Detrusor contractility and compliance characteristics in adult male patients with obstructive and nonobstructive voiding dysfunction

PURPOSE: To understand better the contractility and compliance characteristics of the detrusor in patients with varying degrees of outlet obstruction, we analyzed urodynamic studies in elderly men with obstructive and nonobstructive voiding dysfunction. MATERIALS AND METHODS: All patients were evaluated with video urodynamics, including cystometry, isometric tests, voiding profilometry and post-void residual measurement. Bladder compliance, detrusor contractility, detrusor reserve, detrusor instability and the severity of outlet obstruction were determined in each patient. Patients were stratified into 4 groups: urodynamically normal, detrusor instability, outlet obstruction and outlet obstruction with detrusor instability. RESULTS: A significant correlation was found between the maximum isometric contraction pressure and the severity of obstruction in 168 patients. Maximum isometric contraction pressure was significantly greater in patients with than without obstruction, independent of detrusor instability. Although compliance was not significantly different among the groups, the proportion of patients with poor compliance (less than 30 ml./cm. water) was lowest in the normal group. The detrusor reserve was significantly less in patients with chronic retention (post-void residual more than 200 ml.) than in those with lower post-void residuals. CONCLUSIONS: The increase in detrusor contractility with increasing outlet obstruction suggests a compensatory response to obstruction. Furthermore, a decrease in bladder compliance does not appear to be a consistent finding in patients with outlet obstruction, although the proportion of patients with poor compliance is higher in the group with obstruction and/or detrusor instability than in those with normal urodynamic findings. The decrease in detrusor reserve in patients with high post-void residual volumes suggests that the detrusor reserve reflects the degree of detrusor decompensation.     

Correlation of ultrasound-estimated bladder weight with ultrasound appearance of the prostate and postvoid residual urine in men with lower urinary tract symptoms

OBJECTIVES: To reveal the possible relationship of urodynamic tests and transrectal sonography (TRS) of the prostate with bladder hypertrophy as evaluated by ultrasound-estimated bladder weight (UEBW) in men with lower urinary tract symptoms. METHODS: In a total of 234 men aged 50 years or more with a normal prostate or benign prostatic hyperplasia (BPH) as determined by TRS, UEBW was correlated with age, the American Urological Association (AUA) symptom score, postvoid residual urine, maximum flow rate, and transrectal ultrasound planimetry such as prostatic volume and presumed circle area ratio (PCAR). RESULTS: In a simple regression analysis there was a statistically significant correlation between UEBW and the AUA symptom score (R = 0.282, P <0.0001), postvoid residual urine (R = 0.490, P <0.0001), prostatic volume (R = 0.358, P <0.0001), and PCAR (R = 0.468, P <0.0001). A multiple regression analysis demonstrated postvoid residual urine and PCAR to be significant independent determinants of UEBW. The frequency of abnormal UEBW (35.0 g or more) increased significantly with postvoid residual urine (P <0.0001) and PCAR (P <0.0001). CONCLUSIONS: Postvoid residual urine and PCAR were useful parameters for the evaluation of the severity of BPH in terms of bladder hypertrophy probably due to infravesical obstruction.     

Evaluation of the role of neurolinins and urecholine hypersensitivity in an animal model of infravesical outflow obstruction

OBJECTIVES: To determine whether detrusor muscle strips from a male rat with infravesical outflow obstruction model demonstrate supersensitivity to parasympathomimetic and neurokinin NK-1 and NK-2 selective agonists. METHODS: Bladder instability developed after 6 weeks of partial urethral obstruction. The micturition frequency and voided volume were determined in unanesthetized animals. Detrusor hypertrophy was confirmed by evaluation of bladder weight. In vitro organ bath was used to compare the affinity and maximal activity of bethanechol and neurokinin NK-1 and NK-2 selective agonists on strips from the detrusor muscle of sham and obstructed rats. Bethanechol, N-Ac[Arg6, Sar9, Met(O2)]-SP(6-11), and [beta-Ala8]-NKA(4-10) were used to characterize cholinergic muscarinic, neurokinin NK-1 and NK-2 receptors. Results. No significant differences in affinities and maximal responses were found using 10-mg detrusor muscle strips with each of the three agonists. CONCLUSIONS: Bladder instability produced by outlet obstruction does not involve changes in the affinity or maximal activity of cholinergic muscarinic, neurokinin NK-1 and NK-2 receptors. Furthermore, detrusor supersensitivity to neurokinins or bethanechol was not seen. This suggests that bladder instability is not due to an increased affinity or maximal response to neurokinins or parasympathomimetics.     

The maximum watts factor as a measure of detrusor contractility independent of outlet resistance

The maximum watts factor (WFmax) is often used to characterize detrusor contractility. It was recently shown that the WFmax may increase in some patients with chronic outlet obstruction. It is, however, unclear whether this increase reflects a dependence of the WFmax on the degree of outlet obstruction or whether it represents a true increase in detrusor contractility secondary to chronic outlet obstruction. Therefore, this study was performed to investigate this issue using a canine model of acute outlet obstruction. Urodynamic studies were performed on adult canines with surgically exposed lower urinary tracts. Pressure transducers were used to measure the intravesical and the distal urethral pressures, whereas an ultrasonic flow meter was used to obtain a simultaneous measure of the urinary flow rate. Detrusor contractions were induced by electrically stimulating the pelvic nerves bilaterally. Varying degrees of outlet obstruction were created using an inflatable sphincter cuff secured around the bladder outlet. The WFmax, the detrusor pressure at voiding terminus (Pdet.clos), and the passive urethral resistance (R) were computed from measured pressure-flow rate data at each degree of outlet obstruction. The WFmax was not significantly correlated to either the sphincter cuff volume (r = 0.025, p = 0.871), the Pdet.clos (r = 0.286, p = 0.073) or the R (r = 0.110, p = 0.509). The WFmax was not significantly different among mild, moderate, and severe degrees of outlet obstruction (p = 0.176). Our results suggest that the WFmax is independent of the degree of acute outlet obstruction (defined in terms of the sphincter cuff volume, Pdet.clos and R). This validates the current practice of using the WFmax to evaluate detrusor function in patients with voiding dysfunction regardless of outlet resistance. Further, since the WFmax is independent of outlet obstruction acutely, it is reasonable that it would also be independent of outlet obstruction under chronic conditions. Our results, therefore, also imply that the increase in the WFmax with chronic outlet obstruction may represent a true increase in detrusor contractility and not a WFmax dependence on outlet resistance.     

Gas chromatography determination of polychlorinated biphenyls in powdered and liquid soybean milks

OBJECTIVE: To compare the inhibitory effects of propiverine HCl(BUP-4) with those of atropine and oxybutynin on the detrusor instability induced by partial obstruction of the bladder neck of female rats. MATERIALS AND METHODS: Partial obstruction was created using partial ligation of the proximal urethra in 20 female Sprague-Dawley rats. Both the obstructed rats and a control group of 15 rats were evaluated cystometrically about 6 weeks later and the values compared both baseline and after injection with BUP-4, atropine or oxybutynin. During cystometry, the bladder capacity (BC), residual volume (RV), compliance and frequency of spontaneous activity (SA) were determined. RESULTS: The BC, RV and frequency of SA were significantly increased, and compliance markedly decreased, in obstructed compared with normal rats. The micturition pressure was significantly decreased only after injection with BUP-4 in both normal and obstructed rats. For both, the BC was increased significantly after injection with atropine or BUP-4 (P < 0.05), with the increase greater after BUP-4 than after atropine in both groups (P < 0.01). After injecting BUP-4, the RV was significantly increased in both groups (P < 0.05); atropine increased the RV only in normal rats (P < 0.01) and oxybutynin had no significant effect on RV. Increases in compliance after the administration of each drug were significant only in obstructed rats (P < 0.01) and were markedly higher after oxybutynin (780%) than after the other drugs (180-250%). The frequencies and amplitude of SA after injection with each drug were significantly lower only in obstructed rats, but in these rats, there were no significant differences in this reduction after injecting oxybutynin or BUP-4, whereas they were significantly greater after injecting oxybutynin than after atropine. CONCLUSION: Partial bladder outlet obstruction successfully created a hyperactive (unstable) bladder, typified by increased BC, RV, frequency of SA and a marked decrease in compliance. The greater BC, lower MP and frequency and amplitude of SA were prominent after the administration of BUP-4. Thus it is suggested that BUP-4 effectively inhibited bladder instability in rats induced by infravesical outlet obstruction and was more effective than oxybutynin in increasing BC.     

Urinary bladder bilharziasis as a cause of impaired bladder muscle contractility

In an attempt to evaluate the effect of bilharziasis on bladder contractility as a factor in the genesis of voiding disorders, 44 cases of bilharzial bladder neck obstruction diagnosed using traditional methods (symptomatological, radiographic, and endoscopic) were subjected to complete urodynamic evaluation (flowmetry, cystometry, pressure/flow study, and stop-flow test). Their parameters were compared with those of 28 patients with urodynamically obstructed benign prostatic hyperplasia and 8 nonsymptomatic controls. Contractility parameters (isometric detrusor pressure, maximum estimated flow rate, detrusor power at maximum flow) were calculated for the studied cases and their distribution according to the Schafer pressure/flow diagram was evaluated. Bladder biopsy including the detrusor was evaluated in all 72 patients. Poor bladder contractility associated with an extensive bilharzial effect on the detrusor muscle was found to be the major abnormality in 20 of 44 patients with presumed bilharzial bladder neck obstruction with no evidence of urodynamic outflow obstruction. We believe such a workup is essential in cases of suspected obstruction associated with bilharziasis to throw light on the pathophysiology of the voiding disorders, avoid unnecessary surgery, and provide a better prognosis.     

Beneficial effects of Tadenan therapy after two weeks of partial obstruction in the rabbit

Tadenan (Debat Laboratories, France) is a plant extract used in Europe for the treatment of micturition disorders associated with benign prostatic hypertrophy (BPH). Prior studies demonstrated that pretreatment of rabbits with Tadenan significantly reduced the contractile dysfunction observed after 2 weeks of partial outlet obstruction. The specific aim of the present study was to determine the effect of Tadenan therapy following the creation of partial outlet obstruction. Two sets of experiments were performed: one with mild and the other with severe outlet obstruction. For both sets of experiments, male New Zealand rabbits (3-5 kg) were separated into 3 groups of 5 rabbits each. Each rabbit in groups 1 and 2 was obstructed using standard methodology. Rabbits in group 3 served as controls and did not receive any surgery. After 2 weeks, each rabbit in group 1 received Tadenan orally at 100 mg/kg/day for 3 weeks; each rabbit in group 2 received vehicle (peanut oil). After 3 weeks of treatment (5 weeks after partial outlet obstruction), rabbits were anesthetized and cystometries were performed. Immediately after cystometry, the rabbits were euthanized, the bladder rapidly removed, and 4 longitudinal strips prepared and mounted in individual baths for contractile studies. The contractile responses to field stimulation, carbachol, adenosine-5'-triphosphate (ATP), and potassium chloride (KCl) were determined, as follows: (1) Bladder mass approximately doubled in the mildly obstructed groups. Bladder mass increased significantly (3-5-fold) in the severely obstructed groups. (2) Cystometrograms from the mildly obstructed rabbits treated with peanut oil showed low compliance, whereas those of the mildly obstructed rabbits treated with Tadenan showed normal compliance. The cystometrograms of all severely obstructed rabbits showed low compliance. (3) Mild obstruction caused small but significant decreases in the contractile response to field stimulation that were reversed by Tadenan treatment. No changes were noted in response to bethanechol, ATP, and KCl stimulation. (4) Severe obstruction caused significant decreases in the response of bladder strips to field stimulation and bethanechol. Following Tadenan therapy, there was a significant improvement in the response to high-frequency field stimulation and a substantial improvement in the response to bethanechol (response equal to control). No changes were noted in response to ATP and KCl stimulation. In conclusion, Tadenan treatment reversed the bladder dysfunctions induced by mild partial outlet obstruction, and resulted in improved bladder function in the severe model of outlet obstruction. These studies are consistent with previous studies showing that Tadenan pretreatment protects the bladder against the development of contractile dysfunctions.     

Variability of clinical and pressure-flow study variables after 6 months of watchful waiting in patients with lower urinary tract symptoms and benign prostatic enlargement

PURPOSE: We quantified the physiological variability of clinical and pressure-flow study variables in patients with symptomatic benign prostatic enlargement. MATERIALS AND METHODS: Symptom scores were measured, and advanced urodynamic studies with pressure-flow analysis were performed in 178 patients before and 6 months after a period a watchful waiting. RESULTS: Patients without bladder outlet obstruction experienced significant symptomatic improvement. Symptoms in patients with obvious bladder outlet obstruction did not improve significantly. The reproducibility of mean pressure-flow variables was evident. However, there was an important intra-individual variability. Patients with obvious bladder outlet obstruction showed a significant decreases in detrusor pressure at maximal flow of 14cm. water, a significant decrease in the urethral resistance factor of 7 cm. water and a significant decrease of 1 obstruction class on the linear passive urethral resistance relation nomogram, indicating less severe bladder outlet obstruction. CONCLUSIONS: Mean differences among therapy groups must be regarded critically, especially when the difference are slight and possibly within physiological variability.     

Laser prostatectomy: initial experience and urodynamic follow-up

OBJECTIVES: An evolving technology for the treatment of bladder outlet obstruction due to benign prostatic hyperplasia (BPH) is the use of the side-firing neodymium: yttrium-aluminum-garnet (Nd:YAG) laser to achieve prostatic tissue ablation. The purpose of this study was to determine the short-term efficacy of this procedure in both an objective and subjective manner. METHODS: We examined this technique by carefully evaluating our first 25 men undergoing the procedure. Each patient was subjected to careful symptom score analysis using the American Urological Association symptom index and multichannel urodynamics, including pressure-flow studies both preoperatively and at 3 months postoperatively. RESULTS: At the 3-month follow-up, symptom scores improved from a preoperative mean of 11.4 to 7.2 and the mean maximum flow rate improved from 6.1 to 14.5 cc/s. These are both significant at P < 0.001. Statistically similar improvement was seen in detrusor pressure at opening and at maximum flow. Eighty percent of the men studied had at least a 50% reduction in symptom score and a 50% improvement in flow rate. CONCLUSIONS: We conclude that laser prostatectomy is a promising minimally invasive treatment for bladder outlet obstruction secondary to BPH and deserves further evaluation at longer terms of follow-up.     

The role of urodynamics in the evaluation of voiding dysfunction in men after cerebrovascular accident

PURPOSE: The etiology of voiding dysfunction was determined in men after a cerebrovascular accident who were at risk for obstructive uropathy to evaluate whether the cause of voiding dysfunction could be predicted by the type (obstructive or irritative) or onset of symptoms. MATERIALS AND METHODS: We evaluated 38 men with complaints of voiding dysfunction following a cerebrovascular accident. All patients were of the age when bladder outlet obstruction secondary to benign prostatic hyperplasia would otherwise be prevalent. After a comprehensive history and physical examination, all patients underwent multichannel urodynamic studies at a medium fill rate (20 to 50 ml. per minute). Findings were classified by the Abrams-Griffiths nomogram as obstruction, no obstruction or equivocal. RESULTS: Mean patient age was 70 years (range 54 to 87). Patients were grouped according to the presenting voiding complaints (purely irritative in 42%, purely obstructive in 34% or mixed in 24%). In 34 patients (89%) the onset of symptoms paralleled the occurrence of the cerebrovascular accident. Detrusor hyperreflexia was noted in 82% of the patients. There was no statistically significant difference in the occurrence of detrusor hyperreflexia among the 3 symptom groups (Fisher's exact test). Pressure-flow analysis clearly showed obstruction in 24 patients (63%), no obstruction in 9 (24%) and equivocal results in 5 (13%) according to the nomogram. There was no statistically significant difference in the incidence of obstruction among the 3 symptom groups (Fisher's exact test). CONCLUSIONS: Presenting symptoms did not predict the urodynamic findings of bladder outlet obstruction or detrusor hyperreflexia. The significant incidence of onset of symptoms after stroke suggests that the cerebrovascular accident induced voiding dysfunction in the face of preexisting bladder outlet obstruction may exacerbate the symptoms of the latter condition or vice versa.     

Extraorganic hepatic artery aneurysm: failure of transcatheter embolization

BACKGROUND: We evaluated the safety and efficacy of transurethral electrovaporization of the prostate (TVP) as a new alternative treatment for patients with benign prostatic hyperplasia. METHODS: A total of 22 patients with symptomatic benign prostatic hyperplasia, including 4 with urinary retention, underwent TVP. If enough of a cavity was not created after 60 minutes of vaporization, transurethral resection of the prostate (TURP) was performed successively. International Prostate Symptom Score (I-PSS) with quality-of-life index, maximum flow rate, and postvoid residual volume were measured at baseline and at 2 weeks, 1, 3, and 6 months. A pressure-flow study was performed at baseline and at 3 or 6 months after surgery. RESULTS: TURP was required in 10 of 22 patients. At 6 months, mean I-PSS decreased from 20.0 to 5.2, quality-of-life index decreased from 4.6 to 1.1, mean maximum flow rate increased from 6.9 to 16.7 mL/s, and postvoid residual volume decreased from 152 to 32 mL. Detrusor pressure at maximum flow decreased from 108 to 39 cm H2O, with a significant relief of bladder outlet obstruction in 93% of the patients. Mean decrease in hematocrit was 4.4%, and in serum sodium, 4.8 mEq/L. None of the patients required transfusions or had TUR syndrome. A urethral stricture and a severe stress incontinence developed in 1 patient. CONCLUSION: TVP seems to be a safe and effective alternative to a standard TURP associated with fewer intraoperative complications. Although preliminary clinical results have been promising, further study is necessary to establish long-term efficacy and safety of this procedure.     

Effect of partial urinary outlet obstruction in the rabbit on the incorporation of adenine into adenine nucleotides in bladder smooth muscle

Bladder outlet obstruction induces marked morphological, functional, and metabolic changes within the urinary bladder. Recent studies indicate that there is a close correlation between the contractile dysfunction induced by partial outlet obstruction and a marked decrease in mitochondrial oxidative activity of the hypertrophied bladder tissue. The current study investigates the effect of partial outlet obstruction on adenine metabolism within the bladder tissue. After transport into the cell, adenine becomes available as a substrate for adenine phosphoribosyl transferase (APRT), the enzyme that catalyses the non-mitochondrial conversion of adenine into AMP. Subsequently, AMP is phosphorylated to ADP, the phosphate acceptor in mitochondrial oxidative phosphorylation. The results of these studies demonstrate that partial outlet obstruction induces a significant increase in 14C-adenine uptake into the urinary bladder smooth muscle which in turn provides substrate for APRT and results in an increase in 14C-AMP synthesis. In contrast, the rate of incorporation of adenine into ATP+ADP was similar for both control and obstructed tissue. The activity of APRT was not significantly different in control and obstructed tissue.     

Intraprostatic temperature monitoring during transurethral microwave thermotherapy for the treatment of benign prostatic hyperplasia

PURPOSE: We evaluated whether the results of transurethral microwave thermotherapy improve using high intraprostatic temperatures of 55C or greater. MATERIALS AND METHODS: We accrued 30 men 58 to 85 years old (mean age 69) from the waiting list for transurethral prostatic resection in whom maximum urinary flow was less than 13 ml. per second and Madsen score was greater than 8. According to the Abrams-Griffith nomogram all but 1 patient had obstruction. Before treatment 3 thin temperature probes, each containing 5 sensors in a row, were introduced into the prostate from the perineum and positioned using transurethral ultrasound guidance. The microwave power of the transurethral microwave thermotherapy equipment was set based on the actual temperature in the prostatic tissue. A temperature of at least 55C and often more than 60C was reached at the hottest spot. Treatment duration was 1 hour. Postoperatively an indwelling catheter remained in place for 2 weeks. Patients were followed for 6 months with the first followup after 3 months. RESULTS: At the 3-month followup mean maximum urinary flow had increased from 7.4 to 12.5 ml. per second and the mean Madsen score had decreased from 12.6 to 2.9. At the 6-month followup mean maximum urinary flow was 12.2 ml. per second and the mean Madsen score was 3.4. Using pressure-flow data we divided the patients into responders and nonresponders. In the 18 responders maximum urinary flow had increased from 7.2 to 14.6 ml. per second (103%), the Madsen score had decreased from 12.5 to 1.4 (89%) and detrusor pressure had decreased from 9.2 to 6 kPa. (35%). CONCLUSIONS: High energy transurethral microwave thermotherapy relieved bladder outlet obstruction in 60% of the patients and had a good effect on symptoms. Compared with a previous multicenter study with 40% responders, using the same criteria there were 60% responders in our series. Our results indicate that better control of intraprostatic temperature provides better results, approaching those after transurethral prostatic resection.     

Perspective: human immunodeficiency virus type 1 (HIV-1) RNA end points in HIV clinical trials: issues in interim monitoring and early stopping

PURPOSE: The objective of the study was to investigate specificity and sensitivity of bladder wall thickness in the diagnosis of bladder outlet obstruction. MATERIALS AND METHODS: The study included 174 patients referred to our prostate centers for lower urinary tract symptoms. Free uroflowmetry and pressure-flow studies were performed in duplicate as part of the diagnostic evaluation. After the 2 voiding studies were done the bladder was filled to 150 ml. and wall thickness was measured via suprapubic ultrasound. Bladder outlet obstruction was diagnosed and graded according to the Abrams-Griffiths and Sch?fer nomogram as well as to the group specific urethral resistance algorithm. RESULTS: A significant correlation (r > 0.6, p < or = 0.007) was found between bladder wall thickness and all parameters of the pressure-flow study. A bladder wall thickness of 5 mm. appeared to be the best cutoff point to diagnose bladder outlet obstruction, since 63.3% of patients with bladder wall thickness less than 5 mm. were unobstructed while 87.5% of those with a bladder wall thickness 5 mm. or greater were obstructed. Bladder wall thickness out performed uroflowmetry in terms of specificity and sensitivity in the diagnosis of outlet obstruction as demonstrated by an area under curve value of 0.860 versus 0.688 in the receiver operator characteristics analysis. CONCLUSIONS: Measurement of bladder wall thickness appears to be a useful predictor of outlet obstruction with a diagnostic value exceeding free uroflowmetry although it does not represent a substitution to invasive urodynamics. These data support the hypothesis that the relationships between morphology and function are of clinical importance.     

The role of urinary potassium in the pathogenesis and diagnosis of interstitial cystitis

PURPOSE: We determined whether intravesical potassium absorption in normal bladders correlates with increased sensory urgency, and corroborated the hypothesis that mucus is important in the regulation of epithelial permeability. We compared sensory nerve provocative ability of sodium versus potassium, and determined whether intravesical potassium sensitivity discriminates patients with interstitial cystitis from normal subjects and those with other sensory disorders of the bladder. MATERIALS AND METHODS: A total of 231 patients with interstitial cystitis and 41 normal subjects underwent intravesical challenge with 40 ml. water and then 40 ml. of 40 mEq./100 ml. potassium chloride. Subjective responses of urgency or pain stimulation were recorded on a scale of 0 to 5. In 19 normal subjects potassium absorption was measured at baseline, after injury of the bladder mucus with protamine, after heparin treatment to reverse mucus damage and then for a final time. These subjects simultaneously recorded the symptoms of sensory urgency and pain at baseline, after protamine and after heparin. Another group of normal volunteers underwent a challenge with sodium versus potassium to determine which cation was more provocative. Patients with bladder outlet obstruction secondary to benign prostatic hyperplasia (BPH), detrusor instability, and acute and chronic urinary tract infection but no current infection were also evaluated for potassium sensitivity. RESULTS: Neither normal subjects nor patients with interstitial cystitis reacted to water administered intravesically. There was marked sensitivity to intravesical potassium in 75% of patients with interstitial cystitis versus 4% of controls (p <0.01). Only 1 patient with BPH responded to potassium and none of the 5 with chronic urinary tract infection responded. All 4 patients (100%) with a current acute urinary tract infection reacted positively to the potassium challenge. Of 16 patients with detrusor instability 25% responded. Normal subjects had minimal sensitivity to potassium before (11%) and markedly increased sensitivity after (79%) protamine treatment, and these symptoms were reversed by heparin in 42%. Potassium absorption directly correlated with symptoms (0.4, 3.0 and 1.3 mEq. before and after protamine, and after heparin reversal, respectively). In regard to sodium versus potassium provocation, potassium was far more provocative for causing urgency after protamine (10 versus 90%). Neither group underwent provocation before protamine. CONCLUSIONS: Chronic diffusion of urinary potassium into the bladder interstitium may induce sensory symptoms, damage tissue and be a major toxic factor in the pathogenesis of interstitial cystitis. Intravesical potassium sensitivity is a reliable method for detecting abnormal epithelial permeability. It discriminates between patients with interstitial cystitis and normal subjects with intact epithelial function, and it is a useful diagnostic test for interstitial cystitis. Potassium sensitivity correlates with increased potassium absorption in normal subjects, and potassium is far more provocative than sodium. Potassium sensitivity is also present in acute urinary tract infection and occasionally detrusor instability but not in BPH or chronic urinary tract infections.     

Possible involvement of the ampullary electroreceptor system in detection of frequency-modulated electrocommunication signals in Eigenmannia

BACKGROUND: Overactivity of the detrusor due to benign prostatic hyperplasia may be induced by hyperpermeability of the smooth muscle cell membrane to calcium. We investigated the effect of verapamil, a calcium channel blocker, on detrusor function in outflow obstructed and control rat bladders. METHODS: Verapamil was injected intravenously via a catheter inserted into the internal jugular vein in doses of 0.5, 1.0, 2.0, 4.0, and 10.0 mg/kg in rat bladders with and without partial outflow obstruction under urethane anaesthesia. The intravesical pressure was monitored continuously. We measured the tidal voided urine volume, the voiding pressure, the pressure at which micturition was induced, and the end-point pressure of micturition. RESULTS: The tidal voided urine volume was significantly decreased in the obstructed bladders before administration of verapamil. Verapamil had similar effects in cystometric parameters in obstructed and control bladders. Verapamil increased the tidal voided urine volume, the pressure at which micturition was induced, and the end-point pressure of micturition, and reduced the voiding in obstructed and control bladders. Verapamil at doses of 4.0 mg/kg or higher induced significant arrhythmia. CONCLUSIONS: Verapamil reduced the contractile force of the bladder and increased the capacity and residual urine volume in both normal and obstructed bladders. Thus, although calcium channel blockers such as verapamil may be effective in treating a hyperactive bladder, they may have adverse cardiovascular effects.     

Value of the shape of the flowmetry curve in the study of prostatism

OBJECTIVE: To determine the relation of the urinary flow curve morphology of free flowmetry with the status of lower urinary tract dynamics. METHODS: A mathematical model was designed to fit the urinary flow curves to two models: a symmetrical and an asymmetrical model. Based on these models we analyzed the relationship between the presence or absence of obstruction and the type of model which better adjusted the urinary flow curves in a series of 85 males. RESULTS: The urinary flow curves corresponding to absence of obstruction adjusted significantly better to a symmetrical model than those corresponding to bladder outlet obstruction. No correlation was observed between the type of curve and bladder contractibility or type of urinary obstruction. CONCLUSIONS: There is a relationship between the form of the urinary flow curve and bladder obstruction. In the absence of obstruction, the urinary flow curves are more symmetrical.     

Structure of the human paralemmin gene (PALM), mapping to human chromosome 19p13.3 and mouse chromosome 10, and exclusion of coding mutations in grizzled, mocha, jittery, and hesitant mice

OBJECTIVES: To assess the correlation of total prostatic size and prostate transition zone dimensions with various measurements of the severity of bladder outlet obstruction secondary to benign prostatic hyperplasia. METHODS: Prostate-specific antigen, creatinine, American Urological Association symptom score, bother score, urinary history, uroflowmetry, and post-void residual urine volume determination was followed by measurement of the prostate gland and transition zone on transrectal ultrasound images in 136 men undergoing systematic prostate biopsies. Patients were divided into five groups based on past urinary tract treatment history and the presence of prostate cancer on the biopsies. The total prostate and transition zone dimensions, as well as calculated prostate and transition zone volumes, were compared by Pearson correlation with both the subjective and objective voiding parameters in each patient group. RESULTS: The transition zone dimensions correlated positively with American Urological Association symptom score, bother score, and post-void residual urine volume and correlated negatively with maximum and mean flow rates, particularly in patients with no history of prostate surgery, alpha-blocker administration, urinary infections, irritative voiding symptoms, or prostate cancer. CONCLUSIONS: Transrectal ultrasound measurements of transition zone dimensions correlate better than total prostatic dimensions or calculated prostatic or transition zone volumes with the severity of benign prostatic hyperplasia. Of these, the transverse transition zone dimension demonstrated the best correlation; however, this correlation is probably not adequate for clinical utility.     

Evaluation of patients with bladder outlet obstruction and mild international prostate symptom score followed up by watchful waiting

OBJECTIVES: To examine the variability of bladder outlet obstruction and mild lower urinary tract symptoms in patients with benign prostatic hyperplasia (BPH) followed up by watchful waiting. METHODS: The International Prostate Symptom Score (IPSS) has four questions related to voiding symptoms and three related to filling symptoms. Scores of 0 to 7, 8 to 19, and 20 to 35 represent mild, moderate, and severe symptoms, respectively. Over a period of 36 months the IPSS questionnaire was administered to 479 patients 50 to 81 years old (mean age 63) with BPH. A pressure-flow study was used to determine the presence of bladder outlet obstruction. On the basis of their scores, the patients were classified into 50 with mild, 227 with moderate, and 202 with severe symptoms. In the present study only patients with a mild score were analyzed. RESULTS: Of 50 patients with mild symptoms, 16 (32%) had bladder outlet obstruction. After a period of 9 to 22 months (mean 17) of watchful waiting, these 16 patients were reviewed. Twelve (75%) of the 16 had bladder outlet obstruction reconfirmed by pressure-flow studies, and 3 (18.8%) of 16 had increased symptoms (moderate symptomatic) and underwent treatment (1 began pharmacologic treatment, and 2 chose transurethral resection). A total of 4 (25%) of 16 patients still had mild voiding disturbances and refused the second urodynamic evaluation. The remaining 34 patients with no obstruction had annual routine follow-up and had persistent mild symptom scores and normal uroflowmetric results. These patients did not undergo another pressure-flow evaluation. CONCLUSIONS: A pressure-flow study is routinely avoided in patients with a mild IPSS. From symptoms alone it was not possible to diagnose bladder outlet obstruction in these patients. Pressure-flow studies and symptom profiles measure different aspects of the clinical condition. After a mean follow-up of 17 months of watchful waiting, 13 (81.2%) of 1 6 patients were clinically stable. Because the need for therapy is dictated by quality of life, it is difficult to propose treatment for patients with minimal symptoms, even in the presence of bladder outlet obstruction.     

Phospholipase C isozymes in the human brain and their changes in Alzheimer''s disease

OBJECTIVE: We compared the efficacy of bladder training, pelvic muscle exercise with biofeedback-assisted instruction, and combination therapy, on urinary incontinence in women. The primary hypothesis was that combination therapy would be the most effective in reducing incontinent episodes. STUDY DESIGN: A randomized clinical trial with three treatment groups was conducted in gynecologic practices at two university medical centers. Two hundred and four women diagnosed with genuine stress incontinence (n = 145) and/or detrusor instability (n = 59) received a 12-week intervention program (6 weekly office visits and 6 weeks of mail/telephone contact) with immediate and 3-month follow-up. Outcome variables included number of incontinent episodes, quality of life, perceived improvement, and satisfaction. Data analyses consisted of analysis of covariance using baseline values as covariates and chi2 tests. RESULTS: The combination therapy group had significantly fewer incontinent episodes, better quality of life, and greater treatment satisfaction immediately after treatment. No differences among groups were observed 3 months later. Women with genuine stress incontinence had greater improvement in life impact, and those with detrusor instability had less symptom distress at the immediate follow-up; otherwise, no differences were noted by diagnosis, incontinence severity, or treatment site. CONCLUSIONS: Combination therapy had the greatest immediate efficacy in the management of female urinary incontinence regardless of urodynamic diagnosis. However, each of the 3 interventions had similar effects 3 months after treatment. Results suggest that the specific treatment may not be as important as having a structured intervention program with education, counseling, and frequent patient contact.