Esophagogastric junction outflow obstruction on manometry: Outcomes and lack of benefit from CT and EUS.

BACKGROUND: Esophagogastric junction outflow obstruction (EGJOO) is a manometric diagnosis based on the Chicago Classification defined by inadequate relaxation of the gastroesophageal junction (GEJ) with swallowing, but with sufficient peristalsis such that the criteria for achalasia are not met. Possible causes include anatomical and functional etiologies. Further investigations, including computed tomography (CT) of the chest and endoscopic ultrasound (EUS), to help elucidate the etiology of EGJOO have been suggested, but the utility of this approach has not been proven. METHODS: All new diagnoses of EGJOO made in the calendar years 2015-2016 were included. A review was performed for each patient to assess clinical outcomes, diagnostic, and therapeutic interventions after the EGJOO diagnosis. KEY RESULTS: 107 EGJOO patients were included. Their primary complaints were dysphagia (68%), chest pain (12%), reflux (8%), pre-operative assessment (6%), regurgitation (3%), and cough (3%). The mean IRP was 21.8 mm Hg. After a mean follow-up period of 463 days, the etiology of EGJOO remained undetermined in 67% of patients. 48% of patients were investigated with cross-sectional imaging (and 10% with EUS to rule out external compression or malignancy as a cause of EGJOO; none of these tests provided any further useful information). In only two cases did the EGJOO progress to achalasia. CONCLUSIONS & INFERENCES: EGJOO is a manometric diagnosis with unclear clinical significance and outcome. CT and EUS of the GEJ were unhelpful at determining the cause of this entity. In this series, very few appear to progress to achalasia, none were due to malignancy, and many resolved spontaneously.

The prevalence of gestational diabetes mellitus and glucose abnormalities in pregnant women with hepatitis C virus infection in British Columbia.

OBJECTIVE: There is evidence to support an association between diabetes mellitus (DM) and hepatitis C virus (HCV) infection. The insulin resistant state of pregnancy suggests a predisposition to developing gestational diabetes mellitus (GDM) in women infected with HCV. The aim of this study was to compare the prevalence of GDM and impaired glucose tolerance (IGT) of pregnancy between women infected with HCV and the general population of British Columbia screened for GDM. METHODS: The HCV cohort was drawn from a population-based prospective cohort of 148 pregnant women infected with HCV in British Columbia. GDM screening tests were completed in 84 women. The prevalence of GDM and IGT of pregnancy in the general population of British Columbia was estimated by acquiring 24 321 GDM screening tests performed by the two major laboratories in the province. RESULTS: Non-compliance was the primary reason for incomplete screening. The prevalence of GDM was 9.5% in the HCV cohort and 6.8% in the screened general population (chi-square test P = 0.33). Similarly, there was no difference in IGT of pregnancy between the two cohorts (2.4% vs. 3.5%; chi-square test P = 0.57). CONCLUSION: A difference in the prevalence of either GDM or IGT of pregnancy was not detected between HCV-infected patients who were screened for GDM and those screened in the general population. Further studies are required to assess whether HCV infection is an independent risk factor for GDM.

The use of endoscopic ultrasonography and other imaging modalities in the preoperative staging of rectal villous tumours: a case of overstaging by magnetic resonance imaging.

A case of a 60-year-old man with recurrent rectal villous adenoma is described. Preoperative staging with endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI) revealed very discordant results. EUS showed a tumour present in the mucosa with no submucosal invasion, while MRI revealed invasion of the muscularis propria consistent with an invasive stage T2 carcinoma. Based on the MRI findings, the patient underwent a low anterior resection of the tumour. The surgical pathology specimen revealed a villous adenoma with lowgrade dysplasia but no carcinoma and no extension into the muscularis propria. The present case highlights the uncertainty that currently exists as to which imaging modality provides the greatest accuracy in the staging of rectal cancer and in guiding the type of surgical procedure performed. Two recent meta-analyses and a systematic review of the literature point to EUS as the imaging modality of choice for determining muscularis propria and perirectal tissue invasion, as well as nodal involvement.

Thrombin receptor: An endogenous inhibitor of inflammatory pain, activating opioid pathways.

Serine proteases such as thrombin, trypsin and mast cell tryptase can act on different cell types through protease-activated receptors (PARs). These receptors have been shown to be implicated in several phenomena such as inflammation, platelet activation, immune response and atherosclerosis. Several studies recently reported PARs expression on neurons and some of them demonstrated that these receptors could interfere with nociception. The contribution of PAR(1) to inflammatory pain and the mechanism involved in this phenomenon were investigated. Intraplantar injection of PAR(1) agonist increased withdrawal latency and reduced response frequency to von Frey filaments, thus inhibiting nociceptive response to both mechanical and thermal stimuli in mice. PAR(1) agonist also reduced carrageenan-induced inflammatory hyperalgesia. The anti-nociceptive effects of PAR(1) agonist were mediated by endogenous opioids, as this effect was inhibited by local injection of naloxone methiodide, and because intraplantar injection of PAR(1) agonist increased mRNA expression of the endogenous opioid precursor proenkephalin. However, PAR(1) agonist was not able to inhibit calcium signals in isolated sensory neurons exposed to pro-nociceptive agents. Finally, despite similar inflammatory parameters, PAR(1)-deficient mice showed a strong potentiation of inflammatory hyperalgesia induced by the intraplantar injection of either formalin or carrageenan, or in the chronic model of collagen-induced arthritis, compared to wild-type mice. This study highlights a previously unknown endogenous mechanism of analgesia, showing a central role for the thrombin receptor PAR(1) in the regulation of inflammatory pain and as an activator of opioid pathways.

Activation of proteinase-activated receptor-1 inhibits neurally evoked chloride secretion in the mouse colon in vitro.

The proteinase-activated thrombin receptor-1 (PAR-1) belongs to a unique family of G protein-coupled receptors activated by proteolytic cleavage. We studied the effect of PAR-1 activation in the regulation of ion transport in mouse colon in vitro. Expression of PAR-1 in mouse colon was assessed by RT-PCR and immunohistochemistry. To study the role of PAR-1 activation in chloride secretion, mouse colon was mounted in Ussing chambers. Changes in short-circuit current (Isc) were measured in tissues exposed to either thrombin, saline, the PAR-1-activating peptide TFLLR-NH2, or the inactive reverse peptide RLLFT-NH2, before electrical field stimulation (EFS). Experiments were repeated in the presence of either a PAR-1 antagonist or in PAR-1-deficient mice to assess receptor specificity. In addition, studies were conducted in the presence of chloride-free buffer or the muscarinic antagonist atropine to assess chloride dependency and the role of cholinergic neurons in the PAR-1-induced effect. PAR-1 mRNA was expressed in full-thickness specimens and mucosal scrapings of mouse colon. PAR-1 immunoreactivity was found on epithelial cells and on neurons in submucosal ganglia where it was colocalized with both VIP and neuropeptide Y. After PAR-1 activation by thrombin or TFLLR-NH2, secretory responses to EFS but not those to forskolin or carbachol were significantly reduced. The reduction in the response to EFS was not observed in the presence of the PAR-1 antagonist, in PAR-1-deficient mice, when chloride was excluded from the bathing medium, or when atropine was present. PAR-1 is expressed in submucosal ganglia in the mouse colon and its activation leads to a decrease in neurally evoked epithelial chloride secretion.

Activation of proteinase-activated receptor 1 stimulates epithelial chloride secretion through a unique MAP kinase- and cyclo-oxygenase-dependent pathway.

Proteinase-activated receptor 1 (PAR-1) is activated by thrombin and induces chloride secretion by intestinal epithelial cells. To elucidate further the mechanisms whereby PAR-1 stimulates secretion, monolayers of SCBN intestinal epithelial cells were studied in modified Ussing chambers. Short circuit current responses were determined after basolateral application of thrombin and the PAR-1-activating peptide, Ala-parafluoro-Phe-Arg-cyclohexyl-Ala-Citrulline-Tyr (Cit-NH2) in the presence or absence of a variety of signal transduction and cyclo-oxygenase (COX) pathway inhibitors. Increased kinase activity was monitored by immunoprecipitation and Western blot analysis of target phosphoproteins. The PAR-1-induced chloride secretory response was significantly attenuated by inhibitors of the EGF receptor tyrosine kinase, Src-kinase, MEK1/2, as well as by inhibitors of cytosolic phospholipase (cPL) A2, COX-1 and COX-2. PAR-1-induced activation of cPLA2, as shown by Western blot of phosphoserine residues, was blocked in cells treated with the MEK inhibitor U0126, indicating that the MEK-ERK1/2 MAP kinase pathway mediated PAR-1-induced cPLA2 phosphorylation. Our data show that PAR-1-induced chloride secretion in SCBN cells involves Src, EGF receptor trans-activation, activation of a MAPK pathway, phosphorylation of cPLA2, COX activity, but not PGF2alpha or PGE2. These findings may be of clinical importance in inflammatory diseases of the intestine where secretory dysfunction is evident and thrombin levels are elevated.