200 research outputs found

    Multi-Level Issues in International HRM: Mean Differences, Explained Variance, and Moderated Relationships

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    [Excerpt] While neither denying that differences in HR systems exist, nor that some of the variety of practices is due to real differences across countries, we will attempt to dissect the issue of International HRM using ideas, concepts, and models emerging from multilevel theory and research. We posit that three ideas are critical to this line of research: Mean differences in the use of HR practices across countries, the amount of variance in HR practices that is explained by countries, and the extent to which countries (or specifically culture) moderates the relationships between HR practices and outcomes. Our conclusion is that these differences may not be as large as we think they are, and may in fact be due less to differences in culture and more to differences in institutional contexts

    Making Visible the Invisible: Social Justice and Inclusion through the Collaboration of Museums and Spanish Community-Based Learning Projects

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    Concerns about inclusion and social responsibility as conduit for social justice on university campuses offer a platform for interdisciplinary initiatives. Here we focus on one such initiative, which seeks to build community between University of Richmond students and local Latino and Hispanic populations using the University of Richmond Museum collection. Collaborations between museums and Spanish classes, including a community-based learning component (Spanish Community-Based Learning and Museums - SCBLM), provide outreach to the local community and might prompt dialogues about extant social injustices (however overt or subliminal). In these experiential learning projects, the museum serves as a communal resource to embody ACTFL’s Five C’s of language teaching (communication, cultures, connections, comparisons, communities). The SCBLM engagements, typically Spanish museum tours, encourage social awareness, connections, and social justice by way of empathetic inclusion. This paper explains the vision (objectives) of this practice (community-based learning) and the outcomes (implications) with university students; for support, we use research from museum studies, language teaching, and critical pedagogy. As a new endeavor in academic and museum scholarship, this paper provides a model for interdisciplinary teaching and research. Finally, we state the necessity for student-community inclusive projects within universities, as they allow for a more socially aware, empathetic, and connected community

    Synovial Fluid Biomarkers for the Prediction of Patient Outcome following Microfracture or Osteotomy

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    ObjectivesThe ability to predict which patients will improve following routine surgeries aimed at preventing the progression of osteoarthritis is needed to aid patients being stratified to receive the most appropriate treatment. This study aimed to investigate the potential of a panel of biomarkers for predicting (prior to treatment) the clinical outcome following treatment with microfracture or osteotomy.MethodsProteins known to relate to OA severity, with predictive value in autologous cell implantation treatment or that had been identified in proteomic analyses (aggrecanase-1/ ADAMTS-4, cartilage oligomeric matrix protein (COMP), hyaluronic acid (HA), Lymphatic Vessel Endothelial Hyaluronan Receptor-1, matrix metalloproteinases-1 and -3, soluble CD14, S100 calcium binding protein A13 and 14-3-3 protein theta) were assessed in the synovial fluid (SF) of 19 and 13 patients prior to microfracture or osteotomy, respectively, using commercial immunoassays. Levels of COMP and HA were measured in the plasma of these patients. To find predictors of postoperative function, multiple linear regression analyses were performed.ResultsLinear regression analyses demonstrated that a lower concentration of HA in pre-operative SF was predictive of improved knee function (higher Lysholm score) following microfracture surgery. Further, lower pre-operative activity of ADAMTS-4 in SF was a significant, independent predictor of higher post-operative Lysholm score (improved joint function) following osteotomy surgery.ConclusionThis study is novel in identifying biomarkers with the potential to predict clinical outcome in patients treated with microfracture or osteotomy of the knee. Lower concentrations of HA and undetectable activity of ADAMTS-4 in the joint fluid of individuals with cartilage defects/early-OA may be used in algorithms to stratify patients to the most appropriate surgery

    Temporal Analyses of the Response of Intervertebral Disc Cells and Mesenchymal Stem Cells to Nutrient Deprivation

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    Much emphasis has been placed recently on the repair of degenerate discs using implanted cells, such as disc cells or bone marrow derived mesenchymal stem cells (MSCs). This study examines the temporal response of bovine and human nucleus pulposus (NP) cells and MSCs cultured in monolayer following exposure to altered levels of glucose (0, 3.15, and 4.5?g/L) and foetal bovine serum (0, 10, and 20%) using an automated time-lapse imaging system. NP cells were also exposed to the cell death inducers, hydrogen peroxide and staurosporine, in comparison to serum starvation. We have demonstrated that human NP cells show an initial "shock" response to reduced nutrition (glucose). However, as time progresses, NP cells supplemented with serum recover with minimal evidence of cell death. Human NP cells show no evidence of proliferation in response to nutrient supplementation, whereas MSCs showed greater response to increased nutrition. When specifically inducing NP cell death with hydrogen peroxide and staurosporine, as expected, the cell number declined. These results support the concept that implanted NP cells or MSCs may be capable of survival in the nutrient-poor environment of the degenerate human disc, which has important clinical implications for the development of IVD cell therapies

    The synovial fluid from patients with focal cartilage defects contains mesenchymal stem/stromal cells and macrophages with pro- and anti-inflammatory phenotypes

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    Objective The synovial fluid (SF) of patients with focal cartilage defects contains a population of poorly characterised cells that could have pathophysiological implications in early osteoarthritis and joint tissue repair. We have examined the cells within SF of such joints by determining their chondrogenic capacity following culture expansion and establishing the phenotypes of the macrophage subsets in non-cultured cells. Design Knee SF cells were obtained from 21 patients receiving cell therapy to treat a focal cartilage defect. Cell surface immunoprofiling for stem cell and putative chondrogenic markers, and the expression analysis of key chondrogenic and hypertrophic genes were conducted on culture-expanded SF cells prior to chondrogenesis. Flow cytometry was also used to determine the macrophage subsets in freshly isolated SF cells. Results Immunoprofiling revealed positivity for the monocyte/macrophage marker (CD14), the haematopoietic/endothelial cell marker (CD34) and mesenchymal stem/stromal cell markers (CD73, CD90, CD105) on culture expanded cells. We found strong correlations between the presence of CD14 and the vascular cell adhesion marker, CD106 (r=0.81, p=0.003). Collagen type II expression after culture expansion positively correlated with GAG production (r=0.73, p=0.006), whereas CD90 (r=-0.6, p=0.03) and CD105 (r=-0.55, p=0.04) immunopositivity were inversely related to GAG production. Freshly isolated SF cells were positive for both pro- (CD86) and anti-inflammatory markers (CD163 and CD206). Conclusions The cellular content of the SF from patients with focal cartilage injuries is comprised of a heterogeneous population of reparative and inflammatory cells. Additional investigations are needed to understand the role played by these cells in the attempted repair and inflammatory process in diseased joints

    Spinal motor neurite outgrowth over glial scar inhibitors is enhanced by coculture with bone marrow stromal cells.

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    BACKGROUND CONTEXT: Transplantation of bone marrow cells into spinal cord lesions promotes functional recovery in animal models, and recent clinical trials suggest possible recovery also in humans. The mechanisms responsible for these improvements are still unclear. PURPOSE: To characterize spinal cord motor neurite interactions with human bone marrow stromal cells (MSCs) in an in vitro model of spinal cord injury (SCI). STUDY DESIGN/SETTING: Previously, we have reported that human MSCs promote the growth of extending sensory neurites from dorsal root ganglia (DRG), in the presence of some of the molecules present in the glial scar, which are attributed with inhibiting axonal regeneration after SCI. We have adapted and optimized this system replacing the DRG with a spinal cord culture to produce a central nervous system (CNS) model, which is more relevant to the SCI situation. METHODS: We have developed and characterized a novel spinal cord culture system. Human MSCs were cocultured with spinal motor neurites in substrate choice assays containing glial scar-associated inhibitors of nerve growth. In separate experiments, MSC-conditioned media were analyzed and added to spinal motor neurites in substrate choice assays. RESULTS: As has been reported previously with DRG, substrate-bound neurocan and Nogo-A repelled spinal neuronal adhesion and neurite outgrowth, but these inhibitory effects were abrogated in MSC/spinal cord cocultures. However, unlike DRG, spinal neuronal bodies and neurites showed no inhibition to substrates of myelin-associated glycoprotein. In addition, the MSC secretome contained numerous neurotrophic factors that stimulated spinal neurite outgrowth, but these were not sufficient stimuli to promote spinal neurite extension over inhibitory concentrations of neurocan or Nogo-A. CONCLUSIONS: These findings provide novel insight into how MSC transplantation may promote regeneration and functional recovery in animal models of SCI and in the clinic, especially in the chronic situation in which glial scars (and associated neural inhibitors) are well established. In addition, we have confirmed that this CNS model predominantly comprises motor neurons via immunocytochemical characterization. We hope that this model may be used in future research to test various other potential interventions for spinal injury or disease states

    Data Report – Survey of Secondary PGCE trainees 2008/9: Evaluation Virtual Schools Wiki

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    Virtual Schools is a pilot e- learning initiative for trainee teachers on the Postgraduate Certificate of Education (PGCE) programme in the Cass School of Education at the University of East London. It was initiated and developed by Kathy Wright, Director of Secondary Education, with support from colleagues on the secondary teaching team. This data report draws on findings from a survey of trainees in 2008/9 cohort (full details of the survey are set out in the methodology section below) and forms part of a wider on- going research and evaluation of the pilot initiative. The ongoing evaluation is formative in nature and is being used to inform and develop teaching and learning within the Virtual School element of the PGCE programme in particular as well as the programme in general

    The absence of detectable ADAMTS-4 (aggrecanase-1) activity in synovial fluid is a predictive indicator of autologous chondrocyte implantation success

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    Background:Autologous chondrocyte implantation (ACI) is used worldwide in the treatment of cartilage defects in the knee. Several demographic and injury-specific risk factors have been identified that can affect the success of ACI treatment. However, the discovery of predictive biomarkers in this field has thus far been overlooked.Purpose:To identify potential biomarkers in synovial fluid and plasma that can be used in the preoperative setting to help optimize patient selection for cell-based cartilage repair strategies.Study Design:Controlled laboratory study.Methods:Fifty-four ACI-treated patients were included. Cartilage oligomeric matrix protein (COMP), hyaluronan, soluble CD14 levels, and aggrecanase-1 (ADAMTS-4) activity in synovial fluid and COMP and hyaluronan in plasma were measured. Baseline and postoperative functional outcomes were determined using the patient-reported Lysholm score. To find predictors of postoperative function, linear and logistic regression analyses were performed. The dependent variables were the baseline and postoperative Lysholm score; the independent variables were patient age and body mass index, defect location, defect area, having a bone-on-bone defect, type of defect patch (periosteum or collagen), requirement of an extra procedure, and baseline biomarker levels.Results:The mean baseline Lysholm score was 47.4 ± 17.0, which improved to 64.6 ± 21.7 postoperatively. The activity of ADAMTS-4 in synovial fluid was identified as an independent predictor of the postoperative Lysholm score. Indeed, simply the presence or absence of ADAMTS-4 activity in synovial fluid appeared to be the most important predictive factor. As determined by contingency analysis, when ADAMTS-4 activity was detectable, the odds of being a responder were 3 times smaller than when ADAMTS-4 activity was not detectable. Other predictive factors were the baseline Lysholm score, age at ACI, and defect patch type used.Conclusion:The absence of ADAMTS-4 activity in the synovial fluid of joints with cartilage defects may be used in conjunction with known demographic risk factors in the development of an ACI treatment algorithm to help inform the preclinical decision

    An In Vitro System to Study the Effect of Subchondral Bone Health on Articular Cartilage Repair in Humans.

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    Chondrocyte-based cartilage repair strategies, such as articular chondrocyte implantation, are widely used, but few studies addressed the communication between native subchondral bone cells and the transplanted chondrocytes. An indirect co-culture model was developed, representing a chondrocyte/scaffold-construct repair of a cartilage defect adjoining bone, where the bone could have varying degrees of degeneration. Human BM-MSCs were isolated from two areas of subchondral bone in each of five osteochondral tissue specimens from five patients undergoing knee arthroplasty. These two areas underlaid the macroscopically and histologically best and worst cartilage, representing early and late-stage OA, respectively. BM-MSCs were co-cultured with normal chondrocytes suspended in agarose, with the two cell types separated by a porous membrane. After 0, 7, 14 and 21 days, chondrocyte-agarose scaffolds were assessed by gene expression and biochemical analyses, and the abundance of selected proteins in conditioned media was assessed by ELISA. Co-culture with late-OA BM-MSCs resulted in a reduction in GAG deposition and a decreased expression of genes encoding matrix-specific proteins (COL2A1 and ACAN), compared to culturing with early OA BM-MSCs. The concentration of TGF-ß1 was significantly higher in the early OA conditioned media. The results of this study have clinical implications for cartilage repair, suggesting that the health of the subchondral bone may influence the outcomes of chondrocyte-based repair strategies
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