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Biomedical subjects

F Ceriotti

Publications and source records attributed to F Ceriotti.

31 records · Page 2Linked to original sources
PubMed1991

Measurement of alkaline phosphatase activity in serum with N-methyl-D-glucamine as a buffer: evaluation of the method for routine use.

Some aspects of the measurement of alkaline phosphatase activity concentration in human serum, using N-methyl-D-glucamine as a buffer, were evaluated with a view to the possible routine use of the method. The evaluated characteristics included: the temperature-dependence of the pH of the buffer; the effect of adding the magnesium/zinc ions buffer; the effect of the serum volume fraction; the substrate-starter versus the serum-starter mode; the effect of modifying the formulation of reagents; the within-run and the between laboratory imprecision; the correlation with an alternative routine method. Also, sex- and age-related reference values were produced, based on 2968 values from selected reference sample groups in 7 laboratories. In general, the results demonstrate the robustness of the method, its adaptability to a variety of mechanized analysers, and hence its feasibility as a routine measurement method.

Adolescent↗
PubMed1991

Pediatric emergency laboratory.

The laboratory contribution in the care of a seriously ill child is essential to plan and organize the therapy after the first-step emergency care and to know the aethiology of the illness. The most acute syndromes in pediatric emergency care are: coma, convulsions, dehydration, metabolic disequilibrium, hypovolemic or anaphylactic shock, serious infectious diseases and chemical or drug poisoning. The laboratory tests which have to be available within few minutes are blood cell count, hemogasanalysis, sodium, potassium and calcium, glucose. Total proteins, serum creatinine and urea, bleeding tests, blood smear, sedimentation rate, ALT, AST, osmolality, urinary electrolytes and creatinine and cerebrospinal fluid examination should be available within sixty minutes. New accurate and rapid techniques and instrumentations make easier the diagnostic and therapeutical approach to pediatric emergency.

Child↗
PubMed1988

Determination of serum cholesterol on the Reflotron (BBR) dry chemistry analyser. Assessment of accuracy.

This investigation is aimed at assessing the accuracy of S-cholesterol determination by means of the Reflotron, an analytical system based upon the dry chemistry approach. Two sets of sera, one of them including specimens with elevated concentrations of urea, creatinine, glucose, urate or bilirubin, were assayed in parallel with the Refloton system, with a class-A "reference" method (including alkaline hydrolysis and extraction) and with a routine liquid chemistry enzymatic method. Results for both sets of sera indicated good agreement of the tested system with the routine method, whilst a small proportional negative bias was observed in comparison with the "reference" method. The use of the reference method as a basis for comparison allows more conclusive statements about accuracy to be made.

Autoanalysis↗
PubMed1987

Effects of suprofen on renal function in patients with rheumatoid arthritis.

Suprofen is a new potent analgesic with antiinflammatory properties that appears to inhibit prostaglandin synthetase in a tissue-selective manner, having relatively little effect on the kidneys of experimental animals. The effects were studied of one week of treatment of rheumatoid arthritis patients with suprofen or ibuprofen on Na+ and K+ excretion, creatinine clearance, urinary enzymes that are markers for tubular damage, and urinary prostaglandins such as PGE2 and 6-keto PGF1 alpha (a stable metabolite of prostacyclin). Neither compound caused changes in renal function related to the week of treatment, but significant decreases in prostaglandins were observed: this change was fully reversible after discontinuation of the drug.

6-Ketoprostaglandin F1 alpha↗
PubMed1987

Plasma protein glycation as measured by fructosamine assay.

The fructosamine test for assessing control of glucose in blood has been extensively evaluated, but some questions remain regarding its validity. From the analytical and clinical evaluation we present here, we conclude that: the test is sensitive to variations in the composition of the sample protein; the fructosamine reaction is almost completely unaffected by labile fractions; the concentrations of fructosamine correlate well with the degree of glycation of total serum proteins, especially with glycated albumins and glycated immunoglobulins, as determined by affinity chromatography; the correlation with glycated hemoglobin (Hb A1c), measured as the stable fraction, is very poor, in diabetics treated with insulin (r = 0.373), or with oral hypoglycemic agents (r = 0.390); and (e) fructosamine and Hb A1c are, in fact, expressions of different periods of metabolic control and therefore have different clinical meanings.

Adolescent↗
PubMed1987

Erythrocytic glucose-6-phosphate dehydrogenase measured by a differential pH technique.

We propose a new quantitative electrochemical method for determining glucose-6-phosphate dehydrogenase (EC 1.1.1.49) activity in purified erythrocytes or in whole blood, based on measurement of the pH change caused by oxidation of glucose 6-phosphate to 6-phosphogluconic acid, with simultaneous reduction of NADP+ to NADPH + H+. No sample pretreatment (e.g., preparation of hemolysate) is needed, and the automatic correction for sample blanks obviates interference from 6-phosphogluconate dehydrogenase (EC 1.1.1.44). The method is simple and fast, and the standard curve is linear to at least 2200 U/L at 37 degrees C. The within-day CV was 3.9% for activities in healthy individuals (mean value 1204 U/L), and 10% for deficient ones (classified as belonging to class II, mean value 407 U/L). Results (y) correlated well with those obtained with the WHO-recommended method (x): y = 1.13x + 0.02 (r = 0.971) for purified erythrocytes. Normal reference intervals are reported for the enzyme in purified erythrocytes and in whole blood.

Erythrocytes↗
PubMed1986

Measurement of erythrocyte acetylcholinesterase and plasma cholinesterase activity by a differential pH technique.

We describe a new electrochemical method for the determination of erythrocyte acetylcholinesterase activity (EC 3.1.1.7) and plasma cholinesterase (EC 3.1.1.8) activity, based on the measurements of pH variation due to release of acetic acid from acetylcholine. The major advantages of the differential pH procedure are simplicity, high reproducibility, no need for pre-treatment of samples, automatic correction of sample blanks, and speed and direct measurement of enzymatic reaction. The proposed methods are linear up to 7400 U/L at 30 degrees C and correlate well with the manual spectrophotometric method of Ellman for plasma cholinesterase and for washed erythrocytes. We adapted the same technique for the determination of erythrocyte cholinesterase using whole blood as sample and quinidine sulphate as inhibitor of pseudocholinesterase.

Acetylcholinesterase↗
PubMed1985

Optimization of the urinary acid alpha-glucosidase determination.

The optimization of the method for acid alpha-glucosidase determination (EC 3.2.1.3) in human urines, employing the synthetic substrate 4-nitrophenyl-alpha-D-glucopyranoside, is reported. Storage conditions of the specimens and their pretreatment were particularly investigated. The precision of the whole analytical procedure (including gel filtration) is good (within-run CV = 7.4% for normal samples and 3.7% for elevated ones). The correlation with the method using maltose as substrate is excellent (y = -0.01 + 0.13 x; r = 0.9893).

Chromatography, Gel↗
PubMed1985

Measurement of lipase activity by a differential pH technique.

This is a new electrochemical method for determination of lipase activity in biological fluids, including serum, plasma, and duodenal juice. Advantages of turbidimetric methods--short reaction time, and small sample and reagent volumes--are combined with those of titrimetric methods: measurement of absolute activity (i.e., no standardization required), saturated substrate conditions, and direct measurement of reaction products. The proposed method is easy, inexpensive, and takes only 3 min. Precision is good: CV = 3.74% within day and 7.3% between days at the clinical-decision concentration, CV = 1.86% within day and 4.65% between days for above-normal lipase activities. The standard curve is linear up to 4500 U/L. Results (y) correlate well with those by turbidimetry (x): y = 0.9287x - 65.3 (r = 0.9719). Reference values are between 0 and 130 U/L.

Adult↗
PubMed1984

Urea, creatinine, and glucose determined in plasma and whole blood by a differential pH technique.

We report the conditions (buffer composition and enzyme activity) required for estimating three frequently determined analytes--urea, glucose, and creatinine--by use of an improved version of the differential pH apparatus previously described (Clin Chem 29: 80-85, 1983). For each analyte, we used only one specific enzyme, thus avoiding a chain of auxiliary and indicator reactions. The method requires about a minute for each determination in undiluted plasma or whole blood.

Blood Glucose↗
PubMed1980

Improved direct specific determination of serum iron and total iron-binding capacity.

Serum iron is released from transferrin and reduced at pH 1.7 by treating serum with a 10 g/L ascorbic acid solution in 0.1 mol/L HCl. When ferrozine is added to this reagent, it forms a complex with iron that is as intensely colored as at higher pH values, and under these conditions no turbidity is produced. The second major interference, that from copper, is eliminated by adding 1 g of thiosemicarbazide per liter, which at a low pH forms a stable, uncolored complex with copper without affecting the reaction of ferrozine with iron.

Ascorbic Acid↗