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Biomedical subjects

C R Ricketts

Publications and source records attributed to C R Ricketts.

At least 37 records · Page 2Linked to original sources

Mechanism of prophylaxis by silver compounds against infection of burns.

To clarify tthe mechanism by which local application of silver compounds protects burns against infection, an ion-specific electrode was used to measùre the concentration of silver ions in solutions. By this method it was shown that in burn dressings silver ions were reduced to a very low level by precipitation as silver chloride. The antibacterial effect was found to depend on the availability of silver ions from solution in contact with precipitate. Between 10(-5) and 10(-6) molar silver nitrate solution in water was rapidly bactericidal. The minimal amount of silver nitrate causing inhibition of respiration of skin in tissue culture was about 25 times the minimal concentration of silver nitrate that inhibited growth of Pseudomonas aeruginosa.

Adsorption↗

Changes in the molecular composition of circulating hydroxyethyl starch.

1. Hydroxyethyl starch (HES) of molecular weight 450,000 has been extensively investigated as a plasma volume expander and HES of molecular weight 60,000 has been proposed for use as a cryoprotective agent in the freezing for preservation of red blood cells. In these applications considerable amounts of HES may be injected intravenously and it is therefore desirable to understand its behaviour in vivo.2. After intravenous injection into rabbits, plasma levels of HES and clinical dextrans were determined using anthrone. HES persisted longer in the circulation than did the dextrans.3. HES was recovered from the bloodstream of rabbits and shown by gel filtration to be of a narrower molecular size distribution than the injected material. Smaller molecules were removed, presumably by filtration at the glomerulus. Larger molecules may have been removed by cells of the reticuloendothelial system or possibly through the action of amylase.4. The amylase in saliva was shown to break down HES into molecules of intermediate size with very little production of maltose units.

Amylases↗