Single-Walled Carbon Nanotube (SWCNT)-induced interstitial fibrosis in the lungs of rats is associated with increased levels of PDGF mRNA and the formation of unique intercellular carbon structures that bridge alveolar macrophages In Situ

BACKGROUND: Nanotechnology is a rapidly advancing industry with many new products already available to the public. Therefore, it is essential to gain an understanding of the possible health risks associated with exposure to nanomaterials and to identify biomarkers of exposure. In this study, we investigated the fibrogenic potential of SWCNT synthesized by chemical vapor deposition using cobalt (Co) and molybdenum (Mo) as catalysts. Following a single oropharyngeal aspiration of SWCNT in rats, we evaluated lung histopathology, cell proliferation, and growth factor mRNAs at 1 and 21 days post-exposure. Comparisons were made to vehicle alone (saline containing a biocompatible nonionic surfactant), inert carbon black (CB) nanoparticles, or vanadium pentoxide (V(2)O(5)) as a known inducer of fibrosis. RESULTS: SWCNT or CB caused no overt inflammatory response at 1 or 21 days post-exposure as determined by histopathology and evaluation of cells (>95% macrophages) in bronchoalveolar lavage (BAL) fluid. However, SWCNT induced the formation of small, focal interstitial fibrotic lesions within the alveolar region of the lung at 21 days. A small fraction of alveolar macrophages harvested by BAL from the lungs of SWCNT-exposed rats at 21 days were bridged by unique intercellular carbon structures that extended into the cytoplasm of each macrophage. These "carbon bridge" structures between macrophages were also observed in situ in the lungs of SWCNT-exposed rats. No carbon bridges were observed in CB-exposed rats. SWCNT caused cell proliferation only at sites of fibrotic lesion formation as measured by bromodeoxyuridine uptake into alveolar cells. SWCNT increased platelet-derived growth factor (PDGF)-A, PDGF-B, and PDGF-C mRNA levels significantly at 1 day as measured by Taqman quantitative real-time RT-PCR. At 21 days, SWCNT did not increase any mRNAs evaluated, while V(2)O(5 )significantly increased mRNAs encoding PDGF-A, -B, and -C chains, PDGF-Rα, osteopontin (OPN), connective tissue growth factor (CTGF), and transforming growth factor (TGF)-β1. CONCLUSION: Our findings indicate that SWCNT do not cause lung inflammation and yet induce the formation of small, focal interstital fibrotic lesioins in the alveolar region of the lungs of rats. Of greatest interest was the discovery of unique intercellular carbon structures composed of SWCNT that bridged lung macrophages. These "carbon bridges" offer a novel and easily identifiable biomarker of exposure

Respiratory syncytial virus infection reduces lung inflammation and fibrosis in mice exposed to vanadium pentoxide

<p>Abstract</p> <p>Background</p> <p>Vanadium pentoxide (V₂O₅) exposure is a cause of occupational bronchitis and airway fibrosis. Respiratory syncytial virus (RSV) is a ubiquitous pathogen that causes airway inflammation. It is unknown whether individuals with pre-existing respiratory viral infection are susceptible to V₂O₅-induced bronchitis. We hypothesized that respiratory viral infection will exacerbate vanadium-induced lung fibrosis.</p> <p>Methods</p> <p>In this study we investigated the effect of RSV pre- or post-exposure to V₂O₅in male AKR mice. Mice were pre-exposed by intranasal aspiration to RSV or media vehicle prior to intranasal aspiration of V₂O₅or saline vehicle at day 1 or day 7. A parallel group of mice were treated first with V₂O₅or saline vehicle at day 1 and day 7 then post-exposed to RSV or media vehicle at day 8.</p> <p>Results</p> <p>V₂O₅-induced airway inflammation and fibrosis were decreased by RSV pre- or post-exposure. Real time quantitative RT-PCR showed that V₂O₅significantly increased lung mRNAs encoding pro-fibrogenic growth factors (TGF-β1, CTGF, PDGF-C) and collagen (Col1A2), but also increased mRNAs encoding anti-fibrogenic type I interferons (IFN-α, -β) and IFN-inducible chemokines (CXCL9 and CXCL10). RSV pre- or post-exposure caused a significantly reduced mRNAs of pro-fibrogenic growth factors and collagen, yet reduced RNA levels of anti-fibrogenic interferons and CXC chemokines.</p> <p>Conclusions</p> <p>Collectively these data suggest that RSV infection reduces the severity of V₂O₅-induced fibrosis by suppressing growth factors and collagen genes. However, RSV suppression of V₂O₅-induced IFNs and IFN-inducible chemokines suggests that viral infection also suppresses the innate immune response that normally serves to resolve V₂O₅-induced fibrosis.</p

Evaluation of immunoglobulin purification methods and their impact on quality and yield of antigen-specific antibodies

<p>Abstract</p> <p>Background</p> <p>Antibodies are the main effectors against malaria blood-stage parasites. Evaluation of functional activities in immune sera from Phase 2a/b vaccine trials may provide invaluable information in the search for immune correlates of protection. However, the presence of anti-malarial-drugs, improper collection/storage conditions or concomitant immune responses against other pathogens can contribute to non-specific anti-parasite activities when the sera/plasma are tested <it>in vitro</it>. Purification of immunoglobulin is a standard approach for reducing such non-specific background activities, but the purification method itself can alter the quality and yield of recovered Ag-specific antibodies.</p> <p>Methods</p> <p>To address this concern, various immunoglobulin (Ig) purification methods (protein G Sepharose, protein A/G Sepharose, polyethylene glycol and caprylic acid-ammonium sulphate precipitation) were evaluated for their impact on the quality, quantity and functional activity of purified rabbit and human Igs. The recovered Igs were analysed for yield and purity by SDS-PAGE, for quality by Ag-specific ELISAs (determining changes in titer, avidity and isotype distribution) and for functional activity by <it>in vitro </it>parasite growth inhibition assay (GIA).</p> <p>Results</p> <p>This comparison demonstrated that overall polyethylene glycol purification of human serum/plasma samples and protein G Sepharose purification of rabbit sera are optimal for recovering functional Ag-specific antibodies.</p> <p>Conclusion</p> <p>Consequently, critical consideration of the purification method is required to avoid selecting non-representative populations of recovered Ig, which could influence interpretations of vaccine efficacy, or affect the search for immune correlates of protection.</p

Development and Evaluation of a Blocking Enzyme-Linked Immunosorbent Assay for Detection of Avian Metapneumovirus Type C-Specific Antibodies in Multiple Domestic Avian Species

The first cases of infection caused by avian metapneumoviruses (aMPVs) were described in turkeys with respiratory disease in South Africa during 1978. The causative agent was isolated and identified as a pneumovirus in 1986. aMPVs have been detected in domestic nonpoultry species in Europe, but tests for the detection of these viruses are not available in the United States. To begin to understand the potential role of domestic ducks and geese and wild waterfowl in the epidemiology of aMPV, we have developed and evaluated a blocking enzyme-linked immunosorbent assay (bELISA) for the detection of aMPV type C (aMPV-C)-specific antibodies. This assay method overcomes the species-specific platform of indirect ELISAs to allow detection of aMPV-C-specific antibodies from potentially any avian species. The bELISA was initially tested with experimental turkey serum samples, and the results were found to correlate with those of virus neutralization assays and indirect enzyme-linked immunosorbent assay (iELISA). One thousand serum samples from turkey flocks in Minnesota were evaluated by our bELISA, and the level of agreement of the results of the bELISA and those of the iELISA was 94.9%. In addition, we were able to show that the bELISA could detect aMPV-C-specific antibodies from experimentally infected ducks, indicating its usefulness for the screening of serum samples from multiple avian species. This is the first diagnostic assay for the detection of aMPV-C-specific antibodies from multiple avian species in the United States

Understanding the Intersection of Young Age, Mucosal Injury, and HIV Susceptibility

Adolescent boys and girls are disproportionately affected in the current HIV epidemic. Numerous sociobehavioral studies have addressed the indirect drivers surrounding this vulnerability-for example, socioeconomic, geographical locale, and all forms of violence. However, the direct factors that may influence infection, such as the anatomical and physiological maturation of the anogenital tracts of adolescents or the trauma and wound-healing processes of injured mucosal tissue, are understudied and represent a gap within the HIV prevention field. This article reviews the epidemiology of HIV infection and violence in adolescents and the available basic science knowledge attending this research area. More importantly, this review highlights the most critical gaps that need to be addressed to design preventive interventions that are safe and effective for this population, which is key to ending the HIV pandemic

Care recipient self-perceived burden: Perspectives of individuals with chronic health conditions or personal experiences with caregiving on caregiver burden in the US

Introduction: Self-perceived burden refers to the perceived impact of a care recipients’ illness and care needs on their caregiver(s). This study aimed to: 1) examine the components of caregiver burden from a perspective of people with chronic health conditions, 2) explore the extent to which people consider caregiver burden important in their healthcare decision-making, and 3) develop a global item to capture the essential elements of self-perceived burden. Methods: Semi-structured interviews using cognitive debriefing were conducted with US-based individuals with chronic conditions, informal caregivers and social care users between October and December 2018. Components of caregiver burden were organized within a concept analysis framework. The preferred wording for a global self-perceived burden item was explored for face and content validity using five candidate items. Interviews were transcribed verbatim and analyzed using thematic analysis. Results: Total of 19 participants, aged 23–76, completed the interviews. Study identified three main antecedents of caregiver burden: caregiving situation, financial resources, and sociocultural environment. Attributes included physical, emotional, financial, and social aspects. Consequences were financial hardship and decreased health-related quality of life. Most participants distinguished “burden” from related concepts such as “bother” and “stress”. “I feel like a burden to my family/friends” with a severity response option scale, was perceived to broadly encompass the construct. Conclusion: Self-perceived burden was identified as a highly relevant concept in healthcare decision-making for US participants. A global self-perceived burden item can provide a valuable summary measure to inform medical decision-making and potentially capture spillover effects of patient care on family and caregivers