New generation of electrochemical immunoassay based on polymeric nanoparticles for early detection of breast cancer

Screening and early diagnosis are the key factors for the reduction of mortality rate and treatment cost of cancer. Therefore, sensitive and selective methods that can reveal the low abundance of cancer biomarkers in a biological sample are always desired. Here, we report the development of a novel electrochemical biosensor for early detection of breast cancer by using bioconjugated self-assembled pH-responsive polymeric micelles. The micelles were loaded with ferrocene molecules as "tracers" to specifically target cell surface-associated epithelial mucin (MUC1), a biomarker for breast and other solid carcinoma. The synthesis of target-specific, ferrocene-loaded polymeric micelles was confirmed, and the resulting sensor was capable of detecting the presence of MUC1 in a sample containing about 10 cells/mL. Such a high sensitivity was achieved by maximizing the loading capacity of ferrocene inside the polymeric micelles. Every single event of binding between the antibody and antigen was represented by the signal of hundreds of thousands of ferrocene molecules that were released from the polymeric micelles. This resulted in a significant increase in the intensity of the ferrocene signal detected by cyclic voltammetry

A model-based time-reversal of left ventricular motion improves cardiac motion analysis using tagged MRI data

<p>Abstract</p> <p>Background</p> <p>Myocardial motion is an important observable for the assessment of heart condition. Accurate estimates of ventricular (LV) wall motion are required for quantifying myocardial deformation and assessing local tissue function and viability. Harmonic Phase (HARP) analysis was developed for measuring regional LV motion using tagged magnetic resonance imaging (tMRI) data. With current computer-aided postprocessing tools including HARP analysis, large motions experienced by myocardial tissue are, however, often intractable to measure. This paper addresses this issue and provides a solution to make such measurements possible.</p> <p>Methods</p> <p>To improve the estimation performance of large cardiac motions while analyzing tMRI data sets, we propose a two-step solution. The first step involves constructing a model to describe average systolic motion of the LV wall within a subject group. The second step involves time-reversal of the model applied as a spatial coordinate transformation to digitally relax the contracted LV wall in the experimental data of a single subject to the beginning of systole. Cardiac tMRI scans were performed on four healthy rats and used for developing the forward LV model. Algorithms were implemented for preprocessing the tMRI data, optimizing the model parameters and performing the HARP analysis. Slices from the midventricular level were then analyzed for all systolic phases.</p> <p>Results</p> <p>The time-reversal operation derived from the LV model accounted for the bulk portion of the myocardial motion, which was the average motion experienced within the overall subject population. In analyzing the individual tMRI data sets, removing this average with the time-reversal operation left small magnitude residual motion unique to the case. This remaining residual portion of the motion was estimated robustly using the HARP analysis.</p> <p>Conclusion</p> <p>Utilizing a combination of the forward LV model and its time reversal improves the performance of motion estimation in evaluating the cardiac function.</p

Investigating left ventricle wall motion using cardiac magnetic resonance imaging

Dissertation (Ph.D)--University of Kansas, Physics & Astronomy, 2007.Magnetic resonance imaging (MRI) is an established radiological technique for assessment of cardiac function. Various MRI methods are utilized for global and regional evaluation of the myocardium through tracking the motion of tissue as the heart beats. Such tracking of motion reveals local as well as global deformation of the heart wall during contraction and relaxation. It has been shown that wall motion profiles of a healthy heart differ than those of a diseased heart due to variations in contractile behavior resulting from complications and abnormalities. Therefore, understanding heart wall motion and quantifying contractility serve as a valuable tool for evaluating myocardial viability as well as diagnosis of heart condition. Hence, in this presented work the focus is to utilize cardiac MRI techniques to develop computational algorithms that accurately describe myocardial motion in both global and regional aspects. Through acquiring cardiac MRI data from rat subjects, quantitative measurements are performed and mathematical models are formulated to quantify contractility and map local myocardial motion. Such measurements and formulations serve as means for providing important bio-imaging markers that reflect the state of the myocardial tissue, as well as indicators for inspecting the condition of the heart

Monte Carlo simulations and analysis of transmitted gamma ray spectra through various tissue phantoms

Studies of radiation interactions with tissue equivalent material find importance in efforts that seek to avoid unjustifiable dose to patients, also in ensuring quality control of for instance nuclear medicine imaging equipment. Use of the Monte Carlo (MC) simulation tool in such characterization processes allows for the avoidance of costly experiments involving transmitted X- and γ-ray spectrometry. Present work investigates MC simulations of γ-ray transmission through tissue equivalent solid phantoms. Use has been made of a range of radionuclide gamma ray sources, 99m Tc, 131 I, 137 Cs, 60 Co (offering photons in the energy range from a few keV up to low MeV), popularly applied in medicine and in some cases for gauging in industry, obtaining the transmission spectra following their interaction with various phantom materials and thicknesses. In validation of the model, the simulated values of mass attenuation coefficients (μ/ρ) for different phantom materials and thicknesses were found to be in good agreement with reference values (NIST, 2004) to within 1.1% for all material compositions. For all of the primary photon energies and medium thicknesses of interest herein, results show that multiple scattering peaks are generally located at energies lower than 100 keV, although for the larger phantom thicknesses it is more difficult to distinguish single, double and multiple scattering in the gamma spectra. Transmitted photon spectra investigated for water, soft tissue, breast, brain and lung tissue slab phantoms are demonstrated to be practically independent of the phantom material, while a significant difference is observed for the spectra transmitted through bone that was proved to be due to the density effect and not material composition. © 2019 Elsevier Lt

The deformation parameter is plotted against the systolic image numbers, which are directly proportional to the acquisition time in the systolic phase

The curves in the graph exhibits a nonlinear behavior.<p><b>Copyright information:</b></p><p>Taken from "A model-based time-reversal of left ventricular motion improves cardiac motion analysis using tagged MRI data"</p><p>http://www.biomedical-engineering-online.com/content/7/1/15</p><p>BioMedical Engineering OnLine 2008;7():15-15.</p><p>Published online 19 May 2008</p><p>PMCID:PMC2435113.</p><p></p

Displacement vectors (red lines) start from the selected points (blue dots) and project to the end points (green dots)

Please see the text for the detailed explanation of the figure.<p><b>Copyright information:</b></p><p>Taken from "A model-based time-reversal of left ventricular motion improves cardiac motion analysis using tagged MRI data"</p><p>http://www.biomedical-engineering-online.com/content/7/1/15</p><p>BioMedical Engineering OnLine 2008;7():15-15.</p><p>Published online 19 May 2008</p><p>PMCID:PMC2435113.</p><p></p

Thus magnitude of motion is considerably reduced between TR and Ithereby yielding a phase-wrap free HARP motion map

A mask is superimposed on the image frames to indicate the ROI.<p><b>Copyright information:</b></p><p>Taken from "A model-based time-reversal of left ventricular motion improves cardiac motion analysis using tagged MRI data"</p><p>http://www.biomedical-engineering-online.com/content/7/1/15</p><p>BioMedical Engineering OnLine 2008;7():15-15.</p><p>Published online 19 May 2008</p><p>PMCID:PMC2435113.</p><p></p