Ionic selectivity of sodium channels was examined under voltage clamp conditions in normal and denervated twitch fibres and denervated tonic fibres isolated from m. ileofibularis of the frog (R. temporaria). Membrane currents were recorded by means of the Hille-Campbell vaseline-gap voltage clamp method from muscle fibre segments exposed to a potassium-free artificial internal solution. Permeab...

This study was designed to assess the efficacy of vacuum sealing drainage (VSD) on skull exposure wounds in rabbits and to investigate the underlying mechanism of the process. Full-thickness excisional circular wounds 2×2 cm with or without periosteum involvement were created in 88 New Zealand white rabbits (mean body weight: 3.0±0.65 kg). Animals were randomly divided into 4 groups: periosteum...

1. Washed erythrocytes, in both acid and alkaline solutions, hemolyze more rapidly when allowed to settle out on a clean microscope slide than when kept in suspension. 2. This is also true on slides coated with paraffin, paraffin oil, or vaseline, and on mica surfaces. 3. The presence of as little as 0.1 per cent serum inhibits such contact hemolysis, particularly in alkaline solutions. 4. Cont...

Sterile plain broth contains an active oxidation-reduction system, the characteristics of which have been analyzed. 1. Intensity factor: Under vaseline seal, the lot of broth used in these experiments reaches a reduction potential corresponding to reduced indigo disulfonate (rH = 10). All the indicators with a more positive E(0)' are reduced, the others are not affected. It seems probable that ...

Reserpine, on systemic administration (1) as well as after intracerebroventricular injection (2), exerts parasympathomimetic effects such as miosis, salivation, and diarrhoea. These effects have been attributed to increased central parasympathetic activity since reserpine increases the acetylcholine contents of the hy pothalamus (3). A direct parasympathomimetic action of reserpine has been exc...

Pending goals are intentions that are postponed by a planner because they do not fit into the current, ongoing activity. Recognizing later opportunities to achieve pending goals is an important cognitive ability because it allows one to defer work on a goal until one is in a better position to achieve it. This research focuses on when and how pending goals are recognized in everyday planning si...

The relative permeability of endplate channels to many organic cations was determined by reversal-potential criteria. Endplate currents induced by iontophoretic "puffs" of acetylcholine were studied by a Vaseline gap, voltage clamp method in cut muscle fibers. Reversal potential changes were measured as the NaCl of the bathing medium was replaced by salts of organic cations, and permeability ra...

The Brazilian biodiversity offers a multiplicity of raw materials with great potential in cosmetics industry applications. Some vegetable oils and fatty esters increase skin hydration by occlusivity, keeping the skin hydrated and with a shiny appearance. Sunflower (Helianthus annus L.) oil is widely employed in cosmetic emulsions in the form of soaps, creams, moisturizers and skin cleansers due...

An attempt was made to explain the excessive wilting tendency of 3 tomato mutants, notabilis, flacca, and sitiens. The control varieties in which these mutations were induced are Rheinlands Ruhm for flacca and sitiens and Lukullus for notabilis. Although all 3 mutants are alleles of separated loci, they seem to react similarly to water stress. The mutants wilt faster than the control plants whe...

Charge movements similar to those attributed to the sodium channel gating mechanism in nerve have been measured in frog skeletal muscle using the vaseline-gap voltage-clamp technique. The time course of gating currents elicited by moderate to strong depolarizations could be well fitted by the sum of two exponentials. The gating charge exhibits immobilization: at a holding potential of -90 mV th...