Quantification of peripheral whole blood, cell-free plasma and exosome encapsulated mitochondrial DNA copy numbers in patients with atrial fibrillation.

Mitochondrial DNA (mtDNA) copy number changes have been associated with various diseases. Several studies showed that mtDNA content in peripheral blood was associated with oxidative stress and cardiovascular disease. Atrial fibrillation (AF) is one of the severe cardiovascular diseases. We aimed to determine the mtDNA copy numbers in peripheral blood, in cell-free plasma and in exosomes of AF patients and healthy controls. Peripheral blood was drawn from 60 AF patients and 72 healthy controls. DNA was isolated from EDTA blood and plasma. Exosomes were isolated from cell-free plasma and then exosome encapsulated DNA (exoDNA) was extracted. Quantitative-real-time PCR was performed with Human Mitochondrial DNA (mtDNA) Monitoring Primer Set. Statistical analysis of the data was performed. We found statistically significant difference in mtDNA copy numbers in DNA isolated from peripheral whole blood, cell-free plasma and exosome samples of controls' (44.4 ± 18.0, 27.2 ± 30.1, 11.5 ± 8.7), and patients' group (43.4 ± 13.6, 26.2 ± 26.4, 14.5 ± 12.3). However there was no significant difference in mtDNA copy number between the two study groups either in peripheral blood, in cell-free plasma and in exosomes, and even in different sexes and ages. We found the highest copy number of mtDNA in peripheral blood, followed by plasma and exosomes. We did not find differences between patients and controls, neither age nor gender had effect on the mtDNA copy number. According to our results the mtDNA copy numbers did not differ in AF patients.

Expression of CD24 in plasma, exosome and ovarian tissue samples of serous ovarian cancer patients.

CD24 is a small molecular weight cell-surface protein and an independent marker for poor prognosis in the different type of cancers. We aimed to determine the expression of CD24 in plasma, exosomes and ovarian tissue samples of serous ovarian cancer patients. We collected tissue and blood samples from 21 cases of serous ovarian cancer and eight healthy controls. We used silica adsorption method for isolation of RNA. The cDNA was synthesized using quantitative real-time PCR. We used beta-globin as a housekeeping gene for the normalization of the data. Protein-protein and miRNA networking were analyzed. There was a significant difference in the expression of CD24 in ovarian tissue between controls and patients (0.16 ± 0.32 vs. 44.97 ± 68.06; p < 0.01), while CD24 did not show expression in each plasma and exosome samples. There was a correlation in the expression of CD24 and FIGO grading between controls and patients. CD24 expression was detected in exosomes in 38.1% of patients, mainly with FIGO III, and in their plasma in 9.5% of cases. Our network analysis shows LYN, SELP, FGR, and NPM1 proteins are interacting with CD24. Our study demonstrates higher expression of CD24 in ovarian cancer patients' tissue samples, and there is an association with FIGO classification. However, CD24 showed expression only in some cell-free plasma and exosome samples.

Design of a high-sensitivity negative ion source time-of-flight mass analyzer assembly created by cylindrical electrodes with a common axis.

The new design incorporates the negative ion source and the mass analyzer, both constructed from cylindrical electrodes. The ion source is formed by three gridded cylindrical electrodes: a pulsed grid, the intermediate grid and the final accelerating grid. During a first time lapse, the electrons penetrate through the pulsed grid into the retarding field between this grid and the intermediate grid. The electrons are turning at some depth inside this intergrid space, where the attachment to neutral molecules most probably occurs. Next, the pulsed grid becoming strongly negative and ions are extracted towards the final acceleration grid. The ions from the cylindrical surface where they were created concentrate on the common axis of the electrodes (lateral focusing). The source lateral and time focus are coincident. A cylindrical electrostatic mirror is fitted to the source. The design, with a single stage, ensures also lateral focusing of the ions diverging from the common axis of the electrodes. The mirror electric and geometric parameters were selected to ensure both lateral and time focusing on the final detector with subsequent high luminosity. The basic parameters of the specific negative ion source time-of-flight mass analyzer design proposed here, are ion source final acceleration, intermediate, pulsed cylindrical grid radii 10, 20 and 30 mm, respectively, electrostatic mirror earthed grid and ion turning points surface radii 0.6 and 0.8 m, respectively. Ion packet smearing by the ion energy spread (resulting from the initial electron energy spread as electrons are turning at different depths inside the ionization region, from the moment when ions were created, being accelerated towards the pulsed grid during ionization) and by the turnaround time inside the cylindrical field was accounted for. Maintaining very high sensitivity, a resolution of the order of 100 is expected.