Publications (54) View all
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Article: Renal failure after renal sympathetic ablation in a patient with chronic kidney disease - Which came first, the chicken or the egg?
International journal of cardiology 05/2013; · 7.08 Impact Factor -
Article: Arterial and retinal vascular changes in hypertensive and prehypertensive adolescents.
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ABSTRACT: INTRODUCTION Increasing evidence suggests that arterial hypertension (AHT) may begin in childhood and result in the premature development of cardiovascular disease. In view of this, we believed it would be important to investigate the early vascular changes related to early hypertension at the micro- and macrovascular levels both under normal circumstances and after cold-induced sympathetic stimulation. METHODS In a cohort of 121 adolescent subjects, we measured peripheral and central blood pressure (pBP and cBP, respectively), pulse pressure (PP), and the augmentation index (AIx), as well as retinal vascular diameters, at baseline and during a cold pressor test (CPT). We measured the central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) and calculated the retinal arteriolar-to-venular ratio (AVR). We compared macro- and microvascular alterations among normotensive (NT), prehypertensive (PHT), and hypertensive (HT) adolescents. RESULTS Of the adolescent subjects in the study, 54.5% were NT, 25.6% were PHT, and 19.8% were HT. With regard to BMI, central systolic BP (cSBP), aortic pulse pressure (AoPP), and CRAE, the PHT adolescents had values similar to those in the HT group but significantly different than those in the NT group. In the studied population, there was a positive and significant correlation of AIx with cSBP and a negative association of CRAE with both cSBP and peripheral SBP (pSBP). We describe the evolution of these parameters during and after sympathetic stimulation. CONCLUSION As compared with the prevalence of hypertension and prehypertension in large studies, involving teenagers and children, an alarming percentage (45.5%) of the adolescents in our study were HT or PHT. Higher pSBP and cSBP were associated with narrower retinal arterioles but not with changes of arterial elasticity. With particular regard to CRAE, the PHT group was more closely related to the HT group than to the NT group. There were no differences among the NT, PHT, and HT groups in the results of the CPT.American Journal of Hypertension 03/2013; 26(3):400-8. · 3.18 Impact Factor -
Article: Retinal pulse wave velocity in young male normotensive and mildly hypertensive subjects.
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ABSTRACT: OBJECTIVE: Hypertension is characterized by microvascular remodeling resulting in increased wall/lumen ratio and elevated microvascular stiffness. Aiming to transform the measurement of macrovascular stiffness into a microvascular environment we introduce a non-invasive method to assess retinal pulse wave velocity (rPWV). rPWV alterations in early hypertension are investigated in detail. The developed methodology is compared with its possible computational alternatives. METHODS: Time dependent alterations of retinal arterial diameter were assessed non-invasively by the Dynamic Vessel Analyzer in 65 male normoalbuminuric normotensive to mildly hypertensive subjects (age: 28.7±6.0 years). rPWV was computed using three different methods. 'Method1' used filtration at heart rate (HR), 'Method2' filtered at higher HR multiples, 'Method3' used additionally linear fit for data averaging. RESULTS: 'Method2' and 'Method3' applying filtration at high HR multiples showed strong associations with systolic BP throughout the cohort (r=0.49, r=0.63, P<0.001). Based on the highest association 'Method3' was proposed to characterize rPWV. Hypertensive patients showed higher rPWV (1243±694 units/second) than subjects with high-normal BP (786±486 units/second, P<0.01) or normotensive subjects (442±148 units/second, P<0.001). CONCLUSIONS: rPWV demonstrated a strong association with BP and can discriminate between optimal, high-normal and mildly hypertensive BP values. rPWV may add detailed insights to early microvascular pathophysiology, potentially beyond microalbuminuria. © 2013 John Wiley & Sons Ltd.Microcirculation (New York, N.Y.: 1994) 01/2013; · 2.37 Impact Factor -
Article: Risk factors and interventional strategies for BK polyomavirus infection after renal transplantation.
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ABSTRACT: Abstract Objective. BK virus (BKV)-induced viraemia after renal transplantation can be associated with severe impairment of graft function. This study evaluated possible risk factors for BKV replication and examined the outcomes following various currently used treatment approaches. Material and methods. Fifty-seven renal transplant recipients with BKV viraemia were retrospectively compared with 71 BKV-negative recipients to identify risk factors for BKV viraemia. Furthermore, outcome and graft function in 14 patients with BKV replication, in whom mycophenolate mofetil (MMF) was discontinued with a dose reduction of the remaining immunosuppressants, were compared with 32 patients in whom both MMF and the additional immunosuppressants were reduced. Results. Patients with BKV viraemia received MMF (p < 0.01) and triple immunosuppression (p < 0.01) significantly more often, and displayed tacrolimus (p = 0.034) at higher blood concentrations (p = 0.002), a lower lymphocyte count (p = 0.006) and a longer warm ischaemic time (p = 0.019), and were more often male (p = 0.026). Patients in whom MMF was stopped had a higher chance of clearance of BKV viraemia (p = 0.022), which was achieved more rapidly (p = 0.048). Graft function improved during treatment and no graft losses occurred, compared with eight graft losses in the MMF-treated group (p = 0.04). Conclusions. MMF and tacrolimus could promote BKV viraemia after renal transplantation. Discontinuation of MMF together with a reduction of calcineurin inhibitors and glucocorticoids could be an option to reduce BKV replication after renal transplantation.Scandinavian Journal of Urology and Nephrology 09/2012; · 0.99 Impact Factor -
Article: Mineralocorticoid Receptor Antagonism and Aldosterone Synthesis Inhibition Do Not Improve Glomerulosclerosis and Renal Interstitial Fibrosis in a Model of Chronic Kidney Allograft Injury.
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ABSTRACT: Chronic allograft injury (CAI) is a major cause of late graft failure with a multifactorial pathogenesis; however, in different experiments an inhibition of the renin-angiotensin system by angiotensin-converting enzyme inhibitors and angiotensin II type 1 receptor blockers ameliorated the progression of chronic renal disease. Different concepts supposed that aldosterone is involved in development and/or progression of renal diseases via interaction with a non-epithelial mineralocorticoid receptor (MR), e.g. reducing neointima formation. Our examinations therefore targeted on the effects of the aldosterone synthase inhibitor fadrozole and the MR antagonist spironolactone compared to vehicle in an established rat model of CAI. In our model of CAI, neither the aldosterone biosynthesis inhibitor nor a direct MR blockade had a positive effect on renal CAI in rats. Fadrozole- and spironolactone-treated animals demonstrated a higher proteinuria value, pathologically elevated potassium values, higher tubulointerstitial damage and markedly increased heart weight/body weight as compared to vehicle. Our observations also suggest that inhibition of the MR or the biosynthesis itself had a bad influence on the amount of sclerotic glomeruli and tubulointerstitial damage. The positive effects of inhibition of aldosterone as described in cardiac models could not yet be detected in kidney recipients.Kidney and Blood Pressure Research 08/2012; 35(6):561-567. · 1.46 Impact Factor
