Christopher H. Fry

Fourth international consultation on incontinence recommendations of the international scientific committee: Evaluation and treatment of urinary incontinence, pelvic organ prolapse, and fecal incontinence†‡§¶‖

P. Abrams , K.E. Andersson, L. Birder, L. Brubaker, L. Cardozo, C. Chapple, A. Cottenden, W. Davila, D. de Ridder, R. Dmochowski, M. Drake, C. DuBeau, C. Fry, P. Hanno, J. Hay Smith, S. Herschorn, G. Hosker, C. Kelleher, H. Koelbl, S. Khoury,* R. Madoff, I. Milsom, K. Moore, D. Newman, V. Nitti, C. Norton, I. Nygaard, C. Payne, A. Smith, D. Staskin, S. Tekgul, J. Thuroff, A. Tubaro, D. Vodusek, A. Wein, and J.J. Wyndaele and the Members of the Committees

Gap junctions and connexin expression in human suburothelial interstitial cells.

Objective  To determine whether suburothelial interstitial cells of the human bladder express gap junctions, and if so, to establish their extent and composition, using immunocytochemistry, confocal microscopy and electron microscopy.

A QUANTITATIVE STUDY OF ATROPINE-RESISTANT CONTRACTILE RESPONSES IN HUMAN DETRUSOR SMOOTH MUSCLE, FROM STABLE, UNSTABLE AND OBSTRUCTED BLADDERS

PURPOSE The objective of the study was to quantify in vitro the magnitude of atropine-resistant contractions using human detrusor samples and to determine the cellular processes underlying these contractions. MATERIALS AND METHODS Isometric contractile responses were measured in isolated strips of human detrusor muscle obtained from patients with i) stable, ii) unstable or iii) obstructed bladders. Preparations were electrically stimulated or exposed to carbachol and ATP in the superfusate. RESULTS Force-frequency curves were shifted to the right in samples from unstable and obstructed bladders. These same tissue groups also showed significant atropine-resistant contractions which were abolished by the neurotoxin TTX, or the non-hydrolysable ATP analog, alpha,beta-methylene ATP, suggesting that these contractions were mediated by neurally released ATP. Sub-division of the patient group with unstable bladders demonstrated that those with neuropathic instability did not show atropine-resistance, whereas those with idiopathic instability or secondary instability after obstruction did show atropine-resistant contractions. The potency of carbachol in generating a contracture was significantly greater than ATP (mean EC50 0.65 microM and 151 microM respectively) however, for each agonist there was no difference in potency between the three patient groups. Direct muscle excitability was similar in all three patient groups. CONCLUSIONS It is concluded that purinergic, atropine-resistant contractions are present in some types of dysfunctional bladder, and these are not caused by a differential sensitivity of the muscle to ATP and cholinergic agonists.

Randomized clinical trial of epidural, spinal or patient-controlled analgesia for patients undergoing laparoscopic colorectal surgery.

Epidural analgesia is considered fundamental in enhanced recovery protocols (ERPs). However, its value in laparoscopic colorectal surgery is unclear. The aim of this study was to examine the effects of different analgesic regimens on outcomes following laparoscopic colorectal surgery in fluid‐optimized patients treated within an ERP.

Purinergic regulation of guinea pig suburothelial myofibroblasts

The Ca2+‐regulating and electrophysiological properties of guinea‐pig suburothelial myofibroblasts have been measured in order to investigate their potential role in the sensation of bladder fullness, due to their strategic position between the urothelium and afferent fibres. Previous work has shown that stretch of the bladder wall releases ATP. Cells that stain positively for vimentin were isolated. About 45% of cells (median membrane capacitance 13.3 pF) exhibited spontaneous depolarizations to about −25 mV with a physiological Cl− gradient (frequency 2.6 ± 1.5 min−1, duration 14.5 ± 2.2 s, n= 15). Under voltage‐clamp spontaneous inward currents (frequency 1.5 ± 0.2 min−1, duration 14.5 ± 7.0 s, n= 18) were recorded, with a similar reversal potential. The spontaneous currents were preceded by intracellular Ca2+ transients with a magnitude that was independent of membrane potential. All cells tested responded to ATP by generating an intracellular Ca2+ transient, followed by inward currents; the currents had a similar reversal potential and slope conductance to their spontaneous counterparts. ATP‐generated transients were mimicked by UTP and ADP but not by α,β‐methylene‐ATP (1–10 μm) or CTP (30 μm), indicating that ATP acts via a P2Y receptor. Transients were partially attenuated by 1 mm suramin but PPADS (80 μm) had no effect. These data indicate that ATP acts via a P2Y receptor, but responses were resistant to the P2Y1 antagonist MRS2179. ATP‐generated transients were abolished by intracellular perfusion with heparin and TMB‐8 indicating that IP3 was the intracellular second messenger. The reversal potentials of the spontaneous and ATP‐generated currents were shifted by about +45 mV by a 12‐fold reduction of the extracellular [Cl−] and the currents were greatly attenuated by 1 mm DIDS. No transients were generated on exposure to the muscarinic agonist carbachol. We propose that these cells may play a regulatory step in the sensation of bladder fullness by responding to ATP. The precise mechanism whereby they couple urothelial ATP release to afferent excitation is the next step to be elucidated.

Randomized clinical trial on enhanced recovery versus standard care following open liver resection

Enhanced recovery programmes (ERPs) have been shown to reduce length of hospital stay (LOS) and complications in colorectal surgery. Whether ERPs have the same benefits in open liver resection surgery is unclear, and randomized clinical trials are lacking.

Modulation of bladder myofibroblast activity: implications for bladder function.

Bladder suburothelial myofibroblasts may modulate both sensory responses from the bladder wall and spontaneous activity. This study aimed to characterize further these cells in their response to exogenous agents implicated in mediating the above activity. Detrusor strips, with or without mucosa, and isolated suburothelial myofibroblasts were prepared from guinea pig bladders. Isometric tension, intracellular Ca2+, and membrane current were recorded. Cell pairs were formed by pushing two cells together. Tension, intracellular Ca2+, and membrane potential were also recorded from bladder sheets using normal or spinal cord-transected (SCT) rats. Spontaneous contractions were greater in detrusor strips with an intact mucosa and were augmented by 10 μM UTP. ATP, UTP, or reduced extracellular pH elicited Ca2+ transients and inward currents (Erev −30 mV) in isolated cells. Capsaicin (5–30 μM) reduced membrane current (37 ± 12% of control) with minor effects on Ca2+ transients: sodium nitroprusside reduced membrane currents (40 ± 21% of control). Cell pair formation, without an increase in cell capacitance, augmented ATP and pH responses (180 ± 58% of control) and reduced the threshold to ATP and acidosis. Glivec (20–50 μM) reversibly blocked the augmentation and also reduced spontaneous activity in bladder sheets from SCT, but not normal, rats. Glivec also disrupted the spread of Ca2+ waves in SCT sheets, generating patterns similar to normal bladders. Suburothelial myofibroblasts respond to exogenous agents implicated in modulating bladder sensory responses; responses augmented by physical intercellular contact. The action of glivec and its selective suppression of spontaneous activity in SCT rats identifies a possible pathway to attenuate bladder overactivity.

Characterization of the purinergic receptor subtype on guinea‐pig suburothelial myofibroblasts

To identify particular purinoceptor subtypes by immunohistochemical labelling, as a layer of suburothelial myofibroblasts has been identified in the urinary bladder, and these cells respond to exogenous ATP by generating an intracellular Ca2+ transient, but the particular purinoceptor that responds to ATP is unclear.

Suburothelial Myofibroblasts in the Human Overactive Bladder and the Effect of Botulinum Neurotoxin Type A Treatment

BACKGROUND An increasing body of evidence suggests a possible role of suburothelial myofibroblasts (MFs) in bladder mechanosensation and in the pathophysiology of detrusor overactivity (DO). OBJECTIVE To determine whether markers of MFs, including gap junction protein connexin43 (Cx43) and c-kit have altered immunohistochemical expression in the suburothelium of patients with neurogenic DO (NDO) or idiopathic DO (IDO) and whether this is affected by successful treatment of DO with botulinum neurotoxin type A (BoNTA). DESIGN, SETTING, AND PARTICIPANTS Patients with NDO (n=10) or IDO (n=11) were treated in a single-centre, open-label study of intradetrusor BoNTA injections. Control tissue was obtained from 10 patients undergoing pelvic-floor repair procedures who had no overactive bladder (OAB) symptoms. This study is registered with ClinicalTrials.gov, number NCT00662064. INTERVENTIONS Bladder biopsies performed with flexible cystoscopes were obtained from control subjects and from NDO and IDO patients before BoNTA treatment and at 4 wk and 16 wk after treatment. They were studied with quantitative immunofluorescence using antibodies to connexin 43 (Cx43), vimentin, and c-kit. MEASUREMENTS Differences in Cx43, vimentin, and c-kit immunoreactivity between control subjects and NDO or IDO patients (primary outcomes). Changes in NDO or IDO, Cx43 immunoreactivity, and c-kit immunoreactivity after BoNTA treatment (secondary outcomes). RESULTS AND LIMITATIONS Cx43 immunoreactivity was increased in both IDO and NDO patients compared to controls, but remained unchanged after BoNTA treatment. C-kit immunoreactivity was similar in NDO/IDO patients and controls and remained unchanged after BoNTA treatment. CONCLUSIONS Increased gap junction formation in the suburothelium has been demonstrated in biopsies from humans with DO. It is hypothesised that this change could have a significant role in the pathogenesis of the detrusor abnormality. Successful treatment of NDO or IDO does not appear to be associated with changes in the expression of Cx43 or c-kit on suburothelial MFs.

Abnormal action potential conduction in isolated human hypertrophied left ventricular myocardium

AP Conduction in Hypertrophied Myocardium. Introduction: Cardiac hypertrophy is associated with an increased incidence of arrhythmias that result from altered action potential configuration or propagation velocity. These variables were measured in isolated preparations of human left ventricular myocardium and correlated with the degree of hypertrophy.