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C Paris

Publications and source records attributed to C Paris.

At least 19 recordsLinked to original sources
PubMed2007

Mechanism of copper mediated triple helix formation at neutral pH in Drosophila satellite repeats.

The highly repeated Drosophila melanogaster AAGAGAG satellite sequence is present at each chromosome centromere of the fly. We demonstrate here how, under nearly physiological pH conditions, these sequences can form a pyrimidine triple helix containing T.A-T and CCu.G-C base triplets, stabilized by Cu2+ metal ions in amounts mirroring in vivo concentrations. Ultraviolet experiments were used to monitor the triple helix formation at pH 7.2 in presence of Cu2+ ions. Triplex melting is observed at 23 degrees C. Furthermore, a characteristic signature of triple helix formation was obtained by Fourier transform infrared spectroscopy. The stabilization of the C.G-C base triplets at pH 7.2 is shown to occur via interactions of Cu2+ ions on the third strand cytosine N3 atom and on the guanine N7 atom of the polypurine target strand forming CCu.G-C triplets. Under the same neutral pH conditions in absence of Cu2+ ions, the triple helix fails to form. Possible biological implications are discussed.

Animals↗
PubMed2005

Twenty five year mortality and air pollution: results from the French PAARC survey.

AIMS AND METHODS: Long term effects of air pollution on mortality were studied in 14,284 adults who resided in 24 areas from seven French cities when enrolled in the PAARC survey (air pollution and chronic respiratory diseases) in 1974. Daily measurements of sulphur dioxide, total suspended particles, black smoke, nitrogen dioxide, and nitric oxide were made in 24 areas for three years (1974-76). Cox proportional hazards models controlling for individual confounders (smoking, educational level, body mass index, occupational exposure) were applied, and frailty models used to take into account spatial correlation. Indicators of air pollution were the mean concentration. RESULTS: Models were run before and after exclusion of six area monitors influenced by local traffic (NO/NO2 >3 in ppb). After exclusion of these areas, analyses showed that adjusted risk ratios (95% CI) for TSP, BS, NO2, and NO for non-accidental mortality were 1.05 (1.02 to 1.08), 1.07 (1.03 to 1.10), 1.14 (1.03 to 1.25), and 1.11 (1.05 to 1.17) for 10 microg/m3 respectively. Consistent patterns for lung cancer and cardiopulmonary causes were observed. CONCLUSIONS: Urban air pollution assessed in the 1970s was associated with increased mortality over 25 years in France.

Adult↗
PubMed2003

Occupational and nonoccupational factors associated with high grade bronchial pre-invasive lesions.

Besides tobacco exposure, factors associated with the development of pre-invasive bronchial lesions are not known. Autofluorescence bronchoscopy was used to assess the prevalence of severe dysplasia and carcinoma in situ (SD/CIS) of the proximal bronchial tree in relation to occupational or nonoccupational carcinogen exposure. Among the 241 individuals in this study, the overall prevalence of at least one SD/CIS was 9% (21 subjects). Multivariable analysis revealed significant and independent associations between presence of SD/CIS and: 1) active smoking, relative to former smokers; 2) presence of synchronous invasive lung cancer; 3) duration of asbestos exposure and; 4) exposure to other occupational carcinogens. The independent associations of synchronous lung cancer with severe dysplasia and carcinoma, after adjusting for both occupational and nonoccupational carcinogen exposures, suggest other mechanisms than a field cancerisation may be involved in the carcinogenesis of these pre-invasive lesions. Moreover, active smokers, patients with recently resected invasive lung cancer and workers occupationally exposed to bronchial carcinogens may represent a population of choice for early cancer endoscopic detection programmes in view of their high severe dysplasia and carcinoma prevalence.

Asbestos↗
PubMed2002

Incidence of digestive cancers and occupational exposure to asbestos.

While the role of exposure to asbestos in the development of several cancers such as mesotheliomas and bronchopulmonary cancers is now well established, the possible relationship between digestive cancers, other than peritoneal mesotheliomas, and occupational exposure to asbestos is still controversial. The great majority of the studies are based on mortality data. The aim of the study was to analyse the relationship between digestive cancer incidence and occupational exposure to asbestos in a population of subjects for whom precise occupational exposure data and precise incidence data were available. The population consisted of salaried and retired workers from a company using asbestos to manufacture fireproof textiles and friction materials. There were 1454 men (79.9%) and 366 women (20.1%). A cumulative exposure index and a mean exposure concentration in fibres/ml for each subject were calculated with the aid of an in-house job-exposure matrix. The number of cases of digestive cancer observed was compared with the expected and Standardized Incidence Ratio (SIR) was estimated. Precise occupational exposure data allowed us to study the dose-response relationship between asbestos exposure and risk of digestive cancer using Cox model. Fifty-six digestive cancers occurred in the study population over the 18-year follow-up period for 48.4 expected (SIR = 1.16 [0.87-1.50]). Comparing with incidence in the county, SIR was not significant for any of the digestive localization, but for peritoneum. However, even after taking into account the potential confounders via the Cox model, there was a significant dose-response relationship between the occurrence of digestive cancers and the mean exposure concentration, even after exclusion of peritoneum cancers. Our study provides initial evidence suggesting a relationship between occupational exposure to asbestos and the risk of digestive cancer: first, it is a study of incidence although the risk evidenced is not significant; secondly, a dose-effect relationship is demonstrated in the whole population. However, these preliminary results require confirmation by more powerful studies focusing on larger series.

Adult↗
PubMed2002

Asbestos bodies in the sputum of asbestos workers: correlation with occupational exposure.

A cross-sectional medical survey including collection of three consecutive sputum samples was carried out among 270 retired workers of a textile and friction materials factory, in order to investigate the relationship between asbestos body identification and asbestos exposure. The individual cumulative asbestos exposure, determined by means of a plant-specific job-exposure matrix based on asbestos air measurements in the workshops, proved to be heavy with a mean cumulative exposure of 217 fibres x mL(-1) x yr. Macrophages and asbestos bodies were identified in sputum samples by light microscopy. The lung origin of the sputum, suggested by the presence of macrophages and/or asbestos bodies, was confirmed in 82.6% of subjects, and 53% of these samples were positive for asbestos bodies. The prevalence of asbestos bodies was not related to sex, smoking status or latency. Conversely, multivariate analysis showed a positive relationship with cumulative exposure, duration and intensity of exposure to asbestos, as well as age and time since retirement. These findings suggest that sputum analysis for asbestos bodies may remain a relevant and noninvasive marker of heavy occupational exposure to asbestos, even years after retirement. Owing to the new perspectives in lung cancer screening, it might contribute to the identification of high-risk subjects.

Aged↗
PubMed2001

Follow-up of bronchial precancerous lesions and carcinoma in situ using fluorescence endoscopy.

Little is known about the natural history of precancerous bronchial lesions. Histological changes occurring in 416 bronchial intraepithelial lesions (104 high-risk subjects) were assessed over a 2-yr period, using repeated follow-up autofluorescence endoscopies. During the study, 6 of 36 normal epitheliums became dysplastic; 47 of 152 metaplasia evolved to low-grade dysplasia, two progressed to carcinoma in situ, and one to invasive cancer; 6 of 169 low-grade epithelial lesions progressed to a persistent severe dysplasia; 10 of 27 severe dysplastic lesions and 28 of 32 carcinoma in situ persisted or progressed, respectively (p = 0.0005, severe dysplasia versus carcinoma in situ 24 mo outcome). Carcinoma in situ appeared more frequent in patients with a prior history or concomitant cancer (p = 0.003). Persistence of smoking during the study did not influence high-grade lesion outcome. Progression of low-grade epithelial lesions during the study occurred only in patients with at least a high-grade lesion in another site at baseline (9 of 147 lesions, 6.1%). Our study suggests that low-grade epithelial lesions could be safely followed-up at 2 yr in patients without high-grade lesions at baseline, whereas severe dysplasia should be treated if they persist at 3 mo. Immediate treatment of carcinoma in situ appears warranted.

Adult↗
PubMed2001

[Haemophilus influenzae bacterial meningitis: residual risk; case report].

UNLABELLED: Bacterial meningitis due to Haemophilus influenzae has become a rare, albeit not exceptional occurrence since generalized vaccination against that pathogen was instated, concerning as well incapsulated b and non-b Haemophilus influenzae strains, as non-incapsulated strains. CASE REPORT: A 19-month-old fully immunized infant was referred to our hospital for bacterial meningitis. CSF analysis elicited biotype III, non-incapsulated Haemophilus influenzae. CONCLUSION: Generalizing Haemophilus influenzae preventive inoculation has revolutionized the epidemiology of bacterial meningitis; however, a residual risk exists, which deserves to be taken into account.

Female↗
PubMed1999

[Medical impact of screening of broncho-pulmonary cancer in subjects exposed to asbestos].

Most of available data about screening for lung cancer concern smokers. These studies concluded that no benefit can be expected from sputum cytology. Moreover with radiologic screening, early stages and resectability are more frequent and survival of screened patients is longer. Yet lung cancer specific mortality is not influenced. Various explanations are presented. For asbestos workers, lung cancers can occur even without asbestosis. So screening, if any should be applied to any exposed patient with or without radiologic abnormalities. Experts assert that medical data are not conclusive to demonstrate the benefit or the absence of benefit of radiological screening. If a screening program is planned, asbestos workers alone could be included on the condition that such strategy is evaluated. Prospective studies about new procedures, especially Chest-CT, are also advisable.

Asbestosis↗
PubMed1999

[Prevention programs for people exposed to asbestos: results of the ongoing activities].

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.

Aged↗
PubMed1999

[Screening of diseases associated with asbestos. On-going activities, synthesis].

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.

Asbestosis↗
PubMed1998

[Asbestos-related diseases].

The growing use of asbestos in France like in other industrialized countries since the beginning of the century is the reason of the increase of asbestos-related diseases, which occur after long latency periods. From asymptomatic benign pleural plaques up to malignant mesothelioma of poor prognosis, the fibrogenic and carcinogenic properties of asbestos mainly concern occupationally exposed subjects. The Institut national de la santé et de la recherche médicale (INSERM) expert committee concluded that about 1,950 deaths due to asbestos-related cancers occurred in France in 1996. Reinforcement of French legislation aims at reducing all kinds of asbestos exposure.

Asbestosis↗
PubMed1998

Assessment of bibliographic databases performance in information retrieval for occupational and environmental toxicology.

OBJECTIVE: To determine the efficiency of the major bibliographic databases by assessing the percentage of references among the total literature available that can be retrieved from each database. We also evaluated the best database combinations to carry out an exhaustive search. METHODS: BIOSIS, EMBASE, MEDLINE, NIOSH-TIC, and TOXLINE were searched on two topics: allergy to latex and asbestos and mesothelioma, in the title, abstract, or keywords (textwords). This search was performed for the years 1994 and 1995. All the records were classified by journal and author's name and were verified for each record whether or not it was indexed in each database. Statistical analysis was performed with chi 2 test. RESULTS: 777 articles in 510 issues were found. The efficiency of each database (percentage of articles recovered) and of combinations varied between 11% and 63% for one database and between 42% and 86% for a combination of two databases. The reasons why these differences exist between databases, and within a database, between two different subjects or two different years are reported. CONCLUSION: Firstly, it is not advisable to assert that a bibliography is complete when only one database is searched. Secondly, the efficiency of the databases may be quite different. Finally, it is suggested that the best way to be as exhaustive as possible is to search two or more databases-for example, in EMBASE and TOXLINE, or to a lesser extent EMBASE and MEDLINE. This seems to be the best compromise solution between time consumed for searching and efficiency.

Asbestos↗
PubMed1997

[Seroprevalence of cytomegalovirus and Toxoplasma gondii in healthy subjects under 30 years old in Santiago, Chile].

BACKGROUND: Infections by Cytomegalovirus and Toxoplasma gondii are endemic in Chile and only a low proportion of infected individuals have clinical manifestations. AIM: To study the prevalence of infection by Cytomegalovirus and Toxoplasma gondii in Chile. SUBJECTS AND METHODS: The prevalence of IgG antibodies against Cytomegalovirus and Toxoplasma gondii were studied in 560 subjects under 30 years old, using an ELISA technique. Age, socioeconomic level, breast feeding, assistance to nurseries and number of family members were considered as risk factors for these infections. RESULTS: Infection by Cytomegalovirus had a global prevalence of 60%. It showed an epidemiological pattern of late acquisition in high socioeconomic levels and a pattern of early infection in medium and low socioeconomic levels. Eighty to 90% of sera were positive for the infection in adult subjects of the three socioeconomic levels. There was a positive correlation between the duration of breast feeding and the frequency of Cytomegalovirus infection. Infection by Toxoplasma gondii had a global prevalence of 24.6%. The rates of susceptible individuals were 80 and 50% in high and medium-low socioeconomic levels respectively. CONCLUSIONS: The knowledge about the frequency of these infections in high risk populations such as women during their reproductive years and immunodepressed individuals, will allow the implementation of preventive measures.

Adolescent↗
PubMed1996

[Sicca syndrome and hepatitis C virus infection: a Gougerot-Sjögren pseudo-syndrome?].

These last years, different virus have been incriminated in the etiopathogeny of the primary-Sjögren's syndrome and more particularly the hepatitis C virus. We have led a prospective study over 23 patients presenting a primary Sjögren's syndrome, searching for a sign of infection by the hepatitis C virus and over 23 patients presenting an active chronic hepatitis C virus searching for a Gougerot-Sjögren syndrome. The overcoming of the hepatitis C virus in the Sjögren group was 4.7% which was not significatively higher than in our sample of population. Parallelly, the search of the Sjögren's syndrome, in the hepatitis C virus group, found 4 patients (feminine, average age 48.5 years old) whose clinical board was compatible with this diagnostic. Antinuclear antibodies have not been found in any of the 23 patients. The lymphocytic typing of the infiltrate in the minor salivary glands biopsies showed a predominance of the CD8 lymphocytes in a proportion of 2/1, contrasting with what is observed in primary Sjögren's syndrome. We concluded that hepatitis C virus may be more associated with a chronic lymphocytic sialadenitis than an authentic primary Sjögren's syndrome.

Adult↗