RESUMO
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.
Assuntos
Fosfatase Alcalina/sangue , Meglumina , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Soluções Tampão , Criança , Pré-Escolar , Estudos de Avaliação como Assunto , Feminino , Humanos , Concentração de Íons de Hidrogênio , Lactente , Recém-Nascido , Magnésio/farmacologia , Masculino , Métodos , Pessoa de Meia-Idade , Valores de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Especificidade por Substrato , Temperatura , Zinco/farmacologiaRESUMO
A rapid and simple procedure measuring the rate of hemolysis of 50% of erytrocytes suspended in a standardized glycerol mixture (GLT/50) has been compared with the erytrocyte osmotic fragility to NaCl 0.375% concentration, carried out according to Parpat's method modified, in order to estimate the respective behaviour in the screening of beta-thalassemia trait. The GLT/50 is provided with more selectivity especially between beta-thalassemia trait carriers and other subjects with iron deficiency anemia.
