Automated Reconstruction of Evolving Curvilinear Tree Structures

Curvilinear networks are prevalent in nature and span many different scales, ranging from micron-scale neural structures in the brain to petameter-scale dark-matter arbors binding massive galaxy clusters. Reliably reconstructing them in an automated fashion is of great value in many different scientific domains. However, it remains an open Computer Vision problem. In this thesis we focus on automatically delineating curvilinear tree structures in images of the same object of interest taken at different time instants. Unlike virtually all of the existing methods approaching the task of tree structures delineation we process all the images at once. This is useful in the more ambiguous regions and allows to reason for the tree structure that fits best to all the acquired data. We propose two methods that utilize this principle of temporal consistency to achieve results of higher quality compared to single time instant methods. The first, simpler method starts by building an overcomplete graph representation of the final solution in all time instants while simultaneously obtaining correspondences between image features across time. We then define an objective function with a temporal consistency prior and reconstruct the structures in all images at once by solving a mathematical optimization. The role of the prior is to encourage solutions where for two consecutive time instants corresponding candidate edges are either both retained or both rejected from the final solution. The second multiple time instant method uses the same overcomplete graph principle but handles the temporal consistency in a more robust way. Instead of focusing on the very local consistency of single edges of the overcomplete graph we propose a method for describing topological relationships. This favors solutions whose connectivity is consistent over time. We show that by making the temporal consistency more global we achieve additional robustness to errors in the initial features matching step, which is shared by both the approaches. In the end, this yields superior performance. Furthermore, an added benefit of both our approaches is the ability to automatically detect places where significant changes have occurred over time, which is challenging when considering large amounts of data. We also propose a simple single time instant method for delineating tree structures. It computes a Minimum Spanning Arborescence of an initial overcomplete graph and proceeds to optimally prune spurious branches. This yields results of lower but still competitive quality compared to the mathematical optimization based methods, while keeping low computational complexity. Our methods can applied to both 2D and 3D data. We demonstrate their performance in 3D on microscopy volumes of mouse brain and rat brain. We also test them in 2D on time-lapse images of a growing runner bean and aerial images of a road network

The Oxidative Stress May be Induced by the Elevated Homocysteine in Schizophrenic Patients

The mechanisms of oxidative stress in schizophrenic patients are not fully understood. In the present study, we investigated the effect of elevated level of homocysteine (Hcys) on some parameters of oxidative stress, namely thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation in plasma, the level of carbonyl groups in plasma proteins, as well as the amount of 3-nitrotyrosine in plasma proteins isolated from schizophrenic patients. Patients hospitalised in I and II Psychiatric Department of Medical University in Lodz, Poland were interviewed with special questionnaire (treatment, course of diseases, dyskinesis and other EPS). According to DSM-IV criteria all patients had diagnosis of paranoid type. They were treated with antipsychotic drugs (clozapine, risperidone, olanzapine). Mean time of schizophrenia duration was about 5 years. High-performance liquid chromatography was used to analyse the total level of homocysteine in plasma. Levels of carbonyl groups and 3-nitrotyrosine residues in plasma proteins were measured by ELISA and a competition ELISA, respectively. The lipid peroxidation in plasma was measured by the level of TBARS. Our results showed that in schizophrenic patients the amount of homocysteine in plasma was higher in comparison with the control group. We also observed a statistically increased level of biomarkers of oxidative/nitrative stress such as carbonyl groups or 3-nitrotyrosine in plasma proteins from schizophrenic patients. Moreover, our experiments indicate that the correlation between the increased amount of homocysteine and the oxidative stress exists. Considering the data presented in this study, we suggest that the elevated Hcys in schizophrenic patients may stimulate the oxidative stress

Simultaneous Determination of Ciprofloxacin and Ofloxacin in Animal Tissues with the Use of Capillary Electrophoresis with Transient Pseudo-Isotachophoresis

We have developed a precise and accurate method for the determination of ciprofloxacin and ofloxacin in meat tissues. Our method utilizes capillary electrophoresis with a transient pseudoisotachophoresis mechanism and liquid–liquid extraction during sample preparation. For our experiment, a meat tissue sample was homogenized in pH 7.00 phosphate buffer at a ratio of 1:10 (tissue mass: buffer volume; g/mL). The extraction of each sample was carried out twice for 15 min with 600 µL of a mixture of dichloromethane and acetonitrile at a 2:1 volume ratio. We then conducted the electrophoretic separation at a voltage of 16 kV and a temperature of 25 ◦C using a background electrolyte of 0.1 mol/L phosphate–borate (pH 8.40). We used the UV detection at 288 nm. The experimentally determined LOQs for ciprofloxacin and ofloxacin were 0.27 ppm (0.8 nmol/g tissue) and 0.11 ppm (0.3 nmol/g tissue), respectively. The calibration curves exhibited linearity over the tested concentration range of 2 to 10 nmol/g tissue for both analytes. The relative standard deviation of the determination did not exceed 15%, and the recovery was in the range of 85–115%. We used the method to analyze various meat tissues for their ciprofloxacin and ofloxacin contents

Determination of lipoic acid in human plasma by high-performance liquid chromatography with ultraviolet detection

This paper describes the development and validation of an HPLC method for the determination of protein bound and total lipoic acid in human plasma. The essential steps in the total lipoic acid assay include reduction of disulfide bridge with tris(2-carboxyethyl)phosphine, derivatization via thiol group with 1-benzyl-2-chloropyridinium bromide and HPLC analysis of S-pyridinium derivative. Protein-bound lipoic acid is first separated from free lipoic acid with the use of liquid extraction, converted to its reduced counterpart then processed as total lipoic acid. The method is reproducible, precise and accurate. The inter- and intraday related standard deviation varied from 1.5% to 11.5% and from 1.8% to 19.6%, respectively, while recovery is in the range of 80.0–106.0% and 80.4–110.8%, respectively. The mean concentration of total lipoic acid in healthy donors after supplementation with 600 mg and 1200 mg was 0.67 ±0.40 lmol L -1 (137.6± 82.1 lg L -1) and 1.57 ± 0.34 lmol L -1 (323.34 ± 70.07 lg L -1), respectively

Determination of lipoic acid in human plasma by high-performance liquid chromatography with ultraviolet detection

AbstractThis paper describes the development and validation of an HPLC method for the determination of protein bound and total lipoic acid in human plasma. The essential steps in the total lipoic acid assay include reduction of disulfide bridge with tris(2-carboxyethyl)phosphine, derivatization via thiol group with 1-benzyl-2-chloropyridinium bromide and HPLC analysis of S-pyridinium derivative. Protein-bound lipoic acid is first separated from free lipoic acid with the use of liquid extraction, converted to its reduced counterpart then processed as total lipoic acid. The method is reproducible, precise and accurate. The inter- and intraday related standard deviation varied from 1.5% to 11.5% and from 1.8% to 19.6%, respectively, while recovery is in the range of 80.0–106.0% and 80.4–110.8%, respectively. The mean concentration of total lipoic acid in healthy donors after supplementation with 600mg and 1200mg was 0.67±0.40μmolL−1 (137.6±82.1μgL−1) and 1.57±0.34μmolL−1 (323.34±70.07μgL−1), respectively

A Simplified Method for Simultaneous Determination of α-Lipoic Acid and Low-Molecular-Mass Thiols in Human Plasma

α-Lipoic acid, glutathione, cysteine, and cysteinylglycine can be applied as therapeutic agents in civilization diseases such as diabetes mellitus, cardiovascular diseases, and cancers. On the other hand, a higher concentration of homocysteine can result in health problems and has been indicated as an independent risk factor for cardiovascular disease and accelerated atherosclerosis. Here, the first simplified HPLC-UV assay that enables simultaneous determination of α-lipoic acid and low-molecular-mass thiols in plasma, reduces the number of steps, shortens the total time of sample preparation, and limits the amount of single-use polypropylene laboratory materials is described. The assay is based on reversed-phase high performance liquid chromatography with UV detection and simultaneous reduction of disulfide bound with tris(2-carboxyethyl)phosphine and the selective pre-column derivatization of the thiol group with 1-benzyl-2-chloropyridinium bromide. Linearity in the detector responses for plasma samples were observed in ranges: 0.12–5.0 nmol mL−1 for α-lipoic acid; 2.0–20.0 nmol mL−1 for glutathione, cysteinylglycine, and homocysteine; and 40.0–400.0 for cysteine. The LODs for α-lipoic acid and low-molecular-mass thiols were 0.08 and 0.12 nmol mL−1 , respectively, while LOQs were 0.12 and 0.16 nmol mL−1 , respectively. The usefulness of the proposed method has been proven by its application to real samples

Zapalny tętniak aorty brzusznej : opis przypadku

Background: Inflammatory abdominal aneurysm (IAA) is a form of aneurysm of the abdominal aorta which occurs very rarely and is hard to diagnose. A pathogenesis of IAA had not been clarified yet. Its rare occurrence and atypical image and clinical course make diagnosing IAA difficult. Case Report: The authors present a case of 59-year old man with a year-long intra-abdominal and lumbar pains. USG examination showed a aneurysmatic widening of abdominal aorta up to 7 cm within the distance of 12 cm located below the renal arteries reaching the bifurcation of the aorta and including the initial fragments of iliac arteries. The images obtained were considered ambiguous. A possibility of dissecting aneurysm or inflammatory aneurysm were assumed. The CT of abdominal cavity and angio CT of abdominal aorta were performed. The received imaged were reconstructed with MPR and MIP. The wall of abdominal aorta and iliac arteries were thickened and enchanced after intravenous administration of contrast medium The symptoms of morbid changes on the duodenum wall and the first loop of small intestine, wall of vena cava inferior and left renal vein were visible. Results: On the basis of the imaged symptoms a presence of inflammatory abdominal aneurysm was diagnosed. After aneurysmotomy, a bifurcated prosthesis was implanted. The post-operative treatment was without complications. US and CT were of greatest importance in IAA diagnosis. The authors estimate sensitivity of US as 60% and CT as 90%. Diagnostic capacity of CT is increased by angio CT and MPR and MIP image reconstructions

Wartość bronchoskopii wirtualnej (BW) w diagnostyce tchawicy i drzewa oskrzelowego u 5 letniego chłopca : opis przypadku

Background: Progress in multislice computer tomography and computer software is making is possible to achieve high quality images of the trachea and bronchial tree. This new technique, called virtual bronchoscopy (VB), enables non-invasive, painless evaluation of the bronchial tree and trachea in a 3D presentation, which can be applied especially in pediatric diagnostics. Case report: This paper presents the value of VB in trachea and bronchial tree diagnostics in a five-year-old boy admitted to surgery for an operation on the humeral bone. The presence of a tracheal and bronchial tree defect was determined on the basis of the interview and previous examinations. Diagnosis of the upper airways was necessary due to the anesthetic planned for surgery. Virtual bronchoscopy was chosen as a safer, less risky method without general anesthesia. Results: Bronchofiberoscopy and virtual bronchoscopy are valuable and complementary methods for the imaging diagnostics of the trachea and bronchial tree. Virtual bronchoscopy can be a reference examination in many cases, especially in children