Biomedical subjects

J Robeson

Publications and source records attributed to J Robeson.

3 recordsLinked to original sources

PubMed1982

Mixed association of cholesterol with methyl cholate and methyl lithocholate in chloroform solutions.

The concentration-dependent mixed association behavior of cholesterol with methyl cholate (MeC) and methyl lithocholate (MeLC) in chloroform at 37 degrees C has been studied by vapor pressure osmometry (VPO). This study is part of a larger project to investigate the effect of number and position of hydroxyl-bearing steroids. Using theories developed by Adams and by Steiner, the model and appropriate parameters for the nonideal mixed associations were elucidated. For the MeLC/cholesterol system, no mixed association was observed. For the MeC/cholesterol system, both methods of analysis indicate that a nonideal AB complex formation occurs. The best parameters to explain the experimental data are kAB = 0.04 1/g; BAB (the nonideal term) = 1.5 X 10(-5) 1 mol g-2.

Chemical Phenomena↗

PubMed1978

New peroxides and their antimicrobial activity.

Antimicrobial activity of hydroperoxides and cyclic peroxides has been studied. 2,4-Dihydroperoxy-2,4-dimethylpentane (1) and 2,5-dihydroperoxy-2,5-dimethylhexane (2) were active against microorganism, but 1 showed a large specially against C. albicans, M. luteus and B. subtilis with a MIC value of 31.5 mcg/ml.

Bacillus subtilis↗

PubMedDate not supplied

Protein isolation by solution-controlled gel sorption.

Illustrated are the principles for isolating proteins from solution by sorption into a polymer gel phase, driven by the addition of a water-soluble polymer to the protein solution. The separation is shown to be analogous to conventional two-phase aqueous extraction. However, the use of a gel phase rather than a solution for absorbing the protein makes separation of the protein from the polymer and the recycling of the gel phase much simpler. The model system used was linear poly(ethylene glycol) (PEG) and dextran gel. Increasing the molecular weight and concentration of the PEG favored sorption by the gel of ovalbumin, bovine serum albumin, cytochrome c, and hemoglobin. The proteins could be quantitatively recovered by immersing the gel in PEG-free solution.

Chemistry Techniques, Analytical↗