Biomedical subjects

P Wild

Publications and source records attributed to P Wild.

At least 19 recordsLinked to original sources

PubMed1995

Respiratory symptoms, ventilatory impairment, and bronchial reactivity in oil mist-exposed automobile workers.

Studies concerning the respiratory effects of oil mists are sparse and contradictory. The aim of this study was to determine the respective effects of occupational exposure to straight cutting oils and soluble mineral oils on the prevalence of respiratory symptoms, ventilatory impairment, and bronchial reactivity. The population study consisted of 308 male workers of a large French car-making plant, including 40 subjects chronically exposed to straight cutting oils (group S), 51 subjects chronically exposed to soluble mineral oils (group E), 139 subjects with chronic dual exposure to straight cutting oils and soluble mineral oils (group D), and 78 unexposed assembly workers used as a control group (group C). Worker evaluation included a standardized questionnaire, measurement of pulmonary function, and a methacholine challenge. Oil mist concentration at the work place was determined by gravimetric analysis. The arithmetic mean concentration was 2.6 +/- 1.8 mg/m3. The geometric mean concentration was 2.2 +/- 1.9 mg/m3. The prevalence of respiratory symptoms did not differ significantly among the four groups. However, the subjects exposed to straight cutting oils (group S + group D) had a significantly higher prevalence of chronic cough and/or phlegm than the others (group E + group O): 25.7% vs. 16.3% (p = 0.048). Furthermore, the prevalence of cough and/or phlegm increased significantly (p = 0.03) with increasing duration of exposure to straight cutting oils after adjustment on smoking categories. Lung function tests did not differ significantly among the four groups but we observed a significant decrease of forced expiratory volume in 1 sec (FEV1), forced expiratory flow during the middle half of forced vital capacity (FEF25-75), and maximal flow rate at 50% and 25% of exhaled forced vital capacity (V50 and V25) according to duration of exposure among smokers exposed to straight cutting oils, suggesting a synergistic effect of tobacco and insoluble oils. No effect of exposure to mineral oils on bronchial reactivity was demonstrated. It is concluded that despite low levels of pollution by oil mists, the present study has shown tenuous adverse chronic effects of straight cutting oils on respiratory symptoms and lung function. However, no adverse effect of soluble mineral oils was demonstrated. These results suggest that threshold limit values for mineral oils should be reassessed.

Adult↗

PubMed1995

Airway responsiveness to methacholine, respiratory symptoms, and dust exposure levels in grain and flour mill workers in eastern France.

Our goal was to assess the relation between dust exposure levels and the respiratory health status of workers in grain and flour mills in eastern France. We studied 118 male workers from 11 mills and 164 unexposed male controls. Dust concentration was measured by personal sampling methods. Outcome variables included respiratory symptoms, routine pulmonary function tests, and indices of airway responsiveness to methacholine. A great within- and between-area variability of inhalable dust concentration was found in all mills. A dose-response relationship was observed between dust exposure levels and chronic respiratory symptoms, suggesting that exposure to grain and flour dust may lead to chronic bronchitis. A significant relation was found between dust exposure and airway hyper-responsiveness; this finding is important since it has been hypothesized that the latter abnormality may lead to or be a predisposing factor in subsequent chronic, irreversible airflow obstruction.

Adult↗

PubMed1995

Mortality study among workers producing chromate pigments in France.

In a follow-up study of 294 men who had worked for at least 6 months in a chromate-producing factory in France between 1958 and 1987, only 16 were lost to follow-up and the number of person-years in the study was 5207. Occupational data were provided by the administration of the plant. The causes of deaths were ascertained from hospital and general practitioners' records. The observed numbers of deaths were compared with the expected numbers based on local rates with adjustment for age, sex and calendar time (standardized mortality ratio, SMR). The overall mortality did not differ significantly from that expected (SMR = 1.20, 95% CI = 0.98-1.47), whereas mortality due to lung cancer was in significant excess (SMR = 3.60, 95% CI = 2.13-5.68). Significantly higher lung cancer SMRs were found for workers whose duration of employment was more than 10 years. A non-significant excess was observed for all forms of digestive tract cancer (SMR = 1.30, 95% CI = 0.60-2.47). There were two cases of brain cancer when 0.24 was expected (SMR = 8.44, 95% CI = 1.02-30.49). No previous report has mentioned an association of brain cancer with chromate pigments; however, because of the small numbers involved, a chance excess should be considered.

Adult↗

PubMed1995

Designations F18ab and F18ac for the related fimbrial types F107, 2134P and 8813 of Escherichia coli isolated from porcine postweaning diarrhoea and from oedema disease.

The relatedness of the fimbriae produced by eight E. coli strains including type strains with F107 fimbriae, 2134P pili and colonization factor 8813 (preliminary F18), was examined. These strains had been isolated principally from pigs which were affected with postweaning diarrhoea or with oedema disease. The fimbriae were analyzed by means of electron microscopy, slide agglutination, immunofluorescence, immunogold labelling, immuno-diffusion, immunoelectrophoresis and western blot, molecular genetic techniques, and in vitro adhesion. The fimbriae of all the strains were long flexible filaments with a diameter not larger than 4.6 nm showing a zig-zag pattern. Results obtained by the serological techniques confirmed that the fimbriae possessed a common antigenic determinant designated 'a' in addition to a variant-specific determinant designated 'b' or 'c'. Immunoelectron microscopy demonstrated that the determinants 'a' and 'b' or 'a' and 'c' were localized along the same fimbrium. In immunoelectrophoresis, fimbrial extracts of selected strains yielded a single precipitation line towards the cathode. One single major subunit of approximately 15 kDa was recognised in western blots by antisera against the common antigenic determinant and the variant specific determinants. All strains possessed sequences related to gene fedA, coding for the major subunit of fimbriae F107. Two types of fedA-related subunit genes were differentiated, corresponding to the 'ab' and 'ac' types of fimbriae as defined by serological methods. The results demonstrated that F107 fimbriae, 2134P pili and colonization factor 8813 are related, and that two serological variants can be distinguished. We propose designations F18ab (for F107), and F18ac (for 2134P and 8813) in analogy to the nomenclature of F4 fimbriae.

Animals↗

PubMed1995

Mortality from cardiovascular diseases among potash miners exposed to heat.

We assessed mortality rates in a cohort of French potash miners between 1977 and 1987. The cohort comprised all workers of a potash mine active on January 1, 1977, or subsequently hired, with at least 3 years of employment. We compared the mortality of the subcohort exposed to heat from underground work (U) with the mortality of those who had never worked underground (D). The overall mortality was low [standardized mortality ratio (SMR) = 0.89, based on 570 deaths] and was lower among underground workers (age-standardized mortality rate = 660 per 100,000 person-years, 266 deaths) than among daylight workers (age-standardized mortality rate = 710 per 100,000 person-years, 304 deaths). Mortality from ischemic heart diseases (IHD) was higher for underground workers than for daylight workers (relative risk = 1.6). As exposure to heat decreased over time, we analyzed the mortality according to period of hire: within underground workers, we observed a downward trend for mortality from IHD which contrasted with a stable mortality from IHD among daylight workers. Among subjects who left for medical reasons, IHD mortality was five times greater in the heat-exposed group compared with daylight workers. The data are consistent with an increased risk of ischemic heart diseases from a hot environment that is offset by a strong healthy worker effect.

Cardiovascular Diseases↗

PubMed1995

Survey of the respiratory health of the workers of a talc producing factory.

OBJECTIVES: To assess the effect of an occupational exposure to talc dust on respiratory health. METHODS: 166 talc millers from a French factory underwent spirometry and filled in a standardised respiratory questionnaire during their annual medical visit in 1989. A full sized chest radiograph taken in 1987 for the subjects hired before 1982 was also available, for the others a radiograph taken when hired was used. Radiography was repeated in 1992 for all subjects still active at this date (n = 139). The occupational exposure to talc dust was characterised for each workplace with 1440 personal samples collected since 1986 and by semiquantitative estimates of the historical exposure. RESULTS: The geometric mean (range) of estimated exposure was 1.87 (0.5 to 50) mg/m3 and the estimated cumulative exposure at the date of spirometry was > 150 y mg/m3 for 41 subjects. After adjustment for smoking in a linear model the standardised residual values of both forced vital capacity and forced expiratory volume in one second decreased significantly with increasing exposure. The prevalence of dyspnoea also increased after adjustment for smoking categories and age in a logistic regression. The prevalence of small radiological opacities was significantly related to age and to the exposure after adjustment for age and smoking categories. The incidence of new opacities between the two radiographs (11 new opacities with a profusion higher than 0/1) was significantly related to smoking (10 out of 11 are smokers) but not to the exposure. CONCLUSION: This study shows an effect of high levels of talc dust both on functional variables and on the prevalence of small radiological images, but provides no clear evidence about the possible effect of present levels of exposure.

Adult↗

PubMed1995

[Mortality due to bronchopulmonary cancers in workers of 2 foundries].

A mortality study was carried out in two factories producing stainless steel in order to assess lung cancer risk among workers employed in coke oven, blast and open hearth furnaces, foundry, electric furnace, hot and cold rolling mills and pickling areas. Occupational exposures of interest were chromium compounds, nickel compounds, polycyclic aromatic hydrocarbons (PAH), silica and asbestos. All male workers having at least one year of employment between 01.01.1960 and 31.12.1990 were followed up for mortality. The vital status was assessed from birth place registries. Complete job histories since date of first employment were abstracted from the company files. The smoking habits of 50% of the cohort members were known from medical records. The observed number of deaths (obs) were compared with the expected ones based on regional rates with adjustment for age, sex and calendar time (Standardized Mortality Ratio, SMR). The cohorts included 6324 (factory 1) and 5270 (factory 2) workers. The overall mortality did not differ markedly from that expected in both factories: SMR = 0.95 (obs = 1540, p = 0.05) in factory 1 and SMR = 1.06 (obs = 916, non-significant) in factory 2. SMRs for lung cancer did not differ from unity, respectively 0.99 (obs = 105) and 1.00 (obs = 54), in whole cohorts. Non-significant lung cancer excesses were observed among workers of some workshops where exposures of interest might have occurred: coke oven (SMR = 2.04), blast furnace (SMR = 1.36), open hearth furnace (SMR = 1.75), hot rolling mills (SMR = 1.29). These processes, however, are no longer involved in the study factories. Furthermore, no lung cancer excess was observed among workers employed in current workshops: electric furnaces and cold rolling mills.

Adult↗

PubMed1994

A retrospective mortality study of workers exposed to arsenic in a gold mine and refinery in France.

A historical mortality study of a cohort of employees of a gold mining and refining company was carried out in Salsigne, France. A major goal of the study was to investigate the relationship between lung cancer mortality and exposure to arsenic, radon, silica, and other contaminants of the working environment. A twofold excess of lung cancer was found both among miners and smelters, mainly concentrated among workers who had experienced exposure to past levels of arsenic, radon, and silica. The consistency of the results in the mine and the refinery are suggestive of a carcinogenic risk from both soluble and insoluble arsenic, although the potential role of other factors cannot be dismissed.

Arsenic Poisoning↗

PubMed1994

Lung cancer mortality in a French cohort of hard-metal workers.

A cohort mortality study was carried out among workers of a plant producing hard metals using cobalt as a binder. This study was aimed at assessing possible lung cancer risks in relation with cobalt exposure. Seven hundred nine male workers with at least 1 year of employment were included in the cohort and followed for mortality from 1956 to 1989. Job histories were provided by the administration of the plant, whereas smoking habits were collected from medical records and by interview. The causes of deaths were ascertained from hospital and general practitioner records. The observed numbers of deaths (obs) were compared with the expected based on national rates with adjustment for age, sex, and calendar time (standardized mortality ratio; SMR). The overall mortality did not differ from that expected (obs = 75, SMR = 1.05), whereas mortality due to lung cancer was in significant excess (obs = 10, SMR = 2.13). This excess was higher among workers employed in the areas with the highest exposure (obs = 6, SMR = 5.03). No trend was observed, however, with duration of employment or time since first employment. Smoking data were available for 81% of the workers and 69% of the deceased and showed that smoking alone does not account for these lung cancer excesses, yet, because of the small numbers involved, no firm conclusion should be drawn from this study.

Adult↗

PubMed1994

Humoral immune responses of workers occupationally exposed to wheat flour.

Wheat flour is a complex organic dust likely to induce immune responses when inhaled in work environment conditions. We compared the humoral status of 159 exposed workers from 11 flour mills and one industrial bakery with that of 41 workers from a salt factory. IgG, IgA, and IgM levels of antibodies to whole flour and to gliadin were assayed using ELISA tests in serum and saliva samples. Serum levels of IgG and IgA to both antigens were significantly higher (p < 0.0001) in occupationally exposed workers. Exposed workers had significantly higher levels of salivary IgG (p = 0.005) and IgA (p < 0.0001) to whole flour and of salivary IgG (p = 0.0005) to gliadin. In both groups, similar levels of anti-gliadin salivary IgA antibodies were observed. These data suggest that occupational exposure to wheat flour triggers specific immune responses, most likely through stimulation of the mucosal immune system. The presence of significant levels of serum antibodies, however, indicates that a systemic immunologic response is also present among exposed individuals.

Antibody Formation↗

PubMed1994

Respiratory symptoms and airway responsiveness in apparently healthy workers exposed to flour dust.

Our aim was to measure the levels of exposure to wheat flour dust in a modern industrial bakery, and to assess the relationship between respiratory symptoms, sensitization to wheat flour antigens and airway responsiveness in the workforce. Forty four flour-exposed male workers and 164 unexposed controls were examined. Inspirable dust concentrations were measured using personal samplers. Respiratory symptoms were assessed by questionnaire, sensitization to wheat flour antigens by skin-prick tests, and methacholine airway challenge (MAC) test using an abbreviated method. Subjects were labelled MAC+ if forced expiratory volume in one second (FEV1) fell by 20% or more. The linear dose-response slope (DRS) was calculated as the percentage fall in FEV1 at last dose divided by the total dose administered. Inspirable dust concentrations were within acceptable limits in all working areas but one. The proportion of subjects with one or more symptoms and with airway hyperresponsiveness was significantly greater among flour-exposed workers than among controls. Using logistic or linear regression analysis, airway responsiveness was found to be strongly related to working at the bakery and to the baseline level of lung function. A positive skin-prick test was found in only 11% of flour-exposed workers and 6% of controls. In conclusion, our data show that despite exposure to relatively low concentration levels of inspirable flour dust, subjects working in the baking industry are at risk of developing both respiratory symptoms and airway hyperresponsiveness.

Adult↗

PubMed1992

The influence of buffers during fixation on the appearance of smooth endoplasmic reticulum and glycogen in hepatocytes of normal and glycogen-depleted rats.

Liver tissue of normal and glycogen depleted rats was prepared for transmission electron microscopy by perfusion fixation and subsequent osmication in the presence of various buffers, dehydration in aethanol and embedding in epon. The use of Na/K-phosphate or Na-cacodylate to buffer glutaraldehyde led to similar appearance and distribution of SER. When Na-cacodylate was used during osmication, more SER membranes were retained but less accumulations of glycogen were found than after osmication in the presence of Na/K-phosphate. Fixation with s-collidine buffered osmium led to an easily recognisable network of SER comprising wide tubules whereas glycogen was hindered to be stained. Veronal acetate or Na-cacodylate supplemented with sucrose resulted in marked dilation and disintegration of SER. A similar effect was obtained when Na/K-phosphate or Na-cacodylate was used in hyposmolar concentration as buffer for glutaraldehyde. Liver of fasted rats or glucagon-treated rats after perfusion with Na/K-phosphate buffered glutaraldehyde and osmication in the presence of Na/K-phosphate or Na-cacodylate comprised glycogen-depleted hepatocytes which contained abundant SER membranes occupying the entire space between other organelles even in samples harvested 3 h after glucagon administration. The diversity in appearance and distribution of SER and glycogen granules, which depends to a large extend on the buffer used, suggests that SER membranes may not be sufficiently stabilized during aldehyde fixation and osmication. We thus consider it likely that large accumulations of glycogen granules are the consequence of disintegration of SER membranes during processing rather than they represent the morphologic substrate of physiological degradation of SER membranes in the course of glycogen synthesis and deposition.

Animals↗

PubMed1992

Cellular changes in rat parathyroids provoked by progesterone and testosterone.

Male rats kept on a standard diet were treated either with progesterone or testosterone by a single intramuscular injection of preparations which are slowly absorbed and metabolized. The rats were anaesthetized 24 h after application of the hormones, perfused with glutaraldehyde, and the parathyroid glands prepared for electron microscopy. Morphometric analysis revealed that both progesterone and testosterone provoked (1) an increment in nuclear and cell volume and a concomitant increment in cell surface area, and (2) an increment in surface area of rough endoplasmic reticulum by 42% and 49%, and of the Golgi complex by 85% and 63%, respectively. Previously, we had found that oestradiol treatment led to a similar response in parathyroid cells. The conclusion is thus drawn that male and female sex hormones induce membrane synthesis resulting in an enhanced capacity for parathyroid hormone secretion since RER and Golgi complex are concerned with this secretion. It is considered probable that sex hormones have the ability fundamentally to modulate secretory activity in parathyroid cells.

Animals↗

PubMed1992

trans,trans-Muconic acid, a reliable biological indicator for the detection of individual benzene exposure down to the ppm level.

trans,trans-Muconic acid (2,4-hexadienedioic acid) (t,t-MA) is a minor benzene metabolite which can be used as a biological indicator for benzene exposure. The purpose of the study was to evaluate the limits of use of t,t-MA for detection and quantification of occupational exposures to benzene, particularly on an individual scale, phenol being used as the metabolite of reference. A simple and sensitive method previously described by the authors was carried out to analyse t,t-MA in 105 end-of-shift urinary samples from 23 workers exposed to benzene used as an extraction solvent for "concretes" recovery in the perfume industry. Good correlations were found between atmospheric benzene and both metabolites (uncorrected or corrected for creatinine) or between the metabolites themselves, with correlation coefficients from 0.81 to 0.91 (P < 0.0001). Correlation- coefficients were not improved after correction for creatinine. The overall individual benzene exposure range, median, and arithmetic mean were respectively 0.1-75, 4.5, and 9.0 ppm with corresponding t,t-MA excretion of 0.1-47.9, 5.2 and 8.9 mg/l (uncorrected) and phenol excretion of 1.4-298, 30.9, and 42.2 mg/l (uncorrected). In the control group (145 determinations for t,t-MA and 76 for phenol from 79 individuals) the range, median, and arithmetic mean were respectively < 0.04-0.66, 0.08, and 0.13 mg/l (uncorrected t,t-MA) and 1.5-42.0, 9.85 and 11.3 mg/l (uncorrected phenol). t,t-MA was far more specific than phenol and could be easily and practically used to estimate with a given probability the upper or lower corresponding benzene concentrations down to around the ppm level.(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pollutants, Occupational↗

PubMed1992

Bactericidal activities of lysozyme and aprotinin against gram-negative and gram-positive bacteria related to their basic character.

Bactericidal properties of aprotinin, a proteinase inhibitor and possibly a defence molecule in bovine species, and of chicken egg white lysozyme, known as muramidase, were investigated. Incubation of various bacteria in the presence of either aprotinin or lysozyme showed that both proteins killed Gram-positive as well as Gram-negative bacteria without addition of complement or EDTA. Denaturation of the two proteins by dithiothreitol did not lead to loss of their bactericidal potency. Electron microscopic examination of Escherichia coli incubated either with lysozyme or aprotinin revealed that the bacterial cytoplasms gradually disintegrated. Both aprotinin and lysozyme were demonstrated within the affected cytoplasm by immunogold labelling. The results suggest that the bactericidal potency of lysozyme is not only due to muramidase activity but also to its cationic and hydrophobic properties. The bactericidal activity of aprotinin is probably also related to both these properties rather than to its activity as proteinase inhibitor.

Animals↗

PubMed1992

Characterization of F107 fimbriae of Escherichia coli 107/86, which causes edema disease in pigs, and nucleotide sequence of the F107 major fimbrial subunit gene, fedA.

F107 fimbriae were isolated and purified from edema disease strain 107/86 of Escherichia coli. Plasmid pIH120 was constructed, which contains the gene cluster that codes for adhesive F107 fimbriae. The major fimbrial subunit gene, fedA, was sequenced. An open reading frame that codes for a protein with 170 amino acids, including a 21-amino-acid signal peptide, was found. The protein without the signal sequence has a calculated molecular mass of 15,099 Da. Construction of a nonsense mutation in the open reading frame of fedA abolished both fimbrial expression and the capacity to adhere to isolated porcine intestinal villi. In a screening of 28 reference edema disease strains and isolates from clinically ill piglets, fedA was detected in 24 cases (85.7%). In 20 (83.3%) of these 24 strains, fedA was found in association with Shiga-like toxin II variant genes, coding for the toxin that is characteristic for edema disease strains of E. coli. The fimbrial subunit gene was not detected in enterotoxigenic E. coli strains. Because of the capacity of E. coli HB101(pIH120) transformants to adhere to isolated porcine intestinal villi, the high prevalence of fedA in edema disease strains, and the high correlation with the Shiga-like toxin II variant toxin-encoding genes, we suggest that F107 fimbriae are an important virulence factor in edema disease strains of E. coli.

Amino Acid Sequence↗

PubMed1991

A study of the prevalence of acute respiratory disorders among workers in the textile industry.

An epidemiological study of 774 workers in seven eastern France cotton textile factories was conducted to determine the prevalence of acute respiratory disorders. From nine non-textile companies, 464 workers, stratified as to sex, age and tobacco consumption participated in the study as a control population. A questionnaire designed to elicit the respiratory symptoms (in particular the Monday tightness characterizing byssinosis) was administered to the 1238 workers. Peak-expiratory-flow (PEF) measurement was made for each subject, exposed and non-exposed, before the start of the shift on the day of the worker's return to work and repeated at the end of the shift. The PEF's variations during the workshift were studied. Present Monday tightness was mentioned by 48 cotton exposed workers (6.2%) and by 9 non-exposed (1.9%) (P less than 0.001). A 10% decrease in PEF during the shift was present in 63 cotton exposed workers (8.1%) and in 10 non-exposed (2.1%) (P less than 0.001). For the exposed population, Monday tightness was analysed using multiple logistic regression, showing an absence of a link with smoking, an increased occurrence after 20 years of exposure (OR = 7.3) and a link with current job (more frequent among those with the dustiest jobs) (OR = 4.9). The multiple logistic analysis of a 10% decrease in PEF showed effects of smoking habits (OR = 1.86). It also showed a link with "highly polluted job" history (OR = 2.7), but especially with present job (OR = 3.4). The absence of a constant link between Monday tightness and drop of the PEF was found.

Adult↗

PubMed1991

Morphometric analysis of compartments concerned with secretion of parathyroid hormone in male and female rats.

Parathyroid cells responded to estradiol application in rats by increment in surface area of the compartments concerned with parathyroid hormone secretion, i.e. the rough endoplasmic reticulum, Golgi complex and secretory granules. We thus compared the morphology of parathyroids of male rats with those of females of the same age and same weight, respectively. Morphometric analysis revealed that (i) the mean cell volume was significantly larger and, consequently, the number of parathyroid cells lower expressed per 1 mm3 tissue and (ii) the surface area of the Golgi complex was larger expressed per mean parathyroid cell volume and per 1 mm3 tissue in female rats than in males. Diversity in cell volume seems to depend on age rather than on sex, whereas diversity in the Golgi complex is considered to be sex related. The physiological implications remain to be clarified.

Aging↗