https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:36115 Thu 06 Feb 2020 16:38:08 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:36111 Thu 06 Feb 2020 14:25:07 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:20807 V1.5. Many patients with cardiac arrhythmias caused by mutations in SCN5A also have symptoms of irritable bowel syndrome (IBS). We investigated whether patients with IBS have SCN5A variants that affect the function of Na_V1.5. Methods: We performed genotype analysis of SCN5A in 584 persons with IBS and 1380 without IBS (controls). Mutant forms of SCN5A were expressed in human embryonic kidney-293 cells, and functions were assessed by voltage clamp analysis. A genome-wide association study was analyzed for an association signal for the SCN5A gene, and replicated in 1745 patients in 4 independent cohorts of IBS patients and controls. Results: Missense mutations were found in SCN5A in 13 of 584 patients (2.2%, probands). Diarrhea-predominant IBS was the most prevalent form of IBS in the overall study population (25%). However, a greater percentage of individuals with SCN5A mutations had constipation-predominant IBS (31%) than diarrhea-predominant IBS (10%; P <.05). Electrophysiologic analysis showed that 10 of 13 detected mutations disrupted Na_V1.5 function (9 loss-of-function and 1 gain-of-function function). The p. A997T-Na_V1.5 had the greatest effect in reducing Na_V1.5 function. Incubation of cells that expressed this variant with mexiletine restored their sodium current and administration of mexiletine to 1 carrier of this mutation (who had constipation-predominant IBS) normalized their bowel habits. In the genome-wide association study and 4 replicated studies, the SCN5A locus was strongly associated with IBS. Conclusions: About 2% of patients with IBS carry mutations in SCN5A. Most of these are loss-of-function mutations that disrupt Na_V1.5 channel function. These findings provide a new pathogenic mechanism for IBS and possible treatment options.]]> Sat 24 Mar 2018 08:05:59 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:19973 Sat 24 Mar 2018 07:54:29 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:27609 3-fold more likely to report adequate relief than those given placebo (odds ratio = 3.1; 95% confidence interval: 1.1-9.0). Neither amitriptyline nor escitalopram appeared to affect GE or meal-induced satiety after the 10-week period in any group. Subjects with delayed GE were less likely to report adequate relief than subjects with normal GE (odds ratio = 0.4; 95% confidence interval: 0.2-0.8). Both antidepressants improved overall quality of life. Conclusions Amitriptyline, but not escitalopram, appears to benefit some patients with FD, particularly those with ulcer-like (painful) FD. Patients with delayed GE do not respond to these drugs.]]> Sat 24 Mar 2018 07:39:41 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34107 T CC genotype has been previously linked to FD and TT genotype to antidepressant response in depression. The ss genotype of the 5-HTT LPR variant of the serotonin transporter gene (SLC6A4) has been linked to selective serotonin reuptake inhibitor (SSRI) response. We aimed to examine whether GNβ3 825C>T and 5-HTT LPR polymorphisms result in differential treatment effects in FD patients receiving antidepressant therapy. Methods: Participants were randomized to receive placebo, 50 mg AMI, or 10 mg escitalopram (ESC). The primary end point was adequate relief for ≥5 weeks of the last 10 weeks. Genotyping of GNβ3 825C>T and 5-HTT LPR was performed utilizing PCR-based methods. Results: GNβ3 825C>T and 5-HTT LPR genotype data were available for 256 (88%) and 246 (84%) patients, respectively. Both polymorphisms were in Hardy-Weinberg equilibrium. In tests for differential treatment, neither 5-HTT LPR nor GNβ3 825C>T genotype influenced response to therapy (P=0.89 and P=0.54, respectively). Although there was a tendency for a more favorable response to ESC in the SS/LS genotype compared to the LL genotype groups (40% vs. 31% reporting adequate relief of FD symptoms) among those in the ESC treatment arm, this was not significant (P=0.43). Conclusions: GNβ3 825C>T and 5-HTT LPR genetic variants do not alter treatment response to tricyclic and SSRI antidepressants in FD.]]> Fri 08 Feb 2019 10:43:58 AEDT ]]>