Enterotoxigenic Escherichia coli Degrades the Host MUC2 Mucin Barrier To Facilitate Critical Pathogen-Enterocyte Interactions in Human Small Intestine

Enterotoxigenic Escherichia coli (ETEC) isolates are genetically diverse pathological variants of E. coli defined by the production of heat-labile (LT) and/or heat-stable (ST) toxins. ETEC strains are estimated to cause hundreds of millions of cases of diarrheal illness annually. However, it is not clear that all strains are equally equipped to cause disease, and asymptomatic colonization with ETEC is common in low- to middle-income regions lacking basic sanitation and clean water where ETEC are ubiquitous. Recent molecular epidemiology studies have revealed a significant association between strains that produce EatA, a secreted autotransporter protein, and the development of symptomatic infection. Here, we demonstrate that LT stimulates production of MUC2 mucin by goblet cells in human small intestine, enhancing the protective barrier between pathogens and enterocytes. In contrast, using explants of human small intestine as well as small intestinal enteroids, we show that EatA counters this host defense by engaging and degrading the MUC2 mucin barrier to promote bacterial access to target enterocytes and ultimately toxin delivery, suggesting that EatA plays a crucial role in the molecular pathogenesis of ETEC. These findings may inform novel approaches to prevention of acute diarrheal illness as well as the sequelae associated with ETEC and other pathogens that rely on EatA and similar proteases for efficient interaction with their human hosts.

Modeling Epithelial Homeostasis and Reactive Epithelial Changes in Human and Murine Three-Dimensional Esophageal Organoids

The homeostatic proliferation-differentiation gradient in the esophageal epithelium is perturbed under inflammatory disease conditions such as gastroesophageal reflux disease and eosinophilic esophagitis. Herein we describe the protocols for rapid generation (<14 days) and characterization of single-cell-derived, three-dimensional (3D) esophageal organoids from human subjects and mice with normal esophageal mucosa or inflammatory disease conditions. While 3D organoids recapitulate normal epithelial renewal, proliferation, and differentiation, non-cell autonomous reactive epithelial changes under inflammatory conditions are evaluated in the absence of the inflammatory milieu. Reactive epithelial changes are reconstituted upon exposure to exogenous recombinant cytokines. These changes are modulated pharmacologically or genetically ex vivo. Molecular, structural, and functional changes are characterized by morphology, flow cytometry, biochemistry, and gene expression analyses. Esophageal 3D organoids can be translated for the development of personalized medicine in assessment of individual cytokine sensitivity and molecularly targeted therapeutics in esophagitis patients © 2020 by John Wiley & Sons, Inc. Basic Protocol 1: Generation of esophageal organoids from biopsy or murine esophageal epithelial sheets Basic Protocol 2: Propagation and cryopreservation of esophageal organoids Basic Protocol 3: Harvesting of esophageal organoids for RNA isolation, immunohistochemistry, and evaluation of 3D architecture Basic Protocol 4: Modeling of reactive epithelium in esophageal organoids.

The potential for malignancy from atopic disorders and allergic inflammation: A systematic review and meta-analysis

OBJECTIVE

While chronic inflammation is a well-established risk factor for malignancy, studies evaluating the relationship between allergic inflammation and cancer have revealed conflicting results. Here, we aimed to assess the association between allergic inflammation in the lung (asthma), skin (eczema) or oesophagus (eosinophilic oesophagitis; EoE) and cancer at the organ site.

DESIGN

We conducted a systematic review of the literature to identify observational studies (case-control, cohort and cross-sectional) evaluating the association between asthma and lung cancer, eczema and skin cancer, or EoE and oesophageal cancer. Random-effects meta-analysis was performed to define pooled estimates of effects.

DATA SOURCES

PubMed, EMBASE and Web of Science.

ELIGIBILITY CRITERIA FOR SELECTION

Included studies evaluated the incidence of cancer.

RESULTS

Thirty-two studies met the inclusion criteria, 27 in the lung, four in the skin and one in the oesophagus. Meta-analysis of the three studies with prospective data collection of asthma diagnosis revealed a positive association with incident lung cancer (OR 1.27, 95% CI 1.09-1.44); however, this result was not consistently supported by the larger dataset of retrospective studies (OR 1.37, 95% CI 0.90-1.83). Overall, studies in the lung displayed significant heterogeneity (I2 98%, P < .0001), but no significant effect modification on the association between asthma and lung cancer was identified for the variables of sex, smoking or study design. Meta-analysis could not be applied to the four papers reviewed in the skin, but three suggested an association between eczema and non-melanoma skin cancer, while the remaining study failed to identify an association between melanoma and eczema. A single study meeting inclusion criteria showed no association between EoE and oesophageal malignancy.

CONCLUSIONS

The current data cannot exclude the possibility of an association between atopy and malignancy the lung, skin and oesophagus. The relationship between allergy and cancer should be explored further in prospective studies that any association identified between these conditions has the potential for significant public health implications.

Microemboli observed in deaths following cardiopulmonary bypass surgery: silicone antifoam agents and polyvinyl chloride tubing as sources of emboli

Refractile foreign particles within clear vacuoles were observed in capillaries of 17 patients who underwent cardiopulmonary bypass surgery, died, and were autopsied at the George Washington University Hospital from December 1978 through April 1981. The postoperative survival time ranged from less than one day to more than eight months. The approximate maximal diameter of the individual particles was 10 micrometer and that of the vacuoles 60 micrometer. The particle-droplet complexes showed affinity for hydrophobic stains. In all 17 cases, the kidneys were involved in combination with several other organs. In two patients, the emboli were associated with microinfarcts in one or more organs. Scanning electron microscopy (SEM) of the polyvinyl chloride tubing used during four cardiopulmonary bypasses showed spallation and shredding of the luminal surface in the areas exposed to the roller pump heads. This suggested that fragments of polyvinyl chloride might be the particles in the emboli. Another possible source was the antifoam agent used in the bubble oxygenator. Scanning electron microscopy x-ray microprobe analysis of the foreign material within capillaries of several organs showed it to be strongly positive for silicon but not for chlorine. Therefore, it was concluded that the microemboli were droplets of antifoam agent, the refractile particles corresponding to the particulate silica component and the vacuoles corresponding to the dimethylpolysiloxane liquid component. Since x-ray microprobe analysis of the microemboli did not reveal a strong chloride peak, there is as yet no evidence that polyvinyl chloride fragments were involved in the microembolism. The morphologic findings reported here indicate that antifoam microembolization continues to complicate cardiopulmonary bypass surgery and must, therefore, be considered a potential cause of postoperative morbidity. The consequence of the fragments of polyvinyl chloride tubing released into the circulation remains to be established.

Complications of endoscopic retrograde cholangiopancreatography. Analysis of 300 consecutive cases

A retrospective analysis of complications arising from 300 consecutive attempts at endoscopic retrograde cholangiopancreatography (ERCP) in 278 patients was undetaken to determine the rate and severity of complications. An over-all complication rate of 5% (15 cases) was documented. Complications were categorized in terms of those arising from endoscopy itself or from the administration of pharmacological agents (7 cases), and those observed after the injection of radioopaque contrast into the biliary tree or pancreas (8 cases). Complications which might be considered coincidental to a patient's underlying illness were not excluded. Complications were significantly more frequent after injection of diseased duct systems. Brief, self-limited pancreatitis after retrograde pancreatography occurred in 5 of 90 patients with pancreatic disease. No cases of pancreatitis were observed after retrograde pancreatography in 102 patients without pancreatic disease X2 = 5.82, P less than 0.025). Sepsis occurred after retrograde cholangiography in 3 of 56 patients with extrahepatic biliary obstruction. In the absence of extrahepatic obstruction, cholangiography was performed without complication in 85 cases (X2 = 3.62, P less than 0.1), although 25 of these had intense cholestasis due to hepatic parenchymal disease. This analysis provides the basis for modifications of ERCP technique and management that may reduce the future incidence of complications. This study suggests that the incidence and severity of complications that arise from ERCP compare favorably with procedures of equivalent diagnostic yield.