Possible role of a hydrogen peroxide-mediated mechanism in glucocorticoid receptor functional alterations associated with moderate asthma

It is well known that pathogenesis and maintenance of chronic asthma is associated with alterations of glucocorticoid receptor (GR) function, and also with persistent pulmonary inflammation, the important mediators of which are reactive oxygen and nitrogen species. In this paper, we tested a hypothesis that GR functional alterations in asthma result from the action of oxidants. To that end, we conducted a series of ex vivo treatments of peripheral blood mononuclear cells (PBMCs) of healthy donors with oxidizing agents (3 morpholinosydnonimine, SIN1; S-nitroso-N-acetyl-penicillamine, SNAP; and hydrogen peroxide, H2O2) and compared the resulting GR modifications with those previously noticed in asthmatic patients. The results show that treatment of PBMCs by H2O2 provoked an increase in the level of GR protein, accompanied by a rise in the number of hormone-binding sites and a decline in the receptor's affinity for the hormone. The H2O2 induced changes, including a characteristic GR isoprotein expression pattern, were found to be very similar to the GR changes previously observed in PBMCs of moderate asthmatic patients, but not in mild asthmatics and healthy subjects. Treatment with the other oxidants applied herein produced different effects or exerted no influence on GR. Thus, this study provides preliminary data suggesting that functional alterations of the GR associated with moderate asthma may be mediated by redox mechanisms that are based on oxidative and regulatory actions of H2O2

Possible role of a hydrogen peroxide-mediated mechanism in glucocorticoid receptor functional alterations associated with moderate asthma

It is well known that pathogenesis and maintenance of chronic asthma is associated with alterations of glucocorticoid receptor (GR) function, and also with persistent pulmonary inflammation, the important mediators of which are reactive oxygen and nitrogen species. In this paper, we tested a hypothesis that GR functional alterations in asthma result from the action of oxidants. To that end, we conducted a series of ex vivo treatments of peripheral blood mononuclear cells (PBMCs) of healthy donors with oxidizing agents (3 morpholinosydnonimine, SIN1; S-nitroso-N-acetyl-penicillamine, SNAP; and hydrogen peroxide, H2O2) and compared the resulting GR modifications with those previously noticed in asthmatic patients. The results show that treatment of PBMCs by H2O2 provoked an increase in the level of GR protein, accompanied by a rise in the number of hormone-binding sites and a decline in the receptor's affinity for the hormone. The H2O2 induced changes, including a characteristic GR isoprotein expression pattern, were found to be very similar to the GR changes previously observed in PBMCs of moderate asthmatic patients, but not in mild asthmatics and healthy subjects. Treatment with the other oxidants applied herein produced different effects or exerted no influence on GR. Thus, this study provides preliminary data suggesting that functional alterations of the GR associated with moderate asthma may be mediated by redox mechanisms that are based on oxidative and regulatory actions of H2O2.Poznato je da su patogeneza i napredovanje hronične astme povezani sa funkcionalnim promenama glukokortikoidnog receptora (GR) i dugotrajnom inflamacijom disajnih puteva, čiji su medijatori reaktivne vrste kiseonika i azota. U ovom radu testirali smo hipotezu da funkcionalne promene GRu astmi nastaju kao posledica delovanja oksidanata. U tom cilju sproveli smo seriju ex vivo tretmana mononuklearnih ćelija periferne krvi zdravih donora oksidujućim agensima (3-morfolinosidnoniminom, SIN-1; S-nitrozo-N-acetil-penicilaminom, SNAP; i vodonik peroksidom, H2O2) i uporedili nastale modifikacije GR sa onima koje su ranije zapažene kod astmatičnih pacijenata. Rezultati su pokazali da je tretman perifernih limfocita vodonik peroksidom izazvao povećanje koncentracije GR proteina, koje je bilo praćeno povećanjem broja mesta vezivanja hormona i smanjenjem afiniteta receptora prema hormonu. Promene indukovane vodonik peroksidom, uključujući i karakterističnu ekspresiju izoformi GR proteina, bile su vrlo slične promenama koje su ranije zapažene u perifernim limfocitima pacijenata obolelih od srednje teškog oblika astme, ali ne i kod blagih astmatičara i zdravih donora. Tretman drugim primenjenim oksidantima proizveo je drugačije efekte, ili nije imao uticaja na GR. Prema tome, ova studija je dala preliminarne podatke koji ukazuju da su funkcionalne promene GR povezane sa srednje teškom astmom verovatno posredovane redoks mehanizmima koji se zasnivaju na oksidativnoj i regulatornoj ulozi vodonikperoksida.Projekat ministarstva br. 14300

Changes of antioxidant enzyme activity and heat shock protein content in lymphocytes of children with asthma

The aim of the present study was to examine whether changes in the antioxidant status and expression of major intracellular stress proteins are associated with pathophysiology of childhood asthma and severity of the disease. The activities of copper/zinc (CuZn) and manganese (Mn) superoxide dismutase (SOD) and catalase (CAT) in peripheral blood mononuclear cells (PBMCs) of 28 stable pediatric patients (11 mild persistent and 17 moderate persistent asthmatics) and 12 healthy children were assessed by native gel assays. The levels of two heat shock proteins (HSPs), Hsp70 and Hsp90, were examined by quantitative Western blot analysis. Moderate asthmatics, in comparison to healthy children, displayed higher activity of CuZnSOD, while differences of MnSOD and CAT activity between the groups of patients were not found. The levels of Hsp90 and the inducible isoform of Hsp70 were increased in moderate asthmatics as compared to mild asthmatics and healthy children. The results demonstrate an imbalance in cellular antioxidant and stress response systems that may contribute to pathogenesis of childhood asthma, but are not necessarily related to severity of the disease.Cilj ove studije bio je da se ispita da li su promene antioksidativnog statusa i ekspresije glavnih unutar ćelijskih stres proteina povezane sa patogenezom astme i težinom ovog oboljenja kod dece. Aktivnost bakar/cink(CuZn)-i mangan (Mn)-superoksid dismutaze (SOD), i katalaze (CAT) u mononuklearnim ćelijama iz periferne krvi 28 dece sa stabilnom astmom (11 sa blagim i 17 sa srednje teškim oblikom bolesti) i 12 zdrave dece ispitana je enzimskim testom u nativnom gelu. Koncentracije dva ispitivana proteina toplotnog stresa, Hsp70 i Hsp90, određene su tehnikom kvantitativnog imunoblota. Pacijenti sa srednje teškom astmom pokazali su povećanu aktivnost CuZn-SOD upoređenju sa zdravom decom, dok razlike u aktivnosti Mn-SOD i CAT između ispitivanih grupa pacijenata nisu zapažene. Nivo Hsp90 i inducibilne izoforme Hsp70 bio je povećan kod srednje teških astmatičara upoređenju sa blagim astmatičarima i zdravom decom. Rezultati ukazuju da disbalans u ćelijskom antioksidativnom i anti-stres sistemu može doprineti patofiziologiji dečje astme, ali ne mora biti povezan sa težinom oboljenja.nul

Electrical properties of mechanically activated zinc oxide

Microstructural properties of a commercial zinc oxide powder were modified by mechanical activation in a high-energy vibro-mill. The obtained powders were dry pressed and sintered at 1100 degrees C for 2 h. The electrical properties of grain boundaries of obtained ZnO ceramics were studied using an ac impedance analyzer. For that purpose, the ac electrical response was measured in the temperature range from 23 to 240 degrees C in order to determine the resistance and capacitance of grain boundaries. The activation energies of conduction were obtained using an Arrhenius equation. Donor densities were calculated from Mott-Schottky measurements. The influence of microstructure, types and concentrations of defects on electrical properties was discussed

Reaction sintering of the 2ZnO-TiO2 system

Sintering kinetics of the mechanically activated ZnO-TiO2 system was studied. Mixtures of ZnO and TiO2 powders were mechanically activated using a high-energy ball mill for different time intervals from 0 to 300 minutes. Formal phenomenological analyses were performed in order to describe the specimen’s behavior during isothermal sintering at 1100oC. Non-isothermal sintering was investigated by dilatometer measurements up to 1100oC with a constant heating rate. The Dorn method was applied in order to give information on the activation energy

Modification of the structural and optical properties of commercial ZnO powder by mechanical activation

Mechanical activation was used as a method for modification of the structural and optical properties of commercial ZnO powder. For this purpose zinc oxide powder was mechanically treated by grinding in a high-energy vibro-mill in a continual regime in air up to 300 minutes. Starting and modified ZnO samples were characterized using XRD, BET and TEM measurements. Optical properties of these samples were investigated by Raman and photoluminescence (PL) spectroscopy. The color of commercial ZnO powder was white while mechanically activated ZnO powder was dark yellow, indicating the presence of nonstoichiometry. In the Raman spectra of non-activated sample Raman modes of bulk ZnO were observed, while the spectra of modified samples point out structural and stoichiometric changes. The PL spectra of modified samples excited by 325 and 442 nm lines of a He-Cd laser show great difference with respect to the spectra of the original sample. This study confirms that change in the defect structure of the ZnO crystal lattice introduced by mechanical activation affects the optical properties of this material

Synthesis and characterization of zinc titanate nano-crystal powders obtained by mechanical activation

Development of dielectric materials for microwave frequencies is increasing with rapid progress in mobile and satellite communications systems, where zinc titanates have found application due to their semi-conducting and dielectric properties. Mechanical activation by grinding is a well-known method and common part of the powder preparation route in the field of ceramics. The aim of this work is investigation of the influence of experimental conditions for mechanochemical synthesis of zinc orthotitanate. Starting powder mixtures of ZnO and TiO2, in the molar ratio that is in accordance with the stoichiometry of zinc titanate spinel type Zn2TiO4, were mechanically activated using a high-energy planetary ball mill. The process of mechanical activation was performed during different time intervals from 0 to 300 minutes. Microstructure characterization was determined by X-ray diffraction analysis and scanning electron microscopy. Also, the specific surface area (SSA) of powders samples was measured by a nitrogen gas sorption analyzer using the BET method. The very first traces of zinc titanate are detectable after only 5 minutes of activation. The most interesting occurrence during the mechanical method of activation is that we have an almost pure phase after 90 minutes

Promjene intraokularnog tlaka nakon nekomplicirane fakoemulzifikacije u ranom poslijeoperacijskom razdoblju u zdravim očima

The aim was to determine early changes in intraocular pressure (IOP) following uneventful phacoemulsifi-cation and intraocular lens (IOL) implantation in healthy eyes. This prospective interventional case series study was conducted at Ophthalmology Department, Kragujevac Clinical Centre, Kragujevac, Serbia. The study included 123 eyes of 123 cataract patients, 66 women and 57 men, age range 50-88 (mean 70.73±7.94) years having undergone phacoemulsification and in-the-bag implantation of a foldable IOL. The patients were treated at Kragujevac Clinical Centre between June 2015 and May 2016. IOP was measured by Goldmann applanation tonometry preoperatively, then 4-6 hours, 18-24 hours and 7 days postoperatively by the same examiner. The mean IOP preoperatively was 15.10±2.68 mm Hg. In three patients, maximum measured IOP was 22 mm Hg. At 4-6 hours postoperatively, the mean IOP was 24.29±7.56 mm Hg (p<0.001), at 18-24 hours it was 18.37±4.80 mm Hg (p<0.001), and 7 days after the surgery the mean IOP was 16.24±2.90 mm Hg (p<0.05). The measured IOP values were statistically signif-icant in all measured times. However, at 4-6 hours and 18-24 hours, the mean IOP value was highly statis-tically significant (p<0.001). Although 7 days after the surgery IOP normalized, the mean IOP value was statistically significant (p<0.05). In conclusion, our research showed that even eyes with normal preopera-tive values and uncomplicated phacoemulsification course can show very high IOP values postoperative-ly, which can cause pain, blurred vision and, rarely, compromise visual function.Cilj rada je bio utvrditi rane promjene intraokularnog tlaka (IOT) nakon fakoemulzifikacije i implantacije intraoku-larne leće (IOL) u zdrave oči. Ova prospektivna interventna studija slučaja provedena je na Oftalmološkom odjelu Kliničkog centra Kragujevac u Kragujevcu, Srbija. Studija je obuhvatila 123 oka bolesnika s kataraktom, 66 žena i 57 muškaraca, u dobi od 50-88 (srednja dob 70,73±7,94) godina, koji su bili podvrgnuti fakoemulzifikaciji i implan-taciji IOL u kapsularnu vrećicu. Bolesnici su liječeni u Kliničkom centru Kragujevac između lipnja 2015. i svibnja 2016. godine. IOT je mjeren Goldmannovim aplanacijskim tonometrom prijeoperacijski, a zatim 4-6 sati, 18-24 sata i 7 dana poslijeperacijski, a mjerenja je obavio isti ispitivač. Srednja vrijednost IOT prijeoperacijski je iznosila 15,10±2,68 mm Hg. Kod tri bolesnika najviši izmjereni IOT bio je 22 mm Hg. Kod mjerenja provedenog 4-6 sati poslijeoperacijski srednja vrijednost IOT bila je 24,29±7,56 mm Hg (p<0,001), zatim u 18-24 sata bila je 18,37±4,80 mm Hg (p<0,001), a 7 dana nakon operacije srednja vrijednost IOT bila je 16,24±2,90 mm Hg (p<0,05). Izmjerene vrijednosti IOTbile su statistički značajne u svim vremenima mjerenja. Međutim, u 4-6 sati i 18-24 sata srednja vrijednost IOT bila je visoko statistički značajna (p<0,001). Iako se 7 dana nakon operacije vrijednost IOT normali-zirala, srednja vrijednost je bila statistički značajna (p<0,05). U zaključku, naše istraživanje je pokazalo da čak i oči s normalnim prijeoperacijskim vrijednostima i nekompliciranim tijekom fakoemulzifikacije mogu pokazivati vrlo visoke vrijednosti IOT, što može uzrokovati bol, zamagljen vid i, rijetko, ugroziti vidnu oštrinu

History of the Belanovica (Serbia) Neogene lake basin inferred from petrological and geochemical data

The petrological and geochemical composition of Neogene lacustrine successions and basement rocks of the Belanovica basin in Central Serbia, were investigated in three exploration boreholes, drilled in the central part of the former lake. Two boreholes accessed the basement, while the third one terminated in the lowermost Neogene interval, composed of coarse-grained clastics. Formation and diversification of the lake basin was influenced by strong syndepositional volcanic activity. The vertical distribution of selected elements from basal clastics (Cr, Ni, and Mg) and from overlying lake sediments (Ba, Sr, Na, K, etc.) indicates both the southern and northern margins of the basin, as potential source areas. The elemental concentrations are consistent with petrography. Based on the derived data, a reconstruction of the basin history is presented. The lack of index fossils resulted in a less accurate stratigraphy and the need for further updating by employment of the fission-track low-temperature thermochronometers. Additionally, outcrop studies and correlation with lake sediments in the Valjevo-Mionica basin is suggested

Possible role of a hydrogen peroxide-mediated mechanism in glucocorticoid receptor functional alterations associated with moderate asthma

It is well known that pathogenesis and maintenance of chronic asthma is associated with alterations of glucocorticoid receptor (GR) function, and also with persistent pulmonary inflammation, the important mediators of which are reactive oxygen and nitrogen species. In this paper, we tested a hypothesis that GR functional alterations in asthma result from the action of oxidants. To that end, we conducted a series of ex vivo treatments of peripheral blood mononuclear cells (PBMCs) of healthy donors with oxidizing agents (3 morpholinosydnonimine, SIN1; S-nitroso-N-acetyl-penicillamine, SNAP; and hydrogen peroxide, H2O2) and compared the resulting GR modifications with those previously noticed in asthmatic patients. The results show that treatment of PBMCs by H2O2 provoked an increase in the level of GR protein, accompanied by a rise in the number of hormone-binding sites and a decline in the receptor's affinity for the hormone. The H2O2 induced changes, including a characteristic GR isoprotein expression pattern, were found to be very similar to the GR changes previously observed in PBMCs of moderate asthmatic patients, but not in mild asthmatics and healthy subjects. Treatment with the other oxidants applied herein produced different effects or exerted no influence on GR. Thus, this study provides preliminary data suggesting that functional alterations of the GR associated with moderate asthma may be mediated by redox mechanisms that are based on oxidative and regulatory actions of H2O2.Poznato je da su patogeneza i napredovanje hronične astme povezani sa funkcionalnim promenama glukokortikoidnog receptora (GR) i dugotrajnom inflamacijom disajnih puteva, čiji su medijatori reaktivne vrste kiseonika i azota. U ovom radu testirali smo hipotezu da funkcionalne promene GRu astmi nastaju kao posledica delovanja oksidanata. U tom cilju sproveli smo seriju ex vivo tretmana mononuklearnih ćelija periferne krvi zdravih donora oksidujućim agensima (3-morfolinosidnoniminom, SIN-1; S-nitrozo-N-acetil-penicilaminom, SNAP; i vodonik peroksidom, H2O2) i uporedili nastale modifikacije GR sa onima koje su ranije zapažene kod astmatičnih pacijenata. Rezultati su pokazali da je tretman perifernih limfocita vodonik peroksidom izazvao povećanje koncentracije GR proteina, koje je bilo praćeno povećanjem broja mesta vezivanja hormona i smanjenjem afiniteta receptora prema hormonu. Promene indukovane vodonik peroksidom, uključujući i karakterističnu ekspresiju izoformi GR proteina, bile su vrlo slične promenama koje su ranije zapažene u perifernim limfocitima pacijenata obolelih od srednje teškog oblika astme, ali ne i kod blagih astmatičara i zdravih donora. Tretman drugim primenjenim oksidantima proizveo je drugačije efekte, ili nije imao uticaja na GR. Prema tome, ova studija je dala preliminarne podatke koji ukazuju da su funkcionalne promene GR povezane sa srednje teškom astmom verovatno posredovane redoks mehanizmima koji se zasnivaju na oksidativnoj i regulatornoj ulozi vodonikperoksida.Projekat ministarstva br. 14300