Influence of deceased donor corticosteroid treatment on kidney transplant outcome

Uvod: Nedovoljan broj raspoloživih organa za transplantaciju je posledica nedovoljne identifikacije potencijalnih moždano mrtvih davaoca u jedinicama intenzivnog lečenja i nedovoljne konverzije potencijalnih u aktuelne davaoce iz medicinskih i organizacionih razloga. Moždana smrt ima brojne posledice kao što su hemodinamski poremećaji, hormonski disbalans i inflamacija, što sveukupno utiče na kvalitet organa i ishod transplantacije. Hipoperfuzija organa donora ima za posledicu ishemijsko oštećenje i oksidativni stres, što povećava učestalost odložene funkcije alografta (OFA). Zbog povećane ekspresije citokina, adhezivnih molekula i antigena tkivne histokompatibilnosti, nastale inflamatorne promene organa donora utiču na povećanje učestalosti akutnih odbacivanja (AO) posle transplantacije. Zbog prevazilaženja ovih poremećaja, primenjuju se različite terapijske opcije kod donora, koje su važan deo strategije za popravljanje kvaliteta organa i ishoda transplantacije. Ciljevi istraživanja: Sa ciljem održavanja aktivnosti programa kadaverične transplantacije bubrega u Kliničkom centru Srbije ispitivali smo uticaj primene indikatora efikasnosti programa kadaverične transplantacije bubrega u periodu 2010- 2012. Pored toga, ispitivali smo efikasnost primene metil-prednizolona (MP) na hemodinamiku i bubrežnu funkciju davaoca, kao i učestalost OFA, AO i funkciju presađenog bubrega do kraja prve godine od transplantacije. Uzimajući u obzir povezanost moždane smrti, oksidativnog stresa i inflamacije, određivali smo serumsku koncentraciju 8-hidroksi 2-deoksi guanozina (8-OH-dG), trombospondina-1 (TSP-1) i nuklearnog faktora kapa B (NF-κB) kod donora organa posle dijagnoze moždane smrti i njihove kasnije implikacije kod primaoca. Metode: Studija je prospektivna interventna i opservaciona sprovedena je u Centralnoj aseptičnoj jedinici intenzivne nege Urgentnog Centra Kliničkog centra Srbije i Centru za transplantaciju bubrega Kliničkog Centra Srbije u periodu 2010-2013. godine. U periodu istraživanja smo analizirali tri grupe indikatora efikasnosti programa kadaverične transplantacije koji se odnose na potencijal za donaciju organa, organizacione nedostatke i ukupnu efikasnost programa...Introduction: Shortage of organs available from brain dead donors is attributed to the insufficient reporting of potential donors as well as to low conversion rates of potential donors into actual donors due to medical and organisational issues. Brain death has numerous consequences, including hemodynamic disorders, hormonal imbalance and inflammation, which together influence organ quality and consequently transplantation outcome. Hypoperfusion of donor organs leads to ischemic lesions and also increases oxidative stress, which raises the frequency of delayed graft function (DGF). Due to enhanced expression of cytokines, adhesion molecules and tissue histocompatibility antigens, subsequent inflammatory changes in donor organs increase the rate of acute rejection (AR) after transplantation. With the aim of overcoming these disorders donors are subject to various therapy options that are an important part of the strategy for improvement of organ quality and transplantation outcome. Objective: With aim to maintain deceased donor kidney transplant program, we assessed the impact of indicators of program effectiveness application in Clinical center of Serbia, between 2010–2012. In adition, we examined the efficiency of methylprednisolone (MP) applied to potential donors on donor hemodinamics and kidney function, as well as frequency of DGF, AR and kidney allograft function during the first posttransplant year. Considering the link between brain death, oxidative stress and inflammation, we measured the serum concentration of 8-hydroxy 2-deoxy guanosine (8-OH-dG), thrombospondin-1 (TSP-1) and nuclear factor kappa B (NF-κB) in organ donors after diagnosed brain death, as well as their further implications in recipients. Method: Prospective interventional and observational study was conducted in Central aseptic intensive care unit, Emergency center, Clinical center of Serbia and Kidney transplant center, Clinical center of Serbia. Deceased donor kidney transplant program involved 172 potential kidney donors that were identified between 2010-2012. Brain death was confirmed in 163 patients. We conducted an analysis of an effectiveness indicators of deceased donor kidney transplant program. Three groups of indexes presenting potential for donation, areas of improvement and global effectiveness indicators were used..

ESI-MS spectra of 3-cyano-4-(substituted phenyl)-6-phenyl-2(1H)-pyridinones

Twelve 3-cyano-4-(substituted phenyl)-6-phenyl-2(1H)-pyridinones were investigated by tandem mass spectrometry using positive as well as negative electrospray ionization. The influence of the electron affinity of the substituent and the steric effect on the fragmentation is discussed. Pyridinones with a substituent of low proton affinity show loss of water, HCN or benzene from the pyridinone ring in the first step of MS2 fragmentations. Oppositely, if a substituent with high proton affinity is present on the phenyl ring in the 4-position of pyridinone, the fragmentation paths are complex, depending mainly on the substituent proton acceptor ability. Elimination of neutral molecules CO, HCN, H2O, PhH (benzene) or Ph and CN radicals are fragmentation processes common for all compounds in the subsequent steps of the fragmentations

WHEAT STRAW CONVERSION BY ENZYMATIC SYSTEM OF GANODERMA LUCIDUM

The purpose of this study was to resolve the question of whether various nitrogen sources and concentrations affect characteristics of selected G. lucidum ligninolytic enzymes participating in wheat straw fermentation. This is the first study reporting the presence of versatile peroxidase activity in crude extract of G. lucidum culture, as well as isoforms profile of Mn-oxidizing peroxidases. NH4NO3 was the optimum nitrogen source for laccase and Mn-dependent peroxidase activity, while peptone was the optimum one for versatile peroxidase activity. Four bands with laccase activity were obtained by native PAGE and IEF separations from medium enriched with inorganic nitrogen source, and only two bands from medium containing organic source. Medium composition was not shown to affect isoenzyme patterns of Mn-oxidizing peroxidases. Four isoforms of Mn-dependent peroxidase and three of versatile peroxidase were obtained on native PAGE. By IEF separation, five isoforms of Mn-dependent peroxidase and only two of versatile peroxidase were observed. The results demonstrated that G. lucidum has potential for mineralization and transformation of various agricultural residues and should take more significant participation in large-scale biotechnological processes

The effect of boron doping on the structure and properties of carbonized hydrothermal carbon

Structural and surface characterization of pristine and boron doped carbonized hydrothermal carbons (CHTC) is reported. Boron was introduced into glucose precursor solution with concentration of 0.2% and 1%. Following hydrothermal treatment, samples were carbonized to 1000oC and examined by Raman spectroscopy and temperature programmed desorption. Characterization of obtained samples as material for carbon paste electrode was performed by cyclic voltammetry measurements of the Fe (CN)6 3-/4- redox couple. Structural analysis showed that lower boron content in precursor solution induced structure ordering, while higher amount of boron caused structural disorder of CHTC sample. Boron presence in CHTC samples reduced number of surface active sites for oxygen adsorption and consequently improved their electrochemical response as electrode material for carbon paste electrode

Characterisation of surface oxygen groups on different carbon materials by the Boehm method and temperature-programmed desorption

The surface characteristics of different carbon materials: activated carbon, carbon felt, glassy carbon and a porous carbon monolith were investigated. The specific surface area was examined by the BET method with N(2) adsorption, the amount and the type of surface oxygen groups by Boehm titration as well as by temperature-programmed desorption (TPD). By comparing the results obtained using BET analysis with those of TPD and the Boehm method, it was found that the number of surface groups was not proportional to the specific surface area. The total amount of oxygen groups, obtained by TPD, is higher than the amount obtained by Boehms method for porous samples. The inconsistencies between these results originate from the fact that the Boehm method is limited to the determination of acidic and basic groups, whereas TPD provides information on the total number of all surface oxygen groups. In addition, the presence of porosity could reduce the solvent-accessible surface in the Boehm method. The TPD profiles of CO evolution showed the presence of a low temperature maximum, below 650 K, which originates from CO(2) reduction on the carbon material surface

Glassy carbon and boron doped glassy carbon electrodes for voltammetric determination of linuron herbicide in the selected samples

In this study the application of home-made unmodified (GC) and bulk modified boron doped glassy carbon (GCB) electrodes for the voltammetric determination of the linuron was investigated. The electrodes were synthesized with a moderate temperature treatment (1000A degrees C). Obtained results were compared with the electrochemical determination of the linuron using a commercial glassy carbon electrode (GC-Metrohm). The peak potential (E (p) ) of linuron oxidation in 0.1 mol dm(-3) H2SO4 as electrolyte was similar for all applied electrodes: 1.31, 1.34 and 1.28 V for GCB, GC and GC-Metrohm electrodes, respectively. Potential of linuron oxidation and current density depend on the pH of supporting electrolyte. Applying GCB and GC-Metrohm electrodes the most intensive electrochemical response for linuron was obtained in strongly acidic solution (0.1 mol dm(-3) H2SO4). Applying the boron doped glassy carbon electrode the broadest linear range (0.005-0.1 A mu mol cm(-3)) for the linuron determination was obtained. The results of voltammetric determination of the linuron in spiked water samples showed good correlation between added and found amounts of linuron and also are in good agreement with the results obtained by HPLC-UV method. This appears to be the first application of a boron doped glassy carbon electrode for voltammetric determination of the environmental important compounds

A TPD-MS study of glassy carbon surfaces oxidized by CO2 and O-2

The temperature-programmed desorption (TPD) method combined with mass spectrometric (MS) analysis has been applied to investigate the surface properties of carbon materials. The apparatus consisting of a temperature-programmed furnace and a quadrupole Mass spectrometer was constructed in order to characterize the surface of differently treated glassy carbon samples. In this work, samples of glassy carbon exposed to air, CO2 and O-2 were examined. The desorption of H2O, CO and CO2, as major products, indicated the presence of different oxide groups. The amount of these groups for all samples was calculated. It is concluded that oxidation affects the nature and the amount of die surface oxide groups and contributes to their increased stability

Levels of Presepsin and Midregion-Proadrenomedullin in Septic Patients with End-Stage Renal Disease after Cardiovascular Surgery: 1-Year Follow Up Study

Background: Procalcitonin (PCT) is a marker for sepsis diagnosis, identification of bacterial infection and monitoring of antibiotic therapy. It has been shown that PCT is not a good choice in patients with hemodialysis. Therefore, we have explored two biomarkers: a) presepsin, and, b) midregion-proadrenomedullin (MR-proADM) in patients having End-Stage Renal Disease (ESRD). Patients and Methods: We prospectively enlisted 20 patients, who underwent cardiovascular surgery and had been on dialysis. The diagnosis of sepsis has been established clinically and confirmed by PCT. Blood samples were taken before and after dialysis. Additionally, plasma and sera of 10 healthy blood donors without any complications were used as controls. Results: Presepsin plasma concentrations (4368 ± 3088 vs. 694.1 ± 239.1 pg/mL) were significantly higher in patients with sepsis compared with controls (p0.05) with no significance between alive and deceased (p=0.53) patients. Adjustments have shown that the difference for MR-proADM level is due to the random sampling variability (p=0.989), whereas difference for presepsin remained highly significant (p<0.001). Conclusions: Our results indicate that the accuracy of new biomarkers is equal to that of PCT in patients with ESRD. Presepsin might be as good marker in repeated measurements, before and after dialysis, as it is PCT. © 2014 Maravic-Stojkovic V, et al

In-situ grafting of Fe and Cu nanoparticles on carbon for electrolytic hydrogen production

In order to reduce air pollution by green-house gases released during fossil fuels combustion, hydrogen has been suggested as an alternative, clean fuel [1]. The most promising method of obtaining green hydrogen (and oxygen) is electrolytic water splitting [2]. For splitting process to be efficient, it is necessary to useelectrocatalysts with high activity, but they should also be economically accessible. Ionic liquids are used in the most diverse fields of sciencedue to their unique physical and chemical properties, and in this regard, they can be used for the development of electrocatalystsby direct carbonization [3]. Within this study, carbon catalysts doped with iron and copper (Fe/C, Cu/C and FeCu/C) were prepared by carbonization of ionic liquids containing the corresponding metal and characterized for the hydrogen evolution reaction (HER) in alkaline (8 M KOH) media. Electrochemical measurements were made by cyclic voltammetry (CV), linear cyclic voltammetry (LSV), electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA). All electrocatalysts showed good activity for HER. Tafel slope (b) values of -132, 155 and -151 mV dec-1 (Table 1) were obtained for HER at 25 oC for Fe/C, Cu/C and FeCu/C, respectively. Also, the exchange current density (j0) was determined and the values ranged from 1.28 to 2.94 10-2 mAcm-2. The results (Table 1) show that Fe/C, Cu/C and FeCu/Care promisingelectrocatalysts for hydrogen gas production by water splitting.Ninth Symposium Chemistry and Environmental Protection : June 4-7, Kladovo, 2023

Ab Initio Study of Graphene Interaction with O-2, O, and O-

A systematic ab initio (DFT-GGA) study of adsorption of various oxygen species on graphene has been performed in order to find out general trends and provide a good starting point to analyze the oxidation of more complex carbon materials. Particular attention was paid to finding an appropriate supercell model. According to our findings, atomic O is characterized by stable adsorption on graphene and very strong adsorption on defective graphene. On the other hand, O-2 does not adsorb on graphene and is allowed to diffuse freely to the defect, where it is expected to dissociate into two strongly adsorbed O atoms. The obtained results were compared with available theoretical data in the literature and good agreement was achieved