Nonobstructive Hydronephrosis Research Articles

Rab35 Is Required for Embryonic Development and Kidney and Ureter Homeostasis through Regulation of Epithelial Cell Junctions.

Rab35 is a member of a GTPase family of endocytic trafficking proteins. Studies in cell lines have indicated that Rab35 participates in cell adhesion, polarity, cytokinesis, and primary cilia length and composition. Additionally, sea urchin Rab35 regulates actin organization and is required for gastrulation. In mice, loss of Rab35 in the CNS disrupts hippocampal development and neuronal organization. Outside of the CNS, the functions of mammalian Rab35 in vivo are unknown. We generated and analyzed the consequences of both congenital and conditional null Rab35 mutations in mice. Using a LacZ reporter allele, we assessed Rab35 expression during development and postnatally. We assessed Rab35 loss in the kidney and ureter using histology, immunofluorescence microscopy, and western blotting. Congenital Rab35 loss of function caused embryonic lethality: homozygous mutants arrested at E7.5 with cardiac edema. Conditional loss of Rab35, either during gestation or postnatally, caused hydronephrosis. The kidney and ureter phenotype were associated with disrupted actin cytoskeletal architecture, altered Arf6 epithelial polarity, reduced adherens junctions, loss of tight junction formation, defects in EGFR expression and localization, disrupted cell differentiation, and shortened primary cilia. Rab35 is essential for mammalian development and the maintenance of kidney and ureter architecture. Loss of Rab35 leads to non-obstructive hydronephrosis, making the Rab35 mutant mouse a novel mammalian model to study mechanisms underlying this disease.

Scinтigraphy in Children with Urinary Tract Dilatation (Antenatally Detected Hydronephrosis)

The causes of Antenatal Hydronephrosis/Urinary Tract Dilatation (ANH/UTD) vary from transient benign conditions-transit hydronephrosis, (resolves by birth or during infancy) to conditions that can significantly affect renal function. The outcome of depends on the underlying etiology, so it is very important to determine these causes. The definition and grading of ANH is based on the Anteroposterior Pelvic Diameter (APD) of the fetal renal pelvis. Antenatal management includes antenatal ultrasound monitoring, which is usually repeated every 4-6 weeks. It is recommended that the assessment of the severity of postnatal hydronephrosis is based on the APD of the renal pelvis. Extensive postnatal investigation was proposed to be limited to those with moderate or severe dilatation. Voiding cystourethrography and scintigraphy are usually preserved for children with postnatal APD <15 mm and/or abnormal kidney parenchyma, severe caliyx dilatation ureteral dilatation and bladder pathology. Diuretic renal scintigraphy is important in the postnatal evaluation of infants with ANH, particularly in distinguishing kidneys with poor drainage from nonobstructive hydronephrosis with good drainage. According to our diuretic renography results, we conclude that in the presence of partial or no drainage, the separate renal function may not be significantly impaired. The finding of poor renal emptying is significantly more common among children with increasing renal pelvis APD. Technetium 99m-dimercaptosuccinic acid renal scintigraphy (99mTc-DMSA) has been used in renal imaging to estimate the functional renal mass (damage to the kidney) and relative renal function, especially in pediatric patients. A statistically significant correlation between the degree of hydronephrosis (APD) and DMSA scan finding and between the degree of the VUR and DMSA scan finding was established. Other than VUR, CAKUT (pelvic ureteric junction obstruction, pyelon et ureter duplex, megaureter, posterior urethra valves) were not statistically correlated with pathological findings on the DMSA scan.

Ahnak is required to balance calcium ion homeostasis and smooth muscle development in the urinary system

BackgroundVarious renal abnormalities, including hydronephrosis, polycystic kidney disease, and hydroureter, have been reported, and these abnormalities are present in DiGeorge syndrome, renal dysplasia, and acute kidney failure. Previous studies have shown that various genes are associated with renal abnormalities. However, the major target genes of nonobstructive hydronephrosis have not yet been elucidated.ResultsWe examined neuroblast differentiation-associated protein Ahnak localization and analyzed morphogenesis in developing kidney and ureter. To investigated function of Ahnak, RNA-sequencing and calcium imaging were performed in wild type and Ahnak knockout (KO) mice. Ahnak localization was confirmed in the developing mouse kidneys and ureter. An imbalance of calcium homeostasis and hydronephrosis, which involves an expanded renal pelvis and hydroureter, was observed in Ahnak KO mice. Gene Ontology enrichment analysis on RNA-seq results indicated that ‘Channel Activity’, ‘Passive Transmembrane Transporter Activity’ and ‘Cellular Calcium Ion Homeostasis’ were downregulated in Ahnak KO kidney. ‘Muscle Tissue Development’, ‘Muscle Contraction’, and ‘Cellular Calcium Ion Homeostasis’ were downregulated in Ahnak KO ureter. Moreover, peristaltic movement of smooth muscle in the ureter was reduced in Ahnak KO mice.ConclusionsAbnormal calcium homeostasis causes renal disease and is regulated by calcium channels. In this study, we focused on Ahnak, which regulates calcium homeostasis in several organs. Our results indicate that Ahnak plays a pivotal role in kidney and ureter development, and in maintaining the function of the urinary system.

Diuretic Renal Scintigraphy

Hydronephrosis can be caused by obstruction or by nonobstructive disorders such as infection, vesicoureteral reflux, or congenital anomalies. Diuretic renal scintigraphy is critical in differentiating between obstructive and nonobstructive hydronephrosis. Under physiologic conditions, urine may pool

Role of urinary Neutrophil Gelatinase-Associated Lipocalin (NGAL), Monocyte Chemoattractant Protein-1(MCP-1), and Interleukin-6(IL-6) as biomarkers in pediatric patients with hydronephrosis.

The decision to surgically intervene in a hydronephrotic kidney in children is based on many debatable guidelines, some requiring repeated ultrasounds or renal scans. Urinary proteins have the potential to reflect renal disorders and hence can be the alternatives to such scans. Here, we aim to assess the role of urinary Neutrophil Gelatinase-Associated Lipocalin, Monocyte Chemoattractant Protein-1, and Interleukin-6 (IL-6) in such patients. Seventeen children had obstructive hydronephrosis requiring pyeloplasty (UPJO), while seven were kept on conservative management in view of non-obstructivedilation (NOD). Urine samples were measured for the three urinary proteins at the time of presentation and following pyeloplasty using commercially available ELISA kits. The levels of all three urinary proteins were significantly higher in patients with UPJO children compared to the NOD group. Cut-off values to differentiate obstructive from non-obstructive hydronephrosis were obtained. A significant fall in the post-operative value of urinary IL-6 was also observed. This study highlights the potentiality of urinary proteins as biomarkers in identifying children with hydronephrosis and picking out the ones with obstructive hydronephrosis who will require pyeloplasty. The drop in levels after pyeloplasty can be employed to evaluate the effectiveness of pyeloplasty when sent serially.

Role of CT-KUB for Detection of Obstructive and Non-Obstructive Hydronephrosis on The Basis of Frequency of Calculi

The kidneys and ureters are the most prevalent sites for stones. The swelling of the kidneys due to renal stones, most often ureteric stones, is known as hydronephrosis. For detecting the position of stones, CT-KUB has a high sensitivity. Objective: To determine the frequency of obstructive and non-obstructive hydronephrosis due to calculi in CT-KUB. Methods: A cross-sectional study was conducted from January, 2022 to May, 2022 at Tertiary Hospital in Lahore, Pakistan. A sample size of 166 patients was obtained using a non-probability convenient sampling technique based on the previously published articles. All patients with renal calculi were included. 64 Slices Aquilian CT Machine was used. SPSS ver. 22 was used for data entry and analysis. Results: 166 Patients were in the age ranges of (15-25), (26-35), (36-45), (46-55), (56-65), and (66-75) were 27(16.3%), 39(16.3%), 32(19.3%), 37(22.3%), 22(13.3%), 9(5.4%) respectively. There were 126(75.9%) males and 40 (24.1%) females. Flank pain was present in 154(94%) and hematuria in 68(41%) patients. Stones were noted in kidneys 102(46.6%), proximal ureter 35(16%), mid ureter 21(9.6%), distal ureter 51(23.3%), urinary bladder 10(4.6%). 96 patients were diagnosed with obstructing hydronephrosis (57.8%). Conclusion: Urinary tract stones are most commonly seen in the kidneys and ureters. Obstructive and non-obstructive hydronephrosis is mostly caused by kidney stones. Obstructive hydronephrosis accounted for 57.8% of the total, whereas non-obstructive hydronephrosis accounted for 42.2%. CT-KUB plays a vital role in the diagnosis of hydronephrosis.

Spectrum of Disorders Diagnosed on 99mTc-MAG3 Radioisotope Renography: A Report of 260 Saudi Arabian Patients

Background: Diuretic renography using 99mTc-mercaptoacetyltriglycine (99mTc-MAG3) is a relatively non-invasive technique and has been increasingly used as a reliable technique for the evaluation of kidney function in a wide range of kidney disorders. Methods: In this retrospective study, we retrieved the medical records of patients referred to the Radiology Department of Radiology, King Abdulaziz Specialist Hospital, Taif, Saudi Arabia, with suspected kidney disease and underwent 99mTc-MAG3 diuretic renography during January 2020 to November 2021. Results: The medical records of 260 patients were retrieved. Most of the patients had either suspected obstructive (n = 80; 30.7 %) or non-obstructive hydronephrosis (n = 60; 23.1 %). The left kidney was affected in more than half of the patients (n = 155; 59.6 %). In terms of split kidney functions, the right kidney had a median function of 50.9 (38.5–75.5); overall, 39 patients (69.6%) had good right kidney function. The left kidney had a median function of 49.4 (24.5–61.5); overall, 33 patients (58.9%) had good left kidney function. Conclusion: Radioisotope renography is useful for assessing kidney functions in real-life settings. The present study’s results indicate that radioisotope renography using 99mTc-MAG3 is helpful in the visual interpretation of kidney failure, obstructive uropathy and kidney stenosis.

Diuretic Renal Scintigraphy Protocol Considerations.

Diuretic renal scintigraphy plays a critical diagnostic role by providing a physiologic means for differentiating between obstructive and nonobstructive hydronephrosis as well as assessing the function of the affected kidney. The exam accuracy is highly dependent upon and benefits from close attention to the protocol. This article reviews kidney anatomy and physiology, patient preparation, available radiopharmaceuticals, diuretic administration, acquisition, processing, quantification, and interpretation criteria.

FC025: Physiological Role of KV Channel in Ureter Smooth Muscle Cell Investigated Quantitatively by Electrophysiological Modeling

Abstract BACKGROUND AND AIMS Spontaneous peristaltic contraction disorder of the ureter smooth muscle (USM) is an important etiology of congenital giant ureter, congenital ureteropelvic junction deformity and non-obstructive hydronephrosis [1]. The USM cell action potential (AP) plays a key role in commencing USM contraction by allowing influx of Ca2+ from the extra cellular space [2]. Therefore, an in-depth quantitative investigation of the USM cell AP generation will assist in developing better pharmacological therapies for the USM abnormal contraction. The purpose of this in-silico study is to unfold the physiological role of Kv channel in modulating the USM AP generation. METHOD The model consists voltage- dependent Na+ currents (INa), hyperpolarization-activated cyclic nucleotide- gated current (Ih), voltage- dependent Ca2+ currents (ICa), Ca2+ dependent potassium channel (IBKCa) and voltage-dependent potassium channels (IKv) as the components of active electrophysiological characteristics [3]. All ion channels are represented by the Hodgkin–Huxley formalism. The maximum conductance of the is varied to investigate the physiological role of the Kv channel in modulating the USM AP generation. RESULTS The whole cell IKv current is generated by applying the voltage clamp protocol, where the membrane potential is stepped from a holding potential of –80 mV–60 mV for a duration of 500 ms. The half activation potential, half inactivation potential, activation slope factor and inactivation slope factors are: 43 mV, –76.1 mV, 15.4 mV and 6.5 mV, respectively, to fit the Boltzmann function equation. The model reveals that fast activation and inactivation properties are the essential feature of IKv for the USM cell. The resting membrane potential (RMP) is set at –50 mV. The AP was induced in the whole cell model by applying an external stimulus current (10–30 pA), as a brief square pulse of 500 ms duration. It is demonstrated that IKv opposes the Ca2+ current during the first 50 ms of the AP duration and then inactivated. It doesn't contribute to the repolarizing phase of the AP. CONCLUSION The plateau phase of the USM AP shows that the total AP duration much longer than that in other smooth muscle cells. It strongly supports the phenomenon is due to the activation of Ca2+-dependent K+ channel and inactivation of L-type Ca2+ channel. In ureter cells, the IKv does not contribute significantly to the repolarization of the AP, but it may regulate membrane excitability by opposing Ca2+ current activated around the threshold of the AP. Therefore, the agonist and antagonist of the IKv might be useful partially as new pharmacological targets for the USM abnormal contraction.

Evaluating TIMP-2 and IGFBP-7 as a predictive tool for kidney injury in ureteropelvic junction obstruction.

ABSTRACTA major challenge in the management of ureteropelvic junction obstruction (UPJO) is the selection of patients who would benefit from surgical treatment. Tissue inhibitor metalloproteinase-2 (TIMP-2) and insulin-like growth factor-binding protein 7 (IGFBP7) indicate renal cell stress and are associated with cell cycle arrest. The [TIMP-2] [IGFBP7] ratio (Nephrocheck®) has been recently applied in patients in intensive care units patients to predict the development of acute kidney injury. In this study, we evaluated the performance of these biomarkers performance to distinguishing obstructive hydronephrosis (HN) from non-obstructive HN.Materials and Methods:Consecutive patients with UPJO were enrolled in this study. Urinary [TIMP-2] [IGFBP7] and clinical characteristics (hydronephrosis grade, differential renal function, and drainage half-time) were measured in the following groups: 26 children with obstructive HN at initial diagnosis (group 1A) and after six months of dismembered pyeloplasty (group 1B); 22 children with non-obstructive HN (group 2), and 26 children without any urinary tract condition, as the control group (group 3).Results:Comparing the initial samples, [TIMP-2] [IGFBP7] had higher levels in the HN groups and lower levels in the control group; however, no difference was observed between the HN groups (obstructive vs. non-obstructive). After six months of follow-up, patients who underwent dismembered pyeloplasty showed stability in the urinary concentration of [TIMP-2] [IGFBP7]. All patients with [TIMP-2] [IGFBP7] higher than 1.0 (ng/mL)2/1000 had diffuse cortical atrophy on ultrasonography.Conclusions:We showed that urinary levels of urinary [TIMP-2] [IGFBP7] are higher in children with HN than controls. Nephrocheck® is not reliable in predicting the need for surgical intervention for pediatric patients with UPJO.

Correlation of resistive index of main renal artery and inter-lobar artery with degree of hydronephrosis.

Objective: To study the correlation of resistive index of main renal artery and inter-lobar artery with degree of hydronephrosis. For the purpose of this study data collection was carried through different research works conducted previously regarding hydronephrosis and its effects on the resistivity index of renal arteries. Study Design: Systemic Review. Setting: Radiology Research Section, University of Lahore. Period: September 2018 to May 2020. Material & Methods: Research was conducted with the help of keywords. One hundred and three articles were found at initial stage. A table was designed for data collection purpose including the information such as author of article, year of research, type of hydronephrosis, number of patients, and the resistive index of renal arteries. The data included both male and female patients of any age suffering from hydronephrosis of any origin and no area or time limitation was applied. Results: Pooling results of this systematic review depicts that the researchers conducted various researches addressing the cause of hydronephrosis, the effect of type of hydronephrosis on the resistive index, difference between resistivity index of obstructive and non-obstructive hydronephrosis, level of obstruction and its effect on RI of the renal artery, factors that influence RI other than renal in origin but not a single research conducted on human subject represents the correlation of different grades or degrees of hydronephrosis with either main renal artery or inter-lobar arteries. Out of 17 articles, 8 (47%) articles discuss the resistive index for both obstructive and non-obstructive hydronephrosis while remaining 9 (53%) articles discuss only the mean resistive index for the obstructed kidney. Conclusion: Although renal resistive index is the parameter which is influenced by a variety of other factors such as age of patient, plasma renin level, and the simultaneous presence of certain diseases like hypertension, cardiac diseases, diabetes mellitus, and renal disorders. The presence of any of these factors may rise the RI values even if there is no renal obstruction. Yet different research mainly shows that the values of RI are high i.e. >0.70 in case of obstructed kidney while generally the values of RI are <0.70 in case of none obstructed kidney.

Evolution of congenital anomalies of urinary tract in children with and without solitary kidney.

We hypothesized that children with congenital solitary functioning kidney (CSFK) present forms of congenital urinary tract anomalies (CUTA) with higher chance of spontaneous resolution compared with patients with two kidneys. We retrospectively selected 75 consecutive children with CUTA of the CSFK and 75 matched patients with unilateral CUTA but without CSFK (controls) with prenatal suspicion of unilateral CUTA and early evaluation. We compared the spontaneous CUTA resolution and the prevalence of kidney injury between groups at last follow-up. Patients and controls were clustered under the categories of "severe" and "non-severe" CUTA. The mean age at first and last follow-up was 0.17 ± 0.07 and 8.5 ± 5.2 years. Compared with controls, patients with CSFK had lower prevalence of severe CUTA at first evaluation; lower prevalence of febrile urinary tract infections, need of surgical correction, and higher rate of spontaneous CUTA resolution during follow-up; and a similar prevalence of mild kidney injury at last follow-up. CSFK compared with controls presented higher cumulative proportion of spontaneous resolution from severe CUTA (100 vs 41.8%; p < 0.001) and from the single CUTA sub-categories (severe vesicoureteral reflux, non-obstructive hydronephrosis, and megaureter). CSFK patients had lower prevalence of severe forms and better outcomes of their CUTA compared with controls. One-third of patients with congenital solitary functioning kidney (CSFK) present congenital urinary tract anomalies (CUTA) and manifest poorer outcomes compared with CSFK without CUTA. CSFK patients had lower prevalence of severe forms and better outcomes of their CUTA in spite of similar prevalence of kidney injury compared with controls. This adds evidence about disturbed nephrogenesis in CSFK patients and emboldens conservative management of many of their non-obstructive CUTA.

Kidney disease profile and encountered problems during follow-up in Syrian refugee children: a multicenter retrospective study.

Children are one of the most vulnerable groups in conflict zones, especially those with chronic diseases. This study aimed to investigate kidney disease profiles and problems during follow-up in a population of Syrian refugee children residing in Turkey. Syrian refugee children aged between 0 and 18 years were included in the study. Demographic data, diagnosis, particular interventions due to nephrological problems, and problems encountered during follow-up were obtained from all participating pediatric nephrology centers. Data from 633 children from 22 pediatric nephrology centers were included. Mean age of the children was 94.8 ± 61.7 months and 375 were male (59%). 57.7% had parental consanguinity and 23.3% had a close relative(s) with kidney disease. The most common kidney diseases were congenital anomalies of the kidney and urinary tract (CAKUT) (31.0%), glomerular disease (19.9%), chronic kidney disease (CKD) (14.8%), and urolithiasis (10.7%). Frequent reasons for CAKUT were nonobstructive hydronephrosis (23.0%), vesico-ureteral reflux (18.4%), and neurogenic bladder (15.8%). The most common etiology of glomerular diseases was nephrotic syndrome (69%). Ninety-four children had CKD, and 58 children were on chronic dialysis. Six children had kidney transplantation. Surgical intervention was performed on 111 patients. The language barrier, lack of medical records, and frequent disruptions in periodic follow-ups were the main problems noted. CAKUT, glomerular disease, and CKD were highly prevalent in Syrian refugee children. Knowing the frequency of chronic diseases and the problems encountered in refugees would facilitate better treatment options and preventive measures.

A gravity-assisted approach to the management of urinary diversion: 99mTc-MAG3 diuresis renography with F + 10(sp) method.

Radical cystectomy with permanent urinary diversion is the gold standard treatment for invasive muscle bladder cancer. Hydronephrosis is common in these patients, but Ultrasound (US) or Computed Tomography Urography (CTU) scan are unable to discriminate obstructive from non-obstructive hydronephrosis. We used Diuresis Renography (DR) with F + 10 in seated position (sp) method in the identification of patients with a Uretero-ileal Anastomosis Stricture (UAS) who would benefit from surgical therapy. We studied 39 asymptomatic patients, who underwent radical cystectomy and urinary diversion. Based on radiological findings (US, CTU) 44 kidneys were hydronephrotic. All patients underwent a 99mTc-MAG3 DR with F + 10(sp) method. We acquired a DR for 20min with the patient in a seated position. Patient drank 400-500mL of water at 5min after tracer injection and received a 20mg bolus of Furosemide at 10min during dynamic acquisition. The indices Time to peak, diuretic half time, and 20min/peak ratio have been evaluated. Retrograde pyelography confirmed UAS in all patients with DR obstructive findings. We repeated DR as follow-up in two subgroups of patients. DR with F + 10(sp) method showed obstructive findings in 36 out of 44 hydronephrotic kidneys. 6 patients showed non-obstructive findings. 32 patients showed obstructive findings (20 out of 32 developed UAS within 12months after surgery). Fifteen pts underwent a surgical treatment of UAS. In 1 patient with equivocal findings, we observed an ileo-ureteral reflux. The DR with F + 10(sp) method in the seated position has a lower uncertain diagnostic rate, compared to the radiological findings of US or CTU, in management of bladder cancer patients with urinary diversion. The semiquantitative indices diuretic half time and 20min/peak ratio evaluated in a condition of favorable gravity reduce uncertain responses improving interobserver concordance.

Urinary Ultrasound and Other Imaging for Ureteropelvic Junction Type Hydronephrosis (UPJHN).

Ultrasound is the main imaging study used to diagnose ureteropelvic junction (UPJ) obstruction. On ultrasound, abnormal dilatation of the pelvicalyceal system of varying degrees is seen, whereas the ureter is normal in caliber. A properly performed study provides essential information regarding laterality, renal size, thickness, and architecture of the renal cortex and degree of dilatation of the pelvicalyceal system. Doppler ultrasound may identify a crossing vessel, when present. This imaging method also has been used differentiating obstructive from non-obstructive hydronephrosis by renal arterial resistive index measurements. Abdominal radiographs may show soft tissue fullness, bulging of the flank, and displacement of bowel loops from the affected side. The voiding/micturating cystourethrogram helps exclude other causes of upper tract dilatation, including vesicoureteral reflux, urethral valves, and ureteroceles. Computerized Tomography angiography with multiplanar reformation and three-dimensional images may be used to depict suspected crossing vessels as a cause of UPJ obstruction in older children and adults. Magnetic Resonance Urography has progressed significantly in recent years due to the development of both hardware and software that are used to generate high-resolution images. This imaging technique currently allows for the detailed assessment of urinary tract anatomy, while also providing information regarding renal function, including differential renal function, and the presence or absence of obstructive uropathy.

Resolution of Hydronephrosis in Children with Dysfunctional Voiding After Biofeedback Therapy: A Randomized Clinical Trial.

We assessed efficacy of biofeedback therapy and home pelvic floor muscle exercises in children with dysfunctional voiding (DV) associated with mild to moderate hydronephrosis. This prospective study comprised fifty seven children (21 boys, 36 girls; mean age 8.9 ± 2.6) with DV and mild to moderate hydronephrosis. Children were randomly allocated into two treatment groups including control group who underwent standard urotherapy and case group who received biofeedback therapy in addition to standard urotherapy. A 99mTc diethylenetriamine pentaacetic acid (99mDTPA) scan, voiding cystoureterography, kidney and bladder ultrasounds, voiding diary and uroflowmetry with electromyography (EMG) were performed in all study participants at the baseline. Children with evidence of complete obstruction in DTPA scan and vesicoureteral reflux were excluded from enrollment. A complete voiding diary, kidney and bladder ultrasounds and uroflowmetry/EMG were also performed 6months and 1year after completion of the treatment. We noted a more significant decline in anteroposterior pelvic diameter in case group compared to control group (P < 0.05). The mean maximal urine flow rate prior to treatment was 16.5 ± 2.6 and 16.1 ± 3ml/s in case and control groups, respectively. This finding increased significantly 1year after the treatment in case group compared to controls (25 ± 7.2ml/s vs. 18.4 ± 5.9ml/s, respectively; P < 0.001). Improvement of various parameters in voiding diary was also more significant in the case group. Biofeedback therapy can effectively resolve non-refluxing and non-obstructive hydronephrosis in children with DV.

Association between Severity and Etiology of Antenatal Hydronephrosis in Neonates

Background and Aim: Antenatal hydronephrosis refers to the dilation of renal pelvis during fetal development. This condition is commonly diagnosed during intrauterine ultrasonography. According to available statistics, fetal anomalies are seen in about 0.5-2.5% of intrauterine ultrasound examinations. The most common anomaly is hydronephrosis. The severity of renal pelvic dilatation in the first sonography after birth may help to diagnose the underlying cause of antenatal hydronephrosis. On the other hand, knowledge of the etiology of hydronephrosis can help to understand the clinical course of the disease and to determine an appropriate therapeutic protocol for patients.Methods: In this descriptive cross-sectional study, all infants with antenatal hydronephrosis referred to the pediatric nephrology clinic of Imam Khomeini Hospital, Ilam, Iran were evaluated. Considering a hydronephrosis frequency of 50%, confidence interval of 95%, and error rate of 13%, the sample size was calculated at 60 subjects.Results: This study was performed in 61 neonates with antenatal hydronephrosis, including 43 (70.5%) males and 18 (29.5%) females. The frequency of hydronephrosis was significantly higher in boys than girls. Non-obstructive hydronephrosis was the most common underlying etiology in the patients. Most of the infants had a mild hydronephrosis. UPJO (ureteropelvic junction obstruction) was the most common cause of hydronephrosis. Furthermore, most of the patients had bilateral hydronephrosis.Conclusion: Non-obstructive hydronephrosis accounted for about 50% of antenatal hydronephrosis cases in this study. The intensity of the pelvic dilatation was directly associated with obstructive hydronephrosis, which can be used as a diagnostic guide. Keywords: Hydronephrosis; Etiology; Neonates; Severity.

Renal Arterial Doppler Resistive Index in Differentiating Obstructive and Non-Obstructive Hydronephrosis in Children at Tikur Anbessa Specialized Hospital, Ethiopia, October, 2018.

Most congenital anomalies of the urinary tract present with hydronephrosis. Some are physiological while others pathological. Ultrasound, micturating cyst urethrography, dynamic renal scintigraphy, intravenous urography, dynamic and static magnetic resonance urography are used for examination. Currently, renal arterial Doppler resistance index is used as complimentary mechanism. This study assesses our experience in resistive index measurement in differentiating obstructive from non-obstructive hydronephrosis in children. A cross-sectional study of forty-two infants and children (<14 years) with hydronephrosis were enrolled using consecutive sampling. Ultrasonography to assess the degree of hydronephrosis and avoiding cystourethrogram were used for the diagnosis of vesicoureteral reflux and posterior urethral valve. Intravenous urogram and surgery were used to confirm causes for obstructive hydronephrosis. Doppler ultrasonography assessed both kidneys to determine mean resistive index for both obstructive and non-obstructive hydronephrosis as well as nonobstructive kidneys. Independent t test was used for analysis at p< 0.005. The major cause for obstructive hydronephrosis was pelviuretheric junction obstruction (47.6%) followed by posterior urethral valve (16.7%). For non-obstructive hydronephrosis, vesicoureteral reflux was the main cause followed by prune belly syndrome. The mean resistive index for non-hydronephrotic kidneys was 0.6654 ±0.053, for nonobstructive hydronephrotic ones was 0.6825 ± 0.06668 and obstructive ones was 0.7791 ± 0.11977. The mean resistive index difference between the obstructive and non-obstructive hydronephrosis was 0.09661 with standard error of difference 0.02443. The difference was statistically significant (P-<0.001). A mean RI ROC curve showed sensitivity, specificity and accuracy of 71.1%, 81.2%, 75.4% respectively (p=0.003). This study has shown that the mean renal arterial resistive index was significantly higher in obstructive hydronephrotic kidneys than non-obstructive hydronephrotic kidneys. This can be a valuable tool for diagnosis and follow-up after intervention.

Clinical Spectrum of Congenital Anomalies of Kidney and Urinary Tract in Children

To evaluate the clinical spectrum and patterns of clinical presentation in congenital anomalies of kidney and urinary tract. We enrolled 307 consecutively presenting children with congenital anomalies of kidney and urinary tract at the pediatric nephrology clinic. Patients were evaluated clinically, with serum biochemistry, appropriate imaging and radionuclide scans. The most common anomaly was primary vesicoureteric reflux (VUR) (87, 27.3%), followed by pelviureteral junction obstruction (PUJO) (62,20.1%), multicystic dysplastic kidney (51 16.6%), non-obstructive hydronephrosis (32, 10.4%) and posterior urethral valves (PUV) (23, 7.4%). 247 (80.4%) anomalies had been identified during the antenatal period. Another 33 (10.7%) were diagnosed during evaluation of urinary tract infection, and 21 (6.8%) during evaluation for hypertension at presentation. Obstructive anomalies presented earlier than non-obstructive (7 (3, 22.5) vs 10 (4, 24) mo: (P=0.01)). The median (IQR) ages of presentation for children with PUV (n=23), VUR (n=87) and PUJO (n=62) were 4 (2, 14) mo, 10 (5, 27) mo, and 7 (3, 22.5) mo, respectively. Nine (2.9%) children had extrarenal manifestations. The median age at clinical presentation for various subgroups of anomalies indicates delayed referral. We emphasize the need for prompt referral in order to initiate appropriate therapeutic strategies in children with congenital anomalies of kidney and urinary tract.

Mechanisms of Developmental Toxicity of Dioxins and Related Compounds.

Dioxins and related compounds induce morphological abnormalities in developing animals in an aryl hydrocarbon receptor (AhR)-dependent manner. Here we review the studies in which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is used as a prototypical compound to elucidate the pathogenesis of morphological abnormalities. TCDD-induced cleft palate in fetal mice involves a delay in palatogenesis and dissociation of fused palate shelves. TCDD-induced hydronephrosis, once considered to be caused by the anatomical obstruction of the ureter, is now separated into TCDD-induced obstructive and non-obstructive hydronephrosis, which develops during fetal and neonatal periods, respectively. In the latter, a prostaglandin E2 synthesis pathway and urine concentration system are involved. TCDD-induced abnormal development of prostate involves agenesis of the ventral lobe. A suggested mechanism is that AhR activation in the urogenital sinus mesenchyme by TCDD modulates the wingless-type MMTV integration site family (WNT)/β-catenin signaling cascade to interfere with budding from urogenital sinus epithelium. TCDD exposure to zebrafish embryos induces loss of epicardium progenitor cells and heart malformation. AHR2-dependent downregulation of Sox9b expression in cardiomyocytes is a suggested underlying mechanism. TCDD-induced craniofacial malformation in zebrafish is considered to result from the AHR2-dependent reduction in SRY-box 9b (SOX9b), probably partly via the noncoding RNA slincR, resulting in the underdevelopment of chondrocytes and cartilage.