Kinetics of enzymic oxidation of indoleacetic acid (ISA) are interpreted as indicating that the reaction has an autocatalytic, cyclical mechanism invol\-ing unst,ablc intermcdiatcs whose formation and disappearance are important in determining the over-all reaction rate. The kinetics do not supporl the idea that IAA oxidation occurs mainly by reaction with Mnt3, nor that the reaction is an elec...

An apparatus is described for the measurement of the rates of fast precipitation reactions. It consists of a T-tube, where reactants are added to the arms of the T, mixed rapidly at the junction, and the rates of disappearance of reactants or appearance of products are measured along the stem of the T. The geometry of the system results in a steady state being established in the apparatus, enab...

A conditioning treatment of 30 min at 42 degrees C or 43 degrees C, followed by a 4-h recovery period at 37 degrees C, induces thermotolerance state in the cytoskeleton of Reuber H35 hepatoma cells and N2A neuroblastoma cells. Evidence for the involvement of heat shock proteins in the development of thermotolerance in the cytoskeleton has been obtained from the following observations: only thos...

Plasmid-mediated chloramphenicol resistance in Staphylococcus aureus has been shown to involve acetylation of chloramphenicol by an enzyme induced by growth in the presence of the antibiotic and certain analogues. Analysis of the kinetics of induction has been complicated by (i) the intrinsic inhibitory effects of chloramphenicol on induced enzyme synthesis and (ii) the rapid disappearance of i...

Tetraethylammonium (TEA1) is widely used for reversible blockade of K channels in many preparations. We noticed that intracellular perfusion of voltage-clamped squid giant axons with a solution containing K1 and TEA1 irreversibly decreased the potassium current when there was no K1 outside. Five minutes of perfusion with 20 mM TEA1, followed by removal of TEA1, reduced potassium current to <5% ...

Dry matter (DM) degradation of wheat straw (WS), barley straw (BS), lucerne hay (LH) and maize silage (MS) was determined using two different techniques: (i) in vitro gas production and (ii) nylon bag degradability technique. In vitro gas production and in situ DM disappearance were measured after 3, 6, 12, 24, 48, 72 and 96 hours of incubation. In situ and in vitro DM degradation kinetics was ...

Therapy with monoclonal antibodies (mAbs) is characterized by a molar ratio of receptor to drug that is higher than usual in pharmacotherapy. As a consequence, changes in the amount of receptors induced by the therapy may have important consequences for pharmacokinetics. We therefore analyzed the pharmacokinetics and pharmacodynamics of an experimental therapeutic CD3 antibody, CLB-T3/4.A (muri...

Recessed oxygen microelectrodes (tip diameter less than 2 microns) were positioned stereotactically into either the cerebral cortex or the hippocampus of sodium pentobarbital anesthetized gerbils (n = 21). The mean tissue PO2 levels (+/- SEM) were not significantly different between cortex (35.4 +/- 1.7 torr) and hippocampus (33.6 +/- 1.4 torr) although differences in the tissue PO2 distributio...