5th Joint Meeting of ESPU-SPU - Virtual

S2: BASIC RESEARCH 2

Moderators: Magdalena Fossum (Sweden)

ESPU-SPU Meeting on Thursday 23, September 2021, 13:20 - 14:14


13:20 - 13:23
S2-1 (SO)

★ VASCULAR DYSFUNCTION IN BOYS WITH HYPOSPADIAS

Angela LUCAS-HERALD 1, Rheure ALVES-LOPES 2, Laura HADDOW 2, Stuart O'TOOLE 3, Martyn FLETT 3, Boma LEE 3, Mairi STEVEN 3, Syed Basith AMJAD 4, Syed Faisal AHMED 1 and Rhian TOUYZ 5
1) Royal Hospital for Children, Developmental Endocrinology Research Group, Glasgow, UNITED KINGDOM - 2) Institute for Cardiovascular and Medical Sciences, BHF Centre for Research Excellence, University of Glasgow, Glasgow, UNITED KINGDOM - 3) Royal Hospital for Children, Paediatric Urology, Glasgow, UNITED KINGDOM - 4) Royal Hospital for Children, Paediatric Surgery, Glasgow, UNITED KINGDOM - 5) Institute for Cardiovascular and Medical Sciences, BHF Centre for Research Excellence, Glasgow, UNITED KINGDOM

PURPOSE

Hypospadias in boys may be associated with insufficient androgen exposure during the masculinisation programming window in utero. Testosterone has vasoactive actions and accordingly we tested whether vascular function is altered in boys with hypospadias.

MATERIAL AND METHODS

Peripheral arteries were dissected from excess foreskin tissue from boys undergoing hypospadias repair (cases) and boys undergoing circumcision (controls). Vascular function was assessed in isolated arteries by myography and differences in reactive oxygen species generation were investigated in vascular smooth muscle cells (VSMCs).

RESULTS

27 boys with hypospadias and 37 age-matched controls were enrolled in this study (median age 1.9 (range 1.3, 12.2) years). Of the cases, there were 8 (30%) proximal, 6 (22%) mid and 13 (48%) distal hypospadias. Arteries from cases demonstrated increased vasoconstriction versus controls (Emax:137.9 vs 66.3, p<0.001) and reduced endothelium-dependent (Emax:72.4 vs 1.2, p<0.0001) and endothelium-independent vasorelaxation (Emax:42.7 vs 11.8, p<0.0001). VSMCs from cases demonstrated produced more oxidative stress as measured by increased levels of superoxide anion (5.3 fold, p<0.01), hydrogen peroxide (3.3 fold, p<0.001) and total antioxidant capacity (34.4 fold, p<0.0001). Cases also had increased DNA methyltransferase activity (1.2 fold, p<0.05) suggesting epigenetic change. Vascular reactivity was improved when resistance arteries were incubated with N-acetylcysteine, a reactive oxygen species scavenger.

CONCLUSIONS

Small arteries from boys with hypospadias exhibit vascular dysfunction, as measured by increased vascular contractility and decreased vasorelaxation, secondary to increased oxidative stress and possible epigenetic modifications. The implications of these findings on long-term health as well as surgical outcome need further exploration.


13:23 - 13:26
S2-2: Withdrawn (author request)
 

13:26 - 13:29
S2-3 (SO)

ACTIVATION OF CENTRAL IMMUNOSUPPRESSIVE CASCADE PREVENTS ISCHEMIA REPERFUSION INJURY FOLLOWING ACUTE PYELONEPHRITIS

Austin HESTER, Christina HO, Nazanin OMIDI and Daniel CASELLA
Children's National Hospital, Urology, Washington, USA

PURPOSE

Renal dysfunction secondary to scarring and fibrosis of the renal parenchyma is a feared complication of pyelonephritis. The host immune response has been identified as a key mediator of ischemia reperfusion injury (IRI) and renal scar formation. We have previously demonstrated that varenicline, an α7nAChR agonist, activates a central immunosuppressive cascade, limiting IRI following testicular torsion and preventing long-term testicular atrophy. We hypothesized that varenicline would similarly decrease ischemia reperfusion injury and limit renal scar formation in a murine model of pyelonephritis.

MATERIAL AND METHODS

Using a previously-established model, pyelonephritis was induced by inoculating the bladder of C3H/HeOuj mice with uropathogenic E-coli. 5 days following inoculation, the animals were divided into two groups and treated with 5 days of ceftriaxone, or 5 days of ceftriaxone with varenicline in the initial 48 hours. Animals were sacrificed at 14 and 30 days post-inoculation. Quantitative PCR was performed to evaluate expression of mediators of IRI and fibrosis.

RESULTS

14 days following inoculation, central mediators of IRI including Vcam, Serpina, Lyz1, and Lcn2 were downregulated in animals treated with varenicline. 30-day outcomes demonstrated decreased expression of collagen and smooth muscle in animals treated with varenicline.

CONCLUSIONS

The addition of varenicline to antibiotic therapy for acute pyelonephritis reduces ischemia reperfusion injury and renal fibrosis. Further studies are needed to define the optimum dosing and time frame for varenicline administration; however, our initial results suggest that varenicline offers a potentially novel adjunct therapy in the management of pyelonephritis.


13:29 - 13:32
S2-4 (SO)

URINE NGAL IS ELEVATED IN MICE WITH URINARY TRACT INFECTION COMPARED TO MICE WITH ASYMPTOMATIC BACTERIURIA

Olivia LAMANNA 1, Catherine FORSTER 1 and Suzanne GROAH 2
1) Children's National Hospital, Washingon, USA - 2) MedStar National Rehabilitation Hospital, Washington, USA

PURPOSE

Distinguishing urinary tract infections (UTI) from asymptomatic bacteriuria (ABU) in children with neuropathic bladders is difficult. Although urine neutrophil gelatinase-associated lipocalin (uNGAL) is increased in the setting of UTI, it is unknown whether uNGAL levels are elevated in definitive ABU. The objective of this study was to compare uNGAL levels between mice with UTI and ABU. We hypothesized that mice with UTI would have higher uNGAL levels compared to mice with ABU.

MATERIAL AND METHODS

Female C57BL/6 mice were transurethrally inoculated with 1-2 x107 colony-forming units of either uropathogenic Escherichia coli strain CFT073 for the UTI model (n=12),e. coli strain 83972 for the ABU model (n=12), or PBS (n=3) for 72hrs. Urine was collected for uNGAL and creatinine measurements before and 72hrs post-inoculation. uNGAL levels were compared using Kruskal Wallis or Mann-Whitney U as appropriate.

RESULTS

The median (interquartile range) uNGAL was 31 (20, 51)ng/ml in the pre-inoculation mice. Median post-inonculation uNGAL levels were 76 (43, 93)ng/ml for the PBS-inoculated mice, 464 (146,1653)ng/ml for the ABU-inoculated mice, and 1780 (1172, 2573)ng/ml for the UTI-inoculated mice, (p-value < 0.01). The median increase in uNGAL from pre- to post-inoculation levels in UTI mice was significantly higher than that of ABU mice (UTI: 1748 (1141, 2501)ng/ml; ABU: 429 (167, 1429)ng/ml) p=0.04). Results were unchanged for uNGAL normalized by urine creatinine.

CONCLUSIONS

Mice with UTI had higher uNGAL levels than mice with ABU. uNGAL may help guide clinical management around antibiotic use in children with neuropathic bladders who present with bacteriuria.


13:32 - 13:44
Discussion
 

13:44 - 13:47
S2-5 (SO)

★ AUTOMATED KIDNEY STONE CLASSIFICATION WITH MICROSCOPIC IMAGES AND MACHINE LEARNING

Hakan TEKGUL 1 and Ege ONAL 2
1) Georgia Institute of Technology, Electrical and Computer Engineering, Atlanta, USA - 2) University of Illinois Urbana-Champaign, Biomedical Engineering, Champaign, USA

PURPOSE

In circumstances where stones are too large to be treated with SWL, minimally invasive procedures are being used to take out kidney stones. Understanding and detecting the formation of specific types of kidney stone is crucial for prescribing treatment to prevent recurrence. Because of the hybrid and complex nature of stones, there is still significant subjectivity and variability across physicians. In this study, we propose an image recognition system to increase the objectivity of kidney stone classification. Specifically, machine learning algorithms are applied to microscopic images taken from a smartphone to differentiate Calcium Oxalate, Struvite, and Cystine kidney stones.

MATERIAL AND METHODS

An image database is created by taking a total of 179 microscopic images of 20 kidney stones from different parts through a smartphone microscope. Each kidney stone was labeled by the gold standard X-Ray Crystallography technique. Then, all the images are fed to our deep learning algorithms that are based on Tensorflow. The output model was then run on 36 random testing microscopic images. False negative, false positive and accuracy rates are analyzed. As a result, a smartphone application is developed for automated kidney stone classification.

RESULTS

After training with 179 images, our machine learning model outputted a 95% accuracy rate, with only 1% false negative and 0% false positive for each stone type. Additionally, F1 score of our model was 0.88.

CONCLUSIONS

Future applications of this technology can be used as a point of care inexpensive predictive tool for classifying kidney stones in pediatric patients. Our results show that the smartphone application we built can increase the objectivity in kidney stone classification. When combined with the knowledge of a pediatric urologist, this study can increase the effectiveness of kidney stone treatments.


13:47 - 13:50
S2-6 (SO)

HOT SPOT GENE MUTATIONS IDENTIFIED IN PRIMARY HYPEROXALURIA IN CHINESE PEDIATRIC PATIENTS WITH URINARY STONES

Wenying WANG, Yucheng GE, Chen NING and Jun LI
Beijing Friendship Hospital, Capital Medical University, Urology, Beijing, CHINA

PURPOSE

This study was aimed to determine the clinical and mutation spectrum of pediatric patients from mainland China with primary hyperoxaluria(PH).

MATERIAL AND METHODS

The genomes of families of 77 children with calculi were examined via whole-exome sequencing. The results were validated using the Sanger method, and the clinical data and gene reports were analyzed.

RESULTS

Thirty-three PH cases were found, the age of the patients ranged from 7 months to 13 years, with 23 males and 10 females. For PH1 patients, there were three homozygous mutations and 10 compound heterozygous mutations in the AGXT gene. Among them, c.33dupC and c.815_c.816insGA were the most common mutations, accounting for 15.4% of total alleles respectively in the present study. For pH2 patients, the mutation c.864_865delTG accounted for 5/8 of alleles in this study. For type 3 patients, there were four cases of homozygous mutations in the HOGA1 gene and 12 cases of compound heterozygous mutations; the mutations in the c.834_834+1 region, including c.834G>A and c.834_834+1GG>TT, account for 50% of total alleles in this study.

CONCLUSIONS

This is the largest pH cases reported in children from mainland China. PH3 was more common seen in China, followed by PH1 and PH2. The c.33dupC and c.815_c.816insGA were the most common mutations, short repeat of the GA dinucleotide may present a mutation hotspot in Chinese PH1 children. The c.864_865delTG mutation was the hotspot mutation in PH2 patients, and mutation hot spot region (c.834_834+1) in Chinese PH3 pediatric patients was also found.


13:50 - 13:53
S2-7 (SO)

DISMEMBERING THE URETEROVESICAL JUNCTION: A COMPUTATIONAL ANALYSIS OF THE 5:1 URETERAL LENGTH-TO-DIAMETER RATIO

Kourosh KALAYEH 1, Jeffrey FOWLKES 2, William SCHULTZ 3 and Bryan SACK 1
1) University of Michigan, Urology, Ann Arbor, USA - 2) University of Michigan, Radiology, Ann Arbor, USA - 3) University of Michigan, Mechanical Engineering & Naval Architecture and Marine Engineering, Ann Arbor, USA

PURPOSE

The primary theory of the ureterovesical junction (UVJ) anti-refluxing mechanism is based on Paquin's 5:1 ureteral tunnel length-to-diameter ratio (L/D). We hypothesized that the current use of this rule as surgical dogma results in an overestimation of needed tunnel length to prevent vesicoureteral reflux (VUR).

MATERIAL AND METHODS

Using COMSOL Multiphysics finite element solver, bladder filing was modeled under non-linear, large deformation conditions. The bladder was modeled as an incompressible, hyperelastic material and assumed to be a sphere expanding uniformly. Broad parametric studies on different L/D ratios were performed as the bladder fills from 10% to 110% capacity. For all considered ratios, the UVJ resistance to flow was calculated and compared.

RESULTS

The modeling results indicate that implementing the 5:1 ratio at 80% capacity (approximate volume during ureteral reimplantation) corresponds to 7:1 at the rest state (used by Paquin). Similarly, the 5:1 ratio being implemented at the rest state corresponds to 3:1 at 80% capacity. Furthermore, as the bladder fills, the tunnel length for UVJs with higher L/Ds increases while the cross sectional area decreases which is an indication of UVJ collapse. For smaller ratios, the tunnel length decreases and cross sectional area increases with filling. Additionally, as the bladder fills from 10% to 110% capacity, flow resistance for L/D=2.5 (UVJ inserted perpendicular to the bladder wall) decreases to almost zero, while it increases by about 200% for L/D=5.0.

CONCLUSIONS

This model indicates that use of Paquin's ratio during ureteral reimplantation may overestimate the requisite tunnel length to prevent reflux. It also implies that UVJ closure is primarily due to bladder wall deformation rather than the differential pressure across the wall. This points to a need for better understanding of the UVJ structure to reliably predict VUR resolution, risk of infection, and direct anti-reflux surgical technique.


13:53 - 13:56
S2-8 (SO)

URINARY TREFOIL FAMILY FACTORS (TFF) AND NEUTROPHIL GELATINASE-ASSOCIATED LIPOCALCIN (NGAL) IN CONGENITAL UROPATHIES WITH AND WITHOUT GENETIC POLYMORPHISM

Sachit ANAND and Minu BAJPAI
All India Institute of Medical Sciences, Pediatric Surgery, New Delhi, INDIA

PURPOSE

To study the relationship between urinary biomarkers (TFF1,TFF3 and NGAL) and renal outcomes in children with congenital uropathies with & without genetic predisposition to renal injury.

MATERIAL AND METHODS

This study includes children (upto 14 years) with common congenital uropathies registered in our urology clinic from January-June 2019. Measurement of TFF1, TFF3 and NGAL was done by ELISA in spot urinary samples. DNA extraction, amplification and gel electrophoresis were sequentially performed in blood to assess genetic polymorphism of four candidate genes (encoding PAX2, BMP4, ACE and AT2R).

RESULTS

Of the fifty children, 20% had ureteropelvic junction obstruction, 44% had posterior urethral valve and 36% had vesicoureteric reflux. The median (IQR) urinary concentrations of TFF1, TFF3 and NGAL were 25.5 (22.2-29.4) ng/ml, 105.9 (89.2-113.3) ng/ml and 171.7 (143.1-177.4) ng/ml respectively. Among the forty children in whom renal nuclear scans (DTPA-GFR and DMSA) were performed, 47% had early CKD (stage 1,2), 53% had late CKD (stage 3 and above) and 20% had cortical scarring. All three biomarkers were significantly elevated in children with late CKD and cortical scarring. TFF3 predicted CKD progression with highest accuracy (AUC=0.978) on the ROC curve. In a multivariate linear regression analysis in children with early CKD, NGAL significantly predicted the outcome (p=0.013). Children exhibiting polymorphisms of genes encoding ACE and AT2R had significantly higher concentrations of urinary biomarkers.

CONCLUSIONS

Urinary TFF (1 and 3) and NGAL are significantly elevated in the children with congenital uropathies. NGAL and TFF3 strongly predict the early and late stages of CKD respectively. Genetic polymorphism in genes encoding ACE and AT2R confer a high-risk of progressive renal injury.


13:56 - 13:59
S2-9: Withdrawn (presentation merged with S3-1)
 
13:59 - 14:14
Discussion