Antioxidative defense enzyme inhibition in erythrocytes of patients with acute myocardial infarction

Increased amount of reactive oxygen and nitrogen species were detected during myocardial ischemia after acute myocardial infarction (AMI). Decreased activity of some antioxidative defense enzymes in erythrocytes creates conditions for oxidative stress and propagation of thus induced damages. In this study, we tried to detect changes in antioxidative defense enzyme activities in erythrocytes of patients with AMI and to determine a nature of this changes. Activity of copper zinc super oxide dismutase (CuZn SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), glutathione peroxidase (GSH-Px, EC 1.11.1.9) and glutathione reductase (GR, EC 2.5.1.18) were determined in AMI patiens and compared with controls. Activities of CuZn SOD (p<0.005) and CAT (p<0.05), as well as, GSH-Px (p<0.02) were significantly lower comparing with controls. Activity of GR was significantly higher (p<0.005) with respect to controls. Activity of CuZn SOD in patients with AMI were more inhibited (47 ± 5 %) with 6 mM diethyldithiocarbamate (DDC) than corresponding controls (32 ± 3 %). In vitro inhibition of control samples with hydrogen peroxide (H2O2) and electrophoretic analysis indicate H2O2 as potential inhibitor of CuZn SOD in patient with AMI.Povećana količina reaktivnih vrsta kiseonika i azota i snižena aktivnost prirodnih odbrambenih sistema detektovana je tokom srčane ishemije. Enzimske komponente antioksidacione zaštite u eritrocitima smanjuju aktivnost stvarajući uslove za propagaciju oštećenja izazvanih oksidacionim stresom. U ovom radu, pokušali smo da detektujemo promene u aktivnosti antioksidacionih enzima u eritrocitima pacijenata obolelih od AIM-a i utvrdimo prirodu promena. Određivana je aktivnost bakar cink sadržavajuće superoksid dismutaze (CuZn SOD), katalaze (CAT), glutation peroksidaze (GSH-Px) i glutation reduktaze (GR) kod pacijenata obolelih od AIM-a i upoređivana sa aktivnošću kod kontrola. Aktivnosti SOD (p<0.005) i CAT (p<0.05), kao i GSH-Px (p<0.02) bile su značajno niže u odnosu na kontrole. Aktivnost GR (p<0.005) bila je značajno viša u odnosu na kontrolu. Aktivnost CuZn SOD bila je inhibirana 6 mM dietilditiokarbamatom (DDC-om) više kod pacijenata obolelih od akutnog infarkta miokarda (47 ± 5 %) nego kod kontrola (32 ± 3 %). In vitro inhibicija kontrolnih uzoraka sa vodonik peroksidom i elektroforetska analiza ukazuju na vodonik peroksid kao mogući inhibitor CuZn SOD kod AIM-a.nul

Calibration of recycled open-faced charcoal canisters for two- and one-day radon concentration measurements

Charcoal canisters have been used for indoor radon concentration measurements for more than 40 years. Although there are several methods that use charcoal canisters, the basic principle is the same. As air passes through the canister, radon is being adsorbed and the quantity of adsorbed radon is proportional to the radon concentration in air. Radon canisters can be modified in different ways, e.g. by adding diffusion barriers, and different techniques can be used for counting. The method used in Vinča Institute of Nuclear Sciences (VINS) uses open-faced canisters, which are measured on gamma spectrometers, according to US EPA method. In this method, it is necessary to wait 3 hours after closing the canisters in order to reach equilibrium, because radon is determined via gamma emissions of radon progeny - 214Pb and 214Bi. Canisters are commonly exposed for periods between 48 hours and 144 hours. Open faced radon canisters are typically used with calibration factors provided by manufacturers, or with EPA calibration factors. Calibration in EPA method is performed with canisters as received from manufacturers, but most laboratories recycle canisters by drying in order to reuse them. Since calibration factor is calculated based on the canister mass change (due to water adsorption) and duration of exposure, different moisture content due to recycling may introduce a bias in the measurement. A correction for this influence might be necessary. In order to investigate this effect, recycled canisters used in VINS have been exposed to different radon concentrations in a radon calibration chamber in Montenegro Bureau of Metrology. Exposures lasted for 48 h and the results have been used to assess the validity of used calibration factors. Additional measurements lasting (24±2) h have been performed at several selected measurement locations, covering two orders of magnitude of concentrations. Simultaneously, concentrations were measured with an AlphaGUARD detector, which was used as a reference instrument. This experiment allowed determination of calibration factor for short term measurements lasting 1 day. It is, however, necessary to perform additional study of uncertainty before using charcoal canisters for one-day measurements.VIII International Conference on Radiation in Various Fields of Research : RAD 2020 : book of abstracts; Virtual Conferenc

Antimigratory Activity of Royal Jelly on HCT-116 Colorectal Cancer Cells

Royal jelly (RJ) is a natural product, consumed as a functional food and in the form of a food supplement with multiple biological potentials. Apitherapy presents a complementary medical approach using bee products in the treatment of diseases, including cancer. Cancer metastasis implies the acquisition of migratory potential of cancer cells, and RJ already showed remarkable antimetastatic effects. We aimed to investigate the effects of RJ on the migration of colorectal cancer cells and key proteins involved in this process, E- and N-cadherin. Experiments were done 24 h after treatment with two selected concentrations. RJ suppressed the migratory potential of colorectal cancer cell line HCT-116, and enhanced the expression of anti-migratory protein, E-cadherin, while significantly inhibiting the promigratory marker, N-cadherin

The Metrological Traceability, Performance and Precision of European Radon Calibration Facilities

International audienceAn interlaboratory comparison for European radon calibration facilities was conducted to evaluate the establishment of a harmonized quality level for the activity concentration of radon in air and to demonstrate the performance of the facilities when calibrating measurement instruments for radon. Fifteen calibration facilities from 13 different European countries participated. They represented different levels in the metrological hierarchy: national metrology institutes and designated institutes, national authorities for radiation protection and participants from universities. The interlaboratory comparison was conducted by the German Federal Office for Radiation Protection (BfS) and took place from 2018 to 2020. Participants were requested to measure radon in atmospheres of their own facilities according to their own procedures and requirements for metrological traceability. A measurement device with suitable properties was used to determine the comparison values. The results of the comparison showed that the radon activity concentrations that were determined by European calibration facilities complying with metrological traceability requirements were consistent with each other and had common mean values. The deviations from these values were normally distributed. The range of variation of the common mean value was a measure of the degree of agreement between the participants. For exposures above 1000 Bq/m3, the variation was about 4% for a level of confidence of approximately 95% (k=2). For lower exposure levels, the variation increased to about 6%