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

The development of bile acid synthesis, secretion and absorption was studied in laboratory animals and humans. Although there is species variation, a developmental pattern emerges. Bile acid pool size and synthesis rates increase during the final third of gestation and the perinatal period. Similarly, bile acid secretion is a developing function during the final third of gestation and is incompletely developed at birth. The ileal mechanism for active bile acid transport is absent at birth and only develops during the first 2--5 weeks or more of life. It is therefore possible that the intestinal conservation of bile acid is ineffective in the newborn. The combination of immaturity of bile acid synthesis, secretion and absorption probably contributes to the fat malabsorption especially evident in low birth weight infants. Finally, synthesis, secretion and absorption can be induced to develop early by the administration of adrenocortical steroid. The induction of mechanisms for bile acid metabolism raises the possibility of therapeutic intervention in severe cases of neonatal malabsorption of lipid.
 ...
PMID:Bile acid metabolism in the fetus and newborn. 12 Feb 41

The early and late effects of a single high-dose irradiation (100 rad) in the pig small intestine have been studied by histoenzymology and electron microscopy and related to some functional data. 1) The initial atrophy induced by the irradiation appears late (on the 6th day), compared to other species. This is due to the fairly long regeneration time of the villi epithelium in the pig. 2) The initial lesions are similar to those observed in different experimental models (nuclear alterations, karyolytic bodies, etc.). They particularly involve the crypts, and are specially focused in the undifferentiated cells of GS phase or mitosis, but also in goblet and Paneth's cells. 3) The villi regeneration, over on the 23rd day, is preceeded by an active mitotic phase which first renews the undifferentiated cells. This mitotic activity, reaching its highest value on the 16th day, goes on during the whole regeneration period itself. 4) At the beginning, this regeneration is denoted by the high esterase activity of the crypt collar. It appears in many goblet cells and also in some absorptive cells which show, at once, some of the enzymatic activities of the striated border. However, for a short period, lipid absorption is quantitatively reduced. This is connected with the temporary cell immaturity (up to the 20th day) and to the poorly developed rough endoplasmic reticulum and Golgi apparatus. 5) Further on, the persistence of a malabsorption syndrome (lipids, calcium) is not connected, for the main point, with modifications of the morphology or the cytology of the villi (in spite of the abnormally high number of goblet cells and the presence of few pathologic absorptive cells). It is, in fact, related to the persistence of an inflammatory state of the lamina propria associated with an exudative enteropathy. The meaning of this last finding is not clear: it could depend on a primary infectious state due to the modifications of the endoluminal intestinal flora, or, rather, on a secondary infection supported by the trophic epithelial disturbances induced by a continuous vascular dyshoria due to the irradiation.
 ...
PMID:High-dose irradiation in the pig small intestine. Histoenzymology and electron microscopic study. 40 73

As part of a randomised controlled study to assess the effect of pasteurization of breast milk on the growth of very-low-birth-weight infants, the longitudinal changes in serum calcium, phosphorus, alkaline phosphatase, 25-hydroxyvitamin D, and bone-gla-protein concentrations were investigated. Infants fed untreated own mother's milk grew more rapidly than those fed pasteurized pooled preterm milk and had higher serum alkaline phosphatase and lower phosphorus values. Serum calcium and 25-hydroxyvitamin D (25-OHD) concentrations were similar in the two groups. Despite the provision of 750 IU vitamin D daily from the 2nd week of life, serum 25-OHD values remained low in a number of infants in both groups, suggesting that either malabsorption of vitamin D or hepatic immaturity might be responsible for the persistently low values. Bone-gla-protein rose significantly after birth and was correlated with alkaline phosphatase values, but not with 25-OHD or phosphorus values. The study supports previous work that indicates that the low phosphorus content of breast milk is probably responsible for biochemical evidence of inadequate bone mineralization and that despite vitamin D supplementation, 25-OHD values do not rise adequately. Thirty-six infants were reexamined between 4 and 11 months after birth. The 25-OHD values had risen significantly in all infants except one who had vitamin D deficiency rickets.
 ...
PMID:Mineral homeostasis in very low birth weight infants fed either own mother's milk or pooled pasteurized preterm milk. 351 33

A vegetable oil fat blend resulting in formula major fatty acid levels similar to human milk is appropriate for infant feedings even though the palmitic acid may have a somewhat different positional distribution. Growth, bone mineral content, and visual acuity (as measured by the Teller acuity card procedure) achieved in normal infants consuming such formulas are at least as good as those from human milk. The quantitatively minor LC-PUFA levels may also be important in infant development and useful once safety of their sources has been adequately demonstrated. Such formula fat blends mimicking the major fatty acid profiles of human milk are appropriate for infants with relatively normal fat absorptive mechanisms including infants with allergy or inborn errors of metabolism. Formulas designed for such infants (e.g., extensively hydrolyzed protein products for allergic infants) do not need to have MCT oil included in the formulation which alters the fatty acid profile. On the other hand, those infants with immaturity, gastrointestinal disease, and/or fat malabsorption often do benefit by the inclusion of MCT oil in the fat blend of the formula.
 ...
PMID:Challenges of matching human milk fatty acid patterns technically and functionally. 908 18