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)

Activities and isozyme patterns of acid phosphatase and esterase were studied in rat liver at different intervals after partial hepatectomy to clarify the grade of immaturity of normal regenerating liver cells as a control for the unlimited proliferation of hepatoma cells. Acid phosphatase and esterase activities in the liver were elevated during a 12-hr period after hepatectomy, while their isozyme patterns did not change from those of immature liver. Similar findings were also observed in the liver of sham-operated rats. Eighteen hours after the operation, at the S phase before cell division, the isozyme pattern of these enzymes began to shift from an adult liver-type to an immature one resembling those of the infant liver 3 weeks after birth rather than those of newborn or fetal liver. Two or three days after partial hepatectomy, the isozymes characteristic of an immature liver type were more apparent. Although enzyme activities mostly returned to the normal adult level one week after the operation, the isozyme patterns did not completely return to those of an adult liver. These results indicate that despite the rapid proliferation of liver cells, the grade of cell differentiation of the regenerating liver after partial hepatectomy is much nearer to that of the normal adult liver rather than that of the fetal liver.
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PMID:Isozymic changes of acid phosphatase and esterase in regenerating rat liver after partial hepatectomy in relation to cell differentiation. 59 Jun 83

The ultrastructure of feline yolk sacs from 11 stages between the 14th and the 66th day is described with reference to the endoderm and the mesothelium; supplementary histochemical and cytochemical studies are included. Despite the absence of yolk, the endodermal epithelium shows a high degree of differentiation and activity, especially in the period between the 25th and the 38th day. Large stacks of RER, abundant SER, mitochondria enveloped by RER cisternae, and a peculiar type of lysosome are the most prominent organelles. Acid phosphatase, succinic dehydrogenase and NAD- and NADP-diaphorases are found with high activity, whereas the 17beta-hydroxysteroid dehydrogenase assay stains the endothelium only moderately. Indications of reabsorption are less marked. In view of the apparent immaturity of the liver parenchymal cells at this stage, the yolk sac endoderm of cat is suggested to act as an important extraembryonic site of biosynthesis. As preliminary results of a chemical analysis show that the yolk sac fluid has nearly no nutritional value, the substances synthesized are believed to be transported directly to the fetus. The mesothelium shows relatively few alterations over the period studied, is less rich in organelles and is obviously far less active than the endoderm.
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PMID:On the yolk sac of the cat. Endoderm and mesothelium. 103 35