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Biomedical subjects

K Korten

Publications and source records attributed to K Korten.

6 recordsLinked to original sources
PubMed1980

Membrane composition modulates thiopental partitioning in bilayers and biomembranes.

The nonspecific interaction of thiopental with erythrocyte ghosts, synaptic membranes, microsomes and mitochondria has been measured at 25 degrees C and pH 6.6. In cholesterol-depleted erythrocyte ghosts the partition coefficient decreases with increasing cholesterol content. In sonicated liposomes made from egg lecithin and cholesterol the partition coefficient also decreases with increasing cholesterol content. The dependence of the partition coefficient on cholesterol content in the biological membranes, on average, parallels that in the lipid bilayers. The partition coefficient in lipid bilayers made from lipids extracted from erythrocyte ghosts was comparable to that in the corresponding egg lecithin/cholesterol bilayer. The partition coefficients of all the biomembranes are consistently lower than those in the corresponding egg lecithin/cholesterol bilayer, the free energy of transfer between biomembrane and corresponding bilayer being -1 kcal/mol.

Animals↗
PubMed1979

Erythrocyte ghost--buffer partition coefficients of phenobarbital, pentobarbital, and thiopental support the pH-partition hypothesis.

The partition coefficient (lambda) between red cell ghosts and buffer has been determined for three barbiturates over a range of pH. Experimental partition coefficients were linearly proportional to the calculated degree of association of the barbiturates. Lambda was 9.5 +/- 0.52 for phenobarbital, 12.7 +/- 0.91 for pentobarbital, and 27 +/- 4.9 for thiopental in their acid forms. Lambda for all three barbiturates in their anionic forms was zero. Our data support the assumption of the pH-partition hypothesis that the dependence of lambda on pH in biological membranes behaves essentially like that in organic solvents. However, the relative magnitudes of the erythrocyte partition coefficients correlate much more closely with the physiological permeability constants than do those of organic solvents, which tend to overestimate the differences between these compounds.

Buffers↗
PubMed1977

Anesthesia for diagnostic procedures.

Invasive procedures such as angiography, pneumoencephalography and bronchography are often facilitated by the skillful administration of carefully selected anesthesia. The advantages of general anesthesia versus an awake patient during cerebral angiography are not yet resolved. Although computerized tomography and myelography can usually be accomplished with no anesthesia and local anesthesia, respectively, in children and in confused, uncooperative patients, sedation or general anesthesia may be necessary.

Adult↗