Temperature-converting factors for six enzymes, which are determined very often in
the clinical laboratory, are given. The determinations were carried out according to the
recommendations of the German Society for Clinical Chemistry and of the Committee on
Enzymes of the Dutch Society for Clinical Chemistry. These factors are described not only for
human sera but also for some batches of commercial test sera and for the pure enzymes. There are
two main conclusions. (1) Factors determined according to the German recommendations cannot
be used in any simple way to convert enzymatic activities which have been determined according
to the Dutch recommendations. (2) Factors determined using commercial test sera cannot be used
for converting enzymatic activities of human origin.
Severe haemolytic anaemia with hyperbilirubinaemia and erythroblastaemia was observed in nine newborn infants belonging to one large family. One infant was still-born, two died shortly after birth, five recorded after receiving one or more exchange transfusions and one improved without transfusional therapy. In four out of six newborns whose bilirubin levels were determined, a mixed hyperbilirubinaemia was found with high concentrations of both free and conjugated bilirubin. At the end of the first year of life the surviving children, although in satisfactory general condition, showed a mild microcytic hypochromic anaemia with decreased red cell osmotic fragility and morphological abnormalities of the erythrocytes consisting of microcytosis, anisopoikilocytosis and target cells. The serum iron levels were normal. The same haematological picture was also present in those parents of the affected children that are members of this family; these adult had normal levels of Hbs A2 and F. Incorporation of [3H]leucine into the globin chains of two adults with this syndrome revealed a reduced beta-chain synthesis (beta/alpha ratio of 0 . 49 and 0 . 53, respectively). In the two infants available for this investigation, reduced gamma-chain production was found shortly after birth. In parallel with the switch from fetal to adult haemoglobin, the deficient gamma-chain production was replaced by a similar reduction of beta-chain synthesis. These results suggested, therefore, a combined deficiency of gamma- and beta-chain production. The normal levels of Hb A2 were compatible with a defective delta-chain synthesis as well. Analysis with restriction enzymes had shown previously a large deletion, comprising gamma and delta genes, in one of the chromosomes of the affected individuals. The same procedure had established that, in spite of the defective beta-chain production, the beta-globin structural gene is intact.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.