RESUMO
1. Osteoprotegerin (OPG) is a secreted member of the tumour necrosis factor receptor (TNFR) family that leads to the suppression of the differentiation, activation and survival of osteoclasts. The objective was to investigate the in vivo pharmacokinetics and tissue distribution of full-length recombinant human OPG (rhOPG) as well as its clearance mechanism using (125)I-labelled protein ((125)I-rhOPG) after intravenous administration to female Fischer rats. 2. (125)I-rhOPG was rapidly and predominantly distributed to the liver after dosing (3 mg kg(-1)). Immunohistochemical analysis indicated that rhOPG was located in the sinusoids of the liver. 3. The hepatic uptake of (125)I-rhOPG (0.01 mg kg(-1)) was partly regulated under a saturable process. Pre-dosing of some sulfated glycans (20 mg kg(-1)), especially dextran sulfate, heparin and fucoidan, markedly inhibited the hepatic uptake of (125)I-rhOPG. The clearance of (125)I-rhOPG was markedly reduced by the conjugation of dextran sulfate. 4. The results suggested that the hepatic clearance of (125)I-rhOPG was mainly mediated by the interaction with glycosaminoglycans.
Assuntos
Osteoprotegerina/farmacocinética , Proteínas Recombinantes/farmacocinética , Animais , Autorradiografia , Sulfato de Dextrana/farmacologia , Feminino , Heparina/farmacologia , Humanos , Imuno-Histoquímica , Injeções Intravenosas , Fígado/efeitos dos fármacos , Fígado/metabolismo , Osteoprotegerina/administração & dosagem , Osteoprotegerina/genética , Polissacarídeos/farmacologia , Ratos , Ratos Endogâmicos F344 , Proteínas Recombinantes/administração & dosagemRESUMO
Quartz crystal resonators, including electric twins, are investigated. Electric twins are artificially formed in the usual AT-cut quartz crystal resonantor before the deposition of electrodes. We have directly observed that vibrations generated at electrodes propagate into the outside region isotropically, but cannot propagate into the region of electric twin.
RESUMO
Computer simulations of complement titre measurement in sera by linearizing the sigmoidal curve of complement dose response were performed, to simplify the logarithmic calculations of CH50 values. CH50 titres of large variety of human sera including healthy donors and immune deficiency patients were estimated. The values obtained were compared with the hand-simulated results using the Y/(1-Y) conversion table and a log-log graphic paper. Using computer simulation, CH50 can be determined with great ease.
