One-year trial evaluating the durability and antimicrobial efficacy of copper in public transportation systems.

Surfaces on transit vehicles are frequently touched and could potentially act as reservoirs for micro-organism transmission. Regular cleaning and disinfection to minimize the spread of micro-organisms is operationally challenging due to the need to keep vehicles in circulation. The application of copper (Cu) alloys to high- touch surfaces could help reduce the risk of cross-contamination, however, little is known about the durability and efficacy of engineered copper surfaces after prolonged use. Three Cu products (decal, thermal fabrication, and alloy covers) were assessed over a 12-month period. These Cu products were randomly installed on 110 stanchions on three buses and four train (SkyTrain) cars in Vancouver and three buses, two subway cars, and two streetcars in Toronto with mirrored control surfaces directly opposite. Bacterial counts (Colony forming units, CFU) and ATP bioluminescence (ATPB) were measured every two months after peak morning routes. Durability of the Cu products were assessed monthly through visual inspection and colorimetry assays or by ex-situ microscopy. Cu products on stanchions reduced the mean colony forming units (CFU) of all vehicles by 42.7% in the mean CFU (0.573 (CI 95% 0.453-0.726), p-value < 0.001) compared to control surfaces. The three Cu products exhibited an overall 87.1% reduction in the mean ATPB readings (0.129 (CI 95% 0.059-0.285, p-value < 0.001) compared to controls. Surface Cu concentration for all three products was consistent throughout the 12-month period. Electron microscopy (SEM) and Energy-dispersive X-ray Spectroscopy (EDS) cross-sectional analysis showed no change in thickness or dealloying of Cu products, however SEM top-down analysis revealed substantial carbon accumulation on all surfaces. Cu products installed on transit vehicles maintained antimicrobial efficacy and durability after 12 months of use.

In vitro assessment of antibacterial and antiviral activity of three copper products after 200 rounds of simulated use.

Copper has well-documented antibacterial effects but few have evaluated it after prolonged use and against bacteria and viruses. Coupons from three copper formulations (solid, thermal coating, and decal applications) and carbon steel controls were subjected to 200 rounds simulated cleaning using a Wiperator™ and either an accelerated hydrogen peroxide, quaternary ammonium, or artificial sweat products. Antibacterial activity against S. aureus and P. aeruginosa was then evaluated using a modified Environmental Protection Agency protocol. Antiviral activity against coronavirus (229E) and norovirus (MNV-1) surrogates was assessed using the TCID50 method. Results were compared to untreated control coupons. One hour after inoculation, S. aureus exhibited a difference in log kill of 1.16 to 4.87 and P. aeruginosa a log kill difference of 3.39-5.23 (dependent upon copper product and disinfectant) compared to carbon steel. MNV-1 demonstrated an 87-99% reduction on each copper surfaces at 1 h and 99% reduction at 2 h compared to carbon steel. Similarly, coronavirus 229E exhibited a 97-99% reduction after 1 h and 90-99% after 2 h. Simulated use with artificial sweat did not hinder the antiviral nor the antibacterial activity of Cu surfaces. Self-sanitizing copper surfaces maintained antibacterial and antiviral activity after 200 rounds of simulated cleaning.

Upper Respiratory Tract OC43 Infection Model for Investigating Airway Immune-Modifying Therapies.

Respiratory virus infections initiate and transmit from the upper respiratory tract (URT). Coronaviruses, including OC43, are a major cause of respiratory infection and disease. Failure to mount an effective antiviral immune response in the nasal mucosa increases the risk of severe disease and person-to-person transmission, highlighting the need for URT infection models to support the development of nasal treatments that improve coronavirus antiviral immunity. We aimed to determine if OC43 productively infected the mouse URT and would therefore be a suitable model to assess the efficacy and mechanism of action of nasal-targeting immune-modifying treatments. We administered OC43 via intranasal inoculation to wild-type Balb/c mice and assessed virus airway tropism (by comparing total respiratory tract vs. URT-only virus exposure) and characterized infection-induced immunity by quantifying specific antiviral cytokines and performing gene array assessment of immune genes. We then assessed the effect of immune-modulating therapies, including an immune-stimulating TLR2/6 agonist (INNA-X) and the immune-suppressing corticosteroid fluticasone propionate (FP). OC43 replicated in nasal respiratory epithelial cells, with peak viral RNA observed 2 days after infection. Prophylactic treatment with INNA-X accelerated expression of virus-induced IFN-λ and IFN-stimulated genes. In contrast, intranasal FP treatment increased nasal viral load by 2.4 fold and inhibited virus-induced IFN and IFN-stimulated gene expression. Prior INNA-X treatment reduced the immune-suppressive effect of FP. We demonstrate that the mouse nasal epithelium is permissive to OC43 infection and strengthen the evidence that TLR2 activation is a ß-coronavirus innate immune determinant and therapeutic target.

IL-25 blockade augments antiviral immunity during respiratory virus infection.

IL-25 is implicated in the pathogenesis of viral asthma exacerbations. However, the effect of IL-25 on antiviral immunity has yet to be elucidated. We observed abundant expression and colocalization of IL-25 and IL-25 receptor at the apical surface of uninfected airway epithelial cells and rhinovirus infection increased IL-25 expression. Analysis of immune transcriptome of rhinovirus-infected differentiated asthmatic bronchial epithelial cells (BECs) treated with an anti-IL-25 monoclonal antibody (LNR125) revealed a re-calibrated response defined by increased type I/III IFN and reduced expression of type-2 immune genes CCL26, IL1RL1 and IL-25 receptor. LNR125 treatment also increased type I/III IFN expression by coronavirus infected BECs. Exogenous IL-25 treatment increased viral load with suppressed innate immunity. In vivo LNR125 treatment reduced IL-25/type 2 cytokine expression and increased IFN-ß expression and reduced lung viral load. We define a new immune-regulatory role for IL-25 that directly inhibits virus induced airway epithelial cell innate anti-viral immunity.

Tissue-specific transcriptional imprinting and heterogeneity in human innate lymphoid cells revealed by full-length single-cell RNA-sequencing.

The impact of the microenvironment on innate lymphoid cell (ILC)-mediated immunity in humans remains largely unknown. Here we used full-length Smart-seq2 single-cell RNA-sequencing to unravel tissue-specific transcriptional profiles and heterogeneity of CD127+ ILCs across four human tissues. Correlation analysis identified gene modules characterizing the migratory properties of tonsil and blood ILCs, and signatures of tissue-residency, activation and modified metabolism in colon and lung ILCs. Trajectory analysis revealed potential differentiation pathways from circulating and tissue-resident naïve ILCs to a spectrum of mature ILC subsets. In the lung we identified both CRTH2+ and CRTH2- ILC2 with lung-specific signatures, which could be recapitulated by alarmin-exposure of circulating ILC2. Finally, we describe unique TCR-V(D)J-rearrangement patterns of blood ILC1-like cells, revealing a subset of potentially immature ILCs with TCR-δ rearrangement. Our study provides a useful resource for in-depth understanding of ILC-mediated immunity in humans, with implications for disease.

Rhinovirus-induced CCL17 and CCL22 in Asthma Exacerbations and Differential Regulation by STAT6.

The interplay of type-2 inflammation and antiviral immunity underpins asthma exacerbation pathogenesis. Virus infection induces type-2 inflammation-promoting chemokines CCL17 and CCL22 in asthma; however, mechanisms regulating induction are poorly understood. By using a human rhinovirus (RV) challenge model in human airway epithelial cells in vitro and mice in vivo, we assessed mechanisms regulating CCL17 and CCL22 expression. Subjects with mild to moderate asthma and healthy volunteers were experimentally infected with RV and airway CCL17 and CCL22 protein quantified. In vitro airway epithelial cell- and mouse-RV infection models were then used to define STAT6- and NF-κB-mediated regulation of CCL17 and CCL22 expression. Following RV infection, CCL17 and CCL22 expression was higher in asthma, which differentially correlated with clinical and immunological parameters. Air-liquid interface-differentiated primary epithelial cells from donors with asthma also expressed higher levels of RV-induced CCL22. RV infection boosted type-2 cytokine-induced STAT6 activation. In epithelial cells, type-2 cytokines and STAT6 activation had differential effects on chemokine expression, increasing CCL17 and suppressing CCL22, whereas NF-κB promoted expression of both chemokines. In mice, RV infection activated pulmonary STAT6, which was required for CCL17 but not CCL22 expression. STAT6-knockout mice infected with RV expressed increased levels of NF-κB-regulated chemokines, which was associated with rapid viral clearance. Therefore, RV-induced upregulation of CCL17 and CCL22 was mediated by NF-κB activation, whereas expression was differentially regulated by STAT6. Together, these findings suggest that therapeutic targeting of type-2 STAT6 activation alone will not block all inflammatory pathways during RV infection in asthma.

When Doing Wrong Feels So Right: Normalization of Deviance.

Normalization of deviance is a term first coined by sociologist Diane Vaughan when reviewing the Challenger disaster. Vaughan noted that the root cause of the Challenger disaster was related to the repeated choice of NASA officials to fly the space shuttle despite a dangerous design flaw with the O-rings. Vaughan describes this phenomenon as occurring when people within an organization become so insensitive to deviant practice that it no longer feels wrong. Insensitivity occurs insidiously and sometimes over years because disaster does not happen until other critical factors line up. In clinical practice, failing to do time outs before procedures, shutting off alarms, and breaches of infection control are deviances from evidence-based practice. As in other industries, health care workers do not make these choices intending to set into motion a cascade toward disaster and harm. Deviation occurs because of barriers to using the correct process or drivers such as time, cost, and peer pressure. As in other industries, operators will often adamantly defend their actions as necessary and justified. Although many other high-risk industries have embraced the normalization of deviance concept, it is relatively new to health care. It is urgent that we explore the impact of this concept on patient harm. We can borrow this concept from other industries and also the steps these other high-risk organizations have found to prevent it.

Breast MR imaging: computer-aided evaluation program for discriminating benign from malignant lesions.

PURPOSE: To retrospectively determine the sensitivity of kinetic features measured with computer-aided evaluation at breast magnetic resonance (MR) imaging in discriminating benign from malignant lesions, with histopathologic findings used as the reference standard. MATERIALS AND METHODS: Institutional review board approval was obtained for this HIPAA-compliant study. Informed consent was waived. Suspicious breast lesions visible only at MR imaging and in which biopsy had been performed with MR imaging guidance were retrospectively evaluated with a computer-aided evaluation program. Computer-generated kinetic features for each lesion were recorded, and those of benign and malignant lesions were compared. Features analyzed included the presence or absence of computer-aided evaluation "threshold enhancement" at 50% and 100% minimum thresholds; degree of initial peak enhancement; and enhancement profiles composed of lesion percentages of washout, plateau, and persistent enhancement. The Fisher exact test and Student t test were used to assess differences in these analyses. RESULTS: One hundred fifty-four consecutive lesions (41 malignant, 113 benign) in 125 women (age range, 27-86 years; mean age, 52 years) were evaluated. The presence of threshold enhancement at computer-aided evaluation was sensitive for malignancy, with 38 of 41 (93%) malignant lesions demonstrating enhancement at both the 50% and 100% thresholds. Absence of threshold enhancement at computer-aided evaluation helped improve the discrimination between benign and malignant lesions when compared with that at initial interpretation by the radiologists. False-positive rates were reduced by 8.8% at the 50% enhancement threshold (not significant) and by 23.0% at the 100% enhancement threshold (P=.02) when compared with that at initial interpretation. Analyses of initial peak enhancement values and enhancement profiles did not demonstrate further improvements in lesion discrimination. CONCLUSION: The use of computer-aided evaluation for breast MR imaging significantly helped improve the discrimination of benign from malignant lesions when compared with that at initial interpretations by radiologists.

Jacuzzi jet-induced pneumoperitoneum.

Pneumoperitoneum outside the setting of recent surgical intervention usually indicates perforation of the gastrointestinal tract. Following radiologic evidence of pneumoperitoneum, surgical exploration of the abdomen may be indicated depending on the nature of the patient's presentation. We present the radiological findings of a healthy young woman who presented with acute onset of abdominal pain and was found to have extensive pneumoperitoneum. No visceral disruption was evident by multidetector CT or by single-contrast barium fluoroscopic evaluation of the upper gastrointestinal tract. Knowledge of benign causes of pneumoperitoneum by the radiologist may avert an unnecessary laparotomy.