Continence Function Research Articles

Long-term urinary continence and renal function in neonates with posterior urethral valves : J.P. Connor and K.A. Burbige. J Urol 144:1204–1211, (November), 1990

Long-term urinary continence and renal function in neonates with posterior urethral valves : J.P. Connor and K.A. Burbige. J Urol 144:1204–1211, (November), 1990

On the existence of the optimum commodity tax system: A Heuristic Proof

This paper presents a basic proof of the existence of the optimum commodity tax system in a typical economy where a social preference is defined. The proof in this paper utilizes only the fundamental apparatus familiar in the proof of the existence of competetive equilibrium [ as in Debreu (1959)] and the maxima-minima theorem for continous functions. The purpose of the paper is to facilitate the understanding of how the optimum tax is assured, especially for policy-oriented researchers. The paper also intends to show when the existence of the optimum commodity tax is not guaranteed.

Physiologic evaluation of the anorectum

Pelvic floor physiology is a complex area of clinical study. Continence and voiding functions are not completely understood. Incontinence is an especially underrated problem. With the use of manometry and ultrasound, anorectal physiology is evaluated and correlated with clinical dysfunction. A description of a previously undescribed ultrasound technique to evaluate anorectal angles and puborectalis function is presented. The results in 10 controls and 53 symptomatic patients with different degrees of continence dysfunction are discussed. The controls showed anal pressures and anorectal angles of 29 cm H2O and 114 degrees at rest and 67 cm H2O and 95 degrees with contraction. Six of the symptomatic patients had complete incontinence to solid stools. The results of their pressures and angles were 14 cm H2O and 151 degrees at rest and 32 cm H2O and 124 degrees with contraction. The values of this group compared with controls is significantly different (P less than 0.05). Ultrasound is helpful in assessing the pelvic floor, both subjectively and objectively. It has the advantages of avoiding radiation and allowing a longer viewing time. It is less expensive compared with radiographic proctography and the data are complementary. Ultrasound and manometry may be useful for long-term follow-up of anorectal physiology.

Urinary tract reconstruction: Applied urodynamics

AbstractSixty‐four patients underwent urinary reconstruction guided by urodynamic investigation. Twenty‐eight patients had myelodysplasia (MM) and 26 had spinal cord injuries (SCI). Operative outcomes were assessed by repetitive urodynamic testing.Bladder reservoir function and detrusor contractile activity were correctly assessed in all 64 patients. Operative creation of a more adequate reservoir was required in 58 patients.Assessment of urethral continence function was inaccurate in six instances wherein we judged urethral sphincter function adequate when, in fact, it was not. Ureteral function was judged radiographically or by furosimide renography, or Whitaker perfusion testing. In the two instances where ureteral function was in doubt, it made no difference in outcome. There was a striking resolution of ureteral radiographic abnormalities after reconstruction which we attribute to the low‐pressure reservoir.

Continence recovery following radical prostatectomy

AbstractEarly postoperative continence problems following radical prostatectomy may occur in some patients, but continence usually improves during the first year following the operative procedure. The objective of this study was to assess the incidence of early postoperative continence problems and to determine the subsequent continence recovery over time. In 65 patients having a radical prostatectomy, mild and moderate incontinence occurred commonly at one month and three months following surgery. but significant improvement occurred at 6 months and 1 year. While most patients who have early postoperative incontinence will have recovery of continence function during the first year, the more severe early continence problems are more likely to persist as a prolonged continence dysfunction.

Urethral Dilation in the Management of Urological Complications of Myelodysplasia

Urethral dilation was performed in 11 of 65 myelodysplastic children with high intravesical pressures. These 11 children had persistent bladder pressure elevations uncontrolled by intermittent catheterization and anticholinergic agents. After dilation intravesical pressures decreased, and upper tract function and measured bladder compliance improved. No discernible effect on continence function occurred. The procedure appears to be a safe alternative to temporary vesicostomy in myelodysplastic children with high intravesical pressures that cannot be controlled by intermittent catheterization and anticholinergic agents.

Failed ileoanal anastomosis: correlations between clinical function and anal canal neurophysiologic and histologic examinations.

Ten patients with an ileoanal anastomosis had conversion to permanent ileostomy 13 (range, 6-29) months after the primary procedure. Causes for reoperation were incontinence in seven patients, unacceptable stool frequency without incontinence in two patients, and atypia in the mucosal remnant with perfect continence in one patient. Stool frequency, continence function, anal canal resting pressure, external anal sphincter (EAS) EMG/pressure relationship (in terms of slope, m), EAS fiber density (FD), and pressure in the distal ileum were registered, and the mucosa and the anal sphincter muscles were examined histologically. There were significant correlations between continence function and EAS changes in terms of both neurophysiologic tests (m and FD) and the histologic picture. The abnormalities in six incontinent patients were consistent with denervation of the EAS. The main reason for fecal leakage in one patient was the high amplitude of pressure waves in the distal ileum. Preservation of mucosal epithelium proximal to the dentate line per se did not seem essential to maintain continence.

Anal sphincter function after colectomy, mucosal proctectomy, and ileoanal anastomosis.

Anal sphincter investigations were performed in 41 patients with straight ileoanal anastomosis and in 10 controls. In 20 patients (group I) the mucosal stripping had been performed from the abdominal side, leaving 1-2 cm of distal anal mucosa. In 21 patients (group II) the anal mucosa had been stripped from the perineal side as far as the dentate line. Continence was perfect in all patients in group I and poor in 6 of 17 patients in group II, when examined 12 months after the operation. Anal canal resting pressure was normal in group I. In group II the resting pressure was significantly decreased and correlated to continence function. The maximum anal canal squeeze pressure was the same in the two groups. The slope of the regression line between pressure rise and integrated electromyography proved to be a useful criterion of the external anal sphincter function and was significantly correlated to degree of incontinence. This variable was significantly smaller in group II patients than in group I and controls. Thus, function of the anal sphincters was normal after mucosal proctectomy performed from above with preservation of a mucosal brim. Dysfunction of the internal and external anal sphincter was found after perineal mucosal dissection and was correlated to continence function.

A generalized mean-value theorem

We give another proof of Seymour and Zaslavsky's theorem: For every familyf 1,f 2,...,f n of continous functions defined on [0, 1], there exists a finite setF⊂[0, 1] such that the average sum off k overF coincides with the integral off k for everyk=1, 2,...,n.

Results of surgical correction of anorectal malformations. A 10-30 year follow-up.

Of 119 patients with surgical correction of anorectal malformations, 47 who were 10-30 years of age were interviewed personally and had manometric studies to evaluate postoperative continence. This clinical study included not only long-term anorectal function but also sexual function. Patients with low type anomalies or with intermediate type anomalies were more likely to be continent, whereas patients with high type lesions had some problems with continence. However, only two of the 16 patients (12%) with high type anomalies were classified as having poor results. This rate is perhaps lower than might be expected. Thus, incontinent patients may become continent even if they were classified as having fecal incontinence before 6 years of age. Most patients who were 15-30 years of age had normal sexual function except for two females with irregular menstruation. These results indicate that achievement of fecal continence and sexual function in patients with high type anomalies treated by abdominoperineal rectoplasty depends on careful dissection as close as possible to the rectal wall and bringing the terminal bowel down exactly within the sling of the puborectal muscle.

Closed Subspaces of Finite Codimension in Some Function Algebras

We characterize all closed subspaces of finite codimension in some specific types of function algebras e.g. these include $C(X)$: algebra of continous functions on a compact Hausdorff space, ${C^n}[a,b]$: the algebra of $n$-times continuously differentiable functions on the closed interval $[a,b]$. Our work is a generalization of the well-known Gleason-Kahane-Želazko theorem [3, 6] for subspaces of codimension one in arbitrary unitary Banach algebras.

Pointwise ergodic theorems for the symmetric exclusion process

Almost sure convergence theorems are proved for Cesaro averages of continous functions in the case of the symmetric exclsion processes in dimension d≧3. For the occupation time of a single site the same result is proved in all dimensions.

Optiplex: a multidimensional response surface fitting procedure for optimization of instrumental parameters

A new instrumentation optimization algorithm is described which combines the iterative nature of simplex optimization with the global aspect of response surface fitting. The model assumes smooth, second order continous functions which are, in most cases, sufficient to characterize instrumental response with changes in parameter values. In contrast to simplex optimization, in which poorest response data values are discarded and replaced by subsequent better fit inputs, optiplex optimization retains both worst and best response data at all times in order to characterize a response surface as completely as possible within the data set used. Once an optimum location has been found, the optiplex algorithm searches the surface in the vicinity of the maximum, in parameter space, to ascertain whether the maximum response found is local or global. This process is iterated and new points taken until a global maximum has been determined. Three parameter optiplex optimization is presented for computer generated test data with and without randomly superimposed noise; atomic absorption (AAS): observation height, sample uptake rate, and fuel flow; and inductively coupled plasma (ICP): observation height, rf power, and nebulizer pressure. Gross signal, absorbance and net signal were the optimization criteria for the computer generated, AAS and ICP data, respectively.

Closed subspaces of finite codimension in some function algebras

We characterize all closed subspaces of finite codimension in some specific types of function algebras e.g. these include C ( X ) C(X) : algebra of continous functions on a compact Hausdorff space, C n [ a , b ] {C^n}[a,b] : the algebra of n n -times continuously differentiable functions on the closed interval [ a , b ] [a,b] . Our work is a generalization of the well-known Gleason-Kahane-Želazko theorem [3, 6] for subspaces of codimension one in arbitrary unitary Banach algebras.

Astrochemistry of Interstellar Clouds: II. Molecular Formation in a Contracting Cloud

The chemistry of an 667 Mo interstellar cloud was studied using 142 reactions for 40 species during the contraction under self gravity in two steps. At first the contraction is allowed without gas phase reactions untill certain optical depth is reached. Secondly, at this optical depth the chemical reactions are started for sufficient cycles in a time dependant scheme till only very small additionally changes in the abundances occur. The so obtained, relative abundances and coulmn densities for different species represent a continous function of the optical depths. The values arround τ=6.3 represent the observations for H2, H2+, H3+, OH, OH+, CH, CH+, CH2, CH2+, CH3+, H2O and H3O+. The region of τ between 1 and 5 i.e. of particle density between 4 102–6 103 is the preferable formation place for the majority of molecules.

Influence of age and sex on anal sphincters: manometric evaluation of anorectal continence.

To investigate the exact nature of anorectal continence, a manometric evaluation was performed in 88 healthy test persons with a two-balloon catheter. The pressure in the anal canal (PAC) and the rectal ampulla at rest (PAR), the maximum squeeze pressure (PAC max) and pressure rise in the anal canal after dilatation of the rectal ampulla delta PAC) were evaluated separately for men and women, and the test persons were divided into 3 age groups (group I: under 40 years, group II: 40-60 years, group III: over 60 years). PAC showed a statistically significant difference between men and women and a constant decrease with age--statistically significant for men and for women between groups II and III--whereas the statistical significance of the 3 other values had to be restricted to a constant decrease with advance in years. Anorectal continence is characterized by a PAC at rest of over 40 mm Hg, a PAC max reaching at least 80 mm Hg, a pressure gradient between rectal ampulla and anal canal of over 20 mm Hg and a delta PAC of more than 10 mm Hg. These values as well as the differences depending on age and sex should be kept in mind for the evaluation of the continence function.

Voluntary Contractions in the Female Urethra

The continence mechanism of the female urethra has been investigated by a method that makes possible simultaneous recording of an induced intraurethral pressure and the related cross-sectional area. Muscular work, power and velocity of contraction could be calculated on the basis of these recordings at rest and during voluntary contractions of the pelvic floor. With these parameters it was possible to demonstrate 2 different components in the continence function: one in the mid urethra that maintains the closure pressure at rest and another more proximally in the urethra that is capable of fast, powerful contractions.

Parameter identification in distributed systems

This paper describes a method for the identification of the parameters entering into the equations of motion of distributed systems. Because the motion of distributed systems is described in terms of partial differential equations, these parameters are in general continous functions of the spatial variables. For vibrating systems, these parameters ordinarily represent the mass, stiffness and damping distributions. In this paper, these distributions are expanded in terms of finite series of known functions of the spatial variables multiplied by undetermined coefficients. It is assumed that the nature of the equations of motion is known and that a limited number of eigenvalues and eigenfunctions is identified in advance. Use is then made of the least squares method, in conjunction with the eigenfunctions' orthogonality, to compute the undetermined coefficients, thus identifying the system distributed parameters. A method for the identification of the eigensolution is also presented. The procedure for the identification of the eigensolution and of the system parameters is demonstrated via a numerical example.

Mechanisms of urethral continence and their clinical application

Controversy about the basic nature of urethral function does not preclude accurate clinical assessment of disorders of function. While the precise method of treatment of urethral continence dysfunction varies from institution to institution, the basic techniques are quite similar. It is the application of a treatment method to a particular case which causes difficulty. It is important, therefore, to have some understanding of the functional elements in the urethral continence mechanism to be able to determine which element does not function. Most cases of intractable incontinence are associated with poor function of the involuntary part of the sphincter. In general, peak urethral closing pressures are unrelated to continence function unless there is no pressure at all.

Cubic spline techniques for fitting X-ray cross sections

Cubic spline least squares fitting algorithms are developed for continous functions and functions with jump discontinuities. The cubic spline coefficients for incoherent and coherent scattering cross sections for elements from sodium through cobalt are reported for energies from 1 to 150 keV, and when two interior knots (three regions) are used they yield accuracies better than those obtined by a single cubic polynomial. Specialized discontinuous cubic spline functions are used to fit X-ray photoelectric cross sections to allow accurate fitting across the absorption edge discontinuities for a wide range of energies with a very simple function. Cubic spline coefficients for photoelectric cross sections of all elements in the atomic number range from 11 to 27 and in the energy range from 1 to 150 keV are reported. The cubic spline representation provides a computationally faster method of using X-ray cross sections than polynomial interpolation from discrete data sets and requires much less computer storage.