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Query: UMLS:C0240066 (iron deficiency)
 7,156 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Transferrin receptor (TfR) expression is regulated by iron at the level of mRNA stability through a factor (IRF/IRE-BP) which binds to specific iron-responsive elements (IRE). On the other hand, growth-dependent regulation of TfR expression is generally believed to be transcriptionally controlled. We analyzed the molecular mechanisms that control TfR gene expression at the onset of cell proliferation in vivo during liver regeneration after partial hepatectomy. The amount of TfR mRNA increased considerably after partial hepatectomy while run-on assays did not show significant changes in TfR gene transcription. RNA band-shift assays documented a significant activation of IRF/IRE-BP specific for the faster migrating IRE-protein complex (IRFB). These changes occurred in the absence of modifications of total liver iron concentration but together with a significant decrease of ferritin content. Moreover, when extreme variations of liver iron content were achieved by either chronic iron overload or severe iron deficiency, liver regeneration was unable to influence IRE-binding activity. We conclude that IRF/IRE-BP-mediated post-transcriptional control can fully account for TfR mRNA induction during liver cell proliferation in vivo. IRF/IRE-BP activation in the absence of changes in total tissue iron content might depend either on a drop of iron levels into the regulatory pool or on a relatively iron-independent mechanism specific for the faster migrating complex.
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PMID:Transferrin receptor gene expression during rat liver regeneration. Evidence for post-transcriptional regulation by iron regulatory factorB, a second iron-responsive element-binding protein. 811 90

Reticulocyte count in manual method has been the assay traditionally used to evaluate the status of erythropoiesis in haematological disorders with disturbances in erythropoietic activity. But it is a qualitative rather than a quantitative test due to the high variability in manual microscopic method. Automated reticulocyte counting based on flow cytometry has provided much objective and exactly measure of percentage and absolute number of reticulocytes than microscopic method. Besides these two traditional parameters automatic reticulocyte counters can detect differences in the amounts of cellular RNA present in red blood cells which reflects their maturational stages. There are three related parameters which describes the reticulocyte maturation: RMI (reticulocyte maturity index), HFR (high fluorescence reticulocytes), IRF (immature reticulocyte fraction). These parameters can be used as the earliest signs of marrow engraftment after autologous or allogeneic bone marrow transplantations. Reticulocyte cellular indices such as MCVr (mean reticulocyte volume), CHr (reticulocyte hemoglobin content), CHCMr (reticulocyte hemoglobin concentration) entered recently in few automated reticulocyte counters allows for assessment of the functional state of the erythropoiesis in the diagnosis and monitoring of the iron deficiency and rhEpo therapy. Although there is no agreement between various methods of staining and counting of the reticulocytes and lack of standardization materials for this assay automated reticulocyte counting and new reticulocyte parameters probably will improve the diagnosis and monitoring of many haematological diseases.
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PMID:[New reticulocyte indices and their utility in hematologic diagnosis]. 1107 Jul 26