Respiratory infectious disease outbreaks among people experiencing homelessness: a systematic review of prevention and mitigation strategies.

PURPOSE: People experiencing homelessness (PEH) are at increased risk of respiratory infections and associated morbidity and mortality. To characterize optimal intervention strategies, we completed a systematic review of mitigation strategies for PEH to minimize the spread and impact of respiratory infectious disease outbreaks, including COVID-19. METHODS: The study protocol was registered in PROSPERO (#2020 CRD42020208964) and was consistent with the preferred reporting in systematic reviews and meta-analyses guidelines. A search algorithm containing keywords that were synonymous to the terms "Homeless" and "Respiratory Illness" was applied to the six databases. The search concluded on September 22, 2020. Quality assessment was performed at the study level. Steps were conducted by two independent team members. RESULTS: A total of 4468 unique titles were retrieved with 21 meeting criteria for inclusion. Interventions included testing, tracking, screening, infection prevention and control, isolation support, and education. Historically, there has been limited study of intervention strategies specifically for PEH across the world. CONCLUSIONS: Staff and organizations providing services for people experiencing homelessness face specific challenges in adhering to public health guidelines such as physical distancing, isolation, and routine hygiene practices. There is a discrepancy between the burden of infectious diseases among PEH and specific research characterizing optimal intervention strategies to mitigate transmission in the context of shelters. Improving health for people experiencing homelessness necessitates investment in programs scaling existing interventions and research to study new approaches.

Laryngeal varices: an atypical cause of globus.

Laryngeal varices are rare and are usually associated with vocal cord trauma secondary to excessive use of voice. This report is the first documented case of laryngeal varices secondary to thyroid goitre. This is a report of an 83-year-old woman with a known retrosternal goitre chiefly with symptoms of globus. Retrosternal goitre was found to be compressing the pharyngeal venous plexus causing laryngeal venous structures bilaterally to be engorged along the aryepiglottic folds, arytenoids, posterior commissure and extending in to the postcricoid region. The presence of laryngeal varices carries a significant increased risk of haemorrhage. This case presents an atypical presentation of globus and the first reported case in the literature of laryngeal varices secondary to a thyroid goitre.

DNA Methylation of Fibroblast Phenotypes and Contributions to Lung Fibrosis.

Fibroblasts are an integral part of connective tissue and play a crucial role in developing and modulating the structural framework of tissues by acting as the primary source of extracellular matrix (ECM). A precise definition of the fibroblast remains elusive. Lung fibroblasts orchestrate the assembly and turnover of ECM to facilitate gas exchange alongside performing immune functions including the secretion of bioactive molecules and antigen presentation. DNA methylation is the covalent attachment of a methyl group to primarily cytosines within DNA. DNA methylation contributes to diverse cellular phenotypes from the same underlying genetic sequence, with DNA methylation profiles providing a memory of cellular origin. The lung fibroblast population is increasingly viewed as heterogeneous with between 6 and 11 mesenchymal populations identified across health and lung disease to date. DNA methylation has been associated with different lung fibroblast populations in health and with alterations in lung disease, but to varying extents. In this review, we will discuss lung fibroblast heterogeneity and the evidence for a contribution from DNA methylation to defining cell populations and alterations in disease.

Fetal abdominal wall defects in an Australian tertiary setting: contemporary characteristics, ultrasound accuracy, and outcome.

PURPOSE: In this study, we aimed to comprehensively evaluate risk factors, ultrasound estimation of fetal weight, prenatal management, and pregnancy outcomes of gastroschisis and omphalocele at a metropolitan Australian hospital. MATERIAL AND METHODS: This was a retrospective single-center cohort study from 2006 to 2014 at a tertiary hospital with colocated neonatal surgical facilities. Demographic, pregnancy, ultrasound, birth and neonatal data were compared between gastroschisis and omphalocele. Correlation between routine (Hadlock 1 &2) and specific (Siemer) estimated fetal weight (EFW) estimation formulae with birth weight (BW) was made for those 50 gastroschisis cases with ≥2 third trimester scans and last scan ≤2 weeks prior to birth. RESULTS: There were 126 abdominal wall defects: 83 gastroschisis and 43 omphalocele. Consistent with international literature, the average maternal age was lower for gastroschisis and rates of smoking higher, while there were more intrauterine deaths and pregnancy terminations in omphalocele. Gastroschisis mothers were more likely living outside Sydney, had more infections in pregnancy and were followed with a larger number of antenatal visits, with a shorter period from the last visit to birth. In omphalocele pregnancies, amniocentesis was more likely performed, with more abnormal results than in gastroschisis fetuses. All EFW formulae had a good correlation between Z score for the last US and actual BW (ICC 0.693-0.815), with Hadlock 2 being the best. Siemer formula had the best correlation from first to the last scan. Gastroschisis newborns were born earlier (36.8 versus 38.2 wks p = .001), with smaller birthweight (2.52 versus 3.03 kg, p < .001), a longer request of intensive care (central line, parenteral nutrition, intubation) and second surgery, along with more multisystem complications (average 1.5 versus 0.7, p = .004) and a longer hospital stay (58.8 versus 36.8 d, p < .001). CONCLUSION: Demographic, antenatal, and pregnancy outcome data for abdominal wall defects correlated well with the international literature. Hadlock 1-2 gave the most consistent EFW estimate, with all formulae showing good correlation.

TWIST1 DNA methylation is a cell marker of airway and parenchymal lung fibroblasts that are differentially methylated in asthma.

BACKGROUND: Mesenchymal fibroblasts are ubiquitous cells that maintain the extracellular matrix of organs. Within the lung, airway and parenchymal fibroblasts are crucial for lung development and are altered with disease, but it has been difficult to understand their roles due to the lack of distinct molecular markers. We studied genome-wide DNA methylation and gene expression in airway and parenchymal lung fibroblasts from healthy and asthmatic donors, to identify a robust cell marker and to determine if these cells are molecularly distinct in asthma. RESULTS: Airway (N = 8) and parenchymal (N = 15) lung fibroblasts from healthy individuals differed in the expression of 158 genes, and DNA methylation of 3936 CpGs (Bonferroni adjusted p value < 0.05). Differential DNA methylation between cell types was associated with differential expression of 42 genes, but no single DNA methylation CpG feature (location, effect size, number) defined the interaction. Replication of gene expression and DNA methylation in a second cohort identified TWIST1 gene expression, DNA methylation and protein expression as a cell marker of airway and parenchymal lung fibroblasts, with DNA methylation having 100% predictive discriminatory power. DNA methylation was differentially altered in parenchymal (112 regions) and airway fibroblasts (17 regions) with asthmatic status, with no overlap between regions. CONCLUSIONS: Differential methylation of TWIST1 is a robust cell marker of airway and parenchymal lung fibroblasts. Airway and parenchymal fibroblast DNA methylation are differentially altered in individuals with asthma, and the role of both cell types should be considered in the pathogenesis of asthma.

Airway epithelial cell isolation techniques affect DNA methylation profiles with consequences for analysis of asthma related perturbations to DNA methylation.

The airway epithelium forms the interface between the inhaled environment and the lung. The airway epithelium is dysfunctional in asthma and epigenetic mechanisms are considered a contributory factor. We hypothesised that the DNA methylation profiles of cultured primary airway epithelial cells (AECs) would differ between cells isolated from individuals with asthma (n = 17) versus those without asthma (n = 16). AECs were isolated from patients by two different isolation techniques; pronase digestion (9 non-asthmatic, 8 asthmatic) and bronchial brushings (7 non-asthmatic and 9 asthmatic). DNA methylation was assessed using an Illumina Infinium HumanMethylation450 BeadChip array. DNA methylation of AECs clustered by isolation technique and linear regression identified 111 CpG sites differentially methylated between isolation techniques in healthy individuals. As a consequence, the effect of asthmatic status on DNA methylation was assessed within AEC samples isolated using the same technique. In pronase isolated AECs, 15 DNA regions were differentially methylated between asthmatics and non-asthmatics. In bronchial brush isolated AECs, 849 differentially methylated DNA regions were identified with no overlap to pronase regions. In conclusion, regardless of cell isolation technique, differential DNA methylation was associated with asthmatic status in AECs, providing further evidence for aberrant DNA methylation as a signature of epithelial dysfunction in asthma.

Simulated patient and role play methodologies for communication skills training in an undergraduate medical program: Randomized, crossover trial.

Background: Educators utilize real patients, simulated patients (SP), and student role play (RP) in communication skills training (CST) in medical curricula. The chosen modality may depend more on resource availability than educational stage and student needs. In this study, we set out to determine whether an inexpensive volunteer SP program offered an educational advantage compared to RP for CST in preclinical medical students. Methods: Students and volunteer SPs participated in interactions across two courses. Students allocated to SP interactions in one course participated in RP in the other course and vice versa. Audio recordings of interactions were made, and these were rated against criterion descriptors in a modified Calgary-Cambridge Referenced Observation Guide. Results: Independent t-test scores comparing ratings of RP and SP groups revealed no significant differences between methodologies. Discussion: This study demonstrates that volunteer SPs are not superior to RP, when used in CST targeted at preclinical students. This finding is consistent with existing literature, yet we suggest that it is imperative to consider the broader purpose of CST and the needs of stakeholders. Consequently, it may be beneficial to use mixed methods of CST in medical programs.

Altered DNA methylation is associated with aberrant gene expression in parenchymal but not airway fibroblasts isolated from individuals with COPD.

Background: Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease of the lungs that is currently the fourth leading cause of death worldwide. Genetic factors account for only a small amount of COPD risk, but epigenetic mechanisms, including DNA methylation, have the potential to mediate the interactions between an individual's genetics and environmental exposure. DNA methylation is highly cell type-specific, and individual cell type studies of DNA methylation in COPD are sparse. Fibroblasts are present within the airway and parenchyma of the lung and contribute to the aberrant deposition of extracellular matrix in COPD. No assessment or comparison of genome-wide DNA methylation profiles in the airway and parenchymal fibroblasts from individuals with and without COPD has been undertaken. These data provide valuable insight into the molecular mechanisms contributing to COPD and the differing pathologies of small airways disease and emphysema in COPD. Methods: Genome-wide DNA methylation was evaluated at over 485,000 CpG sites using the Illumina Infinium HumanMethylation450 BeadChip array in the airway (non-COPD n = 8, COPD n = 7) and parenchymal fibroblasts (non-COPD n = 17, COPD n = 29) isolated from individuals with and without COPD. Targeted gene expression was assessed by qPCR in matched RNA samples. Results: Differentially methylated DNA regions were identified between cells isolated from individuals with and without COPD in both airway and parenchymal fibroblasts. Only in parenchymal fibroblasts was differential DNA methylation associated with differential gene expression. A second analysis of differential DNA methylation variability identified 359 individual differentially variable CpG sites in parenchymal fibroblasts. No differentially variable CpG sites were identified in the airway fibroblasts. Five differentially variable-methylated CpG sites, associated with three genes, were subsequently assessed for gene expression differences. Two genes (OAT and GRIK2) displayed significantly increased gene expression in cells isolated from individuals with COPD. Conclusions: Differential and variable DNA methylation was associated with COPD status in the parenchymal fibroblasts but not airway fibroblasts. Aberrant DNA methylation was associated with altered gene expression imparting biological function to DNA methylation changes. Changes in DNA methylation are therefore implicated in the molecular mechanisms underlying COPD pathogenesis and may represent novel therapeutic targets.

Epigenetic dysregulation of interleukin 8 (CXCL8) hypersecretion in cystic fibrosis airway epithelial cells.

Airway epithelial cells in cystic fibrosis (CF) overexpress Interleukin 8 (CXCL8) through poorly defined mechanisms. CXCL8 transcription is dependent on coordinated binding of CCAAT/enhancer binding protein (C/EBP)ß, nuclear factor (NF)-κB, and activator protein (AP)-1 to the promoter. Here we show abnormal epigenetic regulation is responsible for CXCL8 overexpression in CF cells. Under basal conditions CF cells had increased bromodomain (Brd)3 and Brd4 recruitment and enhanced NF-κB and C/EBPß binding to the CXCL8 promoter compared to non-CF cells due to trimethylation of histone H3 at lysine 4 (H3K4me3) and DNA hypomethylation at CpG6. IL-1ß increased NF-κB, C/EBPß and Brd4 binding. Furthermore, inhibitors of bromodomain and extra-terminal domain family (BET) proteins reduced CXCL8 production in CF cells suggesting a therapeutic target for the BET pathway.

CXCL8 histone H3 acetylation is dysfunctional in airway smooth muscle in asthma: regulation by BET.

Asthma is characterized by airway inflammation and remodeling and CXCL8 is a CXC chemokine that drives steroid-resistant neutrophilic airway inflammation. We have shown that airway smooth muscle (ASM) cells isolated from asthmatic individuals secrete more CXCL8 than cells from nonasthmatic individuals. Here we investigated chromatin modifications at the CXCL8 promoter in ASM cells from nonasthmatic and asthmatic donors to further understand how CXCL8 is dysregulated in asthma. ASM cells from asthmatic donors had increased histone H3 acetylation, specifically histone H3K18 acetylation, and increased binding of histone acetyltransferase p300 compared with nonasthmatic donors but no differences in CXCL8 DNA methylation. The acetylation reader proteins Brd3 and Brd4 were bound to the CXCL8 promoter and Brd inhibitors inhibited CXCL8 secretion from ASM cells by disrupting Brd4 and RNA polymerase II binding to the CXCL8 promoter. Our results show a novel dysregulation of CXCL8 transcriptional regulation in asthma characterized by a promoter complex that is abnormal in ASM cells isolated from asthmatic donors and can be modulated by Brd inhibitors. Brd inhibitors may provide a new therapeutic strategy for steroid-resistant inflammation.

Ciclesonide inhibits TNFα- and IL-1ß-induced monocyte chemotactic protein-1 (MCP-1/CCL2) secretion from human airway smooth muscle cells.

Monocyte chemotactic protein-1 (MCP-1) is a member of the CC family of cytokines. It has monocyte and lymphocyte chemotactic activity and stimulates histamine release from basophils. MCP-1 is implicated in the pathogenesis of inflammatory diseases, including asthma. The airway smooth muscle (ASM) layer is thickened in asthma, and the growth factors and cytokines secreted by ASM cells play a role in the inflammatory response of the bronchial wall. Glucocorticoids and ß(2)-agonists are first-line drug treatments for asthma. Little is known about the effect of asthma treatments on MCP-1 production from human ASM cells. Here, we determined the effect of ciclesonide (a glucocorticoid) and formoterol (a ß(2)-agonist) on MCP-1 production from human ASM cells. TNFα and IL-1ß induced MCP-1 secretion from human ASM cells. Formoterol had no effect on MCP-1 expression, while ciclesonide significantly inhibited IL-1ß- and TNFα-induced MCP-1. Furthermore, ciclesonide inhibited IL-1ß- and TNFα-induced MCP-1 mRNA and IL-1ß- and TNFα-induced MCP-1 promoter and enhancer luciferase reporters. Western blots showed that ciclesonide had no effect on IκB degradation. Finally, ciclesonide inhibited an NF-κB luciferase reporter. Our data show that ciclesonide inhibits IL-1ß- and TNFα-induced MCP-1 production from human ASM cells via a transcriptional mechanism involving inhibition of NF-κB binding.

Transcriptional regulation of monocyte chemotactic protein-1 release by endothelin-1 in human airway smooth muscle cells involves NF-kappaB and AP-1.

BACKGROUND AND PURPOSE: Endothelin-1 (ET-1) is implicated in airway inflammation in asthma, but the mechanisms of its effects are poorly understood. We studied the effect of ET-1 on expression of the chemokine, monocyte chemotactic protein-1 (MCP-1), in primary cultures of human airway smooth muscle cells. EXPERIMENTAL APPROACH: MCP-1 release was measured by elisa. Pharmacological antagonists/inhibitors, reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting were used to study ET receptors and kinase cascades. Transcriptional regulation was studied by real-time RT-PCR, transient transfection studies and chromatin immunoprecipitation assay. Major findings were confirmed in cells from three donors and mechanistic studies in cells from one donor. KEY RESULTS: ET-1 increased MCP-1 release through an ET(A) and ET(B) receptor-dependent mechanism. ET-1 increased MCP-1 mRNA levels but not mRNA stability suggesting it was acting transcriptionally. ET-1 increased the activity of an MCP-1 promoter-reporter construct. Serial deletions of the MCP-1 promoter mapped ET-1 effects to a region between -213 and -128 base pairs upstream of the translation start codon, containing consensus sequences for activator protein-1 (AP-1) and nuclear factor-kappaB (NF-kappaB). ET-1 promoted binding of AP-1 c-Jun subunit and NF-kappaB p65 subunit to the MCP-1 promoter. Blocking the inhibitor of kappaB kinase-2 with 2-[(aminocarbonyl)amino]-5-[4-fluorophenyl]-3-thiophenecarboxamide (TPCA-1) decreased ET-1-stimulated MCP-1 production. p38 and p44/p42 mitogen-activated protein kinases were involved in upstream signalling. CONCLUSIONS AND IMPLICATIONS: ET-1 regulated MCP-1 transcriptionally, via NF-kappaB and AP-1. The upstream signalling involved ET(A), ET(B) receptors, p38 and p44/p42 mitogen-activated protein kinases. These may be targets for novel asthma therapies.