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Biomedical subjects

A Leclerc

Publications and source records attributed to A Leclerc.

At least 55 records · Page 3Linked to original sources
PubMed1997

Sinonasal cancer and occupation. Results from the reanalysis of twelve case-control studies.

A pooled reanalysis of twelve case-control studies on sinonasal cancer and occupation from seven countries was conducted in order to study associations with occupations other than wood- and leather-related occupations. The pooled data set included a total of 930 cases (680 men and 250 women) and 3,136 controls (2,349 men and 787 women). All the studies included a detailed occupational history for cases and controls. Each job was coded using the same classifications for occupation and industry. Two approaches were used in the analysis: systematic analysis of occupations; a priori analysis using a preestablished list of occupations and industries. The results confirmed associations observed in several studies not included in this analysis. For agricultural workers, significant excesses were observed for squamous cell carcinoma among women (OR = 1.69) and men (OR = 3.72 for ten years or more of employment as an orchard worker), and adenocarcinomas among men (OR = 2.98 for ten years or more of employment). Associations with textile occupations were observed for adenocarcinoma among women (OR = 2.60) and squamous cell carcinoma among men (OR = 5.09 for fiber preparers, 3.01 for bleachers). Elevated risks for both histologic types were observed among men employed in food manufacturing (OR = 3.25, adenocarcinoma), or as food preservers (OR = 13.9, squamous cell carcinoma), and among men employed as cooks (OR = 1.99, squamous cell carcinoma). A positive association with squamous cell carcinoma was observed for male transport equipment operators (OR = 1.21), and also with adenocarcinoma for male motor-vehicle drivers (OR = 2.50). A number of other associations were observed in the systematic analysis.

Adenocarcinoma↗
PubMed1997

Sinonasal cancer and occupational exposure to textile dust.

Data from a case-control study conducted at 27 hospitals in France in 1986-88 were analyzed to examine the association between exposure to textile dust and sinonasal cancer. The study included 207 cases and 409 controls. Detailed information on occupational history and other potential risk factors for sinonasal cancer was collected. Exposure to textile dust (probability and level of exposure, type of textile fiber) was assessed by an expert in industrial hygiene. Among women, exposure to textile dust was associated with an elevated risk of squamous cell carcinoma (odds ratio (OR) = 2.45, 95% confidence interval (CI) = 0.85-7.06, nine exposed cases) and adenocarcinoma (OR = 3.70, 95% CI = 0.56-24.4, three exposed cases). For squamous cell carcinomas, the risk increased with the duration and the level of exposure (P < 0.05): the ORs for the low, medium, and high level of cumulative exposure were 1.00 (95% CI = 0.10-9.43), 2.43 (95% CI = 0.54-11.1), and 3.57 (95% CI = 0.92-13.8), respectively. There was also a limited evidence of an excess risk of squamous cell carcinomas among men exposed to high levels of textile dust (OR = 2.18, 95% CI = 0.65-7.30, four exposed cases). Because of the strong association between wood-dust exposure and adenocarcinoma, an independent effect of textile dust on this type of cancer could not be studied among men. The risks associated with the different types of textile fibers (cotton, wool, and synthetic fibers) were similar and the results did not permit to incriminate a particular type of textile.

Adenocarcinoma↗
PubMed1997

Laryngeal and hypopharyngeal cancer and occupation: results of a case control-study.

OBJECTIVES: To ascertain whether certain occupations are associated with laryngeal or hypopharyngeal cancer. METHODS: A hospital based case-control study was carried out in 15 hospitals in France. It included 528 male cases diagnosed between January 1989 and April 1991, and 305 male controls with various other types of cancer. Interviews were carried out to obtain lifetime job histories and information on potential confounders. Logistic regression was used to compute the odds ratios (OR) for each of about 80 occupations and industries. RESULTS: There was an excess risk of laryngeal and hypopharyngeal cancer among service workers (OR 2.2, 95% confidence interval (95% CI) 1.3 to 3.9), agricultural and animal husbandry workers (OR 1.6, 95% CI 0.9 to 2.8), miners and quarrymen (OR 2.0, 95% CI 0.9 to 4.3), plumbers and pipe fitters (OR 2.6, 95% CI 0.8 to 8.1), glass formers and potters (OR 4.3, 95% CI 1.0 to 18) transport equipment operators (OR 1.5, 95% CI 1.0 to 2.5), and unskilled workers (OR 1.7, 95% CI 1.0 to 2.9). Analysis by industrial branch showed an excess risk for coal mining (OR 2.1, 95% CI 1.1 to 4.1), manufacture of metal products (OR 1.9, 95% CI 1.0 to 3.3), and administration and sanitary services (OR 1.7, 95% CI 1.1 to 2.5). CONCLUSION: These results suggest that occupational exposure might have a role in generating laryngeal and hypopharyngeal cancer, and indicate the need for further evaluation of these findings, an for the identification of the carcinogens which might account for the excess risks found for certain occupations.

Aged↗
PubMed1997

Evaluation of Interventions for Prevention of Back, Neck, and Shoulder Disorders in Three Occupational Groups.

An epidemiologic study was carried out in order to evaluate the effects of prevention programs at the workplace aimed at reducing back, neck, and shoulder morbidity among active workers. The intervention group included 275 workers in three occupational subgroups: hospital workers, warehouse workers, and office workers. The control group included 250 workers as comparable as possible to the intervention group. Comparisons were made, according to one-year changes in morbidity scores, for low back, upper back, neck, and shoulder disorders separately. An overall measure was also used. The one-year change in the overall measure was significantly different between the intervention group and the control group, indicating a positive effect of the prevention programs. Positive effects were stronger for some sites of pain and some occupational groups.

Journal Article↗
PubMed1996

Time-trend of sleep disorder in relation to night work: a study of sequential 1-year prevalences within the GAZEL cohort.

We examined two longitudinal hypotheses: the 1-year prevalence for night workers is consistently higher than for others; the time trend is steeper for night workers than for others. Subjects were 12,779 men (age 40-50) working at Electricité de France-Gaz de France, and recruited in the GAZEL cohort. Five questionnaires were sent to all subjects on 1989 through 1993. Self-reported occurrence of sleep disorder in the previous year was regressed on night work status in 1989 and covariates to estimate prevalence rate differences (PRDs). The estimated PRD for regular night workers versus others was 6.1% (95% CI, 1.1-11.1%). There was a common time trend of 1.4% per year (1.0-1.9%), and evidence of excess trend for regular night workers: 1.1% (-0.7-2.9%). Findings indicate that the effect of night work on sleep complaints manifests itself during the first year of night work and is permanent.

Adult↗
PubMed1995

Wood dust and sino-nasal cancer: pooled reanalysis of twelve case-control studies.

In order to examine the relationship between wood dust and sino-nasal cancer, data from 12 case-control studies conducted in seven countries were pooled and reanalyzed. The relative risks associated with wood-related jobs and with exposure to wood dust, measured using a job exposure matrix based on occupation and industry titles, were examined using logistic regression. The combined data set consisted of 680 male cases, 2,349 male controls, 250 female cases, and 787 female controls. A high risk of adenocarcinoma among men was associated with employment in wood-related occupations (odds ratio [OR] = 13.5, 95% confidence interval [CI] = 9.0-20.0) and the risk was greatest among men who had been employed in jobs with the highest wood dust exposure (OR = 45.5, 95% CI = 28.3-72.9) and increased with duration of exposure. The risk of adenocarcinoma also appeared elevated among women employed in wood-related jobs (OR = 2.5, 95% CI = 0.5-12.3), but the small number of exposed cases precluded detailed analysis. Women in wood dust-exposed jobs appeared to have an excess of squamous cell carcinoma (OR = 2.1, 95% CI = 0.8-5.5) which increased with duration of exposure. An increased risk of squamous cell carcinoma in men was seen only among those employed for 30 or more years in jobs with exposure to fresh wood (OR = 2.4, 95% CI = 1.1-5.0). The results of this analysis provide strong support to the association between exposure to wood dust in a variety of occupations and the risk of sino-nasal adenocarcinoma and are consistent with the results of individual participating studies, although the magnitude of the excess risk varied. The evidence in regard to squamous cell carcinomas was ambiguous and there was a great deal of heterogeneity observed in individual study results. This may be due to differences in risk associated with exposure to hardwoods and softwoods or with other, as yet to be identified, aspects of exposure.

Adenocarcinoma↗
PubMed1994

Sinonasal cancer and wood dust exposure: results from a case-control study.

A case-control study of occupational risk factors for sinonasal cancer was conducted in France in 1986-1988. The study included 207 histologically confirmed cases and 409 controls. Among the male cases were 59 men with squamous cell carcinoma and 82 with adenocarcinoma. The risk of sinonasal cancer in relation to wood dust exposure was studied in these two groups. The analysis was based on a case-by-case assessment of exposure by an industrial hygienist. Hardwood and softwood were distinguished. An approximate twofold increase in risk for squamous cell carcinomas was observed for cases whose first exposure to either hardwood or softwood occurred before 1945; however, the two types of exposure were highly correlated. An exposure to wood dust--from either hardwood alone or hardwood and other kinds of wood--was found for all but two of the 82 male cases with adenocarcinoma. The effects of different elements of exposure to hardwood (duration, level, period) were studied in detail with a logistic model. Two components of exposure--duration and average level--contributed independently to the overall very elevated risk. Additional exposure to wood other than hardwood did not increase the risk.

Adenocarcinoma↗
PubMed1994

A 10-year incidence survey of respiratory cancer and a case-control study within a cohort of nickel mining and refining workers in New Caledonia.

The incidence of lung, pleural, nasal, larynx, and pharynx cancer in relation to work in the nickel mining and refining industry was studied from 1978 to 1987 in the male population of the French territory of New Caledonia in the South Pacific. The results showed no greater risk in the population of nickel workers than in the general male population. The incidence of respiratory cancer in New Caledonia was found to be comparable to that of industrialized countries, except for pleural cancer for which there was an excess risk in New Caledonia. A case-control study within the cohort of nickel industry workers comprised 80 lung cancer, 12 larynx cancer, 20 pharynx cancer cases, and 298 controls, and took account of 18 substances to which workers were exposed, five of them nickel compounds. None of the substances, or any other occupational variable, was shown to increase the risk of respiratory cancer, except for cancer of the larynx in relation to level and duration of exposure to dust and engine exhaust fumes on mining sites (odds ratios ranged from five to 5.4 and were significant). These results provide no evidence that exposures specific to the nickel industry in New Caledonia increase the risk of respiratory cancer. This might be due to the involvement of less airborne nickel than the amount observed in positive studies elsewhere. The high incidence of respiratory cancer in New Caledonia, compared with other South Pacific islands, might be attributable to an environmental risk connected with the presence of mineral fibers in the geologic strata, as well as to tobacco and alcohol consumption levels similar to those prevailing in France.

Age Factors↗
PubMed1994

Localization of merosin-negative congenital muscular dystrophy to chromosome 6q2 by homozygosity mapping.

Congenital muscular dystrophies (CMD) are autosomal recessive, heterogeneous disorders. The commonest forms are the Fukuyama CMD (FCMD), associated with mental retardation and structural brain anomalies, and classical (occidental) CMD, with pure muscle expression. FCMD has been localized to chromosome 9q31-q33. Following the discovery of merosin deficiency in some CMD cases, we have localized, by homozygosity mapping and linkage analysis (Zmax = 5.6; theta = 0.0 for marker AFM127xb2) in four merosin-negative families a CMD gene in a 16 cM region of chromosome 6q2 in the region of the laminin M chain gene. In three consanguineous, merosin-positive, CMD families there was no linkage to either chromosome 6q2 or 9q31-q33.

Chromosome Mapping↗
PubMed1994

First isolations of arboviruses from phlebotomine sand flies in West Africa.

For the first time in West Africa, arboviruses were isolated from phlebotomine sand fly pools. One strain of Chandipura virus (a Vesiculovirus), four strains of Saboya virus (a Flavivirus), and one strain of a not yet identified virus were isolated. Three hundred twenty-two pools were established from a population of 33,917 sand flies caught in CO2 light traps in the Ferlo Sahelian region of Senegal from November 1991 to December 1992. This is the first isolation of Chandipura virus from any arthropod in Africa. Saboya virus has already been isolated from small rodents in Senegal; thus, its transmission cycle probably involves rodentophilic sand flies. No strain of Rift Valley fever phlebovirus, which caused an epizootic in this region in 1987, was isolated. During the same time at the same site, 11 sand fly species were identified from 4,191 specimens caught on sticky traps, including Phlebotomus duboscqi, a leishmaniasis vector.

Animals↗
PubMed1994

Congenital muscular dystrophy with merosin deficiency.

Congenital muscular dystrophy is one of the most frequent and severe childhood muscular dystrophies. Several forms of this disease have been described. The form associated with marked central nervous system disturbances, frequent in Japan, is known as Fukuyama congenital muscular dystrophy and was recently linked to chromosome 9. The most frequent form observed in occidental countries appears to be clinically characterized by exclusive involvement of skeletal muscle, and has been identified by clinico-pathological features which are often fallacious. A predominant histopathological feature is the marked increase in endomysial collagen tissue. We investigate whether laminin, a major component of the extracellular matrix, which is linked to the subsarcolemmal cytoskeleton by a large oligomeric complex of dystrophin-associated glycoproteins, could be involved in this form. We observed a specific absence of merosin, the laminin M chain, in 13 patients affected by classical non-Japanese form of congenital muscular dystrophy. This result allows the precise identification of a particular form of congenital muscular dystrophy and gives a clue to understanding its molecular pathogenesis.

Child↗
PubMed1994

[Prevalence of health problems in the Gazel (EDF-GDF) cohort: regional distribution and disparities].

This study deals with regional differences in annual prevalence of 44 declared diseases or clinical disorders in 1989 in GAZEL cohort participants from "Electricité de France-Gaz de France" company. The studied sample consisted of 20,325 people, from 35 to 50 years old, living in France, who answered to a mail questionnaire in 1989. The collected data from one year were analysed. An overall "regional effect" was searched about every listed disease in the questionnaire. For this purpose, a logistic model, controlling for age and sex, was used. For comparing prevalence of a disease in one region with average prevalence, an odds ratio (OR) was calculated: it was defined here as the ratio of disease odd in the region to the average French odd. The regional effect was studied in greater detail for five diseases, making allowance for extra factors of adjustment (tobacco and alcohol consumption, Quetelet index, salary category, number of declared diseases). The regional effect remained significative for four diseases: hypertension with OR from 1.26 to 1.68 in northern regions, and from 0.63 to 0.75 in southeastern ones; osteoarthrosis with OR lower than 1 in western regions (0.60 to 0.79), and larger in the South (1.24 to 1.46); hyperthyroidism, goiter with OR elevated in Midi-Pyrénées (2.91) and Lorraine (1.82) [corrected]; renal stones with OR high in the South (1.85 in Provence Riviera). These results can be compared to known observations about geographical differences in mortality. They also suggest persistence of hazardous areas for some diseases.

Adult↗
PubMed1993

Prion protein is abnormally accumulated in inclusion-body myositis.

In muscle biopsies of 8 sporadic inclusion-body myositis (S-IBM) and 4 hereditary inclusion-body myopathy (H-IBM) patients, vacuolated muscle fibers contained within their vacuoles strongly immunoreactive inclusions with 2 polyclonal and 1 monoclonal antibodies against prion protein (PrP). By light-microscopy, PrP deposits co-localized with beta-amyloid protein (A beta) and ubiquitin (Ub). By immuno-electronmicroscopy, both PrP and A beta were present on amorphous material and on 6-10 nm amyloid-like fibrils; and PrP and Ub co-localized on cytoplasmic twisted tubulofilaments (TTFs) and on amorphous material. Our study provides the first demonstration of abnormally accumulated PrP in pathological tissue other than brain, and it suggests that PrP may play a role in the pathogenesis of IBM.

Adult↗
PubMed1993

Prion protein is strongly immunolocalized at the postsynaptic domain of human normal neuromuscular junctions.

Using three well-characterized polyclonal and monoclonal antibodies against prion protein (PrP), we demonstrated a strong concentration of PrP at human neuromuscular junctions (NMJs). Applying double and triple fluorescence-labeling, we found that PrP immunoreactivity exactly co-localized with alpha-bungarotoxin (alpha-BT) identified acetylcholine receptors, as well as with the high junctional concentrations of beta-amyloid precursor protein, beta-amyloid protein, desmin, ubiquitin and dystrophin. Therefore, PrP was considered to be located on the postsynaptic muscle membrane. At all NMJs identified by bound alpha-BT, strong PrP immunoreactivity was obtained with all PrP antibodies. This appears to be the first demonstration of PrP concentrated at human NMJs.

Antibodies, Monoclonal↗
PubMed1993

Sinonasal cancer and occupational exposure to formaldehyde and other substances.

A case-control study of cancer of the nose and paranasal sinuses was conducted in France to determine whether occupational exposure to formaldehyde was associated with an increased risk of sinonasal cancer. Exposures to 14 other substances or groups of substances were also studied (wood dust, leather dust, textile dust, flour dust, sugar dust, coal/coke dust, nickel compounds, chromium compounds, chromium VI, welding fumes, soldering fumes, cutting oils, paints and lacquers, glues and adhesives). Cases (n = 207) and controls (n = 409) were interviewed to obtain detailed information on job history and other potential risk factors for sinonasal cancer. In addition, a questionnaire specially designed for this study was used to help assess exposures to formaldehyde and other substances of interest. The questionnaires were translated into history of occupational exposure by an expert in industrial hygiene, without knowledge of case-control status. Several exposure variables (lifetime average level, duration, cumulative level) were used to describe the risk related to exposure to formaldehyde. Potential confounding factors (occupational and non-occupational) were examined and adjusted for when necessary. No significant association was found between exposure to formaldehyde and squamous-cell carcinomas of the sinonasal cavities. Because of the strong association between exposure to wood dust and nasal adenocarcinoma, it was not possible to assess an independent effect of formaldehyde on this type of cancer. However, among males exposed to medium or high levels of wood dust, the risk of adenocarcinoma associated with formaldehyde was significantly elevated for the highest exposure categories for average level (OR = 5.3, 95% confidence interval = 1.3-22.2), cumulative level (OR = 6.9, 95% CI = 1.7-28.2) and duration of exposure (OR = 6.9, 95% CI = 1.7-27.8). Although a residual confounding effect of wood dust could not be excluded, this study suggests that exposure to both formaldehyde and wood dust may increase the risk of nasal adenocarcinoma, by comparison with the risk due to wood dust alone. This study also indicated an increased risk among males who had been exposed to glues and adhesives, for all histologic types, which was not explained by a confounding effect of paints and lacquers, wood dust or formaldehyde. No other significant association was observed.

Adenocarcinoma↗
PubMed1993

Ubiquitin and beta-amyloid-protein in inclusion body myositis (IBM), familial IBM-like disorder and oculopharyngeal muscular dystrophy: an immunocytochemical study.

We used immunocytochemistry to identify ubiquitin and beta-amyloid-protein in muscle biopsies from patients with three neuromuscular disorders characterized by the presence of rimmed vacuoles in muscle fibres: inclusion body myositis (IBM), familial IBM-like disorder and oculopharyngeal muscular dystrophy (OPMD). Labelling with anti-ubiquitin antibodies was observed in all three diseases, but it was frequent in IBM, less common in familial IBM-like disorder and rare in OPMD. This labelling is thought to correspond to the presence of IBM-type filaments (16-18 nm in external diameter) which are characteristic but not specific for IBM or familial IBM-like disorder, as they may also occur in other diseases including OPMD. Labelling with anti-beta-amyloid-protein antibody was seen in a few fibres in IBM but not in the other two conditions. The structures labelled with this antibody have yet to be determined. Labelling with anti-ubiquitin or anti-beta-amyloid-protein antibodies was not correlated with the presence of acid phosphatase activity.

Adult↗
PubMed1993

Sources of discrepancies between a job exposure matrix and a case by case expert assessment for occupational exposure to formaldehyde and wood-dust.

Two methods used for retrospective evaluation of occupational exposures, a case by case assessment by expert and the application of a job exposure matrix (JEM), are compared using occupational histories collected for a case-control study on sinonasal cancer. The objective was to identify the main sources of discrepancies and to contribute to an optimal use of a JEM for population-based case-control studies. Comparisons were based on job periods, and were performed separately for two substances: formaldehyde and wood-dust. Job periods were classified according to the category of exposure assigned by the matrix, and to the probability and level of exposure assessed by the study expert. The sources of discrepancies were examined for job periods probably or definitely exposed according to the JEM and unexposed for the expert, or unexposed in the JEM and probably or definitely exposed to medium or high level for the expert. Such discrepancies were observed for 8% of the job periods for formaldehyde and 3% of the job periods for wood-dust. The agreement between the two approaches was better for wood-dust than for formaldehyde. The relative importance of different sources of discrepancies was not the same for formaldehyde and wood-dust. For formaldehyde a substantial part of the discrepancies was due to disagreements between the study expert and the matrix experts, which were mostly differences in threshold limits between 'not exposed' and 'definitely exposed at a low level'. Differences between experts' opinions did not explain the discordances observed for wood-dust. The presence of additional information in the questionnaire was an important source of discrepancy for the two substances.(ABSTRACT TRUNCATED AT 250 WORDS)

Case-Control Studies↗