Design and testing of a microelectrode array with spatial resolution for detection of cancerous cells in mixed cultures

We present the design, construction and testing of a microelectrode array with spatial resolution which can be used for the detection of cancerous cells in a mixed cell culture by means of the impedance spectroscopy technique. Two different microelectrode diameters, namely 57 m and 211 m, were tested. A layer of an AuCu alloy was deposited between the glass substrate and the exterior Au layer, enhancing the adhesion of the microelectrodes to the substrate and at the same time showing lower impedance than the commonly used material Au. Characteristic features were extracted from the impedance measurements at different phases (growth, confluence, wound and healing) and used to feed a Linear Discriminant Analysis algorithm in order to discriminate between normal and cancerous cells. Relevant statistical tests were applied in the discrimination model for each phase. Finally, it was determined that the larger microelectrodes have a superior discriminant capacity: no incorrect classifications were obtained with microelectrodes measuring 211 m in diameter, while 23.5% false positives and 5.6% false negatives were obtained with 57 m microelectrodes.Fil: Giana, Fabián Eduardo. Comisión Nacional de Energía Atómica. Gerencia de Área de Energía Nuclear. Gerencia de Ingeniería Nuclear (CAB). Laboratorio Cavitación y Biotecnología; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bonetto, Fabian Jose. Comisión Nacional de Energía Atómica. Gerencia de Área de Energía Nuclear. Gerencia de Ingeniería Nuclear (CAB). Laboratorio Cavitación y Biotecnología; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bellotti, M. I.. Comisión Nacional de Energía Atómica. Gerencia de Área de Energía Nuclear. Gerencia de Ingeniería Nuclear (CAB). Laboratorio Cavitación y Biotecnología; Argentin

A new technique to detect ocular pathologies based on electrical measurement implemented on programmable logic

We developed a technique that detects superficial ocular pathologies based on the measurement of electrical impedance spectra. The sensor used is a small microelectrode made of platinum insulated from a cylindrical counterelectrode built of surgical stainless steel. The sensor has the shape of a truncated cone made of acrylic with dimensions identical to that of a standard Goldman prism. The sensor is applied to normal and pathological subject eyes with a constant force provided by a commercial tonometer. The circuit is closed through the lacrimal layer and the epithelial and endothelial cells. We measure the electrical impedance with a programmable logic device in which we implemented all the significant functions. These are the synthesis of the seventeen sines for the excitation, one lock-in, and delta-sigma modulators for the digital-to-analog converter and analog-to-digital converter requirements. A simple analog circuit filters the output, implements a voltage divider, and acts as current limiter in order not to damage the cells. We convert the measurements to resistance and capacitance as a function of frequencies. Consistent results are obtained for left and right eyes of the normal subjects. Significant differences are detected between the results for normal eyes and pathological eyes.Fil: Bellotti, Mariela I.. Comisión Nacional de Energía Atómica. Gerencia de Área de Energía Nuclear. Gerencia de Ingeniería Nuclear (CAB). Laboratorio Cavitación y Biotecnología; ArgentinaFil: Dellavale Clara, Hector Damian. Comisión Nacional de Energía Atómica. Gerencia de Área de Energía Nuclear. Gerencia de Ingeniería Nuclear (CAB). Laboratorio Cavitación y Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Bonetto, Fabian Jose. Comisión Nacional de Energía Atómica. Gerencia de Área de Energía Nuclear. Gerencia de Ingeniería Nuclear (CAB). Laboratorio Cavitación y Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentin

Specification and Verification of Media Constraints using UPPAAL

We present the formal specification and verification of a multimedia stream. The stream is described in a timed automata notation. We verify that the stream satisfies certain quality of service properties, in particular, throughput and end-to-end latency. The verification tool used is the real-time model checker UPPAAL

Results of a search for 2β\beta-decay of 136^{136}Xe with high-pressure copper proportional counters in Baksan Neutrino Observatory

The experiment for the 2$\beta$-decay of $^{136}$Xe search with two high-pressure copper proportional counters has been held in Baksan neutrino observatory. The search for the process is based on comparison of spectra measured with natural and enriched xenon. No evidence has been found for 2$\beta$(2$\nu$)- and 2$\beta$(0$\nu$)-decay. The decay half lifetime limit based on data measured during 8000 h is T$_{1/2}$$\geq8.5\cdot10^{21}$yr for 2$\nu$-mode and T$_{1/2}$$\geq3.1\cdot10^{23}$yr for 0$\nu$-mode (90%C.L.).Comment: 9 pages, 8 figures; talk at the NANP'05 Conference; submitted to Phys. At. Nuc

Random forests highlight the combined effect of environmental heavy metals exposure and genetic damages for cardiovascular diseases

Heavy metals are a dangerous source of pollution due to their toxicity, permanence in the environment and chemical nature. It is well known that long-term exposure to heavy metals is related to several chronic degenerative diseases (cardiovascular diseases, neoplasms, neurodegenerative syndromes, etc.). In this work, we propose a machine learning framework to evaluate the severity of cardiovascular diseases (CVD) from Human scalp hair analysis (HSHA) tests and genetic analysis and identify a small group of these clinical features mostly associated with the CVD risk. Using a private dataset provided by the DD Clinic foundation in Caserta, Italy, we cross-validated the classification performance of a Random Forests model with 90 subjects affected by CVD. The proposed model reached an AUC of 0.78 ± 0.01 on a three class classification problem. The robustness of the predictions was assessed by comparison with different cross-validation schemes and two state-ofthe-art classifiers, such as Artificial Neural Network and General Linear Model. Thus, is the first work that studies, through a machine learning approach, the tight link between CVD severity, heavy metal concentrations and SNPs. Then, the selected features appear highly correlated with the CVD phenotype, and they could represent targets for future CVD therapies

C. elegans expressing human β2-microglobulin: a novel model for studying the relationship between the molecular assembly and the toxic phenotype.

Availability of living organisms to mimic key step of amyloidogenesis of human protein has become an indispensable tool for our translation approach aiming at filling the deep gap existing between the biophysical and biochemical data obtained in vitro and the pathological features observed in patients. Human β(2)-microglobulin (β(2)-m) causes systemic amyloidosis in haemodialysed patients. The structure, misfolding propensity, kinetics of fibrillogenesis and cytotoxicity of this protein, in vitro, have been studied more extensively than for any other globular protein. However, no suitable animal model for β(2)-m amyloidosis has been so far reported. We have now established and characterized three new transgenic C. elegans strains expressing wild type human β(2)-m and two highly amyloidogenic isoforms: P32G variant and the truncated form ΔN6 lacking of the 6 N-terminal residues. The expression of human β(2)-m affects the larval growth of C. elegans and the severity of the damage correlates with the intrinsic propensity to self-aggregate that has been reported in previous in vitro studies. We have no evidence of the formation of amyloid deposits in the body-wall muscles of worms. However, we discovered a strict correlation between the pathological phenotype and the presence of oligomeric species recognized by the A11 antibody. The strains expressing human β(2)-m exhibit a locomotory defect quantified with the body bends assay. Here we show that tetracyclines can correct this abnormality confirming that these compounds are able to protect a living organism from the proteotoxicity of human β(2)-m

Lung Nodule Detection in Screening Computed Tomography

A computer-aided detection (CAD) system for the identification of pulmonary nodules in low-dose multi-detector helical Computed Tomography (CT) images with 1.25 mm slice thickness is presented. The basic modules of our lung-CAD system, a dot-enhancement filter for nodule candidate selection and a neural classifier for false-positive finding reduction, are described. The results obtained on the collected database of lung CT scans are discussed.Comment: 3 pages, 4 figures; Proceedings of the IEEE NNS and MIC Conference, Oct. 29 - Nov. 4, 2006, San Diego, Californi