Significant Fall In FEV1 Research Articles

MicroRNA Profiling of the Inflammatory Response after Early and Late Asthmatic Reaction.

A high proportion of house dust mite (HDM)-allergic asthmatics suffer from both an early asthmatic reaction (EAR) and a late asthmatic reaction (LAR) which follows it. In these patients, allergic inflammation is more relevant. MiRNAs have been shown to play an important role in the regulation of asthma's pathology. The aim of this study was to analyze the miRNA profile in patients with mild asthma and an HDM allergy after bronchial allergen provocation (BAP). Seventeen patients with EAR/no LAR and 17 patients with EAR plus LAR, determined by a significant fall in FEV1 after BAP, were differentially analyzed. As expected, patients with EAR plus LAR showed a more pronounced allergic inflammation and FEV1 delta drop after 24 h. NGS-miRNA analysis identified the down-regulation of miR-15a-5p, miR-15b-5p, and miR-374a-5p after BAP with the highest significance in patients with EAR plus LAR, which were negatively correlated with eNO and the maximum decrease in FEV1. These miRNAs have shared targets like CCND1, VEGFA, and GSK3B, which are known to be involved in airway remodeling, basement membrane thickening, and Extracellular Matrix deposition. NGS-profiling identified miRNAs involved in the inflammatory response after BAP with HDM extract, which might be useful to predict a LAR.

P200 Use of hypertonic saline in bronchoprovocation for the diagnosis of bronchial asthma

PurposeTo find out a simple, chief, standard & easily available agent for bronchoprovocation & also to determine the provocating dose of hypertonic saline, which will reduce at least 20% of...

The reciprocal influences of asthma and obesity on lung function testing, ahr, and airway inflammation in prepubertal children

Although asthma and obesity are among the major chronic disorders their reciprocal or independent influences on lung function testing, airways hyperresponsiveness (AHR) and bronchial inflammation has not been completely elucidated. In 118 pre-pubertal Caucasian children anthropometric measurements functional respiratory parameters (flow/volume curves at baseline and after 6-minute walk test [6MWT]) together with bronchial inflammatory index (FeNO) were assessed. The study population was divided into four groups according to BMI and the presence or absence of asthma: Obese asthmatic (ObA) Normal-weight asthmatic (NwA), Obese non-asthmatic (Ob), non-asthmatic normal-weight children (Nw). Baseline PEF and MEF(75) (%-expected) were significantly different across the four groups with significantly lower values of MEF(75) in ObA and Ob children when compared to Nw children (P = 0.004 and P = .0001, respectively) and this independent role of obesity on upper respiratory flows was confirmed by multiple analysis of covariance. After 6 MWT respiratory parameters decreased only in ObA and NwA children and 12 children presented a positive fall in FEV(1), in contrast no changes of respiratory function testing were detected in Ob and Nw children, and only 2 Ob children presented a significant fall in FEV(1). FeNO analysis demonstrated significantly higher values in ObA and NwA children when compared to Ob (P = 0.008 and P = 0.0002, respectively) and Nw children (P = 0.0001 and P = 0.0003, respectively), although a significant difference was found between Ob and Nw children (P = 0.0004). Multiple analysis of covariance confirmed an independent role of asthma on this parameter. In conclusion while AHR and airway inflammation are clearly associated with an asthmatic status, obesity seems to induce reduction of upper airways flows associated with a certain degree of pro-inflammatory changes.

Evaluation of Fitness to Utilize Self-Contained Breathing Apparatus (SCBA)

Background. Breathing dry, cold air may cause bronchoconstriction in asthmatics working with self-contained breathing apparatus (SCBA). Air delivered by SCBA is cooler than ambient air. It is unclear whether a bronchial challenge test using mannitol (BCTM) can predict a fall in forced expiratory volume in one second (FEV1) during exercise with SCBA. Methods. A prospective study of army recruits assigned to work with SCBA was carried out. Participants completed self-administered questionnaires on respiratory symptoms, BCTM, and measurement of exhaled nitric oxide. A subgroup of participants with a positive BCTM (BTCM+) and with negative BCTM underwent exercise test on bicycle ergometer (ET) while using SCBA. Results. One hundred and six recruits participated in this study. One hundred and two underwent BCTM and 28 ET. Nineteen out of 97 participants had a positive BCTM and 6 out of 27 had a positive ET. Seventeen out of 19 participants with a positive BCTM had current respiratory symptoms such as wheeze, cough, chest tightness, or dyspnea. Sensitivity, specificity, positive predictive value, and negative predictive value for a positive ET under SCBA were 100%, 64%, 43%, and 100% for the BCTM, respectively. BCTM-positive participants with respiratory symptoms had more physician consultations during MBT compared to BCTM-negative participants. Conclusion. Despite medical evaluation and exclusion of asthmatics by a physician during conscription, a high proportion of recruits assigned to work with SCBA smoke, have respiratory symptoms, and have a positive BCTM suggesting current asthma. BCTM has a high sensitivity to predict a significant fall in FEV1 after exercise with SCBA and participants with a positive BCTM tend to use more health care resources during basic military training. Recruits should be counseled about smoking cessation prior and during basic military training.

Inhibitory effects of azelastine hydrochloride in alcohol-induced asthma.

Alcohol-induced bronchoconstriction is due to high blood concentrations of acetaldehyde, a metabolic product of ethanol, which lead to the release of histamine from basophils and mast cells. We examined the inhibitory effects of azelastine hydrochloride, which inhibits histamine release and blocks H1 receptors, in alcohol-induced asthma. Subjects were 13 Japanese asthmatic patients. We measured the change in FEV1 after ingestion of 30 g of pure ethanol. Blood ethanol, acetaldehyde, histamine, leukotriene C4 (LTC4), and thromboxane B2 (TXB2) concentrations were also measured. Alcohol challenge test was repeated in responders after administration of azelastine for 1 week at 4 mg/day. Of 13 asthmatic patients, five (38.5%) tested positive during an ethanol challenge test, represented by a fall more than 20% in FEV1. The responders had a high blood ethanol, and showed a rise in blood acetaldehyde and histamine concentrations, but not in LTC4 or TXB2. After azelastine treatment, there was no significant fall in FEV1 among responders. Neither the rise in blood ethanol nor blood acetaldehyde levels were blunted by treatment with azelastine, but the rise in blood histamine was blunted by this treatment. Our results suggest that antihistamine agents may be effective against alcohol-induced asthma by both blocking H1 receptors and inhibiting histamine release.

Prevalence and characteristics of exercise-induced asthma in children.

We have evaluated the prevalence and the characteristics of exercise-induced asthma (EIA) in a group of 71 patients with a prior history of mild, moderate or severe asthma (42 males and 29 females), aged 6-16 years-old. Measurements of the forced expiratory volume in 1 second (FEV1) were obtained before and at regular intervals up to 8 hours following exercise. As a control, the same patients were evaluated at similar time intervals on another day when they had not been submitted to an exercise challenge. Using pre-exercise FEV1 values as the reference, 32 patients (45.1%) had a positive exercise challenge, defined as a fall in FEV1 value equal to or greater than 15% from baseline following exercise. Among the patients with a positive exercise challenge, the majority (23/32, 71.8%) had an immediate response alone, with no significant changes in FEV1 within the 8-hour follow-up. However, a subgroup of patients (9/32, 28.1%) had both an immediate and a late-phase response to exercise. During the control day, no significant fall in FEV1 were observed. In keeping with previous investigations, no correlation was found between a history of EIA and a positive exercise challenge in the present study. Positive exercise challenges were found more frequently among patients with moderate and severe asthma than patients with mild asthma.

Effect of tonicity of nebulised colistin on chest tightness and pulmonary function in adults with cystic fibrosis.

BACKGROUND: Inhalation of hypertonic nebulised colistin causes chest tightness and is a reason for discontinuing the treatment. This study examines the relationship of chest tightness and change in lung function...

Respiratory and systemic reaction following exposure to heated electrostatic polyester paint

A 39 year old nonatopic man developed episodes of cough, dyspnoea, sweating and shivers within 2-3 weeks of starting a new job in a factory where metallic boards were treated with an electrostatic powder paint, made of an epoxy resin and a carboxylated polyester containing polyethylene terephthalate and polybutylene terephthalate. The subject sprayed the metallic boards which were then heated in 200 degrees C ovens. The subject was first seen in an emergency room after being at work for 4 h. The physical examination revealed bilateral wheezing with fever (39 degrees C), hypoxaemia (arterial oxygen tension (PaO2) 58 torr (7.7 kPa), leucocytosis (white blood count cells.mm-3 17,000 (17 x 10(9) cells.l-1) and severe airway obstruction (forced expiratory volume in one second (FEV1)/forced vital capacity, (FVC) 1.3/2.4 l, improving to 2.2/3.8 l after bronchodilator; predicted values = 3.4/4.1 l). The subjects condition improved after being treated with oral steroids. His spirometry was normal two weeks later, although he showed mild bronchial hyperresponsiveness to methacholine with the (provocative concentration producing a 20% fall in FEV1 (PC20) being 1.7 mg.ml-1). The subject underwent specific inhalation challenges at the workplace 4 months later. After being exposed at work for 4 h, he developed a significant fall in FEV1 (-40%), fever, leucocytosis, and a fall in diffusing capacity. Lung function tests were back to normal two weeks later. Exposing the subject to heated granulated polyester for one hour in a hospital laboratory produced a fall in FEV1 of 41%, fever, leucocytosis and a fall in diffusing capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Cross-tachyphylactic airway response to inhaled bradykinin, kallidin and [desArg9]-bradykinin in asthmatic subjects

Kinins are oligopeptides that may act as mediators in the pathogenesis of bronchial asthma by interacting with specific cell surface receptors designated B1 and B2. When administered by inhalation to asthmatic subjects, bradykinin and kallidin, but not [desArg9]-bradykinin, provoke potent bronchoconstriction, thus suggesting a specific effect compatible with the stimulation of B2 receptors. To characterize further the receptor(s) mediating this bronchospastic response we have carried out cross-tachyphylactic studies with inhaled bradykinin, kallidin, and [desArg9]-bradykinin, administered in a randomized double-blind fashion in a group of 10 asthmatic subjects. Inhalation of bradykinin and kallidin, but not [desArg9]-bradykinin, elicited concentration-related falls in forced expiratory volume in one second (FEV1) in all the subjects studied. The geometric mean provocation concentrations of inhaled agonists reducing FEV1 by 20% of baseline (PC20) were 0.12 and 0.28 mg.ml-1 for bradykinin and kallidin, respectively. When inhaled at concentrations up to 10.62 mg.ml-1, [desArg9]-bradykinin failed to provoke any significant fall in FEV1 from baseline in any of the subjects studied. Following recovery from the second bradykinin challenge, provocation with kallidin revealed a reduced response to this agonist, the PC20 value increasing from 0.28 to 1.23 mg.ml-1. Similarly, once the airways had recovered from the second kallidin challenge, provocation with bradykinin also showed a reduced response, the PC20Bk increasing from 0.12 to 0.94 mg.ml-1. Surprisingly, despite failing to cause bronchoconstriction, repeated exposures with inhaled [desArg9]-bradykinin reduced the airway response to bradykinin, the PC20Bk increasing from 0.12 to 0.41 mg.ml-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Validation of an Exposure System to Particles for the Diagnosis of Occupational Asthma

We previously described a closed-circuit system for exposure to particles in humans. This system has three components: a particle generator, an exposure chamber connected to an orofacial mask, and monitors. We describe results of challenges in 56 subjects who underwent challenges with the apparatus using occupational sensitizers in particles. Fifty-six consecutive subjects referred for the investigation of occupational asthma to occupational sensitizers in particles were included. The agents were the following: flour and grains (n = 19), cedar (n = 10), psyllium (n = 9), guar gum (n = 9), drugs (n = 3), persulfate (n = 2), and miscellaneous (n = 4). The duration of exposure was progressive and varied from one breath to a maximum of 180 min depending on the reaction. When no significant fall in FEV1 occurred after exposure with the aerosolization device, the standard approach of tipping particles from one tray to another was used. Twenty-nine subjects (52 percent) had a significant (greater than or equal to 20 percent) fall in FEV1 after exposure. This includes 18 subjects with isolated immediate reactions, four with dual asthmatic reactions, and two with atypical reactions. In 20/24 instances (83 percent), the percentage of fall in FEV1 did not exceed 30 percent, thus showing that dose-response curves can generally be obtained in a safe way. In all instances except one (26/27 cases), subsequent exposures using the traditional method did not result in significant falls in FEV1. This new procedure results in safe tests in terms of the percentage of changes in FEV1 during the immediate reactions and very rare false-negative challenges.

Ventilatory function during urography: a comparison of iopamidol and sodium iothalamate

The effects on respiratory function during intravenous urography of the ionic contrast medium sodium iothalamate and the non-ionic contrast medium iopamidol were compared. Forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were recorded in 37 non-atopic patients referred for intravenous urography. Nineteen patients received iopamidol and 18 patients received sodium iothalamate. Both the sodium iothalamate and the iopamidol groups showed a significant fall in FEV1 and FVC (P less than 0.001). The reductions in FEV1 and FVC were comparable and were not symptomatic. The differences in the percentage changes of the FEV1 and FVC in the iopamidol and the sodium iothalamate groups were not statistically significant (P greater than 0.5 and P greater than 0.1 respectively). No significant change in the ratio of the FEV1 and the FVC was demonstrated in either the iopamidol or the sodium iothalamate groups. Both the ionic and the non-ionic contrast media produced a measurable but asymptomatic and biologically insignificant fall in static ventilatory function. Bronchospasm does not appear to be an important contrast-induced effect in non-atopic individuals. Iopamidol offers no advantage over sodium iothalamate with respect to ventilatory effects in non-atopic patients undergoing intravenous urography.

An Epidemiologic Study of the Respiratory Effects of Trona Dust

Trona (sodium sesquicarbonate) is mined from an underground deposit in Wyoming and processed for use in glass, paper, detergent, and chemical applications. Trona dust is alkaline (pH 10.5) and can have an irritant effect on respiratory airways, mucous membranes, and the skin. A study population of 142 underground miners and 88 surface workers from one facility volunteered for an epidemiologic study. Their mean age was 37.6 yr and mean duration of employment was 10.0 yr. The percentage with chronic cough and phlegm was 23%; both symptoms were more common among smokers than nonsmokers. Thirty-three percent of the workers complained of dyspnea when hurrying on level ground or walking up a slight hill. Half of the workers complained of upper respiratory tract symptoms and eye irritation. Both smokers and exsmokers had significant declines of forced expiratory volume in 1 sec (FEV1.0) with age; exsmokers also had declines with work-years when compared to a nonsmoking comparison population. Nonsmokers with personal dust measurements had a significant decline of FEV1.0 related to respirable dust exposure. A shift study of 104 workers revealed a significant fall in FEV1.0 among nonsmokers and surface workers. Significance was approached in the high dust exposure group. An increase in the mean percent predicted forced vital capacity and FEV1.0 was shown for the 125 workers who had a 5-yr follow-up of pulmonary function. There was no correlation between the shift study decrements and the longitudinal 5-yr follow-up. Industrial hygiene dust sampling found elevated levels of total dust but lower respirable dust, with no detectable free silica.

Bronchial provocation studies in workers exposed to the fumes of electronic soldering fluxes.

Flux cored solder commonly used in the electronics industry is a metal alloy, based on tin and lead, and a flux consisting of colophony with a small concentration of an activator. Thirty-four electronics workers with occupational asthma and seventeen with respiratory symptoms, probably from other causes, have been investigated by occupational type bronchial provocation testing. All the sensitized workers had a significant fall in FEV1 after exposure to colophony fumes for 15 min or less. The non-sensitized workers had no significant reactivity to this test. There was little correlation between the reaction to colophony fumes and the non specific reactivity to histamine, suggesting that colophony fumes were causing specific sensitization. In sensitized workers Portuguese Y colophony was found to cause slightly larger reactions than similar exposures to American WW colophony. In the six workers tested reactions followed exposure to abietic acid alone, the principal resin acid in colophony. Methylation of the carboxyl group of colophony was associated with decreased reactivity. Workers with non-specific bronchial hyperreactivity also sometimes reacted after exposure to fumes from the flux activators alone, but even this reaction could show specificity for the specific activator to which the workers was exposed. Finally two non-colophony substitute materials were evaluated.

Cotton dust exposure during lint removal. Airborne dust concentrations and effect of the ventilatory capacity of exposed workers.

In the newly established cotton seed lint removal and crushing industry in New South Wales, high concentrations of dust were recorded ranging from 15 to 37 mg/cu m. Sampling was by Greenburg Smith impinger into 10% alcohol, Lung function tests were conducted on employees by McDermott dry spirometer. This instrument records vital capacities and forced expiratory volume per second (FEV1) at the same time. These tests were taken mid-week as most of the operators were on rotating shift, and It was impossible to obtain tests on what was the first day of the person’s shift. Workers exposed to high dust concentrations in the lint removal sections showed a significant fall in FEV1 with exposure, whereas other workers in the same plant not exposed to cotton dust were not affected.