339 research outputs found
Free evolution of an incoherent mixture of states: a quantum mechanical approach to the van Cittert-Zernike theorem
We study the time evolution of an incoherent mixture of quantum states and demonstrate, in very simple terms, a quantum mechanical equivalent of van Cittert–Zernike theorem, which can be easily explained to Quantum Physics students with a basic knowledge of the density matrix theory. Finally, we exemplify this result by applying it to the quantitative analysis of the coherence of a beam of particles in atomic collisions.Fil: Fabre, Ignacio. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Navarrete, Francisco Oscar. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sarkadi, L.. Hungarian Academy of Sciences; HungríaFil: Barrachina Tejada, Raul Oscar. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
The usefulness of mesenchymal stem cells beyond the musculoskeletal system in horses
The differentiation ability of mesenchymal stem cells (MSCs) initially raised interest for treating musculoskeletal injuries in horses, but MSC paracrine activity has widened their scope for inflammatory and immune-mediated pathologies in both equine and human medicine. Further-more, the similar etiopathogenesis of some diseases in both species has advanced the concept of “One Medicine, One Health”. This article reviews the current knowledge on the use of MSCs for equine pathologies beyond the locomotor system, highlighting the value of the horse as translational model. Ophthalmologic and reproductive disorders are among the most studied for MSC application. Equine asthma, equine metabolic syndrome, and endotoxemia have been less explored but offer an interesting scenario for human translation. The use of MSCs in wounds also provides a potential model for humans because of the healing particularities in both species. High-burden eq-uine-specific pathologies such as laminitis have been suggested to benefit from MSC-therapy, and MSC application in challenging disorders such as neurologic conditions has been proposed. The available data are preliminary, however, and require further development to translate results into the clinic. Nevertheless, current evidence indicates a significant potential of equine MSCs to enlarge their range of application, with particular interest in pathologies analogous to human conditions
Practical considerations for clinical use of mesenchymal stem cells: From the laboratory to the horse
Since the clinical use of mesenchymal stem cells (MSCs) for treating musculoskeletal injuries is gaining popularity, practitioners should be aware of the factors that may affect MSCs from tissue harvesting for MSC isolation to cell delivery into the injury site. This review provides equine practitioners with up-to-date, practical knowledge for the treatment of equine patients using MSCs. A brief overview of laboratory procedures affecting MSCs is provided, but the main focus is on shipping conditions, routes of administration, injection methods, and which commonly used products can be combined with MSCs and which products should be avoided as they have deleterious effects on cells. There are still several knowledge gaps regarding MSC-based therapies in horses. Therefore, it is important to properly manage the factors which are currently known to affect MSCs, to further strengthen the evidence basis of this treatment
Differentiation of equine bone marrow derived mesenchymal stem cells increases the expression of immunogenic genes
Mesenchymal stem cells (MSCs) are a promising treatment for equine musculoskeletal injuries because of their ability to regulate the inflammation and to differentiate into other cell types. Since interest in allogeneic therapy is rising, concerns about MSC immunogenicity need to be addressed. Differentiated MSCs from several species increase their expression of immunogenic molecules and induce alloresponses, but equine MSC immunogenic profile after differentiation has not been reported. Therefore, the aim of this study was to assess the gene expression of immunogenic markers in tri-lineage differentiated equine bone marrow derived MSCs (eBM-MSCs). For this purpose, eBM-MSCs (n = 4) were differentiated into osteoblasts, adipocytes and chondrocytes. Differentiation was confirmed by specific staining and gene expression of lineage-related markers. Subsequently, gene expression of MHC-I, MHC-II, CD40 and CD80 was analyzed in undifferentiated (control) and tri-lineage differentiated eBM-MSCs. Osteogenesis and adipogenesis, but not chondrogenesis, significantly upregulated MHC-I; MHC-II expression significantly increased in the three lineages, while CD40 and CD80 expression did not change. Despite this, MHC-I and MHC-II upregulation after differentiation might lead to increased immunogenicity and risk of allorecognition, either eBM-MSCs differentiate in vivo after administration or they are differentiated prior to administration, with potential negative consequences for effectiveness and safety of allogeneic therapy
Assessment of the effect of a new technique for laparoscopic partial closure of the inguinal canal on sperm production and testicular perfusion in stallions
In order to simplify other laparoscopic techniques, a new standing laparoscopic technique for partial closure of inguinal canal (PCIC) has been developed. This technique uses a new anchoring device and can be performed without advanced laparoscopic skills. The aim of this study was to develop a prior evaluation of the effects of this new technique on the stallion reproductive capacity, assessing the sperm production and testicular perfusion. Standing laparoscopic PCIC was performed unilaterally in 8 experimental stallions without evidence of inguinal hernia, using the contralateral canal and testicle as control
Humoral immune response against allogeneic equine mesenchymal stem cells (MSCs) mediated by the major histocompatibility complex (MHC): an issue to take into account for the safety and efficacy of treatment with MSCs
Allogeneic mesenchymal stem cells (MSCs) present several advantages, but recipient immune response needs to be further elucidated. Proinflammatory priming of MSCs activated their in vivo regulatory capacity, but repeated administrations led to slight inflammatory reaction in an osteoarthritis equine model. This may be associated with higher major histocompatibility complex (MHC) expression, which would increase MSC immunogenicity potentially inducing humoral mediated immune memory. This study aimed at assessing allo-antibody production against donor’s equine MHC (equine leukocyte antigen, ELA) in animals that received intra-articular repeated administration of allogeneic MSC-primed. For this purpose, we used stored samples from a previous study. Donor and recipients ELA-haplotypes were stablished by microsatellite typing and complementmediated microcytoxicity assays were carried out by exposing target cells from the donor (unstimulated MSCs [MSC-nai¨ve], MSC-primed or lymphocytes [control]) to sera collected at different time-points from 10 recipients: ELA-mismatched MSCnai ¨ve recipients, ELA-mismatched MSC-primed recipients or ELA-partially matched MSC-primed recipients. All animals receiving allogeneic MSCs produced allo-antibodies after the first injection, regardless of the matching degree. However, antibody peak production after second administration was only observed in ELA-mismatched recipients, both of MSC-nai¨ve and MSCprimed. Horses injected with MSC-primed produced fewer antibodies but MSC-primed were more targeted in the microcytoxicity assay. Thus, activated immunomodulatory profile of MSC-primed could have led to slighter humoral response after ..
Mesenchymal stromal cells for articular cartilage repair: preclinical studies
Rheumatic diseases such as osteoarthritis (OA) are a major social and economic burden because of the population aging and the lack of curative solutions. An effective cell therapy may be the best treatment option for OA and other cartilage diseases. However, the main cellular strategy used to repair articular cartilage, the transplantation of autologous chondrocytes, is limited to a small number of patients with traumatic lesions. The use of joint replacement after years of disease progression proves the great medical need in current practice. Mesenchymal stromal/stem cells (MSCs) provide an alternative cell source for cartilage regeneration due to numerous advantages, comprising relative ease to isolate and culture, chondrogenic capacity, and anti-inflammatory effects. Initial clinical trials with MSCs have led to encouraging results, but many variables have to be considered to attain true amelioration of disease or repair (type and status of cartilage disease, source and conditions of cells, administration regime, combinatorial approaches). Particularly, allogeneic MSCs are an advantageous cellular product. The animal models chosen for preclinical evaluation are also relevant for successful translation into clinical practice. Considering the limitations in the field, rigorous comparative and validating studies in well-established animal models (including large animals) are still needed to set up the bases for additional clinical trials. The present review of studies performed in small and large animal models should help clarify the applicability of MSC-based therapies for articular cartilage repair
Analysis of platelets from a diet-induced obesity rat model: elucidating platelet dysfunction in obesity
Obesity is one of the main health problems in industrialized countries. The contribution of multiple factors developed in obesity can hardly be modeled in vitro. In this context, the development of animal models mimicking human obesity could be essential. The aim of the present study was to compare platelets from a diet-induced obesity (DIO) rat model with their lean control group in order to elucidate platelet dysfunction mechanisms in obesity and correlate the results with previous data from morbid obese patients. In parallel, we also established a blood collection and platelet isolation methodology to study the DIO rat model at biochemical and functional level. Optimal blood collection was obtained from vena cava and platelet isolation was based on a serial of centrifugations avoiding platelet activation. Our results show that the DIO rat model simulate obesity pathologically since weight gain, fasting glucose and platelet counts are increased in obese rats. Interestingly, platelet levels of the active form of Src (pTyr(419)) showed a tendency to increase in DIO rats pointing towards a potential dysfunction in Src family kinases-related signalling pathways in obesity. Moreover, platelets from DIO rats adhere more to collagen compared with the control group, pointing towards Glycoprotein VI (GPVI) as one of the dysregulated receptors in obesity, in agreement with our recent studies in humans. These results confirm that obesity, in line with human studies, present a platelet dysregulation, and highlight the relevance of considering novel antithrombotic drug targets in these patients, such as GPVI
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