Ethylene-propene copolymerization was carried out with Cp2MC12 (Cp = cyclopentadienyl), r~c-Et(Ind)~MCl,, ra~-Me,Si(Ind)~MCl~ (Et = ethylene, Me2Si = dimethylsilyl, Ind = indenyl, M = Zr or Hf)/methylaluminoxane. In the case of using ansa-hafnocenes, the minimum molecular size (extended chain length) of ethylene-propene copolymer was obtained at about 50 mol-% of propene content in the copolymer. The polymerization activity decreased with increase of propene feed ratio in non-bridged non-specific metallocenes. Higher polymerization activities were observed for the copolymerization compared to ethylene and propene homo-polymerization with ansa-isospecific metallocenes. The factor of molecular size lowering was studied by the chain propagation and chain transfer reaction.

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Serum erythropoietin (Epo) titers in patients with various hematological malignancies and related diseases were determined by radioimmunoassay. Serum Epo titer was inversely correlated with hemoglobin concentration in iron deficiency anemia, aplastic anemia, myelodysplastic syndromes (MDS), acute leukemia, malignant lymphoma, multiple myeloma and myelofibrosis, but there was no correlation between serum Epo titer and hemoglobin concentration in chronic myelogenous leukemia or polycythemias. Serum Epo titers in aplastic anemia were much higher than those in iron deficiency anemia. Serum Epo titers in MDS, malignant lymphoma and multiple myeloma differed considerably among patients. Serum Epo titers in untreated polycythemia vera were significantly lower than in treated polycythemia vera or secondary polycythemia.

A 64-year-old woman developed pure red cell aplasia (PRCA) 4 years after thymectomy for thymoma. During anti-thymocyte globulin treatment, the patient developed cytomegalovirus pneumonia and was thus unable to continue immunosuppressive therapy and became transfusion dependent. Deferasirox was started for treatment with iron overload when serum ferritin increased to >1000 ng/mL. Seven months after initiation of deferasirox treatment, serum ferritin level decreased the normal range and the patient has remained transfusion independent thereafter. Deferasirox was discontinued when serum ferritin level decreased below 500 ng/mL, and she has maintained in complete remission over the last 15 months. Hypotheses have been raised regarding the improvement of hematopoiesis by deferasirox treatment, but the mechanism whereby this might be achieved remains unclear. Deferasirox treatment may be clinically beneficial both by reducing iron overload and by improving hematopoiesis in patients with PRCA.