Responsiveness of the OARSI-OMERACT osteoarthritis pain and function measures

OBJECTIVE

To assess the responsiveness of the Intermittent and Constant Osteoarthritis Pain (ICOAP) measure, Hip Disability and Osteoarthritis Outcome Score Physical Function Short Form (HOOS-PS), and the Knee Disability and Osteoarthritis Outcome Score Physical Function Short Form (KOOS-PS) in a pharmacological trial.

METHODS

Data were obtained from a randomized double-blind trial comparing naproxcinod with naproxen and ibuprofen in individuals with hip or knee osteoarthritis (OA) (NCT00662896). Participants completed the ICOAP, HOOS-PS/KOOS-PS, and Western Ontario and McMaster Universities OA Index (WOMAC) Likert version 3.0 before and 13 weeks after treatment. In hip and knee OA participants separately, the mean pre-post treatment change in scores, effect size (ES) and standardized response mean (SRM) were determined for each measure by treatment arm, and for all arms combined.

RESULTS

Of 349 trial participants, 156 with knee OA and 48 with hip OA completed all measures at both time-points and were included (mean age 61 years; two-thirds female). Although there was both within treatment and between treatment variability in response, among knee OA participants, ICOAP intermittent, constant, and total scores and KOOS-PS scores showed, on average, moderate effects, with ESs ranging from 0.46 to 0.54 and SRMs from 0.49 to 0.56. Similar changes were seen for the WOMAC pain and function subscales (0.58 and 0.58, respectively). In those with hip OA, no significant improvement in symptoms was seen for any measure.

CONCLUSION

Responsiveness to pharmaceutical intervention was demonstrated for ICOAP and KOOS-PS among participants with knee OA. Absence of treatment response precluded assessment of responsiveness in hip OA.

Systematic review of the effectiveness of weight management schemes for the under fives

Overweight and obesity in pre-school children are an increasing problem, with poor diet and exercise habits laying the foundation for serious health risks in later life. Yet most research into childhood obesity has focused on school-age children. Two previous systematic reviews of pre-school children have included uncontrolled designs and self-report outcomes potentially biasing the results in favour of the interventions. We have conducted a systematic review of the effectiveness and cost-effectiveness of weight management schemes for the under fives restricting the inclusion criteria to controlled trials with objective measures. We found four effectiveness randomized controlled trials of prevention. No treatment or cost-effectiveness studies were found. Only one study in a Latino community showed a statistically significant advantage from the intervention in a slower rate of increase in body mass index. However, trends in decrease in body mass index and weight loss favoured the intervention groups in other studies. From the studies characteristics we hypothesize that important features to include in future interventions may be; cultural sensitivity, sustained moderate to vigorous exercise, active engagement of the parents in the programme and as role models of healthy living and active engagement of the children in nutrition education. Further randomized controlled trials are needed in this population.

Everolimus for the second-line treatment of advanced and/or metastatic renal cell cancer: a critique of the submission from Novartis

This paper represents a summary of the evidence review group (ERG) report into the clinical efficacy, safety and cost-effectiveness of everolimus plus best supportive care (BSC) for the treatment of advanced renal cell carcinoma (RCC) which has progressed following or on vascular endothelial growth factor-targeted therapy (sunitinib, sorafenib, bevacizumab), compared to BSC alone. The submitting manufacturer's case for clinical effectiveness and cost-effectiveness was mainly based on a well-conducted randomised controlled trial (RCT), Renal Cell Cancer Treatment with Oral RAD001 Given Daily-1 (RECORD-1), comparing BSC plus everolimus with BSC plus placebo and a de novo economic model. The RCT indicated a marked statistically significant effect on progression-free survival. The base-case incremental cost-effectiveness ratio (ICER) estimate was 52,000 pounds per quality-adjusted life-year (this included a reduction in drug cost associated with an approved patient access scheme). The ERG undertook a critical appraisal of the submission. The ERG was generally in agreement with the submitting manufacturer concerning its estimates of effectiveness; however, there was greater concern surrounding the estimates of cost-effectiveness. The ERG judged that if potential errors in the model were corrected, the ICERs offered by the submitting manufacturer would overstate the cost-effectiveness of everolimus for the second-line treatment of metastatic RCC (that this ICER would be a higher value). Concerning the estimates of cost-effectiveness in RCC, the observations in the ERG report provide strong further support for research collecting rigorous estimates of utilities associated with the main health states likely to be experienced by patients with renal cell cancer. At the time of writing, NICE was yet to issue the Appraisal Consultation Document for this appraisal.

Everolimus for the second-line treatment of advanced and/or metastatic renal cell cancer: a critique of the submission from Novartis

This paper represents a summary of the evidence review group (ERG) report into the clinical efficacy, safety and cost-effectiveness of everolimus plus best supportive care (BSC) for the treatment of advanced renal cell carcinoma (RCC) which has progressed following or on vascular endothelial growth factor-targeted therapy (sunitinib, sorafenib, bevacizumab), compared to BSC alone. The submitting manufacturer’s case for clinical effectiveness and cost-effectiveness was mainly based on a well-conducted randomised controlled trial (RCT), Renal Cell Cancer Treatment with Oral RAD001 Given Daily-1 (RECORD-1), comparing BSC plus everolimus with BSC plus placebo and a de novo economic model. The RCT indicated a marked statistically significant effect on progression-free survival. The base-case incremental cost-effectiveness ratio (ICER) estimate was £52,000 per quality-adjusted life-year (this included a reduction in drug cost associated with an approved patient access scheme). The ERG undertook a critical appraisal of the submission. The ERG was generally in agreement with the submitting manufacturer concerning its estimates of effectiveness; however, there was greater concern surrounding the estimates of cost-effectiveness. The ERG judged that if potential errors in the model were corrected, the ICERs offered by the submitting manufacturer would overstate the cost-effectiveness of everolimus for the second-line treatment of metastatic RCC (that this ICER would be a higher value). Concerning the estimates of cost-effectiveness in RCC, the observations in the ERG report provide strong further support for research collecting rigorous estimates of utilities associated with the main health states likely to be experienced by patients with renal cell cancer. At the time of writing, NICE was yet to issue the Appraisal Consultation Document for this appraisal.

Systematic review of the effectiveness and cost-effectiveness of weight management schemes for the under fives: a short report

OBJECTIVE

To search for, review and synthesise studies of the effectiveness and cost-effectiveness of weight management schemes for the under fives.

DATA SOURCES

MEDLINE [Ovid], MEDLINE In-Process [Ovid], EMBASE [Ovid], CAB [Ovid], Health Management Information Consortium [Ovid], The Cochrane Database of Systematic Reviews, Cochrane Register of Controlled Trials, Science Citation Index Expanded [Web of Science], Conference Proceedings Citation Index [The Web of Science], Database of Abstract Reviews [CRD; Centre for Reviews and Dissemination], HTA [CRD], PsycINFO [Ebsco], NHS CRD. These databases were searched from 1990 to February 2009. Supplementary internet searches were additionally conducted.

REVIEW METHODS

Relevant clinical effectiveness studies were identified in two stages. Titles and abstracts returned by the search strategy were examined independently by three researchers and screened for possible inclusion. Disagreements were resolved by discussion. Full texts of the identified studies were obtained. Three researchers examined these independently for inclusion or exclusion, and disagreements were again resolved by discussion.

RESULTS

One of the randomised controlled trials (RCTs) was from the UK. It measured the effects of a physical activity intervention for children in nurseries combined with home-based health education for their parents; this was compared to usual care. The main outcome measure was body mass index (BMI); secondary measures were weight and physical activity. At the 12-month follow-up, no statistically significant differences were found between the groups on any measure. However, a trend, favouring the intervention, was found for BMI and weight. The other two RCTs were from the USA. The larger trial investigated the effects of a combined preschool and home intervention in African American and Latino communities. Nutrition education and physical activity programmes were aimed at under fives in preschool. The home component consisted of related health education and homework for the parents, who received a small financial reward on completion. The 1- and 2-year results for the African American sites showed a significantly slower rate of increase in BMI than for results at baseline, for the intervention group than for the control group. However, in the Latino communities no such differences were found. The second US trial was a much smaller home-based parental education programme in Native American communities in the USA and Canada. The intervention consisted of a parental skills course for parents to improve their children's diet and physical activity. This was compared with a course providing skills to improve child behaviour. Follow-up was at 16 weeks and showed no significant differences between groups in BMI.

CONCLUSIONS

No controlled trials addressing the issue of treating obesity or evidence of cost-effectiveness studies in the under fives' population were found. From the three prevention studies, apart from the larger US trial, the interventions showed no statistically significant differences in BMI and weight between the intervention and control groups (although there was some evidence of positive trends for BMI and weight). It should also be noted that these conclusions are based on only three dissimilar studies, thereby making the drawing of firm conclusions difficult. Research is urgently needed in further well-designed UK-based RCTs of weight management schemes aimed at the prevention of obesity, that combine with cost-effectiveness studies targeted at preschool children with long-term follow-up.

Sunitinib for the treatment of gastrointestinal stromal tumours: a critique of the submission from Pfizer

The submission's evidence for the clinical effectiveness and cost-effectiveness of sunitinib for the treatment of gastrointestinal stromal tumours (GISTs) is based on a randomised controlled trial (RCT) comparing sunitinib with placebo for people with unresectable and/or metastatic GIST after failure of imatinib and with Eastern Cooperative Oncology Group (ECOG) progression status 0-1, and an ongoing, non-comparative cohort study of a similar population but with ECOG progression status 0-4. The searches are appropriate and include all relevant studies and the RCT is of high quality. In the RCT sunitinib arm overall survival was 73 median weeks [95% confidence interval (CI) 61 to 83] versus 75 median weeks (95% CI 68 to 84) for the cohort study. However, time to tumour progression in the cohort study was different from that in the RCT sunitinib arm [41 (95% CI 36 to 47) versus 29 (95% CI 22 to 41) median weeks respectively]. Median progression-free survival with sunitinib was 24.6 weeks (95% CI 12.1 to 28.4) versus 6.4 weeks (95% CI 4.4 to 10.0) on placebo (hazard ratio 0.333, 95% CI 0.238 to 0.467, p < 0.001). The manufacturer used a three-state Markov model to model the cost-effectiveness of sunitinib compared with best supportive care for GIST patients; the modelling approach and sources and justification of estimates are reasonable. The base-case incremental cost-effectiveness ratio (ICER) was 27,365 pounds per quality-adjusted life-year (QALY) with the first cycle of sunitinib treatment not costed; when we included the cost of the first treatment cycle we estimated a base-case ICER of 32,636 pounds per QALY. Pfizer's sensitivity analysis produced a range of ICERs from 15,536 pounds per QALY to 59,002 pounds per QALY. Weaknesses of the manufacturer's submission include that the evidence is based on only one published RCT; that 84% of the RCT control population crossed over to the intervention group, giving rise to the use of unusual rank preserved structural failure time (RPSFT) analysis to correct for possible bias; and that a number of errors and omissions were made in the probabilistic sensitivity analysis, meaning that it is not possible to come to firm conclusions about the cost-effectiveness of sunitinib for GIST in this patient population. In conclusion, during the blinded phase of the RCT, overall survival was significantly longer in the sunitinib arm than in the placebo arm (hazard ratio 0.491, 95% CI 0.290 to 0.831, p <0.007). However, intention-to-treat analysis of the entire study showed no statistically significant difference in overall survival for those who received sunitinib (73 weeks) versus those who received placebo (65 weeks) (hazard ratio 0.876, 95% CI 0.679 to 1.129, p = 0.306).

The effectiveness and cost-effectiveness of cochlear implants for severe to profound deafness in children and adults: a systematic review and economic model

OBJECTIVES

To investigate whether it is clinically effective and cost-effective to provide (i) a unilateral cochlear implant for severely to profoundly deaf people (using or not using hearing aids), and (ii) a bilateral cochlear implant for severely to profoundly deaf people with a single cochlear implant (unilateral or unilateral plus hearing aid).

DATA SOURCES

Main electronic databases [MEDLINE; EMBASE; Cochrane Database of Systematic Reviews; CENTRAL; NHS EED; DARE; HTA (NHS-CRD); EconLit; National Research Register; and ClinicalTrials.gov] searched in October 2006, updated July 2007.

REVIEW METHODS

A systematic review of the literature was undertaken according to standard methods. A state-transition (Markov) model of the main care pathways deaf people might follow and the main complications and device failures was developed.

RESULTS

The clinical effectiveness review included 33 papers, of which only two were RCTs. They used 62 different outcome measures and overall were of moderate to poor quality. All studies in children comparing one cochlear implant with non-technological support or an acoustic hearing aid reported gains on all outcome measures, some demonstrating greater gain from earlier implantation. The strongest evidence for an advantage from bilateral over unilateral implantation was for understanding speech in noisy conditions (mean improvement 13.2%, p < 0.0001); those receiving their second implant earlier made greater gains. Comparison of bilateral with unilateral cochlear implants plus an acoustic hearing aid was compromised by small sample sizes and poor reporting, but benefits were seen with bilateral implants. Cochlear implants improved children's quality of life, and those who were implanted before attending school were more likely to do well academically and attend mainstream education than those implanted later. In adults, there was a greater benefit from cochlear implants than from non-technological support in terms of speech perception. Increased age at implantation may reduce effectiveness and there is a negative correlation between duration of deafness and effectiveness. Speech perception measures all showed benefits for cochlear implants over acoustic hearing aids [e.g. mean increase in score of 37 points in noisy conditions (p < 0.001) with BKB sentences]; however, prelingually deafened adults benefited less than those postlingually deafened (mean change scores 20% versus 62%). For unilateral versus bilateral implantation, benefits in speech perception were significant in noisy conditions on all measures [e.g. 76% for HINT sentences (p < 0.0001)]. Quality of life measured with generic and disease-specific instruments or by interview mostly showed significant gains or positive trends from using cochlear implants. The Markov model base-case analysis estimated that, for prelingually profoundly deaf children, the incremental cost-effectiveness ratio (ICER) for unilateral implantation compared with no implantation was 13,413 pounds per quality-adjusted life-year (QALY). Assuming the utility gain for bilateral implantation is the same for adults and children, the ICERs for simultaneous and sequential bilateral implantation versus unilateral implantation were 40,410 pounds and 54,098 pounds per QALY respectively. For postlingually sensorineurally profoundly deaf adults, the corresponding ICERs were 14,163 pounds, 49,559 pounds and 60,301 pounds per QALY respectively. Probabilistic threshold analyses suggest that unilateral implants are highly likely to be cost-effective for adults and children at willingness to pay thresholds of 20,000 pounds or 30,000 pounds per QALY. There are likely to be overall additional benefits from bilateral implantation, enabling children and adults to hold conversations more easily in social situations.

CONCLUSIONS

Unilateral cochlear implantation is safe and effective for adults and children and likely to be cost-effective in profoundly deaf adults and profoundly and prelingually deaf children. However, decisions on the cost-effectiveness of bilateral cochlear implants should take into account the high degree of uncertainty within the model regarding the probable utility gain.

Sunitinib for the treatment of gastrointestinal stromal tumours: a critique of the submission from Pfizer

The submission’s evidence for the clinical effectiveness and cost-effectiveness of sunitinib for the treatment of gastrointestinal stromal tumours (GISTs) is based on a randomised controlled trial (RCT) comparing sunitinib with placebo for people with unresectable and/or metastatic GIST after failure of imatinib and with Eastern Cooperative Oncology Group (ECOG) progression status 0–1, and an ongoing, non-comparative cohort study of a similar population but with ECOG progression status 0–4. The searches are appropriate and include all relevant studies and the RCT is of high quality. In the RCT sunitinib arm overall survival was 73 median weeks [95% confidence interval (CI) 61 to 83] versus 75 median weeks (95% CI 68 to 84) for the cohort study. However, time to tumour progression in the cohort study was different from that in the RCT sunitinib arm [41 (95% CI 36 to 47) versus 29 (95% CI 22 to 41) median weeks respectively]. Median progression-free survival with sunitinib was 24.6 weeks (95% CI 12.1 to 28.4) versus 6.4 weeks (95% CI 4.4 to 10.0) on placebo (hazard ratio 0.333, 95% CI 0.238 to 0.467, p < 0.001). The manufacturer used a three-state Markov model to model the cost-effectiveness of sunitinib compared with best supportive care for GIST patients; the modelling approach and sources and justification of estimates are reasonable. The base-case incremental cost-effectiveness ratio (ICER) was £27,365 per quality-adjusted life-year (QALY) with the first cycle of sunitinib treatment not costed; when we included the cost of the first treatment cycle we estimated a base-case ICER of £32,636 per QALY. Pfizer’s sensitivity analysis produced a range of ICERs from £15,536 per QALY to £59,002 per QALY. Weaknesses of the manufacturer’s submission include that the evidence is based on only one published RCT; that 84% of the RCT control population crossed over to the intervention group, giving rise to the use of unusual rank preserved structural failure time (RPSFT) analysis to correct for possible bias; and that a number of errors and omissions were made in the probabilistic sensitivity analysis, meaning that it is not possible to come to firm conclusions about the cost-effectiveness of sunitinib for GIST in this patient population. In conclusion, during the blinded phase of the RCT, overall survival was significantly longer in the sunitinib arm than in the placebo arm (hazard ratio 0.491, 95% CI 0.290 to 0.831, p <0.007). However, intention-to-treat analysis of the entire study showed no statistically significant difference in overall survival for those who received sunitinib (73 weeks) versus those who received placebo (65 weeks) (hazard ratio 0.876, 95% CI 0.679 to 1.129, p = 0.306).

The effectiveness and cost-effectiveness of methods of storing donated kidneys from deceased donors: a systematic review and economic model

OBJECTIVE

To review the evidence for the effectiveness and cost-effectiveness of storing kidneys from deceased donors prior to transplantation, using cold static storage solutions or pulsatile hypothermic machine perfusion.

DATA SOURCES

Electronic databases were searched in January 2008 and updated in May 2008 for systematic reviews and/or meta-analyses, randomised controlled trials (RCTs), other study designs and ongoing research. Sources included: Cochrane Library, MEDLINE, EMBASE, CINAHL, ISI Web of Knowledge, DARE, NRR, ReFeR, Current Controlled Trials, and (NHS) HTA. Bibliographies of articles were searched for further relevant studies, and the Food and Drugs Administration (FDA) and European Regulatory Agency Medical Device Safety Service websites were searched. Only English language papers were sought.

REVIEW METHODS

The perfusion machines identified were the LifePort Kidney Transporter (Organ Recovery Systems) and the RM3 Renal Preservation System (Waters Medical Systems). The cold storage solutions reviewed were: University of Wisconsin, ViaSpan; Marshall's hypertonic citrate, Soltran; and Genzyme, Celsior. Each intervention was compared with the others as data permitted. The population was recipients of kidneys from deceased donors. The main outcomes were measures of graft survival, patient survival, delayed graft function (DGF), primary non-function (PNF), discard rates of non-viable kidneys, health-related quality of life and cost-effectiveness. Where data permitted the results of studies were pooled using meta-analysis. A Markov (state transition) model was developed to simulate the main post-transplantation outcomes of kidney graft recipients.

RESULTS

Eleven studies were included: three full journal published RCTs, two ongoing RCTs [European Machine Preservation Trial (MPT) and UK Pulsatile Perfusion in Asystolic donor Renal Transplantation (PPART) study], one cohort study, three full journal published retrospective record reviews and two retrospective record reviews published as posters or abstracts only. For LifePort versus ViaSpan, no significant differences were found for DGF, PNF, acute rejection, duration of DGF, creatinine clearance or toxicity, patient survival or graft survival at 6 months, but graft survival was better at 12 months post transplant with machine perfusion (LifePort = 98%, ViaSpan = 94%, p < 0.03). For LifePort versus RM3, all outcomes favoured RM3, although the results may be unreliable. For ViaSpan versus Soltran, there were no significant differences in graft survival for cold ischaemic times up to 36 hours. For ViaSpan versus Celsior, no significant differences were found on any outcome measure. In terms of cost-effectiveness, data from the MPT suggested that machine preservation was cheaper and generated more quality-adjusted life-years (QALYs), while the PPART study data suggested that cold storage was preferable on both counts. The less reliable deterministic outputs of the cohort study suggested that LifePort would be cheaper and would generate more QALYs than Soltran. Sensitivity analyses found that changes to the differential kidney storage costs between comparators have a very low impact on overall net benefit estimates; where differences in effectiveness exist, dialysis costs are important in determining overall net benefit; DGF levels become important only when differences in graft survival are apparent between patients experiencing immediate graft function (IGF) versus DGF; relative impact of differential changes to graft survival for patients experiencing IGF as opposed to DGF depends on the relative proportion of patients experiencing each of these two outcomes.

CONCLUSIONS

The conclusions drawn for the comparison of machine perfusion with cold storage depend on which trial data are used in the model. Owing to the lack of good research evidence that either ViaSpan or Soltran is better than the other, the cheaper, Soltran, may be preferable. In the absence of a cost-utility analysis, the results of our meta-analysis of the RCTs comparing ViaSpan with Celsior indicate that these cold storage solutions are equivalent. Further RCTs of comparators of interest to allow for appropriate analysis of subgroups and to determine whether either of the two machines under consideration produces better outcomes may be useful. In addition, research is required to: establish the strength and reliability of the presumed causal association between DGF and graft, and patient survival; investigate the utility impacts of renal replacement therapy; determine what the additional cost, survival and QALY impacts are of decreased or increased non-viable kidneys when discarded pre transplantation; and identify a reliable measure for predicting kidney viability from machine perfusion.

AKAP-scaffolding proteins and regulation of cardiac physiology

A kinase anchoring proteins (AKAPs) compose a growing list of diverse but functionally related proteins defined by their ability to bind to the regulatory subunit of protein kinase A. AKAPs perform an integral role in the spatiotemporal modulation of a multitude of cellular signaling pathways. This review highlights the extensive role of AKAPs in cardiac excitation/contraction coupling and cardiac physiology. The literature shows that particular AKAPs are involved in cardiac Ca(2+) influx, release, reuptake, and myocyte repolarization. Studies have also suggested roles for AKAPs in cardiac remodeling. Transgenic studies show functional effects of AKAPs, not only in the cardiovascular system but in other organ systems as well.

Acute inhibition of superoxide formation and Rac1 activation by nitric oxide and iloprost in human vascular smooth muscle cells in response to the thromboxane A2 analogue, U46619

BACKGROUND

The over-production of superoxide (O(2)(-)) derived from NADPH oxidase (NOX) plays a central role in cardiovascular diseases. By contrast, nitric oxide (NO) and prostacyclin (PGI(2)) are vasculoprotective. The effect of the NO donor, NONOate and iloprost on O(2)(-) formation, p47(phox) and Rac(1) activation in human vascular smooth muscle cells (hVSMCs) was investigated.

METHODS

hVSMCs were incubated with 10nM thromboxane A(2) analogue, U46619 for 16h, and then with apocynin (a NOX inhibitor), NONOate or iloprost for 1h and O(2)(-) measured spectrophometrically. The role of cyclic AMP and cyclic GMP was examined by co-incubation of drugs with protein kinase (PK) A and G inhibitors listed above. Rac(1) was studied using pull-down assays.

RESULTS

NONOate and iloprost inhibited O(2)(-) formation, acutely, effects blocked by inhibition of PKG and PKA, respectively. Rac(1) and p47(phox) activation and translocation to the plasma membrane was completely inhibited by NONOate and iloprost, effects again reversed by co-incubation with PKG or PKA inhibitors.

CONCLUSIONS

NO and PGI(2) block the acute activity of NOX in hVSMCs via the cGMP-PKG axis (for NO) and by the cAMP-PKA axis (for iloprost) through inhibition of Rac(1) and p47(phox) translocation. These findings have implications in the pathophysiology and treatment of CVD.

Selective iNOS inhibition enhances spontaneous gallbladder motility in the Australian possum

Gallbladder inflammation is a common and painful disease. Inducible nitric oxide synthase (iNOS) plays a major role in inflammatory diseases, and iNOS inhibitors are being developed as therapeutic agents. Reports are inconsistent regarding iNOS expression in normal gallbladder. The aim of this study was to determine the effect of iNOS inhibition on spontaneous gallbladder motility. mRNA extracted from normal possum gallbladders was analysed by PCR. Gallbladder contractility was evaluated using a highly selective iNOS inhibitor AR-C102222AA (AR-C) in in vitro muscle strips (0.1-10 000 microm) and in vivo (0.1-30 micromol kg(-1)) experiments. Gene expression analysis revealed the presence of iNOS mRNA in normal gallbladder (n = 3). In vitro, AR-C (0.1-1000 micromol L(-1)) produced a concentration-dependent increase in spontaneous gallbladder contractile activity and basal tension (P < 0.05; n = 6). The maximum effect was a 1.8-fold increase in activity and 2.1-fold increase in basal tension. Pretreatment of muscle strips with tetrodotoxin (1 micromol L(-1)) did not block the AR-C-induced response (n = 5). In vivo, AR-C (30 micromol kg(-1), i.v.) increased gallbladder contraction frequency (P < 0.05; n = 8). These data suggest that iNOS is continually expressed in the normal gallbladder, which presumably releases low levels of nitric oxide and in turn may modulate spontaneous gallbladder motility. AR-C may be a beneficial treatment for patients suffering from acute cholecystitis.