A comparative study of diagnostic and imaging techniques for osteoarthritis of the trapezium

Objectives. The aims of this study were to determine whether micro-CT is a reliable investigation method to evaluate the severity of OA in the trapezium and to develop a novel micro-CT scoring system based on a quantitative assessment of the subchondral bone thickness in order to better assess OA through an objective parameter.Methods. We compared different diagnostic and imaging techniques performed consecutively on each sample: X-ray, visual analysis, micro-CT and histology. OA and healthy trapezia were subjected to semi-quantitative and quantitative analyses to be classified in four degrees of severity in OA (control, OA-2, OA-3 and OA-4). Specifically, samples were analysed using Dell's score for X-ray, Brown's score for visual analysis and Mankin's score for histology. Micro-CT was scored using a novel quantitative scoring system based on subchondral bone thickness measurements. Results obtained with each technique were then compared and correlated.Results. X-ray analysis showed a higher frequency of OA-2 (27%) and OA-3 (32%) compared with OA-4 (5%), whereas visual analysis, micro-CT and histology showed a lower percentage for OA-2 (18%, 18% and 14%) and OA-3 (23%) and increased frequency for OA-4 (45%, 32% and 40%). Only the micro-CT score of subchondral bone thickness correlated significantly with all the other techniques (P < 0.05).Conclusion. This is the first comparison of techniques proposing a novel scoring system based on objective and quantitative micro-CT data that can be applied as a useful diagnostic tool for OA, providing a deeper comprehension of the pathophysiology of OA in trapezium

Systemic and Local Administration of Antimicrobial and Cell Therapies to Prevent Methicillin-Resistant Staphylococcus epidermidis-Induced Femoral Nonunions in a Rat Model

S. epidermidis is responsible for biofilm-related nonunions. This study compares the response to S. epidermidis-infected fractures in rats systemically or locally injected with vancomycin or bone marrow mesenchymal stem cells (BMSCs) in preventing the nonunion establishment. The 50% of rats receiving BMSCs intravenously (s-rBMSCs) died after treatment. A higher cytokine trend was measured in BMSCs locally injected rats (l-rBMSCs) at day 3 and in vancomycin systemically injected rats (l-VANC) at day 7 compared to the other groups. At day 14, the highest cytokine values were measured in l-VANC and in l-rBMSCs for IL-10. \ub5CT showed a good bony bridging in s-VANC and excellent both in l-VANC and in l-rBMSCs. The bacterial growth was lower in s-VANC and l-VANC than in l-rBMSCs. Histology demonstrated the presence of new woven bone in s-VANC and a more mature bony bridging was found in l-VANC. The l-rBMSCs showed a poor bony bridging of fibrovascular tissue. Our results could suggest the synergic use of systemic and local injection of vancomycin as an effective treatment to prevent septic nonunions. This study cannot sustain the systemic injection of BMSCs due to high risks, while a deeper insight into local BMSCs immunomodulatory effects is mandatory before developing cell therapies in clinics

Polymer-based injectable bone substitute materials: in vitro and in vivo evaluation

Contains fulltext : 117442.pdf (Publisher’s version ) (Open Access)Radboud Universiteit Nijmegen, 31 mei 2013Promotor : Jansen, J.A. Co-promotores : Beucken, J.J.J.P van den, Leeuwenburgh, S.C.G

ESTIMATION SNOW PARAMETERS USING DIGITAL IMAGERY

In this paper, we present newly established webcam monitoring system in Finland for monitoring and phenology and snow cover. Main motivation of this work is to facilitate Earth Observation (EO) systems by providing time-series of field observation for calibration and validation, as well as to improve the assessment of ecosystem services. Images have been used in phenological analyses of birches along a latitudinal gradient across Finland, snow cover and compared to greenhouse gas fluxes on Scots pine and wetland ecosystems. Finnish Meteorological Institute image PROcessing Toolbox (FMIPROT) is developed to analyse the images for the extraction of environmental data. The Images from the camera network, producing a continuous image series in Finland, are used in the analysis of Fractional Snow Cover (FSC). Another camera network, producing continuous image series in the SPICE site, Sodankyla, Finland, is used for the analysis of Snow Depth (SD). SPICE (Solid Precipitation Intercomparison Experiment) is a WMO/CIMO multi-sites intercomparison of instruments and systems of observation for the measurement of solid precipitation. Analyses are done using the FMIPROT. We discuss on estimation of FSC and SD using digital imagery and utilizing the digital imagery to complement FSC and SD retrieval algorithms from remote sensing data and/or to validate Earth-observed FSC and SD introducing MONIMET camera network and FMIPROT. We also tested this method in mountain region, the Careser Dam (at an altitude of 2600 m a.s.l.), in Trentino's Region (Italy) in the south-eastern part of the Ortles-Cevedale massif the largest glacierised mountain group of the Italian Alps

Biomimetic modification of synthetic hydrogels by incorporation of adhesive peptides and calcium phosphate nanoparticles: in vitro evaluation of cell behavior.

Contains fulltext : 95676.pdf (publisher's version ) (Open Access)The ultimate goal of this work was to develop a biocompatible and biomimetic in situ crosslinkable hydrogel scaffold with an instructive capacity for bone regenerative treatment. To this end, synthetic hydrogels were functionalized with two key components of the extracellular matrix of native bone tissue, i.e. the three-amino acid peptide sequence RGD (which is the principal integrin-binding domain responsible for cell adhesion and survival of anchorage-dependent cells) and calcium phosphate (CaP) nanoparticles in the form of hydroxyapatite (which are similar to the inorganic phase of bone tissue). Rat bone marrow osteoblast-like cells (OBLCs) were encapsulated in four different biomaterials (plain oligo(poly(ethylene glycol) fumarate) (OPF), RGD-modified OPF, OPF enriched with CaP nanoparticles and RGD-modified OPF enriched with CaP nanoparticles) and cell survival, cell spreading, proliferation and mineralized matrix formation were determined via cell viability assay, histology and biochemical analysis for alkaline phosphatase activity and calcium. This study showed that RGD peptide sequences promoted cell spreading in OPF hydrogels and hence play a crucial role in cell survival during the early stage of culture, whereas CaP nanoparticles significantly enhanced cell-mediated hydrogel mineralization. Although cell spreading and proliferation activity were inhibited, the combined effect of RGD peptide sequences and CaP nanoparticles within OPF hydrogel systems elicited a better biological response than that of the individual components. Specifically, both a sustained cell viability and mineralized matrix production mediated by encapsulated OBLCs were observed within these novel biomimetic composite systems

Cellule staminali

Le cellule staminali sono cellule non specializzate presenti in tutti gli organismi viventi. Diversamente da una cellula epiteliale, capace di produrre una barriera biologica a difesa del nostro organismo, o da un globulo rosso, in grado di trasportare l\u2019ossigeno attraverso il circolo sanguigno, una cellula staminale non possiede alcuna specializzazione fisiologica. La definizione di cellula staminale si basa essenzialmente su due caratteristiche: a) autorinnovamento, ossia la capacit\ue0 di generare una cellula indifferenziata esattamente uguale alla cellula-madre attraverso numerosi cicli cellulari; b) potenza, vale a dire la capacit\ue0 di differenziarsi in tipi cellulari specializzati. Si distinguono diversi stadi di potenza delle cellule staminali: la totipotenza \ue8 la capacit\ue0 di generare tutti i tessuti embrionali ed extraembrionali, tipica delle cellule della morula; la pluripotenza \ue8 la capacit\ue0 di differenziarsi in tutti i tessuti embrionali, tipica delle cellule staminali embrionali (ES, Embryonic Stem cells) che compongono la massa cellulare interna della blastocisti, capacit\ue0 che recentemente \ue8 stata riferita anche a cellule somatiche riprogrammate; la multipotenza \ue8 la capacit\ue0 di differenziare in tutti i tipi cellulari di un foglietto germinativo (endoderma, mesoderma o ectoderma); l\u2019unipotenza \ue8 la capacit\ue0 di differenziarsi in un unico tipo cellulare, tipico dei progenitori. In questo saggio verranno descritte le cellule staminali embrionali e adulte fino alle innovative cellule staminali pluripotenti indotte (iPS, induced Pluripotent Stem cells), la sfida scientifica del nuovo secolo