Biomonitoring of polycyclic aromatic hydrocarbons exposure and short-time health effects in wildland firefighters during real-life fire events

Human biomonitoring data retrieved from real-life wildland firefighting in Europe and, also, worldwide are scarce. Thus, in this study, 176 Portuguese firefighters were biomonitored pre- and post- unsimulated wildfire combating (average:12-13 h; maximum: 55 h) to evaluate the impact on the levels of urinary polycyclic aromatic hydrocarbons hydroxylated metabolites (OHPAH; quantified by high-performance liquid chromatography with fluorescence detection) and the associated short-term health effects (symptoms, and total and differentiated white blood cells). Correlations between these variables and data retrieved from the self-reported questionnaires were also investigated. Firefighters were organized into four groups according to their exposure to wildfire emissions and their smoking habits: non-smoking non-exposed (NSNExp), non-smoking exposed (NSExp), smoking non-exposed (SNExp), and smoking and exposed (SExp). The most abundant metabolites were 1-hydroxynaphthalene and 1-hydroxyacenaphthene (1OHNaph + 1OHAce) (98-99 %), followed by 2-hydroxyfluorene (2OHFlu) (0.2-1.1 %), 1-hydroxyphenanthrene (1OHPhen) (0.2-0.4 %), and 1-hydroxypyrene (1OHPy) (0.1-0.2 %); urinary 3-hydroxybenzo(a)pyrene was not detected. The exposure to wildfire emissions significantly elevated the median concentrations of each individual and total OHPAH compounds in all groups, but this effect was more pronounced in non-smoking (1.7-4.2 times; p ≤ 0.006) than in smoking firefighters (1.3-1.6 times; p ≤ 0.03). The greatest discriminant of exposure to wildfire emissions was 1OHNaph + 1OHAce (increase of 4.2 times), while for tobacco smoke it was 2OHFlu (increase of 10 times). Post-exposure, white blood cells count significantly increased ranging from 1.4 (smokers, p = 0.025) to 3.7-fold (non-smokers, p < 0.001), which was accompanied by stronger significant correlations (0.480 < r < 0.882; p < 0.04) between individual and total OHPAH and total white blood cells (and lymphocytes > monocytes > neutrophils in non-smokers), evidencing the impact of PAH released from wildfire on immune cells. This study identifies Portuguese firefighters with high levels of biomarkers of exposure to PAH and points out the importance of adopting biomonitoring schemes, that include multiple biomarkers of exposure and biomarkers of effect, and implementing mitigations strategies.

Photoreactivity of polycyclic aromatic hydrocarbons (PAHs) and their mechanisms of phototoxicity against human immortalized keratinocytes (HaCaT)

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous organic compounds in the environment. They are produced by many anthropogenic sources of different origins and are known for their toxicity, carcinogenicity, and mutagenicity. Sixteen PAHs have been identified as Priority Pollutants by the US EPA, which are often associated with particulate matter, facilitating their dispersion through air and water. When human skin is exposed to PAHs, it might occur simultaneously with solar radiation, potentially leading to phototoxic effects. Phototoxic mechanisms involve the generation of singlet oxygen and reactive oxygen species, DNA damage under specific light wavelengths, and the formation of charge transfer complexes. Despite predictions of phototoxic properties for some PAHs, there remains a paucity of experimental data. This study examined the photoreactive and phototoxic properties of the 16 PAHs enlisted in the Priority Pollutants list. Examined PAHs efficiently photogenerated singlet oxygen and superoxide anion in simple solutions. Furthermore, singlet oxygen phosphorescence was detected in PAH-loaded HaCaT cells. Phototoxicity against human keratinocytes was evaluated using various assays. At 5 nM concentration, examined PAHs significantly reduced viability and mitochondrial membrane potential of HaCaT cells following the exposure to solar simulated light. Analyzed compounds induced a substantial peroxidation of cellular proteins after light treatment. The results revealed that a majority of the examined PAHs exhibited substantial reactive oxygen species photoproduction under UVA and violet-blue light, with their phototoxicity corresponding to their photoreactive properties. These findings improve our comprehension of the interactions between PAHs and human skin cells under environmental conditions, particularly when exposed to solar radiation.

Dermal absorption of high molecular weight parent and alkylated polycyclic aromatic hydrocarbons from manufactured gas plant soils using in vitro assessment

An enhanced in vitro human dermal bioavailability method was developed to measure the release of twenty parent and seven alkylated high molecular weight (HMW) polycyclic aromatic hydrocarbons (PAHs) from contaminated soils collected from five former manufactured Gas Plants (MGP) in England. GC-MS/MS was used to quantify HMW PAHs in soil, Strat-M artificial membrane representing skin, and synthetic receptor solution (RS) representing systemic circulation at 1-h, 10-h, and 24-h timesteps. Fluoranthene and pyrene exhibited the highest fluxes from soils to membrane (ranging from 9.5 - 281 ng/cm2/h) and soil to RS ( Collapse

Key Words

• Bioavailability
• PAH
• Percutaneous
• Risk assessment

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MESH Headings

• Humans
• Polycyclic Aromatic Hydrocarbons/analysis
• Soil
• Tandem Mass Spectrometry
• Molecular Weight
• Soil Pollutants/analysis
• Pyrenes
• Environmental Monitoring/methods
• Fluorenes

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Affiliation(s)

Alison M Williams-Clayson British Geological Survey, Keyworth, Nottinghamshire, UK; University of Nottingham, Nottingham, UK
Christopher H Vane British Geological Survey, Keyworth, Nottinghamshire, UK
Matthew D Jones University of Nottingham, Nottingham, UK
Russell Thomas WSP UK, Bristol, UK
Christopher Taylor National Grid, Warwick, UK
Darren J Beriro British Geological Survey, Keyworth, Nottinghamshire, UK.

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Impact of heterozygous ALK1 mutations on the transcriptomic response to BMP9 and BMP10 in endothelial cells from hereditary hemorrhagic telangiectasia and pulmonary arterial hypertension donors

Heterozygous activin receptor-like kinase 1 (ALK1) mutations are associated with two vascular diseases: hereditary hemorrhagic telangiectasia (HHT) and more rarely pulmonary arterial hypertension (PAH). Here, we aimed to understand the impact of ALK1 mutations on BMP9 and BMP10 transcriptomic responses in endothelial cells. Endothelial colony-forming cells (ECFCs) and microvascular endothelial cells (HMVECs) carrying loss of function ALK1 mutations were isolated from newborn HHT and adult PAH donors, respectively. RNA-sequencing was performed on each type of cells compared to controls following an 18 h stimulation with BMP9 or BMP10. In control ECFCs, BMP9 and BMP10 stimulations induced similar transcriptomic responses with around 800 differentially expressed genes (DEGs). ALK1-mutated ECFCs unexpectedly revealed highly similar transcriptomic profiles to controls, both at the baseline and upon stimulation, and normal activation of Smad1/5 that could not be explained by a compensation in cell-surface ALK1 level. Conversely, PAH HMVECs revealed strong transcriptional dysregulations compared to controls with > 1200 DEGs at the baseline. Consequently, because our study involved two variables, ALK1 genotype and BMP stimulation, we performed two-factor differential expression analysis and identified 44 BMP9-dysregulated genes in mutated HMVECs, but none in ECFCs. Yet, the impaired regulation of at least one hit, namely lunatic fringe (LFNG), was validated by RT-qPCR in three different ALK1-mutated endothelial models. In conclusion, ALK1 heterozygosity only modified the BMP9/BMP10 regulation of few genes, including LFNG involved in NOTCH signaling. Future studies will uncover whether dysregulations in such hits are enough to promote HHT/PAH pathogenesis, making them potential therapeutic targets, or if second hits are necessary.

Remediation of phenanthrene by highly efficient CdS-SnS photocatalyst and its cytotoxic assessments

Cadmium sulfide-tin sulfide (CdS-SnS) nanoparticles are a novel kind of photocatalyst. These CdS-SnS nanoparticles are synthesized and characterized using UV-Vis, FT-IR, XRD, SEM-EDX, and DLS techniques, to understand their size distribution, crystalline nature, morphology, shape, optical properties, and elemental composition. This research offers insight into the efficient photocatalytic degradation of Phenanthrene (PHE) using CdS-SnS. The CdS-SnS NPs as photocatalyst can effectively photodegrade the polycyclic aromatic hydrocarbons (PAH) such as phenanthrene under simulated solar and UV light. UV-vis spectra of these nanoparticles exhibit peaks at 365 and 546 cm-1 respectively, the mean size of the CdS-SnS NPs in DLS is determined to be 78 nm. The CdS-SnS stretching frequency was observed at wave numbers below 700 cm-1, the absorption peak at 1123 cm-1 indicates the presence of C-N stretch or CS bond of thiourea, while the peak at 1350.38 cm-1 corresponds to the tris-amine C-N stretch in FT-IR. Additionally, the peaks observed at 2026 cm-1 indicate the presence of isothiocyanate (NCS). 1456.23 cm-1 represents the asymmetric scissor deformation vibration. EDAX revealed the presence of elemental Cd and Sn oxides. The antimicrobial studies showed that the CdS-SnS NPs at the concentration of 150 μg/mL, exhibit maximum inhibition (15 ± 1.25 mm) against the strains Proteus mirabilis followed by Staphylococcus epidermidis and Clostridium spp. Among fungal strains Colletotrichum spp. exhibits the maximum zone of inhibition (9 ± 0.25). This research also observed the cytotoxic effects of CdS-SnS NPs on HepG2 and ZF4 cells. HepG2 cells exhibited 50% inhibition at 50 μg/mL and 70% inhibition at 100 μg/mL concentrations, while ZF4 cells exhibited 50% inhibition at 50 μg/mL and 78% inhibition at 100 μg/mL concentrations, respectively. The parameters like concentration of PHE, concentration of CdS-SnS NPs, pH, and sources of irradiation on batch adsorption were examined to maximize the efficiency of the photodegradation process.

Emergencies in Pulmonary Hypertension

Pulmonary hypertension is a challenging disease entity with various underlying etiologies. The management of patients with pulmonary arterial hypertension (WHO Group 1) remains challenging especially in the critical care setting. With risk of high morbidity and mortality, these patients require a multidisciplinary team approach at a speciality care facility for pulmonary hypertension for comprehensive evaluation and rapid initiation of treatment. For acute decompensated right heart failure, management should concentrate on optimizing preload and after load with use of pulmonary vasodilator therapy. A careful evaluation of specialized situations is required for appropriate treatment response.

Safety and Efficacy of Para-Aminohippurate Coinfusion for Renal Protection During Peptide Receptor Radiotherapy in Patients with Neuroendocrine Tumors

Para-aminohippurate, also known as p-aminohippuric acid (PAH), is used clinically to measure effective renal plasma flow. Preclinically, it was shown to reduce 177Lu-DOTATOC uptake in the kidneys while improving bioavailability compared with amino acid (AA) coinfusion. We report the safety and efficacy of PAH coinfusion during peptide receptor radiotherapy in patients with neuroendocrine tumors. Methods: Twelve patients with metastatic or unresectable gastroenteropancreatic neuroendocrine tumors received 177Lu-DOTATOC in 33 treatment cycles. Either 8 g of PAH or a mixture of 25 g of arginine and 25 g of lysine were coinfused. Safety was assessed by monitoring laboratory data, including hematologic and renal data, as well as electrolytes obtained before and 24 h after treatment. For radiation dosimetry, whole-body scans were performed at 1, 24, and 48 h and a SPECT/CT scan was performed at 48 h, along with blood sampling at 5 min and 0.5, 2, 4, 24, and 48 h after administration. Absorbed dose estimations for the kidneys and bone marrow were performed according to the MIRD concept. Results: In 15 treatment cycles, PAH was coinfused. No changes in mean creatinine level, glomerular filtration rate, and serum electrolytes were observed before or 24 h after treatment when using PAH protection (P ≥ 0.20), whereas serum chloride and serum phosphate increased significantly under AA (both P < 0.01). Kidney-absorbed dose coefficients were 0.60 ± 0.14 Gy/GBq with PAH and 0.53 ± 0.16 Gy/GBq with AA. Based on extrapolated cumulative kidney-absorbed doses for 4 cycles, 1 patient with PAH protection and 1 patient with AA protection in our patient group would exceed the 23-Gy conservative threshold. The bone marrow-absorbed dose coefficient was 0.012 ± 0.004 Gy/GBq with PAH and 0.012 ± 0.003 Gy/GBq with AA. Conclusion: PAH is a promising alternative to AA for renal protection during peptide receptor radiotherapy. Further research is required to systematically investigate the safety profile and radiation dosimetry at varying PAH plasma concentrations.

Ecotoxicological and health risks associated with sediment-bound polycyclic aromatic hydrocarbons in peri-urban closed and open coastal lagoons

Coastal urbanisation has ramifications for the sustainable development of developing nations. There are often unquantified ecological and health risks associated with urbanisation. Sixteen polycyclic aromatic hydrocarbons (PAHs) were analysed in surface sediment from three peri-urban coastal lagoons in southern Ghana. We found significant spatial variations of sediment PAHs. These variations were attributed to physiography of the lagoons and diverse anthropogenic activities surrounding them. Total PAHs ranged from 20.81 to 24,801.38 μg/kg (dry weight), underscoring a low to very high pollution level. Diagnostic ratios revealed both pyrogenic and petrogenic origins. Over 50 % of individual PAHs were of moderate ecological risk to benthic organisms, and cancer risk to humans was above the World Health Organisation's recommended safety limit (1 × 10-6). These ecological and health risks should be wake-up call for a more integrated urban planning approach to coastal urbanisation as coastal communities largely depend on natural ecosystems for food and livelihood opportunities.

Simultaneous removal of phenanthrene and Pb using novel PPG-CNTs-nZVI beads

PPG-CNTs-nZVI bead was synthesized by polyvinyl alcohol, pumice, carbon nanotube, and guar gum-nanoscale zero-valent iron to be applied on simultaneously removal of polycyclic aromatic hydrocarbons (PAHs; phenanthrene) and heavy metals (Pb2+) via adsorption. The individual and simultaneous removal efficiency of phenanthrene and Pb2+ using the PPG-CNTs-nZVI beads was evaluated with a range of initial concentrations of these two pollutants. The kinetics and isotherms of phenanthrene and Pb2+ adsorption by the PPG-CNTs-nZVI beads were also determined. The PPG-CNTs-nZVI beads show reasonably high phenanthrene adsorption capacities (up to 0.16 mg/g), and they absorbed 85% of the phenanthrene (initial concentration 0.5 mg/L) in 30 min. High Pb2+ adsorption capabilities were also demonstrated by the PPG-CNTs-nZVI beads (up to 11.6 mg/g). The adsorption fits the Langmuir model better than the Freundlich model. The adsorption still remained stable with various ionic strength circumstances and a wide pH range (2-5). Additionally, the co-adsorption of phenanthrene and Pb2+ by the PPG-CNTs-nZVI beads resulted in synergistic effects. Particularly, phenanthrene-Pb2+ complex formation via π-cation interactions demonstrated a greater affinity than phenanthrene or Pb2+ alone. The present findings suggest that PPG-CNTs-nZVI beads may be effective sorbents for the simultaneous removal of PAHs and heavy metals from contaminated waters.

Non-target analysis of crude oil photooxidation products at high latitudes and their biological effects

With new oil and gas lease sales in high-latitude regions, there exists a need to better understand the chemical fate of spilled oil and its effects on biological life. To address this need, laboratory simulations of crude oil spills under sub-Arctic conditions were conducted using artificial seawater and exposure to solar irradiation to create Hydrocarbon Oxidation Products (HOPs). HOPs characterization and their biological effects were assessed using ultra high-performance liquid chromatography (UHPLC) with high resolution mass Orbitrap spectrometry and the aryl hydrocarbon receptor (AhR) chemically activated luciferase gene expression (CALUX) assay. Non-target UHPLC-Orbitrap mass spectrometry analysis identified 251 HOPs that were in greater abundance in light-exposed samples than dark controls. Oxidized polycyclic aromatic hydrocarbons were also detected, including phenanthrene quinone, anthraquinone, hydroxyanthraquinone, and 9-fluoreneone. The composition of HOPs were consistent with photo-products of alkylated two to four ring PAHs, primarily compounds between 1 and 3 aromatic rings and 1-3 oxygens. The HOP mixture formed during photochemical weathering of Cook Inlet crude oil induced greater AhR activity than parent petroleum products solubilized in dark controls, indicating that HOPs, as a complex mixture, may contribute to petroleum toxicity more than the parent petroleum compounds. These non-targeted approaches provide the most comprehensive analysis of hydrocarbon oxidation products to date, highlighting the diversity of the complex mixture resulting from the photooxidation of crude oil and the limitations of targeted analyses for adequately monitoring HOPs in the environment. Taken together, these data identify a critical "blind spot" in environmental monitoring and spill clean-up strategies as there is a diverse pool of HOPs that may negatively impact human and ecosystem health.

Perillaldehyde ameliorates lipopolysaccharide-induced acute lung injury via suppressing the cGAS/STING signaling pathway

Acute lung injury (ALI) is a common life-threatening illness characterized by a lung inflammatory response and oxidative stress, and effective agent therapies are currently lacking. mtDNA can be recognized by cGAS/STING, the dysregulation of which leads to inflammatory diseases, such as ALI. Perillaldehyde(PAH), one of the major active components of traditional Chinese medicine made from Perilla frutescens, has antioxidant and antiinflammatory effects. The aim of this study was to explore whether PAH can protect against lipopolysaccharide (LPS)-induced ALI and whether its protective effect is exerted through the regulation of cGAS/STING signaling. We found that PAH significantly inhibited lung histological changes, inflammatory cell infiltration, and the overproduction of inflammatory cytokines induced by LPS. Moreover, PAH inhibited LPS-induced oxidative stress, as shown by the deceases in superoxide dismutase (SOD) and glutathione(GSH) levels and increased in malondialdehyde (MDA) and lactate dehydrogenase (LDH) levels. In addition, PAH markedly downregulated the expression of cGAS, STING, p-TBK, p-IRF3, p-P65, and p-IκB, and pharmacological inhibition of cGAS/STING inhibited ALI- induced by LPS. Furthermore, the levels of mitochondrial ROS (mROS) and mtDNA were increased, and cGAS/STING-mediated IRF3/NF-κB signaling was activated during the inflammatory response- induced by LPS in RAW264.7 cells. In addition, pretreatment with the STING activator partially abolished the inhibitory effect of PAH on the inflammation and activation of STING-mediated IRF3/NF-κB signaling induced by LPS. Overall, the results revealed that PAH can effectively alleviate ALI by inhibiting cGAS/STING-mediated IRF3/NF-κB signaling, and that PAH may be a potential candidate agent for the treatment of ALI.

Asymmetric Dimethylarginine and NT-proBNP Levels Provide Synergistic Information in Pulmonary Arterial Hypertension

BACKGROUND

Plasma asymmetric dimethylarginine (ADMA) is elevated in pulmonary arterial hypertension (PAH) and is associated with unfavorable outcomes.

OBJECTIVES

The aim of this study was to assess changes in ADMA plasma levels for monitoring disease progression and outcomes during PAH-specific therapy.

METHODS

ADMA was measured at baseline and after at least 6 months of follow-up using enzyme-linked immunosorbent assay and high-performance liquid chromatography. Changes in ADMA were analyzed in relation to changes in established PAH markers, including hemodynamic status, N-terminal pro-brain natriuretic peptide (NT-proBNP) and risk assessment scores. Impact on survival was assessed using Kaplan-Meier curves and Cox proportional hazards models.

RESULTS

Between 2008 and 2019, ADMA samples were collected prospectively from 215 patients with PAH. Change in ADMA plasma level was a predictor of disease progression and survival. ΔADMA (median -0.03 μmol/L; 95% CI: -0.145 to 0.0135) was correlated with change in mean pulmonary arterial pressure (P < 0.005; rS = 0.287) but was not significantly correlated with ΔNT-proBNP (P = 0.056; rS = 0.135). Patients with decreased ADMA plasma levels at follow-up had better 3-year and 5-year survival rates (88% and 80%, respectively, vs 72% and 53% in those without decreases in ADMA) (P < 0.005; pulmonary hypertension-related mortality or lung transplantation). Patients with decreases in both ADMA and NT-proBNP had better survival rates compared with patients in whom only 1 parameter improved (P < 0.005). ΔADMA was a significant predictor of survival in Cox regression analysis and also when corrected for ΔNT-proBNP (HRs: 1.27 and 1.35, respectively; P < 0.005).

CONCLUSIONS

ADMA and NT-proBNP provide synergistic prognostic information for patients with PAH. ADMA could be used as an objective and distinct biomarker for monitoring treatment response in PAH.

Monk seals (Monachus monachus) in the Mediterranean Sea: The threat of organochlorine contaminants and polycyclic aromatic hydrocarbons

The Mediterranean monk seal (Monachus monachus) is an emblematic species of conservation concern. Anthropogenic pressures have led to severe population declines and significant fragmentation of the remaining populations. Because of their close relationship with coastal areas, Mediterranean monk seals may be potentially exposed to pollution from agricultural sources, as well as from oil tanker spills. Although monitoring of pollution has long been considered a priority for this species, data on monk seal contamination levels are scarce. In this study, 55 blubber samples of all genders and age classes collected during necropsies (1995-2013) from seals of the Eastern Mediterranean subpopulation were analyzed for organochlorine compounds (OCs), i.e., hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDTs), and polycyclic aromatic hydrocarbons (PAHs). Overall, PCBs > DDTs ≫ PAHs > HCB in all samples. Results showed a significant downward trend over the 19-year period for DDTs and HCB. No marked pattern was found for PAHs, even though relative abundance of cancerogenic PAH fraction rose in recent years. PCB levels in subadult specimens increased noticeably over time despite worldwide ban. Our findings did not suggest recent releases of DDT or new pesticides (e.g., Dicofol) in the environment, but may indicate an improper disposal of ancient storages of PCBs or a remobilization from reservoirs. OC levels exceeded thresholds that are commonly associated with immunosuppression and reproductive impairment in other pinnipeds. Hence, OCs could be responsible of potential toxicological effects in this subpopulation. This study represents the first report on PAH and one of the few reports on OC bioaccumulation in Mediterranean monk seals. Based on the levels found in the blubber of monk seals from the Eastern Mediterranean, and given the known harmful effects associated to the prolonged exposure to these substances and the reduced long-term expectations of species recovery, regular monitoring is advocated.

Mechanistic Investigation of Calcium Channel Regulation-Associated Genes in Pulmonary Arterial Hypertension and Signatures for Diagnosis

Pulmonary arterial hypertension (PAH) is a severe cardiopulmonary disorder with complex causes. Calcium channel blockers have long been used in its treatment. Our study aimed to validate experimental results showing increased calcium ion concentration in PAH patients. We investigated the impact of genes related to calcium channel regulation on PAH development and developed an accurate diagnostic model. Clinical trial data from serum of 18 healthy individuals and 18 patients with PAH were retrospectively analyzed. Concentrations of calcium and potassium ions were determined and compared. Datasets were retrieved, selecting genes associated with calcium ion release. R packages processed the datasets, filtering 174 common genes, and conducting Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses. Six hub genes were identified, and nomogram and logistic regression prediction models were constructed. Random forest filtered cross genes, and a diagnostic model was developed and validated using an artificial neural network. The 174 intersection genes related to calcium ions showed significant correlations with biological processes, cellular components, and molecular functions. Six key genes were obtained by constructing a protein-protein interaction network. A diagnostic model with high accuracy (> 90%) and diagnostic capability (AUC = 0.98) was established using a neural network algorithm. This study validated the experimental results, identified key genes associated with calcium ions, and developed a highly accurate diagnostic model using a neural network algorithm. These findings provide insights into the role of calcium release genes in PAH and demonstrate the potential of the diagnostic model for clinical application. However, due to limitations in sample size and a lack of prognosis data, the regulatory mechanisms of calcium ions in PAH patients and their impact on the clinical prognosis of PAH patients still need further exploration in the future.

Weakened tanning ability is an important mechanism for evolutionary skin lightening in East Asians

The evolution of light skin pigmentation among Eurasians is considered an adaptation to the high-latitude environments. East Asians are ideal populations for studying skin color evolution because of the complex environment of East Asia. Here, we report a strong selection signal for the pigmentation gene PAH in light-skinned Han Chinese individuals. The intron mutation rs10778203 in PAH was enriched in East Asians and significantly associated with skin color of the back of the hand in Han Chinese males (P <0.05). In vitro luciferase and transcription factor binding assays showed that the ancestral allele of rs10778203 could bind to SMAD2 and has significant enhancer activity for PAH. However, the derived T allele (the major allele in East Asians) of rs10778203 decreases the binding activity of transcription factors and enhancer activity. Meanwhile, the derived T allele of rs10778203 showed a weaker ultraviolet radiation response in A375 cells and zebrafish embryos. Furthermore, rs10778203 decreases melanin production in transgenic zebrafish embryos after UVB treatment. Collectively, PAH is a potential pigmentation gene that regulates skin tanning ability. Natural selection has enriched the adaptive allele, resulting in weakened tanning ability in East Asians, suggesting a unique genetic mechanism for evolutionary skin lightening in East Asians.

Metabolomic profiling reveals altered phenylalanine metabolism in Parkinson's disease in an Egyptian cohort

Introduction: Parkinson's disease (PD) is the most common motor neurodegenerative disease worldwide. Given the complexity of PD etiology and the different metabolic derangements correlated to the disease, metabolomics profiling of patients is a helpful tool to identify patho-mechanistic pathways for the disease development. Dopamine metabolism has been the target of several previous studies, of which some have reported lower phenylalanine and tyrosine levels in PD patients compared to controls. Methods: In this study, we have collected plasma from 27 PD patients, 18 reference controls, and 8 high-risk controls to perform a metabolomic study using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). Results: Our findings revealed higher intensities of trans-cinnamate, a phenylalanine metabolite, in patients compared to reference controls. Thus, we hypothesize that phenylalanine metabolism has been shifted to produce trans-cinnamate via L-phenylalanine ammonia lyase (PAL), instead of producing tyrosine, a dopamine precursor, via phenylalanine hydroxylase (PAH). Discussion: Given that these metabolites are precursors to several other metabolic pathways, the intensities of many metabolites such as dopamine, norepinephrine, and 3-hydroxyanthranilic acid, which connects phenylalanine metabolism to that of tryptophan, have been altered. Consequently, and in respect to Metabolic Control Analysis (MCA) theory, the levels of tryptophan metabolites have also been altered. Some of these metabolites are tryptamine, melatonin, and nicotinamide. Thus, we assume that these alterations could contribute to the dopaminergic, adrenergic, and serotonergic neurodegeneration that happen in the disease.

Occurrence of traffic related trace elements and organic micropollutants in tunnel wash water

Substantially polluted tunnel wash water (TWW) is produced during road tunnel maintenance. Previous literature has reported the presence of trace elements and polycyclic aromatic hydrocarbons (PAHs). However, it was hypothesized that other organic pollutants are present, and more knowledge is needed to prevent environmental harm. This study reveals for the first time the presence of four short- and 17 long-chained per- and polyfluoroalkyl substances (PFASs), three benzothiazoles (BTHs), six benzotriazoles (BTRs), four bisphenols, and four benzophenones in TWW from a Norwegian road tunnel over a period of three years. Concentrations of PAHs, PFASs, BTHs, and BTRs were higher than previously reported in e.g., road runoff and municipal wastewater. Trace elements and PAHs were largely particulate matter associated, while PFASs, BTHs, BTRs, bisphenols, and benzophenones were predominantly dissolved. 26 of the determined contaminants were classified as persistent, mobile, and toxic (PMT) and are of special concern. It was recommended that regulations for TWW quality should be expanded to include PMT contaminants (such as PFPeA, PFBS, BTR, and 4-OH-BzP) and markers of pollution (like 2-M-BTH, 2-OH-BTH, and 2-S-BTH from tire wear particles). These findings highlight the need to treat TWW before discharge into the environment, addressing both, particulate matter associated and dissolved contaminants.

Determination of Soil Contamination at the Wildland-Urban Interface after the 2021 Marshall Fire in Colorado, USA

Wildfires at the wildland-urban interface (WUI) are increasingly common. The impacts of such events are likely distinct from those that occur strictly in wildland areas, as we would expect an elevated likelihood of soil contamination due to the combustion of anthropogenic materials. We evaluated the impacts of a wildfire at the WUI on soil contamination, sampling soils from residential and nonresidential areas located inside and outside the perimeter of the 2021 Marshall Fire in Colorado, USA. We found that fire-affected residential properties had elevated concentrations of some heavy metals (including Zn, Cu, Cr, and Pb), but the concentrations were still below levels of likely concern, and we observed no corresponding increases in concentrations of polycyclic aromatic hydrocarbons (PAHs). The postfire increases in metal concentrations were not generally observed in the nonresidential soils, highlighting the importance of combustion of anthropogenic materials for potential soil contamination from wildfires at the WUI. While soil contamination from the 2021 Marshall Fire was lower than expected, and likely below the threshold of concern for human health, our study highlights some of the challenges that need to be considered when assessing soil contamination after such fires.

Occurrence, sources and water column distribution trends of suspended particle-associated aliphatic and polycyclic aromatic hydrocarbons in the open northeastern Mediterranean Sea

Herein, we study the occurrence and water column distribution trends of suspended particle-associated aliphatic (AHCs) and polycyclic aromatic hydrocarbons (PAHs) collected from 36 offshore/deep sea locations across the open northeastern Mediterranean Sea. Total concentrations of the determined compounds fall within the range previously reported for non-polluted coastal and open sea locations worldwide. Mixed natural and anthropogenic sources were evident for the studied compounds, based on their molecular profile and several diagnostic indices. In all cases, an enhanced fossil signal typifying chronic oil pollution was evident along the water column. AHCs and PAHs mixtures characteristics varied significantly within the studied sub-regions, highlighting the importance of inputs from various point sources and dispersion pathways. The circulation characteristics of water masses along with biogeochemical features impact on the water column distribution trends and overall fate of the determined compounds in the study area.

Ralinepag Phase II Open-Label Extension Study in Patients with Pulmonary Arterial Hypertension

INTRODUCTION

Ralinepag is a potent, titratable, orally administered prostacyclin (IP) receptor agonist to treat pulmonary arterial hypertension. A phase II randomized, double-blind, parallel-group, placebo-controlled, 22-week study of immediate-release (IR) ralinepag safety and efficacy met its primary endpoint, significantly reducing pulmonary vascular resistance (PVR) compared with placebo. This phase II open-label extension (OLE) study assessed long-term safety and tolerability of ralinepag.

METHODS

Participants were eligible for the OLE if they completed the parent study or experienced a clinical worsening event while receiving placebo. Those previously receiving IR ralinepag remained on their current dose, and participants formerly administered placebo were titrated to the highest tolerated dose. Participants were transitioned to an extended-release ralinepag formulation toward the end of the OLE. The primary objective evaluated long-term safety and tolerability; secondary endpoints included changes in 6-min walk distance (6MWD), World Health Organization/New York Heart Association functional class, clinical worsening, and hemodynamic measures.

RESULTS

In total, 45/61 participants enrolled in the OLE study, 30 from the IR ralinepag group and 15 from the placebo group. The most common adverse events (AEs) were known prostacyclin-related effects (e.g., headache, 64.4%; diarrhea, 37.8%; jaw pain, 33.3%). There was a notable decline in AEs after reaching and maintaining a stable dose. At month 24 after entering the OLE, 6MWD significantly increased by a mean of 36.3 m (P = 0.004) from OLE baseline, and most participants remained stable in their functional class (84.8%). Post-baseline PVR in 1 or 2 years decreased by a median of 52.2 dyn.s/cm5 and mean pulmonary arterial pressure decreased by a median of 2.0 mmHg (P = 0.05).

CONCLUSION

Ralinepag produced sustained, durable improvements in 6MWD along with durable reductions in PVR and a manageable AE profile. Most participants continuing treatment with ralinepag maintained functional measures throughout the OLE and those switching from placebo to ralinepag often experienced functional improvements.

Fatty acid metabolism promotes TRPV4 activity in lung microvascular endothelial cells in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a morbid disease characterized by significant lung endothelial cell (EC) dysfunction. Prior work has shown that microvascular endothelial cells (MVECs) isolated from animals with experimental PAH and patients with PAH exhibit significant abnormalities in metabolism and calcium signaling. With regards to metabolism, we and others have shown evidence of increased aerobic glycolysis and evidence of increased utilization of alternate fuel sources (such as fatty acids) in PAH EC. In the realm of calcium signaling, our prior work linked increased activity of the transient receptor potential vanilloid-4 (TRPV4) channel to increased proliferation of MVECs isolated from the Sugen/Hypoxia rat model of PAH (SuHx-MVECs). However, the relationship between metabolic shifts and calcium abnormalities was not clear. Specifically, whether shifts in metabolism were responsible for increasing TRPV4 channel activity in SuHx-MVECs was not known. In this study, using human data, serum samples from SuHx rats, and SuHx-MVECs, we describe the consequences of increased MVEC fatty acid oxidation in PAH. In human samples, we observed an increase in long-chain fatty acid levels that was associated with PAH severity. Next, using SuHx rats and SuHx-MVECs, we observed increased intracellular levels of lipids. We also show that increasing intracellular lipid content increases TRPV4 activity, whereas inhibiting fatty acid oxidation normalizes basal calcium levels in SuHx-MVECs. By exploring the fate of fatty acid-derived carbons, we observed that the metabolite linking increased intracellular lipids to TRPV4 activity was β-hydroxybutyrate (BOHB), a product of fatty acid oxidation. Finally, we show that BOHB supplementation alone is sufficient to sensitize the TRPV4 channel in rat and mouse MVECs. Returning to humans, we observe a transpulmonary BOHB gradient in human patients with PAH. Thus, we establish a link between fatty acid oxidation, BOHB production, and TRPV4 activity in MVECs in PAH. These data provide new insight into metabolic regulation of calcium signaling in lung MVECs in PAH.NEW & NOTEWORTHY In this paper, we explore the link between metabolism and intracellular calcium levels in microvascular endothelial cells (MVECs) in pulmonary arterial hypertension (PAH). We show that fatty acid oxidation promotes sensitivity of the transient receptor potential vanilloid-4 (TRPV4) calcium channel in MVECs isolated from a rodent model of PAH.

Preliminary analyses of accumulation of carcinogenic contaminants on retired firefighter ensembles

Personal protective equipment (PPE) is designed to protect firefighters from hazards encountered on the fire scene, including heat and products of combustion. Decontamination practices for firefighter turnout gear have been developed to remove combustion products and other contaminants from the fabric of structural firefighting ensembles (i.e., turnout or bunker gear). Chronic exposures to residual polycyclic aromatic hydrocarbons (PAH) are a contributing cause of firefighter cancers. To identify and quantify residual contamination of PAH, samples were taken from two individual decommissioned structural firefighting ensembles and analyzed by layer (outer canvas shell, moisture barrier, and the thermal protective liner) for (1) textile integrity via field emission scanning electron microscopy and (2) quantity of PAH contamination by high-pressure liquid chromatography with ultraviolet/fluorescence detection. The results of these analyses show the presence of the PAH compounds pyrene (35% of the total mass of PAH), phenanthrene (21%), benzo(a)pyrene (14%), and benzo(a)anthracene (14%) which present a risk for dermal absorption. The data also revealed that PAH penetration through the layers of the firefighting ensemble was strongly inhibited by the moisture barrier layer.

Development of a novel tyrosine-based selection system for generation of recombinant Chinese hamster ovary cells

Efficiently expanding Chinese hamster ovary (CHO) cells, which serve as the primary host cells for recombinant protein production, have gained increasing industrial significance. A significant hurdle in stable cell line development is the low efficiency of the target gene integrated into the host genome, implying the necessity for an effective screening and selection procedure to separate these stable cells. In this study, the genes of phenylalanine hydroxylase (PAH) and pterin 4 alpha carbinolamine dehydratase 1 (PCBD1), which are key enzymes in the tyrosine synthesis pathway, were utilized as selection markers and transduced into host cells together with the target genes. This research investigated the enrichment effect of this system and advanced further in understanding its benefits for cell line development and rCHO cell culture. A novel tyrosine-based selection system that only used PCBD1 as a selection marker was designed to promote the enrichment effect. Post 9 days of starvation, positive transductants in the cell pool approached 100%. Applied the novel tyrosine-based selection system, rCHO cells expressing E2 protein were generated and named CHO TS cells. It could continue to grow, and the yield of E2 achieved 95.95 mg/L in a tyrosine-free and chemically-defined (CD) medium. Herein, we introduced an alternative to antibiotic-based selections for the establishment of CHO cell lines and provided useful insights for the design and development of CD medium.

Polycyclic Aromatic Hydrocarbons and Pancreatic Cancer: An Analysis of the Blood Biomarker, r-1,t-2,3,c-4-Tetrahydroxy-1,2,3,4-tetrahydrophenanthrene and Selected Metabolism Gene SNPs

Exposure to polycyclic aromatic hydrocarbons (PAHs), byproducts of incomplete combustion, and their effects on the development of cancer are still being evaluated. Recent studies have analyzed the relationship between PAHs and tobacco or dietary intake in the form of processed foods and smoked/well-done meats. This study aims to assess the association of a blood biomarker and metabolite of PAHs, r-1,t-2,3,c-4-tetrahydroxy-1,2,3,4-tetrahydrophenanthrene (PheT), dietary intake, selected metabolism SNPs, and pancreatic cancer. Demographics, food-frequency data, SNPs, treatment history, and levels of PheT in plasma were determined from 400 participants (202 cases and 198 controls) and evaluated based on pancreatic adenocarcinoma diagnosis. Demographic and dietary variables were selected based on previously published literature indicating association with pancreatic cancer. A multiple regression model combined the significant demographic and food items with SNPs. Final multivariate logistic regression significant factors (p-value < 0.05) associated with pancreatic cancer included: Type 2 Diabetes [OR = 6.26 (95% CI = 2.83, 14.46)], PheT [1.03 (1.02, 1.05)], very well-done red meat [0.90 (0.83, 0.96)], fruit/vegetable servings [1.35 (1.06, 1.73)], recessive (rs12203582) [4.11 (1.77, 9.91)], recessive (rs56679) [0.2 (0.06, 0.85)], overdominant (rs3784605) [3.14 (1.69, 6.01)], and overdominant (rs721430) [0.39 (0.19, 0.76)]. Of note, by design, the level of smoking did not differ between our cases and controls. This study does not provide strong evidence that PheT is a biomarker of pancreatic cancer susceptibility independent of dietary intake and select metabolism SNPs among a nonsmoking population.

PAHs in high Arctic copepods Calanus hyperboreus following exposure of residues from in situ burning of oil spill

In situ burning of marine oil spills reduces the total amount of oil in the environment, but a negative side effect may be the generation of environmentally hazardous polycyclic aromatic hydrocarbons (PAHs) that may pose a risk for bioaccumulation, particularly in organisms having a high lipid content. In this study uptake of PAHs from oil and burn residue were examined in the high arctic copepod Calanus hyperboreus. A major part of the low ring number petrogenic PAHs in the oil was removed during burning and relative higher concentrations of pyrogenic high ring number PAHs was found in the burn residue. This suggests that burning markedly reduces the general PAH exposure load. Furthermore, the pyrogenic PAHs generated during the burn were not bioconcentrated to quantifiable levels in the copepods. We conclude that in situ burning can mitigate the potential risk of PAH uptake for copepods and other pelagic organisms in the marine environment as the pyrogenic PAHs only pose low risk for uptake from the water by the copepods and other pelagic organisms.

Micro/nanoplastics: Critical review of their impacts on plants, interactions with other contaminants (antibiotics, heavy metals, and polycyclic aromatic hydrocarbons), and management strategies

Microplastic/nanoplastics (MPs/NPs) contamination is not only emerging threat to the agricultural system but also constitute global hazard to the environment worldwide. Recent review articles have addressed the environmental distribution of MPs/NPs and their single-exposure phytotoxicity in various plant species. However, the mechanisms of MPs/NPs-induced phytotoxicity in conjunction with that of other contaminants remain unknown, and there is a need for strategies to ameliorate such phytotoxicity. To address this, we comprehensively review the sources of MPs/NPs, their uptake by and effects on various plant species, and their phytotoxicity in conjunction with antibiotics, heavy metals, polycyclic aromatic hydrocarbons (PAHs), and other toxicants. We examine mechanisms to ameliorate MP/NP-induced phytotoxicity, including the use of phytohormones, biochar, and other plant-growth regulators. We discuss the effects of MPs/NPs -induced phytotoxicity in terms of its ability to inhibit plant growth and photosynthesis, disrupt nutrient metabolism, inhibit seed germination, promote oxidative stress, alter the antioxidant defense system, and induce genotoxicity. This review summarizes the novel strategies for mitigating MPs/NPs phytotoxicity, presents recent advances, and highlights research gaps, providing a foundation for future studies aimed at overcoming the emerging problem of MPs/NPs phytotoxicity in edible crops.

Activation of the p62-Keap1-Nrf2 pathway improves pulmonary arterial hypertension in MCT-induced rats by inhibiting autophagy

Autophagy is implicated in the pathogenesis of pulmonary arterial hypertension (PAH). We aimed to investigate whether the p62-Keap1-Nrf2 pathway affects the development of PAH by mediating autophagy. A PAH rat model was established using monocrotaline (MCT). Pulmonary artery smooth muscle cells (PASMCs) were extracted, and the changes in proliferation, migration, autophagy, and oxidative stress were analyzed following overexpression or knockdown of p62. The impact of p62 on the symptoms of PAH rats was assessed by the injection of an adenovirus overexpressing p62. We found that the knockdown of p62 increased the proliferation and migration of PASMCs, elevating the oxidative stress of PASMCs and upregulating gene expression of NADPH oxidases. Co-IP assay results demonstrated that p62 interacted with Keap1. p62 knockdown enhanced Keap1 protein stability and Nrf2 ubiquitination. LC3II/I and ATG5 were expressed more often when p62 was knocked down. Treating with an inhibitor of autophagy reversed the impact of p62 knockdown on PASMCs. Nrf2 inhibitor treatment reduced the expression of Nrf2 and p62, while increasing the expression of Keap1, LC3II/I, and ATG5 in PASMCs. However, overexpressing p62 diminished mRVP, SPAP, and Fulton index in PAH rats and attenuated pulmonary vascular wall thickening. Overexpression of p62 also decreased the expression of Keap1, LC3II/I, and ATG5 and increased the nuclear expression of Nrf2 in PAH rats. Importantly, overexpression of p62 reduced oxidative stress and the NADPH oxidase expression in PAH rats. Overall, activation of the p62-Keap1-Nrf2 positive feedback signaling axis reduces the proliferation and migration of PASMCs and alleviates PAH by inhibiting autophagy and oxidative stress.

Sodium butyrate alleviates right ventricular hypertrophy in pulmonary arterial hypertension by inhibiting H19 and affecting the activation of let-7g-5p/IGF1 receptor/ERK

Pulmonary arterial hypertension (PAH) is a complex and fatal cardio-pulmonary vascular disease. Decompensated right ventricular hypertrophy (RVH) caused by cardiomyocyte hypertrophy often leads to fatal heart failure, the leading cause of mortality among patients. Sodium butyrate (SB), a compound known to reduce cardiac hypertrophy, was examined for its potential effect and the underlying mechanism of SB on PAH-RVH. The in vivo study showed that SB alleviated RVH and cardiac dysfunction, as well as improved life span and survival rate in MCT-PAH rats. The in vivo and in vitro experiments showed that SB could attenuate cardiomyocyte hypertrophy by reversing the expressions of H19, let-7g-5p, insulin-like growth factor 1 receptor (IGF1 receptor), and pERK. H19 inhibition restored the level of let-7g-5p and prevented the overexpression of IGF1 receptor and pERK in hypertrophic cardiomyocytes. In addition, dual luciferase assay revealed that H19 demonstrated significant binding with let-7g-5p, acting as its endogenous RNA. Briefly, SB attenuated PAH-RVH by inhibiting the H19 overexpression, restoring the level of let-7g-5p, and hindering IGF1 receptor/ERK activation.

Case report: Extracorporeal life support as a successful bridge to recovery in an incident case of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is characterized by a progressive increase in pulmonary vascular resistance (PVR) due to vascular remodeling of the small pulmonary arteries. In advanced RV failure or severe hypoxemia, extra corporeal life support (ECLS) is now to be considered, with the objective to bridge patients back to their baseline clinical state while waiting or right after lung transplantation, or bridge to pharmacological optimization of PAH (i.e., bridge to recovery). We describe herein a case of a 30-year-old woman (gravida 6, para 6) with an incident case of heritable PAH revealed by refractory hypoxemia. Despite the use of mechanical ventilation and fluid optimization, the patient remained profoundly hypoxemic. ECLS was then initiated to avoid tissue hypoxia. The mechanical option chosen was peripheral femoro-femoral venoarterial extracorporeal membrane oxygen (VA-ECMO), percutaneously implanted. Due to the absence of evidence of chronic respiratory disease or chronic thromboembolic pulmonary hypertension, this severe pre-capillary pulmonary hypertension was attributed to PAH. Therefore, epoprostenol infusion and an association of oral treatments (bosentan and tadalafil) were administered. A dramatic improvement was observed, allowing decannulation 7 days after the initiation of pharmacological treatment. After 29 days, the patient was discharged from the hospital with epoprostenol, bosentan, and tadalafil. The assessment has been completed by positive research on mutations (c.741C > G, p.Tyr247) corresponding to a loss of function of the bone morphogenetic protein receptor 2 (BMPR2) gene. The final diagnosis was heritable PAH. The use of ECLS has been well demonstrated in patients with PAH complicated by acute RV failure or refractory hypoxemia in the "bridge-to-transplantation" strategy. Only a few reports have described the use of ECLS as a "bridge-to-recovery" with PAH drugs in untreated or undertreated PAH patients, but none has described such a rapid improvement with resolution of refractory hypoxemia. More studies are needed to assess the benefits and limitations of the "bridge-to-recovery" strategy and to identify the patients most likely to benefit from it.

Organic contaminants levels, distribution and risk assessment in Jeddah marine coastal zone sediments

Herein, various organic contaminants were determined in surface sediments collected from the Jeddah coastal zone, Saudi Arabia, to assess their levels, origin and probable toxic effects on marine organisms. High hydrocarbons concentrations, indicative of an enhanced pollutant burden, were recorded in the Jeddah Lagoon (mean value 4100 mg/kg for total aliphatic hydrocarbons (∑AHC) and 5800 μg/kg for total polycyclic aromatic hydrocarbons (∑PAH)), whereas mean values in Mena Jeddah were 258 mg/kg for ∑AHC and 615 μg/kg for ∑PAH. By using molecular diagnostic ratios/indices and applying Positive Matrix Factorization, petroleum related pollution seems to predominate in Jeddah lagoons, whereas carcinogenic contaminants of pyrolytic origin were dominant in Mena Jedda. Additionally, municipal wastewaters were identified as a major source of pollution in Jeddah lagoons. Comparison of the concentrations of individual PAHs and polychlorinated biphenyls with sediment quality guidelines indicates that, despite their high total values, adverse biological effects are unlikely to occur.

Disease characteristics, treatments, and outcomes of patients with pulmonary arterial hypertension treated with selexipag in real-world settings from the SPHERE registry (SelexiPag: tHe usErs dRug rEgistry)

BACKGROUND

Selexipag is an oral prostacyclin receptor agonist, indicated for pulmonary arterial hypertension to delay disease progression and reduce the risk of pulmonary arterial hypertension-related hospitalization. SelexiPag: tHe usErs dRug rEgistry (NCT03278002) was a US-based, prospective, real-world registry of selexipag-treated patients.

METHODS

Adults with pulmonary hypertension (enrolled 2016-2020) prescribed selexipag were followed for ≤18 months, with data collected at routine clinic visits. Patients were defined as newly or previously initiated if they had started selexipag ≤60 days or >60 days, respectively, before enrollment.

RESULTS

The registry included 829 patients (430 newly initiated, 399 previously initiated; 759 with pulmonary arterial hypertension), of whom 55.6% were World Health Organization functional class (FC) 3/4; 57.3% were intermediate or high risk per Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) 2.0. In patients with pulmonary arterial hypertension, 18-month discontinuation rates for adverse events were 22.0%, 32.0%, and 11.9%, and 18-month survival rates were 89.4%, 84.2%, and 94.5% in the overall, newly, and previously initiated patient populations, respectively. From baseline to month 18, most patients had stable or improved FC and stable or improved REVEAL 2.0 risk category status. Discontinuation for adverse events, hospitalization, and survival were similar regardless of patients' individually tolerated selexipag maintenance dose. No new safety signals were identified.

CONCLUSIONS

In this real-world analysis of patients initiating selexipag, most patients had stable or improved FC and REVEAL 2.0 risk category. Similar to the GRIPHON trial, outcomes with selexipag in this real-world study were comparable across maintenance dose strata, with no new safety signals.

Structural Insights into the Activation of Human Aryl Hydrocarbon Receptor by the Environmental Contaminant Benzo[a]pyrene and Structurally Related Compounds

The aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor belonging to the bHLH/PAS protein family and responding to hundreds of natural and chemical substances. It is primarily involved in the defense against chemical insults and bacterial infections or in the adaptive immune response, but also in the development of pathological conditions ranging from inflammatory to neoplastic disorders. Despite its prominent roles in many (patho)physiological processes, the lack of high-resolution structural data has precluded for thirty years an in-depth understanding of the structural mechanisms underlying ligand-binding specificity, promiscuity and activation of AHR. We recently reported a cryogenic electron microscopy (cryo-EM) structure of human AHR bound to the natural ligand indirubin, the chaperone Hsp90 and the co-chaperone XAP2 that provided the first experimental visualization of its ligand-binding PAS-B domain. Here, we report a 2.75 Å resolution structure of the AHR complex bound to the environmental pollutant benzo[a]pyrene (B[a]P). The structure substantiates the existence of a bipartite PAS-B ligand-binding pocket with a geometrically constrained primary binding site controlling ligand binding specificity and affinity, and a secondary binding site contributing to the binding promiscuity of AHR. We also report a docking study of B[a]P congeners that validates the B[a]P-bound PAS-B structure as a suitable model for accurate computational ligand binding assessment. Finally, comparison of our agonist-bound complex with the recently reported structures of mouse and fruit fly AHR PAS-B in different activation states suggests a ligand-induced loop conformational change potentially involved in the regulation of AHR function.

Integrating Network Pharmacology and Experimental Verification to Explore the Pharmacological Mechanisms of Cordycepin against Pulmonary Arterial Hypertension in Rats

BACKGROUND

Pulmonary Arterial Hypertension (PAH) is a fatal disease with high morbidity and mortality. Cordycepin has anti-inflammatory, antioxidant and immune enhancing effects. However, the role of Cordycepin in the treatment of PAH and its mechanism is not clear.

METHODS

The Cordycepin structure and PAH-related gene targets were obtained from public databases. The KEGG and GO enrichment analysis of common targets was performed in DAVID. PPI networks were also mapped using the STRING platform. AutoDock Vina, AutoDockTools, ChemBio3D and Pymol tools were selected for molecular docking of key targets. The therapeutic effects of Cordycepin on PAH were observed in Monocrotaline(MCT)-induced PAH rats and platelet-derived growth factor BB (PDGFBB)-induced rat pulmonary artery smooth muscle cells (PASMCs). The right ventricular systolic pressure (RVSP) was detected. HE staining, Western Blot, Scratch assay, EDU and TUNEL assays were used respectively.

RESULTS

Through Network Pharmacology and molecular docking , the Cordycepin-PAH core genes were found to be TP53, AKT1, CASP3, BAX and BCL2L1. In MCT-induced PAH rats, the administration of Cordycepin significantly reduced RVSP, and inhibited pulmonary vascular remodeling. In PDGFBB-induced PASMCs, Cordycepin reduced the migration and proliferation of PASMCs and promoted apoptosis. After the Cordycepin treatment, the protein expressions of TP53, Cleaved CASP3 and BAX were significantly increased, while the protein expressions of p-AKT1 and BCL2L1 were significantly decreased in MCT-PAH rats and PDGFBB-induced PASMCs.

CONCLUSION

This study identified that TP53, AKT1, CASP3, BAX, and BCL2L1 were the potential targets of Cordycepin against PAH by ameliorating pulmonary vascular remodeling, inhibiting the abnormal proliferation and migration of PASMCs and increasing apoptosis of PASMCs. which provided a new understanding of the pharmacological mechanisms of Cordycepin in the treatment of PAH.

Recycled pulp and paper sludge, potential source of cellulose: feasibility assessment and characterization

The pulp and paper industry stands out as an example of a technology based on a renewable resource, cellulose. The sludge, however, poses major environmental and public health problems. To effectively manage the sludge wastes, it is critical to fully evaluate its composition, possible environmental impacts, and the total amount of exploitable renewable resources. The study established the pH of the sludge to be 7.32 ± 0.98, an electrical conductivity (1.84 mS/cm), nitrogen concentration (2.65 ± 0.21%), and total organic matter (41.23 ± 3.11%). The cellulosic content was established to be 74.07 ± 2.71% which contributes to 53.07 ± 1.23% water holding capacity (WHC). The most abundant elements were C and O, followed by Cl, Si, Al, and Mg, with lower concentrations of S, Si, K, and iron. The polycyclic aromatic compounds (PAHs) levels ranged from 0.29 to 322.56 ng.g-1 with 1-methyl pyrene posting the highest concentration (322.56 ng.g-1. XRD peaks at 17.10°, 23.86°, 30.14°, and 36.57°, which imply the existence of CaCO3. SEM indicated that the sludge was majorly comprised of fibers materials with average particle sizes of 280 micrometers. TGA/DTG analysis showed that the sludge had the greatest cellulose and hemicellulose (64.7 wt. %).

Genome-Centric Metatranscriptomics Reveals Multiple Co-occurring Routes for Hydrocarbon Degradation in Chronically Contaminated Marine Microbial Mats

Long-term hydrocarbon pollution is a devious threat to aquatic and marine ecosystems. However, microbial responses to chronic pollution remain poorly understood. Combining genome-centric metagenomic and metatranscriptomic analyses of microbial mat samples that experienced chronic hydrocarbon pollution for more than 80 years, we analyzed the transcriptomic activity of alkane and aromatic hydrocarbon degradation pathways at the population level. Consistent with the fluctuating and stratified redox conditions of the habitat, both aerobic and anaerobic hydrocarbon degradation pathways were expressed by taxonomically and metabolically contrasted lineages including members of Bacteroidiales, Desulfobacteraceae, Pseudomonadales; Alcanivoraceae and Halieaceae populations with (photo)-heterotrophic, sulfur- and organohalide-based metabolisms, providing evidence for the co-occurrence and activity of aerobic and anaerobic hydrocarbon degradation pathways in shallow marine microbial mats. In addition, our results suggest that aerobic alkane degradation in long-term pollution involved bacterial families that are naturally widely distributed in marine habitats, but hydrocarbon concentration and composition were found to be a strong structuring factor of their intrafamily diversity and transcriptomic activities.

Single-Cell Imaging Maps Inflammatory Cell Subsets to Pulmonary Arterial Hypertension Vasculopathy

Rationale: Unraveling immune-driven vascular pathology in pulmonary arterial hypertension (PAH) requires a comprehensive understanding of the immune cell landscape. Although patients with hereditary (H)PAH and bone morphogenetic protein receptor type 2 (BMPR2) mutations have more severe pulmonary vascular pathology, it is not known whether this is related to specific immune cell subsets. Objectives: This study aims to elucidate immune-driven vascular pathology by identifying immune cell subtypes linked to severity of pulmonary arterial lesions in PAH. Methods: We used cutting-edge multiplexed ion beam imaging by time of flight to compare pulmonary arteries (PAs) and adjacent tissue in PAH lungs (idiopathic [I]PAH and HPAH) with unused donor lungs, as controls. Measurements and Main Results: We quantified immune cells' proximity and abundance, focusing on those features linked to vascular pathology, and evaluated their impact on pulmonary arterial smooth muscle cells (SMCs) and endothelial cells. Distinct immune infiltration patterns emerged between PAH subtypes, with intramural involvement independently linked to PA occlusive changes. Notably, we identified monocyte-derived dendritic cells within PA subendothelial and adventitial regions, influencing vascular remodeling by promoting SMC proliferation and suppressing endothelial gene expression across PAH subtypes. In patients with HPAH, pronounced immune dysregulation encircled PA walls, characterized by heightened perivascular inflammation involving T cell immunoglobulin and mucin domain-3 (TIM-3)+ T cells. This correlated with an expanded DC subset expressing indoleamine 2,3-dioxygenase 1, TIM-3, and SAM and HD domain-containing deoxynucleoside triphosphate triphosphohydrolase 1, alongside increased neutrophils, SMCs, and alpha-smooth muscle actin (ACTA2)+ endothelial cells, reinforcing the heightened severity of pulmonary vascular lesions. Conclusions: This study presents the first architectural map of PAH lungs, connecting immune subsets not only with specific PA lesions but also with heightened severity in HPAH compared with IPAH. Our findings emphasize the therapeutic potential of targeting monocyte-derived dendritic cells, neutrophils, cellular interactions, and immune responses to alleviate severe vascular pathology in IPAH and HPAH.

Polycyclic aromatic hydrocarbons (PAHs) in coal preparation plant products: A contributor to environmental pollution

Coal and coal gangue are petrogenic sources of polycyclic aromatic hydrocarbons (PAHs), which cause adverse impacts on the environment. Raw coal, cleaned coal, slime, slack gangue, and lump gangue from the Pingshuo No. 1 Coal Preparation Plant, China, were analyzed to determine the concentrations and compositions of 16 priority parent PAHs (16PAHs) and their alkylated derivatives (aPAHs). The ∑16PAH and ∑aPAH concentrations in the samples ranged from 18.7 to 139.2 mg/kg and 22.2 to 262.3 mg/kg, respectively, and ranked as follows: cleaned coal > raw coal > slime > lump gangue > slack gangue. Coal gangues had a higher proportion and lower degree of alkylation of 4-6-ring PAHs than coals. A summary analysis of references related to coal and coal gangue diagnostic ratios showed that their ratios could not be used to differentiate them from other PAH sources, indicating that the release of particulate coal and coal gangue would increase the uncertainty of environmental PAH identification results. The diagnostic ratios of coal gangue were relatively concentrated, and comparing the ratio distribution could reveal the coal gangue source PAHs. The toxicity risk of slack gangue was higher than that of lump gangue based on the benzo[a]pyrene-equivalent concentration; hence, more attention should be given to its escape to the environment.

Umnutzung von Gewerbegebäuden in Wohnraum: Was ist bezüglich möglicher Schadstoffbelastungen in der Innenraumluft zu beachten?

The conversion of industrial buildings into residential space requires special consideration of the inherited building fabric and associated pollutants. Due to the previous industrial use at contaminated sites, certain pollutants may play a significant role that are normally not the focus of refurbishments activities of residential spaces. In order to comply with the increased requirements with respect to indoor air quality in residential spaces, and to avoid unnecessary efforts and costs of amendments to the refurbishment, the Indoor Air Hygiene Commission (IRK) provides advice on how to prepare the conversion of commercial buildings so that healthy living conditions are ensured.

Predicted no-effect concentration for eight PAHs and their ecological risks in seven major river systems of China

The initial step in the assessment of the ecological risk of pollutants is to determine the predicted no-effect concentration (PNEC). However, ecological risk assessments of eight carcinogenic polycyclic aromatic hydrocarbons (PAHs), including dimethylbenz[a]anthracene (DMBA), methylcholanthrene (MCA), benzo(a)anthracene (BaA), chrysene (CHR), benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (BkF), benzo(a)pyrene (BaP), and dibenzo(a,h)anthracene (DBA), are rarely conducted due to the lack of their PNECs based on test data. In this study, quantitative structure-activity relationship (QSAR) models and interspecies correlation estimation (ICE) models were combined to predict the acute toxicity of these eight target PHAs. A Kolmogorov-Smirnov analysis for species sensitivity distributions (SSDs) of native and all species was conducted. There was no significant difference between the predictions for native Chinese species and the predictions for all species by the QSAR-ICE models. In addition, the feasibility of the QSAR-ICE models was demonstrated by comparing the SSD curves constructed by measured toxicity data of BaP and those predicted by the QSAR-ICE models. The PNECs of the eight PAHs were estimated based on the SSDs and acute to chronic ratio (ACR) method; these data were 0.071 μg/L, 0.033 μg/L, 0.049 μg/L, 0.114 μg/L, 0.019 μg/L, 0.021 μg/L, 0.038 μg/L and 0.054 μg/L for DMBA, DBA, BaP, MCA, BaA, CHR, BbF, BkF, respectively. The higher PNECs of the alkylated PAHs suggested their lower ecological risks. Based on the mixed risk quotient (mRQ) of PAHs through the concentration addition (CA) model, high ecological risk watersheds, such as the Songhua River (mRQ = 1.95), the Liao River (mRQ = 4.59), and the Huai River (mRQ = 1.93), were identified.

Matrine alleviates hypoxia-induced inflammation and pulmonary vascular remodelling via RPS5/NF-κB signalling pathway

Hypoxia-induced vasoconstriction and vascular remodelling are the main pathological features of hypoxic pulmonary arterial hypertension (HPAH), and inflammation is participated in the occurrence of pulmonary vascular remodelling (PVR). Matrine is an alkaloid with the effects of anti-inflammation, antifibrosis and antitumour. But, few studies have explored the role of matrine in regulating PVR, and the related mechanisms are still unknown. In this study, we found that hypoxia-induced pulmonary artery smooth muscle cells (PASMCs) proliferation and inhibited its apoptosis, reduced the expression of ribosomal protein s5 and activated the nuclear factor kappa-B (NF-κB) signalling. Matrine, sildenafil and NF-κB inhibitor Bay 11-7082 could reverse these changes and impel the cell cycle in phase S retardation, and reduced the expression of p50, p65, proliferating cell nuclear antigen (PCNA), Bcl-2. In addition, matrine could lower right ventricular systolic pressure and mean pulmonary artery pressure of rats, α-smooth muscle actin and PCNA expression in pulmonary artery media, the levels of tumor necrosis factor-α and interleuki-1β, thus improved hypoxia-induced PVR. This study indicated that matrine could alleviate inflammation and improve PVR through reversing the imbalance of proliferation and apoptosis of PASMCs, thus it had a therapeutic effect on HPAH.

Impact of Systemic Sclerosis-Associated Interstitial Lung Disease With and Without Pulmonary Hypertension on Survival: A Large Cohort Study of the German Network for Systemic Sclerosis

BACKGROUND

Pulmonary involvement is the leading cause of death in systemic sclerosis (SSc) and may manifest as interstitial lung disease (ILD), pulmonary arterial hypertension (PAH), or in combination of both (ILD with pulmonary hypertension [ILD-PH]). The aim of this analysis was to determine prevalence, clinical characteristics, and survival of these different forms within the registry of the German Network for Systemic Sclerosis.

RESEARCH QUESTION

Does SSc-associated ILD-PH or ILD without PH affect survival differently, and are there any risk factors that have an additional impact?

STUDY DESIGN AND METHODS

Clinical data of 5,831 patients with SSc were collected in the German Network for Systemic Sclerosis registry. Kaplan-Meier estimates were used to compare overall survival in patients with SSc-associated ILD-PH and ILD without PH with patients without pulmonary involvement and those with PAH. The Cox proportional hazard model was used to analyze the influence of pulmonary involvement and other potential predictors on patient survival.

RESULTS

Clinical data of 3,257 patients with a mean follow-up time of 3.45 ± 1.63 years have been included in our analysis. At baseline, ILD was present in 34.5%, whereas PH without ILD had a lower prevalence with 4.5%. At the end of follow-up, 47.6% of patients with SSc had ILD, 15.2% had ILD-PH, and 6.5% had PAH. ILD was more frequent in the diffuse cutaneous form (57.3%), whereas PAH did not differ significantly between SSc subtypes. Significant differences in baseline characteristics between PAH vs ILD-PH vs ILD without PH were found for age at diagnosis, sex, SSc subsets, antibody status, FVC, diffusing capacity of the lung for carbon monoxide, and therapy. Overall survival at 5 years was 96.4% for patients without pulmonary involvement and differed significantly between patients with ILD without PH, PAH, and being worst in patients with ILD-PH. Female sex (hazard ratio [HR], 0.3), higher BMI (HR, 0.9), and higher diffusing capacity of the lung for carbon monoxide values (HR, 0.98) were associated with a lower mortality risk.

INTERPRETATION

ILD is the most prevalent pulmonary involvement in SSc, whereas the combination of ILD and PH is associated with the most detrimental survival.

Mendelian randomization study on causal association of IL-6 signaling with pulmonary arterial hypertension

BACKGROUND

A recent Mendelian randomization (MR) did not support an effect of the lead interleukin-6 receptor (IL-6 R) variant on risk of pulmonary arterial hypertension (PAH). Thus, we used two sets of genetic instrumental variants (IVs) and publicly available PAH genome-wide association studies (GWAS) to reassess the genetic causal link between IL-6 signaling and PAH.

METHODS

Six independent IL-6 signaling and 34 independent soluble IL-6 receptor (sIL-6 R) genetic IVs from recent MR reports and PAH GWAS including 162,962 European individuals were used to perform this two-sample MR study.

RESULTS

We found that as IL-6 signaling genetically increased, the risk of PAH reduced using IVW (odds ratio [OR] = 0.023, 95% confidence interval [CI]: 0.0013-0.393; p = .0093) and weighted median (OR = 0.033, 95% CI: 0.0024-0.467; p = .0116). Otherwise, as sIL-6 R genetically increased, the risk of PAH increased using IVW (OR = 1.34, 95% CI: 1.16-1.56; p = .0001), weighted median (OR = 1.36, 95% CI: 1.10-1.68; p = .005), MR-Egger (OR = 1.43, 95% CI: 1.05-1.94; p = .03), and weighted mode (OR = 1.35, 95% CI for OR: 1.12-1.63; p = .0035).

CONCLUSION

Our analysis suggested the causal link between genetically increased sIL-6 R and increased risk of PAH and between genetically increased IL-6 signaling and reduced risk of PAH. Thus, higher sIL-6 R levels may be a risk factor for patients with PAH, whereas higher IL-6 signaling may be a protective factor for patients with PAH.

Combined Surface-Enhanced Raman and Infrared Absorption Spectroscopies for Streamlined Chemical Detection of Polycyclic Aromatic Hydrocarbon-Derived Compounds

Polycyclic aromatic hydrocarbons (PAHs) constitute a class of universally prevalent carcinogenic environmental contaminants. It is increasingly recognized, however, that PAHs derivatized with oxygen, sulfur, or nitrogen functional groups are frequently more dangerous than their unfunctionalized counterparts. This much larger family of chemicals─polycyclic aromatic compounds─PACs─is far less well characterized than PAHs. Using surface-enhanced Raman and IR Absorption spectroscopies (SERS + SEIRA) combined on a single substrate, along with density functional theoretical (DFT) calculations, we show that direct chemical detection and identification of PACs at sub-parts-per-billion concentration can be achieved. Focusing our studies on 9,10-anthraquinone, 5,12-tetracenequinone, 9-nitroanthracene, and 1-nitropyrene as model PAC contaminants, detection is made possible by incorporating a hydroxy-functionalized self-assembled monolayer that facilitates hydrogen bonding between analytes and the SERS + SEIRA substrate. 5,12-Tetracenequinone was detected at 0.3 ppb, and the limit of detection was determined to be 0.1 ppb using SEIRA alone. This approach is straightforwardly extendable to other families of analytes and will ultimately facilitate fieldable chemical detection of these dangerous yet largely overlooked environmental contaminants.

Polycyclic aromatic hydrocarbon record in an urban secondary carbonate deposit over the last three centuries (Paris, France)

Preserving water resources and limiting pollution are central environmental issues in the current context of intense anthropization. Among organic pollutants, polycyclic aromatic hydrocarbons (PAHs) are commonly analysed as part of water quality assessments. After being emitted into the atmosphere, these persistent organic pollutants are deposited on the continental surface, where they are transported to the aquatic environment by run-off and infiltration waters. Mainly due to anthropogenic emissions, PAHs can therefore be considered as a proxy for human activities. Urban secondary carbonate deposits (USCDs), similar to cave speleothems, have recently been studied for their potential as natural archives of water quality. However, USCDs have never been used to trace water organic pollution and only a few studies on PAHs in speleothems are available. This study focuses on a well-dated USCD covering the last 300 years from the Great Aqueduct of Belleville (north-east of Paris, France). The aim is to determine the nature and variation of trapped organic compounds over time and to discuss their origin, transport, and link with changes in soil occupation due to human activities. To do so, high-resolution solid-phase UV fluorescence imaging analyses were combined with chemical analyses of PAHs and organic carbon carried out on low-weight samples. The results show that PAHs have been present in urban surface water for 300 years. Over the last few decades, a 7-fold increase is observed, accompanied by a change in the pollution source, enriched in high-molecular-weight PAHs, probably linked to urban dust. This study also reveals modes of transport directly influenced by changes in the soil occupation that are very different from those usually encountered in natural environments. This work thus paves the way for a better long-term understanding of the impact of human activity on the transfer of pollutants to sub-surface waters.

Mind the gap - Relevant design for laboratory oil exposure of fish as informed by a numerical impact assessment model

Laboratory experiments provide knowledge of species-specific effects thresholds that are used to parameterize impact assessment models of oil contamination on marine ecosystems. Such experiments typically place individuals of species and life stages in tanks with different contaminant concentrations. Exposure concentrations are usually fixed, and the individuals experience a shock treatment being moved from clean water directly into contaminated water and then back to clean water. In this study, we use a coupled numerical model that simulates ocean currents and state, oil dispersal and fate, and early life stages of fish to quantify oil exposure histories, specifically addressing oil spill scenarios of high rates and long durations. By including uptake modelling we also investigate the potential of buffering transient high peaks in exposure. Our simulation results are the basis for a recommendation on the design of laboratory experiments to improve impact assessment model development and parameterization. We recommend an exposure profile with three main phases: i) a gradual increase in concentration, ii) a transient peak that is well above the subsequent level, and iii) a plateau of fixed concentration lasting ∼3 days. In addition, a fourth phase with a slow decrease may be added.

An integrated biological effects assessment of the discharge water into the Sunndalsfjord from an aluminium smelter

An integrated biological effects study using field transplanted mussels was applied to determine the potential biological effects of an effluent discharge from an aluminium smelter into a Norwegian fjord. Chemical body burden and biological effects were measured in mussels positioned downstream (1, 2, 5, 10 and 20 km) from the aluminium smelters discharge for a period of 6 weeks. A suite of biomarkers, from whole organism to subcellular responses were measured. Chemical concentrations in mussel tissues were low; however, a change in the PAC (polyaromatic compound) profile from high to low pyrogenic influence provided evidence of exposure to the smelter's effluent. Overall, the biological responses observed where greater in the mussels positioned closest to the smelter (1-5 km). Lowest chemical accumulation and biomarker responses were observed in mussels positioned 10 km from the smelter and were considered as the reference field population. Mussels located furthest from the smelter (20 km) exhibited significant biomarker responses and suggested a different contaminant source within the fjord. The integrated biological response index (IBR) was applied and reflected the expected level of exposure to the smelters discharge, with highest IBR calculated in mussels positioned closest to the discharge (1-5 km). Principal component analysis (PCA) also differentiated among mussel groups, with the most impacted located closest to the smelter. Not one chemical factor could explain the biological responses observed in mussels, but the presence of PAH16, PAH41 and metals Mn, Ni and Cr were the main contributors measured to the higher stress seen in the mussels from the 1 and 5 km groups.

Characterisation of former manufactured gas plant soils using parent and alkylated polycyclic aromatic hydrocarbons and Rock-Eval(6) pyrolysis

Soils sampled from 10 former manufactured gas plants (MGP) in the UK were investigated using gas chromatography mass spectrometry (GC-MS/MS) and Rock-Eval (6) Pyrolysis (RE). RE is a screening tool used to characterise bulk organic matter in soils via the release of carbon compounds during pyrolysis and oxidation. Both the distributions and concentrations of 30 parent and 21 alkylated polycyclic aromatic hydrocarbons (PAHs) and the parameters of RE were analysed to establish relationships between soils and the MGP processes history. Principal component analysis (PCA) using the PAHs distributions and RE parameters can assist with differentiating between MGP processes. MGP processes utilizing oil provided the clearest results, attributed to petrogenic signatures with high proportions of low molecular weight PAHs. Processes using lower temperature processes were distinguished by higher proportions of high molecular weight PAHs. RE parameters alone were unable to distinguish MGP processes but showed potential in estimating the lability and thus the amount of PAH that could be released from soils. This research provides new insights that may be useful in understanding and characterising the risks posed to human health from PAHs in soils.

Biomonitoring of polycyclic aromatic hydrocarbons in firefighters at fire training facilities and in employees at respiratory protection and hose workshops

Introduction

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic to humans and are formed by incomplete combustion. PAHs are always present during firefighting operations, and fire department members can be exposed to them in the workplace.

Methods

In this study, we analyzed 1-hydroxypyrene (1-OHP) in 36 urine samples from nine firefighters, collected before and after fire training sessions, and 32 urine samples from eight employees at respiratory protection and hose workshops. To assess breakthrough PAH exposure through personal protective equipment and potential dermal uptake, some of the workshop employees wore cotton garments under their regular workwear. Cotton samples were then examined for the presence of 17 semi-volatile and low-volatility PAHs.

Results

After firefighting exercises, we observed approximately a fivefold increase in mean 1-OHP concentrations in samples from firefighters, from 0.24 μg/L to 1.17 μg/L (maximum: 5.31 μg/L). In contrast, 1-OHP levels in workshop employees were found to be low, with the majority of urine samples yielding concentrations below the limit of quantification (LOQ: 0.05 μg/L, maximum: 0.11 μg/L). Similarly, low PAH levels were found on the workshop employees' cotton undergarments, with maximum concentrations of 250 and 205 ng/g for pyrene and benzo[a]pyrene, respectively.

Discussion

In conclusion, significant increases in 1-OHP in urine were observed in firefighters after training sessions, whereas work-related exposure remained low among workshop employees.

Transects of polycyclic aromatic hydrocarbons and organochlorine pesticides in an urban estuary using passive samplers

Hydrophobic organic contaminants (HOCs) are tracers of anthropogenic impacts, which can negatively affect water quality. The relative importance of new emissions versus the remobilization of HOCs from legacy reservoirs is not well constrained. Polyethylene passive samplers were deployed in vertical profiles at four sites to determine the concentrations and gradients of atmospheric and freely dissolved polycyclic aromatic hydrocarbons (PAHs) and freely dissolved organochlorinated pesticides (OCPs) in Narragansett Bay, an urban estuary. The concentrations of the sum of 20 PAHs ranged from 4.3 to 240 ng/m3 in the air and 3.2-21 ng/L in the water column, dominated by phenanthrene and pyrene. OCP concentrations varied from below the detection limit to 150 ng/L in the water column. Common OCPs included α-hexachlorocyclohexane, hexachlorobenzene, and aldrin. Gradients displayed net deposition for PAHs, but equilibrium through the water column. Results from this study provided evidence that key OCPs displayed mostly similar concentrations (at or near equilibrium) in the water at both Conimicut Point and Block Island.

Loss of prolyl hydroxylase 1 and 2 in SM22α-expressing cells prevents Hypoxia-Induced pulmonary hypertension

Pulmonary arterial hypertension (PAH) is a disease characterized by increased vasoconstriction and vascular remodeling. Pulmonary artery smooth muscle cells (PASMCs) highly express the transcription factor hypoxia-inducible factor-1α (HIF-1α), yet the role of PASMC HIF-1α in the development of PAH remains controversial. To study the role of SMC HIF-1α in the pulmonary vascular response to acute and chronic hypoxia, we used a gain-of-function strategy to stabilize HIF-1α in PASMC by generating mice lacking prolyl hydroxylase domain (PHD) 1 and 2 in SM22α-expressing cells. This strategy increased HIF-1α expression and transcriptional activity under conditions of normoxia and hypoxia. Acute hypoxia increased right ventricular systolic pressure (RVSP) in control, but not in SM22α-PHD1/2-/- mice. Chronic hypoxia increased RVSP and vascular remodeling more in control SM22α-PHD1/2+/+ than in SM22α-PHD1/2-/- mice. In vitro studies demonstrated increased contractility and myosin light chain phosphorylation in isolated PHD1/2+/+ compared with PHD1/2-/- PASMC under both normoxic and hypoxic conditions. After chronic hypoxia, there was more p27 and less vascular remodeling in SM22α-PHD1/2-/- compared with SM22α-PHD1/2+/+ mice. Hypoxia increased p27 in PASMC isolated from control patients, but not in cells from patients with idiopathic pulmonary arterial hypertension (IPAH). These findings highlight an SM22α-expressing cell-specific role for HIF-1α in the inhibition of pulmonary vasoconstriction and vascular remodeling. Modulating HIF-1α expression in PASMC may represent a promising preventative and therapeutic strategy for patients with PAH.NEW & NOTEWORTHY In a mouse model wherein hypoxia-inducible factor 1 alpha (HIF-1α) is stabilized in vascular smooth muscle cells, we found that HIF-1α regulates vasoconstriction by limiting phosphorylation of myosin light chain and regulates vascular remodeling through p27 induction. These findings highlight a cell-specific role for HIF-1α in the inhibition of pulmonary vasoconstriction and vascular remodeling.