16 research outputs found

    Elevated serum uric acid reduce heart damage in patients undergoing open-heart surgery

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    Objectives: Peroxynitrite is species claimed to propagate ischemia/reperfusion damage. In this report levels of serum uric acid (UA), a peroxynitrite scavenger, are compared with creatine phosphokinase (CPK) in male patients before and after open-heart surgery in order to asses if increased levels of UA may protect heart from biochemical damage induced by peroxynitrite during the coronary by-pass grafting (CABG) intervention. Methods: 45 male patients (16 carvedilol pretreated (6.25 mg/ daily, during 6 weeks before surgery, mean age 55.3Ā±1.7 years, range 50-71) and 29 patients without carvedilol pretreatment (mean age 58.3Ā±1.4 years, range 47-73) underwent elective CABG were examined. Study inclusion criteria were CABG performed on two and more coronary-vessels with aortic crossclamp during 30-40 minutes. For assessment of patients objective health status before operations Euro- SCORE were used. Serum uric acid (UA) levels and creatine phosphokinase (CPK) were measured spectrophotometricaly by using a quantitative enzymatic assay. Results: Carvedilol pretreated patients had higher amount of serum UA (p<0.05) comparing to non-treated patients. During the surgical procedure patients are subjected to temporary ischemia due to transfer from corporeal to extracorporeal circulation. In this period of time the amount of UA decreased in carvedilol pretreated group (406Ā±46 (t1) vs. 300Ā±22 mmol/L (t2)) to the level of non-treated patients (328Ā±14 (t1) vs. 322Ā±18 mmol/L. Carvedilol pretreated patients and non-treated patients had the same level of CPK at the beginning of the surgical procedure (t1) (78Ā±6 vs. 83+13 U/L) but lower increase (p<0.05) in CPK activity in carvedilol pretreated patients in respect to nontreated patients (338Ā±46 vs. 644Ā±103 U/L) at the end of procedure (t2). Such results suggest that open heart surgery led to elevated CPK levels, but this effect was less pronounced in patients with higher level of UA. Conclusions: Our results suggest possible role of UA in the protection from reperfusion injury. Increase of UA before surgery may be beneficial factor during CABG procedure in patients treated with carvedilol by decreasing level of peroxynitrite as one of molecular causes of reperfusion injury. Our results showed influence of UA on CPK levels at the end of surgical procedure, indicating that increased levels of UA may protect heart from biochemical damage induced by peroxynitrite during the CABG intervention.Ciljevi: Postoji miÅ”ljenje da Peroxynitrite Å”iri - pojačava oÅ”tećenja koja potiču od ishemije /reperfuzije. U ovom radu poređen je nivo mokraćne kiseline (UA) u serumu, sakupljača peroksinitrita, sa nivoom kreatin fosfokinaze (CPK) kod muÅ”karaca pre i nakon operacije na otvorenom srcu, a u cilju procene da li povećani nivoi UA mogu služiti kao zaÅ”tita od biohemijskih oÅ”tećenja izazvanih upotrebom peroksinitrita tokom hirurÅ”ke CABG intervencije. Metode: Ispitivano je 45 bolesnika (16 je prethodno primalo karvedilol - 6.25 mg dnevno, tokom 6 nedelja pre operacije, prosečne starosti 55.3Ā±1.7 godina, 55-71, i 29 bolesnika koji nisu primali karvedilol, prosečne starosti 58.3Ā±1.4 godina, 47-73) koji su bili podvrgnuti CABG hirurÅ”koj intervenciji. Kriterijumi za uključenje u studiju su bili izvođenje CABG na dva ili viÅ”e sudova sa klemovanjem aorte u trajanju od 30 - 40 minuta. Za procenu zdravstvenog stanja bolesnika pre operacije koriŔćen je EuroSCORE. Nivoi UA i kreatin fosfokinaze (CPK) u serumu su mereni uz pomoć spektrofotometrije koriŔćenjem kvantitativnog enzimskog eseja. Rezultati: U bolesnika koji su prethodno primali karvedilol uočeni su uvećani nivoi UA u serumu (p< 0.05) u poređenju sa bolesnicima koji nisu primali pomenuti lek. Tokom hirurÅ”ke procedure bolesnici su podvrgnuti privremenoj ishemiji zbog prebacivanja sa telesnog na vantelesni krvotok. U tom periodu vrednosti UA su snižene u bolesnika koji su prethodno primali karvedilol (406+46 (t1) naspram 300Ā±22 mol/L (t2)) bolesnika koji ga nisu primali (328Ā±14 (t1) naspram 322Ā±18 mol/L). Bolesnici koji su primali karvedilol i oni koji nisu imali su isti nivo CPK na početku hirurÅ”ke procedure (t1) (78Ā±6 naspram 83Ā±13 U/L) ali je na kraju procedure uočen niži porast aktivnosti CPK (p<0.05) u bolesnika koji su primali karvedilol u poređenju sa bolesnicima koji nisu (338Ā±46 prema 644Ā±103 U/L) (t2). Ovakvi rezultati sugeriÅ”u da intervencija na otvorenom srcu dovodi do povećanja nivoa CPK, ali je taj efekat bio manje izražen u bolesnika koji su imali viÅ”i nivo UA. Zaključak: NaÅ”i rezultati ukazuju na moguću pozitivnu ulogu mokraćne kiseline u zaÅ”titi od oÅ”tećenja koja može prouzrokovati reperfuzija. Povećanje nivoa UA pre operacije može predstavljati koristan faktor tokom CABG procedure u bolesnika koji su primali karvedilol, jer snižava nivo peroksinitrita kao jedan od uzroka oÅ”tećenja od reperfuzije. NaÅ”i rezultati pokazuju uticaj UA na nivoe CPK pri kraju hirurÅ”ke intervencije, Å”to pak ukazuje na to da uvećani nivoi UA mogu Å”tititi srce od biohemijskih oÅ”tećenja izazvana peroksinitritom tokom CABG intervencije

    IMPACT OF DIFFERENCES IN ECONOMIC DEVELOPMENT AND SOCIOECONOMIC STABILITY ON BENZODIAZEPINE EXPOSURE BETWEEN THE THREE BALKANS COUNTRIES

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    Introduction: Anxiety disorders are among the most common mental disorders. Benzodiazepines belong to the group of anxiolytic sedatives and the most prescribed drugs in the world. The aim in ours study was to evaluate the differences in the exposure of the population to benzodiazepines (in period from 2014-2018) be tween Serbia, Slovenia and Croa tia, the three countries of th e Southwestern Balkans with varying degrees of socioeconomic development. Study design: A academic investigator initiated, pharmacoepidemiological difference-in -difference time se ries analysis of population exposure to benzodiazepines between the three, geogr aphically close Balkans countries (Slovenia, Serbia, Croatia) wi th varying degrees of socioeconomic developmen t has been carried out. Study was conducted as academic investigator initiated, in a retrospective manner on monthly basis international data set from January 2014 to December 2018. Results: At the annual level, during the study period from Januar y 2014 to December 2018, compared to Slovenia, Serbia and Croatia had higher DIDs, from 5 fold (Croatia) to 6 fold (Serbi a), for all benzodiazepines in total. By analyzing the differenc es-in- difference, we have shown that influence of both time (month) and c ountry on DIDs is significant as well as their mutual intera ction (the country Ɨ month) for all benzodiazepines in total. Conclusion: Serbia and Croatia must implement exp licit measures of reduci ng benzodiazepine prescription in health primary care based on evidence-based recommendations in the indicati ons where general medicine practitioners/family doctors most commonly prescribe these medicines. Without providing a realistic supplement/alternative to benzodiazepines such as increasing the availability of psychotherapy and impr oving the structure of psyc hiatric professionals in healthcare settings, implicit measures are not recommended for reducing pr escription, implementing accountability measures for prolonged prescription of benzodiazepines, and in particular forā€œ masked ā€somatic diseases . All this comes to the fore by raising economic development and socioeconomic stabilit

    IMPACT OF DIFFERENCES IN ECONOMIC DEVELOPMENT AND SOCIOECONOMIC STABILITY ON BENZODIAZEPINE EXPOSURE BETWEEN THE THREE BALKANS COUNTRIES

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    Introduction: Anxiety disorders are among the most common mental disorders. Benzodiazepines belong to the group of anxiolytic sedatives and the most prescribed drugs in the world. The aim in ours study was to evaluate the differences in the exposure of the population to benzodiazepines (in period from 2014-2018) be tween Serbia, Slovenia and Croa tia, the three countries of th e Southwestern Balkans with varying degrees of socioeconomic development. Study design: A academic investigator initiated, pharmacoepidemiological difference-in -difference time se ries analysis of population exposure to benzodiazepines between the three, geogr aphically close Balkans countries (Slovenia, Serbia, Croatia) wi th varying degrees of socioeconomic developmen t has been carried out. Study was conducted as academic investigator initiated, in a retrospective manner on monthly basis international data set from January 2014 to December 2018. Results: At the annual level, during the study period from Januar y 2014 to December 2018, compared to Slovenia, Serbia and Croatia had higher DIDs, from 5 fold (Croatia) to 6 fold (Serbi a), for all benzodiazepines in total. By analyzing the differenc es-in- difference, we have shown that influence of both time (month) and c ountry on DIDs is significant as well as their mutual intera ction (the country Ɨ month) for all benzodiazepines in total. Conclusion: Serbia and Croatia must implement exp licit measures of reduci ng benzodiazepine prescription in health primary care based on evidence-based recommendations in the indicati ons where general medicine practitioners/family doctors most commonly prescribe these medicines. Without providing a realistic supplement/alternative to benzodiazepines such as increasing the availability of psychotherapy and impr oving the structure of psyc hiatric professionals in healthcare settings, implicit measures are not recommended for reducing pr escription, implementing accountability measures for prolonged prescription of benzodiazepines, and in particular forā€œ masked ā€somatic diseases . All this comes to the fore by raising economic development and socioeconomic stabilit

    Elevated serum uric acid reduce heart damage in patients undergoing open-heart surgery

    Get PDF
    Objectives: Peroxynitrite is species claimed to propagate ischemia/reperfusion damage. In this report levels of serum uric acid (UA), a peroxynitrite scavenger, are compared with creatine phosphokinase (CPK) in male patients before and after open-heart surgery in order to asses if increased levels of UA may protect heart from biochemical damage induced by peroxynitrite during the coronary by-pass grafting (CABG) intervention. Methods: 45 male patients (16 carvedilol pretreated (6.25 mg/ daily, during 6 weeks before surgery, mean age 55.3Ā±1.7 years, range 50-71) and 29 patients without carvedilol pretreatment (mean age 58.3Ā±1.4 years, range 47-73) underwent elective CABG were examined. Study inclusion criteria were CABG performed on two and more coronary-vessels with aortic crossclamp during 30-40 minutes. For assessment of patients objective health status before operations Euro- SCORE were used. Serum uric acid (UA) levels and creatine phosphokinase (CPK) were measured spectrophotometricaly by using a quantitative enzymatic assay. Results: Carvedilol pretreated patients had higher amount of serum UA (p<0.05) comparing to non-treated patients. During the surgical procedure patients are subjected to temporary ischemia due to transfer from corporeal to extracorporeal circulation. In this period of time the amount of UA decreased in carvedilol pretreated group (406Ā±46 (t1) vs. 300Ā±22 mmol/L (t2)) to the level of non-treated patients (328Ā±14 (t1) vs. 322Ā±18 mmol/L. Carvedilol pretreated patients and non-treated patients had the same level of CPK at the beginning of the surgical procedure (t1) (78Ā±6 vs. 83+13 U/L) but lower increase (p<0.05) in CPK activity in carvedilol pretreated patients in respect to nontreated patients (338Ā±46 vs. 644Ā±103 U/L) at the end of procedure (t2). Such results suggest that open heart surgery led to elevated CPK levels, but this effect was less pronounced in patients with higher level of UA. Conclusions: Our results suggest possible role of UA in the protection from reperfusion injury. Increase of UA before surgery may be beneficial factor during CABG procedure in patients treated with carvedilol by decreasing level of peroxynitrite as one of molecular causes of reperfusion injury. Our results showed influence of UA on CPK levels at the end of surgical procedure, indicating that increased levels of UA may protect heart from biochemical damage induced by peroxynitrite during the CABG intervention.Ciljevi: Postoji miÅ”ljenje da Peroxynitrite Å”iri - pojačava oÅ”tećenja koja potiču od ishemije /reperfuzije. U ovom radu poređen je nivo mokraćne kiseline (UA) u serumu, sakupljača peroksinitrita, sa nivoom kreatin fosfokinaze (CPK) kod muÅ”karaca pre i nakon operacije na otvorenom srcu, a u cilju procene da li povećani nivoi UA mogu služiti kao zaÅ”tita od biohemijskih oÅ”tećenja izazvanih upotrebom peroksinitrita tokom hirurÅ”ke CABG intervencije. Metode: Ispitivano je 45 bolesnika (16 je prethodno primalo karvedilol - 6.25 mg dnevno, tokom 6 nedelja pre operacije, prosečne starosti 55.3Ā±1.7 godina, 55-71, i 29 bolesnika koji nisu primali karvedilol, prosečne starosti 58.3Ā±1.4 godina, 47-73) koji su bili podvrgnuti CABG hirurÅ”koj intervenciji. Kriterijumi za uključenje u studiju su bili izvođenje CABG na dva ili viÅ”e sudova sa klemovanjem aorte u trajanju od 30 - 40 minuta. Za procenu zdravstvenog stanja bolesnika pre operacije koriŔćen je EuroSCORE. Nivoi UA i kreatin fosfokinaze (CPK) u serumu su mereni uz pomoć spektrofotometrije koriŔćenjem kvantitativnog enzimskog eseja. Rezultati: U bolesnika koji su prethodno primali karvedilol uočeni su uvećani nivoi UA u serumu (p< 0.05) u poređenju sa bolesnicima koji nisu primali pomenuti lek. Tokom hirurÅ”ke procedure bolesnici su podvrgnuti privremenoj ishemiji zbog prebacivanja sa telesnog na vantelesni krvotok. U tom periodu vrednosti UA su snižene u bolesnika koji su prethodno primali karvedilol (406+46 (t1) naspram 300Ā±22 mol/L (t2)) bolesnika koji ga nisu primali (328Ā±14 (t1) naspram 322Ā±18 mol/L). Bolesnici koji su primali karvedilol i oni koji nisu imali su isti nivo CPK na početku hirurÅ”ke procedure (t1) (78Ā±6 naspram 83Ā±13 U/L) ali je na kraju procedure uočen niži porast aktivnosti CPK (p<0.05) u bolesnika koji su primali karvedilol u poređenju sa bolesnicima koji nisu (338Ā±46 prema 644Ā±103 U/L) (t2). Ovakvi rezultati sugeriÅ”u da intervencija na otvorenom srcu dovodi do povećanja nivoa CPK, ali je taj efekat bio manje izražen u bolesnika koji su imali viÅ”i nivo UA. Zaključak: NaÅ”i rezultati ukazuju na moguću pozitivnu ulogu mokraćne kiseline u zaÅ”titi od oÅ”tećenja koja može prouzrokovati reperfuzija. Povećanje nivoa UA pre operacije može predstavljati koristan faktor tokom CABG procedure u bolesnika koji su primali karvedilol, jer snižava nivo peroksinitrita kao jedan od uzroka oÅ”tećenja od reperfuzije. NaÅ”i rezultati pokazuju uticaj UA na nivoe CPK pri kraju hirurÅ”ke intervencije, Å”to pak ukazuje na to da uvećani nivoi UA mogu Å”tititi srce od biohemijskih oÅ”tećenja izazvana peroksinitritom tokom CABG intervencije

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

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    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 (24Ā±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

    freeCappuccino - An Open Source Software Library for Computational Continuum Mechanics

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    The paper describes development of an open-source library (www.github.com/nikola-m/freeCappuccino) for computational fluid dynamics and in general computational continuum mechanics. The code is based on finite volume method on arbitrary unstructured polyhedral meshes. The interfaces to highly abstract data types such as arbitrary order tensor fields on discretized finite volume domains, and scalar and vector sparse linear systems resulting from finite volume discretization of partial differential equations are provided. Explicit manipulation of tensor fields through high level, highly abstract programming syntax is explained. Also, implicit operation over tensor fields pertinent to discretization of partial differential operators is provided and explained. The library is developed in modern version of Fortran. Code parallelization is achieved through domain decomposition and implemented using MPI and OpenMP. While avoiding the usual class syntax of object-oriented programming, the code has essentially object oriented design. Comparison is made with the well-known OpenFOAM library. The purpose of the ongoing development is providing researchers with a tool for easy transfer of mathematical operations of their physical models into functional and efficient simulation software based on finite volume method. The guiding principle of development is exchange of ideas and reproducibility in computational science in general

    Mobility and Bioavailability of Metals in sediments of Skadar Lake - Montenegro

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    Metals in sediments are present in different chemical forms, which mostly affect their ability to transfer in water and plants i.e. their bioavailability. The mobile part of metals is potentially toxic, thus for the evaluation of the bioavailability it is often enough to determine the metal content in the available and potentially available fraction of sediment. The aim of this study was to compare some methods of determination of mobile forms of heavy metals and to determine their share related to the ā€œpseudo-totalā€ metal content in the sediment from Skadar Lake, Montenegro. Mobile forms of Cu, Co, Cr, Mn, Ni, Pb, Zn, Sr and V were determined using: 0.1M NH4Cl (buffered to pH 9), 0.1M CaCl2 (pH 6), 0.1M CH3COONa (pH 9), 0.1M H2C2O4 (pH 2) and 0.1M EDTA (pH 6),. The largest amounts of Co (42.2 wt.%), Cr (11.4%) , Mn (59.9%), Ni (13.5%), Zn (41.0%) and V (42.2%) were extracted with oxalic acid and Cu (44.7 wt.%), Pb (49.3%), and Sr (61.2%) with EDTA. With NH4Cl, CaCl2 and CH3COONa small amounts of metals were extracted (except Sr), generally below 1%. Based on these results we can conclude that the metals in the sediments of Lake Skadar are found in a negligible amount in easily mobile, acid soluble and carbonate-related phase

    Numerical aerodynamic-thermal-structural analyses of missile fin configuration during supersonic flight conditions

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    Attention in this work is focused on aerodynamic heating and aero-thermo-mechanical analysis of fin type structures on the missile at supersonic flight. At high Mach number the heat due to friction between body and flow, i.e. viscous heating must be taken into account because the velocity field is coupled with the temperature field. The flow field around the fins of the missile and especially the temperature distribution on its surface, as well as aerodynamic-thermal-structural analyses are numerically modeled in ANSYS Workbench environment. The investigation was carried out for two Mach numbers (M = 2.3 and M = 3.7). Own available structural experimental results have been used for computational structural mechanics (CSM) validation and verification, in order to assure credibility of numerical fluid-thermal-structure interaction (FTSI). Conducted simulations were carried out to better understand the FTSIs of the missile fin during supersonic flight

    Operating cost analysis of anaesthesia: Activity based costing (ABC analysis)

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    Introduction. Cost of anaesthesiology represent defined measures to determine a precise profile of expenditure estimation of surgical treatment, which is important regarding planning of healthcare activities, prices and budget. Objective. In order to determine the actual value of anaestesiological services, we started with the analysis of activity based costing (ABC) analysis. Methods. Retrospectively, in 2005 and 2006, we estimated the direct costs of anestesiological services (salaries, drugs, supplying materials and other: analyses and equipment.) of the Institute of Anaesthesia and Resuscitation of the Clinical Centre of Serbia. The group included all anesthetized patients of both sexes and all ages. We compared direct costs with direct expenditure, ā€œeach cost object (service or unit)ā€ of the Republican Health-care Insurance. The Summary data of the Departments of Anaesthesia documented in the database of the Clinical Centre of Serbia. Numerical data were utilized and the numerical data were estimated and analyzed by computer programs Microsoft Office Excel 2003 and SPSS for Windows. We compared using the linear model of direct costs and unit costs of anaesthesiological services from the Costs List of the Republican Health-care Insurance. Results. Direct costs showed 40% of costs were spent on salaries, (32% on drugs and supplies, and 28% on other costs, such as analyses and equipment. The correlation of the direct costs of anaestesiological services showed a linear correlation with the unit costs of the Republican Healthcare Insurance. Conclusion. During surgery, costs of anaesthesia would increase by 10% the surgical treatment cost of patients. Regarding the actual costs of drugs and supplies, we do not see any possibility of costs reduction. Fixed elements of direct costs provide the possibility of rationalization of resources in anaesthesia

    Numerical Simulation of Crack Propagation in Seven-Wire Strand

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    This paper discusses certain aspects of numerical simulation of crack propagation in wire ropes subjected to axial loading, with the aim to explore and to demonstrate the capacity, performances and difficulties of crack propagation modeling by usage of numerical computational methods in such complex structures. For this purpose, the finite element method (FEM) was used, and 3D numerical analyses were performed in Ansys Workbench software. In order to validate and verify performed numerical modeling, crack growth rate based on calculated stress intensity factors (SIFs) along the crack fronts was obtained for the model for which experimental results could be found in the available literature. Finally, using the advanced modeling techniques, the parametric 3D model of seven-wire strand was analyzed. Conducted analysis showed that FEM could be a powerful tool for fatigue life predictions in order to reduce the need for experiments, which are still the only successful method for fatigue life estimation of wire ropes. Ā© Springer Nature Switzerland AG 2020.In: Mitrovic N., Milosevic M., Mladenovic G. (eds) Computational and Experimental Approaches in Materials Science and Engineering. CNNTech 2018. Lecture Notes in Networks and Systems, vol 90. Springer, Cha
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