28 research outputs found
Muscle-derived stem/progenitor cell dysfunction in Zmpste24-deficient progeroid mice limits muscle regeneration
Introduction. Loss of adult stem cell function during aging contributes to impaired tissue regeneration. Here, we tested the aging-related decline in regeneration potential of adult stem cells residing in the skeletal muscle. Methods. We isolated muscle-derived stem/progenitor cells (MDSPCs) from progeroid Zmpste24-deficient mice (Zmpste24§ssup§-/-§esup§) with accelerated aging phenotypes to investigate whether mutation in lamin A has an adverse effect on muscle stem/progenitor cell function. Results: Our results indicate that MDSPCs isolated from Zmpste24§ssup§-/- §esup§mice show reduced proliferation and myogenic differentiation. In addition, Zmpste24§ssup§-/- §esup§MDSPCs showed impaired muscle regeneration, with a limited engraftment potential when transplanted into dystrophic muscle, compared with wild-type (WT) MDSPCs. Exposure of progeroid Zmpste24§ssup§-/- §esup§MDSPCs to WT MDSPCs rescued the myogenic differentiation defect in vitro. Conclusions: These results demonstrate that adult stem/progenitor cell dysfunction contributes to impairment of tissue regeneration and suggest that factors secreted by functional cells are indeed important for the therapeutic effect of adult stem cells. © 2013 Song et al.; licensee BioMed Central Ltd
Recurrent hepatitis in two iranian children: A novel (Q166R) mutation in EIF2AK3 leading to wolcott-rallison syndrome
Early-onset diabetes, liver dysfunction, growth retardation, spondyloepiphyseal dysplasia, and tendency to skeletal fractures due to osteopenia are characteristics of Wolcott-Rallison syndrome (WRS). Eukaryotic translation initiation factor 2α kinase (EIF2AK3) is the only known gene, which is responsible for this rare autosomal recessive disorder. Here, we report two siblings a girl and a boy with diabetes mellitus (DM) who presented in one and two months of age respectively. Recurrent self-limiting hepatitis developed later, and severe hepatic failure resulted in death of the first child. The second child visited was a 7.75 year old boy who had spondyloepiphyseal dysplasia and subclinical hypothyroidism besides DM and recurrent hepatitis. We suggested WRS for this patient, and it was confirmed by identification of a novel homozygous missense mutation (Q166R) in exon 3 of the EIF2AK3 gene. The aim of this report is to remind the possibility of WRS in isolated neonatal diabetes; while, the other clinical manifestations of this syndrome including its major symptom of recurrent hepatitis may appear later. © 2013, Kowsar Corp
Subjective and objective measures
One of the greatest challenges in the study of emotions and emotional states is their measurement. The techniques used to measure emotions depend essentially on the authors’ definition of the concept of emotion. Currently, two types of measures are used: subjective and objective. While subjective measures focus on assessing the conscious recognition of one’s own emotions, objective measures allow researchers to quantify and assess the conscious and unconscious emotional processes. In this sense, when the objective is to evaluate the emotional experience from the subjective point of view of an individual in relation to a given event, then subjective measures such as self-report should be used. In addition to this, when the objective is to evaluate the emotional experience at the most unconscious level of processes such as the physiological response, objective measures should be used. There are no better or worse measures, only measures that allow access to the same phenomenon from different points of view. The chapter’s main objective is to make a survey of the main measures of evaluation of the emotions and emotional states more relevant in the current scientific panorama.info:eu-repo/semantics/acceptedVersio
Platelet-Rich Plasma Promotes the Proliferation of Human Muscle Derived Progenitor Cells and Maintains Their Stemness
Human muscle-derived progenitor cells (hMDPCs) offer great promise for muscle cell-based regenerative medicine; however, prolonged ex-vivo expansion using animal sera is necessary to acquire sufficient cells for transplantation. Due to the risks associated with the use of animal sera, the development of a strategy for the ex vivo expansion of hMDPCs is required. The purpose of this study was to investigate the efficacy of using platelet-rich plasma (PRP) for the ex-vivo expansion of hMDPCs. Pre-plated MDPCs, myoendothelial cells, and pericytes are three populations of hMDPCs that we isolated by the modified pre-plate technique and Fluorescence Activated Cell Sorting (FACS), respectively. Pooled allogeneic human PRP was obtained from a local blood bank, and the effect that thrombin-activated PRP-releasate supplemented media had on the ex-vivo expansion of the hMDPCs was tested against FBS supplemented media, both in vitro and in vivo. PRP significantly enhanced short and long-term cell proliferation, with or without FBS supplementation. Antibody-neutralization of PDGF significantly blocked the mitogenic/proliferative effects that PRP had on the hMDPCs. A more stable and sustained expression of markers associated with stemness, and a decreased expression of lineage specific markers was observed in the PRP-expanded cells when compared with the FBS-expanded cells. The in vitro osteogenic, chondrogenic, and myogenic differentiation capacities of the hMDPCs were not altered when expanded in media supplemented with PRP. All populations of hMDPCs that were expanded in PRP supplemented media retained their ability to regenerate myofibers in vivo. Our data demonstrated that PRP promoted the proliferation and maintained the multi-differentiation capacities of the hMDPCs during ex-vivo expansion by maintaining the cells in an undifferentiated state. Moreover, PDGF appears to be a key contributing factor to the beneficial effect that PRP has on the proliferation of hMDPCs. © 2013 Li et al
Social media marketing strategy: definition, conceptualization, taxonomy, validation, and future agenda
Although social media use is gaining increasing importance as a component of firms’ portfolio of strategies, scant research has systematically consolidated and extended knowledge on social media marketing strategies (SMMSs). To fill this research gap, we first define SMMS, using social media and marketing strategy dimensions. This is followed by a conceptualization of the developmental process of SMMSs, which comprises four major components, namely drivers, inputs, throughputs, and outputs. Next, we propose a taxonomy that classifies SMMSs into four types according to their strategic maturity level: social commerce strategy, social content strategy, social monitoring strategy, and social CRM strategy. We subsequently validate this taxonomy of SMMSs using information derived from prior empirical studies, as well with data collected from in-depth interviews and a quantitive survey among social media marketing managers. Finally, we suggest fruitful directions for future research based on input received from scholars specializing in the field
Aridity trend and response to vegetation restoration in the loess hilly region of northern Shaanxi Province
Application of an indirect MilA ELISA for the detection of Mycoplasma bovis antibodies in bovine milk
The objective of this study was to detect Mycoplasma bovis specific antibodies using a recently reported MilA ELISA with the aim to detect M. bovis antibodies in milk. An indirect ELISA, based on a recombinant fragment of the Mycoplasma immunogenic lipase A (MilA) protein, was conducted on 291 milk samples for the detection of M. bovis antibodies. Samples were also tested with conventional Mycoplasma culture and M. bovis PCR. Samples were collected from individual cows from 2 commercial dairy herds in South Australia. Of 291 samples tested, 68 (23.4%) were detected positive for M. bovis antibodies, 150 (51.5%) were positive for M. bovis in PCR and 166 (57.0%) in bacterial culture. These results indicate that MilA indirect ELISA can be utilized for the detection of M. bovis antibodies in milk