Dynamic analysis of renal nerve activity responses to baroreceptor denervation in hypertensive rats.

PubMed

DiBona, G F; Jones, S Y

2001-04-01

Sinoaortic and cardiac baroreflexes exert important control over renal sympathetic nerve activity. Alterations in these reflex mechanisms contribute to renal sympathoexcitation in hypertension. Nonlinear dynamic analysis was used to examine the chaotic behavior of renal sympathetic nerve activity in normotensive Sprague-Dawley and Wistar-Kyoto rats and spontaneously hypertensive rats before and after complete baroreceptor denervation (sinoaortic and cardiac baroreceptor denervation). The peak interval sequence of synchronized renal sympathetic nerve discharge was extracted and used for analysis. In all rat strains, this yielded systems whose correlation dimensions converged to similar low values over the embedding dimension range of 10 to 15 and whose greatest Lyapunov exponents were positive. In Sprague-Dawley and Wistar-Kyoto rats, compete baroreceptor denervation was associated with decreases in the correlation dimensions (Sprague-DAWLEY: 2.42+/-0.04 to 2.16+/-0.04; Wistar-KYOTO: 2.44+/-0.04 to 2.34+/-0.04) and in the greatest Lyapunov exponents (Sprague-DAWLEY: 0.199+/-0.004 to 0.130+/-0.015; Wistar-KYOTO: 0.196+/-0.002 to 0.136+/-0.010). Spontaneously hypertensive rats had a similar correlation dimension, which was unaffected by complete baroreceptor denervation (2.42+/-0.02 versus 2.42+/-0.03), and a lower value for the greatest Lyapunov exponent, which decreased to a lesser extent after complete baroreceptor denervation (0.183+/-0.006 versus 0.158+/-0.006). These results indicate that removal of sinoaortic and cardiac baroreceptor regulation of renal sympathetic nerve activity is associated with a greater decrease in the chaotic behavior of renal sympathetic nerve activity in normotensive compared with hypertensive rats. This suggests that the central neural mechanisms that regulate renal sympathetic nerve activity in response to alterations in cardiovascular reflex inputs are different in spontaneously hypertensive rats from those in Sprague-Dawley and

Functional Renal Imaging with 2-Deoxy-2-18F-Fluorosorbitol PET in Rat Models of Renal Disorders.

PubMed

Werner, Rudolf A; Wakabayashi, Hiroshi; Chen, Xinyu; Hirano, Mitsuru; Shinaji, Tetsuya; Lapa, Constantin; Rowe, Steven P; Javadi, Mehrbod S; Higuchi, Takahiro

2018-05-01

Precise regional quantitative assessment of renal function is limited with conventional 99m Tc-labeled renal radiotracers. A recent study reported that the PET radiotracer 2-deoxy-2- 18 F-fluorosorbitol ( 18 F-FDS) has ideal pharmacokinetics for functional renal imaging. Furthermore, 18 F-FDS is available via simple reduction from routinely used 18 F-FDG. We aimed to further investigate the potential of 18 F-FDS PET as a functional renal imaging agent using rat models of kidney disease. Methods: Two different rat models of renal impairment were investigated: induction of acute renal failure by intramuscular administration of glycerol in the hind legs, and induction of unilateral ureteral obstruction by ligation of the left ureter. At 24 h after these procedures, dynamic 30-min 18 F-FDS PET data were acquired using a dedicated small-animal PET system. Urine 18 F-FDS radioactivity 30 min after radiotracer injection was measured together with coinjected 99m Tc-diethylenetriaminepentaacetic acid urine activity. Results: Dynamic PET imaging demonstrated rapid 18 F-FDS accumulation in the renal cortex and rapid radiotracer excretion via the kidneys in healthy control rats. On the other hand, significantly delayed renal radiotracer uptake (continuous slow uptake) was observed in acute renal failure rats and unilateral ureteral obstruction kidneys. Measured urine radiotracer concentrations of 18 F-FDS and 99m Tc-diethylenetriaminepentaacetic acid correlated well with each other ( R = 0.84, P < 0.05). Conclusion: 18 F-FDS PET demonstrated favorable kinetics for functional renal imaging in rat models of kidney diseases. 18 F-FDS PET imaging, with its advantages of high spatiotemporal resolution and simple tracer production, could potentially complement or replace conventional renal scintigraphy in select cases and significantly improve the diagnostic performance of renal functional imaging. © 2018 by the Society of Nuclear Medicine and Molecular Imaging.

Symplicity multi-electrode radiofrequency renal denervation system feasibility study.

PubMed

Whitbourn, Robert; Harding, Scott A; Walton, Antony

2015-05-01

The aim of this study was to test the safety and performance of the Symplicity™ multi-electrode radio-frequency renal denervation system which was designed to reduce procedure time during renal denervation. The multi-electrode radiofrequency renal denervation system feasibility study is a prospective, non-randomised, open label, feasibility study that enrolled 50 subjects with hypertension. The study utilises a new renal denervation catheter which contains an array of four electrodes mounted in a helical configuration at 90 degrees from each other to deliver radiofrequency energy simultaneously to all four renal artery quadrants for 60 seconds. The protocol specified one renal denervation treatment towards the distal end of each main renal artery with radiofrequency energy delivered for 60 seconds per treatment. Total treatment time for both renal arteries was two minutes. The 12-month change in office systolic blood pressure (SBP) and 24-hour SBP was -19.2±25.2 mmHg, p<0.001, and -7.6±20.0 mmHg, p=0.020, respectively. There were three patients with access-site complications, none of which was related to energy delivery; all were treated successfully. No new renal artery stenosis or hypertensive emergencies occurred. The Symplicity multi-electrode radiofrequency renal denervation system was associated with a significant reduction in SBP at 12 months and minimal complications whilst it also reduced procedure time. NCT01699529.

Effects of Renal Denervation from the Intima and the Adventitia of Renal Arteries on Renal Sympathetic Nerve Activity in Dogs: A Comparative Study.

PubMed

Bai, Minfu; Yang, Chaokuan; Gao, Chuanyu; Wang, Xianpei; Liu, Hongzhi; Zhang, You; Liu, Jun; Wu, Jintao; Jian, Dongdong; Zhu, Lijie; Zhao, Wenli; Ma, Peiyao; Han, Yaqi

2015-01-01

This study was designed to observe the efficacy and safety of renal denervation from the inside and outside of renal arteries. Fourteen beagles were randomly divided into a control group (n = 4) and treatment group (n = 10). One renal artery in every beagle of the treatment group was randomly assigned to an intimal group (10 renal arteries) which underwent percutaneous renal denervation from the inside, and another renal artery was assigned to an adventitial group (10 renal arteries) which underwent renal denervation from the outside by laparotomy. Compared with the intimal group, the renal norepinephrine (NE) concentration in the adventitial group had significantly decreased (p = 0.003) at 3 months postsurgery. Renal artery HE staining showed that the perineurium from the adventitial group appeared thickened. Western blotting showed that renal tissue tyrosine hydroxylase (TH) protein expression in the adventitial group was significantly lower than that in the intimal group (p < 0.01) at 3 months postsurgery. There was a renal artery stenosis and a renal atrophy in the intimal group after 1 month of follow-up. The inhibitory effect on renal sympathetic nerve activity was more effective in the adventitial group than the intimal group, and renal denervation in the former group was safe. © 2015 S. Karger AG, Basel.

The dynamic process of adherence to a renal therapeutic regimen: perspectives of patients undergoing continuous ambulatory peritoneal dialysis.

PubMed

Lam, Lai Wah; Lee, Diana T F; Shiu, Ann T Y

2014-06-01

The nature of end-stage renal disease and the need for continuous ambulatory peritoneal dialysis require patients to manage various aspects of the disease, its symptoms and treatment. After attending a training programme, patients are expected to adhere to the renal therapeutic regimen and manage their disease with the knowledge and skills learned. While patients are the stakeholders of their health and related behaviour, their perceptions of adherence and how they adhere to their renal therapeutic regimen remains unexplored. To understand adherence from patients' perspectives and to describe changes in adherence to a therapeutic regimen among patients undergoing continuous ambulatory peritoneal dialysis. This study used a mixed methods design with two phases - a survey in phase I and semi-structured interviews in phase II. This paper presents phase II of the study. The study was conducted at a renal unit of an acute hospital in Hong Kong. Based on the phase I survey results, maximum variation sampling was employed to purposively recruit 36 participants of different genders (18 males, 18 females), ages (35-76 years), and lengths of dialysis experience (11-103 months) for the phase II interviews. Data were collected by tape-recorded semi-structured interviews. Content analysis was employed to analyse the transcribed data. Data collection and analysis were conducted simultaneously. Adherence was a dynamic process with three stages. At the stage of initial adherence, participants attempted to follow instructions but found that strict persistent adherence was impossible. After the first 2-6 months of dialysis, participants entered the stage of subsequent adherence, when they adopted selective adherence through experimenting, monitoring and making continuous adjustments. The stage of long-term adherence commenced after 3-5 years of dialysis, when participants were able to assimilate the modified therapeutic regimen into everyday life. The process of adherence was

Recirculation zone length in renal artery is affected by flow spirality and renal-to-aorta flow ratio.

PubMed

Javadzadegan, Ashkan; Fulker, David; Barber, Tracie

2017-07-01

Haemodynamic perturbations such as flow recirculation zones play a key role in progression and development of renal artery stenosis, which typically originate at the aorta-renal bifurcation. The spiral nature of aortic blood flow, division of aortic blood flow in renal artery as well as the exercise conditions have been shown to alter the haemodynamics in both positive and negative ways. This study focuses on the combinative effects of spiral component of blood flow, renal-to-aorta flow ratio and the exercise conditions on the size and distribution of recirculation zones in renal branches using computational fluid dynamics technique. Our findings show that the recirculation length was longest when the renal-to-aorta flow ratio was smallest. Spiral flow and exercise conditions were found to be effective in reducing the recirculation length in particular in small renal-to-aorta flow ratios. These results support the hypothesis that in renal arteries with small flow ratios where a stenosis is already developed an artificially induced spiral flow within the aorta may decelerate the progression of stenosis and thereby help preserve kidney function.

Renal hemodynamics: the influence of the renal artery ostium flow diverter

NASA Astrophysics Data System (ADS)

Rossmann, Jenn Stroud; Albert, Scott; Balaban, Robert

2013-11-01

The recently identified renal artery ostium flow diverter may preferentially direct blood flow to the renal arteries, and may also influence flow patterns and recirculation known to be involved in atherogenesis. Three-dimensional computational fluid dynamics (CFD) simulations of steady and pulsatile blood flow are performed to investigate the influence of diverter size and position, and vascular geometry, on the flow patterns and fluid mechanical forces in the neighborhood of the diverter. CFD results show that the flow diverter does affect the blood distribution: depending on the diverter's position, the flow to the renal arteries may be increased or reduced. The results of simulations also show the diverter's effect on the Wall Shear Stress (WSS) distribution, and suggest that the diverter contributes to an atherogenic environment in the abdominal aorta, while being atheroprotective in the renal arteries themselves. These results support previous clinical findings, and suggest directions for further clinical study. The results of this work have direct implications in understanding the physiological significance of the diverter, and its potential role in the pathophysiological development of atherosclerosis.

[Renal hemodynamic in hydronephrosis concurrent with hepatobiliary system disorders, its dynamics in the course of treatment].

PubMed

Mambetov, Zh S; Salimov, B G

2016-02-01

This article examines measurements of renal vascular ultrasound in 85 patients with hydronephrosis concurrent with disorders of the gallbladder and biliary tract, depending on severity and dynamics during treatment. The estimation of blood flow changes depending on applied renoprotective and hepatoprotective therapy is provided.

Fluid dynamic modelling of renal pelvic pressure during endoscopic stone removal

NASA Astrophysics Data System (ADS)

Oratis, Alexandros; Subasic, John; Bird, James; Eisner, Brian

2015-11-01

Endoscopic kidney stone removal procedures are known to increase internal pressure in the renal pelvis, the kidney's urinary collecting system. High renal pelvic pressure incites systemic absorption of irrigation fluid, which can increase the risk of postoperative fever and sepsis or the unwanted absorption of electrolytes. Urologists choose the appropriate surgical procedure based on patient history and kidney stone size. However, no study has been conducted to compare the pressure profiles of each procedure, nor is there a precise sense of how the renal pelvic pressure scales with various operational parameters. Here we develop physical models for the flow rates and renal pelvic pressure for various procedures. We show that the results of our models are consistent with existing urological data on each procedure and that the models can predict pressure profiles where data is unavailable.

[Quality assurance of the renal applications software].

PubMed

del Real Núñez, R; Contreras Puertas, P I; Moreno Ortega, E; Mena Bares, L M; Maza Muret, F R; Latre Romero, J M

2007-01-01

The need for quality assurance of all technical aspects of nuclear medicine studies is widely recognised. However, little attention has been paid to the quality assurance of the applications software. Our work reported here aims at verifying the analysis software for processing of renal nuclear medicine studies (renograms). The software tools were used to build a synthetic dynamic model of renal system. The model consists of two phases: perfusion and function. The organs of interest (kidneys, bladder and aortic artery) were simple geometric forms. The uptake of the renal structures was described by mathematic functions. Curves corresponding to normal or pathological conditions were simulated for kidneys, bladder and aortic artery by appropriate selection of parameters. There was no difference between the parameters of the mathematic curves and the quantitative data produced by the renal analysis program. Our test procedure is simple to apply, reliable, reproducible and rapid to verify the renal applications software.

Renal denervation by intravascular ultrasound: Preliminary in vivo study

NASA Astrophysics Data System (ADS)

Sinelnikov, Yegor; McClain, Steve; Zou, Yong; Smith, David; Warnking, Reinhard

2012-10-01

Ultrasound denervation has recently become a subject of intense research in connection with the treatment of complex medical conditions including neurological conditions, development of pain management, reproduction of skin sensation, neuropathic pain and spasticity. The objective of this study is to investigate the use of intravascular ultrasound to produce nerve damage in renal sympathetic nerves without significant injury to the renal artery. This technique may potentially be used to treat various medical conditions, such as hypertension. The study was approved by the Institutional Animal Care and Use Committee. Ultrasound was applied to renal nerves of the swine model for histopathological evaluation. Therapeutic ultrasound energy was delivered circumferentially by an intravascular catheter maneuvered into the renal arteries. Fluoroscopic imaging was conducted pre-and post-ultrasound treatment. Animals were recovered and euthanized up to 30 hours post procedure, followed by necropsy and tissue sample collection. Histopathological examination showed evidence of extensive damage to renal nerves, characterized by nuclear pyknosis, hyalinization of stroma and multifocal hemorrhages, with little or no damage to renal arteries. This study demonstrates the feasibility of intravascular ultrasound as a minimally invasive renal denervation technique. Further studies are necessary to evaluate the long-term safety and efficacy of this technique and its related clinical significance.

Rotational digital subtraction angiography of the renal arteries: technique and evaluation in the study of native and transplant renal arteries.

PubMed

Seymour, H R; Matson, M B; Belli, A M; Morgan, R; Kyriou, J; Patel, U

2001-02-01

Rotational digital subtraction angiography (RDSA) allows multidirectional angiographic acquisitions with a single injection of contrast medium. The role of RDSA was evaluated in 60 patients referred over a 7-month period for diagnostic renal angiography and 12 patients referred for renal transplant studies. All angiograms were assessed for their diagnostic value, the presence of anomalies and the quantity of contrast medium used. The effective dose for native renal RDSA was determined. 41 (68.3%) native renal RDSA images and 8 (66.7%) transplant renal RDSA images were of diagnostic quality. Multiple renal arteries were identified in 9/41 (22%) native renal RDSA diagnostic images. The mean volume of contrast medium in the RDSA runs was 51.2 ml and 50 ml for native and transplant renal studies, respectively. The mean effective dose for 120 degrees native renal RDSA was 2.36 mSv, equivalent to 1 year's mean background radiation. Those RDSA images that were non-diagnostic allowed accurate prediction of the optimal angle for further static angiographic series, which is of great value in transplant renal vessels.

Determination of single-kidney glomerular filtration rate (GFR) with CT urography versus renal dynamic imaging Gates method.

PubMed

You, Shan; Ma, XianWu; Zhang, ChangZhu; Li, Qiang; Shi, WenWei; Zhang, Jing; Yuan, XiaoDong

2018-03-01

To present a single-kidney CT-GFR measurement and compare it with the renal dynamic imaging Gates-GFR. Thirty-six patients with hydronephrosis referred for CT urography and 99mTc-DTPA renal dynamic imaging were prospectively included. Informed consent was obtained from all patients. The CT urography protocol included non-contrast, nephrographic, and excretory phase imaging. The total CT-GFR was calculated by dividing the CT number increments of the total urinary system between the nephrographic and excretory phase by the products of iodine concentration in the aorta and the elapsed time, then multiplied by (1- Haematocrit). The total CT-GFR was then split into single-kidney CT-GFR by a left and right kidney proportionality factor. The results were compared with single-kidney Gates-GFR by using paired t-test, correlation analysis, and Bland-Altman plots. Paired difference between single-kidney CT-GFR (45.02 ± 13.91) and single-kidney Gates-GFR (51.21 ± 14.76) was 6.19 ± 5.63 ml/min, p<0.001, demonstrating 12.1% systematic underestimation with ±11.03 ml/min (±21.5%) measurement deviation. A good correlation was revealed between both measurements (r=0.87, p<0.001). The proposed single-kidney CT-GFR correlates and agrees well with the reference standard despite a systematic underestimation, therefore it could be a one-stop-shop for evaluating urinary tract morphology and split renal function. • A new CT method can assess split renal function • Only using images from CT urography and the value of haematocrit • A one-stop-shop CT technique without additional radiation dose.

Usefulness of parametric renal clearance images in the assessment of basic risk factors for renalnal clearance images in the assessment of basic risk factors for renal scarring in children with recurrent urinary tract infections.

PubMed

Pietrzak-Stelasiak, Ewa; Bieńkiewicz, Małgorzata; Woźnicki, Wojciech; Bubińska, Krystyna; Kowalewska-Pietrzak, Magdalena; Płachcińska, Anna; Kuśmierek, Jacek

2017-01-01

Clinically confirmed incidents of acute pyelonephritis (APN) following recurrent infections of urinary tract (UTI) form basic risk factors for renal scarring in children. Vesico-uretheral reflux (VUR) of higher grade is additional risk factor for this scarring. Opinions on diagnostic value of summed sequential images of renal uptake phase (SUM) of dynamic renal scintigraphy in detection of renal scars are diverse. However, several publications point to higher diagnostic efficacy of clearance parametric images (PAR) generated from this study. To establish a clinical value of parametric renal clearance images in detection of renal scarring. A prospective study was performed in a group of 91 children at the age of 4 to 18 years with recurrent UTI. Clinically documented incidents of APN were noted in 32 children: in 8 cases - one and in the remaining 24 - 2 to 5 (mean 3) incidents. In the remaining 59 patients only infections of the lower part of urinary tract were diagnosed. Static renal 99mTc-DMSA SPECT study and after 2-4 days dynamic renal studies (99mTc-EC) were performed in every patient not earlier than 6 months after the last documented incident of UTI. PAR images generated from a dynamic study by in-house developed software and SUM images were compared with a gold standard SPECT study. Percentages of children with detected renal scar(s) with SPECT and PAR methods amounted to 55% and 54%, respectively and were statistically significantly higher (p < 0.0001) than with SUM method - 31%. Scars in children with history of APN detected with SPECT and PAR methods were significantly more frequent than with infections of only lower part of urinary tract (72% vs. 46%; p = 0.017 and 69% vs. 46%; p = 0.036, respectively). A SUM method did not reveal statistically significant differences between frequencies of detection of scars in groups specified above - 38% vs. 27% (p = 0.31). Both SPECT and PAR methods showed also that frequencies of occurrence of renal scars in

Effect of endogenous angiotensin II on the frequency response of the renal vasculature.

PubMed

Dibona, Gerald F; Sawin, Linda L

2004-12-01

The renal vasculature functions as an efficient low-pass filter of the multiple frequencies contained within renal sympathetic nerve activity. This study examined the effect of angiotensin II on the frequency response of the renal vasculature. Physiological changes in the activity of the endogenous renin-angiotensin system were produced by alterations in dietary sodium intake. The frequency response of the renal vasculature was evaluated using pseudorandom binary sequence renal nerve stimulation, and the role of angiotensin II was evaluated by the administration of the angiotensin II AT(1)-receptor antagonist losartan. In low-sodium-diet rats with increased renin-angiotensin system activity, losartan steepened the renal vascular frequency response (i.e., greater attenuation); this was not seen in normal- or high-sodium-diet rats with normal or decreased renin-angiotensin system activity. Analysis of the transfer function from arterial pressure to renal blood flow, i.e., dynamic autoregulation, showed that the tubuloglomerular feedback but not the myogenic component was enhanced in low- and normal- but not in high-sodium-diet rats and that this was reversed by losartan administration. Thus physiological increases in endogenous renin-angiotensin activity inhibit the renal vascular frequency response to renal nerve stimulation while selectively enhancing the tubuloglomerular feedback component of dynamic autoregulation of renal blood flow.

Dynamic Contrast-enhanced MR Imaging in Renal Cell Carcinoma: Reproducibility of Histogram Analysis on Pharmacokinetic Parameters

PubMed Central

Wang, Hai-yi; Su, Zi-hua; Xu, Xiao; Sun, Zhi-peng; Duan, Fei-xue; Song, Yuan-yuan; Li, Lu; Wang, Ying-wei; Ma, Xin; Guo, Ai-tao; Ma, Lin; Ye, Hui-yi

2016-01-01

Pharmacokinetic parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) have been increasingly used to evaluate the permeability of tumor vessel. Histogram metrics are a recognized promising method of quantitative MR imaging that has been recently introduced in analysis of DCE-MRI pharmacokinetic parameters in oncology due to tumor heterogeneity. In this study, 21 patients with renal cell carcinoma (RCC) underwent paired DCE-MRI studies on a 3.0 T MR system. Extended Tofts model and population-based arterial input function were used to calculate kinetic parameters of RCC tumors. Mean value and histogram metrics (Mode, Skewness and Kurtosis) of each pharmacokinetic parameter were generated automatically using ImageJ software. Intra- and inter-observer reproducibility and scan–rescan reproducibility were evaluated using intra-class correlation coefficients (ICCs) and coefficient of variation (CoV). Our results demonstrated that the histogram method (Mode, Skewness and Kurtosis) was not superior to the conventional Mean value method in reproducibility evaluation on DCE-MRI pharmacokinetic parameters (K trans & Ve) in renal cell carcinoma, especially for Skewness and Kurtosis which showed lower intra-, inter-observer and scan-rescan reproducibility than Mean value. Our findings suggest that additional studies are necessary before wide incorporation of histogram metrics in quantitative analysis of DCE-MRI pharmacokinetic parameters. PMID:27380733

Salt loading produces severe renal hemodynamic dysfunction independent of arterial pressure in spontaneously hypertensive rats.

PubMed

Matavelli, Luis C; Zhou, Xiaoyan; Varagic, Jasmina; Susic, Dinko; Frohlich, Edward D

2007-02-01

We have previously shown that salt excess has adverse cardiac effects in spontaneously hypertensive rats (SHR), independent of its increased arterial pressure; however, the renal effects have not been reported. In the present study we evaluated the role of three levels of salt loading in SHR on renal function, systemic and renal hemodynamics, and glomerular dynamics. At 8 wk of age, rats were given a 4% (n = 11), 6% (n = 9), or 8% (n = 11) salt-load diet for the ensuing 8 wk; control rats (n = 11) received standard chow (0.6% NaCl). Rats had weekly 24-h proteinuria and albuminuria quantified. At the end of salt loading, all rats had systemic and renal hemodynamics measured; glomerular dynamics were specially studied by renal micropuncture in the control, 4% and 6% salt-loaded rats. Proteinuria and albuminuria progressively increased by the second week of salt loading in the 6% and 8% salt-loaded rats. Mean arterial pressure increased minimally, and glomerular filtration rate decreased in all salt-loaded rats. The 6% and 8% salt-loaded rats demonstrated decreased renal plasma flow and increased renal vascular resistance and serum creatinine concentration. Furthermore, 4% and 6% salt-loaded rats had diminished single-nephron plasma flow and increased afferent and efferent arteriolar resistances; glomerular hydrostatic pressure also increased in the 6% salt-loaded rats. In conclusion, dietary salt loading as low as 4% dramatically deteriorated renal function, renal hemodynamics, and glomerular dynamics in SHR independent of a minimal further increase in arterial pressure. These findings support the concept of a strong independent causal relationship between salt excess and cardiovascular and renal injury.

Development and prospective evaluation of an automated software system for quality control of quantitative 99mTc-MAG3 renal studies.

PubMed

Folks, Russell D; Garcia, Ernest V; Taylor, Andrew T

2007-03-01

Quantitative nuclear renography has numerous potential sources of error. We previously reported the initial development of a computer software module for comprehensively addressing the issue of quality control (QC) in the analysis of radionuclide renal images. The objective of this study was to prospectively test the QC software. The QC software works in conjunction with standard quantitative renal image analysis using a renal quantification program. The software saves a text file that summarizes QC findings as possible errors in user-entered values, calculated values that may be unreliable because of the patient's clinical condition, and problems relating to acquisition or processing. To test the QC software, a technologist not involved in software development processed 83 consecutive nontransplant clinical studies. The QC findings of the software were then tabulated. QC events were defined as technical (study descriptors that were out of range or were entered and then changed, unusually sized or positioned regions of interest, or missing frames in the dynamic image set) or clinical (calculated functional values judged to be erroneous or unreliable). Technical QC events were identified in 36 (43%) of 83 studies. Clinical QC events were identified in 37 (45%) of 83 studies. Specific QC events included starting the camera after the bolus had reached the kidney, dose infiltration, oversubtraction of background activity, and missing frames in the dynamic image set. QC software has been developed to automatically verify user input, monitor calculation of renal functional parameters, summarize QC findings, and flag potentially unreliable values for the nuclear medicine physician. Incorporation of automated QC features into commercial or local renal software can reduce errors and improve technologist performance and should improve the efficiency and accuracy of image interpretation.

A clinical evaluation of renal amyloidosis in the Japan renal biopsy registry: a cross-sectional study.

PubMed

Nishi, Shinichi; Muso, Eri; Shimizu, Akira; Sugiyama, Hitoshi; Yokoyama, Hitoshi; Ando, Yukio; Goto, Shunsuke; Fujii, Hideki

2017-08-01

The available clinical data are limited in a rare glomerular disease, renal amyloidosis. We aimed to clarify the clinical features of renal amyloidosis from database of the Japan Renal Biopsy Registry (J-RBR). We performed a cross-sectional study with database of the J-RBR of the Japanese Society of Nephrology. We identified 281 cases of renal amyloidosis from 20,997 cases enrolled into the J-RBR from 2007 to 2014. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were compared among the levels of ages, amount of urine protein excretion (AUPE) or CKD G stages. The prevalence of renal amyloidosis was 1.3 % (281/20,997). DBP significantly decreased in higher age quartiles (P = 0.034). SBP and DBP did not increase in the progression of AUPE levels and CKD G stages. In multiple regression analysis, eGFR was a significant independent factor for SBP in all cases and a subgroup without hypertensive agents. There was a reverse significant relationship between SBP and eGFR. Blood pressure did not significantly increase in elderly and much proteinuric condition in renal amyloidosis. The progression of CKD and decrease of eGFR did not produce the higher SBP. The mechanism underlying these results remains unclear; however, they are unique features of renal amyloidosis. The couple of hypotensive and hypertensive conditions might produce no relationship between blood pressure and CKD stages.

Changes of renal sinus fat and renal parenchymal fat during an 18-month randomized weight loss trial.

PubMed

Zelicha, Hila; Schwarzfuchs, Dan; Shelef, Ilan; Gepner, Yftach; Tsaban, Gal; Tene, Lilac; Yaskolka Meir, Anat; Bilitzky, Avital; Komy, Oded; Cohen, Noa; Bril, Nitzan; Rein, Michal; Serfaty, Dana; Kenigsbuch, Shira; Chassidim, Yoash; Sarusi, Benjamin; Thiery, Joachim; Ceglarek, Uta; Stumvoll, Michael; Blüher, Matthias; Haviv, Yosef S; Stampfer, Meir J; Rudich, Assaf; Shai, Iris

2018-08-01

Data regarding the role of kidney adiposity, its clinical implications, and its dynamics during weight-loss are sparse. We investigated the effect of long-term weight-loss induced intervention diets on dynamics of renal-sinus-fat, an ectopic fat depot, and %renal-parenchymal-fat, lipid accumulation within the renal parenchyma. We randomized 278 participants with abdominal obesity/dyslipidemia to low-fat or Mediterranean/low-carbohydrate diets, with or without exercise. We quantified renal-sinus-fat and %renal-parenchymal-fat by whole body magnetic-resonance-imaging. Participants (age = 48 years; 89% men; body-mass-index = 31 kg/m 2 ) had 86% retention to the trial after 18 months. Both increased renal-sinus-fat and %renal-parenchymal-fat were directly associated with hypertension, and with higher abdominal deep-subcutaneous-adipose-tissue and visceral-adipose-tissue (p of trend < 0.05 for all) after adjustment for body weight. Higher renal-sinus-fat was associated with lower estimated-glomerular-filtration-rate and with higher microalbuminuria and %HbA1C beyond body weight. After 18 months of intervention, overall renal-sinus-fat (-9%; p < 0.05 vs. baseline) but not %renal-parenchymal-fat (-1.7%; p = 0.13 vs. baseline) significantly decreased, and similarly across the intervention groups. Renal-sinus-fat and %renal-parenchymal-fat changes were correlated with weight-loss per-se (p < 0.05). In a model adjusted for age, sex, and visceral-adipose-tissue changes, 18 months reduction in renal-sinus-fat associated with decreased pancreatic, hepatic and cardiac fats (p < 0.05 for all) and with decreased cholesterol/high-density lipoprotein-cholesterol (HDL-c) (β = 0.13; p = 0.05), triglycerides/HDL-c (β = 0.13; p = 0.05), insulin (β = 0.12; p = 0.05) and gamma glutamyl transpeptidase (β = 0.24; p = 0.001), but not with improved renal function parameters or blood pressure. Decreased intake of sodium was associated with a reduction in

Role of angiotensin II in dynamic renal blood flow autoregulation of the conscious dog

PubMed Central

Just, Armin; Ehmke, Heimo; Wittmann, Uwe; Kirchheim, Hartmut R

2002-01-01

The influence of angiotensin II (ANGII) on the dynamic characteristics of renal blood flow (RBF) was studied in conscious dogs by testing the response to a step increase in renal artery pressure (RAP) after a 60 s period of pressure reduction (to 50 mmHg) and by calculating the transfer function between physiological fluctuations in RAP and RBF. During the RAP reduction, renal vascular resistance (RVR) decreased and upon rapid restoration of RAP, RVR returned to baseline with a characteristic time course: within the first 10 s, RVR rose rapidly by 40 % of the initial change (first response, myogenic response). A second rise began after 20–30 s and reached baseline after an overshoot at 40 s (second response, tubuloglomerular feedback (TGF)). Between both responses, RVR rose very slowly (plateau). The transfer function had a low gain below 0.01 Hz (high autoregulatory efficiency) and two corner frequencies at 0.026 Hz (TGF) and at 0.12 Hz (myogenic response). Inhibition of angiotensin converting enzyme (ACE) lowered baseline RVR, but not the minimum RVR at the end of the RAP reduction (autoregulation-independent RVR). Both the first and second response were reduced, but the normalised level of the plateau (balance between myogenic response, TGF and possible slower mechanisms) and the transfer gain below 0.01 Hz were not affected. Infusion of ANGII after ramipril raised baseline RVR above the control condition. The first and second response and the transfer gain at both corner frequencies were slightly augmented, but the normalised level of the plateau was not affected. It is concluded that alterations of plasma ANGII within a physiological range do not modulate the relative contribution of the myogenic response to the overall short-term autoregulation of RBF. Consequently, it appears that ANGII augments not only TGF, but also the myogenic response. PMID:11773325

TH-EF-207A-04: A Dynamic Contrast Enhanced Cone Beam CT Technique for Evaluation of Renal Functions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Z; Shi, J; Yang, Y

Purpose: To develop a simple but robust method for the early detection and evaluation of renal functions using dynamic contrast enhanced cone beam CT technique. Methods: Experiments were performed on an integrated imaging and radiation research platform developed by our lab. Animals (n=3) were anesthetized with 20uL Ketamine/Xylazine cocktail, and then received 200uL injection of iodinated contrast agent Iopamidol via tail vein. Cone beam CT was acquired following contrast injection once per minute and up to 25 minutes. The cone beam CT was reconstructed with a dimension of 300×300×800 voxels of 130×130×130um voxel resolution. The middle kidney slices in themore » transvers and coronal planes were selected for image analysis. A double exponential function was used to fit the contrast enhanced signal intensity versus the time after contrast injection. Both pixel-based and region of interest (ROI)-based curve fitting were performed. Four parameters obtained from the curve fitting, namely the amplitude and flow constant for both contrast wash in and wash out phases, were investigated for further analysis. Results: Robust curve fitting was demonstrated for both pixel based (with R{sup 2}>0.8 for >85% pixels within the kidney contour) and ROI based (R{sup 2}>0.9 for all regions) analysis. Three different functional regions: renal pelvis, medulla and cortex, were clearly differentiated in the functional parameter map in the pixel based analysis. ROI based analysis showed the half-life T1/2 for contrast wash in and wash out phases were 0.98±0.15 and 17.04±7.16, 0.63±0.07 and 17.88±4.51, and 1.48±0.40 and 10.79±3.88 minutes for the renal pelvis, medulla and cortex, respectively. Conclusion: A robust method based on dynamic contrast enhanced cone beam CT and double exponential curve fitting has been developed to analyze the renal functions for different functional regions. Future study will be performed to investigate the sensitivity of this technique in the

Correlation between differential renal function estimation using CT-based functional renal parenchymal volume and (99m)Tc - DTPA renal scan.

PubMed

Sarma, Debanga; Barua, Sasanka K; Rajeev, T P; Baruah, Saumar J

2012-10-01

Nuclear renal scan is currently the gold standard imaging study to determine differential renal function. We propose helical CT as single modality for both the anatomical and functional evaluation of kidney with impaired function. In the present study renal parenchymal volume is measured and percent total renal volume is used as a surrogate marker for differential renal function. The objective of this study is to correlate between differential renal function estimation using CT-based renal parenchymal volume measurement with differential renal function estimation using (99m)TC - DTPA renal scan. Twenty-one patients with unilateral obstructive uropathy were enrolled in this prospective comparative study. They were subjected to (99m)Tc - DTPA renal scan and 64 slice helical CT scan which estimates the renal volume depending on the reconstruction of arterial phase images followed by volume rendering and percent renal volume was calculated. Percent renal volume was correlated with percent renal function, as determined by nuclear renal scan using Pearson coefficient. RESULTS AND OBSERVATION: A strong correlation is observed between percent renal volume and percent renal function in obstructed units (r = 0.828, P < 0.001) as well as in nonobstructed units (r = 0.827, P < 0.001). There is a strong correlation between percent renal volume determined by CT scan and percent renal function determined by (99m)TC - DTPA renal scan both in obstructed and in normal units. CT-based percent renal volume can be used as a single radiological tests for both functional and anatomical assessment of impaired renal units.

Persistent Increase in Blood Pressure After Renal Nerve Stimulation in Accessory Renal Arteries After Sympathetic Renal Denervation.

PubMed

de Jong, Mark R; Hoogerwaard, Annemiek F; Gal, Pim; Adiyaman, Ahmet; Smit, Jaap Jan J; Delnoy, Peter Paul H M; Ramdat Misier, Anand R; van Hasselt, Boudewijn A A M; Heeg, Jan-Evert; le Polain de Waroux, Jean-Benoit; Lau, Elizabeth O Y; Staessen, Jan A; Persu, Alexandre; Elvan, Arif

2016-06-01

Blood pressure response to renal denervation is highly variable, and the proportion of responders is disappointing. This may be partly because of accessory renal arteries too small for denervation, causing incomplete ablation. Renal nerve stimulation before and after renal denervation is a promising approach to assess completeness of renal denervation and may predict blood pressure response to renal denervation. The objective of the current study was to assess renal nerve stimulation-induced blood pressure increase before and after renal sympathetic denervation in main and accessory renal arteries of anaesthetized patients with drug-resistant hypertension. The study included 21 patients. Nine patients had at least 1 accessory renal artery in which renal denervation was not feasible. Renal nerve stimulation was performed in the main arteries of all patients and in accessory renal arteries of 6 of 9 patients with accessory arteries, both before and after renal sympathetic denervation. Renal nerve stimulation before renal denervation elicited a substantial increase in systolic blood pressure, both in main (25.6±2.9 mm Hg; P<0.001) and accessory (24.3±7.4 mm Hg; P=0.047) renal arteries. After renal denervation, renal nerve stimulation-induced systolic blood pressure increase was blunted in the main renal arteries (Δ systolic blood pressure, 8.6±3.7 mm Hg; P=0.020), but not in the nondenervated renal accessory renal arteries (Δ systolic blood pressure, 27.1±7.6 mm Hg; P=0.917). This residual source of renal sympathetic tone may result in persistent hypertension after ablation and partly account for the large response variability. © 2016 American Heart Association, Inc.

Influence of the renal endothelin system on the autoregulation of renal blood flow in spontaneously hypertensive rats.

PubMed

Braun, C; Lang, C; Hocher, B; Gretz, N; van der Woude, F J; Rohmeiss, P

1997-01-01

The renal endothelin (ET) system has been claimed to play an important role in the regulation of renal blood flow (RBF) and sodium excretion in primary hypertension. The aim of the present study was to investigate the contribution of the endogenous ET system in the autoregulation of total RBF, cortical blood flow (CBF), pressure-dependent plasma renin activity (PRA) and pressure natriuresis in spontaneously hypertensive rats (SHR) by means of the combined (A/B) ET-receptor antagonist, bosentan. In anesthetized rats, RBF was measured by transit-time flow probes and CBF by laser flow probes. During the experiments, the rats received an intrarenal infusion of either bosentan (1 mg/kg/h) or vehicle. Renal perfusion pressure (RPP) was lowered in pressure steps of 5 mm Hg with a servo-controlled electropneumatic device via an inflatable suprarenal cuff. Bosentan had no effect on resting RPP, CBF, PRA and renal sodium excretion, whereas RBF was lowered by 30% (p < 0.05). Furthermore after bosentan the rats revealed a complete loss of RBF autoregulation. In contrast no changes in autoregulation of CBF, pressure-dependent PRA and pressure natriuresis were observed. Our findings demonstrate a significant impairment in total RBF autoregulatory ability during renal ET-receptor blockade which is not confined to the cortical vessels. These data suggest that the renal ET system plays an important role in the dynamic regulation of renal blood flow in SHR.

Renal hemodynamic effects of activation of specific renal sympathetic nerve fiber groups.

PubMed

DiBona, G F; Sawin, L L

1999-02-01

To examine the effect of activation of a unique population of renal sympathetic nerve fibers on renal blood flow (RBF) dynamics, anesthetized rats were instrumented with a renal sympathetic nerve activity (RSNA) recording electrode and an electromagnetic flow probe on the ipsilateral renal artery. Peripheral thermal receptor stimulation (external heat) was used to activate a unique population of renal sympathetic nerve fibers and to increase total RSNA. Total RSNA was reflexly increased to the same degree with somatic receptor stimulation (tail compression). Arterial pressure and heart rate were increased by both stimuli. Total RSNA was increased to the same degree by both stimuli but external heat produced a greater renal vasoconstrictor response than tail compression. Whereas both stimuli increased spectral density power of RSNA at both cardiac and respiratory frequencies, modulation of RBF variability by fluctuations of RSNA was small at these frequencies, with values for the normalized transfer gain being approximately 0.1 at >0.5 Hz. During tail compression coherent oscillations of RSNA and RBF were found at 0.3-0.4 Hz with normalized transfer gain of 0.33 +/- 0.02. During external heat coherent oscillations of RSNA and RBF were found at both 0.2 and 0.3-0.4 Hz with normalized transfer gains of 0. 63 +/- 0.05 at 0.2 Hz and 0.53 +/- 0.04 to 0.36 +/- 0.02 at 0.3-0.4 Hz. Renal denervation eliminated the oscillations in RBF at both 0.2 and 0.3-0.4 Hz. These findings indicate that despite similar increases in total RSNA, external heat results in a greater renal vasoconstrictor response than tail compression due to the activation of a unique population of renal sympathetic nerve fibers with different frequency-response characteristics of the renal vasculature.

Renal sympathetic denervation increases renal blood volume per cardiac cycle: a serial magnetic resonance imaging study in resistant hypertension.

PubMed

Delacroix, Sinny; Chokka, Ramesh G; Nelson, Adam J; Wong, Dennis T; Sidharta, Samuel; Pederson, Stephen M; Rajwani, Adil; Nimmo, Joanne; Teo, Karen S; Worthley, Stephen G

2017-01-01

Preclinical studies have demonstrated improvements in renal blood flow after renal sympathetic denervation (RSDN); however, such effects are yet to be confirmed in patients with resistant hypertension. Herein, we assessed the effects of RSDN on renal artery blood flow and diameter at multiple time points post-RSDN. Patients (n=11) with systolic blood pressures ≥160 mmHg despite taking three or more antihypertensive medications at maximum tolerated dose were recruited into this single-center, prospective, non-blinded study. Magnetic resonance imaging indices included renal blood flow and renal artery diameters at baseline, 1 month and 6 months. In addition to significant decreases in blood pressures ( p <0.0001), total volume of blood flow per cardiac cycle increased by 20% from 6.9±2 mL at baseline to 8.4±2 mL ( p =0.003) at 1 month and to 8.0±2 mL ( p =0.04) 6 months post-procedure, with no changes in the renal blood flow. There was a significant decrease in renal artery diameters from 7±2 mm at baseline to 6±1 mm ( p =0.03) at 1 month post-procedure. This decrease was associated with increases in maximum velocity of blood flow from 73±20 cm/s at baseline to 78±19 cm/s at 1 month post-procedure. Notably, both parameters reverted to 7±2 mm and 72±18 cm/s, respectively, 6 months after procedure. RSDN improves renal physiology as evidenced by significant improvements in total volume of blood flow per cardiac cycle. Additionally, for the first time, we identified a transient decrease in renal artery diameters immediately after procedure potentially caused by edema and inflammation that reverted to baseline values 6 months post-procedure.

High temporal resolution dynamic contrast-enhanced MRI using compressed sensing-combined sequence in quantitative renal perfusion measurement.

PubMed

Chen, Bin; Zhao, Kai; Li, Bo; Cai, Wenchao; Wang, Xiaoying; Zhang, Jue; Fang, Jing

2015-10-01

To demonstrate the feasibility of the improved temporal resolution by using compressed sensing (CS) combined imaging sequence in dynamic contrast-enhanced MRI (DCE-MRI) of kidney, and investigate its quantitative effects on renal perfusion measurements. Ten rabbits were included in the accelerated scans with a CS-combined 3D pulse sequence. To evaluate the image quality, the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were compared between the proposed CS strategy and the conventional full sampling method. Moreover, renal perfusion was estimated by using the separable compartmental model in both CS simulation and realistic CS acquisitions. The CS method showed DCE-MRI images with improved temporal resolution and acceptable image contrast, while presenting significantly higher SNR than the fully sampled images (p<.01) at 2-, 3- and 4-X acceleration. In quantitative measurements, renal perfusion results were in good agreement with the fully sampled one (concordance correlation coefficient=0.95, 0.91, 0.88) at 2-, 3- and 4-X acceleration in CS simulation. Moreover, in realistic acquisitions, the estimated perfusion by the separable compartmental model exhibited no significant differences (p>.05) between each CS-accelerated acquisition and the full sampling method. The CS-combined 3D sequence could improve the temporal resolution for DCE-MRI in kidney while yielding diagnostically acceptable image quality, and it could provide effective measurements of renal perfusion. Copyright © 2015 Elsevier Inc. All rights reserved.

Relationship between renal function and renal volume in autosomal dominant polycystic kidney disease: cross-sectional study.

PubMed

Torres-Sánchez, M J; Ávila-Barranco, E; Esteban de la Rosa, R J; Fernández-Castillo, R; Esteban, M A; Carrero, J J; García-Valverde, M; Bravo-Soto, J A

2016-03-01

To determine in patients with autosomal dominant polycystic kidney disease the relationship between total renal volume (the sum of both kidneys, TRV) as measured by magnetic resonance and renal function; and its behaviour according to sex and the presence of arterial hypertension, hypercholesterolaemia and hyperglycemia. Cross-sectional study including patients with autosomal dominant polycystic kidney disease who underwent periodic reviews at Nephrology external consultations at Hospital de las Nieves de Granada, and who underwent an magnetic resonance to estimate renal volume between January 2008 and March 2011. We evaluated 67 patients (59.7% women, average age of 48±14.4 years) and found a significant positive association between TRV and serum creatinine or urea, which was reversed compared with estimated glomerular filtration by MDRD-4 and Cockcroft-Gault. Women showed an average serum creatinine level and a significantly lower TRV level compared with males. Subgroups affected by arterial hypertension and hyperuricemia presented average values for serum creatinine and urea, higher for TRV and lower for estimated glomerular filtration. The hypercholesterolaemia subgroup showed higher average values for urea and lower for estimated glomerular filtration, without detecting significant differences compared with TRV. The volume of polycystic kidneys measured by magnetic resonance is associated with renal function, and can be useful as a complementary study to monitor disease progression. The presence of arterial hypertension, hyperuricemia or hypercholesterolaemia is associated with a poorer renal function. Copyright © 2015 Elsevier España, S.L.U. y Sociedad Española de Medicina Interna (SEMI). All rights reserved.

Renal Interstitial Arteriosclerotic Lesions in Lupus Nephritis Patients: A Cohort Study from China

PubMed Central

Qin, Dan-dan; Wu, Li-hua; Song, Yan; Yu, Feng; Wang, Su-xia; Liu, Gang; Zhao, Ming-hui

2015-01-01

Objective The aim of this study was to evaluate renal arteriosclerotic lesions in patients with lupus nephritis and investigate their associations with clinical and pathological characteristics, especially cardio-vascular features. Design A retrospective cohort study. Participants Seventy-nine patients with renal biopsy-proven lupus nephritis, diagnosed between January 2000 and June 2008 from Peking University First Hospital. Results In clinico-pathological data, patients with arteriosclerosis had higher ratio of hypertension and more severe renal injury indices compared with patients with no renal vascular lesions. More importantly, patients with renal arteriosclerosis had worse cardiac structure and function under transthoracic echocardiographic examination. Patients with renal arteriosclerosis tend to have higher ratios of combined endpoints compared with those of no renal vascular lesions, although the difference didn’t reach statistical meanings (P = 0.104). Conclusion Renal arteriosclerotic lesion was common and associated with vascular immune complex deposits in lupus nephritis. It might have a certain degree of association with poor outcomes and cardiovascular events, which needs further explorations. PMID:26544865

Evaluation of renal function in patients with a main renal stone larger than 1 cm and perioperative renal functional change in minimally invasive renal stone surgery: a prospective, observational study.

PubMed

Piao, Songzhe; Park, Juhyun; Son, Hwancheol; Jeong, Hyeon; Cho, Sung Yong

2016-05-01

To compare the perioperative relative renal function and determine predictors of deterioration and recovery of separate renal function in patients with renal stones >10 mm and who underwent mini-percutaneous nephrolithotomy or retrograde intra-renal surgery. A main stone >10 mm or stones growing, high-risk stone formers and extracorporeal shock-wave lithotripsy-resistant stones were prospectively included in 148 patients. Patients with bilateral renal stones and anatomical deformities were excluded. Renal function was evaluated by estimated glomerular filtration rate, 99m-technetium dimercaptosuccinic acid and 99m-technetium diethylenetriamine pentaacetate prior to intervention and at postoperative 3 months. Logistic regression analyses were performed to find predictors of functional deterioration and recovery. The overall stone-free rate was 85.1 %. A third of patients (53/148, 35.8 %) with renal stones >10 mm showed deterioration of separate renal function. Mean renal function of operative sites showed 58.2 % (36.8 %/63.2 %) of that of contralateral sites in these patients. Abnormal separate renal function showed postoperative recovery in 31 patients (58.5 %). Three cases (5.7 %) showed deterioration of separate renal function despite no presence of remnant stones. Improvement rates of the abnormal separate renal function did not differ according to the type of surgery. The presence of hydronephrosis and three or more stones were significant predictors for renal function deterioration. Female gender and three or more stones were significantly correlated with postoperative recovery. Mini-percutaneous nephrolithotomy or retrograde intra-renal surgery was effective and safe for renal function preservation. Patients with multiple large stones should be considered for candidates of active surgical removal.

The Medical and Endovascular Treatment of Atherosclerotic Renal Artery Stenosis (METRAS) study: rationale and study design.

PubMed

Rossi, G P; Seccia, T M; Miotto, D; Zucchetta, P; Cecchin, D; Calò, L; Puato, M; Motta, R; Caielli, P; Vincenzi, M; Ramondo, G; Taddei, S; Ferri, C; Letizia, C; Borghi, C; Morganti, A; Pessina, A C

2012-08-01

It is unclear whether revascularization of renal artery stenosis (RAS) by means of percutaneous renal angioplasty and stenting (PTRAS) is advantageous over optimal medical therapy. Hence, we designed a randomized clinical trial based on an optimized patient selection strategy and hard experimental endpoints. Primary objective of this study is to determine whether PTRAS is superior or equivalent to optimal medical treatment for preserving glomerular filtration rate (GFR) in the ischemic kidney as assessed by 99mTcDTPA sequential renal scintiscan. Secondary objectives of this study are to establish whether the two treatments are equivalent in lowering blood pressure, preserving overall renal function and regressing target organ damage, preventing cardiovascular events and improving quality of life. The study is designed as a prospective multicentre randomized, un-blinded two-arm study. Eligible patients will have clinical and angio-CT evidence of RAS. Inclusion criteria is RAS affecting the main renal artery or its major branches either >70% or, if <70, with post-stenotic dilatation. Renal function will be assessed with 99mTc-DTPA renal scintigraphy. Patients will be randomized to either arms considering both resistance index value in the ischemic kidney and the presence of unilateral/bilateral stenosis. Primary experimental endpoint will be the GFR of the ischemic kidney, assessed as quantitative variable by 99TcDTPA, and the loss of ischemic kidney defined as a categorical variable.

Modified dixon‐based renal dynamic contrast‐enhanced MRI facilitates automated registration and perfusion analysis

PubMed Central

Leiner, Tim; Vink, Eva E.; Blankestijn, Peter J.; van den Berg, Cornelis A.T.

2017-01-01

Purpose Renal dynamic contrast‐enhanced (DCE) MRI provides information on renal perfusion and filtration. However, clinical implementation is hampered by challenges in postprocessing as a result of misalignment of the kidneys due to respiration. We propose to perform automated image registration using the fat‐only images derived from a modified Dixon reconstruction of a dual‐echo acquisition because these provide consistent contrast over the dynamic series. Methods DCE data of 10 hypertensive patients was used. Dual‐echo images were acquired at 1.5 T with temporal resolution of 3.9 s during contrast agent injection. Dixon fat, water, and in‐phase and opposed‐phase (OP) images were reconstructed. Postprocessing was automated. Registration was performed both to fat images and OP images for comparison. Perfusion and filtration values were extracted from a two‐compartment model fit. Results Automatic registration to fat images performed better than automatic registration to OP images with visible contrast enhancement. Median vertical misalignment of the kidneys was 14 mm prior to registration, compared to 3 mm and 5 mm with registration to fat images and OP images, respectively (P = 0.03). Mean perfusion values and MR‐based glomerular filtration rates (GFR) were 233 ± 64 mL/100 mL/min and 60 ± 36 mL/minute, respectively, based on fat‐registered images. MR‐based GFR correlated with creatinine‐based GFR (P = 0.04) for fat‐registered images. For unregistered and OP‐registered images, this correlation was not significant. Conclusion Absence of contrast changes on Dixon fat images improves registration in renal DCE MRI and enables automated postprocessing, resulting in a more accurate estimation of GFR. Magn Reson Med 80:66–76, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access

Bronchiectasis diagnosed after renal transplantation: a retrospective multicenter study.

PubMed

Dury, Sandra; Colosio, Charlotte; Etienne, Isabelle; Anglicheau, Dany; Merieau, Elodie; Caillard, Sophie; Rivalan, Joseph; Thervet, Eric; Essig, Marie; Babinet, François; Subra, Jean-François; Toubas, Olivier; Rieu, Philippe; Launois, Claire; Perotin-Collard, Jeanne-Marie; Lebargy, François; Deslée, Gaëtan

2015-11-07

Bronchiectasis is characterized by abnormal, permanent and irreversible dilatation of the bronchi, usually responsible for daily symptoms and frequent respiratory complications. Many causes have been identified, but only limited data are available concerning the association between bronchiectasis and renal transplantation. We conducted a retrospective multicenter study of cases of bronchiectasis diagnosed after renal transplantation in 14 renal transplantation departments (French SPIESSER group). Demographic, clinical, laboratory and CT scan data were collected. Forty-six patients were included (mean age 58.2 years, 52.2 % men). Autosomal dominant polycystic kidney disease (32.6 %) was the main underlying renal disease. Chronic cough and sputum (50.0 %) were the major symptoms leading to chest CT scan. Mean duration of symptoms before diagnosis was 1.5 years [0-12.1 years]. Microorganisms were identified in 22 patients, predominantly Haemophilus influenzae. Hypogammaglobulinemia was observed in 46.9 % patients. Bronchiectasis was usually extensive (84.8 %). The total bronchiectasis score was 7.4 ± 5.5 with a significant gradient from apex to bases. Many patients remained symptomatic (43.5 %) and/or presented recurrent respiratory tract infections (37.0 %) during follow-up. Six deaths (13 %) occurred during follow-up, but none were attributable to bronchiectasis. These results highlight that the diagnosis of bronchiectasis should be considered in patients with de novo respiratory symptoms after renal transplantation. Further studies are needed to more clearly understand the mechanisms underlying bronchiectasis in this setting.

Augmented renal clearance in the ICU: results of a multicenter observational study of renal function in critically ill patients with normal plasma creatinine concentrations*.

PubMed

Udy, Andrew A; Baptista, João P; Lim, Noelle L; Joynt, Gavin M; Jarrett, Paul; Wockner, Leesa; Boots, Robert J; Lipman, Jeffrey

2014-03-01

To describe the prevalence and natural history of augmented renal clearance in a cohort of recently admitted critically ill patients with normal plasma creatinine concentrations. Multicenter, prospective, observational study. Four, tertiary-level, university-affiliated, ICUs in Australia, Singapore, Hong Kong, and Portugal. Study participants had to have an expected ICU length of stay more than 24 hours, no evidence of absolute renal impairment (admission plasma creatinine < 120 µmol/L), and no history of prior renal replacement therapy or chronic kidney disease. Convenience sampling was used at each participating site. Eight-hour urinary creatinine clearances were collected daily, as the primary method of measuring renal function. Augmented renal clearance was defined by a creatinine clearance more than or equal to 130 mL/min/1.73 m. Additional demographic, physiological, therapeutic, and outcome data were recorded prospectively. Nine hundred thirty-two patients were admitted to the participating ICUs over the study period, and 281 of which were recruited into the study, contributing 1,660 individual creatinine clearance measures. The mean age (95% CI) was 54.4 years (52.5-56.4 yr), Acute Physiology and Chronic Health Evaluation II score was 16 (15.2-16.7), and ICU mortality was 8.5%. Overall, 65.1% manifested augmented renal clearance on at least one occasion during the first seven study days; the majority (74%) of whom did so on more than or equal to 50% of their creatinine clearance measures. Using a mixed-effects model, the presence of augmented renal clearance on study day 1 strongly predicted (p = 0.019) sustained elevation of creatinine clearance in these patients over the first week in ICU. Augmented renal clearance appears to be a common finding in this patient group, with sustained elevation of creatinine clearance throughout the first week in ICU. Future studies should focus on the implications for accurate dosing of renally eliminated pharmaceuticals

Patient-specific evolution of renal function in chronic heart failure patients dynamically predicts clinical outcome in the Bio-SHiFT study.

PubMed

Brankovic, Milos; Akkerhuis, K Martijn; van Boven, Nick; Anroedh, Sharda; Constantinescu, Alina; Caliskan, Kadir; Manintveld, Olivier; Cornel, Jan Hein; Baart, Sara; Rizopoulos, Dimitris; Hillege, Hans; Boersma, Eric; Umans, Victor; Kardys, Isabella

2018-04-01

Renal dysfunction is an important component of chronic heart failure (CHF), but its single assessment does not sufficiently reflect clinically silent progression of CHF prior to adverse clinical outcome. Therefore, we aimed to investigate temporal evolutions of glomerular and tubular markers in 263 stable patients with CHF, and to determine if their patient-specific evolutions during this clinically silent period can dynamically predict clinical outcome. We determined the risk of clinical outcome (composite endpoint of Heart Failure hospitalization, cardiac death, Left Ventricular Assist Device placement, and heart transplantation) in relation to marker levels, slopes and areas under their trajectories. In each patient, the trajectories were estimated using repeatedly measured glomerular markers: creatinine/estimated glomerular filtration rate (eGFR), cystatin C (CysC), and tubular markers: urinary N-acetyl-beta-D-glucosaminidase (NAG) and kidney injury molecule (KIM)-1, plasma and urinary neutrophil gelatinase-associated lipocalin (NGAL). During 2.2 years of follow-up, we collected on average 8 urine and 9 plasma samples per patient. All glomerular markers predicted the endpoint (univariable hazard ratio [95% confidence interval] per 20% increase: creatinine: 1.18[1.07-1.31], CysC: 2.41[1.81-3.41], and per 20% eGFR decrease: 1.13[1.05-1.23]). Tubular markers, NAG, and KIM-1 also predicted the endpoint (NAG: 1.06[1.01-1.11] and KIM-1: 1.08[1.04-1.11]). Larger slopes were the strongest predictors (creatinine: 1.57[1.39-1.84], CysC: 1.76[1.52-2.09], eGFR: 1.59[1.37-1.90], NAG: 1.26[1.11-1.44], and KIM-1: 1.64[1.38-2.05]). Associations persisted after multivariable adjustment for clinical characteristics. Thus, during clinically silent progression of CHF, glomerular and tubular functions deteriorate, but not simultaneously. Hence, patient-specific evolutions of these renal markers dynamically predict clinical outcome in patients with CHF. Copyright © 2017

Comparative study on the National Renal Disease Registry in America, England and Iran.

PubMed

Ajami, Sima; Askarianzadeh, Mahdi; Saghaeiannejad-Isfahani, Sakineh; Mortazavi, Mojgan; Ehteshami, Asghar

2014-01-01

A disease registry is a database that includes information about people diagnosed with specific types of diseases. The registry collects information that can be used for capturing, managing, and organizing specific information for patients. The aim of this study was to identify and compare the National Renal Disease Registry (NRDR) in selected countries including the United States, United Kingdom, and Iran. Retrieval of data of the NRDR performed through scholars responsible in related agencies, including the Ministry of Health and Medical Education, and Renal Disease charity, and data registries in the United States, United Kingdom, and Iran. This research was an applied and descriptive, comparative study. The study population consisted of the National Renal Disease Registry of the selected countries including the United States, United Kingdom, and Iran, from which data were collected using forms that were designed according to the study objectives. Sources of data were researchers, scholars responsible in related agencies, including the Ministry of Health and Medical Education, and Renal Disease charity, data registries, articles, books, journals, databases, websites, and related documents. Data were gathered through phone, e-mail, study, observation, and interview. The researchers collected data for each country based on the study objectives and then put them in comparative tables. Data were analyzed by descriptive, comparative, and theoretical methods. There is no NRDR in Iran to report the short- and long-term results of renal disease. Most of the renal transplant teams report their own results as single-center experiences. America and Britain have pre-eminent national registry of renal disease, compared to other countries. The Iranian Society of Nephrology should be actively involved to create a National Renal Registry in Iran. The registry should have representatives from the universities, government, armed forces, and private sectors. Researchers proposed

The effect of anatomic differences on the relationship between renal artery and diaphragmatic crus.

PubMed

Esen, K; Tok, S; Balci, Yuksel; Apaydin, F D; Kara, E; Uzmansel, D

2018-01-01

The aim of this study is to investigate the effect of anatomic differences on the relationship between renal artery and diaphragmatic crus via the touch of two structures. The study included dynamic computed tomography (CT) scans of 308 patients performed mainly for characterisation of liver and renal masses. Anatomic differences including the thickness of the diaphragmatic crus, the localisation of renal artery ostium at the wall of aorta, the level of renal artery origin with respect to superior mesenteric artery were evaluated. Statistical relationships between renal artery-diaphragmatic crus contact and the anatomic differences were assessed. Thickness of the diaphragmatic crus at the level of renal artery origin exhibited a statistically significant relationship to renal artery-diaphragmatic crus contact at the left (p < 0.001) and right side (p < 0.001). There was a statistically significant relationship between high renal artery origin and renal artery- -diaphragmatic crus contact at the left (p < 0.001) and right side (p = 0.01). The localisation of renal artery ostium at the wall of aorta (right side, p = 0.436, left side, p = 0.681) did not demonstrate a relationship to renal artery-diaphragmatic crus contact. Thickness of the diaphragmatic crus and high renal artery origin with respect to superior mesenteric artery are crucial anatomic differences determining the relationship of renal artery and diaphragmatic crus. (Folia Morphol 2018; 77, 1: 22-28).

Renal Heme Oxygenase-1 Induction with Hemin Augments Renal Hemodynamics, Renal Autoregulation, and Excretory Function

PubMed Central

Botros, Fady T.; Dobrowolski, Leszek; Navar, L. Gabriel

2012-01-01

Heme oxygenases (HO-1; HO-2) catalyze conversion of heme to free iron, carbon monoxide, and biliverdin/bilirubin. To determine the effects of renal HO-1 induction on blood pressure and renal function, normal control rats (n = 7) and hemin-treated rats (n = 6) were studied. Renal clearance studies were performed on anesthetized rats to assess renal function; renal blood flow (RBF) was measured using a transonic flow probe placed around the left renal artery. Hemin treatment significantly induced renal HO-1. Mean arterial pressure and heart rate were not different (115 ± 5 mmHg versus 112 ± 4 mmHg and 331 ± 16 versus 346 ± 10 bpm). However, RBF was significantly higher (9.1 ± 0.8 versus 7.0 ± 0.5 mL/min/g, P < 0.05), and renal vascular resistance was significantly lower (13.0 ± 0.9 versus 16.6 ± 1.4 [mmHg/(mL/min/g)], P < 0.05). Likewise, glomerular filtration rate was significantly elevated (1.4 ± 0.2 versus 1.0 ± 0.1 mL/min/g, P < 0.05), and urine flow and sodium excretion were also higher (18.9 ± 3.9 versus 8.2 ± 1.0 μL/min/g, P < 0.05 and 1.9 ± 0.6 versus 0.2 ± 0.1 μmol/min/g, P < 0.05, resp.). The plateau of the autoregulation relationship was elevated, and renal vascular responses to acute angiotensin II infusion were attenuated in hemin-treated rats reflecting the vasodilatory effect of HO-1 induction. We conclude that renal HO-1 induction augments renal function which may contribute to the antihypertensive effects of HO-1 induction observed in hypertension models. PMID:22518281

The impact of daily temperature on renal disease incidence: an ecological study.

PubMed

Borg, Matthew; Bi, Peng; Nitschke, Monika; Williams, Susan; McDonald, Stephen

2017-10-27

Extremely high temperatures over many consecutive days have been linked to an increase in renal disease in several cities. This is becoming increasingly relevant with heatwaves becoming longer, more intense, and more frequent with climate change. This study aimed to extend the known relationship between daily temperature and kidney disease to include the incidence of eight temperature-prone specific renal disease categories - total renal disease, urolithiasis, renal failure, acute kidney injury (AKI), chronic kidney disease (CKD), urinary tract infections (UTIs), lower urinary tract infections (LUTIs) and pyelonephritis. Daily data was acquired for maximum, minimum and average temperature over the period of 1 July 2003 to 31 March 2014 during the warm season (October to March) in Adelaide, South Australia. Data for daily admissions to all metropolitan hospitals for renal disease, including 83,519 emergency department admissions and 42,957 inpatient admissions, was also obtained. Renal outcomes were analyzed using time-stratified negative binomial regression models, with the results aggregated by day. Incidence rate ratios (IRR) and 95% confidence intervals (CI) were estimated for associations between the number of admissions and daily temperature. Increases in daily temperature per 1 °C were associated with an increased incidence for all renal disease categories except for pyelonephritis. Minimum temperature was associated with the greatest increase in renal disease followed by average temperature and then maximum temperature. A 1°C increase in daily minimum temperature was associated with an increase in daily emergency department admissions for AKI (IRR 1.037, 95% CI: 1.026-1.048), renal failure (IRR 1.030, 95% CI: 1.022-1.039), CKD (IRR 1.017, 95% CI: 1.001-1.033) urolithiasis (IRR 1.015, 95% CI: 1.010-1.020), total renal disease (IRR 1.009, 95% CI: 1.006-1.011), UTIs (IRR 1.004, 95% CI: 1.000-1.007) and LUTIs (IRR 1.003, 95% CI: 1.000-1.006). An increased

Absolute quantification of regional renal blood flow in swine by dynamic contrast-enhanced magnetic resonance imaging using a blood pool contrast agent.

PubMed

Lüdemann, Lutz; Nafz, Benno; Elsner, Franz; Grosse-Siestrup, Christian; Meissler, Michael; Kaufels, Nicola; Rehbein, Hagen; Persson, Pontus B; Michaely, Henrik J; Lengsfeld, Philipp; Voth, Matthias; Gutberlet, Matthias

2009-03-01

To evaluate for the first time in an animal model the possibility of absolute regional quantification of renal medullary and cortical perfusion by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using a blood pool contrast agent. A total of 18 adult female pigs (age, 16-22 weeks; body weight, 45-65 kg; no dietary restrictions) were investigated by DCE-MRI. Absolute renal blood flow (RBF) measured by an ultrasound transit time flow probe around the renal vein was used as the standard of reference. An inflatable stainless cuff placed around the renal artery near its origin from the abdominal aorta was used to reduce RBF to 60%, 40%, and 20% of the baseline flow. The last measurement was performed with the cuff fully reopened. Absolute RBF values during these 4 perfusion states were compared with the results of DCE-MRI performed on a 1.5-T scanner with an 8-channel phased-array surface coil. All scans were acquired in breath-hold technique in the coronal plane using a field of view of 460 mm.Each dynamic scan commenced with a set of five 3D T1-weighted gradient echo sequences with different flip angles (alpha = 2 degrees, 5 degrees, 10 degrees, 20 degrees, 30 degrees): TE, 0.88 milliseconds; TR, 2.65 milliseconds; slice thickness, 8.8 mm for 4 slices; acquisition matrix, 128 x 128; and acquisitions, 4. These data served to calculate 3D intrinsic longitudinal relaxation rate maps (R10) and magnetization (M0). Immediately after these images, the dynamic 3D T1-weighted gradient echo images were acquired with the same parameters and a constant alpha = 30 degrees, half Fourier, 1 acquisition, 64 frames, a time interval of 1.65 seconds between each frame, and a total duration of 105.6. Three milliliters of an albumin-binding blood pool contrast agent (0.25 mmol/mL gadofosveset trisodium, Vasovist, Bayer Schering Pharma AG, Berlin, Germany) was injected at a rate of 3 mL/s. Perfusion was calculated using the arterial input function from the aorta, which was

Cost analysis of substitutive renal therapies in children.

PubMed

Camargo, Maria Fernanda Carvalho de; Barbosa, Klenio de Souza; Fetter, Seiji Kumon; Bastos, Ana; Feltran, Luciana de Santis; Koch-Nogueira, Paulo Cesar

End-stage renal disease is a health problem that consumes public and private resources. This study aimed to identify the cost of hemodialysis (either daily or conventional hemodialysis) and transplantation in children and adolescents. This was a retrospective cohort of pediatric patients with End-stage renal disease who underwent hemodialysis followed by kidney transplant. All costs incurred in the treatment were collected and the monthly total cost was calculated per patient and for each renal therapy. Subsequently, a dynamic panel data model was estimated. The study included 30 children who underwent hemodialysis (16 conventional/14 daily hemodialysis) followed by renal transplantation. The mean monthly outlay for hemodialysis was USD 3500 and USD 1900 for transplant. Hemodialysis costs added up to over USD 87,000 in 40 months for conventional dialysis patients and USD 131,000 in 50 months for daily dialysis patients. In turn, transplant costs in 50 months reached USD 48,000 and USD 70,000, for conventional and daily dialysis patients, respectively. For conventional dialysis patients, transplant is less costly when therapy exceeds 16 months, whereas for daily dialysis patients, the threshold is around 13 months. Transplantation is less expensive than dialysis in children, and the estimated thresholds indicate that renal transplant should be the preferred treatment for pediatric patients. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Renal angioplasty and stenting: is it still indicated after ASTRAL and STAR studies?

PubMed

Henry, M; Benjelloun, A; Henry, I; Polydorou, A; Hugel, M

2010-10-01

A renal artery stenosis (RAS) is common among patients with atherosclerosis, up to a third of patients undergoing cardiac catheterization. Fibromuscular dysplasia is the next cause of RAS, commonly found in young women. Atherosclerosis RAS generally progresses overtime and is often associated with loss of renal mass and worsening renal function (RF). Percutaneous renal artery stent placement is the preferred method of revascularization for hemodynamically significant RAS according to ACC and AHA guidelines. Several randomized trials have shown the superiority of endovascular procedures to medical therapy alone. However, two studies ASTRAL and STAR studies were recently published and did not find any difference between renal stenting and medical therapy. But these studies have a lot of limitations and flaws as we will discuss (poor indications, poor results, numerous complications, failures, poor technique, inexperienced operators, ecc.). Despite these questionable studies, renal stenting keeps indications in patients with: uncontrolled hypertension; ischemic nephropathy; cardiac disturbance syndrome (e.g. "flash" pulmonary edema, uncontrolled heart failure or uncontrolled angina pectoris); solitary kidney. To improve the clinical response rates, a better selection of the patients and lesions is mandatory with: good non-invasive or invasive imaging; physiologic lesion assessment using transluminal pressure gradients; measurements of biomarkers (e.g., BNP); fractional flow reserve study. A problem remains after renal angioplasty stenting, the deterioration of the RF in 20-30% of the patients. Atheroembolism seems to play an important role and is probably the main cause of this R.F deterioration. The use of protection devices alone or in combination with IIb IIa inhibitors has been proposed and seems promising as shown in different recent reports. Renal angioplasty and stenting is still indicated but we need: a better patient and lesion selection; improvements in

The correlation between effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) with renal scintigraphy 99mTc-DTPA study

NASA Astrophysics Data System (ADS)

Ratnasari, D.; Nazir, F.; Toresano, L. O. H. Z.; Pawiro, S. A.; Soejoko, D. S.

2016-03-01

The prevalence of chronic renal diseases in Indonesia has an increasing annual trend, because it is frequently unrecognized and often co-exists with other disease. GFR and ERPF are parameters currently utilized to estimate renal function at routine renal scintigraphy 99m-Tc DTPA study. This study used 99m-Tc DTPA to measure GFR and ERPF. The purpose of this study was to find the correlation between ERPF and GFR, for ERPF analysis with Schlegel's method, and GFR analysis with Gate's method, as well as to find correction factor between both variables. Analysis of renal scintigraphy has been performed at Department of Nuclear Medicine Pertamina Center Hospital to thirty patient images acquired from 2014 to 2015 which were analyzed retrospectively data, using gamma camera dual head with counting method from renal scintigraphy 99m-Tc DTPA study. The calculation was executed by means of both display and manual calculation. Pearson's statistical analysis resulted on Positive Correlation for all data, with ERPF and GFR (display) showing Strongly Positive Correlation (r = 0.82; p- value < 0.05). Standard deviation was found to be 27.58 and 107.64 for GFR and ERPF (display), respectively. Our result indicated that the use of 99mTc-DTPA measure ERPF was not recommended.

A PET Tracer for Renal Organic Cation Transporters, ¹¹C-Metformin: Radiosynthesis and Preclinical Proof-of-Concept Studies.

PubMed

Jakobsen, Steen; Busk, Morten; Jensen, Jonas Brorson; Munk, Ole Lajord; Zois, Nora Elisabeth; Alstrup, Aage K O; Jessen, Niels; Frøkiær, Jørgen

2016-04-01

Organic cation transporters (OCTs) in the kidney proximal tubule (PT) participate in renal excretion of drugs and endogenous compounds. PT function is commonly impaired in kidney diseases, and consequently quantitative measurement of OCT function may provide an important estimate of kidney function. Metformin is a widely used drug and targets OCT type 2 located in the PT. Thus, we hypothesized that (11)C-labeled metformin would be a suitable PET tracer for quantification of renal function. (11)C-metformin was prepared by (11)C-methylation of 1-methylbiguanide. In vitro cell uptake of (11)C-metformin was studied in LLC-PK1 cells in the presence of increasing doses of unlabeled metformin. In vivo small-animal PET studies in Sprague-Dawley rats were performed at baseline and after treatment with OCT inhibitors to evaluate renal uptake of (11)C-metformin. Kidney and liver pharmacokinetics of (11)C-metformin was investigated in vivo by dynamic (11)C-metformin PET/CT in 6 anesthetized pigs, and renal clearance of (11)C-metformin was compared with renal clearance of (51)Cr-ethylenediaminetetraacetic acid (EDTA). Formation of (11)C metabolites was investigated by analysis of blood and urine samples. The radiochemical yield of (11)C-metformin was 15% ± 3% (n= 40, decay-corrected), and up to 1.5 GBq of tracer were produced with a radiochemical purity greater than 95% in less than 30 min. Dose-dependent uptake of (11)C-metformin in LLC-PK1 cells was rapid. Rat small-animal PET images showed (11)C-metformin uptake in the kidney and liver, the kinetics of which were changed after challenging animals with OCT inhibitors. In pigs, 80% of the injected metformin dose was rapidly present in the kidney, and a high dose of metformin caused a delayed renal uptake and clearance compared with baseline consistent with transporter-mediated competition. Renal clearance of (11)C-metformin was approximately 3 times the renal clearance of (51)Cr-EDTA. We successfully synthesized an (11)C

Lymphatic Drainage from Renal Tumors In Vivo: A Prospective Sentinel Node Study Using SPECT/CT Imaging.

PubMed

Kuusk, Teele; De Bruijn, Roderick; Brouwer, Oscar R; De Jong, Jeroen; Donswijk, Maarten; Grivas, Nikolaos; Hendricksen, Kees; Horenblas, Simon; Prevoo, Warner; Valdés Olmos, Renato A; Van Der Poel, Henk G; Van Rhijn, Bas W G; Wit, Esther M; Bex, Axel

2018-06-01

Lymphatic drainage from renal tumors is unpredictable. In vivo drainage studies of primary lymphatic landing sites may reveal the variability and dynamics of lymphatic connections. The purpose of this study was to investigate the lymphatic drainage pattern of renal tumors in vivo with single photon emission/computerized tomography after intratumor radiotracer injection. We performed a phase II, prospective, single arm study to investigate the distribution of sentinel nodes from renal tumors on single photon emission/computerized tomography. Patients with cT1-3 (less than 10 cm) cN0M0 renal tumors of any subtype were enrolled in analysis. After intratumor ultrasound guided injection of 0.4 ml 99m Tc-nanocolloid we performed preoperative imaging of sentinel nodes with lymphoscintigraphy and single photon emission/computerized tomography. Sentinel and locoregional nonsentinel nodes were resected with a γ probe combined with a mobile γ camera. The primary study end point was the location of sentinel nodes outside the locoregional retroperitoneal templates on single photon emission/computerized tomography. Using a Simon minimax 2-stage design to detect a 25% extralocoregional retroperitoneal template location of sentinel nodes on imaging at α = 0.05 and 80% power at least 40 patients with sentinel node imaging on single photon emission/computerized tomography were needed. Of the 68 patients 40 underwent preoperative single photon emission/computerized tomography of sentinel nodes and were included in primary end point analysis. Lymphatic drainage outside the locoregional retroperitoneal templates was observed in 14 patients (35%). Eight patients (20%) had supradiaphragmatic sentinel nodes. Sentinel nodes from renal tumors were mainly located in the respective locoregional retroperitoneal templates. Simultaneous sentinel nodes were located outside the suggested lymph node dissection templates, including supradiaphragmatic sentinel nodes in more than a third of the

Spiral blood flow in aorta-renal bifurcation models.

PubMed

Javadzadegan, Ashkan; Simmons, Anne; Barber, Tracie

2016-01-01

The presence of a spiral arterial blood flow pattern in humans has been widely accepted. It is believed that this spiral component of the blood flow alters arterial haemodynamics in both positive and negative ways. The purpose of this study was to determine the effect of spiral flow on haemodynamic changes in aorta-renal bifurcations. In this regard, a computational fluid dynamics analysis of pulsatile blood flow was performed in two idealised models of aorta-renal bifurcations with and without flow diverter. The results show that the spirality effect causes a substantial variation in blood velocity distribution, while causing only slight changes in fluid shear stress patterns. The dominant observed effect of spiral flow is on turbulent kinetic energy and flow recirculation zones. As spiral flow intensity increases, the rate of turbulent kinetic energy production decreases, reducing the region of potential damage to red blood cells and endothelial cells. Furthermore, the recirculation zones which form on the cranial sides of the aorta and renal artery shrink in size in the presence of spirality effect; this may lower the rate of atherosclerosis development and progression in the aorta-renal bifurcation. These results indicate that the spiral nature of blood flow has atheroprotective effects in renal arteries and should be taken into consideration in analyses of the aorta and renal arteries.

Dynamic Geometric Analysis of the Renal Arteries and Aorta following Complex Endovascular Aneurysm Repair.

PubMed

Ullery, Brant W; Suh, Ga-Young; Kim, John J; Lee, Jason T; Dalman, Ronald L; Cheng, Christopher P

2017-08-01

Aneurysm regression and target vessel patency during early and mid-term follow-up may be related to the effect of stent-graft configuration on the anatomy. We quantified geometry and remodeling of the renal arteries and aneurysm following fenestrated (F-) or snorkel/chimney (Sn-) endovascular aneurysm repair (EVAR). Twenty-nine patients (mean age, 76.8 ± 7.8 years) treated with F- or Sn-EVAR underwent computed tomography angiography at preop, postop, and follow-up. Three-dimensional geometric models of the aorta and renal arteries were constructed. Renal branch angle was defined relative to the plane orthogonal to the aorta. End-stent angle was defined as the angulation between the stent and native distal artery. Aortic volumes were computed for the whole aorta, lumen, and their difference (excluded lumen). Renal patency, reintervention, early mortality, postoperative renal impairment, and endoleak were reviewed. From preop to postop, F-renal branches angled upward, Sn-renal branches angled downward (P < 0.05), and Sn-renals exhibited increased end-stent angulation (12 ± 15°, P < 0.05). From postop to follow-up, branch angles did not change for either F- or Sn-renals, whereas F-renals exhibited increased end-stent angulation (5 ± 10°, P < 0.05). From preop to postop, whole aortic and excluded lumen volumes increased by 5 ± 14% and 74 ± 81%, whereas lumen volume decreased (39 ± 27%, P < 0.05). From postop to follow-up, whole aortic and excluded lumen volumes decreased similarly (P < 0.05), leaving the lumen volume unchanged. At median follow-up of 764 days (range, 7-1,653), primary renal stent patency was 94.1% and renal impairment occurred in 2 patients (6.7%). Although F- and Sn-EVAR resulted in significant, and opposite, changes to renal branch angle, only Sn-EVAR resulted in significant end-stent angulation increase. Longitudinal geometric analysis suggests that these anatomic alterations are primarily generated early as a

RenalGuard system to prevent contrast-induced acute kidney injury in Japanese patients with renal dysfunction; RESPECT KIDNEY study.

PubMed

Katoh, Hiromasa; Nozue, Tsuyoshi; Horie, Kazuki; Sozu, Takashi; Inoue, Naoto; Michishita, Ichiro

2018-05-05

Increasing the urine flow rate (UFR) reduces the toxic effect of contrast media. Use of the RenalGuard system enables the achievement of a high UFR by maintaining intravascular volume and prevents the development of contrast-induced acute kidney injury (CI-AKI). However, the efficacy and safety of RenalGuard system have not yet been evaluated in Japan. This multicenter prospective study evaluated the efficacy and safety of the RenalGuard therapy in preventing CI-AKI development in 60 Japanese patients with renal dysfunction [estimated glomerular filtration rate (eGFR) < 45 mL/min/1.73 m 2 ] undergoing catheter procedures. Baseline eGFR and Mehran's CIN (contrast-induced nephropathy) risk score were 35.1 ± 8.5 mL/min/1.73 m 2 and 11.7 ± 4.3, respectively. Regardless of this high-risk profile, the incidence of CI-AKI was 8.6% (5/58) compared with the 26.1% incidence estimated by the CIN risk score. Moreover, two-sided 95% (Fisher's) exact confidence interval was 2.9-19.0 and its upper limit (i.e., 19.0) was less than the prespecified threshold incidence of 25.0. Univariate logistic regression analysis demonstrated that the UFR during catheter procedure was one of the most important factor associated with CI-AKI (odds ratio 0.99, confidence interval 0.98-1.00, p = 0.03). In conclusion, RenalGuard therapy may prevent CI-AKI development in Japanese patients with renal dysfunction. Further large-scale prospective multicenter studies are necessary to confirm our findings.

Prognostic value of renal fractional flow reserve in blood pressure response after renal artery stenting (PREFER study).

PubMed

Kądziela, Jacek; Januszewicz, Andrzej; Prejbisz, Aleksander; Michałowska, Ilona; Januszewicz, Magdalena; Florczak, Elżbieta; Kalińczuk, Łukasz; Norwa-Otto, Bożena; Warchoł, Ewa; Witkowski, Adam

2013-01-01

The aim of our study was to determine a potential relationship between resting translesional pressures ratio (Pd/Pa ratio), renal fractional flow reserve (rFFR) and blood pressure response after renal artery stenting. Thirty five hypertensive patients (49% males, mean age 64 years) with at least 60% stenosis in angiography, underwent renal artery stenting. Translesional systolic pressure gradient (TSPG), Pd/Pa ratio (the ratio of mean distal to lesion and mean proximal pressures) and hyperemic rFFR - after intrarenal administration of papaverine - were measured before stent implantation. Ambulatory blood pressure measurements (ABPM) were recorded before the procedure and after 6 months. The ABPM results were presented as blood pressure changes in subgroups of patients with normal (≥ 0.9) vs. abnormal (< 0.9) Pd/Pa ratio and normal (≥ 0.8) vs. abnormal (< 0.8) rFFR. Median Pd/Pa ratio was 0.84 (interquartile range 0.79-0.91) and strongly correlated with TSPG (r = -0.89, p < 0.001), minimal lumen diameter (MLD; r = 0.53, p < 0.005) and diameter stenosis (DS; r = -0.51, p < 0.005). Median rFFR was 0.78 (0.72-0.82). Similarly, significant correlation between rFFR and TSPG (r = -0.86, p < 0.0001), as well as with MLD (r = 0.50, p < 0.005) and DS (r = -0.51, p < 0.005) was observed. Procedural success was obtained in all patients. Baseline Pd/Pa ratio and rFFR did not predict hypertension response after renal artery stenting. Median changes of 24-h systolic/diastolic blood pressure were comparable in patients with abnormal vs. normal Pd/Pa ratio (-4/-3 vs. 0/2 mm Hg; p = NS) and with abnormal vs. normal rFFR (-2/-1 vs. -2/-0.5 mm Hg, respectively). Physiological assessment of renal artery stenosis using Pd/Pa ratio and papaverine- induced renal fractional fl ow reserve did not predict hypertension response after renal artery stenting.

Quantitative analysis of the renal aging in rats. Stereological study.

PubMed

Melchioretto, Eduardo Felippe; Zeni, Marcelo; Veronez, Djanira Aparecida da Luz; Martins, Eduardo Lopes; Fraga, Rogério de

2016-05-01

To evaluate the renal function and the renal histological alterations through the stereology and morphometrics in rats submitted to the natural process of aging. Seventy two Wistar rats, divided in six groups. Each group was sacrificed in a different age: 3, 6, 9, 12, 18 and 24 months. It was performed right nephrectomy, stereological and morphometric analysis of the renal tissue (renal volume and weight, density of volume (Vv[glom]) and numerical density (Nv[glom]) of the renal glomeruli and average glomerular volume (Vol[glom])) and also it was evaluated the renal function for the dosage of serum creatinine and urea. There was significant decrease of the renal function in the oldest rats. The renal volume presented gradual increase during the development of the rats with the biggest values registered in the group of animals at 12 months of age and significant progressive decrease in older animals. Vv[glom] presented statistically significant gradual reduction between the groups and the Nv[glom] also decreased significantly. The renal function proved to be inferior in senile rats when compared to the young rats. The morphometric and stereological analysis evidenced renal atrophy, gradual reduction of the volume density and numerical density of the renal glomeruli associated to the aging process.

Worsening renal function defined as an absolute increase in serum creatinine is a biased metric for the study of cardio-renal interactions.

PubMed

Testani, Jeffrey M; McCauley, Brian D; Chen, Jennifer; Shumski, Michael; Shannon, Richard P

2010-01-01

Worsening renal function (WRF) during the treatment of decompensated heart failure, frequently defined as an absolute increase in serum creatinine >or=0.3 mg/dl, has been reported as a strong adverse prognostic factor in several studies. We hypothesized that this definition of WRF is biased by baseline renal function secondary to the exponential relationship between creatinine and renal function. We reviewed consecutive admissions with a discharge diagnosis of heart failure. An increase in creatinine >or=0.3 mg/dl (WRF(CREAT)) was compared to a decrease in GFR >or=20% (WRF(GFR)). Overall, 993 admissions met eligibility. WRF(CREAT) occurred in 31.5% and WRF(GFR) in 32.7%. WRF(CREAT) and WRF(GFR) had opposing relationships with baseline renal function (OR = 1.9 vs. OR = 0.51, respectively, p < 0.001). Both definitions had similar unadjusted associations with death at 30 days [WRF(GFR) OR = 2.3 (95% CI 1.1-4.8), p = 0.026; WRF(CREAT) OR = 2.1 (95% CI 1.0-4.4), p = 0.047]. Controlling for baseline renal insufficiency, WRF(GFR) added incrementally in the prediction of mortality (p = 0.009); however, WRF(CREAT) did not (p = 0.11). WRF, defined as an absolute change in serum creatinine, is heavily biased by baseline renal function. An alternative definition of WRF should be considered for future studies of cardio-renal interactions. Copyright 2010 S. Karger AG, Basel.

Analysis of the dynamics of renal vascular resistance and urine flow rate in the cat following electrical stimulation of the renal nerves.

PubMed

Celler, B G; Stella, A; Golin, R; Zanchetti, A

1996-08-01

In ten sino aortic denervated, vagotomized and aneasthetized cats, renal efferent nerves were stimulated for 30 s with trains of constant current pulses at frequencies in the range 5-30 Hz. The arterial pressure, heart rate, urine flow rate (electronic drop counter) and renal blood flow (electromagnetic technique) were recorded. Subsequent computer processing gave the true means of renal artery pressure (MRAP) and renal blood flow (MRBF) and hence the renal vascular resistance (MRVR), over each cardiac cycle. Recovery of MRVR after the end of stimulation exhibited two distinct time constants. The fast component had a time constant of 2.03 +/- 0.26 s and represented 60.2 +/- 1.71% of the recovery. The time constant of the slower component was 14.1 +/- 1.9 s and represented 36.0 +/- 1.6% of the recovery. The relationship between MRVR and stimulus frequency was sigmoidal with maximum sensitivity at stimulus frequencies of 12.6 +/- 0.76 Hz. Changes in urine flow rate, in contrast, followed a hyperbolic function with maximum response sensitivity occurring at very low stimulus frequencies. Changes in urine flow rate were 50% complete at stimulus frequencies of 5 Hz. Identification of two distinct components in the relaxation phase of renal vascular resistance leads to a reasonable hypothesis that 60% of total renal vascular resistance may lie proximal to the glomerulus, whereas 36% may be accounted for by the efferent arterioles.

Renal Blood Flow, Glomerular Filtration Rate, and Renal Oxygenation in Early Clinical Septic Shock.

PubMed

Skytte Larsson, Jenny; Krumbholz, Vitus; Enskog, Anders; Bragadottir, Gudrun; Redfors, Bengt; Ricksten, Sven-Erik

2018-06-01

Data on renal hemodynamics, function, and oxygenation in early clinical septic shock are lacking. We therefore measured renal blood flow, glomerular filtration rate, renal oxygen consumption, and oxygenation in patients with early septic shock. Prospective comparative study. General and cardiothoracic ICUs. Patients with norepinephrine-dependent early septic shock (n = 8) were studied within 24 hours after arrival in the ICU and compared with postcardiac surgery patients without acute kidney injury (comparator group, n = 58). None. Data on systemic hemodynamics and renal variables were obtained during two 30-minute periods. Renal blood flow was measured by the infusion clearance of para-aminohippuric acid, corrected for renal extraction of para-aminohippuric acid. Renal filtration fraction was measured by renal extraction of chromium-51 labeled EDTA. Renal oxygenation was estimated from renal oxygen extraction. Renal oxygen delivery (-24%; p = 0.037) and the renal blood flow-to-cardiac index ratio (-21%; p = 0.018) were lower, renal vascular resistance was higher (26%; p = 0.027), whereas renal blood flow tended to be lower (-19%; p = 0.068) in the septic group. Glomerular filtration rate (-32%; p = 0.006) and renal sodium reabsorption (-29%; p = 0.014) were both lower in the septic group. Neither renal filtration fraction nor renal oxygen consumption differed significantly between groups. Renal oxygen extraction was significantly higher in the septic group (28%; p = 0.022). In the septic group, markers of tubular injury were elevated. In early clinical septic shock, renal function was lower, which was accompanied by renal vasoconstriction, a lower renal oxygen delivery, impaired renal oxygenation, and tubular sodium reabsorption at a high oxygen cost compared with controls.

Cellular localization of uranium in the renal proximal tubules during acute renal uranium toxicity.

PubMed

Homma-Takeda, Shino; Kitahara, Keisuke; Suzuki, Kyoko; Blyth, Benjamin J; Suya, Noriyoshi; Konishi, Teruaki; Terada, Yasuko; Shimada, Yoshiya

2015-12-01

Renal toxicity is a hallmark of uranium exposure, with uranium accumulating specifically in the S3 segment of the proximal tubules causing tubular damage. As the distribution, concentration and dynamics of accumulated uranium at the cellular level is not well understood, here, we report on high-resolution quantitative in situ measurements by high-energy synchrotron radiation X-ray fluorescence analysis in renal sections from a rat model of uranium-induced acute renal toxicity. One day after subcutaneous administration of uranium acetate to male Wistar rats at a dose of 0.5 mg uranium kg(-1) body weight, uranium concentration in the S3 segment of the proximal tubules was 64.9 ± 18.2 µg g(-1) , sevenfold higher than the mean renal uranium concentration (9.7 ± 2.4 µg g(-1) ). Uranium distributed into the epithelium of the S3 segment of the proximal tubules and highly concentrated uranium (50-fold above mean renal concentration) in micro-regions was found near the nuclei. These uranium levels were maintained up to 8 days post-administration, despite more rapid reductions in mean renal concentration. Two weeks after uranium administration, damaged areas were filled with regenerating tubules and morphological signs of tissue recovery, but areas of high uranium concentration (100-fold above mean renal concentration) were still found in the epithelium of regenerating tubules. These data indicate that site-specific accumulation of uranium in micro-regions of the S3 segment of the proximal tubules and retention of uranium in concentrated areas during recovery are characteristics of uranium behavior in the kidney. Copyright © 2015 John Wiley & Sons, Ltd.

Detection of early changes in renal function using 99mTc-MAG3 imaging in a murine model of ischemia-reperfusion injury

PubMed Central

Roberts, John; Chen, Bo; Curtis, Lisa M.; Agarwal, Anupam; Sanders, Paul W.; Zinn, Kurt R.

2012-01-01

Accurate determination of renal function in mice is a major impediment to the use of murine models in acute kidney injury. The purpose of this study was to determine whether early changes in renal function could be detected using dynamic gamma camera imaging in a mouse model of ischemia-reperfusion (I/R) injury. C57BL/6 mice (n = 5/group) underwent a right nephrectomy, followed by either 30 min of I/R injury or sham surgery of the remaining kidney. Dynamic renal studies (21 min, 10 s/frame) were conducted before surgery (baseline) and at 5, 24, and 48 h by injection of 99mTc-mercaptoacetyltriglycine (MAG3; ~1.0 mCi/mouse) via the tail vein. The percentage of injected dose (%ID) in the kidney was calculated for each 10-s interval after MAG3 injection, using standard region of interest analyses. A defect in renal function in I/R-treated mice was detected as early as 5 h after surgery compared with sham-treated mice, identified by the increased %ID (at peak) in the I/R-treated kidneys at 100 s (P < 0.01) that remained significantly higher than sham-treated mice for the duration of the scan until 600 s (P < 0.05). At 48 h, the renal scan demonstrated functional renal recovery of the I/R mice and was comparable to sham-treated mice. Our study shows that using dynamic imaging, renal dysfunction can be detected and quantified reliably as early as 5 h after I/R insult, allowing for evaluation of early treatment interventions. PMID:17634403

Prognosis of clinical renal disease and incidence of new renal findings in patients with rheumatoid arthritis: follow-up of a population-based study.

PubMed

Karstila, K; Korpela, M; Sihvonen, S; Mustonen, J

2007-12-01

The objective of this study was to assess the long-term prognosis of nephropathy findings and the incidence of new abnormal clinical renal findings in patients with rheumatoid arthritis (RA). The original population-based cross-sectional study of 604 RA patients was carried out in 1988, 103 nephropathy patients being found. Controls matched for age, sex, and duration of RA were selected from among RA patients with normal renal function and urinalysis in 1988. In 2003, a follow-up study was made of the 103 nephropathy patients and 102 controls, and the median follow-up time was 13 years. In the original nephropathy group, serum creatinine exceeded 200 mumol/l in 8% of the original isolated hematuria patients, in 30% of the isolated proteinuria patients, in 57% of the combined hematuria and proteinuria patients, but in none of the isolated chronic renal failure (CRF) patients (p = 0.001 for the difference). Probable or definitive renal amyloidosis was diagnosed in 19% of the nephropathy patients. Dialysis therapy was given to 10 out of the 103 nephropathy patients, nine of them belonging to the original isolated proteinuria or combined hematuria and proteinuria groups. There were six renal deaths among the nephropathy patients, and none in the controls. In the control group, new abnormal renal findings, in most cases mild, were detected in 28%. Serum creatinine exceeded 200 mumol/l in 4% of the controls, and dialysis therapy was given to 2% of the controls. Probable or definitive renal amyloidosis was diagnosed in 4% of this group. With regards to the development or progression of chronic renal failure, the long-term clinical prognosis of isolated hematuria and isolated CRF was found to be favorable. Proteinuria alone or combined with hematuria or CRF was related to evidently poorer prognosis.

Assessing the kidney function parameters glomerular filtration rate and effective renal plasma flow with dynamic FDG-PET/MRI in healthy subjects.

PubMed

Geist, Barbara K; Baltzer, Pascal; Fueger, Barbara; Hamboeck, Martina; Nakuz, Thomas; Papp, Laszlo; Rasul, Sazan; Sundar, Lalith Kumar Shiyam; Hacker, Marcus; Staudenherz, Anton

2018-05-09

A method was developed to assess the kidney parameters glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) from 2-deoxy-2-[ 18 F]fluoro-D-glucose (FDG) concentration behavior in kidneys, measured with positron emission tomography (PET) scans. Twenty-four healthy adult subjects prospectively underwent dynamic simultaneous PET/magnetic resonance imaging (MRI) examination. Time activity curves (TACs) were obtained from the dynamic PET series, with the guidance of MR information. Patlak analysis was performed to determine the GFR, and based on integrals, ERPF was calculated. Results were compared to intra-individually obtained reference values determined from venous blood samples. Total kidney GFR and ERPF as estimated by dynamic PET/MRI were highly correlated to their reference values (r = 0.88/p < 0.0001 and r = 0.82/p < 0.0001, respectively) with no significant difference between their means. The study is a proof of concept that GFR and ERPF can be assessed with dynamic FDG PET/MRI scans in healthy kidneys. This has advantages for patients getting a routine scan, where additional examinations for kidney function estimation could be avoided. Further studies are required for transferring this PET/MRI method to PET/CT applications.

Anatomic variations of the renal vessels: focus on the precaval right renal artery.

PubMed

Bouali, Ourdia; Labarre, David; Molinier, François; Lopez, Raphaël; Benouaich, Vincent; Lauwers, Frédéric; Moscovici, Jacques

2012-07-01

The aim of this study was to determine the prevalence of precaval right renal artery and to investigate the distribution of renal arteries and veins. We discuss a theory of development of renal vascular variants. We retrospectively reviewed 120 arterial phase contrast material-enhanced spiral computerized tomography scans of the abdomen (1- to 2-mm section thickness) performed during a two-month period. Forty percent of the study group (48 patients) had one artery and one vein on each side, with typical course. There was a 9.17% prevalence of precaval right renal artery: 10 patients had a lower pole accessory artery in precaval position and one patient had the main and the accessory arteries that pass anterior to the inferior vena cava. In these cases, associated variations of renal vessels were higher than in the patients without precaval artery variant. There were multiple arteries in 28.3% of the right kidneys and in 26.7% of the left ones. Variants of the right renal vein consisted in multiple veins in 20% (24 cases). We detected no case of multiple left renal veins, but we described variations of its course (circum- or retroaortic vein) in 9.17% (11 cases). Twenty-six patients (21.7%) had associated variations of the renal pedicle. The current technical support allows for a minimally invasive study of vessels anatomy. In our study the prevalence of a precaval right renal artery appears to be higher than previously reported (9.17%). Knowledge on anatomical variations of right renal artery and associated renal vessels variations has major clinical implications.

Micro-anatomy of the renal sympathetic nervous system: a human postmortem histologic study.

PubMed

Atherton, Daniel S; Deep, Nicholas L; Mendelsohn, Farrell O

2012-07-01

Hypertension remains an epidemic uncontrolled with pharmacologic therapies. A novel catheter inserted into the renal artery has been shown to lower blood pressure by ablating the renal sympathetic nerves with radiofrequency energy delivered through the arterial wall. We report a histologic study describing the anatomic substrate for this technique, specifically the renal sympathetic nervous system. Histological sections from proximal, middle, and distal renal artery segments from nine renal arteries (five human autopsies) were analyzed. Nerves were manually counted and their distance from the lumen-intima interface was measured using a micrometer. The nerves were then categorized by location into 0.5-mm-wide "rings" that were arranged circumferentially around the renal artery lumen. Of all nerves detected, 1.0% was in the 0-0.5 mm ring, 48.3% were in the 0.5-1.0 mm ring, 25.6% were in the 1.0-1.5 mm ring, 15.5% were in the 1.5-2.0 mm ring, and 9.5% were in the 2.0-2.5 mm ring. Beyond 0.5 mm, the proportion of nerves tended to decrease as the distance from the lumen increased. Totally, 90.5% of all nerves in this study existed within 2.0 mm of the renal artery lumen. Additionally, the number of nerves tended to increase along the length of the artery from proximal to distal segments (proximal = 216; middle = 323; distal = 417). In conclusion, our analysis indicates that a great proportion of renal sympathetic nerves have close proximity to the lumen-intima interface and should thus be accessible via renal artery interventional approaches such as catheter ablation. This data provides important anatomic information for the development of ablation and other type devices for renal sympathetic denervation. © 2011 Wiley Periodicals, Inc.

Retrospective morphometric study of the suitability of renal arteries for renal denervation according to the Symplicity HTN2 trial criteria

PubMed Central

Schönherr, Elisabeth; Rehwald, Rafael; Nasseri, Parinaz; Luger, Anna K; Grams, Astrid E; Kerschbaum, Julia; Rehder, Peter; Petersen, Johannes; Glodny, Bernhard

2016-01-01

Objective The aim of this study was to describe the renal arteries of humans in vivo, as precisely as possible, and to formulate an expected value for the exclusion of renal denervation due to the anatomical situation based on the criteria of the Symplicity HTN trials. Design and setting In a retrospective cohort study, the renal arteries of 126 patients (57 women, 69 men, mean age 60±17.2 years (CI 57.7 to 63.6)) were segmented semiautomatically from high-contrast CT angiographies. Results Among the 300 renal arteries, there were three arteries with fibromuscular dysplasia and one with ostial renal artery stenosis. The first left renal artery was shorter than the right (34±11.4 mm (CI 32 to 36) vs 45.9±15 mm (CI 43.2 to 48.6); p<0.0001), but had a slightly larger diameter (5.2±1.4 mm (CI 4.9 to 5.4) vs 4.9±1.2 mm (CI 4.6 to 5.1); p>0.05). The first left renal arteries were 1.1±0.4 mm (CI 0.9 to 1.3), and the first right renal arteries were 0.3±0.6 mm (CI 0.1 to 0.5) thinner in women than in men (p<0.05). Ostial funnels were up to 14 mm long. The cross-sections were elliptical, more pronounced on the right side (p<0.05). In 23 cases (18.3%), the main artery was shorter than 2 cm; in 43 cases (34.1%), the diameter was not >4 mm. Some 46% of the patients, or 58.7% when variants and diseases were taken into consideration, were theoretically not suitable for denervation. Conclusions Based on these precise measurements, the anatomical situation as a reason for ruling out denervation appears to be significantly more common than previously suspected. Since this can be the cause of the failure of treatment in some cases, further development of catheters or direct percutaneous approaches may improve success rates. PMID:26729385

Renal studies in safety pharmacology and toxicology: A survey conducted in the top 15 pharmaceutical companies.

PubMed

Benjamin, Amanda; Gallacher, David J; Greiter-Wilke, Andrea; Guillon, Jean-Michel; Kasai, Cheiko; Ledieu, David; Levesque, Paul; Prelle, Katja; Ratcliffe, Sian; Sannajust, Frederick; Valentin, Jean-Pierre

2015-01-01

With the recent development of more sensitive biomarkers to assess kidney injury preclinically, a survey was designed i) to investigate what strategies are used to investigate renal toxicity in both ICH S7A compliant Safety Pharmacology (SP) studies after a single dose of a compound and within repeat-dose toxicity studies by large pharmaceutical companies today; ii) to understand whether renal SP studies have impact or utility in drug development and/or if it may be more appropriate to assess renal effects after multiple doses of compounds; iii) to ascertain how much mechanistic work is performed by the top 15 largest pharmaceutical companies (as determined by R&D revenue size); iv) to gain an insight into the impact of the validation of DIKI biomarkers and their introduction in the safety evaluation paradigm; and v) to understand the impact of renal/urinary safety study data on progression of projects. Two short anonymous surveys were submitted to SP leaders of the top 15 pharmaceutical companies, as defined by 2012 R&D portfolio size. Fourteen multiple choice questions were designed to explore the strategies used to investigate renal effects in both ICH S7A compliant SP studies and within toxicology studies. A 67% and 60% response rate was obtained in the first and second surveys, respectively. Nine out of ten respondent companies conduct renal excretory measurements (eg. urine analysis) in toxicology studies whereas only five out of ten conduct specific renal SP studies; and all of those 5 also conduct the renal excretory measurements in toxicology studies. These companies measure and/or calculate a variety of parameters as part of these studies, and also on a case by case basis include regulatory qualified and non-qualified DIKI biomarkers. Finally, only one company has used renal/urinary functional data alone to stop a project, whereas the majority of respondents combine renal data with other target organ assessments to form an integrated decision-making set

Estimation of pressure gradients at renal artery stenoses

NASA Astrophysics Data System (ADS)

Yim, Peter J.; Cebral, Juan R.; Weaver, Ashley; Lutz, Robert J.; Vasbinder, G. Boudewijn C.

2003-05-01

Atherosclerotic disease of the renal artery can reduce the blood flow leading to renovascular hypertension and ischemic nephopathy. The kidney responds to a decrease in blood flow by activation of the renin-angiotensin system that increases blood pressure and can result in severe hypertension. Percutaneous translumenal angioplasty (PTA) may be indicated for treatment of renovascular hypertension (RVH). However, direct measurement of renal artery caliber and degree of stenosis has only moderate specificity for detection of RVH. A confounding factor in assessment of the proximal renal artery is that diffuse atherosclerotic disease of the distal branches of the renal artery can produce the same effect on blood-flow as atherosclerotic disease of the proximal renal artery. A methodology is proposed for estimation of pressure gradients at renal artery stenoses from magnetic resonance imaging that could improve the evaluation of renal artery disease. In the proposed methodology, pressure gradients are estimated using computational fluid dynamics (CFD) modeling. Realistic CFD models are constructed from images of vessel shape and measurements of blood-flow rates which are available from magnetic resonance angiography (MRA) and phase-contrast magnetic resonance (MR) imaging respectively. CFD measurement of renal artery pressure gradients has been validated in a physical flow-through model.

Histopathological retrospective study of canine renal disease in Korea, 2003~2008

PubMed Central

Yhee, Ji-Young; Yu, Chi-Ho; Kim, Jong-Hyuk; Im, Keum-Soon; Chon, Seung-Ki

2010-01-01

Renal disease includes conditions affecting the glomeruli, tubules, interstitium, pelvis, and vasculature. Diseases of the kidney include glomerular diseases, diseases of the tubules and interstitium, diseases of renal pelvis, and developmental abnormalities. Renal tissue samples (n = 70) submitted to the Department of Veterinary Pathology of Konkuk University from 2003 to 2008 were included in this study. Tissue histopathology was performed using light microscopy with hematoxylin and eosin stains. Masson's trichrome, Congo Red, and Warthin starry silver staining were applied in several individual cases. Glomerular diseases (22.9%), tubulointerstitial diseases (8.6%), neoplastic diseases (8.6%), conditions secondary to urinary obstruction (24.3%), and other diseases (35.7%) were identified. Glomerulonephritis (GN) cases were classified as acute proliferative GN (5.7%), membranous GN (4.3%), membranoproliferative GN (4.3%), focal segmental GN (2.9%), and other GN (4.2%). The proportion of canine GN cases presently identified was not as high as the proportions identified in human studies. Conversely, urinary obstruction and end-stage renal disease cases were relatively higher in dogs than in human populations. PMID:21113095

A quantitative systems physiology model of renal function and blood pressure regulation: Model description.

PubMed

Hallow, K M; Gebremichael, Y

2017-06-01

Renal function plays a central role in cardiovascular, kidney, and multiple other diseases, and many existing and novel therapies act through renal mechanisms. Even with decades of accumulated knowledge of renal physiology, pathophysiology, and pharmacology, the dynamics of renal function remain difficult to understand and predict, often resulting in unexpected or counterintuitive therapy responses. Quantitative systems pharmacology modeling of renal function integrates this accumulated knowledge into a quantitative framework, allowing evaluation of competing hypotheses, identification of knowledge gaps, and generation of new experimentally testable hypotheses. Here we present a model of renal physiology and control mechanisms involved in maintaining sodium and water homeostasis. This model represents the core renal physiological processes involved in many research questions in drug development. The model runs in R and the code is made available. In a companion article, we present a case study using the model to explore mechanisms and pharmacology of salt-sensitive hypertension. © 2017 The Authors CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

Cordyceps sinensis attenuates renal fibrosis and suppresses BAG3 induction in obstructed rat kidney.

PubMed

Du, Feng; Li, Si; Wang, Tian; Zhang, Hai-Yan; Zong, Zhi-Hong; Du, Zhen-Xian; Li, De-Tian; Wang, Hua-Qin; Liu, Bo; Miao, Jia-Ning; Bian, Xiao-Hui

2015-01-01

BAG3 regulates a number of cellular processes, including cell proliferation, apoptosis, adhesion and migration, and epithelial-mesenchymal transition (EMT). However, the role of BAG3 in renal tubular EMT and renal interstitial fibrosis remains elusive. This study aimed to examine the dynamic expression of BAG3 during renal fibrosis, and to investigate the efficacy of Cordyceps sinensis (C. sinensis) on renal fibrosis. A rat model of unilateral ureteral obstruction (UUO) was established, and the expression of BAG3 and α-SMA, and the efficacy of C. sinensis on renal fibrosis induced by UUO were examined. The results showed that UUO led to collagen accumulation, which was significantly suppressed by C. sinensis. UUO increased the expression of BAG3 and α-SMA, a mesenchymal marker, while UUO induced BAG3 and α-SMA expression was significantly inhibited by C. sinensis. In addition, immunohistochemical staining demonstrated that BAG3 immunoreactivity was restricted to tubular epithelium. In conclusion, BAG3 is a potential target for the prevention and/or treatment of renal fibrosis, and C. Sinensis is a promising agent for renal fibrosis.

Endothelin-A Receptor Antagonism after Renal Angioplasty Enhances Renal Recovery in Renovascular Disease

PubMed Central

Tullos, Nathan; Stewart, Nicholas J.; Surles, Bret

2015-01-01

Percutaneous transluminal renal angioplasty/stenting (PTRAS) is frequently used to treat renal artery stenosis and renovascular disease (RVD); however, renal function is restored in less than one half of the cases. This study was designed to test a novel intervention that could refine PTRAS and enhance renal recovery in RVD. Renal function was quantified in pigs after 6 weeks of chronic RVD (induced by unilateral renal artery stenosis), established renal damage, and hypertension. Pigs with RVD then underwent PTRAS and were randomized into three groups: placebo (RVD+PTRAS), chronic endothelin-A receptor (ET-A) blockade (RVD+PTRAS+ET-A), and chronic dual ET-A/B blockade (RVD+PTRAS+ET-A/B) for 4 weeks. Renal function was again evaluated after treatments, and then, ex vivo studies were performed on the stented kidney. PTRAS resolved renal stenosis, attenuated hypertension, and improved renal function but did not resolve renal microvascular rarefaction, remodeling, or renal fibrosis. ET-A blocker therapy after PTRAS significantly improved hypertension, microvascular rarefaction, and renal injury and led to greater recovery of renal function. Conversely, combined ET-A/B blockade therapy blunted the therapeutic effects of PTRAS alone or PTRAS followed by ET-A blockade. These data suggest that ET-A receptor blockade therapy could serve as a coadjuvant intervention to enhance the outcomes of PTRAS in RVD. These results also suggest that ET-B receptors are important for renal function in RVD and may contribute to recovery after PTRAS. Using clinically available compounds and techniques, our results could contribute to both refinement and design of new therapeutic strategies in chronic RVD. PMID:25377076

Design and simulation of novel laparoscopic renal denervation system: a feasibility study.

PubMed

Ye, Eunbi; Baik, Jinhwan; Lee, Seunghyun; Ryu, Seon Young; Yang, Sunchoel; Choi, Eue-Keun; Song, Won Hoon; Yuk, Hyeong Dong; Jeong, Chang Wook; Park, Sung-Min

2018-05-18

In this study, we propose a novel laparoscopy-based renal denervation (RDN) system for treating patients with resistant hypertension. In this feasibility study, we investigated whether our proposed surgical instrument can ablate renal nerves from outside of the renal artery safely and effectively and can overcome the depth-related limitations of the previous catheter-based system with less damage to the arterial walls. We designed a looped bipolar electrosurgical instrument to be used with laparoscopy-based RDN system. The tip of instrument wraps around the renal artery and delivers the radio-frequency (RF) energy. We evaluated the thermal distribution via simulation study on a numerical model designed using histological data and validated the results by the in vitro study. Finally, to show the effectiveness of this system, we compared the performance of our system with that of catheter-based RDN system through simulations. Simulation results were within the 95% confidence intervals of the in vitro experimental results. The validated results demonstrated that the proposed laparoscopy-based RDN system produces an effective thermal distribution for the removal of renal sympathetic nerves without damaging the arterial wall and addresses the depth limitation of catheter-based RDN system. We developed a novel laparoscope-based electrosurgical RDN method for hypertension treatment. The feasibility of our system was confirmed through a simulation study as well as in vitro experiments. Our proposed method could be an effective treatment for resistant hypertension as well as central nervous system diseases.

Serum osteoprotegerin and renal function in the general population: the Tromsø Study.

PubMed

Vik, Anders; Brodin, Ellen E; Mathiesen, Ellisiv B; Brox, Jan; Jørgensen, Lone; Njølstad, Inger; Brækkan, Sigrid K; Hansen, John-Bjarne

2017-02-01

Serum osteoprotegerin (OPG) is elevated in patients with chronic kidney disease (CKD) and increases with decreasing renal function. However, there are limited data regarding the association between OPG and renal function in the general population. The aim of the present study was to explore the relation between serum OPG and renal function in subjects recruited from the general population. We conducted a cross-sectional study with 6689 participants recruited from the general population in Tromsø, Norway. Estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equations. OPG was modelled both as a continuous and categorical variable. General linear models and linear regression with adjustment for possible confounders were used to study the association between OPG and eGFR. Analyses were stratified by the median age, as serum OPG and age displayed a significant interaction on eGFR. In participants ≤62.2 years with normal renal function (eGFR ≥90 mL/min/1.73 m 2 ) eGFR increased by 0.35 mL/min/1.73 m 2 (95% CI 0.13-0.56) per 1 standard deviation (SD) increase in serum OPG after multiple adjustment. In participants older than the median age with impaired renal function (eGFR <90 mL/min/1.73 m 2 ), eGFR decreased by 1.54 (95% CI -2.06 to -1.01) per 1 SD increase in serum OPG. OPG was associated with an increased eGFR in younger subjects with normal renal function and with a decreased eGFR in older subjects with reduced renal function. Our findings imply that the association between OPG and eGFR varies with age and renal function.

Renal function in pregnant rats with two-kidney goldblatt hypertension.

PubMed

Dal Canton, A; Sabbatini, M; Esposito, C; Altomonte, M; Romano, G; Uccello, F; Conte, G; Fuiano, G; Russo, D; Andreucci, V E

1983-01-01

This study was carried out in female Wistar-Münich rats with two-kidney, one-clip hypertension, using clipped normotensive rats as controls. Metabolic studies were performed in the first two weeks of pregnancy, consisting of daily measurement of systolic blood pressure (BP) (tail-cuff), body weight (BW), and salt and water balance. At the end of metabolic studies, glomerular dynamics were studied in the unclipped kidney by micropuncture. During pregnancy, urinary output of Na+ and water was greater in hypertensive than normotensive rats. The greater natriuresis accounted for a reduced Na+ retention and a lower increase in maternal BW. Micropuncture studies showed an impaired renal auto-regulation. These results show that hypertension in pregnancy causes a salt-losing tendency, that may be secondary to incomplete renal autoregulation.

Anatomic Patterns of Renal Arterial Sympathetic Innervation: New Aspects for Renal Denervation.

PubMed

Imnadze, Guram; Balzer, Stefan; Meyer, Baerbel; Neumann, Joerg; Krech, Rainer Horst; Thale, Joachim; Franz, Norbert; Warnecke, Henning; Awad, Khaled; Hayek, Salim S; Devireddy, Chandan

2016-12-01

Initial studies of catheter-based renal arterial sympathetic denervation to lower blood pressure in resistant hypertensive patients renewed interest in the sympathetic nervous system's role in the pathogenesis of hypertension. However, the SYMPLICITY HTN-3 study failed to meet its prespecified blood pressure lowering efficacy endpoint. To date, only a limited number of studies have described the microanatomy of renal nerves, of which, only two involve humans. Renal arteries were harvested from 15 cadavers from the Klinikum Osnabruck and Schuchtermann Klinik, Bad Rothenfelde. Each artery was divided longitudinally in equal thirds (proximal, middle, and distal), with each section then divided into equal superior, inferior, anterior, and posterior quadrants, which were then stained. Segments containing no renal nerves were given a score value = 0, 1-2 nerves with diameter <300 µm a score = 1; 3-4 nerves or nerve diameter 300-599 µm a score = 2, and >4 nerves or nerve diameter ≥600 µm a score = 3. A total of 22 renal arteries (9 right-sided, 13 left-sided) were suitable for examination. Overall, 691 sections of 5 mm thickness were prepared. Right renal arteries had significantly higher mean innervation grade (1.56 ± 0.85) compared to left renal arteries (1.09 ± 0.87) (P < 0.001). Medial (1.30 ± 0.59) and distal (1.39 ± 0.62) innervation was higher than the proximal (1.17 ± 0.55) segments (p < 0.001). When divided in quadrants, the anterior (1.52 ± 0.96) and superior (1.71 ± 0.89) segments were more innervated compared to posterior (0.96 ± 0.72) and inferior (0.90 ± 0.68) segments (P < 0.001). That the right renal artery has significantly higher innervation scores than the left. The anterior and superior quadrants of the renal arteries scored higher in innervation than the posterior and inferior quadrants did. The distal third of the renal arteries are more innervated than the more

Chemical renal denervation in the rat.

PubMed

Consigny, Paul M; Davalian, Dariush; Donn, Rosy; Hu, Jie; Rieser, Matthew; Stolarik, Deanne

2014-02-01

The recent success of renal denervation in lowering blood pressure in drug-resistant hypertensive patients has stimulated interest in developing novel approaches to renal denervation including local drug/chemical delivery. The purpose of this study was to develop a rat model in which depletion of renal norepinephrine (NE) could be used to determine the efficacy of renal denervation after the delivery of a chemical to the periadventitial space of the renal artery. Renal denervation was performed on a single renal artery of 90 rats (n = 6 rats/group). The first study determined the time course of renal denervation after surgical stripping of a renal artery plus the topical application of phenol in alcohol. The second study determined the efficacy of periadventitial delivery of hypertonic saline, guanethidine, and salicylic acid. The final study determined the dose-response relationship for paclitaxel. In all studies, renal NE content was determined by liquid chromatography-mass spectrometry. Renal NE was depleted 3 and 7 days after surgical denervation. Renal NE was also depleted by periadventitial delivery of all agents tested (hypertonic saline, salicylic acid, guanethidine, and paclitaxel). A dose response was observed after the application of 150 μL of 10(-5) M through 10(-2) M paclitaxel. We developed a rat model in which depletion of renal NE was used to determine the efficacy of renal denervation after perivascular renal artery drug/chemical delivery. We validated this model by demonstrating the efficacy of the neurotoxic agents hypertonic saline, salicylic acid, and guanethidine and increasing doses of paclitaxel.

Use of nonsteroidal anti-inflammatory drugs and renal failure in nursing home residents-results of the study "Inappropriate Medication in Patients with Renal Insufficiency in Nursing Homes".

PubMed

Dörks, Michael; Herget-Rosenthal, Stefan; Schmiemann, Guido; Hoffmann, Falk

2016-04-01

Use of potentially inappropriate medications may result in increased morbidity, mortality and resource utilisation. Due to polypharmacy and age-related decline in renal function the elderly population is at particular risk. Therefore, the Beers Criteria include use of nonsteroidal anti-inflammatory drugs in chronic renal failure stage 4 and 5 as these drugs may worsen renal function. According to the summary of product characteristics, the nonsteroidal anti-inflammatory drugs ibuprofen and diclofenac are contraindicated in these patients. Objective was to assess the extent of nonsteroidal anti-inflammatory drug use in nursing homes with a focus on residents with severe renal failure. Multi-centre cross-sectional study in 21 German nursing homes. The study population comprised residents for whom at least one serum creatinine value and information about sex were available, so that creatinine clearance rate could be estimated. In all, 685 of 852 residents were included as they fulfilled the abovementioned criteria. Renal failure was severe (estimated creatinine clearance rate < 30 ml/min) in 106 residents (15.5 %). Approximately one-fifth was treated with at least one nonsteroidal anti-inflammatory drug in both the total study population (20.3 %) and that with severe renal failure (20.8 %). With one exception, all residents prescribed nonsteroidal anti-inflammatory drugs with severe renal failure were treated with at least one nonsteroidal anti-inflammatory drug that was contraindicated due to the underlying renal function. Notwithstanding their classification as potentially inappropriate medications and underlying contraindications, use of nonsteroidal anti-inflammatory drugs is common among nursing home residents with severe renal failure.

Current practice in continuous renal replacement therapy: An epidemiological multicenter study.

PubMed

Tomasa Irriguible, T M; Sabater Riera, J; Poch López de Briñas, E; Fort Ros, J; Lloret Cora, M J; Roca Antònio, J; Navas Pérez, A; Ortiz Ballujera, P; Servià Goixart, L; González de Molina Ortiz, F J; Rovira Anglès, C; Rodríguez López, M; Roglan Piqueras, A

2017-05-01

The aim of the study is to ascertain the most relevant aspects of the current management of renal replacement therapy (RRT) in critically ill patients, and to analyze renal function recovery and mortality in patients undergoing RRT. A non-interventional three-month observational study was made in 2012, with a follow-up period of 90 days, in 21 centers in Catalonia (Spain). Demographic information, severity scores and clinical data were obtained, as well as RRT parameters. patients aged ≥ 16 years admitted to Intensive Care Units (ICUs) and subjected to RRT. A total of 261 critically ill patients were recruited, of which 35% had renal dysfunction prior to admission. The main reason for starting RRT was oliguria; the most widely used RRT modality was hemodiafiltration; and the median prescribed dose at baseline was 35mL/kg/h. The median time of RRT onset from ICU admission was one day. The mortality rate at 30 and 90 days was 46% and 54%, respectively, and was associated to greater severity scores and a later onset of RRT. At discharge, 85% of the survivors had recovered renal function. Current practice in RRT in Catalonia abides with the current clinical practice guidelines. Mortality related to RRT is associated to later onset of such therapy. The renal function recovery rate at hospital discharge was 85% among the patients subjected to RRT. Copyright © 2016 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

Dynamic Contrast-Enhanced Magnetic Resonance Imaging as a Pharmacodynamic Biomarker for Pazopanib in Metastatic Renal Carcinoma.

PubMed

Sweis, Randy F; Medved, Milica; Towey, Shannon; Karczmar, Gregory S; Oto, Aytekin; Szmulewitz, Russell Z; O'Donnell, Peter H; Fishkin, Paul; Karrison, Theodore; Stadler, Walter M

2017-04-01

Traditional imaging assessment criteria might not correlate well with clinical benefit from vascular endothelial growth factor pathway-directed therapy in metastatic renal cancer. Preclinical data suggest tumor growth is preceded by a rise in K trans level, a parameter derived from dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) that reflects vascular permeability. We thus hypothesized that K trans might be a predictive biomarker for pazopanib. Patients with metastatic renal cancer were treated with pazopanib at 800 mg oral daily until disease progression. MRI of the abdomen and pelvis with a DCE-MRI sequence was obtained at baseline and every 8 weeks. Seventy-three DCE-MRI scans were completed and 66 were technically assessable. Of the 17 patients with at least 1 DCE-MRI scan after the baseline scan, 16 (94%) had a decline in K trans level. Changes in K trans compared with baseline after 1, 8, 16, and 24 weeks were -49%, -65%, -63%, and -53%, respectively (P = .0052, repeated measures analysis of variance). The median K trans nadir occurred at 8 weeks. The median progression-free survival (PFS) was 32.1 weeks. PFS was longer in patients with higher baseline K trans values (P = .036, log rank). Baseline K trans did not reach significance in a Cox proportional hazard model including clinical prognostic index and previous treatments (P = .083). We show that K trans is a pharmacodynamic biomarker for pazopanib therapy in metastatic renal cancer. Because of the small sample size, the predictive capacity of K trans recovery could not be assessed, but baseline K trans correlated with PFS. Copyright © 2016 Elsevier Inc. All rights reserved.

Impact on creatinine renal clearance by the interplay of multiple renal transporters: a case study with INCB039110.

PubMed

Zhang, Yan; Warren, Mark S; Zhang, Xuexiang; Diamond, Sharon; Williams, Bill; Punwani, Naresh; Huang, Jane; Huang, Yong; Yeleswaram, Swamy

2015-04-01

Serum creatinine is commonly used as a marker of renal function, but increases in serum creatinine might not represent changes in glomerular filtration rate (GFR). INCB039110 (2-(3-(4-(7H-pyrrolo[2,3-day]pyrimidin-4-yl)-1H-pyrazol-1-yl)-1-(1-(3-fluoro-2-(trifluoromethyl)isonicotinoyl)piperidin-4-yl)azetidin-3-yl)acetonitrile) is an inhibitor of the Janus kinases (JAKs) with selectivity for JAK1. In a phase 1 study, a modest and reversible increase in serum creatinine was observed after treatment with INCB039110. However, a dedicated renal function study with INCB039110, assessed by iohexol plasma clearance, conducted in healthy volunteers indicated no change in GFR. In vitro studies were therefore conducted to investigate the interaction of INCB039110 with five transporters that are likely involved in the renal clearance of creatinine. Cell systems expressing individual or multiple transporters were used, including a novel quintuple-transporter model OAT2/OCT2/OCT3/MATE1/MATE2-K. INCB039110 potently inhibited OCT2-mediated uptake of creatinine as well as MATE1-/MATE2-K-mediated efflux of creatinine. Given the interactions of INCB039110 with multiple transporters affecting creatinine uptake and efflux, an integrated system expressing all five transporters was sought; in that system, INCB039110 caused a dose-dependent decrease in transcellular transport of creatinine with weaker net inhibition compared with the effects on individual transporters. In summary, a molecular mechanism for the increase in serum creatinine by INCB039110 has been established. These studies also underline the limitations of using serum creatinine as a marker of renal function. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

[Clinical and experimental study of the production of renal hemodynamic effects of IABP-assisted pulsatile flow extracorporeal circulation].

PubMed

Moro, H

1992-01-01

Renal hemodynamics during IABP-assisted pulsatile flow extracorporeal circulation was assessed in terms of measurement values for intraoperative renal blood flow obtained by the local thermodilution method in human clinical patients. In addition, the effect of IABP on renal hemodynamics was investigated in an animal model of renal denervation in a study undertaken to elucidate the action mechanism of IABP. Eighteen patients with acquired heart disease were involved in the study and measured for the renal blood flow (RBF), cardiac output (CO), renal-systemic partition coefficient for blood flow (RBF/CO), renal vascular resistance (RVR) and perfusion pressure. In the pulsatile flow group, the RBF/CO increased as the number of pump runs increased, whole the RVR was conversely reduced with increasing pump runs. The experimental study without extracorporeal circulation was conducted on 19 mongrel dogs. During IABP runs RBF/CO increased, while the RVR decreased. After renal denervation, no noticeable influence of IABP upon renal hemodynamics was observed. Following a loading dose of noradrenaline (Norad), the RVR increased in a Norad concentration-dependent fashion, independently of IABP and renal denervation. These results indicate that IABP reduces the RVR and thereby exerts a favorable action on renal hemodynamics during pump times. The study thus warrants us to surmise that a mechanism involving the renal sympathetic nerves might play an important role in the production of favorable renal hemodynamic effects of IABP-assisted pulsatile flow extracorporeal circulation.

Renal arteriography

MedlinePlus

Renal angiogram; Angiography - kidney; Renal angiography; Renal artery stenosis - arteriography ... an artery by a blood clot Renal artery stenosis Renal cell cancer Angiomyolipomas (noncancerous tumors of the ...

Are gadolinium-based contrast media nephrotoxic? A renal biopsy study.

PubMed

Akgun, Hulya; Gonlusen, Gulfiliz; Cartwright, Joiner; Suki, Wadi N; Truong, Luan D

2006-09-01

Gadolinium-based contrast media were originally introduced as alternatives to iodinated media for magnetic resonance imaging. Although originally thought to be nonnephrotoxic, gadolinium-based contrast media have recently been reported to be associated with acute renal failure; the mechanism and the underlying renal injury are not completely understood. We report what is, to our knowledge, the first renal biopsy in this context. A 56-year-old patient underwent 2 consecutive vascular imaging procedures in conjunction with gadolinium-based contrast medium administration. A few days later, the patient developed acute renal failure. A renal biopsy showed acute tubular cell injury including patchy tubular cell necrosis, tubular cell degeneration, and marked proliferation of tubular cells, together with mild interstitial edema and interstitial inflammation, but without significant glomerular or vascular changes. During supportive therapy, renal function was partially regained. This case emphasizes the potential nephrotoxicity of gadolinium-based contrast media and suggests that the nephrotoxicity is related to potentially reversible acute tubular cell injury.

Multiple Renal Artery Pseudoaneurysms in Patients Undergoing Renal Artery Embolization Following Partial Nephrectomy: Correlation with RENAL Nephrometry Scores

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, Nakul; Patel, Anish; Ensor, Joe

PurposeTo describe the incidence of multiple renal artery pseudoaneurysms (PSA) in patients referred for renal artery embolization following partial nephrectomy and to study its relationship to RENAL nephrometry scores.Materials and MethodsThe medical records of 25 patients referred for renal artery embolization after partial nephrectomy were retrospectively reviewed for the following parameters: size and number of tumors, RENAL nephrometry scores, angiographic abnormalities, technical and clinical outcomes, and estimated glomerular filtration rates (eGFRs) after embolization.ResultsTwenty-four patients had primary renal tumors, while 1 patient had a pancreatic tumor invading the kidney. Multiple tumors were resected in 4 patients. Most patients (92 %) were symptomatic,more » presenting with gross hematuria, flank pain, or both. Angiography revealed PSA with (n = 5) or without (n = 20) AV fistulae. Sixteen patients (64 %) had multiple PSA involving multiple renal vessels. Higher RENAL nephrometry scores were associated with an increasing likelihood of multiple PSA. Multiple vessels were embolized in 14 patients (56 %). Clinical success was achieved after one (n = 22) or two (n = 3) embolization sessions in all patients. Post-embolization eGFR values at different time points after embolization were not significantly different from the post-operative eGFR.ConclusionA majority of patients requiring renal artery embolization following partial nephrectomy have multiple pseudoaneurysms, often requiring selective embolization of multiple vessels. Higher RENAL nephrometry score is associated with an increasing likelihood of multiple pseudoaneurysms. We found transarterial embolization to be a safe and effective treatment option with no long-term adverse effect on renal function in all but one patient with a solitary kidney.« less

Inhibiting aerobic glycolysis suppresses renal interstitial fibroblast activation and renal fibrosis.

PubMed

Ding, Hao; Jiang, Lei; Xu, Jing; Bai, Feng; Zhou, Yang; Yuan, Qi; Luo, Jing; Zen, Ke; Yang, Junwei

2017-09-01

Chronic kidney diseases generally lead to renal fibrosis. Despite great progress having been made in identifying molecular mediators of fibrosis, the mechanism that governs renal fibrosis remains unclear, and so far no effective therapeutic antifibrosis strategy is available. Here we demonstrated that a switch of metabolism from oxidative phosphorylation to aerobic glycolysis (Warburg effect) in renal fibroblasts was the primary feature of fibroblast activation during renal fibrosis and that suppressing renal fibroblast aerobic glycolysis could significantly reduce renal fibrosis. Both gene and protein assay showed that the expression of glycolysis enzymes was upregulated in mouse kidneys with unilateral ureter obstruction (UUO) surgery or in transforming growth factor-β1 (TGF-β1)-treated renal interstitial fibroblasts. Aerobic glycolysis flux, indicated by glucose uptake and lactate production, was increased in mouse kidney with UUO nephropathy or TGF-β1-treated renal interstitial fibroblasts and positively correlated with fibrosis process. In line with this, we found that increasing aerobic glycolysis can remarkably induce myofibroblast activation while aerobic glycolysis inhibitors shikonin and 2-deoxyglucose attenuate UUO-induced mouse renal fibrosis and TGF-β1-stimulated myofibroblast activation. Furthermore, mechanistic study indicated that shikonin inhibits renal aerobic glycolysis via reducing phosphorylation of pyruvate kinase type M2, a rate-limiting glycolytic enzyme associated with cell reliance on aerobic glycolysis. In conclusion, our findings demonstrate the critical role of aerobic glycolysis in renal fibrosis and support treatment with aerobic glycolysis inhibitors as a potential antifibrotic strategy. Copyright © 2017 the American Physiological Society.

[Aortic dissection spread to the renal arteries: role of renal volumetry after angioplasty].

PubMed

Vautrin, E; Thony, F; Chavanon, O; Hannachi, I; Barone-Rochette, G; Pierre, H; Baguet, J-P

2012-06-01

Type A or B aortic dissection can extend to renal arteries, causing a renal ischemia which treatment is usually endovascular. The aim of our study is to show the interest of the renal volumetry in the follow-up of these patients. Twenty-two patients (16 men, mean age 63.4±11.8years, BMI 25.2±3.4kg/m(2)) with a type A or B aortic dissection spread to one or to both renal arteries and followed at Grenoble university hospital were consecutively included. All patients underwent renal angiography with aorto-renal pressure gradients measurements and follow-up by renal volumetry (scanner Siemens(®)). A renal ischemia was defined by a decrease of 20% or more of the volumetry. Sixteen patients (73%) were hypertensive before the aortic dissection among which ten (62%) were treated. Eight patients (36%) have a significant renal pressure gradient among which five (62%) underwent renal endovascular therapy. The renal volumetry of these five patients remained unchanged while six of 17 patients (36%) without angioplasty have a decreasing volumetry. Renal volumetry appeared an effective and attractive option for the follow-up of the patients with aortic dissection spread to the renal arteries. These results should be taken into account to put the indication of an endovascular treatment. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Evidence of uncoupling between renal dysfunction and injury in cardiorenal syndrome: insights from the BIONICS study.

PubMed

Legrand, Matthieu; De Berardinis, Benedetta; Gaggin, Hanna K; Magrini, Laura; Belcher, Arianna; Zancla, Benedetta; Femia, Alexandra; Simon, Mandy; Motiwala, Shweta; Sambhare, Rasika; Di Somma, Salvatore; Mebazaa, Alexandre; Vaidya, Vishal S; Januzzi, James L

2014-01-01

The objective of the study was to assess urinary biomarkers of renal injury for their individual or collective ability to predict Worsening renal function (WRF) in patients with acutely decompensated heart failure (ADHF). In a prospective, blinded international study, 87 emergency department (ED) patients with ADHF were evaluated with biomarkers of cardiac stretch (B type natriuretic peptide [BNP] and its amino terminal equivalent [NT-proBNP], ST2), biomarkers of renal function (creatinine, estimated glomerular filtration rate [eGFR]) and biomarkers of renal injury (plasma neutrophil gelatinase associated lipocalin [pNGAL], urine kidney injury molecule-1 [KIM-1], urine N-acetyl-beta-D-glucosaminidase [NAG], urine Cystatin C, urine fibrinogen). The primary endpoint was WRF. 26% developed WRF; baseline characteristics of subjects who developed WRF were generally comparable to those who did not. Biomarkers of renal function and urine biomarkers of renal injury were not correlated, while urine biomarkers of renal injury correlated between each other. Biomarker concentrations were similar between patients with and without WRF except for baseline BNP. Although plasma NGAL was associated with the combined endpoint, none of the biomarker showed predictive accuracy for WRF. In ED patients with ADHF, urine biomarkers of renal injury did not predict WRF. Our data suggest that a weak association exists between renal dysfunction and renal injury in this setting (Clinicaltrials.gov NCT#0150153).

Evidence of Uncoupling between Renal Dysfunction and Injury in Cardiorenal Syndrome: Insights from the BIONICS Study

PubMed Central

Legrand, Matthieu; De Berardinis, Benedetta; Gaggin, Hanna K.; Magrini, Laura; Belcher, Arianna; Zancla, Benedetta; Femia, Alexandra; Simon, Mandy; Motiwala, Shweta; Sambhare, Rasika; Di Somma, Salvatore; Mebazaa, Alexandre; Vaidya, Vishal S.; Januzzi, James L.; (GREAT), from the Global Research on Acute Conditions Team

2014-01-01

Objective The objective of the study was to assess urinary biomarkers of renal injury for their individual or collective ability to predict Worsening renal function (WRF) in patients with acutely decompensated heart failure (ADHF). Methods In a prospective, blinded international study, 87 emergency department (ED) patients with ADHF were evaluated with biomarkers of cardiac stretch (B type natriuretic peptide [BNP] and its amino terminal equivalent [NT-proBNP], ST2), biomarkers of renal function (creatinine, estimated glomerular filtration rate [eGFR]) and biomarkers of renal injury (plasma neutrophil gelatinase associated lipocalin [pNGAL], urine kidney injury molecule-1 [KIM-1], urine N-acetyl-beta-D-glucosaminidase [NAG], urine Cystatin C, urine fibrinogen). The primary endpoint was WRF. Results 26% developed WRF; baseline characteristics of subjects who developed WRF were generally comparable to those who did not. Biomarkers of renal function and urine biomarkers of renal injury were not correlated, while urine biomarkers of renal injury correlated between each other. Biomarker concentrations were similar between patients with and without WRF except for baseline BNP. Although plasma NGAL was associated with the combined endpoint, none of the biomarker showed predictive accuracy for WRF. Conclusions In ED patients with ADHF, urine biomarkers of renal injury did not predict WRF. Our data suggest that a weak association exists between renal dysfunction and renal injury in this setting (Clinicaltrials.gov NCT#0150153). PMID:25386851

Neural control of renal function: role of renal alpha adrenoceptors.

PubMed

DiBona, G F

1985-01-01

Adrenoceptors of various subtypes mediate the renal functional responses to alterations in efferent renal sympathetic nerve activity, the neural component, and renal arterial plasma catecholamine concentrations, the humoral component, of the sympathoadrenergic nervous system. Under normal physiologic as well as hypertensive conditions, the influence of the renal sympathetic nerves predominates over that of circulating plasma catecholamines. In most mammalian species, increases in efferent renal sympathetic nerve activity elicit renal vasoconstrictor responses mediated predominantly by renal vascular alpha-1 adrenoceptors, increases in renin release mediated largely by renal juxtaglomerular granular cell beta-1 adrenoceptors with involvement of renal vascular alpha-1 adrenoceptors only when renal vasoconstriction occurs, and direct increases in renal tubular sodium and water reabsorption mediated predominantly by renal tubular alpha-1 adrenoceptors. In most mammalian species, alpha-2 adrenoceptors do not play a significant role in the renal vascular or renin release responses to renal sympathoadrenergic stimulation. Although renal tubular alpha-2 adrenoceptors do not mediate the increases in renal tubular sodium and water reabsorption produced by increases in efferent renal sympathetic nerve activity, they may be involved through their inhibitory effect on adenylate cyclase in modulating the response to other hormonal agents that influence renal tubular sodium and water reabsorption via stimulation of adenylate cyclase.

Barriers to preemptive renal transplantation: a single center questionnaire study.

PubMed

Knight, Richard J; Teeter, Larry D; Graviss, Edward A; Patel, Samir J; DeVos, Jennifer M; Moore, Linda W; Gaber, A Osama

2015-03-01

Preemptive transplantation results in excellent patient and graft survival yet most transplant candidates are referred for transplantation after initiation of dialysis. The goal of this study was to determine barriers to preemptive renal transplantation. A nonvalidated questionnaire was administered to prospective kidney transplant recipients to determine factors that hindered or favored referral for transplantation before the initiation of dialysis. One hundred ninety-seven subjects referred for a primary renal transplant completed the questionnaire. Ninety-one subjects (46%) had been informed of preemptive transplantation before referral, and 80 (41%) were predialysis at the time of evaluation. The median time from diagnosis of renal disease to referral was 60 months (range, 2-444 months). In bivariate analysis, among other factors, knowledge of preemptive transplantation was highly associated (odds ratio=94.69) with referral before initiation of dialysis. Given the strong association between knowledge of preemptive transplantation and predialysis referral, this variable was not included in the multivariate analysis. Using multivariate logistic regression analysis, white recipient race, referral by a transplant nephrologist, recipient employment, and the diagnosis of polycystic kidney disease were significantly associated with presentation to the pretransplant clinic before initiation of dialysis. The principle barrier to renal transplantation referral before dialysis was patient education regarding the option of preemptive transplantation. Factors significantly associated with referral before dialysis were the diagnosis of polycystic kidney disease, white recipient race, referral by a transplant nephrologist, and employed status. Greater effort should be applied to patient education regarding preemptive transplantation early after the diagnosis of end-stage renal disease.

Compliance in peritoneal dialysis: a qualitative study of renal nurses.

PubMed

McCarthy, Alexandra; Cook, Peta S; Fairweather, Carrie; Shaban, Ramon; Martin-McDonald, Kristine

2009-06-01

End-stage renal failure is a life-threatening condition, often treated with home-based peritoneal dialysis (PD). PD is a demanding regimen, and the patients who practise it must make numerous lifestyle changes and learn complicated biomedical techniques. In our experience, the renal nurses who provide most PD education frequently express concerns that patient compliance with their teaching is poor. These concerns are mirrored in the renal literature. It has been argued that the perceived failure of health professionals to improve compliance rates with PD regimens is because 'compliance' itself has never been adequately conceptualized or defined; thus, it is difficult to operationalize and quantify. This paper examines how a group of Australian renal nurses construct patient compliance with PD therapy. These empirical data illuminate how PD compliance operates in one practice setting; how it is characterized by multiple and often competing energies; and how ultimately it might be pointless to try to tame 'compliance' through rigid definitions and measurement, or to rigidly enforce it in PD patients. The energies involved are too fractious and might be better spent, as many of the more experienced nurses in this study argue, in augmenting the energies that do work well together to improve patient outcomes.

Renal Drug Dosing

PubMed Central

Vogel, Erin A.; Billups, Sarah J.; Herner, Sheryl J.

2016-01-01

Summary Objective The purpose of this study was to compare the effectiveness of an outpatient renal dose adjustment alert via a computerized provider order entry (CPOE) clinical decision support system (CDSS) versus a CDSS with alerts made to dispensing pharmacists. Methods This was a retrospective analysis of patients with renal impairment and 30 medications that are contraindicated or require dose-adjustment in such patients. The primary outcome was the rate of renal dosing errors for study medications that were dispensed between August and December 2013, when a pharmacist-based CDSS was in place, versus August through December 2014, when a prescriber-based CDSS was in place. A dosing error was defined as a prescription for one of the study medications dispensed to a patient where the medication was contraindicated or improperly dosed based on the patient’s renal function. The denominator was all prescriptions for the study medications dispensed during each respective study period. Results During the pharmacist- and prescriber-based CDSS study periods, 49,054 and 50,678 prescriptions, respectively, were dispensed for one of the included medications. Of these, 878 (1.8%) and 758 (1.5%) prescriptions were dispensed to patients with renal impairment in the respective study periods. Patients in each group were similar with respect to age, sex, and renal function stage. Overall, the five-month error rate was 0.38%. Error rates were similar between the two groups: 0.36% and 0.40% in the pharmacist- and prescriber-based CDSS, respectively (p=0.523). The medication with the highest error rate was dofetilide (0.51% overall) while the medications with the lowest error rate were dabigatran, fondaparinux, and spironolactone (0.00% overall). Conclusions Prescriber- and pharmacist-based CDSS provided comparable, low rates of potential medication errors. Future studies should be undertaken to examine patient benefits of the prescriber-based CDSS. PMID:27466041

Renal MR angiography and perfusion in the pig using hyperpolarized water.

PubMed

Wigh Lipsø, Kasper; Hansen, Esben Søvsø Szocska; Tougaard, Rasmus Stilling; Laustsen, Christoffer; Ardenkjaer-Larsen, Jan Henrik

2017-09-01

To study hyperpolarized water as an angiography and perfusion tracer in a large animal model. Protons dissolved in deuterium oxide (D 2 O) were hyperpolarized in a SPINlab dissolution dynamic nuclear polarization (dDNP) polarizer and subsequently investigated in vivo in a pig model at 3 Tesla (T). Approximately 15 mL of hyperpolarized water was injected in the renal artery by hand over 4-5 s. A liquid state polarization of 5.3 ± 0.9% of 3.8 M protons in 15 mL of deuterium oxide was achieved with a T 1 of 24 ± 1 s. This allowed injection through an arterial catheter into the renal artery and subsequently high-contrast imaging of the entire kidney parenchyma over several seconds. The dynamic images allow quantification of tissue perfusion, with a mean cortical perfusion of 504 ± 123 mL/100 mL/min. Hyperpolarized water MR imaging was successfully demonstrated as a renal angiography and perfusion method. Quantitative perfusion maps of the kidney were obtained in agreement with literature and control experiments with gadolinium contrast. Magn Reson Med 78:1131-1135, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Mineral Metabolism in European Children Living with a Renal Transplant: A European Society for Paediatric Nephrology/European Renal Association–European Dialysis and Transplant Association Registry Study

PubMed Central

Bonthuis, Marjolein; Busutti, Marco; Jager, Kitty J.; Baiko, Sergey; Bakkaloğlu, Sevcan; Battelino, Nina; Gaydarova, Maria; Gianoglio, Bruno; Parvex, Paloma; Gomes, Clara; Heaf, James G.; Podracka, Ludmila; Kuzmanovska, Dafina; Molchanova, Maria S.; Pankratenko, Tatiana E.; Papachristou, Fotios; Reusz, György; Sanahuja, Maria José; Shroff, Rukshana; Groothoff, Jaap W.; Schaefer, Franz; Verrina, Enrico

2015-01-01

Background and objectives Data on mineral metabolism in pediatric renal transplant recipients largely arise from small single-center studies. In adult patients, abnormal mineral levels are related to a higher risk of graft failure. This study used data from the European Society for Paediatric Nephrology/European Renal Association–European Dialysis and Transplant Association Registry to study the prevalence and potential determinants of mineral abnormalities, as well as the predictive value of a disturbed mineral level on graft survival in a large cohort of European pediatric renal transplant recipients. Design, setting, participants, & measurements This study included 1237 children (0–17 years) from 10 European countries, who had serum calcium, phosphorus, and parathyroid hormone measurements from 2000 onward. Abnormalities of mineral metabolism were defined according to European guidelines on prevention and treatment of renal osteodystrophy in children on chronic renal failure. Results Abnormal serum phosphorus levels were observed in 25% (14% hypophosphatemia and 11% hyperphosphatemia), altered serum calcium in 30% (19% hypocalcemia, 11% hypercalcemia), and hyperparathyroidism in 41% of the patients. A longer time since transplantation was associated with a lower risk of having mineral levels above target range. Serum phosphorus levels were inversely associated with eGFR, and levels above the recommended targets were associated with a higher risk of graft failure independently of eGFR. Conclusions Abnormalities in mineral metabolism are common after pediatric renal transplantation in Europe and are associated with graft dysfunction. PMID:25710805

Renal Cell Carcinoma Perfusion before and after Radiofrequency Ablation Measured with Dynamic Contrast Enhanced MRI: A Pilot Study.

PubMed

Wah, Tze Min; Sourbron, Steven; Wilson, Daniel Jonathan; Magee, Derek; Gregory, Walter Martin; Selby, Peter John; Buckley, David L

2018-01-08

To investigate if the early treatment effects of radiofrequency ablation (RFA) on renal cell carcinoma (RCC) can be detected with dynamic contrast enhanced (DCE)-MRI and to correlate RCC perfusion with RFA treatment time. 20 patients undergoing RFA of their 21 RCCs were evaluated with DCE-MRI before and at one month after RFA treatment. Perfusion was estimated using the maximum slope technique at two independent sittings. Total RCC blood flow was correlated with total RFA treatment time, tumour location, size and histology. DCE-MRI examinations were successfully evaluated for 21 RCCs (size from 1.3 to 4 cm). Perfusion of the RCCs decreased significantly ( p < 0.0001) from a mean of 203 (±80) mL/min/100 mL before RFA to 8.1 (±3.1) mL/min/100 mL after RFA with low intra-observer variability ( r ≥ 0.99, p < 0.0001). There was an excellent correlation ( r = 0.95) between time to complete ablation and pre-treatment total RCC blood flow. Tumours with an exophytic location exhibit the lowest mean RFA treatment time. DCE-MRI can detect early treatment effects by measuring RCC perfusion before and after RFA. Perfusion significantly decreases in the zone of ablation, suggesting that it may be useful for the assessment of treatment efficacy. Pre-RFA RCC blood flow may be used to predict RFA treatment time.

Renal echo-3D and microalbuminuria in children of diabetic mothers: a preliminary study.

PubMed

Cappuccini, B; Torlone, E; Ferri, C; Arnone, S; Troiani, S; Bini, V; Bellomo, G; Barboni, G; Di Renzo, G

2013-08-01

Maternal diabetes has assumed epidemic relevance in recent years and animal studies have provided some evidence that it may cause abnormalities in renal development and a reduction in nephron endowment in the offspring; however, human data are lacking. The renal cortex contains ∼95% of the glomeruli and its volume could be taken as a surrogate measure of glomerular number; based on this assumption, we measured renal cortex volume and in addition, microalbuminuria in a homogeneous sample of 42 children of diabetic (pregestational, n = 13, and gestational, n = 29) mothers, compared with 21 healthy children born of non-diabetic mothers. The offspring of diabetic mothers showed a significant reduction of renal cortex volume and higher albumin excretion compared with controls, possibly attributable to a reduction in the number of nephrons and the difference was statistically significant (P < 0.001). Although further studies on a larger sample are necessary, our preliminary findings suggest that maternal diabetes may affect renal development with sequelae later in life, requiring closer monitoring and follow-up. Furthermore, the importance of strict maternal diabetes management and control must be emphasized.

Renal hemodynamics in space.

PubMed

Kramer, H J; Heer, M; Cirillo, M; De Santo, N G

2001-09-01

Renal excretory function and hemodynamics are determined by the effective circulating plasma volume as well as by the interplay of systemic and local vasoconstrictors and vasodilators. Microgravity results in a headward shift of body fluid. Because the control conditions of astronauts were poorly defined in many studies, controversial results have been obtained regarding diuresis and natriuresis as well as renal hemodynamic changes in response to increased central blood volume, especially during the initial phase of space flight. Renal excretory function and renal hemodynamics in microgravity are affected in a complex fashion, because during the initial phase of space flight, variable mechanisms become operative to modulate the effects of increased central blood volume. They include interactions between vasodilators (dopamine, atrial natriuretic peptide, and prostaglandins) and vasoconstrictors (sympathetic nervous system and the renin-angiotensin system). The available data suggest a moderate rise in glomerular filtration rate during the first 2 days after launch without a significant increase in effective renal plasma flow. In contrast, too few data regarding the effects of space flight on renal function during the first 12 hours after launch are available and are, in addition, partly contradictory. Thus, detailed and well-controlled studies are required to shed more light on the role of the various factors besides microgravity that determine systemic and renal hemodynamics and renal excretory function during the different stages of space flight.

Comparison of renal ultrasonography and dimercaptosuccinic acid renal scintigraphy in febrile urinary tract infection.

PubMed

Ayazi, Parviz; Mahyar, Abolfazl; Noroozian, Elham; Esmailzadehha, Neda; Barikani, Ameneh

2015-12-01

Accurate and early diagnosis and appropriate treatment of patient with urinary tract infection (UTI) are essential for the prevention or restriction of permanent damage to the kidneys in children. The aim of this study was to compare renal ultrasonography (US) and dimercaptosuccinic acid (DMSA) renal scan in the diagnosis of patients with febrile urinary tract infection. This study involved the medical records of children with febrile urinary tract infection who were admitted to the children's hospital in Qazvin, Iran. Pyelonephritis was diagnosed on the basis of clinical symptoms, laboratory tests and abnormal DMSA renal scans. The criteria for abnormality of renal US were an increase or a decrease in diffuse or focal parenchymal echogenicity, loss of corticomedullary differentiation, kidney position irregularities, parenchymal reduction and increased kidney size. Of the 100 study patients, 23% had an abnormal US and 46% had an abnormal DMSA renal scan. Of the latter patients, 15 had concurrent abnormal US (P value ≤ 0.03, concordance rate: 18%). Renal US had a sensitivity of 32%, specificity of 85%, positive predictive value of 65% and negative predictive value of 60%. Of the 77 patients with normal US, 31 (40.2%) had an abnormal DMSA renal scan. Despite the benefits and accessibility of renal US, its value in the diagnosis of pyelonephritis is limited.

99mtechnetium-dimercapto-succinic acid renal scanning and excretory urography in diagnosis of renal scars in children

DOE Office of Scientific and Technical Information (OSTI.GOV)

McLorie, G.A.; Aliabadi, H.; Churchill, B.M.

1989-09-01

We compared the ability of excretory urography (without tomography) and 99mtechnetium-dimercapto-succinic acid renal scanning to detect renal scars in 32 children with primary vesicoureteral reflux. These children did not have hydronephrosis, renal failure or urinary tract obstruction. In all cases both studies were conducted within a 10-month period. The findings from both modalities were in agreement for 51 of the 64 renal units evaluated (80%). Evaluation of the excretory urogram indicated 6 cases of diffuse and 2 of focal scarring that were not detected by evaluation of the renal scan. The sensitivity of excretory urography to detect renal scars wasmore » 84% and the specificity was 83%. The 99mtechnetium-dimercapto-succinic acid renal scan showed 5 cases of focal renal scarring not detected by excretory urography. The sensitivity of the renal scan to detect renal scars was 77% and the specificity was 75%. We conclude that neither study alone could effectively replace the other for the detection of renal scars, and recommend that both be included in the initial evaluation and followup of patients with renal scars.« less

Accessory renal arteries: Prevalence in resistant hypertension and an important role in nonresponse to radiofrequency renal denervation.

PubMed

VonAchen, Paige; Hamann, Jason; Houghland, Thomas; Lesser, John R; Wang, Yale; Caye, David; Rosenthal, Kristi; Garberich, Ross F; Daniels, Mary; Schwartz, Robert S

The aim of this study was to understand the role of accessory renal arteries in resistant hypertension, and to establish their role in nonresponse to radiofrequency renal denervation (RDN) procedures. Prior studies suggest a role for accessory renal arteries in hypertensive syndromes, and recent clinical trials of renal denervation report that these anomalies are highly prevalent in resistant hypertension. This study evaluated the relationships among resistant hypertension, accessory renal arteries, and the response to radiofrequency (RF) renal denervation. Computed Tomography Angiography (CTA) and magnetic resonance imaging (MRI) scans from 58 patients with resistant hypertension undergoing RF renal denervation (RDN) were evaluated. Results were compared with CT scans in 57 healthy, normotensive subjects undergoing screening as possible renal transplant donors. All scans were carefully studied for accessory renal arteries, and were correlated with long term blood pressure reduction. Accessory renal arteries were markedly more prevalent in the hypertensive patients than normotensive renal donors (59% vs 32% respectively, p=0.004). RDN had an overall nonresponse rate of 29% (response rate 71%). Patients without accessory vessels had a borderline higher response rate to RDN than those with at least one accessory vessel (83% vs 62% respectively, p=0.076) and a higher RDN response than patients with untreated accessory arteries (83% vs 55%; p=0.040). For accessory renal arteries and nonresponse, the sensitivity was 76%, specificity 49%, with positive and negative predictive values 38% and 83% respectively. Accessory renal arteries were markedly over-represented in resistant hypertensives compared with healthy controls. While not all patients with accessory arteries were nonresponders, nonresponse was related to both the presence and non-treatment of accessory arteries. Addressing accessory renal arteries in future clinical trials may improve RDN therapeutic efficacy

Can MR Measurement of Renal Artery Flow and Renal Volume Predict the Outcome of Percutaneous Transluminal Renal Angioplasty?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Binkert, Christoph A.; Debatin, Jorg F.; Schneider, Ernst

2001-07-15

Purpose: Predicting therapeutic benefit from percutaneous transluminal renal angioplasty (PTRA) in patients with renal artery stenosis (RAS) remains difficult. This study investigates whether magnetic resonance (MR)-based renal artery flow measurements relative to renal parenchymal volume can predict clinical outcome following PTRA.Methods: The data on 23 patients (13 men, 10 women; age range 47-82 years, mean age 64 years) were analyzed. The indication for treatment was hypertension (n = 18) or renal insufficiency (n = 5). Thirty-four cases of RAS were identified: bilateral disease was manifest in 11 and unilateral disease in 12 patients. The MR imaging protocol included a breath-hold,more » cardiac-gated cine phase-contrast sequence for renal flow measurement and a fast multiplanar spoiled gradient-echo sequence for renal volume measurement. MR measurements were performed on the day prior to and the day following PTRA. Clinical success was defined as (a) a reduction in diastolic blood pressure > 15% or (b) a reduction in serum creatinine > 20%. Kidneys were categorized as normal volume or low volume. A renal flow index (RFI) was calculated by dividing the renal flow (ml/min) by the renal volume (cm{sup 3}).Results: Clinical success was observed in 11 patients. Twelve patients did not benefit from angioplasty. Normal kidney volume was seen in 10 of 11 responders and in 8 of 12 nonresponders, resulting in a sensitivity of 91%, specificity of 33%, a positive predictive value (PPV) of 56% and a negative predictive value (NPV) of 80%. A RFI below a threshold of 1.5 ml/min/cm{sup 3} predicted successful outcome with 100% sensitivity, 33% specificity, 58% PPV, and 100% NPV. The combination of normal renal volume and a RFI below 1.5 ml/min/cm{sup 3} identified PTRA responders with a sensitivity of 91%, a specificity of 67%, a PPV of 71%, and a NPV of 89%. PTRA resulted in a greater increase in renal flow in responders compared with nonresponders (p < 0.001).Conclusion

A study of the role of renal nerves in the renal responses to 60° head-up tilt in the anaesthetized dog

PubMed Central

DiBona, G. F.; Johns, E. J.

1980-01-01

1. Renal responses to 10 min of 60° head-up tilt were measured in anaesthetized dogs in which renal perfusion pressure was maintained at a relatively constant value. 2. Tilting was associated with a fall in systemic blood pressure and an increase in heart rate. Renal blood flow and glomerular filtration rate remained constant while there was a significant decrease in both absolute and fractional excretion of sodium. 3. Animals which had undergone acute renal denervation were tilted. The cardiovascular responses were similar to intact animals. A fall in renal blood flow was observed but the glomerular filtration rate was maintained at a steady value during tilting. The decreased renal tubular excretion of sodium measured in intact animals was abolished. 4. Alpha-adrenergic blockade of the kidney was achieved by infusion of phentolamine into the renal artery. Tilting of these animals caused cardiovascular changes similar to those observed in control animals but renal blood flow, glomerular filtration rate and sodium handling remained unchanged. 5. Animals in which both carotid sinuses had been acutely denervated were tilted. Systemic blood pressure fell as in intact animals, but the rise in heart rate was significantly less. Renal blood flow, glomerular filtration rate and the rate of sodium excretion were unchanged. 6. A 10 min period of 60° head-up tilt in anaesthetized dogs resulted in an unchanged renal blood flow and glomerular filtration rate which was associated with a decrease in both fractional excretion of sodium and sodium excretion. The renal sympathetic nerves were shown to be responsible for these changes in tubular sodium handling which appeared to exert their action via renal tubular α-adrenergic receptors. This activation of the renal nerves appeared to be mediated by the carotid sinus baroreceptor reflex. PMID:7381761

Renal telemedicine through video-as-a-service delivered to patients on home dialysis: A qualitative study on the renal care team members' experience.

PubMed

Ditchburn, Jae-Llane; Marshall, Alison

2017-09-01

The Lancashire Teaching Hospitals NHS Trust in the UK has been providing renal care through video-as-a-service (VAAS) to patients since 2013, with support from the North West NHS Shared Infrastructure Service, a collaborative team that supports information and communication technology use in the UK National Health Service. Renal telemedicine offered remotely to patients on home dialysis supports renal care through the provision of a live high-quality video link directly to unsupported patients undergoing haemodialysis at home. Home haemodialysis is known to provide benefits to patients, particularly in making them more independent. The use of a telemedicine video-link in Lancashire and South Cumbria, UK, further reduces patient dependence on the professional team. The purpose of this paper is to present the perspectives of the renal care team members using the renal telemedicine service to understand the perceived benefits and issues with the service. Ten semi-structured interviews with members of the renal care team (two renal specialists, one matron, two renal nurses, one business manager, one renal technical services manager, two IT technicians and one hardware maintenance technician) were conducted. Thematic analysis was undertaken to analyse the qualitative data. A range of incremental benefits to the renal team members were reported, including more efficient use of staff time, reduced travel, peace of mind and a strong sense of job satisfaction. Healthcare staff believed that remote renal care through video was useful, encouraged concordance and could nurture confidence in patients. Key technological issues and adjustments which would improve the renal telemedicine service were also identified. The impact of renal telemedicine was positive on the renal team members. The use of telemedicine has been demonstrated to make home dialysis delivery more efficient and safe. The learning from staff feedback could inform development of services elsewhere. © 2017

Renal contrast-enhanced MR angiography: timing errors and accurate depiction of renal artery origins.

PubMed

Schmidt, Maria A; Morgan, Robert

2008-10-01

To investigate bolus timing artifacts that impair depiction of renal arteries at contrast material-enhanced magnetic resonance (MR) angiography and to determine the effect of contrast agent infusion rates on artifact generation. Renal contrast-enhanced MR angiography was simulated for a variety of infusion schemes, assuming both correct and incorrect timing between data acquisition and contrast agent injection. In addition, the ethics committee approved the retrospective evaluation of clinical breath-hold renal contrast-enhanced MR angiographic studies obtained with automated detection of contrast agent arrival. Twenty-two studies were evaluated for their ability to depict the origin of renal arteries in patent vessels and for any signs of timing errors. Simulations showed that a completely artifactual stenosis or an artifactual overestimation of an existing stenosis at the renal artery origin can be caused by timing errors of the order of 5 seconds in examinations performed with contrast agent infusion rates compatible with or higher than those of hand injections. Lower infusion rates make the studies more likely to accurately depict the origin of the renal arteries. In approximately one-third of all clinical examinations, different contrast agent uptake rates were detected on the left and right sides of the body, and thus allowed us to confirm that it is often impossible to optimize depiction of both renal arteries. In three renal arteries, a signal void was found at the origin in a patent vessel, and delayed contrast agent arrival was confirmed. Computer simulations and clinical examinations showed that timing errors impair the accurate depiction of renal artery origins. (c) RSNA, 2008.

Simultaneous evaluation of renal morphology and function in live kidney donors using dynamic magnetic resonance imaging.

PubMed

Artunc, F; Yildiz, S; Rossi, C; Boss, A; Dittmann, H; Schlemmer, H P; Risler, T; Heyne, N

2010-06-01

Evaluation of potential kidney donors requires the assessment of both kidney anatomy and function. In this prospective study, we sought to expand the diagnostic yield of magnetic resonance (MR) by adding functional measurements of glomerular filtration rate (GFR) and split renal function. Between 2007 and 2009, all potential kidney donors presenting to our facility underwent a comprehensive single-stop MR study that included an assessment of anatomy, angiography and functional measurements. GFR was measured after a bolus injection of gadobutrol (4 ml, approximately 0.05 mmol/kg) and calculated from the washout of the signal intensity obtained over the liver. Split renal function was calculated from the increase of signal intensity over the renal cortex. Values were compared to renal scintigraphy with (99m)Tc-DTPA from the same day. The MR investigation was successfully performed in 21 participants. The GFR derived from MR (MR-GFR) correlated well (r = 0.84) with the GFR derived from scintigraphy (DTPA-GFR). The mean value of the paired differences was 4 +/- 13 [SD] ml/min/1.73 m(2) and was not significantly different from zero. The ratio between right and left kidney function was similar with both techniques (1.01 +/- 0.17 with MR and 1.06 +/- 0.12 with scintigraphy, P = 0.20). We demonstrate an MR-based approach to comprehensively evaluate both kidney anatomy and function in a single investigation, thereby facilitating the evaluation of potential kidney donors.

Vitamin E Intake and Risk of Renal Cell Carcinoma: A Meta-Analysis of 7 Case-Control Studies.

PubMed

Shang, Yonggang; Yi, Shanhong; Cui, Dong; Han, Guangwei; Liu, Chengcheng

2015-07-01

Vitamin E intake may reduce the risk of renal cell carcinoma, but the results were inconsistent. Hence, we conducted a meta-analysis to assess the association between dietary vitamin E intake and the risk of renal cell carcinoma. We searched PubMed to identify the relevant case-control studies up to June 2014. Reference lists of retrieved articles were also reviewed. Odds ratios and corresponding 95% confidence intervals were used to estimate the association between dietary vitamin E intake and the risk of renal cell carcinoma. We identified 7 case-control studies regarding dietary vitamin E intake and risk of renal cell carcinoma, involving 5789 cases and 14866 controls. The odds ratio of renal cell carcinoma for the highest compared with the lowest dietary vitamin E intake was 0.75 (95% confidence interval: 0.59-0.91), and heterogeneity was observed across studies. The association between dietary vitamin E intake and the risk of renal cell carcinoma was not significantly differed by gender, but this association were inconsistent in the North American and European populations. Our study provided a evidence that there was a significant inverse association of dietary vitamin E intake with risk of renal cell carcinoma. However, this finding was based on the case-control studies, more well-designed cohort studies are needed. Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Dynamic PET evaluation of elevated FLT level after sorafenib treatment in mice bearing human renal cell carcinoma xenograft.

PubMed

Ukon, Naoyuki; Zhao, Songji; Yu, Wenwen; Shimizu, Yoichi; Nishijima, Ken-Ichi; Kubo, Naoki; Kitagawa, Yoshimasa; Tamaki, Nagara; Higashikawa, Kei; Yasui, Hironobu; Kuge, Yuji

2016-12-01

Sorafenib, an oral multikinase inhibitor, has anti-proliferative and anti-angiogenic activities and is therapeutically effective against renal cell carcinoma (RCC). Recently, we have evaluated the tumor responses to sorafenib treatment in a RCC xenograft using [Methyl- 3 H(N)]-3'-fluoro-3'-deoxythythymidine ([ 3 H]FLT). Contrary to our expectation, the FLT level in the tumor significantly increased after the treatment. In this study, to clarify the reason for the elevated FLT level, dynamic 3'-[ 18 F]fluoro-3'-deoxythymidine ([ 18 F]FLT) positron emission tomography (PET) and kinetic studies were performed in mice bearing a RCC xenograft (A498). The A498 xenograft was established in nude mice, and the mice were assigned to the control (n = 5) and treatment (n = 5) groups. The mice in the treatment group were orally given sorafenib (20 mg/kg/day p.o.) once daily for 3 days. Twenty-four hours after the treatment, dynamic [ 18 F]FLT PET was performed by small-animal PET. Three-dimensional regions of interest (ROIs) were manually defined for the tumors. A three-compartment model fitting was carried out to estimate four rate constants using the time activity curve (TAC) in the tumor and the blood clearance rate of [ 18 F]FLT. The dynamic pattern of [ 18 F]FLT levels in the tumor significantly changed after the treatment. The rate constant of [ 18 F]FLT phosphorylation (k 3 ) was significantly higher in the treatment group (0.111 ± 0.027 [1/min]) than in the control group (0.082 ± 0.009 [1/min]). No significant changes were observed in the distribution volume, the ratio of [ 18 F]FLT forward transport (K 1 ) to reverse transport (k 2 ), between the two groups (0.556 ± 0.073 and 0.641 ± 0.052 [mL/g] in the control group). Our dynamic PET studies indicated that the increase in FLT level may be caused by the phosphorylation of FLT in the tumor after the sorafenib treatment in the mice bearing a RCC xenograft. Dynamic PET studies with kinetic

Influence of the renal artery ostium flow diverter on hemodynamics and atherogenesis.

PubMed

Albert, Scott; Balaban, Robert S; Neufeld, Edward B; Rossmann, Jenn Stroud

2014-05-07

The structure and function of the renal artery ostium flow diverter on the caudal side of the renal branch point were previously reported; in this study, we further evaluate the diverter׳s possible functions. The protrusion of this structure into the abdominal aorta suggests that the diverter may preferentially direct blood flow to the renal arteries, and that it may also influence flow patterns and recirculation known to be involved in atherogenesis. Three-dimensional computational fluid dynamics (CFD) simulations of steady and pulsatile blood flow are performed to investigate the influence of diverter size and position, and vascular geometry, on the flow patterns and fluid mechanical forces in the neighborhood of the diverter. CFD results show that the flow diverter does affect the blood distribution; depending on the diverter׳s position, the flow to the renal arteries may be increased or reduced. Calculated results also demonstrate the diverter׳s effect on the wall shear stress (WSS) distribution, and suggest that the diverter contributes to an atherogenic environment in the abdominal aorta, while being atheroprotective in the renal arteries themselves. These results support previous clinical findings, and suggest directions for further clinical study. The results of this work have direct implications in understanding the physiological significance of the diverter, and its potential role in the pathophysiological development of atherosclerosis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of the renal artery ostium flow diverter on hemodynamics and atherogenesis

PubMed Central

Albert, Scott; Balaban, Robert S.; Neufeld, Edward B.; Rossmann, Jenn Stroud

2014-01-01

The structure and function of the renal artery ostium flow diverter on the caudal side of the renal branch point were previously reported; in this study, we further evaluate the diverter’s possible functions. The protrusion of this structure into the abdominal aorta suggests that the diverter may preferentially direct blood flow to the renal arteries, and that it may also influence flow patterns and recirculation known to be involved in atherogenesis. Three-dimensional computational fluid dynamics (CFD) simulations of steady and pulsatile blood flow are performed to investigate the influence of diverter size and position, and vascular geometry, on the flow patterns and fluid mechanical forces in the neighborhood of the diverter. CFD results show that the flow diverter does affect the blood distribution: depending on the diverter’s position, the flow to the renal arteries may be increased or reduced. Calculated results also demonstrate the diverter’s effect on the Wall Shear Stress (WSS) distribution, and suggest that the diverter contributes to an atherogenic environment in the abdominal aorta, while being atheroprotective in the renal arteries themselves. These results support previous clinical findings, and suggest directions for further clinical study. The results of this work have direct implications in understanding the physiological significance of the diverter, and its potential role in the pathophysiological development of atherosclerosis. PMID:24703300

Renal Hemodynamics and Ammoniagenesis

PubMed Central

Lemieux, Guy; Vinay, Patrick; Cartier, Pierre

1974-01-01

Renal production of ammonia by the left kidney was studied in 31 acidotic dogs (NH4Cl) after acute constriction of the renal artery. Renal ammoniagenesis fell in direct proportion with the reduction in glomerular filtration rate and renal plasma flow. The renal extraction of glutamine by the experimental kidney fell in direct proportion with the reduction in renal hemodynamics. Extracted glutamine remained greater than filtered glutamine indicating that both the luminal and antiluminal transport sites were operative. The relationship between renal extraction of glutamine and ammoniagenesis observed during control was maintained after renal artery constriction (1.7 μmol NH3 produced for each μmol of glutamine extracted). Systemic venous or renal intra-arterial infusion of glutamine during arterial constriction increased renal production of ammonia to or above control values. These observations indicate that the mechanisms responsible for glutamine extraction and ammonia production were operating normally despite reduced hemodynamics. When measured immediately after arterial clamping, the renal venous pNH3 was found to rise significantly decreasing progressively thereafter towards control values. The extracted fraction of total glutamine delivered to the kidney (31%) did not change after acute reduction of the glutamine load. Thus, the antiluminal extraction site was incapable of lowering renal venous plasma glutamine concentration below 0.33 μM/ml. In a second series of experiments, the properties of the antiluminal site of transport for glutamine were studied after complete occlusion of the left ureter in acidotic and nonacidotic animals. Under these circumstances, it was demonstrated that the antiluminal site is capable of extracting sufficient glutamine to maintain total ammonia production at 60% or more of control. In acidotic animals, changes in cellular pNH3 appeared to play a key role on the antiluminal extraction of glutamine since the significant rise in

Long-term verification of functional and structural renal damage after renal sympathetic denervation.

PubMed

Dörr, Oliver; Liebetrau, Christoph; Möllmann, Helge; Gaede, Luise; Troidl, Christian; Wiebe, Jens; Renker, Matthias; Bauer, Timm; Hamm, Christian; Nef, Holger

2016-06-01

Previous studies of renal sympathetic denervation (RSD) excluded patients with impaired renal function to avoid potential RSD-related renal damage. Measurement of the highly sensitive biomarkers neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) has shown that RSD does not aggravate renal damage during the early post-procedural period. The aim of the present study was to examine the effect of RSD on blood pressure (BP) reduction and renal function after a long-term follow-up. A total of 62 consecutive patients undergoing RSD were included in this study. Serum NGAL and KIM-1 were collected prior to RSD and at 24 hr, 48 hr, and 3 months after RSD. BP measurements, antihypertensive medication use, and safety events were followed over a three-year period. Follow-up data were available over 36.9[±3.4] months in 47 of 62 (75.8%) of the initially included patients. At this time point a significant systolic BP reduction of 23 mm Hg (P > 0.001) was documented, and there were no significant changes in serum creatinine (P = 0.14), blood urea nitrogen (P = 0.33), or estimated glomerular filtration rate (eGFR) (P = 0.2) values. There were also no significant changes documented in patients with impaired renal function (eGFR < 45 mL/min) during the early post- procedural period or the long-term follow-up (P = 0.34). The results of the present study show a sustained effect of RSD on BP reduction after a three-year follow-up, and there was no evidence of renal failure. These results provide verification of the long-term safety and effectiveness of RSD, even in patients with impaired renal function. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Use of computed tomography renal angiography for screening feline renal transplant donors.

PubMed

Bouma, Jennifer L; Aronson, Lillian R; Keith, Dennis G; Saunders, H Mark

2003-01-01

Preoperative knowledge of the renal vascular anatomy is important for selection of the appropriate feline renal donor. Intravenous urograms (IVUs) have been performed routinely to screen potential donors at the Veterinary Hospital of the University of Pennsylvania (VHUP), but the vascular phase views lack sufficient detail of the renal vascular anatomy. Computed tomography angiography (CTA), which requires a helical computed tomography (CT) scanner, has been found to provide superior renal vascular anatomic information of prospective human renal donors. The specific aims of this study were as follows: 1) develop the CTA technique for the feline patient; and 2) obtain preliminary information on feline renal vessel anatomy in potential renal donors. Ten healthy, potential feline renal donors were anesthetized and imaged using a third-generation helical CT scanner. The time delay between i.v. contrast medium injection and image acquisition, and other parameters of slice collimation, slice interval, pitch, exposure settings, and reconstruction algorithms were varied to maximize contrast medium opacification of the renal vascular anatomy. Optimal CTA acquisition parameters were determined to be: 1) 10-sec delay post-i.v. bolus of iodinated contrast medium; 2) two serially acquired (corresponding to arterial and venous phases) helical scans through the renal vasculature; 3) pitch of 2 (4 mm/sec patient translation, 2 mm slice collimation); and 4) 120-kVp, 160-mA, and 1-sec exposure settings. Retrospective reconstructed CTA transverse images obtained at a 2-mm slice width and a 1-mm slice interval in combination with two-dimensional reformatted images and three-dimensional reconstructed images were qualitatively evaluated for vascular anatomy; vascular anatomy was confirmed at surgery. Four cats had single renal arteries and veins bilaterally; four cats had double renal veins. One cat had a small accessory artery supplying the caudal pole of the left kidney. One cat had a

[Pleural metastases of renal carcinoma].

PubMed

Giigoruk, O G; Lazarev, A F; Doroshenko, V S

2007-01-01

Metastases in renal carcinoma are diagnosed at initial diagnosis in 25% examinees. Traditional renal carcinoma has higher metastatic potential, is associated with worse survival of the patients compared to papillary cancer. We studied cytological characteristics of renal carcinoma metastases to the pleura in comparison with histological studies of the primary lesion using immunohistochemical findings. We examined cytologically pleural liquid in renal carcinoma metastases to the pleura in 6 patients (2.3% of carcinomatous pleuricies). High efficacy was shown by a cytocentrifuge CYTOSPIN-4. In 3 cases initial cancer was renal cell carcinoma, pleural exudation developed 2 years later, clear cell carcinoma appeared 6 years later and papillary cancer--10 years later. In the other 3 cases malignant cells were detected in new-onset cases. Renal carcinoma was diagnosed in one case. Cytological preparations were studied with identification of cytological signs typical for classic clear cell, granulocell and papillary renal cancer. Immunohistochemical examination of primary tumor lesion in the kidney discovered high proliferative activity of tumor cells by Ki-67 index to 5.28%. The tumors had solitary Bcl-2 positive cells. Expression of mutant p-53 took place in 0.93%. Her-2/neu hyperexpression was not found in the tumors of the above patients. Such immunohistochemical parameters point to poor prognosis. This is confirmed by renal carcinoma metastases to the pleura.

Precise measurement of renal filtration and vascular parameters using a two-compartment model for dynamic contrast-enhanced MRI of the kidney gives realistic normal values.

PubMed

Tofts, Paul S; Cutajar, Marica; Mendichovszky, Iosif A; Peters, A Michael; Gordon, Isky

2012-06-01

To model the uptake phase of T(1)-weighted DCE-MRI data in normal kidneys and to demonstrate that the fitted physiological parameters correlate with published normal values. The model incorporates delay and broadening of the arterial vascular peak as it appears in the capillary bed, two distinct compartments for renal intravascular and extravascular Gd tracer, and uses a small-vessel haematocrit value of 24%. Four physiological parameters can be estimated: regional filtration K ( trans ) (ml min(-1) [ml tissue](-1)), perfusion F (ml min(-1) [100 ml tissue](-1)), blood volume v ( b ) (%) and mean residence time MRT (s). From these are found the filtration fraction (FF; %) and total GFR (ml min(-1)). Fifteen healthy volunteers were imaged twice using oblique coronal slices every 2.5 s to determine the reproducibility. Using parenchymal ROIs, group mean values for renal biomarkers all agreed with published values: K ( trans ): 0.25; F: 219; v ( b ): 34; MRT: 5.5; FF: 15; GFR: 115. Nominally cortical ROIs consistently underestimated total filtration (by ~50%). Reproducibility was 7-18%. Sensitivity analysis showed that these fitted parameters are most vulnerable to errors in the fixed parameters kidney T(1), flip angle, haematocrit and relaxivity. These renal biomarkers can potentially measure renal physiology in diagnosis and treatment. • Dynamic contrast-enhanced magnetic resonance imaging can measure renal function. • Filtration and perfusion values in healthy volunteers agree with published normal values. • Precision measured in healthy volunteers is between 7 and 15%.

3.0Tesla magnetic resonance angiography (MRA) for comprehensive renal evaluation of living renal donors: pilot study with computerized tomography angiography (CTA) comparison.

PubMed

Gulati, Mittul; Dermendjian, Harout; Gómez, Ana M; Tan, Nelly; Margolis, Daniel J; Lu, David S; Gritsch, H Albin; Raman, Steven S

2016-01-01

Most living related donor (LRD) kidneys are harvested laparoscopically. Renal vascular anatomy helps determine donor suitability for laparoscopic nephrectomy. Computed tomography angiography (CTA) is the current gold standard for preoperative imaging; magnetic resonance angiography (MRA) offers advantages including lack of ionizing radiation and lower incidence of contrast reactions. We evaluated 3.0T MRA for assessing renal anatomy of LRDs. Thirty consecutive LRDs underwent CTA followed by 3.0T MRA. Data points included number and branching of vessels, incidental findings, and urothelial opacification. Studies were individually evaluated by three readers blinded to patient data. Studies were reevaluated in consensus with discrepancies revealed, and final consensus results were labeled "truth". Compared with consensus "truth", both computed tomography (CT) and magnetic resonance imaging were highly accurate for assessment of arterial and venous anatomy, although CT was superior for detection of late venous confluence as well as detection of renal stones. Both modalities were comparable in opacification of lower ureters and bladder; MRA underperformed CTA for opacification of upper urinary tracts. 3.0T MRA enabled excellent detection of comprehensive renal anatomy compared to CTA in LRDs. Copyright © 2016 Elsevier Inc. All rights reserved.

Four-dimensional MRI of renal function in the developing mouse.

PubMed

Xie, Luke; Subashi, Ergys; Qi, Yi; Knepper, Mark A; Johnson, G Allan

2014-09-01

The major roles of filtration, metabolism and high blood flow make the kidney highly vulnerable to drug-induced toxicity and other renal injuries. A method to follow kidney function is essential for the early screening of toxicity and malformations. In this study, we acquired high spatiotemporal resolution (four dimensional) datasets of normal mice to follow changes in kidney structure and function during development. The data were acquired with dynamic contrast-enhanced MRI (via keyhole imaging) and a cryogenic surface coil, allowing us to obtain a full three-dimensional image (isotropic resolution, 125 microns) every 7.7 s over a 50-min scan. This time course permitted the demonstration of both contrast enhancement and clearance. Functional changes were measured over a 17-week course (at 3, 5, 7, 9, 13 and 17 weeks). The time dimension of the MRI dataset was processed to produce unique image contrasts to segment the four regions of the kidney: cortex (CO), outer stripe (OS) of the outer medulla (OM), inner stripe (IS) of the OM and inner medulla (IM). Local volumes, time-to-peak (TTP) values and decay constants (DC) were measured in each renal region. These metrics increased significantly with age, with the exception of DC values in the IS and OS. These data will serve as a foundation for studies of normal renal physiology and future studies of renal diseases that require early detection and intervention. Copyright © 2014 John Wiley & Sons, Ltd.

Metabolic bone disease in chronic renal failure. II. Renal transplant patients.

PubMed Central

Huffer, W. E.; Kuzela, D.; Popovtzer, M. M.; Starzl, T. E.

1975-01-01

Trabecular vertebral bone of renal transplant patients was quantitatively compared with bone from normal individuals and dialyzed and nondialyzed patienets with chronic renal failure reported in detail in an earlier study. Long- and short-term transplant patients have increased bone resorption and mineralization defects similar to renal osteodystrophy in dialyzed and nondialyzed patients. However, in transplant patients the magnitude of resorption is greater, and bone volume tends to decrease rather than increase. Resorptive activity in transplant patients is maximal during the first year after transplantation. Bone volume decreases continuously for at least 96 months after transplantation. Only decreased bone volume correlated with success or failure of the renal transplant. Morphologic findings in this study correlate with other clinical and morphologic data to suggest that reduction in bone volume in transplant patients results from a combination of persistent hyperparathyroidism and suppression of bone formation by steroid therapy. Images Fig 1 PMID:1091152

[Anatomy character of renal artery and treatment of living-donor renal transplantation].

PubMed

Zhang, Lei; Fei, Ji-guang; Chen, Li-zhong; Wang, Chang-xi; Deng, Su-xiong; Qiu, Jiang; Li, Jun; Chen, Guo-dong; Huang, Gang

2009-12-15

To study the anatomy characters of renal artery and the treatment of multiple arteries in living donor renal grafts. Records of 142 living donors were analyzed in our center. We analyzed the anatomic structure of renal arteries by DSA and CTA pre-transplantation. Thirty-one kidneys with multiple arteries were transplanted after reconstruction. Then clinical effects were compared between multiple-renal-arteries group (n=31) and single-renal-artery group (n=111). The incidence of multiple renal artery was 30.99%, and there was no difference between both sides (left kidney 22.54%, right kidney 22.13%). If the multiple artery occurred in left or right kidney, the incidence of the multiple artery occurred in the other side was 56.25% and 60.00%, respectively. The diameter of left main renal artery was more magnanimous (P=0.001) and the first branch was more closed to abdominal aorta (P=0.004). Operation time and warm/cool ischemia time were longer in the multiple-renal-arteries group. However, estimated blood loss, delayed graft function, acute rejection and flow rate of arcuate artery were similar in both groups, the same as serum creatinine and serum creatinine clearance rate on day 7, 1 month and 3 month post-operation. It was shown by repeated measures ANOVA that graft with multiple arteries didn't affect the tendency of renal function at early time post-operation. Comprehending the character of renal artery and accurate treatment of multiple artery anastomosis are critical for the effect of the living kidney transplantation.

Effect of suprarenal versus infrarenal aortic endograft fixation on renal function and renal artery patency: a comparative study with intermediate follow-up.

PubMed

Lau, L Louis; Hakaim, Albert G; Oldenburg, W Andrew; Neuhauser, Beate; McKinney, J Mark; Paz-Fumagalli, Ricardo; Stockland, Andrew

2003-06-01

12 months (P <.001), whereas in group 2 SCr also increased at 6 and 12 months, but not significantly. The change in SCr over time was not significantly different between the two groups. In two of 32 patients in group 2, renal artery occlusion developed, associated with perfusion defects in renal parenchyma and persistently elevated SCr. Analysis of renal artery patency did not demonstrate any association between patency and treatment. No patient developed hypertension during follow-up. Suprarenal endograft fixation does not lead to significant renal dysfunction, and renal artery occlusion is uncommon within 12 months. A larger study with longer follow-up is essential to determine overall effects on renal function and renal artery patency.

Renal denervation prevents long-term sequelae of ischemic renal injury

PubMed Central

Kim, Jinu; Padanilam, Babu J.

2014-01-01

Signals that drive interstitial fibrogenesis after renal ischemia reperfusion injury remain undefined. Sympathetic activation is manifest even in the early clinical stages of chronic kidney disease and is directly related to disease severity. A role for renal nerves in renal interstitial fibrogenesis in the setting of ischemia reperfusion injury has not been studied. In male 129S1/SvImJ mice, ischemia reperfusion injury induced tubulointerstitial fibrosis as indicated by collagen deposition and profibrotic protein expression 4 to 16 days after the injury.. Leukocyte influx, proinflammatory protein expression, oxidative stress, apoptosis, and cell cycle arrest at G2/M phase were enhanced after ischemia reperfusion injury. Renal denervation at the time of injury or up to 1 day post-injury improved histology, decreased proinflammatory/profibrotic responses and apoptosis, and prevented G2/M cell cycle arrest in the kidney. Treatment with afferent nerve-derived calcitonin gene-related peptide (CGRP) or efferent nerve-derived norepinephrine in denervated and ischemia reperfusion injury-induced kidneys mimicked innervation, restored inflammation and fibrosis, induced G2/M arrest, and enhanced TGF-β1 activation. Blocking norepinephrine or CGRP function using respective receptor blockers prevented these effects. Consistent with the in vivo study, treatment with either norepinephrine or CGRP induced G2/M cell cycle arrest in HK-2 proximal tubule cells, whereas antagonists against their respective receptors prevented G2/M arrest. Thus, renal nerve stimulation is a primary mechanism and renal nerve-derived factors drive epithelial cell cycle arrest and the inflammatory cascade causing interstitial fibrogenesis after ischemia reperfusion injury. PMID:25207878

Resting Afferent Renal Nerve Discharge and Renal Inflammation: Elucidating the Role of Afferent and Efferent Renal Nerves in Deoxycorticosterone Acetate Salt Hypertension.

PubMed

Banek, Christopher T; Knuepfer, Mark M; Foss, Jason D; Fiege, Jessica K; Asirvatham-Jeyaraj, Ninitha; Van Helden, Dusty; Shimizu, Yoji; Osborn, John W

2016-12-01

Renal sympathetic denervation (RDNx) has emerged as a novel therapy for hypertension; however, the therapeutic mechanisms remain unclear. Efferent renal sympathetic nerve activity has recently been implicated in trafficking renal inflammatory immune cells and inflammatory chemokine and cytokine release. Several of these inflammatory mediators are known to activate or sensitize afferent nerves. This study aimed to elucidate the roles of efferent and afferent renal nerves in renal inflammation and hypertension in the deoxycorticosterone acetate (DOCA) salt rat model. Uninephrectomized male Sprague-Dawley rats (275-300 g) underwent afferent-selective RDNx (n=10), total RDNx (n=10), or Sham (n=10) and were instrumented for the measurement of mean arterial pressure and heart rate by radiotelemetry. Rats received 100-mg DOCA (SC) and 0.9% saline for 21 days. Resting afferent renal nerve activity in DOCA and vehicle animals was measured after the treatment protocol. Renal tissue inflammation was assessed by renal cytokine content and T-cell infiltration and activation. Resting afferent renal nerve activity, expressed as a percent of peak afferent nerve activity, was substantially increased in DOCA than in vehicle (35.8±4.4 versus 15.3±2.8 %Amax). The DOCA-Sham hypertension (132±12 mm Hg) was attenuated by ≈50% in both total RDNx (111±8 mm Hg) and afferent-selective RDNx (117±5 mm Hg) groups. Renal inflammation induced by DOCA salt was attenuated by total RDNx and unaffected by afferent-selective RDNx. These data suggest that afferent renal nerve activity may mediate the hypertensive response to DOCA salt, but inflammation may be mediated primarily by efferent renal sympathetic nerve activity. Also, resting afferent renal nerve activity is elevated in DOCA salt rats, which may highlight a crucial neural mechanism in the development and maintenance of hypertension. © 2016 American Heart Association, Inc.

Does the presence of accessory renal arteries affect the efficacy of renal denervation?

PubMed

Id, Dani; Kaltenbach, Benjamin; Bertog, Stefan C; Hornung, Marius; Hofmann, Ilona; Vaskelyte, Laura; Sievert, Horst

2013-10-01

This study sought to assess the efficacy of catheter-based renal sympathetic denervation in patients with accessory renal arteries and to compare the blood pressure (BP)-lowering effect with that observed in patients with bilateral single renal arteries after renal denervation. Catheter-based renal sympathetic denervation causes significant BP reductions in patients with resistant hypertension. Seventy-four patients were included in this study. Patients were assigned to 2 main groups: a bilateral single renal arteries group I (n = 54) and an accessory renal arteries group II (n = 20). Group II consisted of 9 patients whose accessory renal arteries were all denervated (group IIa), and 11 patients whose accessory renal arteries were not, or only incompletely, denervated (group IIb). The primary endpoint was the change in office systolic BP after 6 months. The procedure was successful in all patients. Group I: mean BP at baseline was 166.2/89.4 ± 20.5/14.6 mm Hg and decreased by -16.6 (p < 0.001)/-6.7 (p = 0.016) ± 16.4/11 mm Hg at 6-month follow-up. Group II: mean BP at baseline was 164.2/89.1 ± 19.9/15.4 mm Hg and decreased by -6.2 (p = 0.19)/-0.2 (p = 0.5) ± 19.7/11.3 mm Hg at 6-month follow-up. Patients in group IIa had an office BP reduction of -8.8 (p = 0.2)/1.1 ± 17.9/10.8 mm Hg and patients in group IIb of -4.1 (p = 0.55)/-1.3 ± 20.8/11.6 mm Hg. Similarly, significant improvements in 24-h mean systolic BP were seen in group I (-8.3 ± 17.4 mm Hg, p < 0.01), whereas none were seen in group II (-3.7 ± 8.3 mm Hg, p = 0.38). BP reduction achieved after renal denervation in patients with accessory renal arteries is less pronounced than in patients with bilateral single renal arteries. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Pharmacokinetics and pharmacodynamics study of rhein treating renal fibrosis based on metabonomics approach.

PubMed

Sun, Hao; Luo, Guangwen; Xiang, Zheng; Cai, Xiaojun; Chen, Dahui

2016-12-01

The selection of effect indicators in the pharmacokinetic/ pharmacodynamic study of complex diseases to describe the relationship between plasma concentration and effect indicators is difficult. Three effect indicators of renal fibrosis were successfully determined. The relationship between pharmacokinetics and pharmacodynamics of rhein in rhubarb was elucidated. The study was a metabolomics analysis of rat plasma and pharmacokinetics/ pharmacodynamics of rhein. A sensitive and simple ultra performance liquid chromatography-tandem triple quadrupole mass spectrometry (UPLC-MS/MS) method was applied to determine the rhein plasma concentration in the rat model of renal fibrosis and rat sham-operated group after the administration of rhubarb decoction. Then, the ultra performance liquid chromatography-Micromass quadrupole-time of flight mass spectrometry (UPLC-QTOF/MS) metabolomics method was used to screen biomarkers of renal fibrosis in rat plasma. Furthermore, the relationship between the plasma concentration of rhein and the concentration of three biomarkers directly related to renal fibrosis were analyzed. The three screened biomarkers could represent the effect of rhein treatment on renal fibrosis. Increasing the plasma concentration of rhein tended to restore the concentration of the three biomarkers in the model group compared with that in the sham-operated group. Evident differences in the area under the plasma concentration-time curve (AUC) of rhein were also observed under different pathological states. The results provide valuable information for the clinical application of rhubarb. Rhein intervention could recover the physiological balance in living organisms from the pharmacokinetic/pharmacodynamic levels. New information on the pharmacokinetic/pharmacodynamic study of complex diseases is provided. Copyright © 2016 Elsevier GmbH. All rights reserved.

Renal Carcinogenesis After Uninephrectomy1

PubMed Central

Sui, Yi; Zhao, Hai-Lu; Lee, Heung Man; Guan, Jing; He, Lan; Lai, Fernand MM; Tong, Peter CY; Chan, Juliana CN

2009-01-01

Nephrectomized rats have widely been used to study chronic renal failure. Interestingly, renal cell carcinoma occurred in the remnant kidney after uninephrectomy (UNX). In this study, we probed insulin-like growth factor (IGF)-1 signaling pathway in UNX-induced renal cancer. Adult male Sprague-Dawley rats were randomized into two groups: UNX rats (n = 22) and sham-operated rats (n = 12). Rats were killed at 3, 7, and 10 months. After 7 months after nephrectomy, the UNX rats developed renal cell carcinoma with increased expression of proliferating cell nuclear antigen, and 68.2% (15/22) of the animals exhibited invasive carcinoma. Western blot demonstrated significant down-regulation of IGF binding protein 3 contrasting with the up-regulation of protein kinase Cζ and Akt/protein kinase B in the renal cancer tissues. These findings indicate a unique rat model of UNX-induced renal cancer associated with enhanced IGF-1 signaling pathway. PMID:19956387

Renal sympathetic nervous system and the effects of denervation on renal arteries

PubMed Central

Kannan, Arun; Medina, Raul Ivan; Nagajothi, Nagapradeep; Balamuthusamy, Saravanan

2014-01-01

Resistant hypertension is associated with chronic activation of the sympathetic nervous system resulting in various comorbidities. The prevalence of resistant hypertension is often under estimated due to various reasons. Activation of sympathetic nervous system at the renal- as well as systemic- level contributes to the increased level of catecholamines and resulting increase in the blood pressure. This increased activity was demonstrated by increased muscle sympathetic nerve activity and renal and total body noradrenaline spillover. Apart from the hypertension, it is hypothesized to be associated with insulin resistance, congestive heart failure and obstructive sleep apnea. Renal denervation is a novel procedure where the sympathetic afferent and efferent activity is reduced by various techniques and has been used successfully to treat drug-resistant hypertension improvement of various metabolic derangements. Renal denervation has the unique advantage of offering the denervation at the renal level, thus mitigating the systemic side effects. Renal denervation can be done by various techniques including radiofrequency ablation, ultrasound guided ablation and chemical ablation. Various trials evaluated the role of renal denervation in the management of resistant hypertension and have found promising results. More studies are underway to evaluate the role of renal denervation in patients presenting with resistant hypertension in different scenarios. Appropriate patient selection might be the key in determining the effectiveness of the procedure. PMID:25228960

Renal sympathetic nervous system and the effects of denervation on renal arteries.

PubMed

Kannan, Arun; Medina, Raul Ivan; Nagajothi, Nagapradeep; Balamuthusamy, Saravanan

2014-08-26

Resistant hypertension is associated with chronic activation of the sympathetic nervous system resulting in various comorbidities. The prevalence of resistant hypertension is often under estimated due to various reasons. Activation of sympathetic nervous system at the renal- as well as systemic- level contributes to the increased level of catecholamines and resulting increase in the blood pressure. This increased activity was demonstrated by increased muscle sympathetic nerve activity and renal and total body noradrenaline spillover. Apart from the hypertension, it is hypothesized to be associated with insulin resistance, congestive heart failure and obstructive sleep apnea. Renal denervation is a novel procedure where the sympathetic afferent and efferent activity is reduced by various techniques and has been used successfully to treat drug-resistant hypertension improvement of various metabolic derangements. Renal denervation has the unique advantage of offering the denervation at the renal level, thus mitigating the systemic side effects. Renal denervation can be done by various techniques including radiofrequency ablation, ultrasound guided ablation and chemical ablation. Various trials evaluated the role of renal denervation in the management of resistant hypertension and have found promising results. More studies are underway to evaluate the role of renal denervation in patients presenting with resistant hypertension in different scenarios. Appropriate patient selection might be the key in determining the effectiveness of the procedure.

Renal manifestations of primary mitochondrial disorders

PubMed Central

Finsterer, Josef; Scorza, Fulvio

2017-01-01

The aim of the present review was to summarize and discuss previous findings concerning renal manifestations of primary mitochondrial disorders (MIDs). A literature review was performed using frequently used databases. The study identified that primary MIDs frequently present as mitochondrial multiorgan disorder syndrome (MIMODS) at onset or in the later course of the MID. Occasionally, the kidneys are affected in MIDs. Renal manifestations of MIDs include renal insufficiency, nephrolithiasis, nephrotic syndrome, renal cysts, renal tubular acidosis, Bartter-like syndrome, Fanconi syndrome, focal segmental glomerulosclerosis, tubulointerstitial nephritis, nephrocalcinosis, and benign or malign neoplasms. Among the syndromic MIDs, renal involvement has been most frequently reported in patients with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes syndrome, Kearns-Sayre syndrome, Leigh syndrome and mitochondrial depletion syndromes. Only in single cases was renal involvement also reported in chronic progressive external ophthalmoplegia, Pearson syndrome, Leber's hereditary optic neuropathy, coenzyme-Q deficiency, X-linked sideroblastic anemia and ataxia, myopathy, lactic acidosis, and sideroblastic anemia, pyruvate dehydrogenase deficiency, growth retardation, aminoaciduria, cholestasis, iron overload, lactacidosis, and early death, and hyperuricemia, pulmonary hypertension, renal failure in infancy and alkalosis syndrome. The present study proposes that the frequency of renal involvement in MIDs is probably underestimated. Diagnosis of renal involvement follows general guidelines and treatment is symptomatic. Thus, renal manifestations of primary MIDs require recognition and appropriate management, as they determine the outcome of MID patients. PMID:28515908

Renal accumulation of pentosidine in non-diabetic proteinuria-induced renal damage in rats.

PubMed

Waanders, Femke; Greven, Wendela L; Baynes, John W; Thorpe, Suzanne R; Kramer, Andrea B; Nagai, Ryoji; Sakata, Noriyuki; van Goor, Harry; Navis, Gerjan

2005-10-01

Advanced glycation end-products (AGEs) contribute to the pathogenesis of diabetic glomerulopathy. The role of AGEs in non-diabetic renal damage is not well characterized. First, we studied whether renal AGE accumulation occurs in non-diabetic proteinuria-induced renal damage and whether this is ameliorated by renoprotective treatment. Secondly, we investigated whether renal AGE accumulation was due to intrarenal effects of local protein trafficking. Pentosidine was measured (by high-performance liquid chromatography) in rats with chronic bilateral adriamycin nephropathy (AN), untreated and treated with lisinopril. Age-matched healthy rats served as negative controls. Secondly, we compared renal pentosidine in mild proteinuric and non-proteinuric kidneys of unilateral AN and in age-matched controls at 12 and 30 weeks. Intrarenal localization of pentosidine was studied by immunohistochemistry. Renal pentosidine was elevated in untreated AN (0.14+/-0.04 micromol/mol valine) vs healthy controls (0.04+/-0.01 micromol/mol valine, P<0.01). In lisinopril-treated AN, pentosidine was lower (0.09+/-0.02 micromol/mol valine) than in untreated AN (P<0.05). In unilateral proteinuria, pentosidine was similar in non-proteinuric and proteinuric kidneys. After 30 weeks of unilateral proteinuria, pentosidine was increased in both kidneys (0.26+/-0.10 micromol/mol valine) compared with controls (0.18+/-0.06 micromol/mol valine, P<0.05). Pentosidine (AN, week 30) was also increased compared with AN at week 12 (0.16+/-0.06 micromol/mol valine, P<0.01). In control and diseased kidneys, pentosidine was present in the collecting ducts. In proteinuric kidneys, in addition, pentosidine was present in the brush border and cytoplasm of dilated tubular structures, i.e. at sites of proteinuria-induced tubular damage. Pentosidine accumulates in non-diabetic proteinuric kidneys in damaged tubules, and renoprotective treatment by angiotensin-converting enzyme (ACE) inhibitors inhibits AGE

Using OCT to predict post-transplant renal function

NASA Astrophysics Data System (ADS)

Andrews, Peter M.; Chen, Yu; Wierwille, Jeremiah; Joh, Daniel; Alexandrov, Peter; Rogalsky, Derek; Moody, Patrick; Chen, Allen; Cooper, Matthew; Verbesey, Jennifer E.; Gong, Wei; Wang, Hsing-Wen

2013-03-01

The treatment of choice for patients with end-stage renal disease is kidney transplantation. However, acute tubular necrosis (ATN) induced by an ischemic insult (e.g., from prolonged ex vivo storage times, or non-heart beating cadavers) is a major factor limiting the availability of donor kidneys. In addition, ischemic induced ATN is a significant risk factor for eventual graft survival and can be difficult to discern from rejection. Currently, there are no rapid and reliable tests to determine ATN suffered by donor kidneys and whether or not donor kidneys might exhibit delayed graft function. OCT (optical coherence tomography) is a rapidly emerging imaging modality that can function as a type of "optical biopsy", providing cross-sectional images of tissue morphology in situ and in real-time. In a series of recent clinical trials, we evaluated the ability of OCT to image those features of the renal microstructure that are predictive of ATN. Specifically, we found that OCT could effectively image through the intact human renal capsule and determine the extent of acute tubular necrosis. We also found that Doppler based OCT (i.e., DOCT) revealed renal blood flow dynamics that is also reported to be a determiner of post-transplant renal function. This kind of information will allow transplant surgeons to make the most efficient use of available donor kidneys, eliminate the possible use of bad donor kidneys, provide a measure of expected post-transplant renal function, and allow better distinction between post-transplant immunological rejection and ischemic-induced acute renal failure.

Urinary Biomarkers for Screening for Renal Scarring in Children with Febrile Urinary Tract Infection: Pilot Study.

PubMed

Kitao, Tetsuya; Kimata, Takahisa; Yamanouchi, Sohsaku; Kato, Shogo; Tsuji, Shoji; Kaneko, Kazunari

2015-09-01

Recurrent febrile urinary tract infections during infancy cause renal scarring, which is characterized by progressive focal interstitial fibrosis and may lead to renal failure. Renal scarring can be diagnosed through scintigraphy, although it seems impractical to perform renal scintigraphy for all infants with febrile urinary tract infections. Therefore, it is important to search for a biomarker to identify the presence of renal scarring. We hypothesized that urinary biomarkers of nephropathy may increase in infants with renal scarring following febrile urinary tract infections. A total of 49 infants who underwent renal scintigraphy for febrile urinary tract infections were enrolled in the study. Several measurements were performed using urine samples, including total proteins, beta2-microglobulins, N-acetyl-β-D-glucosaminidase, neutrophil gelatinase associated lipocalin, liver-type fatty acid binding protein and angiotensinogen. Values were corrected by creatinine and compared between patients with and without renal scarring. Among urinary biomarkers only angiotensinogen in patients with scarring (median 14.6 μg/gm creatinine) demonstrated significantly higher levels than in patients without scarring (3.6 μg/gm creatinine, p <0.001). Urinary angiotensinogen may be useful for diagnosing the presence of renal scarring. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Effects of exercise and excitement on mesenteric and renal dynamics in conscious, unrestrained baboons

NASA Technical Reports Server (NTRS)

Vatner, S. F.

1978-01-01

Radiotelemetry was used to measure arterial pressure and mesenteric and renal blood flows from nine unrestrained, conscious baboons during periods of rest, moderate exercise, and extreme excitement. A description of the experiments hardware is presented, including artificial depressants phenylcyclidine hydrochloride, 0.5-1.0 mg/kg, and pentobarbital sodium, 15 mg/kg, and an ultrasonic telemetry flow meter. Results showed rising heart rate and arterial pressure coupled with a reduction of mesenteric and renal flows as the level of exercise was increased. These findings are compared with mesenteric and renal flows somewhat above control level, but relatively stable heart rate and arterial pressure, postprandially. Attention is given to a quantitative analysis of the experimental results.

Evidence of a heterogeneous tissue oxygenation: renal ischemia/reperfusion injury in a large animal model

NASA Astrophysics Data System (ADS)

Crane, Nicole J.; Huffman, Scott W.; Alemozaffar, Mehrdad; Gage, Frederick A.; Levin, Ira W.; Elster, Eric A.

2013-03-01

Renal ischemia that occurs intraoperatively during procedures requiring clamping of the renal artery (such as renal procurement for transplantation and partial nephrectomy for renal cancer) is known to have a significant impact on the viability of that kidney. To better understand the dynamics of intraoperative renal ischemia and recovery of renal oxygenation during reperfusion, a visible reflectance imaging system (VRIS) was developed to measure renal oxygenation during renal artery clamping in both cooled and warm porcine kidneys. For all kidneys, normothermic and hypothermic, visible reflectance imaging demonstrated a spatially distinct decrease in the relative oxy-hemoglobin concentration (%HbO2) of the superior pole of the kidney compared to the middle or inferior pole. Mean relative oxy-hemoglobin concentrations decrease more significantly during ischemia for normothermic kidneys compared to hypothermic kidneys. VRIS may be broadly applicable to provide an indicator of organ ischemia during open and laparoscopic procedures.

Radiation Dose Index of Renal Colic Protocol CT Studies in the United States

PubMed Central

Lukasiewicz, Adam; Bhargavan-Chatfield, Mythreyi; Coombs, Laura; Ghita, Monica; Weinreb, Jeffrey; Gunabushanam, Gowthaman; Moore, Christopher L.

2016-01-01

Purpose To determine radiation dose indexes for computed tomography (CT) performed with renal colic protocols in the United States, including frequency of reduced-dose technique usage and any institutional-level factors associated with high or low dose indexes. Materials and Methods The Dose Imaging Registry (DIR) collects deidentified CT data, including examination type and dose indexes, for CT performed at participating institutions; thus, the DIR portion of the study was exempt from institutional review board approval and was HIPAA compliant. CT dose indexes were examined at the institutional level for CT performed with a renal colic protocol at institutions that contributed at least 10 studies to the registry as of January 2013. Additionally, patients undergoing CT for renal colic at a single institution (with institutional review board approval and informed consent from prospective subjects and waiver of consent from retrospective subjects) were studied to examine individual renal colic CT dose index patterns and explore relationships between patient habitus, demographics, and dose indexes. Descriptive statistics were used to analyze dose indexes, and linear regression and Spearman correlations were used to examine relationships between dose indexes and institutional factors. Results There were 49 903 renal colic protocol CT examinations conducted at 93 institutions between May 2011 and January 2013. Mean age ± standard deviation was 49 years ± 18, and 53.9% of patients were female. Institutions contributed a median of 268 (interquartile range, 77–699) CT studies. Overall mean institutional dose-length product (DLP) was 746 mGy · cm (effective dose, 11.2 mSv), with a range of 307–1497 mGy · cm (effective dose, 4.6–22.5 mSv) for mean DLPs. Only 2% of studies were conducted with a DLP of 200 mGy · cm or lower (a “reduced dose”) (effective dose, 3 mSv), and only 10% of institutions kept DLP at 400 mGy · cm (effective dose, 6 mSv) or less in at

Longitudinal prospective observational type study about determinants of renal resistive index variations in chronic renal failure patients treated with conventional medical and dietetic therapy.

PubMed

Brardi, Simone; Cevenini, Gabriele; Giovannelli, Vanni; Romano, Giuseppe

2017-12-31

This longitudinal prospective observational type study was conceived with the aim to examine the impact on renal resistive index (RRI) of the variables that we can manipulate with therapeutic and or dietetic interventions in a chronic kidney disease population in order to known which of these variables was statistically related to changes in RRI and therefore could become the object of the greatest therapeutic effort. This study was undertaken between May 2016 to May 2017 in the outpatient nephrology and urology clinic of San Donato Hospital in Arezzo. The study population (84 patients: 47 males and 37 females) was randomly selected among the chronic kidney patients (with various degrees of renal impairment) affected by hypertension and or diabetes mellitus. After a comprehensive medical examination these patients were submitted to determination of serum creatinine, glycated hemoglobin, 24-hour urinary albumin excretion and finally renal Doppler ultrasonography. Then the patients were submitted to a full therapeutic and dietetic intervention to ameliorate the renal impairment by a wide range of actions and after on average a one-year interval were submitted again to a new medical examination and a second determination of serum creatinine, glycated hemoglobin, 24-hour urinary albumin excretion and a new renal Doppler ultrasonography too. The comparison between basal and final data revealed a slight reduction in the mean of bilateral renal resistance indices (Delta RRI: -0.0182 ± 0.08), associated to a slight increase in the mean glomerular filtration rate (Delta GFR: 0.8738 ± 10.95 ml/min/1.73 m2), a reduction in mean body weight (Delta weight: -1.9548 ± 5.26 Kg) and mean BMI (Delta BMI: -0.7643 ± 2.10 Kg/m2) as well as a reduction in the mean systolic blood pressure (Delta systolic blood pressure: -8.8333 ± 25.19 mmHg). Statistical analysis showed statistically significant correlations (p < 0.05) between Delta RRI and Delta weight (p < 0.03), Delta BMI (p < 0

Renal Salvage with Renal Artery Stenting Improves Long-term Survival.

PubMed

Modrall, J Gregory; Trimmer, Clayton; Tsai, Shirling; Kirkwood, Melissa L; Ali, Mujtaba; Rectenwald, John E; Timaran, Carlos H; Rosero, Eric B

2017-11-01

The Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) Trial cast doubt on the benefits of renal artery stenting (RAS). However, the outcomes for patients with chronic kidney disease (CKD) were not analyzed separately in the CORAL Trial. We hypothesized that patients who experienced a significant improvement in renal function after RAS would have improved long-term survival, compared with patients whose renal function was not improved by stenting. This single-center retrospective study included 60 patients with stage 3 or worse CKD and renal artery occlusive disease who were treated with RAS for renal salvage. Patients were categorized as "responders" or "nonresponders" based on postoperative changes in estimated glomerular filtration rate (eGFR) after RAS. "Responders" were those patients with an improvement of at least 20% in eGFR over baseline; all others were categorized as "nonresponders." Survival was analyzed using the Kaplan-Meier method. Cox proportional hazards regression was used to identify predictors of long-term survival. The median age of the cohort was 66 years (interquartile range [IQR], 60-73). Median preoperative eGFR was 34 mL/min/1.73 m 2 (IQR, 24-45). At late follow-up (median 35 months, IQR, 22-97 months), 16 of 60 patients (26.7%) were categorized as "responders" with a median increase in postoperative eGFR of 40% (IQR, 21-67). Long-term survival was superior for responders, compared with nonresponders (P = 0.046 by log-rank test). Cox proportional hazards regression identified improved renal function after RAS as the only significant predictor of increased long-term survival (hazard ratio = 0.235, 95% confidence interval = 0.075-0.733; P = 0.0126 for improved versus worsened renal function after RAS). Successful salvage of renal function by RAS is associated with improved long-term survival. These data provide an important counter argument to the prior negative clinical trials that found no benefit to RAS

Associations Between Renal Duplex Parameters and Adverse Cardiovascular Events in the Elderly: A Prospective Cohort Study

PubMed Central

Pearce, Jeffrey D.; Craven, Timothy E.; Edwards, Matthew S.; Corriere, Matthew A.; Crutchley, Teresa A.; Fleming, Shawn H.; Hansen, Kimberley J.

2010-01-01

Background Atherosclerotic renovascular disease is associated with an increased risk of cardiovascular disease (CVD) events. This study examines associations between Doppler-derived parameters from the renal artery and renal parenchyma and all-cause mortality and fatal and nonfatal CVD events in a cohort of elderly Americans. Study Design Cohort study. Setting A subset of participants from the Cardiovascular Health Study (CHS). Through an ancillary study, 870 (70% recruitment) Forsyth County, NC, CHS participants consented to undergo renal duplex sonography to define the prevalence of renovascular disease in the elderly, resulting in 726 (36% men; mean age, 77 years) technically adequate complete studies included in this investigation. Predictor Renal duplex sonography–derived Doppler signals from the main renal arteries and renal parenchyma. Spectral analysis from Doppler-shifted frequencies and angle of insonation were used to estimate renal artery peak systolic and end diastolic velocity (both in meters per second). Color Doppler was used to identify the corticomedullary junction. Using a 3-mm Doppler sample, the parenchymal peak systolic and end diastolic frequency shift (both in kilohertz) were obtained. Resistive index was calculated as (1 – [end diastolic frequency shift/peak systolic frequency shift]) using Doppler samples from the hilar arteries of the left or right kidney with the higher main renal artery peak systolic velocity. Outcomes & Measurements Proportional hazard regression analysis was used to determine associations between renal duplex sonography–derived Doppler signals and CVD events and all-cause mortality adjusted for accepted cardiovascular risk factors. Index CVD outcomes were defined as coronary events (angina, myocardial infarction, and coronary artery bypass grafting/percutaneous coronary intervention), cerebrovascular events (stroke or transient ischemic attack), and any CVD event (angina, congestive heart failure, myocardial

[THE ORGANIZATION OF PREVENTION OF RENAL PATHOLOGY IN PREGNANT WOMEN IN BAKU].

PubMed

Kadimova, Sh G

2015-01-01

Nowadays, increasing of renal pathology, especially of its chronic forms characterized by long clinical duration and frequent exacerbations is observed in pregnant women. The study was carried out to analyze prevalence and structure of renal pathology in pregnant women with further development of social economic basics of its prevention. The epidemiological analysis established that during 2009-2011 in Baku prevalence of renal pathology in pregnant women amounted to 11%. The analysis of structure and dynamics of renal pathology in pregnant women during the same period revealed that leading positions are taken by chronic pyelonephritis (27.2%), hydronephrosis (14.8%) and eclampsia (12%). The percentage of cystitis amounted to 4.8%, urolithiasis - 3.2%, renal colic - 2.4% and renal anomalies - 0.8%. The study established that under application of scientifically valid preventive measures an effective prevention of disease is achieved. In particular risk of morbidity is decreased up to 4.18 times. After 10-12 months after implementation of explanatory work degree of implementation of preventive measures among female patients with close adherence to these measures attained maximal level (88.6±2.8%) and among female patients attaching no importance to them in many ways implementation remained low (41±5.6%). At the same time, organization and implementation of developed complex of preventive measures are available. They have no requirement in an additional manpower and material technical resources and are applied using sanitary agitation among population. The task-oriented and permanent explanatory work increases responsibility of population for one's own health, activates population to implement complex of preventive measure. On the whole, workable premises both to stabilize level of morbidity of renal pathology and its consistent decreasing are established.

Effects of levosimendan on glomerular filtration rate, renal blood flow, and renal oxygenation after cardiac surgery with cardiopulmonary bypass: a randomized placebo-controlled study.

PubMed

Bragadottir, Gudrun; Redfors, Bengt; Ricksten, Sven-Erik

2013-10-01

Acute kidney injury develops in a large proportion of patients after cardiac surgery because of the low cardiac output syndrome. The inodilator levosimendan increases cardiac output after cardiac surgery with cardiopulmonary bypass, but a detailed analysis of its effects on renal perfusion, glomerular filtration, and renal oxygenation in this group of patients is lacking. We therefore evaluated the effects of levosimendan on renal blood flow, glomerular filtration rate, renal oxygen consumption, and renal oxygen demand/supply relationship, i.e., renal oxygen extraction, early after cardiac surgery with cardiopulmonary bypass. Prospective, placebo-controlled, and randomized trial. Cardiothoracic ICU of a tertiary center. Postcardiac surgery patients (n=30). The patients were randomized to receive levosimendan, 0.1 µg/kg/min after a loading dose of 12 µg/kg (n=15), or placebo (n=15). The experimental procedure started 4-6 hours after surgery in the ICU during propofol sedation and mechanical ventilation. Systemic hemodynamic were evaluated by a pulmonary artery thermodilution catheter. Renal blood flow and glomerular filtration rate were measured by the renal vein retrograde thermodilution technique and by renal extraction of Cr-EDTA, respectively. Central venous pressure was kept constant by colloid/crystalloid infusion. Compared to placebo, levosimendan increased cardiac index (22%), stroke volume index (15%), and heart rate (7%) and decreased systemic vascular resistance index (21%), whereas mean arterial pressure was not affected. Levosimendan induced significant increases in renal blood flow (12%, p<0.05) and glomerular filtration rate (21%, p<0.05), decreased renal vascular resistance (18%, p<0.05) but caused no significant changes in filtration fraction, renal oxygen consumption, or renal oxygen extraction, compared to placebo. After cardiac surgery with cardiopulmonary bypass, levosimendan induces a vasodilation, preferentially of preglomerular resistance

320-row CT renal perfusion imaging in patients with aortic dissection: A preliminary study.

PubMed

Liu, Dongting; Liu, Jiayi; Wen, Zhaoying; Li, Yu; Sun, Zhonghua; Xu, Qin; Fan, Zhanming

2017-01-01

To investigate the clinical value of renal perfusion imaging in patients with aortic dissection (AD) using 320-row computed tomography (CT), and to determine the relationship between renal CT perfusion imaging and various factors of aortic dissection. Forty-three patients with AD who underwent 320-row CT renal perfusion before operation were prospectively enrolled in this study. Diagnosis of AD was confirmed by transthoracic echocardiography. Blood flow (BF) of bilateral renal perfusion was measured and analyzed. CT perfusion imaging signs of AD in relation to the type of AD, number of entry tears and the false lumen thrombus were observed and compared. The BF values of patients with type A AD were significantly lower than those of patients with type B AD (P = 0.004). No significant difference was found in the BF between different numbers of intimal tears (P = 0.288), but BF values were significantly higher in cases with a false lumen without thrombus and renal arteries arising from the true lumen than in those with thrombus (P = 0.036). The BF values measured between the true lumen, false lumen and overriding groups were different (P = 0.02), with the true lumen group having the highest. Also, the difference in BF values between true lumen and false lumen groups was statistically significant (P = 0.016), while no statistical significance was found in the other two groups (P > 0.05). The larger the size of intimal entry tears, the greater the BF values (P = 0.044). This study shows a direct correlation between renal CT perfusion changes and AD, with the size, number of intimal tears, different types of AD, different renal artery origins and false lumen thrombosis, significantly affecting the perfusion values.

Preparation of positional renal slices for study of cell-specific toxicity.

PubMed

Ruegg, C E; Gandolfi, A J; Nagle, R B; Krumdieck, C L; Brendel, K

1987-04-01

To reduce structural complexity, rabbit kidneys were sliced perpendicular to their cortical-papillary axis to isolate four distinct cell groupings. This positional orientation allows identification of each renal cell type based on its location within the slice. A mechanical slicer was used to make several precision-cut slices rapidly from an oriented cylindrical core of renal tissue, with minimal tissue trauma. Slices were then submerged under a gently circulating oxygenated media in a fritted glass support system that maintains viability (intracellular K+/DNA ratio) and structural integrity (histology) for at least 30 h. A high dose of mercuric chloride (10(-3) M) was used to demonstrate the structural and biochemical changes of intoxicated slices. This method provides a controlled subchronic in vitro system for the study of the individual cell types involved in cell-specific renal toxicities and may also be a useful tool for addressing other pharmacological and physiological research questions.

Neural control of renal function.

PubMed

Johns, Edward J; Kopp, Ulla C; DiBona, Gerald F

2011-04-01

The kidney is innervated with efferent sympathetic nerve fibers that directly contact the vasculature, the renal tubules, and the juxtaglomerular granular cells. Via specific adrenoceptors, increased efferent renal sympathetic nerve activity decreases renal blood flow and glomerular filtration rate, increases renal tubular sodium and water reabsorption, and increases renin release. Decreased efferent renal sympathetic nerve activity produces opposite functional responses. This integrated system contributes importantly to homeostatic regulation of sodium and water balance under physiological conditions and to pathological alterations in sodium and water balance in disease. The kidney contains afferent sensory nerve fibers that are located primarily in the renal pelvic wall where they sense stretch. Stretch activation of these afferent sensory nerve fibers elicits an inhibitory renorenal reflex response wherein the contralateral kidney exhibits a compensatory natriuresis and diuresis due to diminished efferent renal sympathetic nerve activity. The renorenal reflex coordinates the excretory function of the two kidneys so as to facilitate homeostatic regulation of sodium and water balance. There is a negative feedback loop in which efferent renal sympathetic nerve activity facilitates increases in afferent renal nerve activity that in turn inhibit efferent renal sympathetic nerve activity so as to avoid excess renal sodium retention. In states of renal disease or injury, there is activation of afferent sensory nerve fibers that are excitatory, leading to increased peripheral sympathetic nerve activity, vasoconstriction, and increased arterial pressure. Proof of principle studies in essential hypertensive patients demonstrate that renal denervation produces sustained decreases in arterial pressure. © 2011 American Physiological Society. Compr Physiol 1:699-729, 2011.

Does renal ageing affect survival?

PubMed

Razzaque, M Shawkat

2007-10-01

The effects of ageing on progressive deterioration of renal function, both in human and experimental animals, are described elsewhere, but the effect of renal damage on overall survival and longevity is not yet clearly established. The wild-type animals of various genetic backgrounds, fed with regular diet, overtime develop severe age-associated nephropathy, that include but not limited to inflammatory cell infiltration, glomerulosclerosis, and tubulointerstitial fibrosis. Such renal damage significantly reduces their survival. Reducing renal damage, either by caloric restriction or by suppressing growth hormone (GH)/insulin-like growth factor-1 (IGF-1) activity could significantly enhance the longevity of these animals. Available survival studies using experimental animals clearly suggest that kidney pathology is one of the important non-neoplastic lesions that could affect overall survival, and that restoration of renal function by preventing kidney damage could significantly extend longevity. Careful long-term studies are needed to determine the human relevance of these experimental studies.

Acoustic and mechanical properties of renal calculi: implications in shock wave lithotripsy.

PubMed

Chuong, C J; Zhong, P; Preminger, G M

1993-12-01

The acoustic and mechanical properties of renal calculi dictate how a stone interacts with the mechanical forces produced by shock wave lithotripsy; thus, these properties are directly related to the success of the treatment. Using an ultrasound pulse transmission technique, we measured both longitudinal and transverse (or shear) wave propagation speeds in nine groups of renal calculi with different chemical compositions. We also measured stone density using a pycnometer based on Archimedes' principle. From these measurements, we calculated wave impedance and dynamic mechanical properties of the renal stones. Calcium oxalate monohydrate and cystine stones had higher longitudinal and transverse wave speeds, wave impedances, and dynamic moduli (bulk modulus, Young's modulus, and shear modulus), suggesting that these stones are more difficult to fragment. Phosphate stones (carbonate apatite and magnesium ammonium phosphate hydrogen) were found to have lower values of these properties, suggesting they are more amenable to shock wave fragmentation. These data provide a physical explanation for the significant differences in stone fragility observed clinically.

Acute renal haemodynamic and renin-angiotensin system responses to graded renal artery stenosis in the dog.

PubMed Central

Anderson, W P; Johnston, C I; Korner, P I

1979-01-01

1. The acute renal haemodynamic and renin-angiotensin system responses to graded renal artery stenosis were studied in chronically instrumented, unanaesthetized dogs. 2. Stenosis was induced over 30 sec by inflation of a cuff around the renal artery to lower distal pressure to 60, 40 or 20 mmHg, with stenosis maintained for 1 hr. This resulted in an immediate fall in renal vascular resistance, but over the next 5--30 min both resistance and renal artery pressure were restored back towards prestenosis values. Only transient increases in systemic arterial blood pressure and plasma renin and angiotensin levels were seen with the two milder stenoses. Despite restoration of renal artery pressure, renal blood flow remained reduced at all grades of stenosis. 3. Pre-treatment with angiotensin I converting enzyme inhibitor or sarosine1, isoleucone8 angiotensin II greatly attenuated or abolished the restoration of renal artery pressure and renal vascular resistance after stenosis, and plasma renin and angiotensin II levels remained high. Renal dilatation was indefinitely maintained, but the normal restoration of resistance and pressure could be simulated by infusing angiotensin II into the renal artery. 4. The effective resistance to blood flow by the stenosis did not remain constant but varied with changes in the renal vascular resistance. PMID:219182

Renal manifestations in children with Alagille syndrome.

PubMed

Di Pinto, Diana; Adragna, Marta

2018-04-01

Alagille syndrome (AS) is a cholestatic disease secondary to scarcity of interlobular bile ducts. It is associated with extrahepatic manifestations, and renal involvement is frequent. To describe the prevalence, type and outcome of renal pathology in children with AS. The presence and outcome of renal pathology was retrospectively studied in 21 children who met AS criteria. Renal pathology was observed in 18 patients (85.7%): (1) ultrasound variations in 7 patients (6 cases of bilateral renal dysplasia and 1 case of renal agenesis); (2) distal renal tubular acidosis in 2 patients; (3) a drop in glomerular filtration and/or proteinuria in 16 patients. The frequency of a drop in glomerular filtration was similar between patients with and without pathological kidney ultrasound findings. Our study confirms a high prevalence of renal involvement, which enhances the importance of diagnosis and renal function follow-up in children with AS. Sociedad Argentina de Pediatría.

Geometric Alteration of Renal Arteries After Fenestrated Grafting and the Impact on Renal Function.

PubMed

Ou, Jiale; Chan, Yiu-Che; Chan, Crystal Yin-Tung; Cheng, Stephen W K

2017-05-01

This study aims to investigate the degree of geometric change on renal arteries and its impact on renal function after fenestrated endovascular aortic repair (fEVAR). Twenty-five patients with fEVAR were included. There were 47 renal arteries target vessels, and 43 of these (22 left and 21 right vessels) stented successfully. Their preoperative and first postoperative follow-up computed tomography (CT) images were reconstructed using the Aquarius workstation (TeraRecon, San Mateo, CA, USA). The superior mesenteric artery (SMA) or celiac axis (if SMA was stented) was appointed as reference origin. The longitudinal orientation of a renal artery or a stent was represented by a takeoff angle (ToA) between the renal artery or stent and the distal abdominal aorta. The postoperative stent ToAs were compared with those of preoperative renal arteries. Preoperative and short-term postoperative serum creatinine levels were measured. Renal function impairment was indicated as a >30% or >2.0 mg/dL rise in serum creatinine compared to the preoperative level. The relationship between postoperative renal function impairment and the stent orientation or geometric changes in renal arteries was correlated. The patency rate of renal arteries was 100% at the first postoperative CT review. The average ToAs of both renal arteries were significantly enlarged after stenting (P < 0.05). Seven stent deformations (16.3%) in four patients (16.0%) were observed. They were attributed to caudal misalignment of the fenestrated stent graft (n = 6) or inaccurate graft sizing (n = 1). There was no stent fracture or target vessel loss. Postoperatively, nine patients (36.0%) at day 1 and 10 patients (41.7%) after 3 months suffered the renal function impairment. This was found not to be associated with the stent angulation or angular change of the renal arteries (both P > 0.05). The three patients with stent deformation due to misalignment suffered postoperative renal function impairment and

The Studies on the Gastrin Levels in the Patients with Renal Failure

PubMed Central

Kim, Myung Hwan; Kim, Han Su; Rim, Kyu Sung; Bang, Ik Soo; Kim, Myung Jae; Chang, Rin; Min, Young II

1986-01-01

Fasting and postprandial gastrin levels were measured by radioimmunoassay in serum from 15 patients with renal failure and compared with those in 15 healthy controls. Pre- and posthemodialysis gastrin levels were also measured. The fasting serum gastrin levels and serum gastrin response to a standard meal in the patients with renal failure were significantly higher than those in normal controls. Fasting and meal stimulated gastrin levels were not significantly different in renal failure patients with peptic ulcer when compared with those in renal failure patients without peptic ulcer. There were no statistically significant differences in the serum gastrin levels before and after hemodialysis in patients with renal failure. PMID:15759375

Non-diabetic renal disease in patients with type 2 diabetes: a single centre study.

PubMed

Fan, Jian-Zhen; Wang, Rong

2018-04-01

Non-diabetic renal disease (NDRD) has been widely known in diabetic patients. The clinical differentiation between diabetic nephropathy (DN) and NDRD is still not so clear and effective. To analyse the pathological characteristics and distribution of renal injury in selected type 2 diabetic patients. Comparison between DN and NDRD in clinical characteristics, to find important predictors for NDRD. To conduct retrospective analysis of clinical, laboratory and pathohistological data of type 2 diabetic patients in whom renal biopsies were performed from March 2010 to September 2014 in Shandong Provincial Hospital affiliated to Shandong University (n = 88). According to the findings of renal biopsy, the incidences of DN, NDRD and DN complicated with NDRD were 20.46, 72.73 and 6.82% respectively. The most common NDRD found were: membranous nephropathy, followed by IgA nephropathy and focal segmental glomerulosclerosis. In multivariate logistic-analysis, fasting blood glucose (odds ratio (OR) 0.714; 95% confidence interval (CI) = 0.543-0.939; P = 0.016) and absence of diabetic retinopathy (OR 18.602; 95% CI = 2.176-159.018; P = 0.003) were independent predictors of NDRD. This study confirmed a considerably high prevalence of NDRD in type 2 diabetic patients with renal injury. As some cases of NDRD are readily treatable or remittable, we should consider renal biopsy in selected diabetic patients with renal involvement, especially in those with effective blood glucose control and the absence of diabetic retinopathy. © 2017 Royal Australasian College of Physicians.

Effects of hypercholesterolemia of renal hemodynamics: study in patients with nephrotic syndrome.

PubMed

Fuiano, G; Esposito, C; Sepe, V; Colucci, G; Bovino, M; Rosa, M; Balletta, M; Bellinghieri, G; Conte, G; Cianciaruso, B; Dal Canton, A

1996-01-01

Experimental and clinical studies have demonstrated a positive relationship between hyperlipidemia and rate of progression of renal disease, suggesting that lipids can induce or aggravate glomerular injury mainly by interacting with mesangial cells. Nevertheless, recently has been demonstrated that increased cholesterol levels can also induce endothelial cell dysfunction. Thus, since endothelium is known to play a major role in modulating the vascular tone, we have tested the possibility that hypercholesterolemia impairs the renal hemodynamics in patients with active nephrotic syndrome and elevated serum cholesterol levels. In this single-blind, nonrandom study, 12 patients were treated with pravastatin (group T, treated, n = 12) and 8 with placebo (group C, controls, n = 8). The controls were studied after the pravastatin group had been completed. Before starting the treatment the patients underwent basal determinations including routine laboratory investigations and PAH and inulin clearances. The same determinations were repeated after 48 h, and 6 and 12 weeks from the beginning of the treatment. The study at 48 h was performed to see if pravastatin had a direct, cholesterol-independent effect on renal function. The following basal results were reported (mean +/- SEM; group T vs. group C): serum cholesterol (mmol/l) 9.7 +/- 0.4 vs. 9.1 +/- 0.3 (NS); proteinuria (g/24 h): 6.2 +/- 0.2 vs. 7.0 +/- 0.7 (NS); PAH clearance (ml/min): 353 +/- 21 vs. 385 +/- 31 (NS); inulin clearance (ml/min): 62.5 +/- 7.7 vs. 67 +/- 9.3 (NS). After 48 h, no changes were observed in both groups. Subsequently, in group T, the following percentage changes of basal levels were observed: serum cholesterol -21.4 +/- 3.2% at 6 weeks (p < 0.05) and -34.9 +/- 3.2% at 12 weeks (p < 0.01); inulin clearance +3 +/- 3.7% at 6 weeks (NS) and +9.3 +/- 2.9% at 12 weeks (p < 0.05); PAH clearance +7 +/- 3.1% at 6 weeks (p < 0.05) and +21.2 +/- 5.5% at 12 weeks (p < 0.01). By contrast, no significant

Renal function following xenon anesthesia for partial nephrectomy-An explorative analysis of a randomized controlled study.

PubMed

Stevanovic, Ana; Schaefer, Patrick; Coburn, Mark; Rossaint, Rolf; Stoppe, Christian; Boor, Peter; Pfister, David; Heidenreich, Axel; Christ, Hildegard; Hellmich, Martin; Fahlenkamp, Astrid V

2017-01-01

Perioperative preservation of renal function has a significant impact on morbidity and mortality in kidney surgery. Nephroprotective effects of the anesthetic xenon on ischemia-reperfusion injury were found in several experimental studies. We aimed to explore whether xenon anesthesia can reduce renal damage in humans undergoing partial nephrectomy and to gather pilot data of possible nephroprotection in these patients. A prospective randomized, single-blinded, controlled study. Single-center, University Hospital of Aachen, Germany between July 2013-October 2015. Forty-six patients with regular renal function undergoing partial nephrectomy. Patients were randomly assigned to receive xenon- (n = 23) or isoflurane (n = 23) anesthesia. Primary outcome was the maximum postoperative glomerular filtration rate (GFR) decline within seven days after surgery. Secondary outcomes included intraoperative and tumor-related data, assessment of further kidney injury markers, adverse events and optional determination of renal function after 3-6 months. Unexpected radical nephrectomy was performed in 5 patients, thus they were excluded from the per-protocol analysis, but included in the intention-to-treat analysis. The maximum postoperative GFR decline was attenuated by 45% in the xenon-group (10.9 ml min-1 1.73 cm-2 versus 19.7 ml min-1 1.73 cm-2 in the isoflurane group), but without significance (P = 0.084). Occurrence of adverse events was reduced (P = 0.003) in the xenon group. Renal function was similar among the groups after 3-6 months. Xenon anesthesia was feasible and safe in patients undergoing partial nephrectomy with regard to postoperative renal function. We found no significant effect on early renal function but less adverse events in the xenon group. Larger randomized controlled studies in more heterogeneous collectives are required, to confirm or refute the possible clinical benefit on renal function by xenon. ClinicalTrials.gov NCT01839084 and EudraCT 2012-005698-30.

Renal perfusion scintiscan

MedlinePlus

... Radionuclide renal perfusion scan; Perfusion scintiscan - renal; Scintiscan - renal perfusion Images Kidney anatomy Kidney - blood and urine flow Intravenous pyelogram References Rottenberg G, Andi AC. Renal ...

Congestive renal failure: the pathophysiology and treatment of renal venous hypertension.

PubMed

Ross, Edward A

2012-12-01

Longstanding experimental evidence supports the role of renal venous hypertension in causing kidney dysfunction and "congestive renal failure." A focus has been heart failure, in which the cardiorenal syndrome may partly be due to high venous pressure, rather than traditional mechanisms involving low cardiac output. Analogous diseases are intra-abdominal hypertension and renal vein thrombosis. Proposed pathophysiologic mechanisms include reduced transglomerular pressure, elevated renal interstitial pressure, myogenic and neural reflexes, baroreceptor stimulation, activation of sympathetic nervous and renin angiotensin aldosterone systems, and enhanced proinflammatory pathways. Most clinical trials have addressed the underlying condition rather than venous hypertension per se. Interpreting the effects of therapeutic interventions on renal venous congestion are therefore problematic because of such confounders as changes in left ventricular function, cardiac output, and blood pressure. Nevertheless, there is preliminary evidence from small studies of intense medical therapy or extracorporeal ultrafiltration for heart failure that there can be changes to central venous pressure that correlate inversely with renal function, independently from the cardiac index. Larger more rigorous trials are needed to definitively establish under what circumstances conventional pharmacologic or ultrafiltration goals might best be directed toward central venous pressures rather than left ventricular or cardiac output parameters. Copyright © 2012 Elsevier Inc. All rights reserved.

High sensitive volumetric imaging of renal microcirculation in vivo using ultrahigh sensitive optical microangiography

NASA Astrophysics Data System (ADS)

Zhi, Zhongwei; Jung, Yeongri; Jia, Yali; An, Lin; Wang, Ruikang K.

2011-03-01

We present a non-invasive, label-free imaging technique called Ultrahigh Sensitive Optical Microangiography (UHSOMAG) for high sensitive volumetric imaging of renal microcirculation. The UHS-OMAG imaging system is based on spectral domain optical coherence tomography (SD-OCT), which uses a 47000 A-line scan rate CCD camera to perform an imaging speed of 150 frames per second that takes only ~7 seconds to acquire a 3D image. The technique, capable of measuring slow blood flow down to 4 um/s, is sensitive enough to image capillary networks, such as peritubular capillaries and glomerulus within renal cortex. We show superior performance of UHS-OMAG in providing depthresolved volumetric images of rich renal microcirculation. We monitored the dynamics of renal microvasculature during renal ischemia and reperfusion. Obvious reduction of renal microvascular density due to renal ischemia was visualized and quantitatively analyzed. This technique can be helpful for the assessment of chronic kidney disease (CKD) which relates to abnormal microvasculature.

Prospective study comparing three-dimensional computed tomography and magnetic resonance imaging for evaluating the renal vascular anatomy in potential living renal donors.

PubMed

Bhatti, Aftab A; Chugtai, Aamir; Haslam, Philip; Talbot, David; Rix, David A; Soomro, Naeem A

2005-11-01

To prospectively compare the accuracy of multislice spiral computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) in evaluating the renal vascular anatomy in potential living renal donors. Thirty-one donors underwent multislice spiral CTA and gadolinium-enhanced MRA. In addition to axial images, multiplanar reconstruction and maximum intensity projections were used to display the renal vascular anatomy. Twenty-four donors had a left laparoscopic donor nephrectomy (LDN), whereas seven had right open donor nephrectomy (ODN); LDN was only considered if the renal vascular anatomy was favourable on the left. CTA and MRA images were analysed by two radiologists independently. The radiological and surgical findings were correlated after the surgery. CTA showed 33 arteries and 32 veins (100% sensitivity) whereas MRA showed 32 arteries and 31 veins (97% sensitivity). CTA detected all five accessory renal arteries whereas MRA only detected one. CTA also identified all three accessory renal veins whereas MRA identified two. CTA had a sensitivity of 97% and 47% for left lumbar and left gonadal veins, whereas MRA had a sensitivity of 74% and 46%, respectively. Multislice spiral CTA with three-dimensional reconstruction was more accurate than MRA for both renal arterial and venous anatomy.

Association of Serum Bicarbonate With Risk of Renal and Cardiovascular Outcomes in CKD: A Report From the Chronic Renal Insufficiency Cohort (CRIC) Study

PubMed Central

Dobre, Mirela; Yang, Wei; Chen, Jing; Drawz, Paul; Hamm, L. Lee; Horwitz, Edward; Hostetter, Thomas; Jaar, Bernard; Lora, Claudia M; Nessel, Lisa; Ojo, Akinlolu; Scialla, Julia; Steigerwalt, Susan; Teal, Valerie; Wolf, Myles; Rahman, Mahboob

2013-01-01

Background The purpose of this study is to evaluate serum bicarbonate as a risk factor for renal outcomes, cardiovascular events and mortality in patients with chronic kidney disease (CKD). Study Design Observational cohort study. Setting & Participants 3939 participants with CKD stages 2-4 who enrolled in the Chronic Renal Insufficiency Cohort (CRIC) between June 2003 - December 2008. Predictor Serum bicarbonate. Outcomes Renal outcomes, defined as end-stage renal disease (either initiation of dialysis or kidney transplantation) or 50% reduction in eGFR; atherosclerotic events (myocardial infarction, stroke, peripheral arterial disease); congestive heart failure events; and death. Measurements Time to event. Results The mean eGFR was 44.8 ± 16.8 (SD) mL/min/1.73 m2, and the median serum bicarbonate was 24 (IQR, 22-26) mEq/L. During a median follow-up of 3.9 years, 374 participants died, 767 had a renal outcome, and 332 experienced an atherosclerotic event and 391 had a congestive heart failure event. In adjusted analyses, the risk of developing a renal endpoint was 3% lower per mEq/L increase in serum bicarbonate (HR, 0.97; 95% CI, 0.94-0.99; p=0.01). The association was stronger for participants with eGFR> 45ml/min/1.73m2 (HR, 0.91; 95%CI, 0.85-0.97; p=0.004). The risk of heart failure increased by 14% (HR, 1.14; 95%CI, 1.03-1.26; p=0.02) per mEq/L increase in serum bicarbonate over 24 mEq/L. Serum bicarbonate was not independently associated with atherosclerotic events (HR, 0.99; 95%CI, 0.95-1.03; p=0.6) and all-cause mortality (HR, 0.98; 95%CI, 0.95-1.02; p=0.3). Limitations Single measurement of sodium bicarbonate. Conclusions In a cohort of participants with CKD, low serum bicarbonate was an independent risk factor for kidney disease progression, particularly for participants with preserved kidney function. The risk of heart failure was higher at the upper extreme of serum bicarbonate. There was no association between serum bicarbonate and all

Does the type of renal artery anatomic variant determine the diameter of the main vessel supplying a kidney? A study based on CT data with a particular focus on the presence of multiple renal arteries.

PubMed

Majos, Marcin; Stefańczyk, Ludomir; Szemraj-Rogucka, Zofia; Elgalal, Marcin; De Caro, Raffaele; Macchi, Veronica; Polguj, Michał

2018-04-01

An in-depth knowledge of renal vascular anatomy is essential when planning many surgical procedures; however, a few data exists regarding renal artery diameter. The aim of this study was to assess this morphological feature and to investigate whether a correlation exists between renal artery diameter and the type of arterial supply, with a particular emphasis on variant anatomy and the presence of multiple renal arteries. Computed tomography angiography (CTA) studies of 248 patients, i.e., a total of 496 kidneys, were evaluated. The mean age of the patients was 66.4 ± 15.01 years. Renal artery diameter was measured based on the type of arterial blood supply. The frequency of occurrence of three anatomic variants of renal arterial supply was established: single renal artery (RA) 43.35%, single artery with prehilar branching (pRA) 37.30%, and multiple renal artery (mRA) 19.35%. The diameter of single renal arteries, with either prehilar or hilar branching, was significantly larger than when multiple arteries were present. A detailed analysis of just the mRA variant demonstrated that the diameter of the renal arteries in men was larger (p = 0.012) than those in women and that there was no difference in diameter with regard to the side of the body (p = 0.219). The classification described in our study containing a detailed description of renal artery diameter. It may be helpful in clinical practice, especially for transplantologists, surgeons, and vascular surgeons.

Renal denervation in a patient with Alport syndrome and rejected renal allograft.

PubMed

Raju, Narayana; Lloyd, Vincent; Yalagudri, Sachin; Das, Bharati; Ravikishore, A G

2015-12-01

Renal denervation is a new intervention to treat resistant hypertension. By applying radiofrequency (RF) to renal arteries, sympathetic nerves in adventitia layer of vascular wall can be denervated. Sympathetic hyperactivity is an important contributory factor in hypertension of hemodialysis patients. Hyperactive sympathetic nervous system aggravates hypertension and it can cause complications like left ventricular hypertrophy, heart failure, arrhythmias and atherogenesis. Our report illustrates the use of renal denervation using conventional RF catheter for uncontrolled hypertension in a patient with Alport syndrome and rejected renal allograft. Progressive and sustained reduction of blood pressure was obtained post-procedure and at 24 months follow-up with antihypertensives decreased from 6 to 2 per day, thereby demonstrating the safety, feasibility, and efficacy of the procedure. There are some reports available on the usefulness of this technique in hemodialysis patients; however, there are no studies of renal denervation in patients with Alport syndrome and failed allograft situation. Copyright © 2015 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

Renal incidental findings on computed tomography

PubMed Central

Meyer, Hans Jonas; Pfeil, Alina; Schramm, Dominik; Bach, Andreas Gunter; Surov, Alexey

2017-01-01

Abstract Renal incidental findings (IFs) are common. However, previous reports investigated renal IFs were limited to patient selection. The purpose of this study was to estimate the prevalence and distribution of all renal IFs on computed tomography (CT) in a large patient collective. All patients, who underwent CT investigations of the abdominal region at our institution in the time period between January 2006 and February 2014 were included in this study. Inclusion criteria were as follows: no previous history of renal diseases and well image quality. Patients with known kidney disorders were excluded from the study. Overall, 7365 patients meet the inclusion criteria were identified. There were 2924 (39.7%) women and 4441 men (60.3%) with a mean age of 59.8 ± 16.7 years. All CTs were retrospectively analyzed in consensus by 2 radiologists. Collected data were evaluated by means of descriptive statistics. Overall, 2756 patients (37.42% of all included patients) showed 3425 different renal IFs (1.24 findings per patient). Of all renal IFs, 123 (3.6%) findings were clinically relevant, 259 (7.6%) were categorized as possibly clinically relevant, and 3043 (88.8%) were clinically non relevant. Different renal IFs can be detected on CT. The present study provides a real prevalence and proportion of them in daily clinical routine. Kidneys should be thoroughly evaluated because of the fact that incidental renal findings occur frequently. PMID:28658098

Personalized design and virtual evaluation of physician-modified stent grafts for juxta-renal abdominal aortic aneurysms

NASA Astrophysics Data System (ADS)

Sanathkhani, Soroosh; Shroff, Sanjeev G.; Menon, Prahlad G.

2017-02-01

Endovascular aneurysm repair (EVAR) of juxtarenal aortic aneurysms (JAA) is particularly challenging owing to the requirement of suprarenal EVAR graft fixation, which has been associated with significant declines in long term renal function. Therefore, the ability to design fenestrated EVAR grafts on a personalized basis in order to ensure visceral and renal perfusion, is highly desirable. The objectives of this study are: a) To demonstrate novel 3D geometric methods to virtually design and deploy EVAR grafts into a virtually designed JAA, by applying a custom surface mesh deformation tool to a patient-specific descending aortic model reconstructed from computed tomographic (CT) images; and b) To virtually evaluate patient-specific renal flow and wall stresses in these patient-specific virtually EVAR geometries, using computational fluid dynamics (CFD). The presented framework may provide the modern cardiovascular surgeon the ability to leverage non-invasive, pre-operative imaging equipment to personalize and guide EVAR therapeutic strategy. Our CFD studies revealed that virtual EVAR grafting of a patient-specific JAA, with optimal fenestration sites and renal stenting, led to a 179.67±15.95% and 1051.43±18.34% improvement in right and left renal flow rates, respectively, when compared with the baseline patient-specific aortic geometry with renal stenoses, whereas a right and left renal flow improved by 36.44±2.24% and 885.93±12.41%, respectively, relative to the equivalently modeled JAA with renal stenoses, considering averages across the three simulated inflow rate cases. The proposed framework have utility to iteratively optimize suprarenal EVAR fixation length and achieve normal renal wall shear stresses and streamlined juxtarenal hemodynamics.

Gallium-68 EDTA PET/CT for Renal Imaging.

PubMed

Hofman, Michael S; Hicks, Rodney J

2016-09-01

Nuclear medicine renal imaging provides important functional data to assist in the diagnosis and management of patients with a variety of renal disorders. Physiologically stable metal chelates like ethylenediaminetetraacetic acid (EDTA) and diethylenetriamine penta-acetate (DTPA) are excreted by glomerular filtration and have been radiolabelled with a variety of isotopes for imaging glomerular filtration and quantitative assessment of glomerular filtration rate. Gallium-68 ((68)Ga) EDTA PET usage predates Technetium-99m ((99m)Tc) renal imaging, but virtually disappeared with the widespread adoption of gamma camera technology that was not optimal for imaging positron decay. There is now a reemergence of interest in (68)Ga owing to the greater availability of PET technology and use of (68)Ga to label other radiotracers. (68)Ga EDTA can be used a substitute for (99m)Tc DTPA for wide variety of clinical indications. A key advantage of PET for renal imaging over conventional scintigraphy is 3-dimensional dynamic imaging, which is particularly helpful in patients with complex anatomy in whom planar imaging may be nondiagnostic or difficult to interpret owing to overlying structures containing radioactive urine that cannot be differentiated. Other advantages include accurate and absolute (rather than relative) camera-based quantification, superior spatial and temporal resolution and integrated multislice CT providing anatomical correlation. Furthermore, the (68)Ga generator enables on-demand production at low cost, with no additional patient radiation exposure compared with conventional scintigraphy. Over the past decade, we have employed (68)Ga EDTA PET/CT primarily to answer difficult clinical questions in patients in whom other modalities have failed, particularly when it was envisaged that dynamic 3D imaging would be of assistance. We have also used it as a substitute for (99m)Tc DTPA if unavailable owing to supply issues, and have additionally examined the role of

Blood Pressure Response to Main Renal Artery and Combined Main Renal Artery Plus Branch Renal Denervation in Patients With Resistant Hypertension.

PubMed

Fengler, Karl; Ewen, Sebastian; Höllriegel, Robert; Rommel, Karl-Philipp; Kulenthiran, Saaraaken; Lauder, Lucas; Cremers, Bodo; Schuler, Gerhard; Linke, Axel; Böhm, Michael; Mahfoud, Felix; Lurz, Philipp

2017-08-10

Single-electrode ablation of the main renal artery for renal sympathetic denervation showed mixed blood pressure (BP)-lowering effects. Further improvement of the technique seems crucial to optimize effectiveness of the procedure. Because sympathetic nerve fibers are closer to the lumen in the distal part of the renal artery, treatment of the distal main artery and its branches has been shown to reduce variability in treatment effects in preclinical studies and a recent randomized trial. Whether this optimized technique improves clinical outcomes remains uncertain. We report a 2-center experience of main renal artery and combined main renal artery plus branches renal denervation in patients with resistant hypertension using a multielectrode catheter. Twenty-five patients with therapy-resistant hypertension underwent renal sympathetic denervation with combined main renal artery and renal branch ablation and were compared to matched controls undergoing an ablation of the main renal artery only. BP change was assessed by ambulatory measurement at baseline and after 3 months. At baseline, BP was balanced between the groups. After 3 months, BP changed significantly in the combined ablation group (systolic/diastolic 24-hour mean and daytime mean BP -8.5±9.8/-7.0±10.7 and -9.4±9.8/-7.1±13.5 mm Hg, P <0.001/0.003 and <0.001/0.016, respectively), but not in patients with main artery treatment (-3.5±11.1/-2.0±7.6 and -2.8±10.9/-1.8±7.7 mm Hg, P =0.19/0.20 and 0.19/0.24, respectively). Systolic daytime BP was significantly more reduced in patients with combined ablation than in patients with main artery ablation ( P =0.033). Combined ablation of the main renal artery and branches appears to improve BP-lowering efficacy and should be further investigated. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Live Donor Renal Anatomic Asymmetry and Posttransplant Renal Function.

PubMed

Tanriover, Bekir; Fernandez, Sonalis; Campenot, Eric S; Newhouse, Jeffrey H; Oyfe, Irina; Mohan, Prince; Sandikci, Burhaneddin; Radhakrishnan, Jai; Wexler, Jennifer J; Carroll, Maureen A; Sharif, Sairah; Cohen, David J; Ratner, Lloyd E; Hardy, Mark A

2015-08-01

Relationship between live donor renal anatomic asymmetry and posttransplant recipient function has not been studied extensively. We analyzed 96 live kidney donors, who had anatomical asymmetry (>10% renal length and/or volume difference calculated from computerized tomography angiograms) and their matching recipients. Split function differences (SFD) were quantified with technetium-dimercaptosuccinic acid renography. Implantation biopsies at time 0 were semiquantitatively scored. A comprehensive model using donor renal volume adjusted to recipient weight (Vol/Wgt), SFD, and biopsy score was used to predict recipient estimated glomerular filtration rate (eGFR) at 1 year. Primary analysis consisted of a logistic regression model of outcome (odds of developing eGFR>60 mL/min/1.73 m(2) at 1 year), a linear regression model of outcome (predicting recipient eGFR at one-year, using the chronic kidney disease-epidemiology collaboration formula), and a Monte Carlo simulation based on the linear regression model (N=10,000 iterations). In the study cohort, the mean Vol/Wgt and eGFR at 1 year were 2.04 mL/kg and 60.4 mL/min/1.73 m(2), respectively. Volume and split ratios between 2 donor kidneys were strongly correlated (r = 0.79, P < 0.001). The biopsy scores among SFD categories (<5%, 5%-10%, >10%) were not different (P = 0.190). On multivariate models, only Vol/Wgt was significantly associated with higher odds of having eGFR > 60 mL/min/1.73 m (odds ratio, 8.94, 95% CI 2.47-32.25, P = 0.001) and had a strong discriminatory power in predicting the risk of eGFR less than 60 mL/min/1.73 m(2) at 1 year [receiver operating curve (ROC curve), 0.78, 95% CI, 0.68-0.89]. In the presence of donor renal anatomic asymmetry, Vol/Wgt appears to be a major determinant of recipient renal function at 1 year after transplantation. Renography can be replaced with CT volume calculation in estimating split renal function.

Modeling of the aorta artery aneurysms and renal artery stenosis using cardiovascular electronic system

PubMed Central

Hassani, Kamran; Navidbakhsh, Mahdi; Rostami, Mostafa

2007-01-01

Background The aortic aneurysm is a dilatation of the aortic wall which occurs in the saccular and fusiform types. The aortic aneurysms can rupture, if left untreated. The renal stenosis occurs when the flow of blood from the arteries leading to the kidneys is constricted by atherosclerotic plaque. This narrowing may lead to the renal failure. Previous works have shown that, modelling is a useful tool for understanding of cardiovascular system functioning and pathophysiology of the system. The present study is concerned with the modelling of aortic aneurysms and renal artery stenosis using the cardiovascular electronic system. Methods The geometrical models of the aortic aneurysms and renal artery stenosis, with different rates, were constructed based on the original anatomical data. The pressure drop of each section due to the aneurysms or stenosis was computed by means of computational fluid dynamics method. The compliance of each section with the aneurysms or stenosis is also calculated using the mathematical method. An electrical system representing the cardiovascular circulation was used to study the effects of these pressure drops and the compliance variations on this system. Results The results showed the decreasing of pressure along the aorta and renal arteries lengths, due to the aneurysms and stenosis, at the peak systole. The mathematical method demonstrated that compliances of the aorta sections and renal increased with the expansion rate of the aneurysms and stenosis. The results of the modelling, such as electrical pressure graphs, exhibited the features of the pathologies such as hypertension and were compared with the relevant experimental data. Conclusion We conclude from the study that the aortic aneurysms as well as renal artery stenosis may be the most important determinant of the arteries rupture and failure. Furthermore, these pathologies play important rules in increase of the cardiovascular pulse pressure which leads to the hypertension

Effect of renal nerve stimulation on responsiveness of the rat renal vasculature.

PubMed

DiBona, Gerald F; Sawin, Linda L

2002-11-01

When the renal nerves are stimulated with sinusoidal stimuli over the frequency range 0.04-0.8 Hz, low (< or =0.4 Hz)- but not high (> or =0.4 Hz)-frequency oscillations appear in renal blood flow (RBF) and are proposed to increase responsiveness of the renal vasculature to stimuli. This hypothesis was tested in anesthetized rats in which RBF responses to intrarenal injection of norepinephrine and angiotensin and to reductions in renal arterial pressure (RAP) were determined during conventional rectangular pulse and sinusoidal renal nerve stimulation. Conventional rectangular pulse renal nerve stimulation decreased RBF at 2 Hz but not at 0.2 or 1.0 Hz. Sinusoidal renal nerve stimulation elicited low-frequency oscillations (< or =0.4 Hz) in RBF only when the basal carrier signal frequency produced renal vasoconstriction, i.e., at 5 Hz but not at 1 Hz. Regardless of whether renal vasoconstriction occurred, neither conventional rectangular pulse nor sinusoidal renal nerve stimulation altered renal vasoconstrictor responses to norepinephrine and angiotensin. The RBF response to reduction in RAP was altered by both conventional rectangular pulse and sinusoidal renal nerve stimulation only when renal vasoconstriction occurred: the decrease in RBF during reduced RAP was greater. Sinusoidal renal nerve stimulation with a renal vasoconstrictor carrier frequency results in a decrease in RBF with superimposed low-frequency oscillations. However, these low-frequency RBF oscillations do not alter renal vascular responsiveness to vasoconstrictor stimuli.

Renal volume assessed by magnetic resonance imaging volumetry correlates with renal function in living kidney donors pre- and postdonation: a retrospective cohort study.

PubMed

Lange, Daniel; Helck, Andreas; Rominger, Axel; Crispin, Alexander; Meiser, Bruno; Werner, Jens; Fischereder, Michael; Stangl, Manfred; Habicht, Antje

2018-07-01

Renal function of potential living kidney donors is routinely assessed with scintigraphy. Kidney anatomy is evaluated by imaging techniques such as magnetic resonance imaging (MRI). We evaluated if a MRI-based renal volumetry is a good predictor of kidney function pre- and postdonation. We retrospectively analyzed the renal volume (RV) in a MRI of 100 living kidney donors. RV was correlated with the tubular excretion rate (TER) of MAG3-scintigraphy, a measured creatinine clearance (CrCl), and the estimated glomerular filtration rate (eGFR) by Cockcroft-Gault (CG), CKD-EPI, and modification of diet in renal disease (MDRD) formula pre- and postdonation during a follow-up of 3 years. RV correlated significantly with the TER (total: r = 0.6735, P < 0.0001). Correlation between RV and renal function was the highest for eGFR by CG (r = 0.5595, P < 0.0001), in comparison with CrCl, MDRD-GFR, and CKD-EPI-GFR predonation. RV significantly correlated with CG-GFR postdonation and predicted CG-GFR until 3 years after donation. MRI renal volumetry might be an alternative technique for the evaluation of split renal function and prediction of renal function postdonation in living kidney donors. © 2018 Steunstichting ESOT.

Epidemiologic Study and Genotyping of BK Virus in Renal Transplant Recipients.

PubMed

Cobos, M; Aquilia, L; Garay, E; Ochiuzzi, S; Alvarez, S; Flores, D; Raimondi, C

2018-03-01

BK virus (BKV) infection occurs during childhood and remains latent in the urinary tract. The virus is reactivated in immunosuppressed patients, particularly in those with cellular immunity deficiency, allowing its detection in urine and blood. Nephropathy caused by the virus in renal transplantation recipients may lead to graft failure. The purpose of this study is to know the prevalence of BKV variables in renal transplantation recipients and to evaluate their clinical evolution through molecular methods of "in house" development. Urine and peripheral blood samples from 66 renal transplantation recipients from the province of Buenos Aires, Argentina, were systematically analyzed every 3 months as well as when there was graft dysfunction. Renal biopsies, which were included in the BKV detection study, were performed on those patients with graft dysfunction. Genotyping of 24 BKVs was performed, and the following distribution was found: 21 (87.5%) belonged to subtype I, 3 (12.5%) to subtype II. BKV belonging to subtypes III or IV were not found. As regards subtype I subgroups, the following were identified: 1 (4.76%) from Ia, 10 (47.61%) from Ib1 and 10 (47.61%) from Ib2. Presence of subgroup Ic was not shown. Viremia presented in 33.33% of cases, whereas 75% corresponded to subgroup Ib 1. Genotype Ib1 is prevailing in Southeast Asia, while Ib2 is prominent in Europe. Although an important proportion of the inhabitants of the province of Buenos Aires are European descendants, the prevailing genotype is Ib1, the Asian type. Genotyping might be related to the evolution of the disease in the recipient. Copyright © 2017 Elsevier Inc. All rights reserved.

Increased renal sympathetic nerve activity leads to hypertension and renal dysfunction in offspring from diabetic mothers.

PubMed

de Almeida Chaves Rodrigues, Aline Fernanda; de Lima, Ingrid Lauren Brites; Bergamaschi, Cássia Toledo; Campos, Ruy Ribeiro; Hirata, Aparecida Emiko; Schoorlemmer, Guus Hermanus Maria; Gomes, Guiomar Nascimento

2013-01-15

The exposure of the fetus to a hyperglycemic environment promotes the development of hypertension and renal dysfunction in the offspring at adult age. We evaluated the role of renal nerves in the hypertension and renal changes seen in offspring of diabetic rats. Diabetes was induced in female Wistar rats (streptozotocin, 60 mg/kg ip) before mating. Male offspring from control and diabetic dams were studied at an age of 3 mo. Systolic blood pressure measured by tail cuff was increased in offspring of diabetic dams (146 ± 1.6 mmHg, n = 19, compared with 117 ± 1.4 mmHg, n = 18, in controls). Renal function, baseline renal sympathetic nerve activity (rSNA), and arterial baroreceptor control of rSNA were analyzed in anesthetized animals. Glomerular filtration rate, fractional sodium excretion, and urine flow were significantly reduced in offspring of diabetic dams. Two weeks after renal denervation, blood pressure and renal function in offspring from diabetic dams were similar to control, suggesting that renal nerves contribute to sodium retention in offspring from diabetic dams. Moreover, basal rSNA was increased in offspring from diabetic dams, and baroreceptor control of rSNA was impaired, with blunted responses to infusion of nitroprusside and phenylephrine. Thus, data from this study indicate that in offspring from diabetic mothers, renal nerves have a clear role in the etiology of hypertension; however, other factors may also contribute to this condition.

Clinical course of dengue fever and its impact on renal function in renal transplant recipients and patients with chronic kidney disease.

PubMed

Arun Thomas, E T; George, Jacob; Sruthi, Devi; Vineetha, N S; Gracious, Noble

2018-04-01

Dengue fever is a mosquito-borne viral disease endemic in many tropical and sub-tropical countries. There is only limited data in the literature about dengue fever in renal transplant recipients and patients with chronic kidney disease. This study compares the clinical course of dengue fever and its impact on renal function in renal transplant recipients, patients with chronic kidney disease and patients with normal base line renal function. An observational study was conducted from 1 st May to 31 st July 2017, at a tertiary care centre of South India. A major epidemic of dengue had occurred during the study period. Twelve renal transplant recipients, 22 patients with CKD and 58 patients with normal baseline renal function (control group) admitted with dengue fever were prospectively studied. Nadir WBC count was lowest in renal transplant recipients (2575 + 1187/mm 3 ), [P<0.001]. Renal transplant recipients took more time for normalisation of platelet count (6 + 4.5 days), [P<0.001]. All 22 patients with CKD and 11 of 12 renal transplant recipients had worsening of renal function where as only 17 of 58 patients in the control group had worsening [P<0.001]. Sixteen patients with CKD, one renal transplant recipient and none among control group required hemodialysis [P<0.001]. Dialysis requiring patients had more hemoconcentration (52.5+ 19.9% increase in haemoglobin), [P<0.001]. Seven patients with CKD were dialysis dependent at the end of 2 weeks. Clinical features of dengue fever were different in renal transplant recipients and patients with CKD. Severe worsening of renal function was common in CKD patients. Worsening of renal function in renal transplant recipients was less severe and transient. This article is protected by copyright. All rights reserved.

Renal autotransplantation--a possibility in the treatment of complex renal vascular diseases and ureteric injuries.

PubMed

Hau, Hans Michael; Bartels, Michael; Tautenhahn, Hans-Michael; Morgul, Mehmet Haluk; Fellmer, Peter; Ho-Thi, Phuc; Benckert, Christoph; Uhlmann, Dirk; Moche, Michael; Thelen, Armin; Schmelzle, Moritz; Jonas, Sven

2012-12-31

We report our contemporary experiences with renal autotransplantation in patients with complicated renal vascular diseases and/or complex ureteral injuries. Since its first performance, renal autotransplantation has been steadily improved and become a safe and effective procedure. Between 1998 and 2006, 6 renal autotransplantations in 6 patients were performed at the University Medical Center of Leipzig. After nephrectomy and renal perfusion ex vivo, the kidney was implanted standardized in the fossa iliaca. The vessels were anastomized to the iliac vessels, the ureter was reimplanted in an extravesical tunneled ureteroneocystostomy technique according to Lich-Gregoir. Demographic, clinical, and laboratory data of the patients were collected and analyzed for pre-, intra-, and postoperative period. Indications for renal autotransplantation were complex renovascular diseases in 2 patients (1 with fibromuscular dysplasia and 1 with Takayasu's arteritis) and in 4 patients with complex ureteral injuries. The median duration of follow-up was 9.7 years (range: 5.6-13.3). The laboratory values of our 6 patients showed improvements of creatinine, urea and blood pressure levels in comparison to the preoperative status at the end of follow-up period. The present study reports excellent results of renal autotransplantation in patients with renovascular disease or complex ureteric injuries. After a median follow-up of 9.7 years all 6 patients present with stable renal function as well as normal blood pressure values. Postoperative complications were observed with a rate comparable to other studies.

A simulation model to investigate the impact of cardiovascular risk in renal transplantation.

PubMed

McLean, D R; Jardine, A G

2005-06-01

Premature cardiovascular (CV) disease is the leading cause of death following renal transplantation and, as a consequence of death with a functioning graft, it is a major cause of graft loss. Renal transplant recipients have a high prevalence of CV risk factors that influence both patient and graft survival. We used data on the relationship between CV risk factors and graft and patient survivals to develop a discrete event simulation model to study the possible impact of CV risk factor reduction on transplant outcome. The simulation was based on a renal unit in a population that has the risk factor profile of patients from the West of Scotland. We studied the dynamic between patient numbers on the waiting list compared to the transplanted list. After establishing results pertinent to the renal unit, we investigated in what way potential changes to transplant policy affected patient numbers. These perturbations included changing the number of transplants performed, changing the incidence of acute rejection, and interventional policies where patients on the waiting list were selectively transplanted taking into account their CV risk factor profiles. Overall, the model predicts that reducing CV risk in the population with end-stage renal failure awaiting kidney transplantation will have comparable benefits to foreseeable developments in immunosuppression or attainable increases in transplant numbers. Moreover, addressing CV risk has benefits for all patients regardless of whether or not they ultimately receive a kidney transplant.

ANCA-Associated Glomerulonephritis: Risk Factors for Renal Relapse.

PubMed

Göçeroğlu, Arda; Berden, Annelies E; Fiocco, Marta; Floßmann, Oliver; Westman, Kerstin W; Ferrario, Franco; Gaskin, Gill; Pusey, Charles D; Hagen, E Christiaan; Noël, Laure-Hélène; Rasmussen, Niels; Waldherr, Rüdiger; Walsh, Michael; Bruijn, Jan A; Jayne, David R W; Bajema, Ingeborg M

2016-01-01

Relapse in ANCA-associated vasculitis (AAV) has been studied previously, but there are few studies on renal relapse in particular. Identifying patients at high risk of renal relapse may aid in optimizing clinical management. We investigated which clinical and histological parameters are risk factors for renal relapse in ANCA-associated glomerulonephritis (AAGN). Patients (n = 174) were newly diagnosed and had mild-moderate or severe renal involvement. Data were derived from two trials of the European Vasculitis Society: MEPEX and CYCAZAREM. The Cox regression model was used to identify parameters increasing the instantaneous risk (= rate) of renal relapse (useful for instant clinical decisions). For identifying predictors of renal relapse during follow-up, we used Fine & Gray's regression model. Competing events were end-stage renal failure and death. The cumulative incidence of renal relapse at 5 years was 9.5% (95% CI: 4.8-14.3%). In the Cox model, sclerotic class AAGN increased the instantaneous risk of renal relapse. In Fine & Gray's model, the absence of interstitial infiltrates at diagnosis was predictive for renal relapse. In this study we used two different models to identify possible relationships between clinical and histopathological parameters at time of diagnosis of AAV with the risk of experiencing renal relapse. Sclerotic class AAGN increased the instantaneous risk of renal relapse. This association is most likely due to the high proportion of sclerosed glomeruli reducing the compensatory capacity. The absence of interstitial infiltrates increased the risk of renal relapse which is a warning sign that patients with a relatively benign onset of disease may also be prone to renal relapse. Renal relapses occurring in patients with sclerotic class AAGN and renal relapses occurring in patients without interstitial infiltrates were mutually exclusive, which may indicate that they are essentially different.

ANCA-Associated Glomerulonephritis: Risk Factors for Renal Relapse

PubMed Central

Göçeroğlu, Arda; Berden, Annelies E.; Fiocco, Marta; Floßmann, Oliver; Westman, Kerstin W.; Ferrario, Franco; Gaskin, Gill; Pusey, Charles D.; Hagen, E. Christiaan; Noël, Laure-Hélène; Rasmussen, Niels; Waldherr, Rüdiger; Walsh, Michael; Bruijn, Jan A.; Jayne, David R. W.; Bajema, Ingeborg M.

2016-01-01

Relapse in ANCA-associated vasculitis (AAV) has been studied previously, but there are few studies on renal relapse in particular. Identifying patients at high risk of renal relapse may aid in optimizing clinical management. We investigated which clinical and histological parameters are risk factors for renal relapse in ANCA-associated glomerulonephritis (AAGN). Patients (n = 174) were newly diagnosed and had mild–moderate or severe renal involvement. Data were derived from two trials of the European Vasculitis Society: MEPEX and CYCAZAREM. The Cox regression model was used to identify parameters increasing the instantaneous risk (= rate) of renal relapse (useful for instant clinical decisions). For identifying predictors of renal relapse during follow-up, we used Fine & Gray’s regression model. Competing events were end-stage renal failure and death. The cumulative incidence of renal relapse at 5 years was 9.5% (95% CI: 4.8–14.3%). In the Cox model, sclerotic class AAGN increased the instantaneous risk of renal relapse. In Fine & Gray’s model, the absence of interstitial infiltrates at diagnosis was predictive for renal relapse. In this study we used two different models to identify possible relationships between clinical and histopathological parameters at time of diagnosis of AAV with the risk of experiencing renal relapse. Sclerotic class AAGN increased the instantaneous risk of renal relapse. This association is most likely due to the high proportion of sclerosed glomeruli reducing the compensatory capacity. The absence of interstitial infiltrates increased the risk of renal relapse which is a warning sign that patients with a relatively benign onset of disease may also be prone to renal relapse. Renal relapses occurring in patients with sclerotic class AAGN and renal relapses occurring in patients without interstitial infiltrates were mutually exclusive, which may indicate that they are essentially different. PMID:27973575

Prophylactic role of phycocyanin: a study of oxalate mediated renal cell injury.

PubMed

Farooq, Shukkur Muhammed; Asokan, Devarajan; Kalaiselvi, Periandavan; Sakthivel, Ramasamy; Varalakshmi, Palaninathan

2004-08-10

Oxalate induced renal calculi formation and the associated renal injury is thought to be caused by free radical mediated mechanisms. An in vivo model was used to investigate the effect of phycocyanin (from Spirulina platensis), a known antioxidant, against calcium oxalate urolithiasis. Male Wistar rats were divided into four groups. Hyperoxaluria was induced in two of these groups by intraperitoneal infusion of sodium oxalate (70 mg/kg) and a pretreatment of phycocyanin (100 mg/kg) as a single oral dosage was given, 1h prior to sodium oxalate infusion. An untreated control and drug control (phycocyanin alone) were also included in the study. We observed that phycocyanin significantly controlled the early biochemical changes in calcium oxalate stone formation. The antiurolithic nature of the drug was evaluated by the assessment of urinary risk factors and light microscopic observation of urinary crystals. Renal tubular damage as divulged by urinary marker enzymes (alkaline phosphatase, acid phosphatase and gamma-glutamyl transferase) and histopathological observations such as decreased tubulointerstitial, tubular dilatation and mononuclear inflammatory cells, indicated that renal damage was minimised in drug-pretreated group. Oxalate levels (P < 0.001) and lipid peroxidation (P < 0.001) in kidney tissue were significantly controlled by drug pretreatment, suggesting the ability of phycocyanin to quench the free radicals, thereby preventing the lipid peroxidation mediated tissue damage and oxalate entry. This accounts for the prevention of CaOx stones. Thus, the present analysis revealed the antioxidant and antiurolithic potential of phycocyanin thereby projecting it as a promising therapeutic agent against renal cell injury associated kidney stone formation.

The Effects of Renal Denervation on Renal Hemodynamics and Renal Vasculature in a Porcine Model

PubMed Central

Verloop, Willemien L.; Hubens, Lisette E. G.; Spiering, Wilko; Doevendans, Pieter A.; Goldschmeding, Roel; Bleys, Ronald L. A. W.; Voskuil, Michiel

2015-01-01

Rationale Recently, the efficacy of renal denervation (RDN) has been debated. It is discussed whether RDN is able to adequately target the renal nerves. Objective We aimed to investigate how effective RDN was by means of functional hemodynamic measurements and nerve damage on histology. Methods and Results We performed hemodynamic measurements in both renal arteries of healthy pigs using a Doppler flow and pressure wire. Subsequently unilateral denervation was performed, followed by repeated bilateral hemodynamic measurements. Pigs were terminated directly after RDN or were followed for 3 weeks or 3 months after the procedure. After termination, both treated and control arteries were prepared for histology to evaluate vascular damage and nerve damage. Directly after RDN, resting renal blood flow tended to increase by 29±67% (P = 0.01). In contrast, renal resistance reserve increased from 1.74 (1.28) to 1.88 (1.17) (P = 0.02) during follow-up. Vascular histopathology showed that most nerves around the treated arteries were located outside the lesion areas (8±7 out of 55±25 (14%) nerves per pig were observed within a lesion area). Subsequently, a correlation was noted between a more impaired adventitia and a reduction in renal resistance reserve (β: -0.33; P = 0.05) at three weeks of follow-up. Conclusion Only a small minority of renal nerves was targeted after RDN. Furthermore, more severe adventitial damage was related to a reduction in renal resistance in the treated arteries at follow-up. These hemodynamic and histological observations may indicate that RDN did not sufficiently target the renal nerves. Potentially, this may explain the significant spread in the response after RDN. PMID:26587981

Retroperitoneal laparoscopic pyelolithotomy in renal pelvic stone versus open surgery - a comparative study.

PubMed

Singal, Rikki; Dhar, Siddharth

2018-01-01

The introduction of endourological procedures such as percutaneous nephrolithotomy and ureterorenoscopy have led to a revolution in the the management of urinary stone disease. The indications for open stone surgery have been narrowed significantly, making it a second- or third-line treatment option. To study the safety and efficacy of retroperitoneal laparoscopic pyelolithotomy in retroperitoneal renal stone. We compared the results of laparoscopic and open surgery in terms of easy accessibility, operative period, renal injuries, and early recovery. This prospective study was conducted on renal pelvic stone cases from January 2009 to February 2016 in Suchkhand Hospital, Agra, India. The study included a total of 1700 cases with the diagnosis of solitary renal pelvic stones. In group A - 850 cases - retroperitoneal laparoscopic pyelolithotomy was performed, while group B - 850 cases - underwent open pyelolithotomy. The mean operative time was less in group B than group A (74.83 min vs. 94.43 min) which was significant (p<0.001). The blood loss was less in the laparoscopic group than in the open group (63 mL vs. 103mL). There were statistically significant differences in the post-operative pain scores, and postoperative complications compared to group B (p<0.001). The mean hospital stay was less in group A (p<0.03), which was significant. Laparoscopic surgery reduces analgesic requirements, hospital stay, and blood loss. The disadvantages include the reduced working space, the cost of equipment and the availability of a trained surgeon.

Increasing Body Mass Index Predicts Rapid Decline in Renal Function: A 5 Year Retrospective Study.

PubMed

Ma, Xiaojing; Zhang, Chengyin; Su, Hong; Gong, Xiaojie; Kong, Xianglei

2018-05-02

While obesity is a recognized risk factor for chronic kidney disease, it remains unclear whether change in body mass index (ΔBMI ) is independently associated with decline in renal function (evaluated by the change in estimated glomerular filtration rate, ΔeGFR) over time. Accordingly, to help clarify this we conducted a retrospective study to measure the association of ΔBMI with decline in renal function in Chinese adult population. A total of 4007 adults (aged 45.3±13.7 years, 68.6% male) without chronic kidney disease at baseline were enrolled between 2008 and 2013. Logistic regression models were applied to explore the relationships between baseline BMI and ΔBMI, and rapid decline in renal function (defined as the lowest quartile of ΔeGFR ). During 5 years of follow-up, the ΔBMI and ΔeGFR were 0.47±1.6 (kg/m 2 ) and -3.0±8.8 (ml/min/1.73 m 2 ), respectively. After adjusted for potential confounders, ΔBMI (per 1 kg/m 2 increase) was independently associated with the rapid decline in renal function [with a fully adjusted OR of 1.12 (95% CI, 1.05 to 1.20). By contrast, the baseline BMI was not associated with rapid decline in renal function [OR=1.05 (95% CI, 0.98 to 1.13)]. The results were robust among 2948 hypertension-free and diabetes-free participants, the adjusted ORs of ΔBMI and baseline BMI were 1.14 (95% CI, 1.05 to 1.23) and 1.0 (95% CI, 0.96 to 1.04) for rapid decline in renal function, respectively. The study revealed that increasing ΔBMI predicts rapid decline in renal function. © Georg Thieme Verlag KG Stuttgart · New York.

Resting afferent renal nerve discharge and renal inflammation: Elucidating the role of afferent and efferent renal nerves in DOCA-salt hypertension

PubMed Central

Banek, Christopher T.; Knuepfer, Mark M.; Foss, Jason D.; Fiege, Jessica K.; Asirvatham-Jeyaraj, Ninitha; Van Helden, Dusty; Shimizu, Yoji; Osborn, John W.

2016-01-01

Renal sympathetic denervation (RDNx) has emerged as a novel therapy for hypertension; however, the therapeutic mechanisms remain unclear. Efferent renal sympathetic nerve activity (RSNA) has recently been implicated in trafficking renal inflammatory immune cells and inflammatory chemokine and cytokine release. Several of these inflammatory mediators are known to activate or sensitize afferent nerves. This study aimed to elucidate the roles of efferent and afferent renal nerves in renal inflammation and hypertension in the deoxycorticosterone acetate (DOCA)-salt rat model. Uninephrectomized male Sprague Dawley rats (275–300g) underwent selective afferent-selective RDNx (A-RDNx; n=10), total RDNx (T-RDNx; n=10), or Sham (n=10) and were instrumented for measurement of mean arterial pressure (MAP) and heart rate (HR) by radiotelemetry. Rats received 100mg DOCA (s.c.) and 0.9% saline for 21 days. Resting afferent renal nerve activity (ARNA) in DOCA and Vehicle animals was measured after the treatment protocol. Renal tissue inflammation was assessed by renal cytokine content and T-cell infiltration and activation. Resting ARNA, expressed as a percent of peak afferent nerve activity (%Amax), was substantially increased in DOCA vs. Vehicle (35.8±4.4 vs. 15.3±2.8%Amax). The DOCA-Sham hypertension (132±12 mmHg) was attenuated by ~50% in both T-RDNx (111±8) and A-RDNx (117±5mmHg) groups. Renal inflammation induced by DOCA-salt was attenuated by T-RDNx, and unaffected by A-RDNx. These data suggest ARNA may mediate the hypertensive response to DOCA-salt, but inflammation may be mediated primarily by efferent RSNA. Also, resting ARNA is elevated in DOCA-salt rats, which may highlight a crucial neural mechanism in the development and maintenance of hypertension. PMID:27698066

Stage progression and need for renal replacement therapy in a renal protection programme in Colombia. A cohort study.

PubMed

Yepes Delgado, Carlos Enrique; Pérez Dávila, Sara; Montoya Jaramillo, Marcela; Orrego Orozco, Beatriz Elena

Due to the global burden represented by chronic kidney disease (CKD), the World Health Organization encouraged the implementation of renal protection programmes (RPP) to affect its incidence through prevention and control measures. To assess the effectiveness of a Colombian RPP in terms of its effect on the stage progression of CKD and the need for renal replacement therapy (RRT). An analytical study that monitored 2cohorts of patients diagnosed with CKD. The study compares the behaviour of clinical and renal impairment indicators from patients exposed to a RPP with that of patients following conventional treatment (CT). The population of both intervention groups was considered when determining the sample size. The incidence rate was calculated as well as patient survival (Kaplan Meier). In addition, a multivariate analysis (Cox) was used to calculate the influence that exposure to the RPP had on the outcomes of the patients following the RPP and those following CT. The patients exposed to the RPP took longer to advance to the next CKD stage and require RRT. The incidence rate for progression is higher for the patients following CT (0.050, IC 95%: 0.040-0.064) compared to those in the RPP (0.034, IC 95%: 0.030-0.039). The ratio of incidence rates was 1.480 (IC 95% 1.21-1.90). The hazard of progression was lower for the RPP (HR: 0.855, IC 95%: 0.74- 0.98), as was the hazard of requiring RRT (HR: 0.797, IC 95%: 0.606-1.049). The RPP is a secondary prevention strategy against CKD which has an effect on the stage progression of CKD and the need for RRT. Early patient detection has a positive effect on the outcomes studied. Copyright © 2017 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

Gastrin stimulates renal dopamine production by increasing the renal tubular uptake of l-DOPA.

PubMed

Jiang, Xiaoliang; Zhang, Yanrong; Yang, Yu; Yang, Jian; Asico, Laureano D; Chen, Wei; Felder, Robin A; Armando, Ines; Jose, Pedro A; Yang, Zhiwei

2017-01-01

Gastrin is a peptide hormone that is involved in the regulation of sodium balance and blood pressure. Dopamine, which is also involved in the regulation of sodium balance and blood pressure, directly or indirectly interacts with other blood pressure-regulating hormones, including gastrin. This study aimed to determine the mechanisms of the interaction between gastrin and dopamine and tested the hypothesis that gastrin produced in the kidney increases renal dopamine production to keep blood pressure within the normal range. We show that in human and mouse renal proximal tubule cells (hRPTCs and mRPTCs, respectively), gastrin stimulates renal dopamine production by increasing the cellular uptake of l-DOPA via the l-type amino acid transporter (LAT) at the plasma membrane. The uptake of l-DOPA in RPTCs from C57Bl/6J mice is lower than in RPTCs from normotensive humans. l-DOPA uptake in renal cortical slices is also lower in salt-sensitive C57Bl/6J than in salt-resistant BALB/c mice. The deficient renal cortical uptake of l-DOPA in C57Bl/6J mice may be due to decreased LAT-1 activity that is related to its decreased expression at the plasma membrane, relative to BALB/c mice. We also show that renal-selective silencing of Gast by the renal subcapsular injection of Gast siRNA in BALB/c mice decreases renal dopamine production and increases blood pressure. These results highlight the importance of renal gastrin in stimulating renal dopamine production, which may give a new perspective in the prevention and treatment of hypertension. Copyright © 2017 the American Physiological Society.

The role of the renal specialist nurse in prevention of renal failure.

PubMed

Hurst, J

2002-01-01

This article will investigate the care required for those with reduced renal function before renal replacement therapy (RRT) commences. Renal nurses are often involved with the technical, monitoring and evaluative aspects of RRT for those with end stage renal failure. However, many patients may experience reduced renal function many years before reaching the stage of needing RRT. Renal nurses are already involved in the preparation of patients for RRT, but are not presently exercising their specialist skills in the period before this time by contributing to the prevention of end stage renal failure (ESRF). Screening programmes carried out in various parts of the world demonstrate that many members of the population have undetected renal insufficiency, and may benefit from intervention from the nephrology team to prevent further renal dysfunction. It is for this group of patients that this article will consider the potential for the renal nurse to expand their scope of practice.

Transarterial Embolization of a Renal Artery Aneurysm Concomitant With Renal Arteriovenous Fistula.

PubMed

Hongsakul, Keerati; Bannangkoon, Kittipitch; Boonsrirat, Ussanee; Kritpracha, Boonprasit

2018-01-01

Congenital renal artery aneurysm is uncommon. Moreover, renal artery aneurysm concomitant with a congenital renal arteriovenous fistula is extremely rare. Transarterial embolization is the first-line treatment for these conditions. We report a case of a patient with congenital renal artery aneurysm concomitant with a congenital renal arteriovenous fistula of the upper polar left renal artery which was successfully treated by transarterial embolization with coil, glue, and Amplatzer vascular plug.

Pharmacokinetic Properties of Fostamatinib in Patients With Renal or Hepatic Impairment: Results From 2 Phase I Clinical Studies.

PubMed

Martin, Paul; Oliver, Stuart; Gillen, Michael; Marbury, Thomas; Millson, David

2015-12-01

Phase III trials of fostamatinib, an oral spleen tyrosine kinase inhibitor, in the treatment of rheumatoid arthritis have been completed. Herein, we report the effects of renal and hepatic impairment on the pharmacokinetic (PK) properties of the active metabolite of fostamatinib, R406, in plasma, and on the urinary excretion of R406 and its metabolite N-glucuronide. Two Phase I, single-center, open-label clinical trials determined the PK properties and tolerability of fostamatinib in subjects with normal or impaired renal or hepatic function. Twenty-four subjects in the study in renal impairment (8 per group: normal renal function, moderate renal dysfunction, or end-stage renal disease [ESRD]), and 32 subjects in the study in hepatic impairment (8 per group: normal hepatic function or mild, moderate, or severe hepatic impairment) received a single 150-mg dose of fostamatinib. Patients with ESRD in the study in renal impairment participated in 2 treatment periods separated by a ≥1-week washout. In these patients, fostamatinib was administered after dialysis or 2 hours before dialysis. Geometric mean R406 Cmax and AUC values were less in the combined renally impaired group than in the group with normal renal function; Tmax was similar across groups. However, renal impairment had no apparent effect considered clinically relevant on unbound R406. In patients with ESRD, R406 exposure was less when fostamatinib was administered after compared with before dialysis. Urinary excretion of R406 N-glucuronide was decreased with increasing severity of renal impairment. Renal elimination of R406 was negligible in all groups. Varying degrees of hepatic impairment had no consistent effects on the PK properties of R406. R406 Cmax values were 10% to 15% less in all hepatically impaired groups than in the group with normal hepatic function. AUC and Tmax values were similar between the groups with normal and severely impaired hepatic function; in the groups with mild or moderate

Sinomenine Hydrochloride Attenuates Renal Fibrosis by Inhibiting Excessive Autophagy Induced by Adriamycin: An Experimental Study

PubMed Central

Zhao, Ming-ming

2017-01-01

The objective of this study is to investigate if sinomenine hydrochloride (SIN-HCl) could be effective against adriamycin-induced renal fibrosis by regulating autophagy in a rat model. Forty male Sprague-Dawley (SD) rats were randomly divided into control group, model group, telmisartan group, and SIN-HCl group; rat model was induced by adriamycin; all rats were given intragastric administration for 6 weeks. Urine was collected from rats in metabolic cages to determine 24 h protein level. This was done after intragastric administration for the first two weeks and then once for every two weeks. Renal pathological changes were examined by the staining of HE, Masson, and PASM. Expressions and distributions of fibronectin (FN), laminin (LN), light chain 3 (LC3), and Beclin-1 were observed by immunohistochemistry. SIN-HCl ameliorates proteinuria, meanwhile attenuating the renal pathological changes in adriamycin-induced rats and also attenuating renal fibrosis and excessive autophagy by reducing the expression of FN, LN, LC3, and Beclin-1. SIN-HCl attenuates renal fibrosis by inhibiting excessive autophagy induced by adriamycin and upregulates the basal autophagy. PMID:28798804

Association of serum bicarbonate with risk of renal and cardiovascular outcomes in CKD: a report from the Chronic Renal Insufficiency Cohort (CRIC) study.

PubMed

Dobre, Mirela; Yang, Wei; Chen, Jing; Drawz, Paul; Hamm, L Lee; Horwitz, Edward; Hostetter, Thomas; Jaar, Bernard; Lora, Claudia M; Nessel, Lisa; Ojo, Akinlolu; Scialla, Julia; Steigerwalt, Susan; Teal, Valerie; Wolf, Myles; Rahman, Mahboob

2013-10-01

The purpose of this study is to evaluate serum bicarbonate level as a risk factor for renal outcomes, cardiovascular events, and mortality in patients with chronic kidney disease (CKD). Observational cohort study. 3,939 participants with CKD stages 2-4 who enrolled in the Chronic Renal Insufficiency Cohort (CRIC) between June 2003 and December 2008. Serum bicarbonate level. Renal outcomes, defined as end-stage renal disease (either initiation of dialysis therapy or kidney transplantation) or 50% reduction in estimated glomerular filtration rate (eGFR); atherosclerotic events (myocardial infarction, stroke, or peripheral arterial disease); congestive heart failure events; and death. Time to event. Mean eGFR was 44.8 ± 16.8 (SD) mL/min/1.73 m(2), and median serum bicarbonate level was 24 (IQR, 22-26) mEq/L. During a median follow-up of 3.9 years, 374 participants died, 767 had a renal outcome, 332 experienced an atherosclerotic event, and 391 had a congestive heart failure event. In adjusted analyses, the risk of developing a renal end point was 3% lower per 1-mEq/L increase in serum bicarbonate level (HR, 0.97; 95% CI, 0.94-0.99; P = 0.01). The association was stronger for participants with eGFR >45 mL/min/1.73 m(2) (HR, 0.91; 95% CI, 0.85-0.97; P = 0.004). The risk of heart failure increased by 14% (HR, 1.14; 95% CI, 1.03-1.26; P = 0.02) per 1-mEq/L increase in serum bicarbonate level over 24 mEq/L. Serum bicarbonate level was not associated independently with atherosclerotic events (HR, 0.99; 95% CI, 0.95-1.03; P = 0.6) and all-cause mortality (HR, 0.98; 95% CI, 0.95-1.02; P = 0.3). Single measurement of sodium bicarbonate. In a cohort of participants with CKD, low serum bicarbonate level was an independent risk factor for kidney disease progression, particularly for participants with preserved kidney function. The risk of heart failure was higher at the upper extreme of serum bicarbonate levels. There was no association between serum bicarbonate level and all

Potential Use of Autologous Renal Cells from Diseased Kidneys for the Treatment of Renal Failure.

PubMed

George, Sunil K; Abolbashari, Mehran; Jackson, John D; Aboushwareb, Tamer; Atala, Anthony; Yoo, James J

2016-01-01

Chronic kidney disease (CKD) occurs when certain conditions cause the kidneys to gradually lose function. For patients with CKD, renal transplantation is the only treatment option that restores kidney function. In this study, we evaluated primary renal cells obtained from diseased kidneys to determine whether their normal phenotypic and functional characteristics are retained, and could be used for cell therapy. Primary renal cells isolated from both normal kidneys (NK) and diseased kidneys (CKD) showed similar phenotypic characteristics and growth kinetics. The expression levels of renal tubular cell markers, Aquaporin-1 and E-Cadherin, and podocyte-specific markers, WT-1 and Nephrin, were similar in both NK and CKD kidney derived cells. Using fluorescence- activated cell sorting (FACS), specific renal cell populations were identified and included proximal tubular cells (83.1% from NK and 80.3% from CKD kidneys); distal tubular cells (11.03% from NK and 10.9% from CKD kidneys); and podocytes (1.91% from NK and 1.78% from CKD kidneys). Ultra-structural analysis using scanning electron microscopy (SEM) revealed microvilli on the apical surface of cultured cells from NK and CKD samples. Moreover, transmission electron microscopy (TEM) analysis showed a similar organization of tight junctions, desmosomes, and other intracellular structures. The Na+ uptake characteristics of NK and CKD derived renal cells were also similar (24.4 mmol/L and 25 mmol/L, respectively) and no significant differences were observed in the protein uptake and transport characteristics of these two cell isolates. These results show that primary renal cells derived from diseased kidneys such as CKD have similar structural and functional characteristics to their counterparts from a normal healthy kidney (NK) when grown in vitro. This study suggests that cells derived from diseased kidney may be used as an autologous cell source for renal cell therapy, particularly in patients with CKD or end

Moment-to-moment characteristics of the relationship between arterial pressure and renal interstitial hydrostatic pressure.

PubMed

Komolova, Marina; Adams, Michael A

2010-10-01

The kidney is a key controller of the long-term level of arterial pressure, in part through pressure-natriuresis. Although direct coupling of changes in renal arterial pressure to renal interstitial hydrostatic pressure (RIHP) and consequent sodium excretion is well established, few studies have characterized the moment-to-moment aspects of this process. These studies characterized the short-term hemodynamic component of pressure-natriuresis in vivo before and after autonomic nervous system and renin-angiotensin system inhibition. Changes in RIHP were determined over a range of renal arterial pressures in Wistar rats receiving no treatment, a ganglionic blocker (hexamethonium; 20 mg/kg per hour IV), or an angiotensin II type 1 receptor blocker (losartan; 10 mg/kg per hour IV). After a series of changes in renal arterial pressure, a delay of only ≈1 second was found for the onset of RIHP responses that was independent of the stimulus magnitude and neurohumoral manipulation; however, completion of the full RIHP response was within ≈15 seconds for renal arterial pressure changes of ≤30 mm Hg. The overall slope of the renal arterial pressure- RIHP relationship (0.09±0.01) was also not affected by autonomic nervous system and renin-angiotensin system inhibition despite decreasing renal arterial pressure (↓40% and ↓28%, respectively). Separate assessment of this relationship above and below the prevailing arterial pressure revealed that the pressor versus the depressor portion was blunted (P<0.001), a difference that was abolished after autonomic nervous system and renin-angiotensin system inhibition. The results suggest that spontaneous changes in arterial pressure are coupled to moment-to-moment changes in RIHP over a wide range of pressures, emphasizing a likely role for the dynamic component of the renal arterial pressure-RIHP relationship in the modulation of sodium excretion and, hence, arterial pressure.

High-NaCl intake impairs dynamic autoregulation of renal blood flow in ANG II-infused rats.

PubMed

Saeed, Aso; Dibona, Gerald F; Marcussen, Niels; Guron, Gregor

2010-11-01

The aim of this study was to investigate dynamic autoregulation of renal blood flow (RBF) in ANG II-infused rats and the influence of high-NaCl intake. Sprague-Dawley rats received ANG II (250 ng·kg(-1)·min(-1) sc) or saline vehicle (sham) for 14 days after which acute renal clearance experiments were performed during thiobutabarbital anesthesia. Rats (n = 8-10 per group) were either on a normal (NNa; 0.4% NaCl)- or high (HNa; 8% NaCl)-NaCl diet. Separate groups were treated with 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (tempol; 1 M in drinking water). Transfer function analysis from arterial pressure to RBF in the frequency domain was used to examine the myogenic response (MR; 0.06-0.09 Hz) and the tubuloglomerular feedback mechanism (TGF; 0.03-0.06 Hz). MAP was elevated in ANG II-infused rats compared with sham groups (P < 0.05). RBF in ANG II HNa was reduced vs. sham NNa and sham HNa (6.0 ± 0.3 vs. 7.9 ± 0.3 and 9.1 ± 0.3 ml·min(-1)·g kidney wt(-1), P < 0.05). transfer function gain in ANG II HNa was significantly elevated in the frequency range of the MR (1.26 ± 0.50 dB, P < 0.05 vs. all other groups) and in the frequency range of the TGF (-0.02 ± 0.50 dB, P < 0.05 vs. sham NNa and sham HNa). Gain values in the frequency range of the MR and TGF were significantly reduced by tempol in ANG II-infused rats on HNa diet. In summary, the MR and TGF components of RBF autoregulation were impaired in ANG II HNa, and these abnormalities were attenuated by tempol, suggesting a pathogenetic role for superoxide in the impaired RBF autoregulatory response.

Assessment of renal function and electrolytes in patients with thyroid dysfunction in Addis Ababa, Ethiopia: a cross sectional study.

PubMed

Abebe, Nardos; Kebede, Tedla; Wolde, Mistire

2016-01-01

Studies demonstrated that abnormal thyroid functions may result in decreased or increased kidney size, kidney weight, and affect renal functions. In this regard, studies on the association of abnormal thyroid functions and renal function tests are scarcely found in Ethiopia. To assess renal function and electrolytes in patients with thyroid dysfunction, in Addis Ababa, Ethiopia. Cross sectional study was conducted from March 21/2015-May 27/2015 at Arsho Advanced Medical Laboratory. During the study period, 71 patients with thyroid dysfunction were eligible, and socio demographic data collected by structured questionnaire. Then blood sample was collected for thyroid function tests, renal function and blood electrolyte analysis. The collected data was analyzed by SPSS version 20. ANOVA and binary logistic regression were employed to evaluate the mean deference and associations of thyroid hormone with renal function and electrolyte balances. Among the renal function tests, serum uric acid, and creatinine mean values were significantly decreased in hyperthyroid patients; whereas, eGFR mean value was significantly increased in hyperthyroid study patients (P<0.05). Meanwhile, from the electrolyte measurements made, only the mean serum sodium value was significantly increased in hyperthyroid study participants. Binary logistic regression analysis on the association of thyroid dysfunction with electrolyte balance and renal function tests indicated that serum sodium, creatinine, eGFR values and hyperthyroidism have a statistical significant association at AOR 95% CI of 0.141(0.033-0.593, P=0.008); 16.236(3.481-75.739, P=0.001), and 13.797(3.261-58.67, P=0.001) respectively. The current study reveals, thyroid abnormalities may lead to renal function alterations and also may disturb electrolyte balance. Knowledge of this significant association has worthwhile value for clinicians, to manage their patients' optimally.

Renal amyloidosis. Evaluation by gallium imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, V.W.; Skinner, M.; Cohen, A.S.

1986-09-01

A study has been performed to evaluate the efficacy of gallium imaging in the detection of renal amyloidosis. Ten of the 11 patients who had biopsy-proven renal amyloidosis demonstrated marked uptake in both kidneys. One patient revealed moderate gallium uptake in his kidneys. None of the patients had underlying renal or extrarenal pathology other than amyloidosis, which could account for renal gallium uptake (renal infection, neoplasm, hepatic failure or frequent blood transfusions). Four patients also had extrarenal foci of abnormal gallium uptake, suggesting other sites of amyloid deposits. Our data strongly suggest that gallium imaging has a high sensitivity formore » detection of renal amyloidosis. Its specificity is enhanced significantly by careful review of the clinical history to exclude other known causes of renal gallium uptake. Potentially, gallium imaging may be used to monitor the progress of patients under experimental therapy.« less

Live Donor Renal Anatomic Asymmetry and Post-Transplant Renal Function

PubMed Central

Tanriover, Bekir; Fernandez, Sonalis; Campenot, Eric S.; Newhouse, Jeffrey H.; Oyfe, Irina; Mohan, Prince; Sandikci, Burhaneddin; Radhakrishnan, Jai; Wexler, Jennifer J.; Carroll, Maureen A.; Sharif, Sairah; Cohen, David J.; Ratner, Lloyd E.; Hardy, Mark A.

2014-01-01

Background Relationship between live donor renal anatomic asymmetry and post-transplant recipient function has not been studied extensively. Methods We analyzed 96 live-kidney donors, who had anatomical asymmetry (>10% renal length and/or volume difference calculated from CT angiograms) and their matching recipients. Split function differences (SFD) were quantified with 99mTc-DMSA renography. Implantation biopsies at time-zero were semi-quantitatively scored. A comprehensive model utilizing donor renal volume adjusted to recipient weight (Vol/Wgt), SFD, and biopsy score was used to predict recipient estimated glomerular filtration rate (eGFR) at one-year. Primary analysis consisted of a logistic regression model of outcome (odds of developing eGFR>60ml/min/1.73 m2 at one-year), a linear regression model of outcome (predicting recipient eGFR at one-year, using the CKD-EPI formula), and a Monte Carlo simulation based on the linear regression model (N=10,000 iterations). Results In the study cohort, the mean Vol/Wgt and eGFR at one-year were 2.04 ml/kg and 60.4 ml/min/1.73m2, respectively. Volume and split ratios between two donor kidneys were strongly correlated (r=0.79, p-value<0.001). The biopsy scores among SFD categories (<5%, 5–10%, >10%) were not different (p=0.190). On multivariate models, only Vol/Wgt was significantly associated with higher odds of having eGFR>60ml/min/1.73 m2 (OR=8.94, 95% CI 2.47–32.25, p=0.001) and had a strong discriminatory power in predicting the risk of eGFR<60ml/min/1.73m2 at one-year (ROC curve=0.78, 95% CI 0.68–0.89). Conclusion In the presence of donor renal anatomic asymmetry, Vol/Wgt appears to be a major determinant of recipient renal function at one-year post-transplantation. Renography can be replaced with CT volume calculation in estimating split renal function. PMID:25719258

Reduction of severe mitral regurgitation with the MitraClip system improves renal function in two patients presenting with acute kidney injury and progressive renal failure due to cardio renal syndrome.

PubMed

Asdonk, T; Nickenig, G; Hammerstingl, C

2014-10-01

Mitral regurgitation (MR) is a frequent valve disorder in elderly patients, often accompanied by multiple comorbidities such as renal impairment. In these patients percutaneous mitral valve (MV) repair has become an established treatment option but the role of MR on renal dysfunction is not yet well defined. We here report on two cases presenting with severe MR and progressive renal failure caused by cardio renal syndrome, in which percutaneous MV treatment with the MitraClip system significantly improved renal function. These findings suggest that interventional MV repair can prevent progression of renal deterioration in patients suffering from combined advanced heart and renal failure. Further clinical studies are necessary to support our finding and to answer the question whether optimizing renal function by implantation of the MitraClip device is also of prognostic relevance in these patients. © 2014 Wiley Periodicals, Inc.

Variability in the reporting of renal function endpoints in immunosuppression trials in renal transplantation: time for consensus?

PubMed

Knight, Simon R; Hussain, Samia

2016-12-01

Early measures of graft function are increasingly used to assess efficacy in clinical trials of kidney transplant immunosuppression. This study aimed to assess the variability and quality of reporting of these endpoints in contemporary trials. Data regarding renal function endpoints were extracted from 213 reports from randomized controlled trials comparing immunosuppressive interventions in renal transplant recipients published between 2010 and 2014. A total of 174 (81.7%) reports included a measure of renal function; in 44 (20.7%), this was the primary endpoint. A total of 103 manuscripts (48.4%) reported serum creatinine, 142 (66.6%) reported estimated glomerular filtration rate (eGFR), and 26 (12.2%) reported measured GFR. Formulas used for GFR estimation were modification of diet in renal disease (42.3%), Cockroft-Gault (23.5%), Nankivell (15.0%), and CKD-EPI (0.9%). Six studies (2.8%) did not report the formula used to estimate GFR. A total of 13.9% of endpoints had missing data. In 10 studies, disagreement was found in the significance of findings using different measures of renal function. There is a great deal of variability in the reporting of renal function endpoints, with a significant proportion of studies using underperforming or inappropriate estimates. There is a need for consensus as to the best tool for monitoring and reporting renal function post-transplant, and in particular for use in clinical trials and registries. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Renal function improvement in liver transplant recipients after early everolimus conversion: A clinical practice cohort study in Spain.

PubMed

Bilbao, Itxarone; Salcedo, Magdalena; Gómez, Miguel Angel; Jimenez, Carlos; Castroagudín, Javier; Fabregat, Joan; Almohalla, Carolina; Herrero, Ignacio; Cuervas-Mons, Valentín; Otero, Alejandra; Rubín, Angel; Miras, Manuel; Rodrigo, Juan; Serrano, Trinidad; Crespo, Gonzalo; De la Mata, Manuel; Bustamante, Javier; Gonzalez-Dieguez, M Luisa; Moreno, Antonia; Narvaez, Isidoro; Guilera, Magda

2015-08-01

A national, multicenter, retrospective study was conducted to assess the results obtained for liver transplant recipients with conversion to everolimus in daily practice. The study included 477 recipients (481 transplantations). Indications for conversion to everolimus were renal dysfunction (32.6% of cases), hepatocellular carcinoma (HCC; 30.2%; prophylactic treatment for 68.9%), and de novo malignancy (29.7%). The median time from transplantation to conversion to everolimus was 68.7 months for de novo malignancy, 23.8 months for renal dysfunction, and 7.1 months for HCC and other indications. During the first year of treatment, mean everolimus trough levels were 5.4 (standard deviation [SD], 2.7) ng/mL and doses remained stable (1.5 mg/day) from the first month after conversion. An everolimus monotherapy regimen was followed by 28.5% of patients at 12 months. Patients with renal dysfunction showed a glomerular filtration rate (4-variable Modification of Diet in Renal Disease) increase of 10.9 mL (baseline mean, 45.8 [SD, 25.3] versus 57.6 [SD, 27.6] mL/minute/1.73 m(2) ) at 3 months after everolimus initiation (P < 0.001), and 6.8 mL at 12 months. Improvement in renal function was higher in patients with early conversion (<1 year). Adverse events were the primary reason for discontinuation in 11.2% of cases. The probability of survival at 3 years after conversion to everolimus was 83.0%, 71.1%, and 59.5% for the renal dysfunction, de novo malignancy, and HCC groups, respectively. Everolimus is a viable option for the treatment of renal dysfunction, and earlier conversion is associated with better recovery of renal function. Prospective studies are needed to confirm advantages in patients with malignancy. © 2015 American Association for the Study of Liver Diseases.

Infra-renal angles, entry into inferior vena cava and vertebral levels of renal veins.

PubMed

Satyapal, K S

1999-10-01

Current norms for renal vasculature hold true in only half the population. Standard textbooks perpetuate old misconceptions regarding renal venous anatomy. This study is aimed to determine left and right infra-renal angles (L-IRA, R-IRA); entry level of renal veins into the inferior vena cava (IVC), and height of IVC under renal vein influence; and their vertebral level. One hundred morphologically normal en-bloc renal specimens randomly selected from post-mortem examinations were dissected and resin casted. IRA were also measured from venograms of 32 adult and 11 foetal cadavers, as were vertebral entry levels. IRA measurements (degrees) were as follows: left, 55 degrees +/- 16 degrees (20 degrees -102 degrees ); right, 60 degrees +/- 17 degrees (10 degrees -93 degrees ). Left vein entered IVC higher than right 54%, lower 36%, and opposite each other 10%. Vertical distance between lower borders of veins was 1.0 +/- 0.9 cm. Vertical distance of IVC under renal vein influence was 2.3 +/- 1.0 cm. Vertebral level of veins in adults lies between TI2-L2. In foetuses, IRA was as follows: left, 65 degrees +/- 12 degrees (45 degrees -90 degrees ); right, 58 degrees +/- 7 degrees (40 degrees -70 degrees ); vertebral level between T12 and L3. Similar IRA values from literature noted on right, 51 degrees (26 degrees -100 degrees ); differences on left, 77 degrees (43 degrees -94 degrees ), clearly differing from Williams et al. (Gray's Anatomy, 37(th) ed, 1989) statement that renal veins "open into the inferior vena cava almost at right angles." Large variations of IRA are not surprising since kidneys are considered normally "floating viscera," varying position with posture and respiratory movement as well as in live vs. cadaveric subjects. The entry level into the IVC also differs from Williams et al. This study uniquely quantitated actual height difference between lower borders of left and right veins. The data presented appears to be the first documentation of vertebral

Validation of an Experimental Model to Study Less Severe Chronic Renal Failure.

PubMed

Fernandes-Charpiot, Ida Mária Maximina; Caldas, Heloisa Cristina; Mendes, Glória Elisa Florido; Gomes de Sá Neto, Luiz; Oliveira, Henrique Lacativa; Baptista, Maria Alice Sperto Ferreira; Abbud-Filho, Mario

2016-10-01

The 5/6 nephrectomy, mimics the stages of human chronic renal failure (CRF), but the procedure causes severe renal functional and morphological damage that could interfere with the evaluation of therapies for slowing the progression of the disease. This study summarizes the results of renal function, histology, and immunohistochemical findings in rats undergoing a 2/3 nephrectomy. The rats were distributed in groups according to the type of nephrectomy: CRF5/6: induced by a 5/6 renal mass reduction and CRF2/3: less severe CRF. The body weight and blood pressure were monitored, and the serum creatinine (SCr), creatinine clearance (CCr), urine osmolality, and 24-h proteinuria (PT24h) were measured. CRF progression was evaluated by the rate of decline of CCr (RCCr). Histology and immunohistochemistry were performed in the remnant kidneys. Statistical analysis was done by unpaired t-test, and a P-value < 0.05 was taken as a statistical significance. Compared to the CRF5/6 group, the CRF2/3 model had a lower SCr, PT24h, CCr, and variations of the SCr from baseline. The disease progression was also significantly slower. The renal histopathological findings revealed fewer chronic lesions in rats with CRF2/3. Similarly, we observed less macrophage accumulation as well as lower proliferative activity and expression of fibronectin and a-smooth muscle-actin in the CRF2/3 model. The CRF2/3 model presented with a pattern of less severe CRF, functionally and morphologically, compared to the classical CRF5/6 model, and the CRF2/3 model may be useful for evaluating therapeutic interventions that target the early stages of CRF.

[Renal oncocytoma in the single kidney after previous surgery of renal carcinoma. Apropos of 2 cases].

PubMed

Veneroni, L; Canclini, L; Berti, G L; Giola, V; Leidi, G L; Maccaroni, A; Raimoldi, A; Sironi, M; Assi, A; Bacchioni, A M

1997-12-01

Renal oncocytoma is a neoplasm which rarely occurs in patients with solitary kidney, the other being absent because of a previous nephrectomy performed for renal cancer. We present two case reports and a literature review. We have studied some important problems such as the histogenesis, the potential for malignancy, the diagnosis, the treatment and the follow up. The high incidence of coexistence of renal oncocytoma and renal cell carcinoma has important clinical implications. We would like to emphasize the importance of preoperatory FNAB, nephron sparing surgery and very careful follow up.

A clinico-pathological study of lupus nephritis based on the International Society of Nephrology-Renal Pathology Society 2003 classification system.

PubMed

Satish, Suchitha; Deka, Pallavi; Shetty, Manjunath Sanjeev

2017-01-01

Lupus nephritis (LN) is a major complication of systemic lupus erythematosus (SLE). Renal involvement is a major determinant of the prognosis of SLE. The histological classification of LN is a key factor in determining the renal survival of patients with LN. Prompt recognition and treatment of renal disease are important, as early response to therapy is correlated with better outcome and renal biopsy plays an important role in achieving this. The objective of this study was to correlate the clinical and laboratory findings with histopathological classes of LN as per the 2003 International Society of Nephrology-Renal Pathology Society (ISN/RPS) classification system. Fifty-six patients with SLE, undergoing a renal biopsy for renal dysfunction were studied. The comparison of data from multiple groups was made by Pearson's Chi-square test and between two groups by independent samples t -test. The values of P < 0.05 were considered statistically significant. Of the 56 cases studied, 51 (91.1%) were females. The most common presenting symptoms were edema, arthralgia, and hypertension. Class IV (55.4%) was the most common class. Thirty-nine (69.6%) cases showed full house immunostaining. Hypertension, hematuria, proteinuria, and tubulo-interstitial disease showed a significant correlation ( P < 0.05) with ISN/RPS classification, 2003. Assessment and management of patients with suspected LN are greatly facilitated through information obtained by renal biopsy. Since renal morphology may predict long-term prognosis, and no clinical or laboratory feature uniformly predicts prognosis, it is important to study the constellation of features in LN for better patient management.

Lower Incidence of End-Stage Renal Disease but Suboptimal Pre-Dialysis Renal Care in Schizophrenia: A 14-Year Nationwide Cohort Study

PubMed Central

Ouyang, Wen-Chen; Lin, Chen-Li; Huang, Chi-Ting; Hsu, Chih-Cheng

2015-01-01

Schizophrenia is closely associated with cardiovascular risk factors which are consequently attributable to the development of chronic kidney disease and end-stage renal disease (ESRD). However, no study has been conducted to examine ESRD-related epidemiology and quality of care before starting dialysis for patients with schizophrenia. By using nationwide health insurance databases, we identified 54,361 ESRD-free patients with schizophrenia and their age-/gender-matched subjects without schizophrenia for this retrospective cohort study (the schizophrenia cohort). We also identified a cohort of 1,244 adult dialysis patients with and without schizophrenia (1:3) to compare quality of renal care before dialysis and outcomes (the dialysis cohort). Cox proportional hazard models were used to estimate the hazard ratio (HR) for dialysis and death. Odds ratio (OR) derived from logistic regression models were used to delineate quality of pre-dialysis renal care. Compared to general population, patients with schizophrenia were less likely to develop ESRD (HR = 0.6; 95% CI 0.4–0.8), but had a higher risk for death (HR = 1.2; 95% CI, 1.1–1.3). Patients with schizophrenia at the pre-ESRD stage received suboptimal pre-dialysis renal care; for example, they were less likely to visit nephrologists (OR = 0.6; 95% CI, 0.4–0.8) and received fewer erythropoietin prescriptions (OR = 0.7; 95% CI, 0.6–0.9). But they had a higher risk of hospitalization in the first year after starting dialysis (OR = 1.4; 95% CI, 1.0–1.8, P < .05). Patients with schizophrenia undertaking dialysis had higher risk for mortality than the general ESRD patients. A closer collaboration between psychiatrists and nephrologists or internists to minimize the gaps in quality of general care is recommended. PMID:26469976

A randomised controlled trial evaluating renal protective effects of selenium with vitamins A, C, E, verapamil, and losartan against extracorporeal shockwave lithotripsy-induced renal injury.

PubMed

El-Nahas, Ahmed R; Elsaadany, Mohamed M; Taha, Diaa-Eldin; Elshal, Ahmed M; El-Ghar, Mohamed Abo; Ismail, Amani M; Elsawy, Essam A; Saleh, Hazem H; Wafa, Ehab W; Awadalla, Amira; Barakat, Tamer S; Sheir, Khaled Z

2017-01-01

To evaluate the protective effects of selenium with vitamins A, C and E (selenium ACE, i.e. antioxidants), verapamil (calcium channel blocker), and losartan (angiotensin receptor blocker) against extracorporeal shockwave lithotripsy (ESWL)-induced renal injury. A randomised controlled trial was conducted between August 2012 and February 2015. Inclusion criteria were adult patients with a single renal stone (<2 cm) suitable for ESWL. Patients with diabetes, hypertension, congenital renal anomalies, moderate or marked hydronephrosis, or preoperative albuminuria (>300 mg/L) were excluded. ESWL was performed using the electromagnetic DoLiS lithotripter. Eligible patients were randomised into one of four groups using sealed closed envelopes: Group1, control; Group 2, selenium ACE; Group 3, losartan; and Group 4, verapamil. Albuminuria and urinary neutrophil gelatinase-associated lipocalin (uNGAL) were estimated after 2-4 h and 1 week after ESWL. The primary outcome was differences between albuminuria and uNGAL. Dynamic contrast-enhanced magnetic resonance imaging was performed before ESWL, and at 2-4 h and 1 week after ESWL to compare changes in renal perfusion. Of 329 patients assessed for eligibility, the final analysis comprised 160 patients (40 in each group). Losartan was the only medication that showed significantly lower levels of albuminuria after 1 week (P < 0.001). For perfusion changes, there was a statistically significant decrease in the renal perfusion in patients with obstructed kidneys in comparison to before ESWL (P = 0.003). These significant changes were present in the control or antioxidant group, whilst in the losartan and verapamil groups renal perfusion was not significantly decreased. Losartan was found to protect the kidney against ESWL-induced renal injury by significantly decreasing post-ESWL albuminuria. Verapamil and losartan maintained renal perfusion in patients with post-ESWL renal obstruction. © 2016 The Authors BJU International �

Anatomical study of renal arterial vasculature and its potential impact on partial nephrectomy.

PubMed

Macchi, Veronica; Crestani, Alessandro; Porzionato, Andrea; Sfriso, Maria Martina; Morra, Aldo; Rossanese, Marta; Novara, Giacomo; De Caro, Raffaele; Ficarra, Vincenzo

2017-07-01

To validate Graves' classification of the intrarenal arteries and to verify the absence of collateral arterial blood supply between different renal segments, in order to maximize peri-operative and functional outcomes of partial nephrectomy. The study was performed on 15 normal kidneys sampled from eight unembalmed cadavers. Kidneys with the surrounding perirenal fat tissue were removed en bloc with the abdominal segment of the aorta. The renal artery was injected with acrylic and radiopaque resins, with the specimen suspended in water. CT examination of the injected kidneys was performed to analyse the branches located deeply. After imaging acquisition, the specimens were treated with sodium hydroxide for removal of the parenchyma to obtain vascular casts. Ten casts (66.6%) showed the classic subdivision of the main artery into single posterior and anterior branches. With regard to the distribution of the segmental or second-order arteries, only two casts (13%) showed a pattern similar to that described by Graves, characterized by four segmental (second-order) branches coming from the anterior renal artery (apical, superior, middle and inferior). In the remaining 13 kidneys (87%) a different arterial vascular network was detected. In 10 casts (80%) a single renal segment was vascularized by two or more different branches coming from an artery leading to another segment (multiple vascularization). Multiple vascularization was observed in three (20%) apical segments, five (33%) superior segments, six (40%) middle segments, seven (47%) inferior segments and two (13%) posterior segments. This study shows that in the human kidneys the arterial vasculature is frequently different from that described by Graves. Moreover, in a significant percentage of cases, a single renal segment receives two or more branches that originate from an artery leading to another segment. © 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.

Retroperitoneal laparoscopic pyelolithotomy in renal pelvic stone versus open surgery - a comparative study

PubMed Central

DHAR, SIDDHARTH

2018-01-01

Background The introduction of endourological procedures such as percutaneous nephrolithotomy and ureterorenoscopy have led to a revolution in the the management of urinary stone disease. The indications for open stone surgery have been narrowed significantly, making it a second- or third-line treatment option. Aims and Objectives To study the safety and efficacy of retroperitoneal laparoscopic pyelolithotomy in retroperitoneal renal stone. We compared the results of laparoscopic and open surgery in terms of easy accessibility, operative period, renal injuries, and early recovery. Methods This prospective study was conducted on renal pelvic stone cases from January 2009 to February 2016 in Suchkhand Hospital, Agra, India. The study included a total of 1700 cases with the diagnosis of solitary renal pelvic stones. In group A - 850 cases - retroperitoneal laparoscopic pyelolithotomy was performed, while group B - 850 cases – underwent open pyelolithotomy. Results The mean operative time was less in group B than group A (74.83 min vs. 94.43 min) which was significant (p<0.001). The blood loss was less in the laparoscopic group than in the open group (63 mL vs. 103mL). There were statistically significant differences in the post-operative pain scores, and postoperative complications compared to group B (p<0.001). The mean hospital stay was less in group A (p<0.03), which was significant. Conclusion Laparoscopic surgery reduces analgesic requirements, hospital stay, and blood loss. The disadvantages include the reduced working space, the cost of equipment and the availability of a trained surgeon. PMID:29440956

Longitudinal development of renal damage and renal function in infants with high grade vesicoureteral reflux.

PubMed

Sjöström, Sofia; Jodal, Ulf; Sixt, Rune; Bachelard, Marc; Sillén, Ulla

2009-05-01

We sought to study renal abnormality and renal function through time in infants with high grade vesicoureteral reflux. This prospective observational study included 115 infants (80 boys and 35 girls) younger than 1 year with grade III to V vesicoureteral reflux. The diagnosis was made after prenatal ultrasound in 26% of the patients and after urinary tract infection in 71%. Patients were followed by renal scintigraphy, 51chromium edetic acid clearance and video cystometry. Median followup was 62 months. Renal abnormality, which was found in 90% of the children at followup, was generalized in 71% and focal in 29%. The abnormality was bilateral in 28% of the affected patients. Total glomerular filtration rate was less than 80% of expected in 30% of the patients. Single kidney function was less than 40% of expected total glomerular filtration rate in 71% of the patients. Renal status (parenchymal abnormality and function) remained unchanged through time in 84 of 108 available cases (78%), improved in 5 (5%) and deteriorated in 19 (18%). Predictive factors for deterioration were recurrent febrile urinary tract infection, bilateral abnormality and reduced total glomerular filtration rate. Deteriorated renal status was more common in cases diagnosed prenatally than in those detected after urinary tract infection. Among these infants with high grade vesicoureteral reflux renal abnormality was frequent and was associated with subnormal filtration of one of the kidneys. Decreased total glomerular filtration rate was seen in about a third of the patients. Overall deterioration of renal status was seen in only a fifth of the patients. Infection control seems to be an important factor to minimize the risk.

Atheroembolic renal disease

MedlinePlus

Renal disease - atheroembolic; Cholesterol embolization syndrome; Atheroemboli - renal; Atherosclerotic disease - renal ... disorder of the arteries. It occurs when fat, cholesterol, and other substances build up in the walls ...

Renal denervation decreases blood pressure and renal tyrosine hydroxylase but does not augment the effect of hypotensive drugs.

PubMed

Skrzypecki, Janusz; Gawlak, Maciej; Huc, Tomasz; Szulczyk, Paweł; Ufnal, Marcin

2017-01-01

The effect of renal denervation on the efficacy of antihypertensive drugs has not yet been elucidated. Twenty-week-old spontaneously hypertensive rats were treated with metoprolol, losartan, indapamide, or saline (controls) and assigned to renal denervation or a sham procedure. Acute hemodynamic measurements were performed ten days later. Series showing a significant interaction between renal denervation and the drugs were repeated with chronic telemetry measurements. In the saline series, denervated rats showed a significantly lower mean arterial blood pressure (blood pressure) than the sham-operated rats. In contrast, in the metoprolol series denervated rats showed a significantly higher blood pressure than sham rats. There were no differences in blood pressure between denervated and sham rats in the losartan and indapamide series. In chronic studies, a 4-week treatment with metoprolol caused a decrease in blood pressure. Renal denervation and sham denervation performed 10 days after the onset of metoprolol treatment did not affect blood pressure. Denervated rats showed markedly reduced renal nerve tyrosine hydroxylase levels. In conclusion, renal denervation decreases blood pressure in hypertensive rats. The hypotensive action of metoprolol, indapamide, and losartan is not augmented by renal denervation, suggesting the absence of synergy between renal denervation and the drugs investigated in this study.

Lithium intoxication: Incidence, clinical course and renal function - a population-based retrospective cohort study.

PubMed

Ott, Michael; Stegmayr, Bernd; Salander Renberg, Ellinor; Werneke, Ursula

2016-10-01

When prescribing lithium, the risk of toxicity remains a concern. In this study, we examined a cohort of patients exposed to lithium between 1997 and 2013. The aims of this study were to determine the frequency of lithium intoxication and to evaluate the clinical course and changes in renal function. Of 1340 patients, 96 had experienced at least one episode of lithium levels ⩾1.5 mmol/L, yielding an incidence of 0.01 per patient-year. Seventy-seven patients available for review had experienced 91 episodes, of whom 34% required intensive care and 13% were treated with haemodialysis. There were no fatalities. Acute kidney injury occurred, but renal function at baseline was not different to renal function after the episode. Renal impairment was often associated with co-morbidities and other factors. Both intermittent and continuous-venovenous haemodialysis were used, but the clearance of continuous-venovenous haemodialysis can be too low in cases where large amounts of lithium have been ingested. Saline and forced diuresis have been used and are safe. Lithium intoxication seems rare and can be safely managed in most cases. Physicians should not withhold lithium for fear of intoxication in patients who benefit from it. Yet, physicians should have a low threshold to screen for toxicity. © The Author(s) 2016.

Effects of Renal Transplantation on Female Sexual Dysfunction: Comparative Study With Hemodialysis and a Control Group.

PubMed

Kurtulus, F O; Salman, M Y; Fazlioglu, A; Fazlioglu, B

2017-11-01

Sexual dysfunction occurs commonly in individuals with end-stage renal disease. Chronic renal failure as well as the treatments used for it generally has a negative impact on sexual function with a subsequent increase in the risk of depression. There is scarcity of published data on female sexual dysfunction and the degree of improvement in patients on hemodialysis (HD) and transplant (Tx) recipients. The aim of this study was to compare the sexual function and degree of depression in HD and Tx patients with control group. For this purpose, we used the validated Female Sexual Function Index (FSFI) and Beck Depression Inventory (BDI). A total of 23 renal Tx, 29 HD, and 30 control patients were enrolled in the study. HD patients were required to be undergoing HD for ≥6 months, and for renal Tx recipients, the Tx had to be performed ≥6 months before study entry. All women underwent a general and urogynecologic examination. Demographic and clinical variables were documented. FSFI and BDI scale scores were compared among groups. The rates of female sexual dysfunction were 56.7%, 89.7%, and 73.9% in the control, HD, and Tx, patients respectively. Total FSFI scores in HD group were significantly lower than those in Tx and control patients (P < .05). FSFI scores improved significantly in the Tx group. BDI scores in HD and control subjects were 23.24 and 14.17, respectively, with a significant difference between the 2 groups (P < .005). BDI score in the Tx group was 16.65 and the difference was statistically insignificant. This preliminary study documented that successful Tx may positively affect sexual life in women with chronic renal failure. A diagnosis of female sexual dysfunction should be made routinely in patients with chronic renal failure. Copyright © 2017 Elsevier Inc. All rights reserved.

Renal cell carcinoma

MedlinePlus

Renal cancer; Kidney cancer; Hypernephroma; Adenocarcinoma of renal cells; Cancer - kidney ... 2016:chap 57. National Cancer Institute website. Renal cell cancer treatment (PDQ) - health professional version. February 23, 2018. ...

Assessment of myocardial mechanics in patients with end-stage renal disease and renal transplant recipients using speckle tracking echocardiography.

PubMed

Pirat, Bahar; Bozbas, Huseyin; Simsek, Vahide; Sade, L Elif; Sayin, Burak; Muderrisoglu, Haldun; Haberal, Mehmet

2015-04-01

Velocity vector imaging allows quantitation of myocardial strain and strain rate from 2-dimensional images based on speckle tracking echocardiography. The aim of this study was to analyze the changes in myocardial strain and strain rate patterns in patients with end-stage renal disease and renal transplant recipients. We studied 33 patients with end-stage renal disease on hemodialysis (19 men; mean age, 36 ± 8 y), 24 renal transplant recipients with functional grafts (21 men; mean age, 36 ± 7 y) and 26 age- and sex-matched control subjects. Longitudinal peak systolic strain and strain rate for basal, mid, and apical segments of the left ventricular wall were determined by velocity vector imaging from apical 4- and 2-chamber views. The average longitudinal strain and strain rate for the left ventricle were noted. From short-axis views at the level of papillary muscles, average circumferential, and radial strain, and strain rate were assessed. Mean heart rate and systolic and diastolic blood pressure during imaging were similar between the groups. Longitudinal peak systolic strain and strain rate at basal and mid-segments of the lateral wall were significantly higher in renal transplant recipients and control groups than endstage renal disease patients. Average longitudinal systolic strain from the 4-chamber view was highest in control subjects (-14.5% ± 2.9%) and was higher in renal transplant recipients (-12.5% ± 3.0%) than end-stage renal disease patients (-10.2% ± 1.6%; P ≤ .001). Radial and circumferential strain and strain rate at the level of the papillary muscle were lower in patients with end-stage renal disease than other groups. Differences in myocardial function in patients with end-stage renal disease, renal transplant recipients, and normal controls can be quantified by strain imaging. Myocardial function is improved in renal transplant recipients compared with end-stage renal disease patients.

Medial arcuate ligament: a new anatomic landmark facilitates the location of the renal artery in retroperitoneal laparoscopic renal surgery.

PubMed

Cai, Wei; Li, Hong Zhao; Zhang, Xu; Song, Yong; Ma, Xin; Dong, Jun; Chen, Wenzheng; Chen, Guang-Fu; Xu, Yong; Lu, Jin Shan; Wang, Bao-Jun; Shi, Tao-Ping

2013-01-01

The purpose of this study was to introduce a new method for locating the renal artery during retroperitoneal laparoscopic renal surgery. The medial arcuate ligament (MAL) is a tendinous arch in the fascia under the diaphragm that arches across the psoas major muscle and is attached medially to the side of the first or the second lumbar vertebra. The renal artery arises at the level of the intervertebral disc between the L1 and L2 vertebrae. We evaluate the role of the MAL that serves as an anatomic landmark for locating the renal artery during retroperitoneal laparoscopic renal surgery. There is a reproducible consistent anatomic relationship between MAL and the renal artery in 210 cases of retroperitoneal laparoscopic renal surgery. Two main types of the MAL, the "narrow arch" and the "fascial band" types, can be observed. MAL can serve as an accurate and reproducible anatomic landmark for the identification of the renal artery during retroperitoneal laparoscopic renal surgery.

Correlation of renal histopathology with renal echogenicity in dogs and cats: an ex-vivo quantitative study.

PubMed

Zotti, Alessandro; Banzato, Tommaso; Gelain, Maria Elena; Centelleghe, Cinzia; Vaccaro, Calogero; Aresu, Luca

2015-04-25

Increased cortical or cortical and medullary echogenicity is one of the most common signs of chronic or acute kidney disease in dogs and cats. Subjective evaluation of the echogenicity is reported to be unreliable. Patient and technical-related factors affect in-vivo quantitative evaluation of the echogenicity of parenchymal organs. The aim of the present study is to investigate the relationship between histopathology and ex-vivo renal cortical echogenicity in dogs and cats devoid of any patient and technical-related biases. Kidney samples were collected from 68 dog and 32 cat cadavers donated by the owners to the Veterinary Teaching Hospital of the University of Padua and standardized ultrasonographic images of each sample were collected. The echogenicity of the renal cortex was quantitatively assessed by means of mean gray value (MGV), and then histopathological analysis was performed. Statistical analysis to evaluate the influence of histological lesions on MGV was performed. The differentiation efficiency of MGV to detect pathological changes in the kidneys was calculated for dogs and cats. Statistical analysis revealed that only glomerulosclerosis was an independent determinant of echogenicity in dogs whereas interstitial nephritis, interstitial necrosis and fibrosis were independent determinants of echogenicity in cats. The global influence of histological lesions on renal echogenicity was higher in cats (23%) than in dogs (12%). Different histopathological lesions influence the echogenicity of the kidneys in dogs and cats. Moreover, MGV is a poor test for distinguishing between normal and pathological kidneys in the dog with a sensitivity of 58.3% and specificity of 59.8%. Instead, it seems to perform globally better in the cat, resulting in a fair test, with a sensitivity of 80.6% and a specificity of 56%.

Renal function and acute heart failure outcome.

PubMed

Llauger, Lluís; Jacob, Javier; Miró, Òscar

2018-06-05

The interaction between acute heart failure (AHF) and renal dysfunction is complex. Several studies have evaluated the prognostic value of this syndrome. The aim of this systematic review, which includes non-selected samples, was to investigate the impact of different renal function variables on the AHF prognosis. The categories included in the studies reviewed included: creatinine, blood urea nitrogen (BUN), the BUN/creatinine quotient, chronic kidney disease, the formula to estimate the glomerular filtration rate, criteria of acute renal injury and new biomarkers of renal damage such as neutrophil gelatinase-associated lipocalin (NGAL and cystatin c). The basal alterations of the renal function, as well as the acute alterations, transient or not, are related to a worse prognosis in AHF, it is therefore necessary to always have baseline, acute and evolutive renal function parameters. Copyright © 2018 Elsevier España, S.L.U. All rights reserved.

Pharmacokinetics of brotizolam in renal failure

PubMed Central

Evers, J.; Renner, E.; Bechtel, W. D.

1983-01-01

1 Kinetics of brotizolam (0.25 mg) were studied in patients with different degrees of renal failure after single and repeated oral ingestion. Serum levels were analysed by radio-immunoassay. 2 Patients were divided into three groups according to their renal function, i.e. creatinine clearance values of 45-80, 15-45, or less than 15 ml/min. 3 The mean elimination half-life was 6.9-8.15 h, with a considerable variation of the peak concentration and elimination half-life in slight to moderate renal failure. There was no delay in elimination in severe renal failure and there was no drug accumulation. 4 No dose adjustment is necessary for brotizolam in renal failure. PMID:6661376

[Asymptomatic Renal Stones: Do they really Exist?].

PubMed

Seseke, S; Rudolph, R; Rebmann, U

2011-11-01

Asymptomatic renal calculi without any history of colic, hematuria or infection can be found as an incidental finding during preven-tive check-ups. The aim of our study was to eval-uate whether these stones provoke symptoms with the need for further treatment during the follow-up and whether they cause cortical defects which may consecutively affect the renal func-tion. In a prospective study we evaluated 104  patients with renal calculi. The -medical history, radiological findings and functional imaging as well as urine and blood analyses were recorded and evaluated. The influence of stone size and localisation on the development of acute stone-related symptoms, renal function and renal scarring were evaluated. Furthermore, we analysed whether localised pathological findings in radiographic or functional imaging may influence the creatinine level. The follow-up was be-tween 12 and 48  months (median: 25  months). During the study period 27 / 104 of our patients (26 %) developed symptomatic events (renal colic, hematuria, infection) in which patients with middle pole calculi with a mean -cumulative stone diameter of 9.8  mm had the -highest risk. A localised renal scarring could be found in 36.6 %. These patients had a significantly higher risk in presenting an increased creatinine level. Increasing stone size was diagnosed in 39  cases (37.5 %). Asymptomatic renal stones have to be controlled regularly in order to prevent the -patient from loss of renal function and hypertension caused by increasing stones or urinary tract infection. © Georg Thieme Verlag KG Stuttgart ˙ New York.

Functions of the Renal Nerves.

ERIC Educational Resources Information Center

Koepke, John P.; DiBona, Gerald F.

1985-01-01

Discusses renal neuroanatomy, renal vasculature, renal tubules, renin secretion, renorenal reflexes, and hypertension as related to renal nerve functions. Indicates that high intensitites of renal nerve stimulation have produced alterations in several renal functions. (A chart with various stimulations and resultant renal functions and 10-item,…

Long-Term Renal Function Recovery following Radical Nephrectomy for Kidney Cancer: Results from a Multicenter Confirmatory Study.

PubMed

Zabor, Emily C; Furberg, Helena; Lee, Byron; Campbell, Steven; Lane, Brian R; Thompson, R Houston; Antonio, Elvis Caraballo; Noyes, Sabrina L; Zaid, Harras; Jaimes, Edgar A; Russo, Paul

2018-04-01

We sought to confirm the findings from a previous single institution study of 572 patients from Memorial Sloan Kettering Cancer Center in which we found that 49% of patients recovered to the preoperative estimated glomerular filtration rate within 2 years following radical nephrectomy for renal cell carcinoma. A multicenter retrospective study was performed in 1,928 patients using data contributed from 3 independent centers. The outcome of interest was postoperative recovery to the preoperative estimated glomerular filtration rate. Data were analyzed using cumulative incidence and competing risks regression with death from any cause treated as a competing event. This study demonstrated that 45% of patients had recovered to the preoperative estimated glomerular filtration rate by 2 years following radical nephrectomy. Furthermore, this study confirmed that recovery of renal function differed according to preoperative renal function such that patients with a lower preoperative estimated glomerular filtration rate had an increased chance of recovery. This study also suggested that larger tumor size and female gender were significantly associated with an increased chance of renal function recovery. In this multicenter retrospective study we confirmed that in the long term a large proportion of patients recover to preoperative renal function following radical nephrectomy for kidney tumors. Recovery is more likely among those with a lower preoperative estimated glomerular filtration rate. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Comparison of ASL and DCE MRI for the non-invasive measurement of renal blood flow: quantification and reproducibility.

PubMed

Cutajar, Marica; Thomas, David L; Hales, Patrick W; Banks, T; Clark, Christopher A; Gordon, Isky

2014-06-01

To investigate the reproducibility of arterial spin labelling (ASL) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and quantitatively compare these techniques for the measurement of renal blood flow (RBF). Sixteen healthy volunteers were examined on two different occasions. ASL was performed using a multi-TI FAIR labelling scheme with a segmented 3D-GRASE imaging module. DCE MRI was performed using a 3D-FLASH pulse sequence. A Bland-Altman analysis was used to assess repeatability of each technique, and determine the degree of correspondence between the two methods. The overall mean cortical renal blood flow (RBF) of the ASL group was 263 ± 41 ml min(-1) [100 ml tissue](-1), and using DCE MRI was 287 ± 70 ml min(-1) [100 ml tissue](-1). The group coefficient of variation (CVg) was 18 % for ASL and 28 % for DCE-MRI. Repeatability studies showed that ASL was more reproducible than DCE with CVgs of 16 % and 25 % for ASL and DCE respectively. Bland-Altman analysis comparing the two techniques showed a good agreement. The repeated measures analysis shows that the ASL technique has better reproducibility than DCE-MRI. Difference analysis shows no significant difference between the RBF values of the two techniques. Reliable non-invasive monitoring of renal blood flow is currently clinically unavailable. Renal arterial spin labelling MRI is robust and repeatable. Renal dynamic contrast-enhanced MRI is robust and repeatable. ASL blood flow values are similar to those obtained using DCE-MRI.

Active video gaming in patients with renal transplant: a pilot study

PubMed Central

2014-01-01

Background Patients with renal transplant are at higher risk of mortality from cardiovascular disease (CVD) compared with the general population. Physical activity has been shown to reduce the risk of CVD mortality in these patients. Unfortunately, barriers such as the harsh Canadian climate prevent patients from engaging in and harvesting the health benefits of physical activity. This pilot study explored active video gaming (AVG) as a way for patients with renal transplant to obtain physical activity and examined its effect on their functional status and quality of life (QOL). Main text We recruited nine patients for an 8-week prospective pilot study. All patients received a Microsoft Xbox 360™ video gaming console, a Microsoft Kinect™ sensor, and the video game Your Shape Fitness Evolved 2012. Assessment of each participant before and after the intervention included blood pressure measures, a 6-minute walk test, and the Godin Leisure Time Questionnaire (GLTQ). We analyzed all nine patients at the end of the 8-week study period, and found no changes in blood pressure or GLTQ scores. However, there was a significant increase in the 6-minute walk distance (P = 0.022), which represented a consistent increase for most patients (correlation = 0.977). In addition, participants over the age of 45 years (n = 4) were more likely to use the AVG system (P = 0.042). Conclusion AVG has the potential to improve the functional status in patients with renal transplant. Further research is required to corroborate the full health benefits of AVG in this patient population. PMID:25114788

Renal Perfusion and Function during Pneumoperitoneum: A Systematic Review and Meta-Analysis of Animal Studies

PubMed Central

Warlé, Michiel C.; Hooijmans, Carlijn R.

2016-01-01

Both preclinical and clinical studies indicate that raised intra-abdominal pressure (IAP) associated with pneumoperitoneum during laparoscopic surgical procedures can cause renal damage, the severity of which may be influenced by variables such as pressure level and duration. Several of these variables have been investigated in animal studies, but synthesis of all preclinical data has not been performed. This systematic review summarizes all available pre-clinical evidence on this topic, including an assessment of its quality and risk of bias. We performed meta-analysis to assess which aspects of the pneumoperitoneum determine the severity of its adverse effects. A systematic search in two databases identified 55 studies on the effect of pneumoperitoneum on renal function which met our inclusion criteria. There was high heterogeneity between the studies regarding study design, species, sex, pressure and duration of pneumoperitoneum, and type of gas used. Measures to reduce bias were poorly reported, leading to an unclear risk of bias in the majority of studies. Details on randomisation, blinding and a sample size calculation were not reported in ≥80% of the studies. Meta-analysis showed an overall increase in serum creatinine during pneumoperitoneum, and a decrease in urine output and renal blood flow. Subgroup analysis indicated that for serum creatinine, this effect differed between species. Subgroup analysis of pressure level indicated that urine output decreased as IAP level increased. No differences between types of gas were observed. Data were insufficient to reliably assess whether sex or IAP duration modulate the effect of pneumoperitoneum. Four studies assessing long-term effects indicated that serum creatinine normalized ≥24 hours after desufflation of pneumoperitoneum at 15mmHg. We conclude that harmful effects on renal function and perfusion during pneumoperitoneum appear to be robust, but evidence on long-term effects is very limited. The

Studies of the mechanism of contralateral polyuria after renal artery stenosis.

PubMed Central

Galvez, O G; Roberts, B W; Mishkind, M H; Bay, W H; Ferris, T F

1977-01-01

Acute renal artery stenosis in hydropenic dogs caused a contralateral increase in urine volume and free water clearance without change in glomerular filtration, renal blood flow, or osmolar clearance. The increase in urine volume was not dependent on the development of hypertension since it occurred in animals pretreated with trimethaphan but was dependent upon angiotensin since it was presented with angiotensin blockade with Saralasin. The effect was not caused by angiotensin inhibiting antidiuretic hormone release since the polyuria occurred in hypophysectomized animals receiving a constant infusion of 10 muU/kg per min of aqueous Pitressin. Since the rise in urine volume was associated with an increase in renal vein prostaglandin E concentration and was prevented by pretreatment with indomethacin (5 mg/kg) the results suggest that the rise in plasma angiotensin after renal artery stenosis causes an increase in contralateral prostaglandin E synthesis with resultant antagonism to antidiuretic hormone at the collecting tubule. PMID:845253

Management of renal transplant urolithiasis: a multicentre study by the French Urology Association Transplantation Committee.

PubMed

Branchereau, J; Timsit, M O; Neuzillet, Y; Bessède, T; Thuret, R; Gigante, M; Tillou, X; Codas, R; Boutin, J; Doerfler, A; Sallusto, F; Culty, T; Delaporte, V; Brichart, N; Barrou, B; Salomon, L; Karam, G; Rigaud, J; Badet, L; Kleinklauss, F

2018-01-01

Urolithiasis is rare among renal transplant recipients and its management has not been clearly defined. This multicentre retrospective study was organised by the Comité de Transplantation de l'Association Française d'Urologie (French Urology Association transplantation committee). Statistical analysis was performed with SPSS 19 software. Ninety-five patients were included in this study. Renal transplant urolithiasis was an incidental finding in 55% of cases, mostly on a routine follow-up ultrasound examination. One half of symptomatic stones were due to urinary tract infection and the other half were due to an episode of acute renal failure. The initial management following diagnosis of urolithiasis was double J stenting (27%), nephrostomy tube placement (21%), or watchful waiting (52%). Definitive management consisted of: watchful waiting (48%), extracorporeal lithotripsy (13%), rigid or flexible ureteroscopy (26%), percutaneous nephrolithotomy (11%) and surgical pyelotomy (2%). All transplants remained functional following treatment of the stone. The main limitation is the retrospective design. The incidence of lithiasis could be higher in kidney transplanted patients due to a possible anatomical or metabolical abnormalities. The therapeutic management of renal transplant urolithiasis appears to be comparable to that of native kidney urolithiasis.

A population approach to renal replacement therapy epidemiology: lessons from the EVEREST study.

PubMed

Caskey, Fergus J; Jager, Kitty J

2014-08-01

The marked variation that exists in renal replacement therapy (RRT) epidemiology between countries and within countries requires careful systematic examination if the root causes are to be understood. While individual patient-level studies are undoubtedly important, there is a complementary role for more population-level, area-based studies--an aetiological approach. The EVEREST Study adopted such an approach, bringing RRT incidence rates, survival and modality mix together with macroeconomic factors, general population factors and renal service organizational factors for up to 46 countries. This review considers the background to EVEREST, its key results and then the main methodological lessons and their potential application to ongoing work. © The Author 2013. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Multimarker assessment for the prediction of renal function improvement after percutaneous revascularization for renal artery stenosis.

PubMed

Staub, Daniel; Partovi, Sasan; Zeller, Thomas; Breidthardt, Tobias; Kaech, Max; Boeddinghaus, Jasper; Puelacher, Christian; Nestelberger, Thomas; Aschwanden, Markus; Mueller, Christian

2016-06-01

Identifying patients likely to have improved renal function after percutaneous transluminal renal angioplasty and stenting (PTRA) for renal artery stenosis (RAS) is challenging. The purpose of this study was to use a comprehensive multimarker assessment to identify those patients who would benefit most from correction of RAS. In 127 patients with RAS and decreased renal function and/or hypertension referred for PTRA, quantification of hemodynamic cardiac stress using B-type natriuretic peptide (BNP), renal function using estimated glomerular filtration rate (eGFR), parenchymal renal damage using resistance index (RI), and systemic inflammation using C-reactive protein (CRP) were performed before intervention. Predefined renal function improvement (increase in eGFR ≥10%) at 6 months occurred in 37% of patients. Prognostic accuracy as quantified by the area under the receiver-operating characteristics curve for the ability of BNP, eGFR, RI and CRP to predict renal function improvement were 0.59 (95% CI, 0.48-0.70), 0.71 (95% CI, 0.61-0.81), 0.52 (95% CI, 0.41-0.65), and 0.56 (95% CI, 0.44-0.68), respectively. None of the possible combinations increased the accuracy provided by eGFR (lower eGFR indicated a higher likelihood for eGFR improvement after PTRA, P=ns for all). In the subgroup of 56 patients with pre-interventional eGFR <60 mL/min/1.73 m(2), similar findings were obtained. Quantification of renal function, but not any other pathophysiologic signal, provides at least moderate accuracy in the identification of patients with RAS in whom PTRA will improve renal function.

Mannitol increases renal blood flow and maintains filtration fraction and oxygenation in postoperative acute kidney injury: a prospective interventional study.

PubMed

Bragadottir, Gudrun; Redfors, Bengt; Ricksten, Sven-Erik

2012-08-17

Acute kidney injury (AKI), which is a major complication after cardiovascular surgery, is associated with significant morbidity and mortality. Diuretic agents are frequently used to improve urine output and to facilitate fluid management in these patients. Mannitol, an osmotic diuretic, is used in the perioperative setting in the belief that it exerts reno-protective properties. In a recent study on uncomplicated postcardiac-surgery patients with normal renal function, mannitol increased glomerular filtration rate (GFR), possibly by a deswelling effect on tubular cells. Furthermore, experimental studies have previously shown that renal ischemia causes an endothelial cell injury and dysfunction followed by endothelial cell edema. We studied the effects of mannitol on renal blood flow (RBF), glomerular filtration rate (GFR), renal oxygen consumption (RVO2), and extraction (RO2Ex) in early, ischemic AKI after cardiac surgery. Eleven patients with AKI were studied during propofol sedation and mechanical ventilation 2 to 6 days after complicated cardiac surgery. All patients had severe heart failure treated with one (100%) or two (73%) inotropic agents and intraaortic balloon pump (36%). Systemic hemodynamics were measured with a pulmonary artery catheter. RBF and renal filtration fraction (FF) were measured by the renal vein thermo-dilution technique and by renal extraction of chromium-51-ethylenediaminetetraacetic acid (51Cr-EDTA), respectively. GFR was calculated as the product of FF and renal plasma flow RBF × (1-hematocrit). RVO2 and RO2Ex were calculated from arterial and renal vein blood samples according to standard formulae. After control measurements, a bolus dose of mannitol, 225 mg/kg, was given, followed by an infusion at a rate of 75 mg/kg/h for two 30-minute periods. Mannitol did not affect cardiac index or cardiac filling pressures. Mannitol increased urine flow by 61% (P < 0.001). This was accompanied by a 12% increase in RBF (P < 0.05) and a 13

Mannitol increases renal blood flow and maintains filtration fraction and oxygenation in postoperative acute kidney injury: a prospective interventional study

PubMed Central

2012-01-01

Introduction Acute kidney injury (AKI), which is a major complication after cardiovascular surgery, is associated with significant morbidity and mortality. Diuretic agents are frequently used to improve urine output and to facilitate fluid management in these patients. Mannitol, an osmotic diuretic, is used in the perioperative setting in the belief that it exerts reno-protective properties. In a recent study on uncomplicated postcardiac-surgery patients with normal renal function, mannitol increased glomerular filtration rate (GFR), possibly by a deswelling effect on tubular cells. Furthermore, experimental studies have previously shown that renal ischemia causes an endothelial cell injury and dysfunction followed by endothelial cell edema. We studied the effects of mannitol on renal blood flow (RBF), glomerular filtration rate (GFR), renal oxygen consumption (RVO2), and extraction (RO2Ex) in early, ischemic AKI after cardiac surgery. Methods Eleven patients with AKI were studied during propofol sedation and mechanical ventilation 2 to 6 days after complicated cardiac surgery. All patients had severe heart failure treated with one (100%) or two (73%) inotropic agents and intraaortic balloon pump (36%). Systemic hemodynamics were measured with a pulmonary artery catheter. RBF and renal filtration fraction (FF) were measured by the renal vein thermo-dilution technique and by renal extraction of chromium-51-ethylenediaminetetraacetic acid (51Cr-EDTA), respectively. GFR was calculated as the product of FF and renal plasma flow RBF × (1-hematocrit). RVO2 and RO2Ex were calculated from arterial and renal vein blood samples according to standard formulae. After control measurements, a bolus dose of mannitol, 225 mg/kg, was given, followed by an infusion at a rate of 75 mg/kg/h for two 30-minute periods. Results Mannitol did not affect cardiac index or cardiac filling pressures. Mannitol increased urine flow by 61% (P < 0.001). This was accompanied by a 12% increase in

[Renal elastography].

PubMed

Correas, Jean-Michel; Anglicheau, Dany; Gennisson, Jean-Luc; Tanter, Mickael

2016-04-01

Renal elastography has become available with the development of noninvasive quantitative techniques (including shear-wave elastography), following the rapidly growing field of diagnosis and quantification of liver fibrosis, which has a demonstrated major clinical impact. Ultrasound or even magnetic resonance techniques are leaving the pure research area to reach the routine clinical use. With the increased incidence of chronic kidney disease and its specific morbidity and mortality, the noninvasive diagnosis of renal fibrosis can be of critical value. However, it is difficult to simply extend the application from one organ to the other due to a large number of anatomical and technical issues. Indeed, the kidney exhibits various features that make stiffness assessment more complex, such as the presence of various tissue types (cortex, medulla), high spatial orientation (anisotropy), local blood flow, fatty sinus with variable volume and echotexture, perirenal space with variable fatty content, and the variable depth of the organ. Furthermore, the stiffness changes of the renal parenchyma are not exclusively related to fibrosis, as renal perfusion or hydronephrosis will impact the local elasticity. Renal elastography might be able to diagnose acute or chronic obstruction, or to renal tumor or pseudotumor characterization. Today, renal elastography appears as a promising application that still requires optimization and validation, which is the contrary for liver stiffness assessment. Copyright © 2016 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.

Efficacy and safety of gadobutrol-enhanced MRA of the renal arteries: Results from GRAMS (Gadobutrol-enhanced renal artery MRA study), a prospective, intraindividual multicenter phase 3 blinded study.

PubMed

Fabrega-Foster, Kelly E; Agarwal, Sheela; Rastegar, Neda; Haverstock, Daniel; Agris, Jacob M; Kamel, Ihab R

2018-02-01

To compare the performance of magnetic resonance angiography (MRA) with 1M gadobutrol, a high relaxivity macrocyclic contrast agent, to 2D time-of-flight MRA (ToF-MRA) using computed tomographic angiography (CTA) as the standard of reference. Primary objectives were evaluation for superiority of structural delineation and noninferiority for detection and exclusion of clinically significant disease. In all, 315 subjects underwent unenhanced and contrast-enhanced MRA with 1M gadobutrol (CE-MRA) and were scanned with 1.5T MRI equipped with an at least 6-element body coil. Evaluations were based on both centralized blinded read (BR) performed by six readers as well as investigator site interpretations for the 292 subjects who completed the study. Quantitative evaluations including percent stenosis and normal vessel measurements were also performed. Secondary endpoints included identification of accessory renal arteries, diagnosis of fibromuscular dysplasia (FMD), diagnostic confidence, and need for additional imaging. A total of 292 patients suspected of renal artery disease completed the study. CE-MRA demonstrated statistically significant improvement in assessability of vascular segments compared to ToF: 95.9% vs. 77.6% (P < 0.0001). In the BR, the sensitivity and specificity of CE-MRA were noninferior to ToF-MRA (53.4% vs. 46.6% and 95.1% vs. 85.7%, respectively). There was less error in the CE-MRA stenosis measurements (0.15 mm gadobutrol vs. 0.41 mm ToF, P < 0.05). FMD was correctly diagnosed more frequently, 10% more accessory renal arteries were identified (P < 0.01), diagnostic confidence increased (P < 0.01), and fewer additional imaging studies were recommended (P < 0.01). Gadobutrol-enhanced MRA of the renal arteries has superior visualization, more accurate vessel measurements, and may serve as a CTA alternative without any ionizing radiation. 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:572-581. © 2017 International Society for Magnetic

Renal artery anatomy assessed by quantitative analysis of selective renal angiography in 1,000 patients with hypertension.

PubMed

Lauder, Lucas; Ewen, Sebastian; Tzafriri, Abraham Rami; Edelman, Elazer Reuven; Lüscher, Thomas Felix; Blankenstijn, Peter J; Dörr, Oliver; Schlaich, Markus; Sharif, Faisal; Voskuil, Michiel; Zeller, Thomas; Ukena, Christian; Scheller, Bruno; Böhm, Michael; Mahfoud, Felix

2018-05-20

With increasing attention to renovascular causes and targets for hypertension there arises a critical need for more detailed knowledge of renal arterial anatomy. However, a standardised nomenclature is lacking. The present study sought to develop a standardised nomenclature for renal anatomy considering the complexity and variation of the renal arterial tree and to assess the applicability of the nomenclature. One thousand hypertensive patients underwent invasive selective renal artery angiography in nine centres. Further, renovasography was performed in 249 healthy swine as a surrogate for normotensive anatomy. Anatomical parameters were assessed by quantitative vascular analysis. Patients' mean blood pressure was 168/90±26/17 mmHg. The right main renal artery was longer than the left (41±15 mm vs. 35±13 mm, p<0.001), but the left had a greater diameter (5.4±1.2 vs. 5.2±1.2 mm, p<0.001). Accessory renal arteries and renal artery disease were documented in 22% and 9% of the patients, respectively. Other than exhibiting a longer left main renal artery in uncontrolled hypertensives (+2.7 mm, p=0.034) there was no anatomical difference between patients with controlled and uncontrolled hypertension. Main renal artery mean diameter was smaller in patients with impaired kidney function (GFR <90 ml/min, left -0.5 mm, right -0.4 mm, both p<0.001). Renal arterial anatomy differs between sides but shows no difference between patients with and without blood pressure control. Impaired GFR was associated with small main renal artery diameter.

Renal Tumors

PubMed Central

Tan, Puay Hoon; Cheng, Liang; Rioux-Leclercq, Nathalie; Merino, Maria J.; Netto, George; Reuter, Victor E.; Shen, Steven S.; Grignon, David J.; Montironi, Rodolfo; Egevad, Lars; Srigley, John R.; Delahunt, Brett; Moch, Holger

2016-01-01

The International Society of Urological Pathology convened a consensus conference on renal cancer, preceded by an online survey, to address issues relating to the diagnosis and reporting of renal neoplasia. In this report, the role of biomarkers in the diagnosis and assessment of prognosis of renal tumors is addressed. In particular we focused upon the use of immunohistochemical markers and the approach to specific differential diagnostic scenarios. We enquired whether cytogenetic and molecular tools were applied in practice and asked for views on the perceived prognostic role of biomarkers. Both the survey and conference voting results demonstrated a high degree of consensus in participants’ responses regarding prognostic/predictive markers and molecular techniques, whereas it was apparent that biomarkers for these purposes remained outside the diagnostic realm pending clinical validation. Although no individual antibody or panel of antibodies reached consensus for classifying renal tumors, or for confirming renal metastatic disease, it was noted from the online survey that 87% of respondents used immunohistochemistry to subtype renal tumors sometimes or occasionally, and a majority (87%) used immunohistochemical markers (Pax 2 or Pax 8, renal cell carcinoma [RCC] marker, panel of pan-CK, CK7, vimentin, and CD10) in confirming the diagnosis of metastatic RCC. There was consensus that immunohistochemistry should be used for histologic subtyping and applied before reaching a diagnosis of unclassified RCC. At the conference, there was consensus that TFE3 and TFEB analysis ought to be requested when RCC was diagnosed in a young patient or when histologic appearances were suggestive of the translocation subtype; whereas Pax 2 and/or Pax 8 were considered to be the most useful markers in the diagnosis of a renal primary. PMID:24025522

Frequency and clinical predictors of coronary artery disease in chronic renal failure renal transplant candidates.

PubMed

de Albuquerque Seixas, Emerson; Carmello, Beatriz Leone; Kojima, Christiane Akemi; Contti, Mariana Moraes; Modeli de Andrade, Luiz Gustavo; Maiello, José Roberto; Almeida, Fernando Antonio; Martin, Luis Cuadrado

2015-05-01

Cardiovascular diseases are major causes of mortality in chronic renal failure patients before and after renal transplantation. Among them, coronary disease presents a particular risk; however, risk predictors have been used to diagnose coronary heart disease. This study evaluated the frequency and importance of clinical predictors of coronary artery disease in chronic renal failure patients undergoing dialysis who were renal transplant candidates, and assessed a previously developed scoring system. Coronary angiographies conducted between March 2008 and April 2013 from 99 candidates for renal transplantation from two transplant centers in São Paulo state were analyzed for associations between significant coronary artery diseases (≥70% stenosis in one or more epicardial coronary arteries or ≥50% in the left main coronary artery) and clinical parameters. Univariate logistic regression analysis identified diabetes, angina, and/or previous infarction, clinical peripheral arterial disease and dyslipidemia as predictors of coronary artery disease. Multiple logistic regression analysis identified only diabetes and angina and/or previous infarction as independent predictors. The results corroborate previous studies demonstrating the importance of these factors when selecting patients for coronary angiography in clinical pretransplant evaluation.

Chromophobe Renal Cell Carcinoma is the Most Common Nonclear Renal Cell Carcinoma in Young Women: Results from the SEER Database.

PubMed

Daugherty, Michael; Blakely, Stephen; Shapiro, Oleg; Vourganti, Srinivas; Mollapour, Mehdi; Bratslavsky, Gennady

2016-04-01

The renal cell cancer incidence is relatively low in younger patients, encompassing 3% to 7% of all renal cell cancers. While young patients may have renal tumors due to hereditary syndromes, in some of them sporadic renal cancers develop without any family history or known genetic mutations. Our recent observations from clinical practice have led us to hypothesize that there is a difference in histological distribution in younger patients compared to the older cohort. We queried the SEER (Surveillance, Epidemiology and End Results) 18-registry database for all patients 20 years old or older who were surgically treated for renal cell carcinoma between 2001 and 2008. Patients with unknown race, grade, stage or histology and those with multiple tumors were excluded from study. Four cohorts were created by dividing patients by gender, including 1,202 females and 1,715 males younger than 40 years old, and 18,353 females and 30,891 males 40 years old or older. Chi-square analysis was used to compare histological distributions between the cohorts. While clear cell carcinoma was still the most common renal cell cancer subtype across all genders and ages, chromophobe renal cell cancer was the most predominant type of nonclear renal cell cancer histology in young females, representing 62.3% of all nonclear cell renal cell cancers (p <0.0001). In all other groups papillary renal cell cancer remained the most common type of nonclear renal cell cancer. It is possible that hormonal factors or specific pathway dysregulations predispose chromophobe renal cell cancer to develop in younger women. We hope that this work provides some new observations that could lead to further studies of gender and histology specific renal tumorigenesis. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Blood transfusion improves renal oxygenation and renal function in sepsis-induced acute kidney injury in rats.

PubMed

Zafrani, Lara; Ergin, Bulent; Kapucu, Aysegul; Ince, Can

2016-12-20

The effects of blood transfusion on renal microcirculation during sepsis are unknown. This study aimed to investigate the effect of blood transfusion on renal microvascular oxygenation and renal function during sepsis-induced acute kidney injury. Twenty-seven Wistar albino rats were randomized into four groups: a sham group (n = 6), a lipopolysaccharide (LPS) group (n = 7), a LPS group that received fluid resuscitation (n = 7), and a LPS group that received blood transfusion (n = 7). The mean arterial blood pressure, renal blood flow, and renal microvascular oxygenation within the kidney cortex were recorded. Acute kidney injury was assessed using the serum creatinine levels, metabolic cost, and histopathological lesions. Nitrosative stress (expression of endothelial (eNOS) and inducible nitric oxide synthase (iNOS)) within the kidney was assessed by immunohistochemistry. Hemoglobin levels, pH, serum lactate levels, and liver enzymes were measured. Fluid resuscitation and blood transfusion both significantly improved the mean arterial pressure and renal blood flow after LPS infusion. Renal microvascular oxygenation, serum creatinine levels, and tubular damage significantly improved in the LPS group that received blood transfusion compared to the group that received fluids. Moreover, the renal expression of eNOS was markedly suppressed under endotoxin challenge. Blood transfusion, but not fluid resuscitation, was able to restore the renal expression of eNOS. However, there were no significant differences in lactic acidosis or liver function between the two groups. Blood transfusion significantly improved renal function in endotoxemic rats. The specific beneficial effect of blood transfusion on the kidney could have been mediated in part by the improvements in renal microvascular oxygenation and sepsis-induced endothelial dysfunction via the restoration of eNOS expression within the kidney.

Neurogenic regulation of renal tubular sodium reabsorption.

PubMed

DiBona, G F

1977-08-01

The evidence supporting a role for direct neurogenic control of renal tubular sodium reabsorption is reviewed. Electron microscopic and fluorescence histochemical studies have demonstrated adrenergic nerve terminals in direct contact with basement membranes of mammalian (rat, dog, and monkey) renal tubular epithelial cells. Low-level direct or baroreceptor reflex stimulation of renal sympathetic nerves produces an increase in renal tubular sodium reabsorption without alterations in glomerular filtration rate, renal blood flow, or intrarenal distribution of blood flow. Antinatriuresis was prevented by prior treatment of the kidney with guanethidine or phenoxybenzamine. Rat kidney micropuncture studies have localized a site of enhanced tubular sodium reabsorption to the proximal tubule. Possible indirect mediation of the antinatriuresis by other humoral agents known to be released from the kidney on renal nerve stimulation (angiotensin II, prostaglandin) was excluded by experiments with appropriate blocking agents. The possible effects of anesthesia and uncertainties about the completeness of surgical renal denervation and other tubular segmental sites of action are critically analyzed. The clinical implications of this mechanism in pathologic conditions of sodium and water retention are discussed and and a prospectus for future work is presented.

USE OF THE SPONTANEOUS TSC2 KNOCKOUT (EKER) RAT MODEL OF HEREDITARY RENAL CELL CARCINOMA FOR THE STUDY OF RENAL CARCINOGENS

EPA Science Inventory

The kidney is a frequent site for chemically induced cancers in rodents and among the ten most frequent sites for cancer in human patients. Renal cell carcinoma (RCC) is the most frequent upper urinary tract cancer in humans and accounts for 80-85% of malignant renal tumors. He...

Multimarker assessment for the prediction of renal function improvement after percutaneous revascularization for renal artery stenosis

PubMed Central

Partovi, Sasan; Zeller, Thomas; Breidthardt, Tobias; Kaech, Max; Boeddinghaus, Jasper; Puelacher, Christian; Nestelberger, Thomas; Aschwanden, Markus; Mueller, Christian

2016-01-01

Background Identifying patients likely to have improved renal function after percutaneous transluminal renal angioplasty and stenting (PTRA) for renal artery stenosis (RAS) is challenging. The purpose of this study was to use a comprehensive multimarker assessment to identify those patients who would benefit most from correction of RAS. Methods In 127 patients with RAS and decreased renal function and/or hypertension referred for PTRA, quantification of hemodynamic cardiac stress using B-type natriuretic peptide (BNP), renal function using estimated glomerular filtration rate (eGFR), parenchymal renal damage using resistance index (RI), and systemic inflammation using C-reactive protein (CRP) were performed before intervention. Results Predefined renal function improvement (increase in eGFR ≥10%) at 6 months occurred in 37% of patients. Prognostic accuracy as quantified by the area under the receiver-operating characteristics curve for the ability of BNP, eGFR, RI and CRP to predict renal function improvement were 0.59 (95% CI, 0.48–0.70), 0.71 (95% CI, 0.61–0.81), 0.52 (95% CI, 0.41–0.65), and 0.56 (95% CI, 0.44–0.68), respectively. None of the possible combinations increased the accuracy provided by eGFR (lower eGFR indicated a higher likelihood for eGFR improvement after PTRA, P=ns for all). In the subgroup of 56 patients with pre-interventional eGFR <60 mL/min/1.73 m2, similar findings were obtained. Conclusions Quantification of renal function, but not any other pathophysiologic signal, provides at least moderate accuracy in the identification of patients with RAS in whom PTRA will improve renal function. PMID:27280085

Partial renal coverage in endovascular aneurysm repair causes unfavorable renal flow patterns in an infrarenal aneurysm model.

PubMed

van de Velde, Lennart; Donselaar, Esmé J; Groot Jebbink, Erik; Boersen, Johannes T; Lajoinie, Guillaume P R; de Vries, Jean-Paul P M; Zeebregts, Clark J; Versluis, Michel; Reijnen, Michel M P J

2018-05-01

To achieve an optimal sealing zone during endovascular aneurysm repair, the intended positioning of the proximal end of the endograft fabric should be as close as possible to the most caudal edge of the renal arteries. Some endografts exhibit a small offset between the radiopaque markers and the proximal fabric edge. Unintended partial renal artery coverage may thus occur. This study investigated the consequences of partial coverage on renal flow patterns and wall shear stress (WSS). In vitro models of an abdominal aortic aneurysm were used to visualize pulsatile flow using two-dimensional particle image velocimetry under physiologic resting conditions. One model served as control and two models were stented with an Endurant endograft (Medtronic Inc, Minneapolis, Minn), one without and one with partial renal artery coverage with 1.3 mm of stent fabric extending beyond the marker (16% area coverage). The magnitude and oscillation of WSS, relative residence time, and backflow in the renal artery were analyzed. In both stented models, a region along the caudal renal artery wall presented with low and oscillating WSS, not present in the control model. A region with very low WSS (<0.1 Pa) was present in the model with partial coverage over a length of 7 mm compared with a length of 2 mm in the model without renal coverage. Average renal backflow area percentage in the renal artery incrementally increased from control (0.9%) to the stented model without (6.4%) and with renal coverage (18.8%). In this flow model, partial renal coverage after endovascular aneurysm repair causes low and marked oscillations in WSS, potentially promoting atherosclerosis and subsequent renal artery stenosis. Awareness of the device-dependent offset between the fabric edge and the radiopaque markers is therefore important in endovascular practice. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Renal denervation: a new therapeutic approach for resistant hypertension.

PubMed

Cao, Longxing; Fu, Qiang; Wang, Binghui; Li, Zhiliang

2014-01-01

To review the advances in studies on renal denervation. References concerning renal denervation and resistant hypertension cited in this review were collected from PubMed published in English and those of renal denervation devices from official websites of device manufacturers up to January 2014. Articles with keywords "renal denervation" and "resistant hypertension" were selected. Renal and systemic sympathetic overactivity plays an important role in pathology of hypertension as well as other diseases characterized by sympathetic overactivity. Renal denervation is a new, catheter based procedure to reduce renal and systemic sympathetic overactivity by disruption of renal sympathetic efferent and afferent nerves through radiofrequency or ultrasound energy delivered to the endoluminal surface of both renal arteries. Although several studies have shown the efficacy and safety of renal denervation in the treatment of resistant hypertension and the potential benefit of the procedure in other diseases, Symplicity HTN 3 study, the most rigorous clinical trial of renal denervation to date, failed to meet its primary endpoint. The procedure also has other limitations such as the lack of long term, efficacy and safety data and the lack of the predictors for the blood pressure lowering response and nonresponse to the procedure. An overview of current renal denervation devices holding Conformité Européenne mark is also included in this review. Renal denervation is a promising therapeutic approach in the management of resistant hypertension and other diseases characterized by sympathetic overactivity. In its early stage of clinical application, the efficacy of the procedure is still controversial. Large scale, blind, randomized, controlled clinical trials are still necessary to address the limitations of the procedure.

Case-control study of renal cell carcinoma in relation to occupation, smoking, and alcohol consumption

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brownson, R.C.

1988-05-01

A case-control study based on data from a cancer registry was conducted to evaluate the effects of smoking, alcohol use, and occupation on renal cell cancer risk. Information was obtained for 326 male and female cases and 978 age- and sex-matched controls. Elevated risks were identified for cigarette smokers and for men employed as truck drivers. No relationship between alcohol consumption and renal cancer was observed.

Endovascular Management of Atherosclerotic Renal Artery Stenosis: Post-Cardiovascular Outcomes in Renal Atherosclerotic Lesions Era Winner or False Alarm?

PubMed Central

Karanikola, Evridiki; Karaolanis, Georgios; Galyfos, George; Barbaressos, Emmanuel; Palla, Viktoria; Filis, Konstantinos

2017-01-01

Renal artery stenosis (RAS) is frequently associated with severe comorbidities such as reduced renal perfusion, hypertension, and end-stage renal failure. In approximately 90% of patients, renal artery atherosclerosis is the main cause for RAS, and it is associated with an increased risk for fatal and non-fatal cardiovascular and renal complications. Endovascular management of atherosclerotic RAS (ARAS) has been recently evaluated by several randomized controlled trials that failed to demonstrate benefit of stenting. Furthermore, the Cardiovascular Outcomes in Renal Atherosclerotic Lesions study did not demonstrate any benefit over the revascularization approach. In this review, we summarized the available data from retrospective, prospective and randomized trials on ARAS to provide clinicians with sufficient data in order to produce useful conclusions for everyday clinical practice. PMID:28377906

Renal Denervation: a Field in Flux.

PubMed

Laffin, Luke J; Bakris, George L

2016-07-01

SYMPLICITY HTN-3 was a pivotal moment for renal denervation as a treatment option for resistant hypertension. Prior unblinded studies were called into question given the negative results of the first sham-controlled trial of renal denervation. Reevaluation of the renal denervation procedure demonstrated that a more precise approach was needed to adequately denervate the kidney. This new approach has been implemented in two ongoing clinical trials, one on and one off medications to assess the new procedure's efficacy and safety. These and other ongoing trials will be discussed in the context of older studies in this field. We focus on novel findings published following the release of SYMPLICITY HTN-3 data in early 2014 and look to the future of renal denervation in the treatment of primary hypertension.

Relationship between histopathological changes in post partum renal biopsies and renal function tests of African women with early onset pre-eclampsia.

PubMed

Khedun, S M; Naicker, T; Moodley, J

2000-05-01

To improve the diagnostic accuracy of concurrent renal disease in hypertension of pregnancy, biopsy evaluation is essential. In addition, establishing underlying renal disease is important for prognosis on future pregnancies. We therefore designed a study to determine the diagnostic yield of postpartum renal biopsy and the nature and frequency of complications associated with this procedure. Also, to determine relationships, if any, between renal function tests and ultrastructural and histopathological findings. Fifty renal biopsies were performed in the immediate postpartum period in black African women with early onset pre-eclampsia. Each biopsy specimen was placed in a separate container and coded so that sampling was unknown to the electron microscopist. Each biopsy specimen was divided into three parts, and processed and stained for light, fluorescent and transmission electron microscopy using conventional techniques. Renal tissue biopsies were adequate for diagnostic purposes in all cases. There were no complications in any of the 50 patients studied. Ultrastructural examination confirmed the light microscopy findings. In addition the ultrastructural findings showed intramembranous deposits, foot process fusion and mesangial deposits. In 16 patients with normal renal function tests; the biopsies evaluation from these patients showed ultrastructural changes. In the remaining 34 patients with abnormal renal function tests of varying severity; biopsy evaluation from these patients showed both ultrastructural and histopathological changes. Renal biopsy procedure is safe, and ultrastructural and histological findings obtained from postpartum renal biopsies are more informative than the routine renal function tests.

Microwave treatment of renal cell carcinoma adjacent to renal sinus.

PubMed

Gao, Yongyan; Liang, Ping; Yu, Xiaoling; Yu, Jie; Cheng, Zhigang; Han, Zhiyu; Duan, Shaobo; Huang, Hui

2016-11-01

To evaluate the efficacy and safety of ultrasound (US)-guided percutaneous microwave ablation (MWA) for renal cell carcinoma (RCC) adjacent to renal sinus. This retrospective study included 41 patients who underwent US-guided percutaneous MWA of 41 RCCs adjacent to the renal sinus from April 2006 to December 2015. Contrast-enhanced images of US and computed tomography (CT) or magnetic resonance (MR) imaging were performed at pre-ablation and 1day, 1 month, 3 months, and every 6 months after ablation. Initial ablation success (IAS), disease-free survival (DFS), RCC-related survival (RRS), and overall survival (OS) were recorded at the follow-up visits. IAS was achieved in 92.7% (38/41) of the study subjects. The IAS significantly differed between patients with RCCs ≤4cm (100%, 29/29) and RCCs >4cm (75%, 9/12, p=0.021). During the median follow-up of 37.6 (range, 3.0-97.3) months, the estimated 1-, 3-, and 5-year DFS of patients with an initial tumor of ≤4cm were 100%, 89.7%, and 81.5%, respectively. The 1-, 3-, and 5-year RRS were 100%, 93.3%, and 93.3%, respectively. The 1-, 3-, and 5-year OS were 97.1%, 87.8%, and 83.6%, respectively. The multivariate analysis using the Cox proportional hazard model revealed no independent predictor of recurrence among all the variables. There were no MWA-related deaths among the study subjects. One patient developed a retroperitoneal abscess after ablation. US-guided percutaneous MWA appears to be a promising method for RCCs adjacent to renal sinus, especially for tumors ≤4cm. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

A case of reocclusion of the renal artery diagnosed by the color Doppler method with evaluation of blood flow direction in the collateral circulation of the kidney in addition to the non-detectable blood signal in the renal artery.

PubMed

Hirano, Megumi; Ohta, Tomoyuki; Nakata, Norio; Kawakami, Reina; Takamura, Kimihiro; Matsuda, Tosiharu; Nishioka, Makiko; Sakurai, Tomoo; Matsuo, Kouichi; Miyamoto, Yukio

2014-10-01

A 23-year-old woman was referred to our hospital for an interventional procedure for chronic total occlusion of the right renal artery, probably due to fibromuscular dysplasia (FMD), and for control of renal vascular hypertension. Before percutaneous transluminal renal angioplasty (PTRA), aortography revealed collateral circulation to the right kidney from the lower lumbar artery. After PTRA, however, blood flow in the renal side of the collateral circulation flowed outside from the right renal parenchyma. 4 months later, we could not find a blood flow signal in the right renal artery, and there was a contrary flow signal in the right kidney parenchyma continuously from the extrahilar vessel, possibly a collateral artery. These findings indicated reocclusion of the right artery. We confirmed reocclusion of the renal artery and collateral feeding by contrast dynamic computed tomography (CT), and PTRA was performed again without any complications or reocclusion for 5 months. This is the first case report showing that a back-flowing signal in the right renal parenchyma from the extrahilar artery is useful as an indirect finding suggesting reocclusion.

General Information about Renal Cell Cancer

MedlinePlus

... Renal Cell Cancer Treatment (PDQ®)–Patient Version General Information About Renal Cell Cancer Go to Health Professional ... the PDQ Adult Treatment Editorial Board . Clinical Trial Information A clinical trial is a study to answer ...

Study of the renal segmental arterial anatomy with contrast-enhanced multi-detector computed tomography.

PubMed

Rocco, Francesco; Cozzi, Luigi Alberto; Cozzi, Gabriele

2015-07-01

To use triphasic multi-detector computed tomography (MDCT) to study the renal segmental arterial anatomy and its relationship with the urinary tract to plan nephron-sparing surgery (NSS). One hundred and fifty nine patients underwent abdominal contrast-enhanced MDCT. We evaluated renal arteries and parenchymal vasculature. In 61 patients, the arteries and the urinary tract were represented simultaneously. 86.60% presented a single renal artery; 13.4%, multiple arteries. All single renal arteries divided into anterior and posterior branch before the hilum. The anterior artery branched into a superior, middle, and inferior branch. In 43.14%, the inferior artery arose before the others; in 45.75%, the superior artery arose before the others; in 9.80%, the branches shared a common trunk. In 26.80%, the posterior artery supplies the entire posterior surface; in 73.20%, it ends along the inferior calyx. In 96.73%, the upper pole was vascularized by the anterior superior branch and the posterior artery: the "tuning fork". MDCT showed four vascular segments in 96.73% and five in 3.27%. MDCT showed two avascular areas: the first along the projection of the inferior calyx on the posterior aspect, the second between the branches of the "tuning fork". The arterial phase provides the arterial tree representation; the delayed phase shows arteries and urinary tract simultaneously. MDCT provides a useful representation of the renal anatomy prior to intervascular-intrarenal NSS.

Cinacalcet for hypercalcaemic secondary hyperparathyroidism after renal transplantation: a multicentre, retrospective, 3-year study.

PubMed

Torregrosa, Jose-Vicente; Morales, Enrique; Díaz, Juan Manuel; Crespo, Josep; Bravo, Juan; Gómez, Gonzalo; Gentil, Miguel Ángel; Rodríguez Benot, Alberto; García, Minerva Rodríguez; Jiménez, Verónica López; Gutiérrez Dalmau, Alex; Jimeno, Luisa; Sáez, María José Pérez; Romero, Rafael; Gómez Alamillo, Carlos

2014-02-01

Our aim was to evaluate the long-term effect of cinacalcet in patients with hypercalcaemic secondary hyperparathyroidism (SHPT) after renal transplantation (RT) in order to expand real-world data in this population. We performed a multicentre, observational, retrospective study in 17 renal transplant units from Spain. We collected data from renal recipients with hypercalcaemic (calcium >10.2 mg/dL) SHPT (intact parathyroid hormone (iPTH) > 120 pg/mL) who initiated cinacalcet in the clinical practice. We included 193 patients with a mean (standard deviation (SD)) age of 52 (12) years, 58% men. Cinacalcet treatment was initiated at a median of 20 months after RT (median dose 30 mg/day). Mean calcium levels decreased from a mean (SD) of 11.1 (0.6) at baseline to 10.1 (0.8) at 6 months (9.0% reduction, P < 0.0001). Median iPTH was reduced by 23.0% at 6 months (P = 0.0005) and mean phosphorus levels increased by 11.1% (P < 0.0001). The effects were maintained up to 3-years. No changes were observed in renal function or anticalcineurin drug levels. Only 4.1% of patients discontinued cinacalcet due to intolerance and 1.0% due to lack of efficacy. In renal transplant patients with hypercalcaemic SHPT, cinacalcet controlled serum calcium, iPTH and phosphorus levels up to 3 years. Tolerability was good. © 2013 Asian Pacific Society of Nephrology.

Preoperative evaluation of renal anatomy and renal masses with helical CT, 3D-CT and 3D-CT angiography.

PubMed

Toprak, Uğur; Erdoğan, Aysun; Gülbay, Mutlu; Karademir, Mehmet Alp; Paşaoğlu, Eşref; Akar, Okkeş Emrah

2005-03-01

The aim of this prospective study was to determine the efficacy of three-dimensional computed tomography (3D-CT) and three-dimensional computed tomographic angiography (3D-CTA) that were reconstructed by using the axial images of the multiphasic helical CT in the preoperative evaluation of renal masses and demonstration of renal anatomy. Twenty patients that were suspected of having renal masses upon initial physical examination and ultrasonographic evaluation were examined through multiphasic helical CT. Two authors executed CT evaluations. Axial images were first examined and then used to reconstruct 3D-CT and 3D- CTA images. Number, location and size of the renal masses and other findings were noted. Renal vascularization and relationships of the renal masses with the neighboring renal structures were further investigated with 3D-CT and 3D-CTA images. Out of 20 patients, 13 had histopathologically proven renal cell carcinoma. The diagnoses of the remaining seven patients were xanthogranulomatous pyelonephritis, abscess, simple cyst, infected cyst, angiomyolipoma, oncocytoma and arteriovenous fistula. In the renal cell carcinoma group, 3 patients had stage I, 7 patients had stage II, and 3 patients had stage III disease. Sizes of renal cell carcinoma masses were between 23 mm to 60 mm (mean, 36 mm). Vascular invasion was shown in 2 renal cell carcinoma patients. Collecting system invasion was identified in 11 of 13 renal cell patients. These radiologic findings were confirmed with surgical specimens. Three-dimensional CT and 3D-CTA are non-invasive, effective imaging techniques for the preoperative evaluation of renal masses.

Intakes of coffee, tea, milk, soda and juice and renal cell cancer in a pooled analysis of 13 prospective studies.

PubMed

Lee, Jung Eun; Hunter, David J; Spiegelman, Donna; Adami, Hans-Olov; Bernstein, Leslie; van den Brandt, Piet A; Buring, Julie E; Cho, Eunyoung; English, Dallas; Folsom, Aaron R; Freudenheim, Jo L; Gile, Graham G; Giovannucci, Edward; Horn-Ross, Pamela L; Leitzmann, Michael; Marshall, James R; Männistö, Satu; McCullough, Marjorie L; Miller, Anthony B; Parker, Alexander S; Pietinen, Pirjo; Rodriguez, Carmen; Rohan, Thomas E; Schatzkin, Arthur; Schouten, Leo J; Willett, Walter C; Wolk, Alicja; Zhang, Shumin M; Smith-Warner, Stephanie A

2007-11-15

Specific beverage intake may be associated with the risk of renal cell cancer through a diluting effect of carcinogens, alterations of hormone levels, or other changes in the renal tubular environment, but few prospective studies have examined these associations. We evaluated the associations between coffee, tea, milk, soda and fruit and vegetable juice intakes and renal cell cancer risk in a pooled analysis of 13 prospective studies (530,469 women and 244,483 men). Participants completed a validated food-frequency questionnaire at baseline. Using the primary data, the study-specific relative risks (RRs) were calculated and then pooled using a random effects model. A total of 1,478 incident renal cell cancer cases were identified during a follow-up of 7-20 years across studies. Coffee consumption was associated with a modestly lower risk of renal cell cancer (pooled multivariate RR for 3 or more 8 oz (237 ml) cups/day versus less than one 8 oz (237 ml) cup/day = 0.84; 95% CI = 0.67-1.05; p value, test for trend = 0.22). Tea consumption was also inversely associated with renal cell cancer risk (pooled multivariate RR for 1 or more 8 oz (237 ml) cups/day versus nondrinkers = 0.85; 95% CI = 0.71-1.02; pvalue, test for trend = 0.04). No clear associations were observed for milk, soda or juice. Our findings provide strong evidence that neither coffee nor tea consumption increases renal cell cancer risk. Instead, greater consumption of coffee and tea may be associated with a lower risk of renal cell cancer. (c) 2007 Wiley-Liss, Inc. (c) 2007 Wiley-Liss, Inc.

Anatomic study of juxta renal aneurysms: impact on fenestrated stent-grafts.

PubMed

Azzaoui, Richard; Sobocinski, Jonathan; Maurel, Blandine; D'Elia, Piervito; Perrot, Céline; Bianchini, Aurélia; Guillou, Matthieu; Haulon, Stéphan

2011-04-01

Fenestrated stent-grafts allow for treatment of patients with juxtarenal aneurysms (JRA) when they present with contraindications for conventional treatment. The fenestrated module is a custom-made module, specially designed to fit a specific patient, using computed tomographic scan measurements, which entails manufacturing delay and high cost. The aim of our study was to evaluate the possibility to reproduce the interrenal aorta anatomy to design a standard fenestrated module that would fit the maximum number of patients with JRA. On a three-dimensional working station, we analyzed 289 preoperative computed tomographic scan results of patients with JRA and who were treated with fenestrated stent-grafts comprising two fenestrations for the renal arteries and a scallop for the superior mesenteric artery (SMA). On curvilinear reconstructions, we successively measured the interrenal aorta diameter, its orientation, as well as the height of each renal ostium, taking the ostium center of the SMA as a reference mark. Later, a statistical analysis of these measures distribution was performed so as to design a fenestrated module that would fit the maximum number of patients. The center of the left renal artery presented with a median orientation of 82.5° (range, 37.5-150) and a median distance of 9 mm (range, 0-30), in relation to the SMA ostium. The ostium center of the right renal artery presented with a median orientation of 285° (range, 240-337.5) and a median distance of 8 mm (range, 3-30), in relation to the SMA ostium. By positioning the current renal fenestrations (6-mm wide), on the basis of the calculated median positions, in our series, only 20% of the patients could be treated with a standard fenestrated module. Should the diameter of these fenestrations be increased by 10 mm, it would then be possible to treat 50% of our patients. The anatomy of the interrenal aorta and its branches is quite reproducible to design standard fenestrated stent-grafts that could

Renal cell tumour characteristics in patients with the Birt-Hogg-Dubé cancer susceptibility syndrome: a retrospective, multicentre study.

PubMed

Benusiglio, Patrick R; Giraud, Sophie; Deveaux, Sophie; Méjean, Arnaud; Correas, Jean-Michel; Joly, Dominique; Timsit, Marc-Olivier; Ferlicot, Sophie; Verkarre, Virginie; Abadie, Caroline; Chauveau, Dominique; Leroux, Dominique; Avril, Marie-Françoise; Cordier, Jean-François; Richard, Stéphane

2014-10-29

The Birt-Hogg-Dubé syndrome is a rare cancer susceptibility syndrome characterised by renal tumours, lung cysts and pneumothoraces, and fibrofolliculomas. It is caused by dominantly inherited mutations in FLCN. Our objective was to report renal tumour characteristics in a large series of patients with the Birt-Hogg-Dubé syndrome. We studied French Birt-Hogg-Dubé patients with a history of renal tumour. We included 33 patients with 21 distinct germline FLCN mutations. Median age at diagnosis of first renal tumour was 46, and age varied from 20 to 83. Twenty cases had one renal tumour, the remainder had two or more tumours. Most cases (23/33, 70%) had oncocytoma or renal cell carcinoma of the chromophobe or hybrid chromophobe-oncocytoma type, three had clear cell carcinoma (9%), and the other seven had carcinoma of papillary, undifferentiated or undetermined histology. Four cases had metastatic disease, although none died of it. Age at renal tumour diagnosis was highly variable, highlighting the need for regular surveillance from young adulthood to old age. Most cases had tumour types classically associated with Birt-Hogg-Dubé, i.e. oncocytoma or renal cell carcinoma of the chromophobe or hybrid type. Nevertheless, 9% had clear cell renal cell carcinoma. Geneticists, urologists and oncologists should therefore be alert to the possibility of Birt-Hogg-Dubé in patients with renal cell carcinoma of clear cell histology, especially if there are associated manifestations. Finally, the behaviour of metastatic carcinoma seemed more indolent than in sporadic renal cancers.

The modern spectrum of biopsy-proven renal disease in Chinese diabetic patients-a retrospective descriptive study.

PubMed

Liu, Diankun; Huang, Ting; Chen, Nan; Xu, Gang; Zhang, Ping; Luo, Yang; Wang, Yongping; Lu, Tao; Wang, Long; Xiong, Mengqi; Geng, Jian; Nie, Sheng

2018-01-01

Renal biopsies performed in diabetic patients are increasing and becoming more complex. Comprehensive data on modern spectrum of biopsy-proven renal disease in Chinese diabetic patients are lacking. In a nationwide renal biopsy survey including 71,151 native biopsies from 2004 to 2014, diabetic patients were identified according to the clinical diagnosis from referral records. The clinical data were extracted from referral records and pathological reports. A total of 1,604 diabetic patients, including 61 patients with T1DM, were analyzed in this study. The median age is 51.39 ± 11.37 years. Male patients accounted for 58% of the population. We found that only 44.7% of diabetic patients had the isolated pathological diagnosis of diabetic nephropathy (DN), while 49.1% had non-diabetic renal disease (NDRD) alone, and 6.2% had NDRD superimposed on DN. Nephrotic syndrome ( n  = 824, 51.4%) was the most common clinical indication for renal biopsy. Among 887 patients with NDRD, membranous nephropathy ( n  = 357) was the leading diagnosis, followed by IgA nephropathy ( n  = 179). Hypertensive renal disease ( n  = 32), tubulointerstitial nephropathy ( n  = 27) and acute tubular necrosis ( n  = 16) accounted for 3.5%, 2.9%, 1.7% of the NDRD cases respectively. Nearly a half (49.2%) of patients with T1DM had NDRD. Over 55% diabetic patients with kidney disease were diagnosed as non-diabetic renal disease, among which MN and IgAN were the most common two pathological types.

Challenges in Pathologic Staging of Renal Cell Carcinoma: A Study of Interobserver Variability Among Urologic Pathologists.

PubMed

Williamson, Sean R; Rao, Priya; Hes, Ondrej; Epstein, Jonathan I; Smith, Steven C; Picken, Maria M; Zhou, Ming; Tretiakova, Maria S; Tickoo, Satish K; Chen, Ying-Bei; Reuter, Victor E; Fleming, Stewart; Maclean, Fiona M; Gupta, Nilesh S; Kuroda, Naoto; Delahunt, Brett; Mehra, Rohit; Przybycin, Christopher G; Cheng, Liang; Eble, John N; Grignon, David J; Moch, Holger; Lopez, Jose I; Kunju, Lakshmi P; Tamboli, Pheroze; Srigley, John R; Amin, Mahul B; Martignoni, Guido; Hirsch, Michelle S; Bonsib, Stephen M; Trpkov, Kiril

2018-06-06

Staging criteria for renal cell carcinoma differ from many other cancers, in that renal tumors are often spherical with subtle, finger-like extensions into veins, renal sinus, or perinephric tissue. We sought to study interobserver agreement in pathologic stage categories for challenging cases. An online survey was circulated to urologic pathologists interested in kidney tumors, yielding 89% response (31/35). Most questions included 1 to 4 images, focusing on: vascular and renal sinus invasion (n=24), perinephric invasion (n=9), and gross pathology/specimen handling (n=17). Responses were collapsed for analysis into positive and negative/equivocal for upstaging. Consensus was regarded as an agreement of 67% (2/3) of participants, which was reached in 20/33 (61%) evaluable scenarios regarding renal sinus, perinephric, or vein invasion, of which 13/33 (39%) had ≥80% consensus. Lack of agreement was especially encountered regarding small tumor protrusions into a possible vascular lumen, close to the tumor leading edge. For gross photographs, most were interpreted as suspicious but requiring histologic confirmation. Most participants (61%) rarely used special stains to evaluate vascular invasion, usually endothelial markers (81%). Most agreed that a spherical mass bulging well beyond the kidney parenchyma into the renal sinus (71%) or perinephric fat (90%) did not necessarily indicate invasion. Interobserver agreement in pathologic staging of renal cancer is relatively good among urologic pathologists interested in kidney tumors, even when selecting cases that test the earliest and borderline thresholds for extrarenal extension. Disagreements remain, however, particularly for tumors with small, finger-like protrusions, closely juxtaposed to the main mass.

Computer simulation analysis of the behavior of renal-regulating hormones during hypogravic stress

NASA Technical Reports Server (NTRS)

Leonard, J. I.

1982-01-01

A computer simulation of a mathematical circulation model is used to study the alterations of body fluids and their electrolyte composition that occur in weightlessness. The behavior of the renal-regulating hormones which control these alterations is compared in simulations of several one-g analogs of weightlessness and space flight. It is shown that the renal-regulating hormones represent a tightly coupled system that responds acutely to volume disturbances and chronically to electrolyte disturbances. During hypogravic conditions these responses lead to an initial suppression of hormone levels and a long-term effect which varies depending on metabolic factors that can alter the plasma electrolytes. In addition, it is found that if pressure effects normalize rapidly, a transition phase may exist which leads to a dynamic multiphasic endocrine response.

Clinical application of calculated split renal volume using computed tomography-based renal volumetry after partial nephrectomy: Correlation with technetium-99m dimercaptosuccinic acid renal scan data.

PubMed

Lee, Chan Ho; Park, Young Joo; Ku, Ja Yoon; Ha, Hong Koo

2017-06-01

To evaluate the clinical application of computed tomography-based measurement of renal cortical volume and split renal volume as a single tool to assess the anatomy and renal function in patients with renal tumors before and after partial nephrectomy, and to compare the findings with technetium-99m dimercaptosuccinic acid renal scan. The data of 51 patients with a unilateral renal tumor managed by partial nephrectomy were retrospectively analyzed. The renal cortical volume of tumor-bearing and contralateral kidneys was measured using ImageJ software. Split estimated glomerular filtration rate and split renal volume calculated using this renal cortical volume were compared with the split renal function measured with technetium-99m dimercaptosuccinic acid renal scan. A strong correlation between split renal function and split renal volume of the tumor-bearing kidney was observed before and after surgery (r = 0.89, P < 0.001 and r = 0.94, P < 0.001). The preoperative and postoperative split estimated glomerular filtration rate of the operated kidney showed a moderate correlation with split renal function (r = 0.39, P = 0.004 and r = 0.49, P < 0.001). The correlation between reductions in split renal function and split renal volume of the operated kidney (r = 0.87, P < 0.001) was stronger than that between split renal function and percent reduction in split estimated glomerular filtration rate (r = 0.64, P < 0.001). The split renal volume calculated using computed tomography-based renal volumetry had a strong correlation with the split renal function measured using technetium-99m dimercaptosuccinic acid renal scan. Computed tomography-based split renal volume measurement before and after partial nephrectomy can be used as a single modality for anatomical and functional assessment of the tumor-bearing kidney. © 2017 The Japanese Urological Association.

Cytochrome P450 and Lipoxygenase Metabolites on Renal Function

PubMed Central

Imig, John D.; Hye Khan, Md. Abdul

2018-01-01

Arachidonic acid metabolites have a myriad of biological actions including effects on the kidney to alter renal hemodynamics and tubular transport processes. Cyclooxygenase metabolites are products of an arachidonic acid enzymatic pathway that has been extensively studied in regards to renal function. Two lesser-known enzymatic pathways of arachidonic acid metabolism are the lipoxygenase (LO) and cytochrome P450 (CYP) pathways. The importance of LO and CYP metabolites to renal hemodynamics and tubular transport processes is now being recognized. LO and CYP metabolites have actions to alter renal blood flow and glomerular filtration rate. Proximal and distal tubular sodium transport and fluid and electrolyte homeostasis are also significantly influenced by renal CYP and LO levels. Metabolites of the LO and CYP pathways also have renal actions that influence renal inflammation, proliferation, and apoptotic processes at vascular and epithelial cells. These renal LO and CYP pathway actions occur through generation of specific metabolites and cell-signaling mechanisms. Even though the renal physiological importance and actions for LO and CYP metabolites are readily apparent, major gaps remain in our understanding of these lipid mediators to renal function. Future studies will be needed to fill these major gaps regarding LO and CYP metabolites on renal function. PMID:26756638

Dinitrotoluene exposure in the copper mining industry and renal cancer: a case-cohort study.

PubMed

Seidler, Andreas; Harth, Volker; Taeger, Dirk; Möhner, Matthias; Gawrych, Katarzyna; Bergmann, Annekatrin; Haerting, Johannes; Kahmann, Hans-Joachim; Bolt, Hermann Maximilian; Straif, Kurt; Brüning, Thomas

2014-04-01

To evaluate the association between dinitrotoluene (DNT) exposure and renal cancer in a case-cohort study. This case-cohort study was conducted among men born between 1920 and 1974 (n=16 441) who were gainfully employed between 1953 and 1990 in one of two copper mines in Mansfeld, Saxony-Anhalt, former German Democratic Republic, and followed up till 31 December 2006. The study included 109 cases with renal cancer identified by record linkage with the Common Cancer Registry of the New Federal States of Germany (GKR) or by a network of pathology institutes. A comparison subcohort of 999 cohort members was selected at random from the total cohort. Duration and intensity of inhalation and dermal exposure to DNT were assessed on the basis of a job exposure matrix. A time-dependent Cox proportional hazards model modified for case-cohort design was used to assess the relationship between cumulative inhalation and dermal DNT exposure and renal cancer. Elevated risks were found for medium (HR=2.73; 95% CI 1.00 to 7.42) and high (HR=1.81; 95% CI 0.75 to 4.33) dermal exposure to DNT. Relative risks for medium inhalation exposure to DNT were not increased (HR=0.93; 95% CI 0.48 to 1.79) while relative risks for high inhalation exposure to DNT were elevated to 1.36 (95% CI 0.84 to 2.21). We found a statistically significant HR of 2.12 (95% CI 1.03 to 4.37) for combined medium or high inhalation and medium or high dermal exposure to DNT. According to our case-cohort study, dermal and inhalation exposure to DNT is associated with increased renal cancer risk.

Assessment of the relationship between renal volume and renal function after minimally-invasive partial nephrectomy: the role of computed tomography and nuclear renal scan.

PubMed

Bertolo, Riccardo; Fiori, Cristian; Piramide, Federico; Amparore, Daniele; Barrera, Monica; Sardo, Diego; Veltri, Andrea; Porpiglia, Francesco

2018-05-14

To evaluate the correlation between the loss of renal function as assessed by Tc99MAG-3 renal scan and the loss of renal volume as calculated by volumetric assessment on CT-scan in patients who underwent minimally-invasive partial nephrectomy (PN). PN prospectively-maintained database was retrospectively queried for patients who underwent minimally-invasive PN (2012-2017) for renal mass renal scan and contrast-enhanced CT-scan (both performed in our Institution) both at preoperative assessment and at the third postoperative month follow-up. Tc99MAG-3 renal scan was performed to get renal functional data; renal volume was calculated by dedicated software from CT-scan with a semiautomated method. Statistical analysis aimed to identify relationships between loss of renal volume and loss of renal function and other patients' and surgical variables, particularly regarding lesion complexity (assessed by PADUA score). 57 patients were analyzed. Both at univariate and multivariate analysis, the percentage of loss of renal function was significantly correlated to the loss of renal volume (p<0.001). Warm ischemia significantly correlated with the loss of renal volume (p=0.003). After stratification according to PADUA score categories, higher surgical complexity renal masses had stronger correlation between the loss of renal volume and the loss of renal function. The use of the semiautomated method for the 3D segmentation of the kidney to get the volumetric assessment could be a valid tool to support the future use of CT-scan as the tool to pair the oncological and the functional follow-up after PN.

Lithium intoxication: Incidence, clinical course and renal function – a population-based retrospective cohort study

PubMed Central

Ott, Michael; Stegmayr, Bernd; Salander Renberg, Ellinor; Werneke, Ursula

2016-01-01

When prescribing lithium, the risk of toxicity remains a concern. In this study, we examined a cohort of patients exposed to lithium between 1997 and 2013. The aims of this study were to determine the frequency of lithium intoxication and to evaluate the clinical course and changes in renal function. Of 1340 patients, 96 had experienced at least one episode of lithium levels ⩾1.5 mmol/L, yielding an incidence of 0.01 per patient-year. Seventy-seven patients available for review had experienced 91 episodes, of whom 34% required intensive care and 13% were treated with haemodialysis. There were no fatalities. Acute kidney injury occurred, but renal function at baseline was not different to renal function after the episode. Renal impairment was often associated with co-morbidities and other factors. Both intermittent and continuous-venovenous haemodialysis were used, but the clearance of continuous-venovenous haemodialysis can be too low in cases where large amounts of lithium have been ingested. Saline and forced diuresis have been used and are safe. Lithium intoxication seems rare and can be safely managed in most cases. Physicians should not withhold lithium for fear of intoxication in patients who benefit from it. Yet, physicians should have a low threshold to screen for toxicity. PMID:27307388

Less contribution of mast cells to the progression of renal fibrosis in Rat kidneys with chronic renal failure.

PubMed

Baba, Asuka; Tachi, Masahiro; Ejima, Yutaka; Endo, Yasuhiro; Toyama, Hiroaki; Saito, Kazutomo; Abe, Nozomu; Yamauchi, Masanori; Miura, Chieko; Kazama, Itsuro

2017-02-01

Chronic renal failure (CRF) is histopathologically characterized by tubulointerstitial fibrosis in addition to glomerulosclerosis. Although mast cells are known to infiltrate into the kidneys with chronic inflammation, we know little about their contribution to the pathogenesis of renal fibrosis associated with CRF. The aim of this study was to reveal the involvement of mast cells in the progression of renal fibrosis in CRF. Using a rat model with CRF resulting from 5/6 nephrectomy, we examined the histopathological features of the kidneys and the infiltration of mast cells into the renal interstitium. By treating the rats with a potent mast cell stabilizer, tranilast, we also examined the involvement of mast cells in the progression of renal fibrosis associated with CRF. The CRF rat kidneys were characterized by the wide staining of collagen III and increased number of myofibroblasts, indicating the progression of renal fibrosis. Compared to T-lymphocytes or macrophages, the number of tryptase-positive mast cells was much smaller within the fibrotic kidneys and they did not proliferate in situ. The mRNA expression of mast cell-derived fibroblast-activating factors was not increased in the renal cortex isolated from CRF rat kidneys. Treatment with tranilast did not suppress the progression of renal fibrosis, nor did it ameliorate the progression of glomerulosclerosis and the interstitial proliferation of inflammatory leukocytes. This study demonstrated for the first time that mast cells are neither increased nor activated in the fibrotic kidneys of CRF rats. Compared to T-lymphocytes or macrophages that proliferate in situ within the fibrotic kidneys, mast cells were less likely to contribute to the progression of renal fibrosis associated with CRF. © 2016 Asian Pacific Society of Nephrology.

Improved survival with renal transplantation for end-stage renal disease due to granulomatosis with polyangiitis: data from the United States Renal Data System.

PubMed

Wallace, Zachary S; Wallwork, Rachel; Zhang, Yuqing; Lu, Na; Cortazar, Frank; Niles, John L; Heher, Eliot; Stone, John H; Choi, Hyon K

2018-05-14

Renal transplantation is the optimal treatment for selected patients with end-stage renal disease (ESRD). However, the survival benefit of renal transplantation among patients with ESRD attributed to granulomatosis with polyangiitis (GPA) is unknown. We identified patients from the United States Renal Data System with ESRD due to GPA (ESRD-GPA) between 1995 and 2014. We restricted our analysis to waitlisted subjects to evaluate the impact of transplantation on mortality. We followed patients until death or the end of follow-up. We compared the relative risk (RR) of all-cause and cause-specific mortality in patients who received a transplant versus non-transplanted patients using a pooled logistic regression model with transplantation as a time-varying exposure. During the study period, 1525 patients were waitlisted and 946 received a renal transplant. Receiving a renal transplant was associated with a 70% reduction in the risk of all-cause mortality in multivariable-adjusted analyses (RR=0.30, 95% CI 0.25 to 0.37), largely attributed to a 90% reduction in the risk of death due to cardiovascular disease (CVD) (RR=0.10, 95% 0.06-0.16). Renal transplantation is associated with a significant decrease in all-cause mortality among patients with ESRD attributed to GPA, largely due to a decrease in the risk of death to CVD. Prompt referral for transplantation is critical to optimise outcomes for this patient population. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Inflammation in renal atherosclerotic disease.

PubMed

Udani, Suneel M; Dieter, Robert S

2008-07-01

The study of renal atherosclerotic disease has conventionally focused on the diagnosis and management of renal artery stenosis. With the increased understanding of atherosclerosis as a systemic inflammatory process, there has been increased interest in vascular biology at the microvasculature level. While different organ beds share some features, the inflammation and injury in the microvasculature of the kidney has unique elements as well. Understanding of the pathogenesis yields a better understanding of the clinical manifestations of renal atherosclerotic disease, which can be very subtle. Furthermore, identifying the molecular mechanisms responsible for the progression of kidney damage can also direct clinicians and scientists toward targeted therapies. Existing therapies used to treat atherosclerotic disease in other vascular beds may also play a role in the treatment of renal atherosclerotic disease.

Renal dopamine containing nerves. What is their functional significance?

PubMed

DiBona, G F

1990-06-01

Biochemical and morphological studies indicate that there are nerves within the kidney that contain dopamine and that various structures within the kidney contain dopamine receptors. However, the functional significance of these renal dopamine containing nerves in relation to renal dopamine receptors is unknown. The functional significance could be defined by demonstrating that an alteration in one or more renal functions occurring in response to reflex or electrical activation of efferent renal nerves is dependent on release of dopamine as the neurotransmitter from the renal nerve terminals acting on renal dopamine receptors. Thus, the hypothesis becomes: reflex or electrical activation of efferent renal nerves causes alterations in renal function (eg, renal blood flow, water and solute handling) that are inhibited by specific and selective dopamine receptor antagonists. As reviewed herein, the published experimental data do not support the hypothesis. Therefore, the view that alterations in one or more renal functions occurring in response to reflex or electrical activation of efferent renal nerves are dependent on release of dopamine as the neurotransmitter from the renal nerve terminals acting on renal dopamine receptors remains unproven.

Renal Arterial Pseudoaneurysm and Renal Arteriovenous Fistula Following Partial Nephrectomy.

PubMed

Chen, Jinchao; Yang, Min; Wu, Pengjie; Li, Teng; Ning, Xianghui; Peng, Shuanghe; Wang, Jiangyi; Qi, Nienie; Gong, Kan

2018-01-01

Renal arterial pseudoaneurysm (RAP) and renal arteriovenous fistula (RAVF) are rare but can cause fatal bleeding. A retrospective review was conducted for patients undergoing partial nephrectomy (PN) in our department. The clinical features and treatment methods were analysed, and the relationships between RAP/RAVF and the surgical methods and R.E.N.A.L. score were investigated. Eleven patients were diagnosed with RAP/RAVF (9 with RAP and 2 with RAVF). The incidence of RAP/RAVF after laparoscopic PN showed no significant difference compared to that after open PN (p = 0.47). A low R.E.N.A.L. score was present in 6 patients, while an intermediate/high score was present in the other 5 patients. The major clinical manifestations included haematuria and haemorrhagic shock, and the median time of occurrence was 8 days after the operation. Six patients underwent an ultrasound examination. Of the 4 patients who underwent enhanced CT, 2 patients were diagnosed with RAP. All 11 patients were diagnosed by renal angiography and were cured after super-selective arterial embolization. The serum creatinine levels before and after embolization showed no significant differences (p = 0.14). RAP/RAVF may not have any relationship with the surgical procedure or R.E.N.A.L. score. Renal angiography and super-selective arterial embolization are the preferred methods for diagnosing and treating RAP/RAVF. © 2016 S. Karger AG, Basel.

Pathophysiology of renal denervation procedures: from renal nerve anatomy to procedural parameters.

PubMed

Ammar, Sonia; Ladich, Elena; Steigerwald, Kristin; Deisenhofer, Isabel; Joner, Michael

2013-05-01

Endovascular renal denervation techniques have been clinically adopted for the treatment of resistant arterial hypertension with great success. Despite the favourable early results achieved with this technology, a clear understanding of the pathophysiology underlying this novel treatment is lacking. In addition, non-responsiveness to renal denervation remains a nidus for treatment failure in distinct patients. In search of meaningful surrogate parameters relating to treatment responsiveness, the current article reviews the existing knowledge on renal nerve anatomy, changes occurring after denervation and procedural parameters collected during denervation. From preclinical experience, the most reliable morphological parameter reflecting successful renal denervation is the presence of axonal degeneration. Most procedural and clinical parameters need extended investigation before adopting them as potential surrogate parameters for successful renal denervation. As a consequence, there is an imperative need for dedicated research revealing the pathophysiology of renal denervation procedures. In this regard, close co-operation of engineers, researchers and clinicians is warranted to turn renal denervation into a milestone treatment of arterial hypertension.

Early impact of robot-assisted partial nephrectomy on renal function as assessed by renal scintigraphy.

PubMed

Luciani, Lorenzo G; Chiodini, Stefano; Donner, Davide; Cai, Tommaso; Vattovani, Valentino; Tiscione, Daniele; Giusti, Guido; Proietti, Silvia; Chierichetti, Franca; Malossini, Gianni

2016-06-01

To measure the early impact of robot-assisted partial nephrectomy (RAPN) on renal function as assessed by renal scan (Tc 99m-DTPA), addressing the issue of risk factors for ischemic damage to the kidney. All patients undergoing RAPN for cT1 renal masses between June 2013 and May 2014 were included in this prospective study. Renal function as expressed by glomerular filtration rate (GFR) was assessed by Technetium 99m-diethylenetriaminepentaacetic acid (Tc 99m-DTPA) renal scan preoperatively and postoperatively at 1 month in every patient. A multivariable analysis was used for the determination of independent factors predictive of GFR decrease of the operated kidney. Overall, 32 patients underwent RAPN in the time interval. Median tumor size, blood loss, and ischemia time were 4 cm, 200 mL, and 24 min, respectively. Two grade III complications occurred (postoperative bleeding in the renal fossa, urinoma). The GFR of the operated kidney decreased significantly from 51.7 ± 15.1 mL/min per 1.73 m(2) preoperatively to 40, 12 ± 12.4 mL/min per 1.73 m(2) 1 month postoperatively (p = 0.001) with a decrease of 22.4 %. On multivariable analysis, only tumor size (p = 0.05) was a predictor of GFR decrease of the operated kidney. Robotic-assisted partial nephrectomy had a detectable impact on early renal function in a series of relatively large tumors and prevailing intermediate nephrometric risk. A mean decrease of 22 % of GFR as assessed by renal scan in the operated kidney was found at 1 month postoperatively. In multivariable analysis, tumor size only was a significant predictor of renal function loss.

Inhibition of p38 MAPK attenuates renal atrophy and fibrosis in a murine renal artery stenosis model.

PubMed

Wang, Diping; Warner, Gina M; Yin, Ping; Knudsen, Bruce E; Cheng, Jingfei; Butters, Kim A; Lien, Karen R; Gray, Catherine E; Garovic, Vesna D; Lerman, Lilach O; Textor, Stephen C; Nath, Karl A; Simari, Robert D; Grande, Joseph P

2013-04-01

Renal artery stenosis (RAS) is an important cause of chronic renal dysfunction. Recent studies have underscored a critical role for CCL2 (MCP-1)-mediated inflammation in the progression of chronic renal damage in RAS and other chronic renal diseases. In vitro studies have implicated p38 MAPK as a critical intermediate for the production of CCL2. However, a potential role of p38 signaling in the development and progression of chronic renal disease in RAS has not been previously defined. We sought to test the hypothesis that inhibition of p38 MAPK ameliorates chronic renal injury in mice with RAS. We established a murine RAS model by placing a cuff on the right renal artery and treated mice with the p38 inhibitor SB203580 or vehicle for 2 wk. In mice treated with vehicle, the cuffed kidney developed interstitial fibrosis, tubular atrophy, and interstitial inflammation. In mice treated with SB203580, the RAS-induced renal atrophy was reduced (70% vs. 39%, P < 0.05). SB203580 also reduced interstitial inflammation and extracellular matrix deposition but had no effect on the development of hypertension. SB203580 partially blocked the induction of CCL2, CCL7 (MCP-3), CC chemokine receptor 2 (CCR2), and collagen 4 mRNA expression in the cuffed kidneys. In vitro, blockade of p38 hindered both TNF-α and TGF-β-induced CCL2 upregulation. Based on these observations, we conclude that p38 MAPK plays a critical role in the induction of CCL2/CCL7/CCR2 system and the development of interstitial inflammation in RAS.

Renal venogram

MedlinePlus

... be black. Other structures will be shades of gray. Veins are not normally seen in an x- ... Venogram - kidney; Renal vein thrombosis - venogram Images Kidney anatomy Kidney - blood and urine flow Renal veins References ...

Aquatic models for the study of renal transport function and pollutant toxicity.

PubMed Central

Miller, D S

1987-01-01

Studies of renal cell transport mechanisms and their impairment by xenobiotics are often limited by technical difficulties related to renal tubule complexity. Problems include the juxtaposition of multiple tubule segments with different transport functions and severely limited access to the tubular lumen. Some limitations can be overcome by the careful selection of an appropriate aquatic experimental system. Two aquatic models for the vertebrate proximal segment are discussed here. The first is the kidney from certain marine flounder, which offers the following advantages: long-term viability, little tissue of nonproximal origin, and easy tubule isolation. Data are presented to demonstrate how studies with flounder kidney can be used to elucidate cellular mechanisms whereby different classes of toxic pollutants may interact. Results from these experiments indicate that the excretion of certain anionic xenobiotics can be delayed by other anionic xenobiotics that compete for secretory transport sites and by compounds that disrupt cellular ion gradients and energy metabolism needed to drive transport. The second system is the crustacean urinary bladder, a simple, flatsheet epithelium. Bladder morphology and transport physiology closely resemble those of vertebrate proximal segment. Electron micrographs show a brush border membrane at the luminal surface, numerous mitochondria, and an infolded serosal membrane, while in vivo and in vitro transport studies show reabsorption of NaCl, nutrients and water and secretion of organic cations; organic anions are secreted in bladders from some species and reabsorbed in others. Moreover, since bladders can be mounted as flat sheets in flux chambers, studies with this tissue avoid the problems of complex renal tubule geometry and tissue heterogeneity that limit transport studies in proximal tubule. Images FIGURE 3. FIGURE 6. PMID:3297665

The renal response to electrical stimulation of renal efferent sympathetic nerves in the anaesthetized greyhound.

PubMed Central

Poucher, S M; Karim, F

1991-01-01

1. The effect of direct electrical stimulation of the renal efferent nerves upon renal haemodynamics and function was studied in greyhounds anaesthetized with chloralose and artificially ventilated. The left kidney was neurally and vascularly isolated, and perfused with blood from one of the femoral arteries at a constant pressure of 99 +/- 1 mmHg. Renal blood flow was measured with a cannulating electromagnetic flow probe placed in the perfusion circuit, glomerular filtration rate by creatinine clearance, urinary sodium excretion by flame photometry and solute excretion by osmometry. Beta-Adrenergic receptor activation was blocked by the infusion of dl-propranolol (17 micrograms kg-1 min-1). The peripheral ends of the ligated renal nerves were stimulated at 0.5, 1.0, 1.5 and 2.0 Hz. 2. At 0.5 Hz frequency only osmolar excretion was significantly reduced (10.3 +/- 3.2%, P less than 0.05, n = 6). Reductions in sodium excretion (53.6 +/- 8.5%, P less than 0.01, n = 6) and water excretion (26.9 +/- 8.0%, P less than 0.05, n = 6) and further reductions of osmolar excretion (20.7 +/- 3.7%, P less than 0.01, n = 6) were observed at 1.0 Hz; however, these were observed in the absence of significant changes in renal blood flow and glomerular filtration rate. Significant reductions were observed in glomerular filtration rate at 1.5 Hz (16.3 +/- 4.1%, P less than 0.02, n = 5) and in renal blood flow at 2.0 Hz (13.1 +/- 4.0%, P less than 0.05, n = 5). Further reductions in urine flow and sodium excretion were also observed at these higher frequencies. 3. These results clearly show that significant changes in renal tubular function can occur in the absence of changes in renal blood flow and glomerular filtration rate when the renal nerves are stimulated electrically from a zero baseline activity up to a frequency of 1.5 Hz. Higher frequencies caused significant changes in both renal haemodynamics and function. PMID:2023113

Contrast medium administration and image acquisition parameters in renal CT angiography: what radiologists need to know.

PubMed

Saade, Charbel; Deeb, Ibrahim Alsheikh; Mohamad, Maha; Al-Mohiy, Hussain; El-Merhi, Fadi

2016-01-01

Over the last decade, exponential advances in computed tomography (CT) technology have resulted in improved spatial and temporal resolution. Faster image acquisition enabled renal CT angiography to become a viable and effective noninvasive alternative in diagnosing renal vascular pathologies. However, with these advances, new challenges in contrast media administration have emerged. Poor synchronization between scanner and contrast media administration have reduced the consistency in image quality with poor spatial and contrast resolution. Comprehensive understanding of contrast media dynamics is essential in the design and implementation of contrast administration and image acquisition protocols. This review includes an overview of the parameters affecting renal artery opacification and current protocol strategies to achieve optimal image quality during renal CT angiography with iodinated contrast media, with current safety issues highlighted.

The incidence of renal calcification in preterm infants.

PubMed Central

Short, A; Cooke, R W

1991-01-01

A total of 79 infants born at less than 32 weeks' gestation were studied with serial renal ultrasound scans to assess the incidence of nephrocalcinosis. Twenty one infants developed renal calcification giving an overall incidence of 26.6% in the study group. Affected infants were significantly smaller (mean (SD) birth weight 940 (323) g) and significantly less mature (mean (SD) gestation 26.9 (1.9) weeks). In 17 patients the calcification was represented by hyperechogenic renal pyramids alone, and in four patients renal calculi were demonstrated. Factors associated with renal calcification included hypophosphataemia, hypercalcaemia, hypercreatininaemia, and prolonged oxygen requirement during the first month of life. Multivariate analysis showed that the strongest clinical indicator of calcification was duration of oxygen treatment. Infants who still required oxygen treatment at 28 days had a 62% chance of developing renal calcification. Images Figure 4 Figure 5 PMID:2025034

Curcumin prevents mitochondrial dynamics disturbances in early 5/6 nephrectomy: Relation to oxidative stress and mitochondrial bioenergetics.

PubMed

Aparicio-Trejo, Omar Emiliano; Tapia, Edilia; Molina-Jijón, Eduardo; Medina-Campos, Omar Noel; Macías-Ruvalcaba, Norma Angélica; León-Contreras, Juan Carlos; Hernández-Pando, Rogelio; García-Arroyo, Fernando E; Cristóbal, Magdalena; Sánchez-Lozada, Laura Gabriela; Pedraza-Chaverri, José

2017-03-01

Five-sixths nephrectomy (5/6NX) is a widely used model to study the mechanisms leading to renal damage in chronic kidney disease (CKD). However, early alterations on renal function, mitochondrial dynamics, and oxidative stress have not been explored yet. Curcumin is an antioxidant that has shown nephroprotection in 5/6NX-induced renal damage. The aim of this study was to explore the effect of curcumin on early mitochondrial alterations induced by 5/6NX in rats. In isolated mitochondria, 5/6NX-induced hydrogen peroxide production was associated with decreased activity of complexes I and V, decreased activity of antioxidant enzymes, alterations in oxygen consumption and increased MDA-protein adducts. In addition, it was found that 5/6NX shifted mitochondrial dynamics to fusion, which was evidenced by increased optic atrophy 1 and mitofusin 1 (Mfn1) and decreased fission 1 and dynamin-related protein 1 expressions. These data were confirmed by morphological analysis and immunoelectron microscopy of Mfn-1. All the above-described mechanisms were prevented by curcumin. Also, it was found that curcumin prevented renal dysfunction by improving renal blood flow and the total antioxidant capacity induced by 5/6NX. Moreover, in glomeruli and proximal tubules 5/6NX-induced superoxide anion production by uncoupled nitric oxide synthase (NOS) and nicotinamide adenine dinucleotide phosphate oxidase (NOX) dependent way, this latter was associated with increased phosphorylation of serine 304 of p47phox subunit of NOX. In conclusion, this study shows that curcumin pretreatment decreases early 5/6NX-induced altered mitochondrial dynamics, bioenergetics, and oxidative stress, which may be associated with the preservation of renal function. © 2016 BioFactors, 43(2):293-310, 2017. © 2016 International Union of Biochemistry and Molecular Biology.

Reinnervation following catheter-based radio-frequency renal denervation.

PubMed

Booth, Lindsea C; Nishi, Erika E; Yao, Song T; Ramchandra, Rohit; Lambert, Gavin W; Schlaich, Markus P; May, Clive N

2015-04-20

were normal, indicating reinnervation. Anatomical measures of renal innervation by sympathetic efferent nerves (tissue noradrenaline and tyrosine hydroxylase) and afferent sensory nerves (calcitonin gene-related peptide) demonstrated large decreases at 1 week postdenervation, but normal levels at 11 months postdenervation. In summary, catheter-based renal denervation is effective, but reinnervation occurs. Studies of central and renal changes postdenervation are required to understand the causes of the prolonged hypotensive response to catheter-based renal denervation in human hypertension. © 2015 The Authors. Experimental Physiology © 2015 The Physiological Society.

SGLT2 inhibitors and renal outcomes in type 2 diabetes with or without renal impairment: A systematic review and meta-analysis.

PubMed

Seidu, Samuel; Kunutsor, Setor K; Cos, Xavier; Gillani, Syed; Khunti, Kamlesh

2018-06-01

Sodium-glucose co-transporter 2 (SGLT2) inhibitors may have renal protective effects in people with impaired kidney function. We assessed the use of SGLT2 inhibitors in people with type 2 diabetes with or without renal impairment [defined as estimated glomerular filtration rate (eGFR) of ≥30 and <60ml/min/1.73m 2 and/or UACR>300 and ≤5000mg/g] by conducting a systematic review and meta-analysis of available studies. Randomised controlled trials (RCTs) were identified from MEDLINE, EMABASE, Web of Science, the Cochrane Library, and search of bibliographies to March 2017. No relevant observational study was identified. Summary measures were presented as mean differences and narrative synthesis performed for studies that could not be pooled. 42 articles which included 40 RCTs comprising 29,954 patients were included. In populations with renal impairment, SGLT2 inhibition compared with placebo was consistently associated with an initial decrease in eGFR followed by an increase and return to baseline levels. In pooled analysis of 17 studies in populations without renal impairment, there was no significant change in eGFR comparing SGLT2 inhibitors with placebo (mean difference, 0.51ml/min/1.73m 2 ; 95% CI: -0.69, 1.72; p=403). SGLT2 inhibition relative to placebo was associated with preservation in serum creatinine levels or initial increases followed by return to baseline levels in patients with renal impairment, but levels were preserved in patients without renal impairment. In populations with or without renal impairment, SGLT2 inhibitors (particularly canagliflozin and empagliflozin) compared with placebo were associated with decreased urine albumin, improved albuminiuria, slowed progression to macroalbuminuria, and reduced the risk of worsening renal impairment, the initiation of kidney transplant, and death from renal disease. Emerging data suggests that with SGLT2 inhibition, renal function seems to be preserved in people with diabetes with or without renal

MRI to assess renal structure and function.

PubMed

Artunc, Ferruh; Rossi, Cristina; Boss, Andreas

2011-11-01

In addition to excellent anatomical depiction, MRI techniques have expanded to study functional aspects of renal physiology, such as renal perfusion, glomerular filtration rate (GFR) or tissue oxygenation. This review will focus on current developments with an emphasis on clinical applicability. The method of GFR determination is largely heterogeneous and still has weaknesses. However, the technique of employing liver disappearance curves has been shown to be accurate in healthy persons and patients with chronic kidney disease. In potential kidney donors, complete evaluation of kidney anatomy and function can be accomplished in a single-stop investigation. Techniques without contrast media can be utilized to measure renal tissue oxygenation (blood oxygen level-dependent MRI) or perfusion (arterial spin labeling) and could aid in the diagnosis and treatment of ischemic renal diseases, such as renal artery stenosis. Diffusion imaging techniques may provide information on spatially restricted water diffusion and tumor cellularity. Functional MRI opens new horizons in studying renal physiology and pathophysiology in vivo. Although extensively utilized in research, labor-intensive postprocessing and lack of standardization currently limit the clinical applicability of functional MRI. Further studies are necessary to evaluate the clinical value of functional magnetic resonance techniques for early discovery and characterization of kidney disease.

Adherence with renal dosing recommendations in outpatients undergoing haemodialysis.

PubMed

Kim, G J; Je, N K; Kim, D-S; Lee, S

2016-02-01

Adjustment of drug dosage in patients with end-stage renal disease prevents serious adverse effects, which occur due to the accumulation of drugs or other toxic metabolites. Nevertheless, dosing errors occur most commonly among patients with end-stage renal disease. The aim of this study was to assess the quality of care for end-stage renal disease outpatients using their renal dosing adjustment status. A cross-sectional study was performed using the data collected from 43 South Korean medical institutions via questionnaires. A total of 2428 patients on haemodialysis, who were at least 18 years of age, were included. Among these patients, the study population was confined to patients who were taking medications and required renal dosing adjustments from three therapeutic classes: antihypertensives, antihyperglycaemics and lipid-modifying agents. The study population (n = 828) was prescribed a total of 1097 drug orders for the target drugs. Determination of appropriate dosage adjustment was based on GFR (glomerular filtration rate) using the Modification of Diet in Renal Disease revised 4-variable equation. The primary outcome was non-adherence to drug dosing requirements for end-stage renal disease patients with consideration to their renal function. Among the study population (n = 828), 469 haemodialysis patients were identified as having drug orders that were adherent to renal dosing recommendations. There were significant differences between the patient groups who received recommendation-adherent and non-adherent drug orders in the characteristics of the medical institutions they visited, causes of chronic renal failure and prevalence of concurrent diabetes mellitus. The primary factor of non-adherence to renal dosing adjustment recommendations was characteristics of medical institutions. Compared to tertiary hospitals, secondary hospitals and primary care clinics were 1·16 and 1·22 times, respectively, more non-adherent in accordance with the multivariate

[Polythelia and renal malformation].

PubMed

Jójárt, G; Seres, E

1992-07-12

The authors found 241 polythelia (5.86) among 4113 schoolchildren (aged 6-14 years). They investigated 236 of the 241 with ultrasound and found 10 renal malformations (4.24%). Among 280 controls with respiratory infection, accident or tonsillectomy they found 9 renal malformations (3.21%). With screening of 1635 neonates they found 66 with accessory nipples (4.05%). Two of the 66 had renal malformations (3.03%), while among the 1957 control neonates 37 had renal malformations (1.89%). In the hospital and ambulancy the authors found 106 polythelia, five of them had renal abnormalities (4.72%). The authors did not found association of polythelia and renal malformation with ultrasound investigation of 408 children with polythelia.

Predictors of the development of myocarditis or acute renal failure in patients with leptospirosis: An observational study

PubMed Central

2012-01-01

Background Leptospirosis has a varied clinical presentation with complications like myocarditis and acute renal failure. There are many predictors of severity and mortality including clinical and laboratory parameters. Early detection and treatment can reduce complications. Therefore recognizing the early predictors of the complications of leptospirosis is important in patient management. This study was aimed at determining the clinical and laboratory predictors of myocarditis or acute renal failure. Methods This was a prospective descriptive study carried out in the Teaching Hospital, Kandy, from 1st July 2007 to 31st July 2008. Patients with clinical features compatible with leptospirosis case definition were confirmed using the Microscopic Agglutination Test (MAT). Clinical features and laboratory measures done on admission were recorded. Patients were observed for the development of acute renal failure or myocarditis. Chi-square statistics, Fisher's exact test and Mann-Whitney U test were used to compare patients with and without complications. A logistic regression model was used to select final predictor variables. Results Sixty two confirmed leptospirosis patients were included in the study. Seven patients (11.3%) developed acute renal failure and five (8.1%) developed myocarditis while three (4.8%) had both acute renal failure and myocarditis. Conjunctival suffusion - 40 (64.5%), muscle tenderness - 28 (45.1%), oliguria - 20 (32.2%), jaundice - 12 (19.3%), hepatomegaly - 10 (16.1%), arrhythmias (irregular radial pulse) - 8 (12.9%), chest pain - 6 (9.7%), bleeding - 5 (8.1%), and shortness of breath (SOB) 4 (6.4%) were the common clinical features present among the patients. Out of these, only oliguria {odds ratio (OR) = 4.14 and 95% confidence interval (CI) 1.003-17.261}, jaundice (OR = 5.13 and 95% CI 1.149-28.003), and arrhythmias (OR = 5.774 and 95% CI 1.001-34.692), were predictors of myocarditis or acute renal failure and none of the laboratory

The Renal Arterial Resistance Index Predicts Worsening Renal Function in Chronic Heart Failure Patients

PubMed Central

Iacoviello, Massimo; Monitillo, Francesco; Leone, Marta; Citarelli, Gaetano; Doronzo, Annalisa; Antoncecchi, Valeria; Puzzovivo, Agata; Rizzo, Caterina; Lattarulo, Maria Silvia; Massari, Francesco; Caldarola, Pasquale; Ciccone, Marco Matteo

2016-01-01

Background/Aim The renal arterial resistance index (RRI) is a Doppler measure, which reflects abnormalities in the renal blood flow. The aim of this study was to verify the value of RRI as a predictor of worsening renal function (WRF) in a group of chronic heart failure (CHF) outpatients. Methods We enrolled 266 patients in stable clinical conditions and on conventional therapy. Peak systolic velocity and end diastolic velocity of a segmental renal artery were obtained by pulsed Doppler flow, and RRI was calculated. Creatinine serum levels were evaluated at baseline and at 1 year, and the changes were used to assess WRF occurrence. Results During follow-up, 34 (13%) patients showed WRF. RRI was associated with WRF at univariate (OR: 1.13; 95% CI: 1.07–1.20) as well as at a forward stepwise multivariate logistic regression analysis (OR: 1.09; 95% CI: 1.03–1.16; p = 0.005) including the other univariate predictors. Conclusions Quantification of arterial renal perfusion provides a new parameter that independently predicts the WRF in CHF outpatients. Its possible role in current clinical practice to better define the risk of cardiorenal syndrome progression is strengthened. PMID:27994601

Effects of early overnutrition on the renal response to Ang II and expression of RAAS components in rat renal tissue.

PubMed

Granado, M; Amor, S; Fernández, N; Carreño-Tarragona, G; Iglesias-Cruz, M C; Martín-Carro, B; Monge, L; García-Villalón, A L

2017-10-01

The aim of this study was to analyze the effects of early overnutrition (EON) on the expression of the renin angiotensin aldosterone system (RAAS) components in renal cortex, renal arteries and renal perivascular adipose tissue (PVAT), as well as the vascular response of renal arteries to Angiotensin II (Ang II). On birth day litters were adjusted to twelve (L12-control) or three (L3-overfed) pups per mother. Half of the animals were sacrificed at weaning (21 days old) and the other half at 5 months of age. Ang II-induced vasoconstriction of renal artery segments increased in young overfed rats and decreased in adult overfed rats. EON decreased the gene expression of angiotensinogen (Agt), Ang II receptors AT1 and AT2 and eNOS in renal arteries of young rats, while it increased the mRNA levels of AT-2 and ET-1 in adult rats. In renal PVAT EON up-regulated the gene expression of COX-2 and TNF-α in young rats and the mRNA levels of renin receptor both in young and in adult rats. On the contrary, Ang II receptors mRNA levels were downregulated at both ages. Renal cortex of overfed rats showed increased gene expression of Agt in adult rats and of AT1 in young rats. However the mRNA levels of AT1 were decreased in the renal cortex of overfed adult rats. EON is associated with alterations in the vascular response of renal arteries to Ang II and changes in the gene expression of RAAS components in renal tissue. Copyright © 2017 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

Role of bone morphogenetic protein-7 in renal fibrosis

PubMed Central

Li, Rui Xi; Yiu, Wai Han; Tang, Sydney C. W.

2015-01-01

Renal fibrosis is final common pathway of end stage renal disease. Irrespective of the primary cause, renal fibrogenesis is a dynamic process which involves a large network of cellular and molecular interaction, including pro-inflammatory cell infiltration and activation, matrix-producing cell accumulation and activation, and secretion of profibrogenic factors that modulate extracellular matrix (ECM) formation and cell-cell interaction. Bone morphogenetic protein-7 is a protein of the TGF-β super family and increasingly regarded as a counteracting molecule against TGF-β. A large variety of evidence shows an anti-fibrotic role of BMP-7 in chronic kidney disease, and this effect is largely mediated via counterbalancing the profibrotic effect of TGF-β. Besides, BMP-7 reduced ECM formation by inactivating matrix-producing cells and promoting mesenchymal-to-epithelial transition (MET). BMP-7 also increased ECM degradation. Despite these observations, the anti-fibrotic effect of BMP-7 is still controversial such that fine regulation of BMP-7 expression in vivo might be a great challenge for its ultimate clinical application. PMID:25954203

Endoglin regulates renal ischaemia-reperfusion injury.

PubMed

Docherty, Neil G; López-Novoa, José M; Arevalo, Miguel; Düwel, Annette; Rodriguez-Peña, Ana; Pérez-Barriocanal, Fernando; Bernabeu, Carmelo; Eleno, Nélida

2006-08-01

Renal ischaemia-reperfusion (I-R) can cause acute tubular necrosis and chronic renal deterioration. Endoglin, an accessory receptor for Transforming Growth Factor-beta1 (TGF-beta1), is expressed on activated endothelium during macrophage maturation and implicated in the control of fibrosis, angiogenesis and inflammation. Endoglin expression was monitored over 14 days after renal I-R in rats. As endoglin-null mice are not viable, the role of endoglin in I-R was studied by comparing renal I-R injury in haploinsufficient mice (Eng(+/-)) and their wild-type littermates (Eng(+/+)). Renal function, morphology and molecular markers of acute renal injury and inflammation were compared. Endoglin mRNA up-regulation in the post-ischaemic kidneys of rats occurred at 12 h after I-R; endoglin protein levels were elevated throughout the study period. Expression was initially localized to the vascular endothelium, then extended to fibrotic and inflamed areas of the interstitium. Two days after I-R, plasma creatinine elevation and acute tubular necrosis were less marked in Eng(+/-) than in Eng(+/+) mice. Significant up-regulation of endoglin protein was found only in the post-ischaemic kidneys of Eng(+/+) mice and coincided with an increased mRNA expression of the TGF-beta1 and collagen IV (alpha1) chain genes. Significant increases in vascular cell adhesion molecule-1 (VCAM-1) and inducible nitric oxide synthase (iNOS) expression, nitrosative stress, myeloperoxidase activity and CD68 staining for macrophages were evident in post-ischaemic kidneys of Eng(+/+), but not Eng(+/-) mice, suggesting that impaired endothelial activation and macrophage maturation may account for the reduced injury in post-ischaemic kidneys of Eng(+/-) mice. Endoglin is up-regulated in the post-ischaemic kidney and endoglin-haploinsufficient mice are protected from renal I-R injury. Endoglin may play a primary role in promoting inflammatory responses following renal I-R.

Effects of endothelin receptor antagonists on renal hemodynamics in angiotensin II-infused rats on high NaCl intake.

PubMed

Saeed, Aso; Dibona, Gerald F; Guron, Gregor

2012-01-01

The aim was to investigate effects of selective endothelin (ET) receptor antagonists on renal hemodynamics and dynamic renal blood flow autoregulation (RBFA) in angiotensin II (Ang II)-infused rats on a high NaCl intake. Sprague-Dawley rats received Ang II (250 ng/kg/min, s.c.) and an 8% NaCl diet for 14 days after which renal clearance experiments were performed. After baseline measurements animals were administered either: (a) saline vehicle; (b) ETA receptor antagonist BQ-123 (30 nmol/kg/min); (c) ETB receptor antagonist BQ-788 (30 nmol/kg/min); or (d) BQ-123 + BQ-788, for six consecutive 20-minute clearance periods. BQ-123 reduced arterial pressure (AP) and selectively increased outer medullary perfusion versus vehicle (p<0.05). These effects were attenuated or abolished by combined BQ-123 and BQ-788. BQ-788 reduced renal blood flow and increased renovascular resistance (p<0.05). Ang II-infused rats on high NaCl intake showed abnormalities in dynamic RBFA characterized by an impaired myogenic response that were not significantly affected by ET receptor antagonists. In hypertensive Ang II-infused rats on a high-NaCl intake selective ETA antagonism with BQ-123 reduced AP and specifically increased OM perfusion and these effects were dependent on intact ETB receptor stimulation. Furthermore, ET receptor antagonists did not attenuate abnormalities in dynamic RBFA. Copyright © 2012 S. Karger AG, Basel.

[Renal arterial spin labeling magnetic resonance imaging in normal adults: a study with a 3.0 T scanner].

PubMed

Zhang, Fan; Zhang, Xuelin; Yang, Li; Shen, Jie; Gao, Wei

2013-10-01

To analyze the renal relative blood flow value (rBFV) and image quality in normal adults using single-shot fast spin echo, flow sensitive invention recovery (SSFSE-FAIR) magnetic resonance (MR) sequence and echo planar imaging, and flow sensitive invention recovery (EPI-FAIR) MR sequence, and assess its value for clinical application in routine renal examination. Forty volunteers (25 male and 15 female adults, aged 30 to 62 years) with normal renal function were included in this prospective study. All the subjects underwent 3.0 Tesla MR scanning using 3 MR scan modes, namely breath-holding EPI-FAIR, breath-holding SSFSE-FAIR and free breathing SSFSE-FAIR. SSFSE-FAIR without breath-holding was capable of differentiating the renal cortex and medulla with the corresponding rBFVs of 111.48∓9.23 and 94.98∓3.38, respectively. Breath-holding SSFSE-FAIR and EPI-FAIR failed to distinguish the borders of the renal cortex and medulla. The EPI-FAIR rBFV of mixed cortex and medulla value was 178.50∓17.17 (95%CI: 167.59, 189.41). Breath-holding SSFSE-FAIR and EPI-FAIR can not distinguish the renal cortex and medulla due to a poor spatial resolution but can be used for rough evaluation of renal blood perfusion. Free breathing SSFSE-FAIR with an improved spatial resolution allows evaluation of the status of renal perfusion of the cortex and medulla.

Metastatic renal cell carcinoma associated with acquired cystic kidney disease 15 years after successful renal transplantation.

PubMed

Lien, Y H; Kam, I; Shanley, P F; Schröter, G P

1991-12-01

Renal cell carcinoma (RCC) is a relatively uncommon cancer in renal transplant patients. From 1968 to 1987, 101 cases of RCC of native kidneys have been reported to the Cincinnati Transplant Tumor Registry. We describe here a case of metastatic RCC associated with acquired cystic kidney disease (ACKD) 15 years after successful renal transplantation. The patient presented with a subcutaneous nodule, which led to discovery of a large primary tumor in the left kidney. ACKD was present in the atrophic right kidney. The reported cases of ACKD-associated RCC in renal transplant recipients were reviewed. Most of these cases are middle-aged men with a long posttransplant course, good graft function, and usage of azathioprine and prednisone as immunosuppressive agents. ACKD can develop or persist and progress to RCC many years after successful renal transplantation. Transplant patients with flank pain, hematuria, or other suspicious symptoms should have imaging studies of their native kidneys.

The Prognostic Importance of Changes in Renal Function during Treatment for Acute Heart Failure Depends on Admission Renal Function

PubMed Central

Reid, Ryan; Ezekowitz, Justin A.; Brown, Paul M.; McAlister, Finlay A.; Rowe, Brian H.; Braam, Branko

2015-01-01

Background Worsening and improving renal function during acute heart failure have been associated with adverse outcomes but few studies have considered the admission level of renal function upon which these changes are superimposed. Objectives The objective of this study was to evaluate definitions that incorporate both admission renal function and change in renal function. Methods 696 patients with acute heart failure with calculable eGFR were classified by admission renal function (Reduced [R, eGFR<45 ml/min] or Preserved [P, eGFR≥45 ml/min]) and change over hospital admission (worsening [WRF]: eGFR ≥20% decline; stable [SRF]; and improving [IRF]: eGFR ≥20% increase). The primary outcome was all-cause mortality. The prevalence of Pres and Red renal function was 47.8% and 52.2%. The frequency of R-WRF, R-SRF, and R-IRF was 11.4%, 28.7%, and 12.1%, respectively; the incidence of P-WRF, P-SRF, and P-IRF was 5.7%, 35.3%, and 6.8%, respectively. Survival was shorter for patients with R-WRF compared to R-IRF (median survival times 13.9 months (95%CI 7.7–24.9) and 32.5 months (95%CI 18.8–56.1), respectively), resulting in an acceleration factor of 2.3 (p = 0.016). Thus, an increase compared with a decrease in renal function was associated with greater than two times longer survival among patients with Reduced renal function. PMID:26380982

Fructokinase activity mediates dehydration-induced renal injury.

PubMed

Roncal Jimenez, Carlos A; Ishimoto, Takuji; Lanaspa, Miguel A; Rivard, Christopher J; Nakagawa, Takahiko; Ejaz, A Ahsan; Cicerchi, Christina; Inaba, Shinichiro; Le, MyPhuong; Miyazaki, Makoto; Glaser, Jason; Correa-Rotter, Ricardo; González, Marvin A; Aragón, Aurora; Wesseling, Catharina; Sánchez-Lozada, Laura G; Johnson, Richard J

2014-08-01

The epidemic of chronic kidney disease in Nicaragua (Mesoamerican nephropathy) has been linked with recurrent dehydration. Here we tested whether recurrent dehydration may cause renal injury by activation of the polyol pathway, resulting in the generation of endogenous fructose in the kidney that might subsequently induce renal injury via metabolism by fructokinase. Wild-type and fructokinase-deficient mice were subjected to recurrent heat-induced dehydration. One group of each genotype was provided water throughout the day and the other group was hydrated at night, after the dehydration. Both groups received the same total hydration in 24 h. Wild-type mice that received delayed hydration developed renal injury, with elevated serum creatinine, increased urinary NGAL, proximal tubular injury, and renal inflammation and fibrosis. This was associated with activation of the polyol pathway, with increased renal cortical sorbitol and fructose levels. Fructokinase-knockout mice with delayed hydration were protected from renal injury. Thus, recurrent dehydration can induce renal injury via a fructokinase-dependent mechanism, likely from the generation of endogenous fructose via the polyol pathway. Access to sufficient water during the dehydration period can protect mice from developing renal injury. These studies provide a potential mechanism for Mesoamerican nephropathy.

Mathematical model of renal elimination of fluid and small ions during hyper- and hypovolemic conditions.

PubMed

Gyenge, Christina C; Bowen, Bruce D; Reed, Rolf K; Bert, Joel L

2003-02-01

This study is concerned with the formulation of a 'kidney module' linked to the plasma compartment of a larger mathematical model previously developed. Combined, these models can be used to predict, amongst other things, fluid and small ion excretion rates by the kidney; information that should prove useful in evaluating values and trends related to whole-body fluid balance for different clinical conditions to establish fluid administration protocols and for educational purposes. The renal module assumes first-order, negative-feedback responses of the kidney to changes in plasma volume and/or plasma sodium content from their normal physiological set points. Direct hormonal influences are not explicitly formulated in this empiric model. The model also considers that the renal excretion rates of small ions other than sodium are proportional to the excretion rate of sodium. As part of the model development two aspects are emphasized (1): the estimation of parameters related to the renal elimination of fluid and small ions, and (2) model validation via comparisons between the model predictions and selected experimental data. For validation, model predictions of the renal dynamics are compared with new experimental data for two cases: plasma overload resulting from external fluid infusion (e.g. infusions of iso-osmolar solutions and/or hypertonic/hyperoncotic saline solutions), and untreated hypo volemic conditions that result from the external loss of blood. The present study demonstrates that the empiric kidney module presented above can provide good short-term predictions with respect to all renal outputs considered here. Physiological implications of the model are also presented. Copyright Acta Anaesthesiologica Scandinavica 47 (2003)

Enhanced renal prostaglandin production in the dog. I. Effects on renal function.

PubMed

Tannenbaum, J; Splawinski, J A; Oates, J A; Nies, A S

1975-01-01

The changes in renal function produced by endogenous synthesis of prostaglandins by the kidney were evaluated by infusing sodium arachidonate, the prescursor of the prostaglandins, into one renal artery of the dog. These changes were compared with those produced by similar infusions on performed prostaglandin (PG) E2 and F2alpha.PGE2given at 0.01-0.3 mug/kg min--1 produced dose-related increases in urine flow, sodium and potassium excretion, free water clearance, and renal blood flow. The glomerular filtration rage increased only at the lowest dose and the calculated filtration fraction fell. Arachidonic acid at 1.0-30.0 mug/kg min--1 similarly produced dose-related increases in electrolyte excretion, but the increase in renal blood flow was much less than that produced by PGE2 and there were no changes in glomerular filtration rate, filtration fraction, or free water clearances. PGF2alpha had essentially no effects at infusion rates of 0.03-1.0 mug/kg min--1. All renal effects of arachidonic acid were inhibited by simultaneous infusions of an inhibitor of prostaglandin synthetase, 5, 8, 11,14-eicosatetraynoic acid (20:4). None of the effects produced by PGE2 were inhibited by 20:4. These results indicate that enhanced endogenous renal prostaglandin synthesis, which can be produced by arachidonate infusion, results in significant alterations of renal function. This finding strengthens the hypothesis that renal prostaglandins formed in vivo have physiological importance as regulators of renal function.

Adrenalectomy prevents renal ischemia-reperfusion injury.

PubMed

Ramírez, Victoria; Trujillo, Joyce; Valdes, Rafael; Uribe, Norma; Cruz, Cristino; Gamba, Gerardo; Bobadilla, Norma A

2009-10-01

Spironolactone treatment prevents renal damage induced by ischemia-reperfusion (I/R), suggesting that renoprotection conferred by spironolactone is mediated by mineralocorticoid receptor (MR) blockade. It is possible, however, that this effect is due to other mechanisms. Therefore, this study evaluated whether adrenalectomy prevented renal damage induced by I/R. Three groups of Wistar rats were studied: 1) a group subjected to a sham surgery, 2) a group subjected to bilateral I/R, and 3) a group of rats in which adrenal glands were removed 3 days before induction of I/R. As expected, I/R resulted in renal dysfunction and severe tubular injury that was associated with a significant increase in tubular damage markers. In contrast, there was no renal dysfunction or tubular injury in rats that were adrenalectomized before I/R. These effects were demonstrated by normalization of glomerular filtration rate, markers of oxidative stress, and tubular injury markers in adrenalectomized rats. The renoprotection observed was associated with the reestablishment of nitric oxide metabolites, increased endothelial nitric oxide synthase expression and its activating phosphorylation, as well as normalization of Rho-kinase expression and ET(A) mRNA levels. Our results show that aldosterone plays a central role in the pathogenesis of renal damage induced by I/R and that MR blockade may be a promising strategy that opens a new therapeutic option for preventing acute renal injury.

Renal in-patient ward nurse experience and job satisfaction: A qualitative study.

PubMed

McKenzie, Aisha Tamika; Addis, Gulen

2018-06-13

The aim of this study was to examine the experience of registered nurses working in renal inpatients wards at an acute National Health Service (NHS) hospital Trust. Nurse perceptions of their experience particularly in relation to job satisfaction was analysed. Increased understanding of workplace organisation and culture can contribute to improved nurse work experience and better patient care. Worldwide many studies conducted on nurse experience and job satisfaction show that job satisfaction level varies across work settings so analysis of job satisfaction at a local level such as in a ward is important for producing useful analysis and recommendations. Using purposive sampling, semi structured individual interviews were conducted on twelve registered nurses working on renal inpatient wards. The study identified three themes: safe care, organisational culture and work environment. Although staffing was identified as a key element to providing safe care maintaining adequate staffing levels remained a challenge. Whilst there were opportunities for professional development more support is needed for newly qualified nurses. Findings highlighted that renal patients were complex. It is important to maintain adequate staffing levels. Good clinical leadership is required to support and develop the positive experience of nurses. The high turnover of newly qualified nurses is a particular problem and nurse managers need to develop strategies to retain such nurses. Regular audits on staffing levels as part of improving workforce planning and patient safety need to be conducted. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Renal and adrenal tumors: Pathology, radiology, ultrasonography, therapy, immunology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lohr, E.; Leder, L.D.

1987-01-01

Aspects as diverse as radiology, pathology, urology, pediatrics and immunology have been brought together in one book. The most up-do-date methods of tumor diagnosis by CT, NMR, and ultrasound are covered, as are methods of catheter embolization and radiation techniques in case of primarily inoperable tumors. Contents: Pathology of Renal and Adrenal Neoplasms; Ultrasound Diagnosis of Renal and Pararenal Tumors; Computed-Body-Tomography of Renal Carcinoma and Perirenal Masses; Magnetic Resonance Imaging of Renal Mass Lesions; I-125 Embolotherapy of Renal Tumors; Adrenal Mass Lesions in Infants and Children; Computed Tomography of the Adrenal Glands; Scintigraphic Studies of Renal and Adrenal Function; Surgicalmore » Management of Renal Cell Carcinoma; Operative Therapy of Nephroblastoma; Nonoperative Treatment of Renal Cell Carcinoma; Prenatal Wilms' Tumor; Congenital Neuroblastoma; Nonsurgical Management of Wilms' Tumor; Immunologic Aspects of Malignant Renal Disease.« less

Application of Onyx for Renal Arteriovenous Malformation With First Case Report of a Renal Hyperdense Striation Sign

PubMed Central

Juan, Yu-Hsiang; Lin, Yu-Ching; Sheng, Ting-Wen; Cheung, Yun-Chung; Ng, Shu-Hang; Yu, Chin-Wei; Wong, Ho-Fai

2015-01-01

Abstract Onyx is an emerging treatment modality for visceral vascular malformations, especially in cases in which delicate nidal penetration of the arteriovenous malformation (AVM) is desired. A computed tomography (CT) image presentation of hyperdense striations along the renal medulla secondary to the tantalum powder has not been previously reported. A 65-year-old woman presented to our institution with intermittent gross hematuria and left flank pain for 10 days. Both CT and conventional angiographies confirmed cirsoid-type renal AVM, which was successfully treated with Onyx. Follow-up CT after treatment revealed presence of hyperdense striations along the renal medulla, which resolved during later image follow-up. Despite its frequent usage in neural intervention, the application of Onyx in visceral AVM is gradually gaining interest, especially in cases in which delicate nidal penetration of the AVM is desired. Renal hyperdense striation sign should be recognized to avoid confusion with embolizer migration, and further studies in patients with renal function impairment may be helpful in understanding its influence of renal function. PMID:26426661

Renal Cysts

MedlinePlus

... inside the renal cysts. Your doctor may use ultrasound imaging to monitor renal cysts for any changes over ... Related Articles and Media Ultrasound - Abdomen Children's (Pediatric) Ultrasound - Abdomen Magnetic Resonance Imaging (MRI) - Body Ultrasound - Pelvis Children's (Pediatric) Nuclear Medicine ...

Association Between the Use of Proton Pump Inhibitors and the Risk of ESRD in Renal Diseases: A Population-Based, Case-Control Study

PubMed Central

Peng, Yen-Chun; Lin, Cheng-Li; Yeh, Hong-Zen; Chang, Chi-Sen; Wu, Yu-Lin; Kao, Chia-Hung

2016-01-01

Abstract Proton pump inhibitors (PPIs) use may be associated with nephritis and acute renal injury. The risk of PPIs and deterioration of renal function, in patients with renal diseases, needs to be investigated. A case-control study was conducted in a nation-wide data setting from the Taiwan National Health Insurance Research Database (NHIRD). This case-control study used data extracted from NHIRD between the years 2006 and 2011. We used propensity scores to match 3808 patients suffering from renal diseases (ICD-9-CM codes 580–589), with patients (aged ≥20 years) who had had a recent diagnosis of end-stage renal diseases (ESRDs) and had undertaken renal replacement therapy during the period of 2006 to 2011. The 3808 control subjects were selected from people who had a history of renal diseases, but no ESRD. The risk of ESRD in patients with renal diseases and PPIs use was estimated by using odds ratios (ORs) and 95% confidence intervals (CI). The use of a PPIs was associated with a significantly higher risk of ESRD (adjusted OR = 1.88, 95% CI = 1.71–2.06) in renal disease patients. Of all the types of PPI combined, the adjusted OR was 1.92 (95% CI = 1.74–2.13) for those on <100 cumulative DDD and was 1.74-fold (95% CI = 1.52–2.00) for those on ≥100 cumulative DDD. PPIs use is associated with the risk of ESRD in patients with renal diseases. It is necessary that appropriate prescription of PPIs coordinated with the close monitoring renal function of patients diagnosed with renal disease. PMID:27082596

Renal function, renal volume, and blood pressure in infants with antecedent of antenatal steroids.

PubMed

Carballo-Magdaleno, Deyanira; Guízar-Mendoza, Juan M; Amador-Licona, Norma; Domínguez-Domínguez, Víctor

2011-10-01

Steroids have been used for more than 20 years in preterm infants to induce pulmonary maturity; however, some long-term effects have been reported, such as insulin resistance and elevation of blood pressure. The aim of our study was to compare renal volume, renal function, and blood pressure in infants between 12-36 months of age with and without antecedent of antenatal steroid treatment. This was a cross-sectional study comprised of three groups of infants (n = 30, respectively): preterm infants with and without antecedent of receiving antenatal steroids, respectively, and full-term infants. Blood pressure, renal volume, glomerular filtration rate, and tubular function were measured. Blood pressure and cystatin C levels and glomerular filtration rate were higher in both groups of preterm infants than in the control group (p < 0.01). However, no difference in any of the tested variables between the steroid and non-steroid group of preterm infants. Renal volume was similar in preterm and control infants. Based on these results, we conclude that prematurity independent of antenatal steroid use is associated with higher cystatin C and blood pressure levels and a higher glomerular filtration rate in infants between 12-36 months of age.

Anemia and Long-Term Renal Prognosis in Patients with Post-Renal Acute Kidney Injury of Nonmalignant Cause.

PubMed

Sasaki, Sho; Kawarazaki, Hiroo; Hasegawa, Takeshi; Shima, Hideaki; Naganuma, Toshihide; Shibagaki, Yugo

2017-01-01

The renal prognosis of post-renal acute kidney injury (PoR-AKI) has not been verified so far. The objective of this study was to assess the association of baseline anemia with long-term renal prognosis in patients with PoR-AKI. We performed a multicenter retrospective cohort study. Consecutive adult patients from December 2006 to February 2010, who met the requirements as mentioned in the definition of PoR-AKI, were included. Patients without data on baseline renal function and at 6 months after PoR-AKI were excluded. We set baseline hemoglobin (Hb) level (g/dl) as the main exposure to be tested. The main outcome measure was long-term renal prognosis as determined by the difference between proximate estimated glomerular filtration rate (eGFR) at 6 months after diagnosis of PoR-AKI and baseline eGFR prior to the occurrence of the present PoR-AKI (ΔeGFR after 6 months) using the general linear model. We included 136 patients with PoR-AKI. The most frequent cause of PoR-AKI was malignancy, accounting for 39.0% (n = 53) of cases. Multivariate analysis adjusted for possible confounders showed that ΔeGFR after 6 months significantly changed by -4.28 ml/min/1.73 m2 for every 1 g/dl lower Hb at diagnosis (95% CI 1.86-6.69, p < 0.01). An additional multivariate analysis that was stratified by the presence or absence of malignancy as the cause of PoR-AKI yielded the same significant result only in the stratum of the nonmalignant cause of PoR-AKI. Patients with a nonmalignant cause of PoR-AKI who have baseline anemia may have poor long-term renal prognosis. In these cases, close observation of renal function after renal recovery may be required. © 2016 S. Karger AG, Basel.

Longitudinal changes in kidney parenchymal volume associated with renal artery stenting.

PubMed

Modrall, J Gregory; Timaran, Carlos H; Rosero, Eric B; Chung, Jayer; Plummer, Mitchell; Valentine, R James; Trimmer, Clayton

2012-03-01

This study assessed the longitudinal changes in renal volume after renal artery stenting (RAS) to determine if renal mass is preserved by stenting. The study cohort consisted of 38 patients with longitudinal imaging available for renal volume quantification before and after RAS. Renal volume was estimated as (kidney length) × (width) × (depth/2) based on preoperative renal imaging. For each patient, the clinical response of blood pressure (BP) and renal function to RAS was categorized according to modified American Heart Association guidelines. Changes in renal volume were assessed using paired nonparametric analyses. The cohort was a median age of 69 years (interquartile range [IQR], 60-74 years). A favorable BP response was observed in 11 of 38 patients (28.9%). At a median interval between imaging studies of 21 months (IQR, 13-32 months), ipsilateral renal volume was significantly increased from baseline (146.8 vs 133.8 cm(3);P = .02). This represents a 6.9% relative increase in ipsilateral kidney volume from baseline. A significant negative correlation between preoperative renal volume and the relative change in renal volume postoperatively (r = -0.42; P = .0055) suggests that smaller kidneys experienced the greatest gains in renal volume after stenting. It is noteworthy that the 25 patients with no change in BP or renal function-clinical failures using traditional definitions-experienced a 12% relative increase in ipsilateral renal volume after RAS. Multivariate analysis determined that stable or improved renal volume after stenting was an independent predictor of stable or improved long-term renal function (odds ratio, 0.008; 95% confidence interval, 0.000-0.206; P = .004). These data lend credence to the belief that RAS preserves renal mass in some patients. This benefit of RAS even extends to those patients who would be considered treatment failures by traditional definitions. Patients with stable or increased renal volume after RAS had more stable renal

Renal pelvis urothelial carcinoma of the upper moiety in complete right renal duplex: a case report.

PubMed

Zhang, Yiran; Yu, Quanfeng; Zhang, Zhihong; Liu, Ranlu; Xu, Yong

2015-01-01

Urothelial carcinoma (UC) originated from renal pelvis is the common tumor of the urinary system, however, neoplasia of the renal pelvis in duplex kidneys is extremely rare, especially in the complete renal and ureteral duplex cases. We present the first case of renal pelvis UC of the upper moiety in a complete right renal duplex. This male patient has bilateral complete renal and ureteral duplex. To the best of our knowledge, this is the first reported case of renal pelvis UC in a complete renal duplex system. After this experience we feel that the diagnosis of renal pelvis UC in duplex kidneys is not so easy, and once the diagnosis is determined, the whole renal duplex units and bladder cuff or ectopic orifice should be excised radically.

Technical aspects of renal denervation in end-stage renal disease patients with challenging anatomy.

PubMed

Spinelli, Alessio; Da Ros, Valerio; Morosetti, Daniele; Onofrio, Silvia D; Rovella, Valentina; Di Daniele, Nicola; Simonetti, Giovanni

2014-01-01

We describe our preliminary experience with percutaneous renal denervation in end-stage renal disease patients with resistant hypertension and challenging anatomy, in terms of the feasibility, safety, and efficacy of this procedure. Four patients with end-stage renal disease patients with resistant hypertension (mean hemodialysis time, 2.3 years) who had been taking at least four antihypertensive medications underwent percutaneous renal denervation. Renal artery eligibility included the absence of prior renal artery interventions, vessel stenosis <70%, or extended calcifications (more than 30% of the vessel circumference). No cut off values of vessel diameter were used. All patients were successfully treated with no intra- or postprocedural complications, and all showed 24-hour ambulatory blood pressure reduction at the 12-month follow-up. Percutaneous renal denervation is a feasible approach for end-stage renal disease patients with resistant hypertension with encouraging short-term preliminary results in terms of procedural efficacy and safety.

Correlation analysis of renal ultrasound elastography and clinical and pathological changes in patients with chronic kidney disease
.

PubMed

Peng, Lingyan; Zhong, Tingting; Fan, Qiuling; Liu, Yanjun; Wang, Xuemei; Wang, Lining

2017-06-01

To analyze the correlations of renal tissue elastography with clinical biochemical indicators and pathological changes in patients with chronic kidney disease (CKD) as well as to explore the potential for renal tissue elastography as a new, noninvasive method for the dynamic monitoring of renal disease progression, efficacy assessment, and prognosis evaluation. Patients admitted to the Department of Nephrology of the First Affiliated Hospital of China Medical University from August 2014 to January 2015 who had undergone renal biopsies were selected. A total of 113 patients with CKD and 16 healthy controls were enrolled in this study, including 61 males and 52 females. In total, 23 cases of IgA nephropathy, 39 cases of membranous nephropathy, 15 cases of minimal-change nephropathy (MCN), and 7 cases of focal segmental glomerulosclerosis were included. The Young's moduli (YM) of the renal cortex and medulla were measured using an AixPlorer Doppler ultrasound with full digital color from Supersonic Imagine. The correlations between the YM of renal tissue and clinical biochemical indicators of blood and urine and the differences in Young's moduli among the different pathological changes in the patients with CKD were analyzed. The YM of the CKD patients was significantly higher than that of the control group (p < 0.05), and the YM of the renal cortex and medulla gradually increased with the progression of CKD. The YM of the renal cortex in the stage-G5 CKD patients was significantly higher than that of the CKD patients in stages G1 - G3 (p < 0.05). The YM of the renal medulla of the CKD patients in stages G3 - 5 was significantly higher than that of the CKD patients in stages G1 - G2. On univariate analysis, the YM of the renal cortex was correlated with systolic blood pressure, serum creatinine, cystatin C, serum albumin, serum phosphorus, calcium and phosphorus products, uric acid, iPTH, urinary N-acetyl-glucosaminidase (NAG), eGFR, and hemoglobin levels. And

Ensete superbum ameliorates renal dysfunction in experimental diabetes mellitus.

PubMed

Sreekutty, M S; Mini, S

2016-01-01

Hyperglycemia mediated oxidative stress plays a key role in the pathogenesis of diabetic complications like nephropathy. In the present study, we evaluated the effect of ethanolic extract of Ensete superbum seeds (ESSE) on renal dysfunction and oxidative stress in streptozotocin-induced diabetic rats. Glucose, HbA1c, total protein, albumin, renal function markers (urea, uric acid and creatinine), and lipid peroxidation levels were evaluated. Renal enzymatic and non-enzymatic antioxidants were examined along with renal histopathological study. ESSE (400 mg/kg BW t) administration reduced glucose and HbA1c, and improved serum total protein and albumin in diabetic rats. ESSE in diabetic rats recorded decrement in renal function markers and renal lipid peroxidation products along with significant increment in enzymatic and non-enzymatic antioxidants. Renal morphological abnormalities of diabetic rats were markedly ameliorated by E. superbum. These results suggest that the antioxidant effect of E. superbum could ameliorate oxidative stress and delay/prevent the progress of diabetic nephropathy in diabetes mellitus.

A randomized, controlled, double-blind crossover study on the effects of 2-L infusions of 0.9% saline and plasma-lyte® 148 on renal blood flow velocity and renal cortical tissue perfusion in healthy volunteers.

PubMed

Chowdhury, Abeed H; Cox, Eleanor F; Francis, Susan T; Lobo, Dileep N

2012-07-01

We compared the effects of intravenous infusions of 0.9% saline ([Cl] 154 mmol/L) and Plasma-Lyte 148 ([Cl] 98 mmol/L, Baxter Healthcare) on renal blood flow velocity and perfusion in humans using magnetic resonance imaging (MRI). Animal experiments suggest that hyperchloremia resulting from 0.9% saline infusion may affect renal hemodynamics adversely, a phenomenon not studied in humans. Twelve healthy adult male subjects received 2-L intravenous infusions over 1 hour of 0.9% saline or Plasma-Lyte 148 in a randomized, double-blind manner. Crossover studies were performed 7 to 10 days apart. MRI scanning proceeded for 90 minutes after commencement of infusion to measure renal artery blood flow velocity and renal cortical perfusion. Blood was sampled and weight recorded hourly for 4 hours. Sustained hyperchloremia was seen with saline but not with Plasma-Lyte 148 (P < 0.0001), and fall in strong ion difference was greater with the former (P = 0.025). Blood volume changes were identical (P = 0.867), but there was greater expansion of the extravascular fluid volume after saline (P = 0.029). There was a significant reduction in mean renal artery flow velocity (P = 0.045) and renal cortical tissue perfusion (P = 0.008) from baseline after saline, but not after Plasma-Lyte 148. There was no difference in concentrations of urinary neutrophil gelatinase-associated lipocalin after the 2 infusions (P = 0.917). This is the first human study to demonstrate that intravenous infusion of 0.9% saline results in reductions in renal blood flow velocity and renal cortical tissue perfusion. This has implications for intravenous fluid therapy in perioperative and critically ill patients. NCT01087853.

Unmasking glucose metabolism alterations in stable renal transplant recipients: a multicenter study.

PubMed

Delgado, Patricia; Diaz, Juan Manuel; Silva, Irene; Osorio, José M; Osuna, Antonio; Bayés, Beatriz; Lauzurica, Ricardo; Arellano, Edgar; Campistol, Jose Maria; Dominguez, Rosa; Gómez-Alamillo, Carlos; Ibernon, Meritxell; Moreso, Francisco; Benitez, Rocio; Lampreave, Ildefonso; Porrini, Esteban; Torres, Armando

2008-05-01

Emerging information indicates that glucose metabolism alterations are common after renal transplantation and are associated with carotid atheromatosis. The aims of this study were to investigate the prevalence of different glucose metabolism alterations in stable recipients as well as the factors related to the condition. A multicenter, cross-sectional study was conducted of 374 renal transplant recipients without pre- or posttransplantation diabetes. A standard 75-g oral glucose tolerance test was performed. Glucose metabolism alterations were present in 119 (31.8%) recipients: 92 (24.6%) with an abnormal oral glucose tolerance test and 27 (7.2%) with isolated impaired fasting glucose. The most common disorder was impaired glucose tolerance (17.9%), and an abnormal oral glucose tolerance test was observed for 21.5% of recipients with a normal fasting glucose. By multivariate analysis, age, prednisone dosage, triglyceride/high-density lipoprotein cholesterol ratio, and beta blocker use were shown to be factors related to glucose metabolism alterations. Remarkably, triglyceride levels, triglyceride/high-density lipoprotein cholesterol ratio, and the proportion of recipients with impaired fasting glucose were already higher throughout the first posttransplantation year in recipients with a current glucose metabolism alteration as compared with those without the condition. Glucose metabolism alterations are common in stable renal transplant recipients, and an oral glucose tolerance test is required for its detection. They are associated with a worse metabolic profile, which is already present during the first posttransplantation year. These findings may help planning strategies for early detection and intervention.

Long-term renal outcome in patients with malignant hypertension: a retrospective cohort study

PubMed Central

2012-01-01

Background Malignant hypertension is frequently complicated by renal insufficiency. Although the survival of this hypertensive emergency has improved, recent data on renal outcome and its predictors are lacking. We assessed renal outcome and its predictors in patients with malignant hypertension. Methods Retrospective analysis of patients admitted with malignant hypertension in Amsterdam, the Netherlands between August 1992–January 2010. Follow-up data on vital status, renal function and blood pressure (BP) were obtained from the outpatient department and from general practitioners. The primary composite endpoint was end-stage renal disease (ESRD) defined as the start of kidney replacement therapy (KRT) or ≥ 50% decline of estimated glomerular filtration rate (eGFR). The secondary endpoint was all cause mortality. Results A total of 120 patients admitted with malignant hypertension were included. After a median follow-up period of 67 months (IQR 28 to 108 months) the primary endpoint was reached by 37 (31%) patients, whereas 18 patients (15%) reached the secondary endpoint. Twenty-nine (24%) patients started KRT and 8 patients (7%) had an eGFR decline ≥ 50%. After the acute phase (> 3 months after admission), initial serum creatinine and follow-up BP were the main predictors of future ESRD with hazard ratios of 6.1 (95% CI, 2.2–17) for patients with initial serum creatinine ≥ 175 μmol /L and 4.3 (95% CI, 1.4–14) for patients with uncontrolled hypertension. Conclusions Progressive renal function decline leading to ESRD remains a major threat to patients with malignant hypertension. BP control during follow-up was an important modifiable predictor of renal outcome. PMID:22846257

Value of imaging studies after a first febrile urinary tract infection in young children: data from Italian renal infection study 1.

PubMed

Montini, Giovanni; Zucchetta, Pietro; Tomasi, Lisanna; Talenti, Enrico; Rigamonti, Waifro; Picco, Giorgio; Ballan, Alberto; Zucchini, Andrea; Serra, Laura; Canella, Vanna; Gheno, Marta; Venturoli, Andrea; Ranieri, Marco; Caddia, Valeria; Carasi, Carla; Dall'amico, Roberto; Hewitt, Ian

2009-02-01

We examined the diagnostic accuracy of routine imaging studies (ultrasonography and micturating cystography) for predicting long-term parenchymal renal damage after a first febrile urinary tract infection. This study addressed the secondary objective of a prospective trial evaluating different antibiotic regimens for the treatment of acute pyelonephritis. Data for 300 children < or =2 years of age, with normal prenatal ultrasound results, who completed the diagnostic follow-up evaluation (ultrasonography and technetium-99m-dimercaptosuccinic acid scanning within 10 days, cystography within 2 months, and repeat technetium-99m-dimercaptosuccinic acid scanning at 12 months to detect scarring) were analyzed. Outcome measures were sensitivity, specificity, and negative and positive predictive values for ultrasonography and cystography in predicting parenchymal renal damage on the 12-month technetium-99m-dimercaptosuccinic acid scans. The kidneys and urinary tracts were mostly normal. The acute technetium-99m-dimercaptosuccinic acid scans showed pyelonephritis in 54% of cases. Renal scarring developed in 15% of cases. The ultrasonographic and cystographic findings were poor predictors of long-term damage, showing minor sonographic abnormalities for 12 and reflux for 23 of the 45 children who subsequently developed scarring. The benefit of performing ultrasonography and scintigraphy in the acute phase or cystourethrography is minimal. Our findings support (1) technetium-99m-dimercaptosuccinic acid scintigraphy 6 months after infection to detect scarring that may be related to long-term hypertension, proteinuria, and renal function impairment (although the degree of scarring was generally minor and did not impair renal function) and (2) continued surveillance to identify recurrent urinary tract infections that may warrant further investigation.

Effects of Hyperbaric Oxygen Treatment on Renal System.

PubMed

Tezcan, Orhan; Caliskan, Ahmet; Demirtas, Sinan; Yavuz, Celal; Kuyumcu, Mahir; Nergiz, Yusuf; Guzel, Abdulmenap; Karahan, Oguz; Ari, Seyhmus; Soker, Sevda; Yalinkilic, Ibrahim; Turkdogan, Kenan Ahmet

2017-01-01

Hyperbaric oxygen (HBO) treatment is steadily increasing as a therapeutic modality for various types of diseases. Although good clinical outcomes were reported with HBO treatment for various diseases, the multisystemic effects of this modality are still unclear. This study aimed to investigate the renal effects of HBO experimentally. Fourteen New Zealand White rabbits were divided into 2 groups randomly as the control group and the study group. The study group received HBO treatment for 28 days (100% oxygen at 2.5 atmospheres for 90 minutes daily) and the control group was used to obtain normal renal tissue of the animal genus. After the intervention period, venous blood samples were obtained, and renal tissue samples were harvested for comparisons. Normal histological morphology was determined with Masson trichrome staining and periodic acid-Schiff staining in the control group. Atrophic glomerular structures, vacuolated tubule cells, and degeneration were detected in the renal samples of the study group with Masson trichrome staining. Additionally, flattening was observed on the brush borders of the proximal tubules, and tubular dilatation was visualized with periodic acid-Schiff staining. The histopathologic disruption of renal morphology was verified with detection of significantly elevated kidney function laboratory biomarkers in the study group. Our findings suggests that HBO has adverse effects on renal glomerulus and proximal tubules. However, the functional effects of this alteration should be investigated with further studies.

[Study on the role of the tubule in renal vasoconstriction induced by cyclosporine].

PubMed

Camaño Páez, S; Lázaro Fernández, A; Callejas Martínez, R; Lázaro Manero, J A; Castilla Barba, M; Martín-Vasallo, P; Martínez Escandell, A; Tejedor Jorge, A

2008-01-01

Cyclosporine (CyA) has proved to induce cell apoptosis on cultured proximal tubule cells. However, there is no much data about the in vivo functional consequences of this injury or the long time observed CyA-induced renal vasoconstriction. In a swine model of subacute CyA nephrotoxicity (10 mg/ Kg. dx 15 days), we performed a right nephrectomy, followed by left renal artery, vein and ureter catheterisati8n. After inducing water diuresis, three clearance periods of 15 minutes were performed before and after a furosemide 1 mg/kg infusion. Plasma and urine electrolytes, blood gas, acid excretion, plasma renin activity and aldosterone concentration, GFR, RPF, RBF, intra-renal vascular resistances, glomerular filtration pressure, distal Cl- delivery, water clearance and TTKG were measured or estimated on 7 control and 7 treated animals. Right kidney was processed for NaKATPase activity and immunostaining. Treated animals presented detaching proximal cells, luminal blebbing and loss of tight junctions. Cortical but not medullar sodium pump was internalised and partially inactive. Treated animals showed much lower fractional excretions of Na+, with significantly higher distal fractional reabsorption of Cl. Distal shift in fluid load resulted in a significant rise in renal O2 consumption, and modifications in the global renal estequiometry of Na+ transport/O2 uptake. Several consequences followed this situation: preglomerular resistances increased 3 times with only minor changes in postglomerular resistances and renal blood and plasma flow were significantly reduced. Furosemide partially reversed these effects. A slight increase in fractional filtration prevented GFR differences to become statistically significant. subacute CyA treatment even al doses not modifying GFR, may cause proximal tubule Na+ transport impairment, resulting in increased rates of distal delivery and absorption of fluid load. Renal uptake of O2 may be increased and tubule glomerular feedback should be

Contrast medium administration and image acquisition parameters in renal CT angiography: what radiologists need to know

PubMed Central

Saade, Charbel; Deeb, Ibrahim Alsheikh; Mohamad, Maha; Al-Mohiy, Hussain; El-Merhi, Fadi

2016-01-01

Over the last decade, exponential advances in computed tomography (CT) technology have resulted in improved spatial and temporal resolution. Faster image acquisition enabled renal CT angiography to become a viable and effective noninvasive alternative in diagnosing renal vascular pathologies. However, with these advances, new challenges in contrast media administration have emerged. Poor synchronization between scanner and contrast media administration have reduced the consistency in image quality with poor spatial and contrast resolution. Comprehensive understanding of contrast media dynamics is essential in the design and implementation of contrast administration and image acquisition protocols. This review includes an overview of the parameters affecting renal artery opacification and current protocol strategies to achieve optimal image quality during renal CT angiography with iodinated contrast media, with current safety issues highlighted. PMID:26728701

Physicians attitudes toward living non-related renal transplantation (LNRRT). The Living non-Related Renal Transplant Study Group.

PubMed

1993-06-01

Renal transplantation is considered now the definitive treatment for patients with end-stage renal disease (ESRD). Unfortunately, the worldwide shortage of kidneys remains the most important obstacle to transplantation. In developing countries, including those of the Middle East, the shortage is even more dramatic. Despite great efforts to establish and maintain successful transplant centers, the number of kidneys that have been transplanted in the last few years has actually declined. The lack of a dependable kidney source played well into the hands of unscrupulous entrepreneurs who started brokerage of organs for profit. In this practice, patients with ESRD travel to India and other countries to purchase kidneys from living genetically non-related poor donors. Patient care was therefore relegated to the laws of the marketplace and both patients and donors were exploited to maximize profit. Additionally, reported results of this type of transplantation were inferior to those of other types of transplantation. Not unexpectedly, these issues have created intense controversy among transplant physicians and the general public in which moral, ethical and medical issues were debated. To investigate these issues, we conducted a large multicenter study in Saudi Arabia, Bahrain and Egypt. In the first phase of this study, we surveyed 50 institutions regarding their attitude toward LNRRT, of which 22 responded. The results of our survey clearly show that patients with ESRD take the initiative in seeking LNRRT despite physician discouragement and significant financial burden.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term safety of tiotropium/olodaterol Respimat® in patients with moderate-to-very severe COPD and renal impairment in the TONADO® studies.

PubMed

LaForce, Craig; Derom, Eric; Bothner, Ulrich; Kloer, Isabel M; Trampisch, Matthias; Buhl, Roland

2018-01-01

The safety, lung function efficacy, and symptomatic benefits of combined tiotropium and olodaterol in patients with COPD were established in the 1-year TONADO ® studies (NCT01431274; NCT01431287). As tiotropium is predominantly excreted by the kidneys, the long-term safety profile of tiotropium/olodaterol was investigated in patients with renal impairment in a prespecified safety analysis of the TONADO studies. These were 2 replicate, randomized, double-blind, parallel-group, 52-week Phase III studies that assessed tiotropium/olodaterol compared with tiotropium or olodaterol alone (all via Respimat ® ) in patients with moderate-to-very severe COPD. In this analysis, renal impairment was defined as mild (creatinine clearance [CLcr] 60-89 mL/min), moderate (CLcr 30-59 mL/min) or severe (CLcr 15-29 mL/min). Adverse events (AEs) were pooled from both studies. Of 3,041 patients included in this analysis, 1,333 (43.8%) had mild, 404 (13.3%) had moderate, and 5 (0.2%) had severe renal impairment; these were distributed equally between treatment groups. Almost one-quarter of all treated patients (23.4%) had a history of cardiac disorder, 45.6% had hypertension, and 13.3% had glucose metabolism disorders, including diabetes. AEs with olodaterol, tiotropium, and tiotropium/olodaterol occurred in 75.1%, 70.8%, and 72.0% of patients with no renal impairment, 75.7%, 74.0%, and 73.3% with mild renal impairment, and 84.3%, 79.5%, and 79.7% with moderate renal impairment, respectively. There was no notable effect of renal impairment on the proportion of patients with an AE, and no differences were observed between tiotropium/olodaterol versus the monocomponents. There was no difference in the incidence of major adverse cardiac events, renal and urinary tract AEs, or potential anticholinergic effects with increasing severity of renal impairment. Over half the patients enrolled in the TONADO studies had renal impairment, and there was a high level of pre-existing cardiovascular

[Ethical and legal issues concerning renal replacement therapy withdrawal or withholding].

PubMed

Radziszewski, Andrzej; Stompór, Tomasz; Gajda, Mariusz; Sułowicz, Władysław

2006-01-01

Rapid and dynamic increase of the number of patients that need different forms of renal replacement therapy can be noticed in the developed countries. This increase is associated with increased number of patients with 'diseases of modern civilization', such as diabetes and hypertension, which lead to kidney complications (e.g. diabetic and hypertensive nephropathy). Improved long-term care (especially diabetic and cardiologic) allows these patients to survive longer and to reach the stage of end-stage renal disease. This leads to increasing age and morbidity of patients treated with dialysis. In many cases, due to extremely advanced level of co-morbidity patients on dialysis are exposed to extreme level of suffering and unacceptably low quality of life. Persistent continuing of renal replacement therapy under such circumstances (with no hope for recovery or improvement) raises also some economical issues, especially in the context of permanent crisis and shortage of resources in health systems of most countries in the world. In this review the current practice concerning withdrawal or withholding of renal replacement therapy as well as some legal and ethical issues of this practice are discussed.

Case-control study of hydrocarbon exposures in patients with renal cell carcinoma.

PubMed Central

Sharpe, C R; Rochon, J E; Adam, J M; Suissa, S

1989-01-01

A retrospective case-control study tested the hypothesis that exposure to hydrocarbon combustion products is associated with the development of renal cell carcinoma. One control per case, matched for sex, date of birth (within 5 years) and urologist, was chosen. Controls were patients who presented with hematuria and were shown not to have a urinary tract tumour. A total of 164 cases and 161 controls responded to mailed questionnaires and telephone interviews. Smoking more than 20 cigarettes per day was associated with the presence of metastatic renal cell carcinoma (p less than 0.001). Exposure to burning coal was associated with an increased relative risk of the disease but only when the exposure occurred between the ages of 10 and 24 years (p less than 0.05). Dose-response relations were demonstrated for intensity of exposure (p less than 0.025) and duration of occupational exposure (p less than 0.05). The distribution of latent periods from first exposure to diagnosis was bimodal, with one mode at 21 to 30 years and another at 41 to 50 years. Occupational exposure to tar or pitch or both was also associated with an increased relative risk of renal cell carcinoma (p less than 0.05). PMID:2720514

Rodent renal structure differs among species.

PubMed

Ichii, Osamu; Yabuki, Akira; Ojima, Toshimichi; Matsumoto, Mitsuharu; Suzuki, Shusaku

2006-05-01

In the present study, we histologically and morphometrically investigated species differences in renal structure using laboratory rodents (mice, gerbils, hamsters, rats, and guinea pigs). Morphometric parameters were as follows, 1) diameter of the cortical renal corpuscles, 2) diameter of the juxtamedullary renal corpuscles, 3) percentage of the renal corpuscles with a cuboidal parietal layer, 4) number of nuclei in proximal convoluted tubules (PCTs) per unit area of cortex, 5) semi-quantitative score of the periodic acid-Schiff (PAS) -positive granules in PCTs, and 6) semi-quantitative score of the PAS-positive granules in proximal straight tubules (PSTs). Significant species differences were detected for each parameter, and particularly severe differences were observed in the PAS-positive granules of PCTs and PSTs. Granular scores varied among species and sexes. Vacuolar structures that did not stain with PAS or hematoxylin-eosin were observed in the renal proximal tubules. The appearance and localization of these vacuolar structures differed remarkably between species and sexes.

3D-printed soft-tissue physical models of renal malignancies for individualized surgical simulation: a feasibility study.

PubMed

Maddox, Michael M; Feibus, Allison; Liu, James; Wang, Julie; Thomas, Raju; Silberstein, Jonathan L

2018-03-01

To construct patient-specific physical three-dimensional (3D) models of renal units with materials that approximates the properties of renal tissue to allow pre-operative and robotic training surgical simulation, 3D physical kidney models were created (3DSystems, Rock Hill, SC) using computerized tomography to segment structures of interest (parenchyma, vasculature, collection system, and tumor). Images were converted to a 3D surface mesh file for fabrication using a multi-jet 3D printer. A novel construction technique was employed to approximate normal renal tissue texture, printers selectively deposited photopolymer material forming the outer shell of the kidney, and subsequently, an agarose gel solution was injected into the inner cavity recreating the spongier renal parenchyma. We constructed seven models of renal units with suspected malignancies. Partial nephrectomy and renorrhaphy were performed on each of the replicas. Subsequently all patients successfully underwent robotic partial nephrectomy. Average tumor diameter was 4.4 cm, warm ischemia time was 25 min, RENAL nephrometry score was 7.4, and surgical margins were negative. A comparison was made between the seven cases and the Tulane Urology prospectively maintained robotic partial nephrectomy database. Patients with surgical models had larger tumors, higher nephrometry score, longer warm ischemic time, fewer positive surgical margins, shorter hospitalization, and fewer post-operative complications; however, the only significant finding was lower estimated blood loss (186 cc vs 236; p = 0.01). In this feasibility study, pre-operative resectable physical 3D models can be constructed and used as patient-specific surgical simulation tools; further study will need to demonstrate if this results in improvement of surgical outcomes and robotic simulation education.

Comparative effectiveness studies to improve clinical outcomes in end stage renal disease: the DEcIDE patient outcomes in end stage renal disease study

PubMed Central

2012-01-01

Background Evidence is lacking to inform providers’ and patients’ decisions about many common treatment strategies for patients with end stage renal disease (ESRD). Methods/design The DEcIDE Patient Outcomes in ESRD Study is funded by the United States (US) Agency for Health Care Research and Quality to study the comparative effectiveness of: 1) antihypertensive therapies, 2) early versus later initiation of dialysis, and 3) intravenous iron therapies on clinical outcomes in patients with ESRD. Ongoing studies utilize four existing, nationally representative cohorts of patients with ESRD, including (1) the Choices for Healthy Outcomes in Caring for ESRD study (1041 incident dialysis patients recruited from October 1995 to June 1999 with complete outcome ascertainment through 2009), (2) the Dialysis Clinic Inc (45,124 incident dialysis patients initiating and receiving their care from 2003–2010 with complete outcome ascertainment through 2010), (3) the United States Renal Data System (333,308 incident dialysis patients from 2006–2009 with complete outcome ascertainment through 2010), and (4) the Cleveland Clinic Foundation Chronic Kidney Disease Registry (53,399 patients with chronic kidney disease with outcome ascertainment from 2005 through 2009). We ascertain patient reported outcomes (i.e., health-related quality of life), morbidity, and mortality using clinical and administrative data, and data obtained from national death indices. We use advanced statistical methods (e.g., propensity scoring and marginal structural modeling) to account for potential biases of our study designs. All data are de-identified for analyses. The conduct of studies and dissemination of findings are guided by input from Stakeholders in the ESRD community. Discussion The DEcIDE Patient Outcomes in ESRD Study will provide needed evidence regarding the effectiveness of common treatments employed for dialysis patients. Carefully planned dissemination strategies to the ESRD

Comorbidity and socio-demographic factors associated with renal lithiasis in persons aged 40 to 65: A cross-sectional study.

PubMed

Arias Vega, Raquel; Pérula de Torres, Luis Angel; Jiménez García, Celia; Carrasco Valiente, Julia; Requena Tapia, Maria José; Cano Castiñeira, Roque; Silva Ayçaguer, Luis Carlos

2017-11-09

Renal lithiasis is one of the most important urological diseases. It seems to be related to different socio-demographic and climatic factors, lifestyle and pre-existing comorbidity. The aim of this study was to examine the relationship between socio-demographic variables, certain risk factors and chronic diseases and the renal lithiasis. A cross-sectional population-based study was carried out, selecting the Spanish population aged from 40 to 65 years, combining 2 random samples (PreLiRenA and PreLiRenE studies). Data were collected by personal telephone surveys, gathering information on socio-demographic variables and perceived morbidity. Data on annual average temperatures in each Spanish region were also collected. A bivariate and multivariate analysis was performed. A total of 4,894 subjects were surveyed; 51.3% were women; 25% were aged 40-45 years, 36% had primary school education and 31.4% were of low social class. The overall prevalence of renal lithiasis was 15.0% (95% confidence interval [95% CI] 14.5-15.5). By means of multivariate analysis, the variables that showed a strong statistical relationship with the presence of renal lithiasis were: older age (61-65 years; OR=1.39; 95% CI 1.06-1.80), high social class (OR=1.98; 95% CI 1.29-2.62), family history of renal lithiasis (OR=2.22; 95% CI 1.88-2.65), high blood pressure (OR=1.68; 95% CI 1.39-2.02) and overweight/obesity (OR=1.31; 95% CI 1.12-1.54). A correlation was observed between renal lithiasis and average annual temperatures in the Spanish regions (r=0.59; P=.013). A relationship was observed between renal lithiasis and older age, belonging to higher social classes, the existence of a family history of urolithiasis, and hypertension and overweight or obesity. The prevalence of renal lithiasis is greater in warmer climate zones. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

Renal Sympathetic Denervation: Hibernation or Resurrection?

PubMed

Papademetriou, Vasilios; Doumas, Michael; Tsioufis, Costas

The most current versions of renal sympathetic denervation have been invented as minimally invasive approaches for the management of drug-resistant hypertension. The anatomy, physiology and pathophysiology of renal sympathetic innervation provide a strong background supporting an important role of the renal nerves in the regulation of blood pressure (BP) and volume. In addition, historical data with surgical sympathectomy and experimental data with surgical renal denervation indicate a beneficial effect on BP levels. Early clinical studies with transcatheter radiofrequency ablation demonstrated impressive BP reduction, accompanied by beneficial effects in target organ damage and other disease conditions characterized by sympathetic overactivity. However, the failure of the SYMPLICITY 3 trial to meet its primary efficacy end point raised a lot of concerns and put the field of renal denervation into hibernation. This review aims to translate basic research into clinical practice by presenting the anatomical and physiological basis for renal sympathetic denervation, critically discussing the past and present knowledge in this field, where we stand now, and also speculating about the future of the intervention and potential directions for research. © 2016 S. Karger AG, Basel.

Predictors of renal recovery in patients with pre-orthotopic liver transplant (OLT) renal dysfunction.

PubMed

Iglesias, Jose; Frank, Elliot; Mehandru, Sushil; Davis, John M; Levine, Jerrold S

2013-07-13

Renal dysfunction occurs commonly in patients awaiting orthotopic liver transplantation (OLT) for end-stage liver disease. The use of simultaneous liver-kidney transplantation has increased in the MELD scoring era. As patients may recover renal function after OLT, identifying factors predictive of renal recovery is a critical issue, especially given the scarcity of available organs. Employing the UNOS database, we sought to identify donor- and patient-related predictors of renal recovery among 1720 patients with pre-OLT renal dysfunction and transplanted from 1989 to 2005. Recovery of renal function post-OLT was defined as a composite endpoint of serum creatinine (SCr) ≤1.5 mg/dL at discharge and survival ≥29 days. Pre-OLT renal dysfunction was defined as any of the following: SCr ≥2 mg/dL at any time while awaiting OLT or need for renal replacement therapy (RRT) at the time of registration and/or OLT. Independent predictors of recovery of renal function post-OLT were absence of hepatic allograft dysfunction, transplantation during MELD era, recipient female sex, decreased donor age, decreased recipient ALT at time of OLT, decreased recipient body mass index at registration, use of anti-thymocyte globulin as induction therapy, and longer wait time from registration. Contrary to popular belief, a requirement for RRT, even for prolonged periods in excess of 8 weeks, was not an independent predictor of failure to recover renal function post-OLT. These data indicate that the duration of renal dysfunction, even among those requiring RRT, is a poor way to discriminate reversible from irreversible renal dysfunction.

Predictors of renal recovery in patients with pre-orthotopic liver transplant (OLT) renal dysfunction

PubMed Central

2013-01-01

Background Renal dysfunction occurs commonly in patients awaiting orthotopic liver transplantation (OLT) for end-stage liver disease. The use of simultaneous liver-kidney transplantation has increased in the MELD scoring era. As patients may recover renal function after OLT, identifying factors predictive of renal recovery is a critical issue, especially given the scarcity of available organs. Methods Employing the UNOS database, we sought to identify donor- and patient-related predictors of renal recovery among 1720 patients with pre-OLT renal dysfunction and transplanted from 1989 to 2005. Recovery of renal function post-OLT was defined as a composite endpoint of serum creatinine (SCr) ≤1.5 mg/dL at discharge and survival ≥29 days. Pre-OLT renal dysfunction was defined as any of the following: SCr ≥2 mg/dL at any time while awaiting OLT or need for renal replacement therapy (RRT) at the time of registration and/or OLT. Results Independent predictors of recovery of renal function post-OLT were absence of hepatic allograft dysfunction, transplantation during MELD era, recipient female sex, decreased donor age, decreased recipient ALT at time of OLT, decreased recipient body mass index at registration, use of anti-thymocyte globulin as induction therapy, and longer wait time from registration. Contrary to popular belief, a requirement for RRT, even for prolonged periods in excess of 8 weeks, was not an independent predictor of failure to recover renal function post-OLT. Conclusion These data indicate that the duration of renal dysfunction, even among those requiring RRT, is a poor way to discriminate reversible from irreversible renal dysfunction. PMID:23849513

Can preeclampsia be considered a renal compartment syndrome? A hypothesis and analysis of the literature.

PubMed

Reuter, David G; Law, Yuk; Levy, Wayne C; Seslar, Stephen P; Zierler, R Eugene; Ferguson, Mark; Chattra, James; McQuinn, Tim; Liu, Lenna L; Terry, Mark; Coffey, Patricia S; Dimer, Jane A; Hanevold, Coral; Flynn, Joseph T; Stapleton, F Bruder

2016-11-01

The morbidity and mortality associated with preeclampsia is staggering. The physiology of the Page kidney, a condition in which increased intrarenal pressure causes hypertension, appears to provide a unifying framework to explain the complex pathophysiology. Page kidney hypertension is renin-mediated acutely and ischemia-mediated chronically. Renal venous outflow obstruction also causes a Page kidney phenomenon, providing a hypothesis for the increased vulnerability of a subset of women who have what we are hypothesizing is a "renal compartment syndrome" due to inadequate ipsilateral collateral renal venous circulation consistent with well-known variation in normal venous anatomy. Dynamic changes in renal venous anatomy and physiology in pregnancy appear to correlate with disease onset, severity, and recurrence. Since maternal recumbent position is well known to affect renal perfusion and since chronic outflow obstruction makes women vulnerable to the ischemic/inflammatory sequelae, heightened awareness of renal compartment syndrome physiology is critical. The anatomic and physiologic insights provide immediate strategies to predict and prevent preeclampsia with straightforward, low-cost interventions that make renewed global advocacy for pregnant women a realistic goal. Copyright © 2016 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

A novel role of HIF-1α/PROX-1/LYVE-1 axis on tissue regeneration after renal ischaemia/reperfusion in mice.

PubMed

Meng, Fanwei

2018-04-10

Renal ischaemia reperfusion (I/R) is a common clinical condition with a high morbidity and mortality rate. To date, I/R-induced renal injury remains an ineffective treatment. We hypothesis that angiogenesis and lymphangiogenesis markers, prospero homeobox-1 (PROX-1) and lymphatic endothelial hyaluronan receptor-1 (LYVE-1), are critical during I/R. Kunming mice were subjected to I/R and observed for the following eight consecutive days. Pathology analysis and protein distribution were detected by H&E staining, immunohistochemistry and immunofluorescence confocal analysis. After I/R treatment, renal pathology was changed. HIF-1α was induced in the early stage and colocalisation with PROX-1 mainly in the renal tubular region, whereas PROX-1 and LYVE-1 were colocalised in the glomerulus of the endothelial region. In this study, we revealed HIF-1α/PROX-1/LVYE-1 axis dynamic changes in different regions after I/R and demonstrated for the first time it activates during I/R repair.

Readmission for dehydration or renal failure after ileostomy creation.

PubMed

Paquette, Ian M; Solan, Patrick; Rafferty, Janice F; Ferguson, Martha A; Davis, Bradley R

2013-08-01

Ileostomy creation is a commonly performed operation in colorectal surgery; however, many patients develop complications such as dehydration postoperatively. Dehydration is often severe enough to warrant hospital readmission and may result in renal failure. The true incidence of this complication has not been well described. The aim of this study was to identify the rate of hospital readmission secondary to dehydration or renal failure within 30 days of ileostomy creation. Retrospective review of all patients undergoing ileostomy creation from 2007 to 2011 in a single colorectal practice of 4 surgeons was performed. Charts were reviewed to identify patients readmitted for dehydration or renal failure within 30 days of operation. Data were then analyzed to identify predictors of readmission, dehydration, and renal failure. Subset analysis compared patients readmitted with simple dehydration versus patients with renal failure. Two hundred one patients undergoing colorectal operations that included ileostomy creation within a 4-year period at a single institution for a variety of indications were included. The primary outcome measured was readmission for dehydration or renal failure. We observed a 17% 30-day readmission rate for dehydration or renal failure following ileostomy creation. Age greater than 50 was identified as an independent predictor of readmission with renal failure, whereas IPAA was predictive of readmission for simple dehydration, but not renal failure. Patients admitted with renal failure had significantly longer hospital stays and median hospital charges after readmission in comparison with patients admitted with simple dehydration. This study was limited by its retrospective nature and its limited sample size. Hospital readmission due to dehydration or renal failure following ileostomy creation is common, with age >50 being the strongest predictor for renal failure. Appropriate strategies to decrease dehydration and renal failure following

Renal sympathetic denervation in hypertension.

PubMed

Doumas, Michael; Faselis, Charles; Papademetriou, Vasilios

2011-11-01

Despite the abundance of antihypertensive drugs, resistant hypertension remains a major clinical problem. Recent technological advances render interventional management of resistant hypertension one of the hottest topics in the hypertension field. The aim of this review is to present the pathophysiologic background and the mechanisms mediating blood pressure reduction after renal sympathetic denervation, to analyze recent findings with this fascinating approach and to critically suggest future research directions. Catheter-based, ablation-induced renal sympathetic denervation was initially studied in 45 patients with resistant hypertension in a proof-of-concept study. Impressive blood pressure reductions of about 30/15  mmHg were achieved at 6 months, without serious complications. A second, controlled, randomized (but not blinded) study confirmed the results, verifying the efficacy and safety of the procedure. A recent report revealed the 2-year durability of blood pressure reduction. Data published so far indicate that ablation-induced renal denervation is a feasible, effective, and well tolerated interventional approach for the management of resistant hypertension. The groundbreaking studies of renal denervation in drug-resistant hypertension pave the way for further research in other disease conditions in which sympathetic overactivity seems to play a critical role. This initial wave of enthusiasm needs to be followed by rigorous investigation, for the proper identification of the potential and the limitations, indications, and contraindications of this approach.

Altered renal sodium handling and risk of incident hypertension: Results of the Olivetti Heart Study

PubMed Central

D’Elia, Lanfranco; Cappuccio, Francesco P.; Iacone, Roberto; Russo, Ornella; Galletti, Ferruccio; Strazzullo, Pasquale

2017-01-01

Renal tubular sodium (Na) handling plays a key role in blood pressure (BP) regulation. Several cross-sectional studies reported a positive association between higher proximal tubule fractional reabsorption of Na and BP, but no prospective investigation has been reported of this possible association. Hence, the purpose of this study was to estimate the predictive role of renal Na handling on the risk of incident hypertension and the changes in BP occurring in the 8-year follow-up observation of a sample of initially normotensive men (The Olivetti Heart Study). The study included 294 untreated normotensive non-diabetic men with normal renal function examined twice (1994–95 and 2002–04). Renal tubular Na handling was estimated by exogenous lithium clearance. Fractional reabsorption of Na in proximal and distal tubules was calculated and included in the analysis. At baseline, there was no association between BP and either proximal or distal fractional reabsorption of Na. At the end of the 8-year follow-up, direct associations were observed between baseline proximal (but not distal) Na fractional reabsorption and the changes occurred in systolic and diastolic BP over time (+2.79 and +1.53 mmHg, respectively, per 1SD difference in proximal Na-FR; p<0.01). Also multivariable analysis showed a direct association between baseline proximal Na fractional reabsorption and risk of incident hypertension, independently of potential confounders (OR: 1.34, 95%CI:1.06–1.70). The results of this prospective investigation strongly suggest a causal relationship between an enhanced rate of Na reabsorption in the proximal tubule and the risk of incident hypertension in initially normotensive men. PMID:28196131

A micropuncture study of the effect of parathyroid hormone on renal bicarbonate reabsorption.

PubMed Central

Bank, N; Aynediian, H S

1976-01-01

Renal micropuncture and clearance experiments were carried out in rats to study the effect of parathyroid hormone (PTH) on renal tubular HCO-/3 reabsorption. The rats were studied during an initial period of parathyroid deficiency (acute thyroidparathyroidectomy, TPTX) and during infusion of large amounts of bovine PTH. Under normal acid-base conditions, PTH administration to TPTX rats caused a significant rise in proximal tubular fluid HCO-/3 concentration (TFHCO-/3), a decrease in fluid reabsorption, and a fall in proximal HCO-/3 reabsorption from 94.0 to 88.2% (P less than 0.01). In control experiments with mannitol infusion, a comparable reduction in proximal fluid reabsorption occurred without any significant effect on intraluminal HCO-/3 concentration. During acute intravenous HCO-/3 loading, PTH inhibited proximal HCO-/3 reabsorption. However, no change in whole kidney HCO-/3 reabsorption was observed in these experiments or in the animals studied under normal acid-base conditions. The findings are consistent with the view that PTH inhibits proximal tubular HCO-/3 reabsorption with normal or high filtered loads of HCO-/3, but distal segments of the nephron are able to reabsorb the excess delivered from the proximal tubule. Measurements of urinary ammonium and titratable acid indicate that net acid excretion (NH+/4 + TA -- HCO-/3) increases significantly after PTH administration. These results do not provide support for the view that PTH excess causes metabolic acidosis by reducing renal acid excretion. PMID:956369

Factors Influencing Renal Vasculature during Anesthesia, Trauma, and Oliguric Renal Failure States in Man

DTIC Science & Technology

1980-03-01

striking influence of prior sodium intake on the pathogenesis of acute renal failure, raising the possibility that the renin - angiotensin system was...the product of the renin - angiotensin system , is the most powerful renal vasoconstrictor agent yet identified. These observations, viewed in the light of... angiotensin and, when they became available, to a detailed study of agents suitable for pharmacologic interruption of the renin - angiotensin system . We showed

Effect of Cuscuta chinensis on renal function in ischemia/reperfusion-induced acute renal failure rats.

PubMed

Shin, Sun; Lee, Yun Jung; Kim, Eun Ju; Lee, An Sook; Kang, Dae Gill; Lee, Ho Sub

2011-01-01

The kidneys play a central role in regulating water, ion composition and excretion of metabolic waste products in the urine. Cuscuta chinensis has been known as an important traditional Oriental medicine for the treatment of liver and kidney disorders. Thus, we studied whether an aqueous extract of Cuscuta chinensis (ACC) seeds has an effect on renal function parameters in ischemia/reperfusion-induced acute renal failure (ARF) rats. Administration of 250 mg/kg/day ACC showed that renal functional parameters including urinary excretion rate, osmolality, Na(+), K(+), Cl(-), creatinine clearance, solute-free water reabsorption were significantly recovered in ischemia/reperfusion-induced ARF. Periodic acid Schiff staining showed that administration of ACC improved tubular damage in ischemia/reperfusion-induced ARF. In immunoblot and immunohistological examinations, ischemia/reperfusion-induced ARF decreased the expressions of water channel AQP 2, 3 and sodium potassium pump Na,K-ATPase in the renal medulla. However, administration of ACC markedly incremented AQP 2, 3 and Na,K-ATPase expressions. Therefore, these data indicate that administration of ACC ameliorates regulation of the urine concentration and renal functions in rats with ischemia/reperfusion-induced ARF.

Can renal dysfunction after infra-renal aortic aneurysm repair be modified by multi-antioxidant supplementation?

PubMed

Wijnen, M H W A; Vader, H L; Van Den Wall Bake, A W L; Roumen, R M H

2002-08-01

Renal failure after lower torso ischemia is a serious problem, partly caused by hypotension and indirect reperfusion injury. This injury is partly due to the formation of oxygen free radicals by activated neutrophils. This injury results in albuminuria and renal function impairment. There are indications that free radical damage in indirect reperfusion injury can be diminished by administering extra antioxidants before and during reperfusion. In this prospective randomised study we have looked at the influence of a multi-antioxidant supplementation on renal function in patients undergoing an elective open infrarenal abdominal aneurysm repair. The patients received either standard treatment (n=22) or standard treatment with additional antioxidants perioperatively (Allopurinol, vitamin E and C, N-acetylcysteine and mannitol). For renal function we have looked at the albumin/creatinine ratio in urine and 24 hr creatinine clearance. Despite significantly increased serum total antioxidant capacity, the group receiving extra antioxidants showed no decrease in the albumin/creatinine ratio in urine. There was however a significantly higher creatinine clearance in this group at day 2. The results indicate that the diminished renal function after infrarenal aneurysm repair may be influenced by antioxidant therapy.

Serum uric acid and renal function in patients with type 1 diabetes: a nationwide study in Brazil.

PubMed

Pizarro, Marcela Haas; Santos, Deborah Conte; Barros, Bianca Senger Vasconcelos; de Melo, Laura Gomes Nunes; Gomes, Marilia Brito

2018-01-01

Diabetes nephropathy is a microvascular complication associated with high morbidity and mortality in patients with type 1 diabetes, and its pathogenesis is not fully understood. Our aim was to evaluate the association between levels of serum uric acid and renal function assessed by glomerular filtration rate (GFR) and albuminuria in patients with type 1 diabetes. This is a multicenter, cross-sectional, observational study with 1686 patients, conducted between August 2011 and August 2014 in 14 public clinics from ten Brazilian cities. Renal function was estimated by CKD-EPI (adults) and by Schwartz (adolescents). We analyzed 1686 patients, aged 30.1 ± 12.0, with 15.4 ± 9.3 years of duration of diabetes; 55.8% were female and 54.0% were Caucasians. Serum uric acid was related to renal function, with a mean of 4.8 ± 1.4 (in the normal renal function group) vs 5.2 ± 2.0 (GFR ≥ 60 ml/min and albuminuria) vs 6.5 ± 2.6 mg/dl (GFR < 60 ml/min). In the pooled group, multivariate analysis showed an inverse correlation between serum uric acid and GFR (r = - 0.316, p < 0.001) with a decrease of 4.11 ml/min in the GFR for every increase of 1 mg/dl in serum uric acid. Considering only patients with normal renal function (n = 1170), a decrease of 2.04 ml/min in the GFR for every increase of 1 mg/dl in Serum uric acid was noted using multivariate analysis. Patients with higher levels of serum uric acid have worse renal function, independently of HbA1c or duration of diabetes, which persisted even in patients with normal renal function. Further prospective studies are necessary to establish if patients with higher serum uric acid may have an elevated risk for developing chronic kidney disease.

[Epidemiology of severe acute renal failure in Metropolitan Santiago].

PubMed

Vukusich, Antonio; Alvear, Felipe; Villanueva, Pablo; González, Claudio; Francisco, Olivari; Alvarado, Nelly; Zehnder, Carlos

2004-11-01

There is a paucity of information about the epidemiology of acute renal failure in Chile. To perform a prospective multicentric survey of severe acute renal failure in Chile. All patients admitted to ten hospitals in Metropolitan Santiago, during a period of six months with severe acute renal failure, were studied. The criteria for severity was the requirement of renal replacement therapy. All patients information was gathered in special forms and the type of renal replacement therapy and evolution was registeres. One hundred fourteen patients were studied (65 males, age range 18 to 87 years). The calculated incidence of acute renal failure was 1.03 cases per 1000 hospital discharges. The onset was nosocomial in 79 subjects (69%) and community acquired in the rest. Renal failure was oliguric in 64 cases (56%) and in 60% of patients it had two or more causative factors. Sepsis, isolated or combined with other causes, was present in 51 of patients. Other causes included ischemia in 47%, surgery in 26%, exogenous toxicity in 25%, endocenous toxicity in 11%, acute glomerular damage in 6% and obstructive uropathy in 6%. Cardiac surgery was responsible for 47% of post operative cases of acute renal failure. Intermittent conventional hemodialysis, continuous renal replacement techniques and daily prolonged hemodialysis were used in 66%, 29% and 2% of patients, respectively. Overall mortality was 45% and it was higher in oliguric patients. Gender, age, cause or the type of therapy did not influence survival. Nine percent of surviving patients had some degree of kidney dysfunction at discharge. There is still a great space for prevention of severe acute renal failure in Chile, considering the main etiologies found in this study.

7 T renal MRI: challenges and promises.

PubMed

de Boer, Anneloes; Hoogduin, Johannes M; Blankestijn, Peter J; Li, Xiufeng; Luijten, Peter R; Metzger, Gregory J; Raaijmakers, Alexander J E; Umutlu, Lale; Visser, Fredy; Leiner, Tim

2016-06-01

The progression to 7 Tesla (7 T) magnetic resonance imaging (MRI) yields promises of substantial increase in signal-to-noise (SNR) ratio. This increase can be traded off to increase image spatial resolution or to decrease acquisition time. However, renal 7 T MRI remains challenging due to inhomogeneity of the radiofrequency field and due to specific absorption rate (SAR) constraints. A number of studies has been published in the field of renal 7 T imaging. While the focus initially was on anatomic imaging and renal MR angiography, later studies have explored renal functional imaging. Although anatomic imaging remains somewhat limited by inhomogeneous excitation and SAR constraints, functional imaging results are promising. The increased SNR at 7 T has been particularly advantageous for blood oxygen level-dependent and arterial spin labelling MRI, as well as sodium MR imaging, thanks to changes in field-strength-dependent magnetic properties. Here, we provide an overview of the currently available literature on renal 7 T MRI. In addition, we provide a brief overview of challenges and opportunities in renal 7 T MR imaging.

Impact of Febuxostat on Renal Function in Gout Patients With Moderate-to-Severe Renal Impairment.

PubMed

Saag, Kenneth G; Whelton, Andrew; Becker, Michael A; MacDonald, Patricia; Hunt, Barbara; Gunawardhana, Lhanoo

2016-08-01

Renal impairment is a risk factor for gout and a barrier to optimal gout management. We undertook this exploratory study to obtain data that have been heretofore limited regarding the safety and efficacy of febuxostat in patients with moderate-to-severe renal impairment (estimated glomerular filtration rate [GFR] 15-50 ml/minute/1.73 m(2) ). Ninety-six gout patients with moderate-to-severe renal impairment were enrolled in a 12-month multicenter, randomized, double-blind, placebo-controlled study. Patients were randomly assigned at a 1:1:1 ratio to receive 30 mg febuxostat twice daily, 40/80 mg febuxostat once daily, or placebo. The primary efficacy end point was the change in serum creatinine (Cr) level from baseline to month 12. Secondary end points included the change in estimated GFR from baseline to month 12 and the proportion of patients with a serum uric acid (UA) level of <6.0 mg/dl at month 12. At month 12, there were no significant differences in the change in serum Cr level from baseline, or in the change in estimated GFR from baseline, in either febuxostat group compared to the placebo group. The proportion of patients with a serum UA level of <6.0 mg/dl at month 12 was significantly greater in both febuxostat groups compared to the placebo group (both P < 0.001). At least 1 treatment-emergent adverse event (TEAE) occurred in 78.1% of patients receiving 30 mg febuxostat twice daily, 87.5% of patients receiving 40/80 mg febuxostat once daily, and 78.1% of patients receiving placebo. TEAEs most frequently involved the categories of renal failure and impairment and renal function analyses. Febuxostat proved to be efficacious in serum UA reduction and was well tolerated in gout patients with moderate-to-severe renal impairment. Patients randomly assigned to receive febuxostat demonstrated significantly lower serum UA levels and no significant deterioration in renal function. © 2016, American College of Rheumatology.

Arrangement of Renal Arteries in Guinea Pig.

PubMed

Mazensky, David; Flesarova, Slavka

2017-03-01

The aim of this study was to describe origin, localization, and variations of renal arteries in guinea pig. The study was carried out on 26 adult guinea pigs. We prepared corrosion casts of the guinea pig arterial system. Batson's corrosion casting kit no. 17 was used as the casting medium. In 57.7% of specimens, a. renalis dextra was present as a single vessel with different level of its origin from aorta abdominalis. In 38.5% of specimens, two aa. renales dextrae were present with variable origin and arrangement. The presence of three aa. renales dextrae we found in one specimen. In 76.9% of specimens, a. renalis sinistra was present as a single vessel with different level of its origin from aorta abdominalis and variable arrangement. In 23.1% of specimens, we found two aa. renales sinistrae with variable origin and arrangement. The anatomical knowledge of the renal arteries, and its variations are of extreme importance for the surgeon that approaches the retroperitoneal region in several experiments, results of which are extrapolated in human. This is the first work dealing with the description of renal arteries arrangement in guinea pig. Anat Rec, 300:556-559, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Severe post-renal acute kidney injury, post-obstructive diuresis and renal recovery.

PubMed

Hamdi, Aïcha; Hajage, David; Van Glabeke, Emmanuel; Belenfant, Xavier; Vincent, François; Gonzalez, Frédéric; Ciroldi, Magali; Obadia, Edouard; Chelha, Riad; Pallot, Jean-Louis; Das, Vincent

2012-12-01

Study Type--Therapy (case series) Level of Evidence 4. What's known on the subject? and What does the study add? The pathophysiology of post-renal acute kidney injury (PR-AKI), i.e. caused by urinary tract obstruction, has been extensively studied in animal models but clinical studies on this subject are outdated, and/or have focused on the mechanisms of 'post-obstructive diuresis' (POD), a potentially life-threatening polyuria that can develop after the release of obstruction. In severe PR-AKI, the risk of occurrence of POD is high. POD occurrence predicts renal recovery without the persistence of severe chronic kidney failure. In the present study, the occurrence of POD and the persistence of chronic renal sequelae could be predicted early from clinical variables at admission before the release of obstruction. • To identify predictors of post-obstructive diuresis (POD) occurrence or severe chronic renal failure (CRF) persistence after the release of urinary tract obstruction in the setting of post-renal acute kidney injury (PR-AKI). • Bi-centre retrospective observational study of all patients with PR-AKI treated in two intensive care units (ICUs) from 1998 to 2010. • Clinical, biological and imaging characteristics on admission and after the release of obstruction were analysed with univariate and, if possible, multivariate analysis to search for predictors of (i) occurrence of POD (diuresis >4 L/day) after the release of obstruction; (ii) persistence of severe CRF (estimated glomerular filtration rate <30 mL/min/1.73 m(2), including end-stage CRF) at 3 months. • On admission, median (range) serum creatinine was 866 (247-3119) µmol/L. • POD occurred in 34 (63%) of the 54 analysable patients. On admission, higher serum creatinine (Odds ratio [OR] 1.002 per 1 µmol/L, 95% confidence interval [CI] 1.000-1.004, P = 0.004), higher serum bicarbonate (OR 1.36 per 1 mmol/L, 95% CI 1.13-1.65, P < 0.001), and urinary retention (OR 6.96, 95% CI 1.34-36.23, P

[Acute renal failure and proximal renal tubular dysfuntion in a patient with acquired immunodeficiency syndrome treated with tenofovir].

PubMed

de la Prada, F J; Prados, A M; Tugores, A; Uriol, M; Saus, C; Morey, A

2006-01-01

Tenofovir, a new nucleotide reverse transcriptase inhibitor that has good antiviral activity against drug-resistant strains of HIV, is structurally similar to cidofovir and adefovir and seems to be less nephrotoxic. Nephrotoxicity of cidofovir and adefovir is well established and they have been associated with increase for acute renal insufficiency due to tubular toxicity, possibly induced via mitochondrial deplection. Tenofovir has little mithocondrial toxicity in in vitro assays and early clinical studies. However some cases of renal tubular dysfuntion and renal failure related to tenofovir treatment have been published recently. Increased plasma concentrations of didanosine were observed after the adition of tenofovir and protease inhibitors can interact with the renal transport of organic anions leading to proximal tubular intracellular accumulation of tenofovir, yield Fanconi syndrome-type tubulopathy. We present a case in wich acute renal failure and proximal tubular dysfunction developed after therapy with tenofovir in a patiente with HIV who had suffered from complications of didanosine treatment. Although nephrotoxicity certainly occurs much less frequently with tenofovir that it does with other nuclotide analogues, use of tenofovir by patients with underlying renal disfuntion, for longer durations and/or associated with didanosine or lopinavir-ritonavir, might be associated with renal toxicity. Patients receiving tenofovir must be monitored for sings of tubulopathy with simple tests such us glycosuria, phosphaturia, proteinuria, phosphoremia and renal function, as well as assessment for signs of mithocondrial toxicity when a nucleoside analogue is being administered, and therapy should be stopped to avoid the risk of definitive renal failure.

Vascular reactivity of rabbit isolated renal and femoral resistance arteries in renal wrap hypertension.

PubMed

Khammy, Makhala M; Angus, James A; Wright, Christine E

2016-02-15

In rabbits with cellophane renal wrap hypertension, hindquarter and total vascular resistance changes to pressor and depressor agents are amplified compared to those of normotensive rabbits. The aim of the present study was to evaluate the in vitro pharmacodynamics of hypertensive and normotensive rabbit small artery segments isolated from the renal and hindquarter vascular beds. Using wire myography, the full range (Emax) and sensitivity (EC50) to a range of agonists of segments of renal interlobar (≈ 600 µm i.d.), renal arcuate (≈ 250 µm i.d.) and deep femoral branch (≈ 250 µm i.d.) arteries were assessed under normalised conditions of passive tension. Interlobar arteries from hypertensive rabbits were more sensitive (EC50) than those from normotensive rabbits to noradrenaline (6-fold), methoxamine (3-fold) and angiotensin II (3-fold). Arcuate artery reactivity was largely unaffected by hypertension. Deep femoral arteries from hypertensive rabbits had enhanced sensitivity only to noradrenaline (2-fold) and methoxamine (4-fold). Sensitivity to relaxation by acetylcholine was unaffected by hypertension in all arteries. Deep femoral arteries from hypertensive rabbits were more sensitive to sodium nitroprusside than normotensive counterparts. Adenosine caused little relaxation in renal arteries, but full relaxation in deep femoral arteries, unaltered by hypertension. This study found substantial heterogeneity in the pharmacodynamic profile of vessels isolated from different vascular beds and between arterial segments within the kidney. These profiles were differentially affected by hypertension suggesting that hypertension per se is not a resultant of general vascular dysfunction. Copyright © 2016 Elsevier B.V. All rights reserved.

Neural control of renal tubular sodium reabsorption of the dog.

PubMed

DiBona, G F

1978-04-01

The evidence supporting a role for direct neurogenic control of renal tubular sodium reabsorption is reviewed. Electron microscopic and fluorescence histochemical studies demonstrate adrenergic nerve terminals in direct contact with basement membranes of mammalian renal tubular epithelial cells. Low level direct or baroreceptor reflex stimulation of renal sympathetic nerves produces an increase in renal tubular sodium reabsorption without alterations in glomerular filtration rate, renal blood flow, or intrarenal distribution of blood flow. The antinatriuresis is prevented by prior treatment of the kidney with guanethidine or phenoxybenzamine. Possible indirect mediation of the antinatriuresis by other humoral agents known to be released from the kidney upon renal nerve stimulation (angiotensin II, prostaglandin) was excluded by experiments with appropriate blocking agents. Reflex diminutions in renal nerve activity (left atrial distention, stellate ganglion stimulation) produce a decrease in renal tubular sodium reabsorption independent of glomerular filtration rate or renal blood flow. The anatomically described adrenergic innervation of the renal tubules participates in the direct regulation of renal tubular sodium reabsorption.

Renal function in hepatosplenic schistosomiasis--an assessment of renal tubular disorders.

PubMed

Duarte, Daniella Bezerra; Vanderlei, Lucas Alexandre; Bispo, Raianne Kívia de Azevêdo; Pinheiro, Maria Eliete; da Silva, Geraldo Bezerra; Martins, Alice Maria Costa; Meneses, Gdayllon Cavalcante; Daher, Elizabeth De Francesco

2014-01-01

Renal involvement in Schistosoma mansoni infection is not well studied. The aim of this study is to investigate the occurrence of renal abnormalities in patients with hepatosplenic schistosomiasis (HSS), especially renal tubular disorders. This is a cross-sectional study with 20 consecutive patients with HSS followed in a medical center in Maceió, Alagoas, Brazil. Urinary acidification and concentration tests were performed using calcium chloride (CaCl2) after a 12-h period of water and food deprivation. The biomarker monocyte chemoattractant protein 1 (MCP-1) was quantified in urine. Fractional excretion of sodium (FENa+), transtubular potassium gradient (TTKG) and solute-free water reabsorption (TcH2O) were calculated. The HSS group was compared to a group of 17 healthy volunteers. Patients' mean age and gender were similar to controls. Urinary acidification deficit was found in 45% of HSS patients. Urinary osmolality was significantly lower in HSS patients (588 ± 112 vs. 764 ± 165 mOsm/kg, p = 0,001) after a 12-h period of water deprivation. TcH2O was lower in HSS patients (0.72 ± 0.5 vs. 1.1 ± 0.3, p = 0.04). Urinary concentration deficit was found in 85% of HSS patients. The values of MCP-1 were higher in HSS group than in control group (122 ± 134 vs. 40 ± 28 pg/mg-Cr, p = 0.01) and positively correlated with the values of microalbuminuria and proteinuria. HSS is associated with important kidney dysfunction. The main abnormalities found were urinary concentrating ability and incomplete distal acidification defect, demonstrating the occurrence of tubular dysfunction. There was also an increase in urinary MCP-1, which appears to be a more sensitive marker of renal damage than urinary albumin excretion rate.