1,721,157 research outputs found
Intra-articular 500-730 kDa hyaluronan (Hyalgan®) therapy in the management of osteoarthritis. Can a specific therapeutic profile be defined?
No full textIntra-articular hyaluronic acid (HA) injections for the symptomatic relief of pain have been available for treatment since the 1980s. Practitioner experience and real-world evidence have been accumulated to suggest that HA injections are effective and well tolerated in patients. Treatment guidelines issued by different professional medical societies, however, do not point in a single direction. This appears mainly due to conflicting results of the proposed meta-analyses at least in part associated with a variability between different HA preparations on different outcome parameters, suggesting that intra-articular HA products should not be treated as a group, as there are differences between them influencing both efficacy and safety
MORPHOMETRIC EVALUATION OF POPULATIONS OF NEURONAL PROFILES (CELL-BODIES, DENDRITES, AND NERVE-TERMINALS) IN THE CENTRAL-NERVOUS-SYSTEM
No full textMorphometric techniques have been developed to quantitatively characterize groups of transmitter-identified neuronal profiles, such as cell groups, dendrite and nerve terminal fields. These morphometric techniques will be illustrated by introducing some general tools for image analysis which can be considered as a background for the present specific applications. The following methods have been included: (1) methods to identify and quantitatively characterize, from both numerical and geometrical standpoints, groups of profiles in a two- and three-dimensional frame; (2) methods to evaluate the evenness of a certain distribution of profiles in the plane; (3) methods to identify subgroups of profiles based on their different spatial or optical density; and (4) methods to compare the distributions of two or more groups of profiles. The applications of these general tools to some neuroanatomical problems, such as cell group definition and description, have been illustrated. Practical examples performed on immunocytochemical preparations of neuronal profile populations are also given. Finally, the potentiality of numerical classification to classify and compare morphometric data has been shown. As an example, numerical classification methods have been applied to the morphometric and microdensitometric analysis of adrenaline/neuropeptide Y costoring neuronal systems of the brainstem in adult and aged rats
Spatial Statistics-Based Image Analysis Methods for the Study of Vascular Morphogenesis
No full textSeveral studies are available addressing the mechanisms of vascular morphogenesis in order to unravel how cooperative cell behavior can follow from the underlying, genetically regulated behavior of endothelial cells and from cell-to-cell and cell-to-extracellular matrix interactions. From the morphological standpoint several aspects of the process are of interest. They include the way the pattern of vessels fills the available tissue space and how the network grows during the angiogenic process, namely how a main trunk divides into smaller branches, and how branching occurs at different distances from the root point of a vascular tree. A third morphological aspect of interest concerns the spatial relationship between vessels and tissue cells able to secrete factors modulating endothelial cells self-organization, thus influencing vascular rearrangement. In the present chapter image analysis methods allowing for a quantitative characterization of these morphological aspects will be detailed and discussed. They are almost based on concepts derived from the theoretical framework represented by spatial statistics
Cell sentience and integrative brain actions: possible role of membrane protein energy landscape and of primary cilium function
No full textA boolean network modelling of receptor mosaics relevance of topology and cooperativity
No full textIn the last five years data have been obtained showing that a functional cross-talk among G Protein Coupled receptors (GPCR) exists at the plasma membrane level where they can dimerise and are able to generate high order oligomers. These findings are in agreement with the receptor mosaic (RM) hypothesis that claims the existence of clusters of receptor proteins at the plasma membrane level, where they establish mutual interactions and work as 'intelligent interfaces' between the extra-cellular and the intra-cellular environments. Individual receptor dimers can be considered to have two stable conformational states with respect to the macromolecular effectors: one active, one inactive. Owing to receptor-receptor interactions, however, a state change of a given receptor will change the probability of changing the state for the adjacent receptors in the RM and the effect will propagate throughout the cluster, leading to a complex cooperative behaviour. In this study we explore the properties of a RM on the basis of an equivalence with a Boolean network, a mathematical framework able to describe how complex properties may emerge from systems characterized by deterministic local interactions of many simple components acting in parallel. Computer simulations of receptor clusters arranged according to topologies consistent with available experimental ultrastructural data were performed. They indicated that RMs after a stimulation can achieve a limited number of specific temporary equilibrium configurations (attractors), characterized by the presence of receptor units frozen in the active state. They could be interpreted as a form of information storage and a role of RM in learning and memory could be hypothesized. Moreover, they seem to be at the basis of very common 'macroscopical' properties of a receptor system, such as a sigmoidal response curve to an extracellular ligand, the sensitivity of the mosaic being modulated by changes in the topology and/or in the level of cooperativity among receptors
Fine ultrastructure of chromaffin granules in rat adrenal medulla indicative of a vesicle-mediated secretory process
No full textInner speech mis-exaptation can cause the “Hubris” that speeds up ecosystem over-exploitation
No full textSpatial distribution of blood vessels in the chick embryo chorioallantoic membrane
Full text linkThe chick embryo chorioallantoic membrane (CAM) is a useful tool with which to study both angiogenesis and anti-angiogenesis in vivo. CAM vascular growth pattern - including the way through vessels fills the available space - can be quite easily described and quantified using image analysis procedures, in order to evaluate different parameters, including fractal dimension, lacunarity and non-fractal order-disorder parameters. In the present study, we further expanded this morphological description, by estimating an index expressing the degree of symmetry characterizing the CAM vascular tree structure in the course of the embryonic development. Moreover, a uniformity index was estimated quantitatively to characterize the space-filling features of the vessels, i.e. the degree of spatial uniformity of their distribution in the tissue
G protein-coupled receptor-receptor interactions give integrative dynamics to intercellular communication
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