Association between organic dietary choice during pregnancy and hypospadias in offspring: a study of mothers of 306 boys operated on for hypospadias.

PURPOSE: The etiology of hypospadias is poorly understood. Exposure to pesticides has been considered a risk factor, although findings are inconsistent. Diet constitutes a significant exposure route for pesticides, and pesticide residues are more frequently reported in conventional than organic food products. We examined the association between organic dietary choice during pregnancy and presence of hypospadias in the offspring. MATERIALS AND METHODS: Mothers of 306 boys operated on for hypospadias were frequency matched for geography and child birth year to 306 mothers of healthy boys in a case-control study. Telephone interviews were conducted regarding demographic and lifestyle factors, including intake and organic choice of selected food items (milk, dairy products, egg, fruit, vegetables and meat). Logistic regression models were constructed for dietary variables, and odds ratios were calculated controlling for maternal age, body mass index and alcohol consumption. RESULTS: Overall organic choice of food items during pregnancy was not associated with hypospadias in the offspring. However, frequent current consumption of high fat dairy products (milk, butter) while rarely or never choosing the organic alternative to these products during pregnancy was associated with increased odds of hypospadias (adjusted OR 2.18, 95% CI 1.09-4.36). CONCLUSIONS: This large case-control study of boys operated on for hypospadias suggests an association between hypospadias in the offspring and the mother not choosing the organic alternative, and having a high current intake of nonorganic butter and cheese. This finding could be due to chemical contamination of high fat dairy products. However, general lifestyle and health behavior related to choosing organic alternatives may also explain the finding.

Urinary proteome analysis in congenital bilateral hydronephrosis.

OBJECTIVE: A proteomics strategy was applied to map protein changes in urine after relief of congenital bilateral hydronephrosis to identify proteins correlated with the pathophysiological processes in congenital obstructive nephropathy as potential urinary biomarkers. MATERIAL AND METHODS: Urine samples from 10 infants with bilateral abnormal drainage from the kidneys were collected at the time of relief from obstruction, and after 2 and 4 weeks. Proteomics techniques were used on samples from three patients for identification of protein changes between the three time-points, and enzyme-linked immunosorbent assay (ELISA) was used on samples from all 10 patients for validation of five selected proteins. RESULTS: Mass spectrometry quantified 315 protein hits, out of which 33 proteins showed significantly changed urinary excretion between the time-points. Validation by ELISA showed high urinary excretion of fibrinogen, plasminogen, transthyretin and transferrin at the time of relief from obstruction, followed by a significant reduction. In contrast, Tamm-Horsfall protein exhibited the reverse pattern. CONCLUSION: Using a mass spectrometry-based proteomics approach, this study identified 33 proteins related to congenital bilateral hydronephrosis, and pinpointed a panel of five proteins consistently linked to this congenital kidney disorder as potential urinary biomarkers.

Epidermal growth factor and monocyte chemotactic peptide-1: potential biomarkers of urinary tract obstruction in children with hydronephrosis.

OBJECTIVE: Hydronephrosis is diagnosed in 0.5% of all newborns, and ureteropelvic junction obstruction (UPJO) is a common cause. The aim of this study was to test whether specific urinary cytokines can be used as UPJO biomarkers in children with hydronephrosis. MATERIALS AND METHODS: Twenty-eight children referred for pyeloplasty due to UPJO and 13 controls were included in this prospective study. Kidney function was assessed and urine samples collected pre-, peri-, and post-operatively. Urine levels of epidermal growth factor (EGF), monocyte chemotactic peptide-1 (MCP-1), macrophage inflammatory protein-1α (MIP-1α), interferon-γ-inducible protein-10 (IP-10), and RANTES were measured simultaneously by using a bead-based multiplex sandwich immunoassay. RESULTS: In hydronephrotic children, preoperative urine levels were significantly increased for EGF (median 7.4 [1.2-60.2] vs. median 4.0 [1.2-13.8] ng/mg creatinine) and MCP-1 (median 136.9 [47.7-545.5] vs. median 80.1 [28.8-149.9] pg/mg creatinine) compared to those of controls. Urine levels of EGF and MCP-1 were identical to controls at the postoperative 1-year follow-up exam. CONCLUSION: Urine levels of EGF and MCP-1 were preoperatively increased and postoperatively normalized. This study demonstrates that urine-excreted kidney cytokines may be potential biomarkers of obstruction in children with hydronephrosis.

Identification of risk factors for vascular thrombosis may reduce early renal graft loss: a review of recent literature.

Renal graft survival has improved over the past years, mainly owing to better immunosuppression. Vascular thrombosis, though rare, therefore accounts for up to one third of early graft loss. We assess current literature on transplantation, identify thrombosis risk factors, and discuss means of avoiding thrombotic events and saving thrombosed grafts. The incidence of arterial thrombosis was reported to 0.2-7.5% and venous thrombosis 0.1-8.2%, with the highest incidence among children and infants, and the lowest in living donor reports. The most significant risk factors for developing thrombosis were donor-age below 6 or above 60 years, or recipient-age below 5-6 years, per- or postoperative hemodynamic instability, peritoneal dialysis, diabetic nephropathy, a history of thrombosis, deceased donor, or >24 hours cold ischemia. Multiple arteries were not a risk factor, and a right kidney graft was most often reported not to be. Given the thrombosed kidney graft is diagnosed in time, salvage is possible by urgent reoperation and thrombectomy. Despite meticulous attentions to reduce thrombotic risk factors, thrombosis cannot be entirely prevented and means to an early detection of this complication is desirable in order to save the kidneys through prompt reoperation. Microdialysis may be a new tool for this.

Urinary NGAL, cystatin C, ß2-microglobulin, and osteopontin significance in hydronephrotic children.

BACKGROUND: Ureteropelvic junction obstruction (UPJO) accounts for 35 % of all congenital hydronephrosis cases. The challenge in managing childhood hydronephrosis is to distinguish obstructive from nonobstructive cases and, thereby, identify patients requiring surgical intervention. This study aimed to examine four urinary proteins as potential biomarkers of obstruction in hydronephrosis. METHODS: Urine samples from 24 children with UPJO were collected pre-, peri-, and postoperatively, together with urine samples from healthy children. Neutrophil gelatinase-associated lipocalin (NGAL), cystatin C (CyC), ß2-microglobulin (ß2-M), and osteopontin (OPN) in the samples were measured simultaneously using multiplex sandwich immunoassay technology. RESULTS: Compared with controls, NGAL and ß2-M were significantly increased in urine from patients with obstructed kidneys at the time of surgery. This increase was followed by a decrease and stabilization to the same level as that of the controls. Furthermore, age was negatively correlated with preoperative urinary concentrations of CyC, ß2-M, and OPN. CONCLUSIONS: This study confirms increased concentrations of NGAL and ß2-M in urine from obstructed kidneys and should be tested in larger studies to ascertain their ability to identify obstruction and to determine the importance of age-adjusted reference values.

Early outcome in renal transplantation from large donors to small and size-matched recipients - a porcine experimental model.

Kidney transplantation from a large donor to a small recipient, as in pediatric transplantation, is associated with an increased risk of thrombosis and DGF. We established a porcine model for renal transplantation from an adult donor to a small or size-matched recipient with a high risk of DGF and studied GFR, RPP using MRI, and markers of kidney injury within 10 h after transplantation. After induction of BD, kidneys were removed from ∼63-kg donors and kept in cold storage for ∼22 h until transplanted into small (∼15 kg, n = 8) or size-matched (n = 8) recipients. A reduction in GFR was observed in small recipients within 60 min after reperfusion. Interestingly, this was associated with a significant reduction in medullary RPP, while there was no significant change in the size-matched recipients. No difference was observed in urinary NGAL excretion between the groups. A significant higher level of HO-1 mRNA was observed in small recipients than in donors and size-matched recipients indicating cortical injury. Improvement in early graft perfusion may be a goal to improve short- and long-term GFR and avoid graft thrombosis in pediatric recipients.

International Children's Continence Society's recommendations for initial diagnostic evaluation and follow-up in congenital neuropathic bladder and bowel dysfunction in children.

PURPOSE: The objective of this ICCS standardization document is to report the initial diagnostic evaluation and subsequent work-up of children with neuropathic bladder dysfunction. MATERIALS AND METHODS: Due to a paucity of level I or level II, "levels of evidence" publications, these recommendations are actually a compilation of best practices because they seem to be effective and reliable, although not with any control. RESULTS: Throughout the document, the emphasis is on promoting early, comprehensive evaluation of lower urinary tract function that is thorough but with a minimum of unnecessary testing. This includes what tests to order, when to order them and what to do with the results. Some of the recommendations may not be practical in various worldwide locations but the suggested testing should be considered the ideal approach to completely diagnosing and then promulgating treatments based on the full knowledge of the condition and its effect on urinary tract function. Once the findings are delineated, those lower urinary tract patterns of dysfunction that put the kidneys at risk for deterioration, that are barriers to attaining eventual continence, and that have long-term consequence to the lower urinary track can be obviated by specific management recommendations. The indications and timing of investigations to achieve these objectives are clearly defined in each diagnostic category and during follow-up. RECOMMENDATIONS: This document should be used as a basis for appropriate evaluation and timely surveillance of the various neuro-urologic conditions that affect children.

Urine and kidney cytokine profiles in experimental unilateral acute and chronic hydronephrosis.

OBJECTIVE: In search of potential urinary biomarkers of obstructive nephropathy, this study examined whether a potential change in the concentration of urinary cytokines [interferon-γ(IFN-γ), interleukin-1ß (IL-1ß), IL-2, IL-6, IL-10 and tumour necrosis factor-α (TNF-α)] reliably reflects changes in renal parenchymal levels of the same cytokines following the release of acute and chronic unilateral ureteral obstruction, respectively. MATERIAL AND METHODS: Acute obstruction was performed in 12 adult rats. After 48 h, six rats were used for selective urine collection and six rats had their kidneys removed and dissected into inner medulla and cortex. Chronic obstruction was performed in newborn rats. After 10 weeks, a similar set-up to that of the acute study was implemented. Sham-operated rats were prepared in parallel. Urine and tissue cytokines were measured with a bead-based multiplex sandwich immunoassay and analysed on a Luminex 100 IS instrument. RESULTS: In the acute study, there were significantly increased concentrations of IL-1ß and IL-6 in inner medulla and in urine from the obstructed kidney, significantly increased concentrations of TNF-α in urine from the obstructed kidney and, importantly, significantly increased levels of IL-10 in cortex and in urine from the non-obstructed kidney. In the chronic study, there were similar changes in IL-1ß and IL-6 (not significant) but no changes in TNF-α and IL-10. CONCLUSIONS: This study showed that inflammatory cytokines can be detected both in renal parenchyma and in urine from rats with experimental unilateral ureteral obstruction. Further studies are needed to confirm the diagnostic accuracy of IL-1ß, IL-6, IL-10 and TNF-α in urine.

Regulation of aquaporins and sodium transporter proteins in the solitary kidney in response to partial ureteral obstruction in neonatal rats.

Unilateral ureteral obstruction (UUO) impairs function of the obstructed kidney, and the contralateral nonobstructed kidney compensates depending on the degree and duration of UUO. This study aimed to determine the hemodynamic and molecular changes in the solitary kidney in response to partial ureteral obstruction (PUO) where any compensation from the contralateral kidney was eliminated so that all observed changes in the kidney tissue occurred in the kidney with PUO. Newborn rats were subjected to unilateral left nephrectomy (UNX) within the first 48 h of life and a subset of UNX rats was subjected to severe PUO of the right kidney at day 14. Renal blood flow and whole kidney volume were measured with MRI at week 10. The renal protein abundance of aquaporin 1 (AQP1), AQP2 and AQP3 as well as Na,K-ATPase, NaPi-2 (type 2 sodium-phosphate cotransporter) and NHE3 (type 3 sodium-proton exchanger) were examined by immunoblotting and immunocytochemistry. At 10 weeks of age, the protein abundance of AQP2, AQP3, Na,K-ATPase, NaPi-2 and NHE3 were increased in response to PUO. In contrast, AQP1 expression was markedly decreased compared to sham-operated rats. These findings were confirmed by immunohistochemistry. GFR, urine osmolality and urine sodium excretion were reduced and kidney weight increased in response to PUO. In conclusion, the present study demonstrated major changes in the protein abundance of renal AQP1, AQP2 and AQP3 and sodium transporters in the solitary PUO kidney. These changes were paralleled by decreased urinary sodium excretion and a significant reduction in urinary osmolality from the obstructed kidney, suggesting a functional association between the molecular changes and the ability of the obstructed kidney to handle sodium and water in this solitary kidney model.

Urinary biomarkers in prenatally diagnosed unilateral hydronephrosis.

The introduction of prenatal ultrasonography as a screening method entails an increasing number of infants diagnosed with prenatal hydronephrosis. Ureteropelvic junction obstruction accounts for 35% of prenatal hydronephrotic cases. Urinary tract obstruction that occurs during early kidney development affects renal morphogenesis, maturation and growth, and in the most severe cases this will ultimately cause renal insufficiency. A major challenge in the clinical management of these patients is to preserve renal function by selection of the 15%-20% who require early surgical intervention, leaving those for whom watchful waiting may be appropriate because of spontaneous resolution/stabilization without significant loss of renal function. Today, this requires medical surveillance, including repetitive invasive diuretic renograms relying on arbitrary threshold values, and therefore there is a need for non-arbitrary, non-invasive urinary biomarkers that may be used as predictors for renal structural changes and/or decreasing renal function, and thereby provide the surgeon with more clear indications for surgical intervention. In this review, we summarize the currently well-known facts about urinary biomarkers in ureteropelvic junction obstruction concerning renal function, and we also suggest potential novel urinary biomarkers.

Urinary flow patterns in infants with distal hypospadias.

OBJECTIVE: To investigate preoperative urinary flow patterns in hypospadic infants and compare them to those from normal infant boys. PATIENTS AND METHODS: Twenty-one boys (median age 14.0, range 12.8-21.6 months) referred for distal hypospadias surgery were compared to 19 healthy boys (median age 12.0, 9.2-19.8 months). In both groups a 14-mm transit-time ultrasound flow probe mounted around the base of the penis continuously registered uroflow. RESULTS: Median maximum flow rate (Q(max)) was significantly lower in hypospadics (2.4 vs 4.4 ml/s, P < 0.01) while there was no difference in the voided volume per micturition (19.0 vs 21.0 ml, P 0.33). Flow curve pattern analysis revealed plateau-shaped curves in 31% of hypospadics compared to none in normal infant boys. Interestingly, dyscoordinated flow curves (interrupted, staccato, spike-dome) were less common in the hypospadics (36% vs 64%, P < 0.01). Meatal size did not correlate to Q(max) (rho = 0.26, P = 0.26). CONCLUSIONS: Infants with hypospadias void with a lower Q(max) and a lesser degree of dyscoordination as compared to normal infant boys. It can be speculated that decreased urethral compliance may contribute to the lower Q(max) and may act as a silencer for dyscoordination.

A biomechanical, histological and biochemical study in an experimental rabbit hypospadias repair model using scanning acoustic microscopy.

OBJECTIVE: To investigate the biomechanical, histological and biochemical properties of rabbit urethra at long-term follow up after hypospadias simulation and acute repair. MATERIALS AND METHODS: Thirty-eight white New Zealand male rabbits underwent experimental creation of a hypospadias-like defect and acute repair (mobilization and advancement, tubularized incised posterior urethral plate (TIP), modified TIP) and sham operation. After 23 weeks all groups + controls underwent biomechanical, histological and biochemical assessments. RESULTS: The mobilization and advancement group showed a higher stiffness compared to the TIP groups (P < 0.05) in the posterior urethra, whereas the TIP group was stiffer compared to the other two operative groups (P < 0.001) in the ventral urethra. In the dorsal urethra, the mobilization and advancement group and the modified TIP group had a higher collagen content compared to shams (P < 0.05). No differences in collagen content were found between groups in the ventral urethra. A correlation between acoustic and histological layers was found, partially related to collagen content. CONCLUSION: The urethras had different microelastic properties in different layers of the dorsal and ventral urethra, with higher stiffness in the connective tissue layers surrounding and within the urethra. The repaired urethras had partially recovered their elasticity at micrometer resolution at long-term follow up. Scanning acoustic microscopy elucidated structure-function relationships at microscopic level in normal and operated urethra.

In vivo biomechanical assessment of anterior rabbit urethra after repair of surgically created hypospadias.

PURPOSE: We studied the in vivo biomechanical properties of the anterior urethra in a rabbit hypospadias simulation model at long-term followup after urethroplasty. MATERIALS AND METHODS: A total of 38, 9-week-old white New Zealand male rabbits were randomized into active treatment and control groups. The active treatment group included hypospadias-like simulation and acute repair (sham, mobilization and advancement, tubularized incised posterior urethral plate). After 23 weeks all groups underwent biomechanical investigation using impedance planimetry. Cross-sectional area pressure measurements during bag distention were conducted at 3 different positions along the urethra, and biomechanical (tension-strain) relations were computed. The biomechanical parameters studied were urethral luminal dimension (cross-sectional area pressure relation) and its deformability to luminal pressure (tension-strain relation). RESULTS: The urethral cross-sectional area was significantly larger in the mobilization and advancement group compared to the tubularized incised plate group (p <0.001), shams and controls at the distal distention site (p <0.05), and other groups at the intermediate distention site (p <0.05). The strain-tension curves were not significantly different between the groups. CONCLUSIONS: All groups showed a nonlinear cross-sectional area pressure and circumferential wall tension-strain relationships in the 3 distention sites. The urethras exhibited a decreasing ability to be distended with increasing pressures, indicating self-protection against damage. At long-term followup no differences in tension-strain relations were found between groups, despite the fact that the mobilization and advancement group had enlarged urethras. Our hypospadias simulation animal model could be useful to test commonly used or new urethroplasty techniques and their functional (biomechanical) long-term results before clinical use.

Structural and functional MRI in children with renal disease: first experience.

PURPOSE: This MRI study demonstrates our first clinical experiences with structural and functional evaluation in children with renal dysfunction, and communicates our experience with quantitative measurements of renal function compared to reference values found employing radionucleotides. MATERIAL AND METHODS: We included renal impaired children who were recruited for clinical radioisotopic GFR measurements (n=8). MRI was performed 2 hours after Cr-EDTA measurements and was conducted using a protocol involving both anatomical/structural sequences and a dynamic contrast-enhanced sequence. Data obtained with the dynamic MRI sequence were processed using the graphical Patlak approach to obtain estimates of GFR. RESULTS: We were able to characterize the intrarenal configuration (cortex, medulla, pelvicalyceal arrangement) in all cases. Functional analyses of dynamic contrast-enhanced MRI revealed an overall underestimation of GFR measured by MRI compared to Cr-EDTPA measures (range: -2% to -43%). CONCLUSIONS: We advocate the use of MRI as a single-modality approach in the structural and functional evaluation of impaired kidneys in children, and concurrently, we presented a clinically available strategy for estimations of renal cortical volume and single kidney function. However, the use of MRI contrast agents have recently become controversial in renal patients due to the risk of NSF.

Urinary flow patterns in premature males.

PURPOSE: We sought to assess urinary flow patterns in premature males using ultrasound flow probes. MATERIALS AND METHODS: Specifically customized ultrasound flow probes connected to a flowmeter were mounted on the penis of 29 premature males (median gestational age 31.3 weeks). Flow data were sampled to a personal computer and flow curves were assessed with regard to configuration, maximum flow rate and voided volume. Examinations were performed at the neonatal unit within the ambient environment of the incubators and under the surveillance of a study nurse for a period of 4 hours. RESULTS: Data from 25 boys (98 voids) were applicable for analysis. Flow curve configuration was bell shaped in 48% of patients, interrupted in 44%, staccato in 6% and plateau in 2%. Overall 59% of flows were dyscoordinated, and no patient with more than 1 assessable void had exclusively coordinated flows. Median voided volume was 3.9 ml (range 0.6 to 25.2), median maximum flow rate was 1.0 ml per second (0.3 to 10.0) and median number of voids per hour was 1.0 (0.2 to 3.6). No correlation was found between flow curve configuration and maximum flow rate (p = 0.32). However, plateau shaped curves were associated with larger voided volumes (p = 0.05). CONCLUSIONS: Urinary flow pattern assessment in preterm males is possible and reveals a high degree of dyscoordination. There is a tendency toward a mixture of coordinated and dyscoordinated flow patterns in the same individual.

Long-term follow-up in spinal dysraphism: outcome of renal function and urinary and faecal continence.

OBJECTIVE: This study evaluated the renal and functional outcome in a cohort of adolescents with congenital spinal malformations followed at this department since birth. All patients went through same follow-up and algorithm of intervention during childhood. None of the patients was treated prophylactically, apart from receiving antibiotics. MATERIAL AND METHODS: Sixty children (31 males, 29 females), born in 1989-1995, were evaluated from June 2006 to May 2007. Ultrasound of the bladder and the upper urinary tract was performed in all patients. Surgical and pharmacological intervention, bowel function, faecal and urinary continence were registered. Renal function was assessed by (51)Cr-EDTA and/or MAG-3 scintigraphy in patients who had previously experienced affected renal function or presented with deteriorated bladder function. RESULTS: Two children died during follow-up. In total, 47 urological procedures were performed in 23 patients. The most frequently conducted procedures were appendicovesicostomy (n = 11) and autoaugmentation (n = 11). Fourteen patients underwent untethering procedures, resulting in improved bladder function in five patients; nine were unaltered. Five patients had a moderate and two a severe decrease in glomerular filtration rate. Eighty-one per cent were performing clean intermittent catheterization, starting at a median age of 3.6 years. Anticholinergics were used in 50%. Sixty-two per cent were totally urine continent, 22% used incontinence pads in case of leakage and 16% were urine incontinent. Two patients had Malone procedures; 29% were using trans-anal irrigation. Eighty-three per cent were totally faecal continent. CONCLUSION: Close follow-up and appropriate intervention have improved renal function in children with congenital spinal malformation, but renal deterioration remains a risk. Total faecal and urinary continence could be achieved in 81% and 62%, respectively.

Urinary flow patterns in first year of life.

PURPOSE: We studied the natural development of urinary flow and lower urinary tract function in healthy male infants. MATERIALS AND METHODS: Custom-made ultrasound flow probes connected to a flowmeter were mounted on the penis in 20 infants who previously had been assessed in the immediate postnatal period. Median subject age was 10.7 months (range 9.2 to 19.8). Flow data were sampled to a personal computer and flow curves were assessed regarding configuration, maximum flow rate and voided volume. Results were analyzed statistically and were compared to those obtained in the neonatal period. Comparison of uroflow parameters was assessed by using analysis of variance, while contingency coefficients and Wilcoxon test were used for comparisons involving nominal and paired data, respectively. A p value of less than 0.05 was considered statistically significant. RESULTS: A total of 19 infants had evaluable data, of whom 15 also had evaluable data from the original neonatal study. Flow curve pattern was bell shaped in 32% of patients, interrupted in 46%, staccato in 15%, tower in 3% and spike-dome in 3%. Dyscoordinated patterns accounted for 46% of all flows, a significant increase compared to the neonatal period, in which only 34% of flows were considered dyscoordinated (p <0.01). While voided volume increased significantly with age, maximum flow rate remained more or less stable. CONCLUSIONS: Contrary to conventional wisdom, infants continue to exhibit urinary flow dyscoordination to an even greater extent than in the neonatal period. Therefore, the anticipated normalization of urinary flow is most likely to occur after the first year of life.

Microdialysis for detection of renal ischemia after experimental renal transplantation.

PURPOSE: We designed an experimental renal transplantation model and evaluated microdialysis as a detector of induced postoperative ischemia, a feared complication that when caused by vascular thrombosis most often causes renal graft loss. MATERIALS AND METHODS: Two microdialysis catheters were placed in the left kidney in 16 pigs, including 1 superficially in the renal cortex and 1 fixed on the renal capsule. Two-hour baseline measurements were made at steady state, after which the kidney was removed and subjected to warm and cold ischemia. It was subsequently re-anastomosed end to end in situ and reperfused for 5 hours. Pigs were then randomized into a total renal artery occlusion and a control group. RESULTS: At baseline there were no changes in local metabolites (glucose, glutamate, glycerol and lactate) and no significant difference between the groups. Glycerol increased 4-fold in each group during cold ischemia but there were no pivotal alterations in other metabolites. After kidney reperfusion glycerol decreased and all metabolites were in steady state after 1 hour. At 30 minutes after postoperative ischemia was introduced there were significant increases in all kidneys in ischemia vs steady state reperfusion levels of cortical lactate, glutamate, glycerol and the lactate-to-glucose ratio (each rank sum test p <0.001). No metabolic changes were seen in controls. CONCLUSIONS: Microdialysis detected significant metabolic changes after postoperative ischemia in pigs with experimental renal transplantation, while no metabolic changes were observed in controls. In the future microdialysis may become a valuable tool for postoperative observation of transplanted kidneys, most probably with major impact on early graft survival.