scholarly journals Factors Controlling Erythropoiesis in Birds

Blood ◽  
1966 ◽  
Vol 27 (5) ◽  
pp. 654-661 ◽  
Author(s):  
WENDELL F. ROSSE ◽  
THOMAS A. WALDMANN
Keyword(s):  
Biological Activity ◽  
Protein Structure ◽  
Humoral Factor ◽  
Intact Protein ◽  
Physiologic Response ◽  
Environmental Hypoxia ◽  
Stimulating Factor

Abstract 1. Erythropoiesis in birds is stimulated by bleeding and environmental hypoxia and is suppressed by induced polycythemia, indicating that the physiologic response is similar to that in mammals. 2. This response is mediated through a humoral factor which stimulates erythropoiesis of birds but not of mammals. Similarly, the erythropoietin of mammals does not stimulate the erythropoiesis of birds. 3. Although both the erythropoiesis stimulating factor of birds and of mammals appear to require an intact protein structure for biological activity, the erythropoietin of birds differs from that of mammals in that it is not destroyed by sialidase and does not lose its activity when reacted with antibody to human urinary erythropoietin.

Structure of KW-2228, a tailored human granulocyte colony- stimulating factor with enhanced biological activity and stability

FEBS Letters ◽  
1997 ◽  
Vol 410 (2-3) ◽  
pp. 131-135 ◽  
Author(s):  
Isao Fujii ◽  
Yoshitomo Nagahara ◽  
Motoo Yamasaki ◽  
Yoshiharu Yokoo ◽  
Seiga Itoh ◽  
...  
Keyword(s):  
Biological Activity ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
Stimulating Factor

scholarly journals Localization, purification, and biological activity of a new aldosterone-stimulating factor.

Hypertension ◽  
1981 ◽  
Vol 3 (3_pt_2) ◽  
Author(s):  
S Sen ◽  
R Valenzuela ◽  
R Smeby ◽  
E L Bravo ◽  
F M Bumpus
Keyword(s):  
Biological Activity ◽  
Stimulating Factor

scholarly journals Activated Fes Protein Tyrosine Kinase Induces Terminal Macrophage Differentiation of Myeloid Progenitors (U937 Cells) and Activation of the Transcription Factor PU.1

2002 ◽  
Vol 22 (6) ◽  
pp. 1903-1918 ◽  
Author(s):  
Jynho Kim ◽  
Ricardo A. Feldman
Keyword(s):  
Transcription Factor ◽  
Biological Activity ◽  
Tyrosine Kinase ◽  
Protein Tyrosine Kinase ◽  
U937 Cells ◽  
Colony Stimulating Factor ◽  
Macrophage Differentiation ◽  
Protein Tyrosine ◽  
Downstream Targets ◽  
Stimulating Factor

ABSTRACT The c-fps/fes proto-oncogene encodes a 92-kDa protein tyrosine kinase that is preferentially expressed in myeloid and endothelial cells. Fes is believed to play a role in vascular development and myelopoiesis and in the inflammatory responses of granulocytes and macrophages. To help define the biological role of this kinase and identify its downstream targets, we have developed a gain-of-function allele of Fes that has potent biological activity in myeloid cell progenitors. Introduction of constitutively active Fes into bipotential U937 cells induced the appearance of fully differentiated macrophages within 6 to 12 days. The Fes-expressing differentiated cells became adherent, had distinctive macrophage morphology, and exhibited increased expression of myelomonocytic differentiation markers, including CD11b, CD11c, CD18, CD14, and the macrophage colony-stimulating factor receptor. These cells acquired phagocytic properties and exhibited NADPH oxidase and nonspecific esterase activities, confirming that they were functionally active macrophages. Concomitantly, there was downregulation of the granulocytic marker granulocyte colony-stimulating factor receptor, indicating that the biological activity of Fes was coordinated in a lineage-specific manner. A constitutively active Src did not induce macrophage morphology or upregulation of myelomonocytic markers in U937 cells, suggesting that the biological activity we observed was not a general consequence of expression of an activated nonreceptor tyrosine kinase. Analysis of possible downstream targets of Fes revealed that this kinase activated the ets family transcription factor PU.1, which is essential for macrophage development. Our results strongly implicate Fes as a key regulator of terminal macrophage differentiation and identify PU.1 as a transcription factor that may mediate some of its biological activities in myeloid cells.

FURTHER STUDIES ON A THYROID STIMULATING FACTOR IN CRUDE CHORIONIC GONADOTROPHIN PREPARATIONS AND IN URINE

1967 ◽  
Vol 55 (4) ◽  
pp. 600-610 ◽  
Author(s):  
A. Burger ◽  
R. Kunz
Keyword(s):  
Biological Activity ◽  
Dose Response ◽  
Response Curve ◽  
Gel Filtration ◽  
Chorionic Gonadotrophin ◽  
Dose Response Curve ◽  
Intermediate Step ◽  
Urinary Proteins ◽  
Biological Responses ◽  
Stimulating Factor

ABSTRACT Urine from pregnant women was concentrated by a kaolin-acetone method and tested by the McKenzie bioassay (1958) for thyrotrophin (TSH). Only small responses, without any dose-response curve were found. However, more purified proteins, recovered from an intermediate step in human urinary chorionic gonadotrophin (crude HCG) purification and supplied by Organon, Holland, produced much higher biological responses, when tested in corresponding concentrations. Yet, even here, no straight dose-response curve was obtained and the responses were more prolonged at higher concentrations. As described before (Burger 1967), thyroid stimulating factor in purified human urinary chorionic gonadotrophin (TSF in HCG) produced a straight dose-response curve. In gel filtration studies, TSF in HCG together with the bulk of urinary proteins were eluted more rapidly than bovine TSH (BTSH), suggesting a higher molecular weight of TSF in HCG preparations. By double diffusion technique, uromucoid could be demonstrated immunologically in crude and in purified HCG. To explain the different biological responses in crude and purified urinary proteins in the McKenzie bioassay and the different elution patterns in gel filtration studies with TSF in HCG and TSH, the following hypothesis is advanced: In urine TSH is bound to urinary proteins, possibly to uromucoid, which interfere with its biological activity. The biological activity is regained by purification.

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