This study was designed to investigate developmental changes in contractile protein adenosine 5'-triphosphatase in the rabbit heart. Myofibrils and myosin were isolated from ventricular muscles from the fetal, newborn, and adult rabbits. Actin and troponin-tropomyosin complex were isolated from the adult skeletal muscle. Myofibrillar (actomyosin) adenosine 5'-triphosphatase measured at low ioni...

Adaptation to extrauterine life involves the newborn infant in a series of biological adjustments to a totally new set of environmental conditions. Prime among these is the accommodation to a thermal environment that, in all but the most tropical countries, represents a distinctly "cold" challenge. The failure to accommodate to this cold stress has historically been recognized as perhaps the ea...

Advances in neonatal intensive care have significantly improved the survival rate of premature infants in the past two decades. Modern medical technology has continued to push back the limits of mortality, resulting in more aggressive interventions so that infants as young as 23 weeks gestation with weights as low as 500 grams may now survive (Szatmari, Saigal, Rosenbaum & Campbell, 1994). Data...

Cerebrotendinous xanthomatosis (CTX) is a rare, difficult-to-diagnose genetic disorder of bile acid (BA) synthesis that can cause progressive neurological damage and premature death. Detection of CTX in the newborn period would be beneficial because an effective oral therapy for CTX is available to prevent disease progression. There is no suitable test to screen newborn dried bloodspots (DBS) f...

To determine to what extent intravenous nutrition can reduce proteolysis in very immature and normal newborns, and to assess the capacity of preterm and normal newborns to convert phenylalanine to tyrosine, phenylalanine and leucine kinetics were measured under basal conditions and during parenteral nutrition in clinically stable, extremely premature (approximately 26 wk of gestation) infants a...

The requirements of growth and organ development create a challenge in nutritional management of newborn infants, especially premature newborn and intestinal-failure infants. Since their feeding may increase the risk of necrotizing enterocolitis, some high-risk infants receive a small volume of feeding or parenteral nutrition (PN) without enteral feeding. This review summarizes the current rese...