Neuronal nitric oxide synthase in the neural pathways of the urinary bladder.
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Nitric oxide (NO) is a unique biological messenger molecule. It serves, in part, as a neurotransmitter in the central and peripheral nervous systems. Neurons containing NO have been identified histochemically by the presence of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) reactivity or immunohistochemically by the antibody for neuronal NO synthase (n-NOS). Previous histochemical or pharmacological studies have raised the possibility that NO may play an important role in the neural pathways of the lower urinary tract. There is also considerable evidence to suggest that n-NOS is plastic and could be upregulated following certain lesions in the lower urinary tract. The present review summarises the distribution of n-NOS containing neurons innervating the urinary bladder and the changes of the enzyme expression in some experimentally induced pathological conditions. (+info)
Anterior urethral valve in an adolescent boy.
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A 14 year old boy with a relatively uncommon anterior urethral valve is described herein. (+info)
Diurnal enuresis in childhood.
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OBJECTIVE: To review the clinical classification of childhood diurnal enuresis, to describe the evaluation process, and to discuss principles of management. QUALITY OF EVIDENCE: An extensive literature review was performed with a MEDLINE search. Articles were selected according to date of publication, clinical relevance, and availability. Recent articles, cohort studies of at least 50 patients, and randomized clinical trials were preferred. Recent editions of classic textbooks were consulted. Evaluation and management activities discussed in this article are supported by original and relevant literature. MAIN MESSAGE: Most causes of childhood diurnal enuresis can be determined by a thorough history coupled with a complete physical examination and urinalysis and culture. Supplementary investigations include ultrasonography of the kidneys and bladder to screen for neurogenic bladder and urethral obstruction. When obstruction, ectopic ureter, or bladder dysfunction is suspected, voiding cystourethrography and urodynamic studies are needed. Evaluation of neurogenic bladder includes magnetic resonance imaging of the spine. Treatment is aimed at correcting poor toilet habits, preventing or treating urinary tract infections, and using appropriate medication. CONCLUSIONS: In most instances, diurnal enuresis in childhood is a benign condition with an easily identifiable cause and an excellent prognosis with time and appropriate treatment. (+info)
Fetal serum beta2-microglobulin predicts postnatal renal function in bilateral uropathies.
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BACKGROUND: Predicting postnatal renal function is crucial for the prenatal evaluation of fetal bilateral uropathies. Prenatal ultrasound can identify intrauterine terminal renal failure, but is not sensitive enough to identify those infants who would survive with an impaired renal function. Because it reflects fetal glomerular filtration, fetal serum beta2-microglobulin is a potential predictor of postnatal renal function. METHODS: Fetal serum beta2-microglobulin (beta2m) was assayed in 61 cases of bilateral or low obstructive uropathy, 74 controls, and 17 cases of bilateral renal agenesis, and was correlated with renal function. RESULTS: Fetal serum beta2m was 3.2 mg/L (range 1.5 to 4.7) in controls (N = 74), 9.5 mg/L (range 6.7 to 11.3) in bilateral renal agenesis (N = 17), 7 mg/L (5.1 to 10.6) in uropathy in which terminal renal failure resulted in termination of pregnancy (N = 26), and 3.7 mg/L (range 2.3 to 11.2) in live births with uropathy (N = 35). In the latter subgroup, fetal serum beta2m was significantly and positively correlated (r2 = 0.91) with postnatal serum creatinine. All survivors with a postnatal serum creatinine < or =50 micromol/L ha a fetal serum beta2m lower than 5 mg/L. Four of 6 survivors with a postnatal serum creatinine> 50 micromol/L had a fetal serum beta2m greater than 5 mg/L. CONCLUSION: Fetal serum beta2-microglobulin is a marker for renal function and predicts postnatal serum creatinine in bilateral or low fetal obstructive uropathy. (+info)
Reduction in renal haemodynamics by exaggerated vesicovascular reflex in rats with acute urinary retention.
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1. We examined the possibility that a vesicovascular reflex is exaggerated by acute urinary retention, and that the increase in renal vascular resistance caused by this reflex may lead to renal dysfunction. We evaluated the vesicovascular responses to normal micturition (NM, transcystometric condition) and acute urinary retention (isovolumetric condition mimicking complete bladder-outlet obstruction (CBOO) and partial urethral ligation mimicking partial bladder-outlet obstruction (PBOO)) in anaesthetized female Wistar rats. 2. Acute urinary retention due to CBOO or PBOO provoked a prolonged or increased intravesical pressure, an enhancement in both bladder pelvic afferent and bladder pelvic efferent nervous activity, and an elevation in mean arterial blood pressure. 3. Single-unit analysis showed that these vesicovascular reflexes were triggered by activation of low-threshold and high-threshold bladder mechanoreceptors, but not by renal uretropelvic mechanoreceptors. 4. Bladder contraction in CBOO and PBOO conditions and graded increases in bladder volume significantly reduced renal blood flow and cortical microvascular blood flow. The acute urinary retention-induced renal vasoconstriction was mediated by the renal nerve. Renal denervation, but not bilateral ureteral resection, abolished the renal vasoconstriction associated with the vesicovascular reflexes. 5. These findings indicate that exaggerated activation of bladder afferents exerts a positive feedback effect to increase sympathetic outflow to the kidney further, thereby contributing to significant renal vasoconstriction via a renal nerve-dependent mechanism. (+info)
Prenatal diagnosis of fetal urinary ascites.
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We report on a rare in utero appearance of the rupture of the fetal bladder caused by low urinary tract obstruction with subsequent urinary ascites. The findings on prenatal sonography, postnatal X-ray examinations and postnatal surgical treatment are described and the literature is reviewed. (+info)
Recovery after relief of fetal urinary obstruction: morphological, functional and molecular aspects.
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The effects of obstruction [urinary tract obstruction (UTO)] and relief on renal development were examined in an experimental model in the fetal lamb. Bladder outlet obstruction was performed at 60 days of gestation; relief was performed by vesicoamniotic shunting at 90 days of gestation. Studies were carried out in obstructed (OF60; n = 11), shunted (SF; n = 5), and control fetuses (CF; n = 11) at 120 days of gestation. Fetal UTO produced either hydronephrosis (64%) or dysplasia (36%); dysplasia was always associated with a reduction in the number of glomeruli [950 +/- 99 (dysplasia) vs. 1,852 +/- 249 (CF) glomeruli/section]. Obstructed fetuses had lower creatinine clearance [0.76 +/- 0.41 (OF60) vs. 0.96 +/- 0.21 (CF) ml x min(-1) x kg(-1)], higher sodium fractional excretion [17.2 +/- 20.3 (OF60) vs. 2.4 +/- 3.7% (CF)], and higher urinary concentration [80 +/- 30 (OF60) vs. 43 +/- 22 (CF) micromol/l] than controls. In SF, the number of glomeruli was increased at 120 days of gestation (1,643 +/- 106 glomeruli/section) compared with nondiverted fetuses (1,379 +/- 502 glomeruli/section), and the temporal pattern of PAX2, disrupted after obstruction, was restored. In conclusion, early fetal UTO leads to either renal hydronephrosis with normal glomerular development or dysplasia with a decreased number of glomeruli; in utero urine diversion performed before the end of nephrogenesis may allow a reversal of the glomerulogenesis arrest observed. (+info)
Evrim Bougie: a new instrument in the management of urethral strictures.
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BACKGROUND: In this study a new instrument and technique is described for the endoscopic treatment of complete posterior urethral strictures, which may result in serious complications and sometimes require troublesome treatments. METHODS: Three patients with complete posterior urethral obstruction were treated endoscopically with the guidance of a new instrument: Evrim Bougie. Evrim Bougie looks like a Guyon Bougie, has a curved end, which facilitates getting into the bladder through the cystostomy tract and with a built in channel of 1.5 mm in diameter for a sliding needle exiting at its tip. Having confirmed fluoroscopically and endoscopically that the sliding needle had passed across the strictured segment, the strictured segment was incised with internal urethrotomy, distal to the strictured segment, and urethral continuity was accomplished. At the end of the operation a Foley urethral catheter was easily placed into the bladder per urethra. Patients were instructed in self-catheterization after removal of the urethral catheter. All patients achieved normal voiding at postoperative 7th month follow-up evaluation. CONCLUSION: Internal urethrotomy could be performed under the guidance of the sliding needle of Evrim Bougie advanced from above the posterior urethral strictures, which to our knowledge was described for the first time in the English literature. We also believe that there may be other possible indications of Evrim Bougie for different procedures in urethral surgery. (+info)