A distinctive feature of gonadal maturation in mammals is the movement to an extraabdominal location. Testicular descent is a complex, multistage process whereby the embryonic gonads migrate from their initial abdominal position to the scrotum. Failure in this process results in cryptorchidism, a frequent congenital birth defect in humans. We report here a new mouse transgenic insertional mutation, cryptorchidism with white spotting (crsp). Males homozygous for crsp exhibit a high intraabdominal position of the testes, associated with complete sterility. Heterozygous males have a wild-type phenotype, and homozygous females are fertile. Surgically descended testes in crsp/crsp males show normal spermatogenesis. Using FISH and genetic analyses, the transgenic insert causing the crsp mutation has been mapped to the distal part of mouse chromosome 5. Transgene integration resulted in a 550-kb deletion located upstream of the Brca2 gene. A candidate gene encoding a novel G protein-coupled receptor (Great) with an expression pattern suggesting involvement in testicular descent has been identified.
OBJECTIVE
Our goal is to determine if antimicrobial prophylaxis with trimethoprim/sulfamethoxazole prevents recurrent urinary tract infections and renal scarring in children who are found to have vesicoureteral reflux after a first or second urinary tract infection.
DESIGN, PARTICIPANTS, AND METHODS
The Randomized Intervention for Children With Vesicoureteral Reflux (RIVUR) study is a double-blind, randomized, placebo-controlled trial. Six hundred children aged 2 to 72 months will be recruited from both primary and subspecialty care settings at clinical trial centers throughout North America. Children who are found to have grades I to IV vesicoureteral reflux after the index febrile or symptomatic urinary tract infection will be randomly assigned to receive daily doses of either trimethoprim/sulfamethoxazole or placebo for 2 years. Scheduled follow-up contacts include in-person study visits every 6 months and telephone interviews every 2 months. Biospecimens (urine and blood) and genetic specimens (blood) will be collected for future studies of the genetic and biochemical determinants of vesicoureteral reflux, recurrent urinary tract infection, renal insufficiency, and renal scarring.
RESULTS
The primary outcome is recurrence of urinary tract infection. Secondary outcomes include time to recurrent urinary tract infection, renal scarring (assessed by dimercaptosuccinic acid scan), treatment failure, renal function, resource utilization, and development of antimicrobial resistance in stool flora.
CONCLUSIONS
The RIVUR study will provide useful information to clinicians about the risks and benefits of prophylactic antibiotics for children who are diagnosed with vesicoureteral reflux after a first or second urinary tract infection. The data and specimens collected over the course of the study will allow researchers to better understand the pathophysiology of recurrent urinary tract infection and its sequelae.
Hypospadias repair using transverse island flaps offers reliable and durable outcomes. While overall complication rates were not greatly different between tubularized and onlay flap repairs, onlay repair tended to result in fistulas of smaller size and diverticula did not develop.
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