670 research outputs found
Human Placenta-Derived Mesenchymal Stromal Cells: A Review from Basic Research to Clinical Applications
Placenta-derived mesenchymal stem/stromal cells (PMSC) present several aspects that make them more attractive as cellular therapy than their counterparts from other tissues, such as MSC from bone marrow or adipose tissue in regenerative medicine. Placenta-derived MSC have been used to treat a variety of disorders, such as, cancer, liver and cardiac diseases, ulcers, bone repair, and neurological diseases. Placenta-derived MSC are relatively new types of MSC with specific immunomodulatory properties and whose mechanisms are still unknown. Placenta-derived MSC secrete some soluble factors that seem to be responsible for their therapeutic effects, i.e., they have paracrine effects. On the other hand, Placenta-derived MSC can also serve as cellular vehicles and/or delivery systems for medications due to their migration capacity and their tropism for injury sites. Nanotechnology is an important field, which has undergone rapid development in recent years for the treatment of injured organs. Due to the special characteristics of placenta-derived MSC, the combination of these cells with nanotechnology will be a significant and highly promising field that will provide significant contributions in the regenerative medicine field in the near future
Identification of sequence similarity between 60 kDa and 70 kDa molecular chaperones: evidence for a common evolutionary background?
Análisis de máxima tensión compresiva en incisivos centrales superiores rehabilitados con postes de fibra de vidrio y tres tipos de coronas. Un estudio con método de elementos finitos.
Objective: To evaluate the maximum compressive stress in maxillary central incisors restored with fiberglass posts and three types of crowns by the FEM finite element method. Materials and methods: The study was a virtual, descriptive, and laboratory trial. Three virtual models were made using the SolidWorks 2017 software from upper central incisors rehabilitated with fiberglass posts and a metal-ceramic crown, a monolithic lithium disilicate crown, and a zirconium-ceramic crown. They were then subjected to an oblique occlusal load of 150N with an angulation of 45°, distributed towards the palatal aspect. The stress analysis proceeded by comparing the maximum, minimum, and equivalent von Mises stresses. Results: The maximum compressive stress was found at the cervical level in the vestibular area of each of the crowns. Zirconium-ceramic crown (Design 3) was the one with the highest compressive stress with 73.89 MPa, followed by Lithium Disilicate crown (Design 2) with 63.42 MPa and the metal-ceramic crown (Design 1) with 48.4 MPa. Conclusion: The zirconium-ceramic crown better distributes the stress along the tooth since, due to its rigidity, it absorbs the stresses that are concentrated especially in the cervical area, which could indicate that it is the most appropriate option to rehabilitate endodontically treated teeth.Objetivo: Evaluar la máxima tensión compresiva en incisivos centrales superiores restaurados con postes de fibra de vidrio y tres tipos de coronas por método de elementos finitos MEF. Materiales y métodos: El estudio fue un ensayo de laboratorio virtual y descriptivo. Se confeccionaron 3 modelos virtuales mediante el programa SolidWorks 2017, a partir de incisivos centrales superiores rehabilitados con postes de fibra de vidrio y corona metal-cerámica, corona de disilicato de litio monolítica y corona de zirconio-cerámica; luego, estos fueron sometidos a una carga oclusal oblicua de 150 N con una angulación de 45°, distribuida hacia la cara palatina. El análisis de las tensiones se realizó mediante la comparación de las tensiones máximas, mínimas y equivalentes de Von Mises. Resultados: La máxima tensión compresiva se encontró a nivel cervical en la zona vestibular de cada una de las coronas, siendo el diseño 3 (corona de zirconio-cerámica) el que presentó mayor tensión compresiva, con 73,89 MPa, seguido por el diseño 2 (corona de disilicato de litio), con 63,42 MPa, y el diseño 1 (corona metal-cerámica), con 48,4 MPa. Conclusión: La corona zirconio-cerámica distribuye mejor la tensión a lo largo del diente, ya que, por su rigidez, absorbe las tensiones que se concentran especialmente en cervical, lo que podría indicar que es la opción más apropiada para rehabilitar dientes tratados endodónticamente
Transformaciones de haz mediante microlentes selfoc activas
[EN]: In this paper light propagation in an active selfoc microlens with complex refractive index and gradient parameter are examined. The ray-transfer matrix of an active material regarded as a diffraction-free first order optical system is presented to describe the beam transformations in active selfoc microlenses. Results concerning Gaussian beam transformationsand on-axis irradiance through the active selfoc microlens are discussed and commented. © Sociedad Española de Óptica.[ES]: En este trabajo se estudia la propagación de la luz a través de una microlente selfoc activa con un índice de refracción y parámetro de gradiente complejos. La matriz de transferencia de rayos, vista como un sistema óptico de primer orden libre de efectos de difracción, es introducida para describir las transformaciones que puede sufrir un haz en microlentes selfoc activas. Por último se presentan y comentan los resultados correspondientes a las transformaciones de haces Gaussianos y a la irradiancia en eje a través de la microlente selfoc activa.This work has been sponsored by Xunta de Galicia/Feder (INCITE08PXIB206013PR), Ministerio de Ciencia e Innovación (MAT2010-18519) and CDTI (SURFALUX SOL-00030930), Spain. Besides, Ana I. Gomez-Varela wants to acknowledge the financial support from the FPU (Formación de Profesorado Universitario) grant 2009 (Ministerio de Educación, Spain).Peer Reviewe
Decidua-derived mesenchymal stem cells as carriers of mesoporous silica nanoparticles. In vitro and in vivo evaluation on mammary tumors
The potential use of human Decidua-derived mesenchymal stem cells (DMSCs) as a platform to carry mesoporous silica nanoparticles in cancer therapy has been investigated. Two types of nanoparticles were evaluated. The nanoparticles showed negligible toxicity to the cells, a fast uptake and a long retention inside them. Nanoparticle location in the cell was studied by colocalization with the lysosomes. Moreover, the in vitro and in vivo migration of DMSCs towards tumors was not modified by the evaluated nanoparticles. Finally, DMSCs transporting doxorubicin-loaded nanoparticles were capable of inducing cancer cell death in vitro
Vectorization of ultrasound-responsive nanoparticles in placental mesenchymal stem cells for cancer therapy
A new platform constituted by engineered responsive nanoparticles transported by human mesenchymal stem cells is here presented as a proof of concept. Ultrasound-responsive mesoporous silica nanoparticles are coated with polyethylenimine to favor their effective uptake by decidua-derived mesenchymal stem cells. The responsive-release ability of the designed nanoparticles is confirmed, both in vial and in vivo. In addition, this capability is maintained inside the cells used as carriers. The migration capacity of the nanoparticle-cell platform towards mammary tumors is assessed in vitro. The efficacy of this platform for anticancer therapy is shown against mammary tumor cells by inducing the release of doxorubicin only when the cell vehicles are exposed to ultrasound
The acute asymmetric effects of hemiovariectomy on testosterone secretion vary along the estrous cycle. The participation of the cholinergic system
The presence of asymmetry in the capacity of the left and right ovaries to secrete testosterone was analyzed by studying the effects of hemiovariectomy along the estrus cycle one hour after surgery. The effects of ether anesthesia on hormone serum levels were also analyzed. Bilateral ovariectomy and the extirpation of the left ovary performed on the day of proestrus resulted in significantly lower testosterone levels. Compared to the anesthetized group, the effects of perforating the peritoneum unilaterally varied according to the day of the estrous cycle and the side of the peritoneum surgery was performed on. Injecting atropine sulfate (ATR) to control or anesthetized rats on D1 resulted in a significant increase of testosterone serum levels. The effects of perforating the peritoneum on testosterone levels depended on the cholinergic innervation and varied along the estrous cycle. Blocking the cholinergic system before performing unilateral or bilateral ovariectomy had different effects depending on the day of the estrous cycle. Testosterone plasma levels increased significantly when surgery was performed on the day of diestrus and dropped when surgery was performed on proestrus. Similar effects were observed when the left adrenal was extirpated from animals with the cholinergic system blocked. The results presented herein support the hypothesis of asymmetry in the ovaries' abilities to secrete steroid hormones, and that the capacity to secrete testosterone varies along the estrous cycle
La Cueva de Castañar y su centro de interpretación
Comunicación presentada en Cuevatur 2016: VI Congreso Español sobre Cuevas Turísticas, Nerja (Málaga), 2016.[ES] La Cueva de Castañar constituye una cavidad única tanto por la variedad de minerales y formas de sus espeleotemas,
como por el tono rojizo de sus paredes. Estas dos características responden a las características de los materiales sobre
los que se desarrolla la cueva. Son materiales correspondientes al Ediácarico (635-541 M.a.), que incluyen una amplia
variedad de rocas (dolomías, magnesitas, pizarras y areniscas). Estos materiales, muy ricos en magnesio y sílice, son
los que se disuelven y alteran para dar lugar a la formación de la cavidad y de sus espeleotemas. La alteración de las
pizarras y areniscas, la disolución de las dolomías y magnesitas y la infiltración de arcillas desde el suelo dan lugar a la
formación de un fino tapiz de color rojo intenso que se deposita sobre las paredes de la cueva, sobre el que muchas
veces nuclean los espeleotemas. La disolución de las dolomías y magnesitas aporta mucho magnesio a las aguas que
circulan por la cueva, lo cual favorece la formación no sólo de calcita (que es lo habitual), sino también de aragonito.
Pero además la composición de las aguas no se ha mantenido constante, lo que ha favorecido que se produjeran
muchas transformaciones entre los minerales ya formados. En definitiva, el amplio espectro mineralógico y las variadas
transformaciones mineralógicas que se observan en la cueva, hacen de esta un laboratorio natural y por tanto una
cavidad única, que se debe conocer, para así poderla conservar en las mejores condiciones posibles. Estas condiciones
son las que hacen que el número de visitantes sea muy limitado, por ello el Centro de Interpretación inaugurado en
2010, cumple sobradamente la labor de dar a conocer los valores únicos de la Cueva de Castañar.[EN] Castañar Cave is a unique cavity due to the variety and morphology of the speleothems it contains, as well as to the
red colour of their walls. These characteristics are due to the hostrocks in which it developed, Ediacaric (635-541 M.a)
dolostones, magnesites and siliciclastic rocks. These materials very rich in Mg and silica, weather and dissolve to give
place to the formation of the cavity and their speleothems. The weathering of the siliciclastic rocks, the dissolution of
dolostones and magnesites and the infiltration of the clays from the overlying soil, allows the formation of a thin red
(clays and Fe-oxides) layer that coats the cavity, and constitute the nucleation site for many speleothems. The dissolution of dolostones and magnesites supplies Mg to the cave waters enabling the formation not only of calcite, but also
aragonite and dolomite (which are rarer in caves). In addition water cave composition has changed over time, allowing
many transformations between the previously formed minerals. When relatively more dilute waters prevail aragonite
transforms into calcite or even both can dissolve, forming the large pores visible in some speleothems. On the contrary
Mg-rich minerals (huntite, dolomite and Mg-rich clays) form in more concentrated waters. In short, the wide mineralogical
spectra and their transformations make this cave a unique cavity and a natural lab, whose detailed study will
help to preserve it under the best possible conditions. This is why the number of visitors is very limited; however the
renewed Centro de Interpretación shows in great detail the characteristics of the Castañar Cave.Este trabajo se incluye en los proyectos: “Estudio ambiental y geológico del Monumento Natural
Cueva de Castañar”, financiado por fondos FEADER (contrato Gobierno de Extremadura
y CSIC) y CGL2014-54818P del MINECO.Peer reviewe
Cell therapy for factor V deficiency: an approach based on human decidua mesenchymal stem cells
Deficiency of factor V is a congenital autosomal recessive coagulopathy associated with mutations in the F5 gene that results in mild-to-severe bleeding episodes. Factor V is a component of the prothrombinase complex responsible for accelerating conversion of prothrombin to thrombin. At the present time there are no therapeutic factor V concentrates available. This study was designed to lay the preliminary foundations for future cell-based therapy for patients with severe factor V deficiency. The study showed that hepatospheres, which produce coagulation factors VIII, IX, and V, synthetize and store intracellular glycogen and express albumin levels up to 8 times higher than those of undifferentiated cells. Factor IX and factor V gene expression increased significantly in hepatospheres as compared to undifferentiated cells, whereas factor VIII gene expression remained constant. The factor V protein was detected in the hepatospheres´ secretome. Considering the enormous potential of mesenchymal stem cells as therapeutic agents, this study proposes a highly reproducible method to induce differentiation of mesenchymal stem cells from human placenta to factor V-producing hepatospheres. This strategy constitutes a preliminary step towards a curative treatment of factor V deficiency through advanced therapies such as cell therapy
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