Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To determine if the cellular uptake of iron is associated with internalization of iron-transferrin (TF) complex by the cell, we synthesized a visual probe in which TF is covalently bound to amide-modified latex minibead, submicrometer in size (0.345 micron). Incubation of the probe with L1210 leukemia cells and rat reticulocytes led to the binding of the probe to the cell surface visualized and semiquantified by scanning and transmission electron microscopy. The binding was inhibited by preincubation with nonderivatized iron-TF complex. Internalization of the probe occurred through clathrin-coated pits and vesicles. Minibeads derivatized by nontransport proteins or glycine as well as nonderivatized minibeads did not appreciably bind to the cells and were not internalized. Ethylamine, an inhibitor of receptor-mediated endocytosis abolished the internalization but not the binding of the probe which, then, accumulated on the cell surface. These findings provide direct evidence for internalization of TF during the iron uptake.
 ...
PMID:Internalization of iron-transferrin complex by murine L1210 leukemia cells and rat reticulocytes demonstrated by a minibead probe. 640 54

Spleen cells collected from DBA/2 (H-2d) mice inoculated with the polycythemic variant of Friend-Leukemia Virus Complex (FLV-P) were tested for T-dependent immune functions, such as the in vitro generation of cytotoxic T lymphocytes (CTL) and of non-specific T suppressor lymphocytes (STL). CTL were generated against H-2b splenocytes, and STL were obtained following a 5-day lymphocyte culture without stimulator cells. A progressive and severe impairment of the generation of both CLT and STL was found from 2 weeks onward after infection, being almost totally abolished 3-4 weeks after virus challenge. Suppressor cells (SC) capable of inhibiting CTL generation was detected in FLV-P bearing mice. Suppressor activity was unaffected by anti-Thy 1.2 serum and complement but was removed following iron-magnet depletion or passage through nylon-wool column. Moreover complete recovery of the competence of CTL generation was attained when FLV-P infected splenocytes were passed through nylon-wool column. It is concluded that FLV-P infection depresses T-dependent cytotoxic and suppressor responses in mice, by the appearance of non-T adherent phagocytic cells, capable of impairing CTL generation in vitro.
 ...
PMID:Impairment of in vitro generation of cytotoxic or T suppressor lymphocytes by Friend leukemia virus infection in mice. 645 95

A variant of Rauscher leukemia virus, designated RLV-A, induces a protracted hematopoietic dysplasia characterized by hepatosplenomegaly with erythroblastosis, severe terminal anemia, thrombocytopenia, and erythroblastemia. Erythrocyte and platelet survival is reduced and the ferrokinetic data suggest that iron utilization is faulty. Stem cells (CFU-S, CFU-C, CFU-MK, CFU-E, BFU-E) are reduced in the bone marrow but increased in terminal spleens. The cause(s) of these viral-associated alterations in stem cell numbers is not known.
 ...
PMID:Viral-associated alterations in hematopoiesis in the mouse. 654 51

A clinical phase (spent phase) in the course of polycythaemia vera (PV) cases is described as enlargement of the spleen in spite of treatment, frequent cytopenia of one or several lines, persistent red cell hypervolaemia with considerable increase of plasma volume, persistence of myeloid hyperplasia with no collagen myelofibrosis or osteomyelosclerosis, absence of hepatosplenic erythroblastic metaplasia, as shown by radio-iron kinetics and/or 111In-transferrin scintigraphy. The frequency of this phase was 5% in a study where it was not systematically sought, but it could in fact be greater. Its occurrence is not related to the clinical and biological parameters of PV. On the other hand, it is significantly more frequent and earlier in patients treated by phlebotomies than in those treated by myelosuppression (32P). In four of the 12 cases, this phase was rapidly followed by an acute leukaemia. In eight cases there was a 1-5 year interval before a myelofibrosis with splenic myeloid metaplasia. This evolution could at this stage be delayed by chemotherapy. The efficacy of splenectomy should be studied.
 ...
PMID:The 'spent' phase of polycythaemia vera: hypersplenism in the absence of myelofibrosis. 658 68

In 87 patients with Ph1 positive chronic granulocytic leukaemia (CGL), the bone marrow iron content was studied on smears obtained at diagnosis. A low sideroblast score and a decreased or absent marrow iron on semiquantitative estimation were found in 91% and 85% of cases, respectively. These findings did not correlate with blood parameters reflecting iron status such as Hb concentration, mean corpuscular volume, mean corpuscular haemoglobin, serum iron, total iron-binding capacity and transferrin saturation, which were normal in most cases. In 30 patients, initial serum ferritin was estimated, normal or slightly increased levels being as a rule found. In 24 of such patients, serum ferritin was again measured in remission following busulphan and, although values remained normal, a significant decrease was observed with respect to the initial levels (P less than 0.001). Thus, in spite of the consistent marrow pattern of iron depletion, initial iron stores appear to be normal in CGL. It seems, however, that the disease activity may partially influence the serum ferritin levels.
 ...
PMID:Iron stores in chronic granulocytic leukaemia at presentation. 658 57

It has been suggested that the iron storage protein ferritin has a number of physiological functions not directly related to iron metabolism and a number of these relate to lymphocyte and macrophage activity. The present study demonstrates a selective distribution of ferritin on lymphocyte and macrophage surface membranes which may be relevant to these hypotheses. Flow cytometry using specific antibodies shows 66% of human peripheral blood monocytes, 75% of B cells but only 6% of T cells to have significant amounts of surface ferritin. No difference was found between OKT4 and OKT8 subsets. Ferritin was also found on the surface of the pathological lymphocytes of B cell chronic lymphatic leukaemia (CLL) but not T cell CLL.
 ...
PMID:The expression of cell surface ferritin by peripheral blood lymphocytes and monocytes. 661 Nov 70

Simultaneous bone marrow scintigraphy with 99m Technetium colloids and 111 Indium transferrin was performed on 34 cases of preleukemic anemias and was shown to be of good prognostic value. Groups of different outcome were defined: for a normal and parallel uptake of the two markers, 90% of the patients died of acute leukemia; for a low Indium and high Technetium uptake, only 1 patient out of 15 died of leukemia (P less than 0.001). Standard clinical and hematological data were of no predictive value. Iron kinetic data and CFU/GM colony growth were correlated to the scintigraphic results. Taken together, these three kinetic parameters have a good sensitivity and specificity for the prognosis of preleukemic states.
 ...
PMID:An analysis of prognostic factors in preleukemia: interest of bone marrow scintigraphy. 671 55

Ferritin was prepared from the leucocytes of four patients with acute myeloblastic leukaemia (AML) and eight patients with chronic myeloid leukaemia (CML). Isoelectric focusing demonstrated a prominent relatively basic band in all the CML cell ferritins. The iron content of all the ferritins was very low (max 180 atom/molecule). Thus there was little evidence for the role of leucocyte ferritin as an iron store or for iron as the major factor responsible for the initiation of ferritin synthesis. The iron uptake properties, subunit analyses, immunological reactivities and other immunological studies indicated that leukaemic cell ferritins had similar properties to tissue ferritins.
 ...
PMID:Biochemical and immunological characterization of ferritin from leukaemic cells. 677 79

Iron-excreting goblet cells were observed by chance in a patient with myelogenic leukaemia. Duodenal and jejunal biopsies from patients with a wide spectrum of disorders have therefore been examined retrospectively after staining with Perl's iron method. Thirty-seven of the patients had iron-excreting goblet cells. The presence of iron has been confirmed by X-ray microanalysis and by electron microscopic histochemistry. In addition to iron-excreting goblet cells, most of these patients had iron-containing macrophages in lamina propria. This may indicate that the two types of cells co-operate in the excretion process. It is suggested that iron excretion may be part of the common iron balance mechanism.
 ...
PMID:Iron excretion from the goblet cells of the small intestine in man. An additional regulatory mechanism in iron homeostasis? 694 Feb 36

Out of 412 adult patients classified as aplastic anaemia in a co-operative study group, 22 developed acute leukaemia from 3 months to 5 years after the initial diagnosis. In 21 of these, retrospective analysis elicited one or several clinical and laboratory data which are uncommon in aplastic anaemia but common in pre-leukaemic refractory anaemia. Indeed, one half of these patients should have been classified as pre-leukaemic, and in the remaining half cell kinetics investigations (analysis of radioactive iron renewal, stem cell cultures and 3H-TdR autoradiography of bone marrow), as well as cytogenetic studies, might have led to a more correct classification. Only one patient, who initially had none of the criteria of pre-leukaemic state, responded to androgen treatment with a 4-year complete remission but died on the 5th year of acute myeloblastic leukaemia. It appears from this retrospective analysis that when all signs of pre-leukaemia have been excluded by thorough investigation, aplastic anaemia is never, or only exceptionally (1 out of 412 cases), a pre-leukaemic condition.
 ...
PMID:[Is aplastic anaemia a pre-leukaemic state? (author's transl)]. 694 81


<< Previous 1 2 3 4 5 6 7 8 9 10