[A case of fatal cocaine overdose].

Clinical, biological, and therapeutic description of a lethal case of cocaine overdose.

Determination of cardiac troponin I forms in the blood of patients with unstable angina pectoris.

Objective: To determine the predominant form in which cardiac troponin I circulates in the bloodstream of unstable angina patients.

Design And Methods: The cardiac troponin I forms released in the bloodstream of 25 patients suffering from unstable angina were examined by using three immunoenzymatic assays: the total cTnI assay for detection of free and complexed cTnI, the IC-TIC assay for detection of the IC and TIC troponin complexes, and the IT-TIC assay for detection of the IT and TIC troponin complexes.

Results: Approximately 60% of patients with unstable angina had at least one positive value in the total cTnI assay or in the IC-TIC assay.

Magnesium--a profibrillatory or antifibrillatory drug depending on plasma concentration, heart rate and myocardial perfusion.

Background: The opinions on the efficacy of magnesium as an antiarrhythmic drug vary considerably. The action of magnesium on vulnerability to fibrillation was therefore investigated in anaesthetized, open-chest pigs under different conditions as regards plasma concentration, heart rate and myocardial perfusion.

Methods: Vulnerability to fibrillation was assessed by electrical fibrillation threshold (EFT), measured with 100-ms duration diastolic impulses.

[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].

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.

[Value of a new fast CK-MB determination for the diagnosis of myocardial infarction during the 1st hours. Preliminary study].

This study evaluated the time for a new, rapid and reliable CK-MB analysis to become positive in myocardial infarction and compared it with classical total CK analyses. Serial analyses of total CK and CK-MB were performed in 49 consecutive patients referred to the Coronary Care Unit for suspected acute myocardial infarction. Twenty of these patients had myocardial infarction with rising enzyme levels, which enabled comparison of the precocity of one analysis compared to another.

[Accuracy in thyroid hormonology: evaluation of free T4 by five immunometric methods using cold markers].

During a comparative multicentric evaluation, five commercially available non-isotopic methods for FT4 measurement were tested. As with the radioactive methods the problem with accuracy is again evident. This is true both for setting reference values and standards as well as for the specificity of the methods.

[Assay of digoxin on dry-reagent strips].

An automated immunoassay for Digoxin in serum using dry-reagent strips (Stratus Dade) was evaluated, and compared with two others immunoassays (TDX Abbott and ACA Du Pont). Precision, sensitivity and specificity were satisfying, as well as correlation study, but discrepancies observed for some sera proved that these techniques still pose serious problems of specificity or of standardisation.

[Electrophoresis of urinary proteins on SDS-polyacrylamide gel, without preliminary concentration].

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.

[Physicochemical changes in hemoculture media related to blood].

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.

[Determination of certain physico-chemical parameters in blood culture media].

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.

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 estimation of fibrinogen by kinetic immunonephalometry].

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.