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Sample records for capacidad contractil uterina

  1. Complicaciones puerperales. Atonía uterina

    OpenAIRE

    Asensio Díaz, Ana

    2015-01-01

    Me decidí a tratar el tema de la atonía uterina en mi Trabajo de Fin de Grado porque, según la OMS, es la principal causa de las hemorragias puerperales, que a su vez son responsables de la mayor incidencia de mortalidad materna a nivel mundial. Definiremos la atonía uterina como la pérdida de tono uterino en el puerperio, que impide el proceso de involución uterina y se manifiesta mediante hemorragia vaginal excesiva y persistente y útero de consistencia blanda a la palpación. A lo largo ...

  2. RUPTURA UTERINA ESPONTANEA POR PLACENTA PERCRETA

    OpenAIRE

    2003-01-01

    La rotura uterina en un útero sin cicatriz previa, y temprano en el tercer trimestre, es un evento raro. Se expone el caso clínico de una paciente que se presenta con abdomen agudo, cursando embarazo de aproximadamente 25 semanas, se realiza laparotomía exploradora encontrando hemoperitoneo, feto y placenta libres en la cavidad peritoneal y útero roto en el fondo invadido por la placenta, que compromete epiplón mayor. Se realiza histerectomía y se confirma el diagnóstico con biopsia

  3. Evaluation of corpus luteum, uterine contractility and progesterone and estradiol plasmatic concentrations in recipients of bovine embryos AVALIAÇÃO DO CORPO LÚTEO, CONTRATILIDADE UTERINA E CONCENTRAÇÕES PLASMÁTICAS DE PROGESTERONA E ESTRADIOL EM RECEPTORAS DE EMBRIÕES BOVINOS

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    Carlos Antônio de Carvalho Fernandes

    2009-04-01

    Full Text Available The aims of the present study were to evaluate the size of corpus luteum (CL, uterine contractility and plasma progesterone (P4 and estradiol (17? E2 concentrations in recipients, in the day of embryo transfer. For this, 60 crossbred recipient heifers were used. The pregnancy rate of recipients according to the CL size by rectal palpation was 70.0% (7/10 - small, 38.9% (7/18 - medium and 60.0% (15/25 - large. Ultrasonographic evaluation detected 50.9% (29/57 of the CL with a cystic cavity. The average diameter of the CL was 17.8 ± 6.3 mm (n=57 and of cystic cavity was 6.8 ± 4.2 mm (n= 29. The mean volume of the CL was 4.4 ± 9.1 cm3 (n=57, of cystic cavity was 0.4 ± 1.0 cm3 (n=29 and of luteal mass was 4.2 ± 8.4 cm3 (n=57. In the day of the inovulation, progesterone and estradiol concentrations were respectively 4.9 ± 3.0 ng/mL (n=60 and 4.5 ± 6.0 pg/mL (n=60 in average. There was no statistic difference between progesterone and estradiol concentrations for pregnant and non-pregnant recipients. Forty-nine of the 60 recipients presented flaccid uterus (grade 1 and 11 had uterus in intermediate stage (grade 2. Those presented pregnancy rates of 47.6% (20/42 and 81.8% (9/11 (p<0.05 respectively.

    KEY WORDS: Embryo transfer, estradiol and pregnancy, progesterone, recipients.
    Os objetivos do presente trabalho foram avaliar o corpo lúteo (CL, o tônus uterino e a concentração plasmática de progesterona (P4 e estradiol (17? E2 nas receptoras, no dia da transferência de embriões. Para isso, utilizaram-se sessenta novilhas mestiças como receptoras. A taxa de prenhez segundo o tamanho do CL à palpação transretal foi 70,0% (7/10 - pequeno, 38,9% (7/18 - médio e 60,0% (15/25 - grande. Ao exame ultrassonográfico, 50,9% (29/57 dos CL detectados continham cavidade cística. O diâmetro médio do CL foi 17,8 ± 6,3 mm (n=57 e da cavidade cística 6,8 ± 4,2 mm (n=29. Os volumes médios foram para CL 4,4 ± 9,1 cm3 (n=57

  4. Surface Alteration in Aging of Rat Tubae Uterinae Epithelium

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    Zekiye Suludere

    2012-12-01

    Full Text Available Objective: Aim of the study was evaluating arrangement of apical surface differentiation in cross-sections of tuba uterinae in different age groups by scanning electron microscope.Material and Methods: Six groups were created with 36 Wistar rat; 1st group: neonate (1th day (n=6, 2nd group: young (22nd day (n=6, 3rd group: prepubertal (4-6 week (n=6, 4th group: adult (10 week (n=6, 5th group: premenopausal (8 month (n=6, 6th group: old (18-20 month (n=6. Tissue samples examined with scanning electron microscope.Results: When surface differentiations of epithelial cells in tubae uterinae from birth to menopause were considered, it was determined that the cell with microvilli are first maturing cells and degenerated by ages first. It was observed that the ciliated cells are last maturing cells and subsisting as a mature cell during the postmenopausal period.Conclusion: Towards the menopause degeneration in microvillous cells together with lack of secretion may affect sperm nutrition adversely. The increase of ciliated cells in aging may be a physiological result related to the active role of cilia movement in the sperm and early embryo transport against a probable decrease in muscle contraction in aging.

  5. EMBOLIZACIÓN DE ARTERIAS UTERINAS EN EL TRATAMIENTO DE MIOMAS UTERINOS SINTOMÁTICOS

    OpenAIRE

    Loyola Z,Soledad; Fava R,Mario; Macaya R,Rodrigo; MENESES Q,LUIS

    2007-01-01

    Los miomas uterinos pueden ser causa de menstruaciones abundantes y prolongadas, de síntomas por compresión de órganos vecinos e infertilidad. La embolización de arterias uterinas es una terapia mínimamente invasiva que se ha constituido en una alternativa terapéutica a la histerectomía y la miomectomía múltiple, para el tratamiento de miomas uterinos sintomáticos, en mujeres que no desean fertilidad futura. Esta consiste en ocluir ambas arterias uterinas mediante partículas, con el objetivo ...

  6. 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.

  7. 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

  8. 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...

  9. Perforación uterina y de colon por T de cobre

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    Iván Toribio- Membreño

    2005-01-01

    Full Text Available Se reporta el caso de una paciente de 36 años, con perforación uterina y del colon sigmoides con una Tcu colocada 14 años atrás, y que evolucionó en forma asintomática. El manejo requirió de histerectomía abdominal, con reparación de colon sigmoides y colostomía transversa temporal con evolución final satisfactoria. La perforación uterina por dispositivos intrauterinos (DIU, constituye una complicación poco frecuente, y puede acompañarse de perforación de otras vísceras en el 15%, de los casos principalmente del intestino.

  10. Altas capacidades en el aula /

    OpenAIRE

    Conesa Muñoz., María Gregoria

    2014-01-01

    Las altas capacidades necesitan un tratamiento específico, del mismo modo que lo necesitan otros alumnos con dificultades para el aprendizaje, el hecho de que les sea más fácil aprender no significa que no se deban potenciar sus capacidades. Se analiza el tratamiento que han tenido las altas capacidades intelectuales a lo largo de los diferentes sistemas educativos, se ven las características más importantes que pueden tener estos niños y las diferentes vías de identificación y diagnóstico. ...

  11. 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.

  12. Reembolización de arterias uterinas por hemorragia posparto en una segunda gestación

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    López V,Nuria; Vegas G,Gabriel; Arrieta B,Sara; Iglesias S,Carlos; González G,Antonio

    2012-01-01

    La hemorragia posparto es la principal causa de muerte obstétrica. Presentamos el caso de una gestación y parto normales tras la embolización bilateral de ambas arterias uterinas, por hemorragia posparto en la gestación anterior. La paciente requirió de una nueva embolización bilateral de arterias uterinas en esta segunda gestación con buen resultado obstétrico. La embolización arterial pélvica en el manejo de la hemorragia posparto refractaria al tratamiento médico, permite en ocasiones evit...

  13. Perforación uterina y de colon por T de cobre

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    Iván Toribio- Membreño

    2005-01-01

    Full Text Available Se reporta el caso de una paciente de 36 años, con perforación uterina y del colon sigmoides con una Tcu colocada 14 años atrás, y que evolucionó en forma asintomática. El manejo requirió de histerectomía abdominal, con reparación de colon sigmoides y colostomía transversa temporal con evolución final satisfactoria. La perforación uterina por dispositivos intrauterinos (DIU, constituye una complicación poco frecuente, y puede acompañarse de perforación de otras vísceras en el 15%, de los casos principalmente del intestino.We report the case of 36 years old female, with uterine and sigmoid colon perforation caused by a Tcu placed 14 years previously. She was asymptomatic. The management required an abdominal histerectomy and repair of the sigmoid colon, she also needed a temporary transverse colostomy with final satisfactory outcome. Uterine perforation by intrauterine devices, is an infrequent complication, in 15% of the cases it is associated with perforation of other internal organs, primarily the intestine.

  14. 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.

  15. Malformación arterio-venosa uterina y hemorragia obstétrica: diagnóstico y manejo en tres casos clínicos

    OpenAIRE

    Hasbun H,Jorge; Palavecino R,Patricio; Segura H,Patricia; Chavez R,Ignacio; Burgos S,Nelson; Tobar A,Hermógenes; Aliaga Q,Adolfo

    2014-01-01

    Las malformaciones vasculares uterinas son muy infrecuentes y se presentan asociadas a metrorragia con riesgo vital. Su incidencia no es conocida porque las series son de pocos casos. Presentamos tres pacientes con hemorragia obstétrica cuyo estudio diagnóstico con ultrasonido y angiografía, demostró malformación arteriovenosa uterina. En un caso, dada la extensión de la lesión, el tratamiento fue con embolización bilateral de arterias uterinas seguida de histerectomía. Otras dos pacientes, p...

  16. Rotura uterina en gestante con cesárea anterior tras maniobra de Kristeller: Reporte de caso

    OpenAIRE

    2014-01-01

    Antecedentes: La rotura uterina es una complicación rara (0,7%), pero grave en la práctica obstétrica. La cesárea previa es el factor predisponente más importante para este evento catastrófico. Su aparición espontánea es extremadamente rara, se estima que ocurre en 1 de 8000 a 1 de 15.000 partos. Objetivo: Divulgar un caso clínico de interés para la comunidad médica por la asociación de la rotura uterina con un factor de riesgo poco establecido como es la presión fúndica (Maniobra de Kristell...

  17. 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”.

  18. Capacidade de aprendizagem das empresas familiares

    OpenAIRE

    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 ...

  19. 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.

  20. Modulatory effects of taurine on jejunal contractility

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    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.

  1. Compensatory Hypertrophy of Skeletal Muscle: Contractile Characteristics

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    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…

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. LA CAPACIDAD ACELERATIVA EN EL DEPORTE

    OpenAIRE

    Isidoro Hornillos Baz

    2010-01-01

    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 desa...

  7. Evaluación de diferentes tratamientos en el posparto temprano a vacas lecheras con infecciones uterinas

    OpenAIRE

    Zita Wonchee Solórzano; Renato Raúl Lozano Domínguez; Everardo González Padilla

    2002-01-01

    Se evaluó el uso de tratamientos hormonales (GnRH y PGF2 #945;) y antibióticos (oxitetraciclina) en vacas lecheras Holstein Friesian con infección uterina en el posparto temprano (16.2 ± 3.8 días). Tratamientos: 1) testigo positivo (infectadas, no tratadas; n=30); 2) hormona liberadora de gonadotropinas (GnRH; n=29); 3) Prostaglandina F2 #945; (Pg; n=25); 4) oxitetraciclina (Ab; n=38); 5) GnRH+Pg (n=25); 6) GnRH+Ab (n=33); 7) Ab+Pg (n=25); 8) GnRH+Ab+Pg (n=29) y 9) testigo negativo (no infect...

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

    Directory of Open Access Journals (Sweden)

    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

  9. 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.

  10. El debate sobre el enfoque de las capacidades: las capacidades colectivas

    Directory of Open Access Journals (Sweden)

    Alfonso Dubois Migoya

    2008-01-01

    Desde esta preocupación el artículo pretende indagar hasta dónde las categorías teóricas del enfoque de las capacidades ofrecen bases para elaborar estrategias de desarrollo humano cuyo objetivo sea la consecución de logros de desarrollo humano colectivo. Para ello, se ofrece una perspectiva del estado actual del debate sobre las categorías de análisis colectivas del desarrollo humano, que contempla al enfoque de las capacidades como objeto de análisis, y, por otra parte, presenta diversas propuestas teóricas que pretenden paliar sus carencias en ese sentido. Para ello considera dos grandes apartados: a partiendo del enfoque de las capacidades, qué propuestas se hacen de manera que se integren de manera más decidida las dimensiones relacionales; b partiendo de entender que el enfoque de las capacidades presenta carencias que no pueden suplirse implemente desde la ampliación de nuevas capacidades individuales, qué categorías teóricas se proponen para la consideración de la dimensión colectiva del bienestar.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

  13. Capacidades comunicativas de la música

    OpenAIRE

    Santacreu Fernández, Oscar A.

    2004-01-01

    No son pocos los que afirman que la música es un lenguaje universal, si bien se debe ser cauto a la hora de realizar este tipo de afirmaciones (la música tiene una gran carga cultural y por tanto la forma de entenderla varía entre las distintas culturas). Parece claro que existen nexos de unión entre la música y el lenguaje, siendo el más evidente la capacidad de música y lenguaje para expresar sentimientos y crearlos en quien escucha Facultad de Bellas Artes

  14. 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

  15. 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.

  16. Elastomeric contractile actuators for hand rehabilitation splints

    Science.gov (United States)

    Carpi, Federico; Mannini, Andrea; De Rossi, Danilo

    2008-03-01

    The significant electromechanical performances typically shown by dielectric elastomer actuators make this polymer technology particularly attractive for possible active orthoses for rehabilitation. Folded contractile actuators made of dielectric elastomers were recently described as a simple configuration, suitable to easily implement linear contractile devices. This paper describes an application of folded actuators for so-called hand splints: they consist of orthotic systems for hand rehabilitation. The dynamic versions of the state-of-the-art splints typically include elastic bands, which exert a passive elastic resistance to voluntary elongations of one or more fingers. In order to provide such splints with the possibility of electrically modulating the compliance of the resistive elements, the substitution of the passive elastic bands with the contractile actuators is here described. The electrical activation of the actuators is used to vary the compliance of the system; this enables modulations of the force that acts as an antagonist to voluntary finger movements, according to programmable rehabilitation exercises. The paper reports results obtained from the first prototype implementations of such a type of system.

  17. Fatores determinantes da capacidade funcional entre idosos

    Directory of Open Access Journals (Sweden)

    Rosa Tereza Etsuko da Costa

    2003-01-01

    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.

  18. 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.

  19. Capacidade antioxidante da própolis

    OpenAIRE

    2014-01-01

    A própolis é uma substância resinosa coletada de diversas partes das plantas por abelhas e misturada à cera, pólen e secreções salivares. Sua composição é complexa e está relacionada, principalmente, às características da vegetação de cada região. Trinta e três amostras de própolis foram coletadas em quatro regiões brasileiras (Nordeste, Sudeste, Sul e Centro-Oeste) e analisadas quanto à sua capacidade antioxidante, pela oxidação acoplada do sistema β-caroteno/ácido linoleico. Variação s...

  20. 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

  1. 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.

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

    OpenAIRE

    Martínez Abaunza Víctor Eduardo; Mendoza Castellanos Alfonso; Uribe Pérez Claudia Janeth

    2007-01-01

    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. La...

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. Prevalência de alterações uterinas e tubárias na histerossalpingografia em mulheres inférteis: estudo de 48 casos

    Directory of Open Access Journals (Sweden)

    Pérez Juliano Adams

    2001-01-01

    Full Text Available A histerossalpingografia é um exame realizado para avaliação da anatomia uterina e da permeabilidade tubária, característica esta que torna a pesquisa de causa de infertilidade primária ou secundária sua principal indicação. Este trabalho se propôs a estudar a prevalência de alterações na histerossalpingografia em pacientes com infertilidade. Para tal, foram alocadas todas as pacientes que se submeteram ao exame, num período de quatro meses. Entre as 48 pacientes estudadas, 36 apresentavam infertilidade primária e 12, infertilidade secundária. As pacientes com infertilidade primária apresentaram maior índice de malformações uterinas, enquanto as pacientes com infertilidade secundária apresentaram obstrução tubária como alteração mais freqüente. Não ocorreu nenhuma intercorrência significativa durante a realização dos exames. O trabalho permite afirmar que este exame é muito útil na pesquisa de infertilidade, uma vez que, freqüentemente, diagnostica alterações importantes, sendo um exame barato e de raras complicações.

  8. Contractility is the main determinant of coronary systolic flow impediment.

    Science.gov (United States)

    Krams, R; Sipkema, P; Zegers, J; Westerhof, N

    1989-12-01

    We measured the relation between coronary flow amplitude (delta F = Fd-Fs; where d is diastolic and s is systolic) and developed left ventricular pressure (delta PLV = Ps-Pd) at a constant perfusion pressure of 75 mmHg (10 kPa) in the maximally vasodilated blood-perfused isolated cat heart for different steady-state levels of contractility (protocol A) and during transients in contractility (protocol B). Contractility was defined as the slope of the end-systolic pressure-volume relation (Emax). From protocol A it appeared that the coronary flow amplitude was only weakly related to left ventricular pressure at each steady-state level of contractility studied. However, the coronary flow amplitude was strongly related to the different levels of contractility. In protocol B, contractility was changed over a wide range of values (0-100%) but developed pressure and contractility changed simultaneously. Using multiple linear regression analysis, we found that contractility has approximately 10 times (range: 2.8-57.3) stronger effect than left ventricular pressure on coronary flow amplitude (n = 10 experiments). These data and our earlier observations suggest that it is the difference in stiffness of cardiac muscle between systole and diastole that determines coronary flow amplitude.

  9. Capacidade produtiva de cultivares de berinjela

    Directory of Open Access Journals (Sweden)

    Antonini Antonio C. C.

    2002-01-01

    Full Text Available Determinou-se a capacidade produtiva de diferentes híbridos e cultivares de berinjela. Sete híbridos (Nápoli, Diamante Negro, Ciça, F-100, Super F-100, Kiko e F-2000 e duas cultivares de polinização aberta (Suzuki e Florida Market foram avaliados. O delineamento experimental foi em blocos ao acaso, constituído de nove tratamentos e três repetições. Cada repetição foi composta de oito plantas. As mudas foram plantadas no espaçamento 1,5m x 1,0m. A cultivar Suzuki produziu a maior quantidade de frutos por planta (27 frutos embora tenha apenas diferido significativamente da cultivar Flórida Market (13 frutos. Os híbridos testados apresentaram número de frutos variando de 20 a 25. Não foi verificada diferença significativa para o número de frutos de 1ª e 2ª categoria entre os materiais testados. Flórida Market e Kiko apresentaram a maior massa média do fruto (362,5 e 358,7 g, respectivamente, diferindo significativamente da cultivar Suzuki, que produziu frutos com a menor massa (178,9 g. As maiores produções por planta foram obtidas com o híbrido Kiko que diferiu significativamente da cultivar Suzuki. Foi verificado que os híbridos Kiko, Diamante Negro, Ciça e F-2000 apresentam potencial de produção semelhante ao Nápoli, atual padrão de mercado.

  10. 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.

  11. 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.

  12. 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.

  13. Considerations for contractile electroactive materials and actuators

    Science.gov (United States)

    Rasmussen, Lenore; Schramm, David; Rasmussen, Paul; Mullally, Kevin; Meixler, Lewis D.; Pearlman, Daniel; Kirk, Alice

    2011-04-01

    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.

  14. 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.

  15. CREANDO CAPACIDADES QUE AUMENTEN EL VALOR PARA EL CLIENTE

    Directory of Open Access Journals (Sweden)

    Martelo Landroguez, Silvia

    2011-04-01

    Full Text Available El objetivo de este artículo es contribuir a la literatura al identificar las posibles combinaciones entre tres capacidades organizativas (orientación al mercado, procesos de conocimiento y gestión de la relación con el cliente y analizar su interacción, cuyo resultado será la creación de un mayor valor para el cliente. Nuestra pregunta clave es ‘si los clientes demandan mayor valor, ¿cómo tenemos que combinar las capacidades existentes en la empresa para ofrecerle al cliente ese valor superior?’ Nosotros proponemos que la interacción entre las tres capacidades conforma una capacidad de orden superior.

  16. 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.

  17. Contractile dysfunction of the shoulder (rotator cuff tendinopathy): an overview.

    Science.gov (United States)

    Littlewood, Chris

    2012-11-01

    It is now over a decade since the features defining a contractile dysfunction of the shoulder were first reported. Since this time, some progress has been made to better understand this mechanical syndrome. In response to these developments, this narrative review will explore current understanding in relation to pathology, diagnosis, treatment, and prognosis of this syndrome with reference to literature specifically relating to contractile dysfunction but also literature relating to rotator cuff tendinopathy where necessary. The review not only identifies the strengths of the mechanical diagnosis and therapy approach with reference to a contractile dysfunction of the shoulder but also identifies where further progress needs to be made.

  18. 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...

  19. Ciclo estral, histologia e ultra-estrutura do epitelio da tuba uterina da linhagem de ratos UChA e UChB (bebedores voluntarios de etanol)

    OpenAIRE

    Camila Contin Diniz de Almeida-Francia

    2005-01-01

    Resumo: O alcoolismo é o terceiro problema mais sério de Saúde Pública Mundial. A maioria é constituída de homens, entretanto, o índice de mulheres viciadas em bebidas alcoólicas vem aumentando. A tuba uterina promove o meio necessário para a maturação dos gametas femininos e masculinos (capacitação), a fertilização e o desenvolvimento inicial do embrião. As variedades UChA e UChB constituem modelos para os trabalhos relacionados aos aspectos genéticos, bioquímicos, fisiológicos, nutricionais...

  20. 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.

  1. 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.

  2. 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...

  3. 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...

  4. Caveolin-1 regulates contractility in differentiated vascular smooth muscle.

    Science.gov (United States)

    Je, Hyun-Dong; Gallant, Cynthia; Leavis, Paul C; Morgan, Kathleen G

    2004-01-01

    Caveolin is a principal component of caveolar membranes. In the present study, we utilized a decoy peptide approach to define the degree of involvement of caveolin in PKC-dependent regulation of contractility of differentiated vascular smooth muscle. The primary isoform of caveolin in ferret aorta vascular smooth muscle is caveolin-1. Chemical loading of contractile vascular smooth muscle tissue with a synthetic caveolin-1 scaffolding domain peptide inhibited PKC-dependent increases in contractility induced by a phorbol ester or an alpha agonist. Peptide loading also resulted in a significant inhibition of phorbol ester-induced adducin Ser662 phosphorylation, an intracellular monitor of PKC kinase activity, ERK1/2 activation, and Ser789 phosphorylation of the actin binding protein caldesmon. alpha-Agonist-induced ERK1-1/2 activation was also inhibited by the caveolin-1 peptide. Scrambled peptide-loaded tissues or sham-loaded tissues were unaffected with respect to both contractility and signaling. Depolarization-induced activation of contraction was not affected by caveolin peptide loading. Similar results with respect to contractility and ERK1/2 activation during exposure to the phorbol ester or the alpha-agonist were obtained with the cholesterol-depleting agent methyl-beta-cyclodextrin. These results are consistent with a role for caveolin-1 in the coordination of signaling leading to the regulation of contractility of smooth muscle.

  5. Capacidad económica como principio del sistema tributario

    OpenAIRE

    Piza Rodríguez, Julio Roberto

    2011-01-01

    Este artículo parte del hecho que para financiar los bienes y servicios públicos que el Estado está en la obligación de garantizar a los ciudadanos, es preciso utilizar como criterio de distribución de la carga tributaria la capacidad económica, en virtud del principio de solidaridad del sistema impositivo. Sin embargo, vale señalar que en Colombia, a pesar de la influencia de la constitución española, en nuestra constitución no se consagró expresamente el principio de capacidad económica. Po...

  6. CREANDO CAPACIDADES QUE AUMENTEN EL VALOR PARA EL CLIENTE

    OpenAIRE

    Martelo Landroguez, Silvia; Barroso Castro, Carmen; Cepeda Carrión, Gabriel

    2011-01-01

    El objetivo de este artículo es contribuir a la literatura al identificar las posibles combinaciones entre tres capacidades organizativas (orientación al mercado, procesos de conocimiento y gestión de la relación con el cliente) y analizar su interacción, cuyo resultado será la creación de un mayor valor para el cliente. Nuestra pregunta clave es ‘si los clientes demandan mayor valor, ¿cómo tenemos que combinar las capacidades existentes en la empresa para ofrecerle al cliente ese valor super...

  7. 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.

  8. 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.

  9. Effects of Hindlimb Unweighting on Arterial Contractile Responses in Mice

    Science.gov (United States)

    Ma, Jia; Ren, Xin-Ling; Purdy, Ralph E.

    2003-01-01

    The aim of this work was to determine if hindlimb unweighting in mice alters arterial contractile responses. Sixteen male C57B/6 mice and 16 male Chinese Kunming mice were divided into control and 3 weeks hindlimb unweighting groups, respectively. Using isolated arterial rings from different arteries of mouse, effects of 3 weeks hindlimb unweighting on arterial contractile responsiveness were examined in vitro. The results showed that, in arterial rings from both C57B/6 and Chinese Kunming mice, maximum isometric contractile tensions evoked by either KCl or phenylephrine were significantly lower in abdominal aortic, mesenteric arterial and femoral arterial rings from hindlimb unweighting, compared to control mice. However, the maximal contractile responses of common carotid rings to KCl and PE were not significantly different between control and hindlimb unweighting groups. The sensitivity (EC(sub 50)) of all arteries to KCl or PE showed no significant differences between control and hindlimb unweighting mice. These data indicated that 3 weeks hindlimb unweighting results in a reduced capacity of the arterial smooth muscle of the hindquarter to develop tension. In addition, the alterations in arterial contractile responses caused by hindlimb unweighting in mice are similar as those in rats. Our work suggested that hindlimb unweighting mouse model may be used as a model for the study of postflight cardiovascular deconditioning.

  10. 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.

  11. 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.

  12. 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...

  13. 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

  14. 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.

  15. 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.

  16. Capacidades intangibles para la competitividad microempresarial en México

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    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.

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

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    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

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

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    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.

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

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    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.

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

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    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.

  1. Inhalation of Budesonide/Formoterol Increases Diaphragm Muscle Contractility

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    Chiyohiko Shindoh

    2012-01-01

    Conclusions: BUD/FORM inhalation has an inotropic effect on diaphragm muscle, protects diaphragm muscle deterioration after endotoxin injection, and inhibits NO production. Increments in muscle contractility with BUD/FORM inhalation are induced through a synergistic effect of an anti-inflammatory agent and 02-agonist.

  2. Concordancia entre capacidad vital lenta y capacidad vital forzada en pacientes con enfermedad pulmonar obstructiva crónica o con sospecha de ella

    OpenAIRE

    Hidalgo Martínez, Patricia

    2010-01-01

    Objetivo. Determinar la concordancia en términos de consistencia entre la capacidad vital lenta y la capacidad vital forzada en pacientes con enfermedad pulmonar obstructiva crónica (EPOC) o remitidos por sospecha de EPOC. Diseño. Estudio de concordancia en términos de consistencia entre la capacidad vital lenta (CVL) y la capacidad vital forzada (CVF) en pacientes con EPOC o remitidos por sospecha de EPOC. Lugar. Se llevó a cabo en el Laboratorio de Función Pulmonar del Hospital Universitari...

  3. Airway smooth muscle cell tone amplifies contractile function in the presence of chronic cyclic strain.

    Science.gov (United States)

    Fairbank, Nigel J; Connolly, Sarah C; Mackinnon, James D; Wehry, Kathrin; Deng, Linhong; Maksym, Geoffrey N

    2008-09-01

    Chronic contractile activation, or tone, in asthma coupled with continuous stretching due to breathing may be involved in altering the contractile function of airway smooth muscle (ASM). Previously, we (11) showed that cytoskeletal remodeling and stiffening responses to acute (2 h) localized stresses were modulated by the level of contractile activation of ASM. Here, we investigated if altered contractility in response to chronic mechanical strain was dependent on repeated modulation of contractile tone. Cultured human ASM cells received 5% cyclic (0.3 Hz), predominantly uniaxial strain for 5 days, with once-daily dosing of either sham, forskolin, carbachol, or histamine to alter tone. Stiffness, contractility (KCl), and "relaxability" (forskolin) were then measured as was cell alignment, myosin light-chain phosphorylation (pMLC), and myosin light-chain kinase (MLCK) content. Cells became aligned and baseline stiffness increased with strain, but repeated lowering of tone inhibited both effects (P negative tone-modulation dependence of MLCK, observed in static conditions in agreement with previous reports, with strain and tone together increasing both MLCK and pMLC. Furthermore, contractility increased 176% (SE 59) with repeated tone elevation. These findings indicate that with strain, and not without, repeated tone elevation promoted contractile function through changes in cytoskeletal organization and increased contractile protein. The ability of repeated contractile activation to increase contractility, but only with mechanical stretching, suggests a novel mechanism for increased ASM contractility in asthma and for the role of continuous bronchodilator and corticosteroid therapy in reversing airway hyperresponsiveness.

  4. Predição da restrição do crescimento fetal pela medida da altura uterina Prediction of fetal growth restriction by measurement of uterine height

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    Silvio Martinelli

    2004-06-01

    Full Text Available OBJETIVO: avaliar o emprego da medida da altura uterina para o diagnóstico da restrição do crescimento fetal (RCF, empregando como padrão curvas conhecidas de evolução da altura uterina do próprio serviço. MÉTODOS: entre julho de 2000 e fevereiro de 2003, 238 gestantes de alto risco foram submetidas a medidas de altura uterina, da 20ª à 42ª semana de gestação. Todas possuíam idade gestacional confirmada por ultra-sonografia precoce. Cinqüenta (21,0% gestantes tiveram recém-nascidos pequenos para a idade gestacional. O mesmo observador realizou 1617 medidas de altura uterina, com fita métrica, da borda superior da sínfise púbica ao fundo uterino. A confirmação do diagnóstico de RCF foi dada após o nascimento pela curva de Ramos. Para a análise estatística, as gestantes foram comparadas segundo o peso dos recém-nascidos, por meio do teste exato de Fisher ou teste não paramétrico de Kruskal-Wallis, quando aplicável. Foram calculados: sensibilidade (S, especificidade (E, valor preditivo positivo (VPP e negativo (VPN para o diagnóstico de RCF. Para a análise dos valores contínuos foi utilizado o teste para duas proporções com aproximação normal. RESULTADOS: para a ocorrência de RCF, considerando-se uma medida de altura uterina abaixo do percentil 10 para a idade gestacional, S foi de 78%, E de 77,1%, VPP de 47,6% e VPN de 92,9%. Utilizando como limite o percentil 5, foram obtidos S = 64%, E = 89,9%, VPP = 62,7% e VPN = 90,4%, para o diagnóstico da RCF. CONCLUSÃO: medida de altura uterina abaixo do percentil 10 para a idade gestacional, pela curva local, mostra-se como bom teste para o rastreamento da RCF.OBJECTIVE: to evaluate the measurement of uterine height in order to predict fetal growth restriction (FGR, according to a local curve. METHODS: from July 2000 to February 2003, 238 high-risk pregnant women were submitted to uterine height measurements between the 20th and the 42nd week of gestation. The

  5. Tecnologia de la capacidad funcional del paciente en movimiento

    OpenAIRE

    Sedano Martínez, Esther María; Ventura Rosa, María Carmen; Morillo Vázquez, María F.; Argüelles Menéndez, Ana

    2010-01-01

    En los últimos años la Valoración Funcional se ha convertido en una alternativa a otros exámenes de diagnósticos por imágenes que se utilizan habitualmente, aunque a diferencia de ellas que son estáticas como las Rx, Scaner, RNM etc., la biomecánica mide y registra gráficamente la capacidad funcional del paciente en movimiento de una manera objetiva, fiable, repetible y no manipulable por el paciente. Estas aplicaciones ayudan a objetivar alteraciones de la movilidad articul...

  6. 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...

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

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    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.

  8. Ensayos triaxiales de rocas en celula de gran capacidad

    OpenAIRE

    Casellas Ferrer, Javier

    2013-01-01

    El trabajo realizado en esta tesina se centra en la realización de una serie de ensayos a probetas de roca para poder determinar sus características mecánicas principales. Se realizan ensayos destinados a estudiar los fenómenos de fractura en el campo de lo smateriales cuasi-frágiles, ensayo Wedge Splitting Test. Adicionalmente en esta tesina serealizarán ensayos de compresión, tanto compresión simple como compresión triaxial en una celda de confinamiento de alta capacidad utilizando una pren...

  9. Estudio macro-microscópico de la involución uterina postparto en alpacas - Macro and microscopic of uterine involution postpartum in alpacas

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    MVZ. Augusto Excelmes Loza. Puno-Perú 2005

    2006-07-01

    Full Text Available El presente estudio se llevo a cabo en el Laboratorio de Histología y Embriología de la Facultad de Medicina Veterinaria y Zootecnia de la Universidad Nacional del Altiplano; con alpacas provenientes de la Rural Alianza E.P.S. (4,140m.s.n.m, Centro Experimental Quinsachata-INIA (4,050 m.s.n.m y el Centro de Investigación y Producción La Raya (4,130 m.s.n.m, cuyo objetivo fue el estudio del proceso de la involución uterina post parto en la alpaca, desde el parto hasta los 30dpp. Para tal propósito se estudiaron 34 alpacas multíparas de 4 a 6 años de edad. Los resultados fueron: Macroscópicamente: la perdida de peso del útero fue de: 71.07% (385,25g, 25.54% (138.55g y 3.42% (18.6g al primer, segundo y tercer periodo de la involución uterina. La reducción de Peso del cuerno uterino derecho fue de: 55.26% (37.55g, 38.63% (26.25g y 6.11% (4.15g al primer segundo y tercer periodo respectivamente. La secuencia de la perdida de peso del cuerno uterino izquierdo fue de: 75.50% (159.5g, 19.58% (41.25g, y 4.92% (10.40g al primer, segundo y tercer periodo sucesivamente. El descenso de Peso del cuerpo del útero fue de: 76.60% (87.25g, 17.08% (19.45g y 6.32% (7.2g al primer, segundo y tercer periodo sucesivamente. El Peso de reducción gradual de la cervix fue de: 68% (47,15g, 26,10% (18,00g y 5,51% (3,8g al primer, segundo y tercer periodo respectivamente. This study was carried out in the Histology and Embriology laboratory at the Medicine Veterinary and Zootecny of the Altiplano National University, with alpacas coming from the EPS Rural Alliance (4140 m.a.s.l., Quimsachata Research Center (4050 m.a.s.l. and the Raya Research Center (4130 m.a.s.l. whose objective was the study the process of the uterine involution after parturition from day 0 to 30. For such purpose 34 multiparous alpacas from 4 to 6 year old were selectec. The results were: Macroscopically the uterusweight lost 71,07% (385,25g, 25,54% (138,55g and 3,42% (18,6g at first

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

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    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.

  11. Estudio macro-microscópico de la involución uterina postparto en Alpacas (Macro and microscopic of uterine involution postpartum in alpacas summary

    Directory of Open Access Journals (Sweden)

    MVZ. Augusto Excelmes Loza.

    2006-04-01

    Full Text Available El presente estudio se llevo a cabo en el Laboratorio de Histología y Embriología de la Facultad de Medicina Veterinaria y Zootecnia de la Universidad Nacional del Altiplano; con alpacas provenientes de la Rural Alianza E.P.S. (4,140m.s.n.m, Centro Experimental Quinsachata-INIA (4,050 m.s.n.m y el Centro de Investigación y Producción La Raya (4,130 m.s.n.m, cuyo objetivo fue el estudio del proceso de la involución uterina post parto en la alpaca, desde el parto hasta los 30dpp. Para tal propósito se estudiaron 34 alpacas multíparas de 4 a 6 años de edad. Los resultados fueron: Macroscópicamente: la perdida de peso del útero fue de: 71.07% (385,25g, 25.54% (138.55g y 3.42% (18.6g al primer, segundo y tercer periodo de la involución uterina. La reducción de Peso del cuerno uterino derecho fue de: 55.26% (37.55g, 38.63% (26.25g y 6.11% (4.15g al primer segundo y tercer periodo respectivamente. La secuencia de la perdida de peso del cuerno uterino izquierdo fue de: 75.50% (159.5g, 19.58% (41.25g, y 4.92% (10.40g al primer, segundo y tercer periodo sucesivamente. El descenso de Peso del cuerpo del útero fue de: 76.60% (87.25g, 17.08% (19.45g y 6.32% (7.2g al primer, segundo y tercer periodo sucesivamente. El Peso de reducción gradual de la cervix fue de: 68% (47,15g, 26,10% 18,00g y 5,51% (3,8g al primer, segundo y tercer periodo respectivamente. Histológicamente: durante los primeros días la superficie uterina es irregular y presenta proyecciones endometriales de aspecto fungiforme y esta cubierto por células pavimentosas, estroma con la presencia de linfocitos, macrófagos y fibroblastos, glándulas reducidas en su diámetro. A partir del sexto día, muestra cambio en el regenerativo, el epitelio de hace predominantemente cúbico, Del sexto al doceavo día el epitelio continua irregular con pequeñas áreas con células epiteliales pavimentosas y cúbicas, lo cual coincide con el cambio en el peso del útero en forma significativa

  12. 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.

  13. Distribuição da altura uterina ao longo da gestação em uma coorte brasileira: comparação com a curva de referência do Centro Latino-Americano de Perinatologia

    OpenAIRE

    Oppermann, Maria Lúcia Rocha; Duncan, Bruce Bartholow; Mengue, Sotero Serrate; Ramos, José Geraldo Lopes; Serruya,Suzanne Jacob; Schmidt, Maria Inês

    2006-01-01

    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 ...

  14. Infecção do sítio cirúrgico em pacientes submetidas à cesárea com sutura uterina exteriorizada versus sutura in situ: ensaio clínico randomizado

    OpenAIRE

    Cristina Coutinho de Albuquerque Neiva Coêlho, Isabela

    2007-01-01

    Objetivos: Comparar a sutura uterina extra-abdominal com a sutura in situ na cesárea. Métodos: Foi realizado um ensaio clínico randomizado no IMIP (Recife, Brasil). Os critérios de inclusão foram indicação de cesárea e idade gestacional > 24 semanas. Pacientes com duas ou mais cesáreas anteriores, corioamnionite, hemorragias, incapacidade para consentir e cirurgia abdominal prévia foram excluídas. As variáveis analisadas foram náuseas, vômitos, média do tempo cirúrgico, perda s...

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

    OpenAIRE

    Angela Patricia Cadavid Jaramillo; Beatriz Peña; Julio César Bueno Sánchez

    2000-01-01

    Las células asesinas naturales (NK) uterinas son una subpoblación diferente a las de sangre periférica, expresan los marcadores CD56bright y CD16- VALIDACIÓN DE LA CITOLOGIA CÉRVICO UTERINA CONVENCIONAL CON PRUEBA DE REFERENCIA HISTOPATOLÓGICA EN LA IDENTIFICACIÓN DE CÁNCER ESCAMOCELULAR INVASOR

    OpenAIRE

    García A,Ernesto; Díaz P,Julio; Melo U,Mario; Parra F,Fabián; Vera C,Lina; Orozco V,Luis

    2006-01-01

    Antecedentes: La citología cérvico uterina convencional (CCUC) es la prueba de tamizaje más empleada en la detección del cáncer de cuello uterino, sin embargo su calidad es discutida. Objetivo: Evaluar el rendimiento de la CCUC en el tamizaje de cáncer escamocelular invasor de cuello uterino. Métodos: Fueron seleccionadas 1980 usuarias de la Liga Santandereana de Lucha Contra el Cáncer. Siguiendo un muestreo prospectivo se realizó un análisis estadístico para validar la CCUC en el diagnóstico...

  16. Contractile system of muscle as an auto-oscillator.

    Science.gov (United States)

    Ishiwata, Shin'ichi; Shimamoto, Yuta; Fukuda, Norio

    2011-05-01

    It is widely known that the contractile system of muscle takes on either the state of contraction (force-generating) or the state of relaxation (non-force-generating), which is known as the "all-or-nothing" principle. However, it is important to note that under intermediate activation conditions there exists a third state, which demonstrates auto-oscillatory properties and is termed SPOC (SPontaneous Oscillatory Contraction) state. We present a phase diagram, in which the states of the contractile system of muscle are divided into three regions consisting of contraction, relaxation and SPOC states. In the present review, experimental data related to the characteristics of SPOC are summarized and the mechanism of SPOC is described. We propose that the bio-motile system itself is an auto-oscillator, even in a membrane-less supra-molecular structure composed of an assembly of molecular motors and cytoskeletons (actin filaments and microtubules). Finally, the physiological significance of SPOC is discussed.

  17. Wound-induced contractile ring: a model for cytokinesis.

    Science.gov (United States)

    Darenfed, Hassina; Mandato, Craig A

    2005-12-01

    The actomyosin-based contractile ring is required for several biological processes, such as wound healing and cytokinesis of animal cells. Despite progress in defining the roles of this structure in both wound closure and cell division, we still do not fully understand how an actomyosin ring is spatially and temporally assembled, nor do we understand the molecular mechanism of its contraction. Recent results have demonstrated that microtubule-dependent local assembly of F-actin and myosin-II is present in wound closure and is similar to that in cytokinesis in animal cells. Furthermore, signalling factors such as small Rho GTPases have been shown to be involved in the regulation of actin dynamics during both processes. In this review we address recent findings in an attempt to better understand the dynamics of actomyosin contractile rings during wound healing as compared with the final step of animal cell division.

  18. Intratumoral LIGHT Restores Pericyte Contractile Properties and Vessel Integrity

    OpenAIRE

    Anna Johansson-Percival; Zhi-Jie Li; Devina D. Lakhiani; Bo He; Xiao Wang; Juliana Hamzah; Ruth Ganss

    2015-01-01

    Normalization of the tumor vasculature is an emerging concept shown to improve anti-cancer therapy. However, there are currently no clinical interventions that effect long-lasting normalization. Here, we have developed a strategy for normalization by specific intratumoral delivery of LIGHT/TNFSF14. Importantly, normalization occurs by induced expression of contractile markers in intratumoral pericytes, which in turn re-establishes tight pericyte-vessel alignment. Restoring vessel integrity im...

  19. 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.

  1. 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.

  2. Effect of pentoxifylline on diaphragmatic contractility in septic rats.

    Directory of Open Access Journals (Sweden)

    Ujike,Yoshihito

    2008-04-01

    Full Text Available We investigated the effects of pentoxifylline (PTX on endotoxin-induced diaphragmatic dysfunction in vitro. Seventy-two rats were divided into 3 groups: a group in which endotoxin (20 mg/kg was injected intraperitoneally (endotoxin-group, a group in which PTX (100 mg/kg was injected intraperitoneally 30 min before injection of endotoxin (endotoxin-PTX group, and a group in which only saline was given (sham group. Left hemidiaphragms were removed 4 h after injection of endotoxin. We evaluated the diaphragmatic contractility by twitch characteristics and force-frequency curves in vitro. We measured serum TNF-alpha concentrations, diaphragm malondialdehyde (MDA levels (an index of oxygen-derived free radical-mediated lipid peroxidation, and diaphragm cAMP concentrations. Diaphragmatic force generation capacity was signifi cantly reduced after injection of endotoxin. Serum TNF-alpha concentrations and diaphragmatic MDA levels were significantly elevated after injection of endotoxin. PTX administration significantly improved diaphragmatic contractility and prevented the elevation in TNF-alpha concentrations and MDA levels after injection of endotoxin. There were no significant changes in the diaphragm cAMP concentrations among the 3 groups. These results demonstrated that PTX administration prevented endotoxin-induced diaphragmatic dysfunction without changing diaphragm muscle cAMP concentrations. The protective effects of PTX against endotoxininduced diaphragmatic contractile deterioration might be caused by attenuating TNF-alpha-mediated oxygen-derived free radical production.

  3. Surgical Treatment of Concomitant Atrial Fibrillation: Focus onto Atrial Contractility

    Directory of Open Access Journals (Sweden)

    Claudia Loardi

    2015-01-01

    Full Text Available Background. Maze procedure aims at restoring sinus rhythm (SR and atrial contractility (AC. This study evaluated multiple aspects of AC recovery and their relationship with SR regain after ablation. Methods. 122 mitral and fibrillating patients underwent radiofrequency Maze. Rhythm check and echocardiographic control of biatrial contractility were performed at 3, 6, 12, and 24 months postoperatively. A multivariate Cox analysis of risk factors for absence of AC recuperation was applied. Results. At 2-years follow-up, SR was achieved in 79% of patients. SR-AC coexistence increased from 76% until 98%, while biatrial contraction detection augmented from 84 to 98% at late stage. Shorter preoperative arrhythmia duration was the only common predictor of SR-AC restoring, while pulmonary artery pressure (PAP negatively influenced AC recuperation. Early AC restoration favored future freedom from arrhythmia recurrence. Minor LA dimensions correlated with improved future A/E value and vice versa. Right atrial (RA contractility restoring favored better left ventricular (LV performance and volumes. Conclusions. SR and left AC are two interrelated Maze objectives. Factors associated with arrhythmia “chronic state” (PAP and arrhythmia duration are negative predictors of procedural success. Our results suggest an association between postoperative LA dimensions and “kick” restoring and an influence of RA contraction onto LV function.

  4. 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.

  5. Capacidade combinatoria de capim elefante com base em caracteres morfoagronomicos

    Directory of Open Access Journals (Sweden)

    Vanessa Quitete Ribeiro da Silva

    2014-01-01

    Full Text Available Devido ao grande potencial de produção de biomassa do capim elefante, objetivou-se neste trabalho avaliar genitores para geração de híbridos superiores. Para tanto, foram estimados os efeitos da capacidade geral de combinação (CGC dos genitores e da capacidade específica de combinação (CEC de híbridos de capim elefante por meio de análise dialélica adaptada a dialelos parciais. Foram avaliados 16 híbridos e oito genitores utilizando delineamento em blocos casualizados com três repetições. Verificou-se a presença de variabilidade genética entre os híbridos e genitores, com predominância do efeito gênico de dominância para a maioria das características. De forma geral, os melhores resultados na CGC são os genitores Taiwan A-144, Vruckwona Africana e Taiwan A-146. Os melhores cruzamentos com base na CEC são Taiwan A-144 x Taiwan A-146 e Pusa Napier nº2 x Mercker Santa Rita.

  6. 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.

  7. Estudo ultra-sonográfico da involução uterina pós-parto em cadelas Ultrasonography study of the post-partum uterine involution in bitches

    Directory of Open Access Journals (Sweden)

    S.T.S. Ferri

    2002-02-01

    Full Text Available Utilizando-se 15 cadelas no pós-parto, são descritas as características da involução uterina e determinado o diâmetro do útero, por meio de exames seriados de ultra-som em modo B (tempo real, no período de zero a 28 dias pós-parto. O diâmetro uterino declina progressivamente, sem influência da ordem de parto ou tamanho da ninhada. As características ultra-sonográficas do útero são melhor visualizadas na primeira semana pós-parto e a qualidade da imagem diminui com o progresso da involução. Pela técnica usada são visualizadas apenas três camadas constituintes da parede uterina.The ultrasonographic characteristics and the involution of the uterus were described in 15 pregnant bitches by serial B-mode (real time technique at period of 0 to 28 days postpartum. The uterine diameter decreased progressively, without influence of parity or litter size. The ultrasonographic image of the uterus is better view in the first week and the image quality is poor at subsequent weeks. The uterus was composed of only three ecographic layers.

  8. Perfil docente para alumnos/as con altas capacidades

    Directory of Open Access Journals (Sweden)

    María Leonor Conejeros-Solar

    2013-01-01

    Full Text Available 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-práctica. Las percepciones de los estudiantes, poco incorporadas en discusiones relativas a la enseñanza, permiten repensar y delinear un perfil de las competencias docentes relevadas para un trabajo pedagógico efectivo con talentosos en el aula.

  9. Un estudio exploratorio de capacidades emocionales en adultos mayores

    Directory of Open Access Journals (Sweden)

    Zoe S. Bello Dávila

    2012-01-01

    Full Text Available Abstract The study of the emotional world of the elderly is a fundamental requisite for guaranteeing the well-being and health of this group. The objective of this research paper was to characterize a group of elderly people according to their motional capabilities. The group consisted of 122 elderly persons: 107 female, 15 male. All attendants participated in a “Círculo de Abuelos” (Circle of Grandparents. The study was descriptive, it sought to gather information about the responses of older adults in situations of emotional content by completing a questionnaire. The results provided a profile of capacities where areas of strength and weakness are clearly distinguished. Selfconfidence and the possibility of fulfilling projects are among the strengths while the weaknesses are found in interpersonal or intrapersonal managing of emotions. These results have led to a better understanding of the emotional world of the elderly and guide future educational activities. Resumen El estudio del mundo emocional de los adultos mayores es un requisito fundamental para garantizar el estado de bienestar y salud de los mismos. El presente artículo de investigación se fijó como objetivo caracterizar a un grupo de ancianos, en función de sus capacidades emocionales. Los participantes fueron 122 ancianos, en concreto 107 mujeres y 15 hombres, que asisten a un “Círculo de Abuelos”. El estudio fue de tipo descriptivo, pues pretendió recoger información acerca de las respuestas de los adultos mayores ante situaciones de contenido emocional que se exploran por medio de un cuestionario elaborado al efecto. Los resultados ofrecen un perfil de capacidades en que la autoconfianza y la posibilidad de elaborar proyectos se erigen como fortalezas, mientras que las debilidades se expresan en las dificultades para el manejo emocional tanto a nivel intra como interpersonal. Estos resultados han permitido lograr una mejor comprensión del mundo emocional del

  10. Contractile Units in Disordered Actomyosin Bundles Arise from F-Actin Buckling

    Science.gov (United States)

    Lenz, Martin; Thoresen, Todd; Gardel, Margaret L.; Dinner, Aaron R.

    2012-06-01

    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 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 motor head 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 show contraction at relatively high motor density, and we observe buckling at the predicted length scale.

  11. 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...

  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. Validación del Protocolo para el Estudio de la Hemorragia Uterina Anormal con Ecografía endovaginal y medio de Contraste (Sonohisterografía.

    Directory of Open Access Journals (Sweden)

    Ricardo Rueda Saenz

    2003-08-01

    Full Text Available

    La evaluación del sangrado uterino anormal (SUA especialmente en los años postreproductivos, convencionalmente se hace recurriendo a las biopsias y aspiraciones endometriales ciegas en el consultorio, o al curetaje uterino bajo anestesia general. Dichos procedimientos, además de ser invasivos, han mostrado ser poco sensibles y específicos en la detección y el tratamiento de la patología focal del endometrio (pólipos, leiomiomas submucosos, y además pueden resultar costosos. Con el advenimiento de la histeroscopia, se han obviado muchas de las dificultades atribuidas a la biopsia ciega y el curetaje uterino, pero aquella, además de requerir un entrenamiento específico y un equipo costoso, requiere de anestesia local o general, en ocasiones dilatación del cervix y en muchas instancias arroja resultados negativos.

    De otro lado, la histeroscopia sólo permite evaluar el canal cervical y la cavidad endometrial, sin poder visualizar la pared miometrial, los anexos y otras estructuras pélvicas, lo cual desvirtúa su uso en una gran proporción de pacientes como investigación inicial rutinaria en el sangrado uterino anormal.

    La utilización de la ecografía transvaginal con contraste líquido (sonohisterografía o histerosonografía permite, por el contrario, no solamente una evaluación precisa y detallada del canal cervical y la cavidad endometrial, sino que permite evaluar la pared miometrial, los ovarios y otras estructuras pélvicas, así como la permeabilidad de las trompas uterinas.

    Este procedimiento tiene además un bajo costo, no requiere de entrenamiento especial, tampoco de anestesia ni de dilatación cervical y tiene bajas tasas de complicaciones. Con la sonohisterografía se pueden seleccionar en forma eficiente y rápida, las mujeres que realmente se benefician de una histeroscopia diagnóstica-operatoria o de una biopsia endometrial ciega de consultorio para evaluar el SUA.

    El presente estudio

  14. Papilomavírus humano associado a lesões de cérvice uterina Human papillomavirus associated to uterine cervix lesions

    Directory of Open Access Journals (Sweden)

    Vânia Noronha

    1999-06-01

    Full Text Available Estudou-se a prevalência do papilomavírus humano (HPV em 228 mulheres portadoras de lesões em cérvice uterina, atendidas no Instituto Ofir Loiola, em Belém, Pará, no período de março de 1992 a maio de 1996. As pacientes foram submetidas à biópsia de colo uterino, sendo o material encaminhado para histopatologia e pesquisa de HPV por PCR e hibridização por dot-blot. Distribuíram-se as participantes em três grupos, conforme diagnóstico histopatológico. O grupo A constituiu-se de 155 mulheres com carcinoma epidermóide invasor ou com adenocarcinoma, o grupo B de 54 portadoras de neoplasia intra-epitelial cervical grau II ou III, e o grupo C de 19 pacientes com cervicite crônica. Observaram-se prevalências de HPV em 70,3%, 63,0% e 36,8% das mulheres dos grupamentos A, B e C, respectivamente, sendo o HPV 16 registrado em 60,4% das amostras positivas do grupo A e 54,5% daquelas do grupo B. Os tipos 16, 18 e 33 representaram 71,4% dos detectados no grupo C.It was studied the prevalence of human papillomavirus (HPV among 228 women with lesions of uterine cervix attending the Ofir Loiola Institute, in Belem, Para, from March 1992 to May 1996. Histopathological examination was performed with all cervical biopsy samples obtained from these patients. In addition, specimens were analysed by both polimerase chain reaction and dot-blot hybridization to detect HPV DNA. The patients were assigned to three groups, according to the diagnosis made by histopathology, as follows: A, including 155 women suffering from invasive epidermoid carcinoma or adenocarcinoma; B, 54 patients having either cervical intraepithelial neoplasia grade II or III; and C, involving 19 women with chronic cervicitis. The prevalence rates of HPV in groups A, B and C were 70.3%, 63% and 36.8% respectively. HPV 16 accounted for 60.4% and 54.5% of types identified in groups A and B, respectively. Altogether HPV types 16, 18 and 33 were detected in 71.4% of positive patients

  15. The role of microtubules in contractile ring function

    Science.gov (United States)

    Conrad, A. H.; Paulsen, A. Q.; Conrad, G. W.; Spooner, B. S. (Principal Investigator)

    1992-01-01

    During cytokinesis, a cortical contractile ring forms around a cell, constricts to a stable tight neck and terminates in separation of the daughter cells. At first cleavage, Ilyanassa obsoleta embryos form two contractile rings simultaneously. The cleavage furrow (CF), in the animal hemisphere between the spindle poles, constricts to a stable tight neck and separates the daughter cells. The third polar lobe constriction (PLC-3), in the vegetal hemisphere below the spindle, constricts to a transient tight neck, but then relaxes, allowing the polar lobe cytoplasm to merge with one daughter cell. Eggs exposed to taxol, a drug that stabilizes microtubules, before the CF or the PLC-3 develop, fail to form CFs, but form stabilized tight PLCs. Eggs exposed to taxol at the time of PLC-3 formation develop varied numbers of constriction rings in their animal hemispheres and one PLC in their vegetal hemisphere, none of which relax. Eggs exposed to taxol after PLC-3 initiation form stabilized tight CFs and PLCs. At maximum constriction, control embryos display immunolocalization of nonextractable alpha-tubulin in their CFs, but not in their PLCs, and reveal, via electron microscopy, many microtubules extending through their CFs, but not through their PLCs. Embryos which form stabilized tightly constricted CFs and PLCs in the presence of taxol display immunolocalization of nonextractable alpha-tubulin in both constrictions and show many polymerized microtubules extending through both CFs and PLCs. These results suggest that the extension of microtubules through a tight contractile ring may be important for stabilizing that constriction and facilitating subsequent cytokinesis.

  16. 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.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    information. We developed a genetic fuzzy system (GFS) algorithm that is capable of learning all information in time-domain physiological data. Data on isometric force development of isolated small arteries were used as a framework for developing and optimizing a GFS. GFS performance was improved by several...... 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...

  18. 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.

  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. La autoprotección de las personas con capacidad modificada

    OpenAIRE

    Meléndez Arias, María del Carmen

    2012-01-01

    Las posibilidades que el ordenamiento jurídico español ofrece al sujeto capaz de obrar o con capacidad suficiente, para organizar la protección de su persona y bienes en una situación futura de pérdida de facultades o de modificación de su capacidad.

  1. 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

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

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    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.

  3. Comparing contractile apparatus-driven cytokinesis mechanisms across kingdoms.

    Science.gov (United States)

    Balasubramanian, Mohan K; Srinivasan, Ramanujam; Huang, Yinyi; Ng, Kian-Hong

    2012-11-01

    Cytokinesis is the final stage of the cell cycle during which a cell physically divides into two daughters through the assembly of new membranes (and cell wall in some cases) between the forming daughters. New membrane assembly can either proceed centripetally behind a contractile apparatus, as in the case of prokaryotes, archaea, fungi, and animals or expand centrifugally, as in the case of higher plants. In this article, we compare the mechanisms of cytokinesis in diverse organisms dividing through the use of a contractile apparatus. While an actomyosin ring participates in cytokinesis in almost all centripetally dividing eukaryotes, the majority of bacteria and archaea (except Crenarchaea) divide using a ring composed of the tubulin-related protein FtsZ. Curiously, despite molecular conservation of the division machinery components, division site placement and its cell cycle regulation occur by a variety of unrelated mechanisms even among organisms from the same kingdom. While molecular motors and cytoskeletal polymer dynamics contribute to force generation during eukaryotic cytokinesis, cytoskeletal polymer dynamics alone appears to be sufficient for force generation during prokaryotic cytokinesis. Intriguingly, there are life forms on this planet that appear to lack molecules currently known to participate in cytokinesis and how these cells perform cytokinesis remains a mystery waiting to be unravelled.

  4. Effect of serotonin on small intestinal contractility in healthy volunteers

    DEFF Research Database (Denmark)

    Hansen, M.B.; Arif, F.; Gregersen, H.

    2008-01-01

    The physiological significance of serotonin released into the intestinal lumen for the regulation of motility is unknown in humans. The aim of this study was to evaluate the effect of serotonin infused into the lumen of the gastric antrum, duodenum or the jejunum, on antro-duodeno-jejunal contrac......The physiological significance of serotonin released into the intestinal lumen for the regulation of motility is unknown in humans. The aim of this study was to evaluate the effect of serotonin infused into the lumen of the gastric antrum, duodenum or the jejunum, on antro......-duodeno-jejunal contractility in healthy human volunteers. Manometric recordings were obtained and the effects of either a standard meal, continuous intravenous infusion of serotonin (20 nmol/kg/min) or intraluminal bolus infusions of graded doses of serotonin (2.5, 25 or 250 nmol) were compared. In addition, platelet......-depleted plasma levels of serotonin, blood pressure, heart rate and electrocardiogram were evaluated. All subjects showed similar results. Intravenous serotonin increased migrating motor complex phase In frequency 3-fold and migrating velocity 2-fold. Intraluminal infusion of serotonin did not change contractile...

  5. 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.

  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. 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.

  8. 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....

  9. Unaffected contractility of diaphragm muscle fibers in humans on mechanical ventilation

    NARCIS (Netherlands)

    Hooijman, P.E.; Paul, M.A.; Stienen, G.J.; Beishuizen, A.; Hees, H.W.H. van; Singhal, S.; Bashir, M.; Budak, M.T.; Morgen, J.; Barsotti, R.J.; Levine, S.; Ottenheijm, C.A.C.

    2014-01-01

    Several studies have indicated that diaphragm dysfunction develops in patients on mechanical ventilation (MV). Here, we tested the hypothesis that the contractility of sarcomeres, i.e., the smallest contractile unit in muscle, is affected in humans on MV. To this end, we compared diaphragm muscle fi

  10. 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

  11. 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.

  12. 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...

  13. 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

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

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    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.

  15. Papel da Histerossonografia no Estudo da Cavidade Uterina em Pacientes com Sangramento Uterino Anormal Role of Sonohysterography in the Evaluation of the Uterine Cavity in Patients with Abnormal Uterine Bleeding

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    Angélica Lemos Debs Diniz

    2000-06-01

    Full Text Available Objetivo: determinar o papel da histerossonografia na avaliação das anormalidades da cavidade uterina, em pacientes com sangramento uterino anormal, selecionadas previamente pela ultra-sonografia transvaginal. Métodos: foram selecionadas 48 pacientes na menacme e pós-menopausa, portadoras de sangramento uterino anormal e anormalidades da cavidade uterina, diagnosticadas inicialmente pela ultra-sonografia transvaginal. Todas as pacientes se submeteram à histerossonografia e, posteriormente, aos métodos "padrão ouro", a histeroscopia e/ou histerectomia. As histerossonografias foram avaliadas por dois diferentes médicos e os diagnósticos confrontados. Resultados: a histerossonografia mostrou ter alta sensibilidade e especificidade no diagnóstico das patologias benignas da cavidade uterina. Na presença de pólipo a sensibilidade e a especificidade do método foram, respectivamente, de 100 e 97%, seguido do mioma submucoso cuja sensibilidade e especificidade foram, respectivamente, de 83 e 100%. Já na hiperplasia endometrial e no endométrio normal a sensibilidade e especificidade foram de 100%. Diagnosticamos 33 casos de pólipos, 13 casos de miomas submucosos, quatro casos de hiperplasia endometrial e três casos normais na análise dos métodos "padrão ouro". Houve alta correlação entre os diagnósticos dados pelos dois examinadores. Conclusões: a histerossonografia mostrou ser um exame reprodutível, com alta sensibilidade e especificidade no diagnóstico das patologias benignas da cavidade uterina em pacientes com sangramento uterino anormal.Purpose: to determine the role of sonohysterography in the evaluation of abnormalities in the uterine cavity in patients presenting abnormal uterine bleeding, who had previously been selected by transvaginal ultrasonography. Methods: forty-eight patients presenting abnormal uterine bleeding and changes in the uterine cavity seen by transvaginal ultrasonography were selected, and they were in

  16. Evaluation of a second uterine flushing on embryo recovery in Nelore cows / Avaliação de uma segunda lavagem uterina sobre a recuperacão de embriões em vacas Nelore

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    Marcelo Marcondes Seneda

    2008-08-01

    Full Text Available The objective of the present study was to evaluate the effect of a second uterine flushing on number of recovered embryos. Cyclic Nelore cows (n= were used as donors. Animals were kept under grazing conditions in a farm at Mamborê, Paraná state. Cows were submitted to two sessions of multiple ovulation 80 days apart. At a random stage of estrus cycle (Day 0 donors received an intravaginal device with 1.9 g of progesterone (CIDR; Pfizer; Brasil. Twenty four hours later (Day 1 cows were injected with 2.5 mg/ IM of Estradiol Benzoate (Estrogin, Farmavet, Brasil. Between Day 5 and Day 9, donors received decreasing doses of 250 UI of FSH (Pluset; Calier, Brasil. On Days 7 and cows received 25 mg/ IM of dinoprost (Lutalyse, Pfizer, Brasil and progesterone implants were removed 12 hs later. Artificial insemination was performed 12 and 24 hours after estrus detection. The first embryo recovery was performed 7 days after AI with the Foley catheter positioned in the uterine body. A total of 1.000 mL of PBS (Embriocare, Cultilab, Brasil was used in a closed system of uterine flushing, with a 70 µm filter. Recovered uterine fluid was evaluated under a stereomicroscope (SMZ 654, Nikon, Japan and embryos were classified accord to IETS (1998. Twenty four hours later, the second uterine flushing was performed following the same procedure. Results were analyzed by t-Student test (p O objetivo do presente experimento foi verificar a viabilidade de uma segunda lavagem uterina sobre a recuperação de embriões. Doadoras cíclicas da raça Nelore (n= foram mantidas a pasto no município de Mamborê, Estado do Paraná. Os animais foram submetidos a tratamentos de superovulação com intervalo de 80 dias. Em um dia aleatório do ciclo estral (Dia 0 as doadoras receberam um dispositivo intravaginal contendo 1,9 g de progesterona (CIDR; Pfizer, Brasil. Vinte e quatro horas após (Dia 1 administrou-se , mg de benzoato de Estradiol (Estrogin; Farmavet, Brasil por via

  17. Prevenção do Nascimento Prematuro: Importância da Monitorização das Contrações Uterinas Prevention of Preterm Birth: Role of Uterine Contraction Monitoring

    Directory of Open Access Journals (Sweden)

    Eduardo Sérgio Borges da Fonseca

    1999-10-01

    Full Text Available Objetivo: avaliar a relação entre alterações das contrações uterinas e parto prematuro. Metodologia: entre fevereiro de 1996 e junho de 1998, 73 gestantes com risco para o parto prematuro foram submetidas à monitorização externa das contrações uterinas, da 24ª à 34ª semana de gestação, duas vezes por semana, durante 60 minutos. O teste foi considerado positivo quando as contrações uterinas apresentavam freqüência maior ou igual a 4 contrações/hora antes da 30ª semana e a 6 contrações/hora após esta data. Resultado: foram excluídas da análise 17 pacientes (23,28% por apresentarem patologias obstétricas ou evolução desfavorável para os resultados finais. Das 56 gestantes restantes, a incidência de partos prematuros espontâneos foi de 23,21% (13/56. A freqüência média das contrações uterinas foi significativamente maior no grupo que evoluiu para o parto prematuro. O método revelou uma sensibilidade de 69,23%, uma especificidade de 86,04% e valores preditivos positivo e negativo de 60% e 90,24%, respectivamente. Conclusão: o teste negativo está associado a baixo risco de nascimento prematuro. Contudo, diante do teste positivo, torna-se necessária a associação com outros marcadores do parto prematuro para melhor identificar pacientes com risco elevado.Purpose: to evaluate the relationship between uterine contractions and premature delivery. Methods: between February 1996 and July 1998, 73 high risk pregnant women for preterm delivery, between the 24th and 34th weeks of gestation, were submitted to uterine contraction monitoring with tokodynamometers for 1 hour twice a week. The positive test was the presence of 4 contractions/h before the 30th week of gestation, and after this time, 6 contractions/h. Result: of 73 women, 17 patients (23.28% were excluded from the final analysis because they presented obstetric problems or unfavorable development for the final result. The rate of preterm delivery was 21

  18. Evaluación de la involución, salud uterina y retorno de la actividad ovárica con la adición de zeolita 2% en la dieta basal de vacas lecheras

    OpenAIRE

    Garzón Prado, Juan Pablo

    2016-01-01

    El objetivo de esta investigación fue evaluar el efecto de zeolita (Clinoptilolita) adicionado en la dieta basal de vacas lecheras durante 105 días, 60 días pre-parto (dap) y 45 días post-parto (dpp) y su influencia en la involución (IU) y salud uterina (SU), el retorno de la actividad ovárica (AO) y la condición corporal (CC). El proyecto se realizó en tres ganaderías de la comunidad de Soldados del Cantón Cuenca – Azuay, en 50 vacas secas, con una CC ? 3,5, entre 2 a 5 partos, clínicamente ...

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

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    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.

  20. Contractile analysis with kriging based on MR myocardial velocity imaging.

    Science.gov (United States)

    Lee, Su-Lin; Huntbatch, Andrew; Yang, Guang-Zhong

    2008-01-01

    Diagnosis and treatment of coronary artery disease requires a full understanding of the intrinsic contractile mechanics of the heart. MR myocardial velocity imaging is a promising technique for revealing intramural cardiac motion but its ability to depict 3D strain tensor distribution is constrained by anisotropic voxel coverage of velocity imaging due to limited imaging slices and the achievable SNR in patient studies. This paper introduces a novel Kriging estimator for simultaneously improving the tracking and dense inter-slice estimation of the myocardial velocity data. A harmonic embedding technique is employed to determine point correspondence between left ventricle models between subjects, allowing for a statistical shape model to be reconstructed. The use of different semivariograms is investigated for optimal deformation reconstruction. Results from in vivo data demonstrate a marked improvement in tracking myocardial deformation, thus enhancing the potential clinical value of MR myocardial velocity imaging.

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

    Energy Technology Data Exchange (ETDEWEB)

    Michailov, M.C.; Prechter, I.; Greimel, H.; Welscher, U.E.

    1983-07-01

    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.

  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. Non-muscle contractile proteins in the organ of corti

    Energy Technology Data Exchange (ETDEWEB)

    Thalmann, I.; Giometti, C.S.; Thalmann, R. (Washington Univ., St. Louis, MO (USA))

    1985-01-01

    Evidence indicates that an active contractile process exists in the outer hair cells of the mammalian cochlea. Proteins ordinarily associated with muscle contraction have been identified in the outer hair cells by immunohistologic techniques. On this basis a muscle-like mechanism of contraction/relaxation has been postulated by several investigators. The possibility must be considered, however, that the contractile proteins identified thus far in inner ear structures may be nonmuscle rather than muscle forms. In skeletal muscle, actin and myosin are responsible for the physical movement of the muscle fibers, and tropomyosin and troponin are involved in regulating this movement; these four proteins, as well as a variety of proteins involved with the normal cell maintenance functions are all of a muscle-specific type. Non-muscle-like motion also depends upon the interaction of actin with myosin; however, not only are these proteins structurally different from those specific to skeletal muscle but their proportions are also different. We have used two-dimensional polyacrylamide gel electrophoresis to study the proteins in freeze dried preparations of whole organ of Corti from the guinea pig. The identified proteins include non-muscle actin, three forms of non-muscle tropomyosin, alpha- and beta-tubulin, alpha-actinin, and lactate dehydrogenase (LDH B). Myosin heavy and light chains were not detected in the organ of Corti preparation, but the levels of those proteins might be too low to be detected with the protein load used of those proteins might be too low to be detected with the protein load used for this analysis. Although troponin could not be detected, calmodulin was present. All of these findings tend to indicate that the contraction/relaxation processes that have been associated with the organ of Corti by others are of the non-muscle variety.

  4. 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.

  5. 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

    2014-02-11

    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 Ca(2+)-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 Ca(2+) 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.

  6. La capacidad de carga como herramienta de ordenación del Territorio.

    OpenAIRE

    Cortés Chavez, Sandra

    2011-01-01

    Índice Introducción El área de estudio y sus características Características ambientales y evaluación de impactos Cruce entre conflictos ambientales y la valoración del ecosistema en los instrumentos de Planificación Los intrumentos de Planificación Territorial Capacidad de carga Análisis de casos de aplicación de la capacidad de carga Modelos de la capacidad de carga Revalorización de los instrumentos de planificación territorial Bibliografía Resumen El análisis de las condicionantes de...

  7. El desarrollo de la capacidad de estimación temporal

    OpenAIRE

    2007-01-01

    Se realizó un estudio descriptivo correlacional con el objetivo de contribuir al esclarecimiento de los mecanismos mentales implicados en la capacidad de estimación temporal subjetiva, especialmente respecto a la distinción entre procesos automáticos y a-reflexivos vs. procesos deliberados y reflexivos. Los objetivos secundarios fueron: elucidar las relaciones entre edad, inteligencia y capacidad de estimación temporal subjetiva, para los paradigmas de estimación prospectivo, retrospectivo y ...

  8. 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.

  9. 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...

  10. 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

  11. 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

  12. 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.

  13. Contractile force measured in unskinned isolated adult rat heart fibres.

    Science.gov (United States)

    Brady, A J; Tan, S T; Ricchiuti, N V

    1979-12-13

    A number of investigators have succeeded in preparing isolated cardiac cells by enzymatic digestion which tolerate external [Ca2+] in the millimolar range. However, a persistent problem with these preparations is that, unlike in situ adult ventricular fibres, the isolated fibres usually beat spontaneously. This spontaneity suggests persistent ionic leakage not present in situ. A preferable preparation for mechanical and electrical studies would be one which is quiescent but excitable in response to electrical stimulation and which does not undergo contracture with repeated stimulation. We report here a modified method of cardiac fibre isolation and perfusion which leaves the fibre membrane electrically excitable and moderately resistant to mechanical stress so that the attachment of suction micropipettes to the fibre is possible for force measurement and length control. Force generation in single isolated adult rat heart fibres is consistent with in situ contractile force. The negative staircase effect (treppe) characteristic of adult not heart tissue is present with increased frequency of stimulation. Isometric developed tension increases with fibre length as in in situ ventricular tissue.

  14. Postextrasystolic potentiation and contractile reserve: requirements and restrictions.

    Science.gov (United States)

    Lust, R M; Lutherer, L O; Gardner, M E; Cooper, M W

    1982-12-01

    These studies were conducted to examine the basic characteristics of postextrasystolic potentiation (PESP) and the relationship of loading effects to PESP. Measurements of left ventricular (LV) and aortic pressures, the rate of pressure rise, and echocardiographically determined LV dimensions were made in anesthetized open-chest dogs. The hearts were paced, and timed extrasystoles were introduced that were followed by postextrasystoles (PES). PES's were elicited after an interval equal to either a full compensatory pause or a time when the diastolic properties of the LV could not be distinguished from control (isolength). Potentiation of contraction for the PES's introduced after an isolength pause was dependent on both the heart rate and the extrasystolic interval, whereas the PES's that occurred after a full pause showed no dependence on either of these intervals. PESP elicited during the isolength period was not dependent on either preload and afterload. It is concluded that PESP depends on the combination of heart rate and extrasystolic and postextrasystolic intervals. Further, PESP may be inaccurate in assessing contractile reserve unless the heart rate and extrasystolic interval are known and the PES is introduced after an isolength pause.

  15. 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.

  16. 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.

  17. 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.

  18. Methanol extract of Tephrosia vogelii leaves potentiates the contractile action of acetylcholine on isolated rabbit jejunum

    Directory of Open Access Journals (Sweden)

    Tavershima Dzenda

    2015-09-01

    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.

  19. Chemical modification of amino acid residues in glycerinated Vorticella stalk and Ca(2+)-induced contractility.

    Science.gov (United States)

    Kono, R; Ochiai, T; Asai, H

    1997-01-01

    The glycerinated stalk of the peritrich ciliate Vorticella, was treated with various reagents to chemically modify the amino acid residues. The influences of these modifcations on spasmoneme contractility were investigated. First, it was confirmed that the spasmoneme contraction is not inhibited by alteration of SH groups. It was also demonstrated that chemical modification of methionine and tryptophan residues abolishes spasmoneme contractility. The reagents used for chemical modification were N-bromosuccinimide (NBS), chloramine T, and 2-hydroxy-5-nitrobenzyl bromide (HNBB), which abolished spasmoneme contractility at concentrations of 40-50 microM, 200-300 microM, and 4 mM, respectively. These results suggest that, along with Ca2+ binding proteins, there are other as yet to be identified proteins involved in contractility.

  20. 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.

  1. 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

  2. Platelets as Contractile Nanomachines for Targeting Drug Delivery in Hemostasis and Thrombosis

    Science.gov (United States)

    2015-12-01

    AWARD NUMBER: W81XWH-13-1-0495 TITLE: Platelets as Contractile Nanomachines for Targeting Drug Delivery in Hemostasis and Thrombosis PRINCIPAL...TITLE AND SUBTITLE 5a. CONTRACT NUMBER Platelets as Contractile Nanomachines for Targeting Drug Delivery in Hemostasis and Thrombosis 5b. GRANT...controlled nanocarriers as a novel and potentially paradigm-shifting strategy for targeted drug delivery to achieve hemostasis during bleeding. We have

  3. 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.

  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. 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

  6. Bienestar psicológico en personas con alta capacidad intelectual

    Directory of Open Access Journals (Sweden)

    Pedro Ramiro Olivier

    2016-12-01

    Full Text Available El bienestar psicológico en las personas de alta capacidad intelectual ha sido motivo de controversia en la literatura especializada. En ocasiones se ha considerado que estas personas son más proclives a un desajuste psicológico, mientras que otras veces los resultados han sido poco concluyentes. En el presente trabajo se ha estudiado el bienestar psicológico en personas de altas capacidades intelectuales, administrando la Escala de Bienestar Psicológico a 28 participantes de edades comprendidas entre los 22 y 34 años de edad. Fueron divididos en 2 grupos, uno de altas capacidades y otro de inteligencia estándar. El grupo de altas capacidades había sido identificado como tal 25 años atrás, cuando tenían una edad comprendida entre los 5 y 13 años, utilizando el modelo de los 3 anillos de Renzulli. Los resultados indicaron la inexistencia de diferencias significativas entre los participantes de altas capacidades e inteligencia estándar en las diferentes subescalas de bienestar personal, a excepción de la subescala de bienestar material.

  7. Comparação entre a histerossonografia, a histeroscopia e a histopatologia na avaliação da cavidade uterina de mulheres na pós-menopausa

    Directory of Open Access Journals (Sweden)

    Accorsi Neto Alfeu Cornélio

    2003-01-01

    Full Text Available OBJETIVOS: comparar os resultados da hístero-sonografia com os da histeroscopia e com os da histopatologia em mulheres na pós-menopausa. MÉTODOS: realizou-se hísterossonografia, histeroscopia e biópsia endometrial dirigida em 58 mulheres que tinham eco endometrial maior que 4 mm, idade superior a 40 anos, tempo de amenorréia superior a um ano e níveis de hormônio folículo-estimulante maiores que 35 mUI/mL. Foram excluídas as pacientes que fizeram uso de hormonioterapia, assim como aquelas com fatores que impedissem a realização dos exames de hísterossonografia, histeroscopia ou o estudo histopatológico. A análise estatística foi obtida pelos testes G de Cochran e McNemar. Foram calculados os valores de sensibilidade, especificidade e preditivos positivo e negativo da hístero-sonografia comparados com os outros exames. RESULTADOS: as taxas de concordância da hísterossonografia comparada aos achados histerpscópicos e histológicos foram de 94,8 e 77,6%, respectivamente. A sensibilidade e a especificidade na detecção de anormalidade da cavidade endometrial da hísterossonografia comparadas com a histeroscopia foram de 98 e de 75%, respectivamente. Já os valores preditivos positivo e negativo da hístero-sonografia foram de 96 e de 86%, respectivamente. Na comparação ao estudo histopatológico para o diagnóstico de alterações da cavidade endometrial, a hísterossonografia revelou sensibilidade de 98%, especificidade de 33% e os valores preditivos positivo e negativo foram de 76 e de 86%, respectivamente. Ressalta-se que das onze pacientes com sinéquia uterina diagnosticada pela hísterossonografia, duas tiveram hiperplasia endometrial. Houve um caso de cavidade normal pela hístero-sonografia em que o resultado da biópsia foi hiperplasia endometrial simples. CONCLUSÕES: nossos dados sugerem que a hísterossonografia tem boa sensibilidade comparada com a histeroscopia. Contudo, há limitações deste método diagn

  8. 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.

  9. Muscle fatigue in frog semitendinosus: alterations in contractile function

    Science.gov (United States)

    Thompson, L. V.; Balog, E. M.; Riley, D. A.; Fitts, R. H.

    1992-01-01

    The purpose of this study was to characterize the contractile properties of the frog semitendinosus (ST) muscle before and during recovery from fatigue, to relate the observed functional changes to alterations in specific steps in the crossbridge model of muscle contraction, and to determine how fatigue affects the force-frequency relationship. The frog ST (22 degrees C) was fatigued by direct electrical stimulation with 100-ms 150-Hz trains at 1/s for 5 min. The fatigue protocol reduced peak twitch (Pt) and tetanic (Po) force to 32 and 8.5% of initial force, respectively. The decline in Pt was less than Po, in part due to a prolongation in the isometric contraction time (CT), which increased to 300% of the initial value. The isometric twitch duration was greatly prolonged as reflected by the lengthened CT and the 800% increase in the one-half relaxation time (1/2RT). Both Pt and Po showed a biphasic recovery, a rapid initial phase (2 min) followed by a slower (40 min) return to the prefatigue force. CT and 1/2RT also recovered in two phases, returning to 160 and 265% of control in the first 5 min. CT returned to the prefatigue value between 35 and 40 min, whereas even at 60 min 1/2RT was 133% of control. The maximal velocity of shortening, determined by the slack test, was significantly reduced [from 6.7 +/- 0.5 to 2.5 +/- 0.4 optimal muscle length/s] at fatigue. The force-frequency relationship was shifted to the left, so that optimal frequency for generating Po was reduced.(ABSTRACT TRUNCATED AT 250 WORDS).

  10. Myeloperoxidase impairs the contractile function in isolated human cardiomyocytes.

    Science.gov (United States)

    Kalász, Judit; Pásztor, Enikő T; Fagyas, Miklós; Balogh, Ágnes; Tóth, Attila; Csató, Viktória; Édes, István; Papp, Zoltán; Borbély, Attila

    2015-07-01

    We set out to characterize the mechanical effects of myeloperoxidase (MPO) in isolated left-ventricular human cardiomyocytes. Oxidative myofilament protein modifications (sulfhydryl (SH)-group oxidation and carbonylation) induced by the peroxidase and chlorinating activities of MPO were additionally identified. The specificity of the MPO-evoked functional alterations was tested with an MPO inhibitor (MPO-I) and the antioxidant amino acid Met. The combined application of MPO and its substrate, hydrogen peroxide (H2O2), largely reduced the active force (Factive), increased the passive force (Fpassive), and decreased the Ca(2+) sensitivity of force production (pCa50) in permeabilized cardiomyocytes. H2O2 alone had significantly smaller effects on Factive and Fpassive and did not alter pCa50. The MPO-I blocked both the peroxidase and the chlorinating activities, whereas Met selectively inhibited the chlorinating activity of MPO. All of the MPO-induced functional effects could be prevented by the MPO-I and Met. Both H2O2 alone and MPO + H2O2 reduced the SH content of actin and increased the carbonylation of actin and myosin-binding protein C to the same extent. Neither the SH oxidation nor the carbonylation of the giant sarcomeric protein titin was affected by these treatments. MPO activation induces a cardiomyocyte dysfunction by affecting Ca(2+)-regulated active and Ca(2+)-independent passive force production and myofilament Ca(2+) sensitivity, independent of protein SH oxidation and carbonylation. The MPO-induced deleterious functional alterations can be prevented by the MPO-I and Met. Inhibition of MPO may be a promising therapeutic target to limit myocardial contractile dysfunction during inflammation.

  11. Menthol inhibits detrusor contractility independently of TRPM8 activation.

    Science.gov (United States)

    Ramos-Filho, Antonio Celso Saragossa; Shah, Ajay; Augusto, Taize Machado; Barbosa, Guilherme Oliveira; Leiria, Luiz Osorio; de Carvalho, Hernandes Faustino; Antunes, Edson; Grant, Andrew Douglas

    2014-01-01

    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.

  12. Desarrollo humano y capacidades. Aplicaciones de la teoría de las capacidades de Amartya Sen a la educación

    OpenAIRE

    Cejudo Córdoba, Rafael

    2006-01-01

    El artículo ofrece un examen crítico de la concepción de la educación implícita en la teoría de las capacidades de Amartya Kumar Sen, uno de los padres del «desarrollo humano» y Premio Nobel de economía en 1998. Tras comparar la función de la educación en las teorías del desarrollo humano y del capital humano, se investigan las aplicaciones educativas de las capacidades más allá del desarrollo socio-económico, concretamente en la relación entre libertad y educación, y en la calidad educat...

  13. La doble cara de la capacidad empresarial: una alternativa a la noción popular

    Directory of Open Access Journals (Sweden)

    Bögenhold , Dieter

    2003-06-01

    Full Text Available La capacidad empresarial es un tema estratégico en los estudios de los procesos que llevan a la prosperidad y a la creación de empleos. Pese a ello, el concepto no está aún bien definido. Este artículo estudia los supuestos centrales y cuestiona lo que muchos contemporáneos dan por supuesto. El artículo muestra la necesidad de definir la capacidad empresarial. La discusión reciente debe explicar el fenómeno, a veces contradictorio, del rápido crecimiento de las grandes empresas y las nuevas microempresas de empleados por cuenta propia que no tienen posibilidades ni intenciones de crecer. Las políticas económicas deben especificar a qué se refieren cuando hablan de capacidad empresarial

  14. 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.

  15. Stable, covalent attachment of laminin to microposts improves the contractility of mouse neonatal cardiomyocytes.

    Science.gov (United States)

    Ribeiro, Alexandre J S; Zaleta-Rivera, Kathia; Ashley, Euan A; Pruitt, Beth L

    2014-09-10

    The mechanical output of contracting cardiomyocytes, the muscle cells of the heart, relates to healthy and disease states of the heart. Culturing cardiomyocytes on arrays of elastomeric microposts can enable inexpensive and high-throughput studies of heart disease at the single-cell level. However, cardiomyocytes weakly adhere to these microposts, which limits the possibility of using biomechanical assays of single cardiomyocytes to study heart disease. We hypothesized that a stable covalent attachment of laminin to the surface of microposts improves cardiomyocyte contractility. We cultured cells on polydimethylsiloxane microposts with laminin covalently bonded with the organosilanes 3-glycidoxypropyltrimethoxysilane and 3-aminopropyltriethoxysilane with glutaraldehyde. We measured displacement of microposts induced by the contractility of mouse neonatal cardiomyocytes, which attach better than mature cardiomyocytes to substrates. We observed time-dependent changes in contractile parameters such as micropost deformation, contractility rates, contraction and relaxation speeds, and the times of contractions. These parameters were affected by the density of laminin on microposts and by the stability of laminin binding to micropost surfaces. Organosilane-mediated binding resulted in higher laminin surface density and laminin binding stability. 3-glycidoxypropyltrimethoxysilane provided the highest laminin density but did not provide stable protein binding with time. Higher surface protein binding stability and strength were observed with 3-aminopropyltriethoxysilane with glutaraldehyde. In cultured cardiomyocytes, contractility rate, contraction speeds, and contraction time increased with higher laminin stability. Given these variations in contractile function, we conclude that binding of laminin to microposts via 3-aminopropyltriethoxysilane with glutaraldehyde improves contractility observed by an increase in beating rate and contraction speed as it occurs during the

  16. Incremento de la capacidad de producción en la linea smag de enlit

    OpenAIRE

    Contreras Chacon, Pedro; Wiesner Falconi, Ignacio

    2009-01-01

    El presente proyecto nace ante la necesidad de aumentar la capacidad de producción de envases sanitarios de tres piezas diámetro 603 por las diferentes alturas: 209, 402 y 408, en la Línea Smag, para poder atender la gran demanda por parte de las empresas empacadoras de atún existentes en el mercado, como son: Nirsa, Isabel, Empesec, Ideal, Spaglio, Marbelize, entre otras. La actual línea Smag tiene una capacidad máxima, limitada por la máquina soldadora, de hasta 50 cuerpos por minuto, d...

  17. 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.

  18. La doble cara de la capacidad empresarial: una alternativa a la noción popular

    OpenAIRE

    2003-01-01

    La capacidad empresarial es un tema estratégico en los estudios de los procesos que llevan a la prosperidad y a la creación de empleos. Pese a ello, el concepto no está aún bien definido. Este artículo estudia los supuestos centrales y cuestiona lo que muchos contemporáneos dan por supuesto. El artículo muestra la necesidad de definir la capacidad empresarial. La discusión reciente debe explicar el fenómeno, a veces contradictorio, del rápido crecimiento de las grandes empresas y las nuevas m...

  19. Capacidad tributaria y finanzas públicas metropolitanas en México

    OpenAIRE

    Genaro Aguilar Gutiérrez

    2010-01-01

    En este artículo se examinan los factores determinantes de la capacidad tributaria del Distrito Federal y 25 municipios en tres zonas metropolitanas de México. Se presentan algunos modelos que han sido formulados en la literatura internacional de frontera para cuantificar el potencial de obtención de recursos tributarios. Su principal contribución consiste en aplicar un modelo econométrico robusto, el Modelo de Frontera Estocástica, para medir la capacidad de obtención de recursos fiscales en...

  20. CAPACIDAD DEL TRÉBOL SUBTERRÁNEO DE PRODUCIR SEMILLAS VIABLES EN SUPERFICIE

    OpenAIRE

    2011-01-01

    Un factor importante para la selección de nuevas variedades de trébol subterráneo (ssp subterraneum) en el S.O. español es la capacidad de producir semillas viables en superficie, debido a la dificultad que encuentra el trébol subterráneo para poder enterrar sus semillas en los suelos duros y compactos de este área. En estas condiciones hemos comprobado que el peso de la semilla desciende considerablemente y que el carácter más significativo que hemos encontrado para medir esta capacidad es l...

  1. Desarrollo de capacidades cognitivas generales en el marco de los cursos de matemática

    OpenAIRE

    Lacués, Eduardo; Pagano, Magdalena; Pollio, Alejandra

    2004-01-01

    El proceso de aprendizaje y, sus relaciones con el proceso de la enseñanza, es complejo pero, sin pretender reducir o simplificar lo que dichos procesos suponen, debemos reconocer que para la apropiación del conocimiento son imprescindibles ciertas capacidades cognitivas generales. Estimular el desarrollo de estas capacidades a través de planteos didácticos adecuados debería, en nuestra opinión, ser considerado como una prioridad a lo largo del proceso de escolarización. En matemáticas se ...

  2. "Capacidade tecnológica das empresas que fabricam medicamentos no Brasil"

    OpenAIRE

    Karina Braga Griguol

    2011-01-01

    A capacidade tecnológica das firmas representa os recursos necessários para gerar e gerenciar mudanças técnicas em suas atividades (LALL, 1992; BELL e PAVITT, 1993; 1995). Esta dissertação tem como objetivo geral analisar o nível da capacidade tecnológica das empresas que fabricam medicamentos no Brasil. Para alcançar este objetivo, foram adaptadas as estruturas analíticas desenvolvidas por Lall (1992), Bell e Pavitt (1993; 1995) e Figueiredo (2001; 2003) e realizado um levantamento descritiv...

  3. Prácticas parentales y capacidades y dificultades en preadolescentes

    OpenAIRE

    María-Pilar Méndez Sánchez; Patricia Andrade Palos; Rafael Peñaloza Gómez

    2013-01-01

    El objetivo de esta investigación fue determinar en qué medida las prácticas parentales predicen las capacidades y dificultades de preadolescentes. La muestra fue de 489 estudiantes de primaria (edad M = 11.2, DE = .82 años). Se utilizaron la Escala de Capacidades y Dificultades (Goodman, 1997) y la Escala de Prácticas Parentales (Andrade y Betancourt, 2010). Los resultados indicaron que los varones presentan más problemas de conducta e hiperactividad/falta de atención en comparación con las ...

  4. Llegó la hora de evaluar las asociaciones de fortalecimiento de las capacidades

    OpenAIRE

    Lauten, Brooke

    2007-01-01

    Desde 2001, la red Alerta sobre Niños y Conflictos Armados trabaja con organizaciones locales de la sociedad civil, redes de protección de menores y organizaciones de base para desarrollar la capacidad de controlar y responder a los abusos de los derechos de los niños. Mediante las asociaciones de fortalecimiento de las capacidades trabajamos para cambiar la estructura de poder que ha definido hasta ahora el papel de las ONG nacionales e internacionales en la programac...

  5. Capacidades y actividades en el autocuidado del paciente con pie diabético

    OpenAIRE

    Balcázar-Ochoa, Mayra; Escate-Ruíz, Yessenia; Choque-Díaz, Cristina; Velásquez-Carranza, Doris

    2015-01-01

    Objetivo: determinar las capacidades y actividades del autocuidado en el paciente con pie diabético. Material y métodos: estudio cuantitativo, descriptivo de corte transversal, la población estuvo conformada por 60 pacientes que se encontraban hospitalizados por presentar pie diabético; se empleó como instrumento el cuestionario sobre capacidades y actividades de autocuidado del paciente con pie diabético, el cual fue elaborado por las investigadoras; la primera parte estuvo conformada por 13...

  6. Capacidade de absorção: bases teóricas, funcionamento e condicionantes

    OpenAIRE

    Marlon Fernandes Rodrigues Alves

    2015-01-01

    Um dos temas de maior interesse na pesquisa em estratégia nos últimos anos tem sido as capacidades dinâmicas, uma abordagem que se baseia nos conceitos de recursos e rotinas organizacionais para explicar a heterogeneidade do desempenho das organizações. Os estudos quantitativos na área são menos frequentes e tendem a usar medidas financeiras e unidimensionais, com particular interesse na relação entre as capacidades dinâmicas e o desempenho em detrimento de seus antecedentes. A fim de contrib...

  7. Estudio de la capacidad estabilizadora del peroné en fracturas de tibia de conejo

    OpenAIRE

    Fornells Miquel, P.; GÓMEZ BENITO, M.J.; García Aznar, J.M.; BEA CASCAROSA, J.A.

    2008-01-01

    El objetivo de este trabajo es estudiar la capacidad estabilizadora del peroné en fracturas de tibia. Si dicha capacidad es suficiente, sería posible evitar el uso de sistemas de fijación en los experimentos de laboratorio con este tipo de fracturas. Para comprobarlo se ha realizado una simulación computacional por elementos finitos de la tibia y el peroné de un conejo, con una fractura en el tercio medio superior de la diáfisis sin ningún elemento estabilizador. El conjunto ha sido sometido ...

  8. ANTECEDENTES DEL USO DE LOS MEDIOS SOCIALES POR EL TURISTA: MOTIVACIÓN, OPORTUNIDAD Y CAPACIDAD

    Directory of Open Access Journals (Sweden)

    Desiderio Gutiérrez Taño

    2013-01-01

    Full Text Available El presente trabajo utiliza el modelo MOA para analizar en qué medida la motivación, la oportunidad y la capacidad de los usuarios son factores determinantes de las intenciones de uso de medios sociales en la organización y desarrollo de viajes turísticos. Las conclusiones del estudio revelan que las intenciones de uso de los medios sociales se ven afectadas por la motivación y las capacidades de los usuarios y, sin embargo, no se ven influenciadas por la oportunidad. A su vez, en las motivaciones influyen los beneficios funcionales y hedónicos, pero no los sociales.

  9. Capacidad, necesidad, esfuerzo fiscal y distribución secundaria de la coparticipación

    OpenAIRE

    2006-01-01

    En este trabajo se demuestra que al diseñar un sistema de transferencias intergubernamentales que contemple las diferencias de capacidad y necesidad fiscal es importante que no se creen incentivos perversos para los gobiernos locales. Las propuestas que se han formulado para la Argentina suponen, en muchos casos, que las elasticidades-alícuotas de las bases imponibles son cero de modo que el gobierno sub-nacional no puede modificar su capacidad tributaria estándar. El caso general, cuando esa...

  10. 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.

  11. Uterine contractility and blood flow are reflexively regulated by cutaneous afferent stimulation in anesthetized rats.

    Science.gov (United States)

    Hotta, H; Uchida, S; Shimura, M; Suzuki, H

    1999-01-15

    The effects of cutaneous mechanical afferent stimulation of various skin areas on uterine contractility and blood flow were examined in anesthetized non-pregnant rats. The contractility of the uterus was measured by the balloon method in the uterus. The uterine blood flow was measured by laser Doppler flowmetry. Noxious pinching stimulation of the perineum for 1 min induced an abrupt contraction of the uterus during stimulation. Pinching of a hindpaw or perineum and innocuous brushing of the perineum for 1 min increased uterine blood flow. Stimulation of other skin areas produced no changes in uterine contractility or blood flow. Most uterine responses were abolished by severance of the pelvic nerves, which innervated the uterus. The activity of pelvic parasympathetic efferent nerves to the uterus increased following perineal pinching. All these cutaneous stimulation-induced responses of uterine contractility, blood flow and pelvic efferent nerve activity still existed, and were even augmented, after acute spinalization. These results indicate that cutaneous mechanical sensory stimulation can regulate uterine contractility and blood flow by a segmental spinal reflex mechanism via uterine parasympathetic efferent nerves.

  12. Qual capacidade crítica? Relendo Luc Boltanski à luz de Margaret Archer

    Directory of Open Access Journals (Sweden)

    Luiz Augusto Campos

    Full Text Available Resumo A chamada “sociologia da capacidade crítica” de Luc Boltanski vem se tornando um dos principais paradigmas teóricos de interpretação das relações sociais. Contrário ao modo como a sociologia crítica à la Bourdieu entende a reflexividade humana, Boltanski propõe tratar os indivíduos como seres reflexivos, plenamente capazes de julgar e criticar o mundo. No entanto, essa “capacidade crítica” funciona em sua sociologia mais como premissa teórica do que como objeto concreto de investigação. Diante disso, este texto argumenta que uma sociologia interessada na capacidade crítica dos sujeitos não pode apenas “supô-la”, deve constituí-la em objeto de estudo sociológico. Para tal, propõe-se reconceituar a capacidade crítica como competência reflexiva, no sentido dado à expressão pela socióloga inglesa Margaret Archer. O recurso às categorias de Archer não apenas ajuda a identificar os limites da sociologia de Boltanski, mas, sobretudo, permite ampliar o seu alcance.

  13. EVALUACION DE LA CAPACIDAD ANTIOXIDANTE DE LOS COMPUESTOS AROMATICOS POLICICLICOS Y SUS DERIVADOS.

    OpenAIRE

    2004-01-01

    ¡a capacidad de los compuestos fenólicos de interactuar con radicales peroxilo es de interés tanto para entender sus procesos de oxidación como para evaluar su rol como antioxidantes en distintos sistemas. En la presente tesis se realizaron una serie de e 194p.

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

    OpenAIRE

    Tournier, Horacio Alfio; 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.

  15. 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

  16. 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.

  17. Multiscale model of the human cardiovascular system: Description of heart failure and comparison of contractility indices.

    Science.gov (United States)

    Kosta, S; Negroni, J; Lascano, E; Dauby, P C

    2017-02-01

    A multiscale model of the cardiovascular system is presented. Hemodynamics is described by a lumped parameter model, while heart contraction is described at the cellular scale. An electrophysiological model and a mechanical model were coupled and adjusted so that the pressure and volume of both ventricles are linked to the force and length of a half-sarcomere. Particular attention was paid to the extreme values of the sarcomere length, which must keep physiological values. This model is able to reproduce healthy behavior, preload variations experiments, and ventricular failure. It also allows to compare the relevance of standard cardiac contractility indices. This study shows that the theoretical gold standard for assessing cardiac contractility, namely the end-systolic elastance, is actually load-dependent and therefore not a reliable index of cardiac contractility.

  18. 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.

  19. Contractile Properties of Esophageal Striated Muscle: Comparison with Cardiac and Skeletal Muscles in Rats

    Directory of Open Access Journals (Sweden)

    Takahiko Shiina

    2010-01-01

    Full Text Available The external muscle layer of the mammalian esophagus consists of striated muscles. We investigated the contractile properties of esophageal striated muscle by comparison with those of skeletal and cardiac muscles. Electrical field stimulation with single pulses evoked twitch-like contractile responses in esophageal muscle, similar to those in skeletal muscle in duration and similar to those in cardiac muscle in amplitude. The contractions of esophageal muscle were not affected by an inhibitor of gap junctions. Contractile responses induced by high potassium or caffeine in esophageal muscle were analogous to those in skeletal muscle. High-frequency stimulation induced a transient summation of contractions followed by sustained contractions with amplitudes similar to those of twitch-like contractions, although a large summation was observed in skeletal muscle. The results demonstrate that esophageal muscle has properties similar but not identical to those of skeletal muscle and that some specific properties may be beneficial for esophageal peristalsis.

  20. 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.

  1. 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....

  2. Modulation of human uterine smooth muscle cell collagen contractility by thrombin, Y-27632, TNF alpha and indomethacin

    Directory of Open Access Journals (Sweden)

    Smith Terry J

    2009-01-01

    Full Text Available Abstract Background Preterm labour occurs in approximately 10% of pregnancies and is a major cause of infant morbidity and mortality. However, the pathways involved in regulating contractility in normal and preterm labour are not fully elucidated. Our aim was to utilise a human myometrial contractility model to investigate the effect of a number of uterine specific contractility agents in this system. Therefore, we investigated the contractile response of human primary uterine smooth muscle cells or immortalised myometrial smooth muscle cells cultured within collagen lattices, to known mediators of uterine contractility, which included thrombin, the ROCK-1 inhibitor Y-27632, tumour necrosis factor alpha (TNF alpha and the non-steroidal anti-inflammatory indomethacin. Methods Cell contractility was calculated over time, with the collagen gel contraction assay, utilising human primary uterine smooth muscle cells (hUtSMCs and immortalised myometrial smooth muscle cells (hTERT-HM: a decrease in collagen gel area equated to an increase in contractility. RNA was isolated from collagen embedded cells and gene expression changes were analysed by real time fluorescence reverse transcription polymerase chain reaction. Scanning electron and fluorescence microscopy were employed to observe cell morphology and cell collagen gel interactions. Statistical analysis was performed using ANOVA followed by Tukey's post hoc tests. Results TNF alpha increased collagen contractility in comparison to the un-stimulated collagen embedded hUtSMC cells, which was inhibited by indomethacin, while indomethacin alone significantly inhibited contraction. Thrombin augmented the contractility of uterine smooth muscle cell and hTERT-HM collagen gels, this effect was inhibited by the thrombin specific inhibitor, hirudin. Y-27632 decreased both basal and thrombin-induced collagen contractility in the hTERT-HM embedded gels. mRNA expression of the thrombin receptor, F2R was up

  3. 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

  4. 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.

  5. 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.

  6. CIUDADES INTELIGENTES COMO ESPACIOS DE INTEGRACIÓN PARA INDIVIDUOS CON CAPACIDADES DIVERSAS

    Directory of Open Access Journals (Sweden)

    Luisenia Fernández O.

    2014-07-01

    Full Text Available Hoy en día las Tecnologías de Información y Comunicación (TIC penetran en el entramado social y sobre él se configura la sociedad. Esta investigación describe el uso de las TIC en ciudades que distan desemejarse de la urbe tradicional gracias al empleo racional de las tecnologías que hacen los entornos más inteligentes, logrando cerrarlas brechas existentes entre sus usuario; generando el confort de aquellos cuyas capacidades son diversas en la diversidad o con capacidades disminuidas. Es decir, estas ciudades ponen a disposición de sus pobladores todos sus recursos tecnológicos disponibles y sus aportes al servicio de sus habitantes. La metodología utilizada para esta investigación fue de tipo exploratorio- descriptivo en la cual se intenta mostrar el uso de las tecnologías (TIC y la transformación del entorno, así como sus bondades en pro de la incorporación de los ciudadanos con capacidades diversas como ciudadanos de primera, a través de la construcción de espacios que aprovechan las aportaciones de las TIC para hacer del medio ambiente un espacio inteligente para la inclusión de los vulnerables cuyo fin último no es otro que el bienestar común. Se concluye que las denominadas ciudades inteligentes son hoy en día urbes que combinan la interconectividad de redes para la confortabilidad del ciudadano con capacidades diversas; éstas procuran el equilibrio, el desarrollo, la inclusión y el bienestar de los todos individuos con capacidades disímiles en la diversidad.

  7. 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.

  8. 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.

  9. 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

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

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    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.

  11. IGF-II and IGFBP-6 regulate cellular contractility and proliferation in Dupuytren's disease.

    Science.gov (United States)

    Raykha, Christina; Crawford, Justin; Gan, Bing Siang; Fu, Ping; Bach, Leon A; O'Gorman, David B

    2013-10-01

    Dupuytren's disease (DD) is a common and heritable fibrosis of the palmar fascia that typically manifests as permanent finger contractures. The molecular interactions that induce the development of hyper-contractile fibroblasts, or myofibroblasts, in DD are poorly understood. We have identified IGF2 and IGFBP6, encoding insulin-like growth factor (IGF)-II and IGF binding protein (IGFBP)-6 respectively, as reciprocally dysregulated genes and proteins in primary cells derived from contracture tissues (DD cells). Recombinant IGFBP-6 inhibited the proliferation of DD cells, patient-matched control (PF) cells and normal palmar fascia (CT) cells. Co-treatments with IGF-II, a high affinity IGFBP-6 ligand, were unable to rescue these effects. A non-IGF-II binding analog of IGFBP-6 also inhibited cellular proliferation, implicating IGF-II-independent roles for IGFBP-6 in this process. IGF-II enhanced the proliferation of CT cells, but not DD or PF cells, and significantly enhanced DD and PF cell contractility in stressed collagen lattices. While IGFBP-6 treatment did not affect cellular contractility, it abrogated the IGF-II-induced contractility of DD and PF cells in stressed collagen lattices. IGF-II also significantly increased the contraction of DD cells in relaxed lattices, however this effect was not evident in relaxed collagen lattices containing PF cells. The disparate effects of IGF-II on DD and PF cells in relaxed and stressed contraction models suggest that IGF-II can enhance lattice contractility through more than one mechanism. This is the first report to implicate IGFBP-6 as a suppressor of cellular proliferation and IGF-II as an inducer of cellular contractility in this connective tissue disease.

  12. Triceps surae contractile properties and firing rates in the soleus of young and old men.

    Science.gov (United States)

    Dalton, Brian H; Harwood, Brad; Davidson, Andrew W; Rice, Charles L

    2009-12-01

    Mean maximal motor unit firing rates (MUFRs) of the human soleus are lower (5-20 Hz) than other limb muscles (20-50 Hz) during brief sustained contractions. With healthy adult aging, maximal MUFRs are 20-40% lower and twitch contractile speed of lower limb muscles are 10-40% slower compared with young adults. However, it is unknown whether the inherently low maximal MUFRs for the soleus are further reduced with aging in association with age-related slowing in contractile properties. The purpose of the present study was to compare the changes in triceps surae contractile properties and MUFRs of the soleus throughout a variety of contraction intensities in six old ( approximately 75 yr old) and six young ( approximately 24 yr old) men. Neuromuscular measures were collected from the soleus and triceps surae during repeated sessions (2-6 sessions). Populations of single MUFR trains were recorded from the soleus with tungsten microelectrodes during separate sustained 6- to 10-s isometric contractions of varying intensities [25%, 50%, 75%, and 100% maximal voluntary isometric contraction (MVC)]. The old men had weaker triceps surae strength (MVC; 35% lower) and slower contractile properties (contraction duration; 20% longer) than the young men. However, there was no difference in average MUFRs of the soleus at 75% and 100% MVC ( approximately 14.5 Hz and approximately 16.5 Hz, respectively). At 25% and 50% MVC, average rates were 10% and 20% lower in the old men compared with young, respectively. Despite a significant slowing in triceps surae contraction duration, there was no age-related change in MUFRs recorded at high contractile intensities in the soleus. Thus the relationship between the whole muscle contractile properties and MUFRs found in other muscle groups may not exist between the triceps surae and soleus and may be muscle dependent.

  13. 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.

  14. 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.

  15. JunB mediates basal- and TGFβ1-induced smooth muscle cell contractility.

    Directory of Open Access Journals (Sweden)

    Aruna Ramachandran

    Full Text Available Smooth muscle contraction is a dynamic process driven by acto-myosin interactions that are controlled by multiple regulatory proteins. Our studies have shown that members of the AP-1 transcription factor family control discrete behaviors of smooth muscle cells (SMC such as growth, migration and fibrosis. However, the role of AP-1 in regulation of smooth muscle contractility is incompletely understood. In this study we show that the AP-1 family member JunB regulates contractility in visceral SMC by altering actin polymerization and myosin light chain phosphorylation. JunB levels are robustly upregulated downstream of transforming growth factor beta-1 (TGFβ1, a known inducer of SMC contractility. RNAi-mediated silencing of JunB in primary human bladder SMC (pBSMC inhibited cell contractility under both basal and TGFβ1-stimulated conditions, as determined using gel contraction and traction force microscopy assays. JunB knockdown did not alter expression of the contractile proteins α-SMA, calponin or SM22α. However, JunB silencing decreased levels of Rho kinase (ROCK and myosin light chain (MLC20. Moreover, JunB silencing attenuated phosphorylation of the MLC20 regulatory phosphatase subunit MYPT1 and the actin severing protein cofilin. Consistent with these changes, cells in which JunB was knocked down showed a reduction in the F:G actin ratio in response to TGFβ1. Together these findings demonstrate a novel function for JunB in regulating visceral smooth muscle cell contractility through effects on both myosin and the actin cytoskeleton.

  16. Effect of Tramadol on Rabbit Uterine Contractile Activity Induced in Late Pregnancy.

    Science.gov (United States)

    Yakovleva, A A; Nazarova, L A; Prokopenko, V M; Pavlova, N G

    2017-01-01

    Effect of Tramadol infusion (5 mg/ml) on oxytocin-induced uterine contractile activity was studied in chronic experiment on female rabbits with different degrees of biological readiness for parturition. In case of sufficient biological readiness for parturition, Tramadol did not change the number of uterine contractions, but increased the amplitude and duration of each contraction against the background of increased creatine phosphate consumption by the myometrium. At the same time, Tramadol infusion to females without biological readiness for partirition suppressed induced uterine contractile activity by reducing the amplitude of each uterine contraction.

  17. Contractile properties are disrupted in Becker muscular dystrophy, but not in limb girdle type 2I

    DEFF Research Database (Denmark)

    Løkken, Nicoline; Hedermann, Gitte; Thomsen, Carsten;

    2016-01-01

    We investigated whether a linear relationship between muscle strength and cross-sectional area (CSA) is preserved in calf muscles of patients with Becker muscular dystrophy (BMD, n = 14) and limb-girdle type 2I muscular dystrophy (LGMD2I, n = 11), before and after correcting for muscle fat...... infiltration. The Dixon magnetic resonance imaging technique was used to quantify fat and calculate a fat-free contractile CSA. Strength was assessed by dynamometry. Muscle strength/CSA relationships were significantly lower in patients versus controls. The strength/contractile-CSA relationship was still...

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

    Energy Technology Data Exchange (ETDEWEB)

    Harmer, A.R., E-mail: alex.harmer@astrazeneca.com; Abi-Gerges, N.; Morton, M.J.; Pullen, G.F.; Valentin, J.P.; Pollard, C.E.

    2012-04-15

    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.

  19. 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

    2017-01-01

    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. PMID:26519302

  20. Regulation of cardiac myocyte contractility by phospholemman: Na+/Ca2+ exchange versus Na+ -K+ -ATPase.

    Science.gov (United States)

    Song, Jianliang; Zhang, Xue-Qian; Wang, JuFang; Cheskis, Ellina; Chan, Tung O; Feldman, Arthur M; Tucker, Amy L; Cheung, Joseph Y

    2008-10-01

    Phospholemman (PLM) regulates cardiac Na(+)/Ca(2+) exchanger (NCX1) and Na(+)-K(+)-ATPase in cardiac myocytes. PLM, when phosphorylated at Ser(68), disinhibits Na(+)-K(+)-ATPase but inhibits NCX1. PLM regulates cardiac contractility by modulating Na(+)-K(+)-ATPase and/or NCX1. In this study, we first demonstrated that adult mouse cardiac myocytes cultured for 48 h had normal surface membrane areas, t-tubules, and NCX1 and sarco(endo)plasmic reticulum Ca(2+)-ATPase levels, and retained near normal contractility, but alpha(1)-subunit of Na(+)-K(+)-ATPase was slightly decreased. Differences in contractility between myocytes isolated from wild-type (WT) and PLM knockout (KO) hearts were preserved after 48 h of culture. Infection with adenovirus expressing green fluorescent protein (GFP) did not affect contractility at 48 h. When WT PLM was overexpressed in PLM KO myocytes, contractility and cytosolic Ca(2+) concentration ([Ca(2+)](i)) transients reverted back to those observed in cultured WT myocytes. Both Na(+)-K(+)-ATPase current (I(pump)) and Na(+)/Ca(2+) exchange current (I(NaCa)) in PLM KO myocytes rescued with WT PLM were depressed compared with PLM KO myocytes. Overexpressing the PLMS68E mutant (phosphomimetic) in PLM KO myocytes resulted in the suppression of I(NaCa) but had no effect on I(pump). Contractility, [Ca(2+)](i) transient amplitudes, and sarcoplasmic reticulum Ca(2+) contents in PLM KO myocytes overexpressing the PLMS68E mutant were depressed compared with PLM KO myocytes overexpressing GFP. Overexpressing the PLMS68A mutant (mimicking unphosphorylated PLM) in PLM KO myocytes had no effect on I(NaCa) but decreased I(pump). Contractility, [Ca(2+)](i) transient amplitudes, and sarcoplasmic reticulum Ca(2+) contents in PLM KO myocytes overexpressing the S68A mutant were similar to PLM KO myocytes overexpressing GFP. We conclude that at the single-myocyte level, PLM affects cardiac contractility and [Ca(2+)](i) homeostasis primarily by its direct

  1. 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.

  2. 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

  3. Histomorfometria e histoquímica da tuba uterina e do útero de ratas púberes e pré-púberes induzidas ao hipertireoidismo Histomorphometry and histochemistry of the uterine tubes and uterus of puberal and prepuberal rats induced for hyperthyroidism

    Directory of Open Access Journals (Sweden)

    T.S. Oliveira

    2005-08-01

    Full Text Available Foram estudadas a histomorfometria e a atividade secretória das tubas uterinas e do útero de 38 ratas Wistar púberes, distribuídas em quatro grupos: (1 eutireóideo em proestro-estro, (2 hipertireóideo em proestro-estro, (3 eutireóideo em metaestro-diestro e (4 hipertireóideo em metaestro-diestro. Posteriormente, foram utilizadas outras 24 ratas Wistar pré-púberes, com 12 dias de idade, distribuídas em dois grupos: (1 hipertireóideo (n=12 e (2 eutireóideo (n=12. O útero e as tubas uterinas foram colhidos para avaliação histomorfométrica e histoquímica. A altura do epitélio da ampola, tanto no proestro-estro quanto no metaestro-diestro, elevou-se com a administração de tiroxina, tornando-se semelhante à do istmo. O hipertireoidismo aumentou a secreção PAS positiva e de mucossubstâncias ácidas do infundíbulo na fase estrogênica, igualando-a à do istmo. A parede uterina apresentou-se mais espessa na fase estrogênica, resultado da ação conjunta da tiroxina no endométrio e no miométrio. A atividade secretória e a composição do colágeno uterino não diferiram entre tratamentos. Nas ratas pré-púberes, o hipertireoidismo aumentou a espessura do miométrio e da parede uterina, mas não alterou a tuba uterina. O hipertireoidismo em ratas pré-púberes induz modificações significativas somente no útero; após a maturidade sexual, as modificações ocorrem no útero e na tuba uterina em intensidade variável e dependentes da fase do ciclo estral.The histomorphometry and the secretory activity of the uterine tubes and uterus of 38 puberal Wistar rats were studied. Rats were divided in four groups: (1 euthyroid in proestrus-estrus, (2 hyperthyroid in proestrus-estrus, (3 euthyroid in metestrus-diestrus and, (4 hyperthyroid in metestrus-diestrus. In other experiment, 24 prepuberal 12-day-old Wistar rats were divided in two groups: (1 hyperthyroid and (2 euthyroid. The uterus and the uterine tubes were collected for

  4. 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

  5. A CAPACIDADE INOVATIVA E O DESEMPENHO ECONÔMICO-FINANCEIRO DE EMPRESAS INOVADORAS BRASILEIRAS

    Directory of Open Access Journals (Sweden)

    Kléber Formiga Miranda

    Full Text Available RESUMOCom base nos pressupostos teóricos da Visão Baseada em Recursos (VBR, considerando a utilização de recursos disponíveis internamente nas organizações para manutenção de sua vantagem competitiva por meio da diferenciação, a pesquisa analisa a relação entre a capacidade inovativa e o desempenho econômico-financeiro de empresas brasileiras. A amostra foi extraída a partir das empresas listadas na BM&FBovespa consideradas inovadoras, segundo o IBI. As variáveis de capacidade inovativa coletadas a partir das PINTECs 2005 e 2008 e de desempenho através do Economática(r foram tratadas por meio de análises de correlação e de regressão. Os resultados indicam que os desempenhos econômico (ROA e operacional (EBITDA/Ativo Total não são significativamente influenciados pela capacidade inovativa. No entanto, quando se separa a capacidade inovativa por seus componentes (inovação de produto, processo, organizacional e marketing, observa-se uma influência positiva de inovação de produto sobre ambos os desempenhos. Por sua vez, o desempenho de valor (MVA é influenciado positiva e significativamente pela capacidade inovativa. Esses resultados sugerem melhores resultados contábeis quando as empresas inovam no produto e maior geração de valor pelo mercado ao possuir um portfólio diversificado de inovação, ou seja, maior capacidade inovativa. Não se pode, entretanto, negligenciar as inovações em processo, organizacional emarketing. A pouca relação dessas inovações, perceptíveis no âmbito interno da empresa, com o desempenho pode residir nas diferentes estratégias inovativas adotadas em prol do objetivo principal de cada empresa.

  6. 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.

  7. 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.

  8. 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

    OpenAIRE

    Maria Lúcia Rocha Oppermann; Bruce Bartholow Duncan; Sotero Serrate Mengue; José Geraldo Lopes Ramos; Suzanne Jacob Serruya; Maria Inês Schmidt

    2006-01-01

    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 ...

  9. Dopplervelocimetria das artérias uterinas no primeiro trimestre de gestação: avaliação dos índices de pulsatilidade e correlação com crescimento intra-uterino restrito e perda gestacional

    OpenAIRE

    Adriana Belo Fernandes

    2006-01-01

    Muitos estudos já demonstraram o valor do doppler de artérias uterinas no segundo trimestre da gestação, apresentando-o como método de rastreamento eficiente para a identificação das pacientes de risco. Tais investigações correlacionam o aumento da resistência ao fluxo e a persistência de incisura protodiastólica nesses vasos com mais probabilidade de desenvolvimento de préeclâmpsia e crescimento intra-uterino restrito. O presente trabalho retrospectivo analisou o banco de dados da Clínica de...

  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

    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

  11. 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

  12. MRTF-A signaling regulates the acquisition of the contractile phenotype in dedifferentiated chondrocytes.

    Science.gov (United States)

    Parreno, Justin; Raju, Sneha; Wu, Po-Han; Kandel, Rita A

    2016-10-14

    Chondrocyte culture as a monolayer for cell number expansion results in dedifferentiation whereby expanded cells acquire contractile features and increased actin polymerization status. This study determined whether the actin polymerization based signaling pathway, myocardin-related transcription factor-a (MRTF-A) is involved in regulating this contractile phenotype. Serial passaging of chondrocytes in monolayer culture to passage 2 resulted in increased gene and protein expression of the contractile molecules alpha-smooth muscle actin, transgelin and vinculin compared to non-passaged, primary cells. This resulted in a functional change as passaged 2, but not primary, chondrocytes were capable of contracting type I collagen gels in a stress-relaxed contraction assay. These changes were associated with increased actin polymerization and MRTF-A nuclear localization. The involvement of actin was demonstrated by latrunculin B depolymerization of actin which reversed these changes. Alternatively cytochalasin D which activates MRTF-A increased gene and protein expression of α-smooth muscle actin, transgelin and vinculin, whereas CCG1423 which deactivates MRTF-A decreased these molecules. The involvement of MRTF-A signaling was confirmed by gene silencing of MRTF or its co-factor serum response factor. Knockdown experiments revealed downregulation of α-smooth muscle actin and transgelin gene and protein expression, and inhibition of gel contraction. These findings demonstrate that passaged chondrocytes acquire a contractile phenotype and that this change is modulated by the actin-MRTF-A-serum response factor signaling pathway.

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

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    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. 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

  15. 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.

  16. 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.

  17. In vitro comparison of isometric and stop-test contractility parameters for the urinary bladder

    NARCIS (Netherlands)

    R. van Mastrigt (Ron); J.J. Glerum (Jacobus)

    1985-01-01

    textabstractContractility parameters in the urinary bladder can be calculated from isometric contractions (no extra patient load as compared to routine cystometry) or from stop-tests (more accurate, simpler analysis). A stop-test involves a voluntarily interrupted micturition with pressure and flow

  18. Biological behavior of fibroblast on contractile collagen hydrogel crosslinked by γ-irradiation.

    Science.gov (United States)

    Zhang, Xiangmei; Zhang, Yaqing; Chen, Wenqiang; Xu, Ling; Wei, Shicheng; Zheng, Yufeng; Zhai, Maolin

    2014-08-01

    Collagen hydrogels exhibited a contractile trend in simulated body fluid. In this study, the internal pore architecture and mechanical properties of collagen hydrogel prepared by radiation crosslinking was evaluated during contraction, and the effect of contractile collagen hydrogels on the biological behavior of fibroblasts were investigated in vitro, such as viability, proliferation, morphology, apoptosis, cycle, and stress fiber. The results showed that accompany with contraction of collagen hydrogel, the pore diameter of the hydrogels decreased and compressive modulus increased. However, fibroblasts can grow on contractile collagen hydrogels. Indeed, collagen hydrogel contracted from circumference to the interior, which retard the spreading of fibroblasts on the dynamic substrate and interrupted the initial attachment of the cell. However, contraction of collagen hydrogel had not only significant influence on the L929 cell proliferation, but also accelerated the apoptosis. Cell cycle analysis showed that contractile collagen hydrogel may promote cell cycle from G0/G1 phase to S phase, and DNA synthesis and cell proliferation were enhanced, but which may be different in contraction process. Therefore, as a scaffold for tissue engineering, the strategy for inhibition of the contraction of collagen hydrogel should be taken into account.

  19. 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

    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...

  20. Effects of Inhalation or Incubation of Oxitropium Bromide on Diaphragm Muscle Contractility in Mice

    Directory of Open Access Journals (Sweden)

    Chiyohiko Shindoh

    2011-01-01

    Conclusions: We speculate that the increment of muscle contractility with the inhalation of oxitropium bromide was induced by the antagonization of musucarinic acetylcholine receptors (mAChR. In addition, the changes of fatigue resistance provoked by oxitropium bromide, which also is speculated to antagonize mAChR, may be beneficial in the treatment of patients with COPD.

  1. 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.

  2. 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

  3. 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.

  4. Calpain mediates cardiac troponin degradation and contractile dysfunction in atrial fibrillation

    NARCIS (Netherlands)

    Ke, Lei; Qi, Xiao Yan; Dijkhuis, Anne-Jan; Chartier, Denis; Nattel, Stanley; Henning, Robert H.; Kampinga, Harm H.; Brundel, Bianca Jj. M.

    2008-01-01

    The self-perpetuation of atrial fibrillation (AF) is associated with atrial remodeling, including the degradation of the myofibril structure (myolysis). Myolysis is related to AF-induced activation of cysteine proteases and underlies loss of contractile function. In this study, we investigated which

  5. Engineering of Three-Dimensional Microenvironments to Promote Contractile Behavior in Primary Intestinal Organoids

    OpenAIRE

    DiMarco, Rebecca L.; Su, James; Yan, Kelley S.; Dewi, Ruby; Kuo, Calvin J.; Heilshorn, Sarah C.

    2014-01-01

    Multiple culture techniques now exist for the long-term maintenance of neonatal primary murine intestinal organoids in vitro; however, the achievement of contractile behavior within cultured organoids has thus far been infrequent and unpredictable. Here we combine finite element simulation of oxygen transport and quantitative comparative analysis of cellular microenvironments to elucidate the critical variables that promote reproducible intestinal organoid contraction. Experimentally, oxygen ...

  6. Assembly and positioning of actomyosin rings by contractility and planar cell polarity.

    Science.gov (United States)

    Sehring, Ivonne M; Recho, Pierre; Denker, Elsa; Kourakis, Matthew; Mathiesen, Birthe; Hannezo, Edouard; Dong, Bo; Jiang, Di

    2015-10-21

    The actomyosin cytoskeleton is a primary force-generating mechanism in morphogenesis, thus a robust spatial control of cytoskeletal positioning is essential. In this report, we demonstrate that actomyosin contractility and planar cell polarity (PCP) interact in post-mitotic Ciona notochord cells to self-assemble and reposition actomyosin rings, which play an essential role for cell elongation. Intriguingly, rings always form at the cells' anterior edge before migrating towards the center as contractility increases, reflecting a novel dynamical property of the cortex. Our drug and genetic manipulations uncover a tug-of-war between contractility, which localizes cortical flows toward the equator and PCP, which tries to reposition them. We develop a simple model of the physical forces underlying this tug-of-war, which quantitatively reproduces our results. We thus propose a quantitative framework for dissecting the relative contribution of contractility and PCP to the self-assembly and repositioning of cytoskeletal structures, which should be applicable to other morphogenetic events.

  7. 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...

  8. Computer analysis of the RR interval-contractility relationship during random stimulation of the isolated heart

    NARCIS (Netherlands)

    Meijler, F.L.; Strackee, J.; Capelle, F.J.L. van; Perron, J.C. du

    1968-01-01

    Hemodynamic variability in patients with atrial fibrillation may originate from a direct influence of the variations in RR intervals on myocardial contractility. With the aid of a computer the serial autocorrelation function and the histogram of the RR intervals of patients with atrial fibrillation

  9. 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 ...

  10. 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

  11. The importance of myocardial contractile reserve in predicting response to cardiac resynchronization therapy

    NARCIS (Netherlands)

    Kloosterman, Mariëlle; Damman, Kevin; Van Veldhuisen, Dirk J; Rienstra, Michiel; Maass, Alexander H

    2017-01-01

    AIM: To perform a meta-analysis and systematic review of published data to assess the relationship between contractile reserve and response to cardiac resynchronization therapy (CRT) in patients with heart failure. METHODS AND RESULTS: We searched MEDLINE/PubMed and Cochrane for all papers published

  12. 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.

  13. Governança e capacidades estatais: uma análise comparativa de programas federais

    Directory of Open Access Journals (Sweden)

    Roberto Rocha Coelho Pires

    Full Text Available Resumo O artigo se dedica ao exame dos arranjos institucionais que marcaram a implementação de políticas públicas pelo governo federal no Brasil na última década. Pretende-se compreender de que forma as características desses arranjos condicionaram as capacidades estatais disponíveis e afetaram o desempenho e os resultados até então observados de políticas públicas pré-selecionadas. A pesquisa se baseia em uma análise comparativa de oito casos de políticas públicas federais prioritárias no período recente (nomeadamente entre os anos de 2003 e 2013. Os casos foram selecionados em função da homogeneidade de seus contextos de implementação e da heterogeneidade de suas áreas temáticas (social, infraestrutura e desenvolvimento industrial. A partir do mapeamento dos arranjos institucionais e da avaliação de capacidades técnico-administrativas e político-relacionais de cada caso, desenvolveu-se uma comparação entre os casos baseada em técnicas de QCA (Qualitative Comparative Analysis, as quais permitiram identificar associações e mecanismos causais entre as características dos arranjos, tipos e níveis de capacidades estatais e o desempenho observado por fontes secundárias das políticas públicas em termos de entrega de resultados e inovação. A análise comparativa indicou uma expressiva variação na configuração dos arranjos institucionais que sustentam a implementação de políticas federais contemporâneas. O exame dessa variação apontou dois achados relevantes. De um lado, verificou-se que os arranjos institucionais indutores de altas capacidades técnico-administrativas, envolvendo combinação de organizações profissionalizadas com mecanismos efetivos de coordenação intra e intergovernamentais, tendem a promover um melhor desempenho relativo em termos de entrega de resultados. De outro lado, arranjos promotores de altas capacidades político-relacionais, envolvendo interações com agentes pol

  14. DESENVOLVIMENTO E SUSTENTABILIDADE DO TURISMO: Preceitos da teoria da capacidade de carga turística

    Directory of Open Access Journals (Sweden)

    Jefferson Marçal da Rocha

    2011-12-01

    Full Text Available Resumo - Neste artigo se analisa o preceito de gestão da denominada Capacidade de Carga Turística (CCT, na concepção de que o turismo só poderá se constituir em estratégia eficaz de desenvolvimento para as regiões e ou lugares, quando a preservação das bases ecológicas e os interesses sociais comunitários estiverem aliados às expectativas de ganhos econômicos. A CCT neste sentido passa a ser um importante instrumento de políticas públicas que definem os caminhos que o setor turístico deverá seguir, especialmente nas regiões com fortes atrativos naturais ainda preservados e geralmente, carentes de opções de desenvolvimento. Palavras-Chave: Turismo Sustentável; Sustentabilidade; Capacidade de Carga.

  15. An Acanthamoeba castellanii metacaspase associates with the contractile vacuole and functions in osmoregulation.

    Science.gov (United States)

    Saheb, Entsar; Trzyna, Wendy; Bush, John

    2013-03-01

    Acanthamoeba castellanii is a free-living protozoan. Some strains are opportunistic pathogens. A type-I metacaspase was identified in A. castellanii (Acmcp) and was shown to be expressed through the encystation process. The model organism, Dictyostelium discoideum, has been used here as a model for studying these caspase-like proteins. Separate cell lines expressing a GFP-tagged version of the full length Acmcp protein, as well as a deletion proline region mutant of Acmcp protein (GFP-Acmcp-dpr), have been introduced into D. discoideum. Both mutants affect the cellular metabolism, characterized by an increase in the growth rate. Microscopic imaging revealed an association between Acmcp and the contractile vacuole system in D. discoideum. The treatment of cells with selected inhibitors in different environments added additional support to these findings. This evidence shows that Acmcp plays an important role in contractile vacuole regulation and mediated membrane trafficking in D. discoideum. Additionally, the severe defect in contractile vacuole function in GFP-Acmcp-dpr mutant cells suggests that the proline-rich region in Acmcp has an essential role in binding this protein with other partners to maintain this process. Furthermore, Yeast two-hybrid system identified there are weak interactions of the Dictyostelium contractile vacuolar proteins, including Calmodulin, RabD, Rab11 and vacuolar proton ATPase, with Acmcp protein. Taken together, our findings suggest that A. castellanii metacaspase associate with the contractile vacuole and have an essential role in cell osmoregulation, which contributes to its attractiveness as a possible target for treatment therapies against A. castellanii infection.

  16. The effects of pentoxifylline on skeletal muscle contractility and neuromuscular transmission during hypoxia

    Directory of Open Access Journals (Sweden)

    Simsek-Duran Fatma

    2009-01-01

    Full Text Available Objectives : The objective of this study was to investigate the effects of pentoxifylline (PTX, a drug that is mainly used for indications related to tissue hypoxia, on hypoxia-induced inhibition of skeletal muscle contractility and neuromuscular transmission in mice. We hypothesized that chronic PTX treatment alters skeletal muscle contractility and hypoxia-induced dysfunction. Materials and Methods : Mice were treated with 50 mg/kg PTX or saline intraperitoneally for a week. Following ether anesthesia, diaphragm muscles were removed; isometric muscle contractions and action potentials were recorded. Time to reach neuromuscular blockade and the rate of recovery of muscle contractility were assessed during hypoxia and re-oxygenation. Results : The PTX group displayed 90% greater twitch amplitudes (P < 0.01. Hypoxia depressed twitch contractions and caused neuromuscular blockade in both groups. However, neuromuscular blockade occurred earlier in PTX-treated animals (P < 0.05. Muscle contractures developed during hypoxia were more pronounced in the PTX group (P < 0.05. Re-oxygenation reduced contracture and indirect muscle contractions resumed. The rate of recovery of contractions was faster (P < 0.05 and the amplitude of contractions was greater (P < 0.01 in the PTX group. PTX treatment increased amplitude (P < 0.05 and shortened action potential (P < 0.05 without altering resting membrane potential, excitation threshold, and neurotransmitter release. Conclusion : Chronic PTX treatment increases diaphragm contractility, but amplifies hypoxia-induced contractile dysfunction in mice. These results may implicate important clinical consequences for clinical usage of PTX in hypoxia-related conditions.

  17. 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.

  18. 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.

  19. À espera da seca que vem: capacidade adaptativa em comunidades rurais do semiárido

    Directory of Open Access Journals (Sweden)

    Ansu Mancal

    Full Text Available Este artigo avalia a disponibilidade de recursos necessários para criação de capacidade adaptativa em comunidades rurais do semiárido brasileiro. A pesquisa utiliza dados primários obtidos por meio de aplicação de questionários. Dada a grande extensão geográfica da região, adota-se como recorte uma amostra de comunidades rurais inseridas em áreas susceptíveis à desertificação no Estado do Ceará. A discussão é feita a partir de um sistema de indicadores definido por meio de consultas a especialistas (método Delphi e subdividido em quatro dimensões da capacidade adaptativa: capital social, capital econômico, capital humano e capital natural, pressupondo que a capacidade adaptativa é definida pela disponibilidade de um conjunto de recursos capazes de promover o bem-estar local. A análise da distribuição dos indicadores selecionados mostra que as comunidades possuem baixos níveis de recursos necessários para adaptação, sendo que os pontos mais críticos são destacados na dimensão de capital humano. No contexto observado acredita-se que as ações governamentais que poderiam melhorar a capacidade adaptativa das comunidades rurais do semiárido em relação às secas não encontram ambiente social propício para expressarem seu potencial, sendo o maior desafio a adoção de estratégias integradas de educação e capacitação da população que atuem de forma transversal em todas as políticas voltadas para o desenvolvimento local.

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

    OpenAIRE

    Campos Sérgio; de Barros Zacarias Xavier; B. Carrega Ellen Fittipaldi; Gehring Cardoso Lincoln; Barbosa Ana Paula

    2011-01-01

    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 subcla...

  1. Treinamento aeróbico melhora a capacidade funcional de pacientes em hemodiálise crônica

    OpenAIRE

    Henrique,Diane Michela Nery; Reboredo, Maycon de Moura; Chaoubah, Alfredo; Paula,Rogério Baumgratz de

    2010-01-01

    FUNDAMENTO: Na população geral, a prática regular de exercícios físicos se associa à melhora da capacidade funcional e à redução de eventos cardiovasculares. Já em portadores de doença renal crônica, uma população com significativo comprometimento da capacidade funcional e elevadas taxas de mortalidade cardiovascular, poucos estudos avaliam os efeitos da atividade física. OBJETIVO: Avaliar o efeito do treinamento aeróbico durante as sessões de hemodiálise, sobre a capacidade funcional e a pre...

  2. ¿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.

  3. Declínio da capacidade cognitiva durante o envelhecimento Decline of cognitive capacity during aging

    Directory of Open Access Journals (Sweden)

    Helenice Charchat-Fichman

    2005-03-01

    Full Text Available O declínio da capacidade cognitiva (DCC decorre dos processos fisiológicos do envelhecimento normal ou de um estágio de transição para as demências. Estudos epidemiológicos mostram que idosos com declínio da capacidade cognitiva apresentam maior risco de desenvolver Doença de Alzheimer (DA, em particular aqueles com déficit de memória episódica. A presente atualização mostra os principais critérios diagnósticos, achados neuropatológicos e neuropsicológicos do declínio da capacidade cognitiva durante o envelhecimento.Decline of cognitive capacity (DCC is due to normal physiological aging processes or to pre-dementia stage. Epidemiological studies show that elderly with decline of cognitive capacity have higher risk to develop Alzheimer's disease (AD, especially those with episodic memory deficits. This review presents the most important diagnosis criteria, neuropathological and neuropsychological findings of decline of cognitive capacity during aging.

  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. 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.

  6. INFLUENCIA DEL GÉNERO Y LA EDAD EN LA CAPACIDAD DE DETECTAR DIFERENCIAS FACIALES

    Directory of Open Access Journals (Sweden)

    JENNIFER BLANCO MARTÍNEZ

    2009-01-01

    Full Text Available Se evaluó el efecto del sexo y la edad de un grupo de personas en la capacidad de de- tectar cambios faciales ligeros en pares de fotografías. Las fotografías estuvieron expues- tas ante la persona durante 1,5 s. Se utilizaron dos tratamientos; uno sin entrenamiento y otro con entrenamiento, donde se presentaba a la persona justo antes de la prueba una pareja de fotografías como ejemplo de los cambios que podrían esperarse. Los hombres y mujeres presentaron diferencias significativas en los resultados de la prueba; siendo las mujeres las que obtuvieron mayor número de aciertos indicando una mayor percepción visual detallada de los rostros. Igualmente, se encontró efecto de la edad sobre la percepción, registrándose un mayor número de aciertos entre los 21 y 30 años; antes de este rango, los valores son menores posiblemente debido a que la capacidad perceptual está en proceso de desarrollo; mientras que después, los valores disminuyen por el patrón normal de envejecimiento. Se encontró un mayor número de aciertos para el tratamiento con entrenamiento, sugiriendo que este método (demostración y ejem- plo es eficaz en facilitar la capacidad de percepción de diferencias faciales.

  7. 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.

  8. 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.

  9. Proposição de um modelo teórico para capacidade de inovação sustentável

    OpenAIRE

    Froehlich, Cristiane; Universidade Feevale; Bitencourt, Claudia Cristina; Universidade do Vale do Rio dos Sinos - UNISINOS

    2015-01-01

    Este estudo trata-se de um ensaio teórico e analisa o desenvolvimento da capacidade de inovação como meio para alavancar a sustentabilidade empresarial. Para atender a esse objetivo, utiliza-se a abordagem das capacidades dinâmicas como auxiliar ao desenvolvimento da capacidade de inovação e mostra como elas podem ser desenvolvidas para suportar a capacidade de inovação. No decorrer da revisão bibliográfica do estudo, verifica-se que essa abordagem esclarece como desenvolver a capacidade de i...

  10. 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.

  11. 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

  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. 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.

  14. 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.

  15. Hemeoxygenase-1 inhibits human myometrial contractility via carbon monoxide and is upregulated by progesterone during pregnancy.

    Science.gov (United States)

    Acevedo, C H; Ahmed, A

    1998-03-01

    Nitric oxide was proposed as an endogenous inhibitor of myometrial contractility during pregnancy. Carbon monoxide (CO) like nitric oxide increases cGMP and is generated during the degradation of heme to biliverdin IX by hemeoxygenases (HO). Here we report that the expression of both HO-1 (inducible) and HO-2 (constitutive) were > 15-fold higher in pregnant myometrium compared to nonpregnant myometrium (n = 4, P synthesis (n = 4, P tin protoporphyrin IX (20 microM). This study clearly demonstrates the expression of HO in the human myometrium and shows that its induction produces CO that limits uterine contractility in pregnant myometrium indicating a role for the HO-CO-cGMP pathway in the maintenance of the quiescent state of the uterus during pregnancy.

  16. 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...

  17. 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.

  18. Does the stalk contractility of Vorticella convallaria depend on the stalk length?

    Science.gov (United States)

    Chung, Eun-Gul; Ryu, Sangjin

    2015-11-01

    Vorticella convallaria is a sessile stalked ciliate living in water, and its stalk coils to move the cell body (zooid) towards its residence substrate at a maximum speed of ~ 50 mm/s. Our previous microfluidics study shows that the isometric tension of the V. convallaria stalk is linearly proportional to the stalk length. Based on this observation, we hypothesize that the contractility of V. convallaria during normal contraction is also dependent on the stalk length. To investigate our hypothesis, we measured the contraction speed of V. convallaria using high-speed videography and evaluated the contractile force and energetics of V. convallaria using fluid dynamics modeling. We appreciate support from UNL Layman Seed Grant and Nebraska EPSCoR First Award Grant.

  19. Pharmacology of Casimiroa edulis; III. Relaxant and contractile effects in rat aortic rings.

    Science.gov (United States)

    Magos, G A; Vidrio, H; Enríquez, R

    1995-06-23

    The relaxant and contractile effects of an aqueous extract of the seeds of the hypotensive plant Casimiroa edulis were investigated in rat aortic rings. The extract inhibited contractions elicited by noradrenaline, serotonin and prostaglandin F2 alpha, but did not affect responses to KCl. Inhibition did not require the presence of intact vascular endothelium and was not affected by histamine antagonists. In this preparation, the extract also elicited concentration-related contractions which were more marked in the absence of endothelium, were not blocked by histamine antagonists, and were completely suppressed by alpha-adrenergic blockade. It was concluded that the relaxant effect of the extract is not exerted through release of an endothelial relaxing factor nor through blockade of calcium channels or of specific smooth muscle receptors, and does not involve histaminergic mechanisms. The contractile effect is modulated by vascular endothelium and is alpha-adrenergic in nature.

  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. 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.

  2. 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

  3. Hemeoxygenase-1 inhibits human myometrial contractility via carbon monoxide and is upregulated by progesterone during pregnancy.

    OpenAIRE

    Acevedo, C H; Ahmed, A

    1998-01-01

    Nitric oxide was proposed as an endogenous inhibitor of myometrial contractility during pregnancy. Carbon monoxide (CO) like nitric oxide increases cGMP and is generated during the degradation of heme to biliverdin IX by hemeoxygenases (HO). Here we report that the expression of both HO-1 (inducible) and HO-2 (constitutive) were > 15-fold higher in pregnant myometrium compared to nonpregnant myometrium (n = 4, P < 0.001, P < 0.005, respectively). Moreover, the activation of the HO-CO pathway ...

  4. Contractile function of the myocardium with prolonged hypokinesia in patients with surgical tuberculosis

    Science.gov (United States)

    Zakutayeva, V. P.; Matiks, N. I.

    1978-01-01

    The changes in the myocardial contractile function with hypokinesia in surgical tuberculosis patients are discussed. The phase nature of the changes is noted, specifically the changes in the various systoles, diastole, and other parts of the cardiac cycle. The data compare these changes during confinement in bed with no motor activity to and with a return to motor activity after leaving the in-bed regimen.

  5. Exposure to a Low Lead Concentration Impairs Contractile Machinery in Rat Cardiac Muscle.

    Science.gov (United States)

    Silva, Marito A S C; de Oliveira, Thiago F; Almenara, Camila C P; Broseghini-Filho, Gilson B; Vassallo, Dalton V; Padilha, Alessandra S; Silveira, Edna A

    2015-10-01

    Lead exposure has been considered to be a risk factor for hypertension and cardiovascular disease. Our purpose was to evaluate the effects of low plasma lead concentration on cardiac contractility in isolated papillary muscles. Wistar rats were divided in control group or group treated with 100 ppm of lead acetate in the drinking water for 15 days. Blood pressure (BP) was measured weekly. At the end of the treatment period, the animals were anesthetized and euthanized, and parameters related to isolated papillary muscle contractility were recorded. The lead concentrations in the blood reached 12.3 ± 2 μg/dL. The BP was increased in the group treated with 100 ppm of lead acetate. Lead treatment did not alter force and time derivatives of the force of left ventricular papillary muscles. In addition, the inotropic response induced by an increase in the extracellular Ca(2+) concentration was reduced in the Pb(2+) group. However, the uptake of Ca(2+) by the sarcoplasmic reticulum and the protein expression of SERCA and phospholamban remained unchanged. Postrest contraction was similar in the both groups, and tetanic peak and plateau tension were reduced in lead group. These results demonstrated that the reduction in the inotropic response to calcium does not appear to be caused by changes in the trans-sarcolemmal calcium flux but suggest that an impairment of the contractile machinery might be taking place. Our results demonstrate that even at a concentration below the limit considered to be safe, lead exerts deleterious effects on the cardiac contractile machinery.

  6. Matching of sarcoplasmic reticulum and contractile properties in rat fast- and slow-twitch muscle fibres.

    Science.gov (United States)

    Trinh, Huong H; Lamb, Graham D

    2006-07-01

    1. The twitch characteristics (fast-twitch or slow-twitch) of skeletal muscle fibres are determined not only by the contractile apparatus properties of the fibre, but also by the time-course of Ca2+ release and re-uptake by the sarcoplasmic reticulum (SR). The present study examined, in individual fibres from non-transforming muscle of the rat, whether particular SR properties are matched to the contractile apparatus properties of the fibre, in particular in the case of fibres with fast-twitch contractile apparatus located in a slow-twitch muscle, namely the soleus. 2. Force was recorded in single, mechanically skinned fibres from extensor digitorum longus (EDL), gastrocnemius, peroneus longus and soleus muscles. Using repeated cycles in which the SR was emptied of all releasable Ca2+ and then reloaded, it was possible to determine the relative amount of Ca2+ present in the SR endogenously, the maximum SR capacity and the rate of Ca2+ loading. The sensitivity of the contractile apparatus to Ca2+ and Sr2+ was used to classify the fibres as fast-twitch (FT), slow-twitch (ST) or mixed (< 3% of the fibres examined) and thereby identify the likely troponin C and myosin heavy chain types present. 3. There was no significant difference in SR properties between the groups of FT fibres obtained from the four different muscles, including soleus. Despite some overlap in the SR properties of individual fibres between the FT and ST groups, the properties of the FT fibres in all four muscles studied were significantly different from those of the ST and mixed fibres. 4. In general, in FT fibres the SR had a larger capacity and the endogenous Ca2+ content was a relatively lower percentage of maximum compared with ST fibres. Importantly, in terms of their SR properties, FT fibres from soleus muscle more closely resembled FT fibres from other muscles than they did ST fibres from soleus muscle.

  7. 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.

  8. Single muscle fibre contractile properties differ between body-builders, power athletes and control subjects

    OpenAIRE

    Meijer, J.P; Jaspers, R.T.; Rittweger, Jörn; SEYNNES, OLIVIER R.; Kamandulis, Sigitas; Brazaitis, M.; Skurvydas, A.; Pisot, Rado; Šimunič, Boštjan; Narici, Maco V.; Degens, Hans

    2016-01-01

    What is the central question of this study? Do the contractile properties of single muscle fibres differ between body-builders, power athletes and control subjects? •What is the main finding and its importance? Peak power normalized for muscle fibre volume in power athletes is higher than in control subjects. Compared with control subjects, maximal isometric tension (normalized for muscle fibre cross-sectional area) is lower in body-builders. Although this difference may be cause...

  9. 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.

  10. 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.

  11. 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.

  12. [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.

  13. 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.

  14. INDICADORES DE CAPACIDAD APLICADOS A LA DESERCIÓN EN LAS UNIVERSIDADES COLOMBIANAS

    Directory of Open Access Journals (Sweden)

    José Daniel Mosquera Artamónov

    2011-01-01

    Full Text Available En este trabajo, se presenta una propuesta para implementar los Índices de Capacidad de un Proceso como herramienta para medir la efectividad de un proceso social. Estos índices son ampliamente empleados en la industria de productos de consumo, pero no es clara la forma como pueden ser usados en el control de procesos sociales. El trabajo se centra en el análisis de aquellos procesos que no están normalmente distribuidos y que por lo tanto, en una primera aproximación teórica, no son susceptibles de ser controlados con el uso de Índices de Capacidad. Mediante un doble ejemplo aplicado al caso de la deserción en las universidades colombianas, se ofrece una metodología detallada de cómo solucionar el problema de la no normalidad de los datos con el uso de la transformación de Box-Cox, la distribución de Weibull y el método de percentiles de Clements. De esta manera, se demuestra la aplicabilidad de los métodos ya contrastados en otros ámbitos, a casos concretos de deserción en las universidades colombianas. El método de índices de capacidad puede usarse para evaluar el proceso de deserción y definir las metas reales de deserción, posibles de cumplir. Se propone además, que esta metodología sea usada en el control de otros procesos sociales.

  15. 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.

  16. Disorders of ventricular contractility and electrogenesis in the early stage of endotoxin shocked rabbits.

    Science.gov (United States)

    Lolov, R; Velkov, Z

    1994-01-01

    This is a report on ventricular contractility and electrogenesis disorders in rabbits, following intravenous injection of E. coli endotoxin at a dose of 2 mg.kg-1. At the 30th min, the right ventricular contractility indices (dP/dtmax)/P and [(dP/dt)/P]max had lower values, whereas end diastolic pressure (EDP), right ventricular systolic pressure (RVSP) and P(dP/dtmax) showed higher values compared to the initial ones. Most of the left ventricular contractility indices tested showed significantly lower values at the 30th and 60th min of the registration. In the scalar orthogonal ECG leads, at the 5th min an increased Qz amplitude, and at the 60th min an increased Rz amplitude, a decreased Ry amplitude, and QRS complex widening and bradicardia, were registered. In the spatial magnitude curve an increased amplitude of the main vectors of ventricular depolarization was documented. The changes in electrogenesis are interpreted first and foremost by the presence of hemodynamic disorders. The inference is reached that both left and right ventricular dysfunction have been already formed during the initial stage of endotoxin shock.

  17. Uterine contractility of plants used to facilitate childbirth in Nigerian ethnomedicine

    Science.gov (United States)

    Attah, Alfred F.; O'Brien, Margaret; Koehbach, Johannes; Sonibare, Mubo A.; Moody, Jones O.; Smith, Terry J.; Gruber, Christian W.

    2012-01-01

    Ethnopharmacological relevance Pregnant women in Nigeria use plant preparations to facilitate childbirth and to reduce associated pain. The rationale for this is not known and requires pharmacological validation. Aim of study Obtain primary information regarding the traditional use of plants and analyze their uterine contractility at cellular level. Materials and methods Semi-structured, open interviews using questionnaires of traditional healthcare professionals and other informants triggered the collection and identification of medicinal plant species. The relative traditional importance of each medicinal plant was determined by its use-mention index. Extracts of these plants were analyzed for their uterotonic properties on an in vitro human uterine cell collagen model. Result The plants Calotropis procera, Commelina africana, Duranta repens, Hyptis suaveolens, Ocimum gratissimum, Saba comorensis, Sclerocarya birrea, Sida corymbosa and Vernonia amygdalina were documented and characterized. Aqueous extracts from these nine plants induced significant sustained increases in human myometrial smooth muscle cell contractility, with varying efficiencies, depending upon time and dose of exposure. Conclusion The folkloric use of several plant species during childbirth in Nigeria has been validated. Seven plants were for the first time characterized to have contractile properties on uterine myometrial cells. The results serve as ideal starting points in the search for safe, longer lasting, effective and tolerable uterotonic drug leads. PMID:22766472

  18. Formation and function of the polar body contractile ring in Spisula.

    Science.gov (United States)

    Pielak, Rafal M; Gaysinskaya, Valeriya A; Cohen, William D

    2004-05-15

    Initial studies suggested that spatial organization of the putative polar body contractile ring was determined by the peripheral aster in Spisula [Biol. Bull. 205 (2003) 192]. Here we report detailed supporting observations, including testing of aster and ring function with inhibitors. The metaphase peripheral aster was confirmed to spread cortically in an umbrella-like pattern, with microtubule-poor center. The aster disassembled during anaphase, leaving the spindle docked at the F-actin-poor center of a newly generated cortical F-actin ring that closely approximated the aster in location, measured diameter range, and pattern. Cytochalasin D and latrunculin-B permitted all events except ring and polar body formation. Nocodazole disassembly or taxol stabilization of the peripheral aster produced poorly defined rings or bulging anaphase asters within the ring center, respectively, inhibiting polar body formation. Polar body extrusion occurred at the ring center, the diameter of which diminished. Ring contractility-previously assumed-was verified using blebbistatin, a myosin-II ATPase inhibitor that permitted ring assembly but blocked polar body extrusion. The data support the hypothesis that peripheral aster spreading, perhaps dynein-driven, is causally related to polar body contractile ring formation, with anaphase entry and aster disassembly also required for polar body biogenesis. Previously reported astral spreading during embryonic micromere formation suggests that related mechanisms are involved in asymmetric somatic cytokinesis.

  19. 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.

  20. From Newborn to Senescence Morphological and Functional Remodeling Leads to Increased Contractile Capacity of Arteries.

    Science.gov (United States)

    Ivic, Ivan; Vamos, Zoltan; Cseplo, Peter; Koller, Akos

    2017-04-01

    Aging induces substantial morphological and functional changes in vessels. We hypothesized that due to morphological remodeling the total contractile forces of arteries increase, especially in older age as a function of age. Mean arterial blood pressure of rats and morphological and functional characteristics of isolated carotid arteries rats, from newborn to senescent, were assessed. The arterial blood pressure of rats increased significantly from 0.25 to the age of 6 months, and then it reached a level, which was maintained until age of 30 months. Wall lumen and wall thickness increased with age, mostly due to media (smooth muscle) thickening, whereas wall tension gradually reduced with age. Contractions of arteries to nonreceptor-mediated vasomotor agent (KCl, 60mM) increased in three consecutive age groups, whereas contractility first increased (until 2 months), then it did not change further with aging. Norepinephrine-induced contractions initially increased in young age and then did not change further in older age. These findings suggest that during normal aging due to remodeling of arterial wall (smooth muscle) the contractile capacity of arteries increases, which seems to be independent from systemic blood pressure. Thus, arterial remodeling can favor the development of increased circulatory resistance in older age.

  1. [Effect of acetylcholine and acetylcholinesterase on the activity of contractile vacuole of Amoeba proteus].

    Science.gov (United States)

    Bagrov, Ia Iu; Manusova, N B

    2011-01-01

    Acetylcholine (ACh, 1 microM) stimulates activity of the contractile vacuole of proteus. The effect of ACh is not mimicked by its analogs which are not hydrolyzed by acetylcholinesterase (AChE), i. e., carbacholine and 5-methylfurmethide. The effect of ACh is not sensitive to the blocking action of M-cholinolytics, atropine and mytolone, but is suppressed by N-cholinolytic, tubocurarine. The inhibitors of AChE, eserine (0.01 microM) and armine (0.1 microM), suppress the effect of ACh on amoeba contractile vacuole. ACh does not affect activation of contractile vacuole induced by arginine-vasopressin (1 microM), but it blocks such effect of opiate receptors agonist, dynorphin A1-13 (0.01 microM). This effect of ACh is also suppressed by the inhibitors of AChE. These results suggest that, in the above-described effects of ACh, AChE acts not as an antagonist, but rather as a synergist.

  2. Kaurane and pimarane-type diterpenes from the Viguiera species inhibit vascular smooth muscle contractility.

    Science.gov (United States)

    Ambrosio, Sergio R; Tirapelli, Carlos R; da Costa, Fernando B; de Oliveira, Ana M

    2006-08-01

    The research, development and use of natural products as therapeutic agents, especially those derived from plants, have been increasing in recent years. Despite the fact that plants provide a rich source of novel biologically active compounds, only a small percentage have been phytochemically investigated and studied for their medical potential. Viguiera is a genus that belongs to the family Asteraceae and to the sunflower tribe Heliantheae, which is widespread mostly in Mexico and in other areas of the Andes and upland areas of Brazil. A review on the secondary metabolites pointed out that sesquiterpene lactones and diterpenes, of the kaurane and pimarane-type, are the main compounds produced by these plants. Some reports have shown that kaurane- and pimarane-type diterpenes exert several biological activities such as anti-inflammatory action, antimicrobial and antispasmodic activities. Kaurenoic and pimaradienoic acids, which are the main secondary metabolites isolated by our research group from the roots of Viguiera robusta and V. arenaria, respectively, have been evaluated on vascular smooth muscle contractility. We showed that these diterpenoids are able to inhibit the vascular contractility mainly by blocking extracellular Ca(2+) influx. Additionally, in this review we discuss the structure-activity relationship of the diterpenes regarding their inhibitory activity on vascular contractility.

  3. Nonmuscle Myosin IIA Regulates Platelet Contractile Forces Through Rho Kinase and Myosin Light-Chain Kinase.

    Science.gov (United States)

    Feghhi, Shirin; Tooley, Wes W; Sniadecki, Nathan J

    2016-10-01

    Platelet contractile forces play a major role in clot retraction and help to hold hemostatic clots against the vessel wall. Platelet forces are produced by its cytoskeleton, which is composed of actin and nonmuscle myosin filaments. In this work, we studied the role of Rho kinase, myosin light-chain kinase, and myosin in the generation of contractile forces by using pharmacological inhibitors and arrays of flexible microposts to measure platelet forces. When platelets were seeded onto microposts, they formed aggregates on the tips of the microposts. Forces produced by the platelets in the aggregates were measured by quantifying the deflection of the microposts, which bent in proportion to the force of the platelets. Platelets were treated with small molecule inhibitors of myosin activity: Y-27632 to inhibit the Rho kinase (ROCK), ML-7 to inhibit myosin light-chain kinase (MLCK), and blebbistatin to inhibit myosin ATPase activity. ROCK inhibition reduced platelet forces, demonstrating the importance of the assembly of actin and myosin phosphorylation in generating contractile forces. Similarly, MLCK inhibition caused weaker platelet forces, which verifies that myosin phosphorylation is needed for force generation in platelets. Platelets treated with blebbistatin also had weaker forces, which indicates that myosin's ATPase activity is necessary for platelet forces. Our studies demonstrate that myosin ATPase activity and the regulation of actin-myosin assembly by ROCK and MLCK are needed for the generation of platelet forces. Our findings illustrate and explain the importance of myosin for clot compaction in hemostasis and thrombosis.

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

    Science.gov (United States)

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

    2009-03-01

    Repeated administration of 3,4-methylenedioxymethamphetamine (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 alpha-methyl dopamine, N-methyl alpha-methyl dopamine and 2,5-bis(glutathion-S-yl)-alpha-MeDA. Dihydroethidium was used to detect drug-induced increases in reactive oxygen species (ROS) production in ventricular myocytes. Contractile function and changes in intracellular calcium transients were measured in paced (1 Hz), Fura-2 AM loaded, myocytes using the IonOptix system. Production of ROS in ventricular myocytes treated with MDMA was not different from control. In contrast, all three metabolites of MDMA exhibited time- and concentration-dependent increases in ROS that were prevented by N-acetyl-cysteine (NAC). The metabolites of MDMA, but not MDMA alone, significantly decreased contractility and impaired relaxation in myocytes stimulated at 1 Hz. These effects were prevented by NAC. Together, these data suggest that MDMA-induced oxidative stress in the left ventricle can be due, at least in part, to the metabolism of MDMA to redox active metabolites.

  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. Bacterial flagellin triggers cardiac innate immune responses and acute contractile dysfunction.

    Directory of Open Access Journals (Sweden)

    Joelle Rolli

    Full Text Available BACKGROUND: Myocardial contractile failure in septic shock may develop following direct interactions, within the heart itself, between molecular motifs released by pathogens and their specific receptors, notably those belonging to the toll-like receptor (TLR family. Here, we determined the ability of bacterial flagellin, the ligand of mammalian TLR5, to trigger myocardial inflammation and contractile dysfunction. METHODOLOGY/PRINCIPAL FINDINGS: TLR5 expression was determined in H9c2 cardiac myoblasts, in primary rat cardiomyocytes, and in whole heart extracts from rodents and humans. The ability of flagellin to activate pro-inflammatory signaling pathways (NF-kappaB and MAP kinases and the expression of inflammatory cytokines was investigated in H9c2 cells, and, in part, in primary cardiomyocytes, as well as in the mouse myocardium in vivo. The influence of flagellin on left ventricular function was evaluated in mice by a conductance pressure-volume catheter. Cardiomyocytes and intact myocardium disclosed significant TLR5 expression. In vitro, flagellin activated NF-kappaB, MAP kinases, and the transcription of inflammatory genes. In vivo, flagellin induced cardiac activation of NF-kappaB, expression of inflammatory cytokines (TNF alpha, IL-1 beta, IL-6, MIP-2 and MCP-1, and provoked a state of reversible myocardial dysfunction, characterized by cardiac dilation, reduced ejection fraction, and decreased end-systolic elastance. CONCLUSION/SIGNIFICANCE: These results are the first to indicate that flagellin has the ability to trigger cardiac innate immune responses and to acutely depress myocardial contractility.

  7. 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.

  8. Mitochondrial fusion dynamics is robust in the heart and depends on calcium oscillations and contractile activity.

    Science.gov (United States)

    Eisner, Verónica; Cupo, Ryan R; Gao, Erhe; Csordás, György; Slovinsky, William S; Paillard, Melanie; Cheng, Lan; Ibetti, Jessica; Chen, S R Wayne; Chuprun, J Kurt; Hoek, Jan B; Koch, Walter J; Hajnóczky, György

    2017-01-31

    Mitochondrial fusion is thought to be important for supporting cardiac contractility, but is hardly detectable in cultured cardiomyocytes and is difficult to directly evaluate in the heart. We overcame this obstacle through in vivo adenoviral transduction with matrix-targeted photoactivatable GFP and confocal microscopy. Imaging in whole rat hearts indicated mitochondrial network formation and fusion activity in ventricular cardiomyocytes. Promptly after isolation, cardiomyocytes showed extensive mitochondrial connectivity and fusion, which decayed in culture (at 24-48 h). Fusion manifested both as rapid content mixing events between adjacent organelles and slower events between both neighboring and distant mitochondria. Loss of fusion in culture likely results from the decline in calcium oscillations/contractile activity and mitofusin 1 (Mfn1), because (i) verapamil suppressed both contraction and mitochondrial fusion, (ii) after spontaneous contraction or short-term field stimulation fusion activity increased in cardiomyocytes, and (iii) ryanodine receptor-2-mediated calcium oscillations increased fusion activity in HEK293 cells and complementing changes occurred in Mfn1. Weakened cardiac contractility in vivo in alcoholic animals is also associated with depressed mitochondrial fusion. Thus, attenuated mitochondrial fusion might contribute to the pathogenesis of cardiomyopathy.

  9. Age- and gender-related changes in contractile properties of non-atrophied EDL muscle.

    Directory of Open Access Journals (Sweden)

    Stephen Chan

    Full Text Available BACKGROUND: In humans, ageing causes skeletal muscles to become atrophied, weak, and easily fatigued. In rodent studies, ageing has been associated with significant muscle atrophy and changes in the contractile properties of the muscles. However, it is not entirely clear whether these changes in contractile properties can occur before there is significant atrophy, and whether males and females are affected differently. METHODS AND RESULTS: We investigated various contractile properties of whole isolated fast-twitch EDL muscles from adult (2-6 months-old and aged (12-22 months-old male and female mice. Atrophy was not present in the aged mice. Compared with adult mice, EDL muscles of aged mice had significantly lower specific force, longer tetanus relaxation times, and lower fatiguability. In the properties of absolute force and muscle relaxation times, females were affected by ageing to a greater extent than males. Additionally, EDL muscles from a separate group of male mice were subjected to eccentric contractions of 15% strain, and larger force deficits were found in aged than in adult mice. CONCLUSION: Our findings provide further insight into the muscle atrophy, weakness and fatiguability experienced by the elderly. We have shown that even in the absence of muscle atrophy, there are definite alterations in the physiological properties of whole fast-twitch muscle from ageing mice, and for some of these properties the alterations are more pronounced in female mice than in male mice.

  10. Age- and Gender-Related Changes in Contractile Properties of Non-Atrophied EDL Muscle

    Science.gov (United States)

    Chan, Stephen; Head, Stewart I.

    2010-01-01

    Background In humans, ageing causes skeletal muscles to become atrophied, weak, and easily fatigued. In rodent studies, ageing has been associated with significant muscle atrophy and changes in the contractile properties of the muscles. However, it is not entirely clear whether these changes in contractile properties can occur before there is significant atrophy, and whether males and females are affected differently. Methods and Results We investigated various contractile properties of whole isolated fast-twitch EDL muscles from adult (2–6 months-old) and aged (12–22 months-old) male and female mice. Atrophy was not present in the aged mice. Compared with adult mice, EDL muscles of aged mice had significantly lower specific force, longer tetanus relaxation times, and lower fatiguability. In the properties of absolute force and muscle relaxation times, females were affected by ageing to a greater extent than males. Additionally, EDL muscles from a separate group of male mice were subjected to eccentric contractions of 15% strain, and larger force deficits were found in aged than in adult mice. Conclusion Our findings provide further insight into the muscle atrophy, weakness and fatiguability experienced by the elderly. We have shown that even in the absence of muscle atrophy, there are definite alterations in the physiological properties of whole fast-twitch muscle from ageing mice, and for some of these properties the alterations are more pronounced in female mice than in male mice. PMID:20808812

  11. 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.

  12. La capacidad empresarial: el boom de la teoría administrativa contemporáea

    OpenAIRE

    Gómez, Orlando Salinas

    2015-01-01

    RESUMENLa interacción básica de este artículo es plantear cómo es desarrollo de la capacidad empresarial no es una moda sino una necesidad histórica de las sociedades que, a través del desarrollo económico construyen un hombre nuevo, autogestor de su futuro. Así mismo formula el papel de la universidad en ese proceso teniendo como parámetro esencial la recuperación. Eje central  de todo quehacer en la educación superior. 

  13. Consumo de drogas psicotrópicas y capacidades de autocuidado en mujeres de Tepic, Nayarit

    OpenAIRE

    Luis Gerardo Valdivia Pérez; Leticia Casique Casique; Teresita de Jesús Muñoz Torres

    2015-01-01

    Objetivo: Determinar la asociación entre el consumo de drogas psicotrópicas y la capacidad de autocuidado en las mujeres. Material y métodos: Estudio no experimental, cuantitativo, aplicado, prolectivo y transversal. La muestra estuvo conformada por 33 mujeres que consumen drogas psicotrópicas de la colonia Tierra y Libertad de Tepic, Nayarit. Resultados: El 73% son solteras, 51.5% tiene depresión, 21.2% insomnio y 15.2% ansiedad. El 69.7% reportó un tiempo de consumo de drogas psicotrópicas ...

  14. Capacidad funcional de pacientes con diabetes mellitus y pié ulcerado

    OpenAIRE

    2009-01-01

    OBJETIVO: Avaliar a capacidade funcional de pessoas com diabetes mellitus e pé ulcerado. MÉTODOS: Estudo analítico, transversal e comparativo, realizado em hospital público do município de São Paulo, sendo os dados coletados no período de 2 de junho a 30 julho de 2008. Foram selecionados para compor o Grupo de Estudo, 20 pacientes com diabetes mellitus e pé ulcerado; para o Grupo Controle 20 pessoas com diagnóstico médico de diabetes mellitus, sem úlcera no pé. O instrumento utilizado foi Hea...

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

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    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.

  16. Robot operating system (ros) como plataforma para extender las capacidades de legos nxt

    OpenAIRE

    Decimavilla Alarcón, Diana Carolina; Utreras Abad, María Fernanda; Ochoa Donoso, Daniel

    2014-01-01

    El presente trabajo muestra el estudio de Robot Operating System (ROS), explica que es ROS, para qué sirve, la arquitectura de ROS y por supuesto muestra a ROS como plataforma para extender las capacidades de Legos NXT. El objetivo de esta investigación nace de la necesidad de fomentar el uso de ROS ya que cabe recalcar que es de libre distribución y de código abierto. ROS es un framework de desarrollo de algoritmos de robótica, el cual permitió implementar la aplicación “LASER SCANNER ”. El ...

  17. 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...

  18. 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...

  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. EXTENSIÓN DE CAPACIDADES DE ANÁLISIS DE DATOS EN ROUTERS CON OPENWRT

    OpenAIRE

    PIZA HERNANDEZ, AMBAR MICHELLE; PEZO ORTIZ, VICTOR HUGO

    2016-01-01

    El siguiente trabajo de investigación presenta la descripción de un sistema automatizado que permite obtener el porcentaje de la señal Wi-Fi recibida por cada red existente en el lugar que nos encontremos a través de un mapa. Como dispositivo de monitoreo usamos un sistema embebido, en un enrutador inalámbrico, al cual se le cambio su firmware de fábrica por OpenWrt (firmware para dispositivos embebidos de código abierto) para poder extender su capacidad de funcionamiento a otras diferente...

  1. Capacidad administrativa como factor de eficiencia interna y global de las organizaciones

    Directory of Open Access Journals (Sweden)

    Carlos E. Martínez Fajardo

    1997-06-01

    Full Text Available El concepto de eficiencia ha sido precisado y simplificado por los autores de la teoría clásica de la administración en el sentido de maximizar la producción de las organizaciones con los mínimos costos. En el presente artículo se analizará la eficiencia interna y global de las organizaciones de acuerdo con nuevos criterios adicionales que permitan estudiar el problema con un enfoque de mayor complejidad la naturaleza, fines y estructura de las organizaciones, entre ellos la incidencia del factor de este siglo denominado capacidad administrativa.

  2. CAPACIDAD estructural DE JUNTAS T de perfilES de acero LAMINADO EN FRÍO

    OpenAIRE

    2011-01-01

    Este estudio es consecuencia del uso extendido de tubo estructural y cajones formados con dos secciones tipo C(ambas de acero laminado en frío) en las estructuras principales de diferentes tipos de edificaciones. Dichas prácticashan puesto en evidencia la necesidad de cuantificar la resistencia de la unión viga y columna elaboradas con estematerial. Se investigaron cuatro diferentes tipos de uniones, con el propósito de determinar la capacidad máximacorrespondiente. Esta evaluación se realizó...

  3. Comparación de índices de capacidad de procesos con datos autocorrelacionados

    OpenAIRE

    2011-01-01

    Los índices de capacidad de un proceso suministran una información numérica acerca de cómo el proceso se ajusta a unos límites de especificación. En el cálculo de estos índices se asume que las observaciones son independientes; sin embargo, en aplicaciones industriales frecuentemente los datos están autocorrelacionados. Este artículo analiza los índices Cp,Cpk,Cpm y Cpmk cuando los datos presentan autocorrelación, se encuentran las varianzas para sus estimadores cuando los procesos son gaussi...

  4. Capacidad oxidativa de los músculos respiratorios y periféricos en la EPOC

    OpenAIRE

    2003-01-01

    Consultable des del TDX Títol obtingut de la portada digitalitzada Los músculos respiratorios están sometidos a sobrecarga crónica. En cambio, los músculos de las extremidades están sometidos a un desuso relativo. Esto determinaría cambios a nivel estructural y metabólico, con impacto en la capacidad oxidativa. En los músculos respiratorios ésta se hallaría conservada o incrementada, con cambios proporcionales a la gravedad de la enfermedad. En los músculos de las extremidades inferiore...

  5. Capacidad del trébol subterráneo de producir semillas viables en superficie

    OpenAIRE

    2011-01-01

    Factor importante en la selección de nuevos cultivares de trébol subterráneo (ssp. subterraneumj en el S.O. español es la capacidad de producir semillas viables en superficie, debido a la dificultad que encuentra el trébol para enterrar sus semillas en los suelos duros y compactos de la zona. Para comprobar qué características más significativas presentan aquellos ecotipos que poseen este carácter, se ha realizado un ensayo comparativo entre cultivares!ecotipos con diferentes ciclos de florac...

  6. Evaluación de las capacidades humanas en el proceso de desarrollo de software

    OpenAIRE

    Acuña, Silvia T.; Sosa, Mabel; Figueroa, Saritha G.; Menini, María de los Ángeles

    2005-01-01

    En los modelos de proceso software actuales las personas son el factor menos formalizado, sin embargo, éstas presentan un comportamiento no determinístico y subjetivo que influye decisivamente en los resultados de la producción de software. Se ha desarrollado un Modelo del Proceso Software Orientado a las Capacidades que define los elementos del proceso software: actividades, productos, técnicas y personas; más los originales de esta investigación: estructuración del trabajo, roles y capac...

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

    OpenAIRE

    Beatriz Yasuko Arita Watanabe

    2005-01-01

    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 Nac...

  8. La diversidad de capacidades para aprender, un valor a ser reconocido en las aulas.

    OpenAIRE

    Erazo Bermúdez, Marly Liliana; Ramírez Plaza, Franqui Idelva; Vélez Correa, Ruth Mary; Yanza Bravo, Alexander Andrés; Restrepo García, Paula Andrea

    2016-01-01

    Artículo (Maestría en Educación desde la Diversidad). Universidad de Manizales. Facultad de Ciencias Sociales y Humanas, 2016 Este artículo es resultado de la investigación denominada Significados y sentidos de la diversidad de capacidades de aprendizaje que han configurado en su contexto educativo los niños, las niñas y jóvenes del grado sexto de la Institución Educativa (IE) El Boquerón, en el municipio de Timbío del departamento del Cauca (Colombia). El estudio hace parte de un proyect...

  9. 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.

  10. 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...

  11. 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

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

    OpenAIRE

    2012-01-01

    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 informació...

  13. O debate de Amartya Sen com Kenneth Arrow e John Rawls e a abordagem das capacidades

    OpenAIRE

    2009-01-01

    O objetivo dessa dissertação é investigar em que sentido é pertinente localizar na teoria da escolha social de Kenneth Arrow e na teoria da justiça de John Rawls as duas principais raízes teóricas da abordagem das capacidades de Amartya Sen. Argumentar-se-á que a teoria da escolha social de Arrow cumpriu o papel de explicitar as deficiências da teoria econômica do bem-estar. Desse modo, as análises de Arrow apontam as limitações a serem superadas para se chegar a uma teor...

  14. CAPACIDADE DE APRENDIZAGEM ORGANIZACIONAL: ESTUDO REALIZADO EM UMA INDÚSTRIA TÊXTIL

    OpenAIRE

    Gonçalves, Andressa, 1988-; da Silva, Liliane Liliane de Souza Vieira

    2016-01-01

    La capacidad de aprendizaje organizacional es definida por Chiva, Alegre e Lapiedra (2007) como un conjunto de características organizacionales que facilitan el aprendizaje en todos los niveles de la empresa. El objetivo de este estudio fue identificar la presencia de las dimensiones de aprendizaje organizacional - Experimentación, Propensión a Riesgos, Interacción con el Ambiente Externo, Diálogo y Toma Participativa de Decisiones en una industria textil. La investigación fue descriptiva, su...

  15. Fadiga e capacidade para o trabalho em turnos fixos de doze horas

    Directory of Open Access Journals (Sweden)

    Metzner Ricardo Jorge

    2001-01-01

    Full Text Available OBJETIVO: Analisar as variáveis que interferem na percepção de fadiga e na capacidade para o trabalho em trabalhadores que executam suas atividades em turnos fixos diurnos e noturnos. MÉTODOS: Estudo transversal, com participação de 43 trabalhadores de turnos diurnos e noturnos de uma indústria têxtil, que trabalhavam em turnos fixos de 12 horas diárias e semana reduzida. Mediante vários questionários, o grupo estudado respondeu a questões sobre: fadiga, índice de capacidade para o trabalho, características individuais, estilos de vida e condições de trabalho. Foi feita análise de regressão linear univariada. RESULTADOS: Os fatores que influenciaram a percepção de fadiga associam-se a estilos de vida dos trabalhadores (a prática de exercício físico é um fator protetor e à dificuldade em manter o sono, que, se presente, aumenta a percepção de fadiga. Os fatores associados à percepção do índice de capacidade para o trabalho (ICT foram o tempo de exercício na função e o turno noturno de trabalho: quanto maior o primeiro, menor o ICT; trabalhar à noite aumenta o ICT. A duração da jornada diária de 12 horas pode provocar aumento considerável na carga de trabalho, influenciando a percepção do trabalhador sobre a capacidade para o trabalho, a fadiga e as alterações do sono. CONCLUSÕES: Os resultados indicam que nem sempre o trabalho noturno mostra-se como fator prejudicial à saúde. Entretanto, a amostra estudada é pequena, o estudo é transversal, e pode ter ocorrido um efeito de seleção. Assim, é necessária a realização de estudos longitudinais, com amostras maiores, dado que o ICT tende a diminuir à medida que aumenta o tempo na função.

  16. 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.

  17. 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.

  18. Uso do Verapamil em Gestantes Hipertensas Crônicas: análise do Fluxo das Artérias Uterinas e Umbilical Use of Verapamil in Chronic Hypertensive Pregnant Women: flow Analysis of Uterine Arteries and Umbilical Artery

    Directory of Open Access Journals (Sweden)

    Marcus Jose do Amaral Vasconcellos

    2000-06-01

    Full Text Available Objetivo: este trabalho, utilizando verapamil, um bloqueador dos canais lentos de cálcio, constituiu ensaio clínico randomizado, duplo-cego e placebo controlado, e objetivou procurar variação do fluxo uteroplacentário e fetoplacentário durante uso oral crônico do fármaco em gestantes com hipertensão crônica leve para moderada. Métodos: 123 pacientes divididas em dois grupos: grupo estudo (n = 61, submetidas a 240 mg/dia de verapamil, e grupo controle (n = 62, submetidas ao placebo. As pacientes randomizadas em grupos de quatro utilizaram a medicação ou placebo durante trinta dias. Um exame do fluxo das artérias uterinas e da artéria umbilical pela dopplervelocimetria foi registrado. Pelo cálculo da média e desvio padrão, foram comparados os valores dos índices de resistência (IR e pulsatilidade (IP e da relação sístole/diástole (A/B das artérias em estudo após administração dos comprimidos. Resultados: o grupo verapamil apresentou os seguintes valores médios para as artérias uterinas: IR = 0,82 (0,28, IP de 1,06 (0,12 e A/B de 2,42 (0,51. O grupo placebo mostrou: IR de 0,75 (0,35, IP de 1,00 (0,18 e A/B de 2,30 (0,38. Quando analisada a artéria umbilical, os valores foram para o grupo verapamil: IR = 0,73 (0,12, IP = 1,04 (0,13 e A/B = 2,94 (0,32. No grupo placebo, IR = 0,70 (0,14, IP = 1,03 (0,07 e A/B = 3,02 (0,78. A análise estatística das diferenças das médias por meio da razão F mostrou não haver diferença entre os dois grupos avaliados. Conclusão: este trabalho referenda o uso do verapamil entre gestantes com hipertensão crônica (leve para moderada, pois não oferece prejuízos no fluxo uteroplacentário e fetoplacentário.Purpose: this study, using verapamil, a slow calcium channel blocker, was a randomized, clinical, double blind and placebo controlled trial, whose objective was to observe if there was a uteroplacental and fetoplacental flow variation during its chronic oral use. Methods: 123

  19. Vascular and cardiac contractile reserve in the dog heart with chronic multiple coronary occlusions.

    Science.gov (United States)

    Schwarz, F; Flameng, W; Mack, B; Türschmann, W; Schaper, W

    1976-11-01

    Nineteen mongrel dogs survived chronic occlusion of the left circumflex and of the right coronary artery without infarction due to the timely development of a collateral circulation. Only 38 per cent of the conductance of the arteries before occlusion was restored by collateral vessels. In these animals and in 15 control dogs with normal coronary arteries myocardial contractility, contractility reserve, and myocardial blood flow were studied. The same was done in dogs with chronic coronary artery occlusion after aortocoronary bypass. Myocardial blood flow was determined woth the tracer microsphere technique. Contractility reserve was tested and defined as isovolumetric left ventricular pressure and dp/dt max with norepinephrine infusion and cross-clamping of the aorta. Contractile reserve was not significantly different between normal dogs and dogs with chronic coronary artery occlusion before and after aortocoronary bypass. Myocardial blood flow during control conditions was homogenously distributed in all three groups studied. The ratio of blood flow to the endocardium and the epicardium was not significantly different from inity. Coronary reserve was determined at peak reactive hyperemia following a 20 second period of coronary artery occlusion, with ongoing norepinephrine infusion. Under these conditions subendocardial fow in normal dogs rose by a factor of 7.9 while subepicardial flow increased 7.4 times. In dogs with chronic occlusion of two coronary arteries the increase of myocardial flow was nonnomogenous; subendocardial flow to areas supplied by a normal coronary artery rose by a factor of 7.0 while subepicardial flow increased 5.7 times control. Subendocardial collateral flow rose by a factor of 2.4 and subepicardial collateral flow increased 3.5 times control. In normal dogs norepinephrine alone did not result in maximal coronary flow but only 57 per cent thereof. Dogs with chronic coronary occlusion, however, required the entire coronary reserve in

  20. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. 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.

  4. Un caso de ética empresarial: factores normativos y capacidades

    Directory of Open Access Journals (Sweden)

    Angela Uribe Botero

    2001-12-01

    Full Text Available En este artículo intentaré llevar a cabo un estudio de caso en el cual las relaciones entre las directivas de una empresa, sus accionistas y sus empleados son vistas desde una perspectiva moral. El análisis del caso tendrá en cuenta estas relaciones en términos del alcance de las obligaciones de las directivas de las empresas hacia los derechos de los accionistas y de otros stakeholders. Para llevar a cabo este propósito, en primer lugar, presentaré el caso considerando sus factores normativos relevantes. Esta primera aproximación permitirá mostrar el estrecho vínculo entre el hecho de que alguien tenga una obligación y el hecho de que otra persona tenga un derecho. De lo anterior intentaré derivar las relaciones entre tener un derecho y lo que Amartya Sen llama "Capacidades". Si esta relación es clara, el artículo dejará ver en qué medida hay ocasiones en las cuales los derechos de los accionistas de maximizar sus utilidades económicas pueden limitar el derecho que tienen otros stakeholders a ejercer sus capacidades.

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    Campos Sérgio

    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.

  8. Capacidad de absorción: aproximaciones teóricas y empíricas para el sector servicios

    Directory of Open Access Journals (Sweden)

    Gabriel Aguilar-Olaves

    2014-01-01

    Full Text Available En este estudio se analizaron los determinantes de la capacidad de absorción en el sector servicios y el poder explicativo de la amplia heterogeneidad que presenta la actividad innovadora de las empresas de este sector. Se empleó un análisis factorial exploratorio, que agrupó los determinantes de la capacidad de absorción en dos dimensiones: capacidades potenciales y capacidades realizables, y un análisis discriminante para establecer, a partir de estas dimensiones, qué diferencias hay entre las empresas de este sector. Los resultados sugieren que estas dimensiones pueden ser cuantificables y explicarían las diferencias significativas en el gasto en innovación y el tipo de innovación que obtienen las empresas del sector servicios. Adicionalmente el estudio concluye, para el caso analizado, que el gasto en innovación no es siempre un elemento determinante de la capacidad de absorción y que la innovación en el sector servicios estaría principalmente orientada al desarrollo de cambios organizativos y de procesos a diferencia de introducir nuevos productos para el mercado.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. 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.

  11. La cultura tecnológica como base de las capacidades y el aprendizaje tecnológico

    Directory of Open Access Journals (Sweden)

    Álvaro Carvajal Villaplana

    2011-11-01

    Full Text Available En este trabajo se parte del supuesto de la existencia de una correlación positiva y robusta entre las capacidades tecnológicas y la cultura tecnológica, al fomentar ésta última, por medio del aprendizaje formal e informal, el surgimiento y el desenvolvimiento de las capacidades tecnológicas en una sociedad determinada. Aquí se analizan tres aproximaciones a la noción de cultura tecnológica: (a epistémico, (b descriptivo y (c prescriptivo. También, se reflexiona sobre un tipo particular de capacidades tecnológicas: las de innovación.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Capacidade antioxidante celular da rutina frente ao dano oxidativo induzido em linhagens mutantes de Saccharomyces cerevisiae

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    George Laylson da Silva Oliveira

    2016-07-01

    Full Text Available A rutina é um tipo de flavonoide encontrado nas plantas e de grande interesse farmacológico, já que muitas propriedades têm sido atribuídas a rutina, incluindo antialérgica, anti-inflamatória, antitumoral e principalmente antioxidante. O objetivo deste estudo foi proporcionar um maior conhecimento sobre a capacidade antioxidante celular da rutina utilizando linhagens de S. cerevisiae proficiente e deficiente em defesas antioxidantes. As linhagens de S. cerevisiae (Sodwt, Sod1∆, Sod2∆, Sod1∆Sod2∆, Cat1∆, Sod1∆Cat1∆ foram expostas as várias concentrações da rutina em três diferentes condições de tratamento (pré-tratamento, co-tratamento e pós-tratamento e assim verificar se a rutina inibe o efeito oxidativo do peróxido de hidrogênio, permitindo o aumento da sobrevivência das linhagens testadas. Os resultados obtidos mostram que a rutina diminui significativamente os danos oxidativos nas linhagens de S. cerevisiae nas condições de pré-tratamento, co-tratamento e pós-tratamento, demonstrando que a rutina apresenta uma elevada capacidade antioxidante celular, sendo importante na proteção ao estresse oxidativo induzido.Palavras-chave: Rutina. S. cerevisiae. capacidade antioxidante. ABSTRACTCellular antioxidant capacity of rutin against the oxidative damage induced in mutant strains of Saccharomyces cerevisiaeRutin is a type of flavonoid found in plants and of great pharmacological interest since many properties have been attributed rutin, including antiallergic, antiinflammatory, antitumor and antioxidant primarily. The aim of this study was to provide greater insight into the cellular antioxidant capacity of rutin using strains of S. cerevisiae proficient and deficient in antioxidant defenses. The strains of S. cerevisiae (Sodwt, Sod1Δ, Sod2Δ, Sod1ΔSod2Δ, Cat1Δ, Sod1ΔCat1Δ were exposed to various concentrations of rutin in three different conditions of treatment (pre-treatment, co-treatment and post

  14. 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....

  15. Aspiração manual intrauterina no tratamento do abortamento incompleto até 12 semanas gestacionais: uma alternativa à curetagem uterina Manual vacuum aspiration uterine treatment of incomplete abortion to 12 gestational weeks: an alternative to curettage

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    Marcio Pedroso Saciloto

    2011-10-01

    Full Text Available OBJETIVO: Analisar a eficácia e a ocorrência de complicações, além do tempo de permanência hospitalar e as perdas sanguíneas. MÉTODOS: Trinta pacientes foram selecionadas, alternada e consecutivamente, em um dos grupos (15 no Grupo Curetagem e 15 no Grupo de Aspiração manual intrauterina. As variáveis analisadas foram: eficácia do método, ocorrência de complicações, tempo pré-procedimento, tempo de execução do procedimento, tempo pós-procedimento e tempo total de permanência hospitalar, além de hematócrito e hemoglobina, medidas antes e após o procedimento. As pacientes foram avaliadas clinicamente 10 a 14 dias após o procedimento. Para a análise estatística, foram aplicados testes paramétricos e não-paramétricos e o nível de significância admitido foi de p>0,05. RESULTADOS: Ambos os métodos foram eficazes e não foi registrada nenhuma complicação. As perdas sanguíneas foram semelhantes e o tempo de permanência hospitalar foi significativamente menor no Grupo de Aspiração Manual Intrauterina (p=0,03. CONCLUSÃO: a aspiração manual intrauterina é tão eficaz e segura quanto à curetagem uterina, com a vantagem de necessitar menor tempo de permanência hospitalar, o que aumenta a resolutividade do método, melhorando a qualidade da assistência a essas pacientes.PURPOSE: To analyze the effectiveness and occurrence of complications, in addition to hospitalization time and blood losses. METHODS: Thirty patients were assigned alternatively and consecutively to one of two groups (15 to the Curettage Group and 15 to the Manual Vacuum Aspiration Group. The following variables were analyzed: effectiveness of the method, occurrence of complications, time before the procedure, time of execution of the procedure, time after the procedure, and total time of hospital permanence, in addition to hematocrit and hemoglobin, which were measured before and after the procedure. Patients were evaluated clinically 10 to 14

  16. 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

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    Dorival Antônio Vitorello

    1998-04-01

    Full Text Available 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 percentagem, média, desvio padrão, mediana, variação e risco relativo (RR com intervalo de confiança de 95% (IC conforme apropriado. Resultados: foram realizadas 50 TIVs e quatro ex-sangüíneo transfusões em 21 fetos. Houve quatro óbitos (20%, três dos quais (75% ocorridos em fetos hidrópicos. A idade gestacional média quando da primeira transfusão foi de 29,1 semanas. A concentração média de hemoglobina foi de 5,69 mg/dl. A taxa de mortalidade decorrente do procedimento foi de 7,4%. A idade gestacional média ao nascimento foi 33,9 semanas e o peso médio foi 2.437 gramas. Sessenta e cinco por cento dos recém-nascidos receberam ex-sangüíneo transfusão complementar. Conclusão: a taxa de mortalidade por procedimento (7,4% foi semelhante à relatada na literatura mundial. A taxa de mortalidade perinatal (20% foi mais elevada do que a relatada na literatura estrangeira, mas inferior à relatada em estudo conduzido no Brasil, no qual a prevalência de fetos hidrópicos foi semelhante.Objective: to report 54 intrauterine intravascular transfusions (IITs, describing procedure related complications and associated perinatal morbidity and mortality. Methods: fetuses undergoing IITs at Clínica Materno-Fetal and Maternidade Carmela Dutra, Florianópolis, SC, between January 1992 and August 1997 were included in the study. Patients demographics, procedure and newborn related data were tabulated for analysis and presented in descriptive form

  17. 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.

  18. La capacidad del directivo y su incidencia en el sistema administrativo en las empresas del sector transporte urbano en Ibagué

    OpenAIRE

    2006-01-01

    El Directivo es concebido como la máxima autoridad en la organización, su estilo de dirección obedece a criterios intrínsecos, que se complementan con las capacidades que la organización posee. De esta manera, se analiza la incidencia entre la capacidad directiva y el sistema del proceso administrativo, en las empresas del sector transporte urbano en Ibagué, a través, de la relación entre las variables que componen la capacidad de directivo, es decir, la edad, experiencia, capacidad de gestió...

  19. Tratamento das pacientes sintomáticas portadoras de miomas uterinos através da associação das técnicas de embolização dos miomas e ligadura endovascular das artérias uterinas

    OpenAIRE

    Ricardo Augusto de Paula Pinto

    2007-01-01

    Os miomas uterinos são os tumores benignos mais comuns do trato genital feminino, sendo que nas mulheres portadoras, 30% são sintomáticos e exigem alguma forma de tratamento. No presente estudo, foram tratadas 35 pacientes sintomáticas com diagnóstico clínico e ultra-sonográfico de mioma uterino, por meio da embolização dos miomas com partículas de polivinil-álcool associadas à obstrução das artérias uterinas com micromolas fibradas. A avaliação clínica e ecográfica foram inicialmente feitas ...

  20. 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...

  1. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. 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.

  4. 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.

  5. Serotonin regulates contractile activity of the uterus in non-pregnant rabbits.

    Science.gov (United States)

    Lychkova, Alla Edward; De Pasquale, Valeria; Avallone, Luigi; Puzikov, Alexander Michael; Pavone, Luigi Michele

    2014-09-01

    Serotonin (5-HT) can stimulate the cholinergic system of the uterus by indirect actions on the modulation of reflexes and a direct action on smooth muscles. We investigated the role of 5-HT in the regulation of the cholinergic activity in the uterine parts of non-pregnant rabbits. The right vagus or pelvic nerve and the left sympathetic trunk were stimulated by an electrical field, and the uterine contractile activity was evaluated by measuring the amplitude and frequency of slow wave electromyogram (EMG), with the surface of microelectrodes applied to the uterus bottom, body, and cervix, respectively. Double stimulation of the vagus or pelvic nerve and the sympathetic trunk increased the frequency and the amplitude of the slow wave EMG in all the uterine parts. Furthermore, the administration of exogenous 5-HT increased the vagus or pelvic induced EMG activity in all parts of the uterus. Overall our results demonstrate that 5-HT enhances the vagus contractile activity with a magnitude of the effect decreasing from the bottom to the cervix, whereas 5-HT enhances the pelvic nerve contractile functions with a magnitude of the response increasing from the bottom to the cervix. The administration of droperidol, a 5-HT3 and 4 receptor inhibitor, and spiperone, a 5-HT2 receptor antagonist, inhibited the effect of the serotoninergic fibers of the sympathetic trunk to increase the vagus and pelvic nerve EMG activity. These data suggest that 5-HT stimulation of the parasympathetic nerves results in the induction of uterine contraction via the activation of 5-HT2, 3, and 4 receptor subfamilies.

  6. 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.

  7. MDMA induces cardiac contractile dysfunction through autophagy upregulation and lysosome destabilization in rats.

    Science.gov (United States)

    Shintani-ishida, Kaori; Saka, Kanju; Yamaguchi, Koji; Hayashida, Makiko; Nagai, Hisashi; Takemura, Genzou; Yoshida, Ken-ichi

    2014-05-01

    The underlying mechanisms of cardiotoxicity of 3,4-methylenedioxymethylamphetamine (MDMA, "ecstasy") abuse are unclear. Autophagy exerts either adaptive or maladaptive effects on cardiac function in various pathological settings, but nothing is known on the role of autophagy in the MDMA cardiotoxicity. Here, we investigated the mechanism through which autophagy may be involved in MDMA-induced cardiac contractile dysfunction. Rats were injected intraperitoneally with MDMA (20mg/kg) or saline. Left ventricular (LV) echocardiography and LV pressure measurement demonstrated reduction of LV systolic contractility 24h after MDMA administration. Western blot analysis showed a time-dependent increase in the levels of microtubule-associated protein light chain 3-II (LC3-II) and cathepsin-D after MDMA administration. Electron microscopy showed the presence of autophagic vacuoles in cardiomyocytes. MDMA upregulated phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) at Thr172, mammalian target of rapamycin (mTOR) at Thr2446, Raptor at Ser792, and Unc51-like kinase (ULK1) at Ser555, suggesting activation of autophagy through the AMPK-mTOR pathway. The effects of autophagic inhibitors 3-methyladenine (3-MA) and chloroquine (CQ) on LC3-II levels indicated that MDMA enhanced autophagosome formation, but attenuated autophagosome clearance. MDMA also induced release of cathepsins into cytosol, and western blotting and electron microscopy showed cardiac troponin I (cTnI) degradation and myofibril damage, respectively. 3-MA, CQ, and a lysosomal inhibitor, E64c, inhibited cTnI proteolysis and improved contractile dysfunction after MDMA administration. In conclusion, MDMA causes lysosome destabilization following activation of the autophagy-lysosomal pathway, through which released lysosomal proteases damage myofibrils and induce LV systolic dysfunction in rat heart.

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

    Directory of Open Access Journals (Sweden)

    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

  9. 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

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

    Science.gov (United States)

    Braun, Martin; Hettinger, Niko; Koentges, Christoph; Pfeil, Katharina; Cimolai, Maria C; Hoffmann, Michael M; Osterholt, Moritz; Doenst, Torsten; Bode, Christoph; Bugger, Heiko

    2015-01-01

    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.

  11. 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.

  12. 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.

  13. 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.

  14. Aportaciones a la evaluación de las Capacidades Físicas en la Educación Primaria

    OpenAIRE

    Velasco Martín, M.

    1994-01-01

    Una de las primeras misiones que debe tener el maestro es un conocimiento, lo más completo posible del niño, porque será la base para poder programar mejor y realizar su trabajo en la escuela. En educación física ese conocimiento viene dado por la Evaluación, entre otras, de las Capacidades Físicas Básicas. Se plantea qué pruebas y cuántas tenemos que hacer para evaluar esas Capacidades Físicas Básicas

  15. Estrategias basadas en los Recursos y Capacidades. Criterios de Evaluación y el Proceso de Desarrollo.

    OpenAIRE

    Cardona, Raúl Armando

    2011-01-01

    El análisis del sector y los recursos y capacidades, han sido los dos campos en los que tradicionalmente se agrupan los estudios de la estrategia. Este trabajo, de corte teórico y realizado en el marco de una investigación, analiza la estrategia basada en los recursos y capacidades de la empresa para buscar fuentes de beneficios potenciales, ventajas competitivas e impactar positivamente en los resultados empresariales; se concentra en el análisis del proceso de identificación y valoración de...

  16. Redes de innovación y capacidad de absorción relativa en un cluster industrial

    OpenAIRE

    Rodríguez Betancourt, Ana Olga

    2016-01-01

    La innovación en las empresas continúa siendo de interés en el mundo académico y de los negocios. Constituye una clave en la competitividad de las organizaciones sobre todo en entornos de rápido cambio tecnológico como el que se vive en la actualidad. A partir de enfoques como el de Clusters de Innovación, la Teoría Evolucionista, la Teoría de Recursos y Capacidades (RBV) y la Perspectiva de Capacidades Dinámicas, se han hecho aportaciones relevantes al tema, en especial lo relacionado con el...

  17. Capacidad empresarial para la absorción de I+D externa: el caso de Bizkaia

    OpenAIRE

    Rodríguez Castellanos, Arturo; Landeta Rodríguez, Jon

    2004-01-01

    [ES] El presente trabajo tiene por objeto llegar a un diagnóstico de la capacidad, por parte de las empresas del Territorio Histórico de Bizkaia, de absorber los resultados de I+D generados por universidades y otros centros de investigación. Para ello, en primer lugar, mediante una revisión de la literatura teórica y empírica existente sobre el tema, se identifican las características empresariales vinculadas a dicha capacidad de absorción; a continuación, se analiza el grado de presencia de ...

  18. 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...

  19. 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.

  20. 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

  1. 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.

  2. Assessment of contractility in intact ventricular cardiomyocytes using the dimensionless 'Frank-Starling Gain' index.

    Science.gov (United States)

    Bollensdorff, Christian; Lookin, Oleg; Kohl, Peter

    2011-07-01

    This paper briefly recapitulates the Frank-Starling law of the heart, reviews approaches to establishing diastolic and systolic force-length behaviour in intact isolated cardiomyocytes, and introduces a dimensionless index called 'Frank-Starling Gain', calculated as the ratio of slopes of end-systolic and end-diastolic force-length relations. The benefits and limitations of this index are illustrated on the example of regional differences in Guinea pig intact ventricular cardiomyocyte mechanics. Potential applicability of the Frank-Starling Gain for the comparison of cell contractility changes upon stretch will be discussed in the context of intra- and inter-individual variability of cardiomyocyte properties.

  3. 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).

  4. Measurement of Contractile Activity in Small Animal's Digestive Organ by Carbon Nanotube-Based Force Transducer

    Science.gov (United States)

    Hirata, Takamichi; Takeda, Naoki; Tsutsui, Chihiro; Koike, Kanako; Shimatani, Yuichi; Sakai, Takafumi; Akiya, Masahiro; Taguchi, Akira

    2011-03-01

    A carbon nanotube (CNT)-based force transducer designed to be embedded in the body of a live animal was fabricated and implanted into the stomach of a rat omit to measure contractile movement. The transducer comprised dispersed poly(ethylene glycol)-grafted multiwalled CNTs applied to a comb-like Au-electrode formed on a poly(dimethylsiloxane) sheet. The implanted rat was injected with acetylcholine to induce muscular contractions and changes in the resistance of the transducer were measured. Such changes arise owing to strain in the CNT network upon distortion. The measured resistance change was found to be proportional to the concentration of injected acetylcholine.

  5. 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.

  6. 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.

  7. ECOCARDIOGRAFÍA FETAL: ¿CÓMO MEJORAR NUESTRA CAPACIDAD DIAGNÓSTICA?

    OpenAIRE

    González G.,Rubén

    2005-01-01

    Se presenta la aplicación de un método simple, para la correcta evaluación rutinaria del corazón fetal, tendiente a mejorar la capacidad del diagnóstico prenatal de anomalías congénitas cardiacas. El sistema se desarrolla durante la ejecución de un Programa de Ecografía Rutinaria en el período de 22 a 26 semanas, realizado en la Unidad de Ecografía Comunal de un Consultorio de Atención Primaria dependiente del SSMS. Se estima que su uso sistemático permitirá a la mayoría de los ecografistas u...

  8. Entrenamiento de la capacidad de salto en el jugador de baloncesto: una revisión

    Directory of Open Access Journals (Sweden)

    Jaime San Román-Quintana

    2011-01-01

    Full Text Available El baloncesto es un deporte intermitente en el que se combinan acciones de intensidad leve, moderada y alta y por tanto el metabolismo aeróbico y anaeróbico se presentan conjuntamente. Una de las acciones más determinantes durante la competición es la capacidad de salto, dado que es utilizada por los jugadores para ejecutar, a su vez, diferentes situaciones específicas del juego como tirar o entrar a canasta, etc., sugiriéndose así, que dicha Expresión de la fuerza es un factor principal en el éxito en este deporte. Por ello, el entrenamiento del salto vertical en el jugador de baloncesto es una cuestión determinante en el rendimiento final del juego.

  9. 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.

  10. 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.

  11. Um estudo das capacidades e deficiências em habilidades sociais na terceira idade

    Directory of Open Access Journals (Sweden)

    Carneiro Rachel Shimba

    2004-01-01

    Full Text Available Esta pesquisa pretende identificar as situações sociais nas quais os idosos apresentam facilidades e dificuldades de se comportar de forma socialmente habilidosa. Foram entrevistados 30 idosos da Universidade Aberta da Terceira Idade. A partir da análise dos dados pôde-se identificar um percentual maior de respostas habilidosas em seis situações sociais. Por outro lado, a maioria dos idosos da amostra apresentou deficiências de desempenho em oito situações sociais. Os resultados propõem o desenvolvimento de programas de treinamento de habilidades sociais como uma forma de aumentar a capacidade do idoso de conquistar e manter apoio social, para assim, alcançar melhor qualidade de vida.

  12. 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.

  13. In vitro drug testing based on contractile activity of C2C12 cells in an epigenetic drug model

    Science.gov (United States)

    Ikeda, Kazushi; Ito, Akira; Imada, Ryusuke; Sato, Masanori; Kawabe, Yoshinori; Kamihira, Masamichi

    2017-01-01

    Skeletal muscle tissue engineering holds great promise for pharmacological studies. Herein, we demonstrated an in vitro drug testing system using tissue-engineered skeletal muscle constructs. In response to epigenetic drugs, myotube differentiation of C2C12 myoblast cells was promoted in two-dimensional cell cultures, but the levels of contractile force generation of tissue-engineered skeletal muscle constructs prepared by three-dimensional cell cultures were not correlated with the levels of myotube differentiation in two-dimensional cell cultures. In contrast, sarcomere formation and contractile activity in two-dimensional cell cultures were highly correlated with contractile force generation of tissue-engineered skeletal muscle constructs. Among the epigenetic drugs tested, trichostatin A significantly improved contractile force generation of tissue-engineered skeletal muscle constructs. Follistatin expression was also enhanced by trichostatin A treatment, suggesting the importance of follistatin in sarcomere formation of muscular tissues. These observations indicate that contractility data are indispensable for in vitro drug screening. PMID:28300163

  14. Modulatory effect of three antibiotics on uterus bovine contractility in vitro and likely therapeutic approaches in reproduction.

    Science.gov (United States)

    Piccinno, M; Rizzo, A; Maselli, M A; Derosa, M; Sciorsci, R L

    2014-12-01

    This in vitro study investigates the modulatory effect of three antibiotics (amoxicillin, enrofloxacin, and rifaximin) on contractility of the bovine uterine tissue in follicular and luteal phases. The effects of these antibiotics at three single doses (10(-6), 10(-5), and 10(-4) M) on their basal contractility were evaluated in isolated organ bath. The functionality of the strip throughout the experiment was evaluated by a dose of carbachol (10(-5) M); the obtained effect had to be repeatable (difference of ≤20%) that is comparable to that induced by the previous administration of the same substance. The results demonstrate the different modulatory activities of these antibiotics on uterine contractility in follicular and luteal phases. The effects induced by amoxicillin and enrofloxacin are opposite: the first relaxes and the second increases the uterine contractility in both cycle phases. Instead, the activity of rifaximin varies depending on the phase of estrous cycle: it increases in the follicular phase and relaxes in the luteal phase. The obtained data provide the hypothesis of possible implications of these drugs in the pharmacologic modulation of uterine contractions. Their action at this level, associated with their specific antimicrobial effects, could suggest using these antibiotics for the treatment of diseases related to postpartum or infections that may occur in pregnant cattle, by virtue of their effects on myometrial contractility too.

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

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    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.

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

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    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.

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

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    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.

  18. PLANIFICACIÓN JERÁRQUICA CON ANÁLISIS DE CARGA-CAPACIDAD

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    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.

  19. Capacidade combinatória em mamoeiro para resistência a oídio

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    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'.

  20. 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.

  1. Late sodium current is a new therapeutic target to improve contractility and rhythm in failing heart.

    Science.gov (United States)

    Undrovinas, Albertas; Maltsev, Victor A

    2008-10-01

    Most cardiac Na+ channels open transiently within milliseconds upon membrane depolarization and are responsible for the excitation propagation. However, some channels remain active during hundreds of milliseconds, carrying the so-called persistent or late Na+ current (I(NaL)) throughout the action potential plateau. I(NaL) is produced by special gating modes of the cardiac-specific Na+ channel isoform. Experimental data accumulated over the past decade show the emerging importance of this late current component for the function of both normal and especially failing myocardium, where I(NaL) is reportedly increased. Na+ channels represent a multi-protein complex and its activity is determined not only by the pore-forming alpha subunit but also by its auxiliary beta subunits, cytoskeleton, and by Ca2+ signaling and trafficking proteins. Remodeling of this protein complex and intracellular signaling pathways may lead to alterations of I(NaL) in pathological conditions. Increased I(NaL) and the corresponding Na+ influx in failing myocardium contribute to abnormal repolarization and an increased cell Ca2+ load. Interventions designed to correct I(NaL) rescue normal repolarization and improve Ca2+ handling and contractility of the failing cardiomyocytes. New therapeutic strategies to target both arrhythmias and deficient contractility in HF may not be limited to the selective inhibition of I(NaL) but also include multiple indirect, modulatory (e.g. Ca(2+)- or cytoskeleton- dependent) mechanisms of I(NaL) function.

  2. Diaphragm atrophy and contractile dysfunction in a murine model of pulmonary hypertension.

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    Bumsoo Ahn

    Full Text Available Pulmonary hypertension (PH causes loss of body weight and inspiratory (diaphragm muscle dysfunction. A model of PH induced by drug (monocrotaline, MCT has been extensively used in mice to examine the etiology of PH. However, it is unclear if PH induced by MCT in mice reproduces the loss of body weight and diaphragm muscle dysfunction seen in patients. This is a pre-requisite for widespread use of mice to examine mechanisms of cachexia and diaphragm abnormalities in PH. Thus, we measured body and soleus muscle weight, food intake, and diaphragm contractile properties in mice after 6-8 weeks of saline (control or MCT (600 mg/kg injections. Body weight progressively decreased in PH mice, while food intake was similar in both groups. PH decreased (P<0.05 diaphragm maximal isometric specific force, maximal shortening velocity, and peak power. Protein carbonyls in whole-diaphragm lysates and the abundance of select myofibrillar proteins were unchanged by PH. Our findings show diaphragm isometric and isotonic contractile abnormalities in a murine model of PH induced by MCT. Overall, the murine model of PH elicited by MCT mimics loss of body weight and diaphragm muscle weakness reported in PH patients.

  3. 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.

  4. 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.

  5. The RhoGEF TEM4 Regulates Endothelial Cell Migration by Suppressing Actomyosin Contractility.

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    Natalia Mitin

    Full Text Available Persistent cellular migration requires efficient protrusion of the front of the cell, the leading edge where the actin cytoskeleton and cell-substrate adhesions undergo constant rearrangement. Rho family GTPases are essential regulators of the actin cytoskeleton and cell adhesion dynamics. Here, we examined the role of the RhoGEF TEM4, an activator of Rho family GTPases, in regulating cellular migration of endothelial cells. We found that TEM4 promotes the persistence of cellular migration by regulating the architecture of actin stress fibers and cell-substrate adhesions in protruding membranes. Furthermore, we determined that TEM4 regulates cellular migration by signaling to RhoC as suppression of RhoC expression recapitulated the loss-of-TEM4 phenotypes, and RhoC activation was impaired in TEM4-depleted cells. Finally, we showed that TEM4 and RhoC antagonize myosin II-dependent cellular contractility and the suppression of myosin II activity rescued the persistence of cellular migration of TEM4-depleted cells. Our data implicate TEM4 as an essential regulator of the actin cytoskeleton that ensures proper membrane protrusion at the leading edge of migrating cells and efficient cellular migration via suppression of actomyosin contractility.

  6. [Contractile Tone and Contraction as Important Physiological Properties of Terminals on the Processes of Living Neurons].

    Science.gov (United States)

    Sotnikov, O S; Vasyagina, N Yu; Podol'skaya, L A

    2015-01-01

    An attempt to summarize some static morphological renderings of reversible structural alterations of nervous processes, as well as receptor and synaptic terminals, to compare them with the mechanisms of actual transformation of living neurons and to find a common kinetic characteristic for these phenomena has been made. The contractile tone and contraction of processes of living isolated neurons are reported. The dependence of the direction of retraction on the localization of the adhesion site of the isolated cell has been detected. The retraction bulb has been identified as an indicator of all contractions of motor and sensory terminals, both alive and fixed. The process of transformation of growth cones into retraction bulbs has been investigated. The presence of mechanical tension in preterminals and interneuronal contacts has been demonstrated in vitro. Similarity of the kinetics of tissue receptor sensory terminals and growth cones has been detected during in vivo experiments. The kinetics of asynaptic dendrite contraction has been compared to the well-characterized structural variability of dendritic spines. The hypothesis of a common origin of the contractile tone of all nervous elements as one of the principal nonelectrophysiological properties of a neuron has been put forward.

  7. Functional insights into modulation of BKCa channel activity to alter myometrial contractility

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    Ramón A Lorca

    2014-07-01

    Full Text Available The large-conductance voltage- and Ca2+-activated K+ channel (BKCa is an important regulator of membrane excitability in a wide variety of cells and tissues. In myometrial smooth muscle, activation of BKCa plays essential roles in buffering contractility to maintain uterine quiescence during pregnancy and in the transition to a more contractile state at the onset of labor. Multiple mechanisms of modulation have been described to alter BKCa channel activity, expression, and cellular localization. In the myometrium, BKCa is regulated by alternative splicing, protein targeting to the plasma membrane, compartmentation in membrane microdomains, and posttranslational modifications. In addition, interaction with auxiliary proteins (i.e., β1- and β2-subunits, association with G-protein coupled receptor signaling pathways, such as those activated by adrenergic and oxytocin receptors, and hormonal regulation provide further mechanisms of variable modulation of BKCa channel function in myometrial smooth muscle. Here, we provide an overview of these mechanisms of BKCa channel modulation and provide a context for them in relation to myometrial function.

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

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    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.

  9. Caffeine and taurine containing energy drink increases left ventricular contractility in healthy volunteers.

    Science.gov (United States)

    Doerner, Jonas M; Kuetting, Daniel L; Luetkens, Julian A; Naehle, Claas P; Dabir, Darius; Homsi, Rami; Nadal, Jennifer; Schild, Hans H; Thomas, Daniel K

    2015-03-01

    To investigate the impact of a caffeine and taurine containing energy drink (ED) on myocardial contractility in healthy volunteers using cardiac MR and cardiac MR based strain analysis. 32 healthy volunteers (mean age 28 years) were investigated before and 1 h after consumption of a caffeine and taurine containing ED. For assessment of global cardiac functional parameters balanced SSFP-Cine imaging was performed, whereas CSPAMM tagging was used to evaluate global and regional myocardial strain. In addition, ten randomly chosen subjects were investigated once more using a caffeine only protocol to further evaluate the effect of caffeine solely. Heart rate and blood pressure were recorded throughout all studies. ED consumption led to a significant increase in peak systolic strain (PSS) and peak systolic strain rate (PSSR) 1 h after consumption (PSS: w/o ED -22.8 ± 2.1%; w ED -24.3 ± 2.4%, P = caffeine only group. In contrast, global left ventricular function was unchanged (P = 0.2076). No significant changes of vital parameters and diastolic filling pattern were detected 1 h after ED consumption. Consumption of a caffeine and taurine containing ED results in a subtle, but significant increase of myocardial contractility 1 h after consumption.

  10. Influence of intracellular acidosis on contractile function in the working rat heart

    Energy Technology Data Exchange (ETDEWEB)

    Jeffrey, F.M.H.; Malloy, C.R.; Radda, G.K. (Univ. of Oxford (England))

    1987-12-01

    The decrease in myocardial contractility during ischemia, hypoxia, and extracellular acidosis has been attributed to intracellular acidosis. Previous studies of the relationship between pH and contractile state have utilized respiratory or metabolic acidosis to alter intracellular pH. The authors developed a model in the working perfused rat heart to study the effects of intracellular acidosis with normal external pH and optimal O{sub 2} delivery. Intracellular pH and high-energy phosphates were monitored by {sup 31}P nuclear magnetic resonance spectroscopy. Hearts were perfused to a steady state with a medium containing 10 mM NH{sub 4}Cl. Acidosis induced a substantial decrease in aortic flow and stroke volume which was associated with little change in peak systolic pressure. It was concluded that (1) for the same intracellular acidosis the influence on tension development was more pronounced with a combined extra- and intracellular acidosis than with an isolated intracellular acidosis, and (2) stroke volume at constant preload was impaired by intracellular acidosis even though changes in developed pressure were minimal. These observations suggest that isolated intracellular acidosis has adverse effects on diastolic compliance and/or relaxation.

  11. 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.

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

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    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.

  13. Effects of histamine on atrial and ventricular contractility in the canine isovolumic heart.

    Science.gov (United States)

    Vidrio, H; Priola, D V

    1990-03-01

    The effects of intracoronary administration of histamine on atrial and ventricular contractility were determined in a paced canine isovolumic heart preparation. Contractility was assessed by recording the pressure developed in saline-filled balloons placed in each of the four cardiac chambers. At doses above 0.1 mg and up to 100 mg histamine produced dose-related positive inotropic responses in all chambers. These were preceded by transient negative effects. The positive responses were not affected by a combination of H1 and H2 receptor antagonists antazoline and cimetidine but were almost completely abolished by the beta adrenoceptor blocker timolol. The negative responses were uninfluenced by either treatment. It was concluded that, in the canine isovolumic heart not subjected to complicating chronotropic and extracardiac factors, moderate doses of histamine are devoid of inotropic effects. Higher doses do produce myocardial stimulation, not mediated by histamine receptors, but probably due to norepinephrine release. These responses are preceded by transient non-specific depressant effects.

  14. EFFECT OF HYDROGEN SULFIDE ON ATRIUM CONTRACTILITY IN CONTROL AND DIABETHIC MICE

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    A. S. Lifanova

    2014-01-01

    Full Text Available Hydrogen sulfide (H2S is endogenously synthesized gasotransmitter that has a regulatory effect in cardiovascular system. Diabetes mellitus leads to an increased risk of hypertension and cardiovascular diseases, so the purpose of the study was to analyze the contractility of the atria mice after application of L-cysteine and H2S. Contractile activity of the myocardium was investigated in the experiment on isolated mouse atria. Alloxan was used for modeling diabetes. Intraperitoneal injection of alloxan resulted in a significant increase of glucose concentration in blood, whereas the concentration of glucose didn’t change at the injection of physiological solution. In control, the addition of NaHS resulted in a significant dose-dependent decrease of the amplitude of contraction of the myocardium, whereas the negative inotropic effect of NaHS was significantly lower in terms of modeling diabetes compare to control conditions. In the control, L-cysteine reduced the amplitude contractions significantly, whereas L-cysteine did not lead to significant changes in the amplitude of contractions in terms of modeling diabetes. These data indicate that the sensitivity of mice’s atria reduced for H2S and L-cysteine in diabetes mellitus.

  15. The actin targeting compound Chondramide inhibits breast cancer metastasis via reduction of cellular contractility.

    Directory of Open Access Journals (Sweden)

    Magdalena H Menhofer

    Full Text Available BACKGROUND: A major player in the process of metastasis is the actin cytoskeleton as it forms key structures in both invasion mechanisms, mesenchymal and amoeboid migration. We tested the actin binding compound Chondramide as potential anti-metastatic agent. METHODS: In vivo, the effect of Chondramide on metastasis was tested employing a 4T1-Luc BALB/c mouse model. In vitro, Chondramide was tested using the highly invasive cancer cell line MDA-MB-231 in Boyden-chamber assays, fluorescent stainings, Western blot and Pull down assays. Finally, the contractility of MDA-MB-231 cells was monitored in 3D environment and analyzed via PIV analysis. RESULTS: In vivo, Chondramide treatment inhibits metastasis to the lung and the migration and invasion of MDA-MB-231 cells is reduced by Chondramide in vitro. On the signaling level, RhoA activity is decreased by Chondramide accompanied by reduced MLC-2 and the stretch induced guanine nucleotide exchange factor Vav2 activation. At same conditions, EGF-receptor autophosphorylation, Akt and Erk as well as Rac1 are not affected. Finally, Chondramide treatment disrupted the actin cytoskeleton and decreased the ability of cells for contraction. CONCLUSIONS: Chondramide inhibits cellular contractility and thus represents a potential inhibitor of tumor cell invasion.

  16. 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.

  17. 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.

  18. Distinct contractile and cytoskeletal protein patterns in the Antarctic midge are elicited by desiccation and rehydration.

    Science.gov (United States)

    Li, Aiqing; Benoit, Joshua B; Lopez-Martinez, Giancarlo; Elnitsky, Michael A; Lee, Richard E; Denlinger, David L

    2009-05-01

    Desiccation presents a major challenge for the Antarctic midge, Belgica antarctica. In this study, we use proteomic profiling to evaluate protein changes in the larvae elicited by dehydration and rehydration. Larvae were desiccated at 75% relative humidity (RH) for 12 h to achieve a body water loss of 35%, approximately half of the water that can be lost before the larvae succumb to dehydration. To evaluate the rehydration response, larvae were first desiccated, then rehydrated for 6 h at 100% RH and then in water for 6 h. Controls were held continuously at 100% RH. Protein analysis was performed using 2-DE and nanoscale capillary LC/MS/MS. Twenty-four identified proteins changed in abundance in response to desiccation: 16 were more abundant and 8 were less abundant; 84% of these proteins were contractile or cytoskeletal proteins. Thirteen rehydration-regulated proteins were identified: 8 were more abundant and 5 were less abundant, and 69% of these proteins were also contractile or cytoskeletal proteins. Additional proteins responsive to desiccation and rehydration were involved in functions including stress responses, energy metabolism, protein synthesis, glucogenesis and membrane transport. We conclude that the major protein responses elicited by both desiccation and rehydration are linked to body contraction and cytoskeleton rearrangements.

  19. 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.

  20. The anatomy and fibre type composition of the human adductor pollicis in relation to its contractile properties.

    Science.gov (United States)

    Round, J M; Jones, D A; Chapman, S J; Edwards, R H; Ward, P S; Fodden, D L

    1984-01-01

    We have examined the anatomy and fibre type composition of the human adductor pollicis in muscles taken post mortem. Histochemical staining of muscle fibres showed that type I fibres predominated in all cases with a mean occurrence of 80%. This composition is similar to that of the soleus muscle and unlike that of the quadriceps which has approximately equal proportions of the two fibre types. Comparing the contractile characteristics, however, the adductor pollicis has similar properties to the quadriceps and both are quite distinct from those of the slowly contracting soleus muscle. The lack of correlation between fibre composition, as revealed by histochemical staining, and contractile properties in these muscles must mean that fibres of the same type from different muscles do not necessarily have the same contractile speed. The results also suggest that the type I fibres of the human adductor pollicis are faster than those of both the soleus and quadriceps muscles.

  1. [Cardiac contractility modulation. A new form of therapy for patients with heart failure and narrow QRS complex?].

    Science.gov (United States)

    Kleemann, T

    2015-11-01

    Cardiac contractility modulation (CCM) is a stimulation therapy by an implantable impulse generator, which enhances ventricular contractile performance by delivering CCM impulses to the right ventricle during the absolute refractory period. The CCM signals mediate increased inotropy by prolonging the duration of the action potential, which leads to an enhanced influx of calcium into cardiomyocytes and a greater release of calcium by the sarcoplasmic reticulum. The increase of cardiac contractility is not associated with increased oxygen consumption. Several small studies have shown that CCM therapy can safely improve symptoms of heart failure and peak oxygen consumption in patients with moderate to severe heart failure who are not eligible for resynchronization therapy. Therefore, CCM is a novel potential therapy for patients with heart failure, an ejection fraction ≤ 35 % and a normal QRS duration failure or mortality.

  2. 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.

  3. La medición de la capacidad de resolución de problemas en las ciencias experimentales

    Directory of Open Access Journals (Sweden)

    José Joaquín García García

    2012-01-01

    Full Text Available Este trabajo presenta un estudio, sobre el diseño de una prueba para medir la capacidad de resolución de problemas utilizando la técnica de análisis factorial. La prueba presentó un alfa de Cronbach (α de 0,76 y 16 peguntas distribuidas en 7 factores ordenados de acuerdo al porcentaje en el cual explicaban la varianza de la capacidad: predicción y transferencia, capacidad de síntesis, lectura crítica del enunciado, análisis, interpretación de información, comprensión metacognitiva de enunciados y procesos, delimitación del problema. Así, la resolución de problemas es una capacidad que está más relacionada con factores de carácter estructural y global, como la selección de soluciones e hipótesis más adecuadas y la representación misma del problema, y en menor medida con aspectos estratégicos de delimitación, precisión y planeación, tal vez por la usual ausencia de dichos aspectos en las aulas de clase.

  4. 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.

  5. Compostos fenólicos e capacidade antioxidante em frutos de tomateiros mutantes fotomorfogenéticos

    Directory of Open Access Journals (Sweden)

    Tiago Dias

    2015-05-01

    Full Text Available Compostos fenólicos e capacidade antioxidante são mecanismos de defesa das plantas aos danos do estresse oxidativo. Os compostos fenólicos são sintetizados pela via dos fenilpropanoides, cuja enzima chave, fenilalanina amônia liase, é influenciada pela luz e ação de fotorreceptores, como o fitocromo. O objetivo do presente trabalho é avaliar a concentração de compostos fenólicos e a capacidade antioxidante de frutos de microtomateiro selvagem, cultivar "Micro-Tom" (MT, e seus mutantes fotomorfogenéticos high pigment 1 (hp1, super-responsivo a eventos mediados por luz e aurea (au, deficiente quantitativo em fitocromos. Vinte frutos maduros de cada genótipo (MT, hp1 e au foram utilizados para as análises, realizadas em triplicata. Para quantificação dos compostos fenólicos totais, foi utilizado o método de Folin-Ciocalteu e a capacidade antioxidante foi realizada pelos métodos Ferric Reducing Antioxidant Power (FRAP e 2,2-diphenyl-1-picrylhydrazyl (DPPH. Os frutos do mutante hp1 apresentaram maiores conteúdos de compostos fenólicos totais e também maior capacidade antioxidante em relação à cultivar selvagem ("MT" e ao mutante au, o qual não diferiu significativamente da cultivar "MT".

  6. 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.

  7. Arginine vasopressin, via activation of post-junctional V1 receptors, induces contractile effects in mouse distal colon.

    Science.gov (United States)

    Mastropaolo, Mariangela; Zizzo, Maria Grazia; Auteri, Michelangelo; Mulè, Flavia; Serio, Rosa

    2013-11-10

    The aim of this study was to analyze whether arginine vasopressin (AVP) may be considered a modulator of intestinal motility. In this view, we evaluated, in vitro, the effects induced by exogenous administration of AVP on the contractility of mouse distal colon, the subtype(s) of receptor(s) activated and the action mechanism. Isometric recordings were performed on longitudinal and circular muscle strips of mouse distal colon. AVP (0.001 nM-100 nM) caused concentration-dependent contractile effects only on the longitudinal muscle, antagonized by the V1 receptor antagonist, V-1880. AVP-induced effect was not modified by tetrodotoxin, atropine and indomethacin. Contractile response to AVP was reduced in Ca(2+)-free solution or in the presence of nifedipine, and it was abolished by depletion of calcium intracellular stores after repetitive addition of carbachol in calcium-free medium with addition of cyclopiazonic acid. U-73122, an inhibitor of the phospholipase C, effectively antagonized AVP effects, whilst it was not affected by an adenylyl cyclase inhibitor. Oxytocin induced an excitatory effect in the longitudinal muscle of distal colon at very high concentrations, effect antagonized by V-1880. The results of this study shown that AVP, via activation of V1 receptors, is able to modulate positively contractile activity of longitudinal muscle of mouse distal colon, independently by enteric nerve activation and prostaglandin synthesis. Contractile response is achieved by increase in cytoplasmatic Ca(2+) concentration via extracellular Ca(2+) influx from L-type Ca(2+) channels and via Ca(2+) release from intracellular stores through phospholipase C pathway. No modulation has been observed on the contractility of the circular muscle.

  8. 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.

  9. 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

    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......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...... detected by OGTT, is independently associated with reduced LV contractile reserve and exercise...

  10. In vitro contractility of normal and aneurysmal abdominal aorta muscle coat sections in human and animal material.

    Science.gov (United States)

    Gnus, Jan; Czerski, Albert; Zawadzki, Wojciech; Witkiewicz, Wojciech; Hauzer, Willy; Rusiecka, Agnieszka; Ferenc, Stanisław

    2012-01-01

    The objective of the study was to demonstrate spontaneous contractile activity of the smooth muscle coat of the aorta in human and animal material. Spontaneous contractility of smooth muscle tissue, or tonus, is essential for the proper function of many internal organs as observed in the many types of muscle cells which make up the internal structures. The spontaneous contractile activity of the muscle tissue in blood vessels is particularly marked in resistance vessels, regulating circulation within organs or tissues. It can also be observed in large blood vessels such as arteries and veins. The contractile activity of muscular tissue isolated from arteries is the result of a number of factors, including endogenous paracrine substances, neurotransmitters released at postganglionic endings (mostly within the sympathetic system), cells capable of spontaneously generation of functional potentials (pacemaking cells) and the vascular endothelium. Pacemaking cells present in the aortic wall are an important factor in the development of the spontaneous contractility of the muscular coat of the aorta. They are capable of generating functional potentials, resulting in the constant tonus of the smooth muscular coat (comprising the aortic wall) due to tonic contraction. In vitro studies were carried out on abdominal aortic sections collected from 30 New Zealand rabbits with a body mass of 3-4 kilograms each and also on aneurysmal abdominal aortic sections collected during elective aneurysm repair procedures in humans (10 abdominal aortic sections). The 1.5 cm-long sections were mounted in chambers of an automated water bath. The sections were oriented in a transverse and longitudal fashion in order to compare contractility. The incubation medium consisted of Krebs-Henseleit buffer. Spontaneous contractile activity was observed during the study, characterized by rhythmic contractions of the muscular layer of the aorta. The contractile tension within the sections was 0.15 m

  11. 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.

  12. Fatores determinantes da capacidade funcional entre idosos Determinant factors of functional status among the elderly

    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.OBJECTIVE: To investigate the impact of health-related demographic and socioeconomic factors, as well as the impact of factors associated to social activity and the subjective health evaluation on the functional status of elderly people. METHODS: A cross-sectional multicentric study was conducted in a representative population

  13. La capacidad de carga turística: Revisión crítica de un instrumento de medida de sostenibilidad

    Directory of Open Access Journals (Sweden)

    Jesús Manuel López Bonilla

    2008-01-01

    Full Text Available La capacidad de carga turística ostenta un interés creciente dado que se vincula estrechamente con el desarrollo turístico sostenible o turismo sustentable1. La capacidad de carga puede tener diferentes acepciones en función de las dimensiones económica, social y medioambiental. El conjunto de estos tipos de capacidad puede constituir lo que se puede denominar como capacidad de carga turística. Sin embargo, la complejidad de la aplicación de este concepto es evidente. La capacidad de carga turística es un concepto tratado en la literatura académica, especialmente desde un punto de vista teórico, dado que son pocos los estudios empíricos sobre dicho concepto, aunque hay una tendencia creciente en los últimos años.

  14. Synthesis and contractile activity of the C-terminal heptapeptide of substance P with N5-dimethyl glutamine in the 6-position. Active site studies.

    Science.gov (United States)

    Poulos, C P; Pinas, N; Theodoropoulos, D

    1980-09-15

    The synthesis and testing of [N5-dimethyl-Gln6]-SP5-11 showed 37 +/- 12% contractile activity relative to SP, and intrinsic efficacy 98 +/- 4%. This finding indicates that the carboxamide groups of the dual Gln5-Cln6 moiety are not equally related with the contractile response of the C-terminal heptapeptide of SP.

  15. La arquitectura organizacional y las capacidades estratégicas empresariales empresariales

    Directory of Open Access Journals (Sweden)

    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.

  16. POTÊNCIA E CAPACIDADE ANAERÓBIA EM ATLETAS DE KARATE

    Directory of Open Access Journals (Sweden)

    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.

  17. Beta adrenergic overstimulation impaired vascular contractility via actin-cytoskeleton disorganization in rabbit cerebral artery.

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    Hyoung Kyu Kim

    Full Text Available BACKGROUND AND PURPOSE: Beta adrenergic overstimulation may increase the vascular damage and stroke. However, the underlying mechanisms of beta adrenergic overstimulation in cerebrovascular dysfunctions are not well known. We investigated the possible cerebrovascular dysfunction response to isoproterenol induced beta-adrenergic overstimulation (ISO in rabbit cerebral arteries (CAs. METHODS: ISO was induced in six weeks aged male New Zealand white rabbit (0.8-1.0 kg by 7-days isoproterenol injection (300 μg/kg/day. We investigated the alteration of protein expression in ISO treated CAs using 2DE proteomics and western blot analysis. Systemic properties of 2DE proteomics result were analyzed using bioinformatics software. ROS generation and following DNA damage were assessed to evaluate deteriorative effect of ISO on CAs. Intracellular Ca(2+ level change and vascular contractile response to vasoactive drug, angiotensin II (Ang II, were assessed to evaluate functional alteration of ISO treated CAs. Ang II-induced ROS generation was assessed to evaluated involvement of ROS generation in CA contractility. RESULTS: Proteomic analysis revealed remarkably decreased expression of cytoskeleton organizing proteins (e.g. actin related protein 1A and 2, α-actin, capping protein Z beta, and vimentin and anti-oxidative stress proteins (e.g. heat shock protein 9A and stress-induced-phosphoprotein 1 in ISO-CAs. As a cause of dysregulation of actin-cytoskeleton organization, we found decreased level of RhoA and ROCK1, which are major regulators of actin-cytoskeleton organization. As functional consequences of proteomic alteration, we found the decreased transient Ca(2+ efflux and constriction response to angiotensin II and high K(+ in ISO-CAs. ISO also increased basal ROS generation and induced oxidative damage in CA; however, it decreased the Ang II-induced ROS generation rate. These results indicate that ISO disrupted actin cytoskeleton proteome network

  18. 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.

  19. Capacidad reguladora de Chrysoperla externa (Hagen sobre mosca blanca Trialeurodes vaporariorum (Westwood en tomate bajo invernadero

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    Mayerly Alejandra Castro-Lopez

    2016-11-01

    Full Text Available Trialeurodes vaporariorum Westwood (Hemíptera: Aleyrodidae es uno de los principales limitantes del cultivo de tomate Solanum lycopersicum, por generar problemas directos e indirectos en este sistema de producción; para el manejo de este insecto (mosca blanca se acude a excesivas aplicaciones de productos de síntesis química, sin obtener los mejores resultados. Este estudio consistió en evaluar, en condiciones de invernadero, la capacidad reguladora de Chrysoperla externa Hagen (Neuróptera: Chrysopidae sobre la mosca blanca presente en tomate. En plantas infestadas con individuos de T. vaporariorum se adicionó C. externa en niveles poblacionales de 80, 160 y 240 individuos en estado larval por planta, y se contó con un testigo sin depredador. Se empleó un diseño completamente al azar en condiciones de invernadero (temperatura promedio de 20 ºC y humedad relativa del 60 %. Se observaron diferencias estadísticamente significativas entre las densidades del depredador, con infestaciones de 35, 52 y 53 % de T. vaporariorum (tras cuatro semanas, correspondientes a las liberaciones de 240, 160 y 80 individuos por planta, respectivamente. Se observó que las plantas del testigo presentaron menor altura y número de ramas, respecto de los tratamientos en los cuales había presencia del depredador C. externa.

  20. 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.

  1. APRENDIZAJE CON BASE EN PROYECTOS PARA DESARROLLAR CAPACIDADES DE PROBLEMATIZACIÓN EN EDUCACION SUPERIOR

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    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.

  2. Impacto da visita domiciliar na capacidade funcional de pacientes com úlceras venosas

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    Fabiana Lopes Joaquim

    2016-06-01

    Full Text Available RESUMO Objetivo: avaliar o impacto da visita domiciliar protocolar na capacidade funcional de pacientes adultos e idosos com úlceras venosas antes e após as orientações recebidas em domicílio. Método: estudo clínico experimental, randomizado não cego e controlado, desenvolvido com 32 pacientes (grupos caso e controle. Os campos de investigação foram o Ambulatório de Reparo de Feridas do Hospital Universitário Antônio Pedro e os domicílios de pacientes atendidos no referido ambulatório. A coleta ocorreu de fevereiro a junho de 2014, por meio de instrumento de avaliação da unidade de saúde, do índice de TINETTI e de roteiro de orientações a serem prestadas aos sujeitos da pesquisa que receberam visita domiciliar. Resultados: os participantes do grupo caso apresentaram melhora significativa e diferenciada pós-intervenção quando comparados aos do grupo controle, que se mantiveram estáveis. Conclusão: as orientações no contexto domiciliar foram benéficas aos integrantes do grupo caso.

  3. [Contractile function of the isolated heart in chronic adriamycin-induced myocardial lesions].

    Science.gov (United States)

    Kapel'ko, V I; Popovich, M I; Golikov, M A; Novikova, N A; Shul'zhenko, V S

    1987-07-01

    Adriamycin, administered to rats for 4 weeks, caused insufficiency of isolated heart contractility with a twofold reduction of cardiac output in surviving animals. The same cumulative dose of adriamycin, administered to rats over 10 weeks, was not associated with any significant reduction of the heart's pumping function. However, heart rate increase by atrial electrostimulation that shortened the diastolic pause to a control level, also reduced the minute and stroke volumes by 38%, as compared to the controls. All animals showed increased diastolic stiffness of the left ventricle that must have interfered with its filling, particularly so in case of low inflow pressure, and disturbed atrial automaticity, as reflected in bradicardia in rats and supraventricular arrhythmia in guinea pigs.

  4. Bidirectional Interplay between Vimentin Intermediate Filaments and Contractile Actin Stress Fibers

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    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.

  5. [Contractile properties of skeletal muscles of rats after flight on "Kosmos-1887"].

    Science.gov (United States)

    Oganov, V S; Skuratova, S A; Murashko, L M

    1991-01-01

    Contractile properties of skeletal muscles of rats were investigated using glycerinated muscle preparations that were obtained from Cosmos-1887 animals flown for 13 days (plus 2 days on the ground) and from rats that remained hypokinetic for 13 days on the ground. In the flow rats, the absolute mass of postural muscles remained unchanged while their relative mass increased; this may be attributed to their enhanced hydration which developed during the first 2 days after landing. Strength losses of the postural muscles were less significant than after previous flights. Comparison of the Cosmos-1887 and hypokinesia control data has shown that even 2-day exposure to 1 G after 13-day flight can modify drastically flight-induced changes.

  6. 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.

  7. Effects of antibiotics on the contractility and Ca2+ transients of rat cardiac myocytes.

    Science.gov (United States)

    Belus, A; White, E

    2001-01-26

    We have compared the effects of streptomycin sulphate, gentamicin sulphate and neomycin sulphate on cell shortening (our index of contractility) and intracellular Ca2+ ([Ca2+](i)) transients of rat ventricular myocytes. All three agents abolished shortening and [Ca2+](i), transients but streptomycin was significantly less potent than the other agents. The IC(50) of streptomycin was 0.37 mM for shortening and 0.78 mM for [Ca2+](i), approximately an order of magnitude greater than equivalent values for gentamicin and neomycin. Gentamicin and streptomycin shortened the action potential duration of most cells but prolonged the action potential duration of others. We therefore conclude that multiple ionic mechanisms affecting action potential duration are modulated by these antibiotics. Our observations are consistent with the negative inotropic effect of antibiotics being caused by a decrease in Ca2+ influx causing a reduction in the [Ca2+](i) transient.

  8. 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.

  9. Hindlimb immobilization - Length-tension and contractile properties of skeletal muscle

    Science.gov (United States)

    Witzmann, F. A.; Kim, D. H.; Fitts, R. H.

    1982-01-01

    Casts were placed around rat feet in plantar flexion position to immobilize the soleus muscle in a shortened position, while the other foot was fixed in dorsal flexion to set the extensor digitorum longus in a shortened position. The total muscular atrophy and contractile properties were measured at 1, 2, 4, 7, 14, 21, 28, 35, and 42 days after immobilization, with casts being replaced every two weeks. The slow twitch soleus and the fast-twitch vastus lateralis and longus muscles were excised after termination of the experiment. The muscles were then stretched and subjected to electric shock to elicit peak tetanic tension and peak tetanic tension development. Force velocity features of the three muscles were assayed in a series of afterloaded contractions and fiber lengths were measured from subsequently macerated muscle. All muscles atrophied during immobilization, reaching a new steady state by day 21. Decreases in fiber and sarcomere lengths were also observed.

  10. Inhibition of MMP-2 Expression with siRNA Increases Baseline Cardiomyocyte Contractility and Protects against Simulated Ischemic Reperfusion Injury

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    Han-Bin Lin

    2014-01-01

    Full Text Available Matrix metalloproteinases (MMPs significantly contribute to ischemia reperfusion (I/R injury, namely, by the degradation of contractile proteins. However, due to the experimental models adopted and lack of isoform specificity of MMP inhibitors, the cellular source and identity of the MMP(s involved in I/R injury remain to be elucidated. Using isolated adult rat cardiomyocytes, subjected to chemically induced I/R-like injury, we show that specific inhibition of MMP-2 expression and activity using MMP-2 siRNA significantly protected cardiomyocyte contractility from I/R-like injury. This was also associated with increased expression of myosin light chains 1 and 2 (MLC1/2 in comparison to scramble siRNA transfection. Moreover, the positive effect of MMP-2 siRNA transfection on cardiomyocyte contractility and MLC1/2 expression levels was also observed under control conditions, suggesting an important additional role for MMP-2 in physiological sarcomeric protein turnover. This study clearly demonstrates that intracellular expression of MMP-2 plays a significant role in sarcomeric protein turnover, such as MLC1 and MLC2, under aerobic (physiological conditions. In addition, this study identifies intracellular/autocrine, cardiomyocyte-produced MMP-2, rather than paracrine/extracellular, as responsible for the degradation of MLC1/2 and consequent contractile dysfunction in cardiomyocytes subjected to I/R injury.

  11. Further identification of bioactive peptides in the anterior byssus retractor muscle of Mytilus: two contractile and three inhibitory peptides.

    Science.gov (United States)

    Fujisawa, Y; Takahashi, T; Ikeda, T; Muneoka, Y; Kubota, I; Minakata, H; Nomoto, K; Nose, T; Miki, W

    1993-09-01

    1. Two contractile and three inhibitory peptides were newly isolated from the anterior byssus retractor muscles (ABRMs) of the bivalve mollusc Mytilus edulis by using the muscle as the bioassay system. 2. The structures of the two contractile peptides were GPFGTHIKamide (GPFG-8) and GPFGLNKHGamide (GPFG-9). The contractile response of the ABRM to the first-time application of GPFG-8 or GPFG-9 was of considerable size. The threshold concentrations of the peptides were around 10(-9) M. However, the contractile response to the second-time application was far smaller than that to the first-time application in both cases. Namely, the muscle showed tachyphylaxis to the peptides. 3. Two of the three inhibitory peptides were members of the Mytilus-inhibitory-peptide (MIP) family. Their structures were RAPLFIamide (MIP6) and RSPMFVamide (MIP7). The peptides, as well as the other MIPs previously identified, showed a potent inhibitory effect on phasic contraction of the ABRM in response to repetitive electrical stimulation. The remaining one was an MIP-related peptide (MIP-RP) having the sequence of MRYFVamide. The MIP-RP was less potent than the two MIPs in inhibiting the contraction of the ABRM.

  12. Reduced Contractility and Motility of Prostatic Cancer-Associated Fibroblasts after Inhibition of Heat Shock Protein 90

    Science.gov (United States)

    Henke, Alex; Franco, Omar E.; Stewart, Grant D.; Riddick, Antony C.P.; Katz, Elad; Hayward, Simon W.; Thomson, Axel A.

    2016-01-01

    Background: Prostate cancer-associated fibroblasts (CAF) can stimulate malignant progression and invasion of prostatic tumour cells via several mechanisms including those active in extracellular matrix; Methods: We isolated CAF from prostate cancer patients of Gleason Score 6–10 and confirmed their cancer-promoting activity using an in vivo tumour reconstitution assay comprised of CAF and BPH1 cells. We tested the effects of heat shock protein 90 (HSP90) inhibitors upon reconstituted tumour growth in vivo. Additionally, CAF contractility was measured in a 3D collagen contraction assay and migration was measured by scratch assay; Results: HSP90 inhibitors dipalmitoyl-radicicol and 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG) reduced tumour size and proliferation in CAF/BPH1 reconstituted tumours in vivo. We observed that the most contractile CAF were derived from patients with lower Gleason Score and of younger age compared with the least contractile CAF. HSP90 inhibitors radicicol and 17-DMAG inhibited contractility and reduced the migration of CAF in scratch assays. Intracellular levels of HSP70 and HSP90 were upregulated upon treatment with HSP90 inhibitors. Inhibition of HSP90 also led to a specific increase in transforming growth factor beta 2 (TGFβ2) levels in CAF; Conclusions: We suggest that HSP90 inhibitors act not only upon tumour cells, but also on CAF in the tumour microenvironment. PMID:27563925

  13. 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...

  14. Alterations in serotonin receptor-induced contractility of bovine lateral saphenous vein in cattle grazing endophyte-infected tall fescue

    Science.gov (United States)

    As part of a large 2-year study documenting the physiologic impact of grazing endophyte-infected tall fescue on growing cattle, 2 experiments were conducted to characterize and evaluate the effects of grazing 2 levels of toxic endophyte-infected tall fescue pastures on vascular contractility and ser...

  15. TRPM4 Is a Novel Component of the Adhesome Required for Focal Adhesion Disassembly, Migration and Contractility.

    Directory of Open Access Journals (Sweden)

    Mónica Cáceres

    Full Text Available Cellular migration and contractility are fundamental processes that are regulated by a variety of concerted mechanisms such as cytoskeleton rearrangements, focal adhesion turnover, and Ca2+ oscillations. TRPM4 is a Ca2+-activated non-selective cationic channel (Ca2+-NSCC that conducts monovalent but not divalent cations. Here, we used a mass spectrometry-based proteomics approach to identify putative TRPM4-associated proteins. Interestingly, the largest group of these proteins has actin cytoskeleton-related functions, and among these nine are specifically annotated as focal adhesion-related proteins. Consistent with these results, we found that TRPM4 localizes to focal adhesions in cells from different cellular lineages. We show that suppression of TRPM4 in MEFs impacts turnover of focal adhesions, serum-induced Ca2+ influx, focal adhesion kinase (FAK and Rac activities, and results in reduced cellular spreading, migration and contractile behavior. Finally, we demonstrate that the inhibition of TRPM4 activity alters cellular contractility in vivo, affecting cutaneous wound healing. Together, these findings provide the first evidence, to our knowledge, for a TRP channel specifically localized to focal adhesions, where it performs a central role in modulating cellular migration and contractility.

  16. Effect of subarachnoid hemorrhage on contractile responses and noradrenaline release evoked in cat cerebral arteries by histamine

    Energy Technology Data Exchange (ETDEWEB)

    Lobato, R.D.; Marin, J.; Salaices, M.; Rico, M.L.; Sanchez, C.F.

    1981-10-01

    This study analyzes the changes induced by subarachnoid hemorrhage (SAH) on the contractile responses and the noradrenaline release evoked in cat cerebral arteries by histamine. The dose-dependent vasoconstriction induced by histamine on the cerebral arteries of normal cats was significantly reduced by diphenhydramine and phentolamine. When SAH was produced 3 and 7 days before the experiment, the histamine-induced vasoconstriction also decreased. Thereafter, a tendency to normalization in the contractile vascular responses was observed such that in 15 days after the hemorrhage it was not significantly different from that found in controls animals. The decrease in the contractile responses to histamine provoked by SAH was similar to that seen after pretreatment with intracisternal injections of 6-hydroxydopamine. The amount of radioactivity released by histamine following preincubation with /sup 3/H-noradrenaline from the cerebral arteries of cats exposed to SAH 3, 7, and 15 days before the experiment was significantly reduced when compared with controls. Moreover, the basal level of tritium release and the radioactivity retained at the end of the experiment were also decreased after SAH. Results indicate histamine releases noradrenaline from cat cerebral arteries, and SAH produce a transient denervation of the perivascular adrenergic nerve endings, which explained by the impairment of the indirect adrenergic mechanism involved in the overall contractile response elicited by this amine in cerebral arteries. Histamine does not seem to play a significant role in the production of the cerebral vasospasm occurring after SAH.

  17. Reduced Contractility and Motility of Prostatic Cancer-Associated Fibroblasts after Inhibition of Heat Shock Protein 90

    Directory of Open Access Journals (Sweden)

    Alex Henke

    2016-08-01

    Full Text Available Background: Prostate cancer-associated fibroblasts (CAF can stimulate malignant progression and invasion of prostatic tumour cells via several mechanisms including those active in extracellular matrix; Methods: We isolated CAF from prostate cancer patients of Gleason Score 6–10 and confirmed their cancer-promoting activity using an in vivo tumour reconstitution assay comprised of CAF and BPH1 cells. We tested the effects of heat shock protein 90 (HSP90 inhibitors upon reconstituted tumour growth in vivo. Additionally, CAF contractility was measured in a 3D collagen contraction assay and migration was measured by scratch assay; Results: HSP90 inhibitors dipalmitoyl-radicicol and 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG reduced tumour size and proliferation in CAF/BPH1 reconstituted tumours in vivo. We observed that the most contractile CAF were derived from patients with lower Gleason Score and of younger age compared with the least contractile CAF. HSP90 inhibitors radicicol and 17-DMAG inhibited contractility and reduced the migration of CAF in scratch assays. Intracellular levels of HSP70 and HSP90 were upregulated upon treatment with HSP90 inhibitors. Inhibition of HSP90 also led to a specific increase in transforming growth factor beta 2 (TGFβ2 levels in CAF; Conclusions: We suggest that HSP90 inhibitors act not only upon tumour cells, but also on CAF in the tumour microenvironment.

  18. 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.

  19. Blockade of Rho-associated protein kinase (ROCK) inhibits the contractility and invasion potential of cancer stem like cells.

    Science.gov (United States)

    Srinivasan, Srisathya; Ashok, Vandhana; Mohanty, Sagarajit; Das, Alakesh; Das, Sreya; Kumar, Sushant; Sen, Shamik; Purwar, Rahul

    2017-02-10

    Recent studies have implicated the roles of cancer stem like cells (CSCs) in cancer metastasis. However, very limited knowledge exists at the molecular and cellular level to target CSCs for prevention of cancer metastasis. In this study, we examined the roles of contractile dynamics of CSCs in cell invasion and delineated the underlying molecular mechanisms of their distinct cell invasion potential. Using de-adhesion assay and atomic force microscopy, we show that CSCs derived from melanoma and breast cancer cell lines exhibit increased contractility compared to non-CSCs across all tumor types. In addition, CSCs possess increased ECM remodeling capacity as quantified by collagen degradation assay. More importantly, pharmacological blockade of Rho-associated protein kinase completely abolished the contractility and collagen degradation capacity of both CSCs and non-CSCs. In conclusion, our study demonstrates the importance of cell contractility in regulating invasiveness of CSCs and suggests that pharmacological targeting of ROCK pathway represents a novel strategy for targeting both CSCs and bulk population for the treatment of cancer metastasis.

  20. Microtubule depolymerization normalizes in vivo myocardial contractile function in dogs with pressure-overload left ventricular hypertrophy

    Science.gov (United States)

    Koide, M.; Hamawaki, M.; Narishige, T.; Sato, H.; Nemoto, S.; DeFreyte, G.; Zile, M. R.; Cooper G, I. V.; Carabello, B. A.

    2000-01-01

    BACKGROUND: Because initially compensatory myocardial hypertrophy in response to pressure overloading may eventually decompensate to myocardial failure, mechanisms responsible for this transition have long been sought. One such mechanism established in vitro is densification of the cellular microtubule network, which imposes a viscous load that inhibits cardiocyte contraction. METHODS AND RESULTS: In the present study, we extended this in vitro finding to the in vivo level and tested the hypothesis that this cytoskeletal abnormality is important in the in vivo contractile dysfunction that occurs in experimental aortic stenosis in the adult dog. In 8 dogs in which gradual stenosis of the ascending aorta had caused severe left ventricular (LV) pressure overloading (gradient, 152+/-16 mm Hg) with contractile dysfunction, LV function was measured at baseline and 1 hour after the intravenous administration of colchicine. Cardiocytes obtained by biopsy before and after in vivo colchicine administration were examined in tandem. Microtubule depolymerization restored LV contractile function both in vivo and in vitro. CONCLUSIONS: These and additional corroborative data show that increased cardiocyte microtubule network density is an important mechanism for the ventricular contractile dysfunction that develops in large mammals with adult-onset pressure-overload-induced cardiac hypertrophy.

  1. 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.

  2. 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.

  3. Serum response factor regulates smooth muscle contractility via myotonic dystrophy protein kinases and L-type calcium channels

    Science.gov (United States)

    Lee, Moon Young; Park, Chanjae; Ha, Se Eun; Park, Paul J.; Berent, Robyn M.; Jorgensen, Brian G.; Corrigan, Robert D.; Grainger, Nathan; Blair, Peter J.; Slivano, Orazio J.; Miano, Joseph M.; Ward, Sean M.; Smith, Terence K.; Sanders, Kenton M.

    2017-01-01

    Serum response factor (SRF) transcriptionally regulates expression of contractile genes in smooth muscle cells (SMC). Lack or decrease of SRF is directly linked to a phenotypic change of SMC, leading to hypomotility of smooth muscle in the gastrointestinal (GI) tract. However, the molecular mechanism behind SRF-induced hypomotility in GI smooth muscle is largely unknown. We describe here how SRF plays a functional role in the regulation of the SMC contractility via myotonic dystrophy protein kinase (DMPK) and L-type calcium channel CACNA1C. GI SMC expressed Dmpk and Cacna1c genes into multiple alternative transcriptional isoforms. Deficiency of SRF in SMC of Srf knockout (KO) mice led to reduction of SRF-dependent DMPK, which down-regulated the expression of CACNA1C. Reduction of CACNA1C in KO SMC not only decreased intracellular Ca2+ spikes but also disrupted their coupling between cells resulting in decreased contractility. The role of SRF in the regulation of SMC phenotype and function provides new insight into how SMC lose their contractility leading to hypomotility in pathophysiological conditions within the GI tract. PMID:28152551

  4. 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…

  5. 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...

  6. Análisis de la capacidad de aceleración en mujeres atletas de modalidades de velocidad

    Directory of Open Access Journals (Sweden)

    Gerard Carmona Dalmases

    2012-03-01

    Full Text Available Objetivos. Caracterizar la capacidad de aceleración con relación al rendimiento (tiempo en sprint de 30 m, la velocidad máxima y las manifestaciones de fuerza (capacidad de salto y potencia (en ½ squat musculares en 4 mujeres atletas de especialidades de velocidad de nivel nacional. Métodos. Se realizaron dos días de pruebas (pista y laboratorio. Se valoró la capacidad de aceleración (velocidades instantánea a 1, 2 y 3 s –vi1, vi2 i vi3–, aceleración inicial (ainicial, tiempo de sprint en 30 m (rendimiento, velocidad máxima (vmàx, capacidad de salto (SJ, CMJ, LJ bw y RJ 5s y potencia media máxima (Pm màx desarrollada en ½ squat. Resultados. Se hallaron correlaciones significativas entre el rendimiento (t30m y la vmáx (r = –0,980; P < 0,01, la capacidad de aceleración (velocidades instantáneas y el t30m (r = –0,954; P < 0,05 y la vmáx (r = 0,992 y 0,979; P < 0,01 y 0,05, la manifestación elástica de la fuerza (CMJ y el t30m (r = –0,983; P < 0,05 y la fuerza dinámica máxima relativa y la ainicial (r = 0,980; P < 0,01. Conclusiones. El principal hallazgo del presente estudio fue que la vmáx era el mayor determinante del t30m. También la capacidad de aceleración, sobretodo la vi2, y el CMJ tuvieron una gran ascendencia sobre el t30m y la vmáx.

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

    Directory of Open Access Journals (Sweden)

    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

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. Colon-specific contractile responses to tetrodotoxin in the isolated mouse gastrointestinal tract.

    Science.gov (United States)

    Okuno, Y; Kondo, T; Saeki, A; Uchida, E; Teraoka, H; Kitazawa, T

    2011-01-01

    1 Tetrodotoxin (TTX) is a useful pharmacological tool for distinguishing neural and myogenic responses of isolated visceral organs to drugs. Although TTX does not generally affect smooth muscle tonus, in this study, we have found that TTX causes contraction of the mouse colon. The aim of this study was to characterize this TTX-induced contraction in the mouse gastrointestinal tract. 2 Longitudinal and circular muscle strips from the stomach and small intestine were less sensitive to TTX. However, TTX contracted both smooth muscle strips from the proximal colon and distal colon. 3 Pretreatment with TTX, Nω -nitro-L-arginine methyl ester (L-NAME), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) and apamin inhibited the TTX-induced contraction. L-NAME, ODQ or apamin itself caused contraction in the colon but not in the gastric and small intestinal strips. Region dependency of L-NAME, ODQ and apamin-induced contraction correlated with that of TTX-induced contraction. 4 L-arginine but not D-arginine inhibited contractility of the colonic strips without affecting the contractility of muscle strips from other regions. Sodium nitroprusside caused strong relaxation of the colonic strips. 5 1,1-dimethyl-4-phenylpiperazinium (DMPP) caused relaxation of proximal and distal colons, which was significantly decreased by L-NAME or apamin. 6 In conclusion, among mouse gastrointestinal preparations, TTX induces contraction of colonic strips preferentially through blockade of potent tonic inhibitory neural outflow, which involves nitrergic and apamin-sensitive pathways. Colon-specific responses to L-arginine, L-NAME, ODQ and apamin support the hypothesis that there is a continuous suppression of colonic motility by enteric inhibitory neurons.

  13. 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.

  14. 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.

  15. Left ventricular diastolic dysfunction limits use of maximum systolic elastance as an index of contractile function.

    Science.gov (United States)

    Zile, M R; Izzi, G; Gaasch, W H

    1991-02-01

    We tested the hypothesis that maximum systolic elastance (Emax) fails to detect a decline in left ventricular (LV) contractile function when diastolic dysfunction is present. Canine hearts were studied in an isolated blood-perfused heart apparatus (isovolumic LV); contractile dysfunction was produced by 60 or 90 minutes of global ischemia, followed by 90 minutes of reperfusion. Nine normal hearts underwent 60 minutes of ischemia, and five underwent 90 minutes of ischemia. After the ischemia-reperfusion sequence, developed pressure, pressure-volume area, and myocardial ATP level were significantly less than those at baseline in all 14 hearts. In the group undergoing 60 minutes of ischemia, LV diastolic pressure did not increase, whereas Emax decreased from 5.2 +/- 2.5 to 2.9 +/- 1.4 mm Hg/ml (p less than 0.05). In the group undergoing 90 minutes of ischemia, diastolic pressure increased (from 10 +/- 2 to 37 +/- 20 mm Hg, p less than 0.05), and Emax did not change significantly (from 5.1 +/- 4.3 to 4.3 +/- 2.5 mm Hg/ml). A second series of experiments was performed in 13 hearts with pressure-overload hypertrophy (aortic-band model with echocardiography and catheterization studies before the ischemia-reperfusion protocol). Five had evidence for pump failure, whereas eight remained compensated. After 60 minutes of ischemia and 90 minutes of reperfusion, developed pressure, pressure-volume area, and myocardial ATP level were significantly less than those at baseline in all 13 hearts. In the group with compensated LV hypertrophy, LV diastolic pressure did not change, whereas Emax decreased from 6.9 +/- 3.0 to 3.1 +/- 2.3 mm Hg/ml (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

  16. 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.

  17. 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.

  18. 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.

  19. β-Arrestin mediates the Frank-Starling mechanism of cardiac contractility.

    Science.gov (United States)

    Abraham, Dennis M; Davis, Robert T; Warren, Chad M; Mao, Lan; Wolska, Beata M; Solaro, R John; Rockman, Howard A

    2016-12-13

    The Frank-Starling law of the heart is a physiological phenomenon that describes an intrinsic property of heart muscle in which increased cardiac filling leads to enhanced cardiac contractility. Identified more than a century ago, the Frank-Starling relationship is currently known to involve length-dependent enhancement of cardiac myofilament Ca(2+) sensitivity. However, the upstream molecular events that link cellular stretch to the length-dependent myofilament Ca(2+) sensitivity are poorly understood. Because the angiotensin II type 1 receptor (AT1R) and the multifunctional transducer protein β-arrestin have been shown to mediate mechanosensitive cellular signaling, we tested the hypothesis that these two proteins are involved in the Frank-Starling mechanism of the heart. Using invasive hemodynamics, we found that mice lacking β-arrestin 1, β-arrestin 2, or AT1R were unable to generate a Frank-Starling force in response to changes in cardiac volume. Although wild-type mice pretreated with the conventional AT1R blocker losartan were unable to enhance cardiac contractility with volume loading, treatment with a β-arrestin-biased AT1R ligand to selectively activate β-arrestin signaling preserved the Frank-Starling relationship. Importantly, in skinned muscle fiber preparations, we found markedly impaired length-dependent myofilament Ca(2+) sensitivity in β-arrestin 1, β-arrestin 2, and AT1R knockout mice. Our data reveal β-arrestin 1, β-arrestin 2, and AT1R as key regulatory molecules in the Frank-Starling mechanism, which potentially can be targeted therapeutically with β-arrestin-biased AT1R ligands.

  20. Occupational stress and work capacity of nurses of a hospital group Estrés laboral y capacidad para el trabajo de enfermeros de un grupo hospitalario Estresse laboral e capacidade para o trabalho de enfermeiros de um grupo hospitalar

    Directory of Open Access Journals (Sweden)

    Christian Negeliskii

    2011-06-01

    Full Text Available The study aimed to evaluate the relationship between occupational stress and the work capacity index of 368 nurses (82.1% of the population of a Hospital Group. A questionnaire with socio-occupational questions was used as well as two scales: the Job Stress Scale and the Work Capacity Index. The group of nurses was predominantly female (93.2%, worked in care activities (63.9%, had undertaken at least one Postgraduate course (76% and were satisfied with the unit where they worked (70.5%. Occupational stress was present in 23.6% of the nurses, of these 15.2% presented High Strain work and 8.4% Passive Work. Social Support exercised a significant positive influence on all groups - exposed or not to occupational stress. Regarding the Work Capacity, this was Moderate (28-36 points for 51.4% of the nurses and Good (37-43 points for 47.4%. There was no correlation between stress and work capacity.Se trata de un estudio con objetivo de evaluar la relación entre el estrés laboral y el índice de capacidad para el trabajo de 368 enfermeros (82,1% de la población de un Grupo Hospitalario. Se utilizó un cuestionario con cuestiones socio ocupacionales y dos escalas: la Job Stress Scale y el Índice de Capacidad para el Trabajo. El grupo de enfermeros es predominantemente femenino (93,2%, trabaja en actividades asistenciales (63,9%, posee por lo menos un curso de posgraduación (76% y está satisfecho con la unidad donde trabaja (70,5%. El estrés laboral está presente en 23,6% de los enfermeros, de estos 15,2% presentan Alta Exigencia en el trabajo y 8,4% Trabajo Pasivo. El Apoyo Social ejerce influencia positiva significativa sobre todos los grupos expuestos y no expuestos al estrés laboral. En cuanto a la Capacidad para el Trabajo, está es Moderada (28-36 puntos para 51,4% de los enfermeros y Buena (37-43 puntos para 47,4%. No se encontró correlación entre el estrés y la capacidad para el trabajo.Este estudo teve como objetivo avaliar a rela

  1. 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.

  2. A Small Molecule Inhibitor of Sarcomere Contractility Acutely Relieves Left Ventricular Outflow Tract Obstruction in Feline Hypertrophic Cardiomyopathy

    Science.gov (United States)

    Stern, Joshua A.; Markova, Svetlana; Ueda, Yu; Kim, Jae B.; Pascoe, Peter J.; Evanchik, Marc J.; Green, Eric M.; Harris, Samantha P.

    2016-01-01

    Hypertrophic cardiomyopathy (HCM) is an inherited disease of the heart muscle characterized by otherwise unexplained thickening of the left ventricle. Left ventricular outflow tract (LVOT) obstruction is present in approximately two-thirds of patients and substantially increases the risk of disease complications. Invasive treatment with septal myectomy or alcohol septal ablation can improve symptoms and functional status, but currently available drugs for reducing obstruction have pleiotropic effects and variable therapeutic responses. New medical treatments with more targeted pharmacology are needed, but the lack of preclinical animal models for HCM with LVOT obstruction has limited their development. HCM is a common cause of heart failure in cats, and a subset exhibit systolic anterior motion of the mitral valve leading to LVOT obstruction. MYK-461 is a recently-described, mechanistically novel small molecule that acts at the sarcomere to specifically inhibit contractility that has been proposed as a treatment for HCM. Here, we use MYK-461 to test whether direct reduction in contractility is sufficient to relieve LVOT obstruction in feline HCM. We evaluated mixed-breed cats in a research colony derived from a Maine Coon/mixed-breed founder with naturally-occurring HCM. By echocardiography, we identified five cats that developed systolic anterior motion of the mitral valve and LVOT obstruction both at rest and under anesthesia when provoked with an adrenergic agonist. An IV MYK-461 infusion and echocardiography protocol was developed to serially assess contractility and LVOT gradient at multiple MYK-461 concentrations. Treatment with MYK-461 reduced contractility, eliminated systolic anterior motion of the mitral valve and relieved LVOT pressure gradients in an exposure-dependent manner. Our findings provide proof of principle that acute reduction in contractility with MYK-461 is sufficient to relieve LVOT obstruction. Further, these studies suggest that feline

  3. Cardiac-specific catalase overexpression rescues anthrax lethal toxin-induced cardiac contractile dysfunction: role of oxidative stress and autophagy

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    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.

  4. 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.

  5. 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.

  6. Recovery of the Frank-Starling mechanism by coenzyme Q10 in patients with load-induced contractility depression.

    Science.gov (United States)

    Oda, T

    1993-01-01

    Load-induced contractility depression, in which supernormal left ventricular ejection fraction and contractility at rest decrease by added afterload, is most often found in children with mitral valve prolapse who have symptoms. Patients have high ventricular end-diastolic pressure at rest, which is further increased by afterload challenge. The Frank-Starling mechanism may be maximally mobilized with high preload even at rest to compensate for the intrinsically depressed inotropic state. Therefore, preload reserve may be easily exhausted due to afterload addition. We aimed to determine left ventricular end-diastolic fiber length, stroke work, and contractility before and during handgrip by echocardiograms to obtain evidence for the Frank-Starling mechanism in patients and controls, including patients treated with coenzyme Q10. The subjects were divided into four groups, each consisting of 30 children aged 6-16 years: group 1, normals; group 2, patients; group 3, the same patients as in group 2 after coenzyme Q10 therapy; and group 4, patients with asymptomatic mitral valve prolapse. Baseline values and percentage increases in systolic blood pressure, heart rate, and left ventricular wall stress showed no differences among the groups. Only in group 2 were the percentage increase in ejection fraction, fiber shortening velocity, contractility, and end-diastolic dimension strongly negative, despite supernormal baseline levels. In other groups, these were significantly positive, without intergroup differences. We conclude that in the heart with load-induced contractility depression, the Frank-Starling mechanism deviates from normal. The normal Frank-Starling mechanism was recovered due to coenzyme Q10, which may improve disturbed bioenergetic function at the molecular level.

  7. Capacidade institucional: uma revisão de conceitos e programas federais de governo para o fortalecimento da administração pública

    Directory of Open Access Journals (Sweden)

    Fabiana Silva Fernandes

    Full Text Available Resumo Este artigo é uma revisão de conceitos sobre a capacidade institucional e de alguns programas federais implementados para fortalecer a capacidade institucional de estados, municípios e órgãos da administração pública. Para a elaboração deste trabalho, realizou-se um levantamento bibliográfico e documental sobre, respectivamente, o conceito de capacidade institucional e os programas e ações do governo federal para o fortalecimento de sua capacidade institucional. Verificou-se que o conceito tem caráter polissêmico e pragmático e foi desenvolvido para mensurar e elaborar estratégias de fortalecimento da capacidade das instituições. Da mesma forma, notou-se a existência de estreita vinculação entre capacidade institucional e capacidade de planejamento e de gestão das políticas públicas.

  8. Hysteroscopic sterilization with occlusion of sheep uterine tube using n-butyl-2-cyanoacrylate adhesive Esterilização histeroscópica com oclusão da tuba uterina de ovelha com adesivo de n-butil-2-cianoacrilato

    Directory of Open Access Journals (Sweden)

    Sergio Bigolin

    2007-10-01

    Full Text Available PURPOSE: To evaluate the fertility and analyze the macroscopic, microscopic and morphometric aspects of sheep uterine tube sterilization with a hysteroscopically insert of n-butyl-2-cyanoacrylate adhesive. METHODS: 12 adult sheep, with one previous pregnancy, were distributed as follows: group L (n=3 subjected to laparotomy and Pomeroy uterine tube ligation, group S (n=3 subjected to hysteroscopic application of saline solution in tube isthmus and group AD(n=6, that was subjected to hysteroscopic application of 0.5 ml of n-2-butil-cyanoacrylate in tube isthmus. They were mated with fertile males for ninety days. The non pregnant sheep, at the 90th day, were subjected to laparotomy with uterus and tubes uterine resection. The fragments of uterine tubes were fixated in 10% formalin and processes for histology evaluated, and slices dyes for H.E. Data were evaluated by Wilcoxon and Mann-Whitney and Fisher's exact test. RESULTS: All sheep from groups L and AD did not get pregnant (0% in contrast with sheep from group S (100%; the adhesive remained integral in the uterine tube lumen. The percentual of adherences (66.6% and fibrosis responses (100% was significantly higher in the group L than group AD (0% (pOBJETIVO: Avaliar a fertilidade e aspectos macroscópicos, microscópicos e morfométricos da esterilização histeroscópica de tubas uterinas de ovelhas com o adesivo de n-butil-2-cianoacrilato. MÉTODOS: 12 ovelhas adultas, com uma prenhez anterior, foram distribuídas como segue: o grupo L (n=3 submetidas à laparotomia e laqueadura tipo Pomeroy, grupo S (n=3 submetidas à aplicação histeroscópica de solução salina no istmo tubário e grupo AD (n=6, com aplicação histeroscópica de 0,5 ml de cianoacrilato. As ovelhas foram acasaladas com machos de comprovada fertilidade por noventa dias. As ovelhas não prenhes aos 90 dias, foram submetidas à laparotomia com ressecção do útero e tubas uterinas, que foram fixadas em formalina 10%s e os

  9. 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

  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. Capacidades institucionales y desempeño de los organismos operadores de agua en Hermosillo, Sonora, y Mexicali, Baja California

    Directory of Open Access Journals (Sweden)

    Edmundo Loera Burnes

    2017-01-01

    Full Text Available Con el enfoque de capacidad institucional, aquí se analizan los factores políticos que influyeron en la asignación de recursos jurídicos, organizacionales y humanos para la Comisión Estatal de Servicios Públicos de Mexicali y para Agua de Hermosillo. También cómo influye el titular del Ejecutivo en su operación, y cómo se refleja la influencia de los factores institucionales en su desempeño. Si bien el estudio muestra la baja capacidad de ambos organismos en el aspecto de recursos humanos, el de Mexicali es superior en los otros rubros, y eso se traduce en más planeación y, por lo tanto, en mejor desempeño.

  12. Inteligencia y memoria de trabajo: la relación entre factor g, complejidad cognitiva y capacidad de procesamiento

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    Roberto Colom

    Full Text Available La psicologia experimental ha estudiado extensivamente las características de la memoria, mientras que la psicología correlacional ha actualizado las principales propiedades de la inteligencia. El acercamiento entre ambos enfoques se basa en el análisis de las relaciones entre un concepto nuclear de la memoria -- la memoria de trabajo -- y el principal ingrediente del concepto psicométrico de inteligencia -- el factor g. Las evidencias disponibles sugieren que las diferencias individuales en g podrían ser explicadas por los conceptos cognitivos de capacidad y de velocidad asociados a la memoria de trabajo. Esas evidencias sugieren nuevos modos de mejorar la inteligencia -- y, por tanto, los correlatos asociados a ella -- a través del incremento de la capacidad del sistema para procesar información de manera eficiente.

  13. 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”

  14. Um modelo de simulação para gestão da capacidade dos aeroportos brasileiros

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    Antonio Rodolfo Araujo Marcos

    Full Text Available A importância do setor aéreo para o desenvolvimento de um país e o crescimento da demanda aérea brasileira implica na necessidade de uma gestão eficiente dos aeroportos, buscando o equilíbrio entre a capacidade e a demanda aérea. Diante disso, este artigo apresenta um modelo em Dinâmica de Sistemas capaz de auxiliar a gestão aeroportuária brasileira em relação ao dimensionamento dos subsistemas de um aeroporto (Terminal de Passageiros, Pistas e Pátio. O modelo utiliza dados sobre demanda aérea de passageiros, número médio de passageiros por voo, demanda hora-pico, nível de serviço do terminal de passageiros e tempo médio de estacionamento das aeronaves para analisar a situação de treze aeroportos brasileiros. Por fim, através da comparação da capacidade ideal produzida pelo modelo de simulação com a capacidade real instalada, o artigo classifica a situação de cada um dos subsistemas dos aeroportos estudados em adequada, crítica e preocupante. Entre os principais resultados obtidos pode-se destacar que: a Pista é o subsistema que apresenta melhores condições, enquanto que o terminal de passageiros é o subsistema em pior condição; os investimentos e aumento da capacidade são insuficientes para atender uma demanda de crescimento de 5% ao ano na hora-pico.

  15. 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.

  16. 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.

  17. 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

  18. Capacidade materna de cuidar e desnutrição infantil

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    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

  19. Capacidade materna de cuidar e desnutrição infantil

    Directory of Open Access Journals (Sweden)

    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

  20. Capacidades tecnológicas para la innovación en la industria del software: un caso de éxito.

    OpenAIRE

    Vargas Vega, Tatiana

    2012-01-01

    En este artículo se estudia la formación y acumulación de capacidades tecnológicas para el caso empírico de una empresa costarricense de software líder en el mercado. Asimismo, se analiza la acumulación de capacidades tecnológicas a través de los diferentes mecanismos existentes de transferencia de conocimiento y actividades de aprendizaje; así como dónde están centradas las capacidades tecnológicas en la empresa. Para alcanzar a comprender los diferentes niveles de innovación de la empresa, ...