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Query: UMLS:C0029713 (immaturity)
 4,335 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Intrahepatic cholestasis associated with both gram-negative bacterial infections and total parenteral nutrition (TPN) is observed more frequently in neonates than in older children or adults. Factors involved in the pathogenesis of this syndrome are uncertain. The cholestatic effects of gram-negative bacterial infections appear to result from the inhibitory effects of endotoxin on bile flow. Since the adverse effects of both endotoxin and TPN on bile flow involve primarily the bile acid-independent portion, the immaturity of the neonatal hepatic excretory system which an inadequate bile acid-dependent fraction of bile would explain the increased susceptibility of the neonate to endotoxin- and, perhaps, to TPN-induced cholestasis.
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PMID:Immaturity of the biliary excretory system predisposes neonates to intrahepatic cholestasis. 11 37

Transient hepatic secretory obstruction manifested primarily by chemical evidence of cholestasis with a conjugated bilirubin above 2.0 mg/100 ml occurred in eight of 19 neonates and infants receiving total parenteral nutrition. The incidence of cholestasis was greater in the premature than full-term infant. Prospective determinations of conjugated bilirubin and 5' nucleotidase are essential to detecting cholestasis before jaundice becomes obvious. These tests are more sensitive than serum alkaline phosphatase which normally rises after birth and during periods of accelerated osteoblastic activity. Preliminary data indicate that the 5' nucleotidase is the most sensitive indicator of secretory obstruction and may become elevated in patients with a normal direct bilirubin. The etiology of hepatic cholestasis during total parenteral nutrition is unknown but is presumed to be caused by interference with hepatocellular enzymes controlling bile secretion; immaturity of these enzyme systems increases the risk of secretory obstruction.
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PMID:Hepatic secretory obstruction with total parenteral nutrition in the infant. 80 74

We report a premature infant with severe hypoglycemia (serum glucose: 6 mg/dl) and cholestasis (serum total bile acids: 211.55 mumol/L) caused by hypoplasia of the interlobular bile ducts. This patient had developed intracranial hemorrhage and sepsis while undergoing treatment for hypoglycemia. As a result of endocrine evaluation, we made a diagnosis of idiopathic panhypopituitarism, congenital absence or hypoplasia of the pituitary gland. Moreover, we found abnormal bile acid profiles: The ratio of cholic acid to chenodeoxycholic acid was abnormally low in serum (0.04) and in biliary bile (0.33). However, 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestan-26-oic acid and bile alcohols were not detected. We therefore suspected that the severe cholestasis and abnormal bile acid profiles in the serum and biliary bile in this patient were related to physiologic immaturity of the enterohepatic circulation of bile acids and immaturity of hepatic 12 alpha-hydroxylation.
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PMID:Abnormal low ratio of cholic acid to chenodeoxycholic acid in a cholestatic infant with severe hypoglycemia. 207 33

The study of bile acids in the newborn permits to the AA. to point out that the beginning of the feeding does not influence the "physiologic cholestasis" of the first days of life. Neonatal cholestasis is the expression of the immaturity of bile acids synthesis and hepatic and intestinal carriage, which is not correlated with the maternal conditions. Furthermore, the AA. discuss about the analogy between cholestasis and "physiologic hyperbilirubinemia", from which it differs for the longer time. In fact, the maturation of the enterohepatic circle occurs very slowly under possible dietetic factors influences.
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PMID:[Serum bile acids in the newborn: our experience]. 227 36

Although immaturity of the liver and synthesis of monohydroxy bile acids have been implicated as pathogenic factors in neonatal cholestasis, there is no direct evidence to show that these bile acids induce cholestasis in the newborn. In the present investigation, we compared the effects of lithocholic acid (LCA) injection on bile flow in suckling (2-week-old) and adult (12-week-old) guinea pigs. Bile flow was not modified by LCA in 2-week-old animals, but it was reduced by 50 to 80% in the adults, the decrease being dose-dependent. In the newborn, the injected LCA was mainly secreted in bile (greater than 90%), while in the adults it was distributed between the liver and bile. The percentage of biliary bile acids (as determined by gas-liquid chromatography) in the two groups was similar before and after LCA injection. Morphologic lesions characteristic of LCA-induced cholestasis were observed only in the adult guinea pigs. This study demonstrates that the newborn guinea pig is less susceptible to cholestasis induced by 90 to 180 mumoles per kg body weight of lithocholate and that, in the neonatal liver, there is no defect in the transport of this bile acid from blood to bile.
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PMID:Resistance of the suckling guinea pig to lithocholic acid-induced cholestasis. 672 16

We have shown that serum bile acid concentrations are elevated in human infants reflecting physiologic immaturity of the enterohepatic circulation. To define further the ontogeny of bile acid metabolism in mammals, we examined maturational changes in the serum concentration of total cholate conjugates by radioimmunoassay in fetal, neonatal, suckling, and mature Sprague-Dawley rats. Fetal (21st day) levels were low (1.4 +/- 0.23 microM; X +/- S.E.), possibly due to minimal enterohepatic cycling in utero. The concentrations in samples obtained minutes after birth, prior to suckling were significantly elevated (12.6 +/- 2.37; p less than 0.001 vs. fetal); these high values persisted after feeding was initiated (6 hr = 13.5 +/- 0.99), but fell at 12 hr (5.2 +/- 0.81) and remained unchanged for the duration of the first day. Serum values fluctuated briefly, being 9.6 +/- 0.73 on Day 4, and the rose progressively through the suckling period (Day 10 = 7.2 +/- 9.57; Day 14 = 10.4 +/- 1.70; Day 21 = 16.8 +/- 1.93); there was a dramatic peak after weaning (Day 28 = 21.8 +/- 1.53). The serum concentration of cholate conjugates then fell (5.6 +/- 0.68 on Day 42) to achieve adult levels by 56 days (4.0 +/- 0.55), a value substantially different from that of all developing animals (p less than 0.025). These data corroborate studies which suggest that a period of physiologic cholestasis occurs in the developing rat. Serum cholate conjugate concentrations likely reflect interrelated morphologic alterations (bile canalicular structure and portal blood flow) and physiologic changes (bile acid synthesis, pool size, and transport) occurring in the enterohepatic circulation during early life.
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PMID:Physiologic cholestasis II: serum bile acid levels reflect the development of the enterohepatic circulation in rats. 730 94

The 24h urinary bile acid excretion was prospectively studied during the neonatal period in healthy, fully breastfed, premature and full-term infants. The urinary bile acids were identified by gas-liquid chromatography (GLC)-mass spectrometry and quantified by GLC. The excretion of bile acids in urine increased after birth, reaching maximum levels by the 3-4th day. Taurine conjugates predominated and the excretion of bile acid sulphates was remarkably low. Cholic acid and atypical bile acids were the main bile acids in urine during the first week. Tetrahydroxylated bile acids carrying hydroxyl groups at C-1, C-2 and C-6 were common, and also other 1- and 6-hydroxylated bile acids, including hyocholic and hyodeoxycholic acids. Three tentatively identified 4-hydroxylated bile acids, including one ketonic bile acid, were also found. Ketonic bile acids constituted an average of 16% of total urinary bile acids during the first week. Unsaturated bile acids were scantily found only during the first days. The excretion of atypical bile acids decreased to 1 month of age, parallel with the total bile acid excretion. The data support earlier hypothesis of a physiological cholestasis in the newborn. Atypical hydroxylated and ketonic bile acids, as well as cholic acid, constituted the major part of the urinary bile acids. The persistent atypical pattern of bile acids in urine during the first month of life indicates a longer period of immaturity of bile acid metabolism in healthy infants than previously described.
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PMID:The urinary bile acid excretion in healthy premature and full-term infants during the neonatal period. 817 Dec 65

The relationships between various hepatobiliary disorders and the administration of total parenteral nutrition (TPN) were reviewed and, in particular, the role of TPN in their pathogenesis was critically evaluated. Several clinical and pathological entities including steatosis, steatohepatitis, cholestasis, and cholelithiasis have been commonly linked to TPN, and instances of chronic decompensated liver disease have been reported. However, it is concluded that it is often difficult to extricate the effects of TPN on hepatobiliary function from many other hepatotoxic factors that may be operative in these patients. Thus, whereas considerable evidence exists to support a role fro carbohydrate or calorie excess in TPN solutions in the pathogenesis of steatosis, a loss of enteric stimulation and not TPN per se may be the primary factor in the development of cholestasis, biliary sludge, and gallstones. The apparent predilection of infants to TPN-related cholestasis may be based on the relative immaturity of the neonatal biliary excretory system.
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PMID:Hepatobiliary complications of total parenteral nutrition. 834 99

We studied, retrospectively, 92 children who were first seen with neonatal cholestasis and who were followed up until liver test results normalized. Among the 92 children, 81 displayed factors responsible for chronic and/or acute perinatal distress. Onset of jaundice was recorded at a mean age of 7 days, and mean duration was 3.5 months. Stools, initially discolored in 39 children, were normally colored at a mean age of 1.7 months. Hepatomegaly present in 90 children resolved at a mean age of 13 months. Liver test results were normal at the age of 1 year in 83 children and normalized at a mean age of 10 months. Liver histologic examination, performed in 70 children, showed moderate portal and lobular fibrosis, multinucleated giant hepatocytes, and hematopoietic foci; findings in follow-up liver biopsy specimens from 15 children were normal or improved. Spontaneously resolving forms of neonatal cholestasis may result from the association of several factors, including immaturity of bile secretion and perinatal disease leading to hepatic hypoxia or ischemia.
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PMID:Transient neonatal cholestasis: origin and outcome. 1035 58

Parenteral nutrition associated cholestasis in preterm infants and newborn children is a frequent and serious disease with an incidence of 23% depended on duration of parenteral nutrition and birthweight. The incidence of liver cirrhosis is 40% when parenteral nutrition is given 74-242 days. The pathogenesis remains unclear. Several predisposing factors are discussed like immaturity, lack of hormonal stimulation by oral feeding, bacterial infection, liver toxicity of aminoacids and their products of photooxidation, lack of taurine, lack of antioxidation substances, hypermanganesaemia and pollution of infusion solutions. Furthermore sepsis during parenteral nutrition seems to multiply the risk of cholestasis. For prevention controlled studies recommend: 1. Early enteral nutrition. 2. The reduction of parenteral amino acids to less than 3 g/kg/d. 3. Light protection for parenteral solutions. 4. Cyclic infusion of parenteral nutrition. 5. The application of antibiotics (metronidazole, gentamicin) during parenteral nutrition. The most important therapeutic intervention is the beginning of oral feeding. Most of the time this leads to a decrease of icterus within two weeks. An icterus persisting longer than 3 weeks should be treated because of the risk of liver cirrhosis. Further therapeutic interventions are: 1. Cholecystokinin, good results in case studies which still has to be verified by a controlled study. 2. Ursodeoxycholic acid, its choleretic effectiveness is verified in several liver diseases by controlled studies, but it is not proven in parenteral nutrition associated cholestasis. 3. Laparoscopic biliary irrigation, successful in several case studies.
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PMID:[Parenteral nutrition associated cholestasis in the newborn]. 987 92


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