tornou possível a utilização de incisões menores, aumentando a chance de preservação do útero.

  10. El derecho a la salud: una visión a partir del enfoque de capacidades

    Directory of Open Access Journals (Sweden)

    Alba L. Vélez Arango

    2015-02-01

    Full Text Available Objetivos: 1 identificar en las tesis libertarias y en la tradición liberal igualitaria de John Rawls la aceptación y/o rechazo de la protección de la salud como requisito de justicia social. 2 Analizar en los idearios teóricos de Amartya Sen y Martha Nussbaum elementos a favor de la protección de la salud y su goce efectivo como parte de los derechos que deben reconocerse por la sociedad, como respuesta a cuestiones de justicia social. Metodología: investigación de carácter filosófico, analizó críticamente los fundamentos morales y políticos que sustentan el reconocimiento del derecho a la salud como un requisito de justicia social. Resultados: en el proyecto rawlsiano la estructura básica de la sociedad debe distribuir ciertos “bienes primarios”, cosas que se presume que todo ser racional desea para poder desarrollar los planes de vida. Amartya Sen y Martha Nussbaum proponen el enfoque de las capacidades humanas básicas; el primero lo justifica en torno a la libertad y la segunda como requisitos básicos para una vida digna. Nussbaum justifica una lista de diez capacidades, dentro de las cuales incluye la vida, la salud física y la integridad física; todas relacionadas directamente con la salud. Así la tutela en salud se torna en condición necesaria de justicia social. El enfoque de las capacidades introduce la idea de un umbral para cada capacidad, por debajo del cual se considera que los ciudadanos no pueden funcionar de un modo auténticamente humano. Conclusiones: la protección de la salud instrumentalizada a través del sistema de salud es condición necesaria para el desarrollo de la vida que cada individuo tiene razones para valorar. Su protección debe darse dentro de los umbrales mínimos de justicia y la meta social debería entenderse en el sentido de lograr que los ciudadanos se sitúen por encima de este conjunto de capacidades entre las que se encuentra la salud.

  11. CAP_USO: Um sistema especialista para determinação da capacidade de uso da terra

    OpenAIRE

    Monica Luri Giboshi; Luiz Henrique Antunes Rodrigues; Francisco Lombardi Neto

    1999-01-01

    O objetivo deste trabalho foi desenvolver um sistema especialista (CAP_USO) para determinar a capacidade de uso da terra, visando auxiliar e dar mais agilidade ao processo de tomada de decisão para o planejamento do uso da terra. O sistema foi desenvolvido utilizando um software conhecido como C Language Integrated Production System (CLIPS), desenvolvido pela National Aeronautics and Space Administration (Nasa). Para determinar a capacidade de uso, foram considerados doze fatores limitantes a...

  12. UN MODELO CAUSAL DE COMPETITIVIDAD EMPRESARIAL PLANTEADO DESDE LA VBR: CAPACIDADES DIRECTIVAS, DE INNOVACIÓN, MARKETING Y CALIDAD

    Directory of Open Access Journals (Sweden)

    Martínez Santa María, R.

    2010-01-01

    Full Text Available El propósito de esta investigación es desarrollar un modelo explicativo de la competitividad empresarial a partir de factores internos a la empresa. Para ello se identifican los factores de competitividad más importantes en el caso de las empresas manufactureras vascas, así como las variables que permiten caracterizarlos, utilizando técnicas cualitativas basadas en entrevistas con directivos. Los factores resultantes son las capacidades directivas, las capacidades de innovación, las capacidades de marketing y las capacidades de calidad. Tras analizar estos factores bajo la Visión de la empresa Basada en Recursos (VBR, y definir sus escalas de medida, se plantea un modelo causal que relaciona cada uno de ellos con la competividad de la empresa. Este modelo otorga una importancia especial a las capacidades directivas al plantear este factor como precedente del resto de capacidades de la empresa. El modelo es contrastado a través de la técnica de modelado con ecuaciones estructurales utilizando una muestra representativa de la población de empresas manufactureras vascas formada por 861 empresas.

  13. Action of progesterone on contractile activity of isolated gastric strips in rats

    Institute of Scientific and Technical Information of China (English)

    Fang Wang; Tian-Zhen Zheng; Wei Li; Song-Yi Qu; Di-Ying He

    2003-01-01

    AIM: To study the effect of progesterone on contractile activity of isolated gastric strips in rats.METHODS: Wistar rats were sacrificed to remove whole stomach. Then, the stomach was opened and the mucosal layer was removed. Parellel to either the circular or the longitudial fibers, muscle strips were cut from fundus, body,antrum and pylorus. Each muscle strip was suspended in a tissue chamber containing 5 mL Krebs solution. Then the motility of gastric strips in tissue chambers was simultaneously recorded. The preparations were subjected to 1 g load tension and washed with 5 ml Krebs solution every 20 min. After 1 h equilibration, progesterone or antagonists were added in the tissue chamber separately. The antagonists were added 3 min before using progesterone (50 μmol. L-1).RESULTS: Progesterone decreased the resting tension of fundus and body longitudinal muscle (LM) (P<0.05). It inhibited the mean contractile amplitude of body and antrum LM and circular muscle (CM), and the motility index of pyloric CM (P<0.05). The inhibition of progesterone on the mean contractile amplitude could be partially blocked by phentolamine in LM of the stomach body (the mean contractile amplitude of body LM decreased from -7.5±5.5to -5.2±4.5 P<0.01), and by phentolamine or indomethacin in CM of body (The inhibition of progesterone on the mean contractile amplitude of body CM decreased from -5.6±3.0to -3.6±2.7 by phentolamine and from -5.6±3.0 to -3.5±2.5by indomethacin, P<0.01). Hexamethonium, propranolol and L-NNA (inhibitor of NO synthetase) didn′t affect the action of progesterone (P>0.05).CONCLUSION: The study suggested that progesterone can inhibit the contractile activity of isolated gastric strips in rats and the mechanism seems to be a direct one except that the action on gastric body is mediated through prostaglandin and adrenergic α receptor partly.

  14. Effect of a crude sulfated polysaccharide from Halymenia floresia (Rhodophyta on gastrointestinal smooth muscle contractility

    Directory of Open Access Journals (Sweden)

    José Ronaldo Vasconcelos Graça

    2011-10-01

    Full Text Available The aim of this work was to study the effect of Halymenia floresia (Hf on duodenum contractility, and on experimental protocols of gastric compliance (GC in rats. Fraction Hf2s exhibited a concentration-dependent myocontractile effect (EC50 12.48 µg/ml, and an inhibitory effect after consecutive washing. The contractile response promoted by Hf2s in the duodenum strips was completely inhibited by verapamil, and the effects were prevented in the presence of Ca2+-free medium. The pretreatment with atropine prevented the Hf2s myocontractile effect. Hf2s was also capable to decrease the GC (from 3.8±0.06 to 3.4±0.13 ml, P<0.05, which did not return to basal levels after more 50 min of observation. These results indicated that the algal polysaccharide possessed in vitro and in vivo gastrointestinal effects.

  15. Myosin-II dependent cell contractility contributes to spontaneous nodule formation of mesothelioma cells

    CERN Document Server

    Tárnoki-Zách, Julia; Méhes, Elod; Paku, Sándor; Neufeld, Zoltán; Hegedus, Balázs; Döme, Balázs; Czirok, Andras

    2015-01-01

    We demonstrate that characteristic nodules emerge in cultures of several malignant pleural mesothelioma (MPM) cell lines. Instead of excessive local cell proliferation, the nodules arise by Myosin II-driven cell contractility. The aggregation process can be prevented or reversed by suitable pharmacological inhibitors of acto-myosin contractility. A cell-resolved elasto-plastic model of the multicellular patterning process indicates that the morphology and size of the nodules as well as the speed of their formation is determined by the mechanical tension cells exert on their neighbors, and the stability of cell-substrate adhesion complexes. A linear stability analysis of a homogenous, self-tensioned Maxwell fluid indicates the unconditional presence of a patterning instability.

  16. Inhibitory effect of pinaverium bromide on gastrointestinal contractile activity in conscious dogs.

    Science.gov (United States)

    Itoh, Z; Takahashi, I

    1981-01-01

    The inhibitory effect of 4-(6-bromoveratryl)-4-(2-[2-(6,6-dimethyl-2-norpinyl)-ethoxy]-ethyl)-morpholinium hydroxide (pinaverium bromide), a quaternary ammonium derivative, on the contractile activity of the gastrointestinal tract from the stomach to the colon was investigated in six conscious dogs. Gastrointestinal motor activity was monitored by means of chronically implanted force transducers. Pinaverium bromide was continuously administered i.v. for 30 min in doses of 10 and 20 mg/kg/h during both the digestive and interdigestive states. It was found that pinaverium bromide strongly inhibited gastrointestinal contractile activity during both the digestive and interdigestive states; contractions in the stomach were most strongly inhibited; however, those in the small and large bowels were also significantly inhibited. No significant side effects in the circulatory and respiratory systems and the gastrointestinal tract such as nausea, vomiting or diarrhea were observed during and after the infusion of this agent. PMID:7197953

  17. Cell contractility facilitates alignment of cells and tissues to static uniaxial stretch

    CERN Document Server

    Rens, Elisabeth G

    2016-01-01

    During animal development and homeostasis, the structure of tissues, including muscles, blood vessels and connective tissues adapts to mechanical strains in the extracellular matrix (ECM). These strains originate from the differential growth of tissues or forces due to muscle contraction or gravity. Here we show using a computational model that by amplifying local strain cues, active cell contractility can facilitate and accelerate the reorientation of single cells to static strains. At the collective cell level, the model simulations show that active cell contractility can facilitate the formation of strings along the orientation of stretch. The computational model is based on a hybrid cellular Potts and finite-element simulation framework describing a mechanical cell-substrate feedback, where: 1) cells apply forces on the ECM, such that 2) local strains are generated in the ECM, and 3) cells preferentially extend protrusions along the strain orientation. In accordance with experimental observations, simulat...

  18. BK channel activation by NS11021 decreases excitability and contractility of urinary bladder smooth muscle

    DEFF Research Database (Denmark)

    Layne, Jeffrey J; Nausch, Bernhard; Olesen, Søren-Peter;

    2009-01-01

    activation of BK channels has the converse effect of reducing UBSM excitability and contractility. Here, we have sought to investigate this possibility by using the novel BK channel opener NS11021. NS11021 (3 microM) caused an approximately threefold increase in both single BK channel open probability (P......Large-conductance Ca(2+)-activated potassium (BK) channels play an important role in regulating the function and activity of urinary bladder smooth muscle (UBSM), and the loss of BK channel function has been shown to increase UBSM excitability and contractility. However, it is not known whether......(o)) and whole cell BK channel currents. The frequency of spontaneous action potentials in UBSM strips was reduced by NS11021 from a control value of 20.9 + or - 5.9 to 10.9 + or - 3.7 per minute. NS11021 also reduced the force of UBSM spontaneous phasic contractions by approximately 50%, and this force...

  19. Contractile activity is required for Z-disc sarcomere maturation in vivo

    Science.gov (United States)

    Geach, Timothy J; Hirst, Elizabeth MA; Zimmerman, Lyle B

    2015-01-01

    Sarcomere structure underpins structural integrity, signaling, and force transmission in the muscle. In embryos of the frog Xenopus tropicalis, muscle contraction begins even while sarcomerogenesis is ongoing. To determine whether contractile activity plays a role in sarcomere formation in vivo, chemical tools were used to block acto-myosin contraction in embryos of the frog X. tropicalis, and Z-disc assembly was characterized in the paralyzed dicky ticker mutant. Confocal and ultrastructure analysis of paralyzed embryos showed delayed Z-disc formation and defects in thick filament organization. These results suggest a previously undescribed role for contractility in sarcomere maturation in vivo. genesis 53:299–307, 2015. © 2015 The Authors. Genesis Published by Wiley Periodicals, Inc. PMID:25845369

  20. Measuring the Contractile Response of Isolated Tissue Using an Image Sensor

    Directory of Open Access Journals (Sweden)

    David Díaz-Martín

    2015-04-01

    Full Text Available Isometric or isotonic transducers have traditionally been used to study the contractile/relaxation effects of drugs on isolated tissues. However, these mechanical sensors are expensive and delicate, and they are associated with certain disadvantages when performing experiments in the laboratory. In this paper, a method that uses an image sensor to measure the contractile effect of drugs on blood vessel rings and other luminal organs is presented. The new method is based on an image-processing algorithm, and it provides a fast, easy and non-expensive way to analyze the effects of such drugs. In our tests, we have obtained dose-response curves from rat aorta rings that are equivalent to those achieved with classical mechanic sensors.

  1. An Estimating Method of Contractile State Changes Come From Continuous Isometric Contraction of Skeletal Muscle

    Energy Technology Data Exchange (ETDEWEB)

    Park, H.J.; Lee, S.J. [Wonkwang University, Iksan (Korea)

    2003-01-01

    In this study was proposed that a new estimating method for investigation of contractile state changes which generated from continuous isometric contraction of skeletal muscle. The physiological changes (EMG, ECG) and the psychological changes by CNS(central nervous system) were measured by experiments, while the muscle of subjects contracted continuously with isometric contraction in constant load. The psychological changes were represented as three-step-change named 'fatigue', 'pain' and 'sick(greatly pain)' from oral test, and the method which compared physiological change with psychological change on basis of these three steps was developed. The result of analyzing the physiological signals, EMG and ECG signal changes were observed at the vicinity of judging point in time of psychological changes. Namely, it is supposed that contractile states have three kind of states pattern (stable, fatigue, pain) instead of two states (stable, fatigue). (author). 24 refs., 7 figs.

  2. Effects of a hydrogen sulfide donor on spontaneous contractile activity of rat stomach and jejunum.

    Science.gov (United States)

    Shafigullin, M Y; Zefirov, R A; Sabirullina, G I; Zefirov, A L; Sitdikova, G F

    2014-07-01

    We studied the effect of sodium hydrosulfite (NaHS), a donor of hydrogen sulfide (H2S), on spontaneous contractive activity of isolated preparations of rat stomach and jejunum under isometric conditions. NaHS in concentrations of 10-200 μM reduced the amplitude, tonic tension, and frequency of contractions of the preparations. Blockade of K(+) channels with a non-specific antagonist tetraethylammonium (10 mM) increased contraction amplitude in the stomach strip and jejunum segment. The effects of NaHS on all parameters of contractile activity of the stomach and jejunum were fully preserved against the background of tetraethylammonium application. These data suggest that H2S in physiologically relevant concentrations inhibited spontaneous contractile activity of smooth muscle cells in rat stomach and jejunum by reducing the amplitude and frequency of contractions and decreased tonic tension without affecting the function of voltage- and calcium-dependent K(+) channels.

  3. [The effect of prostatic peptides on the contractile activity of smooth-muscle cells from the bladder].

    Science.gov (United States)

    Barabanova, V V; Gorbachev, A G; Parastaeva, M M; Khavinson, V Kh

    1993-02-01

    Prostatilene (PST) enhanced the functional activity of the bladder smooth-muscle cells (SMC). The possibility of activation of the SMC contractility by the PST through pharmacomechanical associations, is discussed.

  4. Metabolites of MDMA induce oxidative stress and contractile dysfunction in adult rat left ventricular myocytes

    OpenAIRE

    Shenouda, Sylvia K.; Varner, Kurt J.; Carvalho, Felix; Lucchesi, Pamela A.

    2009-01-01

    Repeated administration of MDMA (ecstasy) produces eccentric left ventricular (LV) dilation and diastolic dysfunction. While the mechanism(s) underlying this toxicity are unknown; oxidative stress plays an important role. MDMA is metabolized into redox cycling metabolites that produce superoxide. In this study, we demonstrated that metabolites of MDMA induce oxidative stress and contractile dysfunction in adult rat left ventricular myocytes. Metabolites of MDMA used in this study included: al...

  5. The p90 ribosomal S6 kinase (RSK is a mediator of smooth muscle contractility.

    Directory of Open Access Journals (Sweden)

    Mykhaylo Artamonov

    Full Text Available In the canonical model of smooth muscle (SM contraction, the contractile force is generated by phosphorylation of the myosin regulatory light chain (RLC20 by the myosin light chain kinase (MLCK. Moreover, phosphorylation of the myosin targeting subunit (MYPT1 of the RLC20 phosphatase (MLCP by the RhoA-dependent ROCK kinase, inhibits the phosphatase activity and consequently inhibits dephosphorylation of RLC20 with concomitant increase in contractile force, at constant intracellular [Ca(2+]. This pathway is referred to as Ca(2+-sensitization. There is, however, emerging evidence suggesting that additional Ser/Thr kinases may contribute to the regulatory pathways in SM. Here, we report data implicating the p90 ribosomal S6 kinase (RSK in SM contractility. During both Ca(2+- and agonist (U46619 induced SM contraction, RSK inhibition by the highly selective compound BI-D1870 (which has no effect on MLCK or ROCK resulted in significant suppression of contractile force. Furthermore, phosphorylation levels of RLC20 and MYPT1 were both significantly decreased. Experiments involving the irreversible MLCP inhibitor microcystin-LR, in the absence of Ca(2+, revealed that the decrease in phosphorylation levels of RLC20 upon RSK inhibition are not due solely to the increase in the phosphatase activity, but reflect direct or indirect phosphorylation of RLC20 by RSK. Finally, we show that agonist (U46619 stimulation of SM leads to activation of extracellular signal-regulated kinases ERK1/2 and PDK1, consistent with a canonical activation cascade for RSK. Thus, we demonstrate a novel and important physiological function of the p90 ribosomal S6 kinase, which to date has been typically associated with the regulation of gene expression.

  6. Contractile properties of the pigeon supracoracoideus during different modes of flight

    OpenAIRE

    Tobalske, Brett W.; Biewener, Andrew Austin

    2008-01-01

    The supracoracoideus (SUPRA) is the primary upstroke muscle for avian flight and is the antagonist to the downstroke muscle, the pectoralis (PECT). We studied in vivo contractile properties and mechanical power output of both muscles during take-off, level and landing flight. We measured muscle length change and activation using sonomicrometry and electromyography, and muscle force development using strain recordings on the humerus. Our results support a hypothesis that the primary role of ...

  7. Doppler-derived myocardial systolic strain rate is a strong index of left ventricular contractility

    Science.gov (United States)

    Greenberg, Neil L.; Firstenberg, Michael S.; Castro, Peter L.; Main, Michael; Travaglini, Agnese; Odabashian, Jill A.; Drinko, Jeanne K.; Rodriguez, L. Leonardo; Thomas, James D.; Garcia, Mario J.

    2002-01-01

    BACKGROUND: Myocardial fiber strain is directly related to left ventricular (LV) contractility. Strain rate can be estimated as the spatial derivative of velocities (dV/ds) obtained by tissue Doppler echocardiography (TDE). The purposes of the study were (1) to determine whether TDE-derived strain rate may be used as a noninvasive, quantitative index of contractility and (2) to compare the relative accuracy of systolic strain rate against TDE velocities alone. METHODS AND RESULTS: TDE color M-mode images of the interventricular septum were recorded from the apical 4-chamber view in 7 closed-chest anesthetized mongrel dogs during 5 different inotropic stages. Simultaneous LV volume and pressure were obtained with a combined conductance-high-fidelity pressure catheter. Peak elastance (Emax) was determined as the slope of end-systolic pressure-volume relationships during caval occlusion and was used as the gold standard of LV contractility. Peak systolic TDE myocardial velocities (Sm) and peak (epsilon'(p)) and mean (epsilon'(m)) strain rates obtained at the basal septum were compared against Emax by linear regression. Emax as well as TDE systolic indices increased during inotropic stimulation with dobutamine and decreased with the infusion of esmolol. A stronger association was found between Emax and epsilon'(p) (r=0.94, P<0.01, y=0.29x+0.46) and epsilon'(m) (r=0.88, P<0.01) than for Sm (r=0.75, P<0.01). CONCLUSIONS: TDE-derived epsilon'(p) and epsilon'(m) are strong noninvasive indices of LV contractility. These indices appear to be more reliable than S(m), perhaps by eliminating translational artifact.

  8. AAV-mediated gene therapy for heart failure: enhancing contractility and calcium handling

    OpenAIRE

    Zouein, Fouad A.; Booz, George W.

    2013-01-01

    Heart failure is a progressive, debilitating disease that is characterized by inadequate contractility of the heart. With an aging population, the incidence and economic burden of managing heart failure are anticipated to increase substantially. Drugs for heart failure only slow its progression and offer no cure. However, results of recent clinical trials using recombinant adeno-associated virus (AAV) gene delivery offer the promise, for the first time, that heart failure can be reversed. The...

  9. Vascular smooth muscle cell-derived adiponectin: a paracrine regulator of contractile phenotype

    OpenAIRE

    Ding, Min; Carrao, Ana Catarina; Wagner, Robert J.; Xie, Yi; Jin, Yu; Rzucidlo, Eva M.; Yu, Jun; Li, Wei; Tellides, George; Hwa, John; Aprahamian, Tamar R.; Martin, Kathleen A.

    2011-01-01

    Adiponectin is a cardioprotective adipokine derived predominantly from visceral fat. We recently demonstrated that exogenous adiponectin induces vascular smooth muscle cell (VSMC) differentiation via repression of mTORC1 and FoxO4. Here we report for the first time that VSMC express and secrete adiponectin, which acts in an autocrine and paracrine manner to regulate VSMC contractile phenotype. Adiponectin was found to be expressed in human coronary artery and mouse aortic VSMC. Importantly, s...

  10. Raloxifene acutely suppresses ventricular myocyte contractility through inhibition of the L-type calcium current

    OpenAIRE

    Liew, Reginald; Stagg, Mark A; MacLeod, Kenneth T; Collins, Peter

    2004-01-01

    The selective oestrogen (ER) receptor modulator, raloxifene, is widely used in the treatment of postmenopausal osteoporosis, but may also possess cardioprotective properties. We investigated whether it directly suppresses myocyte contractility through Ca2+ channel antagonism in a similar way to 17β-oestradiol.Cell shortening and Ca2+ transients were measured in single guinea-pig ventricular myocytes field-stimulated (1 Hz, 37°C) in a superfusion chamber. Electrophysiological recordings were p...

  11. Formation of mitochondrial apparatus of contractile cardiomyocytes during normal and hypoxic injury of cardi-ogenesis

    OpenAIRE

    Ivanchenko M.V.; Tverdokhlib I.V.

    2013-01-01

    Changes of cardiomyocytes mitochondrial apparatus can be marked as the main factors which are the basis of various forms of cardiovascular disease, but the dynamics of morphogenetic rearrangements heart mitochondria are poorly researched under normal conditions and under the influence of harmful factors. Mitochondria of contractile cardiomyocytes are different in their morphology and localization in the cell, the biochemical properties and are able to form differently association with other i...

  12. The contribution of Kv7 channels to pregnant mouse and human myometrial contractility

    OpenAIRE

    McCallum, Laura A; Pierce, Stephanie L.; ENGLAND, SARAH K.; Greenwood, Iain A.; Tribe, Rachel M.

    2010-01-01

    Abstract Premature birth accounts for approximately 75% of neonatal mortality and morbidity in the developed world. Despite this, methods for identifying and treating women at risk of preterm labour are limited and many women still present in preterm labour requiring tocolytic therapy to suppress uterine contractility. The aim of this study was to assess the utility of Kv7 channel activators as potential uterine smooth muscle (myometrium) relaxants in tissues from pregnant mice and women. Myo...

  13. Lymphatic filariasis: Perspectives on lymphatic remodeling and contractile dysfunction in filarial disease pathogenesis

    OpenAIRE

    Chakraborty, Sanjukta; Gurusamy, Manokaran; Zawieja, David C.; Muthuchamy, Mariappan

    2013-01-01

    Lymphatic filariasis, one of the most debilitating diseases associated with the lymphatic system, affects over a hundred million people worldwide and manifests itself in a variety of severe clinical pathologies. The filarial parasites specifically target the lymphatics and impair lymph flow, which is critical for the normal functions of the lymphatic system in maintenance of body fluid balance and physiological interstitial fluid transport. The resultant contractile dysfunction of the lymphat...

  14. Contractile activity-induced adaptations in the mitochondrial protein import system.

    Science.gov (United States)

    Takahashi, M; Chesley, A; Freyssenet, D; Hood, D A

    1998-05-01

    We previously demonstrated that subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondrial subfractions import proteins at different rates. This study was undertaken to investigate 1) whether protein import is altered by chronic contractile activity, which induces mitochondrial biogenesis, and 2) whether these two subfractions adapt similarly. Using electrical stimulation (10 Hz, 3 h/day for 7 and 14 days) to induce contractile activity, we observed that malate dehydrogenase import into the matrix of the SS and IMF mitochondia isolated from stimulated muscle was significantly increased by 1.4-to 1.7-fold, although the pattern of increase differed for each subfraction. This acceleration of import may be mitochondrial compartment specific, since the import of Bcl-2 into the outer membrane was not affected. Contractile activity also modified the mitochondrial content of proteins comprising the import machinery, as evident from increases in the levels of the intramitochondrial chaperone mtHSP70 as well as the outer membrane import receptor Tom20 in SS and IMF mitochondria. Addition of cytosol isolated from stimulated or control muscles to the import reaction resulted in similar twofold increases in the ability of mitochondria to import malate dehydrogenase, despite elevations in the concentration of mitochondrial import-stimulating factor within the cytosol of chronically stimulated muscle. These results suggest that chronic contractile activity modifies the extra- and intramitochondrial environments in a fashion that favors the acceleration of precursor protein import into the matrix of the organelle. This increase in protein import is likely an important adaptation in the overall process of mitochondrial biogenesis. PMID:9612226

  15. Impaired contractility and remodeling of the upper gastrointestinal tract in diabetes mellitus type-1

    Institute of Scientific and Technical Information of China (English)

    Jens Brφndum Frφkjaer; Sφren Due Andersen; Niels Ejskjaer; Peter Funch-Jensen; Asbjφrn Mohr Drewes; Hans Gregersen

    2007-01-01

    AIM: To investigate that both the neuronal function of the contractile system and structural apparatus of the gastrointestinal tract are affected in patients with longstanding diabetes and auto mic neuropathy.METHODS: The evoked esophageal and duodenal contractile activity to standardized bag distension was assessed using a specialized ultrasound-based probe. Twelve type-1 diabetic patients with autonomic neuropathy and severe gastrointestinal symptoms and 12 healthy controls were studied. The geometry and biomechanical parameters (strain, tension/stress, and stiffness) were assessed.RESULTS: The diabetic patients had increased frequency of distension-induced contractions (6.0 ±0.6 vs 3.3 ± 0.5, P < 0.001). This increased reactivity was correlated with the duration of the disease (P =0.009). Impaired coordination of the contractile activity in diabetic patients was demonstrated as imbalance between the time required to evoke the first contraction at the distension site and proximal to it (1.5 ± 0.6 vs 0.5± 0.1, P = 0.03). The esophageal wall and especially the mucosa-submucosa layer had increased thickness in the patients (P < 0.001), and the longitudinal and radial compressive stretch was less in diabetics (P <0.001). The esophageal and duodenal wall stiffness and circumferential deformation induced by the distensions were not affected in the patients (all P > 0.14).CONCLUSION: The impaired contractile activity with an imbalance in the distension-induced contractions likely reflects neuronal abnormalities due to autonomic neuropathy. However, structural changes and remodeling of the gastrointestinal tract are also evident and may add to the neuronal changes. This may contribute to the pathophysiology of diabetic gut dysfunction and impact on future management of diabetic patients with gastrointestinal symptoms.

  16. Inhibitory effects of genistein and resveratrol on guinea pig gallbladder contractility in vitro

    Institute of Scientific and Technical Information of China (English)

    Long-De Wang; Xiao-Qing Qiu; Zhi-Feng Tian; Ying-Fu Zhang; Hong-Fang Li

    2008-01-01

    AIM:To observe and compare the effects of phytoestrogen genistein,resveratrol and 17β-estradiol on the tonic contraction and the phasic contraction of isolated gallbladder muscle strips and to study the underlying mechanisms.METHODS:Isolated strips of gallbladder muscle from guinea pigs were suspended in organ baths containing Kreb's solution,and the contractilities of strips were measured before and after incubation with genistein,resveratrol and 17β-estradiol respectively.RESULTS:Similar to 17β-estradiol,genistein and resveratrol could dose-dependently inhibit the phasic contractile activities,they decreased the mean contractlie amplitude and the contractlie frequencies of gallbladder muscle strips,and also produced a marked reduction in resting tone.The blocker of estrogen receptor ICI 182780 failed to alter the inhibitory effects induced by genistein and resveratrol,but potassium bisperoxo(1,10 phenanthroline)oxovanadate bpV(phen),a potent protein tyrosine phosphatase inhibitor,markedly attenuated the inhibitory effects induced by genistein and resveratrol.In calcium-free Kreb's solution containing 0.01 mmol/L egtazic acid(EGTA),genistein and resveratrol inhibited the first phasic contraction induced by acetylcholine(Ach),but did not affect the second contraction induced by CaCl2.In addition,genistein,resveratrol and 17β-estradiol also could reduce the contractile responses of Ach and KCI,and shift their cumulative concentration-response curves rightward.CONCLUSION:Phytoestrogen genistein and resveratrol can directly inhibit the contractile activity of isolated gallbladder muscle both at rest and in response to stimulation.The mechanisms responsible for the inhibitory effects probably due mainly to inhibition of tyrosine kinase,Ca2+ influx through potential-dependent calcium channels(PDCs)and Ca2+ release from sarcoplasmic reticulum(SR),but were not related to the estrogen receptors.

  17. Physiological and clinical aspects of uterine contractility during the postpartum period in cows

    OpenAIRE

    Bajcsy, Árpád Csaba

    2005-01-01

    The individual studies, presented in separate chapters of this thesis, were designed to get answers to certain methodological problems and biological questions associated with the myometrial function of early postpartum dairy cows. Chapter 1 introduces the topic by briefly summarizing the events occuring in the puerperal uterus, focusing on the role of myometrial contractions, and listing some of the possibilities used to record uterine contractility. The demand for an accurate, non-invasive,...

  18. Capacidad de carga estática en rodamientos. Normalización y tendencias.

    Directory of Open Access Journals (Sweden)

    A. García Toll

    2007-01-01

    Full Text Available Para ilustrar la funcionalidad de la norma NC-ISO 76: 2006, establecida a partir de una adopción idéntica de la Norma ISO 76: 1987/ amd.1: 1999 (E “Cojinetes de Rodamiento – Capacidad de Carga Estática”, son mostradas las correspondencias entre las magnitudes de capacidad de carga estática declaradas en los catálogos técnicos de reconocidos fabricantes de rodamientos con los valores presentes en NC-ISO 76 y considerando diferentes geometrías de rodamientos radiales de bolas rígidos y de contacto angular, rodamientos axiales de bolas y rodamientos de rodillos cilíndricos. Adicionalmente, el estudio ha permitido establecer las dependencias entre la capacidad de carga nominal estática del rodamiento y algunos parámetros geométricos, como el diámetro del elemento rodante, el diámetro interior y la relación diámetro interior - diámetro exterior del cojinete.At the present time, Standard NC-ISO 76: 2006 is a national standard established as identical adoption of ISO standard 76:1987 / amd.1: 1999 (E "Rolling Bearings - Static Load Rating¨. In this sense, the static load rating of rolling bearings declared in technical catalogs of renowned bearing manufacturers and the basic static load rating according to calculation procedures stated in Standard NC-ISO 76 are compared. The evaluation has taken into account different geometries of radial groove ball bearings, angular contact ball bearings, thrust ball bearings and radial roller bearings. Additionally, they are established dependences between the static load rating of rolling bearings and the interior diameter of different types of radial and thrust bearings.

  19. Recursos y Capacidades de Tecnología y Desempeño Organizacional

    Directory of Open Access Journals (Sweden)

    Carmen Berenice Ynzunza Cortés

    2013-01-01

    Full Text Available La evolución tecnológica ha modificado a las organizaciones en todos los ámbitos laborales, poniendo en riesgo la ventaja competitiva y supervivencia de muchas orga nizaciones. Así, este estudio busca explorar los recursos y capacidades de tecnología e innovación y las tecnologías de la información y su relación con el desempeño organizacional , con el fin de encontrar estrategias que contribuyan al fortalecimiento de las PYMES. La población objeto de estudio fueron 646 empresas del sector industrial del Estado de Querétaro. El tamaño de la muestra alcanzado fue de 116 con un muestreo no probabilístico de conveniencia. La recolección de datos se hizo a través de entrevistas y la técnica estadística utilizada fue el análisis estructural con el software AMOS. Los resultados prueban la relación entre los recursos y capacidades de tecnología e innovación con el desempeño organizacional , y su vínculo con las tecnologías de la información , no así de las tecnologías de la información con el desempeño organizacional . Se concluye que los recursos y capacidades de tecnología son un factor clave para un crecimiento sostenido y un desempeño organizacional superior; inciden en todos los procesos productivos, empresariales y de gestión relacionados con la productividad, competitividad organizacional y por supuesto la ventaja competi tiva.

  20. Contractile roots in succulent monocots: convergence, divergence and adaptation to limited rainfall.

    Science.gov (United States)

    North, Gretchen B; Brinton, Erin K; Garrett, Tadao Y

    2008-08-01

    Contractile roots (CRs) that pull shoots further down in the soil are a possible example of convergent evolution in two monocot families, the Agavaceae and the Asphodelaceae. The association between CRs, water uptake and habitat aridity was investigated for agaves, yuccas and aloes by assessing the occurrence of CRs and the amount of root contraction for glasshouse-grown plants with respect to mean annual rainfall of their native habitats. Structural features of CRs as well as root hydraulic conductance were compared with those of non-contractile roots (NCRs). CRs occurred in 55% of the 73 species examined, including 64% of the agaves and 85% of the yuccas, but in none of the aloes despite the occurrence of CRs in related genera. The phylogenetic distribution of CRs was consistent with multiple acquisitions or losses of the trait. The amount of root contraction showed a highly significant negative relationship with mean annual rainfall, although other environmental factors may also be important. Radial hydraulic conductance of the basal (contractile) zone exceeded that of the midroot zone for CRs; for NCRs, the opposite was true. Thus, CRs in the species examined may provide a mechanism for greater water uptake near the soil surface in regions with limited rainfall. PMID:18507804

  1. Proteome dynamics during contractile and metabolic differentiation of bovine foetal muscle.

    Science.gov (United States)

    Chaze, T; Meunier, B; Chambon, C; Jurie, C; Picard, B

    2009-07-01

    Contractile and metabolic properties of bovine muscles play an important role in meat sensorial quality, particularly tenderness. Earlier studies based on Myosin heavy chain isoforms analyses and measurements of glycolytic and oxidative enzyme activities have demonstrated that the third trimester of foetal life in bovine is characterized by contractile and metabolic differentiation. In order to complete this data and to obtain a precise view of this phase and its regulation, we performed a proteomic analysis of Semitendinosus muscle from Charolais foetuses analysed at three stages of the third trimester of gestation (180, 210 and 260 days). The results complete the knowledge of important changes in the profiles of proteins from metabolic and contractile pathways. They provide new insights about proteins such as Aldehyde dehydrogenase family, Enolase, Dihydrolipoyl dehydrogenase, Troponin T or Myosin light chains isoforms. These data have agronomical applications not only for the management of beef sensorial quality but also in medical context, as bovine myogenesis appears very similar to human one. PMID:22444818

  2. Acute pergolide exposure stiffens engineered valve interstitial cell tissues and reduces contractility in vitro.

    Science.gov (United States)

    Capulli, Andrew K; MacQueen, Luke A; O'Connor, Blakely B; Dauth, Stephanie; Parker, Kevin Kit

    2016-01-01

    Medications based on ergoline-derived dopamine and serotonin agonists are associated with off-target toxicities that include valvular heart disease (VHD). Reports of drug-induced VHD resulted in the withdrawal of appetite suppressants containing fenfluramine and phentermine from the US market in 1997 and pergolide, a Parkinson's disease medication, in 2007. Recent evidence suggests that serotonin receptor activity affected by these medications modulates cardiac valve interstitial cell activation and subsequent valvular remodeling, which can lead to cardiac valve fibrosis and dysfunction similar to that seen in carcinoid heart disease. Failure to identify these risks prior to market and continued use of similar drugs reaffirm the need to improve preclinical evaluation of drug-induced VHD. Here, we present two complimentary assays to measure stiffness and contractile stresses generated by engineered valvular tissues in vitro. As a case study, we measured the effects of acute (24 h) pergolide exposure to engineered porcine aortic valve interstitial cell (AVIC) tissues. Pergolide exposure led to increased tissue stiffness, but it decreased both basal and active contractile tone stresses generated by AVIC tissues. Pergolide exposure also disrupted AVIC tissue organization (i.e., tissue anisotropy), suggesting that the mechanical properties and contractile functionality of these tissues are governed by their ability to maintain their structure. We expect further use of these assays to identify off-target drug effects that alter the phenotypic balance of AVICs, disrupt their ability to maintain mechanical homeostasis, and lead to VHD. PMID:27174867

  3. Contractile function is unaltered in diaphragm from mice lacking calcium release channel isoform 3

    Science.gov (United States)

    Clancy, J. S.; Takeshima, H.; Hamilton, S. L.; Reid, M. B.

    1999-01-01

    Skeletal muscle expresses at least two isoforms of the calcium release channel in the sarcoplasmic reticulum (RyR1 and RyR3). Whereas the function of RyR1 is well defined, the physiological significance of RyR3 is unclear. Some authors have suggested that RyR3 participates in excitation-contraction coupling and that RyR3 may specifically confer resistance to fatigue. To test this hypothesis, we measured contractile function of diaphragm strips from adult RyR3-deficient mice (exon 2-targeted mutation) and their heterozygous and wild-type littermates. In unfatigued diaphragm, there were no differences in isometric contractile properties (twitch characteristics, force-frequency relationships, maximal force) among the three groups. Our fatigue protocol (30 Hz, 0.25 duty cycle, 37 degrees C) depressed force to 25% of the initial force; however, lack of RyR3 did not accelerate the decline in force production. The force-frequency relationship was shifted to higher frequencies and was depressed in fatigued diaphragm; lack of RyR3 did not exaggerate these changes. We therefore provide evidence that RyR3 deficiency does not alter contractile function of adult muscle before, during, or after fatigue.

  4. [Contractile reaction of the myocardium of patients with heart diseases to chemical scarification of cell membranes].

    Science.gov (United States)

    Shumakov, V I; Tsyv'ian, P B; Markhasin, V S; Shtengol'd, E Sh

    1978-03-01

    Strips of the myocardium from the auricula atria of patients suffering from mitral stenosis (MS) and septal defects of the heart (SDH) removed during the operation were treated with ethylenediaminetetraacetic acid (DETA)--3mM--to increase the cell membrane permeability (scarification). The mechanical response of the contractile proteins to the change in the Ca2+ was recorded in the ethylene-hexaaminetetraacetic acid (EHTA)--3mM--against the background of increased membrane permeability to the Ca-EHTA complex permitting to regulate Ca2+ concentration in myofibrillae from 10(-9) to 10(-4)M. As shown, with the same threshold concentrations (5.10(-8)M) and saturation concentrations (10(-4)M) of Ca2+ the strips from the patients with MS developed the maximal tension per cross section unit of the strip half as great as the preparations from patients with SDH, this indicating a possible affection of the contractile proteins in the hearts of patients with MS. The ratio between the tension amplitudes under conditions of a complete calcium activation of the contractile proteins and a single isometric contraction for the preparations obtained from the patients with MS was 8 to 10, and with SDH--from 4 to 5. It is supposed that this was the result of more pronounced changes in the apparatus of electromechanical conjugation of the myocardium of patients suffering from MS. PMID:96886

  5. Modulation of ureteric Ca signaling and contractility in humans and rats by uropathogenic E. coli.

    Science.gov (United States)

    Floyd, Rachel V; Winstanley, Craig; Bakran, Ali; Wray, Susan; Burdyga, Theodor V

    2010-04-01

    Ascending urinary tract infections, a significant cause of kidney damage, are predominantly caused by uropathogenic Escherichia coli (UPEC). However, the role and mechanism of changes in ureteric function during infection are poorly understood. We therefore investigated the effects of UPEC on Ca signaling and contractions in rat (n = 17) and human (n = 6) ureters. Ca transients and force were measured and effects of UPEC on the urothelium were monitored in live tissues. In both species, luminal exposure of ureters to UPEC strains J96 and 536 caused significant time-dependent decreases in phasic and high K depolarization-induced contractility, associated with decreases in the amplitude and duration of the Ca transients. These changes were significant after 3-5 h and irreversible over the next 5 h. The infection causes increased activity of K channels, causing inhibition of voltage-gated Ca entry, and K channel blockers could reverse the effects of UPEC on ureteric function. A smaller direct effect on Ca entry also occurs. Nonpathogenic E. coli (TG2) or abluminal application of UPEC did not produce changes in Ca signaling or contractility. UPEC exposure also caused significant impairment of urothelial barrier function; luminal application of the Ca channel blocker nifedipine caused a reduction in contractions as it entered the tissue, an effect not observed in untreated ureters. Thus, UPEC impairs ureteric contractility in a Ca-dependent manner, largely caused by stimulation of potassium channels and this mechanism is dependent on host-urothelium interaction.

  6. Local 3D matrix microenvironment regulates cell migration through spatiotemporal dynamics of contractility-dependent adhesions

    Science.gov (United States)

    Doyle, Andrew D.; Carvajal, Nicole; Jin, Albert; Matsumoto, Kazue; Yamada, Kenneth M.

    2015-11-01

    The physical properties of two-dimensional (2D) extracellular matrices (ECMs) modulate cell adhesion dynamics and motility, but little is known about the roles of local microenvironmental differences in three-dimensional (3D) ECMs. Here we generate 3D collagen gels of varying matrix microarchitectures to characterize their regulation of 3D adhesion dynamics and cell migration. ECMs containing bundled fibrils demonstrate enhanced local adhesion-scale stiffness and increased adhesion stability through balanced ECM/adhesion coupling, whereas highly pliable reticular matrices promote adhesion retraction. 3D adhesion dynamics are locally regulated by ECM rigidity together with integrin/ECM association and myosin II contractility. Unlike 2D migration, abrogating contractility stalls 3D migration regardless of ECM pore size. We find force is not required for clustering of activated integrins on 3D native collagen fibrils. We propose that efficient 3D migration requires local balancing of contractility with ECM stiffness to stabilize adhesions, which facilitates the detachment of activated integrins from ECM fibrils.

  7. Improvement of diaphragm and limb muscle isotonic contractile performance by K+ channel blockade

    Directory of Open Access Journals (Sweden)

    Pollarine Jennifer

    2010-01-01

    Full Text Available Abstract The K+ channel blocking aminopyridines greatly improve skeletal muscle isometric contractile performance during low to intermediate stimulation frequencies, making them potentially useful as inotropic agents for functional neuromuscular stimulation applications. Most restorative applications involve muscle shortening; however, previous studies on the effects of aminopyridines have involved muscle being held at constant length. Isotonic contractions differ substantially from isometric contractions at a cellular level with regards to factors such as cross-bridge formation and energetic requirements. The present study tested effects of 3,4-diaminopyridine (DAP on isotonic contractile performance of diaphragm, extensor digitorum longus (EDL and soleus muscles from rats. During contractions elicited during 20 Hz stimulation, DAP improved work over a range of loads for all three muscles. In contrast, peak power was augmented for the diaphragm and EDL but not the soleus. Maintenance of increased work and peak power was tested during repetitive fatigue-inducing stimulation using a single load of 40% and a stimulation frequency of 20 Hz. Work and peak power of both diaphragm and EDL were augmented by DAP for considerable periods of time, whereas that of soleus muscle was not affected significantly. These results demonstrate that DAP greatly improves both work and peak power of the diaphragm and EDL muscle during isotonic contractions, which combined with previous data on isometric contractions indicates that this agent is suitable for enhancing muscle performance during a range of contractile modalities.

  8. La capacidad de actualizar información inferencial en la lectura

    OpenAIRE

    Ana I. Pérez Muñoz

    2013-01-01

    Durante la comprensión lectora, el proceso de actualización inferencial nos permite sustituir una idea del texto que hayamos generado equívocamente por otra más plausible que aún está por confirmar. Esta habilidad parece depender de nuestra capacidad de Memoria de Trabajo, la cual nos ayuda a mantener una representación coherente de lo que estamos leyendo, mientras que comprendemos la información posterior y descartamos ideas que hemos podido interpretar de forma errónea. El entrenamiento en ...

  9. Personas con diabetes mellitus tipo 2 y su capacidad de agencia de autocuidado, cartagena

    OpenAIRE

    Herrera Lían, Arleth; Andrade, Yesid; Hernández, Orlando; Manrique, Julián; Faria, Karen; Machado, Mayerly

    2012-01-01

    Contexto: La diabetes mellitus tipo 2 se constituye en un problema de salud pública por las repercusiones bio-psicosociales, la presencia de complicaciones neurovasculares y metabólicas en la persona que la padece. Enfermería cumple un papel importante a través de la educación y la capacitación.Objetivo: Identificar la capacidad de agencia de autocuidado de las personas con diagnóstico de diabetes mellitus tipo 2, inscritos en los programas de control de diabetes en 19 UPAS de Cartagena.Metod...

  10. CAPACIDADES TECNOLÓGICAS EN LOS PAÍSES MIEMBROS Y ASOCIADOS DEL MERCOSUR

    OpenAIRE

    Caterina Clemenza; Gabriel Aguilar O.

    2016-01-01

    Este estudio tiene por objeto analizar el perfil de las capacidades Tecnológicas de los Países Miembros y Asociados del Mercado Común del Sur. La investigación es de carácter descriptivo, utilizando técnicas de análisis multivariante para el examen de los datos. Los resultados evidenciaron la existencia de dos grupos de países con gran diferencia, sustentadas en los niveles de inversión que realizan para incrementar el gasto, en actividades científico-tecnológica y de I+D, con limitaciones pa...

  11. La discapacidad dentro del enfoque de capacidades y funcionamientos de Amartya Sen

    Directory of Open Access Journals (Sweden)

    Mario Toboso Martín

    2008-01-01

    Full Text Available En este artículo se describen primeramente los tres modelos tradicionales que a lo largo de la Historia han servido a la sociedad como marco para el tratamiento de la discapacidad: el modelo de prescindencia, el modelo medico-rehabilitador (o asistencial y el modelo social. Se incluye, además, la descripción del recién planteado modelo de la diversidad. Tras ello, se describen los elementos esenciales del enfoque de capacidades y funcionamientos de Amartya Sen y su relación con los logros de bienestar, calidad de vida y libertad por parte de las personas. A continuación se exponen las dos clasificaciones de la OMS que abordan la cuestión de la discapacidad: la Clasificación Internacional de Deficiencias, Discapacidades y Minusvalías (CIDDM, de 1980, y la Clasificación Internacional del Funcionamiento, la Discapacidad y la Salud (CIF, de 2001. La noción de discapacidad se introduce en el enfoque de capacidades y funcionamientos a raíz de la importancia que otorga Sen a la diversidad de características propias y externas de las personas a la hora de valorar la desigualdad en el logro de funcionamientos valiosos. Nuestra propuesta es que el "conjunto capacidad" (que es el formado por todos los funcionamientos al alcance de la persona, y que así engloba sus diferentes formas y estilos de vida posibles no debe limitarse a recoger el conjunto de funcionamientos posibles de una persona "normal", sino que debería ampliar su marco para dar cabida igualmente a los funcionamientos diversos posibles para otras personas, al margen de esa ficción de "normalidad". Esta propuesta, es plenamente coherente con la importancia de la diversidad de las características humanas y circunstancias ambientales en el planteamiento de Amartya Sen, y de hecho lo amplía al incorporar esa misma diversidad en el conjunto de funcionamientos posibles que constituyen el conjunto capacidad de la persona.

  12. Volumen y capacidad: de las unidades de medida antropométricas a las estandarizadas

    OpenAIRE

    Cruz, Angie Carolina; Vargas, Ángel Ricardo; Montes, Yeimy Esperanza

    2012-01-01

    El presente artículo evidencia una experiencia de aula relacionada con la caracterización y comprensión de las unidades de medida antropométricas y estandarizadas para la enseñanza de las magnitudes de volumen y capacidad a estudiantes de quinto grado a través de la resolución de problemas como metodología de clase. El trabajo desarrollado tuvo en cuenta diversos contextos y situaciones cotidianas que promovieron un aprendizaje significativo en los estudiantes sobre el sistema métrico, potenc...

  13. Consideraciones para el desarrollo de capacidades de investigación en universidades privadas

    OpenAIRE

    Maria Luisa Isla; Juan Carlos Seijo; Francisco Javier Espinosa

    2013-01-01

    Se presentan reflexiones y estrategias que contribuyan a formar capacidades de investigación en universidades privadas con investigadores jóvenes comprometidos con el avance del conocimiento en su área de investigación así como con su entorno natural y soc ial. Mediante una combinación de formación en el aula y formación experiencial, se presentan las habilidades investigativas a desarrollar y los ejes de formación universitaria que contribuyen a formar investigadores. Adicionalmente a esta f...

  14. Influência da capacidade de campo na taxa de crescimento do cafeeiro conilon

    Directory of Open Access Journals (Sweden)

    Maria Christina Junger Delôgo Dardengo

    2010-02-01

    Full Text Available O objetivo deste trabalho foi avaliar a influência da capacidade de campo (CC na taxa de crescimento do cafeeiro conilon a partir da adoção de três tensões: 0,006 MPa (CC1, 0,010 MPa (CC2 e 0,033 MPa (CC3, em dois tipos de solo (Latossolo Vermelho-Amarelo e Argissolo Vermelho-Amarelo. O experimento foi montado em casa de vegetação no Núcleo de Estudos e de Difusão de Tecnologia em Floresta, Recursos Hídricos e Agricultura Sustentável, município de Jerônimo Monteiro, Espírito Santo. A espécie vegetal utilizada foi a Coffea canephora Pierre ex A. Froehner, variedade Robusta Tropical (EMCAPER 8151, cultivada em vaso de 12 litros, por um período de 255 dias. As análises de crescimento foram realizadas 15 dias após o transplantio das mudas e no final do experimento, para determinação de matéria seca total e área foliar. O teor de umidade do solo na capacidade de campo varia com a tensão adotada em sua determinação. As maiores taxas de crescimentos relativo e absoluto do cafeeiro conilon foram obtidas quando a umidade do solo foi mantida na capacidade de campos determinada na tensão de 0,010 MPa no Latossolo Vermelho­Amarelo e de 0,006 MPa no Argissolo Vermelho-Amarelo. As menores taxas de crescimento da cultura foram observa­das na capacidade de campo determinada na tensão de 0,033 MPa, o que inviabiliza a sua adoção na estimativa da lâmina de irrigação utilizando-se a câmara de pressão de Richards.

  15. Capacidad de agencia de autocuidado y factores de riesgo cardiovascular en adolescentes

    OpenAIRE

    Morales Aguilar, Rosa del Socorro

    2013-01-01

    Este estudio tuvo como objetivo determinar la relación entre la capacidad de agencia de autocuidado y los factores de riesgo cardiovascular en adolescentes de una Institución de Educación Superior en el Distrito de Barranquilla. Metodología: Estudio descriptivo, exploratorio, de corte transversal, con abordaje cuantitativo, basado en la teoría del déficit de autocuidado de Orem. La muestra fue de 133 adolescentes, seleccionados mediante muestreo aleatorio simple. Se aplicó la escala ASA, el c...

  16. Las Capacidades Dinámicas e Administración Estratégica

    Directory of Open Access Journals (Sweden)

    Vidigal Fernandes Martins

    2011-09-01

    Full Text Available Este ensayo teórico se centra en las teorías que explican cómo las organizaciones a obtener y mantener una ventaja competitiva. Tres Paradigmas se resumen, el paradigma y el paradigma de conflicto estratégico de Porter, y las conversaciones para poner fin al paradigma de recursos basado en recursos. "Capacidad dinámica" se derivan de la fuerte relación entre las nociones generalizadas de eficacia con respecto a los cambios y las fórmulas genéricas e la ventaja competitiva sustentable.

  17. La adquisición de capacidades transversales: una experiencia en asignaturas de Ciencias Sociales

    OpenAIRE

    Juan Vigaray, María Dolores de; González Gascón, Elena; Subiza Martínez, Begoña; Martínez Mora, Carmen; Vallés Amores, María Luisa; Posadas García, José Adolfo; López García, Juan José; Hernández Ricarte, Victoria; Peris Ferrando, Josep Enric; Cuevas Casaña, Joaquim

    2011-01-01

    En este trabajo analizamos, en el contexto de las asignaturas que componen la Red Docente “I+Do+i” (Investigación, Docencia, e Innovación), cómo diferentes materias de ciencias sociales (matemáticas, estadística, distribución comercial y economía de la salud), contribuyen a que el alumnado adquiera distintas capacidades transversales en su formación. Para la realización del estudio se ha elaborado una encuesta que los estudiantes han contestado de manera voluntaria y anónima. Adicionalmente, ...

  18. Papel de las capacidades en la valoración tecnológica

    OpenAIRE

    Jiménez, Claudia Nelcy; Cristancho, Andrés Darío; Castellanos, Oscar Fernando

    2011-01-01

    Tradicionalmente la valoración tecnológica se ha abordado con el enfoque financiero aplicado en la gestión de proyectos, centrándose en la dimensión económica. Sin embargo, diversos autores han detectado falencias en esta aproximación, proponiendo incluir técnicas que permitan tomar en cuenta aspectos cualitativos e intangibles de la tecnología. Considerando la definición amplia de la tecnología que abarca las capacidades tecnológicas de los sistemas y aparatos productivos, el objetivo de est...

  19. Capacidade para o trabalho: revisão de literatura Work ability: a literature review

    Directory of Open Access Journals (Sweden)

    Maria Carmen Martinez

    2010-06-01

    Full Text Available O objetivo deste trabalho é apresentar uma revisão de literatura sobre a capacidade para o trabalho de trabalho e envelhecimento funcional. Foi realizada uma extensa busca de publicações do período de 1966 a 2006, usando as bases de dados MEDLINE, Lilacs e SciELO. São apresentados vários aspectos relativos à capacidade para o trabalho: o contexto histórico no qual o tema emergiu, o referencial teórico, os fatores determinantes, um modelo explicativo, a metodologia atual para avaliar e monitorar a capacidade para o trabalho e a importância de sua promoção. Também é destacada a situação atual da pesquisa, prática e perspectivas futuras relativas ao tema. No contexto do envelhecimento da força de trabalho, a capacidade para o trabalho tornou-se um indicador importante em função de suas consequências para a saúde, bem-estar e empregabilidade dos trabalhadores, com impactos para os indivíduos, organizações e sociedade. As questões sobre o tema, apesar de relevantes, ainda carecem de maior atenção.The aim of this article is to present a literature review on work ability and functional ageing. An extensive search of publications from 1966 to 2006 was conducted using the databases MEDLINE, LILACS and SciELO. Several aspects of work ability are presented in this manuscript: the historical context when the theme emerged, the theoretical framework, the determinant factors and an explanatory model, the current methodology to evaluate and monitor the work ability, the importance of its promotion. Highlights of the current situation about the research, practice and future perspectives regarding the theme are also discussed. In the context of the workforce aging, the work ability became an important indicator because their consequences to the worker's health, well-being and employability, with impacts to the individuals, organizations and society. In spite of their relevance, there is a lack of attention to the issues about work

  20. Las Capacidades Dinámicas e Administración Estratégica

    OpenAIRE

    Vidigal Fernandes Martins; Vinícius Silva Pereira

    2011-01-01

    Este ensayo teórico se centra en las teorías que explican cómo las organizaciones a obtener y mantener una ventaja competitiva. Tres Paradigmas se resumen, el paradigma y el paradigma de conflicto estratégico de Porter, y las conversaciones para poner fin al paradigma de recursos basado en recursos. "Capacidad dinámica" se derivan de la fuerte relación entre las nociones generalizadas de eficacia con respecto a los cambios y las fórmulas genéricas e la ventaja competitiva sustentable.

  1. Capacidade de Carga Turística: Um Estudo no Caminhos Rurais de Porto Alegre, RS

    Directory of Open Access Journals (Sweden)

    Juliane Magagnin Da Soller

    2013-10-01

    Full Text Available Nesse artigo, apresenta-se o contexto do turismo de base comunitária, além de breve histórico e discussão acerca do conceito e da metodologia da Capacidade de Carga Turística, assim como a adaptação da metodologia para estudo aqui relatado. Descreve-se o estudo realizado para determinar a Capacidade de Carga Turística, tendo por amostra as propriedades rurais partícipes da Associação Porto Alegre Rural (POA RURAL, mais especialmente do roteiro Caminhos Rurais de Porto Alegre, no estado do Rio Grande do Sul. Propôs-se adaptar a para o local a metodologia de cálculo de Capacidade de Carga Turística a partir de Cifuentes (1992; et al 1996, considerando suas particularidades, principalmente aquelas que dizem respeito a saúde e ao bem-estar das famílias que recebem os visitantes e aos impactos ambientais causados pelas construções de infraestrutura turística. A Capacidade de Carga Turística é uma metodologia desenvolvida para áreas preservadas de uso público. Assim, não costuma dar enfoque às questões referentes à comunidade local e aos resíduos gerados pelas instalações e pelos serviços prestados no Turismo.  Tourist Carrying Capacity: A study in the Caminhos Rurais de Porto Alegre, RS  - This paper presents the community based tourism and a brief history, concept and methodology of Tourist Carrying Capacity, and the adaptation of that methodology to the present case. The paper presents the study to determine the Tourist Carrying Capacity in rural proprieties that currently constitute the Porto Alegre Rural Association (RURAL POA, the tourist destination Caminhos Rurais de Porto Alegre, Rio Grande do Sul. The research proposes to adapt the methodology of Tourist Carrying Capacity from Cifuentes (1992, et al 1996, to the Caminhos Rurais, considering its particularities, especially those relate to health and well-being of families who receives visitors, and the environmental impacts caused by the construction of

  2. La educación científica intercultural y el enfoque de las capacidades

    OpenAIRE

    Liliana Valladares

    2010-01-01

    En este manuscrito se presentan datos del desarrollo humano de los pueblos indígenas en México que reflejan la exclusión social que viven, particularmente en los ámbitos de la educación y de la educación científica. Se propone la conformación de una educación científica intercultural como estrategia para la expansión de las capacidades de las personas para hacer y ser aquello que tienen razones para valorar. La educación científica intercultural se fundamenta en tres condiciones: 1) una persp...

  3. ESTUDIO DE ALUMNOS DE EDUCACIÓN SECUNDARIA OBLIGATORIA CON ALTAS CAPACIDADES INTELECTUALES

    OpenAIRE

    Anda-Moreno, Verónica

    2012-01-01

    El presente Trabajo de Fin de Máster realizado para la obtención del título del Máster en Formación de Profesorado de Educación Secundaria Obligatoria, Bachillerato, Formación Profesional y Enseñanza de Idiomas, Especialidad en Física y Química, de la Universidad Internacional de La Rioja trata del estudio de Alumnos con Altas Capacidades Intelectuales de la Educación Secundaria Obligatoria del sistema educativo español. En el entorno escolar, siempre se han presentado casos de niños...

  4. Herramientas TIC para la intervención educativa en estudiantes con altas capacidades

    OpenAIRE

    Tárraga Mínguez, Raúl; Sanz-Cervera, Pilar; Pastor Cerezuela, Gemma; Fernández Andrés, María Inmaculada

    2014-01-01

    Los estudiantes con altas capacidades procesan la información de manera distinta, ya que estos poseen una elevada creatividad e implicación en la tarea. Este hecho implica la necesidad de llevar acabo una intervención educativa específica. Algunos modelos teóricos han demostrado la efectividad del uso de las TICs en la intervención de este tipo de alumnado, por lo que en el presente artículo se incluyen diferentes herramientas TIC que pueden ser de gran utilidad para los docentes. Entre estas...

  5. Altas capacidades. Propuesta de intervención para el aprendizaje de la historia

    OpenAIRE

    Gárriz Forné, Javier

    2013-01-01

    El presente estudio de carácter teórico, es una aproximación al conocimiento de las necesidades educativas del alumnado con altas capacidades intelectuales y pretende desarrollar una propuesta educativa que responda a esas necesidades, desde las ciencias sociales, concretamente desde la historia. Partiendo de la legislación vigente y teniendo en cuenta el planteamiento de algunos autores que abordan esta problemática, primero, comenzaré perfilando las características de este alumnado; pos...

  6. Alumnado con altas capacidades intelectuales: Programa de intervención

    OpenAIRE

    Arranz Melado, Luis Alfonso

    2015-01-01

    En el presente trabajo se hace un breve resumen conceptual de la literatura científica sobre las altas capacidades intelectuales. Se hace referencia a conceptos, teorías y modelos. Luego se analiza algunas de las características del alumnado con necesidades educativas especiales. Seguidamente, se hace referencia a los procedimientos y técnicas de evaluación de los estudiantes con necesidades educativas especiales. Se hace mención de las diferentes modalidades de respuesta educativa aplica...

  7. Alumnos con altas capacidades intelectuales: Propuesta de Intervención

    OpenAIRE

    Cano-Aguirre, María Isabel

    2012-01-01

    En este trabajo se ha realizado una revisión bibliográfica acerca de las características de los alumnos de altas capacidades intelectuales, su funcionamiento cerebral y los proyectos que se aplican en la actualidad. En la segunda parte se ha realizado una investigación con un enfoque cualitativo en la cual se proporcionó un cuestionario a un grupo de profesionales que participan en proyectos dirigidos a este tipo de alumnado con el fin de detectar la situación actual en la que se encuentran. ...

  8. Género, adolescencia y altas capacidades : un acercamiento a la afectividad

    OpenAIRE

    González González, Leybiz

    2012-01-01

    El presente estudio fue realizado en un grupo de chicas y chicos adolescentes pertenecientes a la Asociación Onubense de Altas Capacidades ARETÉ. Sus propósitos consistieron en analizar el aspecto afectivo-relacional a través de una perspectiva de género, en la que fueron identificadas las vivencias y áreas de conflictos psicológicos, las preocupaciones, temores, satisfacciones e insatisfacciones presentes. Asimismo, se pretendió develar algunos elementos de la conformación de ...

  9. La evaluación psicopedagógica del alumnado con altas capacidades intelectuales

    OpenAIRE

    Moliner García, Odet; Comes Nolla, Gabriel; Luque, Antonio; Díaz Pareja, Elena María

    2008-01-01

    Tras un análisis de la normativa estatal y autonómica sobre la evaluación psicopedagógica del alumnado con altas capacidades intelectuales, se presentan los aspectos más relevantes que toda evaluación psicopedagógica debe contemplar para que resulte lo más eficaz posible, y permita ofrecer una respuesta educativa adecuada a dicho alumnado e identifique los recursos y apoyos que pueda precisar. Tales decisiones se concretan en el informe psicopedagógico y este artículo recoge...

  10. Alumnos con indicios de altas capacidades en Educación Infantil

    OpenAIRE

    López-Gómez, Sheila

    2012-01-01

    En las aulas se encuentran niños de altas capacidades que no han sido diagnosticados y por lo tanto no se está atendiendo a sus necesidades como se debiera. Mediante este trabajo de fin de grado se ha pretendido señalar las características principales que permiten al tutor del aula reconocer a estos alumnos y poderles derivar a los orientadores que señalarán las pautas necesarias para conseguir que el alumno se desarrolle en plenitud y se sienta integrado en el aula. Para ello se van a exp...

  11. Enfoque de recursos y capacidades dinámicas: planteamientos teóricos

    OpenAIRE

    Fuentelsaz Lamata, Lucio

    2015-01-01

    La consolidación del enfoque de recursos y capacidades dinámicas como marco teórico de referencia requiere la revisión crítica de sus fundamentos y la aplicación a distintas dimensiones estratégicas de la empresa. En esta conferencia revisamos en cuál de dichas dimensiones se están produciendo los mayores avances. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

  12. A functional connection of Dictyostelium paracaspase with the contractile vacuole and a possible partner of the vacuolar proton ATPase

    Indian Academy of Sciences (India)

    Entsar Saheb; Ithay Biton; Katherine Maringer; John Bush

    2013-09-01

    Dictyostelium discoideum possesses only one caspase family member, paracaspase (pcp). Two separate mutant cell lines were first analysed: one cell line was an over-expressed GFP-tagged Pcp (GFP-Pcp), while the other cell line was a pcp-null (pcp-). Microscopic analysis of cells expressing GFP-Pcp revealed that Pcp was associated with the contractile vacuole membrane consisting of bladder-like vacuoles. This association was disrupted when cells were exposed to osmotic stress conditions. Compared with wild-type cells, the GFP-Pcp-over-expressing cells were susceptible to osmotic stress and were seen to be very rounded in hypo-osmotic conditions and contained more abnormally swollen contractile vacuole. Cells with pcp- were also rounded but had few, if any, contractile vacuoles. These observations suggest that Pcp is essential for Dictyostelium osmotic regulation via its functioning in the contractile vacuole system. Subjecting these cells to selected contractile vacuole inhibitor provided additional support for these findings. Furthermore, yeast two-hybrid system identified vacuolar proton ATPase (VatM) as the protein interacting with Pcp. Taken together, this work gives evidence for an eukaryotic paracaspase to be associated with both localization in and regulation of the contractile vacuolar system, an organelle critical for maintaining the normal morphology of the cell.

  13. Comparación de cuatro métodos de restauración del adn en muestras de plasma y láminas de citología cérvico-uterina como una herramienta para mejorar la calidad de la muestra

    OpenAIRE

    Marquez, Pilar caterin

    2011-01-01

    Objetivos: comparar cuatro métodos de restauración del adn en plasma y láminas cérvico-uterinas como una herramienta para mejorar la calidad de la muestra. Métodos: a 20 muestras de plasma sanguíneo y 20 muestras de láminas citológicas, se les realizó aislamiento de adn mediante kit comercial y fenol-cloroformo. A todas las muestras se les realizó un tratamiento pre-pcr con cuatro diferentes tipos de actividad de adn polimerasa: 1. Exonucleasa y endonucleasa 5’-3’. 2. Exonucleasa 5’-3’. 3. Kl...

  14. Effect of rhubarb on contractile response of gallbladder smooth muscle strips isolated from guinea pigs

    Institute of Scientific and Technical Information of China (English)

    Ya-Li Luo; Jun-Wei Zeng; Mei Yu; Yu-Ling Wei; Song-Yi Qu; Wei Li; Tian Zhen Zheng

    2005-01-01

    AIM: To investigate the effect of rhubarb on contractile response of isolated gallbladder muscle strips from guinea pigs and its mechanism.METHODS: Guinea pigs were killed to remove the whole gallbladder. Two or three smooth muscle strips (8 mm×3mm) were cut along the longitudinal direction. The mucosa on each strip was carefully removed. Each longitudinal muscle strip was suspended in a tissue chamber containing 5 mL Krebs solution (37 ℃), bubbled continuously with 950 mL/L O2 and 50 mL/L CO2. The resting tension (g), mean contractile amplitude (mm),and contractile frequency (waves/min) were simultaneously recorded on recorders. After 2-h equilibration, rhubarb (10, 20, 70, 200, 700, 1 000 g/L) was added cumulatively to the tissue chamber in turns every 2 min to observe their effects on gallbladder.Antagonists were given 3 min before administration of rhubarb to investigate the possible mechanism.RESULTS: Rhubarb increased the resting tension (from 0 to 0.40±0.02, P<0.001), and decreased the mean contractile amplitude (from 5.22±0.71 to 2.73±0.41,P<0.001). It also increased the contractile frequency of the gallbladder muscle strips in guinea pigs (from 4.09±0.46to 6.08±0.35, P<0.001). The stimulation of rhubarb on the resting tension decreased from 3.98±0.22 to 1.58±0.12by atropine (P<0.001), from3.98±0.22 to 2.09±0.19 by verapamil (P<0.001) and from 3.98±0.22 to 2.67±0.43by phentolamine (P<0.005). But the effect was not inhibited by hexamethonium (P>0.05). In addition, the action of mean amplitude and frequency was not inhibited by the above antagonists.CONCLUSION: Rhubarb can stimulate the motility of isolated gallbladder muscle strips from guinea pigs. The stimulation of rhubarb might be relevant with M receptor,Ca2+ channel and α receptor partly.

  15. Importância dos parâmetros seminais nos resultados de inseminação intra-uterina Importance of seminal parameters for intrauterine insemination outcomes

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    Edson Borges Junior

    2003-05-01

    Full Text Available OBJETIVOS: analisar a relevância dos parâmetros seminais nos resultados dos ciclos de inseminação intra-uterina (IIU em pacientes com causa masculina de infertilidade e salientar o caráter prognóstico de cada parâmetro para o sucesso da técnica. MÉTODOS: duzentos e trinta e nove ciclos de IIU (155 casais foram analisados durante período de 15 meses. Todos as pacientes foram submetidas à indução da ovulação de acordo com protocolos do I Consenso Brasileiro de Indução de Ovulação. A análise seminal foi realizada de acordo com os critérios da Organização Mundial da Saúde (OMS para parâmetros como concentração e motilidade e critério estrito de Kruger para avaliação da morfologia. O preparo da amostra para IIU foi realizado por meio de gradientes descontínuos de densidade (ISolate®. Foram formados dois grupos de pacientes de acordo com o resultado de gestação: grupo G - gestação positiva e grupo NG - gestação negativa. RESULTADOS: não houve diferença significativa nos valores obtidos relacionados à concentração total de espermatozóides/mL de sêmen, motilidade total, motilidade de formas progressivas antes e depois do processamento seminal. Quando a morfologia estrita de Kruger foi comparada entre os dois grupos, diferenças significativas foram encontradas (grupo G=10,6% de formas normais; grupo NG=6,4% de formas normais; pPURPOSE: to analyze the influence of seminal parameters on intrauterine insemination (IUI outcomes in patients with male factor and to emphasize the predictive value of each parameter for the successful result. METHODS: two hundred and thirty-nine IUI cycles (155 couples were analyzed for 15 months. Female patients were submitted to ovary hyperstimulation according to the "I Consenso Brasileiro de Indução de Ovulação". Seminal analysis based on the World Health Organization (WHO for sperm concentration and motility was used and sperm morphology was evaluated according to Kruger

  16. Gravid med spontan ruptur af arteria uterina

    DEFF Research Database (Denmark)

    Jònsdòttir, Fjòla; Pinborg, Anja; Wilken-Jensen, Charlotte

    2014-01-01

    Pregnant women with acute abdominal pain are a clinical challenge. We present a rare but potential life-threatening condition of a pregnant woman with acute abdominal pain. The woman was in gestational week 37 with severe abdominal pain and was admitted to the labour ward. She became haemo......-dynamic instable 24 hours after vaginal delivery, and emergency laparotomi revealed a spontaneous rupture of the right uterine artery. Spontaneous rupture of the uterine artery is rare but should be considered as a possible cause of acute abdominal pain in pregnant women....

  17. Autoestima dos cuidadores de doentes oncológicos com capacidade funcional reduzida

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    Natália Stanko Moreira

    2015-06-01

    Full Text Available Objetivo: Avaliar a autoestima de cuidadores de doentes oncológicos com capacidade funcional reduzida. Métodos: Trata-se de estudo do tipo transversal, realizado em um hospital público, de grande porte, especializado em oncologia. Utilizou-se uma amostra por conveniência composta por 90 cuidadores principais de doentes com câncer com capacidade funcional (Karnofsky entre 20 e 50. Foram coletados dados sóciodemográficos, sobre os encargos envolvidos no cuidar e a autoestima foi avaliada pela Escala para Medida do Sentimento de Autoestima de Dela Coleta. Os dados foram analisados pelo teste de Mann-Whitney e de Kurskall-Wallis, com nível de significância de 5%. Resultados: A maioria dos cuidadores eram mulheres, com companheiros, com baixa renda mensal, mantinham relações familiares com o doente e apresentavam média autoestima. A autoestima foi associada de forma estatisticamente significante apenas com a renda familiar (p = 0,002. Conclusão: A autoestima dos cuidadores de pacientes oncológicos é influenciada pelas condições de vida, especialmente as financeiras.

  18. Misiones y capacidades del Ejército del Aire en los comienzos del siglo XXI

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    Rubio Villamayor, Ricardo

    2002-02-01

    Full Text Available En este artículo, su autor, el General Jefe del Mando Aéreo de Combate, nos expone, desde un punto de vista esencialmente operativo refrendado por sus últimas actuaciones en conflictos y otras misiones, las características y capacidades del Poder Aéreo.
    Se hacen unas reflexiones sobre las capacidades básicas que debe tener la Fuerza Aérea española para que tenga una dimensión operativa creíble, y que la hagan apta para afrontar con garantías de éxito los nuevos escenarios y retos del futuro, desde el terrorismo hasta las operaciones de paz y humanitarias.
    Desmenuza las misiones que hoy desarrolla el Ejército del Aire, tanto a favor de la consecución de los objetivos de la Defensa Nacional, como en apoyo de la sociedad a la que sirve. Finalmente actualiza otros aspectos relevantes, entre los que destacan la colaboración con los Ejércitos de Tierra y Armada, la denominada

  19. Evaluación de capacidades para testificar en víctimas con discapacidad intelectual

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    María José Contreras

    2015-01-01

    Full Text Available Las habilidades para testificar de las víctimas con discapacidad intelectual (DI suelen ser consideradas de acuerdo con estereotipos más que con su realidad, teniendo en cuenta que se observa una gran heterogeneidad en este colectivo. Por ello es necesario un procedimiento que permita conocer específicamente las características cognitivas de cada víctima con DI con el fin último de adaptar los procedimientos policiales y judiciales a sus capacidades y evaluar adecuadamente la información que aportan en sus testimonios. Con este objetivo se desarrolló el protocolo de entrevista CAPALIST, que evalúa las capacidades cognitivas que intervendrían en la aportación de testimonio. En el presente trabajo se describe la herramienta y se aportan datos sobre su aplicación a cuatro víctimas reales de abuso sexual con DI. Los resultados muestran mínimas diferencias en los acuerdos interjueces. Se concluye que el CAPALIST podría ser de utilidad en la evaluación de las habilidades para testificar en víctimas con DI.

  20. El enfoque de las capacidades, la agencia cognitiva y los recursos morales

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    Agustín Reyes Morela

    2012-02-01

    Full Text Available El enfoque de Sen se presenta como una alternativa en el terreno de la justicia distributiva. Su noción central es la de capacidad de agencia, es decir, la libertad efectiva para alcanzar aquello que se tienen razones para valorar. A su vez, la idea de agencia cognitiva refiere a la capacidad de revisar o reforzar estas razones. Bajo la autocomprensión de las sociedades modernas, la única forma válida de desarrollarla es a través de la deliberación pública. Del intercambio surgen los recursos morales (entre ellos las razones morales que permiten modificar la concepción del bien y fortalecer sentido de justicia de los sujetos.The Sen’s approach is presented as an alternative in the field of distributive justice. Its main concept is the capability of agency, namely the effective freedom to achieve whatever you have reason to value. In turn, the idea of cognitive agency refers to the capability to review and strengthen these reasons. Under the self-understanding of modern societies, the only valid way to develop them is through public deliberation. Through the exchange emerge the moral resources that allow to modify the conception of the good and strengthen the sense of justice of the people.

  1. EFECTIVIDAD DE LA ORIENTACIÓN EMPRENDEDORA: EL PAPEL DEL CAPITAL SOCIAL Y LAS CAPACIDADES

    Directory of Open Access Journals (Sweden)

    Rodrigo-Alarcón, Job

    2014-09-01

    Full Text Available La orientación emprendedora ha sido uno de los aspectos que mayor interés ha suscitado en los últimos años en el campo del entrepreneurship. La revisión de la literatura nos permite señalar la necesidad de abordar la ambigüedad y la complejidad de la relación entre la orientación emprendedora y los resultados empresariales. En este trabajo planteamos esta relación desde un enfoque configuracional, abordando la coherencia de factores relacionales —capital social— y organizativos —capacidades tecnológicas y de marketing— con la orientación emprendedora. El objetivo del trabajo consiste en desarrollar un modelo configuracional que explique el efecto moderador conjunto del capital social y las capacidades empresariales sobre la efectividad de la orientación emprendedora. Se establecen 3 modelos teóricos —universal, contingente y configuracional— que se definen mediante proposiciones teóricas. Exploramos y ejemplificamos empíricamente las relaciones establecidas mediante un estudio de casos de empresas agroalimentarias españolas. Finalmente, extraemos diversas conclusiones a partir de los modelos planteados y proponemos futuras líneas de investigación.

  2. El proyecto político y las capacidades de gobierno

    Directory of Open Access Journals (Sweden)

    Hugo Spinelli

    2012-01-01

    Full Text Available En este trabajo se realiza una revisión teórica sobre las capacidades de gobierno personales (experiencia, liderazgo y conocimiento y las capacidades de gobierno institucionales (capital organizativo disponible y su relación con lo político y las políticas en el contexto de América Latina. A partir de la producción teórica de Carlos Matus sobre la acción de gobernar, se ponen en discusión diversas dimensiones de esta problemática, las que se relacionan con otros autores y experiencias de diferentes momentos históricos. Se desarrollan teorías, métodos y técnicas de gobierno y se analiza la necesidad de la reforma del Estado desde una lógica interna. Se concluye en la necesidad de construir una teoría para la práctica de gobernar/gestionar las organizaciones públicas. Esa construcción requiere de acciones creativas que utilicen la teoría como caja de herramientas.

  3. Capacidad de uso de la tierra en la cuenca de la Corriente del Lobo, Itatinga, São Paulo, Brasil

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    Sérgio Campos

    2011-12-01

    Full Text Available El objetivo del trabajo fue definir las clases de capacidad de uso de 2.403,25 ha de la cuenca de la Corriente del Lobo - Itatinga (SP (22° 03' 56" - 22° 59' 12" de latitud S y 48° 38' 47" - 48° 41' 25" de longitud O. La capacidad de uso de la tierra se obtuvo mediante el SIG-IDRISI 32 del cruzamiento de las cartas clinográfica y de suelos y de la Tabla de juzgamiento de clases de capacidad de uso de la tierra y del levantamiento utilitario del medio físico. Las áreas de las clases y subclases de capacidad de uso presentaron los siguientes valores: IIIa - 68.60 ha (2.85%, IIIe,s - 1919.15 ha (79.86%; IIIe - 210.60 ha (8.76%; IVe - 3.38 ha (0.14%; IVe,s - 157.42 ha (6.55% y VIe,s - 44.10 ha (1.84%. Las tierras de la cuenca se distribuyeron en tres clases (III, IV y VI y seis subclases, pero la mayor extensión (79.9% pertenece a la subclase IIIe,s. Los módulos del IDRISI permitieron discriminar, mapear y cuantificar rápidamente la capacidad de uso de las áreas de las clases y subclases de la cuenca.

  4. Capacidade funcional e cognitiva de idosas praticantes de diferentes modalidades de exercícios físicos

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    Daniel Vicentini de Oliveira

    2015-01-01

    Full Text Available Objetivo: comparar la capacidad funcional y cognitiva de ancianas practicantes de diversas modalidades de ejercicio físico. Métodos: estudio cuantitativo, transversal, descriptivo, de observación y analítico, con 120 voluntarios, divididos en tres grupos de 40 ancianas: aeróbic, Academia de la Tercera Edad y grupo musculación. La capacidad funcional se evaluó mediante evaluación funcional del Protocolo Grupo de Desarrollo de América Latina para madurez, y la evaluación cognitiva se utilizó Mini-Mental del Estado Mental. Resultados: la capacidad funcional de las ancianas en las tres modalidades se clasificaron como débil, mostrando diferencias significativas entre los grupos (p=0,082. La capacidad cognitiva mostró puntajes cerca de puntuación perfecta en las tres modalidades de ejercicio, sin significación estadística (p=0,062. Conclusión: es baja la capacidad funcional de las ancianas evaluadas, así como el tipo de ejercicio no interfiere en el rendimiento cognitivo.

  5. Menor de edad y capacidad de ejercicio: Reto del Derecho Familiar contemporáneo Menor de edad y capacidad de ejercicio: Reto del Derecho Familiar contemporáneo.

    Directory of Open Access Journals (Sweden)

    Jetzabel Mireya Montejo Rivero

    2012-04-01

    Full Text Available Change in family relations that took place at the opening of the 21st comporting new paradigms in conceptions of minor is already in progress. These reflections are referred to understanding child legal status capacity that takes into consideration its legal ability from the perspective of dynamic participation in concrete legal relations according to his progressive ability and secures the protection of his rights at the same time. The present article demonstrate the legal concepts of individual, personality and ability are interpreted the legal ability of child individuals is evaluated following that viewpoint. The study outlines the necessity of harmonizing the notion of child and ability for “child’s best interest” in contemporary family low.Los cambios en las relaciones familiares acaecidos en los albores de siglo XXI, comportan nuevos paradigmas en la concepción de la capacidad del menor. En estas reflexiones, se hace referencia a la enunciación de la capacidad de obrar del menor desde una dinámica participativa en las relaciones jurídicas civiles y familiares acorde a su capacidad progresiva y una más efectiva protección al ejercicio de sus derechos. El presente artículo, expone sucintamente valoraciones sobre el ejercicio de la capacidad del menor a partir de la fundamentación teórica de los conceptos jurídicos de persona, personalidad y capacidad, en aras de armonizar las nociones de menor de edad y capacidad de ejercicio desde el interés superior del niño en el Derecho Familiar contemporáneo.

  6. El enfoque de capacidad de Amartya Sen y sus limitaciones para la ciudadanía y la sociedad civil

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    Maria Rosario Carvajal Muñoz

    2014-01-01

    Full Text Available Este trabajo parte del concepto de “capacidad” de Sen, definido como un aspecto de la libertad que requiere de oportunidades sustantivas, para aproximarse al término de capacidad política. La capacidad política, por tanto, es un aspecto de la libertad que comprende oportunidades de participación política sustantiva. Esta aproximación a la capacidad política está confrontada con dos corrientes del pensamiento: el institucionalismo trascendental o contractualismo y el comparativista. Considerando estas dos corrientes de pensamiento, los conceptos institucionales de ciudadanía activa y sociedad civil, promovidos en las últimas décadas por gobiernos neoliberales, son examinados de forma crítica. Asimismo, se relaciona la capacidad política con modelos teóricos clásicos de sociedad civil. Esta relación entre la capacidad política con los conceptos de ciudadanía y sociedad civil ayudan a barajar la hipótesis de que se privilegia en política el consenso por mayoría (enfoque trascendental o contractualista, frente al consenso por discusión (enfoque comparativista o consecuencialista. La tradición contractualista dificultaría el reconocimiento del enfoque comparativista, fundamentado en la idea de equidad de Sen, y esencial para un gobierno por discusión, limitando así la capacidad política.

  7. Capacidade para o trabalho entre trabalhadores de higiene e limpeza de um hospital universitário público

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    Larissa Gutierrez da Silva

    2010-03-01

    Full Text Available A capacidade para o trabalho é a base do bem-estar para o ser humano e a sua manutenção envolve condições de saúde e trabalho adequadas. Com o objetivo de verificar a capacidade para o trabalho entre trabalhadores de higiene e limpeza,realizou-se uma pesquisa quantitativa, do tipo descritivo-exploratória, em um hospital universitário público do norte paranaense, de março a junho de 2008, por meio da aplicação de um questionário constituído por dados sócio-demográficos e ocupacionais, e pelo Índice de Capacidade para o Trabalho (ICT. Os dados foram analisados pelo programa Epi Info 2002. A população foi composta por 98 trabalhadores, sendo que 82,4% possuem mais de 41 anos e 96,9% são mulheres. Quanto à avaliação da capacidade para o trabalho, 45,9% dos entrevistados obtiveram um ICT bom, 23,5% ótimo, 22,4% moderado e 8,2% baixo, com escore mínimo de 16 e máximo de 49. As doenças músculo esqueléticas foram as mais referidas pelos entrevistados. Os fatores relacionados à capacidade para o trabalho são múltiplos, assim, as ações para a prevenção erecuperação desta capacidade devem ser discutidas e conciliadas entre empregados e empregadores, garantindo um espaço para contextualização e reflexão acerca do processo de trabalho.

  8. Treinamento aerobio e resistido, qualidade de vida e capacidade funcional de hipertensas

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    Thais Inacio Rolim Povoa

    2014-01-01

    Full Text Available INTRODUÇÃO: Pacientes hipertensos podem apresentar comprometimento da qualidade de vida (QV e da qualidade de vida relacionada à saúde (QVRS, tanto pela hipertensão arterial (HA, quanto pelos eventuais efeitos adversos do tratamento. Exercícios físicos, aeróbios e resistidos, melhoram a performance cardiorrespiratória e neuromuscular, mas há poucas evidências sobre seus efeitos na QV, QVRS e capacidade funcional (CF em mulheres hipertensas. OBJETIVO: Avaliar e comparar os efeitos dos treinamentos aeróbio e resistido sobre a QV, QVRS e a capacidade funcional em hipertensas. MÉTODOS: Ensaio clínico randomizado, cego, com total de 18 sessões de exercícios. Foram incluídas mulheres hipertensas sob tratamento medicamentoso, não participantes de programas de exercícios, com 50 anos de idade ou mais, que não apresentaram arritmias e/ou alterações isquêmicas em teste ergométrico (protocolo de Bruce. A amostra foi randomizada como segue: grupo aeróbio (GA (n = 21 e grupo resistido (GR (n = 20. Intensidade GA: leve a moderada (Escala de Borg adaptada; GR: até 50-65% de 1 RM. Duas séries com 12 a 15 repetições. Antes e após a intervenção foram aplicados os questionários WHOQOL-bref (QV e SF-36 (QVRS e realizado o teste de caminhada de 6 minutos (TC6` para avaliar a CF. Estatística: testes Shapiro-Wilk, t de Student, Fisher, U de Mann-Whitney e Wilcoxon. Nível de significância: p 0,05. Após a intervenção houve melhora significativa em todos os domínios do WHOQOL-bref no GA e no GR houve melhora no domínio aspectos físicos. No SF-36, constatou-se melhora significativa em sete de oito domínios tanto no GA quanto no GR. Capacidade funcional: verificou-se melhora nos dois grupos (p < 0,001. CONCLUSÃO: Os dois tipos de treinamento melhoraram a QV e a CF e, dependendo dos objetivos estabelecidos, ambos podem ser eficazes.

  9. CAPACIDAD PREDICTIVA DE MODELOS DE INSOLVENCIA CON BASE EN NÚMEROS CONTABLES Y DATOS DESCRIPTIVOS

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    Júlio Orestes da Silva

    2012-09-01

    Full Text Available En el Brasil la pesquisa sobre modelos de previsión de insolvencia se inició en la década de 1970, siendo que la mayor parte de los trabajos hizo uso del Análisis Discriminante como herramienta estadística del modelo. En los últimos años, se buscó verificar si es posible prever la insolvencia de las empresas utilizando datos descriptivos contenidos en los informes de las organizaciones. Así, este estudio tiene como objetivo verificar la capacidad de algunos modelos de previsión de insolvencia en prever la discontinuidad de empresas brasileñas que decretaron quiebra. La pesquisa se caracteriza como descriptiva y posee abordaje cuantitativo, realizado por medio de pesquisa documental. La muestra totalizó 13 empresas que decretaron quiebra entre los años de 1997 y 2003. Los resultados indican que la mayoría de los modelos de previsión de quiebra testados presentó resultados elevados de previsiones correctas. Los modelos de previsión de discontinuidad con base en informes descriptivos obtuvieron en media más previsiones asertivas en relación a la capacidad de prever la quiebra de las empresas. Esos descubrimientos demuestran que, a pesar de que algunas pesquisas apunten hacia la falta de validez de predictores creados en realidades empresariales diferentes, algunos modelos todavía poseen buena capacidad de previsión de insolvencia. Se concluye que tanto los modelos de previsión de insolvencia con base en números contables en relación a los modelos que se utilizan datos de informes descriptivos pueden prever la discontinuidad de las organizaciones. Por fin, se puede inferir que la mayoría de los modelos de previsión de quiebra que hacen uso de números contables pueden ser funcionales y capaces de prever la discontinuidad de las organizaciones.

  10. El desafío de la justicia global desde el enfoque de la capacidad de Amartya K. Sen

    OpenAIRE

    Tamarit López, Isabel

    2016-01-01

    La tesis se centra en el estudio del enfoque de la capacidad en el economista Amartya K. Sen y su vinculación con la justicia en el ámbito global. En primer lugar nos centramos en el concepto de justicia global frente al de justicia internacional y transnacional. A continuación nos proponemos analizar el potencial de la capacidad (capability) como clave para una justicia de alcance global. A partir de la crítica de otros autores como Pogge, Nussbaum, Ricoeur, Cortina, Conill y Crocker valoram...

  11. Capacidades para el desarrollo rural de grupos de mujeres de cuatro comunidades en la Sierra Nevada de Puebla.

    OpenAIRE

    Ramírez Castel, Verónica

    2014-01-01

    Esta investigación tuvo como objetivo el estudio de los tipos de capacidades de las mujeres rurales participantes en la Asociación para el Desarrollo “Enlace Sierra Nevada, A. C.”, sus efectos en los ámbitos personal, familiar y comunitario y los aspectos que favorecen y limitan este desarrollo de capacidades. El método general de investigación fue el descriptivo explicativo en el que se usaron métodos particulares como las entrevistas a profundidad a las mujeres participantes en los proyecto...

  12. Actividad física y capacidad funcional en el adulto mayor: el taekwondo como alternativa de mejoramiento

    OpenAIRE

    Pedro Carazo Vargas

    2001-01-01

    Con el envejecimiento se presenta una serie decambios de orden fisiológico, psicológico y social, capacesde reducir la capacidad para efectuar eficientemente lastareas de la vida diaria. En la presente revisión de litera-tura se realiza una descripción de estas modificaciones,así como una recopilación de los principales efectos de laactividad física sobre la capacidad funcional del adultomayor. Se analizan los primeros indicios que señalan altaekwondo como una importante alternativa para mejo...

  13. ¿Einstein o Dalí?: altas capacidades e inteligencias múltiples, visión actual.

    OpenAIRE

    Herrera-Parejo, Clara Isabel

    2015-01-01

    La presente investigación trata de acercarse al conocimiento y características propias de los alumnos con altas capacidades intelectuales y su relación con el modelo de las inteligencias múltiples de Howard Gardner, como propuesta que favorece la educación personalizada y el desarrollo de las capacidades y talentos en los niños más dotados, atendiendo a sus necesidades; además de cómo se recoge la atención a estos alumnos en nuestra legislación, algunos programas de intervención en el aula, e...

  14. Diseño de un programa de intervención con alumnos de altas capacidades: Optimismo

    OpenAIRE

    Martínez San José, Bárbara

    2015-01-01

    Este documento presenta un proyecto de intervención para favorecer el optimismo en alumnos con altas capacidades en edades comprendidas entre 12 y 16 años. En un primer momento se han expuesto los objetivos a conseguir con este trabajo. Seguidamente, se han definido con los conceptos de altas capacidades y de optimismo y sentido positivo. Así mismo, se ha explicado en qué contexto y que objetivos tendrá el programa de intervención de optimismo en sí, y se ha desarrollado con diversas activida...

  15. Alumnos con altas capacidades: protocolo de actuación y propuesta de actividades de enriquecimiento curricular

    OpenAIRE

    Aguirre Estarli, Laura

    2016-01-01

    Los alumnos con altas capacidades intelectuales son considerados legalmente como alumnos con necesidades específicas de apoyo educativo, y requieren, por lo tanto, una atención distinta a la ordinaria para que logren el pleno desarrollo de sus capacidades. Sin embargo, en la práctica educativa son los grandes olvidados; apenas se les diagnostica como tales, no se les suele prestar la ayuda que precisan, de modo que un alto porcentaje de niños superdotados presentan fracaso escolar. Aparte de ...

  16. Perfil y necesidades de alumnos universitarios con altas capacidades en la Universidad de Málaga. Datos iniciales

    OpenAIRE

    Fernández Molina, Milagros

    2016-01-01

    La investigación sobre la presencia en las Universidad de alumnos con altas capacidades intelectuales es muy escasa, constituyendo un tema de estudio de importante proyección. Apenas hay publicaciones o informes sobre el acceso a los estudios superiores del alumnado con alta capacidad, el perfil personal e intelectual que presenta, las necesidades que tiene durante su trayectoria universitaria, la tasa de abandonos o de éxito en los estudios universitarios que elige, etc. En este trabajo se p...

  17. Opportunities to Target Specific Contractile Abnormalities with Smooth Muscle Protein Kinase Inhibitors

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    Annegret Ulke-Lemée

    2010-05-01

    Full Text Available Smooth muscle is a major component of most hollow organ systems (e.g., airways, vasculature, bladder and gut/gastrointestine; therefore, the coordinated regulation of contraction is a key property of smooth muscle. When smooth muscle functions normally, it contributes to general health and wellness, but its dysfunction is associated with morbidity and mortality. Rho-associated protein kinase (ROCK is central to calcium-independent, actomyosin-mediated contractile force generation in the vasculature, thereby playing a role in smooth muscle contraction, cell motility and adhesion. Recent evidence supports an important role for ROCK in the increased vasoconstriction and remodeling observed in various models of hypertension. This review will provide a commentary on the development of specific ROCK inhibitors and their clinical application. Fasudil will be discussed as an example of bench-to-bedside development of a clinical therapeutic that is used to treat conditions of vascular hypercontractility. Due to the wide spectrum of biological processes regulated by ROCK, many additional clinical indications might also benefit from ROCK inhibition. Apart from the importance of ROCK in smooth muscle contraction, a variety of other protein kinases are known to play similar roles in regulating contractile force. The zipper-interacting protein kinase (ZIPK and integrin-linked kinase (ILK are two well-described regulators of contraction. The relative contribution of each kinase to contraction depends on the muscle bed as well as hormonal and neuronal stimulation. Unfortunately, specific inhibitors for ZIPK and ILK are still in the development phase, but the success of fasudil suggests that inhibitors for these other kinases may also have valuable clinical applications. Notably, the directed inhibition of ZIPK with a pseudosubstrate molecule shows unexpected effects on the contractility of gastrointestinal smooth muscle.

  18. Active self-polarization of contractile cells in asymmetrically shaped domains

    Science.gov (United States)

    Zemel, A.; Safran, S. A.

    2007-08-01

    Mechanical forces generated by contractile cells allow the cells to sense their environment and to interact with other cells. By locally pulling on their environment, cells can sense and respond to mechanical features such as the local stress (or strain), the shape of a cellular domain, and the surrounding rigidity; at the same time, they also modify the mechanical state of the system. This creates a mechanical feedback loop that can result in self-polarization of cells. In this paper, we present a quantitative mechanical model that predicts the self-polarization of cells in spheroidally shaped domains, comprising contractile cells and an elastic matrix, that are embedded in a three-dimensional, cell-free gel. The theory is based on a generalization of the known results for passive inclusions in solids to include the effects of cell activity. We use the active cellular susceptibility tensor presented by Zemel [Phys. Rev. Lett. 97, 128103 (2006)] to calculate the polarization response and hence the elastic stress field developed by the cells in the cellular domain. The cell polarization is analyzed as a function of the shape and the elastic moduli of the cellular domain compared with the cell-free surrounding material. Consistent with experiment, our theory predicts the development of a stronger contractile force for cells in a gel that is surrounded by a large, cell-free material whose elastic modulus is stiffer than that of the gel that contains the cells. This provides a quantitative explanation of the differences in the development of cellular forces as observed in free and fixed gels. In the case of an asymmetrically shaped (spheroidal) domain of cells, we show that the anisotropic elastic field within the domain leads to a spontaneous self-polarization of the cells along the long axis of the domain.

  19. Poor spontaneous and oxytocin-stimulated contractility in human myometrium from postdates pregnancies.

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    Sarah Arrowsmith

    Full Text Available Prolongation of pregnancy i.e. going more than 10 days over the estimated due date, complicates up to 10% of all pregnancies and is associated with increased risk to both mother and fetus. Despite the obvious need for contractions of the uterus to end pregnancy, there have been no studies directly examining the role of uterine smooth muscle, myometrium, in the aetiology of prolonged pregnancy. This study tested the hypothesis that the intrinsic contractile characteristics of myometrium taken from women with prolonged pregnancy (>41 weeks and 3 days was reduced compared to those delivering at term (39-41 weeks. We recruited women undergoing Caesarean Section (CS delivery either pre-labour (n = 27 or in labour (n = 66 at term or postdates. The contractile ability of the postdates myometrium, whether spontaneous or elicited by oxytocin or high-K solution, was significantly reduced compared to term myometrium. These differences remained when adjusted for parity and other maternal characteristics. The findings remained significant when expressed per cross sectional area. Histological examination revealed no differences between the two groups. The contractile differences were however related to intracellular Ca transients suggesting an effect of [Ca] on reduced force production in the postdates group. In summary, myometrium from prolonged pregnancies contracts poorly in vitro even when stimulated with oxytocin and in active labour. Responses to high K(+ and measurements of Ca suggest that alterations in excitation contraction coupling, rather than any histological changes of the myometrium, may underlie the differences between term and postdates myometrium. We show that postdates pregnancy is associated with poor myometrial activity and suggest that this may contribute to increased myometrial quiescence and hence, prolonged gestation.

  20. Changes of mitochondria in the contractile cardiomyocytes during postnatal rat ontogenesis

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    Kozlov S.V.

    2014-12-01

    Full Text Available Background. CVDs are the number 1 cause of death globally: more people die annually from CVDs than from any other cause. An estimated 17.5 million people died from CVDs in 2012, representing 31% of all global deaths. Of these deaths, an estimated 7.4 million were due to coronary heart disease and 6.7 million were due to stroke. Over three quarters of CVD deaths take place in low- and middle-income countries. Objective. Ultrastructural analysis of mitochondria in the rat contractile cardiomyocytes during postnatal ontogenesis. Methods. As the object of the study were used neonatal rat hearts, on the 5th, 10th, 15th, 30th days of life and mature animals. Hearts were investigated by the transmission electron microscopy. Volume density and numerical density of mitochondria were estimated. The Paired Student’s t-test was applied. Results. Was conducted a comprehensive ultrastructural analysis of mitochondria contractile cardiomyocytes, which allowed us to determine changes in the qualitative and quantitative parameters of mitochondria during postnatal ontogenesis, and helps to explain the dynamics and the development of mitochondria heart muscles cells after birth. Conclusion. It was shown that from the 1st to the 5th day there was a significant increase in volume density of mitochondria, which was accompanied by the increasing complexity of the ultrastructural organization of organelles. Following 20th day of postnatal ontogenesis mitochondrial structure was approaching the definitive condition and on the 30th day was the same as the mature myocardium. Citation: Kozlov SV, Mayevsky AE, Mіshalov VD, Sulayeva ON. [Changes of mitochondria in the contractile cardiomyocytes during postnatal rat ontogenesis]. Morphologia. 2014;8(4:37-42. Russian.

  1. Contractile profile of esophageal and gastric fundus strips in experimental doxorubicin-induced esophageal atresia

    Directory of Open Access Journals (Sweden)

    F.A. Capeto

    2015-05-01

    Full Text Available Esophageal atresia (EA is characterized by esophageal and gastric motility changes secondary to developmental and postsurgical damage. This study evaluated the in vitro contractile profile of the distal esophagus and gastric fundus in an experimental model of EA induced by doxorubicin (DOXO. Wistar pregnant rats received DOXO 2.2 mg/kg on the 8th and 9th gestational days. On day 21.5, fetuses were collected, sacrificed, and divided into groups: control, DOXO without EA (DOXO-EA, and DOXO with EA (DOXO+EA. Strips from the distal esophagus and gastric fundus were mounted on a wire myograph and isolated organ-bath system, respectively, and subjected to increasing concentrations of carbamylcholine chloride (carbachol, CCh. The isolated esophagus was also stimulated with increasing concentrations of KCl. In esophagus, the concentration-effect curves were reduced in response to CCh in the DOXO+EA and DOXO-EA groups compared to the control group (P0.05. In response to KCl, the distal esophagus samples in the three groups were not statistically different with regard to Emax or EC50 values (P>0.05. No significant difference was noted for EC50 or Emax values in fundic strips stimulated with CCh (P>0.05. In conclusion, exposure of dams to DOXO during gestation inhibited the contractile behavior of esophageal strips from offspring in response to CCh but not KCl, regardless of EA induction. The gastric fundus of DOXO-exposed offspring did not have altered contractile responsiveness to cholinergic stimulation.

  2. Isolation and maintenance-free culture of contractile myotubes from Manduca sexta embryos.

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    Amanda L Baryshyan

    Full Text Available Skeletal muscle tissue engineering has the potential to treat tissue loss and degenerative diseases. However, these systems are also applicable for a variety of devices where actuation is needed, such as microelectromechanical systems (MEMS and robotics. Most current efforts to generate muscle bioactuators are focused on using mammalian cells, which require exacting conditions for survival and function. In contrast, invertebrate cells are more environmentally robust, metabolically adaptable and relatively autonomous. Our hypothesis is that the use of invertebrate muscle cells will obviate many of the limitations encountered when mammalian cells are used for bioactuation. We focus on the tobacco hornworm, Manduca sexta, due to its easy availability, large size and well-characterized muscle contractile properties. Using isolated embryonic cells, we have developed culture conditions to grow and characterize contractile M. sexta muscles. The insect hormone 20-hydroxyecdysone was used to induce differentiation in the system, resulting in cells that stained positive for myosin, contract spontaneously for the duration of the culture, and do not require media changes over periods of more than a month. These cells proliferate under normal conditions, but the application of juvenile hormone induced further proliferation and inhibited differentiation. Cellular metabolism under normal and low glucose conditions was compared for C2C12 mouse and M. sexta myoblast cells. While differentiated C2C12 cells consumed glucose and produced lactate over one week as expected, M. sexta muscle did not consume significant glucose, and lactate production exceeded mammalian muscle production on a per cell basis. Contractile properties were evaluated using index of movement analysis, which demonstrated the potential of these cells to perform mechanical work. The ability of cultured M. sexta muscle to continuously function at ambient conditions without medium replenishment

  3. Myocardial mitochondrial and contractile function are preserved in mice lacking adiponectin.

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    Martin Braun

    Full Text Available Adiponectin deficiency leads to increased myocardial infarct size following ischemia reperfusion and to exaggerated cardiac hypertrophy following pressure overload, entities that are causally linked to mitochondrial dysfunction. In skeletal muscle, lack of adiponectin results in impaired mitochondrial function. Thus, it was our objective to investigate whether adiponectin deficiency impairs mitochondrial energetics in the heart. At 8 weeks of age, heart weight-to-body weight ratios were not different between adiponectin knockout (ADQ-/- mice and wildtypes (WT. In isolated working hearts, cardiac output, aortic developed pressure and cardiac power were preserved in ADQ-/- mice. Rates of fatty acid oxidation, glucose oxidation and glycolysis were unchanged between groups. While myocardial oxygen consumption was slightly reduced (-24% in ADQ-/- mice in isolated working hearts, rates of maximal ADP-stimulated mitochondrial oxygen consumption and ATP synthesis in saponin-permeabilized cardiac fibers were preserved in ADQ-/- mice with glutamate, pyruvate or palmitoyl-carnitine as a substrate. In addition, enzymatic activity of respiratory complexes I and II was unchanged between groups. Phosphorylation of AMP-activated protein kinase and SIRT1 activity were not decreased, expression and acetylation of PGC-1α were unchanged, and mitochondrial content of OXPHOS subunits was not decreased in ADQ-/- mice. Finally, increasing energy demands due to prolonged subcutaneous infusion of isoproterenol did not differentially affect cardiac contractility or mitochondrial function in ADQ-/- mice compared to WT. Thus, mitochondrial and contractile function are preserved in hearts of mice lacking adiponectin, suggesting that adiponectin may be expendable in the regulation of mitochondrial energetics and contractile function in the heart under non-pathological conditions.

  4. A single resistance exercise session improves myocardial contractility in spontaneously hypertensive rats

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    A.A. Fernandes

    2015-01-01

    Full Text Available Resistance training evokes myocardial adaptation; however, the effects of a single resistance exercise session on cardiac performance are poorly understood or investigated. This study aimed to investigate the effects of a single resistance exercise session on the myocardial contractility of spontaneously hypertensive rats (SHRs. Male 3-month-old SHRs were divided into two groups: control (Ct and exercise (Ex. Control animals were submitted to sham exercise. Blood pressure was measured in conscious rats before the exercise session to confirm the presence of arterial hypertension. Ten minutes after the exercise session, the animals were anesthetized and killed, and the hearts were removed. Cardiac contractility was evaluated in the whole heart by the Langendorff technique and by isometric contractions of isolated left ventricular papillary muscles. SERCA2a, phospholamban (PLB, and phosphorylated PLB expression were investigated by Western blot. Exercise increased force development of isolated papillary muscles (Ex=1.0±0.1 g/mg vs Ct=0.63±0.2 g/mg, P<0.05. Post-rest contraction was greater in the exercised animals (Ex=4.1±0.4% vs Ct=1.7±0.2%, P<0.05. Papillary muscles of exercised animals developed greater force under increasing isoproterenol concentrations (P<0.05. In the isolated heart, exercise increased left ventricular isovolumetric systolic pressure (LVISP; Δ +39 mmHg; P<0.05 from baseline conditions. Hearts from the exercised rats presented a greater response to increasing diastolic pressure. Positive inotropic intervention to calcium and isoproterenol resulted in greater LVISP in exercised animals (P<0.05. The results demonstrated that a single resistance exercise session improved myocardial contractility in SHRs.

  5. Contractile properties of muscle fibers from the deep and superficial digital flexors of horses.

    Science.gov (United States)

    Butcher, M T; Chase, P B; Hermanson, J W; Clark, A N; Brunet, N M; Bertram, J E A

    2010-10-01

    Equine digital flexor muscles have independent tendons but a nearly identical mechanical relationship to the main joint they act upon. Yet these muscles have remarkable diversity in architecture, ranging from long, unipennate fibers ("short" compartment of DDF) to very short, multipennate fibers (SDF). To investigate the functional relevance of the form of the digital flexor muscles, fiber contractile properties were analyzed in the context of architecture differences and in vivo function during locomotion. Myosin heavy chain (MHC) isoform fiber type was studied, and in vitro motility assays were used to measure actin filament sliding velocity (V(f)). Skinned fiber contractile properties [isometric tension (P(0)/CSA), velocity of unloaded shortening (V(US)), and force-Ca(2+) relationships] at both 10 and 30°C were characterized. Contractile properties were correlated with MHC isoform and their respective V(f). The DDF contained a higher percentage of MHC-2A fibers with myosin (heavy meromyosin) and V(f) that was twofold faster than SDF. At 30°C, P(0)/CSA was higher for DDF (103.5 ± 8.75 mN/mm(2)) than SDF fibers (81.8 ± 7.71 mN/mm(2)). Similarly, V(US) (pCa 5, 30°C) was faster for DDF (2.43 ± 0.53 FL/s) than SDF fibers (1.20 ± 0.22 FL/s). Active isometric tension increased with increasing Ca(2+) concentration, with maximal Ca(2+) activation at pCa 5 at each temperature in fibers from each muscle. In general, the collective properties of DDF and SDF were consistent with fiber MHC isoform composition, muscle architecture, and the respective functional roles of the two muscles in locomotion.

  6. Assessment of Muscle Contractile Properties at Acute Moderate Altitude Through Tensiomyography.

    Science.gov (United States)

    Morales-Artacho, Antonio J; Padial, Paulino; Rodríguez-Matoso, Dario; Rodríguez-Ruiz, David; García-Ramos, Amador; García-Manso, Juan Manuel; Calderón, Carmen; Feriche, Belén

    2015-12-01

    Under hypoxia, alterations in muscle contractile properties and faster fatigue development have been reported. This study investigated the efficacy of tensiomyography (TMG) in assessing muscle contractile function at acute moderate altitude. Biceps femoris (BF) and vastus lateralis (VL) muscles of 18 athletes (age 20.1 ± 6.1 years; body mass 65.4 ± 13.9 kg; height 174.6 ± 9.5 cm) were assessed at sea level and moderate altitude using electrically evoked contractions on two consecutive days. Maximum radial displacement (Dm), time of contraction (Tc), reaction time (Td), sustained contraction time (Ts), and relaxation time (Tr) were recorded at 40, 60, 80, and 100 mA. At altitude, VL showed lower Dm values at 40 mA (p = 0.008; ES = -0.237). Biceps femoris showed Dm decrements in all electrical stimulations (p  0.61). In VL, Tc was longer at altitude at 40 (p = 0.031, ES = 0.56), and 100 mA (p = 0.03, ES = 0.51). Regarding Td, VL showed significant increases in all electrical intensities under hypoxia (p ≤ 0.03, ES ≥ 0.33). TMG appears effective at detecting slight changes in the muscle contractile properties at moderate altitude. Further research involving TMG along with other muscle function assessment methods is needed to provide additional insight into peripheral neuromuscular alterations at moderate altitude. PMID:26562625

  7. Paradoxical effects of ginkgolide B on cardiomyocyte contractile function in normal and high-glucose environments

    Institute of Scientific and Technical Information of China (English)

    Jihye KIM; Qun LI; Cindy X FANG; Jun REN

    2006-01-01

    Aim: Ginkgo biloba extract is a natural product used widely for cerebral and cardiovascular diseases. It is mainly composed of terpene lactones (ginkgolide A and B) and flavone glycosides (eg quercetin and kaempferol).To better understand the cardiac electromechanical action of Ginkgo biloba extract in normal and diabetic states, this study was designed to examine the effect of ginkgolide B on cardiomyocyte contractile function under normal and high-glucose environments. Methods: Isolated adult rat ventricular myocytes were cultured for 6 h in a serum-free medium containing either normal (NG;5.5 mmol/L) or high (HG;25.5 mmol/L) glucose with or without ginkgolide B (0.5-2.0μg/mL). Mechanical properties were evaluated using the IonOptix MyoCam system. Contractile properties analyzed included peak shortening (PS),maximal velocity of shortening/relengthening (+dl/dt),time-to-PS (TPS) and time-to-90% relengthening (TR90). Levels of essential Ca2+ regulatory proteins sarco(endo)plasmic reticulum Ca2+ -ATPase (SERCA2a),phospholamban (PLB) and Na+-Ca2+ exchanger (NCX) were assessed by Western blotting. Results: Ginkgolide B nullified HG-induced prolongation in TR90. However, ginkgolide B depressed PS.±dl/dt and shortened TPS in NG and HG cells. Ginkgolide B also prolonged TR90 in NG cells. Western blot analysis revealed that HG upregulated SERCA2a and downregulated PLB expression without affecting that of NCX. Ginkgolide B disrupted the NG-HG response pattern in SERCA2a and NCX without affecting that of PLB. Conclusion: Ginkgolide B affects cardiomyocyte contractile function under NG or HG environments in a paradoxical manner, which may be attributed to uneven action on Ca2+ regulatory proteins under NG and HG conditions.

  8. Negative Modulation of NO for Diaphragmatic Contractile Reduction Induced by Sepsis and Restraint Position

    Institute of Scientific and Technical Information of China (English)

    XIANG Jian; GUAN Su-dong; SONG Xiang-he; WANG Hui-yun; GU Zhen-yong

    2014-01-01

    In practice of forensic medicine, potential disease can be associated with fatal asphyxia in re-straint position. Research has demonstrated that nitric oxide (NO) and nitric oxide synthase (NOS) are plentifully distributed in skeletal muscle, contributing to the regulation of contractile and relaxation. In the current study, respiratory functions, indices of diaphragmatic biomechanical functions ex vivo, as well as NO levels in serum, the expressions of diaphragmatic inducible NOS (iNOS) mRNA, and the effects of L-NNA on contractility of the diaphragm were observed in sepsis induced by cecal ligation and punc-ture (CLP) under the condition of restraint position. The results showed that in the CLP12-18 h rats, respiratory dysfunctions; indices of diaphragmatic biomechanical functions (Pt, +dT/dtmax, -dT/dtmax, CT, Po, force over the full range of the force-frequency relationship and fatigue resistance ) declined progressive-ly; the NO level in serum, and iNOS mRNA expression in the diaphragm increased progressively; force increased significantly at all stimulation frequencies after L-NNA pre-incubation. Restraint position 1 h in CLP12 h rats resulted in severe respiratory dysfunctions after relative stable respiratory functions, almost all the indices of diaphragmatic biomechanical functions declined further, whereas little change took place in NO level in serum and diaphragmatic iNOS mRNA expression; and the effects of L-NNA were lack of statistical significance compared with those of CLP12 h, but differed from CLP18 h group. These results suggest that restraint position and sepsis act together in a synergistic manner to aggravate the great reduction of diaphragmatic contractility via, at least in part, the negative modulation of NO, which may contribute to the pathogenesis of positional asphyxia.

  9. Adiponectin alleviates contractile dysfunction of genioglossus in rats exposed to chronic intermittent hypoxia

    Institute of Scientific and Technical Information of China (English)

    WANG Wen-jing; LU Gan; DING Ning; HUANG Han-peng; DING Wen-xiao; ZHANG Xi-long

    2013-01-01

    Background Genioglossal dysfuntion takes an important role in pathogenesis of obstructive sleep apnea hypopnea syndrome (OSAHS) in which chronic intermittent hypoxia (CIH) is the major pathological origin.Recent studies have suggested genioglossal injury induced by CIH might be improved by adiponectin.The aim of this study was to investigate the effects of adiponectin on genioglossus contractile properties in rats exposed to CIH.Methods Thirty-nine healthy male Wistar rats were randomly divided into three groups:normal control (NC),CIH and adiponectin supplement (CIH+Ad) with 13 rats in each.Rats in NC were kept breathing normal air,while rats in CIH and CIH+Ad experienced the same CIH environment eight hours per day for 35 successive days.Rats in CIH+Ad were given intravenous adiponectin of 10 μg twice a week for 30 successive days.Rats in the NC and CIH were injected with normal saline as a control.After 35 days' CIH exposure,the levels of serum adiponectin and genioglossus contractile properties were compared.Results Serum adiponectin level was significantly lower in CIH than in NC (1210 ng/ml vs.2236 ng/ml).Serum adiponectin level in CIH+Ad (1844 ng/ml) was significantly higher than CIH but lower than NC.Twitch tension,time to peak tension,half relaxation time and tetanic tension were significantly lower in CIH than NC and improved in CIH+Ad.All mean tetanic fatigue indices decreased more rapidly in the first 20 seconds than during the subsequent 100 seconds.Tetanic fatigue indices in NC and CIH+Ad were significantly higher compared to CIH.Conclusions CIH could lead to hypoadiponectinaemia,impaired genioglossus contractile properties and decreased fatigue resistance in rats.Such changes could be partially offset by supplementation of adiponectin.

  10. Contractility and protein phosphorylation in cardiomyocytes: effects of isoproterenol and AR-L57.

    Science.gov (United States)

    Hayes, J S; Bowling, N; Boder, G B

    1984-08-01

    The cardiotonic drugs AR-L57 [2-(2,4-dimethoxyphenyl)-1H-imidazo(4,5b)-pyridine] and isoproterenol stimulated contractility in cultured heart cells in concentration-dependent manners; only the effects of isoproterenol were blocked by propranolol. Isoproterenol, but not AR-L57, enhanced the phosphorylation state of seven protein bands [relative molecular weights (MrS) 155,000, 96,000, 27,000, 24,000, 20,000, 16,000, 12,000] and resulted in the dephosphorylation of one protein band (Mr 21,000). Also, only isoproterenol increased the activation states of adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase and glycogen phosphorylase. The eight protein bands resolved by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis and detected by autoradiography were altered by isoproterenol in time- and concentration-dependent manners. The 24,000-Mr protein substrate phosphorylated in response to isoproterenol was converted to a 12,000-Mr species by heating in the presence of SDS prior to electrophoresis, suggesting that the two substrates were in fact identical proteins. A comparison of the 2-min responses to varying concentrations of isoproterenol resulted in excellent correlations between the phosphorylation states of individual protein bands and contractility. This was true even for the 21,000-Mr species that was dephosphorylated. However, only the 27,000-, 24-12,000-, and 16,000-Mr substrates were phosphorylated rapidly enough to be associated with the onset of the inotropic response. Cultured myocytes are an important feature of these studies as they are 84% pure ventricular cells that remain 100% viable throughout an experiment. Because this system is suitable for biochemical measurements and the effects of agents on heart cell contractility can be determined, it is possible to correlate changes in biochemical parameters with alterations in physiological state.

  11. Facilitated ethanol metabolism promotes cardiomyocyte contractile dysfunction through autophagy in murine hearts

    Science.gov (United States)

    Guo, Rui; Hu, Nan; Kandadi, Machender R.; Ren, Jun

    2012-01-01

    Chronic drinking leads to myocardial contractile dysfunction where ethanol metabolism plays an essential role. Acetaldehyde, the main ethanol metabolite, mediates alcohol-induced cell injury although the underlying mechanism is still elusive. This study was designed to examine the mechanism involved in accelerated ethanol metabolism-induced cardiac defect with a focus on autophagy. Wild-type FVB and cardiac-specific overexpression of alcohol dehydrogenase mice were placed on a 4% nutrition-balanced alcohol diet for 8 weeks. Myocardial histology, immunohistochemistry, autophagy markers and signal molecules were examined. Expression of micro RNA miR-30a, a potential target of Beclin 1, was evaluated by real-time PCR. Chronic alcohol intake led to cardiac acetaldehyde accumulation, hypertrophy and overt autophagosome accumulation (LC3-II and Atg7), the effect of which was accentuated by ADH. Signaling molecules governing autophagy initiation including class III PtdIns3K, phosphorylation of mTOR and p70S6K were enhanced and dampened, respectively, following alcohol intake. These alcohol-induced signaling responses were augmented by ADH. ADH accentuated or unmasked alcohol-induced downregulation of Bcl-2, Bcl-xL and MiR-30a. Interestingly, ADH aggravated alcohol-induced p62 accumulation. Autophagy inhibition using 3-MA abolished alcohol-induced cardiomyocyte contractile anomalies. Moreover, acetaldehyde led to cardiomyocyte contractile dysfunction and autophagy induction, which was ablated by 3-MA. Ethanol or acetaldehyde increased GFP-LC3 puncta in H9c2 cells, the effect of which was ablated by 3-MA but unaffected by lysosomal inhibition using bafilomycin A1, E64D and pepstatin A. In summary, these data suggested that facilitated acetaldehyde production via ADH following alcohol intake triggered cardiac autophagosome formation along with impaired lysosomal degradation, en route to myocardial defect. PMID:22441020

  12. Nitric oxide in the bovine oviduct: influence on contractile activity and nitric oxide synthase isoforms localization.

    Science.gov (United States)

    Yilmaz, O; Całka, J; Bukowski, R; Zalecki, M; Wasowicz, K; Jaroszewski, J J; Markiewicz, W; Bulbul, A; Ucar, M

    2012-04-15

    The oviducts of 64 Holstein cows in luteal (early I, early II and late) and follicular phases were evaluated to determine the protein expression and mRNA transcription of different nitric oxide synthase isoforms (eNOS, iNOS, nNOS) as well as the effect of nitric oxide (NO) on spontaneous contractility in vitro. The expression patterns of nitric oxide synthase (NOS) isoforms in isthmus and ampulla (n = 6 for each phase) were determined by immunohistochemistry, reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot analysis. In the contractility studies, longitudinal and circular isolated strips of isthmus and ampulla (n = 10 for each phase) of oviducts located ipsilateral to the luteal structure or preovulatory follicle were treated as follows: a) L-arginine, an endogenous NO donor (10(-8) to 10(-3)m), b) N(ω)-nitro-L-arginine methyl ester (L-NAME), a NOS inhibitor (10(-5)m) and L-arginine (10(-3)m), c) methylene blue (MB), an inhibitor of soluble guanylate (10(-5)m) and L-arginine (10(-3)m) and d) sodium nitroprusside (SNP), an exogenous NO donor (10(-8) to 10(-4)m). Immunohistochemical evaluation revealed that endothelial NOS (eNOS) expression detected in epithelial layer of isthmus and ampulla was strong in early I luteal phase, moderate in follicular phase and weak in other phases. Neuronal NOS (nNOS) immunoreactivity was strong in isthmus and moderate in ampulla, and staining of nerve fibers was observed mostly in early I luteal and follicular phases. All eNOS, nNOS and inducible NOS (iNOS) isoforms were detected by RT-PCR. eNOS and iNOS proteins were evident, whereas nNOS was undetectable by Western blot analysis in the tissue examined. L-arginine applied alone or after L-NAME did not alter or increase the contractile tension of the strips in most tissues examined. However, L-arginine applied after MB increased contractile tension in the strips of ampulla and longitudinal isthmus from early I luteal phase and circular isthmus from

  13. Relationship between muscle volume and contractile properties of the human knee extensors.

    Science.gov (United States)

    Behrens, Martin; Brown, Niklas; Bollinger, Robert; Bubeck, Dieter; Mau-Moeller, Anett; Weippert, Matthias; Zschorlich, Volker; Bruhn, Sven; Alt, Wilfried

    2016-01-01

    The present study was designed to investigate the relationship between volume and electrically evoked twitch properties of the quadriceps muscle. Supramaximal single and doublet stimulation of the femoral nerve was used to assess contractile properties at 45° and 80° knee flexion. Muscle volume was measured using a 1.5-Tesla magnetic resonance imaging scanner. Quadriceps muscle volume was only significantly correlated (r = 0.629) with peak twitch torque induced by doublet stimulation at 80° but not at 45° knee flexion.

  14. Effect of aerobic exercise on the contractile function of gastrocnemius myosin heavy chain

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Objective To study the effect of 4-6 weeks' treadmill training of male SD rats on the contractile function of their gastrocnemius myosin heavy chain (MHC). Methods Forty male SD rats were randomly divided into control group and training group. The treadmill training of the training group rats was incessantly performed for 4-6 weeks at an intensity of about 75% VO2max (18.5-24 m/min,gradient of 0°,each training session lasting 50 minutes,twice a day). The content of gastrocnemius MHC mRNA was tested by rever...

  15. Different Anti-Contractile Function and Nitric Oxide Production of Thoracic and Abdominal Perivascular Adipose Tissues.

    Science.gov (United States)

    Victorio, Jamaira A; Fontes, Milene T; Rossoni, Luciana V; Davel, Ana P

    2016-01-01

    Divergent phenotypes between the perivascular adipose tissue (PVAT) surrounding the abdominal and the thoracic aorta might be implicated in regional aortic differences, such as susceptibility to atherosclerosis. Although PVAT of the thoracic aorta exhibits anti-contractile function, the role of PVAT in the regulation of the vascular tone of the abdominal aorta is not well defined. In the present study, we compared the anti-contractile function, nitric oxide (NO) availability, and reactive oxygen species (ROS) formation in PVAT and vessel walls of abdominal and thoracic aorta. Abdominal and thoracic aortic tissue from male Wistar rats were used to perform functional and molecular experiments. PVAT reduced the contraction evoked by phenylephrine in the absence and presence of endothelium in the thoracic aorta, whereas this anti-contractile effect was not observed in the abdominal aorta. Abdominal PVAT exhibited a reduction in endothelial NO synthase (eNOS) expression compared with thoracic PVAT, without differences in eNOS expression in the vessel walls. In agreement with this result, NO production evaluated in situ using 4,5-diaminofluorescein was less pronounced in abdominal compared with thoracic aortic PVAT, whereas no significant difference was observed for endothelial NO production. Moreover, NOS inhibition with L-NAME enhanced the phenylephrine-induced contraction in endothelial-denuded rings with PVAT from thoracic but not abdominal aorta. ROS formation and lipid peroxidation products evaluated through the quantification of hydroethidine fluorescence and 4-hydroxynonenal adducts, respectively, were similar between PVAT and vessel walls from the abdominal and thoracic aorta. Extracellular superoxide dismutase (SOD) expression was similar between the vessel walls and PVAT of the abdominal and thoracic aorta. However, Mn-SOD levels were reduced, while CuZn-SOD levels were increased in abdominal PVAT compared with thoracic aortic PVAT. In conclusion, our results

  16. Changes of mitochondria in the contractile cardiomyocytes during postnatal rat ontogenesis

    OpenAIRE

    Kozlov S.V.; Mayevsky A.E.; Mіshalov V.D.; Sulayeva O.N.

    2014-01-01

    Background. CVDs are the number 1 cause of death globally: more people die annually from CVDs than from any other cause. An estimated 17.5 million people died from CVDs in 2012, representing 31% of all global deaths. Of these deaths, an estimated 7.4 million were due to coronary heart disease and 6.7 million were due to stroke. Over three quarters of CVD deaths take place in low- and middle-income countries. Objective. Ultrastructural analysis of mitochondria in the rat contractile cardiomyoc...

  17. Effect of pinaverium bromide on stress-induced colonic smooth muscle contractility disorder in rats

    Institute of Scientific and Technical Information of China (English)

    Yun Dai; Jian-Xiang Liu; Jun-Xia Li; Yun-Feng Xu

    2003-01-01

    AIM: To investigate the effect of pinaverium bromide, a Ltype calcium channel blocker with selectivity for the gastrointestinal tract on contractile activity of colonic circular smooth muscle in normal or cold-restraint stressed rats and its possible mechanism.METHODS: Cold-restraint stress was conducted on rats to increase fecal pellets output. Each isolated colonic circular muscle strip was suspended in a tissue chamber containing warm oxygenated Tyrode-Ringer solution. The contractile response to ACh or KCl was measured isometrically on inkwriting recorder. Incubated muscle in different concentrations of pinaverium and the effects of pinaverium were investigated on ACh or KCl-induced contraction. Colon smooth muscle cells were cultured from rats and [Ca2+]i was measured in cell suspension using the Ca2+ fluorescent dye fura-2/AlMl.RESULTS: During stress, rats fecal pellet output increased 61% (P<0.01). Stimulated with ACh or KCl, the muscle contractility was higher in stress than that in control. Pinaverium inhibited the increment of [Ca2+]i and the muscle contraction in response to ACh or KCl in a dose dependent manner. A significant inhibition of pinaverium to ACh or KCl induced [Ca2+]i increment was observed at 10-6 mol/L. The IC50 values for inhibition of ACh induced contraction for the stress and control group were 1.66×10-6 mol/L and 0.91×10-6mol/L, respectively. The ICs0 values for inhibition of KCl induced contraction for the stress and control group were 8.13×10-7 mol/L and 3.80×10-7 mol/L, respectively.CONCLUSION: Increase in [Ca2+]i of smooth muscle cells is directly related to the generation of contraction force in colon. L-type Ca2+ channels represent the main route of Ca2+ entry.Pinaverium inhibits the calcium influx through L-type channels;decreases the contractile response to many kinds of agonists and regulates the stress-induced colon hypermotility.

  18. Effect of cholecystokinin and secretin on contractile activity of isolated gastric muscle strips in guinea pigs

    Institute of Scientific and Technical Information of China (English)

    Wei Li; Tian Zhen Zheng; Song Yi Qu

    2000-01-01

    AIM To study the effect of cholecystokininoctapeptide (CCK-8) and secretin on contractile activity of isolated gastric muscle strips in guinea pigs.METHODS Each isolated gastric muscle strip was suspended in a tissue chamber containing5 mL Krebs solution constantly warmed by water jacked at 37℃ and supplied with a mixed gas of 95% O2 and 5% CO2. After incubating for 1 h under 1 g tension, varied concentrations of CCK-8 and secretin were added respectively in the tissue chamber and the contractile response was measured isometrically on ink-writing recorders.circular and longitudinal muscular tension at rest (fundus LM 19.7%±2.1%, P<0.01; fundus CM 16.7%±2.2%, P<0.01; gastric body LM 16.8% ± 2.3%, P<0.01; body CM 12.7% ± 2.6%,P<0.01; antrum LM 12.3%±1.3%, P<0.01;antrum CM 16.7%±4.5%, P<0.01; pylous CM frequencies of body LM, both LM and CM of antrum and pylorus CM (5.1/min ± 0.2/min to 5.6/min ± 0.2/min, 5.9/min ± 0.2/min to 6.6/min ±0.1/min, 5.4/min ± 0.3/min to 6.3/min ± 0.4/min, 1.3/min ± 0.2/min to 2.3/min ± 0.3/min,amplitude of antral circular muscle (58.6%±pylorus CM (145.0% ± 23.8%, P<0.01), but decrease the mean contractile amplitude of gastric body and antral LM ( - 10.3% ± 3.3%, -10.5% ±4.6%, respectively, P<0.05). All the CCK-8 effects were not blocked by atropine or indomethacin. Secretin had no effect on gastric smooth muscle activity.CONCLUSION CCK-8 possessed both excitatory and inhibitory action on contractile activity of different regions of stomach in guinea pigs. Its action was not mediated via cholinergic M receptor and endogenous prostaglandin receptor.

  19. Certain characteristics of myocardial contractility of isovolumic dog heart at randomly variable heart rhythm.

    Science.gov (United States)

    Bershitskaya, O N; Izakov VYa; Lysenko, L T; Protsenko, J L; Trubetskoy, A V

    1985-01-01

    The relationship "heart rate - left ventricular pressure" was investigated in the isolated canine heart perfused with constant pressure at different preloads. Rhythmical stimulation was performed with constant stimulus interval duration and with stimulus intervals randomly changed near the average value (150-200 stimuli in series). Correlation and dispersion function analysis show that rhythm dispersion had a negative inotropic effect which was independent of the preload of the ventricle in the range of 120-180 beat/min, but this dependence occurred with low rats of stimulation. This method is proposed for the assessment of contractility under conditions of heart rate variations (physiological and pathological arrhythmias).

  20. Contractile responses to ergotamine and dihydroergotamine in the perfused middle cerebral artery of rat

    OpenAIRE

    Tfelt-Hansen, Peer; Nilsson, Elisabeth; Edvinsson, Lars

    2007-01-01

    The vasomotor effects of ergotamine and dihydroergotamine (DHE) on the middle cerebral artery (MCA) of rats were studied using the pressurised arteriography method and in vitro myographs. MCAs from Sprague–Dawley rats were mounted on two glass micropipettes using the arteriograph, pressurised to 85 mmHg and luminally perfused. All vessels used attained spontaneous contractile tone (34.9±1.8% of resting tone) and responded to luminal adenosine triphosphate (ATP) with dilatation (24.1±4.0%), wh...

  1. Post-exercise contractility, diastolic function, and pressure: Operator-independent sensor-based intelligent monitoring for heart failure telemedicine

    Directory of Open Access Journals (Sweden)

    Giannoni Massimo

    2009-05-01

    Full Text Available Abstract Background New sensors for intelligent remote monitoring of the heart should be developed. Recently, a cutaneous force-frequency relation recording system has been validated based on heart sound amplitude and timing variations at increasing heart rates. Aim To assess sensor-based post-exercise contractility, diastolic function and pressure in normal and diseased hearts as a model of a wireless telemedicine system. Methods We enrolled 150 patients and 22 controls referred for exercise-stress echocardiography, age 55 ± 18 years. The sensor was attached in the precordial region by an ECG electrode. Stress and recovery contractility were derived by first heart sound amplitude vibration changes; diastolic times were acquired continuously. Systemic pressure changes were quantitatively documented by second heart sound recording. Results Interpretable sensor recordings were obtained in all patients (feasibility = 100%. Post-exercise contractility overshoot (defined as increase > 10% of recovery contractility vs exercise value was more frequent in patients than controls (27% vs 8%, p 1 in 20 patients and in none of the controls (p 1 in only 3 patients (p Conclusion Post-exercise contractility, diastolic time and pressure changes can be continuously measured by a cutaneous sensor. Heart disease affects not only exercise systolic performance, but also post-exercise recovery, diastolic time intervals and blood pressure changes – in our study, all of these were monitored by a non-invasive wearable sensor.

  2. Consideraciones para el desarrollo de capacidades de investigación en universidades privadas

    Directory of Open Access Journals (Sweden)

    Maria Luisa Isla

    2013-01-01

    Full Text Available Se presentan reflexiones y estrategias que contribuyan a formar capacidades de investigación en universidades privadas con investigadores jóvenes comprometidos con el avance del conocimiento en su área de investigación así como con su entorno natural y soc ial. Mediante una combinación de formación en el aula y formación experiencial, se presentan las habilidades investigativas a desarrollar y los ejes de formación universitaria que contribuyen a formar investigadores. Adicionalmente a esta formación básica se plantea la necesidad de generar las condiciones para desarrollar las habilidades de investigación en la práctica, laborando en áreas experimentales en las que se colabore con grupos de investigación activos.

  3. Capacidad predictiva del apoyo social en la inteligencia emocional de adolescentes

    Directory of Open Access Journals (Sweden)

    Lorea Azpiazu

    2015-06-01

    Full Text Available El objetivo de este estudio es analizar la relación entre el apoyo social (familiar, amistades y profesorado y la inteligencia emocional (atención, claridad y reparación. La muestra está compuesta por 1543 adolescentes, 728 chicos (47.18% y 815 chicas (52.81%, entre los 11 y 18 años (Medad = 14.24, DT = 1.63. Los análisis estadísticos se llevan a cabo con el programa SPSS 21 para Windows. Los resultados del análisis correlacional señalan que el apoyo social y la inteligencia emocional están significativamente relacionados en ambos sexos. Por otro lado, el análisis de regresión demuestra la capacidad predictiva de los diferentes apoyos en la inteligencia emocional tanto en la muestra masculina como en la femenina.

  4. Capacidad de transporte de sedimentos en cuencas con información escasa.

    OpenAIRE

    Posada García, Lilian; Montoya Jaramillo, Luis Javier

    2000-01-01

    Existe en la literatura un gran número de metodologías para estimar la capacidad de una corriente para transportar sedimentos y se necesitan suficientes registros simultáneos de caudal líquido y sólido para poder seleccionar el método de estimación más apropiado para una corriente determinada. Después de aplicar distintas metodologías a corrientes del departamento de Antioquia, en la zona Andina Colombiana, se desarrolla un nuevo método para el cálculo de la carga en suspensión y de la car...

  5. Mulheres mastectomizadas : acesso à informação e aprendizagem de capacidades

    OpenAIRE

    Costa, Ilídia

    2011-01-01

    O cancro da mama e tratamento adjuvantes acarretam para a mulher uma série de consequências de índole física e psicológica vastamente descritos na literatura. Alterações ao nível da concepção da saúde e das políticas de saúde quer a nível nacional quer internacional, centram o processo de cuidados na pessoa como parceira activa, detentora de capacidades e como tal responsável pela tomada de decisão livre e esclarecida sobre a sua saúde e tratamento. Na mulher mastectomizada com linfadenectomi...

  6. La capacidad de actualizar información inferencial en la lectura

    Directory of Open Access Journals (Sweden)

    Ana I. Pérez Muñoz

    2013-10-01

    Full Text Available Durante la comprensión lectora, el proceso de actualización inferencial nos permite sustituir una idea del texto que hayamos generado equívocamente por otra más plausible que aún está por confirmar. Esta habilidad parece depender de nuestra capacidad de Memoria de Trabajo, la cual nos ayuda a mantener una representación coherente de lo que estamos leyendo, mientras que comprendemos la información posterior y descartamos ideas que hemos podido interpretar de forma errónea. El entrenamiento en actualización inferencial a edades tempranas podría beneficiar la comprensión lectora de textos a lo largo de toda la vida.

  7. Capacidade funcional e bomba muscular venosa na doença venosa crónica

    OpenAIRE

    Gonçalves, Catarina; Crisóstomo, Rute

    2015-01-01

    Objetivos – Avaliar a capacidade funcional e a função da Bomba Muscular Venosa em sujeitos com Doença Venosa Crónica (DVC) e em saudáveis. Relevância – Os utentes com DVC têm diminuição da qualidade de vida relacionada com a saúde e alterações funcionais dos membros inferiores sendo importante avaliar e intervir nesta área. Amostra – Participaram neste estudo 109 sujeitos (36 saudáveis e 73 com DVC). Material e Métodos – A severidade da DVC foi avaliada através da Venous Clinical Sev...

  8. Enciclomedia como Recurso Didáctico en Niños con Capacidades Diferentes

    Directory of Open Access Journals (Sweden)

    Sara Puentes Jiménez

    2007-01-01

    Full Text Available El presente artículo describe una experiencia que ilustra el impacto de la tecnología educativa moderna sobre la educación especial. La experiencia se realizó en el CAM VII (Centro de Atención Múltiple de Aguascalientes, que ofrece servicios educativos a niños con NEE (Necesidades Educativas Especiales. Se eligió un grupo de niños disfuncionales y se seleccionó un tema de historia de México, el cual fue explicado usando como apoyo didáctico el programa Enciclomedia. Los resultados fueron positivos si bien difíciles de cuantificar. Es importante resaltar que los niños con NEE tienen derecho y capacidad para usar tecnología educativa moderna en beneficio de su educación integral.

  9. Capacidad de reserva de agua en los suelos del Borde Norte de Bogotá

    Directory of Open Access Journals (Sweden)

    Yolima del C. Agualimpia Dualiby

    2013-01-01

    Full Text Available La información aquí presentada corresponde a resultados parciales de la investigación que se adelanta sobre procesos hidrodinámicos que afectan los suelos de la sabana de Bogotá -Colombia y cuyo propósito principal es el cálculo e interpretación de la capacidad de reserva hídrica en los suelos de la reserva forestal borde norte de Bogotá, con el fin de investigar sobre la susceptibilidad a la desertificación que presentan las aproximadamente 1.600 hectáreas que la componen. El análisis se realizó con 407 datos recogidos en campo, geo-referenciados y 17 perfiles de suelos descritos en el área. Como producto de este análisis, se definieron diecisiete áreas hidrológicas de acuerdo a la sectorización morfo-pictórica, con base en la descripción de varios perfiles de suelos dentro de la misma unidad geomorfológica. Se encontró como limitante de la capacidad de almacenamiento del suelo, la compactación natural de algunas de sus capas, cuyos resultados fueron comparados con la humedad natural para verificar el grado de densificación que las afecta. Se efectuó también la descripción de la geometría del poro del suelo y su incidencia en la retención de humedad.

  10. Estudio de la capacidad para intumescer de dos sistemas de pintura expuestos a ambientes internos agresivos

    Directory of Open Access Journals (Sweden)

    Chico, B.

    2005-12-01

    Full Text Available The influence exerted by temperature on the resistant capacity of structural steel is well known. A highly efficient protection system for steel consists of the application of intumescent paints. In the case of fire, their effectiveness is based on the property that when they come into contact with flames they react by swelling to form an insulating layer, referred to as "intumescence", which impedes the propagation of heat. These paints do not require continuous maintenance though their service behaviour depends on the exposure conditions to which they are exposed. This paper studies the behaviour of two acrylated rubber type intumescent systems exposed to a galvanising plant for 16 months, evaluating the effect of the environment on the capacity to intumesce of the coating when subjected to heating.

    Es conocida la influencia que ejerce la temperatura en la capacidad resistente del acero estructural. Un sistema de protección del acero, altamente efectivo, consiste en la utilización de pinturas intumescentes. Su efectividad se basa en el hecho de que, en el caso eventual de un incendio, al entrar en contacto con la llama reaccionan hinchándose y formando una capa aislante que se denomina "intumescencia" y que impide la propagación del calor. Estas pinturas no precisan de un mantenimiento continuo, aunque su comportamiento en servicio depende de las condiciones de exposición. Este trabajo estudia el comportamiento de dos sistemas intumescentes de tipo caucho acrilado expuestos en una planta de galvanizado durante 16 meses, valorando el efecto del medio ambiente sobre la capacidad para intumescer del recubrimiento cuando es sometido a un calentamiento.

  11. ¿Es posible potenciar la capacidad de liderazgo en la universidad?

    Directory of Open Access Journals (Sweden)

    C. Delia Dávila Quintana

    2015-04-01

    Full Text Available El objetivo del trabajo es analizar la importancia de la educación superior, concretamente de los métodos de enseñanza-aprendizaje, en el comportamiento posterior de los graduados en el puesto de trabajo en relación a tres dimensiones del liderazgo: liderazgo orientado a las tareas, a las relaciones y al cambio. Las competencias profesionales desarrolladas por los graduados durante sus estudios son el canal de transmisión desde la educación al futuro desempeño como líderes. Para ello se estimaron modelos de ecuaciones estructurales (SEM con una muestra de aproximadamente 3.500 jóvenes graduados por universidades españolas provenientes de la base de datos reflex. Los resultados obtenidos indican que el comportamiento como líderes en las tres dimensiones analizadas depende crucialmente del nivel competencial de los individuos en determinadas competencias clave. Las competencias relacionadas con la capacidad de liderazgo son desarrolladas durante los estudios universitarios y posteriormente ampliadas a través de la experiencia y formación en el puesto. El análisis también identifica los métodos de enseñanza-aprendizaje que presentan una mayor influencia en el desarrollo de las competencias para el liderazgo. La principal implicación del análisis consiste en que un entorno educativo adecuado puede favorecer la adquisición durante los estudios de las competencias necesarias para el ejercicio de la capacidad de liderazgo, lo que a su vez favorece el desarrollo posterior de estas mismas competencias en las primeras experiencias laborales, incrementando así la propensión de los graduados a actuar efectivamente como líderes en las organizaciones para las que trabajan en las tres dimensiones del liderazgo analizadas.

  12. PLANIFICACIÓN JERÁRQUICA CON ANÁLISIS DE CARGA-CAPACIDAD

    Directory of Open Access Journals (Sweden)

    Tulio Gerardo Motoa

    2001-01-01

    Full Text Available

    La planificación jerárquica de múltiples proyectos, surge como una opción robusta y potente, para resolver el problema de gestión del sistema global. La propuesta se basa en la construcción de una estructura de descomposición-agregación de los proyectos y los recursos, con múltiples niveles, en la cual, los niveles más altos presentan los datos más agregados, con horizontes de tiempo más largos y los niveles inferiores son más detallados y con horizontes más cortos. Dentro del ámbito de la planificación jerárquica, el análisis de carga-capacidad pretende fundamentalmente mejorar la relación entre la oferta y la demanda de recursos en los procesos de planificación de proyectos, de tal manera que se garantice el cumplimiento de las fechas ya establecidas. Este análisis, se implementa midiendo algunos indicadores que reflejan el estado de la relación entre la carga y la capacidad y ejecutando un procedimiento de nivelación que avanza en el equilibrio de tal estado. El procedimiento de análisis se ha experimentado mediante un conjunto de proyectos generados aleatoriamente y los resultados son bastante buenos.

  13. Capacidade combinatória em mamoeiro para resistência a oídio

    Directory of Open Access Journals (Sweden)

    Marcelo Vivas

    2012-01-01

    Full Text Available A resistência genética constitui alternativa sustentável para o controle do oídio. Objetivando indicar possíveis combinações híbridas que contribuam para a redução da severidade de oídio em folha de mamoeiro, foi realizado um cruzamento dialélico envolvendo oito genótipos, sendo quatro do grupo 'Solo' e quatro do grupo 'Formosa'. Os 56 híbridos (F1's e recíprocos juntamente com seus genitores foram avaliados em blocos casualizados com quatro repetições. A severidade do oídio na folha foi quantificada em março e maio de 2010, respectivamente, aos 11 e 13 meses após o plantio. Com a média de cada tratamento foram estimadas as capacidades geral e específica de combinação. Assim, considerando as estimativas da capacidade combinatória obtidas com base na média das duas avaliações, as melhores combinações para os genitores avaliados quanto à severidade do oídio foram 'Maradol x Waimanalo', 'Maradol x Sunrise Solo 72/12', 'JS 12-4 x São Mateus', 'Sekati x Waimanalo', 'Sekati x Golden', 'Sekati x Sunrise Solo 72/12', 'Sekati x São Mateus', 'Waimanalo x São Mateus' e 'Golden x São Mateus'. Os resultados evidenciam ainda a possibilidade de obtenção de híbridos com potencial para redução da severidade do oídio provenientes de cruzamentos entre genótipos dos grupos 'Solo' e 'Formosa' e também em cruzamentos dentro do grupo 'Solo'.

  14. Comportamientos y capacidad de agencia de autocuidado de adultos con insuficiencia cardiaca

    Directory of Open Access Journals (Sweden)

    EDITH ARREDONDO HOLGUÍN

    2010-06-01

    Full Text Available Este estudio tiene como objetivo describir comportamientos y capacidad de agencia de autocuidado de pacientes con insuficiencia cardiaca de una clínica cardiovascular de Medellín entre noviembre de 2007 y mayo de 2008. Es un estudio descriptivo con abordaje cuantitativo. La muestra fue de 206 adultos con insuficiencia cardiaca diagnosticados por sintomatología clínica, fracción de eyección menor o igual a 40%. Se usaron para la recolección de datos la Escala Capacidad de Agencia de Autocuidado desarrollada por Isemberg y Evers et ál. (1993, traducida por Gallego, que mide el nivel de agencia de autocuidado, y la Escala Comportamientos de Autocuidado validada en Colombia en 2007 por Arredondo, que mide la frecuencia de comportamientos de autocuidado de adultos con insuficiencia cardiaca en la solicitud de ayuda, adaptación a vivir con la enfermedad y el régimen terapéutico, modificación del autoconcepto y aceptación de sí mismo, vivir con efectos de la insuficiencia cardiaca y el tratamiento. Concluye que el mayor número de pacientes eran hombres; que factores básicos condicionantes como el apoyo de la familia, desempeño de un trabajo, afiliación al sistema de salud, nivel socioeconómico y acceso a un nivel educativo fueron importantes para los pacientes. La frecuencia de comportamientos de autocuidado fue media en los adultos en la mayoría de las dimensiones y el nivel de agencia fue alto y muy alto. Igualmente se concluyó que no hay una correlación entre agencia y comportamientos de autocuidado. Lo que plantea que los adultos tienen el conocimiento pero no han tomado la decisión de realizar acciones de autocuidado.

  15. Abnormal glucose metabolism is associated with reduced left ventricular contractile reserve and exercise intolerance in patients with chronic heart failure

    DEFF Research Database (Denmark)

    Egstrup, M; Kistorp, C N; Schou, M;

    2013-01-01

    AIMS: To investigate the associations between glucose metabolism, left ventricular (LV) contractile reserve, and exercise capacity in patients with chronic systolic heart failure (HF). METHODS AND RESULTS: From an outpatient HF clinic, 161 patients with systolic HF were included (mean age 70 ± 10...... years, 69% male, 59% had ischaemic heart disease, mean LV ejection fraction (LVEF) 37 ± 9%). Thirty-four (21%) patients had known diabetes mellitus (DM). Oral glucose tolerance testing (OGTT) classified patients without a prior DM diagnosis as normal glucose tolerance (NGT), impaired glucose tolerance...... (467 m) (P <0.001). Differences in clinical variables, resting echocardiographic parameters or contractile reserve, did not explain the exercise intolerance related to diabetes. CONCLUSION: Diabetes, known or newly detected by OGTT, is independently associated with reduced LV contractile reserve and...

  16. Selective increase of the contractile response to endothelin-1 in subcutaneous arteries from patients with essential hypertension

    DEFF Research Database (Denmark)

    Lind, H; Adner, M; Erlinge, D;

    1999-01-01

    arteries from subjects with established essential hypertension with matched controls. Furthermore, with RT-PCR, the occurrence of mRNA for the ETA and ET(B) receptors was shown in the tunica media layer of subcutaneous arteries in controls and hypertensives. The maximum contractile response to endothelin-1...... was significantly higher in the subcutaneous arteries of the hypertensives (by 88% with no change in potency) as compared to controls. The responses to noradrenaline, acetylcholine and potassium chloride did not differ between the groups. This selective increase in the contractile response to......Endothelin-1 has been shown to contribute to basal vascular tone in man. Since endothelin-1 is a potent vasoconstrictor putatively involved in hypertension, we have compared the contractile responses of endothelin-1 and noradrenaline in relation to potassium chloride in subcutaneous resistance...

  17. The Effects of Electroacupuncture at the Heart Meridian on Myocardial Contractile Function in Rabbits with Myocardial Ischemia

    Institute of Scientific and Technical Information of China (English)

    方志斌; 周逸平; 王月兰

    2002-01-01

    @@ Acute myocardial ischemia was induced by intravenous injection of pituitrin, and electroacupuncture (EA) was applied at the Heart and Lung Meridians (HM and LM), 3 points on each meridian. The changes in the left intraventricular pressure (LVP), the maximum rise rate of intraventricular pressure (LVP dp/dtmax), the area of cardiac force loop (ACFL), and the maximum shortening velocity of myocardial contractile element (Vmax) were observed. As a result, there were significant differences in the improvement of LVP, LVP dp/dtmax, ACFL and Vmax between EA at HM and LM. The regulatory action of EA at HM on the myocardial contractile function was significantly better than that of EA at LM, indicating that HM has a close relationship with the myocardial contractile function.

  18. Oxidative Stress in Hypertensive Patients Induces an Increased Contractility in Vein Grafts Independent of Endothelial Function

    Directory of Open Access Journals (Sweden)

    Claudio Joo Turoni

    2011-01-01

    Full Text Available Objective. To evaluate the impact of oxidative stress on vascular reactivity to vasoconstrictors and on nitric oxide (NO bioavailability in saphenous vein (SV graft with endothelial dysfunction from hypertensive patients (HT. Methods. Endothelial function, vascular reactivity, oxidative state, nitrites and NO release were studied in isolated SV rings from HT and normotensive patients (NT. Only rings with endothelial dysfunction were used. Results. HT rings presented a hyperreactivity to vasoconstrictors that was reverted by diphenylene iodonium (DPI. In NT, no effect of DPI was obtained, but Nω-nitro-L-arginine methyl ester (L-NAME increased the contractile response. NO was present in SV rings without endothelial function. Nitrites were higher in NT than in HT (1066.1 ± 86.3 pmol/mg; n=11 versus 487.8 ± 51.6; n=23; P<0.01 and inhibited by nNOS inhibitor. L-arginine reversed this effect. Antioxidant agents increased nitrites and NO contents only in HT. The anti-nNOS-stained area by immunohistochemistry was higher in NT than HT. HT showed an elevation of oxidative state. Conclusions. Extraendothelial NO counter-regulates contractility in SV. However, this action could be altered in hypertensive situations by an increased oxidative stress or a decreased ability of nNOS to produce NO. Further studies should be performed to evaluate the implication of these results in graft patency rates.

  19. Epigenetic Reprogramming of Human Embryonic Stem Cells into Skeletal Muscle Cells and Generation of Contractile Myospheres

    Directory of Open Access Journals (Sweden)

    Sonia Albini

    2013-03-01

    Full Text Available Direct generation of a homogeneous population of skeletal myoblasts from human embryonic stem cells (hESCs and formation of three-dimensional contractile structures for disease modeling in vitro are current challenges in regenerative medicine. Previous studies reported on the generation of myoblasts from ESC-derived embryoid bodies (EB, but not from undifferentiated ESCs, indicating the requirement for mesodermal transition to promote skeletal myogenesis. Here, we show that selective absence of the SWI/SNF component BAF60C (encoded by SMARCD3 confers on hESCs resistance to MyoD-mediated activation of skeletal myogenesis. Forced expression of BAF60C enables MyoD to directly activate skeletal myogenesis in hESCs by instructing MyoD positioning and allowing chromatin remodeling at target genes. BAF60C/MyoD-expressing hESCs are epigenetically committed myogenic progenitors, which bypass the mesodermal requirement and, when cultured as floating clusters, give rise to contractile three-dimensional myospheres composed of skeletal myotubes. These results identify BAF60C as a key epigenetic determinant of hESC commitment to the myogenic lineage and establish the molecular basis for the generation of hESC-derived myospheres exploitable for “disease in a dish” models of muscular physiology and dysfunction.

  20. Long-term vascular contractility assay using genipin-modified muscular thin films

    International Nuclear Information System (INIS)

    Vascular disease is a leading cause of death globally and typically manifests chronically due to long-term maladaptive arterial growth and remodeling. To date, there is no in vitro technique for studying vascular function over relevant disease time courses that both mimics in vivo-like tissue structure and provides a simple readout of tissue stress. We aimed to extend tissue viability in our muscular thin film contractility assay by modifying the polydimethylsiloxane (PDMS) substrate with micropatterned genipin, allowing extracellular matrix turnover without cell loss. To achieve this, we developed a microfluidic delivery system to pattern genipin and extracellular matrix proteins on PDMS prior to cell seeding. Tissues constructed using this method showed improved viability and maintenance of in vivo-like lamellar structure. Functional contractility of tissues fabricated on genipin-modified substrates remained consistent throughout two weeks in culture. These results suggest that muscular thin films with genipin-modified PDMS substrates are a viable method for conducting functional studies of arterial growth and remodeling in vascular diseases. (paper)

  1. Epigenetic reprogramming of human embryonic stem cells into skeletal muscle cells and generation of contractile myospheres.

    Science.gov (United States)

    Albini, Sonia; Coutinho, Paula; Malecova, Barbora; Giordani, Lorenzo; Savchenko, Alex; Forcales, Sonia Vanina; Puri, Pier Lorenzo

    2013-03-28

    Direct generation of a homogeneous population of skeletal myoblasts from human embryonic stem cells (hESCs) and formation of three-dimensional contractile structures for disease modeling in vitro are current challenges in regenerative medicine. Previous studies reported on the generation of myoblasts from ESC-derived embryoid bodies (EB), but not from undifferentiated ESCs, indicating the requirement for mesodermal transition to promote skeletal myogenesis. Here, we show that selective absence of the SWI/SNF component BAF60C (encoded by SMARCD3) confers on hESCs resistance to MyoD-mediated activation of skeletal myogenesis. Forced expression of BAF60C enables MyoD to directly activate skeletal myogenesis in hESCs by instructing MyoD positioning and allowing chromatin remodeling at target genes. BAF60C/MyoD-expressing hESCs are epigenetically committed myogenic progenitors, which bypass the mesodermal requirement and, when cultured as floating clusters, give rise to contractile three-dimensional myospheres composed of skeletal myotubes. These results identify BAF60C as a key epigenetic determinant of hESC commitment to the myogenic lineage and establish the molecular basis for the generation of hESC-derived myospheres exploitable for "disease in a dish" models of muscular physiology and dysfunction.

  2. Effects of Substrate Mechanics on Contractility of Cardiomyocytes Generated from Human Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Laurie B. Hazeltine

    2012-01-01

    Full Text Available Human pluripotent stem cell (hPSC- derived cardiomyocytes have potential applications in drug discovery, toxicity testing, developmental studies, and regenerative medicine. Before these cells can be reliably utilized, characterization of their functionality is required to establish their similarity to native cardiomyocytes. We tracked fluorescent beads embedded in 4.4–99.7 kPa polyacrylamide hydrogels beneath contracting neonatal rat cardiomyocytes and cardiomyocytes generated from hPSCs via growth-factor-induced directed differentiation to measure contractile output in response to changes in substrate mechanics. Contraction stress was determined using traction force microscopy, and morphology was characterized by immunocytochemistry for α-actinin and subsequent image analysis. We found that contraction stress of all types of cardiomyocytes increased with substrate stiffness. This effect was not linked to beating rate or morphology. We demonstrated that hPSC-derived cardiomyocyte contractility responded appropriately to isoprenaline and remained stable in culture over a period of 2 months. This study demonstrates that hPSC-derived cardiomyocytes have appropriate functional responses to substrate stiffness and to a pharmaceutical agent, which motivates their use in further applications such as drug evaluation and cardiac therapies.

  3. Stress activated contractile wavefronts in the mechanically-excitable embryonic heart

    Science.gov (United States)

    Chiou, Kevin; Majkut, Stephanie; Discher, Dennis; Lubensky, Tom; Liu, Andrea

    2014-03-01

    The heart is a prime example of a robust, active system with behavior-the heart beat-that is extraordinarily well timed and coordinated. For more than half a century, electrical activity induced by ion release and diffusion has been argued to be the mechanism driving cardiac action. But recent work indicates that this phenomenon is also regulated by mechanical activity. In the embryonic avian heart tube, the speed of the contractile wavefront traversing the heart tube with each beat is measured to be a monotonic, linear function of tissue stiffness. Traditional electrical conduction models of excitation-contraction cannot explain this dependence; such a result indicates that the myocardium is mechanically excitable. Here, we extend this work by using experimental observations of stiffness-dependent behavior in isolated cardiomyocytes as an input to study contractile wavefronts in the tissue as a whole. We model the heart tube as an active, overdamped elastic network where the primary stress mediator is the extracellular matrix. Using this simple model, we explain experimental observations of the systolic wave and predict qualitatively new behavior.

  4. Oscillatory behaviors and hierarchical assembly of contractile structures in intercalating cells

    Science.gov (United States)

    Fernandez-Gonzalez, Rodrigo; Zallen, Jennifer A.

    2011-08-01

    Fluctuations in the size of the apical cell surface have been associated with apical constriction and tissue invagination. However, it is currently not known if apical oscillatory behaviors are a unique property of constricting cells or if they constitute a universal feature of the force balance between cells in multicellular tissues. Here, we set out to determine whether oscillatory cell behaviors occur in parallel with cell intercalation during the morphogenetic process of axis elongation in the Drosophila embryo. We applied multi-color, time-lapse imaging of living embryos and SIESTA, an integrated tool for automated and semi-automated cell segmentation, tracking, and analysis of image sequences. Using SIESTA, we identified cycles of contraction and expansion of the apical surface in intercalating cells and characterized them at the molecular, cellular, and tissue scales. We demonstrate that apical oscillations are anisotropic, and this anisotropy depends on the presence of intact cell-cell junctions and spatial cues provided by the anterior-posterior patterning system. Oscillatory cell behaviors during axis elongation are associated with the hierarchical assembly and disassembly of contractile actomyosin structures at the medial cortex of the cell, with actin localization preceding myosin II and with the localization of both proteins preceding changes in cell shape. We discuss models to explain how the architecture of cytoskeletal networks regulates their contractile behavior and the mechanisms that give rise to oscillatory cell behaviors in intercalating cells.

  5. Glucagon Increases Beating Rate but Not Contractility in Rat Right Atrium. Comparison with Isoproterenol.

    Directory of Open Access Journals (Sweden)

    Beatriz Merino

    Full Text Available This study evaluated the chronotropic and inotropic responses to glucagon in spontaneously beating isolated right atria of rat heart. For comparison, we also investigated the effects resulting from stimulating β-adrenoceptors with isoproterenol in this tissue. Isoproterenol increased both atrial frequency and contractility but glucagon only enhanced atrial rate. The transcript levels of glucagon receptors were about three times higher in sinoatrial node than in the atrial myocardium. Chronotropic responses to glucagon and isoproterenol were blunted by the funny current (If inhibitor ZD 7288. Inhibitors of protein kinase A, H-89 and KT-5720 reduced the chronotropic response to glucagon but not to isoproterenol. Inhibition of ryanodine receptors and calcium/calmodulin dependent protein kinase II (important regulators of sarcoplasmic reticulum Ca2+ release, with ruthenium red and KN-62 respectively, failed to alter chronotropic responses of either glucagon or isoproterenol. Non selective inhibition of phosphodiesterase (PDE with 3-isobutylmethylxantine or selective inhibition of PDE3 or PDE4 with cilostamide or rolipram respectively did not affect chronotropic effects of glucagon or isoproterenol. Our results indicate that glucagon increases beating rate but not contractility in rat right atria which could be a consequence of lower levels of glucagon receptors in atrial myocardium than in sinoatrial node. Chronotropic responses to glucagon or isoproterenol are mediated by If current but not by sarcoplasmic reticulum Ca2+ release, neither are regulated by PDE activity.

  6. Cell adhesion molecules regulate contractile ring-independent cytokinesis in Dictyostelium discoideum

    Institute of Scientific and Technical Information of China (English)

    Akira Nagasaki; Masamitsu Kanada; Taro QP Uyeda

    2009-01-01

    To investigate the roles of substrate adhesion in cytokinesis, we established cell lines lacking paxiUin (PAXB) or vinculin (VINA), and those expressing the respective GFP fusion proteins in Dictyostelium discoideum. As in mammalian cells, GFP-PAXB and GFP-VINA formed focal adhesion-like complexes on the cell bottom, paxB cells in suspension grew normally, but on substrates, often failed to divide after regression of the furrow. The efficient cytokinesis of paxB cells in suspension is not because of shear forces to assist abscission, as they divided normally in static suspension culture as well. Double knockout strains lacking mhcA, which codes for myosin I1, and paxB or vinA displayed more severe cytokinetic defects than each single knockout strain. In mitotic wild-type cells, GFP-PAXB was diffusely distributed on the basal membrane, but was strikingly condensed along the polar edges in mitotic mhcA cells. These results are consistent with our idea that Dictyostelium displays two forms of cytokinesis, one that is contractile ringdependent and adhesion-independent, and the other that is contractile ring-independent and adhesion-dependent, and that the latter requires PAXB and VINA. Furthermore, that paxB cells fail to divide normally in the presence of substrate adhesion suggests that this adhesion molecule may play additional signaling roles.

  7. Model of myosin node aggregation into a contractile ring: the effect of local alignment

    Energy Technology Data Exchange (ETDEWEB)

    Ojkic, Nikola; Vavylonis, Dimitrios [Department of Physics, Lehigh University, Bethlehem, PA 18015 (United States); Wu Jianqiu, E-mail: vavylonis@lehigh.edu [Department of Molecular Genetics and Department of Molecular and Cellular Biochemistry, Ohio State University, Columbus, OH 43210 (United States)

    2011-09-21

    Actomyosin bundles frequently form through aggregation of membrane-bound myosin clusters. One such example is the formation of the contractile ring in fission yeast from a broad band of cortical nodes. Nodes are macromolecular complexes containing several dozens of myosin-II molecules and a few formin dimers. The condensation of a broad band of nodes into the contractile ring has been previously described by a search, capture, pull and release (SCPR) model. In SCPR, a random search process mediated by actin filaments nucleated by formins leads to transient actomyosin connections among nodes that pull one another into a ring. The SCPR model reproduces the transport of nodes over long distances and predicts observed clump-formation instabilities in mutants. However, the model does not generate transient linear elements and meshwork structures as observed in some wild-type and mutant cells during ring assembly. As a minimal model of node alignment, we added short-range aligning forces to the SCPR model representing currently unresolved mechanisms that may involve structural components, cross-linking and bundling proteins. We studied the effect of the local node alignment mechanism on ring formation numerically. We varied the new parameters and found viable rings for a realistic range of values. Morphologically, transient structures that form during ring assembly resemble those observed in experiments with wild-type and cdc25-22 cells. Our work supports a hierarchical process of ring self-organization involving components drawn together from distant parts of the cell followed by progressive stabilization.

  8. The effects of cannabidiolic acid and cannabidiol on contractility of the gastrointestinal tract of Suncus murinus.

    Science.gov (United States)

    Cluny, Nina L; Naylor, Robert J; Whittle, Brian A; Javid, Farideh A

    2011-09-01

    Cannabidiol (CBD) has been shown to inhibit gastrointestinal (GI) transit in pathophysiologic in vivo models, while having no effect in physiologic controls. The actions of the precursor of CBD, cannabidiolic acid (CBDA), have not been investigated in the GI tract. The actions of these phytocannabinoids on the contractility of the GI tract of Suncus murinus were investigated in the current study. The effects of CBDA and CBD in resting state and pre-contracted isolated intestinal segments, and on the contractile effects of carbachol and electrical field stimulation (EFS) on the intestines of S. murinus were examined. CBDA and CBD induced a reduction in resting tissue tension of isolated intestinal segments which was not blocked by the cannabinoid CB1 receptor antagonist, AM251, the CB(2) receptor antagonist AM630, or tetrodotoxin. CBDA and CBD reduced the magnitude of contractions induced by carbachol and the tension of intestinal segments that were pre-contracted with potassium chloride. In tissues stimulated by EFS, CBDA inhibited contractions induced by lower frequencies (0.1-4.0 Hz) of EFS, while CBD inhibited contractions induced by higher frequencies (4.0-20.0 Hz) of EFS. The data suggest that CBDA and CBD have inhibitory actions on the intestines of S. murinus that are not neuronallymediated or mediated via CB(1) or CB(2) receptors. PMID:21975813

  9. Natural Antioxidant-Isoliquiritigenin Ameliorates Contractile Dysfunction of Hypoxic Cardiomyocytes via AMPK Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Xiaoyu Zhang

    2013-01-01

    Full Text Available Isoliquiritigenin (ISL, a simple chalcone-type flavonoid, is derived from licorice compounds and is mainly present in foods, beverages, and tobacco. Reactive oxygen species (ROS is a critical factor involved in modulating cardiac stress response signaling during ischemia and reperfusion. We hypothesize that ISL as a natural antioxidant may protect heart against ischemic injury via modulating cellular redox status and regulating cardioprotective signaling pathways. The fluorescent probe H2DCFDA was used to measure the level of intracellular ROS. The glucose uptake was determined by 2-deoxy-D-glucose-3H accumulation. The IonOptix System measured the contractile function of isolated cardiomyocytes. The results demonstrated that ISL treatment markedly ameliorated cardiomyocytes contractile dysfunction caused by hypoxia. ISL significantly stimulated cardioprotective signaling, AMP-activated protein kinase (AMPK, and extracellular signal-regulated kinase (ERK signaling pathways. The ROS fluorescent probe H2DCFDA determination indicated that ISL significantly reduced cardiac ROS level during hypoxia/reoxygenation. Moreover, ISL reduced the mitochondrial potential (Δψ of isolated mouse cardiomyocytes. Taken together, ISL as a natural antioxidant demonstrated the cardioprotection against ischemic injury that may attribute to the activation of AMPK and ERK signaling pathways and balance of cellular redox status.

  10. PPARγ Ligands Regulate Noncontractile and Contractile Functions of Airway Smooth Muscle: Implications for Asthma Therapy

    Directory of Open Access Journals (Sweden)

    Chantal Donovan

    2012-01-01

    Full Text Available In asthma, the increase in airway smooth muscle (ASM can contribute to inflammation, airway wall remodeling and airway hyperresponsiveness (AHR. Targetting peroxisome proliferator-activated receptor γ (PPARγ, a receptor upregulated in ASM in asthmatic airways, may provide a novel approach to regulate these contributions. This review summarises experimental evidence that PPARγ ligands, such as rosiglitazone (RGZ and pioglitazone (PGZ, inhibit proliferation and inflammatory cytokine production from ASM in vitro. In addition, inhaled administration of these ligands reduces inflammatory cell infiltration and airway remodelling in mouse models of allergen-induced airways disease. PPARγ ligands can also regulate ASM contractility, with acute treatment eliciting relaxation of mouse trachea in vitro through a PPARγ-independent mechanism. Chronic treatment can protect against the loss of bronchodilator sensitivity to β2-adrenoceptor agonists and inhibit the development of AHR associated with exposure to nicotine in utero or following allergen challenge. Of particular interest, a small clinical trial has shown that oral RGZ treatment improves lung function in smokers with asthma, a group that is generally unresponsive to conventional steroid treatment. These combined findings support further investigation of the potential for PPARγ agonists to target the noncontractile and contractile functions of ASM to improve outcomes for patients with poorly controlled asthma.

  11. Contractile effects of 3,4-methylenedioxymethamphetamine on the human internal mammary artery.

    Science.gov (United States)

    Silva, Sónia; Carvalho, Félix; Fernandes, Eduarda; Antunes, Manuel J; Cotrim, Maria Dulce

    2016-08-01

    Since the late 1980s numerous reports have detailed adverse reactions to the use of 3,4-methylenedioxymethamphetamine (MDMA) associated with cardiovascular collapse and sudden death, following ventricular tachycardia and hypertension. For a better understanding of the effects of MDMA on the cardiovascular system, it is critical to determine their effects at the vasculature level, including the transporter or neurotransmitter systems that are most affected at the whole range of drug doses. With this purpose in mind, the aim of our study was to evaluate the contractile effect of MDMA in the human internal mammary artery, the contribution of SERT for this effect and the responsiveness of this artery to 5-HT in the presence of MDMA. We have also studied the possible involvement of 5-HT2 receptors on the MDMA contractile effect in this human blood vessel using ketanserin. Our results showed that MDMA contracted the studied human's internal mammary artery in a SERT-independent form, through activation of 5-HT2A receptors. Considering the high plasma concentrations achieved in heavy users or in situations of acute exposure to drugs, this effect is probably involved in the cardiovascular risk profile of this psychostimulant, especially in subjects with pre-existing cardiovascular disease. PMID:27079619

  12. A stepwise procedure to test contractility and susceptibility to injury for the rodent quadriceps muscle

    Directory of Open Access Journals (Sweden)

    Stephen J.P. Pratt

    2014-07-01

    Full Text Available In patients with muscle injury or muscle disease, assessment of muscle damage is typically limited to clinical signs, such as tenderness, strength, range of motion, and more recently, imaging studies.  Biological markers can also be used in measuring muscle injury, such as increased creatine kinase levels in the blood, but these are not always correlated with loss in muscle function (i.e. loss of force production.  This is even true of histological findings from animals, which provide a “direct measure” of damage, but do not account for loss of function.  The most comprehensive measure of the overall health of the muscle is contractile force.  To date, animal models testing contractile force have been limited to the muscle groups moving the ankle.  Here we describe an in vivo animal model for the quadriceps, with abilities to measure torque, produce a reliable muscle injury, and follow muscle recovery within the same animal over time.  We also describe a second model used for direct measurement of force from an isolated quadriceps muscle in situ. 

  13. Controlling the contractile strength of engineered cardiac muscle by hierarchal tissue architecture.

    Science.gov (United States)

    Feinberg, Adam W; Alford, Patrick W; Jin, Hongwei; Ripplinger, Crystal M; Werdich, Andreas A; Sheehy, Sean P; Grosberg, Anna; Parker, Kevin Kit

    2012-08-01

    The heart is a muscular organ with a wrapping, laminar structure embedded with neural and vascular networks, collagen fibrils, fibroblasts, and cardiac myocytes that facilitate contraction. We hypothesized that these non-muscle components may have functional benefit, serving as important structural alignment cues in inter- and intra-cellular organization of cardiac myocytes. Previous studies have demonstrated that alignment of engineered myocardium enhances calcium handling, but how this impacts actual force generation remains unclear. Quantitative assays are needed to determine the effect of alignment on contractile function and muscle physiology. To test this, micropatterned surfaces were used to build 2-dimensional myocardium from neonatal rat ventricular myocytes with distinct architectures: confluent isotropic (serving as the unaligned control), confluent anisotropic, and 20 μm spaced, parallel arrays of multicellular myocardial fibers. We combined image analysis of sarcomere orientation with muscular thin film contractile force assays in order to calculate the peak sarcomere-generated stress as a function of tissue architecture. Here we report that increasing peak systolic stress in engineered cardiac tissues corresponds with increasing sarcomere alignment. This change is larger than would be anticipated from enhanced calcium handling and increased uniaxial alignment alone. These results suggest that boundary conditions (heterogeneities) encoded in the extracellular space can regulate muscle tissue function, and that structural organization and cytoskeletal alignment are critically important for maximizing peak force generation.

  14. CAP_USO: Um sistema especialista para determinação da capacidade de uso da terra

    Directory of Open Access Journals (Sweden)

    Monica Luri Giboshi

    1999-05-01

    Full Text Available O objetivo deste trabalho foi desenvolver um sistema especialista (CAP_USO para determinar a capacidade de uso da terra, visando auxiliar e dar mais agilidade ao processo de tomada de decisão para o planejamento do uso da terra. O sistema foi desenvolvido utilizando um software conhecido como C Language Integrated Production System (CLIPS, desenvolvido pela National Aeronautics and Space Administration (Nasa. Para determinar a capacidade de uso, foram considerados doze fatores limitantes ao uso da terra, além da declividade. A validação do sistema mostrou que o CAP_USO foi rigoroso ao determinar as classes de capacidade de uso por considerar a declividade em conjunto com os fatores que apresentam maior restrição ao uso da terra. A técnica de sistemas especialistas mostrou ser eficaz para a classificação de terras segundo a sua capacidade de uso, facilitando a manipulação e o processamento das informações necessárias à sua determinação.

  15. La situación de las personas con capacidad intelectual límite en España

    Directory of Open Access Journals (Sweden)

    Agustín Huete García

    2016-06-01

    Full Text Available Se presentan los resultados principales de un estudio de carácter fundamentalmente descriptivo sobre la situación actual de las personas con capacidad intelectual límite en 2015. Se centra en describir la realidad demográfica y social de las personas con capacidad intelectual límite, sus necesidades de apoyo y extraer propuestas estratégicas hacia una inclusión social efectiva. Metodológicamente, de acuerdo al nivel de análisis, se optó por técnicas cuantitativas (análisis de fuentes estadísticas y cualitativas (entrevistas semiestructuradas a un grupo de personas con capacidad intelectual límite, familias y profesionales. Entre sus principales conclusiones, las personas con capacidad intelectual límite y sus familias demandan una visibilización de sus necesidades de apoyo para una inclusión social efectiva, siendo clave el apoyo para favorecer una vida autónoma e independiente. Las propuestas y buenas prácticas aportan elementos para un modelo de atención individualizada, al mismo tiempo fundamentada en una participación activa en la comunidad.

  16. Efecto de los factores socioculturales en la capacidad de autocuidado del paciente hospitalizado con diabetes tipo 2

    Directory of Open Access Journals (Sweden)

    Mireya Gricelia Galindo-Martínez

    2014-01-01

    Full Text Available Introducción: la diabetes tipo 2 es considerada como un problema de salud pública por su creciente prevalencia e incidencia. Obje- tivo: describir el efecto de los factores socioculturales en la capacidad de autocuidado del paciente hospitalizado con diabetes tipo 2 en el Hospital General de Tecomán, Colima, México. Método: estudio transversal, observacional. Se trabajó con 68 pacientes hospitalizados con diabetes tipo 2; se utilizó un instrumento que midió el efecto de los factores socioculturales en la capacidad de autocuidado. El análisis de datos se realizó con Razón de Momios, intervalos de confianza al 95 % y fracción atribuible en expuestos. Resultados: los factores socioculturales tuvieron un leve efecto positivo en la capacidad de autocuidado (RM = 1,10; IC 95 %: 0,26-4,74 en pacientes hospitali- zados con diabetes tipo 2. Conclusiones: los factores socioculturales: experiencias vitales, experiencias laborales, religión, costumbres y tradiciones, prácticas curativas y ritos, señalados en la Teoría General del Déficit de Autocuidado, muestran un efecto positivo sobre la capacidad de autocuidado de las personas con diabetes tipo 2.

  17. Capacidades de fabricación y almacenaje óptimas en un sistema con logística inversa y demanda aleatoria

    OpenAIRE

    Benedito Benet, Ernest; Corominas Subias, Albert, 1943-

    2009-01-01

    En el presente trabajo se estudia un sistema con demanda y retornos aleatorios para calcular las capacidades óptimas de fabricación y almacenaje. El modelo presentado permite estudiar el comportamiento de las capacidades de fabricación y almacenaje óptimas cuando varían los costes de producción.

  18. Effect of exercise training and myocardial infarction on force development and contractile kinetics in isolated canine myocardium.

    Science.gov (United States)

    Canan, Benjamin D; Haizlip, Kaylan M; Xu, Ying; Monasky, Michelle M; Hiranandani, Nitisha; Milani-Nejad, Nima; Varian, Kenneth D; Slabaugh, Jessica L; Schultz, Eric J; Fedorov, Vadim V; Billman, George E; Janssen, Paul M L

    2016-04-15

    It is well known that moderate exercise training elicits a small increase in ventricular mass (i.e., a physiological hypertrophy) that has many beneficial effects on overall cardiac health. It is also well known that, when a myocardial infarction damages part of the heart, the remaining myocardium remodels to compensate for the loss of viable functioning myocardium. The effects of exercise training, myocardial infarction (MI), and their interaction on the contractile performance of the myocardium itself remain largely to be determined. The present study investigated the contractile properties and kinetics of right ventricular myocardium isolated from sedentary and exercise trained (10-12 wk progressively increasing treadmill running, begun 4 wk after MI induction) dogs with and without a left ventricular myocardial infarction. Exercise training increased force development, whereas MI decreased force development that was not improved by exercise training. Contractile kinetics were significantly slower in the trained dogs, whereas this impact of training was less or no longer present after MI. Length-dependent activation, both evaluated on contractile force and kinetics, was similar in all four groups. The control exercise-trained group exhibited a more positive force-frequency relationship compared with the sedentary control group while both sedentary and trained post-MI dogs had a more negative relationship. Last, the impact of the β-adrenergic receptor agonist isoproterenol resulted in a similar increase in force and acceleration of contractile kinetics in all groups. Thus, exercise training increased developed force but slowed contractile kinetics in control (noninfarcted animals), actions that were attenuated or completely absent in post-MI dogs. PMID:26823341

  19. Effect of exercise training and myocardial infarction on force development and contractile kinetics in isolated canine myocardium.

    Science.gov (United States)

    Canan, Benjamin D; Haizlip, Kaylan M; Xu, Ying; Monasky, Michelle M; Hiranandani, Nitisha; Milani-Nejad, Nima; Varian, Kenneth D; Slabaugh, Jessica L; Schultz, Eric J; Fedorov, Vadim V; Billman, George E; Janssen, Paul M L

    2016-04-15

    It is well known that moderate exercise training elicits a small increase in ventricular mass (i.e., a physiological hypertrophy) that has many beneficial effects on overall cardiac health. It is also well known that, when a myocardial infarction damages part of the heart, the remaining myocardium remodels to compensate for the loss of viable functioning myocardium. The effects of exercise training, myocardial infarction (MI), and their interaction on the contractile performance of the myocardium itself remain largely to be determined. The present study investigated the contractile properties and kinetics of right ventricular myocardium isolated from sedentary and exercise trained (10-12 wk progressively increasing treadmill running, begun 4 wk after MI induction) dogs with and without a left ventricular myocardial infarction. Exercise training increased force development, whereas MI decreased force development that was not improved by exercise training. Contractile kinetics were significantly slower in the trained dogs, whereas this impact of training was less or no longer present after MI. Length-dependent activation, both evaluated on contractile force and kinetics, was similar in all four groups. The control exercise-trained group exhibited a more positive force-frequency relationship compared with the sedentary control group while both sedentary and trained post-MI dogs had a more negative relationship. Last, the impact of the β-adrenergic receptor agonist isoproterenol resulted in a similar increase in force and acceleration of contractile kinetics in all groups. Thus, exercise training increased developed force but slowed contractile kinetics in control (noninfarcted animals), actions that were attenuated or completely absent in post-MI dogs.

  20. Endothelin-1 and endothelin-2 initiate and maintain contractile responses by different mechanisms in rat mesenteric and cerebral arteries

    DEFF Research Database (Denmark)

    Compeer, M. G.; Janssen, G. M. J.; De Mey, J. G. R.

    2013-01-01

    , but relaxed ET-1-induced contractions in MRA. A PLC inhibitor prevented contractile responses to ET-1 and ET-2 in MRA and BA, and relaxed ET-1- and ET-2-induced responses in MRA and ET-1 effects in BA. A Rho-kinase inhibitor did not modify sensitivity, maximum and maintenance of responses to both peptides...... in both arteries but relaxed ET-2, but not ET-1, effects in MRA and ET-1 effects in BA. Conclusions and ImplicationsPLC played a key role in arterial contractile responses to ETs, but ET-1 and ET-2 initiated and maintained vasoconstriction through different mechanisms, and these differed between MRA...

  1. La relación entre la capacidad de atencion dividida y la estimación prospectiva del tiempo

    Directory of Open Access Journals (Sweden)

    Susana Celeste Azzollini

    2004-01-01

    Full Text Available Se realizó una investigación cuyo objetivo fue determinar si la capacidad de atención dividida resultaba explicativa de la variabilidad de las estimaciones prospectivas del tiempo. Los modelos teóricos sobre dicha estimación postulan que los recursos atencionales de procesamiento están divididos entre un procesador temporal, que cuenta y almacena unidades temporales subjetivas (Subjective Temporal Units - STUs y otras actividades de procesamiento no temporal (Zakay, 1993. Se seleccionó una muestra de 36 estudiantes universitarios que fueron asignados al azar a cada una de las seis condiciones experimentales, determinadas por un diseño factorial 3 x 2, y sus factores básicos fueron: cantidad de tareas y niveles de complejidad del material. Se confeccionaron materiales para las diferentes tareas y otros con el fin de evaluar las aptitudes mnémicas y la capacidad de atención dividida. Se solicitó a los sujetos que mientras realizaban las tareas, detuvieran un cronómetro cuando consideraran que había pasado un período de tiempo predeterminado. La estimación del tiempo se calculó por la diferencia en segundos entre el tiempo real y el tiempo estimado. Los datos se procesaron con análisis de correlación, discriminante y factorial de variancia. Los resultados obtenidos indican que la capacidad de atención dividida se correlaciona con la estimación temporal prospectiva y además, la capacidad de atención dividida resulta un buen predictor de la capacidad estimativa de los sujetos, especialmente de los sobre-estimadores. Las diferencias en las aptitudes mnémicas no explicaron la variabilidad de las estimaciones prospectivas.

  2. Toward a Concept of Stretch Coupling in Smooth Muscle: A Thesis by Lars Thuneberg on Contractile Activity in Neonatal Interstitial Cells of Cajal

    DEFF Research Database (Denmark)

    Huizinga, Jan D; Lammers, Wim J E P; Mikkelsen, Hanne B;

    2010-01-01

    for the contractile nature of ICC as perceived by Thuneberg. The contractile activity is shown by video frame subtraction and by tracking areas of interest in sequential video frames. Thuneberg used neonatal ICC in culture maintained between two coverslips thereby allowing growth factors to quickly reach optimal...

  3. Skeletal muscle contractility, self-reported pain and tissue sensitivity in females with neck/shoulder pain and upper Trapezius myofascial trigger points - a randomized intervention study

    DEFF Research Database (Denmark)

    Myburgh, Corrie; Hartvigsen, Jan; Aagaard, Per;

    2012-01-01

    ABSTRACT: BACKGROUND: In relation to Myofascial Triggerpoints (MFTrPs) of the upper Trapezius, this study explored muscle contractility characteristics, the occurrence of post-intervention muscle soreness and the effect of dry needling on muscle contractile characteristics and clinical outcomes...

  4. Qual o melhor período para a realização do doppler das artérias uterinas na predição de complicações da gestação? Which is the best period to perform uterine artery Doppler in the prediction of pregnancy complications?

    Directory of Open Access Journals (Sweden)

    Fabrício da Silva Costa

    2006-04-01

    Full Text Available OBJETIVO: Avaliar, prospectivamente, qual o melhor período para a realização do Doppler das artérias uterinas na predição de complicações da gestação. MATERIAIS E MÉTODOS: Foi conduzido estudo prospectivo em 45 pacientes primigestas, sem história de doenças crônicas. O Doppler das artérias uterinas foi realizado entre 18-20, 24-26, 28-30 e 34-36 semanas, com determinação do índice de resistência, índice de pulsatilidade, relação A/B e a presença ou ausência de incisura na onda de velocidade de fluxo, assim como o resultado da gestação. RESULTADOS: Os índices Doppler apresentaram decréscimo com o decorrer da gestação, mais pronunciado nas gestações normais quando estas foram comparadas com aquelas que tiveram complicações, de maneira mais acentuada no exame realizado entre 24-26 semanas. A melhor relação entre sensibilidade e especificidade para a detecção de complicações durante a gestação foi obtida no exame realizado entre 24-26 semanas. CONCLUSÃO: O melhor período para a realização do Doppler das artérias uterinas na predição de complicações da gestação é o intervalo entre 24-26 semanas.OBJECTIVE: To estimate which is the best period to realize uterine artery Doppler for the prediction of pregnancy complications. MATERIALS AND METHODS: A prospective study was conducted with 45 women without a history of chronic diseases and in their first pregnancy. The uterine artery Doppler was performed between the pregnancy weeks 18-20, 24-26, 28-30 and 34-36, with determination of the resistance index, the pulsatility index, the A/B ratio and presence or absence of notch on the flow velocity waveform, as well as the result of the pregnancy. RESULTS: The Doppler index showed decrease in the course of the pregnancy, more pronounced in the normal pregnancies in comparison with the complicated pregnancies. This was most noticed in the examinations performed between the weeks 24-26. The best sensitivity

  5. Capacidades e trajetórias de inovação de empresas brasileiras

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    Fernanda Maciel Reichert

    2015-10-01

    Full Text Available Todos os tipos de empresas têm condições e precisam inovar? Como se dá o processo de inovação? Quais são as características necessárias para inovar? O setor de atividade e o nível tecnológico influenciam? Para responder a esses questionamentos é preciso ir além do conceito de inovação como a simples criação de algo novo. É preciso considera-la, principalmente, como uma iniciativa de mudança para preencher lacunas de conhecimento e de mercado, e assim, gerar resultados para as empresas. Sabe-se que todas as empresas sempre têm uma base tecnológica (i.e. um produto e seu processo como objeto de seus negócios (a saber, a gestão interna e as transações externas. E, por isso, sempre são constituídas, em menor ou maior grau, por quatro funções básicas - desenvolvimento, operação, gestão e comercialização. A inovação emerge justamente dessas funções e, para cada uma delas, corresponderá uma capacidade de inovação. Assim, o objetivo do presente artigo é identificar as capacidades de inovação de empresas industriais brasileiras e, com isso, explicitar suas trajetórias de inovação. Para realizar o objetivo proposto, utilizou-se como base de dados os resultados oriundos de projeto de pesquisa uma amostra de 1326 empresas industriais brasileiras. O projeto desenvolveu-se em três fases: (i desenvolvimento de um modelo teórico de capacidades de inovação da firma; (ii fase exploratória e; (iii levantamento de dados (survey junto às empresas de setores industriais do estado do Rio Grande do Sul. Considerando o perfil da amostra, concluiu-se que a empresa típica é uma prestadora de serviços industriais, com baixo potencial de inovação. Seja por conta dos ramos de atividade, em sua maioria de baixa e média baixa intensidade tecnológica, seja pela predominância de um modelo de gestão familiar focado em custos, sua trajetória de inovação é restrita à manutenção da qualidade e à maximização da

  6. La arquitectura organizacional y las capacidades estratégicas empresariales empresariales

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    Jesús Perdomo-Ortiz

    2016-05-01

    Full Text Available El diseño organizacional y la teoría basada en los recursos han sido las dos áreas de la economía de la empresa que más desarrollo e impacto en la gerencia, y en el estado del arte de la disciplina, han tenido durante los últimos 15 años. Este documento aborda desde una perspectiva comparada ambos temas y encuentra una estrecha relación de mutuo apoyo conceptual. Es importante precisar que el presente documento no es una revisión de la literatura sobre diseño o arquitectura organizacional; no obstante se soporta en un conjunto de lecturas centradas en dicha temática. En este sentido, el objetivo del documento es hacer una reflexión crítica, planteando unas hipótesis de trabajo y argumentando su elaboración. La literatura sobre dirección estratégica tiene como uno de sus soportes disciplinares la denominada teoría (visión de la empresa basada en los recursos (The Resource-Based View of the Firm, RBV y defiende una lógica implícita de causalidad, al considerar la estructura organizacional como una consecuencia de la estrategia empresarial. Una visión crítica de la arquitectura organizacional contrasta la causalidad estrategia → estructura y puede explicar un vacío en la RBV, cuando ésta trata de explicar el tránsito del concepto de recurso a capacidad, haciendo alusión a un necesario proceso de integración de recursos básicos. Este documento plantea, entonces, la hipótesis de que la arquitectura organizacional es una forma de explicar la conformación de capacidades empresariales y, desde su argumentación, muestra cómo la causalidad → estrategia estructura se puede entender en forma inversa.

  7. POTÊNCIA E CAPACIDADE ANAERÓBIA EM ATLETAS DE KARATE

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    Keith Sato Urbinati

    2011-01-01

    Full Text Available O objetivo do presente estudo foi verificar o nível de potência muscular, bem como a intensidade de esforço durante prova de potência e capacidade anaeróbia em atletas de Karate. Participaram do estudo treze karatekas especialistas em prova de kumitê (luta,sexo masculino, idade média de 20,7±3,79 anos. Realizou-se a avaliação de potência e capacidade anaeróbia (Wingate test, com coleta das variáveis fisiológicas:frequência cardíaca (FC, pressão arterial (PA e lactato sanguíneo (LAC de repouso, imediatamente após e em 5 min de recuperação. Para verificar se ocorrem diferenças nas variáveis fisiológicas durante o teste, realizou-se análise de variância, post hoc de Bonferronie (p?0,05. Verificou-se potência de pico(PP de 8,77 ± 0,99 W/kg-1, potência média (PM de 5,13± 0,49 W.kg-1 e % de fadiga de 50,5 ± 6,45%. Para as variáveis fisiológicas,a FC (F=9,79; p=0,00 pós-teste de Wingate foi estatisticamente maior e diferenteda FC de repouso e recuperação. Não foram encontradas diferenças nos níveis pressatórios e nas concentrações de LAC. Em relação aos valores de FC e LAC tais variáveis pós-teste não se apresentaram elevados. Os valores de potência anaeróbia estão de acordo com a necessidade da modalidade esportiva. Assim, verificou-se menores intensidades de esforço em teste de Wingate quando comparados a de situação real de competição. O nível de potência muscular parece estar adequado ao kumitê.

  8. INFLUÊNCIA DO TIRO COM ZARABATANA NA CAPACIDADE RESPIRATÓRIA DO IDOSO

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    Catarina Leitão

    2015-05-01

    Full Text Available A  respiração é um processo vital e faz parte das funções primordiais do corpo humano. A falta de consciência respiratória é responsável por diversos problemas o que leva a que com o passar do tempo, a respiração, possa provocar não só deformidades no tórax como também modificações posturais, incapacidade funcional e diversas patologias (Tribastone, 2001.O sistema respiratório é o sistema do organismo que envelhece mais rápido devido à exposição aos poluentes ambientais ao longo da vida. A nível clínico ocorrem mudanças relevantes que se traduzem na deterioração da função pulmonar. Calculando-se que em Portugal, as doenças respiratórias a curto prazo sejam a terceira causa de morte e afetem maioritariamente as pessoas idosas (Ruivo et al., 2009. No processo respiratório são essenciais dois tempos, a inspiração e expiração, que resultam de movimentos respiratórios nos quais o diafragma e os pulmões exercem funções fundamentais (Parreiral, 2005. Acreditamos que o tiro com zarabatana, que trabalha a expiração- através da expulsão enérgica de dardos e a inspiração- aquando do início do treino, poderá ser benéfico para a capacidade respiratória dos idosos. Objetivo: O presente estudo visa avaliar os efeitos da prática de Tiro com Zarabatana, na capacidade respiratória de pessoas idosas, mais precisamente as alterações ao nível do débito expiratório máximo.

  9. Upregulation of contractile endothelin type B receptors by lipid-soluble cigarette smoking particles in rat cerebral arteries via activation of MAPK

    DEFF Research Database (Denmark)

    Sandhu, Hardip; Xu, Cang Bao; Edvinsson, Lars

    2010-01-01

    and JNK MAPK-mediated transcription and translation of new contractile ET(B) receptors. Thus, the MAPK-mediated upregulation of contractile ET(B) receptors in cerebral arteries might be a pharmacological target for the treatment of smoke-associated cerebral vascular disease like stroke....... that organ culture per se induced transcriptional upregulation of contractile ET(B) receptors in the cerebral vascular smooth muscle cells. This upregulation was further increased at the translational level by addition of DSP to the organ culture, but this increase was not seen by addition of nicotine...... particles (DSP) induces upregulation of contractile endothelin type B (ET(B)) receptors in rat cerebral arteries and if activation of mitogen activated protein kinase (MAPK) and nuclear factor-kappaB (NF-κB) mediate the upregulation of contractile endothelin receptors in the cerebral arteries. Rat middle...

  10. Upregulation of contractile endothelin type B receptors by lipid-soluble cigarette smoking particles in rat cerebral arteries via activation of MAPK

    DEFF Research Database (Denmark)

    Sandhu, Hardip; Xu, Cang Bao; Edvinsson, Lars

    2010-01-01

    and JNK MAPK-mediated transcription and translation of new contractile ET(B) receptors. Thus, the MAPK-mediated upregulation of contractile ET(B) receptors in cerebral arteries might be a pharmacological target for the treatment of smoke-associated cerebral vascular disease like stroke....... that organ culture per se induced transcriptional upregulation of contractile ET(B) receptors in the cerebral vascular smooth muscle cells. This upregulation was further increased at the translational level by addition of DSP to the organ culture, but this increase was not seen by addition of nicotine...... particles (DSP) induces upregulation of contractile endothelin type B (ET(B)) receptors in rat cerebral arteries and if activation of mitogen activated protein kinase (MAPK) and nuclear factor-kappaB (NF-¿B) mediate the upregulation of contractile endothelin receptors in the cerebral arteries. Rat middle...

  11. Protective Effects of Estradiol on Myocardial Contractile Function Following Hemorrhagic Shock and Resuscitation in Rats

    Institute of Scientific and Technical Information of China (English)

    Mona Soliman

    2015-01-01

    Background:Hemorrhagic shock (HS) results in myocardial contractile dysfunction.Studies showed that 17β-estradiol protects the myocardium against contractile dysfunction.The study investigated the cardioprotective effects of treatment with 17β-estradiol before resuscitation following 1 h of HS and resuscitation.Methods:Male Sprague-Dawley rats were assigned to 2 sets of experimental protocols:Ex vivo and in vivo treatment and resuscitation.Each set had three experimental groups (n =6 per group):Normotensive (N),HS and resuscitation (HS-R) and HS rats treated with 17β-estradiol (E) and resuscitated (HS-E-R).Rats were hemorrhaged over 60-min to reach a mean arterial blood pressure of 40 mmHg.In the ex vivo group,hearts were resuscitated by perfusion in the Langendorff system.In the 17β-estradiol treated group,17β-estradiol 280 μg/kg was added for the first 5 min.Cardiac function was measured.Left ventricular generated pressure (LVGP) and +dP/dt were calculated.In the in vivo group,rats were treated with 17β-estradiol 280 μg/kg s.c.after 60-min HS.Resuscitation was performed in vivo by the reinfusion of the shed blood for 30-min to restore normotension.Results:Treatment with 17β-estradiol before resuscitation in ex vivo treated and resuscitated isolated hearts and in the in vivo treated and resuscitated rats following HS improved myocardial contractile function.In the in vivo treated group,LVGP and +dP/dt max were significantly higher in 17β-estradiol treated rats compared to the untreated group (LVGP 136.40 ± 6.61 compared to 47.58 ± 17.55,and +dP/dt 661.85 ± 49.88 compared to 88.18 ± 0.85).Treatment with 17β-estradiol improved LVGP following HS.Conclusions:The results indicate that treatment with 17β-estradiol before resuscitation following HS protects the myocardium against dysfunction.

  12. Reproducibilidad en la lectura de un set de placas de citología cérvico-uterinas en cuatro centros especializados de Medellín, Antioquia / Reproducibility of reading a set of cervical cytology smears in four specialized centers in Medellin, Antioquia

    Directory of Open Access Journals (Sweden)

    Edwin Guevara

    2014-05-01

    Full Text Available Objetivo: evaluar el grado de reproducibilidad en la lectura de placas de citología cérvico-uterina entre cuatro centros de lectura especializados de la ciudad de Medellín, Colombia. Metodología: 181 placas de citología cérvico-uterina provenientes de un estudio de prevalencia de anormalidades citológicas en Pueblorrico, Antioquia, se sometieron a lectura en cuatro centros especializados de Medellín. Se le pidió a cada centro que realizara una lectura rutinaria manteniendo el estudio en ciego por medio de recodificación de las placas, evitando que se filtrara información entre centros. Se calculó la concordancia general y el índice kappa de Fleiss. Resultados: de las 181 placas, sólo en 55 placas los 4 centros concordaron en el resultado, obteniéndose un porcentaje de concordancia global del 30% y un índice kappa global de 0,31. Según la escala de Fleiss, se observó una baja reproducibilidad en la lectura de las placas citológicas entre los cuatro centros involucrados en el estudio. La concordancia por pares de centros presentó índices de kappa entre 0,3 a 0,7. Discusión: existe una alta variabilidad en la interpretación de los resultados citológicos entre los centros estudiados. Es necesario implementar procesos de entrenamiento y unificación de criterios de lecturas de la citología cervical en nuestro medio Objective: to assess the degree of reproducibility in the reading of cervical cytology smears among four specialized reading centers at Medellin, Colombia. Methodology: 181 cervical cytology smears from a study on the prevalence of cytological abnormalities in Pueblorrico, a town located in the southwestern region of the state of Antioquia in Colombia, were re-read by four specialized centers in Medellin. Each center was asked to conduct a blind routine reading of the smears to avoid disclosure of information between centers. The reproducibility was measured by percentage agreement and kappa. Results: of 181 smears

  13. Determinantes de la capacidad de innovación en PYMES regionales Determinants of innovativeness in regional SMES

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    Carlos Maria Fernández-Jardón

    2013-03-01

    Full Text Available DOI: 10.5902/198346597689La capacidad de innovación es una competencia distintiva que permite innovar y, en consecuencia, potencia la competitividad, especialmente en las pequeñas y medianas empresas (PYME. Dicha capacidad se ve condicionada por factores internos y externos. Este artículo analiza como combina la empresa dichos factores para mejorar la capacidad de innovación. Por un lado, la empresa genera una competencia distintiva denominada gestión de los recursos humanos y tecnológicos a partir del capital intelectual interno. Por otro lado, organiza otra competencia distintiva denominada gestión de los recursos y relaciones territoriales a partir de los recursos tangibles asociados al territorio y del capital intelectual fruto de las relaciones con el entorno. Mediante técnicas de Mínimos cuadrados parciales aplicados  en una muestra de pequeñas y medianas empresas en una región del noroeste de España se demuestra que ambos factores influyen en la capacidad de innovación. Este estudio contribuye a delimitar cuales son los factores que potencian la capacidad de innovación y como la empresa asocia esos factores, indicando cual es el proceso de construcción de competencias básicas para mejorar su capacidad de innovación. Como consecuencia, sugiere elementos de reflexión para elaborar políticas de apoyo a la innovación empresarial.The innovativeness is a core competence to innovate and therefore enhancing competitiveness, especially in small and medium enterprises (SMEs. This capability is constrained by internal and external factors. This article discusses how the company combines these factors to improve innovativeness. First, the company generates a core competence called human resource management and technology from internal intellectual capital. Furthermore, the company organizes another core competence called resource management and territorial relations from tangible resources associated with intellectual capital

  14. Myocardial structural, contractile and electrophysiological changes in the guinea-pig heart failure model induced by chronic sympathetic activation

    DEFF Research Database (Denmark)

    Soltysinska, Ewa; Osadchiy, Oleg; Olesen, Søren-Peter

    2011-01-01

    pressure-volume and stress-strain relationships assessed in isolated, perfused heart preparations), reduced contractile reserve in the presence of acute ß-adrenoceptor stimulation, and pulmonary oedema (increased lung weights). These changes were associated with prolongation of LV epicardial action...

  15. Decrease of contractile properties and transversal stiffness of single fibers in human soleus after 7-day “dry” immersion

    Science.gov (United States)

    Ogneva, I. V.; Ponomareva, E. V.; Kartashkina, N. L.; Altaeva, E. G.; Fokina, N. M.; Kurushin, V. A.; Kozlovskaya, I. B.; Shenkman, B. S.

    2011-05-01

    The simulation model of "dry" immersion was used to evaluate the effects of plantar mechanical stimulation (PMS) and high frequency electromyostimulation (EMS) on the mechanical properties of human soleus fibers under the conditions of gravitational unloading. We examined contractile properties of single fibers by means of tensometry, transversal stiffness of sarcolemma and different areas of the contractile apparatus by means of atomic force microscopy. It was shown that there is a reduction of transversal stiffness in single muscle fibers under hypogravitational conditions. Application of different countermeasures could compensate this effect. Meanwhile pneumostimulation and electro stimulation act in quite different way. Therefore, pneumostimulation seems to be more effective. The data obtained can be considered as the evidence of the fact that such countermeasures as PMS and electromyostimulation influence on muscle fibers in quite different ways and PMS efficiency is likely to be higher. On the basis of our experimental data on transverse stiffness of mechanotransductional nodes and the contractile apparatus, we can assume that support stimulation allows prevention of destructive processes in muscle fibers. Electrostimulation seems to stimulate contractile activity only without suppression of impairment of the fiber mechanical properties.

  16. The Effect of Cleft Palate Repair on Contractile Properties of Single Permeabilized Muscle Fibers From Congenitally Cleft Goats Palates

    Science.gov (United States)

    A cleft palate goat model was used to study the contractile properties of the levator veli palatini (LVP) muscle which is responsible for the movement of the soft palate. In 15-25% of patients that undergo palatoplasty, residual velopharyngeal insufficiency (VPI) remains a problem and often require...

  17. Myocardial performance index is sensitive to changes in cardiac contractility, but is also affected by vascular load condition.

    Science.gov (United States)

    Uemura, Kazunori; Kawada, Toru; Zheng, Can; Li, Meihua; Shishido, Toshiaki; Sugimachi, Masaru

    2013-01-01

    Myocardial performance index (MPI), or Tei index, is measured by Doppler echocardiography in clinical practice. MPI has been shown to be useful in evaluating left ventricular (LV) performance and predicting prognosis in cardiac patients. However, the effects of LV load and contractile states on MPI remain to be thoroughly investigated. In 14 anesthetized dogs, we obtained LV pressure-volume relationship with use of sonomicrometry and catheter-tip manometry. MPI was determined from the time derivative of LV volume and pressure. LV end-systolic pressure-volume ratio (Ees'), effective arterial elastance (Ea) and LV end-diastolic volume (Ved) were used as indices of LV contractility, afterload and preload, respectively. Hemodynamic conditions were varied over wide ranges [heart rate (HR), 66-192 bpm; mean arterial pressure, 71-177 mmHg] by infusing cardiovascular agents, by inducing ischemic heart failure and by electrical atrial pacing. Multiple linear regression analysis of pooled data (66 data sets) indicated that MPI (0.6-1.8) significantly correlated with Ees' [1.5-17.5 mmHg · ml(-1), pVed (11-100 ml, p0.1). Theoretical analysis also indicated that MPI decreases following the increases in LV contractility and in preload, while it increases in response to an increase in LV afterload. We conclude that MPI sensitively detects changes in LV contractility. However, MPI is also affected by changes in LV afterload and preload. PMID:24109782

  18. Effects of testosterone on contractile properties of sexually dimorphic forelimb muscles in male bullfrogs (Rana catesbeiana, Shaw 1802

    Directory of Open Access Journals (Sweden)

    Aaron R. Kampe

    2013-07-01

    This study examined the effects of testosterone (T on the contractile properties of two sexually dimorphic forelimb muscles and one non-dimorphic muscle in male bullfrogs (Rana catesbeiana, Shaw 1802. The dimorphic muscles in castrated males with testosterone replacement (T+ achieved higher forces and lower fatigability than did castrated males without replaced testosterone (T0 males, but the magnitude of the differences was low and many of the pair-wise comparisons of each muscle property were not statistically significant. However, when taken as a whole, the means of seven contractile properties varied in the directions expected of masculine values in T+ animals in the sexually dimorphic muscles. Moreover, these data, compared with previous data on male and female bullfrogs, show that values for T+ males are similar to normal males and are significantly different from females. The T0 males tended to be intermediate in character between T+ males and females, generally retaining masculine values. This suggests that the exposure of young males to T in their first breeding season produces a masculinizing effect on the sexually dimorphic muscles that is not reversed between breeding seasons when T levels are low. The relatively minor differences in contractile properties between T+ and T0 males may indicate that as circulating T levels rise during breeding season in normal males, contractile properties can be enhanced rapidly to maximal functional levels for breeding success.

  19. Effect of training on contractile and metabolic properties of wrist extensors in spinal cord-injured individuals

    DEFF Research Database (Denmark)

    Hartkopp, Andreas; Harridge, Stephen D R; Mizuno, Masao;

    2003-01-01

    Paretic human muscle rapidly loses strength and oxidative endurance, and electrical stimulation training may partly reverse this. We evaluated the effects of two training protocols on the contractile and metabolic properties of the wrist extensor in 12 C-5/6 tetraplegic individuals. The wrist...

  20. Alteration in contractile G-protein coupled receptor expression by moist snuff and nicotine in rat cerebral arteries

    DEFF Research Database (Denmark)

    Sandhu, Hardip; Xu, Cang-Bao; Edvinsson, Lars

    2011-01-01

    was kept at plasma level of snus users (25ng nicotine/ml). A high dose (250ng nicotine/ml) was also included due to the previous results showing alteration in the GPCR expression by nicotine at this concentration. Contractile responses to the ET(B) receptor agonist sarafotoxin 6c, 5-HT(1B) receptor agonist...

  1. Effect of a Periodized Power Training Program on the Functional Performances and Contractile Properties of the Quadriceps in Sprinters

    Science.gov (United States)

    Kamandulis, Sigitas; Skurvydas, Albertas; Brazaitis, Marius; Stanislovaitis, Aleksas; Duchateau, Jacques; Stanislovaitiene, Jurate

    2012-01-01

    Our purpose was to compare the effect of a periodized preparation consisting of power endurance training and high-intensity power training on the contractile properties of the quadriceps muscle and functional performances in well trained male sprinters (n = 7). After 4 weeks of high-intensity power training, 60-m sprint running time improved by an…

  2. Effects of silver ions (Ag+) on contractile ring function and microtubule dynamics during first cleavage in Ilyanassa obsoleta

    Science.gov (United States)

    Conrad, A. H.; Stephens, A. P.; Paulsen, A. Q.; Schwarting, S. S.; Conrad, G. W.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    The terminal phase of cell division involves tight constriction of the cleavage furrow contractile ring, stabilization/elongation of the intercellular bridge, and final separation of the daughter cells. At first cleavage, the fertilized eggs of the mollusk, Ilyanassa obsoleta, form two contractile rings at right angles to each other in the same cytoplasm that constrict to tight necks and partition the egg into a trefoil shape. The cleavage furrow contractile ring (CF) normally constricts around many midbody microtubules (MTs) and results in cleavage; the polar lobe constriction contractile ring (PLC) normally constricts around very few MTs and subsequently relaxes without cleavage. In the presence of Ag+ ions, the PLC 1) begins MT-dependent rapid constriction sooner than controls, 2) encircles more MTs than control egg PLCs, 3) elongates much more than control PLCs, and 4) remains tightly constricted and effectively cleaves the polar lobe from the egg. If Ag(+)-incubated eggs are returned to normal seawater at trefoil, tubulin fluorescence disappears from the PLC neck and the neck relaxes. If nocodazole, a drug that depolymerizes MTs, is added to Ag(+)-incubated eggs during early PLC constriction, the PLC is not stabilized and eventually relaxes. However, if nocodazole is added to Ag(+)-incubated eggs at trefoil, tubulin fluorescence disappears from the PLC neck but the neck remains constricted. These results suggest that Ag+ accelerates and gradually stabilizes the PLC constriction by a mechanism that is initially MT-dependent, but that progressively becomes MT-independent.

  3. CAPACIDAD DE SALTO EN NIÑAS PREPÚBERES QUE PRACTICAN GIMNASIA RÍTMICA

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    R. Arteaga

    2010-10-01

    Full Text Available

    Estudiamos el rendimiento en el salto vertical y como podría verse afectado por lacomposición corporal en 13 niñas que practicaban gimnasia rítmica (GR; 10.4 ± 0.9 años y13 niñas control (CO; 9.9 ± 0.7 años. La composición corporal fue determinada medianteantropometría y DXA. Se realizaron saltos con y sin contramovimiento (CMJ y SJ sobre unaplataforma de fuerza analizándose entre otras variables la altura de vuelo (AV, velocidad dedespegue (VD, velocidad vertical máxima del centro de masas (Vimax, la potencia media(Pm, el impulso mecánico positivo (Ipos, tiempo de fuerza máxima (Tfmax y potenciainstantánea máxima (Pimax. Las gimnastas consiguieron una AV, VD, Ipos y Vimax mayoren ambos saltos y una Pm, Tfmax y Pimax mayores en el CMJ que las control (p<0.05. Enconclusión, prácticar gimnasia rítmica 10 h·sem-1 se asocia a un mayor rendimiento en elsalto vertical.

    Palabras claves: gimnasia rítmica, entrenamiento de fuerza, capacidad de salto.

  4. DESARROLLO DE UNA MANO ROBÓTICA CON CAPACIDAD DE MANIPULACIÓN

    Directory of Open Access Journals (Sweden)

    Iván Pérez

    2008-09-01

    Full Text Available El área que ocupa la presente investigación está relacionada con la robótica, con los tipos de robots autónomos y androide; son autónomos o inteligentes debido a que procesa la información; convirtiéndose en más evolucionados porque ellos responde de acuerdo al ambiente en que se presente sin la intervención del hombre o con una pequeña intervención y androide por que se tratara de imitar una parte del cuerpo humano. Para llevar a cabo un robot con dicha característica es necesario trabajar en el sistema mecánico del mismo teniendo en cuenta la cantidad de articulaciones que permite la movilidad y el control de la misma, se trabaja con la electrónica, que admite controlar el robot y procesar la información para que su respuesta sea la correcta; este estudio, se planteó como objetivo general desarrollo de una mano robótica con capacidad de manipulación que permita imitar la mano humana tocando piezas musicales en un piano digital, para el abordaje metodológico se aplicó la metodología y herramientas para el diseño de sistemas digitales, diseños de circuitos y sistemas electrónicos.

  5. APRENDIZAJE CON BASE EN PROYECTOS PARA DESARROLLAR CAPACIDADES DE PROBLEMATIZACIÓN EN EDUCACION SUPERIOR

    Directory of Open Access Journals (Sweden)

    Juan Manuel Muñoz Cano

    2011-01-01

    Full Text Available El propósito del estudio fue diseñar una intervención educativa para que los estudiantes superaran las dificultades en el manejo autónomo de la Internet, y que a través de este recurso desarrollaran capacidades para la identificación de los problemas de salud que afectan a la población, así como la búsqueda y análisis de información clínica actualizada. Se trabajó con base en proyectos y la solución de problemas durante cuatro meses con 31 estudiantes a quienes se asesoró en el manejo de bibliotecas virtuales. Se emplearon distintas estrategias en el aula para el trabajo en espacio virtual, como la elaboración del árbol de problemas y el árbol de soluciones. La evaluación formativa facilitó el seguimiento del proceso de aprendizaje y la sistematización de los resultados. La evaluación se apoyó en criterios definidos en matrices de evaluación y en el portafolio de evidencias. La acreditación se realizó con base en la calidad de sus informes. La experiencia la terminaron 14 estudiantes, y 12 de ellos lograron elaborar informes complejos que incluyeron conclusiones y recomendaciones y la consulta de varias fuentes localizadas en bibliotecas virtuales.

  6. Bidirectional Interplay between Vimentin Intermediate Filaments and Contractile Actin Stress Fibers

    Directory of Open Access Journals (Sweden)

    Yaming Jiu

    2015-06-01

    Full Text Available The actin cytoskeleton and cytoplasmic intermediate filaments contribute to cell migration and morphogenesis, but the interplay between these two central cytoskeletal elements has remained elusive. Here, we find that specific actin stress fiber structures, transverse arcs, interact with vimentin intermediate filaments and promote their retrograde flow. Consequently, myosin-II-containing arcs are important for perinuclear localization of the vimentin network in cells. The vimentin network reciprocally restricts retrograde movement of arcs and hence controls the width of flat lamellum at the leading edge of the cell. Depletion of plectin recapitulates the vimentin organization phenotype of arc-deficient cells without affecting the integrity of vimentin filaments or stress fibers, demonstrating that this cytoskeletal cross-linker is required for productive interactions between vimentin and arcs. Collectively, our results reveal that plectin-mediated interplay between contractile actomyosin arcs and vimentin intermediate filaments controls the localization and dynamics of these two cytoskeletal systems and is consequently important for cell morphogenesis.

  7. A new strain gage method for measuring the contractile strain ratio of Zircaloy tubing

    International Nuclear Information System (INIS)

    An improved strain gage method for determining the contractile strain ratio (CSR) of Zircaloy tubing was developed. The new method consists of a number of load-unload cyclings at approximately 0.2% plastic strain interval. With this method the CSR of Zircaloy-4 tubing could be determined accurately because it was possible to separate the plastic strains from the elastic strain involvement. The CSR values determined by use of the new method were in good agreement with those calculated from conventional post-test manual measurements. The CSR of the tubing was found to decrease with the amount of deformation during testing because of uneven plastic flow in the gage section. A new technique of inscribing gage marks by use of a YAG laser is discussed. (orig.)

  8. Disordered actomyosin networks are sufficient to produce cooperative and telescopic contractility

    Science.gov (United States)

    Linsmeier, Ian; Banerjee, Shiladitya; Oakes, Patrick W.; Jung, Wonyeong; Kim, Taeyoon; Murrell, Michael P.

    2016-08-01

    While the molecular interactions between individual myosin motors and F-actin are well established, the relationship between F-actin organization and actomyosin forces remains poorly understood. Here we explore the accumulation of myosin-induced stresses within a two-dimensional biomimetic model of the disordered actomyosin cytoskeleton, where myosin activity is controlled spatiotemporally using light. By controlling the geometry and the duration of myosin activation, we show that contraction of disordered actin networks is highly cooperative, telescopic with the activation size, and capable of generating non-uniform patterns of mechanical stress. We quantitatively reproduce these collective biomimetic properties using an isotropic active gel model of the actomyosin cytoskeleton, and explore the physical origins of telescopic contractility in disordered networks using agent-based simulations.

  9. Tuning cell migration: contractility as an integrator of intracellular signals from multiple cues.

    Science.gov (United States)

    Bordeleau, Francois; Reinhart-King, Cynthia A

    2016-01-01

    There has been immense progress in our understanding of the factors driving cell migration in both two-dimensional and three-dimensional microenvironments over the years. However, it is becoming increasingly evident that even though most cells share many of the same signaling molecules, they rarely respond in the same way to migration cues. To add to the complexity, cells are generally exposed to multiple cues simultaneously, in the form of growth factors and/or physical cues from the matrix. Understanding the mechanisms that modulate the intracellular signals triggered by multiple cues remains a challenge. Here, we will focus on the molecular mechanism involved in modulating cell migration, with a specific focus on how cell contractility can mediate the crosstalk between signaling initiated at cell-matrix adhesions and growth factor receptors. PMID:27508074

  10. Orchestrated content release from Drosophila glue-protein vesicles by a contractile actomyosin network.

    Science.gov (United States)

    Rousso, Tal; Schejter, Eyal D; Shilo, Ben-Zion

    2016-02-01

    Releasing content from large vesicles measuring several micrometres in diameter poses exceptional challenges to the secretory system. An actomyosin network commonly coats these vesicles, and is thought to provide the necessary force mediating efficient cargo release. Here we describe the spatial and temporal dynamics of the formation of this actomyosin coat around large vesicles and the resulting vesicle collapse, in live Drosophila melanogaster salivary glands. We identify the Formin family protein Diaphanous (Dia) as the main actin nucleator involved in generating this structure, and uncover Rho as an integrator of actin assembly and contractile machinery activation comprising this actomyosin network. High-resolution imaging reveals a unique cage-like organization of myosin II on the actin coat. This myosin arrangement requires branched-actin polymerization, and is critical for exerting a non-isotropic force, mediating efficient vesicle contraction.

  11. Disordered actomyosin networks are sufficient to produce cooperative and telescopic contractility

    Science.gov (United States)

    Linsmeier, Ian; Banerjee, Shiladitya; Oakes, Patrick W.; Jung, Wonyeong; Kim, Taeyoon; Murrell, Michael P.

    2016-01-01

    While the molecular interactions between individual myosin motors and F-actin are well established, the relationship between F-actin organization and actomyosin forces remains poorly understood. Here we explore the accumulation of myosin-induced stresses within a two-dimensional biomimetic model of the disordered actomyosin cytoskeleton, where myosin activity is controlled spatiotemporally using light. By controlling the geometry and the duration of myosin activation, we show that contraction of disordered actin networks is highly cooperative, telescopic with the activation size, and capable of generating non-uniform patterns of mechanical stress. We quantitatively reproduce these collective biomimetic properties using an isotropic active gel model of the actomyosin cytoskeleton, and explore the physical origins of telescopic contractility in disordered networks using agent-based simulations. PMID:27558758

  12. Pentamidine rescues contractility and rhythmicity in a Drosophila model of myotonic dystrophy heart dysfunction

    Directory of Open Access Journals (Sweden)

    Mouli Chakraborty

    2015-12-01

    Full Text Available Up to 80% of individuals with myotonic dystrophy type 1 (DM1 will develop cardiac abnormalities at some point during the progression of their disease, the most common of which is heart blockage of varying degrees. Such blockage is characterized by conduction defects and supraventricular and ventricular tachycardia, and carries a high risk of sudden cardiac death. Despite its importance, very few animal model studies have focused on the heart dysfunction in DM1. Here, we describe the characterization of the heart phenotype in a Drosophila model expressing pure expanded CUG repeats under the control of the cardiomyocyte-specific driver GMH5-Gal4. Morphologically, expression of 250 CUG repeats caused abnormalities in the parallel alignment of the spiral myofibrils in dissected fly hearts, as revealed by phalloidin staining. Moreover, combined immunofluorescence and in situ hybridization of Muscleblind and CUG repeats, respectively, confirmed detectable ribonuclear foci and Muscleblind sequestration, characteristic features of DM1, exclusively in flies expressing the expanded CTG repeats. Similarly to what has been reported in humans with DM1, heart-specific expression of toxic RNA resulted in reduced survival, increased arrhythmia, altered diastolic and systolic function, reduced heart tube diameters and reduced contractility in the model flies. As a proof of concept that the fly heart model can be used for in vivo testing of promising therapeutic compounds, we fed flies with pentamidine, a compound previously described to improve DM1 phenotypes. Pentamidine not only released Muscleblind from the CUG RNA repeats and reduced ribonuclear formation in the Drosophila heart, but also rescued heart arrhythmicity and contractility, and improved fly survival in animals expressing 250 CUG repeats.

  13. Prostaglandins attenuate cardiac contractile dysfunction produced by free radical generation but not by hydrogen peroxide.

    Science.gov (United States)

    Zimmer, K M; Karmazyn, M

    1997-11-01

    The aim of this study was to examine and compare the potential influence of cyclooxygenase or lipoxygenase derived metabolites of arachidonic acid on myocardial injury produced either by a free radical generating system consisting of purine plus xanthine oxidase or that produced by hydrogen peroxide. A free radical generating system consisting of purine (2.3 mM) and xanthine oxidase (10 U/L) as well as hydrogen peroxide (75 microM) produced significant functional changes in the absence of either significant deficits in high energy phosphates or ultrastructural damage. Prostaglandin F2 alpha (30 nM) significantly attenuated both the negative inotropic effect of purine plus xanthine oxidase as well as the ability of the free radical generator to elevate diastolic pressure. An identical concentration of prostaglandin 12 (prostacyclin) significantly reduced diastolic pressure elevation only and had no effect on contractile depression. The salutary effects of the two PGs occurred in the absence of any inhibitory influence on superoxide anion generation produced by the purine and xanthine oxidase reaction. None of prostaglandins modulated the response to hydrogen peroxide. In addition, neither prostaglandin E2 nor leukotrienes exerted any effect on changes produced by either type of oxidative stress. A 5 fold elevation in the concentrations of free radical generators or hydrogen peroxide produced extensive injury as characterized by a virtual total loss in contractility, 400% elevation in diastolic pressure, ultrastructural damage and significant depletions in high energy phosphate content. None of these effects were modulated by eicosanoid treatment. Our results therefore demonstrate a selective ability of both prostaglandin F2 alpha and to a lesser extent prostacyclin, to attenuate dysfunction produced by purine plus xanthine oxidase but not hydrogen peroxide. It is possible that these eicosanoids may represent endogenous protective factors under conditions of enhanced

  14. Spatio-temporal changes of lymphatic contractility and drainage patterns following lymphadenectomy in mice.

    Directory of Open Access Journals (Sweden)

    Sunkuk Kwon

    Full Text Available OBJECTIVE: To investigate the redirection of lymphatic drainage post-lymphadenectomy using non-invasive near-infrared fluorescence (NIRF imaging, and to subsequently assess impact on metastasis. BACKGROUND: Cancer-acquired lymphedema arises from dysfunctional fluid transport after lymphadenectomy performed for staging and to disrupt drainage pathways for regional control of disease. However, little is known about the normal regenerative processes of the lymphatics in response to lymphadenectomy and how these responses can be accelerated, delayed, or can impact metastasis. METHODS: Changes in lymphatic "pumping" function and drainage patterns were non-invasively and longitudinally imaged using NIRF lymphatic imaging after popliteal lymphadenectomy in mice. In a cohort of mice, B16F10 melanoma was inoculated on the dorsal aspect of the paw 27 days after lymphadenectomy to assess how drainage patterns affect metastasis. RESULTS: NIRF imaging demonstrates that, although lymphatic function and drainage patterns change significantly in early response to popliteal lymph node (PLN removal in mice, these changes are transient and regress dramatically due to a high regenerative capacity of the lymphatics and co-opting of collateral lymphatic pathways around the site of obstruction. Metastases followed the pattern of collateral pathways and could be detected proximal to the site of lymphadenectomy. CONCLUSIONS: Both lymphatic vessel regeneration and co-opting of contralateral vessels occur following lymphadenectomy, with contractile function restored within 13 days, providing a basis for preclinical and clinical investigations to hasten lymphatic repair and restore contractile lymphatic function after surgery to prevent cancer-acquired lymphedema. Patterns of cancer metastasis after lymphadenectomy were altered, consistent with patterns of re-directed lymphatic drainage.

  15. Modeling beta-adrenergic control of cardiac myocyte contractility in silico

    Science.gov (United States)

    Saucerman, Jeffrey J.; Brunton, Laurence L.; Michailova, Anushka P.; McCulloch, Andrew D.; McCullough, A. D. (Principal Investigator)

    2003-01-01

    The beta-adrenergic signaling pathway regulates cardiac myocyte contractility through a combination of feedforward and feedback mechanisms. We used systems analysis to investigate how the components and topology of this signaling network permit neurohormonal control of excitation-contraction coupling in the rat ventricular myocyte. A kinetic model integrating beta-adrenergic signaling with excitation-contraction coupling was formulated, and each subsystem was validated with independent biochemical and physiological measurements. Model analysis was used to investigate quantitatively the effects of specific molecular perturbations. 3-Fold overexpression of adenylyl cyclase in the model allowed an 85% higher rate of cyclic AMP synthesis than an equivalent overexpression of beta 1-adrenergic receptor, and manipulating the affinity of Gs alpha for adenylyl cyclase was a more potent regulator of cyclic AMP production. The model predicted that less than 40% of adenylyl cyclase molecules may be stimulated under maximal receptor activation, and an experimental protocol is suggested for validating this prediction. The model also predicted that the endogenous heat-stable protein kinase inhibitor may enhance basal cyclic AMP buffering by 68% and increasing the apparent Hill coefficient of protein kinase A activation from 1.0 to 2.0. Finally, phosphorylation of the L-type calcium channel and phospholamban were found sufficient to predict the dominant changes in myocyte contractility, including a 2.6x increase in systolic calcium (inotropy) and a 28% decrease in calcium half-relaxation time (lusitropy). By performing systems analysis, the consequences of molecular perturbations in the beta-adrenergic signaling network may be understood within the context of integrative cellular physiology.

  16. Direct, differential effects of tamoxifen, 4-hydroxytamoxifen, and raloxifene on cardiac myocyte contractility and calcium handling.

    Directory of Open Access Journals (Sweden)

    Michelle L Asp

    Full Text Available Tamoxifen (Tam, a selective estrogen receptor modulator, is in wide clinical use for the treatment and prevention of breast cancer. High Tam doses have been used for treatment of gliomas and cancers with multiple drug resistance, but long QT Syndrome is a side effect. Tam is also used experimentally in mice for inducible gene knockout in numerous tissues, including heart; however, the potential direct effects of Tam on cardiac myocyte mechanical function are not known. The goal of this study was to determine the direct, acute effects of Tam, its active metabolite 4-hydroxytamoxifen (4OHT, and related drug raloxifene (Ral on isolated rat cardiac myocyte mechanical function and calcium handling. Tam decreased contraction amplitude, slowed relaxation, and decreased Ca²⁺ transient amplitude. Effects were primarily observed at 5 and 10 μM Tam, which is relevant for high dose Tam treatment in cancer patients as well as Tam-mediated gene excision in mice. Myocytes treated with 4OHT responded similarly to Tam-treated cells with regard to both contractility and calcium handling, suggesting an estrogen-receptor independent mechanism is responsible for the effects. In contrast, Ral increased contraction and Ca²⁺ transient amplitudes. At 10 μM, all drugs had a time-dependent effect to abolish cellular contraction. In conclusion, Tam, 4OHT, and Ral adversely and differentially alter cardiac myocyte contractility and Ca²⁺ handling. These findings have important implications for understanding the Tam-induced cardiomyopathy in gene excision studies and may be important for understanding effects on cardiac performance in patients undergoing high-dose Tam therapy.

  17. Pentamidine rescues contractility and rhythmicity in a Drosophila model of myotonic dystrophy heart dysfunction

    Science.gov (United States)

    Chakraborty, Mouli; Selma-Soriano, Estela; Magny, Emile; Couso, Juan Pablo; Pérez-Alonso, Manuel; Charlet-Berguerand, Nicolas; Artero, Ruben; Llamusi, Beatriz

    2015-01-01

    ABSTRACT Up to 80% of individuals with myotonic dystrophy type 1 (DM1) will develop cardiac abnormalities at some point during the progression of their disease, the most common of which is heart blockage of varying degrees. Such blockage is characterized by conduction defects and supraventricular and ventricular tachycardia, and carries a high risk of sudden cardiac death. Despite its importance, very few animal model studies have focused on the heart dysfunction in DM1. Here, we describe the characterization of the heart phenotype in a Drosophila model expressing pure expanded CUG repeats under the control of the cardiomyocyte-specific driver GMH5-Gal4. Morphologically, expression of 250 CUG repeats caused abnormalities in the parallel alignment of the spiral myofibrils in dissected fly hearts, as revealed by phalloidin staining. Moreover, combined immunofluorescence and in situ hybridization of Muscleblind and CUG repeats, respectively, confirmed detectable ribonuclear foci and Muscleblind sequestration, characteristic features of DM1, exclusively in flies expressing the expanded CTG repeats. Similarly to what has been reported in humans with DM1, heart-specific expression of toxic RNA resulted in reduced survival, increased arrhythmia, altered diastolic and systolic function, reduced heart tube diameters and reduced contractility in the model flies. As a proof of concept that the fly heart model can be used for in vivo testing of promising therapeutic compounds, we fed flies with pentamidine, a compound previously described to improve DM1 phenotypes. Pentamidine not only released Muscleblind from the CUG RNA repeats and reduced ribonuclear formation in the Drosophila heart, but also rescued heart arrhythmicity and contractility, and improved fly survival in animals expressing 250 CUG repeats. PMID:26515653

  18. Continual electric field stimulation preserves contractile function of adult ventricular myocytes in primary culture.

    Science.gov (United States)

    Berger, H J; Prasad, S K; Davidoff, A J; Pimental, D; Ellingsen, O; Marsh, J D; Smith, T W; Kelly, R A

    1994-01-01

    To model with greater fidelity the electromechanical function of freshly isolated heart muscle cells in primary culture, we describe a technique for the continual electrical stimulation of adult myocytes at physiological frequencies for several days. A reusable plastic cover was constructed to fit standard, disposable 175-cm2 tissue culture flasks and to hold parallel graphite electrodes along the long axis of each flask, which treated a uniform electric field that resulted in a capture efficiency of ventricular myocytes of 75-80%. Computer-controlled amplifiers were designed to be capable of driving a number of flasks concurrently, each containing up to 4 x 10(6) myocytes, over a range of stimulation frequencies (from 0.1 to 7.0 Hz) with reversal of electrode polarity after each stimulus to prevent the development of pH gradients around each electrode. Unlike quiescent, unstimulated myocytes, the amplitude of contraction, and velocities of shortening and relaxation did not change in myocytes paced at 3-5 Hz for up to 72 h. The maintenance of normal contractile function in paced myocytes required mechanical contraction per se, since paced myocytes that remained quiescent due to the inclusion of 2.5 microM verapamil in the culture medium for 48 h also exhibited a decline in contractility when paced after verapamil removal. Similarly, pacing increased peak calcium current compared with quiescent cells that had not been paced. Thus myocyte contraction at physiological frequencies induced by continual uniform electric field stimulation in short-term primary culture in defining medium maintains some biophysical parameters of myocyte phenotype that are similar to those observed in freshly isolated adult ventricular myocytes.

  19. Effect of aerobic exercise on the contractile function of gastrocnemius myosin heavy chain

    Institute of Scientific and Technical Information of China (English)

    Wen-jun Ren

    2009-01-01

    Objective To study the effect of 4- 6 weeks' treadmill training of male SD rats on the contractile function of their gnstroenemius myosin heavy chain (MHC). Methods Forty male SD rats were randomly divided into control group and training group. The treadmill training of the training group rats was incessantly performed for 4- 6 weeks at an intensity of about 75% VO2max (18. 5- 24 m/min, gradient of 0°, each training session lasting 50 minutes, twice a day). The content of gastrocnemlas MHC mRNA was tested by reverse transcription polymernse chain reaction (RT-PCR), and the changes of muscle fibre and its cross-section area (CSA) were measured using immunohistochemistry. Electric stimulation tests were used to determine the maximal tension of isometric contraction of the post-training gastrocnemius. Results ① After continuous treadmill training for 4 - 6 weeks, we found that the content of the total MHC, MHC Ⅰ , MHC Ⅱ x, MHC Ⅱ a mRNAs was 105%, 105%, 109% and 108% of that in the resting control group, respectively, and the MHC Ⅱ b mRNA content did not change significantly. The percentage of MHC Ⅰ mRNA in the total MHC mRNA increased while that of MHC Ⅱ mRNA decreased after aerobic training. ② The slow type of fibre type Ⅰ was the main part of the MHC after training and the CSA of the muscle fibres increased simultaneously. ③ The maximal tension of isometric contraction by pulse stimulation of square wave in the training group increased significantly compared with that in the control group (P<0. 01). Conclusion The findings indicate that aerobic exercise may promote an increase in the contractile function of MHC.

  20. Improved Cardiac Contractility of Human Recombinant Growth Hormone on the Congestive Heart Failure of Pig

    Institute of Scientific and Technical Information of China (English)

    Yang Ping; He Yu-quan; Zeng Hong; Ni Jin-song; Yun Qing-jun; Huang Xiao-ping; Li Shu-mei

    2005-01-01

    The enhanced cardiac contractility effect of human recombinant growth hormone (hr-GH) on the congestive heart failure (CHF) was studied on the pig. To build a pig model of congestive heart failure, a temporary artificial cardiac pacemaker was implanted in the pig's body and paced at 220 beats to 240 beats per minute for 1 week. After the model of congestive heart failure was successfully set up, the frequency of the pacemaker was changed to 150 beats to 180 beats per minute to maintain the CHF model stable. Pigs were divided into three groups: The hr-GH group in which 0.5 mg/kg per day of hr-GH was administrated intramuscularly for 15 days, the injection control group in which an equal amount of physiological saline was injected intramuscularly, and a normal control group. The left ventricular diastolic end pressure was (10.60±2.41 ) mmHg in the hr-GH group, but (19.00±3.81) mmHg in the saline control group (P<0.01); Cardiac output was (1.86±0.13) L/min in the hr-GH group, but (1.56 ±0.18) L/min in the saline control group (P<0.05); Peripheral min) -1 in the saline control group (P<0.05); ± dp/dtmax was (2900 ±316.23) and (2280 ±286.36) in the hr-HG group and the saline control group respectively (P<0.05). The results show that hr-GH enhances myocardial contractility of CHF, and the CHF model built by a temporary artificial cardiac pacemaker at a high rate of stimulation is reasonable and applicable.

  1. Effects of benactyzine on action potentials and contractile force of guinea pig papillary muscles

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Aim:To explore the effects of benactyzine (BEN) on the action potential and contractile force in guinea pig papillary muscles.Methods:Conventional microelectrode technique was used to record the fast action potentials (FAP) and slow action potentials (SAP) of guinea pig papillary muscles.Results:Benactyzine 5,10,50 μmol·L-1 suppressed the maximal upstroke velocity (vmax) of FAP and contractile force (Fc) concentration-dependently while prolonged the action potential duration at 50%,90% repolarization (APD50,APD90) and effective refractory period (ERP) of FAP.The suppression on the vmax was frequency-dependent.Benactyzine 5,10,50μmol·L-1 lengthened the APD50,APD90 of SAP induced by isoprenaline or histamine when perfused with KCl 22 mmol·L-1 Tyrode's solution.The vmax of the SAP was not decreased by benactyzine 5,10 μmol·L-1 but by 50 μmol·L-1.The effects on the SAP were antagonized by elevation of the extracellular calcium from 2.0 to 5.6 mmol·L-1.The effects of benactyzine on SAP elicited by tetrodotoxin resembled that by isoprenaline or histamine except the more pronounced suppression on vmax and action potential amplitude (APA).The persistent rapid spontaneous activity and triggered tachyarrhythmia induced by ouabain were also abolished immediately by benactyzine 5 μmol·L-1.Conclusion:Benactyzine can inhibit Na+,K+,Ca2+ transmembrane movement and intracellular Ca2+ mobilization in the myocardium,and this may be the electrophysiological basis of its effects against experimental arrhythmias.

  2. Insulin improves cardiac myocytes contractile function recovery in simulated ischemia-reperfusion: Key role of Akt

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bo; ZHANG Haifeng; FAN Qian; MA Xinliang; GAO Feng

    2003-01-01

    The present study examined cardiac myocyte contractile and Ca2+ transient responses to insulin during simulated ischemia/reperfusion (I/R) and furtherinvestigated the role of protein kinase B (Akt) in the insulin- induced inotropic effect. Ventricular myocytes were enzymatically isolated from adult Sprague-Dawley rats and perfused with Tyrode solution while electrically field-stimulated. Simulated I/R was induced by perfusing the cells with chemical anoxic solution including sodium cyanide-sodium lactate for 15 min followed by reperfusion with normal oxygenated Tyrode solution with or without insulin. It is found that insulin only at concentration as high as 10 IU/L could increase cell shortening (16±5%, P < 0.05) in normal myocytes, whereas it concentration-dependently (0.01-10 IU/L) increased the contraction,the velocity of shortening/releng- theningand Ca2+ transient in I/R myocytes. In addition, insulin treatment (1 IU/L) increased Akt phosphorylation of I/R cardiomyocytes by 2.4-fold compared with that of the control (P < 0.01). Most importantly, pretreatment with LY 294002, a specific inhibitor of phosphatidylinositol 3′-kinase (PI3-kinase), significantly inhibited both Akt phosphorylation and the positive inotropic response to insulin in the I/R cardiomyocytes. These results suggest that insulin exerts direct positive inotropic effect by increasing Ca2+ transient of cardiomyocytes, which is enhanced in the pathological condition of I/R. Akt activation plays an important role in the insulin-induced improvement of myocyte contractile function following I/R.

  3. Pentamidine rescues contractility and rhythmicity in a Drosophila model of myotonic dystrophy heart dysfunction.

    Science.gov (United States)

    Chakraborty, Mouli; Selma-Soriano, Estela; Magny, Emile; Couso, Juan Pablo; Pérez-Alonso, Manuel; Charlet-Berguerand, Nicolas; Artero, Ruben; Llamusi, Beatriz

    2015-12-01

    Up to 80% of individuals with myotonic dystrophy type 1 (DM1) will develop cardiac abnormalities at some point during the progression of their disease, the most common of which is heart blockage of varying degrees. Such blockage is characterized by conduction defects and supraventricular and ventricular tachycardia, and carries a high risk of sudden cardiac death. Despite its importance, very few animal model studies have focused on the heart dysfunction in DM1. Here, we describe the characterization of the heart phenotype in a Drosophila model expressing pure expanded CUG repeats under the control of the cardiomyocyte-specific driver GMH5-Gal4. Morphologically, expression of 250 CUG repeats caused abnormalities in the parallel alignment of the spiral myofibrils in dissected fly hearts, as revealed by phalloidin staining. Moreover, combined immunofluorescence and in situ hybridization of Muscleblind and CUG repeats, respectively, confirmed detectable ribonuclear foci and Muscleblind sequestration, characteristic features of DM1, exclusively in flies expressing the expanded CTG repeats. Similarly to what has been reported in humans with DM1, heart-specific expression of toxic RNA resulted in reduced survival, increased arrhythmia, altered diastolic and systolic function, reduced heart tube diameters and reduced contractility in the model flies. As a proof of concept that the fly heart model can be used for in vivo testing of promising therapeutic compounds, we fed flies with pentamidine, a compound previously described to improve DM1 phenotypes. Pentamidine not only released Muscleblind from the CUG RNA repeats and reduced ribonuclear formation in the Drosophila heart, but also rescued heart arrhythmicity and contractility, and improved fly survival in animals expressing 250 CUG repeats.

  4. Right atrial contractile dynamics are impaired in patients with postcapillary pulmonary hypertension

    Science.gov (United States)

    Bening, Constanze; Leyh, Rainer

    2016-01-01

    Left ventricular (LV) dysfunction in conjunction with postcapillary pulmonary hypertension (PH) is frequently associated with right ventricular (RV) dysfunction, determining the patient prognosis. Compensatory mechanisms for RV dysfunction have not been previously evaluated in detail. Since calcium dependent right atrial (RA) dynamics are a surrogate for RA contractile properties, the present study examined the calcium dependency of RA tissue obtained from patients with or without postcapillary PH. In total, 15 patients with PH (PH group; mean age, 70.7±7.2 years) and 10 patients without postcapillary PH (non-PH group; mean age, 55.7±11.8 years) who were scheduled to undergo elective left heart valve surgery were included in the current study. Calcium concentration (pCa; shown as the negative log10) against force curves were generated, while LV and RV function was evaluated by echocardiography. Echocardiography data revealed a significantly reduced LV function in the PH group, while the RV function was preserved in the two groups, precluding overt RV dysfunction. In the PH group, significantly reduced force values were detected at high pCa values when compared with the non-PH group force, indicating impaired RA function. Furthermore, reduced calcium sensitivity was observed (which was determined as the pCa at half maximal activation) in the PH group, and the presence of a compensatory mechanism for reduced force capacity was hypothesized. In conclusion, the preliminary results of the current study showed impaired RA contractile properties in postcapillary hypertension with preserved RV function. The diminished RA compensatory mechanisms may lead to accelerated RV dysfunction in the clinical course of postcapillary PH.

  5. Cardiac-specific catalase overexpression rescues anthrax lethal toxin-induced cardiac contractile dysfunction: role of oxidative stress and autophagy

    Directory of Open Access Journals (Sweden)

    Kandadi Machender R

    2012-11-01

    Full Text Available Abstract Background Lethal and edema toxins secreted by Bacillus anthracis during anthrax infection were found to incite serious cardiovascular complications. However, the underlying mechanisms in anthrax lethal toxin-induced cardiac anomalies remain unknown. This study was designed to evaluate the impact of antioxidant enzyme catalase in anthrax lethal toxin-induced cardiomyocyte contractile dysfunction. Methods Wild type (WT and cardiac-specific catalase overexpression mice were challenged with lethal toxin (2 μg/g, intraperotineally (i.p.. Cardiomyocyte contractile and intracellular Ca2+ properties were assessed 18 h later using an IonOptix edge-detection system. Proteasome function was assessed using chymotrypsin-like and caspase-like activities. GFP-LC3 puncta and Western blot analysis were used to evaluate autophagy and protein ubiquitination. Results Lethal toxin exposure suppressed cardiomyocyte contractile function (suppressed peak shortening, maximal velocity of shortening/re-lengthening, prolonged duration of shortening/re-lengthening, and impaired intracellular Ca2+ handling, the effects of which were alleviated by catalase. In addition, lethal toxin triggered autophagy, mitochondrial and ubiquitin-proteasome defects, the effects of which were mitigated by catalase. Pretreatment of cardiomyocytes from catalase mice with the autophagy inducer rapamycin significantly attenuated or ablated catalase-offered protection against lethal toxin-induced cardiomyocyte dysfunction. On the other hand, the autophagy inhibitor 3-MA ablated or significantly attenuated lethal toxin-induced cardiomyocyte contractile anomalies. Conclusions Our results suggest that catalase is protective against anthrax lethal toxin-induced cardiomyocyte contractile and intracellular Ca2+ anomalies, possibly through regulation of autophagy and mitochondrial function.

  6. Parasympathetic neurons in the cranial medial ventricular fat pad on the dog heart selectively decrease ventricular contractility.

    Science.gov (United States)

    Dickerson, L W; Rodak, D J; Fleming, T J; Gatti, P J; Massari, V J; McKenzie, J C; Gillis, R A

    1998-05-28

    We hypothesized that selective control of ventricular contractility might be mediated by postganglionic parasympathetic neurons in the cranial medial ventricular (CMV) ganglion plexus located in a fat pad at the base of the aorta. Sinus rate, atrioventricular (AV) conduction (ventricular rate during atrial pacing), and left ventricular contractile force (LV dP/dt during right ventricular pacing) were measured in eight chloralose-anesthetized dogs both before and during bilateral cervical vagus stimulation (20-30 V, 0.5 ms pulses, 15-20 Hz). Seven of these dogs were tested under beta-adrenergic blockade (propranolol, 0.8 mg kg(-1) i.v.). Control responses included sinus node bradycardia or arrest during spontaneous rhythm, high grade AV block or complete heart block, and a 30% decrease in contractility from 2118 +/- 186 to 1526 +/- 187 mm Hg s(-1) (P 0.05) decrease in contractility but still elicited the same degree of sinus bradycardia and AV block (N = 8, P < 0.05). Five dogs were re-tested 3 h after trimethaphan fat pad injection, at which time blockade of vagally-induced negative inotropy was partially reversed, as vagal stimulation decreased LV dP/dt by 19%. The same dose of trimethaphan given either locally into other fat pads (PVFP or IVC-ILA) or systemically (i.v.) had no effect on vagally-induced negative inotropy. Thus, parasympathetic ganglia located in the CMV fat pad mediated a decrease in ventricular contractility during vagal stimulation. Blockade of the CMV fat pad had no effect on vagally-mediated slowing of sinus rate or AV conduction.

  7. Protective effects of anisodamine on cigarette smoke extract-induced airway smooth muscle cell proliferation and tracheal contractility

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Guang-Ni; Yang, Kai; Xu, Zu-Peng; Zhu, Liang; Hou, Li-Na; Qi, Hong; Chen, Hong-Zhuan, E-mail: hongzhuan_chen@hotmail.com; Cui, Yong-Yao, E-mail: yongyaocui@yahoo.com.cn

    2012-07-01

    Anisodamine, an antagonist of muscarinic acetylcholine receptors (mAChRs), has been used therapeutically to improve smooth muscle function, including microvascular, intestinal and airway spasms. Our previous studies have revealed that airway hyper-reactivity could be prevented by anisodamine. However, whether anisodamine prevents smoking-induced airway smooth muscle (ASM) cell proliferation remained unclear. In this study, a primary culture of rat ASM cells was used to evaluate an ASM phenotype through the ability of the cells to proliferate and express contractile proteins in response to cigarette smoke extract (CSE) and intervention of anisodamine. Our results showed that CSE resulted in an increase in cyclin D1 expression concomitant with the G0/G1-to-S phase transition, and high expression of M2 and M3. Functional studies showed that tracheal hyper-contractility accompanied contractile marker α-SMA high-expression. These changes, which occur only after CSE stimulation, were prevented and reversed by anisodamine, and CSE-induced cyclin D1 expression was significantly inhibited by anisodamine and the specific inhibitor U0126, BAY11-7082 and LY294002. Thus, we concluded that the protective and reversal effects and mechanism of anisodamine on CSE-induced events might involve, at least partially, the ERK, Akt and NF-κB signaling pathways associated with cyclin D1 via mAChRs. Our study validated that anisodamine intervention on ASM cells may contribute to anti-remodeling properties other than bronchodilation. -- Highlights: ► CSE induces tracheal cell proliferation, hyper-contractility and α-SMA expression. ► Anisodamine reverses CSE-induced tracheal hyper-contractility and cell proliferation. ► ERK, PI3K, and NF-κB pathways and cyclin D1 contribute to the reversal effect.

  8. Effects of Crocetin Esters and Crocetin from Crocus sativus L. on Aortic Contractility in Rat Genetic Hypertension

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    Silvia Llorens

    2015-09-01

    Full Text Available Background: Endothelial dysfunction, characterized by an enhancement in vasoconstriction, is clearly associated with hypertension. Saffron (Crocus sativus L. bioactive compounds have been recognized to have hypotensive properties. Recently, we have reported that crocetin exhibits potent vasodilator effects on isolated aortic rings from hypertensive rats. In this work, we have aimed to analyze the anticontractile ability of crocetin or crocetin esters pool (crocins isolated from saffron. Thus, we have studied the effects of saffron carotenoids on endothelium-dependent and -independent regulation of smooth muscle contractility in genetic hypertension. Methods: We have measured the isometric responses of aortic segments with or without endothelium obtained from spontaneously hypertensive rats. The effects of carotenoids were studied by assessing the endothelial modulation of phenylephrine-induced contractions (10−9–10−5 M in the presence or absence of crocetin or crocins. The role of nitric oxide and prostanoids was analyzed by performing the experiments with L-NAME (NG-nitro-l-arginine methyl ester or indomethacin (both 10−5 M, respectively. Results: Crocetin, and to a minor extent crocins, diminished the maximum contractility of phenylephrine in intact rings, while crocins, but not crocetin, increased this contractility in de-endothelizated vessels. In the intact vessels, the effect of crocetin on contractility was unaffected by indomethacin but was abolished by L-NAME. However, crocetin but not crocins, lowered the already increased contractility caused by L-NAME. Conclusions: Saffron compounds, but especially crocetin have endothelium-dependent prorelaxing actions. Crocins have procontractile actions that take place via smooth muscle cell mechanisms. These results suggest that crocetin and crocins activate different mechanisms involved in the vasoconstriction pathway in hypertension.

  9. Morfologia e contratilidade em cardiomiócitos de ratos com baixo desempenho para o exercício físico Morphology and contractility in cardiomyocytes of rats with low exercise performance

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    Judson Fonseca Quintão Júnior

    2012-05-01

    Full Text Available FUNDAMENTO: A capacidade aeróbica é fundamental para o desempenho físico, e a baixa capacidade aeróbica está relacionada ao desencadeamento de diversas doenças cardiovasculares. OBJETIVO: Comparar a contratilidade e a morfologia de cardiomiócitos isolados de ratos com baixo desempenho e desempenho padrão para o exercício físico. MÉTODOS: Ratos Wistar, com 10 semanas de idade, foram submetidos a um protocolo de corrida em esteira até a fadiga, e foram divididos em dois grupos: Baixo Desempenho (BD e Desempenho Padrão (DP. Em seguida, após eutanásia, o coração foi removido rapidamente e, por meio de dissociação enzimática, os cardiomiócitos do ventrículo esquerdo foram isolados. O comprimento celular e dos sarcômeros e a largura dos cardiomiócitos foram medidos usando-se um sistema de detecção de bordas. Os cardiomiócitos isolados foram estimulados eletricamente a 1 e 3 Hz e a contração celular foi medida registrando-se a alteração do seu comprimento. RESULTADOS: O comprimento celular foi menor no grupo BD (157,2 ± 1,3µm; p BACKGROUND: Aerobic capacity is essential to physical performance, and low aerobic capacity is related to the triggering of various cardiovascular diseases. OBJECTIVE: To compare the morphology and contractility of isolated rat cardiomyocytes with low performance and standard performance for exercise. METHODS: Wistar rats with 10 weeks of age underwent a protocol of treadmill running to fatigue, and were divided into two groups: Low Performance (LP and Standard Performance (SP. Then, the animals were sacrificed, the heart was quickly removed and, by means of enzymatic dissociation, left ventricular cardiomyocytes were isolated. The cell and sarcomeres length and width of cardiomyocytes were measured using an edge detection system. The isolated cardiomyocytes were electrically stimulated at 1 and 3 Hz and cell contraction was measured by registering the change of their length. RESULTS: The cell

  10. Compuestos polifenólicos y capacidad antioxidante de especias típicas consumidas en México

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    Gilberto Mercado-Mercado

    2013-02-01

    Full Text Available Las especias son plantas aromáticas que han sido utilizadas ampliamente en México para preservar o sazonar diversos alimentos, aunque también se han usado como remedios herbolarios para curar algunas enfermedades. Las propiedades culinarias y medicinales de las especias han sido atribuidas a diversos componentes, entre ellos los fitoquímicos. De estos últimos, los compuestos polifenólicos han sido ampliamente estudiados por el efecto contra enfermedades crónico degenerativas que se les atribuye, posiblemente por su capacidad antioxidante. El estudio de la capacidad antioxidante de las especias mexicanas abre puertas a nuevas investigaciones sobre los posibles beneficios de estas especias en la salud humana. El presente trabajo presenta las principales investigaciones sobre los potenciales efectos beneficiosos de las especias tradicionales mexicanas en la salud humana.

  11. Representações de alunos sobre o domínio de capacidades matemáticas

    OpenAIRE

    Nogueira, Sofia; Tenreiro-Vieira, Celina; Cabrita, Isabel

    2010-01-01

    Reconhecendo a importância de promover as capacidades de resolução de problemas e de comunicação (em) matemática dos alunos, potenciando conexões entre as áreas de matemática e ciências físicas e naturais e articulando contextos de educação formal e não formal, desenvolveu-se um estudo com a finalidade de avaliar o impacto de situações de exploração matemática de módulos interactivos de ciências no desenvolvimento de capacidades matemáticas ligadas à resolução de problemas e à comunicação, po...

  12. Actividad física y capacidad funcional en el adulto mayor: el taekwondo como alternativa de mejoramiento

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    Pedro Carazo Vargas

    2001-01-01

    Full Text Available Con el envejecimiento se presenta una serie decambios de orden fisiológico, psicológico y social, capacesde reducir la capacidad para efectuar eficientemente lastareas de la vida diaria. En la presente revisión de litera-tura se realiza una descripción de estas modificaciones,así como una recopilación de los principales efectos de laactividad física sobre la capacidad funcional del adultomayor. Se analizan los primeros indicios que señalan altaekwondo como una importante alternativa para mejo-rar el desempeño en las tareas de la vida diaria y a la vezse recomiendan las principales pautas a seguir para in-vestigar la temática

  13. EFICACIA EN EL DESARROLLO DE CAPACIDADES TIC EN ESTUDIANTES DE EDUCACIÓN SECUNDARIA DE LIMA, PERÚ

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    Raúl Choque Larrauri

    2009-01-01

    Full Text Available Se evaluó la eficacia de la implementación de las Aulas de Innovación Pedagógica en el desarrollo de capacidades en Tecnologías de la Información y la Comunicación (TIC, en los estudiantes de educación secundaria de Lima. La investigación fue cuasi experimental, con posprueba, con grupo de comparación. La población de estudio estuvo constituido por 1 141 estudiantes del 4to. y 5to. grado de educación secundaria de una red educativa de Lima. Se confirmó la hipótesis de que los estudiantes desarrollaron las capacidades TIC de adquisición de la información, trabajo en equipo y el desarrollo de estrategias de aprendizaje con TIC.

  14. Capacidades Estatais no Programa Bolsa Família: O Desafio de Consolidação do Sistema Único de Assistência Social

    OpenAIRE

    Diogo R. Coutinho

    2013-01-01

    Por meio de uma abordagem centrada na análise de arranjos político-institucionais criados para implementar políticas de desenvolvimento no contexto democrático pós-1988, este trabalho utiliza as categorias de capacidades técnico-administrativas (associadas à dimensão de efetividade) e capacidades políticas (associadas à dimensão de legitimidade) para descrever o Programa Bolsa Família (PBF) em sua interação com o campo da assistência social. Discute como se relacionam tais capacidades no plan...

  15. Las nuevas tecnologías de la información Especial referencia a las empresas con capacidad de aprendizaje (Learning Organizations)

    OpenAIRE

    Jeremias Dutschke, Georg Michaez

    2006-01-01

    El objetivo de nuestro estudio es validar la hipótesis fundamental de que las organizaciones con más capacidad de aprendizaje utilizan el Internet, Intranet y Correo Electrónico, más tiempo y para más funciones, que las organizaciones con menos capacidad de aprendizaje. Basado en la Teoría de los Recursos y Capacidades (Pfeffer y Salancik, 1978) y en el Mo delo de Aprendizaje de Senge (1990), utilizando la análisis de correlaciones y el test de hipótesis, se intentará validar la hipótesis fun...

  16. APRENDIZAJE Y ACUMULACIÓN DE CAPACIDADES TECNOLÓGICAS EN UN GRUPO DEL SECTOR SIDERÚRGICO

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    Rodrigo Ortega Rangel

    2005-12-01

    Full Text Available El aprendizaje y la acumulación de capacidades tecnológicas son unos de los rasgos que integran la sociedad del conocimiento actual. Por ello son parte fundamental de la competitividad entre países, regiones y empresas. El aprendizaje y la acumulación de capacidadesimplican un proceso de desarrollo de capacidades internas que se construyen a partir de esfuerzos propios y de la experiencia y conocimientos disponibles desarrollados por la propia empresa u otras instituciones para generar innovaciones;son, por lo tanto, elementos fundamentales de la competitividad.La regularidad con la que una empresa incorpora mejoras radicales o incrementales en sus productos, procesos o esquemas organizacionales es factor decisivo para el crecimiento de su productividad. Este trabajo analiza el proceso de innovación desde una perspectiva interna, para elucidar la forma en que un grupo industrial del sector siderúrgico desarrolla sus capacidades tecnológicas a través del ejercicio de sus funciones técnicas de inversión, producción y soporte. “Los procesos de aprendizaje comprenden el aprendizaje por la práctica (aumentar por ejemplo, la eficiencia de las operaciones de producción, el aprendizaje por el uso (por ejemplo, utilizar más eficientemente los equipos complejos, el aprendizaje por interacción (asociando usuarios y productores en una interacción en el desarrollo de nuevos productos, y hasta el aprendizaje por aprendizaje, donde la capacidad de las empresas en asimilar las innovaciones realizadas en otra parte depende de su experiencia en materia de aprendizaje, enriquecida por la I&D o por otras inversiones inmateriales”

  17. Capacidades y libertad. Una aproximación a la teoría de Amartya Sen

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    Cejudo Córdoba, Rafael

    2007-08-01

    Full Text Available This paper explains Amartya Sen’s capabilities approach as a way of unifying most of his social philosophy. Capabilites are defined as the opportunities to enjoy several ways of life, and they provide the notion of aggregate welfare used in Human Development Reports of the United Nations Development Programme. Besides, capabilities approach provides a theory of liberty that I have called freedom as capability. In this way, Sen’s researches on famines and development, social choice and rights converge in a notion of freedom which is consistent with cultural differences. This concept is nor the liberal one neither the liberty as non-domination of republicanism, and Sen makes use of it in his defence of social welfare policies.

    Este artículo expone el enfoque de las capacidades de Amartya Sen como elemento unificador de buena parte de su filosofía social. Las capacidades se definen como las oportunidades para llevar una u otra clase de vida, y mediante ellas se obtiene la noción de bienestar agregado utilizada en los Informes sobre Desarrollo Humano elaborados por el Programa de las Naciones Unidas para el Desarrollo. Al mismo tiempo, el enfoque de las capacidades proporciona una teoría de la libertad, que he denominado libertad como capacidad, mediante la cual los estudios de Sen sobre el hambre y el desarrollo, la elección social o los derechos convergen en una noción de libertad que aspira a superar las diferencias culturales. Este concepto ni es el liberal ni es tampoco la libertad como no-dominación del republicanismo, y mediante él Sen defiende la importancia de las políticas de bienestar social.

  18. Capacidades de detección de las herramientas de análisis de vulnerabilidades en aplicaciones web

    OpenAIRE

    Román Muñoz, Fernando; Sabido Cortés, Iván Israel; García Villalba, Luis Javier

    2014-01-01

    Debido al continuo incremento del número de vulnerabilidades en las aplicaciones Web, se han elaborado diversas clasificaciones para mantener organizadas estas vulnerabilidades, y también se han desarrollado herramientas para detectarlas. Hasta este momento, según nuestra información, no se ha realizado ningún estudio sobre las capacidades de estas herramientas en la detección de las vulnerabilidades presentes en las clasificaciones de vulnerabilidades. En este trabajo mapeamos y agrupamos la...

  19. TEORÍA DE LA MENTE EN NIÑOS PREESCOLARES: DIFERENCIAS ENTRE SEXOS Y CAPACIDAD DE MEMORIA DE TRABAJO

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    Michael Padilla-Mora

    2009-01-01

    Full Text Available La teoría de la mente refiere a la habilidad para predecir y explicar el comportamiento de los demás, haciendo referencia a sus estados mentales internos, y es considerada como un aspecto fundamental del desarrollo cognitivo durante los años preescolares. Por otra parte, la capacidad de memoria de trabajo es un sistema que permite mantener en mente un determinado número de representaciones de manera simultánea, y también constituye una habilidad central para el desarrollo cognitivo de la población preescolar. En esta investigación se analizan las relaciones entre el desarrollo de la teoría de la mente y la capacidad de memoria de trabajo en 60 niños y niñas preescolares de entre 5 y 7 años, enfatizando posibles diferencias asociadas con el sexo de los participantes. Para la evaluación de la teoría de la mente se utilizaron 6 pruebas de falsa-creencia, mientras la capacidad de memoria de trabajo fue evaluada por medio de 2 tareas de señalamiento autoordenado. Los resultados revelan diferencias entre los sexos en el desarrollo de la teoría de la mente, y descartan la asociación entre esa misma habilidad y la capacidad de memoria de trabajo. Estos hallazgos se discuten en el contexto del debate actual respecto al de sarrollo de la teoría de la mente y las diferencias entre los sexos en el desarrollo cognitivo.

  20. Alumnos con altas capacidades musicales en Educación Secundaria Obligatoria: una iniciativa de acción

    OpenAIRE

    Campo-Quiralte, Cristina

    2013-01-01

    La presente investigación tiene como objetivo conocer las principales características del alumnado con Necesidades Educativas Especiales, principalmente en aquellos que poseen Altas Capacidades Musicales. Para ello, se definen y elaboran las herramientas indispensables confeccionando medidas de atención personalizadas mediante el desarrollo de materiales y recursos específicos, destacando el papel y actuación de la familia que resulta indispensable para llevar a cabo una educación satisfac...

  1. Alterações histoquímicas das glicosaminoglicanas na cérvice uterina no final da prenhez da rata albina após ministração local de hialuronidase Histochemical changes of the glycosaminoglycans in the uterine cervix of pregnant rats after local injection of hyaluronidase

    Directory of Open Access Journals (Sweden)

    Viviane Almeida de Alcântara Lopes

    2008-07-01

    Full Text Available OBJETIVO: estudar as alterações histoquímicas relacionadas às glicosaminoglicanas da cérvice uterina da rata albina, após ministração local de hialuronidase no final da prenhez. MÉTODOS: dez ratas com teste de prenhez positivo foram distribuídas aleatoriamente em dois grupos, numericamente iguais. O Grupo Controle (Gc foi constituído pelas ratas que receberam 1 mL de água destilada, dose única, no 18º dia da prenhez, sob anestesia, ministrado na cérvice uterina. O Grupo Experimental (Gex constou de ratas que receberam, sob as mesmas condições do Gc, 0,02 mL de hialuronidase, diluído em 0,98 mL de água destilada (total de 1 mL. No 20º dia de prenhez, as ratas foram novamente anestesiadas e submetidas à dissecção, preparando-se a cérvice uterina para estudo histoquímico com coloração de alcian blue e seus bloqueios (pH=0,5, pH=2,5, metilação e saponificação. RESULTADOS: verificou-se na lâmina própria no Gc, reação fortemente positiva (+3 e, no Gex, reação negativa, na coloração de alcian blue no pH=0,5. Em pH=2,5 a coloração também se apresentou fortemente positiva (+4 no Gc e fracamente positiva (+1 no Gex. Após metilação, tanto o Gc quanto o Gex mostraram reação negativa após coloração de alcian blue no pH=2,5. Com a reação de metilação seguida de saponificação e na digestão enzimática em lâmina, a coloração da lâmina própria se mostrou negativa em ambos os grupos. CONCLUSÕES: há uma nítida predominância de glicosaminoglicanas sulfatadas no Gc em relação ao Gex e uma tênue quantidade de glicosaminoglicanas carboxiladas identificadas no Gex. As modificações evidenciadas na matriz extracelular sugerem que a hialuronidase injetada localmente na cérvix uterina promoveu alterações bioquímicas compatíveis com maturação cervical.PURPOSE: to study the histochemical changes related to the uterine cervix glycosaminoglycan of the albino female rat, after local ministration of

  2. Persistencia y capacidad predictiva de márgenes y rotaciones. un análisis empírico

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    Juan Monterrey

    2011-01-01

    Full Text Available En el presente trabajo abordamos el estudio empírico de la persistencia y capacidad predictiva de los componentes margen y rotación de la rentabilidad. A partir de una amplia muestra de compañías españolas, hemos documentado cómo la persistencia de la rotación es superior a la del margen, y cómo los componentes anormales de margen y rotación son menos persistentes que sus componentes sectoriales. Con relación a la capacidad predictiva, nuestros hallazgos confirman que el poder de predicción del margen es más elevado que el de la rotación, aunque su persistencia sea menor. Al separar los componentes sectorial y anormal de margen y rotación hemos comprobado cómo los componentes anormales muestran una capacidad predictiva superior a los componentes sectoriales. Los análisis complementarios muestran el distinto poder predictivo según el signo positivo o negativo de márgenes y rotaciones anormales, y según el signo del resultado, así como la robustez de nuestros hallazgos.

  3. Expressão da capacidade de empatia em bebês de 8 e 18 semanas

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    Kornilia Hatzinikolaou

    2006-04-01

    Full Text Available Este estudo investigou o padrão temporal e expressivo da capacidade de empatia em bebês de 8 e 18 semanas no contexto de interações face-face entre 90 duplas de mãe-bebê. As interações foram analisadas em tempo real e através de micro-análise. Alguns comportamentos infantis apresentaram maior probabilidade de fazerem parte do padrão expressivo da empatia do que outros. Ainda, o padrão expressivo se manifestou diferente em instâncias de empatia com emoções negativas e instâncias de empatia com emoções positivas comunicadas pela mãe. Em relação ao padrão temporal, observou-se que a manifestação da capacidade de empatia ocorreu dentro de um intervalo de tempo igual de ½ segundo antes e 1 segundo depois da mudança emocional da mãe. Os resultados indicam a necessidade de reavaliação das proposições tradicionais sobre as capacidades comunicativas precoces de bebês, e sugerem uma coerência entre os achados e as proposições teóricas contemporâneas na área da Psicologia Infantil.

  4. Capacidades, liderazgos y estrategias de gestión de organizaciones de la sociedad civil en zonas rurales

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    Juan Antonio Hernández Martínez

    2015-01-01

    Full Text Available Un aspecto por demás importante para nuestro país es cómo resolver el problema de pobreza en el medio rural. Al respecto, y por la experiencia en otros países, las organizaciones de la sociedad civil pueden ser aliadas importantes del Estado para contribuir al desarrollo, por los roles y capacidades que ejercen. El presente artículo se realizó a través de una investigación cualitativa de 6 organizaciones de la sociedad civil del Estado de México, analizando sus capacidades para implementar acciones de mejoramiento de las condiciones de vida de sus beneficiarios y beneficiarias. De los resultados obtenidos destacan como principales capacidades observadas el liderazgo y el compromiso de sus fundadoras, así como la estrategia de gestión implementada, definiendo esta última como el modelo metodológico utilizado para generar valor agregado en cada comunidad participante. Derechos Reservados © 2015 Universidad Nacional Autónoma de México, Facultad de Contaduría y Admi- nistración. Este es un artículo de acceso abierto distribuido bajo los términos de la Licencia Creative Commons CC BY-NC-ND 4.0.

  5. Capacidade antioxidante de hortaliças usualmente consumidas Antioxidant capacity of vegetables commonly consumed

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    Enayde de Almeida Melo

    2006-09-01

    Full Text Available Como objetivo de avaliar a capacidade antioxidante de 15 hortaliças comercializadas na Cidade do Recife, extratos metanólicos foram testados quanto a atividade antioxidante em sistema modelo beta-caroteno/ácido linoléico e a habilidade de seqüestrar o radical estável 1,1-difenil-2-picrilhidrazil (DPPH. Todas as hortaliças investigadas exibiram propriedade antioxidante, entretanto a ação foi diferenciada entre os vegetais. Os extratos metanólicos da couve folha, tomate, batata, couve-flor, repolho verde, espinafre e alface crespa, com percentual de inibição superior a 70%, foram os mais eficazes em seqüestrar o radical livre. Os extratos metanólicos da alface lisa, cebola branca e vagem apresentaram ação moderada (60-70% de inibição, enquanto que a cebola roxa, chuchu, pepino e cenoura exibiram a mais fraca capacidade de seqüestrar o radical DPPH. No sistema modelo beta-caroteno/ácido linoléico, os extratos metanólicos do espinafre e couve-folha exibiram a mais elevada atividade antioxidante (superior a 70%. Ação antioxidante moderada (60-70% foi exibida pelos extratos da alface lisa, cebola branca e couve-flor, enquanto que os do chuchu, cenoura, pepino, tomate e vagem, com atividade inferior a 60%, foram considerados com fraca ação antioxidante. As hortaliças testadas podem ser vistas como fontes dietéticas de antioxidantes que podem trazer benefícios à saúde, portanto o seu consumo deve ser estimulado.This study was carried out to determine the antioxidant capacity of 15 vegetables commonly consumed in Recife - PE, Brazil. Methanol extracts were screened for their antioxidant activity using two tests: DPPH free radical scavenging and beta-carotene/linoléico acid assay. All vegetables showed antioxidant properties however the action was differentiated among the kinds of vegetables. The methanol extracts of collard greens, tomatoes, potatoes, cauliflowers, green cabbage, spinach and lettuce "crespa" had the

  6. Capacidade materna de cuidar e desnutrição infantil

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    Carvalhaes Maria Antonieta de BL

    2002-01-01

    Full Text Available OBJETIVOS: Identificar e medir a magnitude do risco de desnutrição associada a fatores determinantes da capacidade materna de cuidado infantil: estrutura familiar, escolaridade, trabalho, saúde física e saúde mental maternas. MÉTODOS: Delineou-se um estudo de casos e controles. Foram selecionados 101 casos (crianças com peso/idade abaixo do percentil 5 e 200 controles (crianças com peso/idade acima do percentil 25 mediante inquéritos antropométricos realizados durante três "Dias Nacionais de Vacinação", em 1996 e 1997. Os dados foram obtidos em entrevistas realizadas nos domicílios com as mães das crianças. Para detectar o efeito-líquido de cada fator em estudo, realizou-se análise de regressão logística multivariada e hierarquizada. Tais fatores e as possíveis variáveis de controle foram agrupados em blocos, ordenados segundo a precedência com que influiriam sobre o estado nutricional infantil. Adotaram-se p<0,20 para seleção das variáveis de controle (mediante análise univariada e p<0,05 para identificação de associação estatisticamente significativa entre fatores de estudo e desnutrição infantil. RESULTADOS: Foram identificados como fatores de risco de desnutrição: (a estrutura familiar adversa indicada pela ausência de companheiro ("odds ratio" [OR] = 2,2; IC95%, 1,1-4,5; (b internação materna durante a gravidez (OR=3,5; IC95%, 1,6-7,7; (c precária saúde mental materna expressa pela presença de três a quatro sintomas de depressão (OR=3,1; IC95%, 0,9-10,3; (d fatores de estresse familiar, no caso, indícios de alcoolismo em pelo menos um membro da família (OR=2,1; IC95%, 1,2-3,9. A idade da criança no início/retorno da mãe ao trabalho também se associou de modo independente à presença de desnutrição, porém os efeitos variaram: retorno precoce (criança com menos de quatro meses não significou risco ou proteção; volta da mãe ao trabalho quando a criança tinha entre quatro meses e 12

  7. Capacidade materna de cuidar e desnutrição infantil

    Directory of Open Access Journals (Sweden)

    Maria Antonieta de BL Carvalhaes

    2002-04-01

    Full Text Available OBJETIVOS: Identificar e medir a magnitude do risco de desnutrição associada a fatores determinantes da capacidade materna de cuidado infantil: estrutura familiar, escolaridade, trabalho, saúde física e saúde mental maternas. MÉTODOS: Delineou-se um estudo de casos e controles. Foram selecionados 101 casos (crianças com peso/idade abaixo do percentil 5 e 200 controles (crianças com peso/idade acima do percentil 25 mediante inquéritos antropométricos realizados durante três "Dias Nacionais de Vacinação", em 1996 e 1997. Os dados foram obtidos em entrevistas realizadas nos domicílios com as mães das crianças. Para detectar o efeito-líquido de cada fator em estudo, realizou-se análise de regressão logística multivariada e hierarquizada. Tais fatores e as possíveis variáveis de controle foram agrupados em blocos, ordenados segundo a precedência com que influiriam sobre o estado nutricional infantil. Adotaram-se p<0,20 para seleção das variáveis de controle (mediante análise univariada e p<0,05 para identificação de associação estatisticamente significativa entre fatores de estudo e desnutrição infantil. RESULTADOS: Foram identificados como fatores de risco de desnutrição: (a estrutura familiar adversa indicada pela ausência de companheiro ("odds ratio" [OR] = 2,2; IC95%, 1,1-4,5; (b internação materna durante a gravidez (OR=3,5; IC95%, 1,6-7,7; (c precária saúde mental materna expressa pela presença de três a quatro sintomas de depressão (OR=3,1; IC95%, 0,9-10,3; (d fatores de estresse familiar, no caso, indícios de alcoolismo em pelo menos um membro da família (OR=2,1; IC95%, 1,2-3,9. A idade da criança no início/retorno da mãe ao trabalho também se associou de modo independente à presença de desnutrição, porém os efeitos variaram: retorno precoce (criança com menos de quatro meses não significou risco ou proteção; volta da mãe ao trabalho quando a criança tinha entre quatro meses e 12

  8. Brote del virus ISA: crisis ambiental y capacidad de la institucionalidad ambiental para manejar el conflicto

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    Beatriz Bustos

    2012-09-01

    Full Text Available La industria salmonera chilena vivió recientemente una crisis de magnitud a partir de la aparición del virus ISA. El artículo examina esta situación, concentrándose en el papel que desempeña la ciencia en las soluciones políticas propuestas, como caso para discutir la capacidad de los mecanismos de gobernanza ambiental neoliberal para solucionar crisis ambientales y económicas. La pregunta que guía el trabajo es: ¿cuál fue el rol de la ciencia en la política ambiental para la industria? El argumento promovido es que la crisis representa un momento de reestructuración de la relación sociedad-naturaleza, en el cual se redefinieron mecanismos de propiedad, control y acceso a recursos naturales, pero en el que, pese al discurso neoliberal de confianza en los expertos y la ciencia como elementos de toma de decisiones, la información científica tuvo escasa relevancia.The Chilean salmon industry recently experienced a crisis due to an outbreak of the ISA virus. The article examines the crisis focusing on the role of science in the policy solutions proposed, to discuss the real capacity of neoliberal environmental governance mechanisms to solve environmental and economic crisis. The question guiding this research is, which was the role of science in environmental policy createdfor the salmon industry? The argument is that the crisis represents a reestructuring of the relationship between society and nature through the redefinition of property rights, control and access to natural resources, but in which, in spite of a neoliberal discourse of trust in experts and science as elements of decision making, scientific information had little relevance.

  9. Confiabilidade teste-reteste do Indice de Capacidade para o Trabalho (ICT em trabalhadores de enfermagem

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    Sergio Henrique Almeida da Silva Junior

    2013-03-01

    Full Text Available Este artigo avalia a confiabilidade teste-reteste do Índice de Capacidade para o Trabalho (ICT em trabalhadores de enfermagem. Foi aplicado questionário autopreenchível duas vezes a um grupo de 80 trabalhadores de enfermagem (enfermeiros, técnicos e auxiliares de enfermagem de um hospital público no Município do Rio de Janeiro, com intervalo entre sete e quinze dias. A confiabilidade foi estimada pela estatística kappa ponderada quadrática, pelo coeficiente de correlação intraclasse (CCI e pelo gráfico de Bland e Altman. Dos participantes, 81% eram mulheres e com idade variando de 22 a 67 anos (média = 39,1; DP = 10,8anos e 36,3% tinham ensino superior completo. O escore global do ICT apresentou CCI = 0,79 (IC95% 0,67 a 0,86 e kappa = 0,69 (IC95% 0,50 a 0,80 para o ICT categórico (classificado em baixo, moderado, bom e ótimo. O kappa dos itens do ICT variou de 0,39 a 0,82 e o gráfico de Bland e Altman não mostrou um padrão sistemático. A concordância entre as medidas de teste-reteste indica grau aceitável de confiabilidade, sugerindo adequação do processo de aferição entre trabalhadores de enfermagem.

  10. Capacidade antioxidante e qualidade pós-colheita de abacate 'Fuerte'

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    Rogério Lopes Vieites

    2012-06-01

    Full Text Available A capacidade antioxidante e a qualidade pós-colheita do abacate 'Fuerte' foram avaliadas. Os frutos foram mantidos sob temperatura ambiente (24 ± 1 ºC e sob refrigeração em 10 ± 1 ºC e 90±5% UR e avaliados durante 15 dias. Determinaram-se a perda de massa e a taxa respiratória. As características físico-químicas avaliadas foram acidez total titulável (AT, sólidos solúveis (SS, ratio, pH, firmeza, atividade da enzima polifenoloxidase (PPO, cor (L, a* e b*, fenólicos totais e atividade antioxidante (AA por DPPH·. Nas duas condições de armazenamento, o pico respiratório ocorreu no 9º dia.Os frutos mantidos sob temperatura refrigerada apresentaram menor perda de massa e maior firmeza em relação àqueles em temperatura ambiente. O comportamento respiratório refletiu na redução dos valores de AT e no conteúdo de SS que diminuíram a partir do pico de respiração. Os valores de pH aumentaram como consequência da diminuição da AT. Os valores de luminosidade mantiveram-se elevados, observando-se diminuição do componente de cor verde na polpa com o armazenamento. A atividade da PPO diminuiu com o armazenamento. Os valores de AA variaram de 17,6 a 68,7%. O conteúdo de fenólicos totais diminuiu após o pico respiratório, e valores crescentes de AA foram observados mesmo após o 9º dia.

  11. Avaliação da capacidade funcional de crianças com paralisia cerebral

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    Carla Ciceri Cesa

    2014-08-01

    Full Text Available Objetivo descrever a capacidade funcional de crianças com paralisia cerebral que realizavam atendimentos de Fisioterapia e Fisioterapia e Fonoaudiologia. Métodos estudo descritivo, de caráter transversal, composto por 14 crianças com PC do tipo quadriplegia espástica (6 realizavam Fisioterapia e 8 Fisioterapia e Fonoaudiologia. Foram utilizados para avaliação o Inventário de Avaliação Pediátrica de Incapacidade (PEDI e o Sistema de Classificação da Função Motora Grossa (GMFCS. As associações entre as variáveis categóricas foram analisadas por meio do teste exato de Fisher. Comparações entre médias foram realizadas utilizando-se o teste t de Student. Resultados não se obteve melhora estatisticamente significante nas áreas de autocuidado, mobilidade e função social entre os dois grupos nos domínios de habilidade funcional e assistência ao cuidador. Conclusão as crianças do grupo Fisioterapia tiveram escores funcionais mais elevados que as do grupo Fisioterapia associado à Fonoaudiologia, mas não houve diferença estatisticamente significante entre os grupos. Isso se deu, provavelmente, devido ao reduzido número de participantes, à diversidade de quadros clínicos que a patologia pode apresentar e a possíveis diferenças na intervenção fisioterapêutica realizada nos dois estados, que possuem situações socioeconômicas bem diversas.

  12. Efecto de las estrategias competitivas y los recursos y capacidades orientados al mercado sobre el crecimiento de las organizaciones

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    Carmen Berenice Ynzunza Cortés

    2013-01-01

    Full Text Available Este estudio analiza las relaciones entre las fuerzas de mercado, las estrategias competitivas, los recursos y capacidades orientados al mercado, así como el desempeño organizacional. La investigación se realizó en Pyme del sector industrial del estado de Querétaro, con un muestreo de conveniencia no probabilístico; asimismo, se diseñó un modelo estructural para probar las relaciones entre las variables, las cuales se analizaron con el software AMOS. El tamaño de muestra alcanzado fue de 116 y la recopilación de información se hizo mediante entrevistas. Las fuerzas de mercado, la estrategia competitiva y la orientación a mercado fueron medidas con las escalas de Kohly y Javorsky (1990, Segev (1987 y Narver y Slater (1990. Los ítems para el desempeño organizacional y los recursos de tecnología e innovación fueron diseñados. Los hallazgos prueban que las fuerzas de mercado tienen un impacto grande en la estrategia competitiva, el cual no es significativo sobre los recursos y capacidades, y es negativo respecto al desempeño, medido por el crecimiento organizacional. El efecto de la estrategia competitiva ha sido significativo sobre los recursos y capacidades de orientación a mercado, tecnología e innovación y no significativo respecto al desempeño. Estos recursos y capacidades influyen de manera significativa en el desempeño organizacional. Los resultados de este estudio enfatizan la implementación de estrategias prospectoras y analizadoras, que crean recursos y capacidades que den valor, con beneficios económicos para las empresas, así como los de orientación a mercado, tecnología e innovación. Estos hallazgos son consistentes con los encontrados en otras investigaciones realizadas en otros países.

  13. Vasodilatory effects of nifedipine, methoxyverapamil, and sodium nitroprusside on contractile responses of the ewe uterine artery at term pregnancy.

    Science.gov (United States)

    Isla, M; Dyer, D C

    1990-10-01

    The differential inhibitory effect of the vasodilators on contractile responses to norepinephrine, serotonin, and potassium on isolated uterine artery ring segments from pregnant ewes within 2 weeks of term was quantified and correlated with the source of Ca++ for the vasoconstrictors producing the smooth muscle contraction. The contraction evoked by the vasoconstrictors was dependent on extracellular Ca++ and in agonist-induced contractions also on an intracellular pool of Ca++. Nifedipine effectively inhibited K(+)-induced (90 mmol/L) contractions (antagonist concentration to reduce the maximum contractile effect to the agonist to 50%, 1.95 +/- 0.9 x 10(-8) mol/L), whereas it was relatively ineffective in blocking norepinephrine-induced (10(-5) mol/L) or serotonin-induced (10(-5) mol/L) vasoconstriction (antagonist concentration to reduce the maximum contractile effect to the agonist to 50%, 1.38 +/- 0.4 x 10(-4) mol/L and 2.04 +/- 0.4 x 10(-5) mol/L, respectively). Methoxyverapamil (D-600) strongly inhibited serotonin-induced contractions (antagonist concentration to reduce the maximum contractile effect to the agonist to 50%, 3.3 +/- 0.3 x 10(-7) mol/L). The phasic rather than the tonic components of the serotonin- and norepinephrine-induced contractions were more effectively inhibited by D-600 (p less than 0.05). Sodium nitroprusside preferentially blocked (p less than 0.05) the sustained tonic components of norepinephrine- and serotonin-induced vasoconstrictions (antagonist concentration to reduce the maximum contractile effect to the agonist to 50%, 7.1 +/- 0.4 x 10(-7) mol/L and 8.2 +/- 0.6 x 10(-7) mol/L, respectively). On the basis of these findings it is concluded that D-600 and sodium nitroprusside are more effective than nifedipine in blocking contractile responses due to receptor stimulation, and therefore might be more effective in the treatment of hypertensive emergencies in which these amines might be implicated. PMID:2220945

  14. Sensibilidad a la temperatura de los fenoles totales y de la capacidad antioxidante y antirradicalaria de los hongos comestibles Clitocybe geotropa, Hygrophorus gliocyclus y Clitocybe alexandrii

    OpenAIRE

    Tufano, Aniello

    2013-01-01

    Medida de los fenoles totales, la capacidad antioxidante y antirradicalaria de las setas comestibles Clitocybe geotropa, Hygrophorus gliocyclus, Clitocybe alexandrii, mediante los métodos Folin–Ciocalteau, CUPRAC y DPPH y estudio de la degradación a diferentes temperaturas y tiempos de los fenoles totales y pérdida de la capacidad antioxidante y antirradicalaria de, Clitocybe geotropa, Hygrophorus gliocyclus, Clitocybe alexandrii, mediante los métodos Folin–Ciocalteau, CUPRA...

  15. Itraconazole decreases left ventricular contractility in isolated rabbit heart: Mechanism of action

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Yusheng, E-mail: yqu@amgen.com [Toxicology Science, Amgen, Inc, One Amgen Center Drive, Thousand Oaks, CA 91320 (United States); Fang, Mei; Gao, BaoXi; Amouzadeh, Hamid R. [Toxicology Science, Amgen, Inc, One Amgen Center Drive, Thousand Oaks, CA 91320 (United States); Li, Nianyu; Narayanan, Padma [Discovery Toxicology, Amgen, Inc, One Amgen Center Drive, Thousand Oaks, CA 91320 (United States); Acton, Paul; Lawrence, Jeff; Vargas, Hugo M. [Toxicology Science, Amgen, Inc, One Amgen Center Drive, Thousand Oaks, CA 91320 (United States)

    2013-04-15

    Itraconazole (ITZ) is an approved antifungal agent that carries a “black box warning” in its label regarding a risk of negative cardiac inotropy based on clinical findings. Since the mechanism of the negative inotropic effect is unknown, we performed a variety of preclinical and mechanistic studies to explore the pharmacological profile of ITZ and understand the negative inotropic mechanism. ITZ was evaluated in: (1) an isolated rabbit heart (IRH) preparation using Langendorff retrograde perfusion; (2) ion channel studies; (3) a rat heart mitochondrial function profiling screen; (4) a mitochondrial membrane potential (MMP) assay; (5) in vitro pharmacology profiling assays (148 receptors, ion channels, transporters, and enzymes); and (6) a kinase selectivity panel (451 kinases). In the IRH, ITZ decreased cardiac contractility (> 30%) at 0.3 μM, with increasing effect at higher concentrations, which indicated a direct negative inotropic effect upon the heart. It also decreased heart rate and coronary flow (≥ 1 μM) and prolonged PR/QRS intervals (3 μM). In mechanistic studies, ITZ inhibited the cardiac NaV channel (IC{sub 50}: 4.2 μM) and was devoid of any functional inhibitory effect at the remaining pharmacological targets. Lastly, ITZ did not affect MMP, nor interfere with mitochondrial enzymes or processes involved with fuel substrate utilization or energy formation. Overall, the cardiovascular and mechanistic data suggest that ITZ-induced negative inotropy is a direct effect on the heart, in addition, the potential involvement of mitochondria function and L-type Ca{sup 2+} channels are eliminated. The exact mechanism underlying the negative inotropy is uncertain, and requires further study. - Highlights: ► Effect of itraconazole (ITZ) was assessed in the isolated rabbit heart (IRH) assay. ► ITZ decreased ventricular contractility in IRH, indicating a direct effect. ► IC{sub 50} of ITZ on L-type I{sub Ca} was greater than 30 μM, on I{sub Na} was 4

  16. Dietary fat influences the expression of contractile and metabolic genes in rat skeletal muscle.

    Directory of Open Access Journals (Sweden)

    Wataru Mizunoya

    Full Text Available Dietary fat plays a major role in obesity, lipid metabolism, and cardiovascular diseases. To determine whether the intake of different types of dietary fats affect the muscle fiber types that govern the metabolic and contractile properties of the skeletal muscle, we fed male Wistar rats with a 15% fat diet derived from different fat sources. Diets composed of soybean oil (n-6 polyunsaturated fatty acids (PUFA-rich, fish oil (n-3 PUFA-rich, or lard (low in PUFAs were administered to the rats for 4 weeks. Myosin heavy chain (MyHC isoforms were used as biomarkers to delineate the skeletal muscle fiber types. Compared with soybean oil intake, fish oil intake showed significantly lower levels of the fast-type MyHC2B and higher levels of the intermediate-type MyHC2X composition in the extensor digitorum longus (EDL muscle, which is a fast-type dominant muscle. Concomitantly, MyHC2X mRNA levels in fish oil-fed rats were significantly higher than those observed in the soybean oil-fed rats. The MyHC isoform composition in the lard-fed rats was an intermediate between that of the fish oil and soybean oil-fed rats. Mitochondrial uncoupling protein 3, pyruvate dehydrogenase kinase 4, and porin mRNA showed significantly upregulated levels in the EDL of fish oil-fed rats compared to those observed in soybean oil-fed and lard-fed rats, implying an activation of oxidative metabolism. In contrast, no changes in the composition of MyHC isoforms was observed in the soleus muscle, which is a slow-type dominant muscle. Fatty acid composition in the serum and the muscle was significantly influenced by the type of dietary fat consumed. In conclusion, dietary fat affects the expression of genes related to the contractile and metabolic properties in the fast-type dominant skeletal muscle, where the activation of oxidative metabolism is more pronounced after fish oil intake than that after soybean oil intake.

  17. Modelling maternal obesity: the effects of a chronic high-fat, high-cholesterol diet on uterine expression of contractile-associated proteins and ex vivo contractile activity during labour in the rat.

    Science.gov (United States)

    Muir, Ronan; Ballan, Jean; Clifford, Bethan; McMullen, Sarah; Khan, Raheela; Shmygol, Anatoly; Quenby, Siobhan; Elmes, Matthew

    2016-02-01

    Maternal obesity is associated with prolonged and dysfunctional labour and emergency caesarean section, but the mechanisms are unknown. The present study investigated the effects of an adiposity-inducing high-fat, high-cholesterol (HFHC) diet on uterine contractile-associated protein (CAP) expression and ex vivo uterine contractility in term non-labouring (TNL) and term labouring (TL) rats. Female rats were fed either control chow (CON n=20) or HFHC (n=20) diet 6 weeks before conception and during pregnancy. On gestational day 21 (TNL) or day 22 (TL) CON and HFHC (n=10) rats were killed to determine plasma cholesterol, triacylglycerol and progesterone concentrations and collection of myometrium for contractility studies and expression of CAPs caveolin-1 (Cav-1), connexin-43 (CX-43) and it's phosphorylated form (pCX-43), oxytocin receptor (OXTR) and cyclooxygenase-2 (COX-2). HFHC feeding increased visceral fat (P≤0.001), plasma cholesterol (P≤0.001) and triacylglycerol (P=0.039) concentrations. Stage of labour effected uterine expression of CAV-1 (Pobesity. Uterine dose response to oxytocin was blunted during labour in HFHC rats with a log EC50 of -8.84 compared with -10.25 M in CON for integral activity (Pobese women.

  18. Capacidade funcional e fatores associados em idosos: estudo populacional Capacidade funcional y factores asociados en ancianos: estudio poblacional Functional capacity and associated factors in the elderly: a population study

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    Roberta Souza Freitas

    2012-01-01

    Full Text Available OBJETIVO: Analisar a associação do comprometimento da capacidade funcional com condições de saúde e fatores sociodemográficos e comportamentais entre idosos residentes em comunidade do interior do Nordeste brasileiro. MÉTODOS: Estudo transversal de base populacional realizado com 316 idosos residentes em Lafaiete Coutinho-BA. A capacidade funcional foi avaliada por escala hierárquica, verificando associação com condições de saúde e fatores sóciodemográficos e comportamentais pela técnica de regressão logística multinomial. RESULTADOS: A dependência nas atividades independentes da vida diária (AIVD foi associada ao grupo etário > 80 anos, uso de dois ou mais medicamentos e comprometimento cognitivo. A dependência nas atividades básicas da vida diária e AIVD foi associada ao grupo etário > 80 anos, falta de participação em atividades religiosas, hospitalização nos últimos 12 meses, comprometimento cognitivo e sobrepeso. CONCLUSÃO: Houve associação com comprometimento da capacidade funcional e condições de saúde e fatores sociodemográficos entre idosos residentes em comunidade no Nordeste brasileiro.OBJETIVO: Analizar la asociación del compromiso de la capacidad funcional con condiciones de salud y factores sociodemográficos y comportamentales entre ancianos residentes en una comunidad del interior del Noreste brasileño. MÉTODOS: Estudio transversal de base poblacional realizado con 316 ancianos residentes en Lafaiete Coutinho-BA. La capacidad funcional fue evaluada por una escala jerárquica, verificando asociación con condiciones de salud y factores sociodemográficos y comportamentales por la técnica de regresión logística multinomial. RESULTADOS: La dependencia en las atividades independentes de la vida diaria (AIVD fue asociada al grupo etáreo > 80 años, uso de dos o más medicamentos y compromiso cognitivo. La dependencia en las actividades básicas de la vida diária y AIVD fue asociada al grupo

  19. Usage of echocardiography with physical loads for diagnosis of myocardial contractile reserve of the left ventricle in athletes

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    Nekhanevich O.B.

    2014-09-01

    Full Text Available The work purpose was studying of myocardial contractile reserve of the left ventricle and cardiohemodynamics infringements character under the influence of physical loads in athletes with functional insufficiency of mitral valve according to stress-echocardiography. We examined 72 athletes the aged 9 to 40 years with functional mitral valve insufficiency and normal systolic function of the heart at rest by echo ECG data. Possibility of stress echocardiography with physical loads usage to diagnose decrease of myocardial contractile reserve of the heart left ventricle was proved. It was found that increase in hemodynamic load during physical exercise leads to the disruption of adaptation and manifestation of systolic dysfunction in athletes with I and II degrees of mitral valve regurgitation. This should be considered when constructing training-competitive loads among athletes in terms of prevention of acute physical overloading.

  20. Fenólicos totais e capacidade antioxidante in vitro de polpas de frutos tropicais

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    Luanne Morais Vieira

    2011-09-01

    Full Text Available O consumo de frutos e suas polpas tem sido muito recomendado por seu valor nutricional, alto teor de fibras, vitamina C e carotenoides. Trabalhos recentes têm apontado esses alimentos como fontes de compostos fenólicos com ação antioxidante, portanto sequestradores de radicais livres, com ação protetora contra o surgimento e/ou desenvolvimento de processos degenerativos que conduzem a doenças crônicas não transmissíveis. Devido à crescente comercialização e consumo de polpas de frutas no Brasil, especialmente na cidade de Teresina-Piauí, este trabalho selecionou um grupo de polpas de frutos de elevado consumo local para avaliação do teor de fenólicos totais e da atividade antioxidante in vitro pelo método de captura de radicais livres: DPPH (radical 1,1-diphenil-2-picrilhydrazil e ABTS (radical 2,2'azinobis(3-ethylbenzthiazoline-6-sulfonic acid. Os frutos selecionados foram: Acerola (Malpighia emarginata DC., Bacuri (Platonia insignis Mart., Cajá (Spondias mombin L., Caju (Anacardium occidentale, Goiaba(Psidium guajava e Tamarindo (Tamarindus indica L.. Os teores de fenólicos totais encontrados nas polpascongeladas destes frutos exibiram quantidades relevantes de polifenóis, destacando-se a polpa de acerola com 835,25 ± 32,44 e 449,63 ± 10,24 mg /100g nos extratos aquosos e hidroalcoólicos, respectivamente, seguido pela polpa de caju com 201,61 ± 19,15 e 165,07 ± 4,10 mg /100g. As polpas de bacuri e tamarindo foram as que apresentaram os menores teores de fenólicos totais. Com relação à atividade antioxidante in vitro, os melhores resultados foram encontrados para os extratos aquosos e hidroalcoólicos das polpas de acerola, caju e goiaba. A capacidade antioxidante destas polpas (EC50 em µg/mL variou de 24,42 a 413,36 e de 1,74 a 259,18 para os extratos aquosos e hidroalcoólicos, respectivamente. Utilizando o radical ABTS, a atividade antioxidante para essas mesmas polpas de frutas apresentou valores TEAC que

  1. Capacidad antiteratogénica del resveratrol en diabetes inducida por estreptozotocina en ratas

    Directory of Open Access Journals (Sweden)

    Ninna Leslie Trejo-González

    2015-07-01

    Full Text Available Objetivos. Evaluar la capacidad antihiperglucémica y antiteratogénica del resveratrol en ratas inducidas a diabetes por estreptozotocina. Materiales y métodos. Estudio de tipo experimental. Se tuvieron tres grupos, de cinco ratas Wistar preñadas cada uno, dos de los cuales fueron tratados el cuarto día de gestación con una dosis de estreptozotocina de 50 mg/kg, disuelta en tampón de citratos, y el otro fue considerado como control, y solo se le administró el tampón de citratos. A uno de los grupos inducidos con estreptozotocina se le administró resveratrol a dosis de 100 mg/kg durante los días 8 al 12 de gestación, cuando sucede la neurulación. Los fetos se obtuvieron el día 19 de gestación y se les realizó un análisis morfológico, y en el hígado fetal se determinó la actividad de las enzimas depuradoras de especies reactivas catalasa, superóxido dismutasa y glutatión peroxidasa. Resultados. La administración de resveratrol (DM+R revierte los parámetros a valores similares a los del grupo control. Las actividades de catalasa y de glutatión peroxidasa, se vieron incrementadas en el grupo tratado con resveratrol con respecto al grupo diabético, en cuanto a la frecuencia de malformaciones en el grupo control y en el grupo tratado con resveratrol no presentaron malformaciones, mientras que en las ratas con diabetes inducida, se encontró una elevada frecuencia de malformaciones. Conclusiones. El resveratrol muestra propiedades antiteratogénicas a través de la disminución del estrés oxidativo que se presenta a causa de la hiperglucemia materna

  2. Capacidad antiteratogénica del resveratrol en diabetes inducida por estreptozotocina en ratas

    Directory of Open Access Journals (Sweden)

    Ninna Leslie Trejo-González

    2015-09-01

    Full Text Available Objetivos. Evaluar la capacidad antihiperglucémica y antiteratogénica del resveratrol en ratas inducidas a diabetes por estreptozotocina. Materiales y métodos. Estudio de tipo experimental. Se tuvieron tres grupos, de cinco ratas Wistar preñadas cada uno, dos de los cuales fueron tratados el cuarto día de gestación con una dosis de estreptozotocina de 50 mg/kg, disuelta en tampón de citratos, y el otro fue considerado como control, y solo se le administró el tampón de citratos. A uno de los grupos inducidos con estreptozotocina se le administró resveratrol a dosis de 100 mg/kg durante los días 8 al 12 de gestación, cuando sucede la neurulación. Los fetos se obtuvieron el día 19 de gestación y se les realizó un análisis morfológico, y en el hígado fetal se determinó la actividad de las enzimas depuradoras de especies reactivas catalasa, superóxido dismutasa y glutatión peroxidasa. Resultados. La administración de resveratrol (DM+R revierte los parámetros a valores similares a los del grupo control. Las actividades de catalasa y de glutatión peroxidasa, se vieron incrementadas en el grupo tratado con resveratrol con respecto al grupo diabético, en cuanto a la frecuencia de malformaciones en el grupo control y en el grupo tratado con resveratrol no presentaron malformaciones, mientras que en las ratas con diabetes inducida, se encontró una elevada frecuencia de malformaciones. Conclusiones. El resveratrol muestra propiedades antiteratogénicas a través de la disminución del estrés oxidativo que se presenta a causa de la hiperglucemia materna

  3. [The effect of prostatilen on the contractile activity of the smooth-muscle cells of the blood vessels and bladder in cats].

    Science.gov (United States)

    al-Shchukri, S Kh; Barabanov, S V; Barabanova, V V; Bobkov, Iu A; Gorbachev, A G; Parastaeva, M M

    1996-07-01

    Prostatilene enhanced the functional activity of the bladder and blood vessels' smooth muscle cells. A possibility of activation of the smooth muscle cells contractility with prostatilene by a pharmaco-mechanical association, is discussed.

  4. THE EFFECT OF HYPOXIA ON ELECTRICAL AND CONTRACTILE PROPERTIES OF SMOOTH MUSCLES OF THE GUINEA PIG URETER

    Directory of Open Access Journals (Sweden)

    I. V. Kovalev

    2016-01-01

    Full Text Available Aim. The effect of hypoxia on the electrical and contractile activities of smooth muscles cells (SMCs of the guinea pig ureter was studied by the method of the double sucrose bridge.Materials and methods. This method allows registering simultaneously parameters of the action potential (AP and the contraction of SMCs, caused by an electrical stimulus.Results. It was found that lowering the oxygen content in the perfusion solution for 10 min resulted to an increase of electrical and contractile activity of ureteral SMCs. Addition of tetraethylammonium chloride (TEA, 5 mM – nonselective blocker of potassium membrane conductance – in hypoxic conditions causing an additional increase in the amplitude of the AP, duration of the AP plateau and the contractile responses of smooth muscles. Thus, the hypoxia decreased the potassium membrane conductance of ureteral SMCs. Inhibition of the effect of the α1 -adrenergic receptors agonist phenylephrine (PE, 10 mM on the electrical and contractile properties of SMCs in hypoxic condition indicate the involvement of the protein kinase C-dependent signaling system in effects of hypoxia. Pretreatment of ureteral smooth muscles with bumetanide (100 mM – selective inhibitor of Na+,K+,2Cl- - cotransporter (NKCC – caused a decrease of the activating effect of hypoxia on the SMCs of guinea pig ureter.Conclusion.Thus, the impact of hypoxia on the regulation of electrical activity and contractions of smooth muscles of guinea pig ureter may be due to changes in ion permeability of membranes SMCs and operation of ion-transporting systems. 

  5. Molecular mechanical differences between isoforms of contractile actin in the presence of isoforms of smooth muscle tropomyosin.

    OpenAIRE

    Lennart Hilbert; Genevieve Bates; Roman, Horia N.; Jenna L Blumenthal; Zitouni, Nedjma B.; Apolinary Sobieszek; Mackey, Michael C.; Anne-Marie Lauzon

    2013-01-01

    The proteins involved in smooth muscle's molecular contractile mechanism - the anti-parallel motion of actin and myosin filaments driven by myosin heads interacting with actin - are found as different isoforms. While their expression levels are altered in disease states, their relevance to the mechanical interaction of myosin with actin is not sufficiently understood. Here, we analyzed in vitro actin filament propulsion by smooth muscle myosin for [Formula: see text]-actin ([Formula: see text...

  6. Acute contractile recovery extent during biventricular pacing is not associated with follow-up in patients undergoing resynchronization

    OpenAIRE

    Federica DeVecchi; Emanuela Facchini; Anna Degiovanni; Chiara Sartori; Chiara Cavallino; Matteo Santagostino; Virginia Di Ruocco; Andrea Magnani; Eraldo Occhetta; Paolo Nicola Marino

    2016-01-01

    Background: It has been reported that contractility, as assessed using dobutamine infusion, is independently associated with reverse remodeling after CRT. Controversy, however, exists about the capacity of this approach to predict a long-term clinical response. This study's purpose was to assess whether long-term CRT clinical effects can be predicted according to acute inotropic response induced by biventricular stimulation (CRT on), as compared with AAI–VVI right stimulation pacing mode (CRT...

  7. Anthrax lethal toxin suppresses murine cardiomyocyte contractile function and intracellular Ca2+ handling via a NADPH oxidase-dependent mechanism.

    Directory of Open Access Journals (Sweden)

    Machender R Kandadi

    Full Text Available OBJECTIVES: Anthrax infection is associated with devastating cardiovascular sequelae, suggesting unfavorable cardiovascular effects of toxins originated from Bacillus anthracis namely lethal and edema toxins. This study was designed to examine the direct effect of lethal toxins on cardiomyocyte contractile and intracellular Ca(2+ properties. METHODS: Murine cardiomyocyte contractile function and intracellular Ca(2+ handling were evaluated including peak shortening (PS, maximal velocity of shortening/ relengthening (± dL/dt, time-to-PS (TPS, time-to-90% relengthening (TR(90, intracellular Ca(2+ rise measured as fura-2 fluorescent intensity (ΔFFI, and intracellular Ca(2+ decay rate. Stress signaling and Ca(2+ regulatory proteins were assessed using Western blot analysis. RESULTS: In vitro exposure to a lethal toxin (0.05-50 nM elicited a concentration-dependent depression on cardiomyocyte contractile and intracellular Ca(2+ properties (PS, ± dL/dt, ΔFFI, along with prolonged duration of contraction and intracellular Ca(2+ decay, the effects of which were nullified by the NADPH oxidase inhibitor apocynin. The lethal toxin significantly enhanced superoxide production and cell death, which were reversed by apocynin. In vivo lethal toxin exposure exerted similar time-dependent cardiomyocyte mechanical and intracellular Ca(2+ responses. Stress signaling cascades including MEK1/2, p38, ERK and JNK were unaffected by in vitro lethal toxins whereas they were significantly altered by in vivo lethal toxins. Ca(2+ regulatory proteins SERCA2a and phospholamban were also differentially regulated by in vitro and in vivo lethal toxins. Autophagy was drastically triggered although ER stress was minimally affected following lethal toxin exposure. CONCLUSIONS: Our findings indicate that lethal toxins directly compromised murine cardiomyocyte contractile function and intracellular Ca(2+ through a NADPH oxidase-dependent mechanism.

  8. Surfactant Proteins SP-A and SP-D Modulate Uterine Contractile Events in ULTR Myometrial Cell Line.

    Directory of Open Access Journals (Sweden)

    Georgios Sotiriadis

    Full Text Available Pulmonary surfactant proteins SP-A and SP-D are pattern recognition innate immune molecules. However, there is extrapulmonary existence, especially in the amniotic fluid and at the feto-maternal interface. There is sufficient evidence to suggest that SP-A and SP-D are involved in the initiation of labour. This is of great importance given that preterm birth is associated with increased mortality and morbidity. In this study, we investigated the effects of recombinant forms of SP-A and SP-D (rhSP-A and rhSP-D, the comprising of trimeric lectin domain on contractile events in vitro, using a human myometrial cell line (ULTR as an experimental model. Treatment with rhSP-A or rhSP-D increased the cell velocity, distance travelled and displacement by ULTR cells. rhSP-A and rhSP-D also affected the contractile response of ULTRs when grown on collagen matrices showing reduced surface area. We investigated this effect further by measuring contractility-associated protein (CAP genes. Treatment with rhSP-A and rhSP-D induced expression of oxytocin receptor (OXTR and connexin 43 (CX43. In addition, rhSP-A and rhSP-D were able to induce secretion of GROα and IL-8. rhSP-D also induced the expression of IL-6 and IL-6 Ra. We provide evidence that SP-A and SP-D play a key role in modulating events prior to labour by reconditioning the human myometrium and in inducing CAP genes and pro-inflammatory cytokines thus shifting the uterus from a quiescent state to a contractile one.

  9. Dynamic dyssynchrony and impaired contractile reserve of the left ventricle in beta-thalassaemia major: an exercise echocardiographic study.

    Directory of Open Access Journals (Sweden)

    Yiu-fai Cheung

    Full Text Available BACKGROUND: Performance of the left ventricle during exercise stress in thalassaemia patients is uncertain. We aimed to explore the phenomenon of dynamic dyssynchrony and assess contractile reserve in patients with beta-thalassaemia major and determine their relationships with myocardial iron load. METHODS AND RESULTS: Thirty-two thalassaemia patients (16 males, aged 26.8 ± 6.9 years, without heart failure and 17 healthy controls were studied. Their left ventricular (LV volumes, ejection fraction, systolic dyssynchrony index (SDI, and myocardial acceleration during isovolumic LV contraction (IVA were determined at rest and during submaximal bicycle exercise testing using 3-dimensional and tissue Doppler echocardiography. Myocardial iron load as assessed by T2* cardiac magnetic resonance in patients were further related to indices of LV dyssynchrony and contractile reserve. At rest, patients had significantly greater LV SDI (p4.6%, control+2SD increased from baseline 25% to 84% in patients. Δ SDI(exercise-baseline correlated with exercise-baseline differences in LV ejection fraction (p<0.001 and stroke volume (p = 0.006. Compared with controls, patients had significantly less exercise-induced increase in LV ejection fraction, cardiac index, and IVA (interaction, all p<0.05 and had impaired contractile reserve as reflected by the gentler IVA-heart rate slope (p = 0.018. Cardiac T2* in patients correlated with baseline LV SDI (r = -0.44, p = 0.011 and IVA-heart rate slope (r = 0.36, p = 0.044. CONCLUSIONS: Resting LV dyssynchrony is associated with myocardial iron load. Exercise stress further unveils LV dynamic dyssynchrony and impaired contractile reserve in patients with beta-thalassaemia major.

  10. Efficacy and Safety of Intravesical OnabotulinumtoxinA Injection in Patients with Detrusor Hyperactivity and Impaired Contractility

    OpenAIRE

    Chung-Cheng Wang; Cheng-Ling Lee; Hann-Chorng Kuo

    2016-01-01

    We investigated the efficacy and safety of intravesical onabotulinumtoxinA injection in patients with detrusor hyperactivity and impaired contractility (DHIC). Twenty-one patients with urodynamically proven DHIC and 21 age-matched patients with overactive bladder (OAB) with urodynamic detrusor overactivity were treated with intravesical injections of 100 U of onabotulinumtoxinA. The overactive bladder symptom score, urgency severity score, patient perception of bladder condition, global respo...

  11. Insulin improves cardiomyocyte contractile function through enhancement of SERCA2a activity in simulated ischemia/reperfusion

    Institute of Scientific and Technical Information of China (English)

    Jie YU; Hai-feng ZHANG; Feng WU; Qiu-xia LI; Heng MA; Wen-yi GUO; Hai-chang WANG; Feng GAO

    2006-01-01

    Aim: Insulin exerts anti-apoptotic effects in both cardiomyocytes and coronary endothelial cells following ischemia/reperfusion (I/R) via the Akt-endothelial nitric oxide synthase survival signal pathway. This important insulin signaling might further contribute to the improvement of cardiac function after reperfusion. In this study, we tested the hypothesis that sarcoplasmic reticulum calcium-AT-Pase (SERCA2a) is involved in the insulin-induced improvement of cardiac contractile function following I/R. Methods: Ventricular myocytes were enzymatically isolated from adult SD rats. Simulated I/R was induced by perfusing cells with chemical anoxic solution for 15 min followed by reperfusion with Tyrode's solution with or without insulin for 30 min. Myocyte shortening and intracellular calcium transients were assessed and underlying mechanisms were investigated. Results: Reperfusion with insulin (10-7 mol/L) significantly improved the recovery of contractile function (n=15-20 myocytes from 6-8 hearts, P<0.05), and increased calcium transients, as evidenced by the increased calcium (Ca2+) fluorescence ratio, shortened time to peak Ca2+ and time to 50% diastolic Ca2+, compared with those in cells reperfused with vehicle (P<0.05). In addition, Akt phosphorylation and SERCA2a activity were both increased in insulin-treated I/R cardiomyocytes, which were markedly inhibited by pretreatment of cells with a specific Akt inhibitor. Moreover, inhibition of Akt activity abolished insulin-induced positive contractile and calcium transients responses in I/R cardiomyocytes. Conclusion: These data demonstrated for the first time that insulin improves the recovery of contractile function in simulated I/R cardiomyocytes in an Akt-dependent and SERCA2a-mediated fashion.

  12. Cardiac-specific knockout of ETA receptor mitigates low ambient temperature-induced cardiac hypertrophy and contractile dysfunction

    Institute of Scientific and Technical Information of China (English)

    Yingmei Zhang; Linlin Li; Yinan Hua; Jennifer M. Nunn; Feng Dong; Masashi Yanagisawa; Jun Ren

    2012-01-01

    Cold exposure is associated with oxidative stress and cardiac dysfunction.The endothelin (ET) system,which plays a key role in myocardial homeostasis,may participate in cold exposure-induced cardiovascular dysfunction.This study was designed to examine the role of ET-1 in cold stress-induced cardiac geometric and contractile responses.Wild-type (WT) and ETA receptor knockout (ETAKO) mice were assigned to normal or cold exposure (4℃) environment for 2 and 5 weeks prior to evaluation of cardiac geometry,contractile,and intracellular Ca2+ properties.Levels of the temperature sensor transient receptor potential vanlllold (TRPV1),mitochondrlal proteins for biogenesis and oxidative phosphorylatlon,Including UCP2,HSP90,and PGC1α were evaluated.Cold stress triggered cardiac hypertrophy,depressed myocardial contractile capacity,including fractional shortening,peak shortening,and maximal velocity of shortening/relengthening,reduced intracellular Ca2+ release,prolonged intracellular Ca2+ decay and relengthening duration,generation of ROS and superoxide,as well as apoptosls,the effects of which were blunted by ETAKO.Western blotting revealed downregulated TRPV1 and PGC1α as well as upregulated UCP2 and activation of GSK3β,GATA4,and CREB in cold-stressed WT mouse hearts,which were obliterated by ETAKO.Levels of HSP90,an essential regulator for thermotolerance,were unchanged.The TRPV1 agonist SA13353 attenuated whereas TRPV1 antagonist capsazepino mimicked cold stress- or ET-1-induced cardiac anomalies.The GSK3β Inhibitor SB216763 ablated cold stress-induced cardiac contractile (but not remodeling) changes and ET-1-induced TRPV1 downregulation.These data suggest that ETAKO protects against cold exposure-induced cardiac remodeling and dysfunction mediated through TRPV1 and mitochondrlal function.

  13. PVP formulated Fullerene (C60) increases Rho-kinase dependent Vascular Tissue Contractility in Pregnant Sprague Dawley Rats

    OpenAIRE

    Vidanapathirana, Achini K.; Thompson, Leslie C.; Mann, Erin E.; Odom, Jillian T.; Holland, Nathan A.; Sumner, Susan J.; Han, Li; Lewin, Anita H.; Fennell, Timothy R.; Brown, Jared M.; Wingard, Christopher J.

    2014-01-01

    Pregnancy is a unique physiological state, in which C60 fullerene is reported to be distributed in both maternal and fetal tissues. Tissue distribution of C60 differs between pregnant and non-pregnant states, presumably due to functional changes in vasculature during pregnancy. We hypothesized that, polyvinylpyrorrolidone (PVP) formulated C60 (C60/PVP) increases vascular tissue contractility during pregnancy by increasing Rho-kinase activity. C60/PVP was administered intravenously to pregnant...

  14. Time-Lapse Imaging as a Tool to Investigate Contractility of the Epididymal Duct – Effects of Cgmp Signaling

    OpenAIRE

    Andrea Mietens; Sabine Tasch; Angelika Stammler; Lutz Konrad; Caroline Feuerstacke; Ralf Middendorff

    2014-01-01

    The well orchestrated function of epididymal smooth muscle cells ensures transit of spermatozoa through the epididymal duct during which spermatozoa acquire motility and fertilizing capacity. Relaxation of smooth muscle cells is mediated by cGMP signaling and components of this pathway are found within the male reproductive tract. Whereas contractile function of caudal parts of the rat epididymal duct can be examined in organ bath studies, caput and corpus regions are fragile and make it diff...

  15. Simulation of the contractile response of cells on an array of micro-posts.

    LENUS (Irish Health Repository)

    McGarry, J P

    2009-09-13

    A bio-chemo-mechanical model has been used to predict the contractile responses of smooth cells on a bed of micro-posts. Predictions obtained for smooth muscle cells reveal that, by converging onto a single set of parameters, the model captures all of the following responses in a self-consistent manner: (i) the scaling of the force exerted by the cells with the number of posts; (ii) actin distributions within the cells, including the rings of actin around the micro-posts; (iii) the curvature of the cell boundaries between the posts; and (iv) the higher post forces towards the cell periphery. Similar correspondences between predictions and measurements have been demonstrated for fibroblasts and mesenchymal stem cells once the maximum stress exerted by the stress fibre bundles has been recalibrated. Consistent with measurements, the model predicts that the forces exerted by the cells will increase with both increasing post stiffness and cell area (or equivalently, post spacing). In conjunction with previous assessments, these findings suggest that this framework represents an important step towards a complete model for the coupled bio-chemo-mechanical responses of cells.

  16. Endothelium protectant and contractile effects of the antivaricose principle escin in rat aorta.

    Science.gov (United States)

    Carrasco, Omar F; Vidrio, Horacio

    2007-07-01

    The triterpene saponin escin is the active component of the extract of seeds of Aesculus hippocastanum used in the treatment of chronic venous insufficiency. Escin is also used experimentally to increase membrane permeability in isolated cells. Since endothelial dysfunction is postulated to be involved in venous insufficiency, the possible endothelium-protectant effect of escin was explored in rat aortic rings, a model widely used to study such effects with cardiovascular agents. Escin enhanced endothelium-dependent relaxation induced by acetylcholine when such relaxation had been reduced by exposure to the superoxide ion generator pyrogallol. This effect was attributed to enhanced nitric oxide production by endothelial nitric oxide synthase, a calcium-dependent enzyme, activated by the increased endothelial cell permeability to calcium induced by escin. Another effect of escin thought to contribute to its therapeutic activity is its ability to produce venous contraction. The compound was found to induce concentration-related contraction also in rat aortic rings. This response was partially inhibited by removal of the endothelium or by preincubation with indomethacin, and was completely abolished by incubation in a calcium-free perfusion fluid. Contraction was considered to be due mainly to the aforementioned effect on calcium permeability, with some mediation by release of endothelial vasoconstrictor prostanoids. It was concluded that, in rat aorta, escin possesses an endothelium-protectant action and a direct contractile effect. The former could contribute to its beneficial effect in the treatment of venous insufficiency, while the latter could constitute a limiting side effect. PMID:17512261

  17. The effects of endurance exercise on dystrophic mdx mice. II. Contractile properties of skinned muscle fibres.

    Science.gov (United States)

    Lynch, G S; Hayes, A; Lam, M H; Williams, D A

    1993-07-22

    Dystrophic (mdx) mice were subjected to a 15 week exercise programme consisting of endurance swimming. Single fibres from the extensor digitorum longus (EDL, fast-twitch) and soleus (SOL, mixed fast- and slow-twitch) muscles were attached to a sensitive force-recording apparatus, and activated in Ca(2+)- and Sr(2+)-buffered solutions. In addition to the normal well-defined fibre types in these muscles, a small number of fibres were also sampled from the soleus of both experimental groups, which were 'Intermediate' to the other two SOL fibre types. Type IIB fibres from the EDL and type IIA fibres from the soleus of the Swim group were significantly less sensitive to Ca2+ and Sr2+ compared with those fibres sampled from the sedentary (Sedent) group, suggesting that endurance exercise was able to modify Ca(2+)- and Sr(2+)-activated contractile characteristics. The swim-trained (Swim) group's increased incidence of SOL fibres with characteristics intermediate to those of the fast- and slow-twitch fibre types suggests a possible exercise-induced fibre type transformation as an adaptation to the functional demand. PMID:8396775

  18. Mechanism of glucose-6-phosphate dehydrogenase-mediated regulation of coronary artery contractility.

    Science.gov (United States)

    Ata, Hirotaka; Rawat, Dhwajbhadur K; Lincoln, Thomas; Gupte, Sachin A

    2011-06-01

    We previously identified glucose-6-phosphate dehydrogenase (G6PD) as a regulator of vascular smooth muscle contraction. In this study, we tested our hypothesis that G6PD activated by KCl via a phosphatase and tensin homologue deleted on chromosome 10 (PTEN)-protein kinase C (PKC) pathway increases vascular smooth muscle contraction and that inhibition of G6PD relaxes smooth muscle by decreasing intracellular Ca(2+) ([Ca(2+)](i)) and Ca(2+) sensitivity to the myofilament. Here we show that G6PD is activated by membrane depolarization via PKC and PTEN pathway and that G6PD inhibition decreases intracellular free calcium ([Ca(2+)](i)) in vascular smooth muscle cells and thus arterial contractility. In bovine coronary artery (CA), KCl (30 mmol/l) increased PKC activity and doubled G6PD V(max) without affecting K(m). KCl-induced PKC and G6PD activation was inhibited by bisperoxo(pyridine-2-carboxyl)oxovanadate (Bpv; 10 μmol/l), a PTEN inhibitor, which also inhibited (P PET-cGMPs (100 nmol/l) diminished 6AN-evoked VASP phosphorylation (P PET-cGMPs increased 6AN-induced relaxation. These findings suggest G6PD inhibition relaxes CA by decreasing Ca(2+) influx, increasing Ca(2+) sequestration, and inhibiting Rho kinase but not by increasing Ca(2+) extrusion or activating PKG. PMID:21398595

  19. Altered right ventricular contractile pattern after cardiac surgery: monitoring of septal function is essential.

    Science.gov (United States)

    Nguyen, Tin; Cao, Long; Movahed, Assad

    2014-10-01

    Assessment of right ventricular (RV) function is important in the management of various forms of cardiovascular disease. Accurately assessing RV volume and systolic function is a challenge in day-to-day clinical practice due to its complex geometry. Tricuspid annular plane systolic excursion (TAPSE) and systolic excursion velocity (S') have been reviewed to further assess their suitability and objectivity in evaluating RV function. Multiple studies have validated their diagnostic and prognostic values in numerous pathologic conditions. Diminished longitudinal contraction after cardiothoracic surgery is a well-known phenomenon, but it is not well validated. Despite significant reduction in RV performance along the long-axis assessed by TAPSE and S' after cardiac surgery, RV ejection fractions did not change as well as the left ventricular parameters and exercise capacity. RV contractile patterns were markedly altered with decreased longitudinal shortening and increased transverse shortening, which are likely resulted from the septal damage during cardiac surgery. The septum is essential for RV performance due to its oblique fiber orientation. This allows ventricular twisting, which is a vital mechanism against increased pulmonary vascular resistance. The septum function along with TAPSE and S' should be adequately assessed during cardiac surgery, and evidence of septal dysfunction should lead to reevaluation of myocardial protection methods. PMID:24919944

  20. Pulsatile cell-autonomous contractility drives compaction in the mouse embryo.

    Science.gov (United States)

    Maître, Jean-Léon; Niwayama, Ritsuya; Turlier, Hervé; Nédélec, François; Hiiragi, Takashi

    2015-07-01

    Mammalian embryos initiate morphogenesis with compaction, which is essential for specifying the first lineages of the blastocyst. The 8-cell-stage mouse embryo compacts by enlarging its cell-cell contacts in a Cdh1-dependent manner. It was therefore proposed that Cdh1 adhesion molecules generate the forces driving compaction. Using micropipette aspiration to map all tensions in a developing embryo, we show that compaction is primarily driven by a twofold increase in tension at the cell-medium interface. We show that the principal force generator of compaction is the actomyosin cortex, which gives rise to pulsed contractions starting at the 8-cell stage. Remarkably, contractions emerge as periodic cortical waves when cells are disengaged from adhesive contacts. In line with this, tension mapping of mzCdh1(-/-) embryos suggests that Cdh1 acts by redirecting contractility away from cell-cell contacts. Our study provides a framework to understand early mammalian embryogenesis and original perspectives on evolutionary conserved pulsed contractions. PMID:26075357

  1. Subendocardial contractile impairment in chronic ischemic myocardium: assessment by strain analysis of 3T tagged CMR

    Directory of Open Access Journals (Sweden)

    Nagao Michinobu

    2012-02-01

    Full Text Available Abstract Background The purpose of this study was to quantify myocardial strain on the subendocardial and epicardial layers of the left ventricle (LV using tagged cardiovascular magnetic resonance (CMR and to investigate the transmural degree of contractile impairment in the chronic ischemic myocardium. Methods 3T tagged CMR was performed at rest in 12 patients with severe coronary artery disease who had been scheduled for coronary artery bypass grafting. Circumferential strain (C-strain at end-systole on subendocardial and epicardial layers was measured using the short-axis tagged images of the LV and available software (Intag; Osirix. The myocardial segment was divided into stenotic and non-stenotic segments by invasive coronary angiography, and ischemic and non-ischemic segments by stress myocardial perfusion scintigraphy. The difference in C-strain between the two groups was analyzed using the Mann-Whitney U-test. The diagnostic capability of C-strain was analyzed using receiver operating characteristics analysis. Results The absolute subendocardial C-strain was significantly lower for stenotic (-7.5 ± 12.6% than non-stenotic segment (-18.8 ± 10.2%, p Conclusions Analysis of tagged CMR can non-invasively demonstrate predominant impairment of subendocardial strain in the chronic ischemic myocardium at rest.

  2. Functional Loss of Bmsei Causes Thermosensitive Epilepsy in Contractile Mutant Silkworm, Bombyx mori

    Science.gov (United States)

    Nie, Hongyi; Cheng, Tingcai; Huang, Xiaofeng; Zhou, Mengting; Zhang, Yinxia; Dai, Fangyin; Mita, Kazuei; Xia, Qingyou; Liu, Chun

    2015-07-01

    The thermoprotective mechanisms of insects remain largely unknown. We reported the Bombyx mori contractile (cot) behavioral mutant with thermo-sensitive seizures phenotype. At elevated temperatures, the cot mutant exhibit seizures associated with strong contractions, rolling, vomiting, and a temporary lack of movement. We narrowed a region containing cot to ~268 kb by positional cloning and identified the mutant gene as Bmsei which encoded a potassium channel protein. Bmsei was present in both the cell membrane and cytoplasm in wild-type ganglia but faint in cot. Furthermore, Bmsei was markedly decreased upon high temperature treatment in cot mutant. With the RNAi method and injecting potassium channel blockers, the wild type silkworm was induced the cot phenotype. These results demonstrated that Bmsei was responsible for the cot mutant phenotype and played an important role in thermoprotection in silkworm. Meanwhile, comparative proteomic approach was used to investigate the proteomic differences. The results showed that the protein of Hsp-1 and Tn1 were significantly decreased and increased on protein level in cot mutant after thermo-stimulus, respectively. Our data provide insights into the mechanism of thermoprotection in insect. As cot phenotype closely resembles human epilepsy, cot might be a potential model for the mechanism of epilepsy in future.

  3. Shortening actin filaments cause force generation in actomyosin network to change from contractile to extensile

    Science.gov (United States)

    Kumar, Nitin; Gardel, Margaret

    Motor proteins in conjunction with filamentous proteins convert biochemical energy into mechanical energy which serves a number of cellular processes including cell motility, force generation and intracellular cargo transport. In-vitro experiments suggest that the forces generated by kinesin motors on microtubule bundles are extensile in nature whereas myosin motors on actin filaments are contractile. It is not clear how qualitatively similar systems can show completely different behaviors in terms of the nature of force generation. In order to answer this question, we carry out in vitro experiments where we form quasi 2D filamentous actomyosin networks and vary the length of actin filaments by adding capping protein. We show that when filaments are much shorter than their typical persistence length (approximately 10 microns), the forces generated are extensile and we see active nematic defect propagation, as seen in the microtubule-kinesin system. Based on this observation, we claim that the rigidity of rods plays an important role in dictating the nature of force generation in such systems. In order to understand this transition, we selectively label individual filaments and find that longer filaments show considerable bending and buckling, making them difficult to slide and extend along their length.

  4. Contractile dysfunction in muscle may underlie androgen-dependent motor dysfunction in spinal bulbar muscular atrophy.

    Science.gov (United States)

    Oki, Kentaro; Halievski, Katherine; Vicente, Laura; Xu, Youfen; Zeolla, Donald; Poort, Jessica; Katsuno, Masahisa; Adachi, Hiroaki; Sobue, Gen; Wiseman, Robert W; Breedlove, S Marc; Jordan, Cynthia L

    2015-04-01

    Spinal and bulbar muscular atrophy (SBMA) is characterized by progressive muscle weakness linked to a polyglutamine expansion in the androgen receptor (AR). Current evidence indicates that mutant AR causes SBMA by acting in muscle to perturb its function. However, information about how muscle function is impaired is scant. One fundamental question is whether the intrinsic strength of muscles, an attribute of muscle independent of its mass, is affected. In the current study, we assess the contractile properties of hindlimb muscles in vitro from chronically diseased males of three different SBMA mouse models: a transgenic (Tg) model that broadly expresses a full-length human AR with 97 CAGs (97Q), a knock-in (KI) model that expresses a humanized AR containing a CAG expansion in the first exon, and a Tg myogenic model that overexpresses wild-type AR only in skeletal muscle fibers. We found that hindlimb muscles in the two Tg models (97Q and myogenic) showed marked losses in their intrinsic strength and resistance to fatigue, but were minimally affected in KI males. However, diseased muscles of all three models showed symptoms consistent with myotonic dystrophy type 1, namely, reduced resting membrane potential and deficits in chloride channel mRNA. These data indicate that muscle dysfunction is a core feature of SBMA caused by at least some of the same pathogenic mechanisms as myotonic dystrophy. Thus mechanisms controlling muscle function per se independent of mass are prime targets for SBMA therapeutics.

  5. PINCH proteins regulate cardiac contractility by modulating integrin-linked kinase-protein kinase B signaling.

    Science.gov (United States)

    Meder, Benjamin; Huttner, Inken G; Sedaghat-Hamedani, Farbod; Just, Steffen; Dahme, Tillman; Frese, Karen S; Vogel, Britta; Köhler, Doreen; Kloos, Wanda; Rudloff, Jessica; Marquart, Sabine; Katus, Hugo A; Rottbauer, Wolfgang

    2011-08-01

    Integrin-linked kinase (ILK) is an essential component of the cardiac mechanical stretch sensor and is bound in a protein complex with parvin and PINCH proteins, the so-called ILK-PINCH-parvin (IPP) complex. We have recently shown that inactivation of ILK or β-parvin activity leads to heart failure in zebrafish via reduced protein kinase B (PKB/Akt) activation. Here, we show that PINCH proteins localize at sarcomeric Z disks and costameres in the zebrafish heart and skeletal muscle. To investigate the in vivo role of PINCH proteins for IPP complex stability and PKB signaling within the vertebrate heart, we inactivated PINCH1 and PINCH2 in zebrafish. Inactivation of either PINCH isoform independently leads to instability of ILK, loss of stretch-responsive anf and vegf expression, and progressive heart failure. The predominant cause of heart failure in PINCH morphants seems to be loss of PKB activity, since PKB phosphorylation at serine 473 is significantly reduced in PINCH-deficient hearts and overexpression of constitutively active PKB reconstitutes cardiac function in PINCH morphants. These findings highlight the essential function of PINCH proteins in controlling cardiac contractility by granting IPP/PKB-mediated signaling.

  6. Human embryonic stem cell derived mesenchymal progenitors express cardiac markers but do not form contractile cardiomyocytes.

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    Christophe M Raynaud

    Full Text Available Mesenchymal progenitors or stromal cells have shown promise as a therapeutic strategy for a range of diseases including heart failure. In this context, we explored the growth and differentiation potential of mesenchymal progenitors (MPs derived in vitro from human embryonic stem cells (hESCs. Similar to MPs isolated from bone marrow, hESC derived MPs (hESC-MPs efficiently differentiated into archetypical mesenchymal derivatives such as chondrocytes and adipocytes. Upon treatment with 5-Azacytidine or TGF-β1, hESC-MPs modified their morphology and up-regulated expression of key cardiac transcription factors such as NKX2-5, MEF2C, HAND2 and MYOCD. Nevertheless, NKX2-5+ hESC-MP derivatives did not form contractile cardiomyocytes, raising questions concerning the suitability of these cells as a platform for cardiomyocyte replacement therapy. Gene profiling experiments revealed that, although hESC-MP derived cells expressed a suite of cardiac related genes, they lacked the complete repertoire of genes associated with bona fide cardiomyocytes. Our results suggest that whilst agents such as TGF-β1 and 5-Azacytidine can induce expression of cardiac related genes, but treated cells retain a mesenchymal like phenotype.

  7. Hadp1, a newly identified pleckstrin homology domain protein, is required for cardiac contractility in zebrafish

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    Joshua D. Wythe

    2011-09-01

    The vertebrate heart is one of the first organs to form, and its early function and morphogenesis are crucial for continued embryonic development. Here we analyze the effects of loss of Heart adaptor protein 1 (Hadp1, which we show is required for normal function and morphogenesis of the embryonic zebrafish heart. Hadp1 is a pleckstrin homology (PH-domain-containing protein whose expression is enriched in embryonic cardiomyocytes. Knockdown of hadp1 in zebrafish embryos reduced cardiac contractility and altered late myocyte differentiation. By using optical mapping and submaximal levels of hadp1 knockdown, we observed profound effects on Ca2+ handling and on action potential duration in the absence of morphological defects, suggesting that Hadp1 plays a major role in the regulation of intracellular Ca2+ handling in the heart. Hadp1 interacts with phosphatidylinositol 4-phosphate [PI4P; also known as PtdIns(4P] derivatives via its PH domain, and its subcellular localization is dependent upon this motif. Pharmacological blockade of the synthesis of PI4P derivatives in vivo phenocopied the loss of hadp1 in zebrafish. Collectively, these results demonstrate that hadp1 is required for normal cardiac function and morphogenesis during embryogenesis, and suggest that hadp1 modulates Ca2+ handling in the heart through its interaction with phosphatidylinositols.

  8. Formation of mitochondrial apparatus of contractile cardiomyocytes during normal and hypoxic injury of cardi-ogenesis

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    Ivanchenko M.V.

    2013-01-01

    Full Text Available Changes of cardiomyocytes mitochondrial apparatus can be marked as the main factors which are the basis of various forms of cardiovascular disease, but the dynamics of morphogenetic rearrangements heart mitochondria are poorly researched under normal conditions and under the influence of harmful factors. Mitochondria of contractile cardiomyocytes are different in their morphology and localization in the cell, the biochemical properties and are able to form differently association with other intracellular structures. Question of the relationship between function and heterogeneity of regional specialization of mitochondria and the realization of the heterogeneity in the cell and the degree of their dependence on the disease during ontogeny is important and relevant. There are relatively few ultrastructural studies that investigate adaptive techniques and alternative processes in the mitochondria of atrial and ventricular myocardium under prenatal hypoxia during the development of the myocardium. It is interesting to find mechanisms for the implementation of the ultrastructural changes in the mitochondrial apparatus and extracellular tissue levels in hypoxic conditions on the stages of ontogeny.

  9. The contribution of Kv7 channels to pregnant mouse and human myometrial contractility.

    Science.gov (United States)

    McCallum, Laura A; Pierce, Stephanie L; England, Sarah K; Greenwood, Iain A; Tribe, Rachel M

    2011-03-01

    Premature birth accounts for approximately 75% of neonatal mortality and morbidity in the developed world. Despite this, methods for identifying and treating women at risk of preterm labour are limited and many women still present in preterm labour requiring tocolytic therapy to suppress uterine contractility. The aim of this study was to assess the utility of Kv7 channel activators as potential uterine smooth muscle (myometrium) relaxants in tissues from pregnant mice and women. Myometrium was obtained from early and late pregnant mice and from lipopolysaccharide (LPS)-injected mice (day 15 of gestation; model of infection in pregnancy). Human myometrium was obtained at the time of Caesarean section from women at term (38-41 weeks). RT-PCR/qRT-PCR detected KCNQ and KCNE expression in mouse and human myometrium. In mice, there was a global suppression of all KCNQ isoforms, except KCNQ3, in early pregnancy (n= 6, P flupirtine (20 μM, Kv7 channel activators) caused profound myometrial relaxation (P < 0.05). In summary, Kv7 activators suppressed myometrial contraction and KCNQ gene expression was sustained throughout gestation, particularly at term. Consequently, activation of the encoded channels represents a novel mechanism for treatment of preterm labour. PMID:20132415

  10. Methanol extract of Tephrosia vogelii leaves potentiates the contractile action of acetylcholine on isolated rabbit jejunum

    Institute of Scientific and Technical Information of China (English)

    Tavershima Dzenda; Joseph Olusegun Ayo; Alexander Babatunde Adelaiye; Ambrose Osemattah Adaudi

    2015-01-01

    To investigate the modulating role of methanol extract of Tephrosia vogelii leaves on acetylcholine (ACh)-induced contraction of isolated rabbit jejunum. Methods: Rabbit jejunum segment was removed and placed in an organ bath containing Tyrode’s solution, and its contractions were recorded isometrically. Results: ACh (2.0 × 10-10 g/mL) and the extract (2.0 × 10-4 g/mL) individually increased the frequency of contraction (mean ± SEM) of the isolated smooth muscle tissue by 47.6% ± 9.5%and 77.8% ± 66.5%, respectively. When ACh and the extract were combined, the frequency of contraction of the tissue was increased by 222.2% ± 25.9%, representing a 366.7% increase (P < 0.001) over the effect of ACh alone. Similarly, ACh (2.0 × 10-9 g/mL) and the extract individually increased significantly (P < 0.001) the amplitude of contraction of the tissue by 685.7% ± 61.1% and 455.2% ± 38.1%, respectively. When ACh and the extract were combined, the amplitude of contraction of the tissue rose by 1263.8% ± 69.0%, representing 84.3% increase over the effect of ACh alone. Conclusions: The findings demonstrate that methanol extract of Tephrosia vogelii leaves potentiates the contractile effect of ACh on intestinal smooth muscle, supporting the traditional claim that the plant is purgative.

  11. Cytoskeletal turnover and Myosin contractility drive cell autonomous oscillations in a model of Drosophila Dorsal Closure

    Science.gov (United States)

    Machado, P. F.; Blanchard, G. B.; Duque, J.; Gorfinkiel, N.

    2014-06-01

    Oscillatory behaviour in force-generating systems is a pervasive phenomenon in cell biology. In this work, we investigate how oscillations in the actomyosin cytoskeleton drive cell shape changes during the process of Dorsal Closure (DC), a morphogenetic event in Drosophila embryo development whereby epidermal continuity is generated through the pulsatile apical area reduction of cells constituting the amnioserosa (AS) tissue. We present a theoretical model of AS cell dynamics by which the oscillatory behaviour arises due to a coupling between active myosin-driven forces, actin turnover and cell deformation. Oscillations in our model are cell-autonomous and are modulated by neighbour coupling, and our model accurately reproduces the oscillatory dynamics of AS cells and their amplitude and frequency evolution. A key prediction arising from our model is that the rate of actin turnover and Myosin contractile force must increase during DC in order to reproduce the decrease in amplitude and period of cell area oscillations observed in vivo. This prediction opens up new ways to think about the molecular underpinnings of AS cell oscillations and their link to net tissue contraction and suggests the form of future experimental measurements.

  12. Accuracy of Dobutamine Stress Echocardiography in Detecting Recovery of Contractile Reserve after Revascularization of Ischemic Myocardium

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    Abas Ali karimi

    2007-09-01

    Full Text Available Background: This study was designed to investigate the accuracy of dobutamine stress echocardiography (DSE in detecting the post-revascularization recovery rate of contractile reserve (CR in ischemic myocardium. Methods: A total of 112 segments from seven patients with low ejection fraction (<35% and coronary artery disease were evaluated with DSE one week before and 12 weeks after coronary artery bypass graft surgery (CABG. Sensitivity, specificity, and positive and negative predictive values of DSE for detecting the recovery rate of CR were calculated based upon their standard definition and were presented with 95% confidence intervals (CI. Results: The mean baseline left ventricular ejection fraction was 31±4%, which reached 35±7% after CABG unremarkably. The recovery rates of resting function and CR were 18.2% and 50% for hypokinetic and 15.6% and 24.1 for akinetic segments respectively. Specificity, sensitivity, and positive and negative predictive values of DSE for detecting the recovery of CR were 83% (CI=69-97, 89% (CI=83-96, 94% (CI = 88-99, and 73 % (CI = 55-88, respectively. Conclusion: Despite acceptable sensitivity, specificity, and positive predictive value, DSE has a relatively lower negative predictive value for detecting the recovery of CR in ischemic myocardium and, consequently, the full extent of myocardial viability. Further sensitive techniques may, therefore, be needed to provide complementary information regarding long-term functional outcome.

  13. The Mitochondrial Calcium Uniporter Selectively Matches Metabolic Output to Acute Contractile Stress in the Heart.

    Science.gov (United States)

    Kwong, Jennifer Q; Lu, Xiyuan; Correll, Robert N; Schwanekamp, Jennifer A; Vagnozzi, Ronald J; Sargent, Michelle A; York, Allen J; Zhang, Jianyi; Bers, Donald M; Molkentin, Jeffery D

    2015-07-01

    In the heart, augmented Ca(2+) fluxing drives contractility and ATP generation through mitochondrial Ca(2+) loading. Pathologic mitochondrial Ca(2+) overload with ischemic injury triggers mitochondrial permeability transition pore (MPTP) opening and cardiomyocyte death. Mitochondrial Ca(2+) uptake is primarily mediated by the mitochondrial Ca(2+) uniporter (MCU). Here, we generated mice with adult and cardiomyocyte-specific deletion of Mcu, which produced mitochondria refractory to acute Ca(2+) uptake, with impaired ATP production, and inhibited MPTP opening upon acute Ca(2+) challenge. Mice lacking Mcu in the adult heart were also protected from acute ischemia-reperfusion injury. However, resting/basal mitochondrial Ca(2+) levels were normal in hearts of Mcu-deleted mice, and mitochondria lacking MCU eventually loaded with Ca(2+) after stress stimulation. Indeed, Mcu-deleted mice were unable to immediately sprint on a treadmill unless warmed up for 30 min. Hence, MCU is a dedicated regulator of short-term mitochondrial Ca(2+) loading underlying a "fight-or-flight" response that acutely matches cardiac workload with ATP production.

  14. The Mitochondrial Calcium Uniporter Selectively Matches Metabolic Output to Acute Contractile Stress in the Heart

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    Jennifer Q. Kwong

    2015-07-01

    Full Text Available In the heart, augmented Ca2+ fluxing drives contractility and ATP generation through mitochondrial Ca2+ loading. Pathologic mitochondrial Ca2+ overload with ischemic injury triggers mitochondrial permeability transition pore (MPTP opening and cardiomyocyte death. Mitochondrial Ca2+ uptake is primarily mediated by the mitochondrial Ca2+ uniporter (MCU. Here, we generated mice with adult and cardiomyocyte-specific deletion of Mcu, which produced mitochondria refractory to acute Ca2+ uptake, with impaired ATP production, and inhibited MPTP opening upon acute Ca2+ challenge. Mice lacking Mcu in the adult heart were also protected from acute ischemia-reperfusion injury. However, resting/basal mitochondrial Ca2+ levels were normal in hearts of Mcu-deleted mice, and mitochondria lacking MCU eventually loaded with Ca2+ after stress stimulation. Indeed, Mcu-deleted mice were unable to immediately sprint on a treadmill unless warmed up for 30 min. Hence, MCU is a dedicated regulator of short-term mitochondrial Ca2+ loading underlying a “fight-or-flight” response that acutely matches cardiac workload with ATP production.

  15. Altered right ventricular contractile pattern after cardiac surgery: monitoring of septal function is essential.

    Science.gov (United States)

    Nguyen, Tin; Cao, Long; Movahed, Assad

    2014-10-01

    Assessment of right ventricular (RV) function is important in the management of various forms of cardiovascular disease. Accurately assessing RV volume and systolic function is a challenge in day-to-day clinical practice due to its complex geometry. Tricuspid annular plane systolic excursion (TAPSE) and systolic excursion velocity (S') have been reviewed to further assess their suitability and objectivity in evaluating RV function. Multiple studies have validated their diagnostic and prognostic values in numerous pathologic conditions. Diminished longitudinal contraction after cardiothoracic surgery is a well-known phenomenon, but it is not well validated. Despite significant reduction in RV performance along the long-axis assessed by TAPSE and S' after cardiac surgery, RV ejection fractions did not change as well as the left ventricular parameters and exercise capacity. RV contractile patterns were markedly altered with decreased longitudinal shortening and increased transverse shortening, which are likely resulted from the septal damage during cardiac surgery. The septum is essential for RV performance due to its oblique fiber orientation. This allows ventricular twisting, which is a vital mechanism against increased pulmonary vascular resistance. The septum function along with TAPSE and S' should be adequately assessed during cardiac surgery, and evidence of septal dysfunction should lead to reevaluation of myocardial protection methods.

  16. Cómo mejorar la capacidad inferencial en estudiantes universitarios Como melhorar a capacidade inferencial em estudantes universitários How to Improve the Inferential Ability of College Students

    OpenAIRE

    Mireya Cisneros-Estupiñán; Giohanny Olave-Arias; llene Rojas-García

    2012-01-01

    La investigación titulada "Mejoramiento de la capacidad inferencial en estudiantes universitarios" se propuso diseñar estrategias didácticas para desarrollarla comprensión lectora de textos académicos entre estudiantes. Se trabajó bajo la modalidad de proyecto factible, con intervención de pilotajes en la fase de desarrollo. El principal hallazgo es la propuesta estructurada, gradual y adaptable de un programa de entrenamiento en lectura comprensiva para los programas universitarios y sus cur...

  17. Contractile Defect Caused by Mutation in MYBPC3 Revealed under Conditions Optimized for Human PSC-Cardiomyocyte Function.

    Science.gov (United States)

    Birket, Matthew J; Ribeiro, Marcelo C; Kosmidis, Georgios; Ward, Dorien; Leitoguinho, Ana Rita; van de Pol, Vera; Dambrot, Cheryl; Devalla, Harsha D; Davis, Richard P; Mastroberardino, Pier G; Atsma, Douwe E; Passier, Robert; Mummery, Christine L

    2015-10-27

    Maximizing baseline function of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) is essential for their effective application in models of cardiac toxicity and disease. Here, we aimed to identify factors that would promote an adequate level of function to permit robust single-cell contractility measurements in a human induced pluripotent stem cell (hiPSC) model of hypertrophic cardiomyopathy (HCM). A simple screen revealed the collaborative effects of thyroid hormone, IGF-1 and the glucocorticoid analog dexamethasone on the electrophysiology, bioenergetics, and contractile force generation of hPSC-CMs. In this optimized condition, hiPSC-CMs with mutations in MYBPC3, a gene encoding myosin-binding protein C, which, when mutated, causes HCM, showed significantly lower contractile force generation than controls. This was recapitulated by direct knockdown of MYBPC3 in control hPSC-CMs, supporting a mechanism of haploinsufficiency. Modeling this disease in vitro using human cells is an important step toward identifying therapeutic interventions for HCM.

  18. The contractile vacuole in Ca2+-regulation in Dictyostelium: its essential function for cAMP-induced Ca2+-influx

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    Schlatterer Christina

    2006-06-01

    Full Text Available Abstract Background cAMP-induced Ca2+-influx in Dictyostelium is controlled by at least two non-mitochondrial Ca2+-stores: acidic stores and the endoplasmic reticulum (ER. The acidic stores may comprise the contractile vacuole network (CV, the endosomal compartment and acidocalcisomes. Here the role of CV in respect to function as a potential Ca2+-store was investigated. Results Dajumin-GFP labeled contractile vacuoles were purified 7-fold by anti-GFP-antibodies in a magnetic field. The purified CV were shown for the first time to accumulate and release Ca2+. Release of Ca2+ was elicited by arachidonic acid or the calmodulin antagonist W7, the latter due to inhibition of the pump. The characteristics of Ca2+-transport and Ca2+-release of CV were compared to similarly purified vesicles of the ER labeled by calnexin-GFP. Since the CV proved to be a highly efficient Ca2+-compartment we wanted to know whether or not it takes part in cAMP-induced Ca2+-influx. We made use of the LvsA--mutant expected to display reduced Ca2+-transport due to loss of calmodulin. We found a severe reduction of cAMP-induced Ca2+-influx into whole cells. Conclusion The contractile vacuoles in Dictyostelium represent a highly efficient acidic Ca2+-store that is required for cAMP-induced Ca2+-influx.

  19. The effects of space flight on the contractile apparatus of antigravity muscles: implications for aging and deconditioning

    Science.gov (United States)

    Baldwin, K. M.; Caiozzo, V. J.; Haddad, F.; Baker, M. J.; Herrick, R. E.

    1994-01-01

    Previous studies have shown that the unloading of skeletal muscle, as occurring during exposure to space flight, exerts a profound effect on both the mass (cross sectional area) of skeletal muscle fibers and the relative expression of protein isoforms comprising the contractile system. Available information suggests that slow (type I) fibers, comprising chiefly the antigravity muscles of experimental animals, in addition to atrophying, undergo alterations in the type of myosin heavy chain (MHC) expressed such that faster isoforms become concomitantly expressed in a sub-population of slow fibers when insufficient force-bearing activity is maintained on the muscle. Consequently, these transformations in both mass and myosin heavy chain phenotype could exert a significant impact on the functional properties of skeletal muscle as manifest in the strength, contractile speed, and endurance scope of the muscle. To further explore these issues, a study was performed in which young adult male rats were exposed to zero gravity for six days, following which, the antigravity soleus muscle was examined for a) contractile properties, determined in situ and b) isomyosin expression, as studied using biochemical, molecular biology, and histochemical/immunohistochemical techniques.

  20. Effects of Using Tricaine Methanesulfonate and Metomidate before Euthanasia on the Contractile Properties of Rainbow Trout (Oncorhynchus mykiss) Myocardium.

    Science.gov (United States)

    Roberts, Jordan C; Syme, Douglas A

    2016-01-01

    Because many anesthetics work through depressing cell excitability, unanesthetized euthanasia has become common for research involving excitable tissues (for example muscle and nerve) to avoid these depressive effects. However, anesthetic use during euthanasia may be indicated for studies involving isolated tissues if the potential depressive effects of brief anesthetic exposure dissipate after subsequent tissue isolation, washout, and saline perfusion. We explore this here by measuring whether, when applied prior to euthanasia, standard immersion doses of 2 fish anesthetics, tricaine methanesulfonate (TMS; 100 mg/L, n = 6) and methyl 1-(1-phenylethyl)-1H-imidazole-5-carboxylate (metomidate, 10 mg/L, n = 6), have residual effects on the contractile properties (force and work output) of isolated and saline-perfused ventricular compact myocardium from rainbow trout (Oncorhynchus mykiss). Results suggest that direct exposure of muscle to immersion doses of TMS-but not metomidate-impairs muscle contractile performance. However, brief exposure (2 to 3 min) to either anesthetic during euthanasia only-providing that the agent is washed out prior to tissue experimentation-does not have an effect on the contractile properties of the myocardium. Therefore, the use of TMS, metomidate, and perhaps other anesthetics that depress cell excitability during euthanasia may be indicated when conducting research on isolated and rinsed tissues. PMID:27657711