Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0029713 (immaturity)
 4,335 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Abnormal lipoprotein (LP-X) represents a specific parameter for the presence of obstructive jaundice in the adult. Since LP-X has also been detected in the serum of newborn infants, both full-term and premature, and in early infancy, in the absence of clinical evidence of obstructive jaundice, extensive investigations were undertaken in infants during the neonatal period to clarify this phenomenon. The present study reports the data obtained in over 2000 sera from over 370 infants (mature newborn and premature newborn and young infants), tested more or less continuously by means of the Rapidophor method, initially on a qualitative, and subsequently, on a semi-quantitative basis. LP-X appears within the first fortnight in newborn infants, irrespective of the mode of feeding. The LP-X concentration was correlated to the birth weight. Premature infants displaying signs of immaturity possessed markedly higher LP-X levels than mature newborn infants. LP-X was not correlated to the alkaline phosphatase level, nor to the gammaglutamyl transferase activity; the bilirubin level, likewise, had no connection with the LP-X concentration. Patients with proven obstructive jaundice showed distinctly higher LP-X concentrations (greater than 56 mg/100 ml), whereby the rise in LP-X level in some cases preceded the appearance of the clinical manifestations of obstructive jaundice. The following hypotheses are advanced in order to explain the presence of LP-X during the neonatal period and are discussed on the basis of clinical observations in adults, the physiological conditions in the newborn infant and the results of the present study: The liver, which occupies the central position amongst metabolic organs, also in the case of the lipoproteins, is at a physiological stage of organic and functional maturation during this early period of life. Under these circumstances, a pseudo-obstructive mechanism on the basis of insufficient excretion of biliary lipoproteins, in conjunction with a simultaneous "physiological" deficiency of lecithin: cholesterol acyl transferase could lead to the appearance of LP-X in the serum. Catabolism of the resultant LP-X cannot take place owing to an inadequate activity of lipoprotein lipase. Functional immaturity can be presumed in the case of both enzyme systems during the neonatal period. On attainment of a degree of maturity compatible with the appropriate neonatal stage, the LP-X values become negative between the 7th and the 16th week of life. It is conceivable that the appearance of LP-X in the newborn infant can be ascribed to LP-X1, since the "physiological" LP-X concentrations in the neonatal period (values of up to 20 mg/100 ml) are distinctly lower than the values found in obstructive jaundice. LP-X determination can be rated as a useful supplementary investigation in the differential diagnosis of extrahepatic biliary atresia during the first weeks or months of life...
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PMID:[Abnormal lipoprotein (LP-X) in the first months of life with particular reference to obstructive jaundice (author's transl)]. 26 15

Measurement of energy balance represents a basic theoretical concept in the determination of nutritional and fluid requirements in humans in health and disease. Infants have special nutrient requirements, more limited reserves and relative immaturity of organ function. Energy requirements of infants have been based either retrospectively on intakes required to achieve normal growth or on equations derived from energy expenditure studies performed early this century. Recently, improved techniques for studying resting energy expenditure (REE), total energy expenditure (TEE) and metabolically active body compartments in infants have facilitated more accurate estimates of energy requirements. Such studies indicated that current reference values for energy requirements are overestimates, and that compared with measured values, predicted values vary markedly between the various predictive equations with wide co-efficients of variation. In disease states with altered body composition, such as cystic fibrosis and end-stage liver disease, predictive equations markedly underestimate both energy and fluid requirements. In cystic fibrosis, both TEE and REE are 25% higher than values in healthy infants. In extrahepatic biliary atresia, energy expenditure per unit body cell mass is markedly elevated, suggesting that this is a catabolic condition in infants. Current estimates of energy and fluid requirements in both health and disease in infants need reappraisal. Bedside and free living energy expenditure methodology should be used to define accurately components of energy requirement in individual infants.
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PMID:Energy expenditure in infants in health and disease. 911 8

We investigated changes in the pattern of hepatic innervation in liver specimens from 15 infants with biliary atresia and 4 age-matched controls by immunohistochemical methods. In the control, nerve fibers identified by immunoreactivity for neural cell adhesion molecule (NCAM) and S100 protein were present around the branches of hepatic arteries, portal veins and bile ducts in the portal areas and the hepatic lobules. In biliary atresia, NCAM and S100 positive nerve fibers were increased in the vicinity of the hepatic arteries and the portal veins in the enlarged portal areas, while no nerve fibers were observed around bile ducts and periportal ductules which became NCAM positive. No innervation in the lobules was seen in any cases regardless of the histological alteration. These findings may suggest that the abnormal innervation in the liver with biliary atresia does not occur as a result of structural changes in liver architecture caused by portal fibrosis and inflammation, but is associated with immaturity or malformation of hepatic innervation in the patients.
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PMID:Abnormal distribution of nerve fibers in the liver of biliary atresia. 914 40

The etiology of biliary atresia (BA) remains unknown, but ductal-plate malformation and insufficient ductal-plate remodeling have been suggested to play important roles, so it is beneficial to examine the maturation and differentiation of bile ducts in BA. Different epithelial types are characterized by the expression of specific cytokeratin (CK) subtypes. CK can therefore serve as a 'lineage marker' of epithelial cells. CK subtypes have not been previously examined in BA. In this study, we examined the maturation of bile-duct cells in BA (n = 45) using immunohistochemistry of CK subtypes, with mouse monoclonal antibodies to CAM5.2, and CK subtypes 7, 8, 13, 14, 17, 19 and 20. We then compared these findings with pediatric non-BA (n = 11) and fetal (n = 21) liver. We semiquantitatively evaluated the findings using a H score method. In the fetal liver, immunoreactivity for CAM5.2, CK-7, CK-8 and CK-19 was detected in bile-duct cells, and CAM5.2 and CK-8 immunoreactivity was also detected in hepatocytes. The distribution of these CK subtypes was the same in fetal, pediatric non-BA and BA liver. However, CK-7 immunoreactivity was markedly weaker in bile ducts of fetal (H scores: ductal plate 0 +/- 0; remodeling 9.5 +/- 40.3; remodeled 37.3 +/- 60.8) and BA (H score: 200.9 +/- 55.3) liver compared to non-BA liver (H score: 251.1 +/- 33.5). In addition, CK-20 was detected in the bile ducts of the fetal and BA liver, but not in non-BA liver. These findings suggest that the expression patterns of CK subtypes in bile-duct cells in BA are similar to that in developing bile-duct cells, which is indicative of bile-duct cell immaturity.
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PMID:Cytokeratin subtypes in biliary atresia: immunohistochemical study. 1147 63

Biliary atresia, a progressive sclerosis of the extrahepatic biliary tree that occurs only within the first 3 months of life, is one of the most common causes of neonatal cholestasis and accounts for over half of children who undergo liver transplantation. In biliary atresia, a number of prenatal or perinatal insults to the biliary tree appear to culminate in complete obliteration of the lumen of the extrahepatic biliary tree and continued injury and sclerosis of intrahepatic bile ducts, even after portoenterostomy is successful. A minority of cases of biliary atresia may be caused by defects in morphogenesis of the bile ducts. Potential etiologies for the more common perinatal form of biliary atresia include viral infections, immune-mediated bile duct injury, and autoimmune disease involving the bile ducts. Two viruses, reovirus and rotavirus, have received increasing attention as possible inciters of an immune-mediated injury to the biliary tree. Fas ligand upregulation and apoptosis of bile duct epithelia have been demonstrated in human specimens, as well as T-lymphocyte and macrophage activation in portal tracts. An experimental model using rotavirus infection in newborn mice has been useful in characterizing the mechanisms underlying bile duct injury. It is proposed that virally induced neoantigens displayed on biliary epithelium may play a role in initiating the immune processes involved in destruction of the extrahepatic bile duct and ongoing intrahepatic ductal injury in the perinatal form of biliary atresia. The short window of time after birth during which this disease presents suggests that immaturity of the neonatal immune system and genetic susceptibility also may be key factors. Delineation of the mechanisms underlying bile duct injury will be essential to the development of new potential therapies for this important pediatric disorder.
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PMID:Etiopathogenesis of biliary atresia. 1174 39

Due to immaturity of mechanisms involved in bile formation, the newborn is more susceptible to develop cholestasis. The causes of neonatal cholestasis are: infection, genetic and metabolic diseases, biliary atresia, and unknown or idiopathic etiologies. Most patients in whom no etiology is found are considered to belong to the group of transient neonatal cholestasis by some authors. Transient neonatal cholestasis is characterized by: early-onset cholestasis, absence of a known cause of neonatal cholestasis, normalization of clinical and biochemical parameters during follow-up, and a history of some neonatal injurious event (asphyxia, sepsis, total parenteral nutrition, etc.).
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PMID:[Transient neonatal cholestasis]. 2146 76