[Immunonephelometric analysis of immunoglobulin light chains: agreement between the theoretical and experimental model. Assessment of the reference values of the kappa/lambda ratio and the heavy to light chain ratio]. / Dosage immunonéphélémétrique des chaînes légères d'immunoglobulines: concordance du modèle théorique et du modèle expérimental. Détermination des valeurs de référence des rapports kappa/lambda et chaînes lourdes/chaînes légères.

Since the introduction of fully automated nephelometric systems simultaneous measurements of immunoglobulin light chains kappa (kappa) and lambda (lambda) and IgG, IgA and IgM have become increasingly used for the routine assessment of humoral immunity. From these data two ratios were calculated, the kappa/lambda ratio and the heavy chains to light chains ratio. As changes in these ratios might have some predictive clinical value besides reflecting a monoclonal component, it is necessary to know mean and reference limits of these ratios. On account of differences in the calibration method of the light chains measurements (either free light chains or light chains bound to a complete molecule) and of differences in the calculation method of the heavy chains to light chains ratio we were led to conduct our own investigation. IgG, IgA and IgM and kappa and lambda light chains were immunonephelometrically measured in the sera of 84 blood donors. For each sample theoretical values for kappa + lambda, kappa and lambda, and kappa/lambda were calculated using the existing relation between the concentration of a given immunoglobulin and the concentration of bound light chains. Using the Valtec Protocole and the t test we were able to evidence highly significant differences (p < 10(-4) between theoretical and experimental values of kappa, lambda and kappa + lambda; those differences could be proved to be directly linked to the nephelometric technique itself. However the experimental kappa/lambda ratio did not appear to differ from the theoretical one nor the standardization method to have an effect on the reference values of this ratio, our values (mean and reference limits, 1.81, 1.29-2.53) being very similar to previously published results. Concerning the so called heavy chains to light chains ratio two methods were used to express it, one consisting in the ratio of the theoretical kappa + lambda value to the experimental one with the following results, 1.05 and 0.93-1.18 for the mean and reference limits and the other one using the raw data. The results were as follows: mean 3.50, reference limits 3.11-3.94.

[Value of immunofixation for the typing of serum and urine monoclonal proteins]. / Valeur de l'immunofixation pour le typage des protéines monoclonales sériques et urinaires.

Typing of monoclonal proteins can be performed, after screening by cellulose acetate electrophoresis, by immunoelectrophoresis (IEP) or immunofixation (IF). For sera, IF must be preferred to IEP because this methods is more sensitive and more easy to interpretate, particularly for small monoclonal components and biclonal abnormalities. For urine, patterns obtained by IF must be interpretated cautionaly because of the frequent polycondensed aspect of the non monoclonal light chains from tubular renal failures, and must be verified by a polyacrylamide agarose electrophoresis.

[High resolution electrophoresis of urinary proteins from unconcentrated samples with silver staining]. / Electrophorèse des protéines urinaries sans concentration préalable en gel de haute résolution et coloration à l'argent.

We have evaluated an electrophoretic technique on agarose gel with silver staining on one hundred pathological urine samples. This method allows to study low proteinuria and to characterize glomerular, tubular electrophoretic patterns and also to detect monoclonal immunoglobulin light chains.

Effects of tiaprofenic acid on interleukin 1, phospholipase A2 activity, prostaglandins, neutral protease, and collagenase activity in rheumatoid synovial fluid.

IL-1 and prostaglandin (PGE2, PGF2 alpha, TXB2) concentrations, PLA2 activity, neutral protease activity, and collagenase activity specific for types I and II collagen were determined in the SF of patients suffering from RA, before and after treatment with TA. Active and latent forms of protease and collagenases were regularly detected but were unrelated to IL-1, PLA2, and PGE2. TA induced a significant decrease in tested eicosanoids but IL-1, PLA2, and proteases were unchanged.

[Sero-epidemiologic study of 277 cases of human leptospirosis in the central eastern region of France between 1972 and 1984]. / Etude seroépidémiologique de 277 cas de leptospirose humaine dans le Centre-Est de la France entre 1972 et 1984.

We reported 277 clinical cases of Leptospirosis with a significant serological title (greater than 100) by lyse-agglutination. Sera were sampled from 1972 to 1984 among 9182 subjects living in Central-Eastern departments of France) for immunological diagnosis of leptospirosis. We noted the stability of the average yearly rate in this region, the difficulty in evaluating the incidence of the disease, the clinical predominance of icterus and the good clinical prognosis with specific antibiotherapy.

[Concentration of serum IGD in monoclonal gammopathies]. / Concentration de l'IgD sérique au cours des gammapathies monoclonales.

Serum immunoglobulin levels IgG, IgA, IgM were assayed by laser-nephelometry and IgD by a liquid phase radio-immunoassay in 133 patients with monoclonal gammopathy. Our result show that IgD concentration decrease in parallel with polyclonal immunoglobulin levels. We observe a decrease of IgD level, more pronounced in malignant gammopathy in which the polyclonal immunoglobulin levels are usually low.

A rapid and sensitive non-competitive avidin-biotin immuno-enzymatic assay for lysozyme.

A non-competitive avidin-biotin immuno-enzymatic assay (NABA) for lysozyme is described. The assay was found to be more sensitive than a competitive assay with biotinylated lysozyme. The lower detection limit of NABA was 0.1 ng lysozyme/ml compared to 1 ng/ml for the competitive assay. The intra-assay and inter-assay coefficients of variation for NABA were 5.9 and 9.1%, respectively. The total time for NABA can be decreased (to less than 1 h) without influencing the detection limit or the analytical range. Serum lysozyme levels measured by NABA and the enzymatic assay in 32 samples showed a correlation coefficient of r = 0.97.

[Electrophoresis of urinary proteins on SDS-polyacrylamide gel, without preliminary concentration]. / Electrophorèse des protéines urinaires en gel de polyacrylamide-SDS sans concentration préalable.

We described a rapid and sensitive method for urinary proteins disc-electrophoresis on unconcentrated urine, by using polyacrylamide-SDS gel in discontinuous gradient. Correlation with a conventional polyacrylamide agarose slab electrophoresis on concentrated urine is good, our technique being more sensitive when proteinuria is low. It had proved to be useful for routine detection of renal failures in clinical laboratories.

[Early detection of Pseudomonas aeruginosa in hemoculture media enriched with nitrates]. / Détection précoce de Pseudomonas aeruginosa dans les milieux pour hémoculture enrichis en nitrates.

Addition of a small amount of nitrates in blood culture media enhances growth of Pseudomonas aeruginosa, and permits earliest detection of that bacteria even in anaerobes media.

Histological, immunofluorescent, and ultrastructural features of lymphogranuloma venereum: a case report.

We studied the course of a case of lymphogranuloma venereum (LGV) over two years. The comparative histological, immunological, and ultrastructural studies showed the existence of characteristic granulations within the macrophages of the granuloma. We suggest that direct immunofluorescence is a specific method for diagnosing cutaneous LGV. Some ultrastructural aspects lead us to believe that different chlamydial bodies exist inside the granuloma.

Purification of soluble specific antigens of systemic candidiasis by antibody affinity chromatography.

Serological methods can be applied to the diagnosis of systemic candidiasis, but cell wall mannans can detect antibodies occurring in several cases unrelated to candidiasis. The present study proposes a procedure for the preparation of specific antigens obtained from an experimental infectious model. The specific immunoglobulins were obtained from rabbits with chronic systemic candidiasis. After precipitation by ammonium sulfate and purification by ion-exchange chromatography on DEAE-Sephadex A-50, these immunoglobulins were fixed on cyanogen bromide-activated Sepharose 4B and used for the preparation of an affinity chromatography column. This column allowed isolation of specifically bound fractions of Candida albicans soluble antigens. When analyzed by quantitative immunoelectrophoresis with a polyvalent hyperimmune antiserum, these fractions showed eight precipitation lines, whereas the complete soluble antigen exhibited 48 lines. Possible applications of these antigens to specific serodiagnosis of systemic candidiasis are being evaluated.

[Physicochemical changes in hemoculture media related to blood]. / Modifications physicochimiques des milieux d'hémoculture liées à l'apport de sang.

Inoculation of sterile blood into a blood culture medium causes changes of some physicochemical properties, whose maintenance is necessary for growth of fastidious micro-organisms. During incubation of these media at +37 degrees C, red cells utilize glucose for their metabolism, causing acidification and increase of carbon dioxide partial pressure, while oxygen partial pressure tends to decrease during first days of incubation, and increase after. Experimental conditions (choice of medium, volume of blood incubates, ventilation, glucose concentration) notably modify these results. This work underlines the necessity for a greater standardization of media and of technical conditions, in execution of blood cultures.

Chromatofocusing of human hemoglobins: application to the quantitation of hemoglobin A2.

Chromatofocusing of various hemoglobins was performed using standard ion exchangers and Ampholine solutions. With DEAE supports and a large difference between the adjusted pH of the ampholyte solution and the pH existing in the column, regular descending pH gradients were generated. Using CM-52 cellulose and small pH differences between the above, more complex pH profiles were obtained. Various hemoglobins generally eluted at a pH higher than their pI in the form of sharp peaks. The elution order was the same as with ion-exchange chromatographic procedures, including the same abnormalities with respect to the pI of some hemoglobins. Microchromatofocusing of DE-52 cellulose proved to be a sensitive and convenient technique for large-scale quantitation of HbA2.

[Determination of certain physico-chemical parameters in blood culture media]. / Intérêt de la détermination de certains paramètres physico-chimiques des milieux d'hémoculture.

Growth of delicate or exacting microorganisms needs the maintenance, in the culture medium, of precise and stable physicochemical conditions. In order to improve knowledge of these medium, and specially of their aerobic or anaerobic state, we measured pH, partial pressures for oxygen and carbon dioxide and glucose concentration of nine commercial blood culture media, in their natural conditions of use. Comparative study of experimental results, and study of successive fabrication lots of two of these media (brain-heart and Schaedler) reveals a great variability of physicochemical parameters, and specially of pO2 and glucose concentration, although initial composition of the media has theoretically not changed. It would be desirable that such parameters be better controlled, so as to encourage regularity of composition of blood culture media and, perhaps, their clinical efficiency.

Laser nephelometry and radial immunodiffusion compared for immunoglobulin quantification in pathological sera.

We evaluated nephelometers from Behring, Hyland, and Beckman for IgG, IgA, and IgM quantitation in sera from patients with monoclonal gammopathies. The intra-batch precision of each instrument for each immunoglobulin class and for different concentrations of the same immunoglobulin was compared to the one obtained with the radial immunodiffusion method. No nephelometer showed a clearly better precision. The correlation with cellulose acetate electrophoresis was good for each of the three nephelometers. The mean value by the radial immunodiffusion method was higher than corresponding determinations by nephelometry.

[The estimation of fibrinogen by kinetic immunonephalometry]. / Dosage du fibrinogène par immunonéphélométrie cinétique.

A new immunonephelometric micromethod for the estimation of fibrinogen is described. The reaction, linear between 0.30 g/l and 11 g/l requires only 5 microliters of plasma. The precision and sensitivity of the method are satisfactory. Comparisons with the chronometric technique of Clauss and with the Mancini immunodiffusion technique were made.