Blocking LOXL2 and TGFß1 signalling induces collagen I turnover in precision-cut lung slices derived from patients with idiopathic pulmonary fibrosis.

We recently identified epigallocatechin gallate (EGCG), a trihydroxyphenolic compound, as a dual inhibitor of lysyl oxidase-like2 and transforming growth factor-ß1 (TGFß1) receptor kinase that when given orally to patients with idiopathic pulmonary fibrosis (IPF) reversed profibrotic biomarkers in their diagnostic biopsies. Here, we extend these findings to advanced pulmonary fibrosis using cultured precision-cut lung slices from explants of patients with IPF undergoing transplantation. During these experiments, we were surprised to discover that not only did EGCG attenuate TGFß1 signalling and new collagen accumulation but also activated matrix metalloproteinase-dependent collagen I turnover, raising the possibility of slow fibrosis resolution with continued treatment.

Developing a Process for Criteria-Led Discharge: Selection of Patients for Efficient and Effective Discharge (SPEED).

BACKGROUND: Criteria-led discharge (CLD) is an approach for maximizing bed capacity by expediting patient discharge. PROBLEM: In acute medicine settings, patients commonly have multiple medical problems, which render single care pathway and clinical protocols of limited use. CLD offers potential, but little evidence exists about how to best implement it in these contexts. APPROACH: Retrospective case note analysis generated characteristics from patients' discharge plans to design a criterion-based framework to aid patient selection for CLD. These criteria were hypothetically tested on patient case notes (n = 50). OUTCOMES: CLD was identified as suitable (n = 27) and unsuitable (n = 23) from 50 case notes. Interrater agreement was 86% between 3 reviewers. CONCLUSIONS: This review has provided greater understanding of the complexity of discharge in acute medicine settings. Implementing CLD to optimize timeliness of patient discharge might offer a solution for selected patients.

Barriers and Facilitators to Implementing Exercise is Medicine Canada on Campus Groups.

The Exercise is Medicine Canada on Campus (EIMC-OC) program was established in 2013 to provide opportunities for students to promote physical activity in their campus communities. Currently, 38 EIMC-OC groups are in operation, and each has encountered challenges and enablers that have yet to be formally documented. This project aimed to (1) identify barriers and facilitators when implementing an EIMC-OC group and (2) investigate levels of implementation at which the barriers and facilitators operate. Throughout winter 2016, 22 EIMC-OC group leaders representing 12 groups contributed data. Participants completed a survey and a semistructured interview developed using the Consolidated Framework for Implementation Research (CFIR). Interviews were transcribed and underwent thematic analysis. Eighteen barriers and 24 facilitators were identified, with four influencers cited as both a barrier and a facilitator. Common barriers included group member time constraints and communicating with health care professionals. Common facilitators included collaborating with other groups and advertising. Most influencers corresponded to the inner setting and process CFIR domains. Findings from this study suggest that EIMC-OC groups face similar barriers and facilitators despite varying local contexts. The influencers identified highlight recommendations to enhance the success of the EIMC-OC program and other multisite health initiatives at academic institutions.

Engaging frontline employees using innovation contests: Lessons from Massachusetts General Hospital.

In this article, we describe how innovation contests-a vehicle to crowdsource ideas and problem-solving efforts-propelled frontline employees to exert discretionary efforts in organizational problem-solving at Massachusetts General Hospital. As designers and administrators of four innovation contests in three disease centers, we share firsthand knowledge of how the contests enabled clinicians and administrative staff, whose primary job is delivering high-quality patient care, to become involved in ideation, selection, and implementation of their own ideas. We describe the processes that we designed and implemented, ideas that these processes generated, and findings from interviewing employees about their experiences afterwards. Our findings suggest that the benefits of implementing innovation contests were multifaceted. To employees, the contests provided a platform to voice suggestions and participate in any aspect of the innovation process that they found interesting. To managers, the contests revealed real, empirical issues affecting operation and patient care based on frontline employees' knowledge. To the organization as a whole, the contests promoted collaborative problem-solving among likeminded, innovative employees.

Reevaluating herpes simplex virus hemifusion.

Membrane fusion induced by enveloped viruses proceeds through the actions of viral fusion proteins. Once activated, viral fusion proteins undergo large protein conformational changes to execute membrane fusion. Fusion is thought to proceed through a "hemifusion" intermediate in which the outer membrane leaflets of target and viral membranes mix (lipid mixing) prior to fusion pore formation, enlargement, and completion of fusion. Herpes simplex virus type 1 (HSV-1) requires four glycoproteins-glycoprotein D (gD), glycoprotein B (gB), and a heterodimer of glycoprotein H and L (gH/gL)-to accomplish fusion. gD is primarily thought of as a receptor-binding protein and gB as a fusion protein. The role of gH/gL in fusion has remained enigmatic. Despite experimental evidence that gH/gL may be a fusion protein capable of inducing hemifusion in the absence of gB, the recently solved crystal structure of HSV-2 gH/gL has no structural homology to any known viral fusion protein. We found that in our hands, all HSV entry proteins-gD, gB, and gH/gL-were required to observe lipid mixing in both cell-cell- and virus-cell-based hemifusion assays. To verify that our hemifusion assay was capable of detecting hemifusion, we used glycosylphosphatidylinositol (GPI)-linked hemagglutinin (HA), a variant of the influenza virus fusion protein, HA, known to stall the fusion process before productive fusion pores are formed. Additionally, we found that a mutant carrying an insertion within the short gH cytoplasmic tail, 824L gH, is incapable of executing hemifusion despite normal cell surface expression. Collectively, our findings suggest that HSV gH/gL may not function as a fusion protein and that all HSV entry glycoproteins are required for both hemifusion and fusion. The previously described gH 824L mutation blocks gH/gL function prior to HSV-induced lipid mixing.

Insertion mutations in herpes simplex virus 1 glycoprotein H reduce cell surface expression, slow the rate of cell fusion, or abrogate functions in cell fusion and viral entry.

Of the four required herpes simplex virus (HSV) entry glycoproteins, the precise role of gH-gL in fusion remains the most elusive. The heterodimer gH-gL has been proposed to mediate hemifusion after the interaction of another required glycoprotein, gD, with a receptor. To identify functional domains of HSV-1 gH, we generated 22 randomized linker-insertion mutants. Analyses of 22 gH mutants revealed that gH is relatively tolerant of insertion mutations, as 15 of 22 mutants permitted normal processing and transport of gH-gL to the cell surface. gH mutants that were not expressed well at the cell surface did not function in fusion or viral entry. The screening of gH mutants for function revealed the following: (i) for wild-type gH and some gH mutants, fusion with nectin-1-expressing target cells occurred more rapidly than with herpesvirus entry mediator (HVEM)-expressing target cells; (ii) some gH mutants reduced the rate of cell fusion without abrogating fusion completely, indicating that gH may play a role in governing the kinetics of fusion and may be responsible for a rate-limiting first stage in HSV-1 fusion; and (iii) only one gH mutant, located within the short cytoplasmic tail, completely abrogated function, indicating that the gH cytoplasmic tail is crucial for cell fusion and viral infectivity.

Distinct Airway Epithelial Stem Cells Hide among Club Cells but Mobilize to Promote Alveolar Regeneration.

Lung injury activates specialized adult epithelial progenitors to regenerate the epithelium. Depending on the extent of injury, both remaining alveolar type II cells (AEC2s) and distal airway stem/progenitors mobilize to cover denuded alveoli and restore normal barriers. The major source of airway stem/progenitors other than basal-like cells remains uncertain. Here, we define a distinct subpopulation (∼5%) of club-like lineage-negative epithelial progenitors (LNEPs) marked by high H2-K1 expression critical for alveolar repair. Quiescent H2-K1high cells account for virtually all in vitro regenerative activity of airway lineages. After bleomycin injury, H2-K1 cells expand and differentiate in vivo to alveolar lineages. However, injured H2-K1 cells eventually develop impaired self-renewal with features of senescence, limiting complete repair. Normal H2-K1high cells transplanted into injured lungs differentiate into alveolar cells and rescue lung function. These findings indicate that small subpopulations of specialized stem/progenitors are required for effective lung regeneration and are a potential therapeutic adjunct after major lung injury.

Antigen-responsive CD4+ T cell clones contribute to the HIV-1 latent reservoir.

Antiretroviral therapy suppresses but does not cure HIV-1 infection due to the existence of a long-lived reservoir of latently infected cells. The reservoir has an estimated half-life of 44 mo and is largely composed of clones of infected CD4+ T cells. The long half-life appears to result in part from expansion and contraction of infected CD4+ T cell clones. However, the mechanisms that govern this process are poorly understood. To determine whether the clones might result from and be maintained by exposure to antigen, we measured responses of reservoir cells to a small subset of antigens from viruses that produce chronic or recurrent infections. Despite the limited panel of test antigens, clones of antigen-responsive CD4+ T cells containing defective or intact latent proviruses were found in seven of eight individuals studied. Thus, chronic or repeated exposure to antigen may contribute to the longevity of the HIV-1 reservoir by stimulating the clonal expansion of latently infected CD4+ T cells.

Fostering quality experiences: Qualitative perspectives from program members and providers in a community-based exercise program for adults with physical disabilities.

BACKGROUND: Opportunities to be physically active within one's community need to be available and accessible to individuals with physical disabilities in order to increase participation; however, what constitutes quality participation within these opportunities and how exercise programs can foster quality experiences for this population have yet to be explored. OBJECTIVES: (1) To explore the participation experiences of adults with physical disabilities in a community-based exercise program from two perspectives; (2) To establish whether the participants' experiences could be understood through an existing quality participation framework. METHODS: Participants were thirteen members and ten providers (i.e., coordinators, trainers, and supervisors) recruited from a community-based exercise program for adults with physical disabilities. Six focus groups (three with program members and three with each distinct group of program providers) were carried out, audio recorded and transcribed. Following an initial inductive thematic analysis, themes were deductively mapped to Martin Ginis and colleagues' (2017) conceptualization of the experiential aspects of participation. RESULTS: Six themes (autonomy, belongingness, challenge, engagement, mastery and meaning) important for experiencing quality participation were identified and were in line with Martin Ginis and colleagues' (2017) framework. CONCLUSION: Findings support the use of Martin Ginis and colleagues' (2017) conceptualization of quality participation within the context of community-based exercise programs for adults with physical disabilities. Practitioners and researchers can use the findings as a starting point for designing, implementing and evaluating programs with the goal of optimizing quality participation.

Secretion of leukotrienes by senescent lung fibroblasts promotes pulmonary fibrosis.

Accumulation of senescent cells is associated with the progression of pulmonary fibrosis, but mechanisms accounting for this linkage are not well understood. To explore this issue, we investigated whether a class of biologically active profibrotic lipids, the leukotrienes (LT), is part of the senescence-associated secretory phenotype. The analysis of conditioned medium (CM), lipid extracts, and gene expression of LT biosynthesis enzymes revealed that senescent cells secreted LT, regardless of the origin of the cells or the modality of senescence induction. The synthesis of LT was biphasic and followed by antifibrotic prostaglandin (PG) secretion. The LT-rich CM of senescent lung fibroblasts (IMR-90) induced profibrotic signaling in naive fibroblasts, which were abrogated by inhibitors of ALOX5, the principal enzyme in LT biosynthesis. The bleomycin-induced expression of genes encoding LT and PG synthases, level of cysteinyl LT in the bronchoalveolar lavage, and overall fibrosis were reduced upon senescent cell removal either in a genetic mouse model or after senolytic treatment. Quantification of ALOX5+ cells in lung explants obtained from idiopathic pulmonary fibrosis (IPF) patients indicated that half of these cells were also senescent (p16Ink4a+). Unlike human fibroblasts from unused donor lungs made senescent by irradiation, senescent IPF fibroblasts secreted LTs but failed to synthesize PGs. This study demonstrates for the first time to our knowledge that senescent cells secrete functional LTs, significantly contributing to the LT pool known to cause or exacerbate IPF.

Sensitivity, specificity, and reliability of the Get Active Questionnaire for identifying children with medically necessary special considerations for physical activity.

Physical activity is promoted for optimal health but may carry risks for children who require medically necessary activity restrictions. The sensitivity, specificity, and reliability of the Get Active Questionnaire (GAQ) for identifying children needing special considerations during physical activity was evaluated among parents of 207 children aged 3 to 14 years (97 (47%) female, mean age of 8.4 ± 3.7 years). GAQ responses were compared with reports obtained directly from the treating physician (n = 192/207) and information in the medical chart (clinic notes/physician letter, n = 111/207). Parent GAQ responses (either "No to all questions" or "Yes to 1 or more questions") agreed with physician (κ = 0.16, p = 0.003) and medical record (κ = 0.15, p = 0.003) reports regarding the need for special consideration during physical activity (Yes/No). Sensitivity was 71% (20/28) and specificity was 59% (96/164), with few false-negative responses. The GAQ was most effective for rheumatology and cardiology patients. False positives were 29% to 46%, except among chronic pain (80%) and rehabilitation (75%) patients. Test-retest reliability was moderate (Cronbach's α = 0.70) among 57 parents who repeated the GAQ 1 week later. The GAQ effectively identified children not requiring physical activity restrictions and those with medical conditions similar to those of concern among adults. Additional questions from a qualified exercise professional, as recommended for a "Yes" response on the GAQ, should reduce the false-positive burden. Indicating the timeframe of reference for each question and including an option to describe other special considerations (e.g., medication, supervision) are recommended.

Hereditary non-polyposis colon cancer: change the name to protect the innocent.

Hereditary non-polyposis colon cancer is a common form of colorectal cancer, accounting for 5%-10% of all colorectal cancers. This cancer is inherited in an autosomal dominant fashion, occurring as early as age 25, with an average age of 45 at diagnosis. Nurses are an integral part of educating patients and families with a history of colon and uterine cancer.

Fibroblast-specific inhibition of TGF-ß1 signaling attenuates lung and tumor fibrosis.

TGF-ß1 signaling is a critical driver of collagen accumulation and fibrotic disease but also a vital suppressor of inflammation and epithelial cell proliferation. The nature of this multifunctional cytokine has limited the development of global TGF-ß1 signaling inhibitors as therapeutic agents. We conducted phenotypic screens for small molecules that inhibit TGF-ß1-induced epithelial-mesenchymal transition without immediate TGF-ß1 receptor (TßR) kinase inhibition. We identified trihydroxyphenolic compounds as potent blockers of TGF-ß1 responses (IC50 ~50 nM), Snail1 expression, and collagen deposition in vivo in models of pulmonary fibrosis and collagen-dependent lung cancer metastasis. Remarkably, the functional effects of trihydroxyphenolics required the presence of active lysyl oxidase-like 2 (LOXL2), thereby limiting effects to fibroblasts or cancer cells, the major LOXL2 producers. Mechanistic studies revealed that trihydroxyphenolics induce auto-oxidation of a LOXL2/3-specific lysine (K731) in a time-dependent reaction that irreversibly inhibits LOXL2 and converts the trihydrophenolic to a previously undescribed metabolite that directly inhibits TßRI kinase. Combined inhibition of LOXL2 and TßRI activities by trihydrophenolics resulted in potent blockade of pathological collagen accumulation in vivo without the toxicities associated with global inhibitors. These findings elucidate a therapeutic approach to attenuate fibrosis and the disease-promoting effects of tissue stiffness by specifically targeting TßRI kinase in LOXL2-expressing cells.

Local lung hypoxia determines epithelial fate decisions during alveolar regeneration.

After influenza infection, lineage-negative epithelial progenitors (LNEPs) exhibit a binary response to reconstitute epithelial barriers: activating a Notch-dependent ΔNp63/cytokeratin 5 (Krt5) remodelling program or differentiating into alveolar type II cells (AEC2s). Here we show that local lung hypoxia, through hypoxia-inducible factor (HIF1α), drives Notch signalling and Krt5pos basal-like cell expansion. Single-cell transcriptional profiling of human AEC2s from fibrotic lungs revealed a hypoxic subpopulation with activated Notch, suppressed surfactant protein C (SPC), and transdifferentiation toward a Krt5pos basal-like state. Activated murine Krt5pos LNEPs and diseased human AEC2s upregulate strikingly similar core pathways underlying migration and squamous metaplasia. While robust, HIF1α-driven metaplasia is ultimately inferior to AEC2 reconstitution in restoring normal lung function. HIF1α deletion or enhanced Wnt/ß-catenin activity in Sox2pos LNEPs blocks Notch and Krt5 activation, instead promoting rapid AEC2 differentiation and migration and improving the quality of alveolar repair.

Hepatitis B & hepatitis C in HIV-infection.

Human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) are the three most common chronic viral infections seen in the world. All three viruses share modes of transmission and hence co-exist in the same host at significantly high rates. HIV-induced immunosuppression has deleterious effects on the natural history, pathophysiology, diagnosis, therapeutic responses to hepatitis viruses. Responses to HBV vaccination are impaired in persons with HIV infection. Co-infection with the hepatitis viruses and HIV is likely to become a major health care catastrophe in the coming years. This review discusses the current trends in the understanding of the biology of co-infection and implications for treating these viruses effectively.

Fusing structure and function: a structural view of the herpesvirus entry machinery.

Herpesviruses are double-stranded DNA, enveloped viruses that infect host cells through fusion with either the host cell plasma membrane or endocytic vesicle membranes. Efficient infection of host cells by herpesviruses is remarkably more complex than infection by other viruses, as it requires the concerted effort of multiple glycoproteins and involves multiple host receptors. The structures of the major viral glycoproteins and a number of host receptors involved in the entry of the prototypical herpesviruses, the herpes simplex viruses (HSVs) and Epstein-Barr virus (EBV), are now known. These structural studies have accelerated our understanding of HSV and EBV binding and fusion by revealing the conformational changes that occur on virus-receptor binding, depicting potential sites of functional protein and lipid interactions, and identifying the probable viral fusogen.

Pseudo-outbreak of Clostridium sordellii infection following probable cross-contamination in a hospital clinical microbiology laboratory.

We report a pseudo-outbreak of infection caused by Clostridium sordellii, an uncommon human pathogen. The pseudo-outbreak involved 6 patients and was temporally associated with a change by the clinical microbiology laboratory in the protocol of handling anaerobic culture specimens. All isolates were genetically indistinguishable from a laboratory reference strain used for quality control.

Vapreotide: a somatostatin analog for the treatment of acute variceal bleeding.

BACKGROUND: Portal hypertension is a clinically important consequence of cirrhosis that can lead to morbidities such as variceal bleeding, hepatic encephalopathy and ascites. All of these outcomes carry high mortality rates. There have been several drugs created to assist with endoscopic therapy for the treatment of acute variceal bleeding. Recently, vapreotide has been studied in patients to evaluate its efficacy as treatment for acute variceal hemorrhage. Although no comparisons have been made between vapreotide and other somatostatin analogues, this drug has been shown to have efficacy in the control of acute variceal bleeding as well as reducing the risk of recurrent bleeding and death, especially when started prior to endoscopy. OBJECTIVE: This paper reviews the literature regarding the basic science and clinical efficacy of vapreotide in acute variceal bleeding. METHODS: We used a PubMed/Medline search in order to review the literature regarding the drug, vapreotide. RESULTS/CONCLUSIONS: Vapreotide appears to have benefit in the control of acute variceal bleeding. It is easy to administer and has few side effects, which are minor. These findings endorse the need for future trials to evaluate vapreotide and its use in acute variceal hemorrhage, a morbidity among patients with cirrhosis.

Innate immunity in HIV infection: enhanced susceptibility to CD95-mediated natural killer cell death and turnover induced by HIV viremia.

In the present study, we performed DNA microarray analyses and phenotypic and functional analyses in an effort to elucidate the mechanisms by which ongoing HIV replication affects the physiologic function of natural killer (NK) cells. Functional assays confirmed an increased propensity of NK cells from HIV-infected viremic individuals to undergo Fas-mediated apoptosis but not CD16- or NKG2D-mediated apoptosis. Serum levels of sFasL and expression of Ki67 on NK cells were markedly elevated in HIV-infected viremic individuals when compared with those of HIV-infected aviremic and HIV-seronegative individuals. Our data demonstrate that ongoing HIV replication results in profound NK-cell abnormalities that are likely to be attributable to the effects of virus-induced immune activation. Of note is an increased susceptibility to cell death mediated by CD95-sFasL interactions. In addition, these NK cells, particularly the CD56(dim) CD16(bright) subset, undergo enhanced cell turnover in vivo, as demonstrated by intracellular Ki67 expression.

Innate immune dysfunction in HIV infection: effect of HIV envelope-NK cell interactions.

We have previously described a number of NK cell dysfunctions in HIV-viremic individuals. In the present study, we performed DNA microarray analysis followed by phenotypic and functional characterization in an effort to investigate which HIV envelope glycoproteins (gp120) affect the physiologic functions of NK cells. Upon treatment of NK cells with HIV gp120, DNA microarray analyses indicated up-regulation of several categories of genes that are associated with apoptosis, suppression of both cellular proliferation and survival, as well as down-regulation of genes that play a vital role in cell proliferation, innate immune defense mechanism, and cell survival. Both subtypes of gp120 suppressed NK cell cytotoxicity, proliferation, and the ability to secrete IFN-gamma. NK cells exposed to X4-subtype HIV gp120 showed a significant decrease in the levels of CC chemokines, while exposure to R5-subtype HIV gp120 had minimal effect. Extended exposure to HIV gp120 resulted in apoptosis of NK cells, further validating the microarray data. Our data demonstrate that exposure of NK cells to HIV envelope proteins results in profound cellular abnormalities at the level of gene expression as well as generic cell functions. These findings are likely to be a consequence of a direct HIV gp120-mediated effect on NK cells. Identification of specific surface receptors on NK cells that interact with HIV envelope proteins might explain how HIV is capable of circumventing innate immune defense mechanisms and establishing infection in susceptible individuals.