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Biomedical subjects

C Peschle

Publications and source records attributed to C Peschle.

At least 199 records · Page 11Linked to original sources
PubMed1983

Expression of Friend leukemia virus and spleen focus-forming virus-specific sequences in erythroid bursts and granulocyte-macrophage colonies from spleen and marrow of mice infected with Friend leukemia virus.

A large number of studies have been carried out to identify the Friend leukemia virus (FV) target cell(s). In FV-infected mice, the kinetics of "primitive" erythroid burst-forming units (P-BFU-E) is perturbed, and their proliferative rate is enhanced. These results indirectly suggest, but do not prove, that cycling P-BFU-E may serve as FV target. In vitro infection studies showed that normal erythroid colony forming units (CFU-E) and "mature" erythroid burst-forming units (M-BFU-E) are targets for FV, while the largely out-of-cycle normal P-BFU-E are not. In an attempt to shed light on these aspects, we have evaluated the expression of viral cytoplasmic RNA sequences in pools of colonies generated by P-BFU-E and granulocyte-macrophage colony forming units (CFU-GM) from spleen and marrow of polycythemic Friend virus (FVP)-infected mice, as measured by liquid hybridization with FVP- or spleen focus-forming polycythemic virus (SFFVp)-specific DNA probes. Moreover, similar assays were performed on RNAs derived from whole spleen or bone marrow from mice treated with FVP or the anemic strain of Friend virus (FVA). Control studies were performed on corresponding colonies and whole tissues from normal animals. FVP- and SFFVp-specific sequences are more abundant in RNA extracted from infected spleen as compared to marrow by a 10-fold factor. On the other hand, FVP and SFFVp-specific sequences are expressed at a comparable level in both P-BFU-E- and CFU-GM-derived colonies from spleen or marrow of FVP-treated mice. Since in vitro spread of FVP infection was excluded by control studies with addition in culture of antibody to the viral glycoprotein with a molecular weight of 70,000 (gp70) these results indicate that P-BFU-E and CFU-GM are infected in vivo by FVP.

Animals↗
PubMed1982

Preferential induction of fetal versus embryonic globin chains in human leukemic cell lines.

By use of a newly developed technique combining affinity chromatography of hemoglobin on haptoglobin-Sepharose and IEF of globin chains, we analyzed the globin synthetic pattern of human K562 cells in both the basal state and after addition of several potential inducers. Hemin only was found effective: its addition at 50 microM results in a quantitative increase of globin chain synthesis (from 0.3 to 1% up to 5%) and a qualitative "switch" with a striking increase of alpha and a decrease of epsilon and zeta chains (relative to the prevailing gamma chains). This system, in which hemin induces changes that mimic to some extent the normal embryonic-fetal switch, might therefore provide a cellular model for investigating molecular mechanisms of globin gene regulation. In addition similar results were obtained with a different human myeloid leukemia cell line, the KG1, thus raising the possibility that the expression of embryonic globin genes in malignant cells might not be simply the consequence of abnormal gene expression but rather reflect a possibly physiological differentiation phenomenon.

Animals↗
PubMed1980

Globin chain synthesis in single erythroid bursts from cord blood: studies on gamma leads to beta and G gamma leads to A gamma switches.

Erythroid bursts from cord or adult blood were grown in methylcellulose cultures (3 international units of erythropoietin per plate). On day 13, single bursts were picked up and reincubated for 16-24 hr with [3H]leucine. Radioactive globin chains [alpha,beta,G gamma, and A gamma (Ala-136)] were analyzed by either isoelectric focusing on polyacrylamide gels and fluorography or carboxymethylcellulose chromatography. In all cases, alpha to non-alpha globin radioactivity ratios were close to 1. In single cord blood bursts, the values of both gamma-to-beta and G gamma-to-A gamma ratios were spread over a large spectrum and further characterized by a continuous rather than a bimodal distribution. Morever, the G gamma-to-A gamma ratios demonstrated in single bursts appeared to be directly correlated with the respective gamma-to-beta ratios. These data suggest that both the gamma leads to beta and the G gamma leads to A gamma switches are mediated via mechanisms modulating the relative activities of the different genes in the non-alpha globin gene cluster rather than via selection of clones committed to the preferential synthesis of beta and A gamma globins. In contrast with the results obtained with cord blood, individual adult blood bursts synthesize a lower and hence relatively more uniform amount of gamma globin chains.

Erythropoiesis↗
PubMed1980

Kinetics of erythroid precursors in mice infected with the anemic or the polycythemic strain of Friend leukemia virus.

The kinetics of both erythroid burst-forming and colony-forming units (BFU-E, CFU-E) and myelomonocytic precursors [myelomacrophage colony-forming unit (CFU-C)] have been evaluated in tibial marrow, peripheral blood, and spleen of DBA/2 mice at time intervals after inoculation of either the anemic (FLV-A) or the polycythemic (FLV-P) strain of Friend leukemia virus. Either one of the viruses induced, at 7-10 days after infection, a massive increase in the number of BFU-Es in peripheral blood, in parallel with their depletion in tibial marrow and increase in spleen. A comparable increase in the blood BFU-E number was observed in splenectomized FLV-infected mice. These results indicate a marrow-spleen migration of BFU-Es. In spleen, the increase of the BFU-E number was associated with an increase in the CFU-E pool. In tibial marrow, a sequence of expansion/depletion waves occurred reciprocally at the level of BFU-E and CFU-E. The cycling of BFU-E([(3)H]thymidine in vitro suicide index) in marrow, blood, and spleen was enhanced, whereas that of CFU-E and CFU-C showed little or no modification. These kinetic data suggest that the main target cell of FLV may be the BFU-E or a closely related element. In plates without added erythropoietin (but containing it in fetal calf serum), expression of CFU-E from FLV-P-treated animals was maximal; that of CFU-E from FLV-A-injected mice was either virtually absent or only slight in marrow or spleen, respectively. BFU-E growth always was fully dependent upon erythropoietin addition. Control studies in FLV-infected resistant mice and in susceptible mice given diluted or heat-inactivated virus provide convincing evidence that the phenomena described are induced by FLV.

Animals↗
PubMed1980

Congenital erythrocytosis: a new form associated with an erythropoietin-dependent mechanism.

Three patients with probable congenital erythrocytosis were studied to determine the role of erythropoietin (ESF) in their disease. In addition, haemoglobin function was measured and ESF excretion determined in response to reduction in the haemoglobin concentration. In two cases ESF excretion was clearly elevated above normal, and in the third excretion was normal even at an elevated PCV. In all, phlebotomy of 15--20% of the blood volume led tomore than doubling in ESF excretion. This occurred in the presence of normal molecular haemoglobin function. Studies of the renal vasculature were normal. These results suggest a new form of congenital erythrocytosis associated with increased ESF production which is reciprocally related to the oxygen carrying capacity of the blood, but in the absence of any demonstrable abnormality in oxygen transport. These findings suggest an inherited defect, likely residing in the renal sensor responsible for the production of ESF. This defect is possible due to impaired recognition of available oxygen or else a decrease in oxygen supply at the subcellular level.

Adolescent↗
PubMed1980

Erythropoiesis.

Explore the source record for details and available documents.

Anemia, Aplastic↗
PubMed1980

Hemoglobin synthesis in individual bursts from normal adult blood: all bursts and subcolonies synthesize G gamma-and A gamma-globin chains.

Gamma-globin chain synthesis has been evaluated in individual bursts and subcolonies that were generated by normal adult blood BFU-Es in methylcellulose cultures containing semipurified erythropoietin (Ep) and then analyzed via either isoelectric focusing (IEF) of globin chains or immunofluorescence techniques. At variance with previously reported results, based on plasma clot culture and immunofluorescence, all bursts and subcolonies analyzed synthesize gamma-globin chains. Identification of gamma-chains has been confirmed by preparative IEF of HbF, followed by either carboxymethylcellulose chromatography or IEF analysis of the resulting globin chains. In all bursts analyzed, the relative synthesis of the two types of gamma-globin chains (G gamma and A gamma) shows an adult ratio (i.e., approximately 1:1). The results obtained via IEF have been confirmed by immunofluorescence studies, which apparently showed presence of at least some HbF-positive cells within all scrutinized bursts or subcolonies. The significance of these studies is discussed in the light of current hypotheses on mechanism(s) underlying HbF synthesis in normal adults.

Cells, Cultured↗
PubMed1980

In vitro interactions of PGE and cAMP with murine and human erythroid precursors.

Addition of prostaglandins of the E series (PGE1, PGE2) in methylcellulose cultures of murine marrow results in a dose-dependent inhibition of the cloning efficiency of both BFU-E and CFU-C. However, CFU-E growth is unaffected. The inhibitory action of PGE is progressively overcome by increasing amounts of colony-stimulating factor (CSF), and with some limitations, also of erythropoietin (Ep). Addition of PGF2 alpha' associated or not with indomethacin, does not exert any significant effect on these hemopoietic precursors. In an attempt to unvail the mechanism(s) underlying these phenomena, dibutyryl-cyclic AMP (db-cAMP), theophylline (an inhibitor of phosphodiesterase), or theophylline + PGE were plated at various concentrations. Both db-cAMP and theophylline induce an inhibitory influence on both BFU-E and CFU-C growth, which mimicks that by PGEs; additionally, theophylline potentiates the inhibitory action of PGE1. In all these studies, the CFU-E number was not significantly modified. PGE action on BFU-E proliferation is clearly species-dependent, since PGE1 addition to human marrow methylcellulose cultures induces a significant enhancement of the number of both BFU-E and CFU-E derived colonies. This action was abolished upon removal of adherent cells, thus suggesting that PGE1 evokes a release of factor(s) enhancing human erythroid colony growth by adherent cells.

Animals↗
PubMed1980

Erythropoietic differentiation in humans: in vitro studies on erythroid progenitors and Hb synthesis in fetal, newborn and adult life.

Human erythroid progenitors from fetal liver, cord or adult blood and adult marrow were cultured in methylcellulose, according to standard techniques. Their clonogenetic features (colony morphology and number, time/growth curve, erythropoietin (Ep) and burst-enhancing factor (BEF) sensitivity, in vitro 3H-thymidine suicide index, etc) were comparatively investigated. Three classes of fetal liver erythroid progenitors (primitive or intermediate BFU-E, CFU-E) have been thereby identified and characterized. Furthermore, globin chains (alpha, beta, G gamma, A gamma) synthesis has been evaluated in single erythroid colonies, either well-or poorly-hemoglobinized, by means of a novel technique including analytical iso-electric focusing (IEF), sometimes preceded by preparative IEF separation of HbF and HbA. On the basis of these results, a model for the regulation of Hb synthesis is proposed here.

Adult↗