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Biomedical subjects

P Brochard

Publications and source records attributed to P Brochard.

At least 19 recordsLinked to original sources
PubMed2000

Environmental exposure to tremolite and respiratory cancer in New Caledonia: a case-control study.

A case-control study on respiratory cancers was conducted in New Caledonia (South Pacific), where a high incidence of malignant pleural mesothelioma had been observed. The disease pattern suggested an environmental exposure to asbestos. The first results showed that, in some areas, tremolite asbestos derived from local outcroppings was used as whitewash (locally named "pö"). All cases diagnosed between 1993 and 1995 (including 15 pleural mesotheliomas, 228 lung cancers, and 23 laryngeal cancers) and 305 controls were included in the study. Detailed information on past or present use of the whitewash, residential history, smoking, diet, and occupation was collected. The risk of mesothelioma was strongly associated with the use of the whitewash (odds ratio (OR) = 40.9; 95% confidence interval (CI): 5.15, 325). All Melanesian cases had been exposed. Among Melanesian women, exposure to the whitewash was associated with an increased risk of lung cancer (OR = 4.89; 95% CI: 1.13, 21.2), and smokers exposed to po had an approximately ninefold risk (OR = 9.26; 95% CI: 1.72, 49.7) compared with women who never smoked and had never used the whitewash. In contrast, no association was noted between exposure to pö and lung cancer risk among Melanesian men, probably because of lower exposure levels. Among non-Melanesians, the numbers of exposed subjects were too small to assess the effect of exposure to po. There was no indication of elevated risks for the other cancer sites.

Adolescent↗
PubMed2000

[Asthma and professional activity].

Occupational asthma is largely documented in the recent medical literature but proposed criteria for its definition remain somewhat ambiguous. The main objective of this discussion is to point out the difficulties raised by individual diagnosis and collective actions related to occupational asthma. The main problems are: 1. Ambiguous definitions of occupational asthma; 2. Insufficient understanding of the different circumstances of diagnosis; 3. Difficulty in objective characterization of etiological agents due to the limitations of diagnostic procedures and interactions between agents; 4. Impact of the social consequences of diagnosis for the patient; 5. Limitations of prevention in the workplace. The coordinated efforts of the French Society of Pneumology and the French Society of Occupational Medicine should help provide answers to these problems.

Asthma↗
PubMed1999

Occupational cancer in France: epidemiology, toxicology, prevention, and compensation.

This article is a description of the current situation in France with regard to occupational cancer: research, prevention, and occupation. Toxicologic experiments are carried out using (italic)in vitro(/italic) and (italic)in vivo(/italic) tests, particularly using transgenic mice. Several epidemiologic studies have been conducted over the last decades: population-based case-control studies; mortality studies and cancer incidence studies carried out in historical cohorts of workers employed in the industry; and case-control studies nested in occupational cohorts. French ethical aspects of toxicologic and epidemiologic studies are described. The results thus obtained are used to establish regulations for the prevention and the compensation of cancers attributable to occupational exposure. This French regulation for prevention of occupational cancer involves several partners: (italic)a(/italic)) the states authorities, including labor inspectors, responsible for preparing and implementing the labor legislation and for supervising its application, particularly in the fields of occupational health and safety and working conditions; (italic)b(/italic)) the Social Security Organisation for the analysis of present or potential occupational risks based on tests, visits in plants, complaints or requests from various sources, and statistics. These activities are performed within the framework of the general French policy for the prevention of occupational cancer. This organization includes the National Institute for Research and Safety, particularly involved in research in the various fields of occupational risks--animal toxicology, biologic monitoring, exposure measurements epidemiology, psychology, ergonomy, electronic systems and machineries, exposure to chemicals, noise, heat, vibration, and lighting; and (italic)c(/italic)) companies where the regulation defines the role of the plant manager, the occupational physician, and the Health, Safety and Working Conditions Committee (comprising the manager, employees' representatives, the occupational physician, and the safety department) in dealing with any problem regarding safety, occupational hygiene, and working conditions. These organizations along with medical practitioners are involved with the compensation of occupational cancers. The regulation for compensation includes the tables of occupational cancer, the possibility of recognition of a cancer case when the requirements of the tables are not met, and the postprofessional follow-up of workers exposed to a carcinogenic agent.

Animals↗
PubMed1999

[Mineralogical analysis and exploration of asbestos diseases].

Several tools are available for the evaluation of the exposure to asbestos, particularly occupational questionnaire and mineralogical analysis of biological samples. These analysis allow quantification of the level of retention of asbestos fibres in the respiratory tract. Two groups of analysis may be used: quantification of asbestos bodies in sputum, bronchoalveolar lavage fluid or lung tissue samples using light microscopy; quantification and identification of asbestos fibres in bronchoalveolar lavage fluid or lung tissue using analytical electron microscopy. Profiles of lung retention of asbestos bodies or asbestos fibres have been described in various asbestos-related disorders, and reference values are available in control populations mainly for asbestos bodies using light microscopy. Mineralogical analysis of biological samples is not required for compensation of occupational asbestos-related diseases. However, this type of analysis may prove to be useful to the chest physician when looking for the etiology of some nonspecific respiratory diseases (interstitial pulmonary fibrosis, lung cancer), particularly when the occupational questionnaire is not contributive. As they are quite easier and less expensive, analysis using light microscopy will be performed first.

Asbestos↗
PubMed1999

[Asbestos-related occupational lung diseases. Role of the pneumology unit in screening and compensation].

The application of new decrees concerning the protection of individuals against sanitary risks linked to the various possible expositions to asbestos dusts is leading to a growing involvement of pulmonologists in diagnosis procedures not only for active workers regularly examined via the occupational medicine healthcare system, but also for those who are no longer, the unemployed or retired previously exposed to asbestos fibres. The present chapter presents and comments the revised guidelines about the compensation procedures for occupational diseases, and provides useful recommendations for establishing the records leading to their medical assessment. It emphasises the importance of a close cooperation between pulmonologists and radiologists in order to avoid radiation overdosing, which could increase the risk of lung cancer, as much as possible.

Asbestos↗
PubMed1999

[Retrospective estimation methods of pesticide occupational exposure].

The extensively growing use of pesticides in the last decades has led to great improvements in agriculture but also to threats for human health. Studying long term effects to assess individual exposures encounters difficulties in exposure assessment. This article summarizes retrospective methods for assessing occupational exposures to pesticides currently used in epidemiological studies. Questionnaires, environmental and biological monitoring constitute direct assessment of exposure, in an individual approach. But the validity of questionnaires is often poor and the metrology rarely reflects past exposures. Some indirect measures have been used together with job exposure matrices. To establish dose-response relationships is important to quantify the risk, but needs accurate exposure assessment based on quantitative indexes.

Bias↗
PubMed1998

Pleural mesothelioma: dose-response relation at low levels of asbestos exposure in a French population-based case-control study.

A hospital-based case-control study of the association between past occupational exposure to asbestos and pleural mesothelioma was carried out in five regions of France. Between 1987 and 1993, 405 cases and 387 controls were interviewed. The job histories of these subjects were evaluated by a group of experts for exposure to asbestos fibers according to probability, intensity, and frequency. A cumulative exposure index was calculated as the product of these three parameters and the duration of the exposed job, summed over the entire working life. Among men, the odds ratio increased with the probability of exposure and was 1.2 (95% confidence interval (CI) 0.8-1.9) for possible exposure and 3.6 (95% CI 2.4-5.3) for definite exposure. A dose-response relation was observed with the cumulative exposure index: The odds ratio increased from 1.2 (95% CI 0.8-1.8) for the lowest exposure category to 8.7 (95% CI 4.1-18.5) for the highest. Among women, the odds ratio for possible or definite exposure was 18.8 (95% CI 4.1-86.2). We found a clear dose-response relation between cumulative asbestos exposure and pleural mesothelioma in a population-based case-control study with retrospective assessment of exposure. A significant excess of mesothelioma was observed for levels of cumulative exposure that were probably far below the limits adopted in most industrial countries during the 1980s.

Adult↗
PubMed1998

[Health effects of artificial mineral fibers].

Data from mortality studies in cohorts of workers employed in the production of man-made mineral fibres, where levels of exposure were generally low, show an excess of mortality by lung cancer, although the role of the fibres themselves remains unclear in this excess. Standardized mortality ratio for lung cancer was lower in glass-wool production workers than in rock-slag-wool workers. Preliminary data for refractory ceramic fibres-exposed workers suggest the occurrence of benign pleural diseases and obstructive functional defects. Attention should be paid to levels of exposure to various man-made mineral fibres encountered by end-users commonly exposed to peaks of fibre concentrations higher than production workers.

Animals↗
PubMed1998

SV40-like DNA sequences in pleural mesothelioma, bronchopulmonary carcinoma, and non-malignant pulmonary diseases.

Pleural and pulmonary malignancies are usually associated with well-known carcinogen exposure. Recently, the presence of simian virus 40 (SV40)-like DNA sequences has been detected in brain and bone-related human cancers and in pleural mesothelioma. In order to determine whether SV40-like DNA sequences are also present in bronchopulmonary carcinoma and non-malignant lung samples, 125 frozen pleural and pulmonary samples (including 21 mesotheliomas, 63 bronchopulmonary carcinomas, 8 other tumours, and 33 non-malignant samples) and 38 additional samples distant from tumours were studied for the occurrence of SV40-like DNA sequences by polymerase chain reaction (PCR) amplification followed by hybridization with specific probes. Sequences related to SV40 large T antigen (Tag) were present in 28.6 per cent of bronchopulmonary carcinomas, 47.6 per cent of mesotheliomas, and 16.0 per cent of cases with non-neoplastic pleural and pulmonary disease. No statistically significant difference in the occurrence of these DNA sequences was found between malignant mesothelioma and bronchopulmonary carcinoma, but a significantly higher number of mesothelioma cases exhibited SV40-like DNA sequences in comparison with cases of non-malignant pleural or pulmonary disease (P < 0.04). Among cases positive for SV40-like DNA sequences, a history of asbestos exposure was found in 3 out of 12 bronchopulmonary carcinomas and 8 out of 10 mesotheliomas. Immunohistochemistry using monoclonal antibodies directed against Tag did not demonstrate nuclear staining. The DNA sequences were not related to BK virus sequences, but three samples were positive with probes hybridizing with JC virus DNA sequences. In conclusion, this study demonstrates the presence of SV40-like DNA sequences in pulmonary neoplasms and in non-malignant lung tissues. It appears that the presence of SV40-like DNA is not unique to cancer.

Adult↗
PubMed1998

[Occupational exposure to cadmium and renal cancer. Apropos of a case].

INTRODUCTION: Cadmium is a carcinogenic substance and bronchial and prostatic cancer may be readily identified as professional diseases. It is also a nephrotoxic substance but renal carcinoma are rarely imputed to this kind of intoxication. CASE REPORT: We report the observation of a 59-year-old woman with a long unprotected professional exposure to cadmium. She developed an epidermoid carcinoma of the kidney and later of the lung. Levels of cadmium in blood samples were abnormally high, confirming the existence of a chronic impregnation. CONCLUSION: We have judged cadmium to be responsible for her renal disease: the fact of a long unprotected professional exposure, the scarcity of renal epidermoid carcinoma, the well established nephrotoxicity of this substance and the association with other cancers, appear to us as convincing evidence, and the kidney cancer of our patient has been considered a professional disease.

Cadmium↗
PubMed1998

Guidelines for mineral fibre analyses in biological samples: report of the ERS Working Group. European Respiratory Society.

Microscopic techniques for analysing asbestos fibres in lung tissue and bronchoalveolar lavage have provided major information in the understanding of asbestos-related diseases. These analyses are increasingly applied for clinical work and medicolegal problems. Differences in sampling, preparation and counting techniques, definitions of reference populations and expression of results have caused major difficulties in comparing results from different laboratories. Therefore it appeared necessary to set a goal to harmonize these analyses between the European laboratories active in this field. This article summarizes the work of a European Respiratory Society working group with participation from nine European laboratories. The five main issues touched upon are: 1) definitions of control populations and reference levels; 2) sampling, preparation and analytical techniques; 3) asbestos fibres in lung tissues in different pathologies; 4) asbestos bodies in lung tissue, bronchoalveolar lavage and sputum; and 5) basis for the interpretation of fibres and asbestos bodies in biological samples. These guidelines indicate the crucial importance of several factors for the interpretation of the results; namely, adequate sampling, comparable analytical procedures and expression of the results, the use of well-defined reference populations, and a comprehensive understanding of the factors affecting the fibre retention and the dose-responses associated with the different asbestos-related diseases.

Asbestos↗
PubMed1998

[Delayed health effects of pesticides: review of current epidemiological knowledge].

The use of pesticides has extensively grown in the last decades, regardless of the economic level of the countries. This led to great improvements in agriculture but also a threat for human health. Short term effects are quite well known through approval procedures for pesticides. On the other hand, long term effects are not properly assessed. A review of epidemiologic knowledge is presented here. Epidemiologic studies on pesticides have found associations with long-term effects on health mainly in three fields: cancer (especially hematological cancer), neurotoxic effects (polyneuropathy, neuro-behavioral hazards, Parkinson's disease), and reproductive disorders (infertility, birth defects, adverse pregnancy outcomes, perinatal mortality). These conclusions have been obtained despite difficulties in exposition assessment due to the retrospective nature of the studies. But the continuous development of pesticide use in agriculture, and also in domestic environment, emphasizes the need for epidemiologic studies on long-term effects of pesticides relying on accurate exposure assessment.

Environmental Exposure↗
PubMed1998

[Mineral analysis and study of asbestos pathology].

Several tools are available for the evaluation of the exposure to asbestos, particularly occupational questionnaire and mineralogical analysis of biological samples. These analysis allow quantification of the level of retention of asbestos fibres in the respiratory tract. Two groups of analysis may be used: quantification of asbestos bodies in sputum, bronchoalveolar lavage fluid or lung tissue samples using light microscopy; quantification and identification of asbestos fibres in bronchoalveolar lavage fluid or lung tissue using analytical electron microscopy. Profiles of lung retention of asbestos bodies or asbestos fibres have been described in various asbestos-related disorders, and reference values are available in control populations mainly for asbestos bodies using light microscopy. Mineralogical analysis of biological samples is not required for compensation of occupational asbestos-related diseases. However, this type of analysis may prove to be useful to the chest physician when looking for the etiology of some nonspecific respiratory diseases (interstitial pulmonary fibrosis, lung cancer), particularly when the occupational questionnaire is not contributive. As they are quite easier and less expensive, analysis using light microscopy will be performed first.

Asbestos↗
PubMed1998

[Rolled atelectasis and asbestosis. Apropos of 26 patients].

Round atelectasis (AE) is a benign form of respiratory problem which develops due to fixing of the visceral pleura. This lesion for which the principal cause is exposure to asbestos may pose problems of differential diagnosis with bronchopulmonary cancer. In a cohort of 286 patients suffering from benign asbestos related pleural disease the diagnosis of round atelectasis was made on computerized tomography in 26 patients (31 AE) on the following criteria: rounded opacities of less than 7 cm in diameter situated at the periphery of the lung in contact with a thickened pleura with an acute angle linking the pleura and the opacity, a reduction of lung volume on the side of the atelectasis and the presence of a "comet tail sign". These patients were investigated to specify the circumstances of the occurrence, including their symptomatology, the changes in lung function, the topography of the round atelectasis and the associated radiological signs. Intense exposure to asbestos either continuous or discontinuous was found in 19 patients; 20 patients presented with some respiratory symptoms (dyspnoea 15/26, cough 11/26 and chest pain 9/26) but the reduction in lung function was moderate (7 had restrictive ventilatory trouble, 4 obstructive problems and a mixed problem in 1). The preferred localisation for round atelectasis was in the inferior lobes in the posterior basal lateral vertebral area (26/31) which may explain their being frequently missed on the standard radiograph (only one case of round atelectasis was visible on the straight chest radiograph in our study). An understanding of the pathology and the computered tomographic characteristics are now well defined and should enable an unnecessary diagnostic thoracotomy to be avoided which besides has no justification from the functional point of view.

Asbestosis↗
PubMed1998

Detection of SV40-like DNA sequences in pleural mesothelioma, bronchopulmonary carcinoma and other pulmonary diseases.

Mesotheliomas are pleural-based tumours mainly associated with asbestos exposure (70% of cases) and the incidence is still raising. Recently, a possible viral connection was reported and 60% of mesotheliomas were demonstrated to contain and express SV40-like DNA sequences. In this study, the presence of SV40-like DNA sequences were investigated in mesotheliomas (15 tissue samples and six cell lines) and in 63 additional bronchopulmonary carcinomas, one parietal osteosarcoma and non-malignant lung samples as well as in organizing pleuritis (8). Finally, 163 samples were analysed by the polymerase chain reaction (PCR) with a set of primers PYV.for and PYV.rev to amplify a 173 bp region of the SV40 Tag. and a 179 bp region JC virus (JCV) as well as a 182 bp region BK virus (BKV). PCR amplification and hybridization with a probe specific for SV40 Tag revealed that 47.6% of mesotheliomas, 28.6% of primary bronchopulmonary carcinomas and 16% of non-neoplasic lung diseases contained SV40-like DNA sequences. No statistically significant difference in the occurrence of these DNA sequences was found between malignant mesothelioma and bronchopulmonary carcinoma. However, a significantly higher number of mesothelioma cases exhibited SV40- like DNA sequences in comparison with non-malignant pleural and pulmonary tissues. The DNA sequences were not related to BK and JC virus sequences. These results indicate that SV40-like DNA sequences are present in mesotheliomas as well as in bronchopulmonary carcinomas and non-malignant pleuropulmonary diseases.

Antigens, Polyomavirus Transforming↗
PubMed1998

[Asbestos-associated occupational lung diseases. Role of the pneumology unit in screening and compensation].

The application of new decrees concerning the protection of individuals against sanitary risks linked to the various possible expositions to asbestos dusts is leading to a growing involvement of pulmonologists in diagnosis procedures not only for active workers regularly examined via the occupational medicine healthcare system, but also for those who are no longer, the unemployed or retired previously exposed to asbestos fibres. The present chapter presents and comments the revised guidelines about the compensation procedures for occupational diseases, and provides useful recommendations for establishing the records leading to their medical assessment. It emphasises the importance of a close cooperation between pulmonologists and radiologists in order to avoid radiation overdosing, which could increase the risk of lung cancer, as much as possible.

Asbestos↗
PubMed1997

[Epidemiological approach to mesothelioma].

Mesothelioma, the primitive cancer of pleura, peritoneum or pericardium, is a tumor for which many etiologic studies have been conducted, because of close relations with environment. If asbestos remains the essential risk factor, many uncertainties persist on extent of phenomena in next decades. Furthermore, emergence of new etiologies, confirmed on human (erionite, ionizing radiations) or only suspected in experimentation (some biopersistent synthetic fibers, some virus as the SV40), ask new questions which are susceptible to modify our view of mesothelioma epidemiology.

Asbestos↗