bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on the biphasic nature of urinary bladder contraction and function
Authors: Levin Robert M. , Ruggieri Michael R. , Gill Harcharan S. , Haugaard Niels , Wein Alan J.
Published: March 2007

The function of the urinary bladder is to store and expell urine. Micturition is accomplished via a coordinated, well‐sustained contraction of sufficient force to expel the entire contents of the urinary bladder. Studies in several labs have demonstrated that a functional bladder contraction consists of two phases: the first phase is represented by a rapid rise in intravesical pressure (isometric contraction) to a peak, followed by a prolonged period of increased (sustained) intravesical pressure (tension). Using isolated strip techniques, the in vitro whole bladder model, and several metabolic methodologies, we have studied contractile, functional, and biochemical parameters of these two phases of contraction.

The results of our studies were as follows: 1) There was a small but significant decrease in net ATP at the peak of contraction, but not during the plateau phase. Creatine phosphate (CP) was significantly reduced at both times. 2) There was a rapid decrease in NADH fluorescence during the peak phase of contraction, which indicates an increase in oxidative metabolisvm. 3) The ED50 for the fluorescence response to bethanechol was significantly lower than the ED50 for contraction. 4) Whereas anoxia produced a gradual decline in both intracellular ATP and peak contraction, there was an immediate loss in the ability to maintain a contraction (ability of the bladder to empty).

The results of these studies indicate that whereas preformed ATP mediates the initial contractile response to bethanechol, the plateau phase of bladder contraction (and the ability of the bladder to empty) may be mediated by high‐energy intermediates of oxidative phosphorylation (aerobic metabolism).
Comparative response of smooth muscle strips of bladder and bowel to various pharmacological agents
Authors: Batra Ashok K. , Wein Alan J. , Ruggieri Michael R. , Levin Robert M.
Published: March 2007

Intestinal segments are commonly incorporated in the urinary system as conduits, reservoirs, and as implants in augmentations of bladders. This practice, initiated in 1888 by Tizzone, only became popular in the 1950s. Although both bladder and intestine are composed primarily of smooth muscle, there are significant morphological and functional differences between these tissues. This present study compares the pharmacological properties of intestinal smooth muscle to those of bladder smooth muscle. Ileum was taken as a representative section from small intestine, sigmoid colon from the large bowel, and the bladder body from the urinary bladder.

The results can be summarized as follows: Bethanechol (cholinergic agonist) produced a rapid and sustained increase in tension in the bladder, a marked increase in the amplitude and frequency of phasic contractions in the ileum, and a sustained increase in tension in the sigmoid colon. Methoxamine (α‐adrenergic agonist) and ATP (purinergic agonist) produced an increase in tension in the bladder, and reduced the tension in both ileum and sigmoid. Isoproterenol (β‐adrenergic agonist) produced a relaxation in all three tissues.
Inhibitory muscarinic receptors and α‐adrenoceptors on cholinergic axon terminals in the urethra of rabbit and man
Authors: Mattiasson Anders , Andersson Karl‐Erik , Sjögren Christer
Published: March 2007

Isolated smooth‐muscle preparations from the rabbit and human urethra were incubated with 3H‐choline, and the influence of drugs on the electrically induced release of 3H was studied. In both rabbit and human urethral smooth muscle, the release was well reproducible and abolished in the presence of tetrodotoxin, indicating a nervous origin. By means of drugs stimulating (carbachol, nicotine amide) and blocking (scopolamine, hexamethonium) cholinoceptors, release‐inhibiting muscarinic but not nicotinic receptors could be demonstrated on the cholinergic axon terminals. The stimulation‐induced efflux of 3H was significantly and concentration‐dependently inhibited by noradrenaline (NA) and the selective α2‐adrenoceptor agonist, clonidine. The effects of NA and clonidine were abolished by phentolamine. Phentolamine by itself did not influence the release, nor did rauwolscine. Morphological investigations have revealed close contacts between adrenergic and cholinergic axon terminals, and the occurrence of muscarinic receptors on adrenergic axon terminals inhibiting release of NA in the urethra has previously been demonstrated. The present results therefore suggest the possibility of a mutual interaction between adrenergic and cholinergic neurons at the axon‐terminal level in the urethra.
New method for static and dynamic measurement of related values of cross‐sectional area and pressure in the female urethra
Authors: Lose Gunnar , Colstrup Hans , Saksager Kim , Kristensen Jørgen K.
Published: March 2007

A new probe for simultaneous measurement of cross‐sectional area and pressure in the female urethra has been devised based on the field‐gradient principle and microtip transducer technique. The system permits measurement during fast inductions of well‐defined cross‐sectional areas in segments of the urethra (experimental stress episodes), contraction of the pelvic floor, and coughing. The measurements make possible a description of the static and dynamic mechanical properties of the female urethra in terms of compliance or elastance, uninstrumented closure pressure, and hysteresis. Furthermore, urethral closure function can be evaluated in terms of work or power created by the urethral closure apparatus during contraction of the pelvic floor and during coughing.
Electrophysiological correlates of sensory innervation of the vesico‐urethral junction and urethra in man
Authors: Sarica Yakup , Karacan Ismet
Published: March 2007

To investigate urethral sensory innervation in man, cerebral evoked potentials (CEPs) and bulbocavernous reflex (BCR) were recorded by stimulation of vesico‐urethral junction (VUJ), prostatic and distal urethra, and penile skin. A specially produced catheter with a pair of electrodes was used for bipolar stimulation along the lower urinary tract. In comparison to the potentials evoked by distal urethral stimulation, the shape differences and protracted latency of CEPs to VUJ stimulation suggest that the distal and proximal urethra are innervated by different peripheral afferents. Similarities of CEPs and BCR latencies produced by prostatic urethral and VUJ stimulation indicate that the sensory innervation of the prostatic urethra is provided by pelvic nerve afferents. The remaining distal parts of the urethra are innervated by pudendal nerves. This is indicated by shape similarities and latency characteristics of both CEPs and BCR when the distal urethra and glans skin are stimulated.
Functional effect of chronic ischemia on the rabbit urinary bladder
Authors: Lin Alex Tong‐Long , Wein Alan J. , Gill Harcharan S. , Levin Robert M.
Published: March 2007

The functional effect of partial ischemia of the rabbit urinary bladder was studied. Unilateral ischemia was created by ligation of one of the two vesical arteries that supply the rabbit bladder. The effect of 1‐day, 1‐, 2‐, and 4‐week chronic unilateral ischemia on in vivo and in vitro cystometry, and the functional response of the in vitro whole bladder model to field stimulation and bethanechol were determined. Within 1 day following the creation of unilateral ischemia, the bladder became hyperreflexic with decreased compliance. This condition was observed in the 1‐ and 2‐week groups. By 4 weeks, the hyperreflexia had decreased, and the compliance increased significantly. Peak pressure generation for in vitro whole bladder in response to field and bethanechol (500 μm) stimulation was maintained the same as control for all groups. However, the ability of the bladder to empty was diminished to about 50% of control values in the 1‐day, 1‐week, and 2‐week groups. The ability to empty recovered to a significant degree by 4 weeks for both field stimulation and bethanechol. Our results show that the bladder function cannot be judged by pressure generation alone; a study of compliance and the ability to empty should be performed to give a true indication of the functional state of the bladder.
Urodynamic responses to sacral stimulation in the chronic spinal dog
Authors: Walter J. S. , Wheeler J. S. , Robinson C. J. , Bolam J. , Wurster R. D.
Published: March 2007

Recent reports have shown that electrical stimulation of the bladder wall or sacral nerves can be effective for bladder management in the spinal‐cord‐injured (SCI) patient. However, unacceptable bladder pressures and urethral resistances have been reported in many of these patients following such stimulation procedures. These problems were evaluated in this study using epidural electrodes in the sacral canal of the chronic spinal male dog. We found that bladder reflex activity is important for sacral stimulation to induce effective voiding. Voiding in response to stimulation was poor during the first week following spinal injury but improved during the next 2 weeks. A significant increase in bladder pressure in response to stimulation occurred during this period, but urethral resistance remained unchanged. Urethral resistance, the ratio of bladder pressure to voiding rate, was lower for poststimulus voiding than for voiding during continuous stimulation. Bladder compliance, measured via cystometry, was improved in one spinal dog during a period of sacral stimulation. However, an adverse trend toward increased bladder thickness was seen on postmortem examination. Overall, this minimally invasive method was encouraging and may be efficacious for bladder control in some SCI patients.
Intrinsic neuromuscular defects in the neurogenic bladder: VIII. Effects of unilateral pelvic and pelvic plexus neurectomy on ultrastructure of the feline bladder base
Authors: Elbadawi Ahmad , Atta Mohamed A. , Hanno Ahmed G.‐E.
Published: March 2007

It has been shown previously that unilateral parasympathetic decentralization of the feline bladder by sacral ventral rhizotomy results in early degenerative and eventual regenerative ultrastructural neuromuscular changes in the bladder base. The present study was conducted to define the effects of unilateral parasympathetic decentralization by pelvic neurectomy and postganglionic “denervation” by pelvic plexus neurectomy on the neuromuscular ultrastructure of the feline bladder base. Eighteen sexually mature male cats were used. Three cats provided the control material; six cats underwent unilateral pelvic and nine unilateral pelvic plexus neurectomy. Bladders were collected for study 2, 3, and 10 weeks following the former and 1–4 days, 3 weeks, and 7–12 weeks following the latter procedure. Samples from both the neurectomized and the intact sides of each bladder were obtained for electron microscopic study. The ultrastructural neuromuscular changes observed after pelvic neurectomy were identical to those previously described following unilateral sacral ventral rhizotomy, except for early developing and persistent, widespread degeneration of myelinated axons in the former model. As in the rhizotomy model, there was cholinergic axonal regeneration, adrenergic hyperinnervation, and a prominent population of probable copeptidergic axons in long‐term samples of the bladder base following pelvic neurectomy. In contrast, pelvic plexus neurectomy (a postganglionic “denervation” procedure) resulted in early developing and persistent degeneration of all axons in the bladder base: i.e., myelinated, cholinergic and adrenergic, with long‐term hypoinnervation by both cholinergic and adrenergic neural elements. Our observations indicate that two forms of the experimentally induced lower‐motor neurogenic bladder can be distinguished ultrastructurally.
Intrinsic neuromuscular defects in the neurogenic bladder: IX. Effects of combined parasympathetic decentralization and hypogastric neurectomy on neuromuscular ultrastructure of the feline bladder base
Authors: Hanno Ahmed G.‐E. , Atta Mohamed A. , Elbadawi Ahmad
Published: March 2007

Previous studies have shown that unilateral decentralization of the feline bladder by sacral ventral rhizotomy results in ultrastructural neuromuscular changes in the bladder base. In the present study, the neuromuscular ultrastructure of the feline bladder base was studied in twenty sexually mature adult male cats 1–4 and 6–10 weeks following bilateral sacral rhizotomy, alone and combined with hypogastric neurectomy. The former procedure resulted in initial degeneration of cholinergic axons with loss of their neuroeffector junctions, but the adrenergic axons and neuroeffector junctions were preserved; within 6–10 weeks, the bladder base became re‐innervated by regenerated cholinergic, increased adrenergic, and abundant probable copeptidergic axons. In contrast, combined sacral rhizotomy and hypogastric neurectomy resulted in persistent (up to 10 weeks) degeneration of both cholinergic and adrenergic axons with loss of their neuroeffector junctions, and no adrenergic hyperinnervation, with only a modest increase in probable copeptidergic axons in long‐term samples. Our observations indicate that intact efferent sympathetic pathways are essential for eventual cholinergic re‐innervation and adrenergic hyperinnervation of the decentralized bladder and suggest that the latter is an important factor in the development of vesical hypertonicity in lower‐motor neuron lesions. On this basis, we introduce the concept that two functional types of the lower motor neurogenic bladder–i.e., the hypertonic with intact and the normotonic with injured efferent sympathetic pathways–may be distinguishable morphologically by ultrastructural study of the vesical muscularis.
Relation between bladder filling and anal sphincter reflexes
Authors: Petersen Thor , Schrøder Henrik D.
Published: March 2007

The effect of bladder filling on the threshold of the perianally elicited anal reflex and the anal reflex elicited by peripheral stimulation of the lower limbs has been studied in seven patients with hyperactive bladder and detrusor‐sphincter dyssynergia and in seven normal controls. No changes were found in the perinally elicited reflex, while the minimal peripheral stimulus necessary for eliciting a reflex changed in both groups but in opposite directions. These observations show that the different anal reflexes use different spinal pathways and that the central control of the interaction between detrusor and sphincters is exerted on the pathway used by the peripheral reflex. These findings, moreover, call for a thorough standardization of the conditions of investigation.
Ambulatory urethro‐cysto‐rectometry: A new technique
Authors: Kulseng‐Hanssen S. , Klevmark B.
Published: March 2007

In some patients complaining of urinary incontinence a leakage is not found during sitting simultaneous urethrocystometry (SUCM). In these patients, who often exhibit marked urethral pressure variations, the closure pressure frequently falls close to zero due to a decrease in the maximum urethral pressure without simultaneous detrusor contraction. In order to see what happens to urethral, bladder, and rectal pressures when these patients leak urine in daily‐life situations, a new ambulatory urethro‐cysto‐rectometric technique (AUCRM) has been developed.

Twenty‐six female patients who had urethral pressure variations of 20–100 cm H2O during SUCM were reinvestigated with this new technique.

Urinary leakage was found significantly more often during AUCRM than during SUCM (21 patients of 26, vs. 13 of 26; P < 0.05).

Twenty‐one of 26 patients complained of the symptom urge incontinence. In these patients urinary leakage was found to be highly significant more often during AUCRM than during SUCM (16 patients of 21, vs. 4 patients of 21; P < 0.001). Leakage was always due to a combination of urethral pressure decrease and detrusor pressure increase, as in normal micturition. The condition unstable urethra was not found.

During SUCM 17 patients were found to have sensory and 4 motor urgency. Performing AUCRM in the same patients, 5 were found to have sensory and 16 motor urgency. By the use of AUCRM the condition sensory urgency has been shown to be less frequent than was previously believed.

The new technique of AUCRM used in the present study is compared to supine and sitting SUCM, judged to be superior for detection of the leakage mechanism.
Correlation of bladder dysfunction and lumbosacral somatosensory evoked potential S‐wave abnormality in spinal‐cord‐injured patients
Authors: Berić Aleksandar , Light J. Keith
Published: March 2007

Thirty‐six patients with stable cervical and high thoracic spinal cord injury underwent urodynamic evaluation and lumbosacral somatosensory evoked potential testing. All these patients had a preserved peripheral sensory neuron (normal R‐wave). Fifteen of the 36 patients had either an abnormal or absent lumbosacral postsynaptic posterior horn potential (S‐wave). Correlation of the S‐wave abnormality and urodynamic evaluation in these patients showed a high incidence of abnormal detrusor contractility (87%). This supports an underlying neurogenic dysfunction for the abnormal detrusor behavior in spinal‐cordinjured patients.
The bladder neck in neurological degenerative disorders
Authors: Sotolongo Jose R.
Published: March 2007

Bladder neck incompetence occurs frequently in the Shy‐Drager syndrome. The behavior of the bladder neck in patients with multiple sclerosis and Parkinson's disease, however, has not been well defined.

Complete urodynamic studies were performed on 48 patients with urgency incontinence and one of the following neurological diagnoses: Parkinson's disease (13 patients), Shy‐Drager syndrome (13 patients), and multiple sclerosis (22 patients). Complete studies were also performed on 73 patients with no neurological diagnoses and no incontinence. None of the patients had ever undergone prior transurethral surgery. All patients with a neurological diagnosis had detrusor hyperreflexia on cystometrogram. Bladder neck function was evaluated with fluoroscopy as well as with intraluminal‐pressure measurements utilizing a 10 French triple‐lumen catheter.

Only 11 (22%) of the neurological patients had an incompetent bladder neck on fluoroscopy (6 with Shy‐Drager, 3 with Parkinson's, and 2 with multiple sclerosis). Mean bladder neck pressures of the 48 neurological patients were as follows: Parkinson's: 12 cm H2O, SE = 5; multiple sclerosis: 15 cm H2O, SE = 1.2; and Shy‐Drager: 7 cm H2O, SE = 2.

Bladder neck incompetence, commonly seen in Shy‐Drager and strongly suggestive of sympathetic dysfunction, is uncommon in incontinent patients with other degenerative neurological disorders and detrusor hyperreflexia.
Use of a previously undescribed elastic lamina of the serosa to characterize connective tissue hypertrophy of the rabbit bladder wall following partial outlet obstruction
Authors: Monson Frederick C. , Goldschmidt M. H. , Zderic S. A. , Ruggieri M. R. , Levin R. M. , Wein A. J.
Published: March 2007

Partial outlet obstruction of the rabbit urinary bladder was induced in New Zealand rabbits through surgical introduction of a silk ligature distal to the urethrovesicular junction. The consequence of this intervention is acute overdistension followed by severe bladder wall hypertrophy. In conjunction with physiological experiments, two additional animals were generated for histological evaluation at each of three time intervals after partial obstruction (1, 7, and 14 days), as well as six sham‐operated and two normal subjects. Bladders were fixed in Bouin's fluid and processed routinely for paraffin embedment. Sections were stained with hematoxylin and eosin (H&E), periodic acid Schiff (PAS), and elastin stains, and Mallory's triple stain for connective tissue (CT). The results of this present study confirm and significantly expand previous reports of CT hypertrophy after partial outlet obstruction. After 14 days of partial obstruction the elastin stains showed a peculiar welldefined lamina of elastin buried in the wall of the bladder. In 7‐day animals, the lamina is either buried as in 14‐day bladders, covered with bands of collagenous CT, or associated with the serosa. The lamina is confined to serosa in normal and sham operated animals and in partially obstructed animals, 24 hr after surgery. In normal and sham‐operated animals the elastic lamina is always found to be uninterrupted. In 1‐, 7‐, and 14‐day obstructed animals, the lamina is typically observed to be broken. The elastic lamina is part of the serosa rather than part of the bladder, and it accompanies the mesothelium wherever it is found. Nonetheless, it is clear from these experiments that the serosa becomes involved in the response of the bladder to the obstructive insult, and a fibrotic reaction of the serosa contributes to the thickening of the wall of the hypertrophic bladder. By using this elastic lamina as a marker, CT hypertrophy can be classified as either intrinsic (that within the original bladder wall) or extrinsic (that within the serosal comartment). Although the precise sources of these additional materials are not known at present, hypotheses are suggested. These distinctions may be important in determining the specific cellular and tissue causes of decreased bladder function that are characteristic of certain bladder pathologies.
Urethral pressure recording—an alternative: Balloon‐covered microtransducer catheter detection
Authors: van Der Kooi J. B. , Kornelis J. A. , De Jonge M. C. , van Wanroy P. J. A. , De Pater L.
Published: March 2007

In order to remove artifacts due to side‐mounted sensor detection, while also retaining the unmatched frequency response of the microtransducer catheter (MTC), pressure detection in the urethra has been carried out by using a MTC with the sensor surrounded by a tiny, water‐filled balloon. In 14 women without stress incontinence, static and dynamic urethral pressures have been determined simultaneously with a balloon‐covered and a plain MTC coupled together.
Quantitative study in vitro of the spontaneous contractions of pig detrusor muscle and their frequency‐selective inhibition by drugs
Authors: Hak Jaap , Griffiths Derek J. , van Mastrigt Ron , Koopal Bouwe , Klück Paul
Published: March 2007

The amplitudes of the various frequency components present in the spontaneous contractions of pig detrusor muscle in vitro have been analysed and their responses to drugs examined. For strips taken from the ventral wall of the bladder the spontaneous contractions typically show one or both of two main frequency components near 0.02 Hz (1 per 50 s) and 0.05 Hz (1 per 20 s), respectively. The relative prominence of the two components differs from strip to strip. Spontaneous activity in strips showing mainly the lower frequency is strongly inhibited by oxyphenonium bromide (3 × 10−5 M). Activity in strips showing mainly the higher frequency is almost unaffected. Atropine sulphate (10−6 M) has no consistent effect on either of the two frequency components. Hexamethonium bromide (10−5) selectively inhibits the low‐frequency component. Histological examination shows that the strips contain ganglion cells and suggests that those with mainly low‐frequency activity contain many more such cells than those with higher‐frequency activity. This observation is consistent with the observed frequency‐selective effect of hexamethonium bromide.
Effect of urinary bladder outlet obstruction on the rabbit ureter
Authors: Ruzich Jeffery , Wein Alan J. , Keating Michael A. , Ruggieri Michael R. , Levin Robert M.
Published: March 2007

Ureters of mature New Zealand white male rabbits were studied at 7 and 14 days following partial bladder outlet obstruction. Muscarinic receptor density; intracellular concentrations of DNA, RNA, lipid, and hydroxyproline; and functional characteristics of the whole ureter were assessed as a means of characterizing the ureteral secondary response to partial bladder obstruction.

Wet weight increased 2‐fold by day 7 and almost to 3‐fold by day 14. Ureteral length increased 15% by day 7 and 29% by day 14. DNA concentration varied only slightly from controls while RNA increased by 68% by day 7 but returned to near normal range by day 14. Total hydroxyproline content increased, although hydroxyproline concentration per mg tissue decreased. Total lipids increased by 73% over the first 7 days but subsequently decreased to 27% above control levels by day 14. After 1 week of obstruction, muscarinic receptor density was 35.5% of controls, and after 2 weeks of obstruction, muscarinic density was 52.5% of controls. Although muscarinic receptor density decreased significantly, the number of receptors per ureter did not substantially change. Flow studies demonstrated increased opening pressures at 7 days and decreased opening pressures by day 14. Flow as a function of constant pressure was not significantly changed by the 7th day but increased 24% by the 14th day. Bethanechol (muscarinic agonist) caused similar decreases in flow in control and 1‐ and 2‐week obstructed ureters.

These studies indicate that 1 week following partial outlet obstruction, ureters demonstrate increased protein synthesis and lipid deposition resulting in increased weight and length. By the 2nd week, protein synthesis and lipid content begin to return to normal. Weight and length remain significantly increased and the capacity for flow through the ureter improves.
Detrusor hyporeflexia after anterior sciatic syndrome. Effect of short‐term maximal electrostimulation
Authors: Eriksen B. C. , Sand T. , Sjaastad O.
Published: March 2007

A 63‐year‐old woman with persisting detrusor hyporeflexia and lack of bladder sensibility 6 weeks after the occurrence of an acute anterior sciatic syndrome was treated with maximal electrical stimulation of the pelvic floor. An immediate improvement of bladder sensibility was observed. A complete normalization of the micturition reflex was obtained after five sessions of maximal stimulation during a period of 8 days. Electrostimulation therapy may restore normal function in the lower urinary tract in selected patients with neurogenic bladder dysfunction.
Structural aspects of urethrovesical function in the female
Authors: Delancey John O. L.
Published: March 2007

Urodynamic investigations have provided detailed physiologic information which raises morphologic questions not easily answered by older descriptions of urethral anatomy. This article describes urethrovesical structure specifically as it has to do with urodynamic evaluation of the lower urinary tract.
Urethrometry: Considerations of static, dynamic, and stability characteristics of the female urethra
Authors: Constantinou C. E.
Published: March 2007

Measurements of resting anterior/posterior urethral pressures and detrusor function are considered with respect to clinical observations made during the physical examination of patients complaining of urinary incontinence. Observations made on a large number of consecutive unselected patients show that the extent of incontinence is much larger than can be determined by the physical examination alone. Urethral profilometry shows that there are statistically significant differences in the anterior and posterior maximum urethral closure pressure between stress‐ and non‐stress‐incontinent patients regardless of age and detrusor function. The measurement of posterior resting urethral closure pressure correlates best with the physical demonstrability of stress incontinence among patients with a stable detrusor function. The age‐related rate of decrease in the maximum resting urethral pressure is approximately the same for both anterior and posterior urethra in the continent patient. Demonstrably incontinent patients show a rate of posterior urethral pressure decrease with age double that of those with no evidence of incontinence on physical examination. The differences between anterior, posterior, and lateral closure pressures are discussed in terms of their correlative anatomical periurethral structures and are graphically represented in a threedimensional perspective schema.

The direction of occlusive forces in the proximal healthy female urethra is critically examined at rest and also during dynamic events such as holding and coughing. The results show that compressive forces in the proximal urethra are asymmetrically distributed with respect to the anterior/posterior plane and are symmetrical in the lateral plane. Resting urethral pressure profiles show that the absolute value of the maximum urethral closure pressure is equal in the anterior/posterior and lateral aspects of the urethra. Dynamic measurement at the proximal urethra in controls shows that holding or coughing produces directional closure from posterior to anterior. The directional forces acting at the proximal urethra are observed in the region coincident with the position of the vaginal attachments to the pelvic diaphragm. Based on resting and dynamic urethral pressure measurements, evidence is presented to indicate that the microtip transducer with sensors oriented in the anterior/posterior plane provides a significant advantage in identifying urethral closure mechanisms and has contributed towards localization of anatomical structures involved in the continence mechanisms. Finally, consideration is made of urethral stability and local pressure variations detected in the absence of external periurethral influences possible interplay between the stability of the urethra on the one hand and the detrusor on the other are discussed with particular emphasis on establishing a link between them.
Bladder instability and stress incontinence
Authors: McGuire Edward
Published: March 2007

The relationship between bladder instability and stress incontinence is complex, but the two conditions frequently coexist; when they do, the unstable bladder appears to be etiologically related to the stress incontinence, since surgical repair of the latter resolves symptomatic bladder instability in about 80% of such patients.
Applications of neurostimulation in urology
Authors: Schmidt Richard A.
Published: March 2007

Electrical stimulation of nerves and muscle is a time honored approach to the treatment of urinary incontinence. The use of implantable neuroprosthetics in the field of urology remains a new frontier. This report presents a summary of seven years experience with neuroprosthetic devices in the treatment of symptomatic voiding dysfunction. The techniques devised to study and evaluate patients for treatment via neurostimulation are described.

The majority of patients were not paraplegic and were significantly incapacitated by dysfunctional voiding patterns. The rationale in using neurostimulation were two: (1) most voiding dysfunctions result from, or are associated with hyperactive striated muscle behavior; (2) neurostimulation has an intrinsic inhibitory effect on this spastic behavior of striated muscle. Very favorable results were obtained. Neurostimulation would appear to be a valuable asset to the urologist from both an investigational as well as a therapeutic viewpoint.
Permanent retention following radical hysterectomy
Authors: Kadar Nicholas
Published: March 2007

Urodynamic findings associated with permanent retention after radical hysterectomy are presented and discussed in the light of previous observations made in women rendered severely incontinent by the operation. These findings suggest that if the operation ablates the micturition reflex, some reduction in urethral pressure is required to achieve balanced bladder function. They also demonstrate that opposite extremes of proximal urethral pressure can occur after a radical hysterectomy and that they are associated with diametrically opposite types of urinary dysfunction even if detrusor function is identical. It is difficult to reconcile these observations with histochemical data which suggest a purely cholinergic efferent nerve supply to the proximal urethra.
Quantification of urethral resistance and bladder function during voiding, with special reference to the effects of prostate size reduction on urethral obstruction due to benign prostatic hyperplasia
Authors: Griffiths Derek , van Mastrigt Ron , Bosch Ruud
Published: March 2007

In pressure/flow studies of adult voiding the behaviour of the urethra can be distinguished from that of the bladder, and quantified separately, as follows. Different degrees of urethral obstruction can be quantified and ranked using a group‐specific resistance factor (URA) that is based empirically on the pressure/flow plots obtained in a large number of voidings of adult patients. Different detrusor contractions can be similarly quantified using a physiologically based measure (WF, abbreviated from power [W] factor) of the contraction strength. Both URA and WF can be calculated by computer from measurements of detrusor pressure, voiding flow rate, and the residual volume in the bladder after voiding. For other groups of patients, e.g., children, different group‐specific resistance factors are appropriate.

In men with obstructed voiding due to benign prostatic hyperplasia (BPH), “chemical castration” with cyproterone acetate or buserelin caused a substantial, reversible reduction in the size of the prostate. The effect on the degree of urethral obstruction and the voiding bladder contraction has been studied using the above‐mentioned methods. There was an increase in peak urinary flow rate, a reduction in residual urine, and a decrease in daytime voiding frequency. Surprisingly, however, there was on average no decrease in urethral resistance but only an increase in the average detrusor contraction strength. In individual patients large increases and decreases of urethral resistance and detrusor contraction strength occurred, which largely cancelled each other out. These large changes masked the relatively modest urethral resistance decrease caused directly by prostate size reduction.
Functional whole rat bladder model
Authors: Chun Alexa L. , Wallace Lane J. , Gerald Michael C. , Wein Alan J. , Levin Robert M.
Published: March 2007

There are many animal models that have been utilized for the study of urinary bladder function including the dog, cat, rabbit, and rat. Although the rat has been used extensively for the study of urinary bladder function, the relatively small size and capacity of the urinary bladder has made the functional evaluation of the bladder difficult. The present study describes an in vitro whole rat bladder preparation with which we were able to measure the following properties of urinary bladder function: (1) the pressure‐volume relationship (cystometry) of the isolated bladder; (2) intravesical pressure in response to pharmacological stimulation (isometric bladder contractility); (3) the ability of the bladder to expel its contents in response to pharmacological agents (isotonic contractility); and (4) the ability of the bladder to expand in response to pharmacological stimulation (isoproterenol).

Bethanechol produced a dose‐related increase in intravesical pressure (“closed system”) in the isolated bladder. The maximal pressure response was inversely proportional to the initial volume of the bladder. Bethanechol also produced a dose‐related isotonic contraction of the bladder (“expulsion system”). Although bladders filled to one‐fourth, one‐half, three‐fourths, or full capacity were able to expel approximately 100% of their initial volume, there was a significant shift in potency. As the initial volume of the bladder increased, a higher concentration of bethanechol was required to empty the bladder.

In general, the in vitro whole rat bladder model is a methodology by which bladder function can be evaluated. In this regard, it has significant advantages over isolated strip methodologies. With this model the ability of the bladder to empty, to generate intravesical pressure, and to relax can be measured. Prior studies have clearly demonstrated that the ability of isolated strips to contract may not accurately reflect the functional ability of the bladder to empty.
Morphometric analysis of muscle cell changes in the short‐term partially obstructed rabbit detrusor
Authors: Meyer Sabine , Atta Mohamed A. , Wein Alan J. , Levin Robert M. , Elbadawi Ahmad
Published: March 2007

It has been shown previously that both degenerative and regenerative muscle cell changes occur in the partially obstructed rabbit detrusor and are largely reversed after relief of the obstruction [Elbadawi et al., 1989]. In the present study, we quantitated these changes in the same animal model to define their chronologic evolution. Specimens for electron microscopic study were obtained from the bladder body detrusor in three normal rabbits, fifteen rabbits with 1–14 days of partial bladder outlet obstruction, and seven rabbits relieved of a 7‐day obstruction for 14 or 28 days. Sections from each specimen were analyzed quantitatively for the prevalence of normal, degenerative, and regenerative muscle cell profiles by determining the percentage of photographic prints showing only normal muscle cells and those depicting muscle cell change. Prints of 684 semirandom and 95 truly random photographs were so analyzed. Absolute counts of the various types of muscle cell profiles were also made in the former group of prints for comparison. In addition, 174 prints were analyzed for the presence of hypertrophic cell profiles. All data were analyzed statistically by the appropriate methods. Our observations led to classification of the material studied into three categories: (a) control, which includes both the normal and 1‐day obstructed groups; (b) obstructed, including the 3–7 day obstructed groups in which both degenerative and regenerative changes were maximal; and (c) recovered, including the 14‐day obstructed and both 14‐ and 28‐day deobstructed groups in which muscle cell changes were markedly—though incompletely—reversed. Our findings form a structural basis for the changes in contractility and biochemical profile of the partially obstructed detrusor that have been described previously in the same model [Malkowicz et al., 1986].
Quantitative analysis of intercellular changes in the short‐term partially obstructed rabbit detrusor
Authors: Meyer Sabine , Levin Robert M. , Ruggieri Michael R. , Wein Alan J. , Elbadawi Ahmad
Published: March 2007

In a previous qualitative ultrastructural study, we developed the impression that muscle cell changes following partial outlet obstruction of the rabbit bladder are associated with an increase in the width of intercellular spaces [Elbadawi et al., 1989]. In the present study, we tested that impression by direct measurement of intercellular distances using a simple method that we devised for that purpose. The material for study was obtained from 25 New Zealand White male rabbits, including three normal controls, 15 with partial bladder outlet obstruction, and seven with 7‐day obstruction followed by deobstruction. Specimens from the body detrusor were obtained from each animal and processed for electron microscopy by standard methods. Multiple sections from each sample were studied. A total of 3,889 individual measurements made in 163 electron photomicrographic prints were evaluated statistically. A statistically significant progressive increase in the width of intercellular spaces was observed over the 14‐day period of obstruction, confirming our previous qualitative impression. On the other hand, there were no significant differences in the width of spaces between the deobstructed and the 7‐day obstructed detrusor. Our observations underscore the fact that evaluation of the intercellular compartment by measuring its volume density does not reflect the true width of spaces between muscle cells of the pathologically altered detrusor. The herein verified progressively wider separation of detrusor muscle cells following partial bladder outlet obstruction probably hampers both electrotonic and mechanical coupling of muscle cells, thus preventing efficient and coordinated detrusor muscular responses to neural stimuli.
Ultrastructural changes in the obstructed pig detrusor: A preliminary report
Authors: Meyer Sabine , Hassouna Magdy , Mokhless Ibrahim , Coolsaet Bo L. R. A. , Elhilali Mostafa M. , Elbadawi Ahmad
Published: March 2007

Interest in using the pig to study the effects of urinary tract obstruction on the kidney has been established for some time. The present study was intended as a pilot investigation to find out whether or not structural changes in the detrusor occur in a chronic obstructive pig model. Because of the pilot nature of the study, and the high cost of purchase and maintenance of pigs, it was limited to one normal and one obstructed animal. Obstruction was created by allowing a young pig to grow for 7 weeks with an inactive inflatable urethral cuff in place. Samples from the bladder body detrusor were obtained from this and from a normal pig. These were then processed for electron microscopy by standard procedures. Multiple sections of each sample were examined and photographed to determine the structural status of muscle cells, the width of intercellular spaces and the relative area of muscle cell junctions. In samples from the obstructed pig, we found (1) no evidence of degeneration or regeneration of muscle cells; (2) hypertrophy of detrusor muscle cells; (3) widening of intercellular spaces (from 237 nm in the normal to 503 nm in the obstructed pig); (4) intercellular deposits of basal lamina‐like material; and (5) reduction of junctional sarcolemmal area relative to total sarcolemmal area as well as total muscle cell volume. All morphometric data were statistically significant. The observed reduction of muscle cell junctional area may be a “dilution” effect secondary to muscle cell hypertrophy, and/or represent a true loss of junctions. Despite the small sample size, our findings suggest that ultrastructural obstructive detrusor changes occur and indicate the need for further investigation to define the scope and chronologic evolution of these changes.
Urodynamics in enuretics I: Reservoir function
Authors: Nørgaard J. P.
Published: March 2007

Cystometry appearance day and night was investigated in children with monosymptomatic nocturnal enuresis. Repeated CMG's were performed on two occasions in the awake state and once during sleep. The study revealed a low incidence of unstable bladder contractions during the day. A significantly higher incidence of unstable bladder at nighttime did not correlate to the enuretic events. Except for the occurrence of unstable bladder contractions, the mean urodynamic data for the group was reproducible. A full bladder from an otherwise normal bladder capacity triggered enuresis. The start of micturition during enuresis was shown to coincide with an abnormally low pelvic floor EMG activity.
Prospective evaluation of the incontan transrectal stimulator in women with urinary incontinence
Authors: Leach G. E. , Bavendam T. G.
Published: March 2007

A prospective study was performed to evaluate the efficacy of transrectal electrical stimulation with the Incontan device in women with urinary incontinence. Since July 1986, 36 women with various types of urodynamically documented urinary incontinence were treated with an integrated, automatic, rectally inserted electrical stimulator (the Incontan device). Despite previous optimistic reports of successful treatment with this device, the study group experienced significant problems with electronic device failure (32 out of 64 Incontan devices distributed), as well as having a high “drop‐out” rate (34 out of 36 women). At 6 months, only 2 of 36 women (6%) experienced subjective benefit from Incontan stimulation, although no significant change was documented on follow‐up urodynamic study. Incontan transrectal electrical stimulation is not a viable treatment option for female urinary incontinence due to poor patient acceptance and an unacceptable electronic failure rate of the device.
Pad‐weighing tests: A literature survey on test accuracy and reproducibility
Authors: Kromann‐Andersen B. , Jakobsen H. , Andersen J. Thorup
Published: March 2007

In this literature survey different tests for quantitation of urinary leakage were assessed. Special attention was paid to test reproducibility and accuracy in the detection of urine loss. It is concluded that the reproducibility of the International Continence Society (ICS) 1‐hour test is not optimal, that the reliability of the ICS 1‐hour test is insufficient, and that the discrimination value for incontinence should be a urine loss of more than 1 g per hour. Recommendations for further research are made.
Effects of guanabenz on bladder function after spinal cord injury
Authors: Sotolongo Jose R. , Tomasula John J. , Naftchi Eric
Published: March 2007

The effect of guanabenz, an alpha‐2 adrenoceptor agonist, on urinary bladder function and neurological recovery was studied in cats subjected to a 400 gm‐cm contusion injury of the thoracic spinal cord. Eight cats were treated with 1.3 mg/kg of guanabenz three hours after injury and then twice daily for eight weeks. Four injured cats were used as controls (untreated), and 12 intact cats were used as normal controls. Cystometrograms were used to measure bladder function in all the animals studied.

Guanabenz given intraperitoneally significantly improved urinary bladder function and neurological recovery. It appears that treatment of spinal cats with guanabenz has an ameliorative effect on functional reorganization of the central spinal pathways modulating spasticity, micturition, and lower limb function.
Functional obstruction of bladder neck in men
Authors: Gilja Ivan , Kovačič Marijan , Radej Marjan , Parazajder Josip
Published: March 2007

Page no. 433, 434 missing.
Mechanical properties of the urethra in females with genuine stress incontinence: Static measurements in the resting urethra
Authors: Lose Gunnar
Published: March 2007

The pressure (Pura)‐cross‐sectional area (CA) relationship in the resting urethra was examined in 30 females with genuine stress incontinence (GSI). Measurements were performed at the bladder neck, in the high‐pressure zone, and in the distal part of the urethra. From the two variables urethral elastance (dPura/dCA) and hysteresis were calculated. The results were compared with those obtained in normal females. Urethral elastance, hysteresis, and urethral pressure showed significant differences at the three sites of measurement. Urethral elastance was significantly decreased at the bladder neck in patients with GSI as compared to normal women, while the urethral pressure was significantly decreased all along the urethra. It is suggested that both mechanical weakness all along the urethra and decreased deformability of the urethral wall may be of pathophysiologic importance in GSI.
Clinical significance of axial variations in female urethral pressure profiles
Authors: Benson J. Thomas
Published: March 2007

It has been demonstrated that when urethral pressure profiles are measured with microtip transducers on relatively stiff catheters, there is an important difference in the profile when measured with the transducers facing anteriorly and posteriorly. It has been suggested that patients with demonstrable genuine stress urinary incontinence had notably lower posteriorly derived urethral pressure profiles than anteriorly derived pressure profiles. A clinical consideration of this factor has been studied in 25 patients; 19 had accepted urodynamic evidence of genuine stress urinary incontinence and 6 did not. The use of posteriorly derived pressure profiles in comparison with anteriorly derived as a test for genuine stress urinary incontinence showed a sensitivity of 84% and specificity of only 33.3%. However, when correlated with patients showing lack of anatomic support of vaginal and paraurethral structures, the sensitivity and specificity is significant. Anatomic considerations leading to these findings are suggested.