RESUMEN
Erythrocyte orientation and deformation cause differences in impedance between flowing and resting blood. Through theoretical calculation and experimental measurements, we studied the effects of these factors on blood impedance. The size and shape of the erythrocyte and the conductivity of the interior medium of the erythrocyte change when the osmotic pressure of plasma is changed. From experimental results, we obtained the following: when the size of the erythrocyte becomes larger than the normal size due to the osmotic pressure change, the beta dispersion frequency decreases and the intra- and extracellular fluid resistance increase. These experimental results corroborate that the change of tissue impedance like muscle impedance during hemodialysis is caused by the change of the fluid distribution and the change of ionic concentration of the electrolyte in tissues during hemodialysis. Also, we could estimate the relative change value of the intra- and extracellular fluid volume by the impedance method, if there were no ionic concentration change in the electrolyte. It would be very difficult to estimate the absolute change value of them because a shadow effect due to the cells depends greatly upon the shape and size of the cells and the cell concentration.
Asunto(s)
Fenómenos Fisiológicos Sanguíneos , Líquidos Corporales/fisiología , Diálisis Renal , Anisotropía , Tamaño de la Célula , Impedancia Eléctrica , Eritrocitos/fisiología , Hematócrito , Humanos , Modelos Biológicos , Cloruro de Sodio/farmacologíaRESUMEN
A new antifungal antibiotic, fusarielin A, and three related compounds, fusarielins B, C and D, were obtained from a culture of a Fusarium sp. The skeletal structure and the relative stereochemistry of fusarielin A were determined mainly on the basis of its NMR data, and the absolute structure was elucidated by using the exciton chirality method and the modified Mosher method. The structures of the other homologues were determined by comparison of their spectral data with those of fusarielin A.
