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This study presents the hierarchical structure of 50 sub-criteria divided into 7 main criteria for the assessment of electric vehicle (EV) deployment. Two options, Average Rank Transformations and Analytic Hierarchy Process methods, were applied in determining the local weights of the sub-criteria. The sufficient compatibility of expert opinions was accomplished using the averages of the ranks of the main criteria and sub-criteria as the result of solving the problem. The averages of the local weights were calculated employing three Multiple Criteria Decision-Making methods that increased the reliability of the research results. Based on this, the global weights and priorities of the sub-criteria were evaluated. The experts suppose that EV deployment at the national level is mainly affected by the higher cost of manufacturing and purchasing EVs, the application of financial incentives for purchasing EVs, the lack of exhausted gasses, the installation of fast charging points, and the absence of infrastructure in the five largest cities nationwide. The obtained results demonstrate that out of 50 sub-criteria, the cumulative global weight of the 10 most important sub-criteria (mainly based in economics) amounts to more than 35%, whereas that of the 22 most important sub-criteria have a weight above the average (0.2), reaching approximately 65%. The findings can be put into practice by state decision makers of EV deployment.

The utilization of “green” hydrogen in transportation areas gives rise to production- and supply infrastructure-related challenges; therefore, its wider application in automotive transport would lead to higher demand with cost reduction and a faster expansion of the hydrogen refuelling network. This study presents energy and environmental performance indicators analyses of a Nissan Qashqai J10 engine during the Worldwide Harmonised Light Vehicles Test Cycle (WLTC), replacing conventional fossil gasoline with dual-fuel (D-F) gasoline and hydrogen. Numerical modelling was conducted using AVL Cruise™ (Version R2022.2) software, utilizing the torque, fuel consumption, and environmental performance data of the HR16DE engine obtained through experimental testing across a wide range of loads and speeds on an engine test bench. The experimental investigation was carried out in two stages: using pure gasoline (G100); injecting a hydrogen additive into the intake air, constituting 5% of the gasoline mass (G95H5). Following similar stages, numerical modelling was conducted using the vehicle’s technical specifications to calculate engine load and speed throughout the WLTC range. Instant fuel consumption and pollutant emissions (CO, CH, NOx) were determined for various driving modes using experimental data maps. CO2 emissions were calculated considering fuel composition and consumption. By integrating the instant values, the total and specific fuel consumption and emissions were calculated. As a result, this study identified the effect of a 5% hydrogen additive in improving engine energy efficiency, reducing incomplete combustion products and lowering greenhouse gas (CO2) emissions under various driving modes. Finally, the results were compared with the requirements of EU standards.

The objective of this research was to examine how personality acts as a mediator in the relationship between reaction time and traffic perception in young adults. Given the increase in the number of road accidents among this age group in the European Union, it is essential to understand the psychological determinants of risky driving behavior. A sample of 60 participants from Poland, Slovakia, and Lithuania was assessed using the Vienna Test System to measure personality, reaction time, time-movement anticipation, and traffic perceptions. The results indicate gender differences in self-control personality factor and motor reaction time, as well as a positive correlation between the sense of responsibility and time-movement anticipation. The proposed model was confirmed, demonstrating that mental stability mediates the relationship between reaction time and traffic perceptions. A driver with high mental stability can react faster to stimuli while accurately perceiving objects in road traffic. This study has implications for road safety policies and practices. Incorporating personality assessments into driver training programs can help develop interventions that target specific personality traits. Furthermore, interventions aimed at enhancing mental stability may help reduce the likelihood of accidents among young drivers. However, this study’s limitations, such as the small sample size and narrow age range, should be considered in future research with other age groups and additional variables that directly impact traffic safety.

Alongside various road safety aspects, vehicle dynamics play a crucial role in enhancing the quality of life in modern society within a holistic traffic safety framework [...]

The goal of the paper is to investigate the impact of tire tread depth on road accident risk and to develop an accident rate prediction model. The state of 4288 vehicle tires using tread depth gauge was inspected and processed statistically. The tread depth of the most worn tire from each vehicle was registered for further analy-sis. Based on the collected data, a statistical tire tread depth model for an insurance company vehicle fleet had been developed. The conformity of the gamma distribu-tion to the data was verified upon applying the Pearson compatibility criterion. The paper provides the histo-grams of the frequencies of tire tread depths and the theoretical curves of the distribution density. The prob-ability of the accident risk depending on the tire tread depth (adaptive risk index) was calculated applying the formed distributions and risk index dependence on the tire tread depth for the inspected vehicle fleet. Accord-ing to the developed prediction model, an upgrade of the regulation for the minimum allowed tire tread depth by 2 mm (up to 3.6 mm) could reduce road accident risk (caused by poor adhesion to road surface) to 19.3% for the chosen vehicle fleet. Such models are useful for road safety experts, insurance companies and accident cost evaluation specialists by predicting expenses related to insurance events.

Monitoring and control systems integrated into agricultural machinery enable the development of agricultural analyses with advanced management tools, but the full use of all available data is often limited by the lack of uniformity among data transmitted from different agricultural machines. This paper presents an agricultural data aggregation and conversion model that allows for the collection and use of data captured from different agricultural machines in the course of work; these data differ in their original file formats and cannot be combined and used in a common analysis system. Programming work was carried out to create the model, and a specialised software interface enabled raster data processing using a Python library together with the open-source Hypertext Preprocessor and JavaScript programming language libraries. A PostGIS extension was utilised to engage field geometry and map-layering tools. Model validation showed that the data aggregation and conversion functions ensure the evaluation of semantic content and the transformation of the aggregated data into a unified format which is suitable for further use in intelligent farming management applications. The developed model will encourage precision agriculture, with the aim of improving work efficiency and the rational use of resources, the economy, and ecology in agriculture.

Vehicle stability during cornering on horizontal road curves is a risky stage of travel because of additional factors acting. The main stability factor is centrifugal force, which depends on road curve sharpness and is very sensitive to driving speed usually controlled by the driver. However, the counterforce is produced at tire-road interaction, where different pavement types and states cause a wide variation of tire contact forces and vehicle stability. In the paper, the part of vehicle suspension performance while moving on a sharp horizontal road curve with different levels of pavement roughness was simulated by 14 degrees of freedom vehicle model. The model was built in MATLAB/Simulink software with available pavement roughness selection according to ISO 8608. The influence of variable suspension damping available in modern vehicles on risky cornering is analysed when a vehicle reaches the edge of the pavement with its specific roughness. Critical parameters of vehicle stability depending on road curvature, pavement roughness and driving speed are selected to assess the solutions for safe cornering.

The purpose of this paper is to analyse the possibility for predicting the outcome of a road traffic accident concerning the traffic environment, personal traits of the traffic participant and the vehicle, i.e. aiming to answer the question whether specific values of the factors analysed to increase the likelihood of a fatal accident. The logistic regression model that allows identifying the relationship between the dependent and independent variables were used in the research. Other methods for describing and analysing categorical variables were also used alongside the logistic regression. When analysing the results, it was recognised that the odds ratio above 1 shows a higher likelihood for a representative of the category in question to be involved in a fatal accident compared to a representative of the base category. Odds ratios of likelihoods for calculation of the road traffic accident types show that the likelihood of a fatal accident is statistically significant affected by rollovers or driving into obstacles, compared to vehicular collisions. When summarising the results, it was stated that most of the factors researched have an impact on the outcome of a road traffic accident. The influence of some factors has a higher probability of resulting in a fatal accident as compared to other factors.

In this paper, a novel adaptive sliding mode controller (SMC) was designed based on a robust law considering disturbances and uncertainties for autonomous ground vehicle (AGV) longitudinal dynamics. The robust law was utilized in an innovative method involving the upper bounds of disturbances and uncertainties. Estimating this lumped uncertainty upper limit based on a neural network approach allowed its online knowledge. It guided the controller to withstand the disturbance and to compensate for the uncertainties. A stability analysis, according to Lyapunov, was completed to confirm the asymptotic convergence of the states to the desired state. The effectiveness and benefits of the planned approach were scrutinized by simulations and comparative studies.

Objectives The article analyzes the driver’s psychophysiological qualities such as complex reaction and individual ability to control the vehicle that has suddenly lost its stability. The comparative analysis of the duration of reaction time was performed to assess the negative influence of speaking on a phone and driving with one hand. Material and Methods The experimental research was carried out on special training grounds with the road surface having low adhesion coefficient, where sudden lateral vehicle destabilization was caused by the moving plate mounted on the road surface. The vehicle onboard equipment was used for identifying the difference between the destabilization moment and the responsive driver’s steering wheel movement which in this research was assumed as the reaction time. Results Statistical methods of research applied for the analysis of results showed high probability that the driver’s actions would be significantly late in controlling a vehicle. When stabilizing a vehicle movement, the complex reaction time of a vehicle driver speaking on a mobile phone is increased by 18.1% as compared with the conventional driving by a driver not speaking on a phone. Conclusions The risk of using the phone depends on the driver characteristics, traits and attitudes that affect the level of their experienced dangers, and the intensity of using mobile phones and driving. Speaking on a phone while driving increases the driver’s reaction time and mental workload, and changes his or her visual overview ability as well as understanding of the situation. Int J Occup Med Environ Health 2018;31(5):633–648

In this paper, the relation of the velocity of a vehicle in the slip mode to the parameters of the tire marks on the road surface is examined. During traffic accident reconstructions, the initial velocity of a sideslipping vehicle is established according to the tire mark trajectory radius, and calculations highly depend on the directly measured parameters of the tire marks, in particular cases known as yaw marks. In this work, a developed and experimentally validated 14-degree-of-freedom mathematical model of a vehicle is used for an investigation of the relation between velocity and trajectories. The dependence of initial vehicle velocity on tire yaw mark length and trajectory radius was found as a characteristic relation. Hence, after approximation of the permanent slipping part by a polynomial, the parameters of the latter were related to vehicle velocity. The dependences were established by specific experimental tests and computer-aided simulation of the developed model.

This paper presents the technological measures currently being developed at institutes and vehicle research centres dealing with forefront road identification. In this case, road identification corresponds with the surface irregularities and road surface type, which are evaluated by laser scanning and image analysis. Real-time adaptation, adaptation in advance and system external informing are stated as sequential generations of vehicle suspension and active braking systems where road identification is significantly important. Active and semi-active suspensions with their adaptation technologies for comfort and road holding characteristics are analysed. Also, an active braking system such as Anti-lock Braking System (ABS) and Autonomous Emergency Braking (AEB) have been considered as very sensitive to the road friction state. Artificial intelligence methods of deep learning have been presented as a promising image analysis method for classification of 12 different road surface types. Concluding the achieved benefit of road identification for traffic safety improvement is presented with reference to analysed research reports and assumptions made after the initial evaluation.

Gravel pavement has lower construction costs but poorer performance than asphalt surfaces on roads. It also emits dust and deforms under the impact of vehicle loads and ambient air factors; the resulting ripples and ruts constantly deepen, and therefore increase vehicle vibrations and fuel consumption, and reduce safe driving speed and comfort. In this study, existing pavement quality evaluation indexes are analysed, and a methodology for adapting them for roads with gravel pavement is proposed. We report the measured wave depth and length of gravel pavement profile using the straightedge method on a 160 m long road section at three stages of road utilization. The measured pavement elevation was processed according to ISO 8608, and the frequency response of a vehicle was investigated using simulations in MATLAB/Simulink. The international roughness index (IRI) analysis showed that a speed of 30–45 km/h instead of 80 km/h provided the objective results of the IRI calculation on the flexible pavement due to the decreasing velocity of a vehicle’s unsprung mass on a more deteriorated road pavement state. The influence of the corrugation phenomenon of gravel pavement was explored, identifying specific driving safety and comfort cases. Finally, an increase in the dynamic load coefficient (DLC) at a low speed of 30 km/h on the most deteriorated pavement and a high speed of 90 km/h on the middle-quality pavement demonstrated the demand for timely gravel pavement maintenance and the complicated prediction of a safe driving speed for drivers. The main relevant objectives of this study are the adaptation of a road roughness indicator to gravel pavement, including the evaluation of vehicle dynamic responses at different speeds and pavement deterioration states.

The article describes a compression-ignition engine working with a dual-fuel system installed in diesel locomotive TEP70 BS. The model of the locomotive engine has been created applying AVL BOOST and Diesel RK software and engine performance simulations. Combustion characteristics have been identified employing the mixtures of different fuels. The paper compares ecological (CO2, NOx, PM) and energy (in-cylinder pressure, temperature and the rate of heat release (ROHR)) indicators of a diesel and fuel mixtures-driven locomotive. The performed simulation has shown that different fuel proportions increased methane content and decreased diesel content in the fuel mixture, as well as causing higher in-cylinder pressure and ROHR; however, in-cylinder temperature dropped. CO2, NOx and PM emissions decrease in all cases thus raising methane and reducing diesel content in the fuel mixture.

The aim of this study has been to propose a new method for automatic rectification and stitching of the images taken on the accident site. The proposed method does not require any measurements to be performed on the accident site and thus it is frsjebalaee of measurement errors. The experimental investigation was performed in order to compare the vehicle trajectory estimation according to the yaw marks in the stitched image and the trajectory, reconstructed using the GPS data. The overall mean error of the trajectory reconstruction, produced by the method proposed in this paper was 0.086 m. It was only 0.18% comparing to the whole trajectory length.

The paper presents Vehicular Ad Hoc Network (VANET) system based on an analysis of the movement of a motorcade in an emergency situation. This analysis seeks to answer the question: when and under what conditions Emergency Message (EM) sent by Vehicle-to-Vehicle (V2V) system reaches the final target to help in preventing of serious accidents, such as multi-vehicle collisions. The model of calculation based on the key principles of vehicle braking enables finding the time to possible collision and the residual velocity of the vehicle. In the calculations, the average values of the driver’s reaction time are accepted; in addition, a sent emergency message is considered to be free of interference. Upon choosing different road and driving conditions, it is found what vehicle of the motorcade stops before the possible obstacle on emergency braking. The performance of vehicles with and without VANET system is compared.

Nowadays, vehicles have advanced driver-assistance systems which help to improve vehicle safety and save the lives of drivers, passengers and pedestrians. Identification of the road-surface type and condition in real time using a video image sensor, can increase the effectiveness of such systems significantly, especially when adapting it for braking and stability-related solutions. This paper contributes to the development of the new efficient engineering solution aimed at improving vehicle dynamics control via the anti-lock braking system (ABS) by estimating friction coefficient using video data. The experimental research on three different road surface types in dry and wet conditions has been carried out and braking performance was established with a car mathematical model (MM). Testing of a deep neural networks (DNN)-based road-surface and conditions classification algorithm revealed that this is the most promising approach for this task. The research has shown that the proposed solution increases the performance of ABS with a rule-based control strategy.

This paper analyzes the lateral dynamics of the vehicle withindependent suspension. The tests have been made driving inan incremental acceleration mode under conditions of a circulartrajectory within 10, 15 and 20-meter radius. The literature reviewprovides a summary of recent research re-lated to the topics discussedin this article. The article looks at the interaction of thesnowy and dry road with wheels and its influence on the lateraloscillation of a vehicle. The displacement of different sides ofvehicle suspension and its variation in acting lateral accelerationhave also been estimated. Data on the performed tests of theconducted research have been graphically plotted thus presentingthe summarized results and conclusions.

The paper deals with the strength analysis of structural devices(platform bridges) that fasten cars to a car carrier frame. Theloads of all bridges are evaluated along with the indication ofthe areas of load concentration. The paper presents a brief structuraldescription of platform bridges, including their drawingsperformed with the help of SolidWorks software. The bridgeloads have been analyzed applying Ansys software. Accordingto the results of computer simulation of the loads, dangerousstructural areas of the bridges have been identified. While makingattempts to solve the established structural problems of suchcar carriers, suggestions for their structural improvement havebeen put forward, and computer simulation of loads and stressspread have been performed. The paper ends with conclusionsand suggestions.

In the work, a mathematical model of a shim valve, used in monotube shock absorbers, designed to determine the deformations of the shims which form during the exploitation of the shock absorbers, is presented. The characteristic of the damping force formed by the shock absorber depends on the deformations. In the designed model, the amount, geometric dimensions, arrangement and the material properties of the shims are evaluated, and the contact forces, which form between the shims, are determined. The described model of the shim valve is presented in the environment of the software package MATLAB/Simulink, the analysis of the designed model is done using the software package ANSYS 15.0. Santrauka Straipsnyje pateikiamas vienvamzdžiuose amortizatoriuose naudojamo plokštelinio vožtuvo matematinis modelis, skirtas vožtuvo plokštelių deformacijoms, susidarančioms eksploatuojant amortizatorių, nustatyti. Nuo deformacijų priklauso amortizatoriaus sukuriama slopinimo jėgos charakteristika. Sudarytame modelyje įvertinamas vožtuvo plokštelių skaičius, geometriniai matmenys, išdėstymas ir medžiagos sa-vybės, nustatomos kontaktinės jėgos, susidarančios tarp vožtuvo plokštelių. Aprašomasis plokštelinio vožtuvo modelis pateikiamas prog-raminio paketo MATLAB/Simulink aplinkoje, atliekama sudaryto modelio analizė naudojantis programiniu paketu ANSYS 15.0. Reikšminiai žodžiai: vienvamzdis amortizatorius, plokštelinis vožtuvas, matematinis modelis, kontaktinės jėgos, slėgių skirtumas.

The paper analyses the impact of the road micro-profile on the duration and the type of the vehicle wheel contact with the road surface driving at different speed. The selected vehicle bicycle model describes vertical displacements of front and rear wheels and their suspension as well as the impact of the vehicle body motion and longitudinal oscillation. International Roughness Index (IRI) and micro-profile irregularities of the road section analysed in the paper were identified using specialized road testing equipment. The experimental investigations measuring the vehicle suspension displacement and the body acceleration were carried out. Frequency characteristics of suspension motion and regularities of vertical movement of the wheel were identified after dividing the investigated road section according to driving modes. The analysis into the wheel contact with the road surface and identified correlations enable to determine the vehicle stability on selected quality roads.

The paper analyses the dynamic characteristics of light vehicles during double lane change manoeuvre (ISO 3888-2). The purpose of research is to determine the angle of vehicle sideslip using the adjusted calculation methodology according to the measured longitudinal and lateral velocity and yaw rate and to estimate vehicle stability and drivability based on the obtained results driving at various speeds. Small (B1 class) vehicles have been selected for this research because of stability problems during sudden manoeuvres. Santrauka Straipsnyje nagrinėjamos lengvųjų automobilių dinaminės charakteristikos dvipusio judėjimo juostos keitimo manevro metu (ISO 3888-2). Tyrimo tikslas – pagal eksperimentinio bandymo metu jutiklių užfiksuotas išilginio ir skersinio greičio projekcijas ir sukimosi greičius apie vertikalią automobilio ašį, pritaikius skaičiavimo metodiką, apskaičiuoti slydimo (skersridės) kampus. Pagal gautus rezultatus įvertinti automobilių stovumą ir valdomumą važiuojant skirtingais greičiais. Tyrimams pasirinkti maži (B1 klasės) automobiliai, nes staigaus manevro metu šios klasės automobiliai gali tapti nestabilūs. Reikšminiai žodžiai: automobilio stovumas; slydimo (skersridės) kampas; dvigubo judėjimo juostos keitimo manevras.

The article analyzes the impact of the longitudinal road profile on the efficiency of car braking estimated applying deceleration value. Different formulas are used for theoretical calculations, and therefore experimental brakes in different road slopes were performed to obtain the most accurate results. Deceleration, as one of the most important safety parameters, depends on the technical condition of the braking system, road conditions and structural and dynamic properties of the other car. Road alignments can significantly affect car manageability, because of weight transfer and extra track resistance, which may change the overall balance of the car and affect the nature of dynamic characteristics that may vary from certain critical values. The results of corrections to deceleration dependence on the road profile can be used for investigating traffic accidents, optimizing traffic control arrangements and implementing advanced systems for automotive active safety. Santrauka Straipsnyje analizuojama kelio išilginio profilio įtaka automobilio stabdymo efektyvumui, kuris įvertinamas lėtėjimo pagreičio reikšme. Atliekant teorinius skaičiavimus taikomos skirtingos formulės, todėl siekiant gauti kuo tikslesnius rezultatus, buvo atliekami eksperimentiniai stabdymai skirtingo nuolydžio keliuose. Lėtėjimo pagreitis, kaip vienas svarbiausių eismo saugumo parametrų, priklauso nuo stabdžių sistemos techninės būklės, kelio sąlygų ir nuo kitų automobilio konstrukcinių ir dinaminių ypatybių. Išilginis kelio profilis gali gerokai paveikti automobilio valdomumą, nes vyksta svorio persislinkimas, atsiranda papildomos kelio varžos, dėl ko pasikeičia bendras automobilio balansas ir nuo tam tikrų kritinių reikšmių keičiasi dinaminių charakteristikų pobūdis. Patikslinus lėtėjimo pagreičio priklausomybę nuo išilginio kelio profilio, rezultatai gali būti pritaikomi tiriant eismo įvykius, optimizuojant eismo reguliavimo priemonių veikimą, diegiant pažangias automobilių aktyviosios saugos sistemas. Raktiniai žodžiai: išilginis kelio profilis; lėtėjimo pagreitis; stabdymo jėga; svorio persislinkimas; eismo saugumas

The current paper presents the structure of the drivers training and examination system existing in Lithuania and describes the interrelations between the institutions involved in the said process. In course of analysis of models of drivers training and examination systems of various countries, their advantages and imperfections are highlighted. The experience of Germany, Holland, Sweden and Great Britain in the sphere of training and examination of motor vehicles drivers is described. In the end of the paper, conclusions and recommendations for improving the quality of drivers training and examination system as well as traffic safety in Lithuania are provided. Santrauka Straipsnyje pateikiama dabartinės vairuotojų rengimo ir egzaminavimo sistemos Lietuvoje struktūra, nurodomi institucijų, dalyvaujančių šiame procese, tarpusavio ryšiai. Analizuojant įvairų šalių vairuotojų rengimo ir egzaminavimo modelius, išryškinami jų privalumai bei trūkumai. Aprašoma Vokietijos, Olandijos, Švedijos ir Didžiosios Britanijos patirtis kelių transporto priemonių vairuotojų rengimo ir egzaminavimo srityje. Pabaigoje pateikiamos išvados ir rekomendacijos, kurias įgyvendinus įmanoma pagerinti ne tik vairuotojų rengimo ir egzaminavimo kokybę, bet ir saugų eismą Lietuvoje. Резюме Представлена структура системы подготовки и аттестации (тестирования) водителей в Литве, названы организации, участвующие в данном процессе, и их взаимосвязь. На основании проведенного анализа моделей подготовки и аттестации водителей в разных странах представлены преимущества и недостатки упомянутых моделей. Рассмотрен опыт Германии, Голландии, Швеции и Великобритании в области подготовки и аттестации водителей транспортных средств. В заключении представлены выводы и рекомендации, принятие которых будет способствовать улучшению не только качества подготовки и аттестации, но и безопасности дорожного движения в Литве. Reikšminiai žodžiai: saugus eismas, vairuotojų rengimas, vairuotojų egzaminavimas, vairuotojo pažymėjimas, transporto priemonė Ключевые слова: безопасность дорожного движения, подготовка водителей, аттестация водителей, тестирование водителей, водительское удостоверение, транспортное средство

Objectives: Chronic transplant dysfunction after kidney transplantation is a major reason of kidney graft loss and is caused by immunological and non-immunological factors. There is evidence that mycophenolate mofetil (MMF) may exert a positive effect on renal damage in addition to immunosuppression, by its direct antifibrotic properties. The aim of our study was to retrospectively investigate the role of MMF doses on progression of chronic allograft dysfunction and fibrosis and tubular atrophy (IF/TA)., Setting: Retrospective, cohort study., Participants: Patients with kidney transplant in a tertiary care institution. This is a retrospective cohort study that included 79 patients with kidney and kidney-pancreas transplantation. Immunosuppression consisted of anti-interleukin 2 antibody induction, MMF, a calcineurin inhibitor±steroids., Primary Outcome Measures: An association of average MMF doses over 1 year post-transplant with progression of interstitial fibrosis (Δci), tubular atrophy (Δct) and estimated-creatinine clearance (eCrcl) at 1 year post-transplant was evaluated using univariate and multivariate analyses., Results: A higher average MMF dose was significantly independently associated with better eCrcl at 1 year post-transplant (b=0.21±0.1, p=0.04). In multiple regression analysis lower Δci (b=-0.2±0.09, p=0.05) and Δct (b=-0.29±0.1, p=0.02) were independently associated with a greater average MMF dose. There was no correlation between average MMF doses and incidence of acute rejection (p=0.68)., Conclusions: A higher average MMF dose over 1 year is associated with better renal function and slower progression of IF/TA, at least partly independent of its immunosuppressive effects., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Frequency and mortality of renal cell carcinoma (RCC) are increasing for decades. However, the molecular background of RCC tumorigenesis is still poorly understood. In current study we investigated the expression of TCF/LEF and SFRP family members (SFRP1 and SFRP3) to gain a better understanding of biological signaling pathways responsible for epidemiology and clinical parameters of clear cell RCC (cRCC). Thirty-six pairs of paraffin-embedded clear cRCC and adjacent nontumoral tissues samples using immunohistochemistry (IHC) were analyzed and compared with corresponding clinicopathological parameters. Immunohistochemistry indicated statistically significant decreased SFRP3 expression in tumor tissues but no consistency in SFRP1 expression in analyzed normal and tumor tissue. The TCF1 expression level was significantly weaker in normal tissue compared to tumor samples while LEF1 protein levels were significantly weaker in tumor tissue. To our knowledge, this is the first report on analysis of the expression of transcription factors TCF1 and LEF1 in clear cell renal cell carcinoma and their comparison with Wnt signal pathway antagonists belonging to SFRP family.

Recombinant activated factor VII (rFVIIa) is approved for prevention and treatment of bleeding in hemophilia patients with inhibitors to FVIII (hemophilia A) or IX (hemophilia B), patients with congenital and acquired hemophilia and in patients with FVII deficiency or Glantzmann thrombasthenia (last indication is approved only in Europe). Off-labeled, the drug has been prescribed for prevention, or treatment of bleeding in severe hepatic disease, neonatal coagulopathies, high-risk surgical procedures, trauma, thrombocytopenia and platelet function disorders, as well as for urgent reversal of oral anticoagulation. Here we report a case of a 53-year-old female patient with delayed graft function after kidney transplantation, who had kidney biopsy complicated with prolonged bleeding. After unsuccessful treatment with desmopressin, the patient was treated with rFVIIa and the bleeding stopped immediately. Only few anecdotal reports of use of rFVIIa for treatment of bleeding in uremic patients have been published thus far. To our knowledge, this is the first case that describes use of rFVIIa for management of bleeding as a complication of renal biopsy in a uremic patient in the early kidney posttransplantation period.

Introduction: Infection is one of the main causes of patient death and graft failure early after kidney transplantation. Effect of pretransplant dialysis modality on incidence of infections after kidney transplantation still remains controversial. The aim of the present study was to determine the impact of pre-transplant dialysis modality on incidence urinary tract infections (UTI) and sepsis in early posttransplant period in kidney transplant recipients., Materials and Methods: In this case-control retrospective study a cohort of 72 kidney, kidney- pancreas or kidney-liver transplant recipients was included. Infection was defined by either clinical presentation or microbiological finding. Infections were categorized by localization and cause of infection. In patients on peritoneal dialysis peritoneal catheter was removed intraoperatively during transplantation. Infection rate during first three months posttransplant was analyzed. Difference in frequencies was calculated using nonparametric tests. Proportions were calculated using chi2 test. Time to first infection was analyzed using Kaplan-Meier survival analysis, p value < 0.05 criterion was used to decide statistical significance., Results: The total number of infections per patient per day was not significantly different in peritoneal vs. hemodialysis modality (0,029 +/- 0.019 to 0,029 +/- 0,031, p=ns). Also, there was no significant difference in peritoneal vs. hemodialysis modality in the number of UTI (0.0156 +/- 0.0144 to 0,0165 +/- 0,0125, p=ns) and sepsis (0.0018 +/- 0.0044 to 0.0026 +/- 0.0019, p=ns) during first three months posttransplant. Similarly, no difference was noted between the groups in the location or cause of infection. Peritonitis prior to transplantation was not an independent risk factor for infections (p=0.37). In Cox regression PD was not an independent risk factor for either total infections, UTI, or sepsis., Conclusion: This study showed that there was not statistically significant difference in the risk for infection in first three months after kidney transplantation with respect to pretransplant dialysis modality. PD should be the first choice for renal replacement therapy in patients with end stage renal disease.

Although transplantation of solid organs has become a more standardized method of treatment, liver transplantation represents an exceptional multidisciplinary clinical procedure requiring understanding of specific pathophysiological changes that occur in the end stage of liver disease. Liver transplantation has been performed at Merkur University Hospital since 1998, with 360 transplantations performed to date. The most common indications are alcohol liver disease, cirrhosis caused by hepatitis B and C virus, hepatocellular carcinoma and cryptogenetic liver cirrhosis. Laboratory tests required for liver transplantation are performed at Department of Clinical Chemistry, Merkur University Hospital, accredited according to ISO 15189 in 2007 for the areas of clinical chemistry, laboratory hematology and coagulation, laboratory immunology-cell immunophenotyping, and molecular diagnosis. The complexity of liver transplant patients requires constant interaction between the anesthesiologist team and clinical laboratory, which has to ensure fast and efficient intraoperative monitoring of biochemical and liver profile: electrolytes and acid-base status, complete blood count, coagulation profile and monitoring of graft function according to the individual patient's health status. Dynamics of intraoperative changes is measured in whole arterial blood samples on a Nova Biomedical Stat Profile Critical Care Xpress mobile acid-base analyzer. Frequent monitoring of ionized calcium and magnesium levels is very important because of citrated blood transfusion and for appropriate therapeutic procedure. During anhepatic stage, there is a progressive increase in lactate level concentration. After reperfusion, a rapid increase in lactate clearance is an excellent indicator of stable graft initial function and its adequate size. During the transplantation procedure, there is usually a biphasic acid-base disturbance characterized by metabolic acidosis and then by metabolic alkalosis. The loss of base equivalents starts during the dissection stage and accelerates during the anhepatic stage. Fast and efficient intraoperative monitoring of hematological tests and coagulation status is of great help in detecting the cause of possible hemorrhage and consequential complications during transplantation procedure. The possibility of organ and tissue transplantation mostly depends on well regulated international cooperation in the areas of donating, transplanting and exchange of required organs and tissues, while laboratory test results must be comparable regardless of their geographical area, methodology employed or analytical equipment used, which is mainly warranted through accreditation according to the international ISO 15189 standard.

Multifocal epithelioid hemangioendothelioma of the liver is a rare primary tumor with a variable course of disease. A case is presented of a 27-year-old female patient with multiple hepatic lesions on ultrasonography, suspect of metastatic tumor of the liver. Serum tumor markers were not elevated, while clinical examination of the lungs, gastrointestinal and gynecologic systems did not confirm the presence of a primary tumor process. Metastatic tumor and primary hepatocellular tumor were ruled out by fine needle aspiration cytology. Along with a characteristic immunophenotype of the vascular cell endothelium (positive for CD31 and CD34), high proliferation demonstrated by the analysis of argyrophilic nucleolar organization regions (AgNOR) and DNA aneuploidy, cytomorphological pattern suggested the diagnosis of angiosarcoma. Histopathologic finding corresponded to epithelioid hemangioendothelioma. Ten years after orthotopic liver transplantation, the patient is free from disease relapse, with regular follow up testing. Hemangioendothelioma of the liver is characterized by multifocality, which excludes resection; thus, liver transplantation is the method of choice. Therefore, preoperative diagnostic workup is of utmost importance to differentiate it from other primary and metastatic tumors of the liver.

Transplantation of solid organs, tissues or hematopoietic cells is now standard in the treatment of patients with terminal stage disease in order to cure and improve the recipients' quality of life. The study included 54 patients having undergone single or multiple organ transplantation. All patients received a combination of immunosuppressant therapy consisting of corticosteroids, calcineurin inhibitor (cyclosporine; tacrolimus), anti-CD25 (daclizumab) and mycophenolate-mofetil. In 24 patients, acute rejection was stratified by histopathologic analysis of renal biopsy. Fifteen highly sensitized patients were administered antithymocyte globulin (ATG) therapy. Absolute count and percentage of B/T lymphocyte subsets, NK cells and CD25+ or CD69+ activated T cells were measured on a flow cytometer (EPICS XL, Coulter) using single platform standardized protocol. Upon ATG therapy, rapid decline to a very low level of T and NK cell lymphocyte count was observed, as well of B lymphocytes, resulting in redistribution of lymphocyte compartment. Between consecutive measurements, kinetic changes of lymphocyte subset numbers (absolute count or percentage) did not differ in a large spectrum of immune parameters between the groups with and without rejection episode and having received quadruple immunosuppressive induction and maintenance therapy. Immunologic monitoring must be initiated prior to transplantation and continued consistently and frequently post-transplantation. Such a program is expensive and time-consuming and stressful for the patient, therefore, prospective studies should identify whether treatment decisions can be based reliably on these immune parameters. Serial measurement of immune cell counts is necessary for maintenance of ATG therapy and could be useful for monitoring patient recovery.

Hepatocellular carcinoma mostly develops in patients with liver cirrhosis due to chronic hepatitis C virus (HCV) infection. A case is presented of a patient with hepatorenal syndrome as a sequel of liver cirrhosis due to HCV infection. Primary tumor of the liver was not diagnosed by routine procedures, but by fine needle aspiration cytology of the extensive osteolytic lesion of the pelvic bone, performed as part of the pre-transplantation workup. Transplantation procedure was abandoned because of inappropriate donor liver (hepatic artery thrombosis), and palliative pain-relieving irradiation was recommended. However, hepatic coma developed very rapidly and the patient died within a month of the diagnosis of metastatic hepatocellular carcinoma. Although hepatocellular carcinoma metastases are not rare, massive bone infiltration from a primary tumor undetectable by routine methods is not frequently encountered.

Chronic shortage of kidney transplants worldwide has led to the use of organs from so called marginal or borderline donors, now termed "expanded-criteria donors". There has been an emerging practice of dual kidney transplantation (DKT) to compensate for sub optimal nephron mass of such kidneys. We performed DKT in "Merkur" University Hospital in August 2005. The donor was a 72-year old female with a history of long-term hypertension, aneurysm of the posterior cerebral artery, cerebrovascular insult (CVI), and with normal creatinine values and kidney function at the time of explantation. Initial biopsy of donor kidneys revealed acute tubular damage, with connective changes in 22% and 11% of glomeruli in the left and the right kidney, respectively. The recipient was a 60-year old male diagnosed with the IgA nephropathy on the last biopsy in 1999, and on dialysis since November 2003. Postoperative course was uneventful without any surgical complications. A triple immunosuppressive protocol was used. On follow-up ultrasonography 4 years posttransplantation both kidneys appeared of normal size and parenchymal pattern and with no signs of dilatation of the canal system, and color Doppler examination demonstrated normal flow in both kidneys. In conclusion, the use of DKT ie. donors by the expanded-criteria will continue to increase, and further studies of the results will, with no doubt, support this method.

Toll-like receptors are key players in initiation of innate immune response of the host. In addition to innate immunity they can also induce adaptive immune responses. The concept that inflammation can promote chronic prostatic diseases, such as benign prostatic hyperplasia or prostate carcinoma is supported by several new findings. Epidemiological data have correlated prostatitis with an increased risk of prostate cancer, while PCR-based analyses of bacterial colonization in prostate cancer specimens and normal prostate tissue showed high correlation of bacterial colonization and chronic inflammation with a diagnosis of prostate carcinoma. Even evidence from genetic studies support the hypothesis that prostate inflammation may be a cause of prostate cancer. From these points of view identification of factors, such as SNPs in TLR genes, associated with risk for prostate carcinoma development seems reasonable. Consequently, there are many investigations showing the connection between SNPs in TLR genes and pronounced susceptibility to different diseases. In this article we review the key findings about the genetic variability of TLR genes and prostate cancer risk.

A 49-year-old woman presented for hirsutism, deep voice and hypertension. Ultrasonography (US) revealed a solitary tumor mass, eight cm in size, of the right adrenal gland. Laboratory tests showed it to be a hormonally active, androgen secreting tumor (elevated testosterone level), which was consistent with the clinical picture of the disease. After histopathological analysis tumor was signed out as adrenocortical carcinoma, a low risk carcinoma according to Weiss' classification. One year later on regular follow up, US revealed a suspicious growth measuring 65 x 43 mm in the projection of the lower pole of the right kidney. The finding was verified by computerized tomography and the patient was reoperated on. Exploration revealed secondary growth in the region of greater omentum, without infiltration of adjacent organs. Histopathologic analysis confirmed metastatic ACC. 8 months after the second operation and after 6 chemotherapy cycles according to EAP protocol, control CT showed enlarged para-aortic lymph nodes and a node along the upper pole of the right kidney. Cytologic puncture was performed. Cytologic opinion was recidive of primary malignant disease. ACC is a rare malignant epithelial tumor of adrenal cortical cells, with high malignant potential. Morphologically (histopathology and cytology), differential diagnosis includes adenoma on the one hand, and renal cell carcinoma (RCC) and hepatocellular carcinoma (HCC) on the other hand. A combined evaluation of clinical features, size or weight, microscopic appearance, immunohistochemical and molecular genetic data is necessary to ensure a correct diagnosis. The purpose of this case report is to present clinical and cytomorphologic features of our case of adrenocortical carcinoma which is very rare in cytology practice.

Polyomavirus virus associated nephropathy (PVAN) is an important cause of graft failure in the renal transplant population. The prevalence of PVAN has increased from 1% to 10% in the past decade, leading to loss of transplanted organ in 30% to 80% of cases. In the absence of specific antiviral drugs, early detection of disease and modification/reduction of immunosuppressive regimen is currently the cornerstone of therapy. In the setting of multiorgan transplantation, like simultaneous pancreas and kidney transplantation (SPKT), diagnosis and therapy of PVAN can be even more challenging problem. We report a first described case of PVAN in patient after SPKT in Croatia. Patient is a 32 years old Caucasian male with type 1 diabetes mellitus and end stage renal failure, diagnosed for PVAN 6 month after SPKT. Patient was treated with reduced immunosuppressive regimen. At 32 month follow up, patient has preserved kidney and pancreas function with estimated glomerular filtration (eGFR) rate of 91 mL/min and no signs of PVAN on his 2 year protocol kidney biopsy.

Childhood infection with polyomaviruses leads to a life-long latent infection of renal and urinary tract epithelia. Replication in the reno-urinary epithelium is associated with viral cytopathic changes such as nuclear inclusions and decoy cells. During the 2005-2009 period, cytological urine analysis was performed in 154 samples (94 male and 60 female) from patients with kidney transplantation (n = 19), simultaneous pancreas-kidney transplantation (SPKT) (n = 9) and simultaneous kidney and liver transplantation (n = 2). Urine samples were analyzed monthly following transplantation according to the protocol. The period from transplantation to the first occurrence of decoy cells in the urine and the period of decoy cell persistence in the urine were assessed. The presence of decoy cells (< 10 and > 10 decoy cells) and red blood cells (< 20 E, 20-100 E and > 100 E) per cytospin smear was semiquantitatively determined, along with analysis of inflammatory cells (neutrophilic granulocytes) and fungi. In patients with decoy cells detected, their sensitivity, specificity, and negative and positive predictive value for BK virus nephropathy were calculated. Correlation of the study parameters was estimated by use of Kruskal-Wallis test (Statistica 7.1, StatSoft Inc., Tulsa, USA). Decoy cells were found in 30 patients (20 male and 10 female), age median 40 (range 16-69) years, at a mean of day 115 (range day 5-747) post transplantation, whereas their presence was recorded for a mean of 141 (range 77-771) days. Immunohistochemical staining of kidney biopsy sample for polyomavirus (SV40 large T-antigen) yielded positive reaction in 2/30 (7%) patients. Erythrocyturia was present in 29/30 patients with decoy cells. The number of decoy cells per cytospin smear generally ranged less than 10 in 25/30 patients, whereas more than 10 decoy cells per cytospin smear were only recorded in 5/30 patients. Immunohistochemistry produced positive finding for BK virus in one patient with SPKT and simultaneous kidney and liver transplantation each, which was statistically significantly more common as compared with patients with kidney transplantation alone (p = 0.0244). Immunohistochemical positivity for BK virus was more significant in cases with more than 10 decoy cells detected in cytospin smear (p = 0.013). In BK nephropathy, the finding of urinary decoy cells showed a 100% sensitivity, 84% specificity, 100% negative predictive value and 6% positive predictive value. BK virus nephropathy remains a significant post transplantation complication.

Renal biopsy is a gold standard for establishing diagnosis of acute rejection of the renal allograft. However, being invasive, renal biopsy has potential significant complications and contraindications. Therefore, possibility to noninvasively diagnose acute rejection would improve follow-up of kidney transplant patients. The purpose of this study was to evaluate urine immunocytology for T cells as a method for noninvasive identification of patients with acute renal allograft rejection in comparison to renal biopsy. In this prospective study a cohort of 56 kidney, or kidney-pancreas transplant recipients was included. Patients either received their transplant at the University Hospital "Merkur", or have been followed at the "Merkur" Hospital. Patients were subject to either protocol or indication kidney biopsy (a total of 70 biopsies), with simultaneous urine immunocytology (determination of CD3-positive cells in the urine sediment). Acute rejection was diagnosed in 24 biopsies. 23 episodes were T-cell mediated (6 grade IA, 5 grade IB, 1 grade IIA, 1 grade III and 10 borderline), while in 1 case acute humoral rejection was diagnosed. 46 biopsies did not demonstrate acute rejection. CD3-positive cells were found in 21% of cases with acute rejection and in 13% of cases without rejection (n.s.). A finding of CD3-positive cells in urine had a sensitivity of 21% and specificity of 87% for acute rejection (including borderline), with positive predictive value of 45% and negative predictive value of 68%. Although tubulitis is a hallmark of acute T cell-mediated rejection, detection of T cells in urine sediment was insufficiently sensitive and insufficiently specific for diagnosing acute rejection in our cohort of kidney transplant recipients.

Since 2003 when the international norm for implementation of quality management in medical laboratories (EN ISO 15189, Medical laboratories--Particular requirements for quality and competence) was established and accepted, accreditation has become practical, generally accepted method of quality management and confirmation of technical competence of medical laboratories in the whole world. This norm has been translated into Croatian and accepted by the Croatian Institute for Norms as Croatian norm. Accreditation is carried out on voluntary basis by the Croatian Accreditation Agency that has up to now accredited two clinical medical biochemical laboratories in the Republic of Croatia. Advantages of accredited laboratory lie in its documented management system, constant improvement and training, reliability of test results, establishing users' trust in laboratory services, test results comparability and interlaboratory (international) test results acceptance by adopting the concept of metrological traceability in laboratory medicine.