A DIC based technique to measure the contraction of a skeletal muscle engineered tissue

Tissue engineering is a multidisciplinary science based on the application of engineering approaches to biologic tissue formation. Engineered tissue internal organization represents a key aspect to increase biofunctionality before transplant and, as regarding skeletal muscles, the potential of generating contractile forces is dependent on the internal fiber organization and is reflected by some macroscopic parameters, such as the spontaneous contraction. Here we propose the application of digital image correlation (DIC) as an independent tool for an accurate and noninvasive measurement of engineered muscle tissue spontaneous contraction. To validate the proposed technique we referred to the X-MET, a promising 3-dimensional model of skeletal muscle. The images acquired through a high speed camera were correlated with a custom-made algorithm and the longitudinal strain predictions were employed for measuring the spontaneous contraction. The spontaneous contraction reference values were obtained by studying the force response.The relative error between the spontaneous contraction frequencies computed in both ways was always lower than 0.15%. In conclusion, the use of a DIC based systemallows for an accurate and noninvasive measurement of biological tissues’ spontaneous contraction, in addition to the measurement of tissue strain field on any desired region of interest during electrical stimulation

A DIC Based Technique to Measure the Contraction of a Skeletal Muscle Engineered Tissue

Tissue engineering is a multidisciplinary science based on the application of engineering approaches to biologic tissue formation. Engineered tissue internal organization represents a key aspect to increase biofunctionality before transplant and, as regarding skeletal muscles, the potential of generating contractile forces is dependent on the internal fiber organization and is reflected by some macroscopic parameters, such as the spontaneous contraction. Here we propose the application of digital image correlation (DIC) as an independent tool for an accurate and noninvasive measurement of engineered muscle tissue spontaneous contraction. To validate the proposed technique we referred to the X-MET, a promising 3-dimensional model of skeletal muscle. The images acquired through a high speed camera were correlated with a custom-made algorithm and the longitudinal strain predictions were employed for measuring the spontaneous contraction. The spontaneous contraction reference values were obtained by studying the force response. The relative error between the spontaneous contraction frequencies computed in both ways was always lower than 0.15%. In conclusion, the use of a DIC based system allows for an accurate and noninvasive measurement of biological tissues' spontaneous contraction, in addition to the measurement of tissue strain field on any desired region of interest during electrical stimulation

Del “vivir bien” al “buen vivir” entre la economía feminista, la filantropía y la migración: hacia la búsqueda de alternativas

El "vivir bien" y el "buen vivir" son formas de rescatar una nueva aportación del desarrollo, y se presentan justo como una alternativa del pensamiento hegemónico. Ana Esther Ceceña en el capítulo primero parte de como se organiza lo económico, Alba Carosio en el capítulo segundo establece el enfoque de asegurar la calidad de vida de las personas; mientras Antonio Palazuelos pone énfasis en el Plan Nacional de Desarrollo para el Buen Vivir centrándose en tres factores importantes: la economía popular y solidaria, la seguridad alimentaria y los grupos vulnerables. Silvia Berger evalúa las implicaciones de haber adoptado en el feminismo latinoamericano las líneas generales del movimiento feministas mundial. Por su parte, Jaqueline Butcher explica el tercer sector en México y su relación con el desarrollo económico y social del país. En el capítulo sexto, Rodolfo García Zamora y Monsterrat García muestran como las organizaciones de migrantes mexicanos han financiado obras de infraestructura básica en sus comunidades de origen. El libro finaliza con el capítulo siete a cargo de Ana María Aragonés y Uberto Salgado quiénes se centran en un análisis comparativo del impacto que la migración de trabajadores altamente calificados y las remesas tienen sobre el desarrollo de seis países

Crisis económica: una perspectiva feminista desde América Latina

ÍNDICE PRÓLOGO / 13 INTRODUCCIÓN / 17 PRIMERA PARTE: CARACTERIZACIÓN DE LA CRISIS Alicia Girón / 31 CIRCUITOS DE LA CRISIS: RESQUEBRAJAMIENTO DEL MODELO ECONÓMICO Y PERSPECTIVA FEMINISTA Alba Carosio / 53 FRENTE A LA CRISIS ECONÓMICA Y CIVILIZATORIA: UN NUEVO CONTRATO SOCIALISTA Y FEMINISTA Magdalena Valdivieso / 77 MUJERES, DESARROLLO Y CRISIS Eugenia Correa / 97 CRISIS DE LA PRIVATIZACIÓN DE LOS FONDOS DE PENSION: ESPECULACIÓN FINANCIERA Y DESAMPARO SOCIAL SEGUNDA PARTE: AMÉRICA LATINA, INEQUIDAD DE GÉNERO Y VIOLENCIA Silvia Berger / 115 AMÉRICA LATINA, LA CRISIS Y EL FEMINISMO. PENSANDO JUNTO CON NANCY FRASER Patricia Rodríguez / 139 REFORMAS FINANCIERAS, PRIVATIZACIÓN DE LOS SISTEMAS DE PENSIONES Y LA INEQUIDAD DE GÉNERO EN AMÉRICA LATINA Blanca Pedroza / 161 DISCRIMINACIÓN Y VIOLENCIA DE GÉNERO Y CRISIS ECONÓMICA EN AMÉRICA LATINA Alejandra Arroyo / 181 EMPODERAMIENTO: ALTERNATIVA PARA LOGRAR DESARROLLO CON EQUIDAD TERCERA PARTE: COLOMBIA, MÉXICO Y BRASIL Consuelo Ahumada / 205 POLÍTICAS PÚBLICAS Y GÉNERO EN COLOMBIA: ENTRE EL AJUSTE FISCAL Y EL CONFLICTO ARMADO María Luisa González Marín / 225 CRISIS FINANCIERA Y MIGRACIÓN FEMENINA DE MÉXICO Maria Cristina Cacciamali / 247 CRISIS ECONÓMICA EN BRASIL Y DISCRIMINACIÓN FEMENINA EN EL MERCADO DE TRABAJ

Erratum to: Analysis of in vitro ADCC and clinical response to trastuzumab: possible relevance of Fc\u3b3RIIIA/Fc\u3b3RIIA gene polymorphisms and HER-2 expression levels on breast cancer cell lines

BACKGROUND: Trastuzumab is a humanized monoclonal antibody (mAb) currently used for the treatment of breast cancer (BC) patients with HER-2 overexpressing tumor subtype. Previous data reported the involvement of FcγRIIIA/IIA gene polymorphisms and/or antibody-dependent cellular cytotoxicity (ADCC) in the therapeutic efficacy of trastuzumab, although results on these issues are still controversial. This study was aimed to evaluate in vitro the functional relationships among FcγRIIIA/IIA polymorphisms, ADCC intensity and HER-2 expression on tumor target cells and to correlate them with response to trastuzumab. PATIENTS AND METHODS: Twenty-five patients with HER-2 overexpressing BC, receiving trastuzumab in a neoadjuvant (NEO) or metastatic (MTS) setting, were genotyped for the FcγRIIIA 158V>F and FcγRIIA 131H>R polymorphisms by a newly developed pyrosequencing assay and by multiplex Tetra-primer-ARMS PCR, respectively. Trastuzumab-mediated ADCC of patients’ peripheral blood mononuclear cells (PBMCs) was evaluated prior to therapy and measured by (51)Chromium release using as targets three human BC cell lines showing different levels of reactivity with trastuzumab. RESULTS: We found that the FcγRIIIA 158F and/or the FcγRIIA 131R variants, commonly reported as unfavorable in BC, may actually behave as ADCC favorable genotypes, in both the NEO (P ranging from 0.009 to 0.039 and from 0.007 to 0.047, respectively) and MTS (P ranging from 0.009 to 0.032 and P = 0.034, respectively) patients. The ADCC intensity was affected by different levels of trastuzumab reactivity with BC target cells. In this context, the MCF-7 cell line, showing the lowest reactivity with trastuzumab, resulted the most suitable cell line for evaluating ADCC and response to trastuzumab. Indeed, we found a statistically significant correlation between an increased frequency of patients showing ADCC of MCF-7 and complete response to trastuzumab in the NEO setting (P = 0.006). CONCLUSIONS: Although this study was performed in a limited number of patients, it would indicate a correlation of FcγR gene polymorphisms to the ADCC extent in combination with the HER-2 expression levels on tumor target cells in BC patients. However, to confirm our findings further experimental evidences obtained from a larger cohort of BC patients are mandatory. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12967-015-0680-0) contains supplementary material, which is available to authorized users

Isolation and culture of satellite cells from mouse skeletal muscle

Skeletal muscle tissue is characterized by a population of quiescent mononucleated myoblasts, localized between the basal lamina and sarcolemma of myofibers, known as satellite cells. Satellite cells play a pivotal role in muscle homeostasis and are the major source of myogenic precursors in mammalian muscle regeneration.This chapter describes protocols for isolation and culturing satellite cells isolated from mouse skeletal muscles. The classical procedure, which will be discussed extensively in this chapter, involves the enzymatic dissociation of skeletal muscles, while the alternative method involves isolation of satellite cells from isolated myofibers in which the satellite cells remain in their in situ position underneath the myofiber basal lamina.In particular, we discuss the technical aspect of satellite cell isolation, the methods necessary to enrich the satellite cell fraction and the culture conditions that optimize proliferation and myotube formation of mouse satellite cells

Feminismo y cambio social en América Latina y el Caribe

La emisión fue en torno al libro "Feminismo y cambio social en América Latina y el Caribe", el cual fue coordinado por la Dra. Alba Carosio, y fue realizado, gracias al apoyo de FLACSO, la presentación de dicho material, informó al auditorio acerca de los cambios que ha presentado este fenómeno durante las últimas dos década

Impact of ageing on muscle cell regeneration

Skeletal muscle regeneration is a coordinate process in which several factors are sequentially activated to maintain and preserve muscle structure and function. The major role in the growth, remodeling and regeneration is played by satellite cells, a quiescent population of myogenic cells that reside between the basal lamina and plasmalemma and are rapidly activated in response to appropriate stimuli. However, in several muscle conditions, including aging, the capacity of skeletal muscle to sustain an efficient regenerative pathway is severely compromised. Nevertheless, if skeletal muscle possesses a stem cell compartment it is not clear why the muscle fails to regenerate under pathological conditions. Either the resident muscle stem cells are too rare or intrinsically incapable of repairing major damage, or perhaps the injured/pathological muscle is a prohibitive environment for stem cell activation and function. Although we lack definitive answers, recent experimental evidences suggest that the mere presence of endogenous stem cells may not be sufficient to guarantee muscle regeneration, and that the presence of appropriate stimuli and factors are necessary to provide a permissive environment that permits stem cell mediated muscle regeneration and repair. In this review we discuss the molecular basis of muscle regeneration and how aging impacts stem cell mediated muscle regeneration and repair. (C) 2009 Elsevier Ireland Ltd. All rights reserved

A digital image correlation based technique to control the development of a skeletal muscle engineered tissue by measuring its surface strain field

X-MET (Ex-vivo Muscle Engineered Tissue) is a promising 3-dimensional model of skeletal muscle for in vitro tests and in vivo transplant. X-MET is an in vitro cultured tissue and has several properties in common with adult skeletal muscle, from biological and morphological to functional ones. To monitor the X-MET's growing improvements, we developed an experimental system based on Digital Image Correlation (DIC) to precisely measure the tissue's contractile capability, thus trying to prevent the formation of any anisotropic or inhomogeneous parts. We employed a high speed camera mounted on a stereomicroscope, and synchronized the image acquisition with the electrical stimulation and the force response measurement. The capability of measuring the 2-dimensional surface strain field in any desired Region Of Interest (ROI) allowed to obtain a comprehensive monitoring of the tissue's formation, both at a global and a local level. Preliminary results confirmed the adequacy of the system to measure tissue's strain field in complete accordance with the force measurement. Moreover, an in-depth analysis allowed to precisely pinpoint the sub-zones where discontinuities arise during tissue formation, returning essential information to improve X-MET generation process