The ion-step measuring method was used to determine absolute heparin concentrations in PBS and blood plasma with a Ta2O5 ISFET on to which a monolayer of protamine had been immobilized. Heparin is a highly negatively charged polysaccharide, which is used clinically to delay the clotting of blood. Protamine acts as an affinity ligand for heparin. The response of the ISFET system on a step-wise i...

The cardiac glycoside, ouabain, inhibits alkali-cation transport in HeLa cells. It binds to 0.75 x 10(6) sites per cell, and the half-time for its dissociation is 16 hr. After partial blockade by ouabain, the cell generates new ouabain-binding sites, with total restoration of transport in 10% of a cell cycle( approximately 3 hr). This recovery requires protein synthesis and appears to be a resp...

The capacitive stimulation of nerve cells from semiconductor chips is a prerequisite for the development of neuroelectronic devices. We report on the primary response of a cell membrane to a voltage step applied to oxidized silicon. It is observed with a luminescent voltage-sensitive dye. We find exponential voltage transients with a time constant of 1-5 micros. We assign the short response to ...

An advanced understanding of acid-base physiology is as central to the practice of critical care medicine, as are an understanding of cardiac and pulmonary physiology. Intensivists spend much of their time managing problems related to fluids, electrolytes, and blood pH. Recent advances in the understanding of acid-base physiology have occurred as the result of the application of basic physical-...

THE ESTIMATION OF PLASMA VOLUME has become a very useful and widely applied tool in the diagnosis and treatment of clinical aberrations of water and electrolyte distribution. Methods utilizing the dilution of radioactive iodinated serum albumin (BISA), have been studied and applied extensively, and most of the strictly methodologic difficulties have been overcome. One step, however, that of inj...