Straneva Je
Indiana University
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Publication
Featured researches published by Straneva Je.
Journal of Clinical Investigation | 1985
Ronald Hoffman; H H Yang; E Bruno; Straneva Je
Human plasma obtained from patients with hypomegakaryocytic thrombocytopenia contains a factor that promotes megakaryocyte colony formation by normal human marrow cells. This megakaryocyte colony-stimulating factor was purified from such a plasma specimen. A four-step purification scheme which included ammonium sulfate precipitation, diethylaminoethyl-Sepharose chromatography, affinity chromatography on wheat germ lectin-Sepharose 6MB, and reverse-phase high performance liquid chromatography resulted in a recovery of 16.6% of the initial biological activity and an increase in specific activity by 3,489-fold. The purified protein produced a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Purified megakaryocyte colony-stimulating factor was capable of promoting megakaryocyte colony formation at a concentration of 7.6 X 10(-8) M. Megakaryocyte colony-stimulating factor was shown to be a glycoprotein and had an apparent 46,000 mol wt. Deglycosylation of megakaryocyte colony-stimulating factor by treatment with trifluoromethane-sulfonate resulted in the loss of its ability to promote megakaryocyte colony formation. Megakaryocyte colony-stimulating factor appears to be an important regulator of in vitro human megakaryocytopoiesis at the level of the colony-forming unit megakaryocyte and may be of importance physiologically.
Journal of Clinical Investigation | 1991
Asok C. Antony; Robert A. Briddell; John E. Brandt; Straneva Je; Rama S. Verma; Michael E. Miller; Lorrie A. Kalasinski; Ronald Hoffman
We tested the hypothesis that anti-placental folate receptor (PFR) antiserum-mediated effects on hematopoietic progenitor cells in vitro of increased cell proliferation and megaloblastic morphology were independent responses. We determined that (a) purified IgG from anti-PFR antiserum reacted with purified apo- and holo-PFR and specifically immunoprecipitated a single (44-kD) iodinated moiety on cell surfaces of low density mononuclear cells (LDMNC); (b) when retained in culture during in vitro hematopoiesis, anti-PFR IgG (in contrast to PFR-neutralized anti-PFR IgG and nonimmune IgG) consistently led to increased cloning efficiency of colony forming unit-erythroid (CFU-E), burst forming unit-E (BFU-E), CFU-granulocyte macrophage (CFU-GM), and CFU-GEM megakaryocyte (CFU-GEMM), and objectively defined megaloblastic changes in orthochromatic normoblasts from CFU-E- and BFU-E-derived colonies; (c) when anti-PFR antiserum was removed after initial (less than 1 h) incubation with LDMNC, a cell proliferation response was induced, but megaloblastic changes were not evident. (d) Conversely, delay at 4 degrees C for 24 h before long-term plating with antiserum resulted in megaloblastosis without increased cell proliferation; (e) however, 500-fold molar excess extracellular folate concentrations completely abrogated the expected anti-PFR antiserum-induced megaloblastic changes, without altering cell proliferative responses. Thus, although cell proliferative and megaloblastic changes are induced after short-term and prolonged interaction of antibody with folate receptors on hematopoietic progenitors, respectively, they are independent effects.
European Journal of Haematology | 2009
Straneva Je; Robert A. Briddell; Siu L. Hui; Ronald Hoffman
Human bone marrow was depleted of progenitors (CFU‐MK), but enriched for recognizable megakaryocytes (MK), and placed in cultures with serum from either normal donors (NABS) or patients with primary (PTS) or secondary (STS) thrombocytosis, autoimmune thrombocytopenia (ATS) or aplastic anemia (AAS). Mean MK diameters shifted during the 3–4 days of incubation. Endomitotic figures were visible and mean ploidy increased slightly during cytoplasmic maturation, where decreases in immature cells (stages 1 and 2) were accompanied by increases in the mature MK (stages 3 and 4). Cytoplasmic maturation was faster in AAS, ATS and STS than PTS or NABS; mean size and ploidy were similar in all cultures. Recognizable MK were not forced to undergo additional endoreduplication in response to stimulation. Only AAS augmented MK colony formation, which indicated that at least two humoral factors can regulate megakaryocytopoiesis at separate levels, the progenitors and morphologically recognizable MK.
Blood | 1989
Robert A. Briddell; John E. Brandt; Straneva Je; Edward F. Srour; Ronald Hoffman
Experimental Hematology | 1987
Douglas E. Williams; Straneva Je; S. Cooper; R. K. Shadduck; Abdul Waheed; Gillis S; D. Urdal; Hal E. Broxmeyer
Blood | 1988
Bruce J. Roth; Gw Jr Sledge; Straneva Je; John E. Brandt; M Goheen; Ronald Hoffman
Experimental Hematology | 1987
Straneva Je; Yang Hh; Hui Sl; Bruno E; Ronald Hoffman
Experimental Hematology | 1987
Douglas E. Williams; Straneva Je; Rong-Nian Shen; H. E. Broxmeyer
Experimental Hematology | 1986
Straneva Je; Goheen Mp; Hui Sl; Bruno E; Ronald Hoffman
Proceedings of the National Academy of Sciences of the United States of America | 1988
Douglas E. Williams; D. C. Bicknell; L S Park; Straneva Je; S. Cooper; Hal E. Broxmeyer