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Biomedical subjects

A Cartier

Publications and source records attributed to A Cartier.

At least 73 records · Page 4Linked to original sources
PubMed1995

Occupational asthma due to formaldehyde resin dust with and without reaction to formaldehyde gas.

We report the cases of three subjects who developed asthma after being exposed to formaldehyde dust or gas. For two subjects, specific bronchial provocation tests with formaldehyde gas did not cause significant bronchoconstriction, whereas exposure to formaldehyde resin dust did. One subject experienced asthmatic reaction after being exposed to formaldehyde resin dust and gas. These findings suggest that the physical and chemical properties of formaldehyde are relevant to its likelihood of causing asthma.

Adult↗
PubMed1994

Survey of construction workers repeatedly exposed to chlorine over a three to six month period in a pulpmill: II. Follow up of affected workers by questionnaire, spirometry, and assessment of bronchial responsiveness 18 to 24 months after exposure ended.

OBJECTIVE: The aim was to determine the prevalence of persistent respiratory symptoms and bronchial hyper-responsiveness due to reactive airways dysfunction syndrome in a population of construction workers at moderate to high risk of developing the syndrome, at an interval of 18 to 24 months after multiple exposures to chlorine gas during renovations to a pulp and paper mill. DESIGN AND PARTICIPANTS: 71 of 289 exposed workers (25%) were identified on the basis of an exposure and the onset of respiratory symptoms shortly after this event (moderate to high risk). A standardised respiratory questionnaire was first presented, followed by spirometry and a methacholine inhalation test on those whose questionnaire suggested the persistence of respiratory symptoms. RESULTS: 64 of 71 (90%) subjects completed the respiratory questionnaire at the time of the follow up. The questionnaire suggested a persistence of respiratory symptoms in 58 of the 64 workers (91%). Of the 58 subjects, 51 underwent spirometry and assessment of bronchial responsiveness. All of them used bronchodilators as required (not regularly) and four required inhaled anti-inflammatory preparations. Sixteen had bronchial obstruction (forced expiratory volume in one second) (FEV1 < 80% predicted) and 29 showed significant bronchial hyper-responsiveness. CONCLUSION: Of the subjects (n = 71) who were at moderate to high risk of developing reactive airways dysfunction syndrome after being exposed to chlorine and were seen 18 to 24 months after exposure ended, 58 (82%) still had respiratory symptoms, 16 (23%) had evidence of bronchial obstruction, and 29 (41%) had bronchial hyper-responsiveness.

Adult↗
PubMed1994

Comparison of circadian variations using FEV1 and peak expiratory flow rates among normal and asthmatic subjects.

BACKGROUND: Most studies that describe circadian variations in asthma have used maximum rate of peak expiratory flow (PEF) rather than forced expiratory volume in one second (FEV1) to assess airway calibre. This study was designed to assess circadian variations in PEF and FEV1 measured simultaneously and to compare variations in these measurements in normal and asthmatic subjects in a stable clinical state. METHODS: Twenty nine subjects (nine asthmatic subjects on bronchodilators, 10 on inhaled steroids, and 10 normal controls) were asked to record their PEF and FEV1 with a new portable instrument every two hours during the day and once on waking at night for two weeks. Circadian variations were examined in different ways using arithmetical indices and cosinor analysis. RESULTS: 78% of PEF values and 75% of FEV1 values were considered to be reproducible and were included in the analysis. Variations obtained using PEF did not differ from those obtained using FEV1. Significant cosinor variations were found in at least 50% of recording days for most of the subjects and showed the same features as for arithmetical indices. Daily variations in PEF and FEV1 were significantly correlated with airway calibre and PC20 methacholine (r approximately 0.5 to approximately 0.6). CONCLUSIONS: PEF is as satisfactory as FEV1 for describing circadian variations among normal subjects and stable asthmatic subjects.

Adolescent↗
PubMed1994

Bronchial hyperresponsiveness can improve while spirometry plateaus two to three years after repeated exposure to chlorine causing respiratory symptoms.

Repeated exposure to chlorine in pulp mills and paper can induce persistent asthma-like symptoms such as bronchial hyperresponsiveness and variable changes in airway caliber. The long-term time course of bronchial hyperresponsiveness has not been examined. We studied 20 of 29 subjects (69% participation rate) who demonstrated bronchial hyperresponsiveness to methacholine when they were first assessed, 18 to 24 mo after repeatedly inhaling "puffs" of high concentrations of chlorine in a paper mill over a 3-mo period. Each subject answered a respiratory questionnaire and underwent spirometry and a methacholine inhalation test 12 mo after the initial survey, 30 to 36 mo after the chlorine inhalations. Three subjects required inhaled steroids at the time of the initial survey and three at the time of the second, including two who carried on using these preparations. Only one subject changed smoking habits. There were no significant overall changes in FEV1 on the two occasions, nine subjects having a FEV1 < 80% on the first occasion and eight on the second. Six of the 18 subjects (33%) who underwent a methacholine inhalation test on both occasions had significantly improved PC20 results, including five for whom the PC20 value was within the normal range. All six subjects had normal FEV1 values on both assessments. Although changes in spirometry induced by repeated exposure to chlorine seem to persist, bronchial hyperresponsiveness can improve significantly in those with normal airway caliber. This suggests that less pronounced bronchial alterations induced by repeated exposures to chlorine may be reversible.

Adult↗
PubMed1994

Prevalence of occupational asthma among workers exposed to eastern white cedar.

We assessed the prevalence of occupational asthma among current (n = 29/31, 94%) and former (n = 13/49, 27%) employees of a sawmill in which eastern white cedar has been made into shingles during the past 3 yr. All participants answered a respiratory questionnaire, and all except one underwent spirometry and methacholine inhalation tests. All those with bronchial hyperresponsiveness (PC20 methacholine < or = 19 mg/ml) were invited to undergo specific inhalation challenges. Mean duration of exposure was 13 mo (19 workers > 12 mo). Twenty-eight workers (65%) reported a history compatible with asthma, and 25 (58%) had symptoms that were suggestive of occupational asthma. Only two subjects had significant airway obstruction (FEV1 < 80% pred) (mean value = 98% pred). Eighteen subjects (42%) had a PC20 < or = 16 mg/ml. Specific inhalation tests with plicatic acid and/or western red cedar (which contains twice as much plicatic acid as eastern white cedar), were done on 12 subjects who had a PC20 < or = 16 mg/ml when they were assessed. Three subjects were considered to have positive tests (one had an isolated immediate reaction, one had a late reaction, and one had significant changes in PC20 each time he was exposed but no changes in FEV1). Environmental monitoring showed concentrations of total dusts above 2 mg/m3 in half of the samples. The prevalence of occupational asthma in this workplace was three of 42 participants (7%) or at least three of 80 (3.8%) of all current or ex-workers. This is comparable to the prevalence of occupational asthma in subjects exposed to western red cedar.

Adult↗
PubMed1994

Aluminium potroom asthma confirmed by monitoring of forced expiratory volume in one second.

Chronic airflow obstruction has long been seen among aluminium potroom workers. Currently referred to as "potroom asthma," it is debatable as to whether it is occupational asthma or nonspecific airway obstruction. A 35-yr-old male lifelong nonsmoker, with no history of asthma or atopy, was hired by an aluminium plant that had begun its operation in 1986. Preemployment screening, consisting of spirometry and a chest radiograph, was normal. During his 12-h shifts, he replaced 10 to 20 anodes (prebake type), spending 5 min each time close to open pots releasing hot fumes. The patient experienced episodes of cough and dyspnea, which were resolved during withdrawal from work in January and December 1991. He resumed work in the potrooms in March 1992, his dyspnea recurred at work and at night with 25% drops in peak expiratory flow rates (PEFR), associated with mild-to-moderate bronchial hyperresponsiveness (PC20 histamine, 1.0 mg/ml). After a chest physician's assessment, he was withdrawn from the potroom department. Assessment of the bronchial response to the occupational exposure in potrooms carried out in November 1992 revealed a pattern of dual asthmatic response, paralleled by a drop in PC20 methacholine from 5.1 to 0.7 mg/ml. A similar pattern was seen again during repeat workplace challenges 3 wk later. Spirometry obtained on control days was stable. We conclude that asthmatic reactions can exist among workers in aluminium smelters.

Adult↗
PubMed1994

Definition and diagnosis of occupational asthma.

Asthma is the most frequent occupational lung disease. The diagnosis of occupational asthma, defined as variable airways narrowing, causally related to exposure in the working environment to specific airborne dusts, gases, vapours or fumes, needs to be confirmed by objective means. This article reviews the different steps of investigation which are: history, pulmonary function tests, immunological tests, monitoring of peak expiratory flows and nonallergic bronchial responsiveness and, finally, the gold standard, specific bronchial provocation.

Asthma↗
PubMed1994

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)

Adult↗
PubMed1994

Airway inflammation after removal from the causal agent in occupational asthma due to high and low molecular weight agents.

In order to determine 1) the features of airway inflammation after removal from exposure to high (HMW) and low (LMW) molecular weight agents 2) if there are any differences in the pattern of inflammation induced by these two types of agents, we studied 18 subjects with a recently confirmed diagnosis of occupational asthma (OA) due to HMW (n = 11) and LMW (n = 7) agents. The duration of asthma symptoms varied from 2 to 108 months (mean 33 months), and withdrawal from exposure to the sensitizing agent from 3 to 24 weeks (mean 10 weeks). All subjects underwent measurements of expiratory flow rates, methacholine inhalation tests, and a flexible bronchoscopy with bronchoalveolar lavage (BAL) and bronchial biopsies. Endoscopic findings were compared with a group of 10 normal subjects. At the time of the bronchoscopy, asthma symptoms were minimal in most subjects. Although 15/18 subjects had normal forced expiratory volume in one second (FEV1 > 80% pred), all subjects had increased airway responsiveness to methacholine (provocation concentration producing a 20% fall in FEV1 = 0.2-10.0 mg.ml-1). BAL analysis showed similar median percentages of the total number of cells and differentials in control subjects and those exposed to HMW and LMW agents. Bronchial biopsies showed that mean inflammatory cell count, both epithelial and sub-epithelial, was similarly raised in OA subjects exposed to either HMW or LMW agents, compared to controls, except for epithelial lymphocyte count. In contrast to the controls, bronchial biopsy of both groups with OA also showed other changes such as extensive epithelial desquamation, ciliary abnormalities of the epithelial cells, smooth muscle hyperplasia and subepithelial fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Patient handling of a multidose dry powder inhalation device for albuterol.

BACKGROUND: Studies have suggested that novel inhaling devices may be misused by patients and medical personnel in the clinical setting soon after their introduction. to assess the adequacy of patient handling of a newer multidose dry powder albuterol inhaler, we conducted a comprehensive survey of use in primary and respiratory practices. METHODS: Patients 6 years of age and older and requiring inhaled beta 2-agonist for the treatment of stable obstructive airways disease were recruited from the practices of primary care and specialist physicians. After instruction from their physician or clinic staff in the use of a multidose dry powder albuterol inhalation device (Diskhaler), patients used the device in unblinded fashion for 2 weeks instead of their usual beta 2-agonist. After 2 weeks, patient use of the device was assessed at a return clinic visit. RESULTS: A total of 4,529 patients with reversible airways obstruction participated in a 2-week assessment of the device and compared it with their previous beta 2-agonist delivery system. Significantly more patients preferred the dry powder device (54 percent) over their previous device (29 percent) (p < 0.001), with 17 percent expressing no preference. After instruction, 98.5 percent of patients could demonstrate adequate use at the initial visit. Performance difficulties at the initial visit resulting in exclusion from the trial were infrequent but more common in the elderly (3 percent vs 0.2 percent for all other age groups combined, p < 0.001). Despite adequate use at the initial visit, at the conclusion of the trial, incorrect use of the device was noted in 10.2 percent of the elderly vs 3.2 percent of all other age groups combined (p < 0.001). Albuterol delivered by Diskhaler was well tolerated in all patient groups. CONCLUSIONS: A majority of patients are able to use a multidose dry powder albuterol inhaler device in the clinical setting, and prefer the device to previously used beta 2-agonist inhalation devices. However, follow-up shows that problems with device handling may become apparent in as little as 2 weeks after initial instruction, thereby mandating the need for periodic follow-up and reinstruction.

Administration, Inhalation↗
PubMed1994

Comparison between peak expiratory flow rates (PEFR) and FEV1 in the monitoring of asthmatic subjects at an outpatient clinic.

Peak expiratory flow rate (PEFR) monitoring is often used alone in evaluating bronchial caliber and the response to a bronchodilator in the assessment of asthmatic subjects. A 15% change in airway caliber has been proposed as the criteria for modifying treatment. Our aim was to determine if changes in PEFR from one visit to the next can adequately evaluate changes in airway caliber as assessed by FEV1, which is considered the gold standard, and to identify the characteristics of subjects whose evaluations were inadequate. This was a retrospective study of 197 asthmatic subjects seen regularly at an outpatient clinic for whom FEV1 and PEFR assessments, prebronchodilator and postbronchodilator, were available for two visits. There was a high correlation between PEFR and FEV1 (in absolute value or percent predicted) (r = 0.83 and r = 0.75). However, 24 of 56 (43%) of those who had a change in FEV1 of 15% or more between two visits (mean change [%] +/- SD, range [best-lowest/best] = 20.9 +/- 5.1%, 15 to 36%) showed changes in PEFR of less than 15% (6.7 +/- 6.5%, 8.0 to 13.9%). On the other hand, 14 of 42 (33%) subjects with changes in FEV1 of less than 15% (9.8 +/- 3.2%, 1.1 to 13.8%) had changes in PEFR of 15% or more (22.2 +/- 10.9%, 16 to 35%). This discrepancy was not related to differences in baseline FEV1, control status, or the relationship between changes in FEV1 and PEFR in response to a bronchodilator. In conclusion, assessment of airway caliber through PEFR monitoring may not be valid in some asthmatic subjects and can often lead to underestimation or overestimation of changes in FEV1. None of the explanations considered made it possible to identify these subjects.

Adolescent↗
PubMed1994

[Effect of an inhaled beta-2-adrenergic agent administered at the time of delayed bronchial reactions to occupational agents].

We previously showed in a retrospective study that the acute response to an inhaled beta-2-adrenergic agent is marked in late asthmatic reactions (J Allergy Clin Immunology 1990;85:834). In a double-blind prospective study, we assessed the magnitude and duration of the effect of inhaled salbutamol (200 micrograms) compared to a placebo in 22 subjects who experienced late asthmatic reactions (sustained fall in FEV 1 > or = 20%) after specific inhalation challenges in the laboratory with various occupational agents (isocyanates in 9 subjects). Before salbutamol was administered, the % in FEV1 over the pre-challenge values did not differ between the placebo (31 +/- 8%, n = 12) and the active (28 +/- 6%, n = 10) groups. The % recovery in FEV1 over the pre-bronchodilator value was 9 +/- 11% in the placebo group and 28 +/- 11% in the active group (t = 4.0, p < 0.001). The % recovery in FEV1 assessed in comparison with pre-challenge values was up to 80 +/- 17% in the placebo group and up to 95 +/- 6% in the active group (t = 2.85, p < 0.01). The 10 subjects on active medication had FEV1 values > or = 80% of the pre-challenge value one hour after inhaling salbutamol. The pattern of diminution in the bronchodilator effect was similar in the eight subjects with occupational asthma on active medication who remained for more than one hour as compared to a control group of asthmatic subjects paired for the degree of baseline airway obstruction. These data show that late asthmatic reactions are satisfactorily reversed with inhaled bronchodilator and that the duration of the effect is as satisfactory for subjects with occupational asthma as it is for asthmatic subjects.

Administration, Inhalation↗
PubMed1994

Occupational asthma due to heated polypropylene.

A 35 year-old nonatopic woman was referred to the hospital for possible work-related asthma. She had worked as an operator, at a plant producing polypropylene bags, for the previous four yrs. Her main complaint was a productive cough with dyspnoea and wheezing, as well as rhinitis over the past 3 yrs. She had been absent from work for 6 months on maternity leave, and had improved greatly. She was on a beta 2-adrenergic agent and had to take it at least four times daily. Baseline spirometry whilst at work showed marked airflow obstruction (forced expiratory volume in one second (FEV1) of 43% predicted (pred). After two months away from work FEV1 improved to 89% pred; provocative concentration of histamine causing a 25% fall in FEV1 (PC20) was 3.6 mg.ml-1 (mild airway hyperresponsiveness). Return to work resulted in a marked deterioration in FEV1, and serial peak expiratory flow (PEFR) values. PC20 was 0.11 mg.ml-1 (severe airway hyperresponsiveness) one week after she had returned to work. Specific inhalation challenges with polypropylene heated to 250 degrees C resulted in a late asthmatic reaction. As formaldehyde is one of the degradation products of heating polypropylene, we exposed her to it for up to 2 h, but we elicited no bronchospastic reaction. We conclude that heated polypropylene should be listed as one of the agents that causes occupational asthma.

Adult↗
PubMed1994

[Measure of bronchial hyperreactivity in epidemiology].

First used to evaluate individuals with symptoms suggestive of asthma, the assessment of bronchial hyperresponsiveness is now commonly used in epidemiological studies, available methods being reproducible and portable. This chapter defines how to assess bronchial hyperresponsiveness in epidemiological studies, which factors need to be considered, what is the prevalence in different populations and finally what are the indications for measuring bronchial hyperresponsiveness in epidemiological studies.

Adolescent↗
PubMed1994

[Role of non-allergenic bronchial hyperreactivity follow-up studies in the assessment of prognosis of asthma].

Asthma is affected by increasing mortality and morbidity as well as by increasing costs due to hospitalizations and visits to the emergency room. It is mandatory to propose an accurate follow-up of asthmatic subjects so that they can live a normal life and avoid hospitalizations. Two tools can be used: 1) notification in a diary of daily symptoms; 2) serial assessment of peak expiratory flow rates and FEV1. These methods are widely suggested and interesting. However, several aspects including the compliance of asthmatic subjects with the assessment, remained to be examined. According to cross-sectional studies, serial measurement of non-allergic bronchial responsiveness is significantly related to the clinical and functional severity of asthma. Nevertheless, longitudinal studies do not show a satisfactory correlation. The reason for these discrepancies is unknown. Although other studies are needed to obtain direct information on the severity of bronchial inflammation, the current state of knowledge does not suggest that serial assessment of bronchial responsiveness is sufficiently valid to introduce its routine use in the follow-up of asthmatic subjects.

Asthma↗
PubMed1993

Should we monitor peak expiratory flow rates or record symptoms with a simple diary in the management of asthma?

BACKGROUND: Various means of monitoring asthma severity have been proposed to reduce morbidity and mortality rates. We compared two means of assessing asthma flare-ups: monitoring peak expiratory flow rate (PEFR) and keeping a symptom diary. METHODS: This was a crossover randomized study. After a 2-week baseline period during which spirometry and PC20 methacholine were assessed, subjects were asked to record either PEFRs or to keep a symptom diary morning and evening for 6 months; a second baseline assessment separated the two periods. Subjects were asked to contact the study coordinator if the following occurred: (1) in the period of PEFR monitoring, daily fluctuations in PEFR were > 20% or the absolute value fell to < 80% of baseline or both occurred; (2) in the period of symptom diary monitoring there were nocturnal symptoms or a persistence of morning dyspnea after inhaled bronchodilator or a reduction in the duration of effect of the bronchodilator or it was impossible to go to work or school or all occurred. In that case they were asked to come to the hospital to confirm the flare-up through investigation for significant changes in FEV1 or PC20 or both. Forty subjects completed a 6-month symptom diary or PEFR recording period respectively, and 20 completed both. RESULTS: A total of 31 exacerbations were reported in 28 different subjects; three subjects had two flare-ups. Thirteen of 19 (69%) flare-ups were confirmed during the symptom diary period and 9 of 12 (75%) during PEFR monitoring. Nocturnal awakenings and morning falls in PEFR > or = 20% were the most frequent occurrences. CONCLUSIONS: We conclude that a simple symptom diary may be as useful as serial PEFR monitoring in documenting asthmatic flare-ups.

Adult↗