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C Flandrois

Publications and source records attributed to C Flandrois.

7 recordsLinked to original sources
PubMed1989

Circadian variations and reference intervals for some enzymes in urine of healthy children.

Circadian variations of alanine aminopeptidase (EC 3.4.11.2), gamma-glutamyltransferase (EC 2.3.2.2), and N-acetyl-beta-glucosaminidase (EC 3.2.1.30) in urine were studied in 10 healthy children, ages six to 15 years. Urine specimens were collected during 24 h, grouped into four time intervals. Enzymes were measured spectrophotometrically, with automation. These enzymes all showed diurnal variation, with morning (8 a.m.-12 noon) excretion being highest. We also analyzed timed urinary specimens (8 a.m.-12 noon) from 136 healthy children, ages two to 11 years. Reference intervals are presented for these enzymes. High excretion of the three enzymes was observed in children two and three years old.

Acetylglucosaminidase↗
PubMed1989

[Optimization of the determination in urine of alanine aminopeptidase, gamma-glutamyltransferase and N acetyl-beta-D-glucosaminidase].

The authors describe the optimization of determination of alanine aminopeptidase (AAP), gamma-glutamyltransferase (GGT) and N-acetyl-beta-D-glucosaminidase (NAG) in urine by multivariate analysis. The optimal conditions found are: for AAP at 30 degrees C TRIS HCl buffer 300 mmol/l pH 7.9, L-alanine-4-nitroanilide 5.8 mmol/l, for GGT at 30 degrees C buffer glycylglycine 150 mmol/l pH 8.0, gamma-L-glutamyl-3-carboxy-4-nitroanilide 9.0 mmol/l, for NAG at 37 degrees C citrate buffer 50 mmol/l pH 5.8, m cresolsulfonphtaleinyl-N-acetyl-beta-D-glucosaminide 5.5 mmol/l. These methods are easy to perform, apply to urine without pretreatment through Sephadex: therefore complete automatization is possible. The stability of enzymatic activities in urine is of ten days at +4 degrees C in the presence of sodium azide at neutral pH. Freezing resulted in a considerable loss of activity for AAP and GGT.

Acetylglucosaminidase↗
PubMed1989

[Evaluation of enzymuria as a tracer in nephrotoxicity: results of a multicenter study].

Urinary excretion of three enzymes of different subcellular location in kidney tissue, alanine aminopeptidase (AAP), gammaglutamyltransferase (GGT), N acetyl-beta-D glucosaminidase (NAG), was carried out in 79 healthy adults and 108 healthy children and in 69 adults with various therapies: antibiotics (32 cases), non steroidal anti-inflammatory drugs (NSAIDs) (22 cases), cisplatinum (12 cases) and cyclosporine (3 cases). A circadian rhythm has been shown in children. In patients treated with antibiotics, the importance and duration of the increased enzymes urinary excretion were variable but the excretion of AAP was always higher than that of GGT and NAG. Short term therapies by NSAIDs were without influence on enzymuria but long term therapies produced a moderate increase of NAG excretion. Enzymuria increased immediately after cisplatinum administration and decreased after each daily dose, except in patients with previously high creatininemia. Cyclosporine induced a slight increase in AAP and NAG excretion. Enzymuria, thus, increased early reflecting a toxic effect of the drug at the cellular level whereas creatininemia increase, marker of renal fonctionnal insufficiency, occurs only occasionally and lately.

Acetylglucosaminidase↗
PubMed1989

[Value of enzymuria during antibacterial therapy].

Enzymuria is a well known parameter of evaluation of drugs nephrotoxicity, particularly of antibiotics. Alanine aminopeptidase (AAP), gamma-glutamyltransferase (GGT) and N-acetyl-bêta-D-glucosaminidase activities were measured in native urine. This study included 19 patients treated by an association of netilmicin-vancomycin. Enzymuria was measured on 24 hours urines at J0 then every two days during treatment. Enzymuria increased 24 or 48 hours after the beginning of the treatment. The Principal Components Analysis (PCA) of the results of enzymuria, seric urea and creatininemia shows the presence of two groups of responses. The first principal component exhibits two populations: the patients with pathological seric urea and pathological seric creatinine and the others. The PCA does not allow this discrimination using only the results of enzymuria; in contrast, with these results, the patients may be classified by the PCA on the basis of treatment duration. The enzymuria allows the clear identification of nephrotoxic drugs but does not allow the prediction of renal injury or of its aggravation.

Acetylglucosaminidase↗
PubMed1988

Urinary alanine aminopeptidase assay improved as result of multivariate response-surface analysis.

Optimization of determination of alanine aminopeptidase in urine by univariate study led to a method involving pretreatment of urine with Sephadex G50. Re-examination of the optimization by multivariate study led us to recommend higher optimal concentrations: 5.8 mmol/L for the substrate and 300 mmol/L for the Tris buffer. Under these new conditions, pretreatment of urine was no longer necessary and the assay could be completely automated.

Aminopeptidases↗
PubMed1986

[Enzymuria].

Study of enzymuria rises more and more interest in human pathology as a diagnosis parameter of renal diseases or as an index of nephrotoxicity. In this two fields, the literature demonstrated the interest of enzymes of the brush border of proximal tubuli (alanine amino peptidase, gamma glutamyl transpeptidase, alkaline phosphatase) and of lysosomal enzymes (beta glucuronidase and N acetyl beta D glucosaminidase). The authors analyse the problems limiting the present use of these methods: incomplete knowledge of enzyme of the different parts of the renal tissue and of the mechanisms of enzymuria (choice of enzymes and time periods for sampling); analytical problems referring to the study of enzymes in a complex medium (treatment and storage of samples, choice of adapted methods for activity measurement); at last the way of expression the results is still to be defined.

Clinical Enzyme Tests↗