Divergent results from in vitro studies on the thickness and appearance of the gastrointestinal mucus layer have previously been reported. With an in vivo model, we studied mucus gel thickness over time from stomach to colon. The gastrointestinal tissues of Inactin-anesthetized rats were mounted luminal side up for intravital microscopy. Mucus thickness was measured with a micropipette before and after mucus removal by suction. The mucus layer was translucent and continuous; it was thickest in the colon (approximately 830 microm) and thinnest in the jejunum (approximately 123 microm). On mucus removal, a continuous, firmly adherent mucus layer remained attached to the epithelial surface in the corpus (approximately 80 microm), antrum (approximately 154 microm), and colon (approximately 116 microm). In the small intestine, this layer was very thin (approximately 20 microm) or absent. After mucus removal, there was a continuous increase in mucus thickness with the highest rate in the colon and the lowest rate in the stomach. In conclusion, the adherent gastrointestinal mucus gel in vivo is continuous and can be divided into two layers: a loosely adherent layer removable by suction and a layer firmly attached to the mucosa.

Gastroesophageal reflux disease is mediated principally by acid. Today, we recognise reflux reaches beyond the esophagus, where pepsin, not acid, causes damage. Extraesophageal reflux occurs both as liquid and probably aerosol, the latter with a further reach. Pepsin is stable up to pH 7 and regains activity after reacidification. The enzyme adheres to laryngeal cells, depletes its defences, and causes further damage internally after its endocytosis. Extraesophageal reflux can today be detected by recognising pharyngeal acidification using a miniaturised pH probe and by the identification of pepsin in saliva and in exhaled breath condensate by a rapid, sensitive, and specific immunoassay. Proton pump inhibitors do not help the majority with extraesophageal reflux but specifically formulated alginates, which sieve pepsin, give benefit. These new insights may lead to the development of novel drugs that dramatically reduce pepsinogen secretion, block the effects of adherent pepsin, and give corresponding clinical benefit. “For now we see through a glass, darkly.” —First epistle, Chapter 13, Corinthians

Background: We report the first meta-analysis on the impact of prophylactic use of a specific design of negative pressure wound therapy (NPWT) device on surgical site complications.Methods: Articles were identified in which the specific single-use NPWT device (PICO⋄, Smith & Nephew) was compared with standard care for surgical site infection (SSI), dehiscence, or length of stay (LOS). Risk ratio (RR) ±95% confidence interval (CI) (SSI; dehiscence) or mean difference in LOS ±95% CI was calculated using RevMan v5.3.Results: There were 1863 patients (2202 incisions) represented by 16 articles. Among 10 randomized studies, there was a significant reduction in SSI rate of 51% from 9.7% to 4.8% with NPWT intervention (RR 0.49 [95% CI 0.34–0.69] p < 0.0001). There were six observational studies assessing reduction in SSI rate of 67% from 22.5% to 7.4% with NPWT (RR 0. 32 [95% CI 0.18–0.55] p < 0.0001). Combining all 16 studies, there was a significant reduction in SSI of 58% from 12.5% to 5.2% with NPWT (RR 0.43 [95% CI 0.32–0.57] p < 0.0001). Similar effects were seen irrespective of the kind of surgery (orthopedic, abdominal, colorectal, or cesarean section), although the numbers needed to treat (NNT) were lower in operations with higher frequencies of complications. There was a significant reduction in dehiscence from 17.4% to 12.8% with NPWT (RR 0.71 [95% CI 0.54–0.92] p < 0.01). The mean reduction in hospital LOS by NPWT was also significant (−0.47 days [95% CI −0.71 to −0.23] p < 0.0001).Conclusions: The significant reduction in SSI, wound dehiscence, and LOS on the basis of pooled data from 16 studies shows a benefit of the PICO single-use NPWT system compared with standard care in closed surgical incisions.

It is not until severe UC that there is a global change in mucosal protection as a consequence of large regions lacking mucus, a decrease in secretory potential caused by a loss of goblet cells and a thinner, less effective mucus layer even when it is present.

Rapid LFD for salivary pepsin has acceptable test characteristics in patients with GERD. A positive salivary pepsin test in this group may obviate the need for more expensive diagnostic testing by EGD or pH monitoring.

No abstract

Laryngopharyngeal reflux (LPR) refers to the backflow of stomach contents into the laryngopharynx. Increasing evidence has demonstrated that LPR is a contributing factor in some cases of hoarseness, vocal fatigue, voice breaks, cough and globus and chronic throat clearing. However, several randomised placebo-controlled trials of proton pump inhibitors in the treatment of LPR have been reported with the majority showing no significant benefit in patient symptom scores over placebo. The aim of this pilot clinical study was to investigate whether any improvement in LPR-related symptoms, using the Reflux Symptom Index (RSI), and clinical findings, using the Reflux Finding Score (RFS), could be achieved with treatment with a liquid alginate suspension compared to control (no treatment). Patients presenting with the symptoms of LPR to the Otorhinolaryngology Outpatient Department at the Queen's Medical Centre, Nottingham, UK were considered eligible if they had an RSI of greater than 10 and an RFS greater than 5 based on a fibreoptic examination of the larynx. A total of 49 patients were randomised into the open, parallel group study; 24 patients were randomised to receive 10 ml liquid alginate suspension (Gaviscon Advance) four times daily after meals and at bedtime, and 25 patients into the control group (no treatment). Patients were assessed pre-treatment and at 2, 4 and 6 months post treatment. Mean (SD) RSI and RFS pre-treatment scores were 23.9 (7.0) and 10.4 (3.6) for the treatment group and 24.6 (7.4) and 10.3 (3.3) for the control group, respectively. Significant differences between treatment and control were observed for RSI at the 2-month (11.2 (7.0) vs. 16.8 (6.4), P=0.005) and 6-month (11.2 (8.1) vs. 18.3 (9.4), P=0.008) assessments and for RFS at the 6-month (7.1 (2.8) vs. 9.5 (3.4), P=0.005) assessment. Significant improvement in symptom scores and clinical findings were achieved with liquid alginate suspension (Gaviscon Advance) compared to control and further evaluation for the management of patients presenting with LPR is warranted.

Mucus is a water-insoluble gel secreted by the gastrointestinal tract. It exists as a protective gel layer adherent to the epithelial surface of the stomach, small intestine and colon. The mucus gel is composed of 1–10% (w/v) mucin glycoprotein in a plasma-like fluid. Since the mucus gel is predominantly water, standard histological techniques dehydrate the mucus, making visualisation of the functional barrier difficult. Specialist techniques have been developed to enable visualisation of the intact mucus layer. A simple histological method using snap-frozen tissue, sectioned with a cryostat and stained with modified periodic acid-Schiff s/Alcian blue in mucus-preserving conditions will be described. A second powerfulin vivoanimal model is described which enables measurement of mucus secretion over time. The use of these two methods has allowed the characterisation of the normal mucus layer in the colon and the determination of how it is affected by disease and dietary intervention, in particular the effect of dietary fibre, and evidence that fibre deficiency results in colonic mucosal fragility is presented.