New and Improved Tissue Engineering Techniques: Production of Exogenous Material-Free Stroma by the Self-Assembly Technique

Tissue engineering results from the use of cells and scaffolds to reproduce structural and spatial organization or function of a tissue. The Production of an ideal engineered tissue depends on its designed purpose. For clinical applications, the main concerns are biocompatibility and the generation of a tissue able to mimic most of its original biological functions. Moreover, the viability of an implanted tissue is associated with its stability to support vascular networks. This chapter summarizes the theory of the self-assembly approach for tissue engineering. Adjustments and modifications in stromal thickness and extracellular matrix composition for various self-assembled tissues are discussed. Methods developed to generate tissue closely mimicking the native morphology and structure, to incorporate capillary-like networks, and to reduce production time and costs are also reviewed. The self-assembly technique leads to the production of a stroma free of exogenous material and can be adapted to generate fastest, inexpensive, and near-to-native tissue bioengineering for medical and fundamental research applications

Apoptosis Modulation as a Promising Target for Treatment of Systemic Sclerosis

Diffuse systemic sclerosis (SSc) is a fatal autoimmune disease characterized by an excessive ECM deposition inducing a loss of function of skin and internal organs. Apoptosis is a key mechanism involved in all the stages of the disease: vascular damage, immune dysfunction, and fibrosis. The purpose of this paper is to gather new findings in apoptosis related to SSc, to highlight relations between apoptosis and fibrosis, and to identify new therapeutic targets

Étude des fonctions anti-apoptotique et de chaperon moléculaire de la sous-unité R1 de la ribonucléotide réductase du virus de l'herpès simplex de type-2

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal

Anticancer properties of chitosan on human melanoma are cell line dependent

Purpose: Chitosan, a natural macromolecule, is widely used in medical and pharmaceutical fields because of its distinctive properties such as bactericide, fungicide and above all its antitumor effects. Although its antitumor activity against different types of cancer had been previously described, its mechanism of action was not fully understood. Materials and methods: Coating of chitosan has been used in cell cultures with A375, SKMEL28, and RPMI7951 cell lines. Adherence, proliferation and apoptosis were investigated. Results: Our results revealed that whereas chitosan decreased adhesion of primary melanoma A375 cell line and decreased proliferation of primary melanoma SKMEL28 cell line, it had potent pro-apoptotic effects against RPMI7951, a metastatic melanoma cell line. In these latter cells, inhibition of specific caspases confirmed that apoptosis was effected through the mitochondrial pathway and Western blot analyses showed that chitosan induced an up regulation of pro-apoptotic molecules such as Bax and a down regulation of anti-apoptotic proteins like Bcl-2 and Bcl-XL. More interestingly, chitosan exposure induced an exposition of a greater number of CD95 receptor at RPMI7951 surface, making them more susceptible to FasL-induced apoptosis. Conclusion: Our results indicate that chitosan could be a promising agent for further evaluations in antitumor treatments targeting melanoma

Gestion prédictive d'un micro-réseau résidentiel

International audienceDans cet article est présentée une stratégie de gestion prédictive destinée au pilotage des systèmes de production et de stockage d'énergie d'un micro-réseau résidentiel. Ainsi, un habitat d'une surface de 190 m2, situé dans le sud de la France et qu'il est possible d'équiper de panneaux solaires photovoltaïques, d'une éolienne à axe vertical et de batteries, a été modélisé. Une tarification dynamique a également été considérée. Cette stratégie tient compte des états actuel et futur du réseau électrique ainsi que des interactions entre ce dernier et le micro-réseau. L'objectif est ici de favoriser l'auto-consommation d'énergie, tout en minimisant l'impact négatif de la production locale sur le réseau électrique. Les résultats obtenus en simulation démontrent notamment que le recours à un système de stockage électrique, piloté grâce à la stratégie proposée, permet d'optimiser l'interaction avec le réseau électrique. Enfin, l'auto-consommation est favorisée par le mix-énergétique considéré

Coastal zone management in the fisheries sector program

International audienceThis paper presents an analysis of censored survival data for breast cancer specific mortality and disease-free survival. There are three stages to the process, namely time-to-event modelling, risk stratification by predicted outcome and model interpretation using rule extraction. Model selection was carried out using the benchmark linear model, Cox regression but risk staging was derived with Cox regression and with Partial Logistic Regression Artificial Neural Networks regularised with Automatic Relevance Determination (PLANN-ARD). This analysis compares the two approaches showing the benefit of using the neural network framework especially for patients at high risk. The neural network model also has results in a smooth model of the hazard without the need for limiting assumptions of proportionality. The model predictions were verified using out-of-sample testing with the mortality model also compared with two other prognostic models called TNG and the NPI rule model. Further verification was carried out by comparing marginal estimates of the predicted and actual cumulative hazards. It was also observed that doctors seem to treat mortality and disease-free models as equivalent, so a further analysis was performed to observe if this was the case. The analysis was extended with automatic rule generation using Orthogonal Search Rule Extraction (OSRE). This methodology translates analytical risk scores into the language of the clinical domain, enabling direct validation of the operation of the Cox or neural network model. This paper extends the existing OSRE methodology to data sets that include continuous-valued variables

Wild Helianthus species: A reservoir of resistance genes for sustainable pyramidal resistance to broomrape in sunflower

Orobanche cumana Wall., sunflower broomrape, is one of the major pests for the sunflower crop. Breeding for resistant varieties in sunflower has been the most efficient method to control this parasitic weed. However, more virulent broomrape populations continuously emerge by overcoming genetic resistance. It is thus essential to identify new broomrape resistances acting at various stages of the interaction and combine them to improve resistance durability. In this study, 71 wild sunflowers and wild relatives accessions from 16 Helianthus species were screened in pots for their resistance to broomrape at the late emergence stage. From this initial screen, 18 accessions from 9 species showing resistance, were phenotyped at early stages of the interaction: the induction of broomrape seed germination by sunflower root exudates, the attachment to the host root and the development of tubercles in rhizotron assays. We showed that wild Helianthus accessions are an important source of resistance to the most virulent broomrape races, affecting various stages of the interaction: the inability to induce broomrape seed germination, the development of incompatible attachments or necrotic tubercles, and the arrest of emerged structure growth. Cytological studies of incompatible attachments showed that several cellular mechanisms were shared among resistant Helianthus species.This study was performed in the frame of a 3-year project (ResODiv), funded by “Promosol” (the association of French Sunflower and Rapeseed Breeders for promoting these crops).Peer reviewe