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Biomedical subjects

P Dumortier

Publications and source records attributed to P Dumortier.

At least 19 recordsLinked to original sources
PubMed2005

Pneumoconiosis after sericite inhalation.

BACKGROUND: Between 1997 and 1999 three sericite plant workers in Parana, Brazil, were diagnosed with pneumoconiosis. AIMS: To investigate and describe the radiological, clinical, and pathological changes in miners and millers exposed to sericite dust with mineralogical characteristics of inhaled dust. METHODS: The working premises were visited to examine the sericite processing and to classify the jobs according to make qualitative evaluation. Respirable dust was collected and the amount of crystalline silica and particle size distribution were measured. Forty four workers were examined by a standard questionnaire for respiratory symptoms, spirometry, and chest x ray. Material from an open lung biopsy was reviewed for histopathological and mineralogical analysis, together with sericite samples from the work site to compare the mineral characteristics in lung lesions and work area. RESULTS: Respirable dust contained 4.5-10.0% crystalline silica. Particle size distribution showed a heavy burden of very fine particles (23-55%) with a mean diameter of <0.5 microm. Mean age of sericite miners was 41.0 (11.9) and mean number of years of exposure was 13.5 (10.1). In 52.3% of workers (23/44), chest radiographs presented a median category of 1/0 or above, and 18.2% (8/44) had a reduced FEV1. There was a significant association between exposure indices and x ray category. Histological studies of the lung biopsy showed lesions compatible with mixed dust fibrosis with no silicotic nodules. x Ray diffraction analysis of the lung dust residue and the bulk samples collected from work area showed similar mineralogical characteristics. Muscovite and kaolinite were the major mineral particle inclusions in the lung. CONCLUSION: Exposure to fine sericite particles is associated with the development of functional and radiological changes in workers inducing mixed dust lesions, which are distinct histologically from silicosis.

Adult↗
PubMed2003

Trends in asbestos body counts in bronchoalveolar lavage fluid over two decades.

As in most western countries, the use of asbestos has decreased in Belgium since the mid 1970's. Successive regulations have lowered the permissible levels of exposure and prohibited the use of various asbestos products. In order to assess the impact of these prevention measures on the pulmonary fibre burden of asbestos-exposed patients, the bronchoalveolar lavage fluid (BALF) asbestos body (AB) analysis database of the authors' laboratory was reviewed for the period 1983-2000. A total of 4,772 cases were considered, of which 95% were males. AB concentration exceeded 1 AB x mL BALF(-1) in 36.1%. There was essentially no change in the mean concentration of AB over the period evaluated. However, the concentrations in individuals with very high levels decreased over time. This was associated with a shift in exposure categories from primary asbestos workers to those exposed during handling of asbestos-containing materials or to asbestos in place in buildings or industrial sites. This is consistent with epidemiological data indicating that the number of severe cases of asbestosis caused by very high cumulated doses decreases but that benign pleural diseases and mesothelioma remain the most frequent asbestos-related diseases. Past prevention measures are not expected to have a measurable influence on the incidence of mesothelioma in the near future.

Asbestos↗
PubMed2002

Chrysotile and tremolite asbestos fibres in the lungs and parietal pleura of Corsican goats.

BACKGROUND AND AIMS: Environmental exposures to chrysotile and tremolite from the soil cause pleural plaques and mesothelioma in northeast Corsica. Goats grazing in the contaminated areas inhale asbestos fibres. We used this natural animal model to study whether these exposures actually result in increased fibre burdens in the lungs and parietal pleura. METHODS: Ten goats from areas with asbestos outcrops and two from other areas were slaughtered. Fibre content of lung and parietal pleural samples was determined by analytical transmission electron microscopy. RESULTS: Both chrysotile and tremolite fibres were detected. In the exposed goats, the geometric mean concentrations of asbestos fibres longer than 1 microm were 0.27 x 10(6) fibres/g dry lung tissue and 1.8 x 10(6) fibres/g dry pleural tissue. Asbestos fibres were not detected in the lungs of the two control goats. Chrysotile fibres shorter than 5 microm were predominant in the parietal pleura. Tremolite fibres accounted for 78% and 86% of the fibres longer than 5 microm in lung and parietal pleural samples, respectively. CONCLUSIONS: Environmental exposure in northeast Corsica results in detectable chrysotile and tremolite fibre loads in the lung and parietal pleura of adult goats. Tremolite fibres of dimensions with a high carcinogenic potency are detected in the parietal pleura.

Animals↗
PubMed2002

[The pneumology department].

The department of pneumology of the Erasme hospital exists since 25 years. The basic clinical activities include pulmonary function testing (7,500 patients per year), endoscopy, including interventional endoscopy (1,500 patients per year), thoracic oncology, allergology, rehabilitation and aid to smoking cessation. The following expertise fields have been largely developed: lung transplantation, treatment of cystic fibrosis in collaboration with the children's hospital Reine Fabiola, occupational.

Belgium↗
PubMed2001

Pseudoasbestos bodies and fibers in bronchoalveolar lavage of refractory ceramic fiber users.

Refractory ceramic fibers (RCF) are widely used to replace asbestos in applications requiring high heat resistance. Ferruginous bodies mimicking asbestos bodies (ABs) have been detected in the lungs of RCF production workers. This raises the question about their presence in other occupational groups and whether "typical ABs" still reflect past asbestos exposures in all settings. An AB counting by phase-contrast light microscopy and a screening test by analytical electron microscopy were systematically performed on all bronchoalveolar lavage fluids (BALF) submitted to our laboratory in 1992 through 1997 (n = 1,800). When RCF were detected in electron microscopy, the structures considered as "typical ABs" were marked under light microscopy and prepared for further chemical and structural analysis. Pseudo-ABs on RCF were detected in samples from nine subjects (0.5%). All of them had worked either as foundry workers, steel workers, or welders. In these subjects, alumino-silicate fibers compatible with RCF accounted for 42% of the core fibers analyzed, other nonasbestos fibers for 28%, and asbestos fibers for 30%. ABs thus remain a valid marker of asbestos retention but attention must be paid to a possible occurrence of pseudo-asbestos bodies on RCF and other nonasbestos fibers in end-users of refractory fibers.

Adult↗
PubMed2001

Erionite bodies and fibres in bronchoalveolar lavage fluid (BALF) of residents from Tuzköy, Cappadocia, Turkey.

OBJECTIVES: The high incidence of malignant mesothelioma in some villages of Cappadocia (Turkey) is due to environmental exposure to erionite fibres. The aim was to evaluate the fibre burden in bronchoalveolar lavage fluid (BALF) from inhabitants of an erionite village and compare it with Turkish subjects with or without environmental exposure to tremolite asbestos. METHODS: Ferruginous bodies (FBs) and fibres were measured and analyzed by light and transmission electron microscopy (TEM) in the BALF of 16 subjects originating from Tuzköy. RESULTS: FBs were detected in the BALF of 12 subjects, with concentrations above 1 FB/ml in seven of them. Erionite was the central fibre of 95.7% of FBs. Erionite fibres were found in the BALF of all subjects, by TEM, and these fibres were low in Mg, K, and Ca compared with erionite from Tuzköy soil. The mean concentration of erionite fibres in BALF was similar to that of tremolite fibres in Turks with environmental exposure to tremolite. The proportion of fibres longer than 8 microm in BALF represented 35.6% for erionite compared with 14.0% for tremolite. The asbestos fibre concentrations in erionite villagers was not different from that in Turks without environmental exposure to tremolite. CONCLUSION: Analysis of BALF gives information about fibre retention in populations environmentally exposed to erionite for whom data on fibre burden from lung tissue samples are scarce. This may apply to exposed Turks having emigrated to other countries.

Adult↗
PubMed2001

The role of environmental and occupational exposures in Turkish immigrants with fibre-related disease.

Environmental exposure to tremolite and erionite causes endemic diseases of the lung and pleura in Turkey. This study aimed to evaluate the impact of these exposures and further occupational exposures on fibre-related diseases in Turkish immigrants living in Belgium. The study included 51 males and 17 females that emigrated < 1-38 yrs ago. Most of them (n=46) had nonmalignant pleural lesions, one had asbestosis and one had mesothelioma. Environmental asbestos exposure was likely for the majority of patients (60%), but there were also reports of possible occupational asbestos (n = 14) and erionite (n = 2) exposure. Tremolite was the main fibre type in bronchoalveolar lavage fluid (BALF). Elevated concentrations of amosite or crocidolite were detected in only two patients. The delay elapsed since the end of the environmental exposure had no influence on the asbestos body or the tremolite fibre concentrations in the BALF of Turkish immigrants. Most fibre-related diseases in Turkish immigrants are probably due to environmental rather than occupational exposure. Precise information about geographical origin and occupation should be obtained when investigating these patients. Mineralogical analysis of bronchoalveolar lavage fluid gives valuable information on the type and intensity of exposure, especially in patients with both environmental and occupational exposure.

Adult↗
PubMed2000

Quasistationary high confinement discharges with trans-greenwald density on TEXTOR-94

Confinement quality as good as ELM-free H-mode at densities substantially above the Greenwald density limit ( &nmacr;(e,0)/n(GW) = 1.4) has been obtained in discharges with a radiative boundary under quasistationary conditions for 20 times the energy confinement time. This is achieved by optimizing the gas-fueling rate of RI-mode discharges which tailors their favorable energy confinement and leads to discharges with beta values just below the operational limit beta(n) = 2 of TEXTOR-94, thereby effectively avoiding confinement back transitions or disruptions. In addition, this high-density regime is favorable for helium removal and results in figures of merit tau(*)(p,He)/tau(E) approximately 10-15, relevant for a future fusion power reactor.

Journal Article↗
PubMed1999

[Role of biometric analysis in the retrospective assessment of exposure to asbestos].

Despite intrinsic limitations due to differences in the bio-persistence of the various asbestos types, in the definition of control populations and in analytical techniques used by the laboratories, mineralogical analysis of biological samples is useful in the assessment of past exposure to asbestos. It provides additional information to occupational and environmental questionnaires, particularly when exposure to asbestos is doubtful, unknown or forgotten by a subject. Results should be interpreted taking into account clinical information. A positive result does not mean existence of asbestos-related disease. A negative result does not exclude previous significant asbestos exposure, clearly identified by an occupational questionnaire (particularly for exposure to chrysotile). Threshold values indicative of a high probability of previous asbestos exposure have been established for bronchoalveolar lavage fluid (BALF) samples and lung tissue samples. Quantification of asbestos bodies by light microscopy is easy to perform. Sensitivity and specificity of this analysis towards the total pulmonary asbestos fiber burden is good. Therefore this analysis should be performed first. Mineralogical analysis in BALF or lung tissue should be considered only when sampling is supported by diagnostic or therapeutic implications.

Asbestos↗
PubMed1998

Assessment of environmental asbestos exposure in Turkey by bronchoalveolar lavage.

Environmental or domestic exposure to asbestos fibers originating from local soil is responsible for a high incidence of diseases in large rural areas of Turkey. Bronchoalveolar lavage fluids (BALF) were obtained for 65 Turkish subjects originating from these areas and for 42 Turkish controls. Asbestos bodies (ABs) and uncovered fibers (UFs) were quantified by phase contrast light microscopy. Total fiber burden was determined by transmission electron microscopy. The main asbestos types disclosed were tremolite and to a lesser extent chrysotile. AB and fiber concentrations were higher in environmentally exposed subjects (geometric mean [geometric standard deviation]: 5.20 [6.22] AB/ml, 444 [11.6] tremolite fibers/ml) than in control subjects (0.22 [1.45] AB/ml, 12.0 [15.4] tremolite fibers/ml) (p < 0.001). In subjects environmentally exposed in Turkey, AB burdens on tremolite were in the same range as those on commercial amphiboles in subjects occupationally exposed in Belgium. In Turkish subjects, values above either 1 AB/ml, 3 uncovered fiber/ml in light microscopy, or 300 fibers/ml in electron microscopy indicated usually an abnormal alveolar retention reflecting a significant cumulative exposure from environmental or domestic origin. These observations are probably valid for other areas in the world where diseases associated with environmental exposure to soil- derived asbestos fibers occur and for immigrants originating from these areas.

Adult↗
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↗
PubMed1997

Analysis of asbestos bodies in BAL from subjects with particular exposures.

Four patients with asbestos-related diseases and with unusual exposures underwent bronchoalveolar lavage (BAL) for mineralogical analysis. Asbestos bodies (AB) were counted by light microscopy and analyzed by transmission electron microscopy and X-ray energy spectrometry. AB's were found in all cases, after a mean delay from the end of exposure of 27.7 years. Analysis of the core fibers indicated the type of alveolar asbestos burden and was compared with the previous exposures: Pleural plaques due to household exposure to amosite and crocidolite. Pleural plaques due to occult occupational exposure to crocidolite in a coal miner. Asbestosis due to environmental exposure to tremolite in Turkey. Asbestosis, pleural plaques, and peritoneal mesothelioma due to a short, intense exposure to crocidolite. AB counting in BAL and identification of the central fibers by analytical electron microscopy is a useful, non-invasive and reliable method to evaluate the alveolar retention of bio-persistent fibers and to relate them to specific exposures.

Aged↗
PubMed1996

Black spots concentrate oncogenic asbestos fibers in the parietal pleura. Thoracoscopic and mineralogic study.

Epidemiologic and pathologic data demonstrate that malignant mesothelioma occurs preferentially after exposure to long amphibole asbestos fibers. However, mineralogic studies have rarely detected such fibers in the parietal pleura. We hypothesized that the distribution of asbestos fibers in the pleura was heterogeneous and that they might concentrate in certain areas, as does coal dust in patients showing anthracotic "black spots" of the parietal pleura during thoracoscopy. We collected thoracoscopic biopsy samples from these black spots and from normal areas of the parietal pleura and lung from 14 subjects (eight with and six without asbestos exposure). Asbestos content was determined by transmission electron microscopy. In exposed subjects, mean fiber concentrations were 12.4 +/- 9.8 x 10(6) fibers/g of dry tissue in lung, 4.1 +/- 1.9 in black spots, and 0.5 +/- 0.2 in normal pleura. In unexposed patients, concentrations were 0, 0.3 +/- 0.1, and 0, respectively. Amphiboles outnumbered chrysotile in all samples. A total of 22.5% of fibers were > or = 5 microns in length in black spots. A histologic similarity of these black spots with milky spots is suggested by conventional and electron microscopy. We conclude that the distribution of asbestos fibers is heterogeneous in the parietal pleura. Indeed, the fibers concentrate in black spots, where they can reach high concentrations. These findings could explain why the parietal pleura is the target organ for mesothelioma and plaques.

Adenocarcinoma↗
PubMed1996

Atypical mycobacteriosis as a complication of talc pneumoconiosis.

A 57 year old man, receiving compensation for talc pneumoconiosis since 1977, was admitted to hospital for the first time in 1987, with symptoms of weight loss, fever, dyspnoea and productive cough. A chest roentgenogram showed bilateral cavitation. Two years later, Mycobacterium xenopi was found in sputum cultures. Despite specific oral antibiotherapy, the patient's health deteriorated and he died in 1990. To the best of our knowledge, this is the first reported case of an association of talcosis with a M. xenopi pneumonia. The relative timing of the two diseases suggests that talc pneumoconiosis predisposed to the infection by M. xenopi.

Diagnosis, Differential↗
PubMed1996

An epidemiological study in an Anatolian village in Turkey environmentally exposed to tremolite asbestos.

After several cases of malignant pleural mesothelioma (MPM) were detected in the village of Kureyşler in the Kütahya district of western Turkey, an epidemiological study was conducted. A questionnaire was completed by 124 villagers who were older than 20 years and standard posteroanterior chest X-rays were taken. The films were evaluated by three chest physicians. Samples of the white stucco that had been used by almost all villagers for indoor painting for many years were mineralogically examined. Chest X-rays showed that 23 (18%) had pleural plaques and calcifications compatible with asbestos exposure. Male sex and old age were associated with occurrence of pleural plaques. An analysis of white stucco samples revealed tremolite asbestos. In conclusion, tremolite fibers might be the cause of the high incidence of pleural plaques and MPM cases in the village of Kureyşler.

Adult↗
PubMed1995

Macroscopic assessment of pulmonary emphysema by image analysis.

AIMS: To propose a computerised image analysis based method for measuring, on paper mounted lung sections, the area macroscopically occupied by emphysema. METHODS: The study was based on the assessment of 69 lung sections prepared following a modified Gough-Wentworth technique. The results obtained from image analysis, point counting, and panel grading methods were compared, as was the repeatability of image analysis and panel grading. RESULTS: The results from image analysis and from point counting were not significantly different (p = 0.609) and significant quadratic regressions (r = 0.96, p < 0.001) were found between measurements from image analysis and from panel grading, the computerised technique being shown to be the most reproducible. CONCLUSIONS: Image analysis is a valuable and reproducible method to measure the area of lung macroscopically involved by emphysema.

Histocytological Preparation Techniques↗