Chronic regulation of colonic epithelial secretory function by activation of G protein-coupled receptors.

BACKGROUND: Enteric neurotransmitters that act at G protein-coupled receptors (GPCRs) are well known to acutely promote epithelial Cl(-) and fluid secretion. Here we examined if acute GPCR activation might have more long-term consequences for epithelial secretory function. METHODS: Cl(-) secretion was measured as changes in short-circuit current across voltage-clamped T(84) colonic epithelial cells. Protein expression was measured by western blotting and intracellular Ca(2+) levels by Fura-2 fluorescence. KEY RESULTS: While acute (15 min) treatment of T(84) cells with a cholinergic G(q) PCR agonist, carbachol (CCh), rapidly stimulated Cl(-) secretion, subsequent CCh-induced responses were attenuated in a biphasic manner. The first phase was transient and resolved within 6 h but this was followed by a chronic phase of attenuated responsiveness that was sustained up to 48 h. CCh-pretreatment did not chronically alter responses to another G(q)PCR agonist, histamine, or to thapsigargin or forskolin which elevate intracellular Ca(2+) and cAMP, respectively. This chronically acting antisecretory mechanism is not shared by neurotransmitters that activate G(s)PCRs. Conditioned medium from CCh-pretreated cells mimicked its chronic antisecretory actions, suggesting involvement of an epithelial-derived soluble factor but further experimentation ruled out the involvement of epidermal growth factor receptor ligands. Acute CCh exposure did not chronically alter surface expression of muscarinic M(3) receptors but inhibited intracellular Ca(2+) mobilization upon subsequent agonist challenge. CONCLUSIONS \u26 INFERENCES: These data reveal a novel, chronically acting, antisecretory mechanism that downregulates epithelial secretory capacity upon repeated G(q)PCR agonist exposure. This mechanism involves release of a soluble factor that uncouples receptor activation from downstream prosecretory signals

The effect of five years versus two years of specialised assertive intervention for first episode psychosis - OPUS II: study protocol for a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>The Danish OPUS I trial randomized 547 patients with first-episode psychosis to a two-year early-specialised assertive treatment programme (OPUS) versus standard treatment. The two years OPUS treatment had significant positive effects on psychotic and negative symptoms, secondary substance abuse, treatment adherence, lower dosage of antipsychotic medication, and a higher treatment satisfaction. However, three years after end of the OPUS treatment, the positive clinical effects were not sustained, except that OPUS-treated patients were significantly less likely to be institutionalised compared with standard-treated patients. The major objective of the OPUS II trial is to evaluate the effects of five years of OPUS treatment versus two years of OPUS treatment.</p> <p>Methods</p> <p>The OPUS II trial is designed as a randomized, open label, parallel group trial with blinded outcome assessment. Based on our sample size estimation, 400 patients treated in OPUS for two years will be randomized to further three years of OPUS treatment versus standard treatment. The specialized assertive OPUS treatment consists of three core elements: assertive community treatment, psycho-educational family treatment, and social skills training.</p> <p>Discussion</p> <p>It has been hypothesized that there is a critical period from onset up to five years, which represents a window of opportunity where a long-term course can be influenced. Extending the specialized assertive OPUS treatment up to five years may allow the beneficial effects to continue beyond the high-risk period, through consolidation of improved social and functional outcome.</p> <p>Trial registration</p> <p>Clinical Trial.gov <a href="http://www.clinicaltrials.gov/ct2/show/NCT00914238">NCT00914238</a></p

Hypertonic saline reduces neutrophil-epithelial interactions in vitro and gut tissue damage in a mouse model of colitis

Transepithelial migration of polymorphonuclear neutrophils (PMN) plays a crucial role in inflammatory conditions of the intestine, such as inflammatory bowel diseases. Hypertonic saline (HS) exerts various inhibitory effects on PMN function. We hypothesized that HS could inhibit transepithelial migration of PMN and thereby prevent inflammatory events in experimental colitis. Isolated human PMN were treated with HS (40 mM), and their transmigration across a monolayer of T84 epithelial cells was induced by N-formyl-methionyl-leucyl-phenylalanine. Monolayer disruption was assessed by monitoring changes in transepithelial conductance in an Ussing chamber. Colitis in mice was induced by oral administration of dextran sulfate sodium (DSS). Animals were treated with 4 or 8 ml/kg of 7.5% saline intraperitoneally two times daily for 7 days. Controls received equivalent volumes of normal saline (NS, n = 6) or no intraperitoneal treatment (DSS, n = 12). The severity of inflammation was evaluated based on disease activity index and histology score. HS treatment of PMN in vitro significantly reduced cell migration and the disruption of T84 monolayers compared with untreated control cells (n = 5, P < 0.05). This effect of HS was dose dependent. HS treatment in vivo also reduced colitis-induced gut tissue damage, as indicated by an improved histology score compared with the NS and DSS groups. We conclude that HS inhibits transepithelial migration of PMN in vitro and gut tissue damage in vivo in a mouse model of colitis. Thus HS may have clinical value to reduce PMN-mediated intestinal damage

Association of Genomic Domains in BRCA1 and BRCA2 with Prostate Cancer Risk and Aggressiveness

Pathogenic sequence variants (PSV) in BRCA1 or BRCA2 (BRCA1/2) are associated with increased risk and severity of prostate cancer. We evaluated whether PSVs in BRCA1/2 were associated with risk of overall prostate cancer or high grade (Gleason 8þ) prostate cancer using an international sample of 65 BRCA1 and 171 BRCA2 male PSV carriers with prostate cancer, and 3,388 BRCA1 and 2,880 BRCA2 male PSV carriers without prostate cancer. PSVs in the 3 0 region of BRCA2 (c.7914þ) were significantly associated with elevated risk of prostate cancer compared with reference bin c.1001c.7913 [HR ¼ 1.78; 95% confidence interval (CI), 1.25–2.52; P ¼ 0.001], as well as elevated risk of Gleason 8þ prostate cancer (HR ¼ 3.11; 95% CI, 1.63–5.95; P ¼ 0.001). c.756-c.1000 was also associated with elevated prostate cancer risk (HR ¼ 2.83; 95% CI, 1.71–4.68; P ¼ 0.00004) and elevated risk of Gleason 8þ prostate cancer (HR ¼ 4.95; 95% CI, 2.12–11.54; P ¼ 0.0002). No genotype–phenotype associations were detected for PSVs in BRCA1. These results demonstrate that specific BRCA2 PSVs may be associated with elevated risk of developing aggressive prostate cancer