Tracy W. Cannon

Improved sphincter contractility after allogenic muscle-derived progenitor cell injection into the denervated rat urethra.

OBJECTIVES To study the physiologic outcome of allogenic transplant of muscle-derived progenitor cells (MDPCs) in the denervated female rat urethra. METHODS MDPCs were isolated from muscle biopsies of normal 6-week-old Sprague-Dawley rats and purified using the preplate technique. Sciatic nerve-transected rats were used as a model of stress urinary incontinence. The experimental group was divided into three subgroups: control, denervated plus 20 microL saline injection, and denervated plus allogenic MDPCs (1 to 1.5 x 10(6) cells) injection. Two weeks after injection, urethral muscle strips were prepared and underwent electrical field stimulation. The pharmacologic effects of d-tubocurare, phentolamine, and tetrodotoxin on the urethral strips were assessed by contractions induced by electrical field stimulation. The urethral tissues also underwent immunohistochemical staining for fast myosin heavy chain and CD4-activated lymphocytes. RESULTS Urethral denervation resulted in a significant decrease of the maximal fast-twitch muscle contraction amplitude to only 8.77% of the normal urethra and partial impairment of smooth muscle contractility. Injection of MDPCs into the denervated sphincter significantly improved the fast-twitch muscle contraction amplitude to 87.02% of normal animals. Immunohistochemistry revealed a large amount of new skeletal muscle fiber formation at the injection site of the urethra with minimal inflammation. CD4 staining showed minimal lymphocyte infiltration around the MDPC injection sites. CONCLUSIONS Urethral denervation resulted in near-total abolishment of the skeletal muscle and partial impairment of smooth muscle contractility. Allogenic MDPCs survived 2 weeks in sciatic nerve-transected urethra with minimal inflammation. This is the first report of the restoration of deficient urethral sphincter function through muscle-derived progenitor cell tissue engineering. MDPC-mediated cellular urethral myoplasty warrants additional investigation as a new method to treat stress urinary incontinence.

The effects of periurethral muscle-derived stem cell injection on leak point pressure in a rat model of stress urinary incontinence

Abstract Our goal was to determine whether periurethral injection of allogenic muscle-derived stem cells (MDSC) could increase the leak point pressure (LPP) in a denervated female rat model of stress urinary incontinence. Cells isolated from the gastrocnemius muscle of normal female rats were purified for a myogenic population by the preplate technique. Three experimental groups were established: a control group (C) had a sham operation without injections; a sciatic nerve transection group (D) had periurethral saline injections; and a sciatic nerve transsection group had periurethral MDSC injections (M). One week following treatment the LPP of groups C, D and M were 25.2±1.9 cmH2O, 28.6±0.8 cmH2O and 36.7±2.3 cmH2O, respectively. At 4 weeks the LPP of groups C, D and M were 25.8±2.5 cmH2O, 18.6±5.2 cmH2O and 44.1±6.6 cmH2O, respectively. Allogenic MDSC significantly improved the LPP in sciatic nerve-transected animals after both 1 and 4 weeks compared to denervated animals injected with saline.

Bladder and sexual function among women with multiple sclerosis.

Objective: Genitourinary dysfunction is common in women with multiple sclerosis (MS), yet few studies have evaluated the association between bladder and sexual dysfunction in these women. The aim of this study was to determine factors, including demographic and bladder function, associated with sexual dysfunction in a sample of women with MS. Methods: One hundred and thirty-three women with MS completed questionnaires related to overall heath status, bladder function and sexual function. Response frequencies and percentages were calculated for questionnaire responses. Multivariate logistic regression analyses were performed to determine predictors of sexual dysfunction. Results: Sixty-one per cent of the sample indicated that they had a problem with bladder control. Forty-seven per cent of respondents indicated that their neurological problems interfered with their sex life. Over 70% of the sample reported that they enjoyed, felt aroused and experienced orgasm during sexual activity. Not having a sexual partner and the indication of bothersome neurological problems were the best predictors of sexual dysfunction. Interestingly, patients bothered by their urge incontinence had higher levels of orgasm compared to women not bothered by urge incontinence. Conclusions: Although over half of the women reported voiding symptoms, most still enjoyed, felt aroused and could experience orgasm. Neurological symptoms and lacking a sexual partner emerged as the best predictors of sexual dysfunction. Urge incontinence may not be a risk factor for anorgasm. Our findings elucidate the complex nature of sexual dysfunction in women with MS.

Muscle-derived stem cells seeded into acellular scaffolds develop calcium-dependent contractile activity that is modulated by nicotinic receptors

OBJECTIVES To explore the contractile activity and physiologic properties of muscle-derived stem cells (MDSCs) incorporated into small intestinal submucosa (SIS) scaffolds. METHODS MDSCs were harvested from mice hind leg muscles using the preplate technique and stably transfected with a plasmid to express the LacZ reporter gene. Fifty different preparations of SIS cultured with MDSCs (MDSC/SIS) or SIS alone were incubated at 37 degrees C for 1, 4, and 8 weeks and also were mounted in a bath to measure the isometric contractions. RESULTS LacZ and Masson-trichrome staining revealed MDSCs could migrate into and distribute throughout the SIS and form myotubes. In MDSC/SIS, spontaneous contractile activities were noted in the 4-week (five of six specimens) and 8-week (eight of eight specimens) cultures, but not in 1-week cultures (n = 11). All SIS control groups after 1 (n = 11), 4 (n = 6), and 8 (n = 8) weeks of incubation did not show any activity. In most of the 4-week, and all of the 8-week, MDSC/SIS cultures, the frequency and amplitude of spontaneous contractile activities were decreased by succinylcholine 10 microM and 20 microM. Electrical field stimulation, carbachol, and KCl did not alter the frequency, amplitude, or pattern of spontaneous contractile activities in MDSC/SIS. Spontaneous contractile activities were blocked by Ca(32+)-free Krebs solution with ethyleneglycoltetraacetic acid 200 microM and distilled water. CONCLUSIONS MDSCs could be incorporated into SIS-forming myotubes capable of contracting. The contractile activity of this three-dimensional construct is Ca(2+) dependent and is modulated by nicotinic receptors. MDSC seeding of an acellular matrix may become a functional sling to reengineer the deficient sphincter or as contractile bladder augmentation.

A tissue‐engineered suburethral sling in an animal model of stress urinary incontinence

To create and evaluate the functional effects of a tissue‐engineered sling in an animal model of stress urinary incontinence (SUI).

Pharmacotherapy of the overactive bladder and advances in drug delivery.

Overactive bladder (OAB) is a clinical definition for symptoms of urinary frequency, urgency, and/or urge incontinence. It is becoming an internationally hot topic in the urogynecologic community and pharmaceutical industry. There are two reasons for the recent spotlight on OAB. First, the tremendous number of patients with this problem is just now becoming recognized, and the potential economic impact is staggering. In the United States, there are an estimated 17 million men and women with bladder control problems, many of whom suffer from OAB. It costs an estimated

Innovations in pharmacotherapy for stress urinary incontinence

26 billion a year in the United States to manage OAB, according to the Agency for Health Care Policy and Research. With the continued aging of the populations in all developed countries, the problems associated with OAB will certainly continue to grow. The second reason why there is such interest in the OAB is the recent availability of improved treatment options. There had been a lull in the development of new treatment options since the introduction of oxybutynin chloride in 1972. However, with the recent introduction of tolterodine (Detrol and Detrol LA, Pharmacia & Upjohn) and the once-a-day controlled-release oxybutynin (Ditropan XL, Alza), physicians are now armed with better tools to help patients with OAB. In this article, we will discuss the latest treatment options for OAB. In addition to the recently introduced tolterodine and oxybutynin XL, we will present other drugs being developed. In the near horizon, we foresee the novel intravesical vanilloid therapies, capsaicin and resiniferatoxin, as challenging the concept of how we treat OAB. We will begin to use such drugs to decrease or prevent the sensation of urgency and frequency leading to urge incontinence (afferent blockade), rather than using anticholinergic drugs to relax the already spastic bladder. This is analogous to preventing a Correspondence: Michael B. Chancellor, MD, Suite 700, Kaufmann Building, 3471 Fifth Avenue, Pittsburgh, PA 15213. E-mail: chancellormb@msx.upmc.edu Supported in part by NIH K12 DK02656. CLINICAL OBSTETRICS AND GYNECOLOGY Volume 45, Number 1, 205–217

Pathophysiology of the lower urinary tract: continence and incontinence.

The purpose of this review article is to highlight new pharmacotherapies on the horizon for the treatment of stress urinary incontinence (SUI). Although behavioral and surgical therapies are currently the mainstay of treating SUI, we believe that medications will take center stage and possibly become first-line therapy. Currently, there are no FDA medications indicated for SUI. However, results are becoming available about an oral medication, duloxetine, which appears to be clinically safe and efficacious for the treatment of SUI. In addition to discussing medications currently under development, we will also discuss exciting pharmacological targets that could be suitable to treat SUI.

Changes in Voiding Patterns in Patients With MS and Extended-Release Oxybutynin

Introduction To better understand the pathophysiologic mechanisms occurring in incontinence, we begin with a brief review of the normal mechanisms of continence. We subsequently review how incontinence can occur when these systems do not function normally. Both anatomic and neurologic hypotheses for the causes of stress urinary incontinence (SUI) are discussed. Pathophysiology of overactive detrusor is discussed in terms of its neurogenic and non-neurogenic causes. The chapter finishes with a review of the relationship between urinary symptoms and pelvic organ prolapse. Normal Mechanisms of Continence In the normal adult, urinary control can be subdivided into a bladder filling and urine storage phase, and a bladder emptying and voiding phase. Therefore, normal lower urinary tract function requires the ability to store urine at low pressure while the detrusor muscle is quiescent, as well as the ability to completely empty the bladder voluntarily with low resistance urine passage. The bladder and urethra are the most important structures for proper storage and emptying. Other important components include pelvic floor musculature, ligaments, and neural control. Anatomy has been discussed in previous sections and bladder filling, emptying, and neural control has been discussed in previous sections and therefore these topics will not be reviewed here. Correspondence: Margot S. Damaser, PhD, Research Biomedical Engineer and Associate Professor, Research Service (151), Hines VA Hospital, 5 Avenue and Roosevelt Road, Hines, IL, 60141. E-mail: margot.Damaser@ med.va.gov CLINICAL OBSTETRICS AND GYNECOLOGY Volume 47, Number 1, 28–35

342: Relationship Between Overactive Bladder (OAB) and Sexual Activity in Women

We evaluated the effects and tolerability of extended-release oxybutynin chloride on the voiding and catheterization frequency of multiple sclerosis (MS) patients with neurogenic bladder. This was a 12-week, prospective, dose-titration study of extended-release oxybutynin (oxybutynin XL). MS patients were recruited for this study from the University of Pittsburgh School of Medicines MS clinic. Entry criteria included a postvoid residual urine volume of less than 200 mL (in noncatheterized subjects). Previous urodynamic testing was not required. Exclusion criteria included individuals with urine results indicating pyuria in the presence of a positive urine culture. These tests were repeated at six and 12 weeks. After a seven-day washout period, patients recorded episodes of voiding or catheterization and incontinence for three consecutive days. Patients received initial daily doses of 10 mg oxybutynin XL in the first week. Doses were increased at weekly or biweekly intervals to a maximum of 30 mg/d. Toler...