287 research outputs found
The Extracellular Matrix, Growth Factors and Morphogens in Biomaterial Design and Tissue Engineering
No full textCells, morphogens, growth factors, and custom scaffolds are the critical ingredients for successful tissue regeneration in which morphogens and growth factors function sequentially. Extensive studies, in vitro and in vivo, have been made to explore the mechanisms and the roles played by these molecules. As a consequence, precise, localized control over the signaling of these factors and appropriate strategy selection, depending on the tissue or organ to be repaired or regenerated, is known to permit specific management of regenerative processes. The first part of the chapter examines natural ECMs which are a set of molecules secreted by cells that provide structural and biochemical support to the surrounding cells. ECMs also perform many other functions, such as actively regulating cell function through the control of biochemical gradients, cell density, spatial organization, and ligand attachment, thus influencing various types of cell processes. Subsequently, growth factors and morphogens are examined in greater depth to clarify to what degree progress has been made into improving methodologies and functionality and, perhaps, to hint at what remains to be done for the future of tissue engineering
Induction of endothelial cell damage by hCMV molecular mimicry
No full textMolecular mimicry between infectious agents and normal human host cell components is one of the mechanisms responsible for autoimmunity. Among infectious agents, some viruses represent ideal candidates for their ability to infect human cells, where they are harbored for the duration of the life of the host in a latent state. Human cytomegalovirus (hCMV) infection has been implicated in the pathogenesis of vascular damage in systemic sclerosis (SSc) and atherosclerosis. Based on recent data describing a cause and effect relationship between hCMV and endothelial cell damage in SSc and atherosclerosis, we propose that the immune response to particular hCMV proteins might result in autoaggression through a mechanism of molecular mimicry of normally expressed endothelial cell surface molecules
-diagram technique for , superfields
No full textWe describe a diagrammatic procedure to carry out the Grassmann integration in super-Feynman diagrams of 4d theories expressed in terms of superfields. This method is alternative to the well known D-algebra approach. We develop it in detail for theories containing vector, chiral and anti-chiral superfields, with the type of interactions which occur in SYM theories with massless matter, but it would be possible to extend it to other cases. The main advantage is that this method is algorithmic; we implemented it as a Mathematica program that, given the description of a super Feynman diagram in momentum space, returns directly the polynomial in the momenta produced by the Grassmann integration
Christian Bason: Design for public service
No full textChristian Bason is the Chief Executive of the Danish Design Center, which works to advance the use of design in business and society. From 2007 to 2014, he was Director of MindLab, the Danish cross-governmental innovation team. Prior to this he was a consultant and business manager with the international advisory group Ramboll. Christian is the author of multiple books on innovation and design in government, including Leading Public Design: Discovering Human-Centred Governance (2017), Design for Policy (2014) and Leading Public Sector Innovation: Co-creating for a Better Society (2010)
Congenital heart block and immune mediated sensorineural hearing loss : possible cross reactivity of immune response
No full textImmune-mediated sensorineural hearing loss may complicate systemic autoimmune diseases. We have previously reported the presence of antibodies directed against inner ear antigens in patients with Cogan syndrome, a disease characterized by sudden hearing loss and interstitial keratitis. Such autoantibodies cross-react with an epitope of SSA/Ro60 protein. Anti-Ro/SSA antibodies in pregnant women cross the placenta and reach the fetal tissues inducing an immune-mediated damage of the cardiac conduction system. We wanted to evaluate whether mothers with anti-Ro/SSA antibodies who gave birth to children with congenital heart block have antibodies directed against inner ear antigens and whether these antibodies are connected with the presence of immune-mediated sensorineural hearing loss. We did not find anti-inner ear antibodies in the majority of the mothers. On the contrary a 13-year-old boy with congenital heart block and sensorineural hearing loss was positive for the presence of anti-inner ear antigens antibodies. Moreover his serum was positive for the presence of anti-Ro60 peptide antibodies but did not recognize the entire protein Ro60 (TROVE2), a behaviour similar to that of sera from patients with Cogan syndrome. In conclusion the data obtained so far show that anti-inner ear antibodies do not recognize the entire protein TROVE2 and do not support the hypothesis that such antibodies may be involved in the pathogenesis of congenital heart block
Human T lymphocyte cell line (Mo) and its subclone (J) produce colony stimulating activity on normal and malignant T cell precursors
No full textConditioned medium from a T-lymphoblastic cell line (Mo) is known to produce factors promoting CFU-GM, BFU-E and CFU-MK In our study we investigated the potential CSA of conditioned media obtained from Mo and its subclone J on normal and malignant lymphoid progenitors of both T and B lineage. Both cell lines release factors inducing a significant increase in number and size of T-lymphoid colonies when compared to standard source of factors (PHA-LCM). On the contrary, they, presented a low CSA on B cell precursors confirming the difficulties in identifying a source of growth and differentiation factors for human B cell ontogeny. This study contributes to the knowledge of biological properties of these tumor cell lines, suggesting the possibility to employ Mo- and J-derived supernatants in vitro for improving growth potential of normal and malignant T cell progenitors
Granulocyte macrophage colony stimulating factor activity in cerebrospinal fluid
No full textAbstract
OBJECTIVES:
The purpose of this study was to analyse the presence of the granulocyte-macrophage colony-stimulating factor (GM-CSF) in human cerebrospinal fluid (SF) of patients affected by multiple sclerosis (MS) in comparison with non-inflammatory neurological diseases.
MATERIAL AND METHODS:
All SFs were collected from 59 patients for diagnostic purpose. The presence of GM-CSF was revealed by measuring its activity and by immunoassay. The data obtained were statistically evaluated.
RESULTS:
We found that GM-CSF is constitutively present in human SF; this presence was confirmed by its stimulating activity of colony-forming-unit granulocyte-macrophage (CFU-GM) production. No significant changes of the GM-CSF concentration in the SFs were observed among different neurological disorders (degenerative or vascular) and MS.
CONCLUSION:
Our data suggest that GM-CSF is a constitutive component of human SF, relatively uninfluenced by the different morbid conditions of the nervous system
Human parvovirus B19 infection and autoimmunity.
No full textHuman parvovirus B19 infection is responsible for a wide range of human diseases ranging from mild erythema infectiosum in immunocompetent children to fetal loss in primary infected pregnant women and aplastic anemia or lethal cytopenias in adult immunocompromised patients. Since persistent viral infection is responsible for an autoimmune response and clinical symptoms can mimic autoimmune inflammatory disorders, parvovirus B19 is the object of intense efforts to clarify whether it is also able to trigger autoimmune diseases. Indeed the virus has been implicated as the causative or the precipitating agent of several autoimmune disorders including rheumatoid arthritis, systemic lupus, antiphospholipid syndrome, systemic sclerosis and vasculitides. Molecular mimicry between host and viral proteins seems to be the main mechanism involved in the induction of autoimmunity. By means of a random peptide library approach, we have identified a peptide that shares homology with parvovirus VP1 protein and with human cytokeratin. Moreover the VP peptide shares similarity with the transcription factor GATA1 that plays an essential role in megakaryopoiesis and in erythropoiesis. These new data sustain the role played by molecular mimicry in the induction of cross-reactive (auto)antibodies by parvovirus B19 infection
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