[Evaluation of a colorimetric enzymatic procedure for determining the total bile acids in the blood]

A simple enzymatic colorimetric procedure for the total serum bile acids determination was evaluated. In 518 normal patients values of statistical analysis ranged from 0.60 to 7.75 mumol/l (mean = 3.38 and S.D. = 2.00).

[Semiautomatic procedure for determining urine iron in subjects treated with deferoxamine B]

A semiautomatic method for the determination of urine iron during treatment with deferoxamine B has been evaluated: samples were diluted 1:10 with a TCA 10% and thioglycolic acid 1.1% solution and processed after centrifugation by the aca III discrete clinical analyzer Du Pont. In this way an overestimation of values depending on the turbidity caused by proteins is avoided and the bad smell is limited thanks to the very low concentration of the thioglycolic acid solution. A good correlation with the atomic absorption spectrophotometry, specially for values less than or equal to 20 mg/l, was observed examining urine samples of 150 patients treated with deferoxamine B.

[Procedure for identifying atypical variants of pseudocholinesterase for the prevention of prolonged apnea induced by succinylcholine]

The simple Sclavo test based on succinyldicholine hydrolysis and on the following reaction with 5,5'-dithio-bis-2-nitrobenzoic acid for detection of the atypical patterns of serum cholinesterase has been investigated. A yellow staining appears but in presence of the atypical forms of the enzyme. Analysis of 4055 serum samples by the 430 Selective Analyzer Sclavo allowed the identification of one atypical homozygous patient. Prolonged apnoea induced by use of succinyldicholine as a neuromuscular blocking agent during anaesthesia may be avoided by use of this test.

[Frequency of microalbuminuria in children]

Urinary samples overnight collected from 550 pediatric patients with normal urine analysis and normal serum levels of creatinine, urea and glucose were tested for the presence of microalbuminuria by a latex test. Only 3 cases (0.6%) were positive even with RIA method; the difference with the percentage observed in adults (4.5%) is highly significant.

[Reference values of serum creatinine measured automatically by the Jaffé fixed-time reaction]

1077 serum samples collected from patients of both sexes showing values of creatininemia less than or equal to 1.4 mg/dl as evaluated by the enzymatic colorimetric method (Wako reagents, Cobas Fara analyzer) have been processed using 430 Selective Analyzer Sclavo. Test for imprecision and inaccuracy within-run and between-day (40) showing very low values (less than 3%) of variation and bias coefficients, preliminarily demonstrated the reliability of the automatic fixed time Jaffé's reaction. Statistical analysis gives these values: means = 0.66 mg/dl, deviation standard (DS) = 0.20 mg/dl, means + 2 DS = 1.06 mg/dl, in good agreement with data provided by the enzymatic procedure.

[Reference values for sialic acid in the urine]

Sialic acid levels were evaluated by means of the enzymatic colorimetric Biochemia method on 24 hours urine samples of 250 males and females; the urine analysis, serum urea and glucose and creatinine clearance were in normal range. Means values of urinary sialic acid on samples treated with charcoal powder activated to remove the pyruvate-oxidase inhibitors were: 53.4 mg/l, 63.5 mg/24 hours and 58.7 mg/24 hours/1.73 m2.

[Frequency of microalbuminuria in an adult population]

Urinary samples overnight collected from the thousand normotensive adults with normal urinalysis and normal serum levels of creatinine, urea and glucose were tested for the presence of microalbuminuria by latex test Sclavo. Fourty-five cases were positive: the values of microalbuminuria in 21 of these cases tested with RIA method exceeded 26 mg/l; one hundred twenty-six latex-negative cases evidenced lower RIA values. The high sensitivity of the test and its clinical significance suggest the need of an automatic procedure for detecting microalbuminuria in Albustix-negative urine samples.

[Evaluation of a colorimetric enzymatic method for the determination of sialic acid in serum]

Evaluation of sialic acid in serum was done by means of an enzymatic colorimetric method using the Biochemia Sialic Acid kit. Precision and accuracy within-run and run-to-run were high and linearity was observed just to a 170 mg/dl concentration. Reference values evaluated in 2700 samples were: mean = 65.3 mg/dl; mean +/- 2 standard deviations = 52.0-78.6 mg/dl.

[Reference values of urinary delta-aminolevulinic acid in children]

Delta-aminolaevulinic acid is well known to be an intermediate in the synthesis of haeme and small amounts are normally excreted in urine (ALA-U). An increased excretion of this substance occurs in porphyria and in lead poisoning. The urine specimens of 670 children (362 boys and 308 girls), aging from less than one to fifteen years and who had no evidence of abnormal exposure to lead, have been collected in order to find out the range of normal values of ALA-U expressed in mg/l for the different age and sex group. Our data can be usefull, together with zincprotoporphyrin (ZPP), for screening of anemias and for monitoring lead exposure.

[Colorimetric determination of urinary iron, chelated with deferoxamine B, using a single reagent]

A new colorimetric method for the determination of urinary iron chelated with desferrioxamine B is proposed. A single reagent (ferrozine plus thioglycolic acid 1%) is utilized. Analytical range reached about 25 mg of iron/l, while the detection limit was 0.2 p.p.m. The evaluation of imprecision and inaccuracy were within acceptable limits. Moreover, there is good correlation with the atomic absorption spectrophotometric technique. This test shows good reliability.

[Creatinine clearance: indirect estimate (author's transl)]

The validity of some formulas proposed to estimate the creatunine clearance by values of serum creatinine and others non analytical parameters (sex, age, weight and height) was tested in a group of 200 adults (100 males and 100 females) and in a group of 134 children (80 males and 54 females). The age ranged from 1 month to 78 years; the values of serum creatinine varied from 0.3 to 10.0 mg/dl; the clearance value was calculated also in the usual way by the AutoAnalyzer (N-11 a Technicon method). The statistical analysis and the comparison of the data show good correlation between the clearance values calculated either by the direct or the indirect method. However the frequency of inacceptable disagreements does not allow the use of these formulas to evaluate the renal function and to regulate the administration of some drugs.

[Rapid determination of creatinine in the blood and urine by 1st-generation Autoanalyzer]

Two procedures for the determination of serum and urinary creatinine by first generation AutoAnalyzer have been positively tested. These methods enable to perform these analyses by cam 60 and 100 respectively, in order to make the influence of carryover neglectable. Very regular peaks with clear-cut resolution can be obtained. The range of concentrations which can be reliably evaluated corresponds to 0,5-10,0 mg/100 ml for serum and to 20-500 mg/100 ml for urine, for this analysis neither diluition nor the dialysis of the sample are required.