Biomedical subjects
Publications and source records attributed to Jacques Ameille.
Exogenous lipid pneumonia can exceptionally be caused by occupational exposure to paraffin. The authors report a case of severe interstitial pulmonary disease induced by occupational exposure to paraffin, leading to delayed fibrosis over a 25-year follow-up, despite cessation of exposure.
BACKGROUND: Natural rubber latex is a recognized allergen, but a recent meta-analysis failed to find any association between latex exposure and allergy in health care workers (HCWs). OBJECTIVES: A meta-analysis was carried out under the auspices of the French National Regulatory Authority to assess the allergic risk induced by latex gloves in HCWs. METHODS: The risk of work-related exposure to latex for the development of latex allergy was assessed. Prevalence and incidence rates of latex sensitization or allergy were compared in HCWs and in the general population. Exposure-response relationships were assessed in HCWs. RESULTS: Latex allergy was found in 4.32% (range, 4.01% to 4.63%) of HCWs and in 1.37% (range, 0.43% to 2.31%) of the general population. Latex-positive skin prick test responses ranged from 2.1% to 3.7% in the general population and from 6.9% to 7.8% for the HCWs. HCWs exposed to latex showed an increased risk of hand dermatitis (odds ratio [OR], 2.46; 95% CI, 2.11-2.86), asthma or wheezing (OR, 1.55; 95% CI, 1.15-2.08), rhinoconjunctivitis (OR, 2.73; 95% CI, 1.97-3.81), and at least one generic symptom (OR, 1.27; 95% CI, 1.09-1.47). Sensitization to latex was significantly associated with asthma and rhinoconjunctivitis. By contrast, exposure to latex was not associated with a significantly increased risk of positive skin prick test responses to latex (OR, 1.47; 95% CI, 0.94-2.30). CONCLUSION: HCWs have an increased risk of sensitization and allergic symptoms to latex. CLINICAL IMPLICATIONS: Prevention of latex allergy in HCWs is needed.
OBJECTIVE: Occupational causes of haematological malignancies are relatively uncommon, under-studied and under-identified. They are also often unrecognized by clinicians. This review summarizes the principal epidemiologic studies on this topic. METHODS: We analyzed the recent relevant human data found in the Medline, the Pascal and the BDSP databases. RESULTS: Benzene and ionizing radiation are the only agents conclusively demonstrated to be carcinogenic to the haematopoietic system. In particular, both exposures are strongly associated with acute myeloid leukaemia. Low doses of both may also be related to myeloid malignancies. Infectious agents and pesticides are also thought to induce lymphoproliferative cancers. Some studies show an association between haematological malignancies and low-frequency electromagnetic fields and organic solvents. All of these suspected occupational causes must be confirmed by further studies. CONCLUSIONS: Better knowledge and understanding of occupational causes of haematological malignancies are necessary to improve their prevention and compensation.
PURPOSE OF REVIEW: Occupational asthma is often associated with serious work and financial consequences. Correct management of occupational asthma must be based on a good knowledge of the natural history of the disease and of its prognostic factors. RECENT FINDINGS: Longitudinal studies have demonstrated that improvement of symptoms and airway hyperresponsiveness may be prolonged after cessation of exposure. Severity of asthma at diagnosis is the best predictor of clinical symptoms and functional impairment at follow-up. The molecular weight of the causal agent does not seem to be a prognostic factor. Airway inflammation is associated with persistence of symptoms and airway hyperresponsiveness after cessation of exposure. Reduction of exposure has proved to be effective in improvement of latex-induced asthma. SUMMARY: Further studies are needed to investigate the prognostic value of sputum eosinophils and neutrophils, and to determine whether some specific agents are associated with a better prognosis than others.
OBJECTIVE: The aim of the study was to determine whether the forced oscillation technique (FOT), which does not require active cooperation, may be useful to assess bronchial responsiveness in patients with suspected occupational asthma (OA). METHODS: Changes in resistances evaluated by FOT, and DeltaFEV1 measured during methacholine challenge test were compared in 77 adults referred for suspected OA. Spearman correlations and ROC curves were used. RESULTS: R0 at the final dose of methacholine (R0hmd) and DeltaR0 were strongly correlated with DeltaFEV1 (p < 0.001). The ROC curves showed that R0hmd >or= 240% predicted was the best cut-off value to discriminate subjects with OA from nonasthmatic subjects (sensitivity: 80%, specificity: 76%). CONCLUSION: FOT can be proposed as an alternative method for the assessment of bronchial responsiveness in subjects with suspected OA, unable to correctly perform forced expiratory maneuvers.
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Due to its remarkable physical properties asbestos has been widely used in the industry. It is estimated that 25% of present French retired workers have been occupationally exposed to asbestos. A causal relationship between asbestos exposure and respiratory cancers is established since 1955 for lung cancer, and since 1960 for pleural mesothelioma. A causal relationship is also demonstrated for peritoneal and pericardic mesotheliomas, and strongly suspected for laryngeal cancers. It is estimated that occupational exposure to asbestos could be responsible for 5 to 20% of lung cancers and 80 to 90% of pleural mesothelioma, in men, in industrialized countries. The risk of cancer is positively correlated to cumulated exposure. No threshold has been demonstrated below which there is no increased risk of respiratory cancer.
Different tools may be used to evaluate previous occupational exposures, either in epidemiological studies or in clinical practice: occupational questionnaire followed by an expertise or the use of a job-exposure matrix; metrology; biometrology. In routine clinical practice, the main tool is an individual questionnaire to identify if a patient has worked in one of the main jobs or tasks known to be associated with an exposure to a definite carcinogen. As individual and collective consequences are important in case of recognition as an occupational disease, looking for the previous main occupational activities entailing exposure to carcinogens should be systematic in some sites of cancer: mesothelioma, lung, ethmoid, bladder and leukemia.
BACKGROUND: Occupational asthma (OA) is a frequent work-related disease in industrialised countries. It often leads to severe social and medical consequences. TWO TYPES OF OA: A distinction must be made between OA with a latency period, the origin of which is essentially allergic, and OA without a latency period or Reactive airways dysfunction syndrome (RADS), induced by acute inhalation of irritant substances. PREVALENCE: This is currently estimated as one case of asthma of occupational origin in one adult out of ten. In many cases its diagnosis is missed because it is not systematically searched for. REGARDING DIAGNOSIS: Diagnosis, initiated on the results of questioning, must be supported by immunological tests whenever possible and notably on functional respiratory explorations (longitudinal monitoring of peak flow or spirometry, repeated measurements of non-specific bronchial reactivity), which objectifies significant variations in the parameters measured and related to professional activity. Bronchial challenge tests specifically identify the causal agent, but such examinations are long, expensive, potentially dangerous and therefore cannot be used in routine. MANAGEMENT OF OA: Both social and medical, the management is aimed at stopping the exposure to the risk whilst protecting the person's employment. The declaration of occupational diseases is one of the principle measures of the medico-social care.
OBJECTIVES: Few studies have been carried out to evaluate the respiratory effects of asbestos exposure of custodian and maintenance workers. METHODS: By a multicentre cross-sectional study, 277 custodian and maintenance employees working in buildings with friable asbestos-containing materials and 87 unexposed subjects were studied for radiological abnormalities by use of the International Labour Office (ILO) classification of radiographs of pneumoconiosis, in relation to parameters of asbestos exposure. RESULTS: The cumulative asbestos exposure index was generally low (fewer than 5 fibres/ml x years in 82.3% of exposed workers). On multivariate analysis, pleural thickening was significantly related to latency since onset of exposure to asbestos in exposed workers, after adjustment for age, body mass index and tobacco smoking. CONCLUSIONS: Asbestos exposure of custodian and maintenance employees in buildings with friable asbestos-containing materials might be associated with an excess of pleural thickening on chest X-rays.
BACKGROUND: In the literature, the criteria used to define pleural plaques (PP) and diffuse pleural thickening (DPT) are very heterogeneous and often imprecise. A multicenter restropective study was conducted to assess the relevance of two radiographic definitions of DPT. METHODS: The study population consisted of 287 subjects with asbestos-related pleural thickening. Two definitions were used to characterize DPT on postero-anterior chest radiographs: definition 1: pleural thickening associated with obliteration of the costophrenic angle; definition 2: pleural thickening at least 5 mm wide, extending for more than one quarter of the chest wall. Prevalence of respiratory symptoms and pulmonary function tests were compared in the DPT and PP groups resulting from the two definitions of DPT. RESULTS: According to definition 1, 34 patients (11.8%) were classified in the DPT group. Prevalence of chronic sputum, dyspnea, and chest pain was significantly higher in this group than in the PP group. FEV(1), FVC, and TLC were significantly lower. The differences persisted after adjustment for confounding factors. According to definition 2,102 patients (36.6%) were classified in the DPT group. DPT and PP groups did not differ in terms of prevalence of respiratory symptoms, or pulmonary function tests. Agreement between readers was significantly better when using definition 1. CONCLUSIONS: Obliteration of costophrenic angle is a much more reliable sign than dimensional criteria to characterize DPT.
OBJECTIVES: Asbestosis remains difficult to diagnose, particularly in its early stages. The aim of this study was to determine criteria for independently associated features of pulmonary fibrosis in high-resolution computed tomograms among persons occupationally exposed to asbestos. METHODS: Retired persons with documented occupational asbestos exposure and no known asbestos-related diseases were assessed for occupational, clinical, functional respiratory, and chest X-ray criteria. In addition, they all underwent high-resolution computed tomography (HRCT) in the prone position. RESULTS: Altogether 51 (7.2%) of the 706 enrolled participants had features of pulmonary fibrosis consistent with asbestosis in the HRCT. Among those with small irregular opacities of <1/0 according to the 1980 International Labour Office Classification (ILO-C) in their X-rays, 5% had asbestosis in the HRCT. In a multivariate analysis, only age [odds ratio (OR) per year 1.08, 95% confidence interval (95% CI) 1.02-1.14], cumulative-exposure index (CEI) for asbestos (OR 6.4, 95% CI 1.5-28.4 for a CEI of > or =100 fibers/ml x years), and the presence of small irregular X-ray opacities of > or =1/0 ILO-C (OR 3.0, 95% CI 1.6-6.0) were independently associated with HRCT asbestosis. No combinations of these criteria simultaneously yielded high sensitivity and specificity for the diagnosis of early-stage HRCT asbestosis. Moreover, only 2% of the persons with a CEI of <25 fibers/ml x years had HRCT asbestosis, the finding confirming the low incidence of asbestosis for such low exposure, as previously reported on the basis of X-ray data. CONCLUSIONS: Additional research is needed to better identify the persons most likely to benefit from HRCT screening for asbestosis.