Cigarette Smoke Triggers Loss of Corneal Endothelial Cells and Disruption of Descemet's Membrane Proteins in Mice.

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.

Validity and reproducibility of VO2 max testing in a respiration chamber.

The aim of this study was to investigate whether VO2 max can be accurately measured in a respiration chamber. Thirty participants aged 23.4 ± 3.9 years with a wide range in VO2 max were included. Participants performed four incremental cycle ergometer tests (VO2 max) with a minimum of 5 days between tests. These tests consisted of one familiarization test with face mask, followed by two VO2 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 VO2 max was 3634 ± 766 ml, which resulted in mean VO2 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; ∆70 ± 302 ml/min; p = .38). There was high concordance between the mean VO2 max from both respiration chamber tests and the mean face mask tests, and no significant difference (Rc = 0.99; ∆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 VO2 max. New research opportunities are possible in the respiration chamber, such as maximal exercise testing during 24-hour measurements.

Effects of Chronic Nicotine Inhalation on Systemic and Pulmonary Blood Pressure and Right Ventricular Remodeling in Mice.

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.

Nicotine e-cigarette vapor inhalation effects on nicotine & cotinine plasma levels and somatic withdrawal signs in adult male Wistar rats.

RATIONALE: Non-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. OBJECTIVES: The 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. METHODS: Male 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). RESULTS: Exposing 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). CONCLUSIONS: The 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.

Characterization of serum metabolites as biomarkers of carbon black nanoparticles-induced subchronic toxicity in rats by hybrid triple quadrupole time-of-flight mass spectrometry with non-targeted metabolomics strategy.

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 ±â€¯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.

Lowering barometric pressure induces neuronal activation in the superior vestibular nucleus in mice.

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.

Chronic intermittent nicotine delivery via lung alveolar region-targeted aerosol technology produces circadian pharmacokinetics in rats resembling human smokers.

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.

Long-term pulmonary and cardiovascular morbidities of neonatal hyperoxia exposure in mice.

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.

Human exposure to polyhexamethylene guanidine phosphate from humidifiers in residential settings: Cause of serious lung disease.

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.

Inhalation Exposure Method for Illegal Drugs.

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.

Reliability of Eustachian tube function measurements in a hypobaric and hyperbaric pressure chamber.

OBJECTIVES: Measurement of the Eustachian tube (ET) function is a challenge. The demand for a precise and meaningful diagnostic tool increases-especially because more and more operative therapies are being offered without objective evidence. The measurement of the ET function by continuous impedance recording in a pressure chamber is an established method, although the reliability of the measurements is still unclear. METHODS: Twenty-five participants (50 ears) were exposed to phases of compression and decompression in a hypo- and hyperbaric pressure chamber. The ET function reflecting parameters-ET opening pressure (ETOP), ET opening duration (ETOD) and ET opening frequency (ETOF)-were determined under exactly the same preconditions three times in a row. The intraclass correlation coefficient (ICC) and Bland and Altman plot were used to assess test-retest reliability. RESULTS: ICCs revealed a high correlation for ETOP and ETOF in phases of decompression (passive equalisation) as well as ETOD and ETOP in phases of compression (active induced equalisation). Very high correlation could be shown for ETOD in decompression and ETOF in compression phases. The Bland and Altman graphs could show that measurements provide results within a 95 % confidence interval in compression and decompression phases. CONCLUSIONS: We conclude that measurements in a pressure chamber are a very valuable tool in terms of estimating the ET opening and closing function. Measurements show some variance comparing participants, but provide reliable results within a 95 % confidence interval in retest. This study is the basis for enabling efficacy measurements of ET treatment modalities.

Omega-3 Polyunsaturated Fatty Acids Protect Against Cigarette Smoke-Induced Oxidative Stress and Vascular Dysfunction.

In cigarette smokers endothelial dysfunction, measured by flow-mediated dilation (FMD), precedes cardiovascular disease (CVD) and can be improved by supplementation with n - 3 polyunsaturated fatty acids (PUFAs). We developed a mouse model of cigarette smoke (CS)-induced endothelial dysfunction that resembles impaired FMD observed in human cigarette smokers and investigated the mechanism by which n - 3 PUFAs mediate vasoprotection. We hypothesized that loss of nitric oxide (NO)-dependent vasodilation in CS-exposed mice would be prevented by dietary n - 3 PUFAs via a decrease in oxidative stress. C57BL/6 mice were fed a chow or n - 3 PUFA diet for 8 weeks and then exposed to mainstream CS or filtered air for 5 days, 2 h/day. Mesenteric arterioles were preconstricted with U46619 and dilated by stepwise increases in pressure (0-40 mmHg), resulting in increases in flow, ± inhibitor of NO production or antioxidant, Tempol. Markers of oxidative stress were measured in lung and heart. CS-exposed mice on a chow diet had impaired FMD, resulting from loss of NO-dependent dilation, compared with air exposed mice. Tempol restored FMD by normalizing NO-dependent dilation and increasing NO-independent dilation. CS-exposed mice on the n - 3 PUFA diet had normal FMD, resulting from a significant increase in NO-independent dilation, compared with CS-exposed mice on a chow diet. Furthermore, n - 3 PUFAs decreased two CS-induced markers of oxidative stress, 8-epiprostaglandin-F2α levels and heme oxygenase-1 mRNA, and significantly attenuated CS-induced cytochrome P4501A1 mRNA expression. These data demonstrate that dietary n - 3 PUFAs can protect against CS-induced vascular dysfunction via multiple mechanisms, including increasing NO-independent vasodilation and decreasing oxidative stress.

Vitamin E supplementation inhibits muscle damage and inflammation after moderate exercise in hypoxia.

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 Lab Assembled Microcontroller-Based Sensor Module for Continuous Oxygen Measurement in Portable Hypoxia Chambers.

BACKGROUND: Hypoxia-based cell culture experiments are routine and essential components of in vitro cancer research. Most laboratories use low-cost portable modular chambers to achieve hypoxic conditions for cell cultures, where the sealed chambers are purged with a gas mixture of preset O2 concentration. Studies are conducted under the assumption that hypoxia remains unaltered throughout the 48 to 72 hour duration of such experiments. Since these chambers lack any sensor or detection system to monitor gas-phase O2, the cell-based data tend to be non-uniform due to the ad hoc nature of the experimental setup. METHODOLOGY: With the availability of low-cost open-source microcontroller-based electronic project kits, it is now possible for researchers to program these with easy-to-use software, link them to sensors, and place them in basic scientific apparatus to monitor and record experimental parameters. We report here the design and construction of a small-footprint kit for continuous measurement and recording of O2 concentration in modular hypoxia chambers. The low-cost assembly (US$135) consists of an Arduino-based microcontroller, data-logging freeware, and a factory pre-calibrated miniature O2 sensor. A small, intuitive software program was written by the authors to control the data input and output. The basic nature of the kit will enable any student in biology with minimal experience in hobby-electronics to assemble the system and edit the program parameters to suit individual experimental conditions. RESULTS/CONCLUSIONS: We show the kit's utility and stability of data output via a series of hypoxia experiments. The studies also demonstrated the critical need to monitor and adjust gas-phase O2 concentration during hypoxia-based experiments to prevent experimental errors or failure due to partial loss of hypoxia. Thus, incorporating the sensor-microcontroller module to a portable hypoxia chamber provides a researcher a capability that was previously available only to labs with access to sophisticated (and expensive) cell culture incubators.

Adverse Outcomes Associated with Cigarette Smoke Radicals Related to Damage to Protein-disulfide Isomerase.

Identification of factors contributing to the development of chronic obstructive pulmonary disease (COPD) is crucial for developing new treatments. An increase in the levels of protein-disulfide isomerase (PDI), a multifaceted endoplasmic reticulum resident chaperone, has been demonstrated in human smokers, presumably as a protective adaptation to cigarette smoke (CS) exposure. We found a similar increase in the levels of PDI in the murine model of COPD. We also found abnormally high levels (4-6 times) of oxidized and sulfenilated forms of PDI in the lungs of murine smokers compared with non-smokers. PDI oxidation progressively increases with age. We begin to delineate the possible role of an increased ratio of oxidized PDI in the age-related onset of COPD by investigating the impact of exposure to CS radicals, such as acrolein (AC), hydroxyquinones (HQ), peroxynitrites (PN), and hydrogen peroxide, on their ability to induce unfolded protein response (UPR) and their effects on the structure and function of PDIs. Exposure to AC, HQ, PN, and CS resulted in cysteine and tyrosine nitrosylation leading to an altered three-dimensional structure of the PDI due to a decrease in helical content and formation of a more random coil structure, resulting in protein unfolding, inhibition of PDI reductase and isomerase activity in vitro and in vivo, and subsequent induction of endoplasmic reticulum stress response. Addition of glutathione prevented the induction of UPR, and AC and HQ induced structural changes in PDI. Exposure to PN and glutathione resulted in conjugation of PDI possibly at active site tyrosine residues. The findings presented here propose a new role of PDI in the pathogenesis of COPD and its age-dependent onset.

Design and characterization of human exposure to generated sulfate and soot particles in a pilot chamber study.

UNLABELLED: A number of literatures have documented adverse health effects of exposure to fine particulate matter (PM2.5), and secondary sulfate aerosol and black carbon may contribute to health impacts of PM2.5 exposure. We designed an exposure system to generate sulfate and traffic soot particles, and assessed the feasibility of using it for human exposure assessment in a pilot human exposure study. In the designed exposure system, average mass concentrations of generated sulfate and soot particles were 74.19 µg/m3 and 11.54 µg/m3 in the chamber and did not vary significantly during two-hour human exposure sessions. The size ranges of generated sulfate were largely between 20 to 200 nm, whereas those of generated soot particles were in the size ranges of 50 to 200 nm. Following two-hour exposure to generated sulfate and soot particles, we observed significant increases in fractional exhaled NO (FeNO) in young and health subjects. Building on established human exposure system and health response follow-up methods, future full-scale studies focusing on the effects of mixed particulates and individual PM2.5 components would provide data in understanding the underpinning cardio-respiratory outcomes in relation to air pollution mixture exposure. IMPLICATIONS: Controlled exposure is a useful design to measure the biological responses repeatedly following particulate exposures of target components and set exposure at target levels of health concerns. Our study provides rational and establishes method for future full-scale studies to focus on examining the effects of mixed particulates and individual PM2.5 components.

Effects of formaldehyde inhalation on humoral immunity and protective effect of Nigella sativa oil: An experimental study.

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.

Análisis de los efectos de la hipoxia en 236 pilotos durante el entrenamiento fisiológico en cámara hipobárica / Analysis of the effects of hypoxy in 236 pilots during physiological training in hyperbaric chamber

Introducción: La hipoxia se define como un estado de deficiencia de oxígeno en el organismo. La reducción de la presión parcial de oxigeno como consecuencia de la reducción de la presión atmosférica con la altitud, establece la hipoxia hipobárica, cuyos síntomas pueden ser estudiados durante el entrenamiento fisiológico de altura. Dicha prueba es una herramienta fundamental, para entrenar a los pilotos mediante equipos en tierra que simulan fielmente las condiciones de un vuelo real, con el propósito de que aprendan a reconocer los síntomas y entrenen la forma de manejarlos cuando estén en vuelo. Ejemplo de este tipo de entrenamiento es el realizado en la cámara de altitud o hipobárica. Objetivos: Analizar los efectos de la hipoxia hipobárica en 236 pilotos de avión. Material y Método: Se tomaron los datos estadísticos de los archivos del departamento de investigación del INMAE de pilotos militares sometidos a la prueba de hipoxia en la cámara hipobárica. Se realizó un estudio retrospectivo, descriptivo, el criterio de inclusión fue de pilotos militares activos sometidos a prueba de hipoxia en cámara hipobárica a una altura de 27.500 que presentaron al menos un síntoma durante la prueba, la muestra final incluyó a 236 casos. Resultados: Se analizaron los datos de 236 pilotos de avión, todos ellos fueron hombres, las edades oscilaron entre 20 y 55 años, la edad media fue de 32 (31,76) años +/-6.8. Los síntomas más frecuentes fueron: calor en general (41.5%), describieron calor en todo el cuerpo y en zonas específicas de las cuales la más frecuente fue la cara (55% del total de calor)le siguieron las manos y las plantas de los pies, parestesias (11.8%), vértigo (9.7%), definida como la dificultad respiratoria con sensación de falta de aires la disnea se presentó en cuarto lugar (8.9%) y también se describieron alteraciones de la visión (7.2%) tales como visión nublada, visión en túnel y visión negra. En cuanto al TUC osciló entre 43 y 226 segundos, el promedio fue de 119 segundos. Conclusiones: Los síntomas más frecuentes fueron Calor sobre todo en la cara, manos y pies, parestesias, vértigo, disnea, alteraciones de la visión, palpitaciones, sudoración, temblor, cianosis, dolor de cabeza, alteraciones cognitivas. El TUC osciló entre 43 y 226 segundos, el promedio fue de 119 segundos. Al comparar el TUC con los grupos de edades establecidos (mayores y menores de 40 años), existe diferencia entre el promedio de los menores de 40 años (121 segundos) y mayores de esa edad (110 segundos) que habla a favor de una relación inversa entre ambas variables, es decir, a mayor edad menor TUC, estadísticamente obtuvimos, con una probabilidad entre 98 y 99 %, que después de los 40 años el tuc disminuye aproximadamente 10%.

Introduction: Hypoxia is defined as a state of oxygen deficiency in the body. The reduction of the oxygen partial pressure as a consequence of the reduction of the atmospheric pressure with the altitude, establishes the hypobaric hypoxia, whose symptoms can be studied during the physiological training of height. This test is a fundamental tool to train pilots using ground equipment that faithfully simulate the conditions of a real flight, so that they learn to recognize the symptoms and train how to handle them when they are in flight. An example of this type of training is that performed in the altitude or hypobaric chamber. Objectives: To analyze the effects of hypobaric hypoxia on 236 aircraft pilots. Material and method: Statistical data were taken from the files of the INMAE research department of military pilots subjected to hypoxia testing in the hypobaric chamber. A retrospective, descriptive study was performed. The inclusion criterion was that of active military pilots who underwent a hypoxia test in a hypobaric chamber at a height of 27,500 who presented at least one symptom during the test. The final sample included 236 cases. Results: We analyzed the data of 236 airplane pilots, all of them men, the ages ranged from 20 to 55 years, the average age was 32 years. The most frequent symptoms were: heat in general, described heat throughout the body and in specific areas of which the most frequent was the face followed by the hands and soles of the feet, paresthesias, vertigo, defined as respiratory difficulty with Sensation of shortness of breath, dyspnea presented in fourth place and also described alterations of vision such as cloudy vision, tunnel vision and black visión Useful time of consciousness (UTC) ranged from 43 to 226 seconds, averaging 119 seconds. Conclusions: The most frequent symptoms were: heat, the most frequent was the face followed by the hands and soles of the feet, paresthesias, vertigo, dyspnea, sweat, palpitations, tremors, cyanosis, headache, cognitive alterations. Useful time of consciousness (UTC) ranged from 43 to 226 seconds, averaging 119 seconds. When comparing UTC with established age groups (older and younger than 40 years), we obtained, with a probability of 98-99%, that after 40 years UTC decreased by approximately 10%.

A normobaric gas exposure animal chamber and its validation in hyperoxia exposure.

We are living in an environment full of gases, and any change in the concentration of a component of the air or contaminants (usually toxic) in the air may significantly threaten human health. Thus, to investigate the influence of gases in animal models it is helpful to elucidate the pathogenesis of gas-related injury. Although there are devices used for gas exposure in animals, there are still limitations in the establishment of these animal models, such as the change in gas concentration during the refreshing of water, food and litter, and the contamination of toxic gases released by animals. Herein, we freshly prepared a chamber for normobaric gas exposure. During the exposure in this chamber, the refreshing of water, food and litter does not require opening of the chamber. The chamber gases are continuously circulated and filtered, and the gas concentration remains very stable. To validate the feasibility of this chamber, rats were exposed to pure oxygen as an example. Results showed that rats with hyperoxia-induced lung injury simulated by pure oxygen exposure displayed the representative characteristics as observed in humans: shortness of breath, lung edema, alveolar septal rupture, infiltration of inflammatory cells, oxidative and inflammatory injury. This suggests that it is feasible to establish animal models using this chamber for the investigation of gas toxicity.

Influence of sexual dimorphism on pulmonary inflammatory response in adult mice exposed to chloroform.

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.