In Vivo Tissue Distribution of Polystyrene or Mixed Polymer Microspheres and Metabolomic Analysis after Oral Exposure in Mice

BACKGROUND

Global plastic use has consistently increased over the past century with several different types of plastics now being produced. Much of these plastics end up in oceans or landfills leading to a substantial accumulation of plastics in the environment. Plastic debris slowly degrades into microplastics (MPs) that can ultimately be inhaled or ingested by both animals and humans. A growing body of evidence indicates that MPs can cross the gut barrier and enter into the lymphatic and systemic circulation leading to accumulation in tissues such as the lungs, liver, kidney, and brain. The impacts of mixed MPs exposure on tissue function through metabolism remains largely unexplored.

OBJECTIVES

This study aims to investigate the impacts of polymer microspheres on tissue metabolism in mice by assessing the microspheres ability to translocate across the gut barrier and enter into systemic circulation. Specifically, we wanted to examine microsphere accumulation in different organ systems, identify concentration-dependent metabolic changes, and evaluate the effects of mixed microsphere exposures on health outcomes.

METHODS

To investigate the impact of ingested microspheres on target metabolic pathways, mice were exposed to either polystyrene (5 μ m ) microspheres or a mixture of polymer microspheres consisting of polystyrene (5 μ m ), polyethylene (1 - 4 μ m ), and the biodegradability and biocompatible plastic, poly-(lactic-co-glycolic acid) (5 μ m ). Exposures were performed twice a week for 4 weeks at a concentration of either 0, 2, or 4 mg / week via oral gastric gavage. Tissues were collected to examine microsphere ingress and changes in metabolites.

RESULTS

In mice that ingested microspheres, we detected polystyrene microspheres in distant tissues including the brain, liver, and kidney. Additionally, we report on the metabolic differences that occurred in the colon, liver, and brain, which showed differential responses that were dependent on concentration and type of microsphere exposure.

DISCUSSION

This study uses a mouse model to provide critical insight into the potential health implications of the pervasive issue of plastic pollution. These findings demonstrate that orally consumed polystyrene or mixed polymer microspheres can accumulate in tissues such as the brain, liver, and kidney. Furthermore, this study highlights concentration-dependent and polymer type-specific metabolic changes in the colon, liver, and brain after plastic microsphere exposure. These results underline the mobility within and between biological tissues of MPs after exposure and emphasize the importance of understanding their metabolic impact. https://doi.org/10.1289/EHP13435.

Characterization of Mild Delayed Gestational Hypertension in Rats Following Ozone Exposure

The contribution of air pollution induced cardio-pulmonary damage on the development of hypertensive disorders of pregnancy and other adverse outcomes of pregnancy has gained increased attention as epidemiological data continues to highlight spatiotemporal pregnancy trends related to air pollution exposure. However clinical mechanistic data surrounding gestational complications remains sparse, necessitating the need for the use of animal models to study these types of complications of pregnancy. The current study seeks to examine the real-time effects of mid-gestational ozone exposure on maternal blood pressure and body temperature through the use of radiotelemetry in a rat model. The exposure resulted in acute depression of heart rate and core body temperature as compared to control animals. Ozone exposed animals also presented with a slight but significant increase in arterial blood pressure which was perpetuated until term. The data presented here illustrates the feasibility of murine models to assess cardiovascular complications caused by inhaled toxicants during the window of pregnancy.

A comparison of chest radiographic findings in human immunodeficiency virus-positive and -negative children with pulmonary tuberculosis

AIM

To compare chest radiography (CXR) findings in human immunodeficiency virus (HIV)-positive and HIV-negative children who had microbiologically confirmed pulmonary tuberculosis (PTB).

MATERIALS AND METHODS

Retrospective analysis of CXRs from children with known HIV status and microbiologically confirmed PTB (culture or GeneXpert Xpert MTB/RIF positive), who were hospitalised or seen at a primary healthcare centre over a 5-year period. Radiological findings were compared according to HIV and nutritional status.

RESULTS

CXRs of 130 children were analysed from 35 (27%) HIV- positive and 95 (73%) HIV-negative children with confirmed PTB, median age 45.7 months (interquartile range [IQR] 18-81.3 months). CXR changes consistent with PTB were reported in 21/35 (60%) of HIV-positive and 59/95 (62%) of HIV-negative patients, (p=0.81). Normal CXR was identified in 3/35 (8.6%) of HIV-positive and 5/95 (5.3%) of HIV-negative patients (p=0.81). Airway compression was present in 3/35 (8.6%) of HIV-positive and 7/95 (7.4%) of HIV-negative patients (p>0.99). Overall, lymphadenopathy was identified in 42/130 (32.3%) of patients, 11/35 (31.4 %) were HIV-positive compared with 31/95 (32.6%) HIV-negative patients. Airspace consolidation was present in 60% of both HIV-positive (21/35) and HIV-negative patients (57/95). Pleural effusion was present in 2/35 (5.7 %) of HIV-negative and 9/95 (9.5 %) of HIV-negative patients. There were no statistically significant radiological differences by HIV group.

CONCLUSION

There were no significant differences in the CXR findings between the HIV-positive and HIV-negative children with confirmed PTB.

Gestational ozone inhalation elicits maternal cardiac dysfunction and transcriptional changes to placental pericytes and endothelial cells

Ozone (O3) is a criteria air pollutant with the most frequent incidence of exceeding air quality standards. Inhalation of O3 is known to cause lung inflammation and consequent systemic health effects, including endothelial dysfunction. Epidemiologic data have shown that gestational exposure to air pollutants correlates with complications of pregnancy, including low birth weight, intrauterine growth deficiency, preeclampsia, and premature birth. Mechanisms underlying how air pollution may facilitate or exacerbate gestational complications remain poorly defined. The current study sought to uncover how gestational O3 exposure impacted maternal cardiovascular function, as well as the development of the placenta. Pregnant mice were exposed to 1PPM O3 or a sham filtered air (FA) exposure for 4 h on gestational day (GD) 10.5, and evaluated for cardiac function via echocardiography on GD18.5. Echocardiography revealed a significant reduction in maternal stroke volume and ejection fraction in maternally exposed dams. To examine the impact of maternal O3 exposure on the maternal-fetal interface, placentae were analyzed by single-cell RNA sequencing analysis. Mid-gestational O3 exposure led to significant differential expression of 4021 transcripts compared with controls, and pericytes displayed the greatest transcriptional modulation. Pathway analysis identified extracellular matrix organization to be significantly altered after the exposure, with the greatest modifications in trophoblasts, pericytes, and endothelial cells. This study provides insights into potential molecular processes during pregnancy that may be altered due to the inhalation of environmental toxicants.

Comparison of single coronal thick-slab minimum intensity projection with flexible bronchoscopy for airway compression in children with lymphobronchial tuberculosis

AIM

To generate standardised coronal minimum intensity projection (MinIP) computed tomography (CT) reconstructions, and compare these with flexible bronchoscopy in children with lymphobronchial tuberculosis (LBTB).

MATERIALS AND METHODS

Standardised coronal MinIP reconstructions were performed from CT images in children with LBTB and the findings of three readers were compared with the reference standard, flexible bronchoscopy (FB), regarding airway narrowing. Intraluminal lesions, the site of the stenosis, and the degree of stenosis were also evaluated. The length of stenosis was evaluated by CT MinIP only.

RESULTS

Sixty-five children (38 males; 58.5% and 27 females; 41.5%), with ages ranging from 2.5 to 144 months were evaluated. Coronal CT MinIP demonstrated a sensitivity of 96% and specificity of 89% against FB. The most common site of stenosis was the bronchus intermedius (91%), followed by the left main bronchus (85%), the right upper lobe bronchus RUL (66%), and the trachea (60%).

CONCLUSION

Coronal CT MinIP reconstruction is useful in demonstrating airway stenosis in children with lymphobronchial TB, with high sensitivity and specificity. CT MinIP had additional advantages over FB in that it allowed objective measurement of the diameter of stenosis, measurement of the length of stenosis, and evaluation of post-stenotic segments of the airways and lung parenchymal abnormalities.

In Vivo Tissue Distribution of Microplastics and Systemic Metabolomic Alterations After Gastrointestinal Exposure

Global plastic use has consistently increased over the past century with several different types of plastics now being produced. Much of these plastics end up in oceans or landfills leading to a substantial accumulation of plastics in the environment. Plastic debris slowly degrades into microplastics (MPs) that can ultimately be inhaled or ingested by both animals and humans. A growing body of evidence indicates that MPs can cross the gut barrier and enter into the lymphatic and systemic circulation leading to accumulation in tissues such as the lungs, liver, kidney, and brain. The impacts of mixed MPs exposure on tissue function through metabolism remains largely unexplored. To investigate the impact of ingested MPs on target metabolomic pathways, mice were subjected to either polystyrene microspheres or a mixed plastics (5 µm) exposure consisting of polystyrene, polyethylene and the biodegradability and biocompatible plastic, poly-(lactic-co-glycolic acid). Exposures were performed twice a week for four weeks at a dose of either 0, 2, or 4 mg/week via oral gastric gavage. Our findings demonstrate that, in mice, ingested MPs can pass through the gut barrier, be translocated through the systemic circulation, and accumulate in distant tissues including the brain, liver, and kidney. Additionally, we report on the metabolomic changes that occur in the colon, liver and brain which show differential responses that are dependent on dose and type of MPs exposure. Lastly, our study provides proof of concept for identifying metabolomic alterations associated with MPs exposure and adds insight into the potential health risks that mixed MPs contamination may pose to humans.

Multi-omic assessment shows dysregulation of pulmonary and systemic immunity to e-cigarette exposure

Electronic cigarette (Ecig) use has become more common, gaining increasing acceptance as a safer alternative to tobacco smoking. However, the 2019 outbreak of Ecig and Vaping-Associated Lung Injury (EVALI) alerted the community to the potential for incorporation of deleterious ingredients such as vitamin E acetate into products without adequate safety testing. Understanding Ecig induced molecular changes in the lung and systemically can provide a path to safety assessment and protect consumers from unsafe formulations. While vitamin E acetate has been largely removed from commercial and illicit products, many Ecig products contain additives that remain largely uncharacterized. In this study, we determined the lung-specific effects as well as systemic immune effects in response to exposure to a common Ecig base, propylene glycol and vegetable glycerin (PGVG), with and without a 1% addition of phytol, a diterpene alcohol that has been found in commercial products. We exposed animals to PGVG with and without phytol and assessed metabolite, lipid, and transcriptional markers in the lung. We found both lung-specific as well as systemic effects in immune parameters, metabolites, and lipids. Phytol drove modest changes in lung function and increased splenic CD4 T cell populations. We also conducted multi-omic data integration to better understand early complex pulmonary responses, highlighting a central enhancement of acetylcholine responses and downregulation of palmitic acid connected with conventional flow cytometric assessments of lung, systemic inflammation, and pulmonary function. Our results demonstrate that Ecig exposure not only leads to changes in pulmonary function but also affects systemic immune and metabolic parameters.

Effect of E-cigarette use on lung immunity to influenza infection

Use of E-cigarettes, also called vaping, has been significantly increasing, with over 10 million adults and 3 million adolescents reported to actively vape. Of particular concern recently is the association of vaping with increased risk of respiratory infection, including influenza and COVID-19. Despite the claims of safety, lung immunological development appears to be impacted by vaping, with associated pulmonary toxicity and potential to impair immunity against respiratory infections.

Immunity against respiratory pathogens, particularly viral pathogens is dependent on a robust CD4 and CD8 T cell responses responsible for viral clearance. CD4 and CD8 T cells then develop memory responses to protect against reinfection. T cell memory also provides protection against infection after vaccination. We asked whether vaping exposure affects T cell responses to influenza infection. We exposed animals for 8 weeks to base components of vape devices, including propylene glycol (PG), vegetable glycerin (VG), and a novel cutting agent, phytol, then assessed immune responses to influenza. We find that PGVG and phytol exposure alters pulmonary function, promotes proteomic changes to the lung, and modify immune cell subsets in the lung. We also find that PGVG and phytol exposure alters T cell responses to influenza infection, particularly T cell memory protection against heterologous infection. These results suggest that vaping affects immune responses to respiratory influenza infection, including T cell memory responses. Effects of vaping on T cell memory may have wide ranging consequences for T cell mediated protection against other respiratory disease including SARS-CoV-2 and protection after vaccination.

Supported by NIH (P20 GM121176; P20GM130422)

Neuroinflammatory and Neurometabolomic Consequences From Inhaled Wildfire Smoke-Derived Particulate Matter in the Western United States

Utilizing a mobile laboratory located >300 km away from wildfire smoke (WFS) sources, this study examined the systemic immune response profile, with a focus on neuroinflammatory and neurometabolomic consequences, resulting from inhalation exposure to naturally occurring wildfires in California, Arizona, and Washington in 2020. After a 20-day (4 h/day) exposure period in a mobile laboratory stationed in New Mexico, WFS-derived particulate matter (WFPM) inhalation resulted in significant neuroinflammation while immune activity in the peripheral (lung, bone marrow) appeared to be resolved in C57BL/6 mice. Importantly, WFPM exposure increased cerebrovascular endothelial cell activation and expression of adhesion molecules (VCAM-1 and ICAM-1) in addition to increased glial activation and peripheral immune cell infiltration into the brain. Flow cytometry analysis revealed proinflammatory phenotypes of microglia and peripheral immune subsets in the brain of WFPM-exposed mice. Interestingly, endothelial cell neuroimmune activity was differentially associated with levels of PECAM-1 expression, suggesting that subsets of cerebrovascular endothelial cells were transitioning to resolution of inflammation following the 20-day exposure. Neurometabolites related to protection against aging, such as NAD+ and taurine, were decreased by WFPM exposure. Additionally, increased pathological amyloid-beta protein accumulation, a hallmark of neurodegeneration, was observed. Neuroinflammation, together with decreased levels of key neurometabolites, reflect a cluster of outcomes with important implications in priming inflammaging and aging-related neurodegenerative phenotypes.

Role of platelet GARP in TGFB activation

Introduction

Transforming growth factor (TGF)β is known to be a central player in the control of cardiac fibroblast properties and fibrosis. However, cellular and molecular mechanisms that trigger its activation remain poorly understood. Platelets are considered as a major source of TGFβ and recent evidence suggest that they are involved in TGFβ activation via Glycoprotein A Repetitions Predominant (GARP) present on their surface.

Purpose

The present study sought to evaluate the role of platelet GARP in TGFβ activation using platelet specific GARP knockout mice.

Methods

We generated a new Cre transgenic mouse strain that allowed Megakaryocyte/platelet specific invalidation of GARP (GpIba-Cre x GARPfl/fl). The impact of GARP deficiency on platelet function was measured in vitro by flow cytometry using thrombin and CRP. Serum production of total and active TGFβ was assessed by ELISA.

Results

Platelet count and other hematological parameters were normal in platelet specific GARP knockout mice, except platelet volume, which was increased by 10.3%, as compared to wild-type platelets. Stimulation by thrombin and CRP increased GARP exposure at platelet surface. However, platelets without GARP displayed normal agonist induced activation, as reflected by CD62P and αIIbβ3 exposure. Interestingly, the generation of active TGFβ was drastically impaired in the serum of platelet specific GARP knockout mice, while the amount of total TGFβ was not affected.

Conclusion

We provided evidence that platelet GARP is a crucial contributor to the systemic activation of TGFβ. Future work will aim to determine its role in cardiac fibroblast myodifferentiation and fibrosis.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): FRIA

An audit of patients clinically deemed as high risk for malignant breast pathology at the Helen Joseph Hospital Breast Clinic

BACKGROUND

The Helen Joseph Hospital Breast Clinic has implemented a clinical triage system for patients presenting with a variety of breast concerns. The goal of this system is to expedite the process from initial presentation to radiological assessment of patients with suspected breast malignancy or breast abscess in a resource limited setting. The objective was to assess the clinical, imaging and histological diagnoses of breast disease in these patients with malignancy and sepsis.

METHODS

A retrospective audit of patients clinically deemed high risk for malignant breast pathology referred to the breast imaging unit (BIU) in 2018. Patients were triaged based on strict clinical criteria: presence of a breast mass with or without lymph nodes or a breast abscess. Patients that were subsequently referred for mammography/ultrasound were identified using the patient files in the BIU. Results were recorded on Microsoft Excel and analysed using SAS version 9.2.

RESULTS

Three hundred and twenty-five patients were included in this study. Eighty-seven (26.8%) were diagnosed with breast cancer and 236 (72.6%) with benign disease. The most common presenting complaint was a palpable mass (n = 227; 69.9%). Ninety-five per cent of patients characterised as BI-RADS 5 had malignant disease. 55.8% of malignancies diagnosed on ultrasound had locally advanced disease. The most common histological diagnosis of malignancy was invasive ductal carcinoma (n = 67, 77%). The most commonly diagnosed benign disease was breast abscess (n = 42, 17.8%).

CONCLUSION

BI-RADS findings correspond to similar studies, however, a large number of benign breast disease was diagnosed. This may indicate heightened clinical awareness of breast cancer diagnosis and early detection. A significant percentage of malignancies presented as locally advanced. Except for a lower number of invasive lobular carcinoma, the histological spectrum of malignant disease is similar to comparative studies.

Early Gestational Exposure to Inhaled Ozone Impairs Maternal Uterine Artery and Cardiac Function

Exposure to air pollutants such as ozone (O3) is associated with adverse pregnancy outcomes, including higher incidence of gestational hypertension, preeclampsia, and peripartum cardiomyopathy; however, the underlying mechanisms of this association remain unclear. We hypothesized that O3 exposures during early placental formation would lead to more adverse cardiovascular effects at term for exposed dams, as compared with late-term exposures. Pregnant Sprague Dawley rats were exposed (4 h) to either filtered air (FA) or O3 (0.3 or 1.0 ppm) at either gestational day (GD)10 or GD20, with longitudinal functional assessments and molecular endpoints conducted at term. Exposure at GD10 led to placental transcriptional changes at term that were consistent with markers in human preeclampsia, including reduced mmp10 and increased cd36, fzd1, and col1a1. O3 exposure, at both early and late gestation, induced a significant increase in maternal circulating soluble FMS-like tyrosine kinase-1 (sFlt-1), a known driver of preeclampsia. Otherwise, exposure to 0.3 ppm O3 at GD10 led to several late-stage cardiovascular outcomes in dams that were not evident in GD20-exposed dams, including elevated uterine artery resistance index and reduced cardiac output and stroke volume. GD10 O3 exposure proteomic profile in maternal hearts characterized by a reduction in proteins with essential roles in metabolism and mitochondrial function, whereas phosphoproteomic changes were consistent with pathways involved in cardiomyopathic responses. Thus, the developing placenta is an indirect target of inhaled O3 and systemic maternal cardiovascular abnormalities may be induced by O3 exposure at a specific window of gestation.

Assessment of particulate matter toxicity and physicochemistry at the Claim 28 uranium mine site in Blue Gap, AZ

Thousands of abandoned uranium mines (AUMs) exist in the western United States. Due to improper remediation, windblown dusts generated from AUMs are of significant community concern. A mobile inhalation lab was sited near an AUM of high community concern ("Claim 28") with three primary objectives: to (1) determine the composition of the regional ambient particulate matter (PM), (2) assess meteorological characteristics (wind speed and direction), and (3) assess immunological and physiological responses of mice after exposures to concentrated ambient PM (or CAPs). C57BL/6 and apolipoprotein E-null (ApoE^-/-) mice were exposed to CAPs in AirCARE1 located approximately 1 km to the SW of Claim 28, for 1 or 28 days for 4 hr/day at approximately 80 µg/m³ CAPs. Bronchoalveolar lavage fluid (BALF) analysis revealed a significant influx of neutrophils after a single-day exposure in C57BL/6 mice (average PM_2.5 concentration = 68 µg/m³). Lungs from mice exposed for 1 day exhibited modest increases in Tnfa and Tgfb mRNA levels in the CAPs exposure group compared to filtered air (FA). Lungs from mice exposed for 28 days exhibited reduced Tgfb (C57BL/6) and Tnfa (ApoE^-/-) mRNA levels. Wind direction was typically moving from SW to NE (away from the community) and, while detectable in all samples, uranium concentrations in the PM_2.5 fraction were not markedly different from published-reported values. Overall, exposure to CAPs in the region of the Blue GAP Tachee's Claim-28 uranium mine demonstrated little evidence of overt pulmonary injury or inflammation or ambient air contamination attributed to uranium or vanadium.

An audit of patients clinically deemed as high risk for malignant breast pathology at the Helen Joseph Hospital Breast Clinic

ABSTRACT BACKGROUND: The Helen Joseph Hospital Breast Clinic has implemented a clinical triage system for patients presenting with a variety of breast concerns. The goal of this system is to expedite the process from initial presentation to radiological assessment of patients with suspected breast malignancy or breast abscess in a resource limited setting. The objective was to assess the clinical, imaging and histological diagnoses of breast disease in these patients with malignancy and sepsis METHODS: A retrospective audit of patients clinically deemed high risk for malignant breast pathology referred to the breast imaging unit (BIU) in 2018. Patients were triaged based on strict clinical criteria: presence of a breast mass with or without lymph nodes or a breast abscess. Patients that were subsequently referred for mammography/ultrasound were identified using the patient files in the BIU. Results were recorded on Microsoft Excel and analysed using SAS version 9.2 RESULTS: Three hundred and twenty-five patients were included in this study. Eighty-seven (26.8%) were diagnosed with breast cancer and 236 (72.6%) with benign disease. The most common presenting complaint was a palpable mass (n = 227; 69.9%). Ninety-five per cent of patients characterised as BI-RADS 5 had malignant disease. 55.8% of malignancies diagnosed on ultrasound had locally advanced disease. The most common histological diagnosis of malignancy was invasive ductal carcinoma (n = 67, 77%). The most commonly diagnosed benign disease was breast abscess (n = 42, 17.8% CONCLUSION: BI-RADS findings correspond to similar studies, however, a large number of benign breast disease was diagnosed. This may indicate heightened clinical awareness of breast cancer diagnosis and early detection. A significant percentage of malignancies presented as locally advanced. Except for a lower number of invasive lobular carcinoma, the histological spectrum of malignant disease is similar to comparative studies Keywords: malignant breast pathology, high risk patient, Helen Joseph Hospital Breast Clinic

Serum-borne factors alter cerebrovascular endothelial microRNA expression following particulate matter exposure near an abandoned uranium mine on the Navajo Nation

Background

Commercial uranium mining on the Navajo Nation has subjected communities on tribal lands in the Southwestern United States to exposures from residual environmental contamination. Vascular health effects from these ongoing exposures are an active area of study. There is an association between residential mine-site proximity and circulating biomarkers in residents, however, the contribution of mine-site derived wind-blown dusts on vascular and other health outcomes is unknown. To assess neurovascular effects of mine-site derived dusts, we exposed mice using a novel exposure paradigm, the AirCARE1 mobile inhalation laboratory, located 2 km from an abandoned uranium mine, Claim 28 in Blue Gap Tachee, AZ. Mice were exposed to filtered air (FA) (n = 6) or concentrated ambient particulate matter (CAPs) (n = 5) for 2 wks for 4 h per day.

Results

To assess miRNA differential expression in cultured mouse cerebrovascular cells following particulate matter (PM) exposure (average: 96.6 ± 60.4 μg/m³ for all 4 h exposures), the serum cumulative inflammatory potential (SCIP) assay was employed. MiRNA sequencing was then performed in cultured mouse cerebrovascular endothelial cells (mCECs) to evaluate transcriptional changes. Results indicated 27 highly differentially expressed (p < 0.01) murine miRNAs, as measured in the SCIP assay. Gene ontology (GO) pathway analysis revealed notable alterations in GO enrichment related to the cytoplasm, protein binding and the cytosol, while significant KEGG pathways involved pathways in cancer, axon guidance and Wnt signaling. Expression of these 27 identified, differentially expressed murine miRNAs were then evaluated in the serum. Nine of these miRNAs (~ 30%) were significantly altered in the serum and 8 of those miRNAs demonstrated the same directional change (either upregulation or downregulation) as cellular miRNAs, as measured in the SCIP assay. Significantly upregulated miRNAs in the CAPs exposure group included miRNAs in the let-7a family. Overexpression of mmu-let-7a via transfection experiments, suggested that this miRNA may mediate mCEC barrier integrity following dust exposure.

Conclusions

Our data suggest that mCEC miRNAs as measured in the SCIP assay show similarity to serum-borne miRNAs, as approximately 30% of highly differentially expressed cellular miRNAs in the SCIP assay were also found in the serum. While translocation of miRNAs via exosomes or an alternative mechanism is certainly possible, other yet-to-be-identified factors in the serum may be responsible for significant miRNA differential expression in endothelium following inhaled exposures. Additionally, the most highly upregulated murine miRNAs in the CAPs exposure group were in the let-7a family. These miRNAs play a prominent role in cell growth and differentiation and based on our transfection experiments, mmu-let-7a may contribute to cerebrovascular mCEC alterations following inhaled dust exposure.

Parent use of complementary medicine remedies and services for the management of respiratory tract infection in children: a qualitative study

BACKGROUND

The use of complementary and alternative medicine (CAM) is increasing globally, in both adults and children. A common condition where CAM is used in children is acute respiratory tract infection (ARTI). However, limited information exists regarding specific CAM modalities used in children, and the factors that influence a parent's decision to use CAM for ARTI in children. This research aimed to address this knowledge gap.

METHOD

This research used a qualitative descriptive approach. Parents residing in Greater Melbourne, Australia, who had children aged from 0-12 years, and had used CAM for treating ARTI in their children in the last 12 months, were eligible to participate. Parents' perspectives were captured using individual semi-structured interviews, which were then transcribed verbatim. Data were analysed using content analysis.

RESULTS

Twenty-four families were interviewed. Several strategies to improve trustworthiness were implemented. Three themes underpinning the parents' decision to use CAM emerged from the data: safety, internal drivers and external drivers. Parents used a breadth of different treatments, predominantly food as medicine, followed by aromatherapy and other CAM remedies typically found in the kitchen, to manage ARTI in their children. Parents often used both CAM practitioners and mainstream medicine to manage ARTI in their children. While mainstream medicine was typically used to rule out any sinister pathology, CAM was often used as a frontline treatment option, with food as medicine (e.g. soups) dominating. This was due in part to concerns regarding the negative aspects of pharmaceutical use. Parents utilised a diverse range of information sources to inform their decision-making, including friends, families and the internet; traditional sources of research evidence were generally not used.

CONCLUSION

Child safety was a major factor influencing a primary carer's decision to utilise CAM for ARTI. The safety and effectiveness of remedies utilised by parents now warrants further investigation.

Backscattered electron emission after proton impact on gold nanoparticles with and without polymer shell coating

This work aims at measuring experimentally proton induced secondary electron energy spectra after interaction with gold nano particles (GNPs) and polymer-coated GNPs. Backscattered electron energy spectra were collected over a 0 to 1000 eV energy range using a retarding field analyzer (RFA). This paper presents the spectra obtained for proton beam energies of 0.5 and 2 MeV and diameter 2.5 and 3.8 nm GNPs. The spectra were also measured for 3.8 nm GNPs after 5 and 10 MeV proton irradiations. GNPs were deposited on a 100 nm carbon film. Each experimental spectrum was compared with dedicated simulations based on existing numerical models used in the TRAX and Geant4 Monte Carlo codes. For 100 nm carbon target, good agreement between experimental, TRAX and Geant4 simulation results can be observed. For 3.8 nm GNPs, the TRAX simulations reproduce with good agreement the electron energy spectra produced after 0.5, 2, 5 and 10 MeV proton irradiations, while Geant4 spectra display a lower secondary electron yield at low energy (<600 eV) for all the studied energies. This underestimation can mostly be explained by the 790 eV threshold applied in the condensed history model used by Geant4 which impacts the secondary electron energy distribution. Results obtained for carbon and gold targets highlight the impact of the secondary electron production threshold for proton ionization process considered in condensed history models. The experimental results demonstrate that the single interaction approach used in TRAX is adapted to reproduce secondary electron emission from GNPs. On the other hand, the standard electron generation threshold implement in G4BetheBlochModel and G4BraggModel condensed-history models used in Geant4 is not adapted to reproduce low energy electron emission in gold targets. Finally, the results highlight that the GNP coating leads to a decrease of the electron yield and mostly affects low energy electrons (<500 eV) emitted from GNPs.

Aging Exacerbates Neuroinflammatory Outcomes Induced by Acute Ozone Exposure

The role of environmental stressors, particularly exposure to air pollution, in the development of neurodegenerative disease remains underappreciated. We examined the neurological effects of acute ozone (O3) exposure in aged mice, where increased blood-brain barrier (BBB) permeability may confer vulnerability to neuroinflammatory outcomes. C57BL/6 male mice, aged 8-10 weeks or 12-18 months were exposed to either filtered air or 1.0 ppm O3 for 4 h; animals received a single IP injection of sodium fluorescein (FSCN) 20 h postexposure. One-hour post-FSCN injection, animals were transcardially perfused for immunohistochemical analysis of BBB permeability. β-amyloid protein expression was assessed via ELISA. Flow cytometric characterization of infiltrating immune cells, including neutrophils, macrophages, and microglia populations was performed 20 h post-O3 exposure. Flow cytometry analysis of brains revealed increased microglia "activation" and presentation of CD11b, F4/80, and MHCII in aged animals relative to younger ones; these age-induced differences were potentiated by acute O3 exposure. Cortical and limbic regions in aged brains had increased reactive microgliosis and β-amyloid protein expression after O3 insult. The aged cerebellum was particularly vulnerable to acute O3 exposure with increased populations of infiltrating neutrophils, peripheral macrophages/monocytes, and Ly6C+ inflammatory monocytes after insult, which were not significantly increased in the young cerebellum. O3 exposure increased the penetration of FSCN beyond the BBB, the infiltration of peripheral immune cells, and reactive gliosis of microglia. Thus, the aged BBB is vulnerable to insult and becomes highly penetrable in response to O3 exposure, leading to greater neuroinflammatory outcomes.

Nurses' experiences of screening for communication difficulties at 18 months of age

AIM

Early identification of communication disorders is important and may be possible through screening in the child health services. The aim of the study was to investigate nurses' experiences and sense of competence when using the Infant-Toddler Checklist (ITC) communication screening at the 18-month health visit.

METHODS

A mixed-methods design including three focus group interviews (n = 14) and a web-based survey (n = 22) among nurses using the ITC or the standard method. Interview data were analysed through systematic text condensation and a deductive analysis based on implementation theory. Groups were compared using Mann-Whitney tests.

RESULT

Three themes emerged: Using a structured evaluation of communication changes, the dynamic, ITC is a beneficial tool and Implementation of the ITC faces a few challenges. Nurses who used the ITC perceived to a greater extent that they used a structured method (p = 0.003, r = 0.9) and felt more secure in describing the child's communication and language development to parents (p = 0.006, r = 0.83) compared to the standard method group.

CONCLUSION

Using the ITC supported the nurses in their assessment of communication at 18 months. Nurses' sense of competence was higher when using the ITC, both in their assessment and in communicating with parents.

Plasma protein adsorption on Fe3O4-PEG nanoparticles activates the complement system and induces an inflammatory response

BACKGROUND

Understanding of iron oxide nanoparticles (IONP) interaction with the body milieu is crucial to guarantee their efficiency and biocompatibility in nanomedicine. Polymer coating to IONP, with polyethyleneglycol (PEG) and polyvinylpyrrolidone (PVP), is an accepted strategy to prevent toxicity and excessive protein binding.

AIM

The aim of this study was to investigate the feature of IONP adsorption of complement proteins, their activation and consequent inflammatory response as a strategy to further elucidate their biocompatibility.

METHODS

Three types of IONP with different surface characteristics were used: bare (IONP-bare), coated with PVP (IONP-PVP) and PEG-coated (IONP-PEG). IONPs were incubated with human plasma and adsorbed proteins were identified. BALB/c mice were intravenously exposed to IONP to evaluate complement activation and proinflammatory response.

RESULTS

Protein corona fingerprinting showed that PEG surface around IONP promoted a selective adsorption of complement recognition molecules which would be responsible for the complement system activation. Furthermore, IONP-PEG activated in vitro, the complement system and induced a substantial increment of C3a and C4a anaphylatoxins while IONP-bare and IONP-PVP did not. In vivo IONP-PEG induced an increment in complement activation markers (C5a and C5b-9), and proinflammatory cytokines (IL-1β, IL-6, TNF-α).

CONCLUSION

The engineering of nanoparticles must incorporate the association between complement proteins and nanomedicines, which will regulate the immunostimulatory effects through a selective adsorption of plasma proteins and will enable a safer application of IONP in human therapy.