Coral mucus: the properties of its constituent mucins.

The gel-forming properties of mucus are closely related to its functioning; although there is limited information available relating to coral mucus gels. The present study investigates coral mucus glycoprotein using rheological methods. We demonstrate the presence of a high-molecular-weight polymeric glycoprotein similar to that found in vertebrates, capable of forming a gel. The milked mucus exuded mostly from the oral cavity of corals is not a gel; however, it does show a tendency to form a gel upon concentration. Such results indicate the potential for corals to produce two different kinds of mucus, each potentially capable of performing different functions.

Thrombin Hemostatic Matrix Reduces Heterotopic Ossification in Acetabular Fractures Fixed Through the Kocher-Langenbeck Approach.

OBJECTIVE: To determine whether an injectable thrombin product [thrombin hemostatic matrix (THM)] at closure of a Kocher-Langenbeck approach reduces the risk of heterotopic ossification (HO) formation after an acetabular fracture. DESIGN: Case control. SETTING: Two Level 1 trauma centers. PATIENTS: Patients with operatively treated acetabulum fractures fixed through Kocher-Langenbeck from 2013 to 2018. INTERVENTION: Records were reviewed for demographics, history of traumatic brain injury, HO medication or radiation prophylaxis, THM (Surgiflo, Ethicon, Bridgewater New Jersey) administration, and length of follow-up. Radiographs were reviewed for dislocation, fracture, Letournel and Orthopaedic Trauma Association classifications, HO, and Brooker grade if applicable. Patients receiving HO prophylaxis (eg, nonsteroidal anti-inflammatory drugs and radiation) were excluded. Remaining patients were divided into 2 groups: THM administration (intervention) and no THM. Continuous variables were compared using t-tests and categorical variables with chi-square or Fisher's exact tests. MAIN OUTCOME MEASUREMENTS: Risk ratios for the association between HO occurrence and THM administration. RESULTS: Three-hundred and twenty-eight acetabular fractures met inclusion criteria (126 intervention, 202 control) in patients with a mean age of 38.7 ± 15.9 years; 62.2% were male, and 42.1% were African American. Traumatic brain injury and posterior dislocation rates were equivalent between groups (P = 0.505, 0.754, respectively). HO rate in the control group was 42.6% compared with 21.4% in the THM group (P < 0.001). Booker grade 3/4 in control group was 17.3% versus 3.2% in the THM group (P < 0.001). Patients receiving THM had a 50% reduced risk of HO (95% confidence interval 0.35-0.73) compared to those who did not; adjustment for age, gender, ethnicity, and traumatic brain injury did not meaningfully change the association (risk ratio 0.46; 95% confidence interval 0.29-0.73; P < 0.001). CONCLUSION: The use of a surgiflo product at closure of a KO approach may reduce the risk of HO formation by 50% after an acetabular fracture. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Prominent members of the human gut microbiota express endo-acting O-glycanases to initiate mucin breakdown.

The thick mucus layer of the gut provides a barrier to infiltration of the underlying epithelia by both the normal microbiota and enteric pathogens. Some members of the microbiota utilise mucin glycoproteins as a nutrient source, but a detailed understanding of the mechanisms used to breakdown these complex macromolecules is lacking. Here we describe the discovery and characterisation of endo-acting enzymes from prominent mucin-degrading bacteria that target the polyLacNAc structures within oligosaccharide side chains of both animal and human mucins. These O-glycanases are part of the large and diverse glycoside hydrolase 16 (GH16) family and are often lipoproteins, indicating that they are surface located and thus likely involved in the initial step in mucin breakdown. These data provide a significant advance in our knowledge of the mechanism of mucin breakdown by the normal microbiota. Furthermore, we also demonstrate the potential use of these enzymes as tools to explore changes in O-glycan structure in a number of intestinal disease states.

Establishment of an immortalized human subglottic epithelial cell line.

OBJECTIVE: Translational research into subglottic disease is restricted by the availability of primary human tissue originating from this subsite. Primary epithelial cells are also limited by their inability to survive beyond several divisions in culture outside of the body. Specific subglottic cell lines, useful for in vitro studies, have not yet been described. We therefore demonstrate what we believe to be the first immortalized subglottic epithelial cell line. METHODS: Subglottic tissue was derived from a single adult patient's neoplasia-free human subglottic brushing specimen. Cells were immortalized using a lentiviral vector expressing simian virus 40 T antigen. Karyotyping was performed on the transformed cells using single nucleotide polymorphism array comparative genomic hybridization. Transformed cells were phenotypically characterized by light microscopy, immunohistochemistry, and electrophysiology studies. RESULTS: The immortalized subglottic cell line (SG01) was able to divide successfully beyond 20 passages. Karyotyping demonstrated no significant genomic imbalance after immortalization. The cells demonstrated normal epithelial morphology and cytokeratin expression throughout. SG01 cells were also successfully cultured at air-liquid interface (ALI). At ALI cells demonstrated cilia, mucus production, and relevant ion channel expression. CONCLUSION: The novel SG01 subglottic epithelial cell line has been established. This cell line provides a unique resource for researchers to investigate subglottic diseases, such as subglottic stenosis. LEVEL OF EVIDENCE: NA. Laryngoscope, 129:2640-2645, 2019.

Effects of bile acids on human airway epithelial cells: implications for aerodigestive diseases.

Gastro-oesophageal reflux and aspiration have been associated with chronic and end-stage lung disease and with allograft injury following lung transplantation. This raises the possibility that bile acids may cause lung injury by damaging airway epithelium. The aim of this study was to investigate the effect of bile acid challenge using the immortalised human bronchial epithelial cell line (BEAS-2B). The immortalised human bronchial epithelial cell line (BEAS-2B) was cultured. A 48-h challenge evaluated the effect of individual primary and secondary bile acids. Post-challenge concentrations of interleukin (IL)-8, IL-6 and granulocyte-macrophage colony-stimulating factor were measured using commercial ELISA kits. The viability of the BEAS-2B cells was measured using CellTiter-Blue and MTT assays. Lithocholic acid, deoxycholic acid, chenodeoxycholic acid and cholic acid were successfully used to stimulate cultured BEAS-2B cells at different concentrations. A concentration of lithocholic acid above 10 µmol·L-1 causes cell death, whereas deoxycholic acid, chenodeoxycholic acid and cholic acid above 30 µmol·L-1 was required for cell death. Challenge with bile acids at physiological levels also led to a significant increase in the release of IL-8 and IL6 from BEAS-2B. Aspiration of bile acids could potentially cause cell damage, cell death and inflammation in vivo. This is relevant to an integrated gastrointestinal and lung physiological paradigm of chronic lung disease, where reflux and aspiration are described in both chronic lung diseases and allograft injury.

Reflux of gastric juice and glue ear in children.

Otitis media with effusion (glue ear) is the most frequent cause of deafness in children. We investigated the role of gastric juice reflux in this disease. We measured pepsin concentrations in middle ear effusions from children using ELISA and enzyme activity assays. 45 (83%) of 54 effusions contained pepsin/pepsinogen at concentrations of up to 1000-fold greater than those in serum. Our data suggest that reflux of gastric juice could be a major cause of glue ear in children.