591 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
An image analysis of the spatial distribution of perivascular mast cells in human melanoma
No full textA mutual spatial and functional relationship occurs between mast cells (MCs) and endothelial cells and the density of MCs is highly correlated with the extent of tumor angiogenesis. The aim of this study was to investigate the pattern of MCs around the blood vessels in melanoma samples by means of an approach derived from spatial statistics, based on the analysis of the distribution of the distances of MCs from vessels to objectively establish if the two structures (MCs and vessels) are distributed independently over the studied area or if they displayed any kind of spatial association. Results showed that a higher number of vessels and MCs can be observed in melanoma as compared with samples from common acquired nevi (control group). The percent of area covered by vessel profiles was significantly higher in the melanoma group than the control group and the MC density was also significantly different; the melanoma group showing a number of MCs per unit area twice as high as the number measured in the control group. Furthermore, in the melanoma group, MCs were closer to each other and to the vessels. In fact, both the mean distance from vessels and the mean distance from the nearest cell profile were significantly lower than in the control group. This close association between MCs and the endothelium does not necessarily imply a participation of MCs in angiogenic processes, but might rather indicate that MCs are involved in the maintenance reaction necessary for the long lasting functional integrity of the endothelium
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
Tumoral mast cells exhibit a common spatial distribution
No full textMast cells (MCs) accumulate in the stroma surrounding tumors and take part in the inflammatory reaction occurring at the margin of the neoplasia. Moreover, MC secretes angiogenic cytokines and matrix metalloproteinases. The aim of this study was to investigate the pattern of distribution of MCs in biopsy samples obtained from four different human tumors, utilizing an image analysis system and a mathematical model to make a quantitative approach to characterizing their spatial distribution. Results showed a similar spatial arrangement of MCs in all the neoplastic tissues examined, despite histological and/or pathologic differences. In all these tissues MCs demonstrated a virtually random spatial distribution, albeit with varying densities. These results suggest that MC-MC interactions could play a minor role in the formation of the MC pattern in neoplastic tissues. The random distribution of the cells in the tissues could be accounted for by a random walk-migration under the influence of cell-matrix interactions or chemotactic fields potentially generated by tumor or endothelial cells
The "self-similarity logic" applied to the development of the vascular system
No full textFrom a structural standpoint, living systems exhibit a hierarchical pattern of organization in which structures
are nested within one another. From a temporal point of view, this type of organization is the outcome of a
‘history’ resulting froma set of developmental steps. Recently, it has been suggested that some auto similarity
prevails at each nested level or time step and a principle of “self-similarity logic” has been proposed to convey
the concept of a multi-level organization in which very similar rules (logic) apply at each level. In this study,
the hypothesis is put forward that such a principle is particularly apparent in many morphological and
developmental aspects of the vascular system. In fact, not only the morphology of the vascular system exhibit
a high degree of geometrical self-similarity, but its remodelling processes also seemto be characterized by the
application of almost the same rules, from the macroscopic to the endothelial cell to the sub-cellular levels,
potentially allowing a unitary description of features such as sprouting and intussusceptive angiogenesis, and
phenotypic differences of endothelial cells. The influence of the “self-similarity logic” shaping the vascular
system on the organogenesis has been also discussed
Differential Sensitivity of A(2A) and Especially D(2) Receptor Trafficking to Cocaine Compared with Lipid Rafts in Cotransfected CHO Cell Lines. Novel Actions of Cocaine Independent of the DA Transporter
No full textThe effects of low and high concentrations of cocaine have been studied in vitro on the trafficking of plasma membrane A(2A) and D(2) immunoreactivities in previously characterized A(2A)-D(2) CHO cell lines. Receptor double immunofluorescence staining was performed with D(2) and A(2A) antibodies, planar lipid rafts immunolabeling with biotinylated cholera toxin subunit B and membrane invaginations with an anti-caveolin-1 antibody. A computer-assisted image analysis demonstrated a substantial and highly significant rise of membrane-associated D(2) immunoreactivity (IR) after 8 h of exposure to a low concentration of cocaine (150 nM). At this low concentration of cocaine, there was also an increase of membrane associated A(2A) immunoreactivity but smaller and less significant. However, this increase became considerably larger and highly significant at 150 microM at which concentration the rise of D(2) immunoreactivity had begun to disappear. It may be suggested that an allosteric action of cocaine at 150 nM on the D(2) receptors may primarily increase the insertion of D(2) monomers, homomers and also of a subpopulation of A(2A)-D(2) heteromers from the cytoplasm into the plasma membrane due to the conformational change induced by cocaine in the D(2) receptor. The planar lipid rafts and the caveolae are only affected by the higher concentrations of cocaine. It is proposed that changes in D(2) and A(2A)-D(2) trafficking induced by allosteric actions of cocaine at D(2) receptors may contribute to the alterations of D(2) signaling found in cocaine abusers
ACTIVATION OF POLYPHOSPHOINOSITIDE METABOLISM AS A SIGNAL-TRANSDUCING SYSTEM COUPLED TO EXCITATORY AMINO-ACID RECEPTORS IN ASTROGLIAL CELLS
No full textExcitatory amino acids (EAA) are known to induce an increase in the breakdown of polyphosphoinositides (PI) in brain slices and in dispersed cultures of neurons. We have now used astroglia cultured from newborn rat cerebra to demonstrate that glutamate provokes, in [3H]inositol-labeled cells, an accumulation of inositol phosphates in a time- and concentration-dependent manner. The ED50 value for glutamate was 40 microM. Quisqualate, ibotenate, and kainate were also active, with their relative potencies in the order of quisqualate greater than ibotenate much greater than kainate. No effect was detected with N-methyl-D-aspartate and quinolinic acid in the absence of Mg2+. The nonselective glutamate receptor antagonist gamma-D-glutamylglycine fully inhibited glutamate agonist-induced PI breakdown. A brief pretreatment of the astroglial cells with phorbol esters negated these effects of EAA receptor agonists, suggesting a feedback role for protein kinase C in phospholipase C action. Glutamate also elevated cytosolic free Ca2+ in Fura-2-loaded astroglial cells, as assessed by digital fluorescence imaging microscopy. Since a close metabolic partnership is known to exist between neurons and glia, these findings may have important functional consequences for neural cells in vivo
UNIPD-BPE: Synchronized RGB-D and Inertial Data for Multimodal Body Pose Estimation and Tracking
No full textThe ability to estimate human motion without requiring any external on-body sensor or marker is of paramount importance in a variety of fields, ranging from human–robot interaction, Industry 4.0, surveillance, and telerehabilitation. The recent development of portable, low-cost RGB-D cameras pushed forward the accuracy of markerless motion capture systems. However, despite the widespread use of such sensors, a dataset including complex scenes with multiple interacting people, recorded with a calibrated network of RGB-D cameras and an external system for assessing the pose estimation accuracy, is still missing. This paper presents the University of Padova Body Pose Estimation dataset (UNIPD-BPE), an extensive dataset for multi-sensor body pose estimation containing both single-person and multi-person sequences with up to 4 interacting people. A network with 5 Microsoft Azure Kinect RGB-D cameras is exploited to record synchronized high-definition RGB and depth data of the scene from multiple viewpoints, as well as to estimate the subjects’ poses using the Azure Kinect Body Tracking SDK. Simultaneously, full-body Xsens MVN Awinda inertial suits allow obtaining accurate poses and anatomical joint angles, while also providing raw data from the 17 IMUs required by each suit. This dataset aims to push forward the development and validation of multi-camera markerless body pose estimation and tracking algorithms, as well as multimodal approaches focused on merging visual and inertial data
Fine ultrastructure of chromaffin granules in rat adrenal medulla indicative of a vesicle-mediated secretory process
No full textObservation by transmission electron microscopy, coupled with morphometric analysis and estimation procedure, revealed unique ultrastructural features in 25.94% of noradrenaline (NA)- and 16.85% of adrenaline (A)-containing granules in the rat adrenal medulla. These consisted of evaginations of the granule limiting membrane to form budding structures having different morphology and extension. In 14.8% of NA-granules and 12.0% of A-granules, outpouches were relatively short, looked like small blebs emerging from the granule surface and generally contained electron-dense material. A proportion of 11.2% of NA-granules and 4.9% of A-granules revealed the most striking ultrastructural features. These secretory organelles presented thin, elongated, tail-like or stem-like appendages, which were variably filled by chromaffin substance and terminated with spherical expansions of different electron-density. A cohort of vesicles of variable size (30 to 150 nm in diameter) and content was found either close to them or in the intergranular cytosol. Examination of adrenal medullary cells fixed by osmium-zinc iodide (ZIO) revealed fine electron dense precipitates in chromaffin granules, budding structures as well as cytoplasmic vesicles. This data indicate that a common constituent is revealed by the ZIO histochemical reaction in chromaffin cells. As catecholic compounds are the main tissue target of ZIO complexes, catecholamines are good candidates to be responsible for the observed ZIO reactivity. This study adds further to the hypothesis that release of secretory material from chromaffin granules may be accomplished by a vesiclular transport mechanism typical of piecemeal degranulation
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
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