Immunosuppressive potential of human amnion epithelial cells in the treatment of experimental autoimmune encephalomyelitis

BACKGROUND: Multiple sclerosis (MS) is an autoimmune inflammatory disease of the central nervous system (CNS). In recent years, it has been found that cells such as human amnion epithelial cells (hAECs) have the ability to modulate immune responses in vitro and in vivo and can differentiate into multiple cell lineages. Accordingly, we investigated the immunoregulatory effects of hAECs as a potential therapy in an MS-like disease, EAE (experimental autoimmune encephalomyelitis), in mice. METHODS: Using flow cytometry, the phenotypic profile of hAECs from different donors was assessed. The immunomodulatory properties of hAECs were examined in vitro using antigen-specific and one-way mixed lymphocyte proliferation assays. The therapeutic efficacy of hAECs was examined using a relapsing-remitting model of EAE in NOD/Lt mice. T cell responsiveness, cytokine secretion, T regulatory, and T helper cell phenotype were determined in the peripheral lymphoid organs and CNS of these animals. RESULTS: In vitro, hAECs suppressed both specific and non-specific T cell proliferation, decreased pro-inflammatory cytokine production, and inhibited the activation of stimulated T cells. Furthermore, T cells retained their naïve phenotype when co-cultured with hAECs. In vivo studies revealed that hAECs not only suppressed the development of EAE but also prevented disease relapse in these mice. T cell responses and production of the pro-inflammatory cytokine interleukin (IL)-17A were reduced in hAEC-treated mice, and this was coupled with a significant increase in the number of peripheral T regulatory cells and naïve CD4+ T cells. Furthermore, increased proportions of Th2 cells in the peripheral lymphoid organs and within the CNS were observed. CONCLUSION: The therapeutic effect of hAECs is in part mediated by inducing an anti-inflammatory response within the CNS, demonstrating that hAECs hold promise for the treatment of autoimmune diseases like MS

Explicit finite element analysis to predict impact damage response of osteoporosis hip bone

Hip fractures due to sideways falls are a worldwide health problem, especially amongst elderly people. The force experienced by the proximal femur during a fall, and therefore hip fracture, is significantly dependent on density, thickness and stiffness of the body during impact. The process of fracture and healing can only be understood in terms of the structure and composition of the bone and also its mechanical properties. Bone fracture analysis investigates the prediction of various failure mechanisms under different loading conditions. An accurate explicit finite element method will assist scientists and researchers to predict the impact damage response of bone structures. In this paper, the effect of low velocity impact on the osteoporotic hip in ageing people will be studied in LSDYNA. The first part aims to create a three-dimensional (3D) reconstruction and registration of semi-transparent computed tomography scan image data using Simpleware software. In the second part, the effect of cortical thickness and impact velocity on the energy absorption of the hip during a fall will be investigated on a 3D model using the latest techniques. The critical impulse loading of the hip will be the benchmark to improve the design of safety instruments and consequently the well-being of elderly people

Experimental and numerical analysis of penetration into Kevlar fabric impregnated with shear thickening fluid

This study presents the high-velocity impact performance of a composite material composed of woven Kevlar fabric impregnated with a colloidal shear thickening fluids (STFs). Although the precise role of the STF in the high-velocity defeat, process is not exactly known but it is suspected to be due to the increased frictional interaction between yarns in impregnated fabrics. In order to explore the mechanism of this enhanced energy absorption, high-velocity impact test was conducted on neat, impregnated fabric and also on pure STF without fabric. A finite element model has been carried out to consider the effect of STF impregnation on the ballistic performance. For this purpose, fabric was modeled using LS-DYNA by employing the experimental results of yarn pull-out tests to characterize the frictional behavior of the STF impregnated fabric. The simulation result is a proof that the increased performance for STF impregnated Kevlar fabric is due to the increased friction. </jats:p