PubMed Health⌕ Search

Biomedical subjects

G Dumont

Publications and source records attributed to G Dumont.

At least 19 recordsLinked to original sources
PubMed1998

Evaluation of GHb assays in France by national quality control surveys.

OBJECTIVE: To evaluate the state of the art concerning GHb assays through analysis of a large-scale quality control survey and to compare the results with those of previous surveys. RESEARCH DESIGN AND METHODS: A lyophilized hemolyzate prepared from human erythrocytes containing a physiological HbA1c level (5.5%) was sent to 3,500 French laboratories in February of 1995 and assayed as a patient's sample under routine conditions. Distribution of values was analyzed from the reported results for each method. The results were compared with the assigned value (acceptable range: +/- 20%) and with the upper value of the reference range currently used. RESULTS: Results were obtained from 2,674 laboratories, among which 39% used cation-exchange chromatography methods, 37.5% affinity chromatography, 16% immunological methods, and 7.5% electrophoresis. The number of laboratories using immunological methods increased from 100 to 400 between 1993 and 1995. The overall interlaboratory coefficient of variation (CV) was 20.2%, with within-method CVs ranging between 3.2 and 29.5%. Method-to-method accuracy varied dramatically, with mean HbA1c values ranging from 4.4 to 8.2%. Results from 75% of the laboratories were comprised in the acceptable range; 88% of them reported a value within the normal range of the method used. CONCLUSIONS: The interlaboratory variability of results illustrates the difficulties encountered by diabetologists in the follow-up of diabetic patients using results obtained from different laboratories. It demonstrates the usefulness of the internationally developed standardization process of GHb measurements and points out the need for laboratories to fulfill good practices.

Data Collection↗
PubMed1997

High prevalence and usual persistence of serum monoclonal immunoglobulins evidenced by sensitive methods in renal transplant recipients.

BACKGROUND: The occurrence of serum monoclonal immunoglobulins in kidney transplant recipients is well known but their significance and predictive value for the occurrence of lymphoma are a matter of debate. We therefore conducted a study of monoclonal immunoglobulins by a sensitive method during the long-term follow up of grafted patients. METHODS: Monoclonal immunoglobulins were characterized by high-resolution electrophoresis, conventional immunoelectrophoretic analysis, and a sensitive Western blotting procedure in the serum from 84 renal transplant recipients prior to grafting and subsequently, with a 1-8-year follow-up and excluding the patients who developed posttransplant lymphoma. RESULTS: Low abundance monoclonal immunoglobulins were detectable prior to transplantation in 56 cases (66.6%) and after graft in 72 cases (85.5%) (and in 1 case (1.2%) and 18 cases (21.4%) of cases respectively, by immunoelectrophoresis). These abnormalities were often multiple in individual sera. Monoclonal components detected by immunoblotting were transient in 23.8% of patients only (whereas those evidenced by immunoelectrophoresis usually became undetectable by this method) and their pattern was remarkably stable in the majority of cases. The frequency of post-transplant monoclonal immunoglobulins was higher in patients of more than 50 years of age than in younger patients. The appearance of monoclonal components after grafting and their transient character correlated with CMV infections. No correlation was found with various other parameters. The isotypic distribution of monoclonal immunoglobulins with an IgM, IgG3, and IgG1 predominance and an abnormally low kappa/lambda ratio was the same as that observed in various immunodeficiency states. The monoclonal immunoglobulin pattern in three further patients who developed post-transplant lymphoma was unremarkable. CONCLUSION: Monoclonal immunoglobulins hence are not discriminant for lymphoma and their characterization does not appear to be necessary in the evaluation of followed up grafted patients, at least for a prediction of post-transplant lymphoma.

Adolescent↗
PubMed1997

Cast nephropathy in mu heavy chain disease.

The occurrence of kidney diseases was very rarely reported in heavy chain diseases (HCD). At variance with gamma and alpha HCD in which there is no free light chain secretion, about two-thirds of mu HCD patients have urinary Bence Jones (BJ) proteins. We report on a 66 year-old man affected with typical mu HCD who developed renal failure after a 3-year follow-up. He had presented with chronic lymphocytic leukemia with bone marrow vacuolated plasma cells, serum mu HCD protein and serum and urine BJ protein. After an apparent hematological remission following fludarabine therapy, anemia and blood hyperlymphocytosis recurred together with microscopic hematuria, proteinuria and increased creatininemia. Kidney biopsy showed numerous tubular eosinophilic casts which stained for kappa chain determinants by immunofluorescence and an interstitial infiltration by lymphocytes and plasma cells. The hematological and renal condition improved after reinitiation of chemotherapy. This appears to be the first documented report of a light chain-dependent visceral complication in HCD.

Aged↗
PubMed1995

Glycohemoglobin assays evaluated in a large-scale quality-control survey.

We report the results of a national quality-control survey on glycohemoglobin (GHb), monitored in France by the Société Française de Biologie Clinique on behalf of the authority of the "Agence du Médicament." A sample of lyophilized hemolysate was sent to 3109 laboratories. Results were obtained from 2770 laboratories. HbA1C, HbA1, and total GHb were measured by 50%, 24%, and 26% of the participants, respectively. Of these measurements, 79% of the HbA1C results and 76% of the total GHb results, but only 48% of the HbA1 results, were within the +/- 20% limits of the indicated target values. Mean values for the hemolysate ranged from 8% to 11% for HbA1C, from 7% to 12% for HbA1, and from 11% to 13% for total GHb. The interlaboratory CVs ranged from 3% to 20%, according to method used. So, methods used for GHb assay, which are based on various principles, exhibit very different analytical performances. Nonetheless, this large-scale study indicates that some techniques can support transferability of results from laboratory to laboratory.

Autoanalysis↗
PubMed1993

Between-country comparability of clinical chemistry results: an international quality assessment survey of 17 analytes in six European countries through existing national schemes.

Two lyophilized control sera were distributed through seven national external quality assessment schemes in six European countries--Belgium, Switzerland, France, The Netherlands, Sweden and the United Kingdom--participated in the study. The results for 17 routine analytes were obtained from almost 5000 laboratories for the two sera. The organizers of the schemes were asked to process the results according to a common outlier removal procedure, and submit method-related data if available. The two sera were also distributed through the external/internal scheme of The Netherlands, and the within-laboratory standard deviations calculated in this scheme have been used in a scaling procedure for the external mean values and between-laboratory standard deviations of the participating countries. The results show remarkable agreement in the national mean values for practically all analytes, but considerable differences in the between-laboratory variation. Data from comparable method groups was obtained for 12 analytes from Belgium, France, The Netherlands and the UK. Though revealing some specific differences between methods and countries, the method-related data are generally in agreement with the all-method data. In this study reference method values were only available for cholesterol. The high degree of agreement found suggests, however, that mutual recognition of all-method mean values in national schemes could be acceptable, especially for analytes for which reliable reference methods are not available. The major element of variation is between-laboratory rather than between-country.

Animals↗
PubMed1992

[Dispersion of biochemical analysis results in Dakar: preliminary results].

Now and then, the conflicting character of results of some analyses is prejudicial to patients (financial and particullary psychological repercussions), to the laboratories (renown) and to the practitioners (difficulties of interpreting). After a study of the dispersion of some analyses results, the authors propose a creation of an Interlaboratory Quality Control in Clinical Biochemistry in Senegal.

Chemistry, Clinical↗
PubMed1990

Immunochemical assays of serum proteins: a European external quality assessment survey and the effects of calibration procedures on interlaboratory agreement.

An external quality assessment survey of immunochemical assays of 9 proteins (immunoglobulins G, A and M, complement components C3 and C4, alpha1-antitrypsin, orosomucoid, haptoglobin and transferrin) in 5 European countries (Austria, France, Hungary, Italy and UK) showed inter-country differences in the mean values obtained. Reprocessing of the results using one of the two specimens distributed as a 'calibrant' effectively eliminated or reduced substantially these differences. Consideration of the methods used by participants confirmed previous indications from national surveys that the differences were due to lack of agreement among commercial calibrants. Such interlaboratory variations were also minimised by the 'calibration' in this survey. The role of European working calibration materials in ensuring interlaboratory agreement on an international basis is discussed.

Blood Proteins↗
PubMed1990

The role of coronary angioplasty in patients with associated noncardiac medical and surgical conditions.

Percutaneous transluminal coronary angioplasty was performed in 22 patients with associated significant medical or surgical conditions. It was successful in 22 patients. Two had procedure-related complications: one femoral hematoma and one small myocardial infarction. The patients were divided into a 'medical' group (12 patients) and a 'surgical' group (10 patients). In the medical group, mean coronary artery stenosis decreased from 87 +/- 5% to 20 +/- 13% and mean coronary artery stenosis decreased from 57 +/- 2% to 16 +/- 7%. In the surgical group coronary artery stenosis decreased from 83 +/- 9% to 18 +/- 9% and the gradient from 49 +/- 16 to 16 +/- 6 mmHg. Percutaneous transluminal coronary angioplasty allowed the safe management of underlying conditions in all patients so that medical treatment could be continued and noncardiac surgery performed.

Adult↗
PubMed1988

Efficacy of delayed percutaneous transluminal coronary angioplasty after intravenous use of streptokinase in myocardial infarction.

Between June 1984 and December 1986, 35 patients with acute myocardial infarction received streptokinase intravenously within 3 hours after the beginning of chest pain and underwent percutaneous transluminal coronary angioplasty (PTCA) either immediately (in 2 cases) or 1 to 19 (mean 4.4) days later (in 33). The rate of successful PTCA was 89%. Reocclusion occurred in one patient. The mean percentage of stenosis decreased from 86% to 11%. The mean trans-stenotic gradient was reduced from 41 to 11 mm Hg. The results suggest that in patients whose condition is stable, PTCA performed a few days after thrombolysis is a valuable alternative to more aggressive treatment with immediate PTCA.

Aged↗
PubMed1986

Cigarette smoking, serum lipids and angiographically-assessed coronary artery disease.

Seventy-six patients underwent cardiac catheterization for evaluation of suspected coronary artery disease and their serum lipid fractions and cigarette smoking habits were evaluated in order to determine the incidence of these risk factors on coronary artery disease. Results showed that patients with angiography defined coronary artery disease (CAD) presented disturbances in their serum lipid fractions, especially LDL-cholesterol, apoprotein B and the ratio HDL-C/(TC-HDL-C). Coronary lesions from smokers were higher when compared with matched non smokers with CAD. Cessation of smoking for two years did not induce regression of CAD among past smokers.

Aged↗
PubMed1985

[Effect of metabolic control on plasma lipids and lipoproteins in insulin-dependent diabetes in children and adolescents].

Plasma triglycerides, total cholesterol, phospholipids, HDL-cholesterol, HDL-phospholipids, apolipoproteins A-I and B, haemoglobin AIc and C-peptide were measured in 113 children and adolescents (49 males and 64 females) with insulin-dependent diabetes. These patients were divided into four groups according to sex and age (more or less than 12 years old) and into three subgroups according to metabolic control. In female adolescents with poor control, triglycerides and apolipoprotein B were increased whereas HDL-cholesterol, HDL-phospholipids and (HDL/LDL + VLDL)-cholesterol were significantly decreased. In poorly-controlled male adolescents, similar changes were observed except for HDL-cholesterol and HDL-phospholipids which were not significantly decreased. In adolescents, haemoglobin AIc correlated directly with triglycerides, total cholesterol, phospholipids, apolipoprotein B and inversely with HDL-cholesterol, HDL-phospholipids and (HDL/LDL + VLDL)-cholesterol. In children aged less than 12 years, no significant change of HDL-cholesterol or apolipoprotein B was observed even in the poorly-controlled group.

Adolescent↗