[Eczema on contact with molecules of the paraphenylenediamine family in the workshop].
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Biomedical subjects
Publications and source records attributed to P Catilina.
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Exposure to certain chemical agents in occupational settings has been identified as carcinogenic to the human bladder. Micronucleus (MN) analysis in exfoliated urothelial cells is an interesting method for biomonitoring genetic damage in human populations. However, few studies have been performed in an occupational context. The aim of this study was to examine whether the occupational use of a mineral jelly induced a genotoxic risk for workers employed at a single factory producing bearings using the MN test on exfoliated urothelial cells. The prevalence of micronucleated exfoliated urothelial cells (MNC) was determined in 35 female workers with dermal exposure to the jelly and 41 female controls. The mean percentage of MNC (expressed as percent cells with MN per 1000 cells scored) observed in the exposed worker group was 0.46 +/- 0.11% (range 0-2.8) and in the control group 0.14 +/- 0.03% (range 0-0.8). There is a significant job effect (P = 0.0018, MANCOVA) on the prevalence of MNC, whereas age and smoking habit had no significant effect (P = 0.90 and 0.91, respectively). There is no interaction between job and smoking habit (P = 0.4421). Exposure to the mineral jelly appeared to be the main factor inducing the increased prevalence of MNC. This may be due to the presence of mutagens/carcinogens in the jelly: an aromatic amine, N-phenyl-1-naphthylamine (CAS no. 90-30-2), which is carcinogenic in mice, or sodium nitrite (CAS no. 7632-00-0), which is genotoxic in human cell systems. In conclusion, these results suggest that use of the mineral jelly could present a genotoxic risk for workers. We think that the MN assay on exfoliated cells could be valuable for biological monitoring purposes in occupational contexts as a marker of significant exposure to bladder mutagenic/carcinogenic agents.
PURPOSE: To assess the reliability of low-dose high-resolution computed tomography (HRCT) in the detection of benign asbestos-related pleural abnormalities. METHODS: Fourty-one patients exposed to asbestos were imaged on two occasions; the first time with conventional HRCT parameters: 140kVp, 220mAs; the second time with low-dose HRCT parameters: 120kVp, 60mAs. RESULTS: The qualitative assessment dit not show any difference in the visibility of benign pleural abnormalities from one technique to the other in 98% cases. CONCLUSION: The detection of pleural plaques and thickening did not vary with the two scanning protocols and, when compared with conventional HRCT, low-dose HRCT allows reduced radiation exposure by at least 76.5%, with an absorbed dose close to that delivered when using conventional chest radiography. Nevertheless, low-dose HRCT is a complementary study to helical acquisitions.
BACKGROUND: Chemical odor intolerance is a benign, non-specific, generally subjective syndrome triggered by inhalation of non-toxic doses of chemical compounds or products which had been previously well tolerated. We report five characteristic cases and discuss current data. CASE REPORTS: Five patients (3 women, 2 men; age range 23-52 years) presented the basic criteria of chemical odor intolerance: acquired syndrome, non-specific signs (headache, nausea, vertigo ...) triggered by the odor of one or more chemical substances. Physical examination and exploratory tests were normal. In 3 cases, the course was favorable after evicting the causal substances. For the other 2 cases, intolerance spread to other compounds. Four of the patients changed their work situation because of the chemical odor intolerance. DISCUSSION: The diagnosis is clinical. Different pathogenic hypotheses have been put forward in the literature: immunological, toxic, neurobiological, psychological, and psychiatric mechanisms have been proposed. The mechanism is probably multifactorial but psychological factors appear to play an important role either as predisposing or triggering factors. CONCLUSION: Due to the social and occupational consequences of chemical odor intolerance, better knowledge of its prevalence and mechanism would be most helpful in managing these patients.
Different studies have proposed that genetic alterations leading to inactivation of a tumor suppressor gene on chromosome 9 is an important early event in bladder tumorigenesis. Recent reports have described the p16 gene as the main target. In order to better define its role, we studied 9p21 deletions by microsatellite analysis and its coding sequence. Forty-eight percent of the 44 samples we studied showed LOH surrounding p16. Three of these 44 samples displayed point mutations in p16 and three others were suspected of homozygous deletion. These results suggest that simultaneous loss of both p16 alleles, by point mutation or homozygous deletion, seems to be infrequent in bladder tumors.
OBJECTIVE: This study was undertaken to determine whether certain criteria could be used to select among asbestos-exposed subjects those who could benefit from computed tomography screening. MATERIALS AND METHODS: Search for criteria enabling the selection of patients who should undergo a CT screening exam after occupational exposure to asbestos was conducted in 150 subjects. All subjects were explored with selected high-resolution CT scans. Studied parameters were age, exposure data, pulmonary function test results. RESULTS: None of the exposure data or pulmonary function test results suggested with certainty the presence or absence of asbestos-related pleural and parenchymal lung disease. The studied parameters could not be used to select patients who could benefit from CT screening. CONCLUSION: None of the studied parameters enabled a selection of asbestos-exposed subjects who should undergo chest CT screening.
Programs of prevention concerning the populations exposed or having been exposed to asbestos include on the one hand, specific programs of medical surveillance and on the other hand, interventions of primary prevention. The latter were essentially anti-smoking campaigns and chemo-prevention trials of lung cancer through taking of vitamin A derivatives. In the first part of this review, the results of the experiments of the medical follow, up organized in France and abroad will be shown. These studies allow particularly to appraise both the usual latency of appearance of lung pathologies due to asbestos and the contribution of thoracic scanography in their diagnosis. The interest of the new techniques, such as the autofluorescence fiberscopy, is tackled too. The studies on primary prevention, detailed in the second part, underline the necessity to stop of tobacco consumption among the smokers exposed to asbestos. Moreover, this study concludes that the chemo-prevention of lung cancer through vitamin A derivatives is not yet effective. Some general principles which may be useful to the setting up programs of prevention are put forward in conclusion.
Medical screening requires always assessment. On the basis of ongoing studies on occupational health asbestos programs, we suggest some recommendations for asbestos screening after occupational exposure. The proposal for asbestos workers post-exposure surveillance should take into account the medical but also the social aspects of the problem. Post-exposure screening of asbestos workers includes an evaluation of occupational exposure, compulsory basis medical check-up, the characteristics of the radiological investigations and schedule of the medical surveillance. In conclusion, we suggest some general recommendations for asbestos screening after occupational exposure, particularly the necessity to obtain a concerted approach of asbestos screening with regional and national networks, the concern of their assessment and the implementation of specific research studies.
Loss of heterozygosity (LOH) on chromosome 9 is the most frequent genetic alteration in bladder cancer identified to date, suggesting the presence of key gene(s) for this pathology. In this study, we examined 44 bladder tumors and 21 normal bladder samples for LOH on both arms of chromosome 9. Sixteen microsatellite markers, 12 on the short arm (encompassing 9p21-22) and 4 on the long arm (encompassing 9q33-34), were chosen for their highly frequent alterations in bladder cancer. LOH for at least one marker was identified in 42 tumor samples (95.5%), and 14 tumors (32%) displayed LOH for all informative tested markers. Detailed analysis showed that 2 markers on chromosome 9p (D9S157 and D9S156) had the highest frequencies of allelic loss (about 70%), independent of tumor grade and stage. The same study was performed on the 21 normal bladder mucosa samples: 50% of informative cases presented a single specific LOH at the D9S156 locus. Normal samples showing LOH at this locus were therefore screened with 3 novel microsatellite markers in the 810-kb region incorporating D9S156. Using this marker, we found no further heterozygous loss in this region. This result allows different interpretations of the D9S156 loss in normal bladder mucosa, and suggests that D9S156 may be more an indicator of bladder epithelium impairment than a tumor-initiation marker. Similarly, this unexpected result calls in question the interpretation of LOH studies.
Bladder cancers display different forms from superficial to aggressive tumours with muscle invasion. Many studies on this disease have been carried out in order to better understand the molecular mechanisms involved in its progression. Two loci are frequently associated with bladder tumorigenesis. The chromosome 9 lesions seem to be earlier involved in carcinogenesis, and suggest the presence of a tumour suppressor gene, and on the other hand the TP53 gene mutations (17q13.1) are later but take place in tumour progression. These alterations could be used as early diagnosis tool in bladder tumours and orientate the search for the bladder cancer gatekeeper gene(s).
Micronuclei observed in exfoliated cells result from DNA-damage of basal epithelium's cells by mutagens. Exfoliated urothelial cells can be collected by non-invasive procedure and may be used as target site to identify genotoxic effects of chemicals. Kinetic studies are important for any biomarker, especially those in which tissue differentiation and maturation processes will heavily influence the time between induction of damage and collection of damaged cells for analysis. This manuscript details the result of a longitudinal study of micronuclei induction in cells isolated from urine samples of 4 healthy women over 6 consecutive days. Three of them were former smokers. Results suggested that micronucleated cell rates were not influenced neither by the day nor by the time of sampling.
OBJECTIVES: Evaluate risk of hepatitis A, B and C infection and anti HBV vaccination policy in hospital personnel. METHODS: A sample of 440 health care workers (7.5% of the personnel at the Clermont-Ferrand University Hospital) representing 74.5% people directly involved in health care and 25.5% other workers were selected at random and stratified by work classification and age. A questionnaire was used to establish personal data on viral hepatitis status and blood samples were drawn for serological tests. RESULTS: Seroprevalence for hepatitis A was 52% with no significant difference between health care and other workers. For hepatitis B, 88.3% of the population had been vaccinated and anti-HBs titre was > or = 10 mIU/ml for 91.6% and > or = 50 mIU/ml for 86.1%. Seroprevalence for anti-HBc was 7% and none of the subjects were positive for HBs antigen. Anti-hepatic C antibodies were found in 2 health care workers (0.7%). CONCLUSION: These findings emphasize the need to persue further preventive actions against hepatitis A, B and C and the requirement for continued efforts in elementary hygiene.
UNLABELLED: The course of Raynaud's phenomenon (RP) after the end of exposure to vinyl chloride monomer (VCM) is not really well known. Fourty four subjects were studied, from 128 retired patients who were exposed to VCM (end of the exposure since 8 years at least): 17 complained of "white finger crisis", and 27 voluntary retired subject without complaints (table II). The aims of this study were to specify capillaroscopic and clinical characteristics of these complaints to define and to assess the role of VCM. Each patient underwent an interview, a clinical examination and a nailfold capillary microscopy examination. RESULTS: 1) The 17 pensioners with complaints suffered from RP. But for 12 of them the onset of RP was in the exposed period (table I). From the clinical interview, the clinical and capillaroscopic examinations in these 12 RP may be attributed to the past exposure to VCM. 2) The majority of 44 subjects showed no capillary abnormalities. For 3 subjects changes consisted in isolated capillary dystrophia (1 with PR, 2 without PR) and for 2 subjects changes consisted in isolated neocapillaries (1 with PR, 1 without PR). The other microvascular changes were not specific (table III). In conclusion, RP secondary to VCM can still persist after the end of exposure in patients who suffered from RP during the exposure, 9% of the population (12/128). In view of discordance of clinical symptoms and capillaroscopic abnormalities, capillary lesions did not appear as the main physiopathologic factor in the persistence of the PR secondary to CVM.
Plasma and blood xanthine and hypoxanthine levels were assayed using a sensitive and specific method involving gas chromatography-mass spectrometry, associated with an optimized sample preparation procedure. Physiological variation was studied in 224 subjects with no purine metabolism disorders. An age dependency for both compounds was found, comparable with that known for uric acid. The mean plasma levels for the 224 subjects were 0.65 +/- 0.24 microM for xanthine and 1.65 +/- 0.78 microM for hypoxanthine. Corresponding mean blood levels were 0.59 +/- 0.21 microM for xanthine and 1.72 +/- 0.74 microM for hypoxanthine. Plasma and blood levels were significantly different, by ca. 10%. Rapid in vitro release of hypoxanthine from erythrocytes and continuation of intraerythrocytal metabolism lead to overestimation exceeding 10% within half an hour after sample blood collection. Hence samples must be deproteinized promptly. Blood can therefore be conveniently used for oxypurine assay instead of plasma when prompt spinning of samples is difficult to manage, as is usually encountered in clinical practice.
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