In vivo base editing rescues primary hyperoxaluria type 1 in rats.

Primary hyperoxaluria type 1 (PH1) is a childhood-onset autosomal recessive disease, characterized by nephrocalcinosis, multiple recurrent urinary calcium oxalate stones, and a high risk of progressive kidney damage. PH1 is caused by inherent genetic defects of the alanine glyoxylate aminotransferase (AGXT) gene. The in vivo repair of disease-causing genes was exceedingly inefficient before the invention of base editors which can efficiently introduce precisely targeted base alterations without double-strand DNA breaks. Adenine base editor (ABE) can precisely convert A·T to G·C with the assistance of specific guide RNA. Here, we demonstrated that systemic delivery of dual adeno-associated virus encoding a split-ABE8e could artificially repair 13% of the pathogenic allele in AgxtQ84X rats, a model of PH1, alleviating the disease phenotype. Specifically, ABE treatment partially restored the expression of alanine-glyoxylate-aminotransferase (AGT), reduced endogenous oxalate synthesis and alleviated calcium oxalate crystal deposition. Western blot and immunohistochemistry confirmed that ABE8e treatment restored AGT protein expression in hepatocytes. Moreover, the precise editing efficiency in the liver remained stable six months after treatment. Thus, our findings provided a prospect of in vivo base editing as a personalized and precise medicine for PH1 by directly correcting the mutant Agxt gene.

Ureterocele with duplex collecting systems and febrile urinary tract infection risk.

PURPOSE: Ureterocele has been hypothesized to be the risk factor for febrile urinary tract infections (F-UTIs) in patients with duplex collecting systems, but this has not been proved, and our goal was to assess the relation between ureterocele with duplex collecting systems and F-UTIs. METHODS: We included individual-participant data from patients seen for complicated duplex collecting systems from 2010 to 2020 retrospectively followed. Those with using continuous low-dose antibiotic prophylaxis and incompletely duplicated systems were removed from the study. The participants were divided into two cohorts according to patients with or without ureterocele. The primary endpoint of this study was recurrent F-UTIs. RESULTS: We analyzed medical reports of 300 patients, of which 75% were female. Among the 300 patients, F-UTIs developed in 111/159 (69.8%) patients in the ureterocele group and in 69/141 (48.9%) patients in the no-ureterocele group. Univariate analysis found no discernible difference except in grade of hydronephrosis between ureterocele group and no-ureterocele group. Moreover, Cox proportional regression analysis revealed that patients of duplex system ureterocele might be intrinsically more prone to develop F-UTIs (adjusted hazard ratio 1.894; 95% CI 1.412-2.542; p  <  0.001). CONCLUSION: Among participants with duplex systems, the risk of recurrent F-UTIs in patients with ureterocele was higher than patients without it, and mini-invasive surgical correction should be considered at young age to reduce F-UTIs.

A comparison of the clinical characteristics of pediatric urolithiasis patients with positive and negative molecular diagnoses.

PURPOSE: To compare the clinical characteristics of pediatric urolithiasis patients with positive and negative molecular diagnoses. METHODS: The clinical characteristics corresponding to pediatric urolithiasis patients that had undergone exome sequencing at our hospital between January 2016 and May 2021 were collected. Genetic analysis results were used to separate patients into positive and negative molecular diagnosis groups. Multivariate logistic regression analyses adjusted for visiting age, sex, ethnicity, province, and body mass index were used to compare differences in medical history, diagnostic imaging findings, and renal function between individuals with and without molecular diagnoses. RESULTS: In total, 194 patients with pediatric urolithiasis of unknown etiology underwent exome sequencing and were included in the present study, of whom 63 obtained urolithiasis-related molecular diagnoses. Relative to cases without a molecular diagnosis, those with a positive molecular diagnosis were more likely to be associated with a positive family history (OR 2.84, 95% CI 1.29-6.29, p = 0.008), consanguineous parents (OR 24.7, 95% CI 1.34-454, p = 0.002), early onset (OR 1.26, 95% CI 1.09-1.45, p < 0.001), nephrocalcinosis (OR 10.6, 95% CI 3.06-36.6, p < 0.001), cast stone (OR 18.9, 95% CI 4.40-81.1, p < 0.001), multiple stones (OR 13.9, 95% CI 6.39-30.2, p < 0.001), bilateral stones (OR 7.04, 95% CI 3.47-14.2, p < 0.001), a lower estimated glomerular filtration rate (OR 1.17, 95% CI 1.07-1.28, p < 0.001), and chronic kidney disease (OR 26.9, 95% CI 1.42-526, p < 0.001). CONCLUSION: A positive family history, consanguineous parents, early onset, nephrocalcinosis, severe stone burden, and impaired renal function are signals of concern that are suggestive of inherited urolithiasis.

Lipidomics characterization of the lipid metabolism profiles in a cystinuria rat model: Precalculus damage in the kidney of cystinuria.

Cystinuria is a genetic disorder of cystine transport, including defective protein b0,+AT (encoded by SLC7A9), and/or rBAT (encoded by SLC3A1). Patients present hyperexcretion of cystine in the urine, recurrent cystine lithiasis, and progressive decline in kidney function. Moreover, heterodimer transport is defective. To date, little omics data are accessible regarding this metabolic disease caused by membrane proteins. Since membrane function is closely related to changes in the lipidome, we decided to explore the changes in kidney tissue of a self-established cystinuria rat model by performing lipidomic analysis by LC-MS/MS. Our results demonstrated that Slc7a9 deficiency changed the lipid profile of the renal cortex and induced vital modifications in the lipidome, including major alterations in ChE, LPA, and PA. Among those alterations, this lipidomic study highlights the lipid changes that participate in inflammatory responses during cystinuria. As a result, lipid research, perhaps has great potential, for it may lead to the identification of novel therapeutic targets for the prevention and treatment of cystinuria.

Generation and characterization of a novel rat model of primary hyperoxaluria type 1 with a nonsense mutation in alanine-glyoxylate aminotransferase gene.

Primary hyperoxaluria type 1 (PH1) is a severe inherited disorder caused by a genetic defect in alanine-glyoxylate aminotransferase (AGXT), which results in recurrent urolithiasis and renal failure. Animal models that precisely reflect human PH1 phenotypes are lacking. We aimed to develop a novel PH1 rat model and study the mechanisms involved in PH1 deterioration. One cell stage Sprague-Dawley embryos were injected with the CRISPR/Cas9 system to introduce a Q84X mutation in Agxt. Liver tissues were harvested to determine Agxt expression. Urine oxalate, crystals, and electrolyte levels in AgxtQ84X and wild-type (WT) littermates were evaluated. Kidney tissues were used for Pizzolato staining and kidney injury evaluation. Data showed that Agxt mRNA and protein were absent in AgxtQ84X rats. At 4 and 24 wk, AgxtQ84X rats displayed 2.1- and 2.9-fold higher urinary oxalate levels, respectively, compared with WT littermates. As a result, calcium oxalate (CaOx) crystals in urine were revealed in all AgxtQ84X rats but in none of the WT rats. We also observed bladder stones in 36.4% of AgxtQ84X rats, of which 44.4% had renal CaOx deposition. Moreover, the elevated serum urea and creatinine levels indicated the impaired renal function in AgxtQ84X rats. Further investigation revealed significantly increased expression of inflammation-, necroptosis-, and fibrosis-related genes in the kidneys of AgxtQ84X rats with spontaneous renal CaOx deposition, indicating that these pathways are involved in PH1 deterioration. Collectively, these results suggest that this rat model has broad applicability in mechanistic studies and innovative therapeutics development for PH1 and other kidney stone diseases.NEW & NOTEWORTHY Primary hyperoxaluria type 1 is a severe inherited disorder that results in recurrent urolithiasis and renal failure. We generated an alanine-glyoxylate aminotransferase (Agxt)Q84X nonsense mutant rat model that displayed an early onset of hyperoxaluria, spontaneous renal CaOx precipitation, bladder stone, and kidney injuries. Our results suggest an interaction of renal CaOx crystals with the activation of inflammation-, fibrosis-, and necroptosis-related pathways. In all, the AgxtQ84X rat strain has broad applicability in mechanistic studies and the development of innovative therapeutics.

Integration of exome sequencing and metabolic evaluation for the diagnosis of children with urolithiasis.

PURPOSE: To investigate the prevalence of inherited causes in an early onset urolithiasis cohort and each metabolic subgroup. METHODS: A retrospective analysis of both metabolic and genomic data was performed for the first 105 pediatric urolithiasis patients who underwent exome sequencing at our hospital from February 2016 to October 2018. Measurements included the diagnostic yield of exome sequencing in the entire cohort and each metabolic subgroup (hyperoxaluria, hypocitraturia, hypercalciuria, hyperuricosuria and cystine stone subgroups). The conformity between molecular diagnoses and metabolic evaluation was also evaluated. RESULTS: The present study involved a cohort of 105 pediatric patients with urolithiasis, from which diagnostic variants were identified in 38 patients (36%), including 27 primary hyperoxaluria and 11 cystinuria. In the metabolic subgroup analyses, 41% hyperoxaluria cases were primary hyperoxaluria caused by monogenic defects, and 100% of the causes of cystine stones could be explained by monogenic defects. However, no appropriate inherited causes were identified for hypocitraturia, hypercalciuria, or hyperuricosuria in the cohort. A high conformity (100%) was obtained between the molecular diagnoses and metabolic evaluation. CONCLUSION: Exome sequencing in a cohort of 105 pediatric patients with urolithiasis yielded a genetic diagnosis in 36% of cases and the molecular diagnostic yield varies substantially across different metabolic abnormalities.

Amelioration of an Inherited Metabolic Liver Disease through Creation of a De Novo Start Codon by Cytidine Base Editing.

Base editing technology efficiently generates nucleotide conversions without inducing excessive double-strand breaks (DSBs), which makes it a promising approach for genetic disease therapy. In this study, we generated a novel hereditary tyrosinemia type 1 (HT1) mouse model, which contains a start codon mutation in the fumarylacetoacetate hydrolase (Fah) gene by using an adenine base editor (ABE7.10). To investigate the feasibility of base editing for recombinant adeno-associated virus (rAAV)-mediated gene therapy, an intein-split cytosine base editor (BE4max) was developed. BE4max efficiently induced C-to-T conversion and restored the start codon to ameliorate HT1 in mice, but an undesired bystander mutation abolished the effect of on-target editing. To solve this problem, an upstream sequence was targeted to generate a de novo in-frame start codon to initiate the translation of FAH. After treatment, almost all C-to-T conversions created a start codon and restored Fah expression, which efficiently ameliorated the disease without inducing off-target mutations. Our study demonstrated that base editing-mediated creation of de novo functional elements would be an applicable new strategy for genetic disease therapy.

CRISPR/Cas9-mediated metabolic pathway reprogramming in a novel humanized rat model ameliorates primary hyperoxaluria type 1.

Primary hyperoxaluria type I is caused by mutations in the alanine glyoxylate aminotransferase gene (AGXT), leading to accumulation of glyoxylate and subsequent production of oxalate and urolithiasis. Here, we generated a novel rat model of primary hyperoxaluria type I that carries a D205N mutation in the partially humanized Agxt gene through the CRISPR/Cas9 system. The AgxtD205N mutant rats showed undetectable alanine glyoxylate aminotransferase protein expression, developed hyperoxaluria at 1 month of age and exhibited severe renal calcium oxalate deposition after ethylene glycol challenge. This suggests our novel model is more relevant to the human disease than existing animal models. To test whether this model could be used for the development of innovative therapeutics, SaCas9 targeting hydroxyacid oxidase 1, responsible for metabolizing glycolate into glyoxylate, was delivered via adeno-associated viral vectors into newborn rats with primary hyperoxaluria type 1. This approach generated nearly 30% indels in the Hao1 gene in the liver, leading to 42% lower urine oxalate levels in the treated group than in the control group and preventing the rats with primary hyperoxaluria type 1 from undergoing severe nephrocalcinosis for at least 12 months. Thus, our results demonstrate that this partially humanized AgxtD205N rat strain is a high-performing model of primary hyperoxaluria type 1 for understanding pathology, and the development of novel therapeutics, such as reprogramming of the metabolic pathway through genome editing.

Cas9-nickase-mediated genome editing corrects hereditary tyrosinemia in rats.

Hereditary tyrosinemia type I (HTI) is a metabolic genetic disorder caused by mutation of fumarylacetoacetate hydrolase (FAH). Because of the accumulation of toxic metabolites, HTI causes severe liver cirrhosis, liver failure, and even hepatocellular carcinoma. HTI is an ideal model for gene therapy, and several strategies have been shown to ameliorate HTI symptoms in animal models. Although CRISPR/Cas9-mediated genome editing is able to correct the Fah mutation in mouse models, WT Cas9 induces numerous undesired mutations that have raised safety concerns for clinical applications. To develop a new method for gene correction with high fidelity, we generated a Fah mutant rat model to investigate whether Cas9 nickase (Cas9n)-mediated genome editing can efficiently correct the Fah First, we confirmed that Cas9n rarely induces indels in both on-target and off-target sites in cell lines. Using WT Cas9 as a positive control, we delivered Cas9n and the repair donor template/single guide (sg)RNA through adenoviral vectors into HTI rats. Analyses of the initial genome editing efficiency indicated that only WT Cas9 but not Cas9n causes indels at the on-target site in the liver tissue. After receiving either Cas9n or WT Cas9-mediated gene correction therapy, HTI rats gained weight steadily and survived. Fah-expressing hepatocytes occupied over 95% of the liver tissue 9 months after the treatment. Moreover, CRISPR/Cas9-mediated gene therapy prevented the progression of liver cirrhosis, a phenotype that could not be recapitulated in the HTI mouse model. These results strongly suggest that Cas9n-mediated genome editing is a valuable and safe gene therapy strategy for this genetic disease.

Identification of 8 novel gene variants in primary hyperoxaluria in 21 Chinese children with urinary stones.

PURPOSE: We analyzed primary hyperoxaluria (PH) genotype and phenotype in Chinese children. Vitamin B6 response in the patients with genetically confirmed PH1 was also studied. METHODS: We, respectively, analyzed 80 children with urinary stones. Sixty-four children were diagnosed with hyperoxaluria. Twenty-one children consented to genetic evaluation (targeted gene panel-based and whole-exome sequencing), and DNA was obtained from the children and both the parents. RESULTS: PH accounted for 57.1% (12/21) of hyperoxaluria cases. We reported 12 PH cases, including 5 PH1, 1 PH2, and 6 PH3 cases; 2 novel mutations in AGXT and GRHPR each and 4 HOGA1 mutations were identified. The mutations in AGXT and GRHPR were c0.1161C>A and c0.551C>A, and c0.370C>T and c0.864_865delTG, respectively. Four HOGA1 mutations, c0.290G>A, c0.110G>A, c0.554C>T and c0.834_834 + 1delinsTT, were not reported previously. The average urine Ox 24 level in the PH patients was 0.91 mmol/1.73 m2. Moreover, the average urine Ox 24 level in the PH1 patients (1.07 mmol/1.73 m2) was higher than that in the PH2 and PH3 patients (0.73 mmol/1.73 m2 and 0.71 mmol/1.73 m2, respectively). The eGFR of the PH1 patients (76.86 mL/min) was lower than that of the PH2 and PH3 patients (132 mL/min and 136 mL/min, respectively). CONCLUSIONS: PH incidence was higher than the reported PH incidence in children with urinary stones. Hence, we suggested that genetic examination was necessary for all the children with hyperoxaluria. These novel mutations broaden the range of known gene mutations in PH.

Nine novel HOGA1 gene mutations identified in primary hyperoxaluria type 3 and distinct clinical and biochemical characteristics in Chinese children.

BACKGROUND: Primary hyperoxaluria type 3 (PH3) is characterized by mutations in the 4-hydroxy-2-oxoglutarate aldolase (HOGA1) gene. PH3 patients are thought to present with a less severe phenotype than PH1 and PH2 patients. However, the clinical characteristics of PH3 patients have yet to be defined in sufficient detail. The aims of this study were to report HOGA1 mutations of PH3 in Chinese children, and to analyze the genotype and clinical characteristics of these PH3 patients. METHODS: Genetic analysis (targeted gene panel-based and/or whole-exome sequencing) of HOGA1 was performed in 52 patients with a high suspicion of PH3, and DNA was obtained from the patient and both the parents. The clinical, biochemical, and genetic data of these 12 patients identified with HOGA1 mutations were subsequently retrospectively reviewed. RESULTS: These 12 patients were identified with HOGA1 mutation. The median onset of clinical symptoms was 18.25 (range 5-38) months. In total, 14 different mutations were identified including 9 novel mutations in these 12 patients with PH3. All of these 12 patients initially presented with urolithiasis, and 3 patients among them comorbid urinary tract infection (UTI) as another initial symptom. Ten patients experienced hyperoxaluria (average oxalate 0.77 mmol/1.73 m2/24h). In contrast, urine calcium excretion was normal in 8 patients and 2 patients with hypercalciuria (urine calcium > 4 mg/kg/24 h). At the time of diagnosis, estimated GFR was 155.6 ml/min per 1.73 m2, and at last follow-up time (17.3 months later from diagnosis on average), estimated GFR was 157.5 ml/min per 1.73 m2. To date, none of the patients has impaired renal function based on and progressed to ESRD. CONCLUSIONS: We found that PH3 was significantly diagnosed in our urolithiasis patients during childhood. Nine novel HOGA1 mutations were identified in association with PH3, which provide a first-line investigation in Chinese PH3 patients. The eGFR was normal in all children with PH3. This finding is in contrast to the early impairment of renal function in PH1 and PH2.

Predictive Factors of Contralateral Operation after Initial Pyeloplasty in Children with Antenatally Detected Bilateral Hydronephrosis Due to Ureteropelvic Junction Obstruction.

OBJECTIVES: This study was performed to analyze the predictive factors of a contralateral operation after initial pyeloplasty in patients with antenatally detected bilateral ureteropelvic junction obstruction. METHODS: Patients with prenatally diagnosed bilateral ureteropelvic junction obstruction who underwent initial pyeloplasty (aged <12 months at initial pyeloplasty) were offered to participate in the study. Patients were recruited from January 2012 to December 2015. The anteroposterior renal pelvic diameter, parenchymal thickness, and calyceal dilatation were evaluated. Predictive factors of contralateral pyeloplasty after initial unilateral pyeloplasty were also examined. RESULTS: In total, 82 patients were included in the study (mean age, 2.8 months). Among all patients who underwent initial pyeloplasty, additional contralateral pyeloplasty was required in 11 patients (13.4%). The outcome of contralateral hydronephrosis was assessed as resolution, persistence, or surgery. The median anteroposterior renal pelvic diameter and calyceal dilatation were significantly different among the groups (p < 0.001). Calyceal dilatation of ≥10 mm and a calyceal dilatation/parenchymal thickness ratio of ≥5 strongly suggested the likelihood of a contralateral operation. CONCLUSIONS: In most patients with bilateral ureteropelvic junction obstruction, improvement or resolution of contralateral hydronephrosis following initial unilateral pyeloplasty can be expected. Patients with contralateral calyceal dilatation >10 mm and the calyceal dilatation/parenchymal thickness ratio >5 are at higher risk of surgery.

Placental pathology and hypospadias.

BACKGROUND: Studies have shown that hypospadias is associated with placenta-mediated pregnancy complication (PMPC). The role of placental lesions is still unclear. We aimed to examine the association between hyposadias and placental pathology, and the effect of PMPC. METHODS: Using data from the US Collaborative Perinatal Project in 1959-1966, we identified 15,780 male subjects (167 hypospadias) for analysis. Detailed placental examinations were conducted following a standard protocol. Subjects were divided into two groups according to whether they had PMPC, including small-for-gestational-age, pre-eclampsia/eclampsia or placental abruption. Logistic regression models were used to explore the association. RESULTS: The prevalence of hypospadias was two times higher in subjects with PMPC than those without. Compared to pregnancies with PMPC but no hypospadias, those with both PMPC and hypospadias had significant higher prevalence of placental lesions, such as low placental weight, vascular lesions, villous lesions, and membranous insertion of cord (adjusted odds ratio (OR) ranging from 2.6 to 5.2) after adjusting for potential confounders. In subjects without PMPC, no significant difference of placental pathology was found between those with or without hypospadias. CONCLUSION: About one third of hypospadias cases were complicated with PMPC and had a higher risk of placental lesions, suggesting heterogeneity of hypospadias etiology and mechanisms.

Curcumin improves tendon healing in rats: a histological, biochemical, and functional evaluation.

Curcumin, a compound extracted from the roots of Zingiberaceae, has been proposed as a treatment for tissue injury but studies are yet to be done on its effect on tendon healing. Therefore, we performed a series of experiments to test our hypothesis that curcumin has positive effects on tendon repair. Patellar tendon window defect was created in Sprague-Dawley rats and these were divided into two groups: (i) control and (ii) curcumin-treated. Curcumin (100 mg/kg body weight) was applied by oral gavage. Its potential for promoting tendon healing was assessed by histological evaluation, mRNA expression of tenocyte-related genes, malondialdehyde (MDA) levels, manganese-dependent superoxide dismutase (MnSOD) activity, quantification of hydroxyproline (HOPro), and biomechanical testing. In this tendon injury model, curcumin significantly improved the healing properties as evidenced by extensive deposition of well-organized collagen fibers, decreased MDA levels, and increase in the biomechanical properties and MnSOD activity of the regenerated tendon tissues. The current study showed that curcumin can improve the quality of tendon rupture healing, and thus represents a promising strategy in the management of injured tendon tissue.

Combined effect of ligament stem cells and umbilical-cord-blood-derived CD34+ cells on ligament healing.

Transplantation of ligament-tissue-derived stem cells has become a promising approach in the repair of injured ligament. Neovascularization plays an important role in ligament healing and remodeling. Recently, human umbilical-cord-blood-derived CD34+ cells have been reported to contribute to neoangiogenesis. Therefore, we performed a series of experiments to test our hypothesis that the combination of medial collateral ligament stem cells (MCL-SCs) and umbilical-cord-blood-derived CD34+ cells has synergistic effects on tendon healing. MCL-SCs and umbilical-cord-blood-derived CD34+ cells were isolated and cultured. Rat MCL injury was treated by MCL-SCs and/or CD34+ cells. Response to the cell therapy was assessed by gross observation, histological evaluation and biomechanical testing at 2 and 4 weeks after each treatment. Although each cell therapy group induced macroscopic and morphological recovery in healing MCLs, the combined use of MCL-SCs/CD34+ cells led to further improvement in healing quality. Capillary density was significantly higher in the CD34+ cell transplantation groups than in the other groups at week 2. Biomechanical testing demonstrated that the failure load of the healing ligament was greatest in the combination therapy group. The combination of MCL-SCs and CD34+ cells as a cell therapeutic thus enhances healing and restores biomechanical function toward normal after MCL injury. The findings obtained in our study suggest that the combination of MCL-SCs and CD34+ cells transplantation represents a promising strategy for ligament injury.

Diacylglycerol kinase κ (DGKK) variants and hypospadias in Han Chinese: association and meta-analysis.

OBJECTIVE: To investigate whether diacylglycerol kinase κ (DGKK) is a susceptibility gene for hypospadias in the Han Chinese population as has been suggested by previous publications. PATIENTS SUBJECTS AND METHODS: A case-control study involving 466 patients with hypospadias and 402 healthy subjects was conducted to assess the relationship between DGKK single nucleotide polymorphisms (SNPs) and hypospadias risk in the Han Chinese population. The 466 hypospadias patients were further divided into mild, moderate and severe subgroups for analysis. RESULTS: Six SNPs (rs1934179, rs4143304, rs9969978, rs1934188, rs4826632 and rs4599945) were marginally associated with mild and moderate hypospadias [odds ratios (ORs) > 1, P = 0.05 to P < 0.1), whereas no significant relationship was seen with the severe cases (ORs >1, P > 0.1). After correcting for multiple testing, it was determined that neither individual SNPs nor individual haplotypes were associated with hypospadias. To evaluate this relationship in multiple populations, we performed a meta-analysis on six SNPs, using combined data from our present results and those of previous studies of different races (including 1966 patients and 2492 controls). Six SNPs (rs1934179, rs4143304, rs9969978, rs1934188, rs7063116 and rs1934190) were significantly associated with mild/moderate hypospadias (ORs >1, P < 0.05), and rs1934179 was significantly associated with severe hypospadias (OR > 1, P < 0.05). CONCLUSIONS: DGKK gene variants do not appear to play a major role in hypospadias susceptibility in the Chinese Han population. Our meta-analysis supports the hypothesis that DGKK is a common risk gene for hypospadias, particularly in cases of mild or moderate hypospadias in Caucasian populations.

[Relationship between anogenital distance and cryptorchidism in human newborns].

OBJECTIVE: To explore the relation of the anogenital distance (AGD) with cryptorchidism in male newborns. METHODS: This study included 350 male infants delivered in two community hospitals between September 2013 and September 2014. Within 24 hours after birth, a pediatric surgeon measured the AGD of the neonates and determined whether they had cryptorchidism. According to the testicular position, we divided the undescended testes into three types: upper scrotal, inguinal, and non-palpable. RESULTS: Totally 39 cases of cryptorchidism were found in the 350 newborns. The AGD of the cryptorchidism infants was significantly shorter than that of the normal neonates ([2.01 ± 0.22] vs [2.35 ± 0.19] cm, P < 0.01), and statistically significant differences remained even when preterm and low birth-weight infants were excluded ([2.32 ± 0.14] vs [2.06 ± 0.19] cm; (2.37 ± 0.17) cm vs (2.12 ± 0.12) cm, all P < 0.01). The newborns with higher-position cryptorchidism had a shorter AGD, though with no significant difference (F = 0.434, P > 0.05). No significant differences were observed in the AGD between unilateral and bilateral cryptorchidism ([1.96 ± 0.13] vs [2.02 ± 0.17] cm, P > 0.05). CONCLUSION: Shorter AGD is associated with a higher incidence of cryptorchidism in male newborns. AGD could serve as a potential biomarker for disruption of androgen action during the male programming window period.

Extracorporeal shock wave lithotripsy is effective in treating single melamine induced urolithiasis in infants and young children.

PURPOSE: We evaluated the safety and efficacy of extracorporeal shock wave lithotripsy in the treatment of single melamine induced urolithiasis in infants and young children. MATERIALS AND METHODS: A total of 189 infants and young children with single melamine induced urolithiasis were referred to our center for treatment with extracorporeal shock wave lithotripsy between March 2009 and July 2010. Location of the calculus was proximal ureteral in 17 patients, mid ureteral in 5, distal ureteral in 26 and kidney in 141. Stone size ranged from 3.8 to 25 mm (mean ± SD 9.79 ± 3.83). RESULTS: All patients underwent extracorporeal shock wave lithotripsy using the same device with an energy ranging from 8 to 12 kV. Stone-free rate was 97.88%, clinically insignificant residual fragment rate was 1.59% and repeat treatment rate was 2.65%. A total of 180 patients (95.24%) required only 1 lithotripsy session and 5 (2.65%) required 2 sessions. Mean ± SD number of shock waves delivered per session was 580.36 ± 190.69 (range 65 to 950). Extracorporeal shock wave lithotripsy failed to fragment stones in only 1 infant, who had a proximal ureteral stone. A total of 181 specimens were collected and analyzed by infrared spectrum, with results demonstrating that the main composition was uric acid and melamine. All patients were followed for a mean of 28 months (range 20 to 36). No severe complication, such as renal subcapsular hemorrhage, hypertension, kidney rupture or lung injury, was observed. CONCLUSIONS: Extracorporeal shock wave lithotripsy with low energy can effectively disintegrate melamine induced calculi. This approach has become our preferred method for treating single melamine induced urolithiasis in infants and young children.