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)

The survival and prognosis of the prematurely born human infant are dependent on a successful transition from the intrauterine to the extrauterine environment. This is largely a consequence of the maturation of sufficient gastrointestinal function to provide adequate nutrition. However, the gastrointestinal tract of the premature infant, and to some extent, of the full-term infant, may be unprepared to provide the requisite absorptive function. Data presented in this symposium emphasize the dissociations in the development of human gastrointestinal function. Morphological maturation is completed early in gestation while glucose absorption increases with gestational age. Sucrase and maltase activities appear early; lactase activity begins to increase at 30 weeks and increases steadily to term. The latter pattern is accompanied by increased production of cortisol and thyroid in the fetus. The intraluminal phase of fat digestion is immature even in the full-term neonate. Both pancreatic secretory function and bile salt metabolism mature postnatally. Despite this relative immaturity, breast milk fat is absorbed with great efficiency by the term infant, and breast milk provides other important influences on intestinal development: mitogenic factor, immunological support, control of intestinal flora. The goals of nutrition support of the premature infant have been to maintain intrauterine growth standards; yet premature infants receiving pooled breast milk from mothers at 40 weeks or more may be given too little protein for their needs. Human milk from mothers of premature infants may be a more appropriate nutrient source. Supplements with higher contents of amino acids may lead to amino acid imbalance or hyperammonaemia. Additional stresses and requirements are imposed by illness or congenital anomalies. While we must apply current research findings to clinical care, we must also extend our knowledge of extrauterine human development. The ultimate measure of success in this field will be the physical and neurological capacities of infants followed prospectively.
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PMID:The immature intestine: implications for nutrition of the neonate. 9 85

Diffuse persistent glomerular immaturity and focal proximal tubular ectasia were seen in bilateral open renal biopsy specimens for an infant with fluid and salt depletion and slowly progressive renal failure. Subsequently, diffuse tubulopapillary renal adenoma subtotally replaced each kidney, thereby, necessitating renal transplantation. Origin of diffuse metanephric adenoma from persistent primitive epithelium of the proximal nephron is postulated and partly substantiated. We propose that this case of persistent proximal nephronic epithelial immaturity and diffuse metanephric adenoma is a variant of nephroblastomatosis and that in this case, a first trimester suicide attempt with aspirin may have initiated the maturation defect that preceded neoplastic transformation.
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PMID:Diffuse metanephric adenoma after in utero aspirin intoxication. A unique case of progressive renal failure. 21 20

Almost all infections of newborn have to be treated with antibiotics before the result of microbiological examination is available since there are either difficulties in identifying the causative organisms(s) or antibiotic treatment must be instituted without delay in view of the patient's life threatening condition. The present paper reports on the therapeutic results obtained in association with the multicentre study of 51 children affected by bacterial infections. 17 (33.0%) patients were newborn up to one week of age. 12 patients were classified as premature babies, some presenting a high degree of immaturity. Treatment with Optocillin (Bay 1-1330), a combination of 6-((R)-2-[3-Methylsulfonyl-2-oxo-imidazolidine-1-carboxamido]-2-phenyl-acetamido)-penicillanic acid sodium salt (mezlocillin, Baypen) and 5-methyl-3-phenyl-4-isoxazolyl-penicillin (oxacillin, Stapenor), proved effective in 90% of the children, although 22 patients had been treated with other antibiotics prior to the use of this compound. An average daily dose of about 225 mg/kg bodyweight was found to be effective and perfectly tolerated even on long-term treatment, as became evident from two cases of extremely premature babies effected by neonatal septicaemia (duration of treatment 38 and 34 days, respectively). The combination showed a perfect local tolerance, exanthema appearing only in one infant.
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PMID:[Therapy with an antibiotic combination mezlocillin/oxacillin and clinical experience/Second communication: Children (author's transl)]. 54 17

Rational pharmacotherapy is dependent upon an understanding of the clinical pharmacokinetic and pharmacodynamic properties of the drugs employed. Although the available data on drug biodisposition and action in the neonate have increased considerably in the last few years, pharmacokinetic-pharmacodynamic interactions for many drugs remain poorly understood. The ontogeny of drug absorption, distribution, metabolism, and elimination are addressed in this review. Drug absorption from any site depends upon both the physicochemical properties of the drug and a variety of patient factors. Absorption of orally administered drugs may be affected by changes in gastric acidity and emptying time as well as by bile salt pool size, bacterial colonisation, and extraintestinal disease states such as congestive heart failure. Factors affecting drug absorption following intramuscular, percutaneous, and rectal administration are also discussed. Drug distribution in the neonate is influenced by a variety of important and predictable age-dependent factors. The developmental aspects of protein binding and body water compartments are described. Additionally, hepatic drug metabolism assumes an important role in understanding the pharmacokinetic and pharmacodynamic properties of many compounds. Certain biotransformation pathways, including hydroxylation by the P450 mono-oxygenase system and glucuronidation, demonstrate only limited activity at birth, while other pathways, such as sulphate or glycine conjugation, appear very efficient at birth. Elimination of drugs excreted unchanged in the urine is dramatically reduced in the newborn, compared with older infants and children, due to immaturity of both glomerular filtration and tubular secretory processes. The glomerular filtration rate remains markedly reduced prior to 34 weeks gestational age, increasing as a function of post-conceptual age until adult values are achieved by approximately 2.5 to 5 months of age. Tubular secretory capacity is also limited at birth, approaching adult values by approximately 7 months of age. Published reports describing the pharmacokinetics and pharmacodynamics of commonly used drugs in the neonatal period, as well as differences in drug biodisposition among premature infants, full term neonates, and older infants and children, are reviewed. Our recommendations for neonatal drug therapy are based upon a critical interpretation of these data, an understanding of fetal development and maturational processes, and an understanding of how disease states may affect drug biodisposition in the neonate.
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PMID:Principles of drug biodisposition in the neonate. A critical evaluation of the pharmacokinetic-pharmacodynamic interface (Part I). 329

The clinical response and changes in water and salt homeostasis during ORT was studied in 15 infants less than 2 months old (range 2-50 days) with acute diarrhoea. Eight patients were neonates and 7 were 1-2 months old. The oral rehydration solution contained 60 mmol sodium per litre. All patients except one were successfully rehydrated. The fluid retention was significantly higher in neonates and young infants than in infants above 3 months of age treated in the same way. One patient in the group of neonates who had a normal sodium level on admission developed hypernatremia with a sodium level of 162 mmol/l 36 hours after the start of ORT. The urinary sodium excretion was lower in the neonates than in the young infants. The results show that neonates and young infants have a lower capacity than older infants to excrete water and salt and therefore run a great risk of developing fluid and salt retention during ORT. The risk is most pronounced in neonates who, due to immaturity of the renal function, are unable to excrete excess fluid and salt.
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PMID:Oral rehydration therapy in neonates and young infants with infectious diarrhoea. 330 Jan 47

In a 7-year prospective follow-up of 104 children with enuresis in 32 cases (19 boys and 13 girls) coexistence of common migraine was found. Twenty-two children had various other seizure-like disorders, particularly tics, febrile convulsions, pavor nocturnus and fainting, and three had absence attacks. In 20 cases vasomotor disturbances and in 17 abnormal Schellong's test were found. The IQ was normal or high in all cases. Emotional disorders were observed in nearly half the cases. The water-salt test of Decourt was done in 9 cases and it was abnormal in 8 cases. At least two abnormal EEG records were obtained in 26 cases, and in 24 of them seizure activity was demonstrated in the EEG. In the period of follow-up disappearance or very marked improvement of enuresis occurred in all cases and migrainous attacks became less frequent and intense in 27 cases, while in 5 the severity of migraine increased. The author discusses the pathological mechanism of these disturbances calling attention to less good efficiency of the regulatory functions of the centrencephalic activating system and hypothalamus connected with biochemical and bioelectric immaturity.
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PMID:[Coexistence of idiopathic spontaneous nocturnal enuresis and migraine in children]. 344 4

In order to interrupt the late stages of pregnancy transcervical amniocentesis was applied. The amniotic fluid was replaced by solutions of sodium chloride or glucose. This operation took 10-15 minutes and was performed on 250 women aged from 13 to 40 years. Reasons for interruption of pregnancy were cardiovascular diseases (55 cases), liver problems (36 cases), immaturity of women (8 cases) and others. Before the replacement of the amniotic fluid folliculin injections were given. A comparison was made between 2 groups of women. In the first (28 women) the amniotic fluid was replaced by 400-500 ml of hypertensive solution of glucose (40%) and in the second (222 women) it was replaced by the same quantity of a sodium chloride solution (10% concentration). The expulsion of the fetus began after 34 hours in the 1st group and after 32 hours in the second. It took 6-8 and 4-6 hours respectively to complete the abortion. The loss of blood was 100-400 ml for the first and 100-500 ml for the 2nd group. When glucose was used an elevation by 20-30% of blood sugar occurred but this index returned to normal after 24 hours. Using the salt solution did not change the chloride concentration in the blood. On the basis of this study it was concluded that transcervical amniocentesis and the replacement of amniotic liquid by solutions of sodium chloride or glucose is an effective, accessible, and safe method for the interruption of the late stages of pregnancy.
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PMID:[Interruption of the late stages of pregnancy by means of transcervical amniocentesis and the replacement of the amniotic fluid]. 447 51

Initiation is the contact-independent phase of sexual conjugation which occurs when mature cells of Tetrahymena thermophila are shifted from growth medium to a low-salt starvation buffer. Immaturity, like high-salt starvation, restricts the ability of cells to conjugate; immature cells do not conjugate in either low- or high-salt buffers. Comparisons between sexually mature cells starved in initiation-restrictive and initiation-permissive buffers, and between immature and mature cells starved in an initiation-permissive buffer permitted the analysis of membrane protein expression correlated with mating competence. No polypeptides identified by lactoperoxidase-catalyzed iodination were found to be specific to mating-competent cells; however, several polypeptides not present in initiated cells were found to be common to the cell surfaces of immature and non-initiated cells which suggests that (1) initiation involves the removal of specific proteins from the cell surface, and (2) immaturity may be due to an inability to initiate.
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PMID:Membrane protein differences correlated with the development of mating competence in Tetrahymena thermophila. 673 14

Studies on the incomplete fat absorption in newborns, particularly preterm ones, are reviewed. In the first week term breastfed newborns have a fat absorption coefficient of 91%. Lyophilization or pasteurigation reduces this figure in term as well as in preterm newborns. Excess Ca++ lowers fat absorption. So far, there is no evidence of immaturity of intracellular fat transport through the enterocyte. In the newborn low pancreatic lipase activity and low intraluminal bile salt concentrations appear to limit fat absorption. The most effective method to improve fat absorption in preterm babies seems to substitute part of the milk fat by medium-chain triglycerides.
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PMID:Fat absorption in low birthweight infants. 696 52

Water metabolism is a major problem in infants of very low birth weight. Their surface is proportionally larger, they have a relatively low intracellular water volume and a high extracellular and total body volume. Kidney function is immature compared to bigger infants, and the neuroendocrine function is also immature. Finally the large surface and the high skin permeability causes a very high insensible water loss in the early neonatal period. Water imbalance presents itself as either dehydration or overhydration. Dehydration gives poor peripheral--and renal circulation and thereby decreased renal function with acidosis. Furthermore hyperosmolar dehydration will give increased hematocrit and blood viscosity and hyperbilirubinaemia. Excessive administration of water will give oedema and congestive heart failure and possibly an increased risk for patent ductus arteriosus, bronchopulmonal dysplasia and necrotising enterocolitis. The evaporative water losses varies according to the thermal environment and air humidity and it is therefore impossible to give narrow limits for the daily water intake. Clinical examination, frequent controls of body weight (twice daily) and measurements of urine volume and osmolarity serve as guide lines. Yet inappropriate secretion of ADH may confuse the value of measuring urine osmolarity. Finally a neonatal weight loss of 5-10% may be beneficial as a decrease in extracellular water may lessen the working load of the heart and therefore possibly lessen the risk for a patent ductus. Renal immaturity in handling sodium reabsorption on the other hand, will often give an excessive dehydration. For this reason about 2 mmol Na/kg body weight should be given daily to very low birth weight infants from the fourth day of life to the 3rd-4th week if the baby is on human milk or a low salt formula.
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PMID:Water--the major nutrient. 2475 24


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