144 research outputs found

    Axonal growth arrests after an increased accumulation of Schwann cells expressing senescence markers and stromal cells in acellular nerve allografts

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    Acellular nerve allografts (ANAs) and other nerve constructs do not reliably facilitate axonal regeneration across long defects (>3 cm). Causes for this deficiency are poorly understood. In this study, we determined what cells are present within ANAs before axonal growth arrest in nerve constructs and if these cells express markers of cellular stress and senescence. Using the Thy1-GFP rat and serial imaging, we identified the time and location of axonal growth arrest in long (6 cm) ANAs. Axonal growth halted within long ANAs by 4 weeks, while axons successfully regenerated across short (3 cm) ANAs. Cellular populations and markers of senescence were determined using immunohistochemistry, histology, and senescence-associated β-galactosidase staining. Both short and long ANAs were robustly repopulated with Schwann cells (SCs) and stromal cells by 2 weeks. Schwann cells (S100β(+)) represented the majority of cells repopulating both ANAs. Overall, both ANAs demonstrated similar cellular populations with the exception of increased stromal cells (fibronectin(+)/S100β(−)/CD68(−) cells) in long ANAs. Characterization of ANAs for markers of cellular senescence revealed that long ANAs accumulated much greater levels of senescence markers and a greater percentage of Schwann cells expressing the senescence marker p16 compared to short ANAs. To establish the impact of the long ANA environment on axonal regeneration, short ANAs (2 cm) that would normally support axonal regeneration were generated from long ANAs near the time of axonal growth arrest (“stressed” ANAs). These stressed ANAs contained mainly S100β(+)/p16(+) cells and markedly reduced axonal regeneration. In additional experiments, removal of the distal portion (4 cm) of long ANAs near the time of axonal growth arrest and replacement with long isografts (4 cm) rescued axonal regeneration across the defect. Neuronal culture derived from nerve following axonal growth arrest in long ANAs revealed no deficits in axonal extension. Overall, this evidence demonstrates that long ANAs are repopulated with increased p16(+) Schwann cells and stromal cells compared to short ANAs, suggesting a role for these cells in poor axonal regeneration across nerve constructs

    ROCK Inhibitor Is Not Required for Embryoid Body Formation from Singularized Human Embryonic Stem Cells

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    We report a technology to form human embryoid bodies (hEBs) from singularized human embryonic stem cells (hESCs) without the use of the p160 rho-associated coiled-coil kinase inhibitor (ROCKi) or centrifugation (spin). hEB formation was tested under four conditions: +ROCKi/+spin, +ROCKi/-spin, -ROCKi/+spin, and -ROCKi/-spin. Cell suspensions of BG01V/hOG and H9 hESC lines were pipetted into non-adherent hydrogel substrates containing defined microwell arrays. hEBs of consistent size and spherical geometry can be formed in each of the four conditions, including the -ROCKi/-spin condition. The hEBs formed under the -ROCKi/-spin condition differentiated to develop the three embryonic germ layers and tissues derived from each of the germ layers. This simplified hEB production technique offers homogeneity in hEB size and shape to support synchronous differentiation, elimination of the ROCKi xeno-factor and rate-limiting centrifugation treatment, and low-cost scalability, which will directly support automated, large-scale production of hEBs and hESC-derived cells needed for clinical, research, or therapeutic applications

    Social determinants of health inequalities in early phase clinical trials in Northern England

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    \ua9 The Author(s) 2024.Background: Early phase clinical trials in Oncology represent a subspecialised area where UK patient selection is influenced by access to Experimental Cancer Medicine Centres (ECMCs). Equity of access with respect to social determinants of health (SDoH) were explored for two major ECMCs. Methods: A retrospective cohort study including all referrals to Newcastle and Manchester ECMCs in 2021 was completed. Consent to screening or pre-screening was stratified against SDoH characteristics, including: Index of Multiple Deprivation (IMD) decile, ethnicity and distance to centre. Results: 1243 patients were referred for trials. IMD quintile 1 (most deprived) patients had reduced likelihood of referral compared to expected population models (OR, 0.67; 95% CI: 0.55 to 0.80, p = <0.0001). IMD quintile 5 (least deprived) had increased likelihood of referral (OR, 1.46; 95% CI: 1.17 to 1.82, p = 0.0007). Living beyond median distance from Manchester reduced the likelihood of consenting to trials (OR, 0.72; 95% CI: 0.55 to 0.94, p = 0.015). Ethnicity data represented a White British propensity. Conclusions: Inequalities in socioeconomic and geographic factors influence referral and enrolment to early phase clinical trials in Northern England. This has implications for equity of access and generalisability of trial results internationally and warrants further study

    A systematic review of the association between nursing staff and nursing-sensitive outcomes in long-term institutional care

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    Aims To examine the association between type of nursing staff and nursing-sensitive outcomes in long-term institutional care. Design This systematic review included studies published in English, German, and Dutch between January 1997 and January 2020. Data sources The databases Medline (PubMed), CINAHL, PsycINFO, Embase, and the Cochrane Library were searched. Original quantitative studies were included. Review methods The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines were followed. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist was used to critically appraise the reporting of the studies. Results Fifteen articles were included. Of 33 quality of care outcomes, 21 were identified as nursing-sensitive outcomes of which 13 showed a significant association with nursing staff, specifically: Activities of daily living, aggressive behavior, bladder/bowel incontinence, contractures, expressive language skills, falls, infection (including vaccination), range of motion, pain, pressure ulcers, and weight loss. However, studies reported inconsistent results regarding the association among RNs, LPNs, CNAs, and HCAs and these nursing-sensitive outcomes, evidence shows that more RNs have a positive impact on nursing-sensitive outcomes. As to the evidence regarding the other type of nursing staff, especially HCA, findings regularly showed a negative association. Conclusion Future research should be expanded with structure and process variables of which the mediating and moderating effect on nursing-sensitive outcomes is known. These may explain variances in quality of care and guide quality improvement initiatives. Researchers should consider fully applying Donabedian's structure-process-outcomes framework as it is a coherent entirety for quality assessment. Impact This review provides an overview of quality of care outcomes that are responsive to nursing interventions in long-term institutional care. As the effects can be monitored and documented, quality assessment should focus on these nursing-sensitive outcomes. The inconclusive results make it difficult to provide recommendations on who should best perform which care

    Disruption of Spectrin-Like Cytoskeleton in Differentiating Keratinocytes by PKCδ Activation Is Associated with Phosphorylated Adducin

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    Spectrin is a central component of the cytoskeletal protein network in a variety of erythroid and non-erythroid cells. In keratinocytes, this protein has been shown to be pericytoplasmic and plasma membrane associated, but its characteristics and function have not been established in these cells. Here we demonstrate that spectrin increases dramatically in amount and is assembled into the cytoskeleton during differentiation in mouse and human keratinocytes. The spectrin-like cytoskeleton was predominantly organized in the granular and cornified layers of the epidermis and disrupted by actin filament inhibitors, but not by anti-mitotic drugs. When the cytoskeleton was disrupted PKCδ was activated by phosphorylation on Thr505. Specific inhibition of PKCδ(Thr505) activation with rottlerin prevented disruption of the spectrin-like cytoskeleton and the associated morphological changes that accompany differentiation. Rottlerin also inhibited specific phosphorylation of the PKCδ substrate adducin, a cytoskeletal protein. Furthermore, knock-down of endogenous adducin affected not only expression of adducin, but also spectrin and PKCδ, and severely disrupted organization of the spectrin-like cytoskeleton and cytoskeletal distribution of both adducin and PKCδ. These results demonstrate that organization of a spectrin-like cytoskeleton is associated with keratinocytes differentiation, and disruption of this cytoskeleton is mediated by either PKCδ(Thr505) phosphorylation associated with phosphorylated adducin or due to reduction of endogenous adducin, which normally connects and stabilizes the spectrin-actin complex

    “And Unto Dust Shalt Thou Return”:Death and the Semiotics of Remembrance in an Ethiopian Orthodox Christian Village

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    This ethnographic article discusses funerary practice, Orthodox Christian ideas of body and spirit, and the ways in which people make memorials for each other on the Zege Peninsulain northwest Ethiopia. I pay special attention to gravestones because, here as in many other places, physical memorials to the dead become locations where latent uncertainties and conflicts about the relationship between spirit and matter, body and soul, and this world and the next, tend to crystallise. I show that material memorials highlight ambiguities in Orthodox attitudes to human embodiment and challenge priestly monopolies over relations between the living and the dead. Because of material chains of mediation and memorialisation, the disaggregating practices of Orthodox funerary ritual can never fully untangle the deceased from their worldly social entanglements
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