Rajko B. Kenda
University of Ljubljana
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Featured researches published by Rajko B. Kenda.
Nephron | 1998
Nina Zidar; Mojca Avguštin Čavić; Rajko B. Kenda; Mira Koselj; Dušan Ferluga
Intrauterine growth retardation (IUGR) resulting in a reduced number of nephrons is one of the nonimmune mechanisms that have been recently proposed as contributing to the progression of renal diseases. The purpose of our study was to determine whether IUGR has any effect on the clinical course and prognosis of IgA glomerulonephritis (IgA GN) in children. Fifty children with biopsy-proven IgA GN, who were followed for at least 3 years, were included. Six of the 50 children (12%) had signs of IUGR at birth, defined as birth weight below the 10th percentile for gestational age. There were no significant differences in initial clinical presentation between children with IUGR and those without IUGR. However, in kidney biopsy specimens, we found a significantly higher mean percentage of sclerotic glomeruli in children with IUGR than in those without IUGR (33 vs. 13%, p < 0.015). At the end of the follow-up period, we observed a significantly higher incidence of arterial hypertension in children with IUGR than in those without IUGR (50 vs. 11%, p < 0.05). Other differences between the two groups of children were not statistically significant. In conclusion, our study demonstrated an increased risk of the development of arterial hypertension and glomerulosclerosis in children with IgA GN who had suffered from IUGR with a birth weight below the 10th percentile for gestational age. IUGR may therefore help to identify early in the course of IgA GN those children who are at higher risk of an unfavorable course.
Blood Purification | 2003
Rina R Rus; Rafael Ponikvar; Rajko B. Kenda; Jadranka Buturovic-Ponikvar
Aim: We investigate the effects of local training on the forearm vessels in patients with end-stage renal disease. Methods: Fourteen hemodialysis patients were included. Handgrip training was performed for 8 weeks. The following parameters were measured at the beginning of the study and 4 and 8 weeks later: forearm circumference, maximal handgrip strength, and artery and vein parameters, including endothelium-dependent and endothelium-independent vasodilatation (using ultrasound and duplex Doppler scanning). Results: The maximal handgrip strength increased significantly. The radial artery diameters were significantly higher after 8 weeks of training. The endothelium-dependent vasodilatation was found to be significantly increased after 4 and 8 weeks of training. The maximal vein diameters increased significantly with training, with preserved distensibility. Conclusions: The present study suggests that regular handgrip training increases the diameters of forearm vessels. It also improves endothelium-dependent vasodilatation. These changes point to the possible beneficial effects of daily handgrip training in chronic renal failure patients before arteriovenous fistula construction.
Journal of Pediatric Psychology | 2010
Urška Zugelj; Maja Zupančič; Luka Komidar; Rajko B. Kenda; Nataša Marčun Varda; Alojz Gregorič
OBJECTIVE This exploratory study examined the role that illness representations and personality play in the various adherence behaviors of adolescents diagnosed with essential hypertension. METHODS The participants were 97 hypertensive adolescents. They completed self-report questionnaires pertaining to (1) demographic and medical data, (2) adherence, (3) illness representations, and (4) personality. Medical charts were also assessed. RESULTS The hierarchical regression analyses indicated that: (1) conscientiousness, agreeableness, and perception of treatment effectiveness account for a significant amount of variance in general adherence; (2) perception of treatment effectiveness is predictive of overall specific adherence; and (3) for adherence to most of the individual specific regimen recommendations, illness representations are more predictive compared to personality dimensions. CONCLUSIONS The personality domains of conscientiousness, extraversion, agreeableness, and illness representation dimensions (treatment control, concern, and emotional burden) were shown to predict adherence behaviors in adolescent hypertensive patients differentially. Study implications and limitations are discussed.
Pediatric Nephrology | 2005
Tanja Kersnik Levart; Rajko B. Kenda; Mojca Avguštin Čavić; Dušan Ferluga; Anastazija Hvala; Alenka Vizjak
C1q nephropathy (C1qNP) is a peculiar form of glomerulonephritis characterized by mesangial immunoglobulin and complement deposits, predominantly C1q, with no evidence of systemic lupus erythematosus. We describe the incidence, manifestation, histopathologic findings, follow-up, treatment and outcome of C1qNP. Twelve C1qNP patients were identified among 131 children who had undergone renal biopsy, accounting for a 9.16% incidence of C1qNP. Light microscopy examination showed focal segmental glomerulosclerosis (FSGS) with or without diffuse mesangial proliferation (n=6), minimal change disease (MCD) (n=4) or focal glomerulonephritis (n=2). C1q deposits were found in all, while electron microscopy revealed visible deposits in nine cases. Eight children presented with nephrotic syndrome, while one had nephrotic proteinuria and renal insufficiency that progressed to end-stage renal failure. The remaining three patients presented with nonnephrotic proteinuria associated with microhematuria, hypertension or renal insufficiency. Only one nephrotic syndrome patient responded excellently to corticosteroids, while four became corticosteroid dependent, and three were corticosteroid resistant, showing a very poor response to other immunosuppressive therapy as well. Patients with non-nephrotic proteinuria demonstrated fixed laboratory findings. Most C1qNP patients had FSGS or MCD, the majority of them presenting with corticosteroid-dependent or corticosteroid-resistant nephrotic syndrome. The latter showed a very poor response to any immunosuppressive therapy and high risk for progressive renal insufficiency.
Therapeutic Apheresis and Dialysis | 2005
Rina Rus; Rafael Ponikvar; Rajko B. Kenda; Jadranka Buturovic-Ponikvar
Abstract: The purpose of our study was to assess the influence of handgrip training and intermittent compression of the upper arm veins on forearm arteries and veins. Eighteen chronic hemodialysis patients performed daily handgrip training for 8 weeks using a rubber ring, together with daily intermittent compression of the upper arm veins by elastic band. The forearm circumference, maximal handgrip strength, and arterial and vein parameters, including endothelium‐dependent vasodilatation, were measured at the beginning, and after 4 and 8 weeks (using ultrasound scanning). The maximal handgrip strength and forearm circumference increased significantly. The radial artery diameters were significantly higher after 8 weeks of training (1.89 mm ± 0.10 at the beginning, 1.95 ± 0.10 mm after 8 weeks, P = 0.007), and endothelium‐dependent vasodilatation was also found to be increased after 4 and 8 weeks of both activities. The venous parameters before tourniquet placement increased significantly after 8 weeks (2.40 ± 0.16 mm at the beginning, 2.62 ± 0.17 mm after 8 weeks, P = 0.014), and the venous parameters after tourniquet placement increased significantly after 4 and 8 weeks (3.36 ± 0.17 mm at the beginning, 3.51 ± 0.18 mm after 4 weeks, P = 0.009), 3.68 ± 0.18 mm after 8 weeks, P < 0.001). The distensibility of veins was preserved. Our results showed that handgrip training and intermittent compression of the upper arm veins, performed daily, increase the diameter of forearm arteries and veins and improve endothelium‐dependent vasodilatation.
Acta Paediatrica | 2007
T Kersnik Levart; Anton Kenig; J Buturović Ponikvar; Dušan Ferluga; M Avguštin Čavić; Rajko B. Kenda
Real‐time ultrasound‐guided renal biopsy (RB) with a biopsy gun has become a standard procedure in the treatment of children. The purpose of the study was to establish the complication rate after real‐time ultrasound‐guided RB with a biopsy gun, the adequacy of renal tissue samples for pathohistological tests, the rate of concurrence between clinical and pathohistological diagnoses, and the benefits of the procedure. From January 1994 to October 1999, 88 renal biopsies were performed on 82 children, 81 of whom (35M, 46F, aged 3‐20 y) were included in this retrospective study. The nephrotic syndrome (in infants, older children, those with evidence of nephritis or failing corticosteroid therapy) was the most frequent indication of RB. Other indications were non‐nephrotic proteinuria, nephritic syndrome, glomerular haematuria, renal allograft dysfunction, unexplained acute or chronic renal failure, and kidney disease progression monitoring. No serious complications were noted. The adequacy rate of renal tissue samples ranged from 93.1 to 96.6%, depending on which definition of the adequacy of renal tissue samples was used. Clinical and pathohistological diagnoses matched in 81.4% of the cases. Data obtained by RB were very beneficial to patients in terms of establishing, confirming or altering the diagnosis and, consequently, the treatment.
Pediatric Nephrology | 2005
Matjaž Kopač; Anton Kenig; Damjana Ključevšek; Rajko B. Kenda
The purpose of our prospective study was to determine the value of indirect voiding urosonography without the use of contrast-media and without filling of the bladder through a catheter (IVUS) for detection of vesicoureteral reflux (VUR) in children, compared with echo-enhanced voiding urosonography (VUS). Among 57 children (45 girls and 12 boys, aged 2.7 to 12.0 years) admitted for echo-enhanced VUS either as part of routine evaluation after urinary tract infection (UTI) or follow-up of a previously detected VUR, IVUS was also successfully performed in 47 children. The results were considered positive when there was any increase in pelvis size and/or ureter lumen width during voiding. The overall sensitivity of IVUS in the detection of VUR was 49%, specificity 75%. The most accurate results were obtained with VUR grade III, where IVUS correctly detected 6 out of 7 cases, a sensitivity of 86%. The average increase of AP pelvis diameter during voiding was highly significant only in uretero-renal units with VUR grade III. Considering the obstacles in conducting the investigation and its relatively low overall sensitivity and specificity, it seems that IVUS is not sufficiently reliable to replace echo-enhanced VUS.
The Journal of Urology | 2010
Gregor Novljan; Tanja Kersnik Levart; Damjana Ključevšek; Anton Kenig; Rajko B. Kenda
PURPOSE We present different ultrasound techniques to detect vesicoureteral reflux in children with special emphasis on voiding urosonography. MATERIALS AND METHODS Urinary tract infection is a common problem in children that may be related to vesicoureteral reflux. Currently there is no consensus on investigations in children after the first urinary tract infection. The least invasive imaging with the smallest radiation burden should be used in children. Ultrasound to detect reflux meets several of these criteria. The development of echo enhancing agents has markedly improved reflux visualization by ultrasound. RESULTS We discuss the clinical relevance of voiding urosonography. We reviewed the currently available literature and the results of our studies of this issue. We also describe our endeavors to avoid catheterization and detect vesicoureteral reflux based on various sonomorphological features, ie indirect voiding urosonography and ureteral jet Doppler waveform analysis, to avoid applying any substance into the bladder. CONCLUSIONS Voiding urosonography is safe and reliable to detect vesicoureteral reflux. When indicated, considerably decreased radiation exposure can be achieved by voiding urosonography instead of established cystography methods. Indirect voiding urosonography and ureteral jet Doppler waveform analysis could be an alternative to invasive voiding cystography, at least in children older than 3 years.
Hemodialysis International | 2005
Rina R Rus; Rafael Ponikvar; Rajko B. Kenda; Jadranka Buturovic-Ponikvar
Native arteriovenous fistula is the best vascular access for chronic hemodialysis. Primary and long‐term success depends, in part, on the state of arteries and veins at the time of the operation. The aim of our study was to investigate the effects of intermittent compression of upper arm veins on forearm vessels in patients with terminal renal disease. The study group was composed of 16 chronic hemodialysis patients who performed daily intermittent compression of the upper arm without vascular access by elastic band (Eschmarch). Ten chronic hemodialysis patients were included in the control group, which performed no specific activity. Forearm measurements were obtained at the beginning of the study and 4 and 8 weeks later during the course of intermittent compression of the upper arm veins. The forearm circumference and maximal handgrip strength were measured. The artery measures, including endothelium‐dependent vasodilatation and forearm vein variables, were obtained by ultrasonography measurements. The forearm circumference, maximal handgrip strength, and artery variables, including endothelium‐dependent vasodilatation, remained unchanged. The basal venous diameters (2.29 ± 0.19 mm at the beginning, 2.46 ± 0.19 mm after 4 weeks, and 2.53 ± 0.18 mm after 8 weeks) were significantly increased in the study group. The distensibility of veins was preserved in the study group. There were no significant changes in the control group. Our study demonstrated that daily intermittent compression of the upper arm veins increases the forearm vein diameter and preserves the distensibility of veins in patients with end‐stage renal failure.
Pediatric Nephrology | 2010
Damjana Ključevšek; Tomaž Ključevšek; Tanja Kersnik Levart; Gregor Novljan; Rajko B. Kenda
In recent years, the exact role of vesicoureteric reflux (VUR) in general has become controversial, though in some groups of children the knowledge of the existence or non-existence of VUR is still a very important issue. The number of techniques available for the assessment of VUR is increasing, and a new classification taking into account their real characteristics (direct/indirect, catheter-using/catheter-free, radiation-giving/radiation-free) has been proposed. The purpose of the following review is to evaluate the currently available evidence supporting the use of various catheter-free methods for VUR detection. We believe that as the clinical role of VUR has been questioned, it is even more important for the method of its detection to be user-friendly as regards catheterisation, radiation and availability. There is still no evidence supporting the assertion that any of the catheter-free methods of VUR detection might be the optimal one for any child. However, there are some groups of children who would benefit from using them. New studies using new, catheter-free methods of VUR detection or a combination of two or more of the methods described may prove useful in improving sensitivity and providing additional data on this important issue.