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Biomedical subjects

D Choudat

Publications and source records attributed to D Choudat.

At least 19 recordsLinked to original sources
PubMed2005

HD-16: a new quality of life instrument specifically designed for insomnia.

BACKGROUND AND PURPOSE: To design a new quality of life (QoL) instrument specifically for insomnia. PATIENTS AND METHODS: Based on severe insomniacs' interviews, we have built a new quality of life scale that has been tested in one group of 240 severe insomniacs, in one group of 422 mild insomniacs and in one group of 391 good sleepers. Ten steps led to the construction of a specific QoL scale. RESULTS: Five dimensions have been validated as both relevant and independent from each other. Sixteen items out of the 43 initially tested were retained and significantly different within the groups in each dimension. Based on the 16 items selected, we called the scale Hotel Dieu 16 (HD-16). We have therefore verified the score's specificity (correlation score of +0.36) and the reliability of the scale (Cronbach coefficient alpha=0.78). CONCLUSION: HD-16 may be used as a focused instrument to better assess an insomniac's quality of life.

Adult↗
PubMed2004

[Human granulocytic ehrlichiosis in Europe].

Human granulocytic ehrlichiosis is an emerging infectious disease, which is transmitted by the tick Ixodes ricinus in Europe, like other diseases: Lyme disease, tick-borne encephalitis, babesiosis... This tick lives in the forest and its hematophagic activity ranges from April to October. Flu and febrile symptoms ten days after tick bite should suggest diagnosing the disease. Disease evolution is generally favorable, even if serious complications may occur. Leukopenia, thrombocytopenia, and elevated serum transaminases are common laboratory findings. Complementary assays useful for the diagnosis are: blood smear, indirect immunofluorescence, and polymerase chain reaction. Biological diagnostic criteria are more and more accurate, with the evolution of knowledge and technique. Tetracycline treatment generally leads to clinical and biological recovery. Informing physicians and occupationally exposed people should reinforce current prevention measures against tick bites.

Animals↗
PubMed2004

Rye flour induces a stronger early bronchial response than wheat flour in occupational asthma.

BACKGROUND: Our aims were to compare the doses of wheat and rye flour that induce early bronchial responses in occupationally exposed asthmatic subjects and to assess the effects of the dose of inhaled flour, the duration of exposure and the dose rate. METHODS: Ten patients underwent tests with lactose, wheat flour and rye flour. We compared the decrease in forced expiratory volume in 1 s (FEV(1)) observed during the challenge with flour and with lactose. We also calculated the amount of flour that was instantaneously active. RESULTS: Seven subjects had significantly decreased FEV(1) values following exposure to wheat and rye flour and two subjects only did so for rye flour. The provocative dose (PD, dose required to reduce FEV(1) by 15%) of rye was lower than that of wheat flour (geometric mean; PD(15) rye: 95 microg; wheat: 368 microg). The calculated doses of rye and wheat flour were better correlated with the change in FEV(1) than were the cumulative doses. CONCLUSION: The bronchial response was greater with rye than with wheat flour. The response was related to the dose of allergen inhaled and to the dose rate.

Asthma↗
PubMed2003

Healthy worker effect and changes in respiratory symptoms and lung function in hairdressing apprentices.

AIMS: To compare the prevalence and incidence of respiratory symptoms and lung function values between hairdressing apprentices and office apprentices. METHODS: A total of 322 hairdressing apprentices and 277 office apprentices (controls) were studied. Two cross sectional surveys were conducted in 1994 and 1996/97 with longitudinal follow up for a subgroup of apprentices (191 hairdressing apprentices and 189 office apprentices). RESULTS: In the initial phase, the prevalence of respiratory symptoms was significantly lower among hairdressing apprentices than among office apprentices. Lung function test results showed significantly higher values for hairdressing apprentices. Non-specific bronchial reactivity was similar in the two groups. In the final phase, results for respiratory symptoms were similar. The incidence of respiratory symptoms was not significantly different between hairdressing apprentices and office apprentices. Subjects who dropped out had lower values for FVC and FEV1 in the initial phase than those who completed the final phase. There was a significant deterioration of FEV1 and FEF25-75% in hairdressing apprentices compared to office apprentices. There was a link between atopy and the incidence of most of the respiratory symptoms (day/night cough, wheezing, dyspnoea, mucosal hyperresponsiveness) and between smoking and the incidence of bronchial hyperreactivity. There was no significant correlation between change in lung function tests and specific hairdressing activities reported at the end of the apprenticeship or with environmental working conditions in hairdressing salons. CONCLUSIONS: Although a healthy worker effect can be suspected, results showed a significant deterioration of baseline values of lung function tests in the hairdressing apprentice group. However, no clear link was shown between change in lung function tests and specific parameters of occupational activities.

Adolescent↗
PubMed2002

Bronchial challenge with flour: early response is dependent on the dose of activated allergen inhaled.

Specific bronchial challenges provide information about the relationship between inhaled dose of allergen and change in lung function, but the intermediate pathways remain largely obscure. The aim of this study was to investigate the relationships between the early asthmatic response and 1) the inhaled dose of wheat flour, 2) the concentration of wheat flour, 3) the duration of the exposure, and 4) the deactivation of inhaled allergens and mediators. Thirty-one patients with occupational asthma to wheat flour were studied. Particle aerosols were generated by a computer-controlled aerosoliser and the results were expressed as the provocative dose causing a 20% fall in forced expiratory volume in one second (FEVi) (PD20). The cumulative dose (from the beginning of the challenge), the last inhaled dose, and an estimated dose (taking into account exponential deactivation), were calculated. Twenty patients had high reactivity to flour (reaching a PD20 value). Eleven patients had intermediate reactivity (no measurable PD20 but significantly greater fall in FEV1 compared with lactose challenge). A better correlation between change in FEV1 and dose was obtained for the estimated dose than for the cumulative or last inhaled dose. The bronchial response to wheat flour can be measured by the individual specific hyperreactivity and is expressed by provocative dose of flour. However, deactivation of the allergen and mediators has to be taken into account. This problem can be addressed by using a mathematical model.

Administration, Inhalation↗
PubMed2001

Detection of avian oncogenic Marek's disease herpesvirus DNA in human sera.

The avian herpesvirus Marek's disease virus (MDV) has a worldwide distribution and is responsible for T-lymphoma in chickens. The question as to whether MDV poses a public health hazard to humans was first raised when the virus was isolated in 1967. However, no irrefutable results have been obtained in immunological and virological studies. We used a nested-PCR to detect MDV DNA in human serum samples. A total of 202 serum samples from individuals exposed and not exposed to poultry was tested by nested-PCR for a target sequence located in the MDV gD gene. The assay system was specific and sensitive, making it possible to detect a single copy of the target sequence. Forty-one (20%) of the 202 serum samples tested positive for MDV DNA. The prevalence of MDV DNA was not significantly different in the group exposed to poultry and the group not exposed to poultry. There was also no difference due to age or sex. Alignment of the 41 gD sequences amplified from human sera with eight gD sequences amplified from MDV-infected chicken sera showed a maximum nucleotide divergence of 1.65%. However, four 'hot-spot' mutation sites were identified, defining four groups. Interestingly, two groups contained only human MDV-gD sequences. The status of the MDV genome detected in human blood is discussed.

Adult↗
PubMed2001

[Specific bronchial provocation test with solid aerosols. Quantification of results].

OBJECTIVES: To determine 1) the level of specific bronchial reactivity by challenge with flour and 2) the criteria of positivity using a new method for the expression of the results. METHOD: Thirty-eight asthmatic subjects, occupationally exposed to wheat flour, performed a challenge with lactose then with flour. The instantaneous measurement of the concentration and of the inspiratory airflow were used to calculate the inhaled dose and to establish the dose-response relationships. The results were given 1) by the dose of flour provoking a 20% fall in FEV1 (PDf20), 2) by the comparison of the variation of the FEV1 during the challenge with flour to the distribution of the values observed during the challenge with lactose (inferior limit of the confidence interval at 99.7%). RESULTS: The variations of the FEV1 were not significantly related to the inhaled dose of lactose. The specific bronchial reactivity to flour was a continuous data and three groups were distinguished: 1) subjects (n = 15) with high bronchial reactivity had a fall of FEV1 of more than 20% 2) subjects (n = 13) without significant variation of the FEV1 for doses higher than 1,400 micrograms by comparison to the distribution of the values of the lactose test 3) subjects (n = 10) with a significant fall of FEV1 by comparison to the distribution of the values of the lactose test but lower than 20%. For this group with moderate reactivity, the flow of the inhaled dose may be determinant for the bronchial response. CONCLUSIONS: PDf 20 measures the specific bronchial reactivity. However, if the fall in FEV1 is lower than 20%, the specific challenge with flour may be compared to the challenge with lactose to detect the subjects with moderate reactivity. Our results confirmed the role of the inhaled dose and suggested the role of the dose rate in the outset of bronchial obstruction among asthmatic subjects.

Administration, Inhalation↗
PubMed2000

Computerized equipment for the delivery of inhaled doses of solid particles in specific bronchial challenge.

An apparatus to generate solid particles was tested for use in diagnosing occupational asthma. This equipment measures the inhaled dose of dry particles during specific inhalation challenge. It includes an aerosol generator, a cyclone type particle size selector, and an inhalation chamber to which a patient breathing at tidal volume can be connected for the test. It is fully controlled by a standard personal computer in automatic mode, acting on the flow rate and the aerosol generator to maintain the concentration at a fixed value, usually 3 mg/m3. The dose of aerosol delivered to the patient was calculated from the aerosol concentration, and the inhaled volume was calculated by integration of the corresponding signals. The coefficient of variation for this measurement was estimated to be 12%. The mass median aerodynamic diameter (MMAD) of aerosol inside the inhalation chamber was measured for three substances: lactose, wheat flour, and buckwheat flour. The MMAD of the aerosol inside the chamber was also estimated from the particle size distribution of the raw powder. The relative difference between the measured MMAD and the calculated value was less than 15%. The corresponding relative difference between the measured geometrical SD and the calculated value was found to be less than 26%.

Administration, Inhalation↗
PubMed2000

Development of an asthma specific job exposure matrix and its application in the epidemiological study of genetics and environment in asthma (EGEA).

OBJECTIVES: To develop a method suitable for estimating exposure risks in population studies of asthma from job titles and international codes, by combining a new job exposure matrix (JEM) with the expert judgement approach. The method was applied in the French epidemiological study of the genetics and environment in asthma (EGEA). METHODS: The JEM contains 22 exposure groups including 18 high risk groups based on known risk factors for occupational asthma, divided into high molecular weight agents, low molecular weight agents, and mixed environments. After applying the JEM to job codes, exposure estimates for each subject were re-evaluated by examining job title texts. Three high risk exposure estimates for asthma were compared: firstly, applying the JEM to original codes (from different coders in each study centre); secondly, applying the JEM to revised codes (from one experienced coder); and thirdly, after reviewing JEM exposure estimates in the light of job title texts. RESULTS: The study comprised 173 cases with asthma and 285 controls (age 18-65). Odds ratios (ORs) for asthma for high risk jobs were 1.0 (95% confidence interval (95% CI) 0.6 to 1.7), applying the JEM to original codes; 1.4 (95% CI 0.8 to 2.3), applying the JEM to revised codes; and 1.7 (95% CI 1.1 to 2.7), applying the JEM and subsequently re-evaluating exposure estimates from job title texts. Asthma ORs were 1.4 (95% CI 0.6 to 2.9) for high molecular weight agents, 2.3 (95% CI 1.2 to 4.4) for low molecular weight agents, and 2.1 (95% CI 0.9 to 5.2) for mixed environments. CONCLUSIONS: This asthma JEM, when enhanced by expert re-evaluation of exposure estimates from job title texts, may be a useful tool in general population studies of asthma. In this study, a 1.7-fold increase in prevalence odds of high risk exposures was found among asthmatic workers compared with controls, with risk magnitude varying for different classes of exposure.

Adult↗
PubMed1999

Quantification of the dose of inhaled flour: relation with nonspecific bronchial and immunological reactivities.

The aim of this study was to investigate the relationship between specific bronchial reactivity and respective nonspecific bronchial and immunological reactivities. Twenty-one patients underwent bronchial challenges with lactose and flour. The aerosol of particles was generated by a computer-controlled aerosolizer. Specific bronchial challenge results were expressed as the provocative dose of flour (PDf) that caused a 20% or 15% decrease in the forced expiratory volume in one second (FEV1). For each subject, the decrease in FEV1 observed during the challenge with flour was compared with the calculated lower limit of the 99.7% confidence interval for the lactose challenge. The subjects also underwent a nonspecific challenge with methacholine and a measurement of the specific immunoglobulin E against wheat. The inhalation of lactose did not significantly affect FEV1. Nine subjects had high reactivity to wheat flour with a PDf20 <400 microg. Five subjects had intermediate reactivity: FEV1 fell by <20% but by significantly more than that in the test with lactose. For 7 subjects, there was no significant change in FEVI for inhaled doses of flour over 1390 microg. The results for specific bronchial challenge were significantly correlated with those for the methacholine test (p<0.02). Positive skin tests and specific immunoglobulin E against wheat were observed more frequently in the high reactivity group. Specific bronchial challenge can be performed safely to establish precise dose-response curves. The provocative dose of flour causing a 20% decrease in forced expiratory volume in one second is useful for evaluating the degree of specific reactivity but is not suitable in cases of intermediate reactivity in which comparison with the lactose test is necessary. Specific reactivity is probably a function of immunological and nonspecific bronchial reactivities.

Adult↗
PubMed1998

[Claim, recognition, compensation of occupational respiratory diseases].

Many occupations involve an environment that may provoke lung diseases. This should be kept in mind whenever lung disease is diagnosed for detection of an occupational factor requires steps toward prevention, and compensation may be due the patient. Counselling the patient on the administrative steps to be taken often requires the advice of the occupational physician, the consultant physician or specialised services in order to maintain the rights of the patient.

Accidents, Occupational↗
PubMed1997

Consequences of occupational asthma on employment and financial status: a follow-up study.

The aim of this study was to describe changes in employment and income following a diagnosis of occupational asthma, and to determine what factors might affect these changes. Two hundred and nine patients with occupational asthma were reviewed on average 3.1 yrs after the diagnosis had been made. They were contacted by telephone or were sent a self-administered questionnaire by post. Multiple logistic regression models were constructed to determine which variables were associated with loss of employment after the diagnosis. At the time of review, 44% of patients had left their previous job and 25% were currently unemployed. Remarkably, 32% remained exposed to the offending agents in the same job. Forty six percent of the patients had suffered a reduction of income (84% of those who had left their employer versus 19% of those still employed in the same company (p < 0.001)). Claims for compensation, size of the company, level of education, and age at the time of diagnosis were significantly associated with a risk for becoming unemployed or having a new employer after the diagnosis of occupational asthma. Occupational asthma results in severe socioeconomic consequences. The French compensation system for occupational asthma should be revised, as the criteria currently used to determine compensation for this disease largely underestimate the social and occupational damages.

Adolescent↗