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Biomedical subjects

C Leroyer

Publications and source records attributed to C Leroyer.

At least 37 records · Page 2Linked to original sources
PubMed1998

Evaluation of a new rapid D-dimer assay for clinically suspected deep venous thrombosis (Liatest D-dimer).

In previous studies, enzyme-linked immunosorbent assays (ELISA) for plasma D-dimer analysis have demonstrated high sensitivity, suggesting their potential usefulness in excluding deep venous thrombosis (DVT). We evaluated the usefulness of a new D-dimer test (Liatest D-dimer) for suspected DVT in a prospective study of patients admitted to the hospital because of recent (not exceeding 1 week before admission) clinical signs. Contrast venography or compression ultrasonography or both were performed within 24 hours of admission. A new quantitative determination of D-dimer concentration using a suspension of microlatex particles coated with specific antibodies was tested. A standard plasma D-dimer ELISA measurement was also performed. Of 464 patients, 276 had a proven DVT (distal, 74; proximal, 202). For a cutoff level of 400 ng/mL, sensitivity of the Liatest method in the diagnosis of overall DVT was 94.6% (95% confidence interval, 92.0%-97.0%), and the specificity was 35% (95% confidence interval, 28%-42%). The sensitivity and negative predictive value were 98.5% and 95.6%, respectively, in the diagnosis of proximal DVT, but only 83.8% and 84.6%, respectively, in the diagnosis of distal DVT. This new rapid Liatest D-dimer assay seems to be highly sensitive and could replace the ELISA method in excluding patients with proximal DVT. Both methods provide lower sensitivity for distal DVT.

Autoanalysis↗
PubMed1998

Assessment of activated protein C resistance using a new and rapid venom-based test: STA Staclot APC-R.

Activated protein C (APC) resistance is related to a single point mutation in the factor V gene (FV:Q506) and appears to be the most common inherited risk factor for venous thromboembolism. A reliable screening test is therefore useful. We aimed to evaluate a new APC resistance test, on the basis of the procoagulant activity present in one snake venom of a crotalidae family: STA Staclot APC-R. We studied 36 consecutive patients with an acute deep venous thrombosis (DVT) confirmed by compression ultrasonography and carrying the FV:Q506 allele, assessed by DNA analysis, 103 of their family members and 35 consecutive patients with a proven DVT but who did not carry the FV:Q506 allele. Blood samples were collected within 24 h of admission for the DVT cases and on the day of medical registration for the family members. Tests were performed blind. The STA Staclot APC-R test, using a cut-off value of 0.80, had an overall sensitivity of 100% (95% CI, 95-100) and a specificity of 98.8% (95% CI, 92.0-99.6). An acute thrombosis process did not influence the performance of the test. We conclude that this test is easy and rapid to perform in every day practice and fulfills the criteria for a screening test.

Adult↗
PubMed1998

Changes in airway function and bronchial responsiveness after acute occupational exposure to chlorine leading to treatment in a first aid unit.

OBJECTIVES: To describe the baseline characteristics and the time course of changes in lung function in workers accidentally inhaling high concentrations of chlorine in a prospective study. METHODS: Baseline spirometry and methacholine challenge test were performed in a cohort of 278 workers at risk of accidental inhalation of chlorine. Workers in whom accidental inhalation led to intervention in a first aid unit were reassessed five to 25 days after the accident and serially thereafter when there where notable changes. RESULTS: During a four year follow up period, 13 workers were seen at the first aid unit after a symptomatic accidental inhalation. Three of them experienced notable functional changes: one worker experienced a 10% fall in forced expiratory volume in one second (FEV1), and the other two had a notable fall in the concentration of methacholine that caused a 20% fall in FEV1 (PC20). Two workers were smokers and one had a personal history of atopy. Baseline assessment was within the normal range in these three workers. Recovery was complete three months after the accidental inhalation. CONCLUSION: Transient but notable decreases in airway function or increases in bronchial responsiveness can occur after an accidental inhalation of high concentrations of chlorine in workers at risk.

Adult↗
PubMed1998

Can reactive airways dysfunction syndrome (RADS) transform into occupational asthma due to "sensitisation" to isocyanates?

The case history is described of a worker who presented with a history suggestive of reactive airways dysfunction syndrome which occurred after an acute high level inhalation of diphenylmethane diisocyanate. Further exposure at work, at a time when concentrations of isocyanates were no longer "irritant", suggested occupational asthma; this diagnosis was confirmed by a specific inhalation challenge test.

Allergens↗
PubMed1998

Dirithromycin concentrations in bronchial mucosa and secretions.

Since a high tissue penetration of dirithromycin (D) has been assessed in early studies, the aims of this study were to determine D concentrations in bronchial mucosa and secretions in patients suffering from an acute exacerbation of chronic bronchitis (AECB), to compare intra-individual bronchial mucosa and secretion concentrations and to relate bronchial concentrations of D and clinical efficacy. The main inclusion criteria were comprised of (1) AECB, defined by the presence of an increase in dyspnea, sputum production and change in sputum purulence, and (2) clinical indication of fiberoptic bronchoscopy allowing performance of bronchial biopsies. All patients were treated with a 500-mg once-daily D dose for 5 days. Patients were randomly divided into three groups, according to sampling times (24, 48 and 72 h after the last dose). Tissue concentration analyses were performed by one blinded microbiologist (microbiological agar diffusion assay). The results showed: (1) 37 out of the 46 patients (80.4%) had a favorable response to treatment at the time of fiberoptic bronchoscopy (14 cured, 23 improved); (2) bronchial mucosa concentrations were high in all groups, and (3) mean values at 24, 48 and 72 h after the last dose were respectively 6.51 +/- 1.44, 6. 61 +/- 2.7, 5.67 +/- 1.02 mg.kg-1; no statistical difference was observed between the groups. In bronchial secretions collected simultaneously, concentrations were lower, i.e. 1.26 +/- 0.3, 0.61 +/- 0.12, 0.84 +/- 0.12. Significant associations were observed between bronchial mucosa and secretion concentrations (r = 0.71, p = 0.0001), and between clinical response and bronchial concentrations (p = 0.03, Kruskall-Wallis test). In conclusion, these results may confirm the clinical significance of tissue concentrations measured in bronchial tissues of patients with AECB.

Anti-Bacterial Agents↗
PubMed1998

Occupational asthma due to chromium.

We describe a 28-year-old subject employed as a roofer in a construction company since the age of 19, who developed work-related symptoms of a cough, shortness of breath, wheezing, rhinitis and headaches. A description of a usual day at work suggested that the symptoms worsened while he was sawing corrugated fiber cement. Baseline spirometry was normal, and there was a mild bronchial hyperresponsiveness to carbachol. A skin patch test to chromium was negative. A specific inhalation challenge showed a boderline fall in forced expiratory volume in 1 s (FEV1) after exposure to fiber cement dust. Exposure to nebulization of potassium dichromate (K2Cr2O7), at 0.1 mg.ml-1 for 30 min, was followed by an immediate fall by 20% FEV1. Simultaneously, a significant increase in bronchial hyperresponsiveness was demonstrated.

Adult↗
PubMed1998

Evaluation of a new, rapid, and quantitative D-Dimer test in patients with suspected pulmonary embolism.

Previous studies have suggested the utility of D-Dimer ELISA assays in eliminating a diagnosis of pulmonary embolism (PE). Our objectives were to evaluate the performance of a new, rapid, quantitative, and automated Liatest D-Dimer Assay in patients with suspected PE. Three hundred eighty-six consecutive patients referred to our institution between March 1992 and December 1996 for clinically suspected PE, with recent clinical signs not exceeding 1 wk, were included in this study. Diagnosis of PE was based on clinical evaluation, radionuclide lung imaging, lower limb examination, and, when required, pulmonary angiography. D-Dimer performances, for both Liatest D-Dimer and standard D-Dimer ELISA (Asserachrom DDi), assays, were assessed at the end of the study. Among the 386 patients tested, 146 (37.8%) were classified as PE-positive. Liatest D-Dimer assay had a 100% sensitivity (95% confidence interval, 97 to 100%) and a negative predictive value of 100% (95% confidence interval, 94 to 100%). A normal result, below the cutoff of 500 ng/ml, occurred in 83 of the 386 (21%) patients. There was a strong agreement between Liatest D-Dimer and Asserachrom DDi analyses. These findings suggest that this rapid, quantitative, and automated D-Dimer assay provides a useful diagnostic tool for the clinician with regard to exclusion of PE.

Adolescent↗
PubMed1998

Comparison of serial monitoring of peak expiratory flow and FEV1 in the diagnosis of occupational asthma.

Peak expiratory flow (PEF) monitoring is often used to establish the relationship between occupational exposure and asthma. FEV1 has been found to be a better physiologic index than PEF in the measurement of airflow obstruction. The aim of this study was to compare the accuracy of serial monitoring of PEF and FEV1 in the diagnosis of occupational asthma. Twenty consecutive subjects referred for possible occupational asthma were asked to perform serial monitoring of PEF and FEV1 using a portable ventilometer. Two sets of graphs were plotted for both PEF and FEV1: graphs with the best of all values and graphs with the best of two reproducible values. Three observers interpreted both PEF and FEV1 recordings by the visual method in a blind, randomized manner as either compatible with occupational asthma or not. Eleven of the subjects had a positive inhalation challenge test (high-molecular-weight agents, n = 6; low-molecular-weight agents, n = 5). In the case of analysis of the graphs plotted with the best of all values, the sensitivity of the PEF recording interpreted by the three observers was 82, 73, and 73%, and of the FEV1 recording as 55, 55, and 45%; specificity of PEF recording was 89, 100, and 100%, and of FEV1 was 56, 89, and 100%. When an agreement between two of the three readers was required to define occupational asthma, sensitivity and specificity were 73 and 100% for PEF and 55 and 89% for FEV1. Lower sensitivities were found when the same analyses were performed with the graphs plotted with the best of two reproducible values. It was concluded that unsupervised FEV1 is not more accurate than unsupervised PEF monitoring in the diagnosis of occupational asthma. Plotting graphs using the best value gives better diagnostic accuracy than plotting them with the best of two reproducible values.

Adult↗
PubMed1998

[The evaluation of the quality of life in asthma patients. Value and implementation].

Asthma, as a chronic condition, alters individual's day-to-day life in functional, emotional and social domains. There has been a recent upsurge of interest in the assessment of quality of life in asthmatic patients. Indeed, there is growing evidence that conventional outcomes of asthma (symptoms assessments, functional measures...) although important, may not detect all the changes experienced by patients. Quality-of-life instruments target two distinct properties. First, discriminative instruments are needed to distinguish between individuals or groups of patients. Second, an evaluative instrument is required to detect such changes in an individual or group of patients, as occur in clinical trials. There are now a number of quality-of-life instruments, with strong measurement properties, that can be used in clinical trials.

Activities of Daily Living↗
PubMed1998

Prevalence of 20210 A allele of the prothrombin gene in venous thromboembolism patients.

BACKGROUND: The 20210 A allele variation in the 3' -untranslated region of the prothrombin gene was recently identified as a risk factor as regards deep venous thrombosis. AIM: To assess the frequency of the variation in unselected patients with a proven venous thromboembolism (VTE). METHODS: The presence of the prothrombin variation was determined in all consecutive patients referred from July 1994 to August 1997 for a clinical suspicion of VTE, and in whom the diagnosis was confirmed. A control group consisted of bone marrow volunteer donors. RESULTS: Of the 366 patients included, 17 (4.6%) were carriers of the 20210 A allele (95% CI, 2.4% to 6.7%). The mutation was present in 1.0% of the 400 controls. Odds ratio for having VTE in the presence of the 20210 A allele was 4.8 (95% CI, 1.5 to 19.8). Forty-six (12.5%) patients had the mutation of the factor V gene and five (1.4%) patients shared both mutations. After excluding the carriers of the factor V mutation, odds ratio for having VTE in the presence of the 20210 A allele was 3.7 (95% CI, 1.1 to 13.6). Mean age at admission as well as mean age of the first VTE episode were both significantly higher in patients free from the two mutations studied, as compared to carriers of the 20210 A allele (p = 0.04 and 0.01, respectively). CONCLUSION: Our findings in a large series of patients (1) confirm the 20210 A allele prothrombin gene as a risk factor for VTE. (2) suggest that its association with the factor V Leiden is not uncommon.

Adult↗
PubMed1998

[Characteristics of patients with domiciliary equipment for chronic respiratory diseases in Martinique].

The incidence of chronic respiratory failure is underestimated in Martinique. The aim of our retrospective study was to determine local particularities. Between December 1991 and December 1995, 128 patients (55% men, mean age 60 years, range 18-89 years) were hospitalized in our pneumology unit to receive a respiratory device (oxygen concentrator, respirator, continuous positive pressure generator). The high percentage of continuous positive pressure generators contrasted with the low number of oxygen concentrators prescribed indicating that obstructive disease is relatively less common due to the absence of widespread smoking habits. Sleep apnea syndrome (SAS) was particularly frequent in women (44% of the SAS patients). 10% of the SAS patients had perturbed blood gases unexplained by an associated bronchopathy. SAS in obese, hypertensive, diabetic women in Martinique is a public health problem and should be assessed by a prospective study. We observed that home care was particularly difficult for the most severely diseased patients, especially those with a tracheotomy, due to the lack of a management structure.

Adolescent↗
PubMed1997

The value of a risk factor analysis in clinically suspected deep venous thrombosis.

BACKGROUND: The value of a risk factor analysis in the presence of a clinically suspected deep venous thrombosis (DVT) has been assessed mainly in inpatient populations. The aim of this prospective study was to evaluate the potential association between DVT and acquired circumstances suspected as risk factors, in a cohort of outpatients with a clinically suspected DVT. METHODS: Consecutive outpatients referred for a clinically suspected DVT, with recent clinical signs, not exceeding 1 week, were included. Before venography, all patients were interviewed by a trained physician to detect the presence of risk factors. RESULTS: From March 1992 to February 1994, 277 patients were included; venography was positive in 162 (58.4%). Five independent variables were significantly associated with the occurrence of DVT; in a multivariate analysis, 64.7% of patients were correctly classified; odds ratios for having DVT in the presence of these underlying conditions were respectively: 1.75 for age over 65 years, 1.68 for prior history of venous thromboembolism, 1.69 for high risk circumstances (any type of surgery or leg trauma within the past 3 months), 5.59 for malignancy, and 2.56 for varicose veins. CONCLUSIONS: In outpatients referred for a clinically suspected DVT, recognition of associated conditions might increase the certainty of the diagnosis.

Adult↗
PubMed1997

Factor V Leiden prevalence in venous thromboembolism patients.

BACKGROUND: Recent findings have demonstrated a high frequency of activated protein C resistance in patients suffering from deep venous thrombosis (DVT). This abnormality has been related to a mutation in the factor V gene (at nucleotide position 1,691, guanine to adenine [G-->A] substitution). AIM: To assess the frequency of the mutation in unselected inpatients with a proved DVT. To study the clinical characteristics of such patients. METHODS: All consecutive patients admitted to the hospital because of a clinical suspicion of DVT were eligible. Diagnosis of DVT with the help of venous ultrasound imaging or venography. Ventilation and perfusion lung scan was performed in all patients, and interpreted according to the Prospective Investigation of Pulmonary Embolism Diagnosis criteria; in patients with a low- or intermediate-probability lung scan, pulmonary angiography was requested. Polymerase chain reaction amplification was performed in patients with a proved DVT. A control group consisted of bone marrow volunteer donors. RESULTS: From July 1994 to November 1995, 165 patients were included. Thrombosis was considered as distal in 77 and proximal in 88; an associated pulmonary embolism (PE) was found in 75 patients. Of 165 patients, 24 (14.5%) showed the factor V gene mutation (95% confidence interval, 9.4 to 19.8); the mutation was present in 3.5% of 200 bone marrow volunteer donors; odds ratio for having DVT in the presence of the mutation was 4.1. No difference in the level of DVT, or the presence of an associated PE was observed according to the presence of the mutation. Patients with the mutation have a significantly more frequent history of DVT (p=0.04) and more previous reported episodes (1.1 vs 0.6; p=0.04). CONCLUSION: The factor V mutation is frequent in unselected DVT patients. No difference in the severity of the thrombosis episode was observed in these patients.

Adult↗
PubMed1997

Diagnostic value of a new sensitive membrane based technique for instantaneous D-dimer evaluation in patients with clinically suspected deep venous thrombosis.

BACKGROUND: Plasma D-Dimer analysis, using ELISA assays, has demonstrated in previous studies a high sensitivity, suggesting its utility in excluding deep venous thrombosis (DVT). AIM: To assess the performance of a new rapid plasma D-Dimer ELISA measurement in suspected DVT patients with recent clinical signs, not exceeding one week. METHODS: A prospective study of patients admitted for a suspected recent DVT. Contrast venography or compression ultrasonography were performed within 24 h of admission. A new membrane based ELISA technique, which uses an immunofiltration and two complementary monoclonal antibodies was tested. Results were expressed as positive or negative. A standard plasma D-Dimer ELISA measurement was also performed. D-Dimer performances were assessed at the end of the study. RESULTS: 265/448 patients had a proven DVT (72 distal, 193 proximal). The sensitivity of the instantaneous method in the diagnosis of overall DVT is 92 +/- 3.4% (95% CI), and specificity is 36.6 +/- 6.9%. Positive predictive value is 67.7 +/- 4.8% and negative predictive value is 76.1 +/- 8.9%. Sensitivity and negative predictive values reach 97.9 and 94.3% in the diagnosis of proximal DVT, but only 76.3 and 79.7% in the diagnosis of distal DVT. Similar results are observed with the standard ELISA method. CONCLUSION: This new rapid plasma D-Dimer measurement appears highly sensitive, and could substitute the older ELISA methods. Both methods provide lower sensitivity in the case of a distal DVT location.

Adolescent↗
PubMed1996

[Prevention of deep venous thrombosis in medical care].

Venous thromboembolism is a frequent and potentially severe ailment in medical patients; the clinical signs are unreliable and as early detection of the thrombosis process by non-invasive techniques is not available, prevention appears to be an alternative. Careful definition of the medical situations at risk from venous thromboembolism is necessary. Age, prior history of venous thromboembolism, and immobilization constitute high risk circumstances. Analysis of the published studies advocates prevention in three circumstances: myocardial infarction, stroke and intensive care. In other cases, further controlled studies, randomized versus placebo, are needed.

Clinical Trials as Topic↗
PubMed1995

Cross-sectional assessment of workers with repeated exposure to chlorine over a three year period.

Airflow obstruction has been described in workers who experienced symptoms after acute exposure to chlorine. Persistent bronchial hyperresponsiveness has also been assessed, but mainly in case studies. In this cross-sectional study, we have assessed the relationship between inhalational accidents ("puffs") involving chlorine and persistent symptoms as well as hyperresponsiveness in 239 out of 255 at-risk workers (94%). No relationship was found between persistent symptoms and the exposure variables studied. Forced vital capacity (FVC) was higher in subjects who had had no symptoms after a "puff", compared with those who had experienced mild symptoms. Forced expiratory volume in one second (FEV1) and FVC were significantly lower in subjects who experienced more than 10 puffs with mild symptoms than in subjects who reported no symptomatic puff. The presence of bronchial hyperresponsiveness was not related to exposure, but the methacholine dose-response slope showed a tendency to increased bronchial responsiveness with increased exposure. A significant difference was shown in subjects who experienced more than 10 puffs with mild symptoms. In this group of workers, repeated exposure to chlorine with acute respiratory symptoms was associated with a slight but significant reduction in expiratory flow rates, together with an increase in bronchial responsiveness, without long-term symptoms.

Adolescent↗