1,721,002 research outputs found
Proteomics changes in adhesion molecules: a driving force for vascular smooth muscle cell phenotypic switch
No full textVascular smooth muscle cells (VSMCs), if activated by growth factors as a consequence of vessel
injuries, acquire the ability to proliferate and migrate thus contributing to the formation of
neointima and atherosclerotic plaque. In this study, a gel-free and label-free proteomic approach
was proposed to highlight factors modulated during VSMC activation. Twenty proteins,
differentially expressed between quiescent and activated cells, were identified. A constellation of
elements, that move together and are closely and functionally related, was visualized. The great
majority of them are involved in cell migration and in adhesion formation, suggesting a pivotal
role of these protein complexes on the phenotypic modulation. This study represents a first step
to ascertain the precise actors of cell activation, their roles and interactions
Stochastic and exponential analysis of precordial washout curves for myocardial blood flow measurement. Experimental evaluation.
No full textUneven myocardial glucose utilization as determined by regional 14C-deoxyglucose uptake.
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Ribozymes as specific therapeutic agents against smooth muscle cell migration and proliferation: a new perspective in gene therapy
No full textPurpose: Cell migration and proliferation are still an open issues concerning atherogenesis and restenosis. The exploitation of ribozyme for the inactivation of genes involved in the phenotype changes responsible for the pathological state, could be a promising and innovative technique. The Purpose of this study was to set up a method for the delivery and the validation of a ribozyme in Vascular Smooth Muscle Cells (VSM cells).
Methods: A minimal ribozyme was tailored on PDGFR-b mRNA target sequence by an "in silico" approach and synthesized with an oligonucleotide synthesizer apparatus. The delivery was accomplished with a new polyplexed vehicle. The complex vehicle-ribozyme was administered to porcine VSM cells in culture in the presence of serum. Cells were stimulated by PDGF-BB after 24 hours and their migration activity monitored according to an "in vitro wound model".
Results: A differential migratory activity was observed: cells stimulated with PDGF-BB, invaded extensively the scratched surface, whereas cells pre-treated with ribozyme (before growth factor stimulation) displayed a considerably reduction of this repair activity. A computational measure of repair demonstrated that the ribozyme reduced the cell migration of about 90%.
Conclusions: These results are very encouraging since the activity of ribozyme was demonstrated in a biological model. Moreover, the vehicle preserved the gene-drug from nucleases and it was highly effective also in the presence of serum, condition thatmimic the effective environment of vascular tissue. Such pilot experiments open actual perspectives for "in vivo" local gene knock-down treatments suggesting therapeutic strategies based on multiple ribozymes targeting different crucial pathological genes
A portable system for autoregulation and wireless control of sensorized left ventricular assist devices
No full textEnd stage heart failure patients could benefit from left ventricular assist device (LVAD) implantation as bridge to heart transplantation or as destination therapy. However, LVAD suffers from several limitations, including the presence of a battery as power supply, the need for cabled connection from inside to outside the patient, and the lack of autonomous adaptation to the patient metabolic demand during daily activity. The authors, in this wide scenario, aim to contribute to advancement of the LVAD therapy by developing the hardware and the firmware of a portable autoregulation unit (ARU), able to fulfill the needs of sensorized VAD in terms of physic/physiological data storing, continuous monitoring, wireless control from the external environment and automatic adaptation to patient activities trough the implementation of autoregulation algorithms. Moreover, in order to answer the rules and safety requirements for implantable biomedical devices, a user control interface (UCI), was developed and associated to the ARU for an external manual safe control. The ARU and UCI functionalities and autoregulation algorithms have been successfully tested on bench and on animal, with a response time of 1 s for activating autoregulation algorithms. Animal experiments showed as the presence of the ARU do not affect the animal cardiovascular system, giving a proof of concept of its applicability in vivo
Two-dimensional near infrared spectroscopic imaging of the hand to assess microvascular abnormalities in systemic sclerosis: A pilot study
No full textPatients affected by systemic sclerosis (SSc) develop functional and structural microvascular alterations and progressive fibrosis of the skin and internal organs. Evaluation of skin microcirculation is an important clinical step in the workup of SSc patients. Near infrared (NIR) spectroscopy is a well-established non-invasive technique to assess haemoglobin oxygen saturation (StO2) in the illuminated tissue. The recent development of NIR spectroscopic two-dimensional (2D) imaging offers the possibility of visualising StO2 distribution in large tissue areas. This is particularly important in SSc characterised by a very heterogeneous spatial distribution of the microvascular abnormalities. In addition, the short acquisition time of NIR spectroscopic images allows microvascular "dynamic" conditions, such as the vascular response to physical or pharmacological stimuli, to be evaluated. The present study reports the results of the test application of NIR spectroscopic 2D imaging of the palmar whole-hand surface for the evaluation of peripheral microcirculatory dysfunction in one patient with SSc, as compared with a healthy control, both in "static" (resting) and in "dynamic" (ischaemia-reperfusion) conditions. Spatial heterogeneity of microvascular alterations associated with temporal heterogeneity in vascular reactivity to ischaemic challenge make 2D NIR spectroscopic imaging a promising tool in the assessment of SSc, as compared with the current available techniques. A NIR spectroscopic camera by Kent Imaging Inc, Calgary, Canada was used
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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