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The aim of this study was to investigate whether VO(2)max can be accurately measured in a respiration chamber. Thirty participants aged 23.4 +/- 3.9 years with a wide range in VO(2)max were included. Participants performed four incremental cycle ergometer tests (VO(2)max) with a minimum of 5 days between tests. These tests consisted of one familiarization test with face mask, followed by two VO(2)max tests in the respiration chamber and one test with face mask in randomized order. Oxygen consumption and CO2 production were measured continuously using Omnical (Maastricht University, the Netherlands) gas analysis system. The mean VO(2)max was 3634 +/- 766 ml, which resulted in mean VO(2)max per lean body mass of 60.8 +/- 8.0 ml/kg. Repeated respiration chamber tests showed a high concordance, and no significant differences were detected between tests (Lin's concordance correlation coefficient (Rc) = 0.99; increment 70 +/- 302 ml/min; p = .38). There was high concordance between the mean VO(2)max from both respiration chamber tests and the mean face mask tests, and no significant difference (Rc = 0.99; increment 41 +/- 173 ml/min; p = .22) was observed. The Bland-Altman plots showed no proportional bias between different tests. In conclusion, the respiration chamber has been found to be a valid and reproducible method for measuring VO(2)max. New research opportunities are possible in the respiration chamber, such as maximal exercise testing during 24-hour measurements.

The objective of the present study was to investigate factors related to variation in feed efficiency (FE) among cows. Data included 841 cow/period observations from 31 energy metabolism studies assembled across 3 research stations. The cows were categorized into low-, medium-, and high-FE groups according to residual feed intake (RFI), residual energy-corrected milk (RECM), and feed conversion efficiency (FCE). Mixed model regression was conducted to identify differences among the efficiency groups in animal and energy metabolism traits. Partial regression coefficients of both RFI and RECM agreed with published energy requirements more closely than cofficients derived from production experiments. Within RFI groups, efficient (Low-RFI) cows ate less, had a higher digestibility, produced less methane (CH4) and heat, and had a higher efficiency of metabolizable energy (ME) utilization for milk production. High-RECM (most efficient) cows produced 6.0 kg/d more of energy-corrected milk (ECM) than their Low-RECM (least efficient) contemporaries at the same feed intake. They had a higher digestibility, produced less CH4 and heat, and had a higher efficiency of ME utilization for milk production. The contributions of improved digestibility, reduced CH4, and reduced urinary energy losses to increased ME intake at the same feed intake were 84, 12, and 4%, respectively. For both RFI and RECM analysis, increased metabolizability contributed to approximately 35% improved FE, with the remaining 65% attributed to the greater efficiency of utilization of ME. The analysis within RECM groups suggested that the difference in ME utilization was mainly due to the higher maintenance requirement of Low-RECM cows compared with Medium- and High-RECM cows, whereas the difference between Medium- and High-RECM cows resulted mainly from the higher efficiency of ME utilization for milk production in High-RECM cows. The main difference within FCE (ECM/DMI) categories was a greater (8.2 kg/d) ECM yield at the expense of mobilization in High-FCE cows compared with Low-FCE cows. Methane intensity (CH4/ECM) was lower for efficient cows than for inefficient cows. The results indicated that RFI and RECM are different traits. We concluded that there is considerable variation in FE among cows that is not related to dilution of maintenance requirement or nutrient partitioning. Improving FE is a sustainable approach to reduce CH4 production per unit of product, and at the same time improve the economics of milk production.

The current state, tools, and applications of personalized medicine with special emphasis on inflammatory skin diseases like psoriasis and atopic dermatitis are discussed. Inflammatory pathways are outlined as well as potential targets for monoclonal antibodies and small‐molecule inhibitors.

Cigarette smoke is an aerosol containing microparticles that carry nicotine into the lung alveolar region where nicotine is rapidly absorbed into circulation. Nicotine exposure in smokers is a chronic intermittent process, with episodic intake during wakefulness and abstinence during sleep resulting in circadian fluctuation of blood nicotine levels. We developed an integrated platform where freely moving rodents can be exposed to episodic nicotine aerosol on an investigator-designed schedule. Plasma nicotine and its metabolite cotinine levels were determined with a LC-MS/MS method. We characterized the aerosol in the breathing zone of the rodent exposure chamber. The droplet-size distribution was within the respirable diameter range. The system can generate a wide range of nicotine concentrations in air that meet a variety of experimental needs. Rats were exposed to nicotine aerosol once every half hour in the dark phase of 12:12-h light-dark cycles for 10 days. We optimized the parameters of aerosol generation and exposure: plasma nicotine and cotinine concentrations reached 30–35 and 190–240 ng/ml, respectively. The nicotine levels and circadian patterns resembled the pharmacokinetic pattern of human smokers. In summary, we developed an aerosol system that can produce clinically relevant chronic intermittent nicotine exposure in unanesthetized, unrestrained rodents with route of administration and circadian blood pharmacokinetics resembling human smokers. This methodology is a novel tool for understanding the health effects of chronic intermittent nicotine exposure such as with tobacco cigarettes and electronic cigarettes for studies of behavior, pharmacology and toxicology, nicotine addiction, tobacco-related diseases, and teratogenicity, and for the discovery of therapeutics. NEW & NOTEWORTHY We developed a lung alveolar region-targeted aerosol method and a system that provides chronic intermittent nicotine exposure in freely moving rodents. The method produces in rodents clinically relevant nicotine exposure with the route and circadian pharmacokinetics resembling human smokers. This method is a novel tool for understanding the health impacts of chronic nicotine exposures such as with tobacco cigarettes and electronic cigarettes, for studying nicotine pharmacology, toxicology, addiction, and tobacco-related diseases, and for the discovery of therapeutics.

Purpose To investigate changes at a molecular level in the mouse corneal endothelium (CE) exposed to chronic cigarette smoke (CS). Methods Pregnant mice (gestation days 18-20) were placed in a whole-body exposure smoking chamber, and a few days later pups were born. After 3.5 months of CS exposure, a ConfoScan4 scanning microscope was used to examine the corneal endothelial cells (CECs) of CS-exposed and control (Ct) mice. The CE was peeled under a microscope and maintained as four biological replicates (two male and two female) for CS-exposed and Ct mice; each replicate consisted of 16 CEs. The proteome of the CE was investigated through mass spectrometry. Results The CE images of CS-exposed and Ct mice revealed a difference in the shape of CECs accompanied by a nearly 10% decrease in CEC density (P < 0.00003) following CS exposure. Proteome profiling identified a total of 524 proteins exhibiting statistically significant changes in CE from CS-exposed mice. Importantly, proteins associated with Descemet's membrane (DM), including COL4α1, COL4α2, COL4α3, COL4α4, COL4α5, COL4α6, COL8α1, COL8α2, and FN1, among others, exhibited diminished protein levels in the CE of CS-exposed mice. Conclusions Our data confirm that exposure to CS results in reduced CEC density accompanied by diminished levels of multiple collagen and extracellular matrix proteins associated with DM.

Experimental hypoxia has been used for decades to examine the adaptive response to low-oxygen environments. Various models have been studied, including flies, worms, fish, rodents, and humans. Our lab has recently used this technology to examine the effect of environmental hypoxia on mammalian heart regeneration. In this chapter, we describe studies of systemic hypoxia in mice. We found that systemic hypoxia can blunt oxidative DNA damage and induce cardiomyocyte proliferation. While our primary interests are focused on cardiovascular research, these hypoxia protocols are applicable to any other organ system.

Cigarette smoking is the single most important risk factor for the development of cardiovascular and pulmonary diseases; however, the role of nicotine in the pathogenesis of these diseases is incompletely understood. The purpose of this study was to examine the effects of chronic nicotine inhalation on the development of cardiovascular and pulmonary disease with a focus on blood pressure and cardiac remodeling. Male C57BL6/J mice were exposed to air (control) or nicotine vapor (daily, 12 hour on/12 hour off) for 8 weeks. Systemic blood pressure was recorded weekly by radio-telemetry, and cardiac remodeling was monitored by echocardiography. At the end of the 8 weeks, mice were subjected to right heart catheterization to measure right ventricular systolic pressure. Nicotine-exposed mice exhibited elevated systemic blood pressure from weeks 1 to 3, which then returned to baseline from weeks 4 to 8, indicating development of tolerance to nicotine. At 8 weeks, significantly increased right ventricular systolic pressure was detected in nicotine-exposed mice compared with the air controls. Echocardiography showed that 8-week nicotine inhalation resulted in right ventricular (RV) hypertrophy with increased RV free wall thickness and a trend of increase in RV internal diameter. In contrast, there were no significant structural or functional changes in the left ventricle following nicotine exposure. Mechanistically, we observed increased expression of angiotensin-converting enzyme and enhanced activation of mitogen-activated protein kinase pathways in the RV but not in the left ventricle. We conclude that chronic nicotine inhalation alters both systemic and pulmonary blood pressure with the latter accompanied by RV remodeling, possibly leading to progressive and persistent pulmonary hypertension.

Antihistamines are easily accessible and cover the vast majority of the medical therapy of allergic rhinitis. However, their systemic administration may more frequently associate with their well-known side-effect, sedation, which is a serious problem in persons in safety-critical jobs such as aviation. We have a poor understanding whether a non-sedative antihistamine has an impact on vigilance when hypobaric hypoxia occurs during flight.In this randomized, placebo-controlled, double-blind, cross-over study the effect of 20 mg bilastine was compared to 10 mg cetirizine and to placebo (20 mg pyridoxine) in 33 individuals at ground level and at 4,000 m altitude simulated in hypobaric chamber. Levels of vigilance, ultrashort memory, combined distributive attention, monotony tolerance and peripheral blood oxygen saturation (SpOBilastine did not impair the tested abilities in comparison with the control groups either at ground level or hypobaric hypoxia. Administration of cetirizine increased the number of errors at ground level. At the simulated altitude, already impaired results were additionally demonstrated with regards to the distributive attention test.From the two examined antihistamines, bilastine should be the preferred medication for by individuals who require constant attention and are exposed to hypobaric hypoxia.

Lead (Pb) is a heavy metal that plays an unknown biological role and is very toxic even at low concentrations. The main sources of Pb are Pb-contaminated areas in industrial areas or landfills. Inhalation is one of the most common routes of exposure to this metal, but there is little information on its effect on the liver. Thirty male mice were exposed to 0.1 M Pb acetate by inhalation for 8 weeks, twice a week for 1h. A recovery group was free of exposure for 4 weeks. Histological evaluation showed an increase in the inflammatory infiltrate and in the percentage of meganuclei in the liver. This was observed since the first week and throughout the whole exposure time. A significant increase in the aspartate aminotransferase concentration was observed in the liver function tests; yet, the alanine aminotransferase concentration did not show significant changes. The 4-hydroxynonenal (4-HNE) and nitrotyrosine levels in Pb-exposed mice, identified by immunohistochemistry, showed a significant increment compared to the controls. This effect was observed throughout Pb exposure. After a 4-week period of suspended exposure, recovery time, the concentration of 4-HNE and nitrotyrosine decreased to similar levels of those previously observed in controls, this suggests a decrease in the generation of oxidative stress by Pb inhalation. Although our results suggest that the lungs are the first contact organs and filters during Pb inhalation, this metal eventually reaches the liver and might cause damage by oxidative stress. This damage can decrease in time if exposure is discontinued.

Pulmonary hypertension (PH) frequently occurs in infants with bronchopulmonary dysplasia (BPD), causing increased mortality and right ventricular (RV) dysfunction that persists into adulthood. A first step in developing better therapeutic options is identifying and characterizing an appropriate animal model. Previously, we characterized the short-term morbidities of a model in which C57BL/6J wild-type (WT) mice were exposed to 70% O2 (hyperoxia) during the neonatal period. Here, we aimed to determine the long-term morbidities using lung morphometry, echocardiography (Echo), and cardiac magnetic resonance imaging (cMRI). The major highlight of this study is the use of the state-of-the art imaging technique, cMRI, in mice to characterize the long-term cardiac effects of neonatal hyperoxia exposure. To this end, WT mice were exposed to 21% O2 (normoxia) or hyperoxia for two weeks of life, followed by recovery in normoxia for six weeks. Alveolarization, pulmonary vascularization, pulmonary hypertension, and RV function were quantified at eight weeks. We found that hyperoxia exposure resulted in persistent alveolar and pulmonary vascular simplification. Furthermore, the Echo and cMRI studies demonstrated that hyperoxia-exposed mice had signs of PH and RV dysfunction as indicated by increased RV pressure, mass, and end-systolic and -diastolic volumes, and decreased RV stroke volume and ejection fractions. Taken together, our results demonstrate that neonatal hyperoxia exposure in mice cause cardiopulmonary morbidities that persists into adulthood and provides evidence for the use of this model to develop novel therapies for BPD infants with PH.

In many physiological systems, real-time endogeneous and exogenous signals in living organisms provide critical information and interpretations of physiological functions; however, these signals or variables of interest are not directly accessible and must be estimated from noisy, measured signals. In this paper, we study an inverse problem of recovering gas exchange signals of animals placed in a flow-through respirometry chamber from measured gas concentrations. For large-scale experiments (e.g., long scans with high sampling rate) that have many uncertainties (e.g., noise in the observations or an unknown impulse response function), this is a computationally challenging inverse problem. We first describe various computational tools that can be used for respirometry reconstruction and uncertainty quantification when the impulse response function is known. Then, we address the more challenging problem where the impulse response function is not known or only partially known. We describe nonlinear optimization methods for reconstruction, where both the unknown model parameters and the unknown signal are reconstructed simultaneously. Numerical experiments show the benefits and potential impacts of these methods in respirometry. Published version

INTRODUCTION: Diving is an activity performed in more than 1 atmosphere absolute pressure (ATA) either underwater or in a hyperbaric chamber. We aimed to compare lung function values of trained divers in 1.5 ATA hyperbaric chambers after inhaling 100% oxygen and regular air. METHODS: This experimental study with crossover design involved 18 trained divers in 1.5 ATA hyperbaric room, which is equivalent s to a 5-meter depth. The eighteen subjects as the supplementation group, using oro-nasal mask, inhaled 100% oxygen for 30 minutes followed by a one-day washout period. The subjects were then crossed-over into control group inhaling only regular air for 30 minutes. Lung function test was performed before and after supplementation. RESULTS: In eighteen subjects inhaling regular air, there was a significant difference (p < 0.05) in FEV 1 /FVC, PEF, FEF25, FEF50, and FEF75. Whereas in eighteen subjects inhaling 100% oxygen, significant difference (p < 0.05) was observed not only in FEV 1 /FVC, PEF, FEF25, FEF50 and FEF75, but also in FEV 1 . CONCLUSIONS: There were significant differences in lung function, especially in dynamic volume of trained divers in 1.5 ATA hyperbaric chamber after inhaling 100% oxygen and regular air for 30 minutes; while there were no significant differences in lung capacity (VC and FVC) in the both groups. Lung function returned to normal following supplementation with a 1-day washout period.

Exposure to the humidifier disinfectant, polyhexamethylene guanidine phosphate (PHMG), in mists generated from ultrasonic humidifiers was studied in a simulation chamber and apartment rooms. PHMG is suspected as a causative agent of lung disease in Korea residences. In the simulation-chamber study, the amount of disinfectant discharged from three different ultrasonic humidifiers was measured. Mists generated at 1, 2, and 4 times the recommended amount of disinfectant were sampled with an impinger, and the effect of relative humidity (RH) on airborne disinfectant concentration was studied by changing RH from 60%–70% to 90%–100%. In addition, particle size distribution (PSD) in mists was measured by scanning mobility particle sizer (SMPS), aerodynamic particle sizer (APS), and Mastersizer. In the apartment study, mists generated from ultrasonic humidifiers were sampled for 6 h in small and large rooms during fall ( n = 10) and winter ( n = 15). In the simulation study, the humidifiers discharged 205 ± 24.6 ml/h of mist at maximum capacity. Concentrations of airborne disinfectant increased with increasing concentration of disinfectant. RH affected airborne disinfectant concentration in the chamber, with increasing concentration with increasing RH. Below RH 70%, no airborne PHMG was detected. PHMG-containing mists generated from ultrasonic humidifier showed various sizes ranging from 149–157 nm to 690–740 nm to larger than 5.4 µm by SMPS, APS, and Mastersizer, respectively. Surface area mean diameter measured by Mastersizer ranged from 5.39 µm to 5.72 µm. In the apartment study conducted during the fall, the geometric mean (GM) and geometric standard deviation (GSD) and arithmetic mean (AM) and standard deviation (SD) of airborne PHMG concentration were 3.22 + 5.13 µg/m3 and 8.26 ± 12.18 µg/m3, respectively. In the winter, GM + GSD and AM ± SD of airborne PHMG concentration were 0.21 + 2.11 µg/m3 and 0.35 ± 0.62 µg/m3, respectively. RH and temperature in the apartment rooms for fall and winter were 22.5 ± 1.7°C, 74.5 ± 15.6% and 22.0 ± 2°C, 51.1 ± 12.9%, respectively. Different RHs in the fall and winter resulted in very different airborne concentrations of disinfectant in the apartment rooms. Exposure levels and PSD of mists generated from ultrasonic humidifiers in apartments are not sufficient to conclude that PHMG causes lung disease in Korean residences.

We developed a new inhalation exposure method to evaluate effects of synthetic cannabimimetics that are being distributed as new, unregulated drugs in the Tokyo area. We selected the commercial product "SOUTOU" containing AB-CHMINACA and 5F-AMB as the test drug and dried marshmallow (Althaea officinalis) leaves as the negative control. A half cigarette packed with dried marshmallow leaves or SOUTOU was ignited, then mainstream smoke from each was delivered to five mice in an exposure box. After the cigarettes were fully consumed, neurobehavioral observations and a catalepsy test were performed at 15, 30 and 60 min after exposure. The effluent air from the exposure box was poured into impingers containing acetonitrile (first impinger) and dimethyl sulfoxide (second impinger). The resulting solutions were analyzed to assess decomposition of the synthetic cannabimimetics. Mice exposed to SOUTOU smoke showed many excitement behaviors and some suppressive behaviors at 15, 30 and 60 min. These clearly included cannabimimetic specific pharmacological actions. Negative control mice also showed some suppressive behaviors at 15 min but these were attenuated at later times, nearly disappearing at 60 min. In addition, the behavioral effects observed in controls were less pronounced than those in SOUTOU exposed mice. The inhalation exposure method developed in our study would be effective for determining cannabinoid specific pharmacological effects of illegal drugs, as well as for assessing the presence of active compound(s) by comparing the test substance with a negative control.

Altitude exposure can exaggerate the transient increase in markers of oxidative stress observed following acute exercise. However, these responses have not been monitored in endurance-trained cyclists at altitudes typically experienced while training. Endurance trained males (n = 12; mean (± SD) age: 28 ± 4 years, V̇O2max 63.7 ± 5.3 ml/kg/min) undertook two 75-min exercise trials at 70% relative V̇O2max; once in normoxia and once in hypobaric hypoxia, equivalent to 2000m above sea level (hypoxia). Blood samples were collected before, immediately after and 2 h postexercise to assess plasma parameters of oxidative stress (protein carbonylation (PC), thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC) and catalase activity (CAT)). Participants cycled at 10.5% lower power output in hypoxia vs. normoxia, with no differences in heart rate, blood lactate or rating of perceived exertion observed. PC increased and decreased immediately after exercise in hypoxia and normoxia respectively (nmol/mg/protein: Normoxia—0.3 ± 0.1, Hypoxia + 0.4 ± 0.1; both p < .05). CAT increased immediately postexercise in both trials, with the magnitude of change greater in hypoxia (nmol/min/ml: Normoxia + 12.0 ± 5.0, Hypoxia + 27.7 ± 4.8; both p < .05). CAT was elevated above baseline values at 2 h postexercise in Hypoxia only (Normoxia + 0.2 ± 2.4, Hypoxia + 18.4 ± 5.2; p < .05). No differences were observed in the changes in TBARS and TAC between hypoxia and normoxia. Trained male cyclists demonstrated a differential pattern/ timecourse of changes in markers of oxidative stress following submaximal exercise under hypoxic vs. normoxic conditions.

Introduction Field studies for allergic rhinitis (AR) commonly have inconsistent allergen concentrations and subject exposure patterns due to varying environmental conditions and subject behaviors. A technical and clinical validation study was conducted for the Allergen BioCube® using timothy grass to confirm uniform allergen concentration and clinically relevant subject symptom responses. Methods Allergen concentrations were verified by laser particle counts. Subjects (N = 14) with positive skin test reactions and no symptoms at screening received four 3‐h timothy grass exposures in the BioCube over consecutive days. Subjects evaluated nasal itching, sneezing, rhinorrhea, and nasal congestion while in the BioCube; Total Nasal Symptom Score (TNSS) was computed. Peak Nasal Inspiratory Flow (PNIF), Peak Expiratory Flow Rate (PEFR), sIgE blood tests, and Nasal Inflammation Score (NIS) were assessed. A correlation analysis was conducted for mean sIgE, skin test, and TNSS. Results Uniform timothy grass concentrations were achieved in the BioCube, both spatially and temporally, at all subject positions. Mean TNSS increased substantially from pre‐exposure levels (0.36 ± 0.74 to 1.86 ± 2.14) to maximums of 7.07 ± 2.76 at 1.5 h and 6.71 ± 2.70 at 3 h BioCube exposure. Twelve (86%) subjects had TNSS increases ≥6 units. PNIF decreased 12–24% from baseline at 3‐h BioCube exposure. NIS increased (baseline = 0) to 3.7 (maximum score = 4). A low/moderate correlation (r = 0.485) occurred between mean sIgE blood levels and mean skin tests; neither sIgE or skin tests correlated with mean TNSS. However, subjects with high skin test scores or positive blood IgE tended to also have higher TNSS. Conclusions The Allergen BioCube achieved technical and clinical validation for uniform timothy grass concentration and clinically meaningful AR sign and symptom responses. The Allergen BioCube can be used to assess the efficacy of therapies for reduction of AR signs and symptoms resulting from grass exposure.

RationaleNon-contingent chronic nicotine exposure procedures have evolved rapidly in recent years, culminating in Electronic Nicotine Delivery Systems (ENDS or e-cigarettes) to deliver vaporized drugs to rodents in standard housing chambers.ObjectivesThe aim of the current work was to use ENDS to test concentration-dependent effects of nicotine e-cigarette vapor inhalation on blood-nicotine concentrations, blood-cotinine concentrations, and somatic withdrawal signs over time in rats.MethodsMale Wistar rats were exposed to vapor containing various concentrations of nicotine (20, 40, 80 mg/mL) for 11 days through ENDS, and blood concentrations of nicotine and cotinine, the major proximate metabolite of nicotine, as well as spontaneous and precipitated somatic withdrawal signs were measured over time (across days of exposure and over hours after termination of vapor exposure).ResultsExposing male Wistar rats to non-contingent nicotine vapor inhalation through ENDS produces somatic withdrawal symptoms and measurable blood-nicotine and blood-cotinine levels that change according to 1) concentration of nicotine in vape solution, 2) number of days of nicotine vapor exposure, 3) time since termination of nicotine vapor exposure, and 4) relative to the withdrawal signs, whether withdrawal was spontaneous or precipitated (by mecamylamine).ConclusionsThe data presented here provide parameters that can be used as a reasonable starting point for future work that employs ENDS to deliver non-contingent nicotine vapor in rats, although many parameters can and should be altered to match the specific goals of future work.

ObjectiveTo assess the effect of topical betahistine on Eustachian tube function in subjectively abnormal subjects in a hyperbaric chamber.MethodActive and passive Eustachian tube function was examined using tympanometry in a pressure chamber.ResultsActive Eustachian tube function was tested against the negative middle ear pressure induced by increasing the chamber pressure to +3 kPa. One voluntary swallow decreased middle-ear pressure by a mean of 1.36 kPa. Passive Eustachian tube function was tested by measuring spontaneous Eustachian tube openings as the chamber pressure dropped from +10 kPa to ambient. Four distinct patterns of Eustachian tube behaviour were seen, three of which indicated Eustachian tube dysfunction. Betahistine had no positive effect on Eustachian tube opening, although previous animal studies had suggested a beneficial effect.ConclusionTopical betahistine had no effect on Eustachian tube function. Combining a hyperbaric chamber with tympanometry proved ideal for evaluating Eustachian tube function.

Carbon black nanoparticles (CBNPs) are one of atmospheric particles components and have been closely related with a series of lung diseases. It can reach the depths of the respiratory tract or even alveolar more easily than those micro-particles. Although some of its toxicities have been confirmed in animals or human bodies, the subchronic toxicity mechanism of CBNPs has been uncertain so far. Therefore, it is very necessary to establish a novel method and clarify the mechanism of subchronic toxicity caused by concentration adjustments of small molecule metabolites in vivo. In animal experiments, CB exposure, recovery and control group were set up. The concentration of CBNPs in chamber was 30.06 ± 4.42 mg/m3. We developed a UHPLC-Q-TOF-MS/MS-based non-targeted metabolomic analysis strategy to analyze serum samples of rats. Then, differential metabolites in serum were found by multivariate data analysis and 39 potential biomarkers were identified. It was showed that main metabolic pathways associated with CBNPs exposure were hormones metabolism, amino acid metabolism, nucleotide metabolism and lipid metabolism. It is worth noting that long-term exposure to CBNPs had the greatest impact on steroid hormones biosynthesis so that the risk of infertility could increase. The results provided a new mechanistic insight into the metabolic alterations owing to CBNPs induced subchronic toxicity.

Objective: Complete systems for laboratory-based inhalation toxicology studies are typically not commercially available; therefore, inhalation toxicologists utilize custom-made exposure systems. Here we report on the design, construction, testing, operation and maintenance of a newly developed in vivo rodent ozone inhalation exposure system. Materials and methods: Key design requirements for the system included large-capacity exposure chambers to facilitate studies with large sample sizes, automatic and precise control of chamber ozone concentrations, as well as automated data collection on airflow and environmental conditions. The exposure system contains two Hazelton H-1000 stainless steel and glass exposure chambers, each providing capacity for up to 180 mice or 96 rats. We developed an empirically tuned proportional-integral-derivative control loop that provides stable ozone concentrations throughout the exposure period (typically 3h), after a short ramp time (∼8 min), and across a tested concentration range of 0.2–2 ppm. Specific details on the combination of analog and digital input/output system for environmental data acquisition, control and safety systems are provided, and we outline the steps involved in maintenance and calibration of the system. Results: We show that the exposure system produces consistent ozone exposures both within and across experiments, as evidenced by low coefficients of variation in chamber ozone concentration and consistent biological responses (airway inflammation) in mice, respectively. Conclusion: Thus, we have created a large and robust ozone exposure system, facilitating future studies on the health effects of ozone in rodents.

Weather changes accompanied by decreases in barometric pressure are suggested to trigger meteoropathy, i.e., weather-related pain. We previously reported that neuropathic pain-related behavior in rats is aggravated by lowering barometric pressure, and that this effect is abolished by inner ear lesions. These results suggest that mechanisms that increase vestibular neuronal activity may parallel those that contribute to meteoropathy generation. However, it remains unknown whether changes in barometric pressure activate vestibular neuronal activity. To address this issue, we used expression of c-Fos protein as a marker for neural activation. Male and female mice were placed in a climatic chamber, and the barometric pressure was lowered by 40 hPa, from 1013 hPa, for 50 min (LP stimulation). The total number of c-Fos-positive cells in the vestibular nuclei was counted bilaterally after LP stimulation. We also video-recorded mouse behaviors and calculated the total activity score during the LP stimulation. LP stimulation resulted in significant c-Fos expression in the superior vestibular nucleus (SuVe) of male and female mice. There was no effect of LP stimulation on the total activity score. These data show that distinct neurons in the SuVe respond to LP stimulation. Similar mechanisms may contribute to the generation of meteoropathy in humans.

Aim: This study was carried out to determine the effects of formaldehyde (FA) inhalation on the humoral immunity of rats and the protective effect of Nigella sativa (NS) oil. Materials and Methods: The rats ( n = 33) were divided into five groups, with five animals in the control group (FA-free air) and seven in the other four groups. Group FA1 was exposed to FA (5 ppm), group FA + NS1 was treated with NS and exposed to FA (5 ppm), group FA2 was exposed to FA (10 ppm), and group FA + NS2 was treated with NS and exposed to FA (10 ppm). At the end of a 4-week study period, blood samples were collected. Enzyme-linked immunosorbent assay was used to determine the levels of serum total immunoglobulin A (IgA), total immunoglobulin M (IgM), total immunoglobulin G (IgG), and complement 3 (C3). Results: FA inhalation significantly increased serum IgA, IgM, and C3 levels and decreased serum IgG levels compared with the control group. NS administration decreased serum IgA, IgM, and C3 levels, which were induced by FA inhalation. Conclusion: FA inhalation significantly increased acute antibody responses and C3 levels in a dose-dependent manner compared with the control group. FA inhalation decreased the secondary immune response compared with the control group. Levels of acute antibody responses and complement following exposure to FA inhalation returned to normal following treatment with NS (immunoregulatory effect). However, NS did not affect the secondary immune response.

PURPOSE To determine if the Schirmer test is affected by environmental humidity, to quantify any effects, and to consider the ways in which this may affect the diagnosis of dry eye disease. METHODS All experiments took place within a controlled environment chamber at a range of 5% to 95% relative humidity (RH). In vitro testing immersed Schirmer strips at 5 mm depth in water for 5 minutes. In vivo tests were conducted using the standard clinical method. All experiments were conducted using both standard Schirmer strips and Schirmer strips sheathed in a plastic film in order to reduce the possible effects of evaporation. RESULTS In vitro results showed a clear decrease in Schirmer wetting length as RH was reduced. Schirmer test strips that were encased within a plastic sheathing were less affected by changing RH. As well as wetting length, the rate of wetting of Schirmer strips was also affected by changes in RH. In vivo data showed that Schirmer results in participants with severe dry eye disease were less affected by changes in RH than "normal" participants. CONCLUSIONS Patients with severe dry eye disease produce Schirmer test results which are unaffected by environmental humidity. However, patients with moderate Schirmer wetting lengths may be falsely diagnosed as having dry eye disease if their test is undertaken in a low-humidity environment. This phenomenon may be overcome with the use of plastic sheathing. Previous studies investigating the effects of environmental conditions on the tear film may have been affected by this phenomenon.

INTRODUCTION Hypoxia caused by high altitude exposure can impair cerebral and mental functions. Blood flow and oxygenation of the buccal tissue can be reliable markers to detect hypoxia. In this study, near infrared spectroscopy was used in combination with a novel optical probe to evaluate the applicability of the novel probe in measuring hypoxia markers in buccal tissue under a hypoxic condition. METHODS Six healthy participants were tested at altitudes from 2000 to 16,000 ft inside a hypobaric chamber. The buccal reference measurements of blood flow and oxygen saturation were synchronized with the spectral measurements of the novel near infrared probe and the relationship between the reference measurements and spectral data were evaluated by multivariate partial least square method. In addition, finger oxygen saturation was measured during the experiment and the recordings were compared with buccal oxygen saturation. RESULTS The spectral analysis illustrated that the spectral data from the near infrared probe correlated strongly with the absorption features of both buccal flow and oxygenation measured by the reflectance sensors (average R(2) = 0.89). The results showed probably overestimated values for buccal oxygen saturation recorded by the reference pulse oximeter in comparison with finger oxygen saturation, with the mean difference increasing from 1.8% at 2000 ft to 11.4% at 16,000 ft. CONCLUSION The novel near infrared probe showed promising results for simultaneous measurement of blood flow and oxygen saturation in the buccal tissue. The suggested method can be used as a new technique for early indication of hypoxia in future clinical applications.

Background Exercise under hypoxic conditions represents an additional stress in relation to exercise in normoxia. Hypoxia induces oxidative stress and inflammation as mediated through tumour necrosis factor (TNF)-α release that might be exacerbated through exercise. In addition, vitamin E supplementation might attenuate oxidative stress and inflammation resulting from hypoxia during exercise. The present study aimed to evaluate the effects of vitamin E supplementation (250 mg) on inflammatory parameters and cellular damage after exercise under hypoxia simulating an altitude of 4200 m. Methods Nine volunteers performed three sessions of 60 min of exercise (70% maximal oxygen uptake) interspersed for 1 week under normoxia, hypoxia and hypoxia after vitamin E supplementation 1 h before exercise. Blood was collected before, immediately after and at 1 h after exercise to measure inflammatory parameters and cell damage. Results Percentage oxygen saturation of haemoglobin decreased after exercise and recovered 1 h later in the hypoxia + vitamin condition (P < 0.05). Supplementation decreased creatine kinase (CK)-TOTAL, CK-MB and lactate dehydrogenase 1 h after exercise (P < 0.05). The exercise in hypoxia increased interleukin (IL)-6, TNF-α, IL-1ra and IL-10 immediately after exercise (P < 0.05). Supplementation reversed the changes observed after exercise in hypoxia without supplementation (P < 0.05). Conclusions We conclude that 250 mg of vitamin E supplementation at 1 h before exercise reduces cell damage markers after exercise in hypoxia and changes the concentration of cytokines, suggesting a possible protective effect against inflammation induced by hypoxia during exercise.

A liquid chromatography-mass spectrometry-based method for the quantification of intracellular concentrations of dietary phenolics in bacteria was developed. Using this assay, the time-dependent uptake of quercetin and two of its glycosides into gut microbiota model organisms (Escherichia coli and Bifidobacterium bifidum) under aerobic and anaerobic conditions was studied. For the first time, quantitative data on the uptake of dietary phenols were obtained indicating a time-dependent differential uptake of the dietary compounds. The shape of the uptake curve and the comparative use of bacterial mutants lacking porins OmpFC or the multi-drug efflux pump AcrAB, respectively, along with the identification and quantification of selected bacterial metabolites provided a mechanistic insight into the uptake process.

The Naval Medical Research Unit Dayton (NAMRU-D) at Wright-Patterson Air Force Base, Ohio, in conjunction with the U.S. Air Force, studied ototoxic effects of JP-8 in rats. NAMRU-D used a multi-chamber whole body exposure facility for up to 96 test animals and 32 control animals at different exposure levels. The objective was to design a noise delivery system that could provide a white noise source one octave band wide, centered at 8 kHz frequency, delivered from outside the exposure chambers. Sound pressure levels were required to be within ±2 dB at all exposure points within each chamber and within ±2 dB over a 6-h run. Electrodynamic shakers were used to produce input noise in exposure chambers by inducing vibration in chamber plenums. Distribution of sound pressure levels across exposure points was controlled within a ±1.5dB prediction interval (α = 0.05) or better. Stability at a central reference point was controlled over 6-h runs within a ±1 dB prediction interval (α = 0.05) or better. The final system allowed NAMRU-D to deliver noise and whole-body aerosol exposures to multiple animals at different levels simultaneously and study the effects that ototoxins may have on hearing loss.

Titanium dioxide (TiO2) nanoparticles are widely used in cosmetics, sunscreen, electronics, drug delivery systems, and diverse bio-application fields. In the workplace, the primary exposure route for TiO2 nanoparticles is inhalation through the respiratory system. Because TiO2 nanoparticles have different physiological properties, in terms of size and bioactivity, their toxic effects in the respiratory system must be determined. In this study, to determine the toxic effect of inhaled TiO2 nanoparticles in the lung and the underlying mechanism, we used a whole-body chamber inhalation system to expose A/J mice to TiO2 nanoparticles for 28 days. During the experiments, the inhaled TiO2 nanoparticles were characterized using a cascade impactor and transmission electron microscopy. After inhalation of the TiO2 nanoparticles, hyperplasia and inflammation were observed in a TiO2 dose-dependent manner. To determine the biological mechanism of the toxic response in the lung, we examined endoplasmic reticulum (ER) and mitochondria in lung. The ER and mitochondria were disrupted and dysfunctional in the TiO2-exposed lung leading to abnormal autophagy. In summary, we assessed the potential risk of TiO2 nanoparticles in the respiratory system, which contributed to our understanding of the mechanism underlining TiO2 nanoparticle toxicity in the lung.

The epithelium that covers the conducting airways and alveoli is a primary target for inhaled toxic substances, and therefore a focus in inhalation toxicology. The increasing concern about the use of animal models has stimulated the development of in vitro cell culture models for analysis of the biological effects of inhaled toxicants. However, the validity of the current in vitro models and their acceptance by regulatory authorities as an alternative to animal models is a reason for concern, and requires a critical review. In this review, focused on human lung epithelial cell cultures as a model for inhalation toxicology, we discuss the choice of cells for these models, the cell culture system used, the method of exposure as well as the various read-outs to assess the cellular response. We argue that rapid developments in the 3D culture of primary epithelial cells, the use of induced pluripotent stem cells for generation of lung epithelial cells and the development of organ-on-a-chip technology are among the important developments that will allow significant advances in this field. Furthermore, we discuss the various routes of application of inhaled toxicants by air-liquid interface models as well as the vast array of read-outs that may provide essential information. We conclude that close collaboration between researchers from various disciplines is essential for development of valid methods that are suitable for replacement of animal studies for inhalation toxicology.

International audience; BACKGROUND:A fixed-dose combination of intranasal azelastine hydrochloride and fluticasone propionate (MP-AzeFlu) is the most effective treatment of allergic rhinitis, but its onset of action requires further investigation.OBJECTIVE:To compare the onset of action of MP-AzeFlu with the free combination of oral loratadine (LORA) and intranasal fluticasone propionate (INFP).METHODS:In this single-center, randomized, placebo-controlled, double-blind, double-dummy, 3-period crossover trial, allergic rhinitis symptoms were induced in asymptomatic patients by ragweed pollen challenge in an allergen environmental exposure chamber. Patients received single-dose MP-AzeFlu, LORA/INFP, or placebo and were monitored for 4 hours. The primary outcome was onset of action measured by total nasal symptom score (TNSS). Secondary measures were total ocular symptom score (TOSS), total score of the 7 nasal and ocular symptoms (T7SS), and the global visual analog scale (VAS).RESULTS:The full analysis set included 82 patients, of which 78 completed all treatments. TNSS was significantly reduced versus placebo from 5 minutes for MP-AzeFlu and 150 minutes for LORA/INFP onward (both P < .05) till the end of assessment (0-4 hours). MP-AzeFlu reduced TNSS to a greater extent at each time point from 5 to 90 minutes (P < .05) and over the entire assessment interval (P ≤ .005) versus LORA/INFP or placebo. No statistically significant difference between LORA/INFP and placebo was observed over the assessment interval (P = .182). The onset of action of MP-AzeFlu assessed by TOSS, T7SS, and VAS was 10 minutes, 2 hours earlier than with LORA/INFP.CONCLUSION:MP-AzeFlu had a more rapid onset of action (5 minutes) and was more effective than LORA/INFP.

Made available in DSpace on 2018-11-26T16:17:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-10-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Occupational toxicology and clinical pharmacology integration will be useful to understand potential exposure-drug interaction and to shape risk assessment strategies in order to improve occupational health. The aim of the present study was to evaluate the effect of exposure to ethanol fuel on in vivo activities of cytochrome P450 (CYP) isoenzymes CYP3A, CYP2C and CYP2D by the oral administration of the probe drugs verapamil, ibuprofen and fluoxetine. Male Wistar rats exposed to filtered air or to 2000 ppm ethanol in a nose-only inhalation chamber during (6 h/day, 5 days/week, 6 weeks) received single oral doses of 10 mg/kg verapamil or 25 mg/kg ibuprofen or 10 mg/kg fluoxetine. The enantiomers of verapamil, norverapamil, ibuprofen and fluoxetine in plasma were analyzed by LC-MS/MS. The area under the curve plasma concentration versus time extrapolated to infinity (AUC(0-infinity)) was calculated using the Gauss-Laguerre quadrature. Inhalation exposure to ethanol reduces the AUC of both verapamil (approximately 2.7 fold) and norverapamil enantiomers (>2.5 fold), reduces the AUC(0-infinity) of (+)-(S)-IBU (approximately 2 fold) and inhibits preferentially the metabolism of (-)-(R)-FLU. In conclusion, inhalation exposure of ethanol at a concentration of 2 TLV-STEL (6 h/day for 6 weeks) induces CYP3A and CYP2C but inhibits CYP2D in rats. (C) 2015 Elsevier Ltd. All rights reserved. Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, Dept Anal Clin Toxicol & Bromatol, BR-05508 Sao Paulo, Brazil Univ Estadual Paulista, Inst Quim, Dept Quim Fis, BR-14801902 Araraquara, SP, Brazil Univ Estadual Paulista, Fac Ciencias Farmaceut, Dept Principios Ativos Nat & Toxicol, BR-14801902 Araraquara, SP, Brazil Univ Estadual Paulista, Inst Quim, Dept Quim Fis, BR-14801902 Araraquara, SP, Brazil Univ Estadual Paulista, Fac Ciencias Farmaceut, Dept Principios Ativos Nat & Toxicol, BR-14801902 Araraquara, SP, Brazil FAPESP: 2009/17532-0

Chloroform is an organic solvent used as an intermediate in the synthesis of various fluorocarbons. Despite its widespread use in industry and agriculture, exposure to chloroform can cause illnesses such as cancer, especially in the liver and kidneys. The aim of the study was to analyze the effects of chloroform on redox imbalance and pulmonary inflammatory response in adult C57BL/6 mice. Forty animals were divided into 4 groups (N = 10): female (FCG) and male (MCG) controls, and females (FEG) and males (MEG) exposed to chloroform (7.0 ppm) 3 times/d for 20 minutes for 5 days. Total and differential cell counts, oxidative damage analysis, and protein carbonyl and antioxidant enzyme catalase (CAT) activity measurements were performed. Morphometric analyses included alveolar area (Aa) and volume density of alveolar septa (Vv) measurements. Compared to FCG and MCG, inflammatory cell influx, oxidative damage to lipids and proteins, and CAT activity were higher in FEG and MEG, respectively. Oxidative damage and enzyme CAT activity were higher in FEG than in FCG. The Aa was higher in FEG and MEG than in FCG and MCG, respectively. The Vv was lower in FEG and MEG than in FCG and MCG, respectively. This study highlights the risks of occupational chloroform exposure at low concentrations and the intensity of oxidative damage related to gender. The results validate a model of acute exposure that provides cellular and biochemical data through short-term exposure to chloroform.

Background A major part of testing of rebreather apparatuses for underwater diving focuses on the oxygen dosage system. Methods A metabolic simulator for testing breathing apparatuses was built and evaluated. Oxygen consumption was achieved through catalytic combustion of propene. With an admixture of carbon dioxide in the propene fuel, the system allowed the respiratory exchange ratio to be set freely within human variability and also made it possible to increase test pressures above the condensation pressure of propene. The system was tested by breathing ambient air in a pressure chamber with oxygen uptake (Vo₂) ranging from 1-4 L · min(-1), tidal volume (VT) from 1-3 L, breathing frequency (f) of 20 and 25 breaths/min, and chamber pressures from 100 to 670 kPa. Results The measured end-tidal oxygen concentration (Fo₂) was compared to calculated end-tidal Fo₂. The largest average difference in end-tidal Fo₂during atmospheric pressure conditions was 0.63%-points with a 0.28%-point average difference during the whole test. During hyperbaric conditions with pressures ranging from 100 to 670 kPa, the largest average difference in Fo₂was 1.68%-points seen during compression from 100 kPa to 400 kPa and the average difference in Fo₂during the whole test was 0.29%-points. Conclusion In combination with a breathing simulator simulating tidal breathing, the system can be used for dynamic continuous testing of breathing equipment with changes in VT, f, Vo2, and pressure.

Introduction An important problem for pilots is visual disturbances occurring under +Gz acceleration. Assessment of the degree of intensification of these disturbances is generally accepted as the acceleration tolerance level (ATL) criterion determined in human centrifuges. The aim of this research was to evaluate the visual-motor responses of pilots during rapidly increasing acceleration contained in cyclic intervals of +6 Gz to the maximum ATL. Methods The study involved 40 male pilots ages 32-41 yr. The task was a quick and faultless response to the light stimuli presented on a light bar during exposure to acceleration until reaching the ATL. Simple response time (SRT) measurements were performed using a visual-motor analysis system throughout the exposures which allowed assessment of a pilot's ATL. Results There were 29 pilots who tolerated the initial phase of interval acceleration and achieved +6 Gz, completing the test at ATL. Relative to the control measurements, the obtained results indicate a significant effect of the applied acceleration on response time. SRT during +6 Gz exposure was not significantly longer compared with the reaction time between each of the intervals. SRT and erroneous reactions indicated no statistically significant differences between the "lower" and "higher" ATL groups. Conclusion SRT measurements over the +6-Gz exposure intervals did not vary between "lower" and "higher" ATL groups and, therefore, are not useful in predicting pilot performance. The gradual exposure to the maximum value of +6 Gz with exposure to the first three intervals on the +6-Gz plateau effectively differentiated pilots.