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)

With respect to the enzymes of NADPH-forming metabolic pathways in human leukocytes: (a) Glucose-6-phosphate dehydrogenase and phosphogluconate dehydrogenase (decarboxylating) were less active in leukocytes (mostly myeloblasts) from eight patients with acute myeloblastic leukemia (I) than in leukocytes (mostly granulocytes) from 16 normal subjects (II). (b) Of the enzymes of the citrate cleavage pathway, ATP citrate lyase and malate dehydrogenase (decarboxylating) (NADP+) were virtually absent in the cells studied. (c) Isocitrate dehydrogenase (NADP+), aspartate aminotransferase, and alanine aminotransferase, which, together with the much more active malate dehydrogenase, constitute a newly proposed NADPH-forming metabolic cycle, showed a higher activity in I than in II or III, and therefore could compensate, as concerns NADPH-generation, for the low activity of pentose cycle dehydrogenases. We are not sure whether the enzymatic characteristic of I cells is attributable to their immaturity or to their leukemic nature.
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PMID:Enzyme activities of NADPH-forming metabolic pathways in normal and leukemic leukocytes. 23 46

Ribose, a critical building block for nucleotides, plays an important role in energy metabolism, transcription, translation, and second messenger systems. This 5-carbon sugar, synthesized from glucose via the pentose phosphate pathway, has a rate-limiting step at glucose-6-phosphate dehydrogenase. Therefore, we hypothesized that when cells are required to proliferate or differentiate, as in an immune response, the requirement for D-ribose may be greater than what could be supplied by the synthetic pathway. We hypothesized that providing an exogenous source of D-ribose during cell differentiation will enhance the process of differentiation. We used a retinoic acid-induced HL-60 cell differentiation culture as a model of neutrophil maturation. The addition of 10 to 25 mmol/L D-ribose was shown to reduce cell proliferation and move the cell population toward apoptosis in a dose-dependent manner. The expression of a cell surface marker representing maturity (CD11b) significantly increased and a cell surface marker indicative of immaturity (CD117) significantly decreased. Functionally, the cells had a greater oxidative burst function dependent on time and dose. The mechanism by which ribose enhances HL-60 cell differentiation is not known; however, as adenosine triphosphate levels did not change, adenosine triphosphate is not thought to be involved. We conclude that in this cell culture model, ribose supplementation enhanced cellular differentiation and function. Thus, ribose might be conditionally essential during time of higher need as in an immune response.
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PMID:Ribose enhances retinoic acid-induced differentiation of HL-60 cells. 1908 87