Indirect treatment comparison (ITC) of medical therapies for an overactive bladder.

BACKGROUND: Overactive bladder syndrome (OAB) is a chronic and prevalent condition which has a negative impact on Quality of Life. The National Institute of Clinical Excellence issued two documents which give slightly varying algorithms of pharmacotherapy for OAB, offering mirabegron as a possible treatment in certain circumstances. In the absence of trials involving a direct comparison of therapies, an indirect comparison can provide useful information on the difference in treatment effects between competing interventions. OBJECTIVE: To compare effectiveness of available medical therapies for OAB using Bucher indirect treatment comparison (ITC) model. METHODS: A systematic literature search identified randomised controlled trials (RCT) assessing effectiveness of drugs for OAB versus placebo. Then indirect comparisons of the treatments effects were made, preserving the randomisation of the originally assigned patient groups, using Bucher method. MAIN RESULTS: 25 RCTs met inclusion criteria. In keeping with ITC method validity, four assessments were undertaken of mirabegron against anticholinergics, which were number of incontinence episodes, micturition episodes, urgency episodes in 24 h and volume of micturition. This indirect treatment analysis suggests that mirabegron is as effective as anticholinergics in managing of OAB, except for solifenacin which appears to be superior. CONCLUSIONS: These findings suggest that work looking into treatment choice should be individualized to patient characteristics rather than fitting patients to a treatment. Further work is required to identify what patient characteristics may be crucial and indicate that studies exploring the most effective sequence of managing treatment naïve patients and those with refractory disease.

Stress neuropeptides evoke epithelial responses via mast cell activation in the rat colon.

BACKGROUND: Previously, we showed that corticotropin-releasing factor (CRF) injected i.p. mimicked epithelial responses to stress, both stimulating ion secretion and enhancing permeability in the rat colon, and mast cells were involved. However, the ability of CRF-sensitive mucosal/submucosal loops to regulate intestinal barrier and the participation of resident mast cells are unclear. METHODS: We examined colonic epithelial responses to stress-like peptides in Wistar-Kyoto (WKY), and mast cell-deficient (Ws/Ws) and their +/+ littermate control rats in distal segments mounted in Ussing chambers. Short-circuit current (ion secretion), flux of horseradish peroxidase (macromolecular permeability), and the release of rat mast cell protease II were measured in response to CRF [10(-6) to 10(-8)M] or sauvagine [10(-8) to 10(-10)M] in tissues pretreated with astressin, doxantrazole, or vehicle. RESULTS: Stress-like peptides (sauvagine > CRF) induced a dose-dependent increase in short-circuit current (maximal at 30 min), and significantly enhanced horseradish peroxidase flux and protease II release in WKY. Epithelial responses were inhibited by both astressin and doxantrazole, and significantly reduced in tissues from Ws/Ws rats. CONCLUSION: The stress mediators CRF and sauvagine modulate barrier function in the rat colon acting on mucosal/submucosal CRF receptor-bearing cells, through mast cell-dependent pathways.

Neonatal maternal separation predisposes adult rats to colonic barrier dysfunction in response to mild stress.

Intestinal dysfunction is related to stress and early life events, but the mechanisms are largely unknown. Our aim was to determine whether early trauma predisposes adult rats to intestinal mucosal dysfunction in response to stress. Neonatal Sprague-Dawley rats were individually separated from their mothers for 3 h/day at 4-21 days of age. Between days 80 and 90, separated and control rats were subjected to mild acute stress (30-min water avoidance) or sham stress. Mucosal barrier function and ion transport were assessed in colonic tissues mounted in Ussing chambers. Mild stress increased short-circuit current, conductance, and transepithelial transport of macromolecules in separated rats, while having minimal effects in controls. Pretreatment of the separated rats with a corticotropin-releasing hormone (CRH) antagonist, the peptide alpha-helical CRH(9-41) injected intraperitoneally 20 min before stress, abolished the stress-induced mucosal changes. Our results indicate that neonatal trauma can induce phenotypic changes in adulthood, including enhanced vulnerability of the gut mucosa to stress via mechanisms involving peripherally located CRH receptors.

Physical and psychological stress in rats enhances colonic epithelial permeability via peripheral CRH.

Stress may be a contributing factor in intestinal inflammatory disease; however, the underlying mechanisms have not been elucidated. We previously reported that acute stress altered jejunal epithelial physiology. In this study, we examined both physical and psychological stress-induced functional changes in colonic mucosa. Colonic mucosal tissue from rats subjected to either 2 hr of cold-restraint stress or 1 hr of water-avoidance stress demonstrated altered ionic transport as well as significantly elevated baseline conductance (ionic permeability) and flux of horseradish peroxidase (macromolecular permeability). Intraperitoneal pretreatment with the corticotropin-releasing hormone (CRH) antagonist, a helical CRH(9-41), inhibited the stress-induced abnormalities, while exogenous intraperitoneal administration of CRH, to control rats, mimicked the stress responses and in vitro CRH increased the macromolecular permeability. These results suggest that peripheral CRH mediates stress-induced colonic pathophysiology. We speculate that a stress-induced barrier defect may allow uptake of immunogenic substances into the colonic mucosa, initiating or exacerbating intestinal inflammation.