A Derivative Recovery Spectral Volume model for the analysis of constituents transport in one-dimensional flows

The treatment of advective fluxes in high-order finite volume models is well established, but this is not the case for diffusive fluxes, due to the conflict between the discontinuous representation of the solution and the continuous structure of analytic solutions. In this paper, a derivative reconstruction approach is proposed in the context of spectral volume methods, for the approximation of diffusive fluxes, aiming at the reconciliation of this conflict. Two different reconstructions are used for advective and diffusive fluxes: the advective reconstruction makes use of the information contained in a spectral cell, and allows the formation of discontinuities at the spectral cells boundaries; the diffusive reconstruction makes use of the information contained in contiguous spectral cells, imposing the continuity of the reconstruction at the spectral cells boundaries. The method is demonstrated by a number of numerical experiments, including the solution of shallow-water equations, complemented with the advective-diffusive transport equation of a conservative substance, showing the promising abilities of the numerical scheme proposed

SILAC labeling coupled to shotgun proteomics analysis of membrane proteins of liver stem/hepatocyte allows to candidate the inhibition of TGF-beta pathway as causal to differentiation

International audienceDespite extensive research on hepatic cells precursors and their differentiated states, much remains to be learned about the mechanism underlying the self-renewal and differentiation. We apply the SILAC (stable isotope labeling by amino acids in cell culture) approach to quantitatively compare the membrane proteome of the resident liver stem cells (RLSCs) and their progeny spontaneously differentiated into epithelial/hepatocyte (RLSCdH). By means of nanoLC-MALDI-TOF/TOF approach, we identified and quantified 248 membrane proteins and 57 of them were found modulated during hepatocyte differentiation. Functional clustering of differentially expressed proteins by Ingenuity Pathway Analysis revealed that the most of membrane proteins found to be modulated are involved in cell-to-cell signaling/interaction pathways. Moreover, the upstream prediction analysis of proteins involved in cell-to-cell signaling and interaction unveiled that the activation of the mesenchymal to epithelial transition (MET), by the repression of TGFB1/Slug signaling, may be causal to hepatocyte differentiation. Taken together, this study increases the understanding of the underlying mechanisms modulating the complex biological processes of hepatic stem cell proliferation and differentiation

Angiotensin receptor I stimulates osteoprogenitor proliferation through TGFβ-mediated signaling:AT1R SIGNALING IN OSTEOBLAST DIFFERENTIATION

Clinical studies of large human populations and pharmacological interventions in rodent models have recently suggested that anti-hypertensive drugs that target angiotensin II (Ang II) activity may also reduce loss of bone mineral density. Here, we identified in a genetic screening the Ang II type I receptor (AT1R) as a potential determinant of osteogenic differentiation and, implicitly, bone formation. Silencing of AT1R expression by RNA interference severely impaired the maturation of a multipotent mesenchymal cell line (W20-17) along the osteoblastic lineage. The same effect was also observed after the addition of the AT1R antagonist losartan but not the AT2R inhibitor PD123,319. Additional cell culture assays traced the time of greatest losartan action to the early stages of W20-17 differentiation, namely during cell proliferation. Indeed, addition of Ang II increased proliferation of differentiating W20-17 and primary mesenchymal stem cells and this stimulation was reversed by losartan treatment. Cells treated with losartan also displayed an appreciable decrease of activated (phosphorylated)-Smad2/3 proteins. Moreover, Ang II treatment elevated endogenous transforming growth factor β (TGFβ) expression considerably and in an AT1R-dependent manner. Finally, exogenous TGFβ was able to restore high proliferative activity to W20-17 cells that were treated with both Ang II and losartan. Collectively, these results suggest a novel mechanism of Ang II action in bone metabolism that is mediated by TGFβ and targets proliferation of osteoblast progenitors

Angiotensin receptor I stimulates osteoprogenitor proliferation through TGFβ-mediated signaling

Clinical studies of large human populations and pharmacological interventions in rodent models have recently suggested that anti-hypertensive drugs that target angiotensin II (Ang II) activity may also improve loss of bone mineral density. Here we identified in a genetic screen the Ang II type I receptor (AT1R) as a potential determinant of osteogenic differentiation and, implicitly, bone formation. Silencing of AT1R expression by RNA interference severely impaired the maturation of a multipotent mesenchymal cell line (W20-17) along the osteoblastic lineage. The same effect was also observed after the addition of the AT1R antagonist losartan but not the AT2R inhibitor PD123,319. Additional cell culture assays traced the time of greatest losartan action to the early stages of W20-17 differentiation, namely during cell proliferation. Indeed, addition of Ang II increased proliferation of differentiating W20-17 and primary mesenchymal stem cells and this stimulation was reversed by losartan treatment. Cells treated with losartan also displayed an appreciable decrease of activated (phosphorylated)-Smad2/3 proteins. Moreover, Ang II treatment elevated endogenous transforming growth factor β (TGFβ) expression considerably and in an AT1R-dependent manner. Finally, exogenous TGFβ was able to restore high proliferative activity to W20-17 cells that were treated with both Ang II and losartan. Collectively, these results suggest a novel mechanism of Ang II action in bone metabolism that is mediated by TGFβ and targets proliferation of osteoblast progenitors

CD10, BCL6, and MUM1 expression in diffuse large B-cell lymphoma on FNA samples

BACKGROUND: Gene expression profiling has divided diffuse large B-cell lymphoma (DLBCL) into 2 main subgroups: germinal center B (GCB) and non-GCB type. This classification is reproducible by immunohistochemistry using specific antibodies such as CD10, B-cell lymphoma 6 (BCL6), and multiple myeloma oncogene 1 (MUM1). Fine-needle aspiration (FNA) plays an important role in the diagnosis of non-Hodgkin lymphoma, and in some cases FNA may be the only available pathological specimen. The objectives of the current study were to evaluate CD10, BCL6, and MUM1 immunostaining on FNA samples by testing the CD10, BCL6, and MUM1 algorithm on both FNA cell blocks (CB) and conventional smears (CS), evaluating differences in CB and CS immunocytochemical (ICC) performance, and comparing results with histological data. METHODS: Thirty-eight consecutive DLBCL cases diagnosed by FNA were studied. Additional passes were used to prepare CB in 22 cases and CS in 16 cases; the corresponding sections and smears were immunostained using CD10, BCL6, and MUM1 in all cases. The data obtained were compared with histological immunostaining in 24 cases. RESULTS: ICC was successful in 33 cases (18 CB and 15 CS) and not evaluable in 5 cases (4 CB and 1 CS). The CD10-BCL6-MUM1 algorithm subclassified DLBCL as GCB (9 cases) and non-GCB (24 cases). ICC data were confirmed on histologic staining in 24 cases. CONCLUSIONS: CD10, BCL6, and MUM1 ICC staining can be performed on FNA samples. The results herein prove it is reliable both on CB and CS, and is equally effective and comparable to immunohistochemistry data

A roadmap for optimizing chronic kidney disease patient care and patient-oriented research in the Eastern European nephrology community

Chronic kidney disease (CKD) is a major health problem because of its high prevalence, associated complications and high treatment costs. Several aspects of CKD differ significantly in the Eastern European nephrology community compared with Western Europe because of different geographic, socio-economic, infrastructure, cultural and educational features. The two most frequent aetiologies of CKD, DM and hypertension, and many other predisposing factors, are more frequent in the Eastern region, resulting in more prevalent CKD Stages 3-5. Interventions may minimize the potential drawbacks of the high prevalence of CKD in Eastern Europe, which include several options at various stages of the disease, such as raising public, medical personnel and healthcare authorities awareness; early detection by screening high-risk populations; preventing progression and CKD-related complications by training health professionals and patients; promoting transplantation or home dialysis as the preferred modality; disseminating and implementing guidelines and guided therapy and encouraging/supporting country-specific observational research as well as international collaborative projects. Specific ways to significantly impact CKD-related problems in every region of Europe through education, science and networking are collaboration with non-nephrology European societies who have a common interest in CKD and its associated complications, representation through an advisory role within nephrology via national nephrology societies, contributing to the training of local nephrologists and stimulating patient-oriented research. The latter is mandatory to identify country-specific kidney disease-related priorities. Active involvement of patients in this research via collaboration with the European Kidney Patient Federation or national patient federations is imperative to ensure that projects reflect specific patient needs.Peer reviewe

Bioreactor manufactured cartilage grafts repair acute and chronic osteochondral defects in large animal studies

Objectives Bioreactor‐based production systems have the potential to overcome limitations associated with conventional tissue engineering manufacturing methods, facilitating regulatory compliant and cost‐effective production of engineered grafts for widespread clinical use. In this work, we established a bioreactor‐based manufacturing system for the production of cartilage grafts. Materials & Methods All bioprocesses, from cartilage biopsy digestion through the generation of engineered grafts, were performed in our bioreactor‐based manufacturing system. All bioreactor technologies and cartilage tissue engineering bioprocesses were transferred to an independent GMP facility, where engineered grafts were manufactured for two large animal studies. Results The results of these studies demonstrate the safety and feasibility of the bioreactor‐based manufacturing approach. Moreover, grafts produced in the manufacturing system were first shown to accelerate the repair of acute osteochondral defects, compared to cell‐free scaffold implants. We then demonstrated that grafts produced in the system also facilitated faster repair in a more clinically relevant chronic defect model. Our data also suggested that bioreactor‐manufactured grafts may result in a more robust repair in the longer term. Conclusion By demonstrating the safety and efficacy of bioreactor‐generated grafts in two large animal models, this work represents a pivotal step towards implementing the bioreactor‐based manufacturing system for the production of human cartilage grafts for clinical applications

Identification of genes involved in osteoblast differentiation with an shRNA-based approach

Mesenchymal stem cells (MSCs) derived from bone marrow and they can differentiate in a variety of cell types, including osteoblasts, adipocytes, chondrocytes, myoblasts, hepatocytes, and neural cells. For this reason they provide a promising role for developing cell-based therapy for degenerative diseases. Understanding the mechanisms behind MSC cell fate determination is not easy, because the molecular processes that drive differentiation are complex and poorly understood. So, also if in the last years many improvements have been done, some problems still remain. We planned to investigate on differentiation of MSC and in particular we wanted to focus our activities towards osteoblast differentiation; at this aim, we silenced specific mRNAs using a mouse shRNA library present in our institute, composed of at least two silencing constructs for each transcript, in a 96-well-plates-based screening strategy. In the first part of this study we set up the components and the experimental conditions to perform the screening. After, we proceeded with the screening and we were able to screen a part of the library. With this methodology we identified genes that are possible candidates to have a role in osteoblast differentiation. First of all, we made a Gene Ontology classification of these candidates using bioinfomatic tools and we identified genes involved in different processes and having different functions. Among the candidate genes, a big part is represented by genes whose function is still unknown, some of which represent putative novel transcription factors that we named ObI- (Osteoblast inducer-). In this study we focused our experiments on the first of these genes that we identified, ObI-1. We also considered genes whose function is known and that are involved in different processes but with a non described role in osteogenic differentiation. Among these genes we focused our attention on Serine racemase, which role in osteogenic differentiation was already suggested, but not largely demonstrated. For both the candidates that we treated in this study we carried out experiments to confirm the impairment in osteogenic differentiation as effects of their silencing and we made expression analyses in tissues and in our cells. Furthermore, as regards ObI-1 candidate, we performed a more deeply analysis due to characterization of his function

About the "Italian Method of the Volume di Invaso"

The paper deals with the method known as "Metodo Italiano del Volume di Invaso" (Italian Method of Stored Water Volumes). It illustrates the fundamentals of the method, showing that it is a semi-distributed, hydrologic-hydraulic model, within the peak flow discharges are obtained by using a "variational" approach. An extension of the method is presented, aiming at obtaining general but, at the same time, quite precise analytic solutions of governing equations