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Biomedical subjects

D Rose

Publications and source records attributed to D Rose.

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

Cation exchange resin and calcium excretion. An experimental study.

It has been suggested that cation exchange resins might be helpful in urinary stone prophylaxis. The effect of the cation exchange resin Dowex 50 WX8 upon calcium absorption and urinary excretion in guinea pigs was investigated. The mean fecal calcium concentration was very close in the Dowex-treated and control animals and the urinary calcium concentration was not reduced in the resin-treated animals. These findings suggest that Dowex was ineffective in binding calcium in the gastrointestinal tract.

Animals↗
PubMed1971

Lignofibrils on the external cell wall surface of cultured plant cells.

Small strands and bundles of strands extend from the outside surface of suspension-cultured cells of Daucus, Ipomoea, and Phaseolus into the medium. This fibrous cell coat is present in all samples from various growth stages but appears to increase in quantity in the order Ipomoea < Phaseolus < Daucus. The bundles are often many microns in length and display great variation in frequency, size, and form. Identification of the composition of the strands and bundles as lignin is consistent with the following observations: alkaline nitrobenzene oxidation of the strands to compounds which resemble monomers of wood lignin; resistance of the strands to pronase, trypsin, pectinase, and lipase; strong irreversible adsorption of heavy metals; deposition of silver granules by treatment with silver nitrate-hexamine reagent; extraction of the bundles with aqueous dioxane (Björkman procedure); presence in quantity of a structured form of Klason lignin; and existence of material giving a positive test with the Wiesner reagent. Large individual strands (lignofibrils) from Phaseolus show the form of a flat ribbon with very thin branches at irregular intervals. This form does not vary with preparatory techniques, although its electron opacity does. Intercellular spaces display considerable structure and sometimes contain sheets of fibrillar material merging with both the middle lamella between the cells and the surface bundles facing the medium. These sheets are probably another form of association of the lignofibrils. It is suggested that natural fibrous lignin may be a much commoner component of plant tissue than suspected hitherto.

Cell Fractionation↗