Diurnal Variation in Urodynamics of Rat

In humans, the storage and voiding functions of the urinary bladder have a characteristic diurnal variation, with increased voiding during the day and urine storage during the night. However, in animal models, the daily functional differences in urodynamics have not been well-studied. The goal of this study was to identify key urodynamic parameters that vary between day and night. Rats were chronically instrumented with an intravesical catheter, and bladder pressure, voided volumes, and micturition frequency were measured by continuous filling cystometry during the light (inactive) or dark (active) phases of the circadian cycle. Cage activity was recorded by video during the experiment. We hypothesized that nocturnal rats entrained to a standard 12:12 light:dark cycle would show greater ambulatory activity and more frequent, smaller volume micturitions in the dark compared to the light. Rats studied during the light phase had a bladder capacity of 1.44±0.21 mL and voided every 8.2±1.2 min. Ambulatory activity was lower in the light phase, and rats slept during the recording period, awakening only to urinate. In contrast, rats studied during the dark were more active, had a lower bladder capacities (0.65±0.18 mL), and urinated more often (every 3.7±0.9 min). Average bladder pressures were not significantly different between the light and dark (13.40±2.49 and 12.19±2.85 mmHg, respectively). These results identify a day-night difference in bladder capacity and micturition frequency in chronically-instrumented nocturnal rodents that is phase-locked to the normal circadian locomotor activity rhythm of the animal. Furthermore, since it has generally been assumed that the daily hormonal regulation of renal function is a major driver of the circadian rhythm in urination, and few studies have addressed the involvement of the lower urinary tract, these results establish the bladder itself as a target for circadian regulation

Management of hydrocele in adolescent patients

Hydrocele is defined as an abnormal collection of serous fluid in the potential space between the parietal and visceral layers of the tunica vaginalis. In the majority of affected adolescents, hydrocele is acquired and is idiopathic in origin. The pathogenesis of idiopathic hydrocele is thought to be an imbalance in the normal process of fluid production and reabsorption. The diagnosis is usually clinical. Taking a thorough history is essential to rule out any fluctuation in size, which is an indication of a patent processus vaginalis. Scrotal ultrasonography is mandatory in nonpalpable testicles to rule out a subtending testicular solid mass requiring inguinal exploration. Otherwise, open hydrocelectomy via a scrotal incision is the standard treatment of idiopathic hydroceles. The second most common cause of hydrocele in adolescents is varicocelectomy. The risk of hydrocele formation is higher with non-artery-sparing procedures or those performed without microsurgical aid, and in surgery requiring cord dissection. If hydrocele occurs after varicocelectomy, initial management should include observation with or without hydrocele aspiration. Large persistent hydroceles are best served by open hydrocelectomy