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J Bienvenu

Publications and source records attributed to J Bienvenu.

At least 91 records · Page 5Linked to original sources
PubMed1992

Study of six antisera used for the immunonephelometric assay of human IgG.

The composition and performance of six commercial antisera for the immunonephelometric assay of IgG were studied. The analysis of the protein content of these reagents revealed significant differences in composition: the total protein contents ranged from 41 to over 130 g/l and gamma-globulins were twice to thirteen times higher than in a normal serum of the species. The antibodies found in these reagents were mostly IgG, with traces of IgM, and no IgA. Precipitation curves yielded by these antisera with a standard nephelometer showed a great diversity of performance. The very different shapes, the span of antigen concentrations and antibody dilutions necessary to obtain comparable quantities of precipitates further demonstrated the wide differences between these reagents. A method previously proposed by other authors was found to be inadequate. The failure of this method is attributed to the different conditions for the antigen-antibody reaction, as determined by the instrumentation used. It is concluded that the fundamental and classical criteria for testing antisera remain valid: specificity and the study of the precipitation curve to define the quantitative limits of the reaction. A simple universal method is inapplicable.

Antibodies, Anti-Idiotypic↗
PubMed1991

Use of immunoglobulin heavy-chain and light-chain measurements in a multicenter trial to investigate monoclonal components: I. Detection.

We assessed the combined use of serum protein electrophoresis (SPE) and nephelometric measurement of immunoglobulin heavy- and light-chain components for detecting serum monoclonal immunoglobulins (monoclonal components, MC) in 4788 unselected samples from 4173 patients. MC were detected in 514 samples from 390 patients. In 356 these were detected by SPE; the other 34 had a normal SPE pattern but an abnormal kappa:lambda light-chain ratio (KLR). Only 208 of the 356 (58%) samples with bands by SPE had abnormal KLRs. Samples with MC concentrations greater than 5 g/L had a higher proportion of abnormal KLRs (75%) than those with concentrations less than 5 g/L (42%). The KLR was abnormal in 13% of samples in which no MC were visible by SPE or immunofixation electrophoresis (IFE). Compared with quantitative measurements of immunoglobulin heavy and light chains, high-quality SPE remains the method of choice for the detection of MC. Quantitative methods, however, are able to detect additional MC, especially those containing free light chains, and in the absence of SPE and IFE will detect about 75% of MC present at greater than 5 g/L.

Antibodies, Monoclonal↗
PubMed1991

Use of immunoglobulin heavy-chain and light-chain measurements in a multicenter trial to investigate monoclonal components: II. Classification by use of computer-based algorithms.

We describe a computer algorithm for classifying serum monoclonal proteins (MC) based on serum protein electrophoresis (SPE) and the automated measurement of kappa and lambda light chains and IgG, IgA, and IgM. We developed the algorithm by using a large database of unselected samples containing MC collected in a multicenter study. The performance of the algorithm was optimized by using iterative computational procedures and was tested on both the development database and on an independent set of MC-containing samples. With the development database, the algorithm correctly classified 50% and misassigned 2.5% of the MC. Where the MC were present in concentrations greater than 10 g/L, the rate of successful classification increased to 72% with 3% misclassification. When the algorithm was tested on a group of 101 MC-containing samples from an independent source, 67% were correctly classified and 8% misclassified, half of the latter being unusual IgD myelomas. We discuss the scope for the application of the algorithm in routine laboratory practice involving personal computer software.

Algorithms↗
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↗
PubMed1989

Effects of serum amyloid A protein on lymphocytes, HeLa, and MRC5 cells in culture.

A major human acute phase protein, the serum amyloid A protein, has been tested in vitro for its effect on lymphocyte proliferation, the formation of E-stable rosettes, as well as the growth of HeLa and MRC5 cell cultures. Serum amyloid A protein has been found to be markedly inhibitory at 30, 100, 200, and 300 micrograms/mL, and is a very potent inhibitor of in vitro biological functions.

Acute-Phase Reaction↗
PubMed1988

[Serum amyloid protein A (SAA) and HDL. Clinical implication and surgical resuscitation].

The variation of Apo SAA has been studied in parallel with HDL disturbances in septic patients to try to define the role of SAA in these lipoproteins abnormalities. 14 septic patients hospitalized in a surgical intensive care unit have been studied. In these patients, the determination of cholesterol, HDL-cholesterol, Apo AI, Apo B, Apo SAA and CRP and lipoprotein electrophoresis have been made between the 4th and the 7th day after admission in the unit. A control group includes 10 patients undergoing an elective knee surgery. Our results show that SAA elevation (480 +/- 250 mg/l) are much greater than CRP ones (137 +/- 38 mg/l) with no correlation between the 2 proteins specially in patients with hepatic failure. As reported by others, we find a diminution of total cholesterol (3.0 +/- 1.2 mmol in our series) and HDL-cholesterol (0.39 +/- 0.18 mmol). Apo AI is dramatically decreased (0.50 +/- 0.29 g/l) such as a negative acute phase protein. The polyacrylamide gel electrophoresis of lipoproteins confirms the HDL decrease and reveals an abnormal migration of this class of lipoprotein in 8 cases/14 cases (4 accelerations and 4 double-bands). From the results, this HDL modification does not seem to correlate with SAA elevation; immunoblotting experiments lead to the same conclusion. The data are discussed and compared to other findings of the literature.

Adult↗
PubMed1988

Development and performance of a fully automated method for assay of C-reactive protein in the aca discrete clinical analyzer.

A quantitative immunoassay for C-reactive protein (CRP) has been developed for use in the Du Pont aca discrete clinical analyzer. Particle-enhanced turbidimetric immunoassay (PE-TIA) technology is used. The method has a CV of less than 10% in the range 2 to 120 mg/L. Neither hemolyzed samples (Hb less than 5 g/L), icteric samples (total bilirubin less than 300 mg/L), lipemic samples (triglyceride less than 15 g/L), nor some commonly used drugs interfere. Dithioerythritol is used to eliminate interference from rheumatoid factor. Good correlation was seen when the Du Pont CRP method was compared with the Beckman ICS, Syva EMIT, TDx, and Behring methods for CRP. The normal reference interval is 0 to 9 mg/L. The method, which is fully automated, is fast, requires only a few microliters of serum, and is well suited to emergency-room requirements.

Autoanalysis↗
PubMed1985

[Detection of hyperamylasuria. Value of a quick test].

A new reactive strip was used in a hospital admission unit, to detect amylasuria in the urine of 76 patients consulting for abdominal pain (population A) and of 68 unselected patients (population B). Detection on admission by this method was concordant with subsequent laboratory detection in 93% of the cases. The fast test was positive for amylasuria in 17 patients: 13 (17.1%) in population A and 4 (5.9%) in population B. The 8 patients recorded as "+" had moderate amylasuria with multiple but ill-defined symptoms mostly abdominal. The 9 patients recorded as "++" had marked amylasuria highly suggestive of an abdominal disease, including 4 cases of chronic pancreatitis.

Acute Disease↗
PubMed1985

Rapid enzyme immunoassay for quantification of C-reactive protein (CRP).

A simple, rapid enzyme immunoassay (EMIT CRP assay) for C-reactive protein (CRP) was assessed using human acute phase sera and purified human CRP. The calibration curve was established from 10 micrograms/mL to 150 micrograms/mL. The precision evaluations of the assay, carried out under optimal conditions of the test, (CRP levels: 20-100 micrograms/mL) showed coefficients of variation less than 7%, both for within-run and day-to-day precision. The limit of sensitivity was 10 micrograms/mL. The coefficients of correlation with radial immunodiffusion and immunonephelometry were respectively 0.988 and 0.956. The dilution assay showed a linear response. No significant changes in the CRP level were observed after sample storage either at 4 degrees C or -20 degrees C for 3 to 10 days, or after removing lipoproteins from sera. The EMIT CRP assay is characterized by its short assay time, its excellent precision, and its sensitivity is sufficient to detect an ongoing inflammatory process.

C-Reactive Protein↗
PubMed1985

Use of acute phase protein changes to assess the effects of a nonsteroidal antiinflammatory drug (niflumic acid) on the inflammation process induced by limited plastic surgery.

Serum levels of acute phase proteins (C-reactive protein, alpha 1 acid glycoprotein, and haptoglobin) have been measured to assess the effects of a nonsteroidal antiinflammatory drug (niflumic acid). Thirty patients undergoing plastic surgery have been studied. The results obtained from this surgical model prove that nonsteroidal antiinflammatory drugs can modify acute phase response and especially acute phase proteins levels. The participation of prostaglandins in the acute phase protein variations is discussed. The authors conclude that haptoglobin could provide a convenient tool for studying some aspects of prostaglandin action in vivo.

Acute-Phase Proteins↗
PubMed1984

A three-step purification of human alpha 1-acid glycoprotein.

alpha 1-Acid glycoprotein (AGP) was purified to homogeneity by a 3-step procedure using pseudo-ligand affinity chromatography on immobilized Cibacron blue F3GA, Procion red HE3B, and preparative column isoelectric focusing. The overall yield of the combined techniques was 88%. Analysis of the purified AGP by lectin affinity chromatography on immobilized Con A and immunoaffino-electrophoresis indicated that the most acidic form did not interact with the lectin, while the two more basic fractions possessed different affinities for Con A. In addition, 3 different populations of AGP were clearly separated by Con A affinity chromatography.

Chromatography, Affinity↗
PubMed1984

Evolution of serum prealbumin, C-reactive protein, and orosomucoid in neonates with bacterial infection.

The simultaneous changes in serum prealbumin, orosomucoid (alpha-acidglycoprotein, AGP), and C-reactive protein (CRP) were evaluated in 36 newborn infants with septicemia (n = 20), meningitis (n = 10), arthritis (n = 5), and peritonitis (n = 1). In 29 patients with a favorable outcome the values for serum prealbumin and CRP showed a rapid return toward normal: in 2 to 3 days serum prealbumin increased by 84% from the basal value and remained at (mean +/- 1 SD) 0.11 +/- 0.02 gm/L. Serum CRP decreased from 85 +/- 75 mg/L (range 0.15 to 206 mg/L) to 49 +/- 64 mg/L (2 to 210 mg/L) at 3 to 4 days of evolution and to normal values at day 13 to 16. The changes in serum orosomucoid values were slower, from 1.33 +/- 0.75 gm/L to 1.16 +/- 0.75 gm/L at day 13 to 16, with normalization after 20 to 30 days. Serum orosomucoid values returned to the normal range with the clinical improvement. In some patients the orosomucoid/prealbumin ratio decreased earlier than the serum orosomucoid concentration. Seven patients died, and in four of these in whom at least three values could be determined serum CRP and orosomucoid remained very high, whereas serum prealbumin did not increase or subsequently decreased. These data show an inverse change in serum CRP and prealbumin concentrations in infected neonates. The immediate decrease in CRP reflects the effect of treatment, whereas the later decrease in serum AGP parallels the clinical course of the infection. Thus the determination of these proteins can help to guide the treatment of infection in newborn infants.

Acute-Phase Proteins↗
PubMed1984

[Proteins of the inflammatory reaction. Definition, physiology and methods for determination].

An inflammatory reaction protein is a protein whose rate of synthesis is greater than its rate of catabolism in the presence of an inflammatory process. This is reflected by an increase in its plasma concentration. In man, orosomucoid, alpha-1 antitrypsin, alpha-1 anti-chymotrypsin, haptoglobin, ceruloplasmin, fibrinogen and C reactive protein (CRP), all conform to this definition. The authors present the principal physicochemical properties of the proteins. However, none of these proteins, on its own, constitutes an ideal marker of inflammation. The authors also propose the use of an inflammatory miniprofile consisting of "CRP, orosomucoid and haptoglobin" to detect, quantify and follow an inflammatory reaction. The authors stress the importance of using a rapid assay technique like immunonephelemetry , which is essential for the clinical usefulness of these proteins. Finally, they discuss the process of synthesis and the biological role of these proteins.

Acute-Phase Proteins↗
PubMed1983

Assessment of the benzethonium chloride method for routine determination of protein in cerebrospinal fluid and urine.

We have tested the characteristics of the method of Iwata and Nishikaze (Clin Chem 25: 1317, 1979). The linearity, sensitivity, and precision are satisfactory and the reactivity of benzethonium chloride with various proteins (albumin, immunoglobulins) is the same. The method has been compared with Meulemans's technique (Clin Chim Acta 5: 757, 1960), routinely used in our laboratories, by analysis of 82 samples of cerebrospinal fluid (CSF) and 119 samples of urine. Our results for cerebrospinal fluid agree well with those of Iwata and Nishikaze (r = 0.976; y = 0.992x - 0.013), but we find their method unsuitable for urinary protein determination, probably because of interfering compounds in urine.

Albumins↗
PubMed1982

Enzyme-linked immunoadsorbent assay for serum IgE: evaluation in four centres.

We report an evaluation of a commercially available kit, the Biomérieux IgE-kit, for determination of total IgE in serum by the EIA double antibody sandwich method. Results by this procedure and PRIST (Pharmacia) show a degree of association (r) of 0.98 and a regression equation of log Y = 0.79 log PRIST + log 3.31. Correlation between the IgE kit and RIST shows a degree of association of 1.00 and a regression equation of log Y = 1.01 log RIST--log 1.05. Between-laboratory standard deviations are 3%, 3%, and 15% for the IgE concentrations of, respectively, 83, 285, and 900 IU/ml. Similarly, intra- and inter-assay correlations were performed on 60 lyophilised serum samples tested in the four centres. No protein interference was found except for cryoprecipitates. The favourable correlation with existing procedures and the feasibility of this kit offer a new way of measuring IgE levels.

Alkaline Phosphatase↗