Randomized controlled trials (RCTs) are at the top of the pyramid of evidence as they offer the best answer on the efficacy of a new treatment. RCTs are true experiments in which participants are randomly allocated to receive a certain intervention (experimental group) or a different intervention (comparison group), or no treatment at all (control or placebo group). Randomization, along with other methodological features such as blinding and allocation concealment, safeguard against biases. This review will focus on parallel group RCT design as it is the most common design in the field of Pediatric Urology. RCTs can be designed using a superiority, equivalency, or non-inferiority hypothesis, and are usually preceded by a pilot, where the trial protocol is implemented in a small number of patients, mimicking the larger, definitive study. Even though regarded as the best available option to bring out scientific data, RCTs might be prone to mislead. If RCTs are small and underpowered, a difference of even one single event between groups, may completely change the trial results. To safeguard against RCTs weakness, a fragility concept of statistical significance was developed and called the Fragility Index (FI). RCTs may not be appropriate, ethical, or feasible for all surgical interventions. They may have limitations such as prohibitive cost and unrealistic large sample sizes. Nearly 60 % of surgical research questions cannot be answered by RCTs. Therefore, clinical practice should be based on the best available evidence on a given topic, regardless of the study design. However, even in these situations, conclusions drawn from observational studies must be interpreted with caution.

Purpose: To evaluate the early histological effects of the intravesical instillation of platelet-rich plasma (PRP) in rabbit models of interstitial and hemorrhagic cystitis. Methods: Thirty-six rabbits were classified into 6 groups: saline (S), S+PRP, hydrochloric acid (HCl), HCl+PRP, cyclophosphamide (CyP), and CyP+PRP. At 48 hours after induction, PRP was prepared and intravesically administered to the S+PRP, HCl+PRP, and CyP+PRP groups. Bladder sections were stained with toluidine blue for mast cell counting and with hematoxylin and eosin for histopathology and mitotic index determination. The proliferation index was determined by proliferating cell nuclear antigen (PCNA) immunolabeling. The nonparametric Mann-Whitney U-test was used for statistical analysis. Results: No abnormalities were observed in the S group, whereas increased interstitial edema and increased average mitotic and proliferation indices were observed in the S+PRP group (P=0.023, P=0.004, and P=0.009, respectively). Intense epithelial loss, hemorrhage, and leukocyte infiltration were detected in the HCl and HCl+PRP groups, whereas a significantly increased average mitotic index was observed in the HCl+PRP group (P=0.002). When compared with its CyP counterpart, a significant reduction in hemorrhage and an increase in leukocyte infiltration and mitotic index were observed in the CyP+PRP group (P=0.006, P=0.038, and P=0.002, respectively). In addition, PCNA staining revealed a significantly increased proliferation index in the HCl+PRP and CyP+PRP groups (P=0.032 and P=0.015, respectively). Conclusions: The intravesical instillation of PRP increased the mitotic index in the saline and cyclophosphamide groups while decreasing macroscopic bleeding.

Posterior urethral valves are the most common cause of partial bladder outlet obstruction (PBOO) in the pediatric population. Pathological changes in the bladder developed during PBOO are responsible for long-lasting voiding dysfunction in this population despite early surgical interventions. Increasing evidence showed PBOO induces an upregulation of hypoxia-inducible factors (HIFs) and their transcriptional target genes, and they play a role in pathophysiological changes in the obstructed bladders. We hypothesized that blocking HIF pathways can prevent PBOO-induced bladder dysfunction. PBOO was surgically created by ligation of the bladder neck in male C57BL/6J mice for 2 wk. PBOO mice received intraperitoneal injection of either saline or 17-DMAG (alvespimycin, 3 mg/kg) every 48 h starting from day 1 postsurgery. Sham-operated animals received injection of saline on the same schedule as PBOO mice and served as controls. The bladders were harvested after 2 wk, and basal activity and evoked contractility of the detrusor smooth muscle (DSM) were evaluated in vitro. Bladder function was assessed in vivo by void spot assay and cystometry in conscious, unrestrained mice. Results indicated the 17-DMAG treatment preserved DSM contractility and partially prevented the development of detrusor over activity in obstructed bladders. In addition, PBOO caused a significant increase in the frequency of micturition, which was significantly reduced by 17-DMAG treatment. The 17-DMAG treatment improved urodynamic parameters, including increases in the bladder pressure at micturition and nonvoid contractions observed in PBOO mice. These results demonstrate that treatment with 17-DMAG, a HIF inhibitor, significantly alleviated PBOO-induced bladder pathology in vivo.

Purpose: To investigate the prevalence of erectile dysfunction (ED) in patients with obstructive sleep apnea (OSA) with and without any other comorbidities. Methods: The patient group was newly diagnosed as having OSA (apnea–hypopnea index [AHI] > 5/h) using a polysomnographic examination. A group of subjects with simple snoring were included into the control group. Clinically relevant comorbidities were systematically assessed in face-to-face interviews. All patients were asked to complete the 15-item International Index of Erectile Function (IIEF-15) questionnaire for the evaluation of ED. The patients with OSA and ED were evaluated according to these comorbidities. Results: Of the 94 patients, 39 patients were excluded because of severe diseases. OSA was observed in 38 (69.1%) of the 55 patients. ED was seen in 24 (63.2%) patients with OSA, and in 8 (47.1%) patients without OSA (p > 0.05). There were no statistical differences between the groups’ ages, IIEF scores, and body mass index (BMI) scores. There were statistically significant differences between the groups’ AHI scores (p < 0.05). There was a significant correlation between the groups’ AHI scores, BMI, and age (p < 0.05). There was no statistically significant difference in patients with OSA, with and without comorbidity in terms of ED. Conclusion: The rate of ED was higher in patients with OSA who had no other comorbidities. Therefore, ED can be a sensitive marker of OSA.

BACKGROUND:Oxidative DNA damage is associated with male infertility. The aim of this study was to evaluate the oxidative DNA damage of sperm cells and blood leukocytes and to determine the levels of MDA and NO levels in seminal and blood plasma of id...