Korzynska A.,Nalecz Institute of Biocybernetics and Biomedical Engineering |
Iwanowski M.,Warsaw University of Technology
Opto-electronics Review | Year: 2012
This paper describes the multistage morphological segmentation method (MSMA) for microscopic cell images. The proposed method enables us to study the cell behaviour by using a sequence of two types of microscopic images: bright field images and/or fluorescent images. The proposed method is based on two types of information: the cell texture coming from the bright field images and intensity of light emission, done by fluorescent markers. The method is dedicated to the image sequences segmentation and it is based on mathematical morphology methods supported by other image processing techniques. The method allows for detecting cells in image independently from a degree of their flattening and from presenting structures which produce the texture. It makes use of some synergic information from the fluorescent light emission image as the support information. The MSMA method has been applied to images acquired during the experiments on neural stem cells as well as to artificial images. In order to validate the method, two types of errors have been considered: the error of cell area detection and the error of cell position using artificial images as the "gold standard". © 2012 Versita Warsaw and Springer-Verlag Wien.
Golczewski T.,Nalecz Institute of Biocybernetics and Biomedical Engineering
Respiratory research | Year: 2012
Recent studies have showed that FEV1/FVC describing correspondence between the forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) depends significantly on age. However, the nature of this dependence is uncertain. The study aim is to analyze mathematically the relationship between FEV1 and FVC to find a cause of the FEV1/FVC dependence on age in healthy subjects. The relationship was examined for 1,120 males and 1,625 females--Polish (Caucasian) population, healthy, never-smoking, aged 18 - 85 years, who performed a technically adequate spirometry maneuver. Lung functions were measured using the LungTest1000 (MES, Poland) with maximal effort according to the ATS/ERS guidelines. A very strong, age-independent linear relationship between FEV1 and FVC was found in healthy individuals (the correlation coefficient r = 0.96). It can be described with the equation FEV1 = A x FVC + C, where A = 0.84 and C = -0.23 (-0.36) for females (males). As C is different from zero, FEV1/FVC depends on FVC because FEV1/FVC = A + C/FVC, in average. And thus, since FVC is significantly age-dependent, FEV1/FVC has to be also age-dependent because of the term C/FVC. In particular, the smaller the FVC value because of advanced age, the more significant the fall of FEV1/FVC. FEV1/FVC dependence on age in healthy individuals is of mathematical rather than biological nature. Due to the strong correlation between FEV1 and FVC in healthy subjects, the difference between patient's FEV1 and the FEV1 value expected for patient's FVC seems to be a more natural, age-independent description of the correspondence between patient's FEV1 and FVC.
Piotrkiewicz M.,Nalecz Institute of Biocybernetics and Biomedical Engineering |
Hausmanowa-Petrusewicz I.,Polish Academy of Sciences
Journal of Physiology | Year: 2011
Motor unit (MU) potentials were registered from 20 ALS patients and 13 age-matched control individuals during isometric constant force contractions of brachial biceps (BB). The registered signals were decomposed into single MU potential trains. The estimates of duration of the afterhyperpolarisation (AHP) in MNs, derived from the interspike interval variability, was compared between ALS patients (124 MNs) and control subjects (111 MNs) and no significant differences were encountered. However, the relationship between TI and age for patients appeared to be qualitatively different from that of the control group. The dependence of patients' AHPs on relative force deficit (RFD), which quantified muscle involvement, was more specific. For RFDs below 30%, the AHP estimate was significantly lower than control values and then increased thereafter with increasing RFDs. Moreover, firing rates of patients with the smallest RFDs were significantly higher while firing rates of patients with the greatest RFDs were significantly lower than control values. The AHP shortening in the early stages of muscle impairment is consistent with the decrease in firing threshold of 'fast' MNs found in spinal cord slices from neonatal SOD1 mice. The later elongation of the AHP may be caused by the higher vulnerability of 'fast' MNs to degeneration and by the influence of reinnervation. Our results are comparable to what has been observed in acute experiments in animal models, providing a bridge between animal and clinical research that may be relevant for identification of mechanism(s) underlying neurodegeneration in ALS. © 2011 The Authors. Journal compilation © 2011 The Physiological Society.
Skubiszak L.,Nalecz Institute of Biocybernetics and Biomedical Engineering
International Journal of Molecular Sciences | Year: 2011
Computer simulation has uncovered the geometrical conditions under which the vertebrate striated muscle sarcomere can contract. First, all thick filaments should have identical structure, namely: three myosin cross-bridges, building a crown, should be aligned at angles of 0°, 120°, 180°, and the successive crowns and the two filament halves should be turned around 120°. Second, all thick filaments should act simultaneously. Third, coordination in action of the myosin cross-bridges should exist, namely: the three cross- bridges of a crown should act simultaneously and the cross-bridge crowns axially 43 and 14.333 nm apart should act, respectively, simultaneously and with a phase shift. Fifth, six thin filaments surrounding the thick filament should be turned around 180° to each other in each sarcomere half. Sixth, thin filaments should be oppositely oriented in relation to the sarcomere middle. Finally, the structure of each of the thin filaments should change in consequence of strong interaction with myosin heads, namely: the axial distance and the angular alignment between neighboring actin monomers should be, respectively, 2.867 nm and 168° instead of 2.75 nm and 166.15°. These conditions ensure the stereo-specific interaction between actin and myosin and good agreement with the data gathered by electron microscopy and X-ray diffraction methods. The results suggest that the force is generated not only by the myosin cross-bridges but also by the thin filaments; the former acts by cyclical unwrapping and wrapping the thick filament backbone, and the latter byelongation. © 2011 by the authors; licensee MDPI, Basel, Switzerland.
Kulikowski J.L.,Nalecz Institute of Biocybernetics and Biomedical Engineering
Advances in Intelligent Systems and Computing | Year: 2016
In the paper a concept of object recognition based on their similarity assessment in case of nonhomogenous qualitative and quantitative objects’ features is presented. Moreover, it is assumed that the features’ intensity values are not given directly but by their pairwise comparative assessment. This corresponds to an intuitive, on human experience-based assessment of the objects’ properties. The proposed object recognition method is based on reference sets divided into credibility layers, according to a relative logical model and conceptual classes of similarity. This concept is illustrated by an example of a conceptual class of “irregular” objects, the “irregularity” being intuitively assessed. The method is presented in the form of an algorithm. © Springer International Publishing Switzerland 2016.
Granicka L.H.,Nalecz Institute of Biocybernetics and Biomedical Engineering
Journal of Nanoscience and Nanotechnology | Year: 2014
This paper reviews the recent research and development of the systems of nano-thin layers coated cells for biomedical applications. Polyelectrolyte based nano-thin polymer coatings, due to their individual layered structure and functionalization ability, are a promising part of the systems involving cells for biological processes regulation. The purpose of the layer-by-layer coating technique application is to minimize capsule void volume and separate cells from the host immunological system eliminating immunosuppressive therapy during transplantation. The materials for polyelectrolyte shells and their modifications, followed by the techniques of forming polymer nano-thin coatings are briefly introduced. The enhanced properties of cell nanocoatings are then discussed, involving usability for encapsulation of live cells, immunological barrier, and coatings detection among others. The systems utilizing layer-by layer coatings without cell participation are briefly mentioned. Finally, the perspectives for the future are discussed in terms of limitations and application in biomedicine. Copyright © 2014 American Scientific Publishers All rights reserved.
Fereniec M.,Nalecz Institute of Biocybernetics and Biomedical Engineering
Medical science monitor : international medical journal of experimental and clinical research | Year: 2011
The effective screening of myocardial infarction (MI) patients threatened by ventricular tachycardia (VT) is an important issue in clinical practice, especially in the process of implantable cardioverter-defibrillator (ICD) therapy recommendation. This study proposes new parameters describing depolarization and repolarization inhomogeneity in high resolution body surface potential maps (HR BSPM) to identify MI patients threatened by VT. High resolution ECGs were recorded from 64 surface leads. Time-averaged HR BSPMs were used. Several parameters for arrhythmia risk assessment were calculated in 2 groups of MI patients: those with and without documented VT. Additionally, a control group of healthy subjects was studied. To assess the risk of VT, the following parameters were proposed: correlation coefficient between STT and QRST integral maps (STT_QRST_CORR), departure index of absolute value of STT integral map (STT_DI), and departure index of absolute value of T-wave shape index (TSI_DI). These new parameters were compared to known parameters: QRS width, QT interval, QT dispersion, Tpeak-Tend interval, total cosines between QRS complex and T wave, and non-dipolar content of QRST integral maps. STT_DI, TSI_DI, STT_QRST_CORR, QRS width, and QT interval parameters were statistically significant (p ≤ 0.05) in arrhythmia risk assessment. The highest sensitivity was found for the STT_DI parameter (0.77) and the highest specificity for TSI_DI (0.79). Arrhythmia risk is demonstrated by both abnormal spatial distribution of the repolarization phase and changed relationship between depolarization and repolarization phases, as well as their prolongation. The proposed new parameters might be applied for risk stratification of cardiac arrhythmia.
Waniewski J.,Nalecz Institute of Biocybernetics and Biomedical Engineering
Archives of Medical Research | Year: 2013
Fluid removal during peritoneal dialysis is controlled by many mutually dependent factors and therefore its analysis is more complex than that of the removal of small solutes used as markers of dialysis adequacy. Many new tests have been proposed to assess quantitatively different components of fluid transport (transcapillary ultrafiltration, peritoneal absorption, free water, etc.) and to estimate the factors that influence the rate of fluid transport (osmotic conductance). These tests provide detailed information about indices and parameters that describe fluid transport, especially those concerning the problem of the permanent loss of ultrafiltration capacity (ultrafiltration failure). Different theories and respective mathematical models of mechanisms and pathways of fluid transport are presently discussed and applied, and some fluid transport issues are still debated. © 2013 IMSS.
Di Ieva A.,University of Toronto |
Di Ieva A.,Medical University of Vienna |
Esteban F.J.,University of Jaén |
Grizzi F.,Humanitas Clinical and Research Center |
And 2 more authors.
Neuroscientist | Year: 2015
It has been ascertained that the human brain is a complex system studied at multiple scales, from neurons and microcircuits to macronetworks. The brain is characterized by a hierarchical organization that gives rise to its highly topological and functional complexity. Over the last decades, fractal geometry has been shown as a universal tool for the analysis and quantification of the geometric complexity of natural objects, including the brain. The fractal dimension has been identified as a quantitative parameter for the evaluation of the roughness of neural structures, the estimation of time series, and the description of patterns, thus able to discriminate different states of the brain in its entire physiopathological spectrum. Fractal-based computational analyses have been applied to the neurosciences, particularly in the field of clinical neurosciences including neuroimaging and neuroradiology, neurology and neurosurgery, psychiatry and psychology, and neuro-oncology and neuropathology. After a review of the basic concepts of fractal analysis and its main applications to the basic neurosciences in part I of this series, here, we review the main applications of fractals to the clinical neurosciences for a holistic approach towards a fractal geometry model of the brain. © The Author(s) 2013.
Ladyzynski P.,Nalecz Institute of Biocybernetics and Biomedical Engineering |
Molik M.,Nalecz Institute of Biocybernetics and Biomedical Engineering |
Foltynski P.,Nalecz Institute of Biocybernetics and Biomedical Engineering
Cancer Treatment Reviews | Year: 2015
Background: A limited evidence exists regarding comparisons of clinical effectiveness of available therapies for first-line treatment of chronic lymphocytic leukemia (CLL). Methods: We compared available therapies for treatment-naïve, symptomatic CLL regarding progression free survival (PFS) and overall survival (OS) in all the identified random control trials and in subgroups composed of younger/fit and older/unfit patients, using a Bayesian network meta-analysis. Results: In younger/fit patients we obtained median of projected mean PFS of: 19, 26, 31, 43, 51 and 75. months for chlorambucil, fludarabine, alemtuzumab, fludarabine with cyclophosphamide (FC), bendamustine and fludarabine with cyclophosphamide and rituximab (FCR), respectively. We noted median OS of: 59, 66, 66, 70. months for FC, chlorambucil, FCR and fludarabine, respectively. In older/unfit patients we noted PFS of: 16, 17, 24, 30, 60. months for chlorambucil, fludarabine and chlorambucil with ofatumumab (OClb) or rituximab (RClb) or obinutuzumab (GClb), respectively. We obtained median OS of: 44, 58, 59 and 90. months for fludarabine, RClb, chlorambucil and GClb, respectively. Conclusions: Our results suggest that: (1) FCR has higher potential of preventing CLL progression in younger/fit patients over four therapy options, which were subject of previous meta-analysis but also over bendamustine; (2) in these patients FCR does not entail prolonging of OS in comparison with chlorambucil and it is outperformed by fludarabine; (3) in older/unfit patients GClb demonstrates longer projected PFS than all assessed comparators; (4) in this group GClb has also the highest potential of increasing OS. © 2014 Elsevier Ltd.