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Biomedical subjects

D Paul

Publications and source records attributed to D Paul.

At least 217 records · Page 12Linked to original sources
PubMed1976

[Rheology and spinning of alkaline solution of field bean protein and casein].

From field bean protein and a mixture of field bean protein with casein to equal parts are prepared with sodium hydroxide high protein-containing alkaline solutions, which show pseudoplastic flow. The flow curves of the pseudoplastic field bean protein-casein (I:I)-solutions are described mathematically with the Ostwaldian power statement. In a suitable scope of spinning of this solutions are carried out complete factorial experiments, which guide to regression equations of lg k and n. g k depends on the concentration of protein; an effect of the sodium hydroxide concentration exists lonly about interactions. On the other hand the flow exponent n depends on the hydroxide concentration. The properties of the spun field bean protein/casein (I:I) fibres are described.

Caseins↗
PubMed1976

[Characterization and spinning of alkaline solutions of wheat protein and casein].

The viscosity behaviour of alkaline solutions of mixtures from different wheat glutens with casein in dependence on the concentration of the whole protein, wheat protein, sodium hydroxide, sodium chloride and on the temperature, time and the effect of treatment of wet wheat gluten with sodium chloride or sodium hydroxide on the properties of the spun wheat protein/casein fibers are described. Based on this model experiments the rheological behaviour of alkaline solutions of wheat protein/casein (I:2) and proceed from the parameters of the spinning process the properties of the corresponding spun fibers are represented.

Caseins↗
PubMed1975

Growth control in primary fetal rat liver cells in culture.

Primary fetal rat liver cells cultured in medium deficient in, but not free of, arginine in the presence of dialyzed fetal calf serum grow until the final cell density is attained and cells become quiescent in the Go phase of the cell cycle. When growing cells are transferred into arginine free medium, cells become reversibly arrested in Go. Fetal rat liver cells can be induced to synthesize DNA by addition of high levels of arginine to serum free medium. Low arginine levels in the culture medium do not induce cell growth unless serum is present. Serum stimulates arginine uptake in fetal rat liver cells suggesting that serum growth factor(s) act by increasing intracellular arginine levels high enough to initiate the growth cycle. Fractionation of fetal calf serum by gel filtration on G-200 Sephadex yields a partially purified arginine uptake stimulating activity which is eluted from the column in the same fractions that contain fetal rat liver cell growth promoting activity. Insulin induces DNA synthesis in quiescent fetal rat liver cells. Glucagon reverses the stimulatory effects of insulin. N-6,O-2-Dibutyryl adenosine 3:5-cyclic monophosphoric acid (But2c-AMP) (10-minus4 M) and theophilline (10-minus3 M) inhibit arginine uptake and the initiation of DNA synthesis by serum. The role of arginine in the control of DNA synthesis in fetal rat liver cells and the mechanism of action of serum growth factors are discussed.

Animals↗
PubMed1975

Production and properties of an extracellular bacteriocin from Streptococcus mutans bacteriocidal for group A and other streptococci.

An extracellular bacteriocidal substance is produced by a serotype c strain of Streptococcus mutans in liquid meduim during the stationary phase of growth. The lethal effect of the substance was demonstrated by the decrease in viable counts of a standardized suspension of group A streptococci in broth. No lysis of affected cells was observed and no changes in appearance of these cells was seen in electron micrographs. The material was effective against certain strains of immmunological groups A, C, D, G, H, L, and O streptococci. It was inactive against strains of S. mutans belonging to the a, b, c, and d serotypes, Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. The factor was purified 273-fold from the culture fluid by column chromatography. It was sensitive to trysin and Pronase and resistant to catalase. It possessed a molecular weight of more than 20,000 and was not dialyzable. The properties of this substance indicate that it is a bacteriocin. Group A streptococci, which had been treated with antiserum specific for the cell wall group and type antigens, were susceptible to the bacteriocin. Streptococcal strains resistant to the lethal action of the bacteriocin adsorbed the bacteriocin from the solutions, as did the sensitive cells. The bacteriocin was not adsorbed at 0 C.

Adsorption↗