1,721,004 research outputs found
Mouse amniotic fluid stem cells are able to differentiate into satellite cells replenishing the depauperated muscle stem cell niche
Full text linkIntroduction: Stem cell biology has received much interest because of its potential in both therapeutic application and in vitro modeling of diseases. In particular embryonic stem cells have good proliferative and differentiative abilities, but their use is still associated to ethical concerns and problems related to their teratogenic potential. Adult stem cells have also been described to be pluripotent both in vitro and in vivo. However, their use is limited because they are difficult to isolate and expand, particularly in a clinical setting. In this scenario, it would be advantageous to obtain a cell population with high selfrenewal and differentiation capacities, without ethical problems. In 2007 our group described that amniotic fluid stem (AFS) cells could be derived selecting amniocytes using c-Kit antibody. AFS cells have clonogenic capability and can be directed into a wide range of cell types representing the three primary embryonic lineages.
Aim: This work aiming at characterize the myogenic potential of mouse AFS cells using a mouse model of spinal muscular atrophy and in particular at analyzing their ability to differentiate into satellite cells and colonize the muscle stem cell niche.
Materials and Methods: Mouse AFS cells were obtained by amniocentesis and selected for the marker c-Kit with immunomagnetic beads. Freshly isolated AFS cells were analyzed for the expression of different markers (CD90, CD45, CD44, CD34, CD31, Flk1, SCA1, CD105) by flow cytometry and the expression of Oct4, Sox2, c-Myc, Klf4 and Sca-1 by qRT-PCR at different embryonic stages. For the treatment of HSA-Cre, SmnF7/F7 mutant mice, GFP+ AFS cells were injected via the tail vein and animals were sacrificed one and fifteen months after transplantation. Clinical aspects were observed and analyzed after transplantation to evaluate AFS cells’ effects. Several muscles were stained with hematoxylin and eosin, Masson’s trichrome and analyzed by immunofluorescence with anti-GFP and anti-dystrophin antibodies. To demonstrate the ability of AFS cells to replenish the muscle niche, staining for satellite cell markers and secondary transplantation were performed. The myogenic potential of AFS cells was also evaluated with transplantation after in vitro expansion.
Results: Mouse AFS cell number changes during the course of gestation. At E12.5 these cells express hematopoietic markers (CD45, CD34, SCA1), mesenchymal markers (CD90, CD105) together with Flk1, CD31 and CD44. Gene expression analysis showed that mouse AFS cells express at low levels Oct4 and Sox2 and at high levels c-Myc and Klf4, whereas they are negative for the expression of myogenic genes.
Mild muscular mutant HSA-Cre, SmnF7/F7 mice die at the age of 10 months and show evident clinical complications such as kyphosis and muscle shrinkage. After transplantation with GFP+ AFS or bone marrow (BM) cells mice survival rate increased by 75% and 50% respectively. Animals treated with AFS cells recovered more than 75% of force compared to the untreated. One month after transplantation, muscles obtained from AFS-treated mice displayed 37% of GFP+ fibers, with very low number of regenerating myofibers (<1%) and normal dystrophin expression. Fifteen months after transplantation BM-treated mice displayed a high number of central nucleated fibers and consistent infiltration of interstitial tissue and no GFP+ myofibers, while AFS-treated mice had a normalized phenotype, close to the same age WT mice, and 58% of the myofibers were GFP+. Similar results were obtained with transplantation of mouse AFS cells expanded in culture.
Discussion: Mouse AFS cells are a heterogeneous population, and their phenotype changes during the course of gestation. At E12.5 they express mesenchymal, hematopoietic and endothelial markers, but most importantly don not express myogenic factors, indicating that no myogenic progenitor cells are present in this stem cell population. When injected in a muscular mutant mouse model, AFS cells showed a myogenic potential, even after long-term transplantation, suggesting an interesting therapeutic potential. They indeed were able to differentiate into satellite cells localizing in the muscle stem cell niche and expressing Pax7, a7integrin and SM/c-2.6, exclusively markers of satellite cell population. Moreover, AFS cells could contribute to the formation of new myofibers even after in vitro expansion
Abordajes en el Área de Delitos Contra la Integridad Sexual de la Secretaría de la Mujer. Aportes del enfoque de derechos humanos y la perspectiva de género
Full text linkPráctica Pre Profesional (Licenciatura en Psicología) -- Universidad Nacional de Córdoba. Facultad de Psicología, 2025.Fil: Garais, Lara María. Universidad Nacional de Córdoba. Facultad de Psicología; Argentina.Fil: Piccoli, Martina. Universidad Nacional de Córdoba. Facultad de Psicología; Argentina.El presente Trabajo de Integración Final consiste en una sistematización de las Prácticas Pre-Profesionales del Contexto Jurídico realizadas en la Secretaría de la Mujer. El objetivo general fue analizar los abordajes que se realizan en el Área de Delitos Contra la Integridad Sexual de la Secretaría de la Mujer desde un Enfoque de Derechos Humanos y Perspectiva de Género, describiendo cada una de las instancias de abordaje y buscando profundizar acerca del rol de las psicólogas y el trabajo interdisciplinario. A tal fin realizamos un estudio descriptivo de tipo cualitativo, haciendo uso de técnicas de recolección de datos como la observación no participante de primeras entrevistas y seguimientos, la lectura de fichas institucionales y entrevistas semiestructuradas a las profesionales del equipo DIS. Como resultados principales encontramos que tanto el enfoque de derechos humanos como la perspectiva de género son transversales a todas las modalidades de abordaje y que los avances en materia teórica y legal han producido importantes cambios en los modos de trabajar con las víctimas de un delito contra la integridad sexual. Estos aportes atraviesan también el abordaje interdisciplinario, que resulta indispensable y al rol de las psicólogas, que en el área DIS está dirigido a la mirada clínica, a través de la escucha, contención, valoración de cada caso, la intervención sobre lo traumático, la evaluación de criterios de riesgo y el acompañamiento no sólo a las víctimas sino a sus familiares.Fil: Garais, Lara María. Universidad Nacional de Córdoba. Facultad de Psicología; Argentina.Fil: Piccoli, Martina. Universidad Nacional de Córdoba. Facultad de Psicología; Argentina
3D in vitro Models of Pathological Skeletal Muscle: Which Cells and Scaffolds to Elect?
Full text linkSkeletal muscle is a fundamental tissue of the human body with great plasticity and adaptation to diseases and injuries. Recreating this tissue in vitro helps not only to deepen its functionality, but also to simulate pathophysiological processes. In this review we discuss the generation of human skeletal muscle three-dimensional (3D) models obtained through tissue engineering approaches. First, we present an overview of the most severe myopathies and the two key players involved: the variety of cells composing skeletal muscle tissue and the different components of its extracellular matrix. Then, we discuss the peculiar characteristics among diverse in vitro models with a specific focus on cell sources, scaffold composition and formulations, and fabrication techniques. To conclude, we highlight the efficacy of 3D models in mimicking patient-specific myopathies, deepening muscle disease mechanisms or investigating possible therapeutic effects
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Evolution Strategies in Transaxillary Robotic Thyroidectomy: Considerations on the First 449 Cases Performed.
Full text linkBACKGROUND: In the past 20 years, the fast spread of new surgical technologies has reached an important peak with the advent of the robotic surgery. Many studies have been run about a cosmetic desire to avoid neck scars after thyroid surgery and this has led to the development of remote access robotic thyroidectomy (RT). Among the various RT approaches, unilateral transaxillary access is one of the most widely used, reporting excellent results in terms of feasibility and patient's compliance. The mini-invasive technique demonstrated many potential shortcoming overcomes with the robotic approach. At our institution a team of 3 skilled endocrine surgeons with experience in laparoscopic and robotic procedures performed RT. Our aim is to report our 8-year single-centre robot-assisted thyroidectomy experience, by applying a gasless unilateral transaxillary approach with the so-called hybrid technique, and to demonstrate its safety and feasibility.
METHODS:
In the period between September 2010 and June 2018 at our institution, a total of 472 patients underwent thyroid and parathyroid transaxillary surgery. The hybrid technique was applied for all the robotic procedures. A total of 412 procedures were performed with the use of external "Modena Retractor" (CEATEC® Medizintechnik) and with 3 surgeons. According to international guidelines, our indications for robotic surgery were benign lesions with a diameter <5 cm, Graves' disease, well-differentiated thyroid cancers, and parathyroid adenomas.
RESULTS:
In this series, a total of 449 cases were registered. General data of patients were analyzed: gender, age, body mass index, tumor size, preoperative fine-needle aspiration examination, definitive histological examination, operative time, and postoperative complications.
CONCLUSIONS:
This study confirms the application of robotic approach in thyroid surgery as a feasible technique in terms of safety and complications risk. The hybrid technique, together with a dedicated surgical team, can lead to obtaining the same outcomes of traditional anterior cervicotomic surgery, adding a scarless thyroidectomy
Sources of mesenchymal stem cells: current and future clinical use
No full textDespitethelackofinternationalcriteriadefiningthebiologicalproperties and surface markers that must possess mesenchymal stem cells (MSC), it become of paramount importance to know the different sources and the clinical applications of these promising stem cells. In this chapter we overview the most important sources of MSC from the inner cell mass of the blastocyst to the adult source and landing to the induced pluripotent stem cells (iPS). Following the criteria defining MSC properties so far observed, we drew the attention on the role of MSC as tool for regenerative medicine and therapeutic purposes
An Overview of 3D Bioprinting Impact on Cell Viability: From Damage Assessment to Protection Solutions
No full textThree-dimensional (3D) bioprinting has become a widely exploited tissue engineering technique for producing functional constructs that can mimic and replace native tissues. To this end, different printing strategies can be adopted, including inkjet-based, light-assisted, and extrusion-based bioprinting. Despite the great improvements that these innovative techniques introduce, cell viability maintenance during and after the bioprinting process remains a challenging open question. Indeed, the reduction in cell viability is generally related to several crucial conditions during printing, such as high shear stresses and a nutrient-deficient environment of printed constructs. In this work, the current literature on 3D bioprinting technologies is reviewed, focusing on the level of cell damage that can be imparted during biomaterial printing. In particular, extrusion bioprinting, extrusion-associated shear stress and its impact on cell viability are described in detail. The simulation of the bioprinting process through computational fluid dynamics is proposed as an appropriate method to analyze the parameters involved during bioprinting. Moreover, the viability of cells encapsulated into bioink is discussed, as well as literature techniques aimed at enhancing it by both biomaterial modifications and cell micro-encapsulation
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