1/4. Possible mechanism of ineffective erythropoiesis by an altered transferrin receptor cycle in erythroleukemia.Involvement of the transferrin receptor cycle was noted in erythroblasts from a patient with erythroleukemia (FAB classification M6). The kinetics of transferrin receptor cycle in bone marrow erythroblasts was obtained by pulse-chase experiments before the initiation of therapy. Internalization of transferrin was impaired and resulted in a delayed peak of internalized transferrin, as compared with the kinetics pattern seen in healthy subjects. The subsequent exocytosis of the internalized ligand was also delayed. Thus, transferrin receptor cycle seems to be influenced all along the transferrin pathway, hence transferrin travels more slowly in erythroblasts in erythroleukemia. The altered transferrin receptor cycle led to a diminished iron uptake per surface transferrin receptor (approximately 30% of that in healthy subjects), and the incorporation of iron into heme was greatly reduced. Our observations suggest a possible role for the altered transferrin receptor cycle in the pathogenesis of defective heme synthesis and ineffective erythropoiesis in erythroleukemia.- - - - - - - - - - ranking = 1keywords = cycle (Clic here for more details about this article) |
2/4. chromosomes and causation of human cancer and leukemia. LIII. Comprehensive cytogenetic analysis of an erythroleukemia.A comprehensive cytogenetic analysis has been performed in a case of erythroleukemia (EL), M6 in the FAB classification. A bone marrow sample was shown to be characterized by an unusually high degree of polyploidy with the presence of a dominating hypotetraploid clone. G-banding analysis revealed extensive structural rearrangements involving chromosomes #1,#3,#12,#16,#17, and #21. The SCE frequency was higher in the cells of the dominant clone when compared to that of near-diploid, presumably nonmalignant cells. cell cycle analysis revealed that the hypotetraploid cells progressed through the cell cycle much slower than did the near-diploid cells.- - - - - - - - - - ranking = 0.22222222222222keywords = cycle (Clic here for more details about this article) |
3/4. Acute erythroleukemia following chemotherapy for Hodgkin's disease.A case of erythroleukemia developing in a patient 6.5 years after therapy for Hodgkin's disease (HD) is described. The patient had chemotherapy alone for a stage III B lymphocyte-predominant HD. He received six cycles MOPP-induction therapy followed by a chlorambucil maintenance therapy with procarbazine and prednisone reinforcements. To our knowledge this is the first case of erythroleukemia following HD treated with chemotherapy alone.- - - - - - - - - - ranking = 0.11111111111111keywords = cycle (Clic here for more details about this article) |
4/4. yersinia enterocolitica transmission from a red cell unit 34 days old.In 1993 the North london blood transfusion Centre received its first report of yersinia enterocolitica transmission from a unit of red cells supplied to a local hospital. The recipient was a 23-year-old male who was neutropenic following a third cycle of chemotherapy for treatment of acute myeloblastic leukaemia (FAB type M6) and received a 34-day-old red cell unit. During transfusion the patient developed septicaemia and endotoxin-mediated shock. The transfusion was stopped immediately and broad spectrum antibiotics administered immediately on suspicion of bacteraemia from the transfused unit. This prompt action undoubtedly prevented a fatal outcome. Y. enterocolitica was isolated from the blood bag. Antibody was also detected in the bag and in a sample taken from the donor 39 days post-donation. Antibody to serotype 03 was identified, the commonest serotype reported in transfusion-transmitted Y. enterocolitica. The donor reported no gastrointestinal upset or illness prior to donation. This transfusion reaction might not have occurred had the red cells been transfused earlier in their storage period, but would not have been prevented by the exclusion of donors with a history of gastrointestinal illness as the donor was asymptomatic. Nor would it have been prevented by inspecting the blood for a change in colour, as no such change was observed. Y. enterocolitica is a significant problem in transfusion medicine and transmission is generally associated with a high mortality rate. hospitals should be urged to investigate bacteriologically all appropriate transfusion reactions so that the true extent of the problem in the United Kingdom can be assessed.- - - - - - - - - - ranking = 0.11111111111111keywords = cycle (Clic here for more details about this article) |