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Voiding Pressure (voiding + pressure)
Selected AbstractsGABAergic mechanism mediated via D1 receptors in the rat periaqueductal gray participates in the micturition reflex: an in vivo microdialysis studyEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 12 2008Takeya Kitta Abstract The periaqueductal gray (PAG) is critically involved in the micturition reflex, but little is known about the neuronal mechanisms involved. The present study elucidated dynamic changes in dopamine (DA), glutamate and ,-aminobutyric acid (GABA) in the rat PAG during the micturition reflex, with a focus on dopaminergic modulation using in vivo microdialysis combined with cystometrography. Extracellular levels of DA and glutamate increased, whereas levels of GABA decreased, in parallel with the micturition reflex. Application of a D1 receptor antagonist into the PAG produced increases in maximal voiding pressure (MVP) and decreases in intercontraction interval (ICI), suggesting that the micturition reflex was facilitated by D1 receptor blockade. The D1 receptor antagonist prevented micturition-induced decreases in GABA efflux but had no effect on DA or glutamate. Neither a D2 receptor antagonist nor a D1/D2 receptor agonist affected these neurochemical and physiological parameters. Micturition-induced inhibition of GABA was not observed in 6-hydroxydopamine (6-OHDA)-lesioned rats, an animal model of Parkinson's disease. 6-OHDA-lesioned rats exhibited bladder hyperactivity evaluated by increases in MVP and decreases in ICI, mimicking facilitation of the micturition reflex induced by D1 receptor blockade. These findings suggest that the micturition reflex is under tonic dopaminergic regulation through D1 receptors, in which a GABAergic mechanism is involved. Bladder hyperactivity observed in 6-OHDA-lesioned rats may be caused by dysfunction of GABAergic regulation underlying the micturition reflex. The present findings contribute to our understanding not only of the neurophysiology of the micturition reflex but also of the pathophysiology of lower urinary tract dysfunction in patients with Parkinson's disease. [source] Comparative study of pressure-flow parametersNEUROUROLOGY AND URODYNAMICS, Issue 3 2002Lars M. Eri Abstract Methods for quantification of bladder outlet obstruction (BOO) are still controversial. Parameters such as detrusor opening pressure (pdet.open), maximum detrusor pressure (pdet.max), minimum voiding pressure (pdet.min.void), and detrusor pressure at maximum flow rate (Pdet.Qmax) separate obstructed from nonobstructed patients to some extent, but two nomograms, the Abrams-Griffiths nomogram and the linearized passive urethral resistance relation (LinPURR), are more accepted for this purpose, along with the urethral resistance algorithm. In this retrospective, methodologic study, we evaluated the properties of these parameters with regard to test-retest reproducibility and ability to detect a moderate (pharmacologic) and a pronounced (surgical) relief of bladder outlet obstruction. We studied the pressure-flow charts of 42 patients who underwent 24 weeks of androgen suppressive therapy, 42 corresponding patients who received placebo, and 30 patients who had prostate surgery. The patients performed repeat void pressure-flow examinations before and after treatment or placebo. The various parameters were compared. Among the bladder pressure parameters, Pdet.Qmax seemed to have some advantages, supporting the belief that it is the most relevant detrusor pressure parameter to include in nomograms to quantify BOO. In assessment of a large decrease in urethral resistance, such as after TURp, resistance parameters that are based on maximum flow rate as well as detrusor pressure are preferable. Neurourol. Urodynam. 21:186,193, 2002. © 2002 Wiley-Liss, Inc. [source] Antenatal urodynamic studies in the fetal lamb: experimental protocol and preliminary resultsPRENATAL DIAGNOSIS, Issue 3 2003Renaud de Tayrac Abstract Objectives To set up a fetal lamb model for intrauterine fetal urodynamic studies. Methods Fourteen fetal lambs underwent placement of a bladder catheter at a mean gestational age of 87 days. Three fetuses also had a partial urethral obstruction by the simultaneous placement of a peri-urethral constricting ring. Urodynamic and ultrasound studies were performed weekly by the filling cystometry method. Results Hundred and six voiding cycles were recorded during 25 urodynamic studies between 84- and 133-days gestation. All voiding profiles were biphasic with a mean duration of 4.2 min (range 1,10), a mean voiding pressure of 23 cm of water (range 7,33) and a mean periodicity of 19.2 min (range 11,50). The obstructed animals had bladder overactivity. This correlated with ultrasound and post-mortem findings of megacystis and bilateral hydroureteronephrosis. The fetal mortality rate was 85.7% and the mean duration of survival post surgery was 45 ± 5.7 days. Conclusion Serial urodynamic studies could be performed in a fetal lamb model. Following partial urethral obstruction, bladder overactivity was observed. Copyright © 2003 John Wiley & Sons, Ltd. [source] Treatment of incontinence after prostatectomy using a new minimally invasive device: adjustable continence therapyBJU INTERNATIONAL, Issue 4 2005Wilhelm A. Hübner OBJECTIVE To evaluate the safety and efficacy of a new minimally invasive urological implant for incontinence after prostatectomy. PATIENTS AND METHODS The adjustable continence therapy device (ProACTTM, Uromedica, Plymouth, MN, USA) consists of two balloons placed via a perineal approach bilaterally at the bladder neck in patients after prostatectomy. Titanium ports, attached via discrete tubing to each balloon, are placed in the scrotum, allowing for separate volume adjustments of the balloons at any time during and after surgery. Changes in a quality-of-life questionnaire (I-QoL), pad usage and a subjective continence grading score were assessed in 117 consecutive men after implanting the Pro-ACT, at baseline and at 1, 3, 6, 12 and 24 months. RESULTS After a mean (range) follow-up of 13 (3,54) months and with a mean of 3 (0,15) adjustments, 67% of men were dry, using at most one ,security' pad daily; 92% were significantly improved, and 8% showed no improvement. The I-QoL score improved from a median of 34.7 to 66.3 after 2 years (42 men; P <,0.001), the daily pad count decreased from a mean of 6 (1,24)/day to 1 (0,6)/day at 2 years (P < 0.001). Continence achieved at ,,6 months after implantation through incremental adjustment remained durable at ,,2 years in most patients. There were complications during and after surgery in 54 patients, mostly minor and decreasing with increasing expertise, primarily reflecting the development and refinement of the new surgical technique and its instrumentation. Re-implantation for complications was required in 32 patients, with a 75% success rate. CONCLUSIONS The ProACT peri-urethral prosthesis produces durable outcomes equivalent or better than other minimally invasive treatments for incontinence after prostatectomy. Its unique design allows for easy adjustment after surgery to achieve the desired urethral resistance, with no further surgical intervention, thus allowing for an optimum balance between voiding pressures and continence. The promising results reported here suggest that this may be an appropriate, effective and durable first-line treatment to offer men with stress urinary incontinence after prostatectomy. [source] | |||||||||||||