THE DEVELOPMENT OF ENZYME SYSTEMS DURING EARLY INFANCY

Abstract

PEDIATRIC literature and clinical experience contain abundant indications of physiologic immaturity in newborn infants, especially in those born prior to term. Functional immaturity of brain, liver, kidney, immune response and blood coagulation are among the well-recognized peculiarities of the newborn period. Exaggerations of these usually mild, transitory phenomena may contribute to grave disorders and possibly prove to be lethal. In addition to apparent derangements of particular systems or organs, there are occasional infants, notably the delicate offspring of diabetic mothers, whose general response and appearance suggest immaturity disproportionate to size and gestational age. In this group, general metabolic disturbances are suspected which await biochemical localization and characterization. Conventional post-mortem examinations may be discouragingly unrevealing in these babies. For example, one of the most commonly encountered problems is that of infants dying following unexplained respiratory distress. Pathologically, only so-called "hyaline membranes" with atelectasis have been found. This pattern can be noted in at least half of all infants of diabetic mothers and prematures and occasionally in a full-term baby, and constitutes one of the most baffling problems in clinical pediatrics today. In contrast, the increasing availability of biochemical methods of study are providing a rapidly growing fund of information concerning the normal fetus and newborn. From studies on the chemical embryology of other species and from limited similar work with human material, characteristic patterns of chemical differentiation are emerging. Extension of such observations may be expected to permit the establishment of new metabolic parameters by which to assess the developing fetus and infant.