Platelet-rich plasma releasate counteracts effects of an inflammatory environment on genes regulating matrix degradation and formation in human chondrocytes. Platelet-rich plasma releasate decreases NFκB activation, a major pathway involved in the pathogenesis of OA. These results encourage further study of PRP as a treatment for OA.

Improving the resolution in magnetic resonance imaging comes at the cost of either lower signal-to-noise ratio, longer acquisition time or both. This study investigates whether so-called super-resolution reconstruction methods can increase the resolution in the slice selection direction and, as such, are a viable alternative to direct high-resolution acquisition in terms of the signal-to-noise ratio and acquisition time trade-offs. The performance of six super-resolution reconstruction methods and direct high-resolution acquisitions was compared with respect to these trade-offs. The methods are based on iterative back-projection, algebraic reconstruction, and regularized least squares. The algorithms were applied to low-resolution data sets within which the images were rotated relative to each other. Quantitative experiments involved a computational phantom and a physical phantom containing structures of known dimensions. To visually validate the quantitative evaluations, qualitative experiments were performed, in which images of three different subjects (a phantom, an ex vivo rat knee, and a postmortem mouse) were acquired with different magnetic resonance imaging scanners. The results show that super-resolution reconstruction can indeed improve the resolution, signal-to-noise ratio and acquisition time trade-offs compared with direct high-resolution acquisition.

A B S T R A C T PurposeTumor-specific immunomonitoring is essential to evaluate the efficacy of vaccination against cancer. In this study, we investigated the predictive value of the presence or absence of antigen-specific T cells in biopsies from delayed-type hypersensitivity (DTH) sites. Patients and MethodsIn our ongoing clinical trials, HLA-A2.1ϩ melanoma patients were vaccinated with mature dendritic cells (DC) pulsed with melanoma-associated peptides (gp100 and tyrosinase) and keyhole limpet hemocyanin. ResultsAfter intradermal administration of a DTH challenge with gp100-and tyrosinase peptideloaded DC, essentially all patients showed a positive induration. In clinically responding patients, T cells specific for the antigen preferentially accumulated in the DTH site, as visualized by in situ tetramer staining. Furthermore, significant numbers of functional gp100 and tyrosinase tetramer-positive T cells could be isolated from these DTH biopsies, in accordance with the applied antigen in the DTH challenge. We observed a direct correlation between the presence of DC vaccine-related T cells in the DTH biopsies of stage IV melanoma patients and a positive clinical outcome (P ϭ .0012). ConclusionThese findings demonstrate the potency of this novel approach in the monitoring of vaccination studies in cancer patients.

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