Development of an Easily Reproducible Cough Simulator With Droplets and Aerosols for Rapidly Testing Novel Personal Protective Equipment.

INTRODUCTION: The current COVID-19 pandemic has produced numerous innovations in personal protective equipment, barrier devices, and infection mitigation strategies, which have not been validated. During high-risk procedures such as airway manipulation, coughs are common and discrete events that may expose healthcare workers to large amounts of viral particles. A simulated cough under controlled circumstances can rapidly test novel devices and protocols and thus aid in their evaluation and the development of implementation guidelines. Physiologic cough simulators exist but require significant expertise and specialized equipment not available to most clinicians. METHODS: Using components commonly found in healthcare settings, a cough simulator was designed for clinicians to easily assemble and use. Both droplet and aerosol particle generators were incorporated into a bimodal experimental system. High-speed flash photography was used for data collection. RESULTS: Using a gas flow analyzer, video recordings, and high-speed digital photography, the cough and particle simulators were quantitatively and qualitatively compared with known physiologic cough parameters and in vivo Schlieren imaging of human coughs. CONCLUSIONS: Based on our validation studies, this cough and particle simulator model approximates a physiologic, human cough in the context of testing personal protective equipment, barrier devices, and infection prevention measures.

Spontaneous Cleavages of a Heterologous Protein, the CenA Endoglucanase of Cellulomonas fimi, in Escherichia coli.

CenA is an endoglucanase secreted by the Gram-positive cellulolytic bacterium, Cellulomonas fimi, to the environment as a glycosylated protein. The role of glycosylation in CenA is unclear. However, it seems not crucial for functional activity and secretion since the unglycosylated counterpart, recombinant CenA (rCenA), is both bioactive and secretable in Escherichia coli. Using a systematic screening approach, we have demonstrated that rCenA is subjected to spontaneous cleavages (SC) in both the cytoplasm and culture medium of E. coli, under the influence of different environmental factors. The cleavages were found to occur in both the cellulose-binding (CellBD) and catalytic domains, with a notably higher occurring rate detected in the former than the latter. In CellBD, the cleavages were shown to occur close to potential N-linked glycosylation sites, suggesting that these sites might serve as 'attributive tags' for differentiating rCenA from endogenous proteins and the points of initiation of SC. It is hypothesized that glycosylation plays a crucial role in protecting CenA from SC when interacting with cellulose in the environment. Subsequent to hydrolysis, SC would ensure the dissociation of CenA from the enzyme-substrate complex. Thus, our findings may help elucidate the mechanisms of protein turnover and enzymatic cellulolysis.

Using Simulation to Develop Solutions for Ventilator Shortages From the Epicenter.

SUMMARY STATEMENT: The COVID-19 pandemic threatened to overwhelm the medical system of New York City, and the threat of ventilator shortages was real. Using high-fidelity simulation, a variety of solutions were tested to solve the problem of ventilator shortages including innovative designs for safely splitting ventilators, converting noninvasive ventilators to invasive ventilators, and testing and improving of ventilators created by outside companies. Simulation provides a safe environment for testing of devices and protocols before use on patients and should be vital in the preparation for emergencies such as the COVID-19 pandemic.

Global smoking trends in inflammatory bowel disease: A systematic review of inception cohorts.

BACKGROUND AND AIMS: The effect of smoking on the risk of developing inflammatory bowel diseases (IBD) may be heterogeneous across ethnicity and geography. Although trends in smoking for the general population are well described, it is unknown whether these can be extrapolated to the IBD cohort. Smoking prevalence trends specific to the global IBD cohort over time have not been previously reported. This is a systematic review of smoking prevalence specific to the IBD cohort across geography. METHODS: A systematic literature search was conducted on Medline and Embase from January 1st 1946 to April 5th 2018 to identify population-based studies assessing the prevalence of smoking at diagnosis in inception cohorts of Crohn's disease(CD) or ulcerative colitis(UC). Studies that did not report smoking data from time of diagnosis or the year of IBD diagnosis were excluded. Prevalence of smoking in IBD was stratified by geography and across time. RESULTS: We identified 56 studies that were eligible for inclusion. Smoking prevalence data at diagnosis of CD and UC was collected from twenty and twenty-five countries respectively. Never-smokers in the newly diagnosed CD population in the West has increased over the last two decades, especially in the United Kingdom and Sweden; +26.6% and +11.2% respectively. Never-smokers at CD diagnosis in newly industrialised nations have decreased over the 1990s and 2000s; China (-19.36%). Never-smokers at UC diagnosis also decreased in China; -15.4%. The former-smoker population at UC diagnosis in China is expanding; 11%(1990-2006) to 34%(2011-2013). CONCLUSION: There has been a reduction in the prevalence of smoking in the IBD cohort in the West. This is not consistent globally. Although, smoking prevalence has decreased in the general population of newly industrialised nations, this remains an important risk factor with longer term outcomes awaiting translation in both UC and CD.

Systematic review with meta-analysis: review of donor features, procedures and outcomes in 168 clinical studies of faecal microbiota transplantation.

BACKGROUND: Faecal microbiota transplantation (FMT) is effective for Clostridium difficile infections (CDI) refractory to standard treatment and is being studied in other diseases. AIM: To evaluate donor characteristics, procedures and clinical outcomes of FMT. METHODS: We systematically reviewed FMT studies published up to 29 August 2018 using MEDLINE (R) and EMBASE and identified clinical studies with FMT donor information. We reported data on donor characteristics, screening criteria, administration, clinical outcomes and adverse events. RESULTS: Among 5267 reports, 239 full-text articles were screened and 168 articles were included. FMT was performed commonly for CDI (n = 108) and inflammatory bowel disease (IBD) (n = 31). We reported characteristics of 1513 donors [58% male; mean age, 34.3 years; mean body mass index, 21.6]. Donors in Asia were younger than the West (mean age 30.7 vs 32.9, P = 0.00075). Less than 50% of studies screened donors for transmittable pathogens. Final cure rate for CDI was 95.6% (95% confidence interval [CI], 93.9%-97.1%) and final remission rates for ulcerative colitis (UC) and Crohn's disease (CD) were 39.6% (95% CI, 25.4%-54.6%) and 47.5% (95% CI, 29.4%-65.8%), respectively. Cure rates in CDI and final remission rates for CD and UC were comparable across all routes of FMT administration. Overall adverse event incidence was <1%, mostly GI-related. Adverse event rates did not differ significantly between routes of FMT administration or indication. CONCLUSIONS: In a systematic review assessing donor characteristics and FMT efficacy, we observed heterogeneity in donor selection, application and outcomes of FMT. These data can facilitate standardisation of FMT protocols for various diseases.

Novel strategy for expression of authentic and bioactive human basic fibroblast growth factor in Bacillus subtilis.

Inteins, also known as "protein introns," have been found to be present in many microbial species and widely employed for the expression and purification of recombinant proteins in Escherichia coli. However, interestingly, until now there has not been much information on the identification and application of inteins to protein expression in Bacillus subtilis. In this article, for the first time, despite the likelihood of absence of inteins in B. subtilis, this bacterium was shown to be able to facilitate auto-catalytic cleavages of fusions formed between inteins and recombinant proteins. Employing a construct expressing the intein, Ssp DnaB, (DnaB), which was fused at its N-terminus with the cellulose-binding domain (CellBD) of an endoglucanase encoded by the cenA gene of Cellulomonas fimi, the construct was demonstrated to be capable of mediating intracellular expression of basic fibroblast growth factor (bFGF), followed by auto-processing of the CellBD-DnaB-bFGF fusion to result in bFGF possessing the 146-residue authentic structure. The mentioned fusion was shown to result in a high yield of 84 mg l-1 of biologically active bFGF. Future work in improving the growth of B. subtilis may enable the use of this bacterium, working in cooperation with inteins, to result in a new platform for efficient expression of valuable proteins.