Hans G. Pohl

The Insulin-3 Gene: Lack of a Genetic Basis for Human Cryptorchidism

PURPOSEnThe etiology of cryptorchidism appears to be multifactorial and related to hormonal and mechanical factors. Recently, the insulin-3 gene (INSL3) was noted to have a role in mouse gubernacular development and testicular descent. Knockout male mice for the INSL3 gene show isolated bilateral cryptorchidism. This phenotype suggests that INSL3 may have a role in the development of human cryptorchidism. Using single strand conformational polymorphism analysis we detected mutations of the INSL3 gene in boys with cryptorchidism.nnnMATERIALS AND METHODSnGenomic DNA from 118 boys with cryptorchidism and 48 normal controls were obtained from 3 institutions. Using polymerase chain reaction with INSL3 sequence specific primers DNA fragments were analyzed using single strand conformational polymorphism reactions. Samples with band shifts were re-amplified and sequenced to detect mutations.nnnRESULTSnA single base substitution (G greater than A) causing an amino acid change (missense mutation) was identified in 27 of 118 cryptorchid (23%) samples and 12 of 48 normal (25%) samples. Two other base substitutions did not produce alterations in the amino acid sequence (silent mutations).nnnCONCLUSIONSnAlthough a common polymorphism was detected in the INSL3 gene, no specific mutations were detected in a large population of individuals with cryptorchidism. Therefore, mutations in the coding region of the INSL3 gene are not a common cause of human cryptorchidism.

Redefining Healthy Urine: A Cross-Sectional Exploratory Metagenomic Study of People With and Without Bladder Dysfunction

PURPOSEnWe used the PathoScope platform to perform species level analyses ofxa0publicly available, 16S rRNA pyrosequenced, asymptomatic urine data to determine relationships between microbiomes, and clinical and functional phenotypes.nnnMATERIALS AND METHODSnWe reanalyzed previously reported, cross-sectionally acquired urine samples from 47 asymptomatic subjects, including 23 controls and 24 subjects with neuropathic bladder. Urine was originally collected by the usual method of bladder drainage and analyzed by urinalysis, culture and pyrosequencing. Urinalysis and culture values were stratified as leukocyte esterase (0, or 1 or greater), nitrite (positive or negative), pyuria (fewer than 5, or 5 or greater white blood cells per high power field), cloudy urine (positive orxa0negative) and urine culture bacterial growth (less than 50,000, or 50,000 or greater cfu/ml). PathoScope was used for next generation sequencing alignment, bacterial classification and microbial diversity characterization.nnnRESULTSnSubjects with neuropathic bladder were significantly more likely to havexa0positive leukocyte esterase and pyuria, cloudy urine and bacterial growth. Of 47 samples 23 showed bacterial growth on culture and in all samples bacteria were identified by pyrosequencing. Nonneuropathic bladder urine microbiomes included greater proportions of Lactobacillus crispatus in females and Staphylococcus haemolyticus in males. The Lactobacillus community differed significantly among females depending on bladder function. Irrespective of gender the subjects with neuropathic bladder had greater proportions of Enterococcus faecalis, Proteus mirabilis and Klebsiella pneumonia. In 4 subjects with neuropathic bladder Actinobaculum sp. was detected by sequencing and by PathoScope but not by cultivation and in all cases it was associated with pyuria.nnnCONCLUSIONSnUsing PathoScope plus 16S pyrosequencing we were able to identify unique, phenotype dependent, species level microbes. Novel findings included absent L. crispatus in the urine of females with neuropathic bladder and the presence of Actinobaculum only in subjects with neuropathic bladder.

Testicular Torsion Presentation Trends before and after Pediatric Urology Subspecialty Certification

Purpose: We examined testicular torsion presentation and referral trends at our institution before and after pediatric urology subspecialty certification. Materials and Methods: We reviewed patients with testicular torsion presenting directly to our pediatric hospital emergency department (“direct”) or transferred urgently from an outside institution (“referred”) who underwent detorsion and orchiopexy or orchiectomy between 2005 and 2015. Presentations were considered acute (less than 24 hours) or delayed (24 hours or greater) based on time from symptom onset. Primary outcomes were case volume and presentation trends through time. Secondary outcomes were effect of presenting location and transport variables on orchiectomy rate. Results: Incidence of testicular torsion increased from 15 cases in 2005 to 32 in 2015. Annual incidence of direct cases increased slightly during the study period from 12 to 17, whereas incidence of referred cases increased from 3 in 2005 to 15 in 2015. Proportion of referred acute cases markedly increased from precertification (4 of 63, 6.3%) to postcertification period (42 of 155, 27.1%; p <0.01). The majority of referred cases (59 of 83, 71.1%) presented during weekday nights or weekends compared to a minority of direct cases (59 of 135, 43.7%; p <0.01). Orchiectomy rates were similar between direct and referred cases across all study periods and were not significantly impacted by presentation location, transport distance or transport modality (all p >0.05). Conclusions: Patients with testicular torsion have been increasingly referred to our institution, with the majority presenting on weekday nights and weekends. Our data do not support routinely transferring these patients to dedicated pediatric hospitals.

Factors Associated with Delayed Presentation and Misdiagnosis of Testicular Torsion: A Case-Control Study

&NA; We identified factors associated with delay in presentation and misdiagnosis of testicular torsion. Compared with acute cases, delayed presentations were more likely to report isolated abdominal pain, developmental disorders, and history of recent genital trauma. Failure to perform a genitourinary examination or scrotal imaging was associated with misdiagnosis.

Prediction of Clinical Outcomes in Prenatal Hydronephrosis: Importance of Gravity Assisted Drainage

Purpose: In infants with SFU (Society for Fetal Urology) grade 3‐4 congenital hydronephrosis, 99mTc‐mercaptoacetyltriglycine diuretic renography assesses differential function and drainage half‐time. We routinely also include the percent of radiotracer drained after 30 minutes of diuresis as well as after 15 minutes with the patient in the upright position. We investigated whether any 1 or more of these parameters on initial diuretic renography predicts persistent or worsening drainage parameters. Materials and Methods: Infants 6 months or younger with grade 3‐4 congenital hydronephrosis who presented between January 2009 and December 2014 were identified from billing data and included in analysis if they underwent at least 1 baseline diuretic renography. Those with structural anomalies were excluded from study. Baseline and followup differential function, diuresis half‐time, clearance at 30 minutes and clearance with the patient upright were abstracted and comparisons were made between those with initially indeterminate diuresis half‐time who underwent pyeloplasty vs those showing spontaneous improvement. Results: A total of 74 patients (82 renal units) with presumed ureteropelvic junction obstruction met inclusion/exclusion criteria. All 10 renal units with initial diuresis half‐time less than 5 minutes resolved spontaneously and all 25 renal units with initial diuresis half‐time greater than 75 minutes underwent pyeloplasty. Therefore, we defined the indeterminate group as the 47 renal units with initial half‐time between 5 and 75 minutes. Of those 47 renal units with indeterminate initial diuresis half‐time 23 (47%) underwent pyeloplasty and 25 (53%) resolved spontaneously. Indications for pyeloplasty included worsening in 17 cases, persistent obstruction in 4 and urinary tract infection in 1. Among renal units with indeterminate drainage clearance while upright and clearance at 30 minutes were the only variables that differed significantly between surgical cases and those that resolved spontaneously. Conclusions: Radiotracer clearance with the patient upright and clearance at 30 minutes are more predictive of surgical management than diuresis half‐time or differential function for renal units with indeterminate drainage. They should be included in the standard assessment of ureteropelvic junction obstruction.

PIC cystography: a selective approach to the diagnosis of vesicoureteral reflux.

WE cannot deny the positive impact that has been made on the incidence of severe acquired renal cortical scarring through the early diagnosis of vesicoureteral reflux (VUR) and the prevention of recurrent acute pyelonephritis (APN) via prophylactic antibiotics and/or surgical intervention as indicated. Proponents of the PIC (positioned instillation of contrast) cystogram advocate its use on the basis that febrile urinary tract infection (UTI) is not associated with VUR in up to 65% of cases evaluated by standard voiding cystourethrography (VCUG) and, thus, the sensitivity of VCUG for the detection of VUR is wanting, and that all VUR should be identified and treated— which is conveniently accomplished under the same anesthetic by endoscopic means. The standard evaluation of febrile UTI in children has long included ultrasonography and VCUG. Using this approach, the prevalence of VUR in children presenting with febrile UTI varies between 25% and 50% (mean 35%) depending on the timing of the VCUG and the number of fill-void cycles performed. Using dimercapto-succinic acid (DMSA) renal scans to document the presence of APN, Majd and Rushton performed a VCUG during hospitalization and found VUR in only 37% of patients with renal cortical abnormalities. Other studies have shown that when a VCUG is delayed 4 to 6 weeks following presentation for febrile UTI the diagnosis of VUR will be missed in as many as 28.5% of children. In addition, it has been reported that grades III and higher VUR can be missed in up to a third of patients undergoing only 1 filling cycle, whereas generally 2 filling cycles increase the yield of identifying low to moderate grade VUR. While it is true that VUR can elude diagnosis depending on the timing and technique used during VCUG, it is illogical to argue that VUR that can only be demonstrated by positioning a stream of contrast at the ureteral orifice is not iatrogenic. Children with presumed PIC positive VUR and uropathogenic bacteria that infect the upper tracts do not have

Identification of Burkholderia fungorum in the urine of an individual with spinal cord injury and augmentation cystoplasty using 16S sequencing: copathogen or innocent bystander?

IntroductionPeople with neuropathic bladder (NB) secondary to spinal cord injury (SCI) are at risk for multiple genitourinary complications, the most frequent of which is urinary tract infection (UTI). Despite the high frequency with which UTI occurs, our understanding of the role of urinary microbes in health and disease is limited. In this paper, we present the first prospective case study integrating symptom reporting, urinalysis, urine cultivation, and 16S ribosomal ribonucleic acid (rRNA) sequencing of the urine microbiome.Case presentationA 55-year-old male with NB secondary to SCI contributed 12 urine samples over an 8-month period during asymptomatic, symptomatic, and postantibiotic periods. All bacteria identified on culture were present on 16S rRNA sequencing, however, 16S rRNA sequencing revealed the presence of bacteria not isolated on culture. In particular, Burkholderia fungorum was present in three samples during both asymptomatic and symptomatic periods. White blood cells of ≥5–10/high power field and leukocyte esterase ≥2 on urinalysis was associated with the presence of symptoms.DiscussionIn this patient, there was a predominance of pathogenic bacteria and a lack of putative probiotic bacteria during both symptomatic and asymptomatic states. Urinalysis-defined inflammatory markers were present to a greater extent during symptomatic periods compared to the asymptomatic state, which may underscore a role for urinalysis or other inflammatory markers in differentiating asymptomatic bacteriuria from UTI in patients with NB. The finding of potentially pathogenic bacteria identified by sequencing but not cultivation, suggests a need for greater understanding of the relationships amongst bacterial species in the bacteriuric neuropathic bladder.

Early Detection of Ureteropelvic Junction Obstruction Using Signal Analysis and Machine Learning: A Dynamic Solution to a Dynamic Problem.

Purpose We sought to define features that describe the dynamic information in diuresis renograms for the early detection of clinically significant hydronephrosis caused by ureteropelvic junction obstruction. Materials and Methods We studied the diuresis renogram of 55 patients with a mean ± SD age of 75 ± 66 days who had congenital hydronephrosis at initial presentation. Five patients had bilaterally affected kidneys for a total of 60 diuresis renograms. Surgery was performed on 35 kidneys. We extracted 45 features based on curve shape and wavelet analysis from the drainage curves recorded after furosemide administration. The optimal features were selected as the combination that maximized the ROC AUC obtained from a linear support vector machine classifier trained to classify patients as with or without obstruction. Using these optimal features we performed leave 1 out cross validation to estimate the accuracy, sensitivity and specificity of our framework. Results were compared to those obtained using post‐diuresis drainage half‐time and the percent of clearance after 30 minutes. Results Our framework had 93% accuracy, including 91% sensitivity and 96% specificity, to predict surgical cases. This was a significant improvement over the same accuracy of 82%, including 71% sensitivity and 96% specificity obtained from half‐time and 30‐minute clearance using the optimal thresholds of 24.57 minutes and 55.77%, respectively. Conclusions Our machine learning framework significantly improved the diagnostic accuracy of clinically significant hydronephrosis compared to half‐time and 30‐minute clearance. This aids in the clinical decision making process by offering a tool for earlier detection of severe cases and it has the potential to reduce the number of diuresis renograms required for diagnosis.