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Peripheral and Central Aspects of Age-related Hearing Loss
Get PDFAge-related hearing loss is a multifactorial disease and besides aging as most important risk factor, it is also associated with gender, diabetes mellitus, a higher blood pressure, a higher BMI, smoking, alcohol intake, educational level and worse quality of the brain white matter. Three hypotheses are discussed in this thesis; either hearing loss affects the brain (sensory-deprivation hypothesis), or brain changes affect the hearing (central-component hypothesis), or mutual factors lead to both (common-cause hypothesis)
Imaging and Treatment of Bronchiectasis: Chest computed tomography to diagnose and quantify bronchiectasis, and to optimise inhalation therapy
Get PDFThis thesis covers image analysis of bronchiectasis and treatment with inhalation antibiotics
The potential of a novel cell-based therapy delivery implant in multiple sclerosis: an early health technology assessment
Get PDFIntra-Articular Application of Mesenchymal Stem Cell Therapy for Osteoarthritis — The Next Step: Optimization of Therapeutic Capacity and Applicability
Get PDFThe thesis describes the development of stem cell therapy as a treatment for the joint disease osteoarthritis. A construct has been developed with stem cells that can be administered in a joint and that allow them to perform their therapeutic effect in the joint for a long time
Is blood always thicker than water? Family firm parents, kinship ties, and the survival of spawns
No full textWe theorize that due to their ability to draw upon the distinctive bonding and bridging social capital resources of their family firm parents, family member spawns have longer early survival times than nonfamily member spawns from family firms, which in turn should have longer early survival times than spawns from nonfamily firm parents. We also predict that the survival enhancing effects of family parent bonding and bridging social capital are conditional on the spatial, cognitive and social proximity between the parent and the spawn. Using a population wide sample of 114,837 spawns founded in Sweden between 2000 and 2007, we find that nonfamily member spawns survive longer than spawns from nonfamily firms, and that this survival enhancing effect is contingent on the spatial and social proximity between the spawn and its parent. We also find that spawns founded by family members, on average, do not survive longer than spawns from family firms founded by nonfamily members, and that greater spatial and cognitive distance even hurt the survival of family member spawns. We discuss the contributions of our research to the spawning, family firm, and entrepreneurship literatures.</p
Recommendations for the safety surveillance of medical devices
Get PDFBackground: Recent safety issues involving medical devices have highlighted the need for better safety surveillance of medical devices. Proactive approaches are becoming more necessary as regulators increase the scrutiny of device safety. This thesis aims to describe the current safety system of medical devices, and how it may be enhanced from a technical and a regulatory perspective.
Methods: We used literature reviews and descriptive analysis of FDA MAUDE data to discuss the following topics associated with safety surveillance of medical devices: identification of key data sources, challenges associated with the process and recommendations to address them, new safety evaluation tools, proposal to improve safety signal detection, and potential applications of blockchain technology.
Results: Completeness and standardization of the collected safety data for medical devices can be improved. Certain features of the drug safety surveillance process could, if adopted and adapted for medical devices, address some of the current challenges and lead to a more proactive surveillance system. One of the new safety surveillance tools for medical devices is the PMS plan. It is our suggestion that the PMS plan should consist of a PMS plan Core and a PMS plan Supplement. The PMS plan Core document will describe the PMS system, and the PMS plan Supplement will outline the specific activities performed by the manufacturer for a particular medical device. A modular approach to structure the contents of the PMS plan will help to consistently update other PMS information. Data source harmonization, the development of gold standard signal detection methodologies and the standardization of coding dictionaries are amongst the recommendations to support the implementation of a new proactive approach to safety surveillance. This new approach can be supported by a secured PMS data permissioned blockchain with a proof-of-authority consensus mechanism. Blockchain has the potential to support the establishment of a more proactive safety surveillance system that could allow real time identification of safety issues, and address some of the challenges associated with safety surveillance of medical devices.
Conclusions: There is a need for regulatory and technical standardization that, together with the creation of big PMS distributed data networks, will support the early detection of potential safety issues associated with medical devices
Chondrogenically Primed Human Mesenchymal Stem Cells Persist and Undergo Early Stages of Endochondral Ossification in an Immunocompetent Xenogeneic Model
No full textTissue engineering approaches using progenitor cells such as mesenchymal stromal cells (MSCs) represent a promising strategy to regenerate bone. Previous work has demonstrated the potential of chondrogenically primed human MSCs to recapitulate the process of endochondral ossification and form mature bone in vivo, using immunodeficient xenogeneic models. To further the translation of such MSC-based approaches, additional investigation is required to understand the impact of interactions between human MSC constructs and host immune cells upon the success of MSC-mediated bone formation. Although human MSCs are considered hypoimmunogenic, the potential of chondrogenically primed human MSCs to induce immunogenic responses in vivo, as well as the efficacy of MSC-mediated ectopic bone formation in the presence of fully competent immune system, requires further elucidation. Therefore, the aim of this study was to investigate the capacity of chondrogenically primed human MSC constructs to persist and undergo the process of endochondral ossification in an immune competent xenogeneic model. Chondrogenically differentiated human MSC pellets were subcutaneously implanted to wild-type BALB/c mice and retrieved at 2 and 12 weeks post-implantation. The percentages of CD4+ and CD8+ T cells, B cells, and classical/non-classical monocyte subsets were not altered in the peripheral blood of mice that received chondrogenic MSC constructs compared to sham-operated controls at 2 weeks post-surgery. However, MSC-implanted mice had significantly higher levels of serum total IgG compared to sham-operated mice at this timepoint. Flow cytometric analysis of retrieved MSC constructs identified the presence of T cells and macrophages at 2 and 12 weeks post-implantation, with low levels of immune cell infiltration to implanted MSC constructs detected by CD45 and CD3 immunohistochemical staining. Despite the presence of immune cells in the tissue, MSC constructs persisted in vivo and were not degraded/resorbed. Furthermore, constructs became mineralised, with longitudinal micro-computed tomography imaging revealing an increase in mineralised tissue volume from 4 weeks post-implantation until the experimental endpoint at 12 weeks. These findings indicate that chondrogenically differentiated human MSC pellets can persist and undergo early stages of endochondral ossification following subcutaneous implantation in an immunocompetent xenogeneic model. This scaffold-free model may be further extrapolated to provide mechanistic insight to osteoimmunological processes regulating bone regeneration and homeostasis.</p