Sebastjan Bevc - Academia.edu (original) (raw)

Papers by Sebastjan Bevc

BMC Medical Informatics and Decision Making, 2017

Background: For an individual participant data (IPD) meta-analysis, multiple datasets must be tra... more Background: For an individual participant data (IPD) meta-analysis, multiple datasets must be transformed in a consistent format, e.g. using uniform variable names. When large numbers of datasets have to be processed, this can be a time-consuming and error-prone task. Automated or semi-automated identification of variables can help to reduce the workload and improve the data quality. For semi-automation high sensitivity in the recognition of matching variables is particularly important, because it allows creating software which for a target variable presents a choice of source variables, from which a user can choose the matching one, with only low risk of having missed a correct source variable. Methods: For each variable in a set of target variables, a number of simple rules were manually created. With logic regression, an optimal Boolean combination of these rules was searched for every target variable, using a random subset of a large database of epidemiological and clinical cohort data (construction subset). In a second subset of this database (validation subset), this optimal combination rules were validated. Results: In the construction sample, 41 target variables were allocated on average with a positive predictive value (PPV) of 34%, and a negative predictive value (NPV) of 95%. In the validation sample, PPV was 33%, whereas NPV remained at 94%. In the construction sample, PPV was 50% or less in 63% of all variables, in the validation sample in 71% of all variables. Conclusions: We demonstrated that the application of logic regression in a complex data management task in large epidemiological IPD meta-analyses is feasible. However, the performance of the algorithm is poor, which may require backup strategies.

Data in Brief, 2017

The data presented in this article are related to the research article entitled "The Diagnostic V... more The data presented in this article are related to the research article entitled "The Diagnostic Value of Rescaled Renal Biomarkers Serum Creatinine and Serum Cystatin C and their Relation with Measured Glomerular Filtration Rate" (Pottel et al. (2017) [1]). Data are presented demonstrating the rationale for the normalization or rescaling Contents lists available at ScienceDirect

Slovenian Nursing Review, 2015

Therapeutic Apheresis and Dialysis, 2011

Carotid-femoral pulse wave velocity (cfPWV) is an important predictor of cardiovascular events in... more Carotid-femoral pulse wave velocity (cfPWV) is an important predictor of cardiovascular events in the general population and also in hemodialysis (HD) patients. In the general population, cfPWV is strongly associated with age and blood pressure (BP). The best timing and method of BP measurement in HD patients is uncertain. Ambulatory blood pressure measurements (ABPM) have been used to better define the relationship between BP, target organ damage, and outcomes in HD patients. The aim of this study was to determine the possible association between cfPWV, cardiovascular risk factors, single BP measurements, and 48-hour ABPM in chronic HD patients. Thirty-three HD patients (22 men, 11 women) were included. After the end of the midweek HD session, BP was measured, arterial stiffness was estimated by cfPWV, and 48-hour ABPM was performed. The mean systolic and diastolic BP readings before cfPWV measurement were 136/79 mm Hg, and the mean 48-hour systolic and diastolic BP readings were 131/76 mm Hg. The mean and range of the cfPWV measurements were 8.31 Ϯ 2.35 m/s and 5.18-16.53 m/s, respectively. Using regression analysis, no association between cfPWV and BP before PWV measurements was found. A statistically significant correlation between cfPWV and 48-hour systolic and diastolic ABPM was found. Using multiple regression analysis (including age, sex, smoking, diabetes, body mass index, total cholesterol, low-and high-density lipoprotein cholesterol, triglycerides, C-reactive protein, albumin, phosphorus, calcium, and iPTH) 48-hour systolic (P < 0.001) and diastolic ABPM (P < 0.005) still remain significantly associated with cfPWV. Only 48-hour ABPM was associated with cfPWV in HD patients in our study. We found no relationship between cfPWV and other cardiovascular risk factors.

Therapeutic Apheresis and Dialysis, 2013

To determine the incidence of contrast-induced nephropathy (CIN) and to assess the effectiveness ... more To determine the incidence of contrast-induced nephropathy (CIN) and to assess the effectiveness of ascorbic acid in the prevention of CIN after coronary angiography in patients with chronic renal impairment. CIN is the third most common cause of hospital-acquired renal failure. It is well documented that periprocedural hydration is effective in the prevention of CIN. Little data exist on the effectiveness of ascorbic acid, a vitamin with antioxidative action. Patients with stable serum creatinine level &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;107 μmol/L (n = 81) undergoing coronary angiography were randomized to receive either ascorbic acid (N = 40) or placebo (N = 41) before the procedure. All patients received intravenous volume expansion with normal saline before the procedure. CIN was defined as an increase of serum creatinine level &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;25% from baseline measured 3 to 4 days after the procedure. CIN occurred totally in 5/81 patients (6.2%); in two patients (3%) in the ascorbic acid group and in three patients (7.3%) in the placebo group (P = 0.512). Postprocedural worsening of renal function (postprocedural increase of serum creatinine level) was present in 10/81 patients (12.3%) in the ascorbic acid group and in 19/81 patients (23.4%) in the placebo group (P = 0.038). No patient required dialysis treatment. We found no statistically significant impact of ascorbic acid on the incidence of CIN in patients with chronic renal impairment undergoing coronary arteriography or angioplasty. Ascorbic acid may still have some protective role in CIN reflected in lower incidence of worsening of renal function in the treated group.

Therapeutic Apheresis and Dialysis, 2013

Existing treatment of proteinuria is not sufficient to halt the chronic kidney disease (CKD) epid... more Existing treatment of proteinuria is not sufficient to halt the chronic kidney disease (CKD) epidemic. Therefore the aim of our study was to evaluate the effect of paricalcitol on proteinuria in non-dialysis CKD patients with secondary hyperparathyroidism treated according to Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. Forty-one non-dialysis CKD patients with secondary hyperparathyroidism (iPTH >65 pg/mL), serum calcium <2.6 mmol/L, serum phosphate <1.8 mmol/L and proteinuria (>150 mg/day) were treated with paricalcitol 1 mg/day. Most were treated for 6 months, with the exception of three patients having iPTH <30 pg/mL after 3 months, in whom therapy was stopped.All patients were followed for 6 months. 24-h ambulatory blood pressure (24hABP) monitoring was performed at 0 and 6 months. Fixed doses of ACE inhibitors and/or ARBs and/or statins were kept for 3 months before and during the study. Forty-one patients (30 men, 11 women; age 62.44 Ϯ 11.93 years) with different primary causes of CKD were enrolled in the study. Urinary albumin/creatinine ratio (UACR), 24-h urinary albuminuria (24hUA) and 24-h urinary quantitative proteinuria (24hUQP) were measured.Values at 0 and 6 months of these parameters were log-transformed for statistical analysis. After treatment with paricalcitol, statistically significant reduction (paired t-test) in 24hUA (P < 0.011) and 24hUQP (P < 0.0001) were found. The reduction of UACR was not significant (P = 0.074). In the observational period no statistically significant reduction in 24hABP was found. Treatment with 1 mg paricalcitol daily according to clinical practice in non-dialysis CKD patients with secondary hyperparathyroidism and proteinuria significantly reduces 24hUA and 24hUQP without significant change in 24hABP.

Biomedicines, 2021

Chronic kidney disease (CKD) is one of the major health problems of the modern age. It represents... more Chronic kidney disease (CKD) is one of the major health problems of the modern age. It represents an important public health challenge with an ever-lasting rising prevalence, which reached almost 700 million by the year 2017. Therefore, it is very important to identify patients at risk for CKD development and discover risk factors that cause the progression of the disease. Several studies have tackled this conundrum in recent years, novel markers have been identified, and new insights into the pathogenesis of CKD have been gained. This review summarizes the evidence on markers of inflammation and their role in the development and progression of CKD. It will focus primarily on cytokines, chemokines, and cell adhesion molecules. Nevertheless, further large, multicenter studies are needed to establish the role of these markers and confirm possible treatment options in everyday clinical practice.

Molecular Biology Reports, 2020

The kidney is a complex organ, comprised primarily of glomerular, tubular, mesangial, and endothe... more The kidney is a complex organ, comprised primarily of glomerular, tubular, mesangial, and endothelial cells, and podocytes. The fact that renal cells are terminally differentiated at 34 weeks of gestation is the main obstacle in regeneration and treatment of acute kidney injury or chronic kidney disease. Furthermore, the number of chronic kidney disease patients is ever increasing and with it the medical community should aim to improve existing and develop new methods of renal replacement therapy. On the other hand, as polypharmacy is on the rise, thought should be given into developing new ways of testing drug safety. A possible way to tackle these issues is with isolation and culture of renal cells. Several protocols are currently described to isolate the desired cells, of which the most isolated are the proximal tubular epithelial cells. They play a major role in water homeostasis, acid-base control, reabsorption of compounds, and secretion of xenobiotics and endogenous metabolites. When exposed to ischemic, toxic, septic, or obstructive conditions their death results in what we clinically perceive as acute kidney injury. Additionally, due to renal cells' limited regenerative potential, the profibrotic environment inevitably leads to chronic kidney disease. In this review we will focus on human proximal tubular epithelial cells. We will cover human kidney culture models, cell sources, isolation, culture, immortalization, and characterization subdivided into morphological, phenotypical, and functional characterization.

Authorea

BackgroundClinical skills are important for medical students and doctors for their everyday work ... more BackgroundClinical skills are important for medical students and doctors for their everyday work and faculties are expected to teach and assess clinical skills and other competencies that medical students should have at the beginning of their career. Among competencies required for a young doctor to begin with his or her career are several clinical skills. The aim of our study was to evaluate in a low-stakes formative assessment the clinical skills level improvement of finishing medical students prior to and after their 9-week Internal medicine clerkship. Methods88 final year medical students participated in the study prior and after their 9-week Internal medicine clerkship. On the first day and on their last day of clerkship, they were assessed in three different clinical skills – history taking, venipuncture and rectal examination. Clinical skills were performed on artificial simulators. Objective Structured Clinical Examination (OSCE) was used to evaluate students and assessors used a prepared checklist for each clinical skill.ResultsA significant improvement was detected in total OSCE (p=0.001), history taking (p=0.001) and rectal examination results (p=0.023) on the second testing. Moreover, reduction of time needed to complete the task was also detected in all clinical skills. ConclusionsFinal year medical students have a lot of practical skills and are well prepared for the clinical environment. They are prepared to perform tested clinical skills on their own, without supervision. Additional activities should be considered to improve performance in the clinical skill.

European Journal of Internal Medicine, 2017

Acute kidney injury (AKI) is common in critically ill patients and is associated with high morbid... more Acute kidney injury (AKI) is common in critically ill patients and is associated with high morbidity and mortality. The availability of several biomarkers of kidney injury offers new tools for its early recognition and management. The early identification of high-risk patients provides an opportunity to develop strategies for the prevention, early diagnosis and treatment of AKI. Despite progress in critical care medicine over the past decade, the treatment strategies for AKI in critically ill patients, such as when to start renal replacement therapy, remain controversial. A recently proposed risk prediction score for AKI, based on routinely available clinical variables, presents a new means of identifying patients at high risk of AKI.

International Urology and Nephrology, 2019

Purpose Hyperuricemia has been associated with higher mortality in the general population, but le... more Purpose Hyperuricemia has been associated with higher mortality in the general population, but less is known about CKD patients. The aim of our study was to determine the impact of elevated serum uric acid on cardiovascular mortality of CKD patients who later progress to hemodialysis. Methods In this retrospective study, 120 CKD patients (entire population of patients with ESKD on January 1st, 2012) were observed from their first visit at the Nephrology outpatient clinic, while transitioning to hemodialysis, and until their death or January 1, 2016. After non-cardiovascular death exclusion, 83 CKD patients (33 female, 50 male) were left for further analysis. The average time of observation was 8.8 ± 4.2 years. Serum uric acid was measured regularly (every 3 months). No patients were treated for hyperuricemia. Mean uric acid of 420 µmol/L was set as a cutoff between normouricemic and hyperuricemic patients as per the laboratory's reference values. Survival rates were analyzed using Kaplan-Meier survival curves. Three Cox regression models were used to assess the influence of uric acid on survival. Results Mean uric acid was 379.8 ± 71.6 µmol/L (range 220-574). Sixty-three (75.9%) patients were normouricemic and 20 (24.1%) were hyperuricemic. Cholesterol was the only variable to show statistically significant difference (p = 0.004) between the groups. Bivariate analysis revealed an association between death and age, hyperuricemia, arterial hypertension, and history of cardiovascular disease. Kaplan-Meier survival analysis showed higher risk of cardiovascular death for hyperuricemic patients (log rank test; p < 0.0005). In Cox regression models, hyperuricemia remained a predictor of cardiovascular mortality (SE = 0.500, Exp(B) = 14.120, 95% CI 5.297-37.640) in our patients next to age and arterial hypertension. Conclusion The results indicate an association between hyperuricemia and cardiovascular mortality in CKD patients who transition to hemodialysis.

Luk Luana Laura, Pulko Nejc, Serdinšek Tamara, Bevc Sebastjan Clinical Skills Laboratory, Centre ... more Luk Luana Laura, Pulko Nejc, Serdinšek Tamara, Bevc Sebastjan Clinical Skills Laboratory, Centre for Medical Education, Faculty of Medicine, University of Maribor – Taborska 8, 2000 Maribor, Slovenia Clinic for Gynaecology and Perinatology, University Medical Centre Maribor – Ljubljanska 5, 2000 Maribor, Slovenia Clinic for Internal Medicine, University Medical Centre Maribor – Ljubljanska 5, 2000 Maribor, Slovenia

Biomedicines, 2021

Chronic kidney disease (CKD) is one of the major health problems of the modern age. It represents... more Chronic kidney disease (CKD) is one of the major health problems of the modern age. It represents an important public health challenge with an ever-lasting rising prevalence, which reached almost 700 million by the year 2017. Therefore, it is very important to identify patients at risk for CKD development and discover risk factors that cause the progression of the disease. Several studies have tackled this conundrum in recent years, novel markers have been identified, and new insights into the pathogenesis of CKD have been gained. This review summarizes the evidence on markers of inflammation and their role in the development and progression of CKD. It will focus primarily on cytokines, chemokines, and cell adhesion molecules. Nevertheless, further large, multicenter studies are needed to establish the role of these markers and confirm possible treatment options in everyday clinical practice.

Molecular Biology Reports, 2020

The kidney is a complex organ, comprised primarily of glomerular, tubular, mesangial, and endothe... more The kidney is a complex organ, comprised primarily of glomerular, tubular, mesangial, and endothelial cells, and podocytes. The fact that renal cells are terminally differentiated at 34 weeks of gestation is the main obstacle in regeneration and treatment of acute kidney injury or chronic kidney disease. Furthermore, the number of chronic kidney disease patients is ever increasing and with it the medical community should aim to improve existing and develop new methods of renal replacement therapy. On the other hand, as polypharmacy is on the rise, thought should be given into developing new ways of testing drug safety. A possible way to tackle these issues is with isolation and culture of renal cells. Several protocols are currently described to isolate the desired cells, of which the most isolated are the proximal tubular epithelial cells. They play a major role in water homeostasis, acid-base control, reabsorption of compounds, and secretion of xenobiotics and endogenous metabolites. When exposed to ischemic, toxic, septic, or obstructive conditions their death results in what we clinically perceive as acute kidney injury. Additionally, due to renal cells' limited regenerative potential, the profibrotic environment inevitably leads to chronic kidney disease. In this review we will focus on human proximal tubular epithelial cells. We will cover human kidney culture models, cell sources, isolation, culture, immortalization, and characterization subdivided into morphological, phenotypical, and functional characterization.

Journal of Health Education Research & Development, 2017

Background Simulation has been widely adopted as a training and assessment tool in medical educat... more Background Simulation has been widely adopted as a training and assessment tool in medical education. The aim of our research was to investigate an influence of hybrid simulation on the students' success at bladder catheterization (BC) procedure, on the knowledge retention and communication with patient-actors. We were interested in the impact of BC protocol repetition and real life clinical experience of BC on the result of BC procedure on the model as well as hybrid model. We also wanted to determine students' opinion about the usefulness of learning by simulation. Methods Repeated measures design was used. 28 students were trained during the workshop to perform BC procedure on the different model and assessed by an objective structured clinical examination (OSCE). They were randomly divided into 2 groups (control group: model of the body part (manikin) and research group: hybrid simulator model (HSM)). The irst OSCE was done 6 weeks and the second OSCE 12 weeks a ter training. Students completed questionnaires on learning by simulation. Results Students performed statistically significantly better at OSCE 2 independent of simulation environment (p<0.001 for male HSM and p=0.023 for female HSM in research group, p<0.001 for male manikin, p=0.014 for female manikin in control group). Research group students have better results than control group but the difference was not statistically significant. Communication errors were less common within research group, especially at OSCE 1. Students assessed hybrid simulation as more useful (p=0.022) than a regular manikin model simulation. Conclusions HSM provides medical students with quality learning of BC procedure. Hybrid simulation improves communication with patient-actor and students perceive it as useful.

Authorea

BackgroundClinical skills are important for medical students and doctors for their everyday work ... more BackgroundClinical skills are important for medical students and doctors for their everyday work and faculties are expected to teach and assess clinical skills and other competencies that medical students should have at the beginning of their career. Among competencies required for a young doctor to begin with his or her career are several clinical skills. The aim of our study was to evaluate in a low-stakes formative assessment the clinical skills level improvement of finishing medical students prior to and after their 9-week Internal medicine clerkship. Methods88 final year medical students participated in the study prior and after their 9-week Internal medicine clerkship. On the first day and on their last day of clerkship, they were assessed in three different clinical skills – history taking, venipuncture and rectal examination. Clinical skills were performed on artificial simulators. Objective Structured Clinical Examination (OSCE) was used to evaluate students and assessors used a prepared checklist for each clinical skill.ResultsA significant improvement was detected in total OSCE (p=0.001), history taking (p=0.001) and rectal examination results (p=0.023) on the second testing. Moreover, reduction of time needed to complete the task was also detected in all clinical skills. ConclusionsFinal year medical students have a lot of practical skills and are well prepared for the clinical environment. They are prepared to perform tested clinical skills on their own, without supervision. Additional activities should be considered to improve performance in the clinical skill.

Clinical Nephrology, 2017

In a healthy individual, ammonia is converted to urea in the liver. Urea is then transported thro... more In a healthy individual, ammonia is converted to urea in the liver. Urea is then transported through the bloodstream and then excreted into the urine by the kidneys. In patients with chronic kidney disease (CKD), the accumulated urea is degraded by salivary urease into ammonia, which is then excreted by breathing. Breath ammonia can therefore be used for detecting the increased nitrogen-bearing wastes. In our pilot study, an electrochemical sensor was used to measure and analyze breath ammonia in healthy volunteers and patients with CKD. In our study, 8 patients with CKD (stages 4 and 5) and 6 healthy volunteers were enrolled. All participants were nonsmokers and without pulmonary or liver disease. One controlled breath sample was collected from each participant. Immediately after the sample was collected, a gas analyzer was used for measuring breath ammonia in our participants. Mean creatinine value of CKD patients was 455.2 ± 294.1 µmol/L and 62.1 ± 7.5 µmol/L for healthy volunteers. Breath ammonia levels (3.32 ± 2.19 ppm vs. 0.49 ± 0.08 ppm; p = 0.003) and measured electric current (4.33 ± 0.25 mA vs. 4.01 ± 0.01 mA; p = 0.003) were significantly higher in the CKD group. The results of our pilot study show that breath monitoring of ammonia can be a simple, useful, fast, and noninvasive tool for detection of advanced kidney impairment. .

European Journal of Internal Medicine, 2017

Acute kidney injury (AKI) is common in critically ill patients and is associated with high morbid... more Acute kidney injury (AKI) is common in critically ill patients and is associated with high morbidity and mortality. The availability of several biomarkers of kidney injury offers new tools for its early recognition and management. The early identification of high-risk patients provides an opportunity to develop strategies for the prevention, early diagnosis and treatment of AKI. Despite progress in critical care medicine over the past decade, the treatment strategies for AKI in critically ill patients, such as when to start renal replacement therapy, remain controversial. A recently proposed risk prediction score for AKI, based on routinely available clinical variables, presents a new means of identifying patients at high risk of AKI.

International Urology and Nephrology, 2019

Purpose Hyperuricemia has been associated with higher mortality in the general population, but le... more Purpose Hyperuricemia has been associated with higher mortality in the general population, but less is known about CKD patients. The aim of our study was to determine the impact of elevated serum uric acid on cardiovascular mortality of CKD patients who later progress to hemodialysis. Methods In this retrospective study, 120 CKD patients (entire population of patients with ESKD on January 1st, 2012) were observed from their first visit at the Nephrology outpatient clinic, while transitioning to hemodialysis, and until their death or January 1, 2016. After non-cardiovascular death exclusion, 83 CKD patients (33 female, 50 male) were left for further analysis. The average time of observation was 8.8 ± 4.2 years. Serum uric acid was measured regularly (every 3 months). No patients were treated for hyperuricemia. Mean uric acid of 420 µmol/L was set as a cutoff between normouricemic and hyperuricemic patients as per the laboratory's reference values. Survival rates were analyzed using Kaplan-Meier survival curves. Three Cox regression models were used to assess the influence of uric acid on survival. Results Mean uric acid was 379.8 ± 71.6 µmol/L (range 220-574). Sixty-three (75.9%) patients were normouricemic and 20 (24.1%) were hyperuricemic. Cholesterol was the only variable to show statistically significant difference (p = 0.004) between the groups. Bivariate analysis revealed an association between death and age, hyperuricemia, arterial hypertension, and history of cardiovascular disease. Kaplan-Meier survival analysis showed higher risk of cardiovascular death for hyperuricemic patients (log rank test; p < 0.0005). In Cox regression models, hyperuricemia remained a predictor of cardiovascular mortality (SE = 0.500, Exp(B) = 14.120, 95% CI 5.297-37.640) in our patients next to age and arterial hypertension. Conclusion The results indicate an association between hyperuricemia and cardiovascular mortality in CKD patients who transition to hemodialysis.

Clinical Nephrology, 2017

In a healthy individual, ammonia is converted to urea in the liver. Urea is then transported thro... more In a healthy individual, ammonia is converted to urea in the liver. Urea is then transported through the bloodstream and then excreted into the urine by the kidneys. In patients with chronic kidney disease (CKD), the accumulated urea is degraded by salivary urease into ammonia, which is then excreted by breathing. Breath ammonia can therefore be used for detecting the increased nitrogen-bearing wastes. In our pilot study, an electrochemical sensor was used to measure and analyze breath ammonia in healthy volunteers and patients with CKD. In our study, 8 patients with CKD (stages 4 and 5) and 6 healthy volunteers were enrolled. All participants were nonsmokers and without pulmonary or liver disease. One controlled breath sample was collected from each participant. Immediately after the sample was collected, a gas analyzer was used for measuring breath ammonia in our participants. Mean creatinine value of CKD patients was 455.2 ± 294.1 µmol/L and 62.1 ± 7.5 µmol/L for healthy volunteers. Breath ammonia levels (3.32 ± 2.19 ppm vs. 0.49 ± 0.08 ppm; p = 0.003) and measured electric current (4.33 ± 0.25 mA vs. 4.01 ± 0.01 mA; p = 0.003) were significantly higher in the CKD group. The results of our pilot study show that breath monitoring of ammonia can be a simple, useful, fast, and noninvasive tool for detection of advanced kidney impairment. .

BMC Medical Informatics and Decision Making, 2017

Background: For an individual participant data (IPD) meta-analysis, multiple datasets must be tra... more Background: For an individual participant data (IPD) meta-analysis, multiple datasets must be transformed in a consistent format, e.g. using uniform variable names. When large numbers of datasets have to be processed, this can be a time-consuming and error-prone task. Automated or semi-automated identification of variables can help to reduce the workload and improve the data quality. For semi-automation high sensitivity in the recognition of matching variables is particularly important, because it allows creating software which for a target variable presents a choice of source variables, from which a user can choose the matching one, with only low risk of having missed a correct source variable. Methods: For each variable in a set of target variables, a number of simple rules were manually created. With logic regression, an optimal Boolean combination of these rules was searched for every target variable, using a random subset of a large database of epidemiological and clinical cohort data (construction subset). In a second subset of this database (validation subset), this optimal combination rules were validated. Results: In the construction sample, 41 target variables were allocated on average with a positive predictive value (PPV) of 34%, and a negative predictive value (NPV) of 95%. In the validation sample, PPV was 33%, whereas NPV remained at 94%. In the construction sample, PPV was 50% or less in 63% of all variables, in the validation sample in 71% of all variables. Conclusions: We demonstrated that the application of logic regression in a complex data management task in large epidemiological IPD meta-analyses is feasible. However, the performance of the algorithm is poor, which may require backup strategies.

Data in Brief, 2017

The data presented in this article are related to the research article entitled "The Diagnostic V... more The data presented in this article are related to the research article entitled "The Diagnostic Value of Rescaled Renal Biomarkers Serum Creatinine and Serum Cystatin C and their Relation with Measured Glomerular Filtration Rate" (Pottel et al. (2017) [1]). Data are presented demonstrating the rationale for the normalization or rescaling Contents lists available at ScienceDirect

Slovenian Nursing Review, 2015

Therapeutic Apheresis and Dialysis, 2011

Carotid-femoral pulse wave velocity (cfPWV) is an important predictor of cardiovascular events in... more Carotid-femoral pulse wave velocity (cfPWV) is an important predictor of cardiovascular events in the general population and also in hemodialysis (HD) patients. In the general population, cfPWV is strongly associated with age and blood pressure (BP). The best timing and method of BP measurement in HD patients is uncertain. Ambulatory blood pressure measurements (ABPM) have been used to better define the relationship between BP, target organ damage, and outcomes in HD patients. The aim of this study was to determine the possible association between cfPWV, cardiovascular risk factors, single BP measurements, and 48-hour ABPM in chronic HD patients. Thirty-three HD patients (22 men, 11 women) were included. After the end of the midweek HD session, BP was measured, arterial stiffness was estimated by cfPWV, and 48-hour ABPM was performed. The mean systolic and diastolic BP readings before cfPWV measurement were 136/79 mm Hg, and the mean 48-hour systolic and diastolic BP readings were 131/76 mm Hg. The mean and range of the cfPWV measurements were 8.31 Ϯ 2.35 m/s and 5.18-16.53 m/s, respectively. Using regression analysis, no association between cfPWV and BP before PWV measurements was found. A statistically significant correlation between cfPWV and 48-hour systolic and diastolic ABPM was found. Using multiple regression analysis (including age, sex, smoking, diabetes, body mass index, total cholesterol, low-and high-density lipoprotein cholesterol, triglycerides, C-reactive protein, albumin, phosphorus, calcium, and iPTH) 48-hour systolic (P < 0.001) and diastolic ABPM (P < 0.005) still remain significantly associated with cfPWV. Only 48-hour ABPM was associated with cfPWV in HD patients in our study. We found no relationship between cfPWV and other cardiovascular risk factors.

Therapeutic Apheresis and Dialysis, 2013

To determine the incidence of contrast-induced nephropathy (CIN) and to assess the effectiveness ... more To determine the incidence of contrast-induced nephropathy (CIN) and to assess the effectiveness of ascorbic acid in the prevention of CIN after coronary angiography in patients with chronic renal impairment. CIN is the third most common cause of hospital-acquired renal failure. It is well documented that periprocedural hydration is effective in the prevention of CIN. Little data exist on the effectiveness of ascorbic acid, a vitamin with antioxidative action. Patients with stable serum creatinine level &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;107 μmol/L (n = 81) undergoing coronary angiography were randomized to receive either ascorbic acid (N = 40) or placebo (N = 41) before the procedure. All patients received intravenous volume expansion with normal saline before the procedure. CIN was defined as an increase of serum creatinine level &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;25% from baseline measured 3 to 4 days after the procedure. CIN occurred totally in 5/81 patients (6.2%); in two patients (3%) in the ascorbic acid group and in three patients (7.3%) in the placebo group (P = 0.512). Postprocedural worsening of renal function (postprocedural increase of serum creatinine level) was present in 10/81 patients (12.3%) in the ascorbic acid group and in 19/81 patients (23.4%) in the placebo group (P = 0.038). No patient required dialysis treatment. We found no statistically significant impact of ascorbic acid on the incidence of CIN in patients with chronic renal impairment undergoing coronary arteriography or angioplasty. Ascorbic acid may still have some protective role in CIN reflected in lower incidence of worsening of renal function in the treated group.

Therapeutic Apheresis and Dialysis, 2013

Existing treatment of proteinuria is not sufficient to halt the chronic kidney disease (CKD) epid... more Existing treatment of proteinuria is not sufficient to halt the chronic kidney disease (CKD) epidemic. Therefore the aim of our study was to evaluate the effect of paricalcitol on proteinuria in non-dialysis CKD patients with secondary hyperparathyroidism treated according to Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. Forty-one non-dialysis CKD patients with secondary hyperparathyroidism (iPTH >65 pg/mL), serum calcium <2.6 mmol/L, serum phosphate <1.8 mmol/L and proteinuria (>150 mg/day) were treated with paricalcitol 1 mg/day. Most were treated for 6 months, with the exception of three patients having iPTH <30 pg/mL after 3 months, in whom therapy was stopped.All patients were followed for 6 months. 24-h ambulatory blood pressure (24hABP) monitoring was performed at 0 and 6 months. Fixed doses of ACE inhibitors and/or ARBs and/or statins were kept for 3 months before and during the study. Forty-one patients (30 men, 11 women; age 62.44 Ϯ 11.93 years) with different primary causes of CKD were enrolled in the study. Urinary albumin/creatinine ratio (UACR), 24-h urinary albuminuria (24hUA) and 24-h urinary quantitative proteinuria (24hUQP) were measured.Values at 0 and 6 months of these parameters were log-transformed for statistical analysis. After treatment with paricalcitol, statistically significant reduction (paired t-test) in 24hUA (P < 0.011) and 24hUQP (P < 0.0001) were found. The reduction of UACR was not significant (P = 0.074). In the observational period no statistically significant reduction in 24hABP was found. Treatment with 1 mg paricalcitol daily according to clinical practice in non-dialysis CKD patients with secondary hyperparathyroidism and proteinuria significantly reduces 24hUA and 24hUQP without significant change in 24hABP.

Biomedicines, 2021

Chronic kidney disease (CKD) is one of the major health problems of the modern age. It represents... more Chronic kidney disease (CKD) is one of the major health problems of the modern age. It represents an important public health challenge with an ever-lasting rising prevalence, which reached almost 700 million by the year 2017. Therefore, it is very important to identify patients at risk for CKD development and discover risk factors that cause the progression of the disease. Several studies have tackled this conundrum in recent years, novel markers have been identified, and new insights into the pathogenesis of CKD have been gained. This review summarizes the evidence on markers of inflammation and their role in the development and progression of CKD. It will focus primarily on cytokines, chemokines, and cell adhesion molecules. Nevertheless, further large, multicenter studies are needed to establish the role of these markers and confirm possible treatment options in everyday clinical practice.

Molecular Biology Reports, 2020

The kidney is a complex organ, comprised primarily of glomerular, tubular, mesangial, and endothe... more The kidney is a complex organ, comprised primarily of glomerular, tubular, mesangial, and endothelial cells, and podocytes. The fact that renal cells are terminally differentiated at 34 weeks of gestation is the main obstacle in regeneration and treatment of acute kidney injury or chronic kidney disease. Furthermore, the number of chronic kidney disease patients is ever increasing and with it the medical community should aim to improve existing and develop new methods of renal replacement therapy. On the other hand, as polypharmacy is on the rise, thought should be given into developing new ways of testing drug safety. A possible way to tackle these issues is with isolation and culture of renal cells. Several protocols are currently described to isolate the desired cells, of which the most isolated are the proximal tubular epithelial cells. They play a major role in water homeostasis, acid-base control, reabsorption of compounds, and secretion of xenobiotics and endogenous metabolites. When exposed to ischemic, toxic, septic, or obstructive conditions their death results in what we clinically perceive as acute kidney injury. Additionally, due to renal cells' limited regenerative potential, the profibrotic environment inevitably leads to chronic kidney disease. In this review we will focus on human proximal tubular epithelial cells. We will cover human kidney culture models, cell sources, isolation, culture, immortalization, and characterization subdivided into morphological, phenotypical, and functional characterization.

Authorea

BackgroundClinical skills are important for medical students and doctors for their everyday work ... more BackgroundClinical skills are important for medical students and doctors for their everyday work and faculties are expected to teach and assess clinical skills and other competencies that medical students should have at the beginning of their career. Among competencies required for a young doctor to begin with his or her career are several clinical skills. The aim of our study was to evaluate in a low-stakes formative assessment the clinical skills level improvement of finishing medical students prior to and after their 9-week Internal medicine clerkship. Methods88 final year medical students participated in the study prior and after their 9-week Internal medicine clerkship. On the first day and on their last day of clerkship, they were assessed in three different clinical skills – history taking, venipuncture and rectal examination. Clinical skills were performed on artificial simulators. Objective Structured Clinical Examination (OSCE) was used to evaluate students and assessors used a prepared checklist for each clinical skill.ResultsA significant improvement was detected in total OSCE (p=0.001), history taking (p=0.001) and rectal examination results (p=0.023) on the second testing. Moreover, reduction of time needed to complete the task was also detected in all clinical skills. ConclusionsFinal year medical students have a lot of practical skills and are well prepared for the clinical environment. They are prepared to perform tested clinical skills on their own, without supervision. Additional activities should be considered to improve performance in the clinical skill.

European Journal of Internal Medicine, 2017

Acute kidney injury (AKI) is common in critically ill patients and is associated with high morbid... more Acute kidney injury (AKI) is common in critically ill patients and is associated with high morbidity and mortality. The availability of several biomarkers of kidney injury offers new tools for its early recognition and management. The early identification of high-risk patients provides an opportunity to develop strategies for the prevention, early diagnosis and treatment of AKI. Despite progress in critical care medicine over the past decade, the treatment strategies for AKI in critically ill patients, such as when to start renal replacement therapy, remain controversial. A recently proposed risk prediction score for AKI, based on routinely available clinical variables, presents a new means of identifying patients at high risk of AKI.

International Urology and Nephrology, 2019

Purpose Hyperuricemia has been associated with higher mortality in the general population, but le... more Purpose Hyperuricemia has been associated with higher mortality in the general population, but less is known about CKD patients. The aim of our study was to determine the impact of elevated serum uric acid on cardiovascular mortality of CKD patients who later progress to hemodialysis. Methods In this retrospective study, 120 CKD patients (entire population of patients with ESKD on January 1st, 2012) were observed from their first visit at the Nephrology outpatient clinic, while transitioning to hemodialysis, and until their death or January 1, 2016. After non-cardiovascular death exclusion, 83 CKD patients (33 female, 50 male) were left for further analysis. The average time of observation was 8.8 ± 4.2 years. Serum uric acid was measured regularly (every 3 months). No patients were treated for hyperuricemia. Mean uric acid of 420 µmol/L was set as a cutoff between normouricemic and hyperuricemic patients as per the laboratory's reference values. Survival rates were analyzed using Kaplan-Meier survival curves. Three Cox regression models were used to assess the influence of uric acid on survival. Results Mean uric acid was 379.8 ± 71.6 µmol/L (range 220-574). Sixty-three (75.9%) patients were normouricemic and 20 (24.1%) were hyperuricemic. Cholesterol was the only variable to show statistically significant difference (p = 0.004) between the groups. Bivariate analysis revealed an association between death and age, hyperuricemia, arterial hypertension, and history of cardiovascular disease. Kaplan-Meier survival analysis showed higher risk of cardiovascular death for hyperuricemic patients (log rank test; p < 0.0005). In Cox regression models, hyperuricemia remained a predictor of cardiovascular mortality (SE = 0.500, Exp(B) = 14.120, 95% CI 5.297-37.640) in our patients next to age and arterial hypertension. Conclusion The results indicate an association between hyperuricemia and cardiovascular mortality in CKD patients who transition to hemodialysis.

Luk Luana Laura, Pulko Nejc, Serdinšek Tamara, Bevc Sebastjan Clinical Skills Laboratory, Centre ... more Luk Luana Laura, Pulko Nejc, Serdinšek Tamara, Bevc Sebastjan Clinical Skills Laboratory, Centre for Medical Education, Faculty of Medicine, University of Maribor – Taborska 8, 2000 Maribor, Slovenia Clinic for Gynaecology and Perinatology, University Medical Centre Maribor – Ljubljanska 5, 2000 Maribor, Slovenia Clinic for Internal Medicine, University Medical Centre Maribor – Ljubljanska 5, 2000 Maribor, Slovenia

Biomedicines, 2021

Chronic kidney disease (CKD) is one of the major health problems of the modern age. It represents... more Chronic kidney disease (CKD) is one of the major health problems of the modern age. It represents an important public health challenge with an ever-lasting rising prevalence, which reached almost 700 million by the year 2017. Therefore, it is very important to identify patients at risk for CKD development and discover risk factors that cause the progression of the disease. Several studies have tackled this conundrum in recent years, novel markers have been identified, and new insights into the pathogenesis of CKD have been gained. This review summarizes the evidence on markers of inflammation and their role in the development and progression of CKD. It will focus primarily on cytokines, chemokines, and cell adhesion molecules. Nevertheless, further large, multicenter studies are needed to establish the role of these markers and confirm possible treatment options in everyday clinical practice.

Molecular Biology Reports, 2020

The kidney is a complex organ, comprised primarily of glomerular, tubular, mesangial, and endothe... more The kidney is a complex organ, comprised primarily of glomerular, tubular, mesangial, and endothelial cells, and podocytes. The fact that renal cells are terminally differentiated at 34 weeks of gestation is the main obstacle in regeneration and treatment of acute kidney injury or chronic kidney disease. Furthermore, the number of chronic kidney disease patients is ever increasing and with it the medical community should aim to improve existing and develop new methods of renal replacement therapy. On the other hand, as polypharmacy is on the rise, thought should be given into developing new ways of testing drug safety. A possible way to tackle these issues is with isolation and culture of renal cells. Several protocols are currently described to isolate the desired cells, of which the most isolated are the proximal tubular epithelial cells. They play a major role in water homeostasis, acid-base control, reabsorption of compounds, and secretion of xenobiotics and endogenous metabolites. When exposed to ischemic, toxic, septic, or obstructive conditions their death results in what we clinically perceive as acute kidney injury. Additionally, due to renal cells' limited regenerative potential, the profibrotic environment inevitably leads to chronic kidney disease. In this review we will focus on human proximal tubular epithelial cells. We will cover human kidney culture models, cell sources, isolation, culture, immortalization, and characterization subdivided into morphological, phenotypical, and functional characterization.

Journal of Health Education Research & Development, 2017

Background Simulation has been widely adopted as a training and assessment tool in medical educat... more Background Simulation has been widely adopted as a training and assessment tool in medical education. The aim of our research was to investigate an influence of hybrid simulation on the students' success at bladder catheterization (BC) procedure, on the knowledge retention and communication with patient-actors. We were interested in the impact of BC protocol repetition and real life clinical experience of BC on the result of BC procedure on the model as well as hybrid model. We also wanted to determine students' opinion about the usefulness of learning by simulation. Methods Repeated measures design was used. 28 students were trained during the workshop to perform BC procedure on the different model and assessed by an objective structured clinical examination (OSCE). They were randomly divided into 2 groups (control group: model of the body part (manikin) and research group: hybrid simulator model (HSM)). The irst OSCE was done 6 weeks and the second OSCE 12 weeks a ter training. Students completed questionnaires on learning by simulation. Results Students performed statistically significantly better at OSCE 2 independent of simulation environment (p<0.001 for male HSM and p=0.023 for female HSM in research group, p<0.001 for male manikin, p=0.014 for female manikin in control group). Research group students have better results than control group but the difference was not statistically significant. Communication errors were less common within research group, especially at OSCE 1. Students assessed hybrid simulation as more useful (p=0.022) than a regular manikin model simulation. Conclusions HSM provides medical students with quality learning of BC procedure. Hybrid simulation improves communication with patient-actor and students perceive it as useful.

Authorea

BackgroundClinical skills are important for medical students and doctors for their everyday work ... more BackgroundClinical skills are important for medical students and doctors for their everyday work and faculties are expected to teach and assess clinical skills and other competencies that medical students should have at the beginning of their career. Among competencies required for a young doctor to begin with his or her career are several clinical skills. The aim of our study was to evaluate in a low-stakes formative assessment the clinical skills level improvement of finishing medical students prior to and after their 9-week Internal medicine clerkship. Methods88 final year medical students participated in the study prior and after their 9-week Internal medicine clerkship. On the first day and on their last day of clerkship, they were assessed in three different clinical skills – history taking, venipuncture and rectal examination. Clinical skills were performed on artificial simulators. Objective Structured Clinical Examination (OSCE) was used to evaluate students and assessors used a prepared checklist for each clinical skill.ResultsA significant improvement was detected in total OSCE (p=0.001), history taking (p=0.001) and rectal examination results (p=0.023) on the second testing. Moreover, reduction of time needed to complete the task was also detected in all clinical skills. ConclusionsFinal year medical students have a lot of practical skills and are well prepared for the clinical environment. They are prepared to perform tested clinical skills on their own, without supervision. Additional activities should be considered to improve performance in the clinical skill.

Clinical Nephrology, 2017

In a healthy individual, ammonia is converted to urea in the liver. Urea is then transported thro... more In a healthy individual, ammonia is converted to urea in the liver. Urea is then transported through the bloodstream and then excreted into the urine by the kidneys. In patients with chronic kidney disease (CKD), the accumulated urea is degraded by salivary urease into ammonia, which is then excreted by breathing. Breath ammonia can therefore be used for detecting the increased nitrogen-bearing wastes. In our pilot study, an electrochemical sensor was used to measure and analyze breath ammonia in healthy volunteers and patients with CKD. In our study, 8 patients with CKD (stages 4 and 5) and 6 healthy volunteers were enrolled. All participants were nonsmokers and without pulmonary or liver disease. One controlled breath sample was collected from each participant. Immediately after the sample was collected, a gas analyzer was used for measuring breath ammonia in our participants. Mean creatinine value of CKD patients was 455.2 ± 294.1 µmol/L and 62.1 ± 7.5 µmol/L for healthy volunteers. Breath ammonia levels (3.32 ± 2.19 ppm vs. 0.49 ± 0.08 ppm; p = 0.003) and measured electric current (4.33 ± 0.25 mA vs. 4.01 ± 0.01 mA; p = 0.003) were significantly higher in the CKD group. The results of our pilot study show that breath monitoring of ammonia can be a simple, useful, fast, and noninvasive tool for detection of advanced kidney impairment. .

European Journal of Internal Medicine, 2017

Acute kidney injury (AKI) is common in critically ill patients and is associated with high morbid... more Acute kidney injury (AKI) is common in critically ill patients and is associated with high morbidity and mortality. The availability of several biomarkers of kidney injury offers new tools for its early recognition and management. The early identification of high-risk patients provides an opportunity to develop strategies for the prevention, early diagnosis and treatment of AKI. Despite progress in critical care medicine over the past decade, the treatment strategies for AKI in critically ill patients, such as when to start renal replacement therapy, remain controversial. A recently proposed risk prediction score for AKI, based on routinely available clinical variables, presents a new means of identifying patients at high risk of AKI.

International Urology and Nephrology, 2019

Purpose Hyperuricemia has been associated with higher mortality in the general population, but le... more Purpose Hyperuricemia has been associated with higher mortality in the general population, but less is known about CKD patients. The aim of our study was to determine the impact of elevated serum uric acid on cardiovascular mortality of CKD patients who later progress to hemodialysis. Methods In this retrospective study, 120 CKD patients (entire population of patients with ESKD on January 1st, 2012) were observed from their first visit at the Nephrology outpatient clinic, while transitioning to hemodialysis, and until their death or January 1, 2016. After non-cardiovascular death exclusion, 83 CKD patients (33 female, 50 male) were left for further analysis. The average time of observation was 8.8 ± 4.2 years. Serum uric acid was measured regularly (every 3 months). No patients were treated for hyperuricemia. Mean uric acid of 420 µmol/L was set as a cutoff between normouricemic and hyperuricemic patients as per the laboratory's reference values. Survival rates were analyzed using Kaplan-Meier survival curves. Three Cox regression models were used to assess the influence of uric acid on survival. Results Mean uric acid was 379.8 ± 71.6 µmol/L (range 220-574). Sixty-three (75.9%) patients were normouricemic and 20 (24.1%) were hyperuricemic. Cholesterol was the only variable to show statistically significant difference (p = 0.004) between the groups. Bivariate analysis revealed an association between death and age, hyperuricemia, arterial hypertension, and history of cardiovascular disease. Kaplan-Meier survival analysis showed higher risk of cardiovascular death for hyperuricemic patients (log rank test; p < 0.0005). In Cox regression models, hyperuricemia remained a predictor of cardiovascular mortality (SE = 0.500, Exp(B) = 14.120, 95% CI 5.297-37.640) in our patients next to age and arterial hypertension. Conclusion The results indicate an association between hyperuricemia and cardiovascular mortality in CKD patients who transition to hemodialysis.

Clinical Nephrology, 2017

In a healthy individual, ammonia is converted to urea in the liver. Urea is then transported thro... more In a healthy individual, ammonia is converted to urea in the liver. Urea is then transported through the bloodstream and then excreted into the urine by the kidneys. In patients with chronic kidney disease (CKD), the accumulated urea is degraded by salivary urease into ammonia, which is then excreted by breathing. Breath ammonia can therefore be used for detecting the increased nitrogen-bearing wastes. In our pilot study, an electrochemical sensor was used to measure and analyze breath ammonia in healthy volunteers and patients with CKD. In our study, 8 patients with CKD (stages 4 and 5) and 6 healthy volunteers were enrolled. All participants were nonsmokers and without pulmonary or liver disease. One controlled breath sample was collected from each participant. Immediately after the sample was collected, a gas analyzer was used for measuring breath ammonia in our participants. Mean creatinine value of CKD patients was 455.2 ± 294.1 µmol/L and 62.1 ± 7.5 µmol/L for healthy volunteers. Breath ammonia levels (3.32 ± 2.19 ppm vs. 0.49 ± 0.08 ppm; p = 0.003) and measured electric current (4.33 ± 0.25 mA vs. 4.01 ± 0.01 mA; p = 0.003) were significantly higher in the CKD group. The results of our pilot study show that breath monitoring of ammonia can be a simple, useful, fast, and noninvasive tool for detection of advanced kidney impairment. .