CGMLab: una GUI MatLab per l'analisi e l'elaborazione di segnali misurati da sensori continui della glicemia

CGMLab è un'interfaccia grafica utente, composta da multipli moduli grafici e di processamento. Essa è stata costruita per rendere utilizzabili e trasferibili gli algoritmi di elaborazione dei segnali CGM sviluppati dal gruppo di ricerca di bioingegneria di Padova. Inoltre, CGMLab consente una gestione versatile e robusta delle serie temporali in esame e comporta una notevole riduzione dei tempi di studio. Fino ad ora sono stati sviluppati i moduli per lo smoothing e per la predizioneope

Fast blood impedance measurements as quality indicators in the pre-analytical phase to prevent laboratory errors

In clinical laboratories, the major proportion of errors regarding blood analyses occurs in the pre-analytical phase. Pre-analytical conditions are key, necessary factors in maintaining the high quality of specimens, limiting day-to-day and batch variations, and guaranteeing the absolute reliability and accuracy of clinical results and related diagnoses. The quality of serum samples must be very high in order to avoid interferences due to hemolysis, thereby preventing measurement errors. In addition, the quality of the blood should always be fast monitored to identify inadequacies and guarantee their complete usability in transfusion procedures. In the near future, the solution could be to supply laboratories with smart and portable devices that are able to perform fast quality tests for every sample. Electrical impedance has relevant potential in analyzing and monitoring blood quality. We propose a new, simple impedancebased biosensor that can perform accurate and efficient single and multi-frequency impedance measurements in the pre-analytical phase and to check the quality of blood samples using quantitative thresholds as useful indicators to ensure the reliability of results and thereby prevent laboratory errors. The proposed sensor allows for discriminating different blood components, identifying hemolysis in serum, evaluating blood quality, and rapidly quantifying its hematocrit

A new method for accurate platelet thrombi volume measurement using a confocal microscope

The accuracy of quantitative measurements represents an essential pre-requisite to the characterization and definition of the complex dynamic phenomena occurring in the field of cell biology. In research projects that involve the induction of blood coagulation under flow in microfluidic artificial channels, thrombus volume is an important quantity for estimation as a significant index related to the individual thrombotic risk profile. Concerning its importance in the early diagnosis of cardiovascular diseases, the estimated thrombus volume should reflect and represent reality. In 3D confocal microscopy, systematic errors can arise from distortions of the axial distance, whose accurate calibration remains a challenge. As a result, the 3D reconstructions show a noticeable axial elongation, and the volume measurements are thus overestimated. In this paper, a 400-600 % volume overestimation is demonstrated, and a new easy to use and automatic calibration procedure is outlined for this specific microfluidic and optical context. The adaptive algorithm proposed leads to the automatic compensation of the elongation error and to the accurate thrombus volume measurement. The method has been calibrated using fluorescent beads of known volume, validated with groups of several distinct platelets and finally applied on platelet thrombi

Bioreattori per l'ingegneria tissutale della cartilagine

Negli ultimi anni l’ingegneria dei tessuti biologici ha permesso un miglioramento della qualità della vita grazie alle sue applicazioni nell’ambito della medicina rigenerativa. In particolare, per l’ingegnerizzazione della cartilagine articolare, tessuto con limitatissima capacità autorigenerativa, sono stati sviluppati diversi tipi di bioreattori che, a differenza delle tradizionali colture cellulari statiche, favoriscono l’adesione e la crescita di condrociti o cellule staminali mesenchimali - in maniera dinamicamente controllata - su supporti polimerici tridimensionali biodegradabili. I bioreattori per il tessuto cartilagineo possiedono, solitamente, un sistema a perfusione per l’ottimizzazione del trasporto di nutrienti, ossigeno e prodotti di scarto, e sistemi di applicazione di stimoli meccanici, quali pressione idrostatica e idrodinamica, sforzi di taglio e compressione dinamica per conferire al neotessuto le proprietà fisiche e strutturali della cartilagine nativa. Un successo in ambito clinico e ospedaliero sarà veramente possibile, però, solo quando verranno colmate le attuali lacune legislative riguardanti l’ingegneria tissutale e quando sarà possibile definire precise relazioni di causa-effetto tra la modulazione dei parametri di coltura e le risultanti proprietà del tessut

FluoLab: A New Easy-to-use Graphical User Interface for the Multi-cell Functional Calcium Signals Analysis

The progress in fluorescence microscopy and information technologies have completely transformed the study on living cells improving the capability to quantify, investigate and analyze, in time and space, single phenomena occurring inside and outside cells. We developed an user-friendly Graphical User Interface (GUI) able to extract and analyze ion calcium (Ca2+) signals and to understand how they regulate cell behavior and metabolism. The software, named FluoLab (Fluorescence Laboratory), works on acquired confocal fluorescence microscopy images and allows to obtain signals of Mean Fluorescence Intensity (MFI). Afterwards, the fluorescence signals are automatically converted in ion calcium concentration values, [Ca2+], expressed in microMolarity (\u3bcM), by using the specific dissociation constant Kd for each kind of fluorescent probes chosen for the experiments. It is possible to analyze contemporaneously more than one object through the Region Of Interest (ROI) defined around them and to follow them in time. FluoLab can also show a normalization of the obtained data, compensating automatically the image background and generating a file that can be used for a fast data analysi

Factor H interferes with the adhesion of sickle red cells to vascular endothelium : a novel disease-modulating molecule

Sickle cell disease is an autosomal recessive genetic red cell disorder with a worldwide distribution. Growing evidence suggests a possible involvement of complement activation in the severity of clinical complications of sickle cell disease. In this study we found activation of the alternative complement pathway with microvascular deposition of C5b-9 on skin biopsies from patients with sickle cell disease. There was also deposition of C3b on sickle red cell membranes, which is promoted locally by the exposure of phosphatidylserine. In addition, we showed for the first time a peculiar "stop-and-go" motion of sickle cell red blood cells on tumor factor-alpha-activated vascular endothelial surfaces. Using the C3b/iC3b binding plasma protein factor H as an inhibitor of C3b cell-cell interactions, we found that factor H and its domains 19-20 prevent the adhesion of sickle red cells to the endothelium, normalizing speed transition times of red cells. We documented that factor H acts by preventing the adhesion of sickle red cells to P-selectin and/or the Mac-1 receptor (CD11b/CD18), supporting the activation of the alternative pathway of complement as an additional mechanism in the pathogenesis of acute sickle cell related vaso-occlusive crises. Our data provide a rationale for further investigation of the potential contribution of factor H and other modulators of the alternative complement pathway with potential implications for the treatment of sickle cell disease.Peer reviewe

Impedance biosensor for <i>real-time</i> monitoring and prediction of thrombotic individual profile in flowing blood

<div><p>A new biosensor for the <i>real-time</i> analysis of thrombus formation is reported. The fast and accurate monitoring of the individual thrombotic risk represents a challenge in cardiovascular diagnostics and in treatment of hemostatic diseases. Thrombus volume, as representative index of the related thrombotic status, is usually estimated with confocal microscope at the end of each <i>in vitro</i> experiment, without providing a useful behavioral information of the biological sample such as platelets adhesion and aggregation in flowing blood. Our device has been developed to work either independently or integrated with the microscopy system; thus, images of the fluorescently labeled platelets are acquired in <i>real-time</i> during the whole blood perfusion, while the global electrical impedance of the blood sample is simultaneously monitored between a pair of specifically designed gold microelectrodes. Fusing optical and electrical data with a novel technique, the dynamic of thrombus formation events in flowing blood can be reconstructed in <i>real-time</i>, allowing an accurate extrapolation of the three-dimensional shape and the spatial distribution of platelet thrombi forming and growing within artificial capillaries. This biosensor is accurate and it has been used to discriminate different hemostatic conditions and to identify weakening and detaching platelet aggregates. The results obtained appear compatible with those quantified with the traditional optical method. With advantages in terms of small size, user-friendliness and promptness of response, it is a promising device for the fast and automatic individual health monitoring at the Point of Care (POC).</p></div

Volumes comparison.

<p>Comparison between volumes <i>V</i>_<i>OT</i> and <i>V</i>_<i>IM</i> obtained at t = 300 s from optical and impedance data (n = 22). Data are highly correlated and exhibit a Pearson’s correlation coefficient <i>r</i> equal to 0.96 (<i>p</i> value < 0.01). The linear representation of data (black line) is shown together with the ideal agreement condition (red dashed line).</p