In Vitro Effects of Strontium on Proliferation and Osteoinduction of Human Preadipocytes.

Development of tools to be used for in vivo bone tissue regeneration focuses on cellular models and differentiation processes. In searching for all the optimal sources, adipose tissue-derived mesenchymal stem cells (hADSCs or preadipocytes) are able to differentiate into osteoblasts with analogous characteristics to bone marrow mesenchymal stem cells, producing alkaline phosphatase (ALP), collagen, osteocalcin, and calcified nodules, mainly composed of hydroxyapatite (HA). The possibility to influence bone differentiation of stem cells encompasses local and systemic methods, including the use of drugs administered systemically. Among the latter, strontium ranelate (SR) represents an interesting compound, acting as an uncoupling factor that stimulates bone formation and inhibits bone resorption. The aim of our study was to evaluate the in vitro effects of a wide range of strontium (Sr2+) concentrations on proliferation, ALP activity, and mineralization of a novel finite clonal hADSCs cell line, named PA20-h5. Sr2+ promoted PA20-h5 cell proliferation while inducing the increase of ALP activity and gene expression as well as HA production during in vitro osteoinduction. These findings indicate a role for Sr2+ in supporting bone regeneration during the process of skeletal repair in general, and, more specifically, when cell therapies are applied

Estrogen Receptor Expression in Cutaneous Melanoma

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Cellular response to photodynamic therapy in chronic wounds

A wound is considered chronic if it does not heal timely. Basic processes at work are similar to acute healing, but their persistence leads to abundant granulation tissue and possibly fibrosis, scar contraction and loss of function [1]. Wounds may become chronic because of local and systemic conditions and are a major concern in clinical dermatology. Photodinamic therapy (PDT) has been proposed for these cases, through the administration of aminolaevulinic acid (ALA), leading to the synthesis of the photosensitizer protoporphyrin IX (PpIX), followed by illumination with visible light [2]. To study the effects of this therapy on the cell infiltrate of chronic wounds, cryosections of lesions before and after PDT were post fixed in cold acetone and stained with haematoxilin and eosin or immunolabeled with antibodies to laminin 5 (for basement membrane), HSP47 (for fibroblasts), alpha-smooth muscle actin (for myofibroblasts), SPM250 (for granulocytes). Intact neighbor skin was used as control. The cellular infiltrate, as well as the thickness of epidermis, the vascularization and the number of fibroblasts appeared increased in chronic wounds over healthy skin. After completion of PDT, fibroblasts appeared further increased in number, the treatment seemed to stimulate the connective tissue cells responsible for tissue repair rather than the inflammatory infiltrate (Supported by Ente Cassa di Risparmio di Firenze, grant 3681 to S.B.)

An Additive Model to Normalize Spotted Arrays Using Spike Controls

Motivation: The study of a metabolic pathway is focused on a limited number of genes in comparison to whole-genome studies. Therefore, a large number of (spike) controls may be printed within slide together with several ESTs replicates to reduce bias and variance of estimates. Results: We develop a linear additive mixed effect model to remove dye and spatial biases using spike controls. We adapt the iterated weighted least squares algorithm to obtain a fast algorithm to search for the optimal model and to perform point estimates of model parameters. Actual data from a very noisy calibration slide have been successfully normalized following our model.JRC.G.9-Econometrics and statistical support to antifrau