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Biomedical subjects

A Leclerc

Publications and source records attributed to A Leclerc.

At least 73 records · Page 4Linked to original sources
PubMed1992

Occupational risk factors for sinonasal cancer: a case-control study in France.

A case-control study was conducted in France to examine occupational risk factors for sinonasal cancer; 207 cases and 409 controls were included in the study. Detailed information was collected on occupational history and other potential risk factors for nasal cancer. Results are presented for three histologic types: adenocarcinoma, squamous cell carcinoma, and others. Among males, the risk of adenocarcinoma was significantly elevated for cabinetmakers (odds-ratio = 35.4, 95% confidence interval = 18.1-69.3), carpenters and joiners (OR = 25.2, 95% CI = 14.6-43.6), and wood-working machine operators (OR = 7.4, 95% CI = 3.4-15.8), whereas the odds-ratios were less than 1 for loggers and wood preparation workers. Odds-ratios associated with cabinetmakers (OR = 11.2, 95% CI = 2.7-45.9)) and carpenters and joiners (OR = 5.8, 95% CI = 1.8-18.6) were also significantly elevated for the other-histologic-types category. Significant excesses in risk of squamous cell cancer were noted for "bakers, pastry cooks, grain millers" (OR = 3.9, 1.2-12.8), construction workers (OR = 3.7, 95% CI = 1.7-8.0), and carpenters and joiners having worked for at least 15 years in the wood manufacturing industry (OR = 8.1, 95% CI = 1.3-50.3). Among females, a significant increase in risk of squamous cell carcinoma (OR = 9.5, 95% CI = 1.7-54.1) and a moderate increase in risk of adenocarcinoma (OR = 4.0, 95% CI = 0.7-23.5) was observed for textile workers. Elevated risks of squamous cell cancer were noted for farm workers of both sexes (males: OR = 2.2, 95% CI = 1.1-4.4; females: OR = 4.9, 95% CI = 1.0-24.9).

Adenocarcinoma↗
PubMed1992

Antibody-dependent cell-mediated immune reactions to Loa loa microfilariae in amicrofilaraemic subjects.

Antibody-mediated mechanisms that could be important in controlling microfilaraemia in Loa loa infected amicrofilaraemic adults (mf-ve) were studied. These subjects were selected as having a verified ocular passage of an adult L. loa but being amicrofilaraemic and without recent diethylcarbamazine treatment. Sera from 37 mf-ve subjects were compared to 14 sera from heavily (greater than 4000 mf/ml) infected subjects (mf+ve) and 9 sera from Caucasian control subjects for their reactions with L. loa mf (mf). Many mf-ve sera (22/37) were strongly positive in immunofluorescence (IFAT) on living mf. Mf+ve sera were negative, or only weakly positive, and Caucasian sera were negative. Clinical signs were not significantly different between IFAT reactive and non-reactive mf-ve subjects. Approximately half of the IFAT positive, mf-ve sera were also able to agglutinate mf; no other sera were active in this test. Titres ranged from log2 3-6 and in most cases, 9/11, the agglutination reaction was mercaptoethanol-sensitive. Antibody-dependent cellular adherence was studied using mf and leukocytes from uninfected donors. Using cryopreserved mf many heat-inactivated mf-ve sera gave strong reactions with obvious adherence by 4 h and few motile mf remained by 16 h but when fresh mf were employed these reactions were weak. However, addition of complement to many (10/11) mf-ve sera considerably enhanced adherence to fresh mf. The effect of various treatments on the complement source indicated a role for both the classical and alternative pathways. The cells attached to mf were mainly neutrophils (83%) with some eosinophils (15%) and few mononuclear cells (2%). The common occurrence of antibodies able to mediate complement-dependent adherence of polymorphonuclear leukocytes to L. loa mf in the sera of mf-ve subjects may indicate that such a mechanism is important in controlling microfilaraemia in vivo.

Adult↗
PubMed1992

Level of education, lifestyle, and morbidity in two groups of white collar workers.

STUDY OBJECTIVE: The aim was to examine the relationship between level of education, lifestyle, and morbidity in two groups of male white collar workers, and to determine whether any differences found could be related to objective differences in working conditions. DESIGN: The study was a survey of a random sample of commercial travellers and a sample of men with sedentary occupations, representing two different groups of white collar workers. Survey interviews were conducted during the annual compulsory medical examination. Subjects were classified into three levels of education and differences according to level of education were studied in relation to 40 frequent health problems, lifestyle variables, body mass index, height, and working conditions. SUBJECTS: There were 1364 men in the commercial traveller group, mean age 39.5 years, and 525 men in the sedentary group, mean age 36.2 years. There were 22 exclusions because of unclassifiable levels of education and four refused to be interviewed. SETTING: The study took place in 11 towns in France. MAIN RESULTS: When age was taken into account there were only minor differences in the prevalence of health disorders. Lifestyle variables and height were clearly related to the level of education. Observed differences could not be explained by constraints or declared difficulties in working conditions. CONCLUSIONS: Differences in health practices related to level of education are observed even in groups that are relatively homogeneous socially. Lifestyle may be important as an intermediate determinant of health disorders among less educated people.

Adult↗
PubMed1992

History of previous nasal diseases and sinonasal cancer: a case-control study.

A case-control study on cancer of the nose and paranasal sinuses, and several risk factors including previous nasal diseases and symptoms, was performed in France from January 1986 through February 1988. The frequency of previous nasal diseases and symptoms was analyzed by histologic type of cancer. Different results were observed for squamous cell carcinomas and adenocarcinomas. In men, there were statistically significant associations between squamous cell carcinomas and sinusitis, bleeding from the nose, polyps, rhinitis, and trauma to the nose; and between adenocarcinomas, bleeding from the nose, and rhinitis. In women, there was an association between squamous cell carcinomas and nasal polyps.

Adenocarcinoma↗
PubMed1992

Low-back pain in commercial travelers.

The role of occupational environment in the occurrence of low-back pain was analyzed for 1719 commercial travelers (1376 men and 343 women). At the beginning of the study (T0) the group was interviewed to determine current lifestyle and occupational factors associated with low-back pain during the previous 12 months. Twelve months later (at T1), a subsample of 1118 persons (893 men, 225 women) was reinterviewed to study the association between the incidence of low-back pain during the year of follow-up and the risk factors at T0. At T0 low-back pain was significantly related with time spent driving a car at work, comfort of the car seat, carrying loads during work, standing for long periods at work, smoking, and psychosomatic factors. At T1 driving 10 h/week or more, seat comfort, and psychosomatic factors were associated with first occurrence of low-back pain.

Adult↗
PubMed1992

[Cost and efficacy of therapeutic strategies in candidates for heart transplantation as salvage therapy].

A study of the real cost, the cost-effectiveness of treatment was performed in 31 cases of cardiogenic shock referred for cardiac transplantation, treated in a flexible therapeutic protocol associating implantation of an expensive mechanical circulatory support system (mechanical bridge) or treatment by drugs alone (pharmacological bridge) depending on the efficacy of IV enoximone. The average patient cost was 238,386 French Francs, ranging from 440,353 FF in patients receiving the mechanical bridge to 199,296 FF in those receiving the pharmacological bridge. The cost-effectiveness ratio expressed either as cost per patient surviving the different stages of the disease or as cost of obtaining an additional day of survival at the same intervals was twice as favourable in the group receiving the pharmacological treatment. This study suggests that IV enoximone and strict selection procedures for candidates for the more expensive option should help bring together the interest of the individual patient and of society as a whole.

Adult↗
PubMed1991

[Sinonasal cancer and occupation: a multicenter case-control study].

A case-control study was conducted to examine occupational risk factors for sinonasal cancer. 207 cases and 409 controls (323 cancer hospital controls and 86 controls selected from lists provided by the cases) were included in the study. All cases and controls were interviewed by specially trained physicians. Detailed information on occupational history was collected, in addition to other potential risk factors for nasal cancer. Results are presented for two histologic types: adenocarcinoma and squamous cell carcinoma. Among males, the risk of adenocarcinoma was significantly elevated for carpenter and joiners (OR = 17.7) and other woodworkers (OR = 26.9). A significant increase in risk of squamous cell cancer (OR = 2.5) and a moderate increase in risk of adenocarcinoma (OR = 1.7; NS) were noted for construction workers. Among females, an excess risk of squamous cell carcinoma was associated with employment in textile industry (OR = 2.9). Elevated risks of squamous cell cancer were observed for farm workers of both sexes (males: OR = 2.2; females OR = 4.9).

Adenocarcinoma↗
PubMed1990

Differential mortality: some comparisons between England and Wales, Finland and France, based on inequality measures.

Inequalities in mortality between social classes or socioeconomic groups were compared in three European countries, using similar sources of data from large national cohort studies. People registered at a census in 1971 (1975 for France) or a sample of them, were followed until 1980 or 1981. The Gini coefficient, a measure widely used in economics, allowed the comparison of various situations involving different numbers and group sizes. It was applied to age groups 35-44, and 45-54 for men only. According to this measure, inequalities were of the same order in England and Wales and Finland, and greater in France. Differences between the three countries concerning the principal causes of death leading to inequalities were cardiovascular diseases in England and Wales, accidents and cardiovascular diseases in Finland, and cancer and cirrhosis in France.

Accidents↗
PubMed1990

Occupational exposure and head and neck carcinoma.

An epidemiological case-control study was conducted to investigate occupational risk factors in cancers of the upper respiratory and digestive tract. Cases were men with squamous cell carcinoma of the oropharynx (667), hypopharynx (348), glottis (246), supraglottis (219), epilarynx (204), and 4 subsites of the oral cavity (787). Controls were healthy patients or patients with cancer of another site or another histological type (147 men). Past occupational exposures of cases and controls were compared. The analysis was performed independently for each site of cancer, controlling for age, amount and type of alcohol and tobacco consumption, and state of dentition. Results showed that cancer of the supraglottis was associated with exposure to oil and grease (odds ratio = 2.4; 95% confidence interval 1.0-5.8), and with exposure to cement (odds ratio = 4.2; 95% confidence interval = 1.1-16.4). Cancer of the glottis was also associated with exposure to dye (odds ratio = 6.4; 95% confidence interval = 0.7-56.6). Exposure to flour occurred more frequently among controls than among patients with pharyngeal or oral cancer. This might reflect an association between this occupational exposure and some particular types of cancer included in the control group.

Alcohol Drinking↗
PubMed1990

Macaca fascicularis, a nonpermissive host for the human filarial parasite Loa loa.

The ability of the filarial nematode Loa loa to infect 2 species of primates was studied. The primate species selected were closely related to species known to be susceptible. A mandrill (Mandrillus sphinx) and 6 cynomolgus monkeys (Macaca fascularis) were infected by subcutaneous injection of third-stage larvae of human L. loa from Gabon. The mandrill developed microfilaremia with an estimated prepatent period of 147 days, but microfilariae were not detected in any of the cynomolgus monkeys. Thus, mandrills appear permissive to human L. loa, whereas cynomolgus monkeys are not. Serum antibody responses were examined on western blots of adult L. loa antigens. Preinfection sera from all animals gave no reactions, but, after infection, sera from cynomolgus monkeys reacted more intensely and with more antigens than mandrill sera. Antibodies were still detectable in cynomolgus monkeys 15 mo postinfection. These reactions were compared with those found using human infection sera. Reactions with the cynomolgus monkey sera resembled those found with resistant endemic and amicrofilaremic human sera.

Animals↗
PubMed1990

[Comparison of observed and expected person-years: a simulated approach].

In Epidemiology, no simple test is available for comparing an observed number of exposed person-years with an expected number. The number of person-years is a sum of lengths of stays which is not normally distributed under the null hypothesis. A method is proposed and an example is given. The objective was to study in the French territory of New-Caledonia the relationship between past places of living and occurrence of respiratory cancers. The total observed number of person-years in a zone, among cases, was compared to an expected distribution, based on censuses and controlling for two confounding factors, period of stay and ethnic group. Different methods are compared: a test based on a simulated distribution, and parametric approaches with normality assumption. If the number of cases is small, the simulation test seems to be the best approach.

Analysis of Variance↗
PubMed1989

Chlamydial antibodies and tubal infertility.

Prevalence of Chlamydia trachomatis antibodies was studied in infertile women with and without tubal obstruction, and in a control group of pregnant women in a Central-African country with a high infertility rate. In comparison with the control group, tubal infertility patients were significantly more likely to have serum antibodies of 1:64 or greater with an age-adjusted odds ratio of 7.8 (95% confidence interval (CI) 3.2-19.1). Infertile women without tubal obstruction had antibody titres similar to the control group with an odds ratio of 1.1 (95% CI: 0.6-1.9). In the tubal infertility group there was a kind of dose-response relationship between chlamydial antibodies and the severity of tubal damage and pelvic adhesions on laparoscopy, with odds ratios of 3.2 (95% CI: 0.7-14.8), 6.2 (95% CI: 1.9-21.6) and 18.1 (95% CI: 6.0-68.5) in the group with mild, moderate and severe pelvic adhesions respectively. This survey adds more evidence to the hypothesis that C. trachomatis is a major agent responsible for tubal infertility in Central Africa.

Adult↗
PubMed1989

Differential recognition of Loa loa antigens by sera of human subjects from a loiasis endemic zone.

Somatic antigens of Loa loa adult worms with molecular weights of 15-180 kDa were identified by Western blot analysis using sera from 3 categories of parasitologically and clinically defined subjects from a loiasis endemic zone. Sera of occult, amicrofilaremic (OL), and 'resistant' individuals with no clinical signs of infection (R) reacted with an antigen of 160 kDa; sera of highly microfilaremic individuals (ML) did not. ML sera strongly reacted with an antigen of 18 kDa which was recognized only weakly or not at all by OL and R sera. At higher dilutions, OL sera only reacted with antigens at 23 and 160 kDa and ML sera reacted with antigens at 18 and 23 kDa, whereas R sera reacted with antigens at 23, 42, 54, 70, 100, and 160 kDa. These data suggested that R sera contained a higher concentration of antibodies which reacted with denatured, nitrocellulose-bound antigens. The IgG4 isotype predominated for all groups of sera, while IgG3 antibody responses were observed only with R sera. IgG1 antibodies were seen in all groups but reacted with fewer antigens than IgG4 antibodies, and no IgG2 antibody responses were detected. Sera against Brugia malayi, Wuchereria bancrofti, Onchocerca volvulus, and Dirofilaria immitis cross-reacted with somatic antigens greater than 70 kDa, whereas none reacted with Loa loa antigens less than 23 kDa.

Animals↗
PubMed1989

[Mortality of unskilled workers in different countries of Europe].

The fact that lower socioeconomic groups experience the highest mortality rates is widely recognized. However, few attempts have been made to compare the situation between countries, taking into consideration the causes of death. The existence of comparable nation-wide data, and collaborative work in the workshops of the European Science Foundation, made possible the comparison presented in this paper. The mortality experience of male unskilled workers is described for Finland, Norway, Denmark, England and Wales, and France. The excess of mortality in the group is more pronounced in some countries; it is especially high in France. The causes of death responsible for extra deaths are not the same in every country: in Finland accidents and cardiovascular diseases have an important place; respiratory diseases are more important in England and Wales than in other countries; in France, a large part of differential mortality is linked to diseases related to alcohol consumption.

Adult↗
PubMed1988

Correspondence analysis and logistic modelling: complementary use in the analysis of a health survey among nurses.

Logistic or other modelling approaches are often appropriate for studying epidemiological data. However, health surveys may be more complex. With numerous variables, there is a need for exploratory analysis. Parsimonious description of the data is also a useful complement to modelling. Correspondence analysis may be useful in such exploratory phases. An example of the complementary use of the two approaches is presented in the context of a health survey among nurses, which focused on the relationship between shift and night work, and declared health problems.

Adult↗
PubMed1988

Infertility in Central Africa: infection is the cause.

Determinants of infertility were studied in 340 women in Eastern Gabon, an area situated in the "infertility belt" of Central Africa. Fallopian tube occlusion was diagnosed in 82.8% of cases, showing the importance of infection-related causes. Women with tubal occlusion did not differ significantly from women with normal tubes in obstetrical history or prevalence of Neisseria gonorrhoeae or Chlamydia trachomatis on endocervical culture. Antecedents of pelvic inflammatory disease or a pelvic mass were significantly more common in the group with tubal occlusion. This group also had a significantly higher prevalence of serum chlamydial antibodies at a titer of 1/64 or higher. Hormonal factors were found in 31.7% of women, a cervical factor in 29.0% and mechanical factors in 5.6%. No diagnosis could be made in 12.2% of cases. During the investigation, 4.4% of women became pregnant. The predominance of infectious related causes of infertility makes it imperative to focus resources on prevention programs of upper genital tract infections in women.

Adult↗
PubMed1988

A study of the interaction of alcohol drinking and tobacco smoking among French cases of laryngeal cancer.

Laryngeal cancer represents an important cause of cancer in France, and the individual effects of alcohol and tobacco on this cancer site are well known. However the problem of the interaction between these agents is less extensively documented, and the role of the high consumptions of alcohol has not been studied frequently. A case-control analysis was undertaken to investigate the joint effect of alcohol and tobacco by comparing 197 glottic and 214 supraglottic cancer cases to 4135 controls representative of the French general population. Heavy drinkers were available from the two groups of cases, the highest alcohol category being equivalent to a consumption of more than 2 litres of wine per day. The relative risks estimated for heavy drinkers and smokers were high, and the results indicated an even stronger effect of alcohol drinking and tobacco smoking on the upper part of the laryngeal region. Additive and multiplicative models were fitted to the data. The multiplicative hypothesis was found to be the most appropriate, implying that the risks associated with alcohol and tobacco multiply when the exposures occur simultaneously. The public health implications of this result and the contribution of heavy drinkers and smokers to the frequency of upper respiratory and digestive tract cancers are discussed.

Adolescent↗