Subject(s)
Biphenyl Compounds/pharmacology , Histamine Antagonists/pharmacology , Nitriles/pharmacology , Obesity/metabolism , Obesity/prevention & control , Pyrrolidines/pharmacology , Receptors, Histamine H3/metabolism , Animals , Biphenyl Compounds/adverse effects , Biphenyl Compounds/chemistry , Diet , Dietary Fats/administration & dosage , Dietary Fats/pharmacology , Histamine Agonists/chemistry , Histamine Agonists/pharmacology , Histamine Antagonists/adverse effects , Histamine Antagonists/chemistry , Male , Mice , Mice, Inbred C57BL , Molecular Structure , Nitriles/adverse effects , Nitriles/chemistry , Obesity/chemically induced , Pyrrolidines/adverse effects , Pyrrolidines/chemistryABSTRACT
Thrombopoietin (TPO) is a primary regulator of megakaryocytopoiesis, a process through which megakaryocytes proliferate and mature into platelets. Recombinant human TPO (rhTPO) was expressed in Chinese hamster ovary (CHO) cells and purified from the culture medium. The cDNA encoding full-length TPO, including the native signal peptide sequence, was amplified by PCR from a human fetal liver cDNA library. The product was cloned into a mammalian expression vector under the control of the SV40 early promoter and enhancer. Secreted rhTPO was purified in three conventional chromatography steps. It migrates on SDS-PAGE as a broad band, characteristic of a heavily glycosylated protein, with an average molecular mass of 85 kDa. rhTPO expressed in CHO cells is biologically active in vitro as demonstrated by its ability to stimulate the proliferation of a megakaryocytic cell line and to trigger the JAK/STAT signal transduction pathway. rhTPO also shows activity in vivo as judged by the elevation of platelet count in treated mice.
Subject(s)
Thrombopoietin/metabolism , Animals , Blotting, Western , CHO Cells , Cell Division/drug effects , Cell Line , Cricetinae , Electrophoresis, Polyacrylamide Gel , Hematocrit , Humans , Male , Mice , Mice, Inbred BALB C , Platelet Count , Receptors, Granulocyte Colony-Stimulating Factor/metabolism , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Recombinant Proteins/pharmacology , Signal Transduction/physiology , Thrombopoietin/genetics , Thrombopoietin/pharmacology , TransfectionABSTRACT
The urine electrical conductivity is a practical guide to the ion-to-water ratio of urine. It may be used to assess the influence of urinary loss upon the total body ion-to-water ratio. It is suggested that the total body ion-to-water ratio is the object of control in water therapy, commonly administered as 5% dextrose. The total body ion-to-water ratio closely accords with the ratio in the extracellular fluid. Since sodium is the predominant extracellular cation, the plasma sodium concentration closely reflects the extracellular and total body ion-to-water ratio. As a consequence the urine electrical conductivity may be used as a continuous signal in the open or closed loop control of water balance as reflected by the plasma sodium concentration.
