"Physiologic" hyperbilirubinemia in the neonatal period

Amelioration of Hyperbilirubinemia in Gunn Rats after Transplantation of Human Induced Pluripotent Stem Cell-Derived Hepatocytes

Hepatocyte transplantation has the potential to cure inherited liver diseases, but its application is impeded by a scarcity of donor livers. Therefore, we explored whether transplantation of hepatocyte-like cells (iHeps) differentiated from human induced pluripotent stem cells (iPSCs) could ameliorate inherited liver diseases. iPSCs reprogrammed from human skin fibroblasts were differentiated to iHeps, which were transplanted into livers of uridinediphosphoglucuronate glucuronosyltransferase-1 (UGT1A1)-deficient Gunn rats, a model of Crigler-Najjar syndrome 1 (CN1), where elevated unconjugated bilirubin causes brain injury and death. To promote iHep proliferation, 30% of the recipient liver was X-irradiated before transplantation, and hepatocyte growth factor was expressed. After transplantation, UGT1A1⁺ iHep clusters constituted 2.5%–7.5% of the preconditioned liver lobe. A decline of serum bilirubin by 30%–60% and biliary excretion of bilirubin glucuronides indicated that transplanted iHeps expressed UGT1A1 activity, a postnatal function of hepatocytes. Therefore, iHeps warrant further exploration as a renewable source of hepatocytes for treating inherited liver diseases.

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Human skin fibroblast-derived iPSCs were differentiated to hepatocyte-like iHeps

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iHeps were transplanted into Gunn rats, a model of Crigler-Najjar syndrome 1

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Engraftment of the iHeps in Gunn rat livers reduced serum bilirubin levels

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iHeps may be potentially useful in treating liver-based metabolic disorders

Personalised medicine in paediatrics: individualising treatment in children with rare neurological diseases

The development of personalised medicine is of considerable importance for paediatric patient populations, and represents a move away from the use of treatment dosages based on experience with the same compounds in adults. Currently, however, we know little about developmental pharmacogenomics and, although many biomarkers are available for clinical research use, there have been few applications in the management of paediatric diseases. This paper reviews where we are in the journey towards achieving paediatric personalised medicine and describes a group of diseases requiring such an approach. The personalised medicine approach is particularly relevant for the treatment of rare childhood diseases, and the group of life-threatening neurological disorders known as lysosomal storage diseases represents a potential study population. The genetic bases of these disorders are generally well defined, there is the potential for diagnosis at birth or prenatally, and there are a range of therapeutic options available or under development.

Pediatric pharmacogenetic and pharmacogenomic studies: the current state and future perspectives

Genetic differences among individuals can explain some of the variability observed during drug treatment. Many studies have correlated the different pharmacological response to genetic variability, but most of them have been conducted on adult populations. Much less attention has been given to the pediatric population. Pediatric patients constitute a vulnerable group with regard to rational drug prescribing since they present differences arising from the various stages of development. However, only a few steps have been made in developmental pharmacogenomics. This review attempts to describe the current methods for pharmacogenetic and pharmacogenomic studies, providing some of the most studied examples in pediatric patients. It also gives an overview on the implication and importance of microRNA polymorphisms, transcriptomics, metabonomics, and proteomics in pharmacogenetics and pharmacogenomics studies.

Lack of relationship of red cell enzyme activity to bilirubin and carboxyhemoglobin levels in healthy term infants

A total of 32 term infants were studied in an attempt to confirm and extend the recent observation of Petrich & associates (14) that minor degrees of transient deficiences of the red cell enzymes glucose phosphate isomerase and glyceraldehyde-3-phosphate dehydrogenase were related to hyperbilirubinemia in otherwise healthy term infants. No relationships could be observed between the activity of these enzymes and the bilirubin level on day three. In addition, no correlation was present between bilirubin values and carboxyhemoglobin levels on day three, suggesting that in the healthy term infant excessive hemolysis is not usually responsible for the variations observed in bilirubin levels.

Effect on neonatal jaundice of oestrogens and progestogens taken before and after conception

Study of 182 newborn babies has shown that among bottle-fed infants the mean plasma bilirubin concentration was slightly but significantly higher (P <0.01) in those whose mothers had previously used steroid contraceptives. A similar finding was not noted among breast-fed infants.A further 16 infants whose mothers had received progestogen therapy during their pregnancy had a mean plasma bilirubin concentration which was significantly higher than each of the four other groups of infants studied (P <0.01). Icterus occasionally reached clinically important levels in these babies.

Endogenous production of carbon monoxide in normal and erythroblastotic newborn infants

The endogenous production of carbon monoxide ( V(CO)) in newborn infants was measured by serial determinations of blood carboxyhemoglobin during rebreathing in a closed system. Mean V(CO) in nine full-term infants was 13.7 +/-3.6 mul CO/kg per hr (SD), and in four erythroblastotic infants V(CO) ranged from 37 to 154 mul CO/kg per hr preceding exchange transfusion. Mean red cell life-span (MLS) and total bilirubin production were calculated from V(CO). MLS in normal newborns was 88 +/-15 days (SD), and bilirubin production was 8.5 +/-2.3 mg/kg per 24 hr. This is more than twice the amount of bilirubin normally produced in the adult per kilogram of body weight. Normal infants achieved a net excretion of bilirubin of at least 5.6 +/-2.3 mg/kg per 24 hr (SD) as calculated from the bilirubin production and the measured rise in serum bilirubin concentration.The measurement of V(CO) should prove valuable in the study of red blood cell survival and bilirubin metabolism in the newborn infant.