bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantification of urethral function based on Griffiths' model of flow through elastic tubes
Authors: Spángberg Anders , Terió Heikki , Engberg Anders , Ask Per 
Published: March 2007

AbstractGriffiths' model of flow‐through elastic tubes makes it possible to relate the elastic properties of the flow‐controlling zone to the pressure/flow relation of the urethra. In this work the pressure function p(A) = Pmo + Kn An, where A is cross‐sectional area, Pmo the minimal opening pressure, and Kn and n parameters describing urethral distensibility, describes the elastic properties of the flow‐controlling zone. By curve‐fitting in the pressure/flow plot, the three parameters pmo, Kn, and n can be estimated analytically. Using this model it is possible to identify three different biomechanical changes that may cause obstruction. First, pmo may be elevated. Second, the urethra can be distended to a certain area only, corresponding to high values of Kn and n. Third, the urethra can be distended but a higher‐than‐normal pressure increase above Pmo is needed, Kn is high, and n is low. With this model it is possible to quantify urethral function for both scientific and clinical purposes.
Pubovesical ligament: A separate structure from the urethral supports (“pubo‐urethral ligaments”)
Authors: DeLancey John O. L. 
Published: March 2007

AbstractThe position and mobility of the vesical neck influences not only continence but also the initiation of micturition. During an examination of urethral topography, there appeared to be two structures running from the region around the vesical neck to the pelvic walls which might influence vesical neck function. These structures, the urethral supports (“pubo‐urethral ligaments”) and pubovesical ligaments, have previously been considered to be synonymous terms for a single structure. To investigate this disparity, 1,500 serial histologic sections from eight normal cadavers were examined, 28 cadavers were dissected, and whole pelvis cross sections from an embalmed cadaver were studied.Our observations indicate that there are two structures which run from the region around the proximal urethra and vesical neck to attach to the pelvic walls. The pubovesical ligaments are an extension of the detrusor muscle and its adventitia. They attach to the pubic bone and arcus tendineus fasciae pelvis. Their structure suggests that they contract to assist in vesical neck opening but would be poorly suited to provide support for the proximal urethra. The other structures represent the urethral supports (“pubo‐urethral ligaments”) which connect the vagina and periurethral tissues to the muscles of the pelvic diaphragm and to the pelvic fasciae. Their structure appears to be adequate to explain urethral support.There are, therefore, two structures running from the tissues around the vesical neck to the pelvic walls. The structure of the pubovesical ligament suggests that it could assist in vesical neck opening, and the urethral supports could determine urethral position.
Biochemical characterization of the rabbit urinary bladder: II. Intracellular concentration of nucleotides
Authors: Levin Robert M. , Moore Debra , Ruggieri Michael R. , Haugaard Niels , Wein Alan J. 
Published: March 2007

AbstractBladder contraction is mediated by a number of intracellular biochemical reactions including glycolysis, mitochondrial respiration, phosphocreatine kinase, and various ATPases. In order to understand how alterations in intracellular metabolism can affect bladder function (or how alterations in bladder function can affect intracellular metabolism), we must first understand and describe normal bladder metabolism. Using the rabbit as a model for bladder function, the present study compares the intracellular concentrations of a variety of important compounds between the bladder base and body.The intracellular concentrations of phosphocreatine (PC), creatine, ATP, ADP, and AMP were determined in samples of rabbit urinary bladder body and base. The values for PC and creatine were significantly lower in the bladder base than in the bladder body. Adenine nucleotide concentrations were similar in the two sections.The concentrations of NAD + NADH, NADP, CTP, CDP, CMP, GTP, GDP, GMP, and UTP, UDP, UMP were also measured. Of these compounds, the concentrations of GTP and UTP in the bladder body were nearly double those in the bladder base. The intracellular concentrations of the other tissue constituents were similar in the two bladder sections.These studies demonstrate that the bladder is not biochemically homogeneous but that the bladder base and body differ not only functionally but also metabolically.Experiments in which strips of bladder body were incubated in vitro in oxygenated Tyrode's solution containing glucose showed that the tissue concentrations of PC, ATP, GTP, and UTP decreased substantially following 30 min of incubation, with no further decrease during a subsequent 60‐min incubation.
Effects of short‐term partial bladder outlet obstruction on the rabbit detrusor: An ultrastructural study
Authors: Elbadawi Ahmad , Meyer Sabine , Malkowicz S. Bruce , Wein Alan J. , Levin Robert M. , Atta Mohamed A. 
Published: March 2007

AbstractIt has been shown previously that partial bladder outlet obstruction in the rabbit results in changes in detrusor contractility and biochemical profile [Malkowicz et al., 1986]. The present study was conducted in the same animal model to define the nature and evolution of concomitant structural neuromuscular changes in the detrusor, as the basis for its altered function following partial outlet obstruction. Twenty‐five New Zealand White rabbits, including three normal controls, were used. The bladder was excised in 15 rabbits at various intervals 1–14 days postoperatively. In the remaining seven rabbits, the obstruction was relieved after 7 days, and the bladders were excised 14 or 28 days later. Multiple samples of the midbody detrusor were obtained from each specimen and processed for electron microscopy by standard techniques. Changes were observed in the smooth muscle, interstitial, and neural compartments. The muscular changes included a combination of muscle cell degeneration and regeneration, and widening of intercellular spaces with deposition of basal lamina‐like material. Both degenerative and regenerative muscle cell profiles were uncommon in the control and 1 day obstructed samples, frequent in the 3–7 day obstructed samples, and less frequent in the 14 day obstructed samples. The spaces between individual muscle cells appeared to become increasingly wider in the 3–14 day obstructed samples. The ultrastructure of smooth muscle in samples from both deobstructed groups was similar to controls, except for thickened basal laminae of muscle cells and consistently widened intercellular spaces. The interstitial compartment appeared to become progressively exaggerated with increasing deposits of collagen and elastin in the 3–14 day obstructed samples; these changes persisted in samples from both deobstructed groups. In regard to the neural compartment, degeneration of both cholinergic and adrenergic nerves with loss of neuroeffector junctions was observed in the 3–7 day obstructed samples; axonal regeneration was seen with re‐establishment of the junctions in the 14 day obstructed and both deobstructed groups. It is concluded that partial bladder outlet obstruction in the rabbit results in partially reversible neuromuscular changes in the detrusor, which can explain the resultant alterations in detrusor contractility and biochemical profile.
Role of ischemia in structural changes in the rabbit detrusor following partial bladder outlet obstruction: A working hypothesis and a biomechanical/structural model proposal
Authors: Elbadawi Ahmad , Meyer Sabine , Regnier Claude H. 
Published: March 2007

AbstractMultidisciplinary studies of the partially obstructed detrusor in a rabbit model have shown that important changes in its structure and functional behavior evolve with time and initially are probably related to rapid changes in smooth muscle. This report presents a working hypothesis on the basis of and the reasons for obstructive structural changes in the detrusor, and their bearing on its function, from a biomechanical viewpoint. In this report, the concept that detrusor changes following short‐term bladder outlet obstruction evolve through an ischemic, an adaptive, and a “recovery” phase will be proposed. In addition, a simple “chain” model will be presented in an attempt to define the possible mechanical correlates of each of these phases with respect to both the structure and function of the detrusor in each.
Morphometry of the obstructed detrusor: I. Review of the issues
Authors: Elbadawi Ahmad , Meyer Sabine 
Published: March 2007

AbstractQualitative and quantitative ultrastructural studies on the rabbit detrusor following partial bladder outlet obstruction indicate the necessity of morphometry in evaluating structure of the dysfunctional detrusor. This report presents a review of the issues involved in such morphometry, as a prelude to presentation of a comprehensive protocol for this purpose in a subsequent report. In the present report, obstructive changes in the structure of smooth muscle are reviewed, the parameters that should be evaluated are defined, the limitations of detrusor morphometry are presented, and the guidelines for a meaningful morphometric protocol for use in future studies on the dysfunctional detrusor are outlined.
Morphometry of the obstructed detrusor: II. Principles of a comprehensive protocol
Authors: Meyer Sabine , Elbadawi Ahmad 
Published: March 2007

AbstractMorphologic studies on the obstructed detrusor have revealed several structural neuromuscular changes that must be evaluated quantitatively by morphometry to be functionally meaningful and clinically relevant. The peculiar structural organization of the detrusor poses important limitations to methods of morphometry that have withstood the test of time in other visceral smooth muscle systems, particularly the intestine. Because of this, conclusions in the literature about structure of the obstructed detrusor based on standard methods of morphometry are in many instances open to question. What is needed for scientifically credible morphometry of the detrusor is a comprehensive protocol that takes into consideration its peculiar structural organization and outlines the most appropriate methods for its processing and study within the context of the morphometric parameters to be evaluated. The principles of such a protocol will be presented in this report after a review of standard methods of morphometry and their applicability to the detrusor.
Successful use of electroejaculation in two multiple sclerosis patients including report of a pregnancy utilizing intrauterine insemination
Authors: Ohl Dana A. , Grainger Ronald , Bennett Carol J. , Randolph John F. , Seager Stephen W. J. , McCabe Marcianna 
Published: March 2007

AbstractWe report two males with multiple sclerosis who were infertile as a result of failure to ejaculate. Electroejaculation was successfully used to recover semen with motile sperm from both men, and the sperm was used for artificial insemination. One pregnancy was achieved by intrauterine insemination, and a healthy male baby was born.
Urodynamics in enuretics II: A pressure/flow study
Authors: Nørgaard J. P. 
Published: March 2007

AbstractThis study dealt with urodynamics during sleep where enuresis was provoked by filling cystometries. Data were compared to the ones obtained in the same patients in urodynamics at awake state. Fifty‐six sleep cystometries resulted in 31 enuretic events and 25 arousals. Comparison of pressures revealed that enuresis was taking place during an increase in maximal bladder pressure of 20 cm H2O (P<0.05) and a prolonged contraction time (P<0.05). The configuration of the pressure tracing was otherwise completely similar to the ones obtained in awake state. Furthermore, these were similar to data available in the literature of normal children. It is hence concluded that enuretics are urodynamically normal and that the enuretic event is a coordinated micturition initiated at maximal bladder capacity with some indication of increased urethral resistance.
Maximal electrostimulation of the pelvic floor in female idiopathic detrusor instability and urge incontinence
Authors: Eriksen B. C. , Bergmann S. , Eik‐Nes S. H. 
Published: March 2007

AbstractA new device for in‐clinic acute maximal electric stimulation of the pelvic floor has been developed to treat motor and sensory dysfunction of the lower urinary tract.Forty‐eight women suffering from idiopathic detrusor instability and urge urinary incontinence received an average of seven treatments, each lasting for 20 minutes. A mean current intensity of 86 mA using monophasic square pulses with a frequency of 5–10 Hz and a pulse width of 1 msec was delivered simultaneously through a vaginal and an anal plug electrode.Initially, clinical and urodynamic cures were obtained in about 50% of the patients. In addition, a significant improvement was observed in approximately 33%. At 1‐year follow‐up, a persisting positive therapeutic effect was found in 77% of the study group, and no serious side effects were registered.The stimulation device used, the “Medicon MS‐103,” which is commercially available, was easy to handle, safe for the patients, and technically reliable. Disposable plugs satisfied hygienic requirements. Low‐frequency, repetitive, short‐term maximal electrostimulation of the pelvic floor is a simple, effective, low‐cost therapeutic method in female idiopathic motor urge incontinence.
Experimental models of reflex contractile activity in the rabbit bladder
Authors: Kitada Shinichiro , Kato Kumiko , Wein Alan J. , Levin Robert M. 
Published: March 2007

AbstractWe were able to produce two highly reproducible experimental models (in the rabbit) that demonstrated a high degree of reflex bladder contractile activity. In one model, a somatovesical reflex was induced by touching or pinching the perineal area. This reflex may be organized through a neurogenic reflex at the spinal level. In another model, rhythmic bladder contractions were produced by distal urethral constriction in the absence of bladder distension. These rhythmic contractions were thought to be due to a supraspinal reflex. In both types of contractile reflexes, intravenous administration of hexamethonium inhibited the reflex contractile activity virtually completely, intravenous atropine inhibited over 90% of the induced contractile activity, thus suggesting that these contractions were mediated reflexly through cholinergic stimulation. These two models of reflex bladder contractions should be useful for the study of hyperreflexic bladders.
Intrinsic neuromuscular defects in the neurogenic bladder: X. Value and limitations of neurohistochemistry
Authors: Elbadawi Ahmad , Atta Mohamed A. 
Published: March 2007

AbstractHistochemical changes in bladder innervation have been described in various types of clinical and experimental neurogenic voiding dysfunction. Recent studies in the cat have shown that both decentralization and postganglionic “denervation” lead to ultrastructural changes in muscular innervation of the bladder base. The present study was conducted to find out whether these changes can be detected histochemically. Decentralization of the bladder by unilateral sacral ventral rhizotomy, bilateral sacral ventral rhizotomy, or unilateral pelvic neurectomy was performed in 25, and postganglionic “denervation” by unilateral pelvic plexus neurectomy in 9, adult male cats. Specimens of the bladder body and bladder base were collected 2–4 and 8–10 weeks after decentralization, and 2–4 weeks and 10 weeks after “denervation.” The specimens were processed by histochemical methods to demonstrate cholinergic and adrenergic nerves. No recognizable differences from the norm were observed in cholinergic muscular innervation of either the body or base specimens of the decentralized bladder. While adrenergic muscular innervation of both regions was similar to normal in short‐term samples of the same specimens, there was an obvious adrenergic hyperinnervation of both in the long‐term samples. By contrast, there was an obvious, early‐developing, and persistent hypoinnervation by both cholinergic and adrenergic nerves in both the body and base regions after postganglionic “denervation.” It is concluded that histochemistry (1) has no value in detecting either short‐ or long‐term changes in cholinergic muscular innervation of the decentralized bladder and (2) is useful for revealing both short‐ and long‐term cholinergic and adrenergic hypoinnervation of the “denervated,” as well as long‐term adrenergic hyperinnervation of the decentralized vesical muscularis.
In vitro effects of intravesical dimethylsulfoxide
Authors: Freedman Alan I. , Wein Alan J. , Whitmore Kristene , Levin R. M. 
Published: March 2007

AbstractThe mainstay of therapy for interstitial cystitis (IC) is intravesical instillation of dimethylsulfoxide (DMSO). Although numerous clinical studies have documented symptomatic improvement in up to 70% of patients, the mechanism of action, and effect on objective parameters of bladder function have not been adequately studied. In this study we have used the in vitro whole bladder model to determine the effect of DMSO on several parameters of bladder function, including in vitro cystometry, pressure generation, and ability to empty in response to both field stimulation and bethanechol. All parameters measured were significantly (P < 0.05) reduced. Bladder capacity was reduced by a mean of 18.71%. Compliance was markedly decreased after instillation of DMSO. The magnitude of pressure generated in response to field stimulation was decreased from a mean of 8.93 cm H2O to a mean of 5.55 cm H2O. In response to bethanechol, the magnitude of pressure generation was decreased from a mean of 9.85 cm H2O to a mean of 7.07 cm H2O after treatment with DMSO. The rate of pressure generation in response to field stimulation was substantially reduced by 46.6%. In response to field stimulation and bethanechol, control bladders emptied 86% and 92%, respectively. After treatment with DMSO, these values were reduced by an average of 33.24% and 14.92%, respectively.This in vitro study has shown that DMSO has a negative effect on multiple parameters of bladder function, including compliance, capacity, and contractile and functional responses to field stimulation and bethanechol.
Influence of renal failure on urodynamic, cystoscopic and radiologic evaluations of the lower urinary tract: Implications for the pre‐renal transplant evaluation
Authors: Steers William D. , Flechner Stuart M. , Kahan Barry D. , Rudy Delbert C. , Benson George S. 
Published: March 2007

AbstractA retrospective analysis of 175 consecutive renal transplant patients who underwent extensive urodynamic evaluation and cystoscopy was performed. Urodynamic abnormalities were few, but general trends appeared. Pretransplant patients tended to have small‐capacity bladders (mean 280 cc) and low urine flow rates (mean 7 cc/sec). The flow rates returned to normal after transplantation regardless of preoperative urine volumes. Cystoscopy failed to demonstrate anatomical abnormalities not discovered on preoperative voiding cystourethrography, and no patient was found to have a lower urinary tract malignancy. A history and physical examination, urinalysis, urine culture, and voiding cystourethrogram constitute an adequate urologic screening evaluation for most renal transplant candidates. Although some patients require cystoscopy and urodynamic evaluation, we have abandoned the “routine” use of these studies.
Use of routine videocystourethrography in the evaluation of female lower urinary tract dysfunction
Authors: Barnick C. G. , Cardozo L. D. , Benness C. 
Published: March 2007

AbstractControversy remains over which tests are necessary in the routine evaluation of women with lower urinary tract dysfunction. Is cystometry alone sufficient, or is a more detailed investigation such as videocystourethrography justified? Two hundred consecutive new patients attending for urodynamic assessment were reviewed. In fifteen (7.5%) patients the correct diagnosis was made only on videocystourethrography. We therefore suggest that videocystourethrography should continue to be used as the routine investigation of female lower urinary tract dysfunction.
Mechanical properties of the urethra in healthy female volunteers: Static measurements in the resting urethra
Authors: Lose Gunnar 
Published: March 2007

AbstractA pressure/cross‐sectional area probe was used for measurement of related values of pressure (Pura) and cross‐sectional area (CA) at static circumstances in the resting urethra in 30 healthy females. Measurements were performed at the bladder neck in the high‐pressure zone and distally in the urethra. From the two variables urethral elastance and hysteresis were calculated.The mean urethral elastance (i.e., dPura/dCA) was found to be of the order of 1 cm H2O/mm2 all along the urethra. No correlation could be established between the elastance and age or parity. The mean hysteresis was of the order of 20–25 cm H2O along the urethra. Urethral hysteresis appeared to be a time‐dependent phenomenon.
Effect of urethral catheterisation on urethral sphincter emg and pressure profile
Authors: Lose Gunnar , Jørgensen Lisbeth 
Published: March 2007

AbstractThe impact on urethral sphincter EMG and pressure profile of the introduction of a catheter per urethram was assessed in 48 women with various voiding dysfunctions. Urethral EMG activity was recorded with vaginal surface electrodes placed behind the midurethra. A 5F urethral profile catheter was used in 13 patients (group I), an 8F in 23 patients (group II), and a 10F in 12 patients (group III).In all three groups a statistically significantly increased EMG activity was observed following the introduction of the catheter. This increased activity ceased after a median time of 3–5 minutes. The increased EMG activity did not affect the maximum urethral closure pressure and functional profile length. No correlation could be established between changes in EMG activity and changes in urethral closure pressure. It is concluded that the increased sphincter EMG activity provoked by catheterisation does not affect the urethral pressure profile significantly.
Urethral pressure measurement: A comparison of profiles obtained by conventional and fibre‐optic microtransducers
Authors: Hilton P. , Mayne C. J. 
Published: March 2007

AbstractResting urethral pressure profile measurements and continuous urethrocystometry traces were carried out in a group of 24 patients by using both conventional microtransducer catheter and fibre‐optic microtransducer techniques in an effort to assess the repeatability of the various profile parameters and to investigate rotational variations in the recordings.The microtransducer technique resulted in profiles with significantly higher values for total profile length (TPL), functional profile length (FPL), length to peak pressure (LtPP), and maximum urethral pressure (MUP), with significantly lower variation in urethral pressure than the fibre‐optic technique. These findings applied in all transducer orientations, even though the microtransducer method showed a greater degree of rotational variation.When a standard catheter orientation was employed (with the transducer facing laterally in the urethra) the microtransducer technique showed significantly greater consistency of profile parameters when an analysis of variance technique was used.