These various markers are involved in a host of cellular functions, including

cell-cycle progression, cell proliferation, AC220 apoptosis, cell adhesion, and tumor vascularity. In this companion article to our first review of Ki-67 as a marker of pituitary adenomas, we present and analyze the literature regarding matrix metalloproteinases and their inhibitors (tissue inhibitor metalloproteinases), vascular endothelial growth factor, fibroblast growth factor and its receptor, apoptotic markers and p53, as well as cyclooxygenase-2, galectin-3, and pituitary tumor transforming gene. Some of these markers, such as fibroblast growth factor and fibroblast growth factor receptor and matrix metalloproteinases, show particular promise in their ability to identify pituitary tumors that behave in an aggressive PRT062607 manner. We suggest the need for uniform design and application of methods and standardized criteria for the interpretation of results. A uniform approach

will establish clinicopathological utility of emerging markers.”
“The Arabidopsis thaliana flower organ specification gene regulatory network (FOS-GRN) has been modeled previously as a discrete dynamical system, recovering as steady states configurations that match the genetic profiles described in primordial cells of inflorescence, sepals, petals, stamens and carpels during early flower development. In this study, we first update the FOS-GRN by adding interactions and modifying some rules according Vitamin B12 to new experimental data. A discrete model of this updated version of the network has a dynamical behavior identical to previous versions, under both wild type and mutant conditions, thus confirming its robustness. Then, we develop a continuous version of the FOS-GRN using a new methodology

that builds upon previous proposals. The fixed point attractors of the discrete system are all observed in the continuous model, but the latter also contains new steady states that might correspond to genetic activation states present briefly during the early phases of flower development. We show that both the discrete and the continuous models recover the observed stable gene configurations observed in the inflorescence meristem, as well as the primordial cells of sepals, petals, stamens and carpels. Additionally, both models are subjected to perturbations in order to establish the nature of additional signals that may suffice to determine the experimentally observed order of appearance of floral organs. Our results thus describe a possible mechanism by which the network canalizes molecular signals and/or noise, thus conferring robustness to the differentiation process. (C) 2010 Elsevier Ltd. All rights reserved.