Exposure Chamber Research Articles

Cat allergen exposure in a naturalistic exposure chamber: Aprospective observational study in cat-allergic subjects.

BackgroundTo determine the proportion and reproducibility of cat‐allergic mild asthmatics with early asthmatic response (EAR) during cat allergen exposure in a naturalistic exposure chamber (NEC).MethodsThis was a prospective, observational study in 30 cat‐allergic mild asthmatics who received two 180‐min cat‐allergen (Felis domesticus allergen 1 [Fel d 1]) challenges 27 days apart in an NEC.ResultsAn EAR (≥20% reduction from baseline in forced expiratory volume in 1 s [FEV1]) was observed in 67% and 52% of subjects at first and second NEC exposure, respectively, with similar median time to EAR; 44% of subjects had an EAR on days 1 and 28. Late asthmatic response (≥15% reduction in FEV1 within 24 h of NEC exit) was observed in 33% of subjects following either exposure. Average FEV1 and total nasal symptom score during NEC exposure were highly correlated within subjects between NEC exposures (r = 0.91, p < 0.0001; r = 0.73, p < 0.001), but total ocular symptom score was not. Time to EAR, but not average FEV1, was significantly associated with NEC Fel d 1 concentration, which was variable. There were no serious adverse events; 12/30 subjects experienced 20 adverse events (including asthma, 10%; headache, 10%).ConclusionsThe NEC model demonstrates that average FEV1 change is highly reproducible and has a low correlation with cat allergen levels. However, time to EAR and incidence of EAR are less reproducible and are highly correlated with NEC allergen levels. Average FEV1, rather than incidence of EAR or time to EAR, could be considered as an endpoint for interventional trials testing cat‐specific anti‐allergy therapies using an NEC.

Long-term benefits of targeted micronutrition with the holoBLG lozenge in house dust mite allergic patients

Summary Purpose The long-term effects of targeted micronutrition with the holoBLG lozenge in house dust mite (HDM) allergic rhinoconjunctivitis (ARC) patients were evaluated at a follow-up visit in an allergen exposure chamber (AEC). Methods Patients who were supplemented for 3‑months with the holoBLG lozenge in a previous study with two controlled HDM-AEC challenges [visits: V1, V3] were recruited for a third AEC challenge (V5) 7–8 months after cessation of supplementation. Symptoms (nose, conjunctival, bronchial, others), well-being, and lung function parameters were recorded exactly as in the previous study. Primary endpoint was change in median Total Nasal Symptom Score (TNSS) at V5 compared to V1. Secondary endpoints included e.g. change in median Total Symptom Score (TSS) and the exploratory analysis of temporal evolution of symptom scores using linear mixed effects models. Results Of the 32 patients included in the original study, 27 could be recruited for the follow-up visit with a third AEC challenge. An improvement of 20% (p = 0.15) in the primary endpoint TNSS [V1: 2.5 (interquartile range [IQR]: 1–4), V5: 2.0 (IQR: 1–3)] was observed; 40% (p = 0.04) improvement was seen for the TSS [V1: 5.0 (IQR: 3–9), V5: 3.0 (IQR: 2–5.5)]. Analysis of temporal evolution of all symptom scores, and the personal well-being revealed sustained, clinically meaningful improvement at V5 compared to V1. No relevant lung function parameter differences were observed. Conclusions Sustained long-term reduction of TNSS (primary endpoint) and sustained long-term improvement of secondary endpoints (temporal evolution of all symptom scores and well-being) were demonstrated 7–8 months after cessation of holoBLG supplementation, indicative of a long-lasting nature of immune resilience induced by holoBLG. Trial registration The study was registered at clinicaltrials.gov (NCT04872868).

Analysis of the Increase of Vascular Cell Adhesion Molecule-1 (VCAM-1) Expression and the Effect of Exposure in a Hyperbaric Chamber on VCAM-1 in Human Blood Serum: A Cross-Sectional Study.

Background and Objectives: Vascular cell adhesion molecule-1 (VCAM-1) was identified as a cell adhesion molecule that helps to regulate inflammation-associated vascular adhesion and the transendothelial migration of leukocytes, such as macrophages and T cells. VCAM-1 is expressed by the vascular system and can be induced by reactive oxygen species, interleukin 1 beta (IL-1β) or tumor necrosis factor alpha (TNFα), which are produced by many cell types. The newest data suggest that VCAM-1 is associated with the progression of numerous immunological disorders, such as rheumatoid arthritis, asthma, transplant rejection and cancer. The aim of this study was to analyze the increase in VCAM-1 expression and the impact of exposure in a hyperbaric chamber to VCAM-1 levels in human blood serum. Materials and Methods: The study included 92 volunteers. Blood for the tests was taken in the morning, from the basilic vein of fasting individuals, in accordance with the applicable procedure for blood collection for morphological tests. In both groups of volunteers, blood was collected before and after exposure, in heparinized tubes to obtain plasma and hemolysate, and in clot tubes to obtain serum. The level of VCAM-1 was determined using the immunoenzymatic ELISA method. Results: The study showed that the difference between the distribution of VCAM-1 before and after exposure corresponding to diving at a depth of 30 m was at the limit of statistical significance in the divers group and that, in most people, VCAM-1 was higher after exposure. Diving to a greater depth had a much more pronounced impact on changes in VCAM-1 values, as the changes observed in the VCAM-1 level as a result of diving to a depth of 60 m were statistically highly significant (p = 0.0002). The study showed an increase in VCAM-1 in relation to the baseline value, which reached as much as 80%, i.e., VCAM-1 after diving was almost twice as high in some people. There were statistically significant differences between the results obtained after exposure to diving conditions at a depth of 60 m and the values measured for the non-divers group. The leukocyte level increased statistically after exposure to 60 m. In contrast, hemoglobin levels decreased in most divers after exposure to diving at a depth of 30 m (p = 0.0098). Conclusions: Exposure in the hyperbaric chamber had an effect on serum VCAM-1 in the divers group and non-divers group. There is a correlation between the tested morphological parameters and the VCAM-1 level before and after exposure in the divers group and the non-divers group. Exposure may result in activation of the endothelium.

Development of a wristband-type wearable device for the colorimetric detection of ammonia emanating from the human skin surface

Human skin gas is the term used to describe gas emanating from the human skin surface. Ammonia, one such gas, has a pungent odor affecting body odor. As ammonia’s dermal emission increases with physical load and/or psychological stress, the resulting body odor is called “fatigue odor.” Previously, human skin gases were collected via direct contact or headspace sampling, using a homemade sampling probe or bag and passive flux sampler. We developed a wristband-type wearable device for rapid, on-site detection of dermal ammonia based on headspace passive sampling coupled with Alizarin red as a pH indicator. Color change was measured with a colorimetric indicator tested in an exposure chamber and calibrated using dermal emission flux measured with a passive flux sampler. The indicator was developed as a tablet-like device comprising a polyethylene terephthalate body with a transparent window, detection sheet, diffuser, and disk with concentric spaces. The detection sheet was prepared by pipetting 50 μL 0.1 % Alizarin red–1 % glycerol into a methanol solution onto a cellulose filter paper and drying. The colorimetric indicator was placed on the skin surface using a wristband. For quantitative evaluation, the color-change amount was evaluated using color difference (ΔE*ab), which was calculated from L*, a*, and b* measured using a spectrophotometer. The colorimetric response to ammonia on the colorimetric indicator was evaluated by comparison with the conventional passive flux sampler. Good correlations were obtained between the color change amounts and those collected with the passive flux sampler. To simulate living human-skin conditions, the influence of temperature and humidity was also tested, and the effect on the passive indicator was clarified. Compared to conventional dermal ammonia-measuring methods, this newly developed passive indicator was more user-friendly because the results were obtained on-site without external evaluation. The passive indicator was also found to be an effective and simplified instrument for dermal ammonia measurements.

Development of a thermal spray coating aerosol generator and inhalation exposure system

Thermal spray coating involves spraying a product (oftentimes metal) that is melted by extremely high temperatures and then applied under pressure onto a surface. Large amounts of a complex metal aerosol (e.g., Fe, Cr, Ni, Zn) are formed during the process, presenting a potentially serious risk to the operator. Information about the health effects associated with exposure to these aerosols is lacking. Even less is known about the chemical and physical properties of these aerosols. The goal was to develop and test an automated thermal spray coating aerosol generator and inhalation exposure system that would simulate workplace exposures. An electric arc wire-thermal spray coating aerosol generator and exposure system was designed and separated into two areas: (1) an enclosed room where the spray coating occurs; (2) an exposure chamber with different measurement devices and controllers. The physicochemical properties of aerosols generated during electric arc wire-thermal spray coating using five different consumable wires were examined. The metal composition of each was determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES), including two stainless-steel wires [PMET720 (82 % Fe, 13 % Cr); PMET731(66 % Fe, 26 % Cr)], two Ni-based wires [PMET876 (55 % Ni, 17 % Cr); PMET885 (97 % Ni)], and one Zn-based wire [PMET540 (99 % Zn)]. The particles generated regardless of composition were poorly soluble, complex metal oxides and mostly arranged as chain-like agglomerates and similar in size distribution as determined by micro-orifice uniform deposit impactor (MOUDI) and electrical low-pressure impactor (ELPI). To allow for continuous, sequential spray coating during a 4-hr exposure period, a motor rotated the metal pipe to be coated in a circular and up-and-down direction. In a pilot animal study, male Sprague-Dawley rats were exposed to aerosols (25 mg/m3 × 4 h/d × 9 d) generated from electric arc wire- thermal spray coating using the stainless-steel PMET720 consumable wire. The targeted exposure chamber concentration was achieved and maintained during a 4-hr period. At 1 d after exposure, lung injury and inflammation were significantly elevated in the group exposed to the thermal spray coating aerosol compared to the air control group. The system was designed and constructed for future animal exposure studies to generate continuous metal spray coating aerosols at a targeted concentration for extended periods of time without interruption.

Influence of alkali content and silica modulus on the carbonation kinetics of alkali-activated slag concrete

Carbonation is inevitable process during the service life of concrete structures, where CO2 causes decalcification of the calcium-bearing phases. These changes affect the durability of concrete and accelerate the corrosion of reinforcement. Alkali-activated materials (AAMs) are alternative, cement-free binders based on aluminosilicate rich precursor and alkaline activator. The interest in AAMs increased during the last century, due to the production process with low CO2 footprint comparing to Portland cement (PC) concrete, the possibility to use wide range of industrial by-products as precursors and comparable performance to PC concrete. Despite the extensive research in this field, the carbonation resistance of AAMs needs to be better understood, due to the differences and complexity of binder chemistry compared to PC concrete. The propagation of carbonation process will depend on chemical composition of the precursors and the type and dosage of activators. This paper presents the results of microstructural changes of three alkali-activated concrete mixes after exposure to accelerated carbonation. Ground granulated blast furnace slag was used as a precursor and sodium hydroxide and sodium silicate as activators. Three mixes have constant water to binder ratio and slag content, while alkali content and silica modulus were varied. The carbonation resistance was evaluated by testing carbonation depth after 7 and 28 days of exposure in carbonation chamber. Microstructural changes during carbonation were investigated by thermogravimetric analysis and mercury intrusion porosimetry.

Utilization of Computational Fluid Dynamics Simulation for Gas Exposure Chamber

Utilization of Computational Fluid Dynamics Simulation for Gas Exposure Chamber

EFFECT OF HYPERBARIC OXYGEN THERAPY ON NERVE REGENERATION IN RATS.

ABSTRACTObjective: To evaluate histological changes in peripheral nerves of rats after sciatic nerve neurorrhaphy, according to the time of exposure to hyperbaric oxygen chamber treatment. Methods: Twenty-five Wistar rats were divided into 5 groups according to the amount of exposure to hyperbaric oxygen chamber treatment. Group 1 was the control and there was no use of hyperbaric oxygen chamber; group 2 received one week of therapy; group 3, two weeks; group 4, three weeks; and group 5, four weeks. After the fourth postoperative week, the animals were submitted to euthanasia and a sciatic nerve sample sent for histological analysis. Axons proximal and distal to the neurorrhaphy were counted with axonal regeneration index measurement. Results: We observed that the number of axons distal to neurorrhaphy increases with the amount of hyperbaric oxygen chamber exposure, the results were more expressive from the third week of treatment. However, the statistical analysis found no significant difference between the groups. Conclusion: The descriptive analysis suggests benefit of using hyperbaric oxygen chamber directly proportional to the time of therapy. The study, however, did not present statistically relevant results, probably due to the reduced sample size. Subsequent studies with more significant sampling would be of great value. Level of Evidence II, Prospective Comparative Study.

CO2 emission rates from sedentary subjects under controlled laboratory conditions

We determined carbon dioxide (CO2) emission rates from sedentary subjects performing light work on tablets or smartphones in controlled chamber exposures. Five groups, each consisting of four people (four groups with two females and two males and one with three males and one female), stayed in a 22.5 m3 stainless steel chamber under different environmental conditions for 3 h in the morning and then 2,5 h in the afternoon after having a light lunch. Three groups consisted of young adults (college students), one of seniors, and one of teenagers. The chamber was ventilated with outdoor air at 3.2 h−1 (per person rate was 5 L/s). The CO2 emission rates per person were calculated using a single-zone mass-balance equation and the measured CO2 concentration once steady state had been reached. Per person emission rates varied between 14.1 and 16.8 L/h in the morning and 15.9–17.8 L/h in the afternoon; higher levels in the afternoon were probably caused by the increased metabolism from diet-induced thermogenesis (DIT). Emission rates were higher with increased temperature when the participants felt warm, but did not change with increased relative humidity or ozone concentration. They differed to some extent from those estimated using ISO 8996 and ASTM DS 6245, but were similar to published measured CO2 emission rates. The present results require confirmation with more people and measurements of CO2 emission rates using the calorimetric method.

Facile Route to Effective Antimicrobial Aluminum Oxide Layer Realized by Co-Deposition with Silver Nitrate

The emergence and spreading of the SARS-CoV-2 pandemic has forced the focus of attention on a significant issue: the realization of antimicrobial surfaces for public spaces, which do not require extensive use of disinfectants. Silver represents one of the most used elements in this context, thanks to its excellent biocidal performance. This work describes a simple method for the realization of anodized aluminum layers, whose antimicrobial features are ensured by the co-deposition with silver nitrate. The durability and the chemical resistance of the samples were evaluated by means of several accelerated degradation tests, such as the exposure in a salt spray chamber, the contact with synthetic sweat and the scrub test, highlighting the residual influence of silver in altering the protective behavior of the alumina layers. Furthermore, the ISO 22196:2011 standard was used as the reference protocol to set up an assay to measure the effective antibacterial activity of the alumina-Ag layers against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, even at low concentrations of silver. Finally, the Ag-containing aluminum oxide layers exhibited excellent antimicrobial performances also following the chemical–physical degradation processes, ensuring good durability over time of the antimicrobial surfaces. Overall, this work introduces a simple route for the realization of anodized aluminum surfaces with excellent antibacterial properties.

Chronic exposure to polluted urban air aggravates myocardial infarction by impaired cardiac mitochondrial function and dynamics

Air pollution exposure positively correlates with increased cardiovascular morbidity and mortality rates, mainly due to myocardial infarction (MI). Herein, we aimed to study the metabolic mechanisms underlying this association, focusing on the evaluation of cardiac mitochondrial function and dynamics, together with its impact over MI progression. An initial time course study was performed in BALB/c mice breathing filtered air (FA) or urban air (UA) in whole-body exposure chambers located in Buenos Aires City downtown for up to 16 weeks (n = 8 per group and time point). After 12 weeks, lung inflammatory cell recruitment was evident in UA-exposed mice. Interestingly, impaired redox metabolism, characterized by decreased lung SOD activity and increased GSSG levels and NOX activity, precede local inflammation in this group. At this selected time point, additional mice were exposed to FA or UA (n = 12 per group) and alveolar macrophage PM uptake and nitric oxide (NO) production was observed in UA-exposed mice, together with increased pro-inflammatory cytokine levels (TNF-α and IL-6) in BAL and plasma. Consequently, impaired heart tissue oxygen metabolism and altered mitochondrial ultrastructure and function were observed in UA-exposed mice after 12 weeks, characterized by decreased active state respiration and ATP production rates, and enhanced mitochondrial H2O2 production. Moreover, disturbed cardiac mitochondrial dynamics was detected in this group. This scenario led to a significant increase in the area of infarcted tissue following myocardial ischemia reperfusion injury in vivo, from 43 ± 3% of the area at risk in mice breathing FA to 66 ± 4% in UA-exposed mice (n = 6 per group, p < 0.01), together with a sustained increase in LVEDP during myocardial reperfusion. Taken together, our data unravel cardiac mitochondrial mechanisms that contribute to the understanding of the adverse health effects of urban air pollution exposure, and ultimately highlight the importance of considering environmental factors in the development of cardiovascular diseases.

Technical standards in allergen exposure chambers worldwide - an EAACI Task Force Report.

Allergen exposure chambers (AECs) can be used for controlled exposure to allergenic and non-allergenic airborne particles in an enclosed environment, in order to (i) characterize the pathological features of respiratory diseases and (ii) contribute to and accelerate the clinical development of pharmacological treatments and allergen immunotherapy for allergic disease of the respiratory tract (such as allergic rhinitis, allergic rhinoconjunctivitis, and allergic asthma). In the guidelines of the European Medicines Agency for the clinical development of products for allergen immunotherapy (AIT), the role of AECs in determining primary endpoints in dose-finding Phase II trials is emphasized. Although methodologically insulated from the variability of natural pollen exposure, chamber models remain confined to supporting secondary, rather than primary, endpoints in Phase III registration trials. The need for further validation in comparison with field exposure is clearly mandated. On this basis, the European Academy of Allergy and Clinical Immunology (EAACI) initiated a Task Force in 2015 charged to gain a better understanding of how AECs can generate knowledge about respiratory allergies and can contribute to the clinical development of treatments. Researchers working with AECs worldwide were asked to provide technical information in eight sections: (i) dimensions and structure of the AEC, (ii) AEC staff, (iii) airflow, air processing, and operating conditions, (iv) particle dispersal, (v) pollen/particle counting, (vi) safety and non-contamination measures, (vii) procedures for symptom assessments, (viii) tested allergens/substances and validation procedures. On this basis, a minimal set of technical requirements for AECs applied to the field of allergology is proposed.

Abstract 11496: Increased Pulmonary Microvascular Endothelial Permeability by E-Cigarette Aerosol: The Pathway from Lung to Peripheral Blood Vessels

Background: We reported that permeability of cultured microvascular endothelial cells is increased by incubation in e-cigarette (e-cig) users’ serum relative to that from smokers or non-users. It is unclear whether this is a direct effect of aerosol chemicals that reach the circulation, or an indirect response mediated by the e-cig users’ pulmonary epithelium. Hypothesis: Vaping increases microvascular endothelial permeability indirectly by signaling from alveolar epithelium. Methods: E-cig aerosol condensates were derived from e-liquids with and without nicotine (12 mg/mL free base), each containing menthol, vanillin, ethyl maltol, or cinnamaldehyde (2 mg/mL). Cell permeability was measured in human lung microvascular endothelial cells (HMVEC-Ls) using electric cell-substrate impedance sensing. Human Type II lung alveolar epithelial cells (ATII) were grown in serum-free air-liquid interface and exposed to e-cig aerosols with 0, 18, or 36 mg/mL nicotine (free base and salt), or air, 1 h/day for 3 days in an exposure chamber inside a CO 2 incubator. Results: Incubation of HMVEC-Ls with 0.3% v/v e-cig aerosol condensates from most e-liquids, with and without nicotine, decreased cell permeability (in contrast to the increased permeability that we reported from incubation with e-cig user serum). The exception was menthol + nicotine, which increased permeability (but reduced viability). When HMVEC-Ls were instead incubated with supernatant collected from ATII cells after exposure to e-cig aerosols, permeability was increased when supernatants were from exposure to aerosol with 36 mg/ml nicotine salt, but not 36 or 18 mg/mL freebase nicotine. Supernatants from similarly exposed ATII cells contained higher levels of the proinflammatory proteins MCP-1, IL-8, GROα, and MIP-1β when aerosol contained 36 mg/mL freebase nicotine (3/6 wells) or nicotine salt (5/6), but not 18 mg/ml nicotine (0/6). Conclusion: HVMEC-L permeability was not directly increased by e-cig aerosol condensate, but was increased by supernatant of alveolar epithelial cells exposed to high-nicotine aerosol, potentially mediated by elevated ATII cytokine production, indicating a potential indirect mechanism by which vaping increases pulmonary microvascular permeability.

PM2.5 induces airway hyperresponsiveness and inflammation via the AhR pathway in a sensitized Guinea pig asthma-like model

Exposure to fine particulate matter (PM2.5) induces airway inflammation and hyperreactivity that lead to asthma. The mechanisms involved are still under investigation. We investigated the effect of resveratrol (3,4’,5-trihydroxystilbene) (RES) on airway hyperresponsiveness, inflammation and CYP1A1 protein expression (an aryl hydrocarbon receptor (AhR) target) induced by PM2.5 exposure in an allergic asthma experimental guinea pig model. The polyphenolic compound RES was used due to its antioxidant and anti-inflammatory properties and as an antagonist of the AhR; thus, providing mechanistic insights.Animals were sensitized with aluminum hydroxide and ovalbumin and exposed to filtered air or PM2.5. Exposure to PM2.5 was conducted using a whole-body chamber particle concentrator (5 h/day) for 15 days. Animals received saline solution or RES (10 mg/kg per day) orally for 21 days simultaneously to the OVA challenge or PM2.5 exposure.PM2.5 exposure (mean 433 ± 111 μg/m3 in the exposure chamber) in OVA challenged animals induced an asthma-like phenotype characterized by increased baseline lung resistance (Rrs) and central airway resistance (Rn) in response to acetylcholine (ACh) evaluated using a flexiVent system®. A parallel increase of pro-inflammatory cytokines (IL-6, IL-17, TNF-α and IFN-γ), inflammatory cells (eosinophils and neutrophils) in bronchoalveolar lavage fluid (BALF) and lung CYP1A1 increase also occurred. RES significantly inhibited airway hyperresponsiveness, inflammation, and CYP1A1 protein expression in the OVA-challenged PM2.5 exposed animals.In summary, with the use of RES we demonstrate that PM-induced airway hyperreactivity is modulated by the inflammatory response via the AhR pathway in an allergic asthma guinea pig model.

A novel clinical method to measure skin staining reveals activation of skin damage pathways by cigarette smoke.

BackgroundLong‐term use of cigarettes can result in localised staining and aging of smokers’ skin. The use of tobacco heating products (THPs) and electronic cigarettes (ECs) has grown on a global scale; however, the long‐term effect of these products’ aerosols on consumers’ skin is unknown. This pilot clinical study aimed to determine whether THP or EC aerosol exposure results in skin staining or activation of biomarkers associated with oxidative stress.Materials and methodsEight areas were identified on the backs of 10 subjects. Two areas were used for air control, and two areas exposed to 32‐puffs of cigarette smoke (CS), THP or EC aerosols, which were delivered to the skin using a 3‐cm diameter exposure chamber and smoke engine. Skin colour was measured using a Chromameter. Squalene (SQ), SQ monohydroperoxide (SQOOH) and malondialdehyde (MDA) levels were measured in sebum samples by mass spectrometry and catalase colorimetry.ResultsCS exposure significantly increased skin staining, SQOOH and MDA levels and SQOOH/SQ ratio. THP and EC values were significantly lower than CS; EC values being comparable to air control. THP values were comparable to EC and air control at all endpoints, apart from skin staining. SQ and catalase levels did not change with exposure.ConclusionsCS stained skin and activated pathways known to be associated with skin damage. THPs and ECs produced significantly lower values, suggesting they could offer hygiene and cosmetic benefits for consumers who switch exclusively from smoking cigarettes. Further studies are required to assess longer‐term effects of ECs and THPs on skin function.

Influence of conversion coatings on the resistance of adhesive joints to undercorrosion

Abstract The paper deals with the application of conversion coatings for the preparation of surfaces before adhesive bonding of galvanized and non-galvanized steels. The morphology of the coatings was monitored by electron microscopy. The corrosion characteristics of the conversion coatings were determined by linear polarization. Steels treated with conversion coatings were used to form bonded joints using three structural adhesives. The resistance of the joints to undercorrosion was determined following the change in the load-bearing capacity of the joints after exposure in the climatic chamber.

P024 THE ENVIRONMENTAL EXPOSURE CHAMBER: A REAL WORLD YET CONTROLLED APPROACH TO ALLERGIC CONJUNCTIVITIS TRIALS

Allergic Conjunctivitis (AC) affects 15-20% of the worldwide population. Environmental exposure chamber (EEC) may facilitate clinical trials as it mimics natural allergen exposure, in a controlled setting which may aid in the selection of adequately allergic AC subjects.

Air pollution and high-intensity interval exercise: Implications to anti-inflammatory balance, metabolome and cardiovascular responses

High-intensity interval exercise (HIIE) is an effective non-pharmacological tool for improving physiological responses related to health. When HIIE is performed in urban centers, however, the exerciser is exposed to traffic-related air pollution (TRAP), which is associated with metabolic, anti-inflammatory imbalance and cardiovascular diseases. This paradoxical combination has the potential for conflicting health effects. Thus, the aim of this study was to determine the effects of HIIE performed in TRAP exposure on serum cytokines, non-target metabolomics and cardiovascular parameters. Fifteen participants performed HIIE in a chamber capable to deliver filtered air (FA condition) or non-filtered air (TRAP condition) from a polluted site adjacent to the exposure chamber. Non-target blood serum metabolomics, blood serum cytokines and blood pressure analyses were collected in both FA and TRAP conditions at baseline, 10 min after exercise, and 1 h after exercise. The TRAP increased IL-6 concentration by 1.7 times 1 h after exercise (p < 0.01) and did not change the anti-inflammatory balance (IL-10/TNF-α ratio). In contrast, FA led to an increase in IL-10 and IL-10/TNF-α ratio (p < 0.01), by 2.1 and 2.3 times, respectively. The enrichment analysis showed incomplete fatty acid metabolism under the TRAP condition (p < 0.05) 10 min after exercise. There was also an overactivity of ketone body metabolism (p < 0.05) at 10 min and at 1 h after exercise with TRAP. Exercise-induced acute decrease in systolic blood pressure (SBP) was not observed at 10 min and impaired at 1 h after exercise (p < 0.05). These findings reveal that TRAP potentially attenuates health benefits often related to HIIE. For instance, the anti-inflammatory balance was impaired, accompanied by accumulation of metabolites related to energy supply and reduction to exercise-induced decrease in SBP.

Dosimetric Comparison of Exposure Pathways to Human Organs and Tissues in Radon Therapy.

Three therapeutic applications are presently prescribed in the radon spas in Gastein, Austria: exposure to radon in a thermal bath, exposure to radon vapor in an exposure chamber (vapor bath), and exposure to radon in the thermal gallery, a former mine. The radiological exposure pathways to human organs and tissues in these therapeutic radon applications are inhalation of radon and radon progeny via the lungs, radon transfer from water or air through the skin, and radon-progeny deposition on the skin in water or air. The objectives of the present study were to calculate radon and radon-progeny doses for selected organs and tissues for the different exposure pathways and therapeutic applications. Doses incurred in red bone marrow, liver, kidneys, and Langerhans cells in the skin may be correlated with potential therapeutic benefits, while doses to the lungs and the basal cells of the skin indicate potential carcinogenic effects. The highest organ doses among the three therapeutic applications were produced in the thermal gallery by radon progeny via inhalation, with lung doses of 5.0 mSv, and attachment to the skin, with skin doses of 4.4 mSv, while the radon contribution was less significant. For comparison, the primary exposure pathways in the thermal bath are the radon uptake through the skin, with lung doses of 334 μSv, and the radon-progeny attachment to the skin, with skin doses of 216 μSv, while the inhalation route can safely be neglected.

Повреждение ДНК в тканях белых крыс при воздействии дыма лесных пожаров

Wildfire smoke affects the health of the population of the entire planet and each year the situation is getting worse. Fire smoke has mutagenic, carcinogenic and other long-term effects. The aim of this paper was to study the genotoxic effect of wildfire smoke on male white rats and the transgenerational effect of wildfire smoke on their offspring. Smoke exposure simulation was performed on 40 male white rats in 200-litre exposure chambers. Forest litter, branches, fallen bark, and the upper layer of soil served as a combustible substrate. The exposure was carried out for 4 hours 5 days a week in the course of 4 weeks. Offspring of both sexes were obtained from the exposed animals and intact females. We analysed DNA fragmentation and global DNA methylation in the gonadal tissue and blood cells of the exposed animals immediately after the exposure and global DNA methylation in the blood cells of the offspring upon reaching sexual maturity. The research was performed using the comet assay with modifications to study global DNA methylation with MspI and HpaII restriction enzymes. The exposed animals showed an increased level of global DNA methylation in their blood cells. In male offspring, a decrease in the level of global DNA methylation in the blood cells was revealed, compared with the controls, while females showed no differences from the controls. The established facts of changes in global DNA methylation after exposure to wildfire smoke require further in-depth research, since the mechanism of the development of this phenomenon remains rather unclear.