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Biomedical subjects

L A Wright

Publications and source records attributed to L A Wright.

32 records · Page 2Linked to original sources
PubMed1981

Properties of Magnesium Chelatase in Greening Etioplasts: METAL ION SPECIFICITY AND EFFECT OF SUBSTRATE CONCENTRATIONS.

Evidence was obtained by means of low temperature spectrofluorimetry and high pressure liquid chromatography for the exclusive chelation of Mg(2+) into protoporphyrin IX by a plastid preparation extracted from greening cucumber cotyledons. Under the experimental conditions which were optimized for Mg(2+) chelation, Zn(2+) chelation was not detected. However, Zn(2+) chelation was observed when ATP was omitted and ZnCl(2) was added to the incubation mixture. The observed Zn(2+) chelation was partially nonenzymic. The requirements for the enzyme, Mg chelatase, are discussed in terms of the regulatory function of this enzyme.

Journal Article↗
PubMed1980

Effect of some commonly prescribed drugs on certain chemistry tests.

Of the 44 commonly prescribed drugs listed only ascorbic acid, at the upper end of its therapeutic range, significantly affected any (glucose, uric acid) of the twenty-three more frequently requested tests measured in the clinical chemistry laboratory. Acetaminophen, acetylsalicylic acid, ascorbic acid, nitrofurantoin, methyldopa and tetracycline at five times the upper end of their therapeutic ranges individually produced consistently significant effects on one or more of the following tests: glucose, bilirubin, carbon dioxide, calcium, cholesterol, uric acid and aspartate aminotransferase. When drugs are added to lyophilized human serum and to fresh human serum in similar concentrations, their effects on clinical chemistry tests performed on these two different sera are not always the same.

Acetaminophen↗
PubMed1975

Photoreactivation of nitrate reductase production in Nicotiana tabacum var. Xanthi.

Ultraviolet (254 nm) irradiation of liquid-cultured tobacco cells inhibited the production of nitrate reductase; subsequent illumination with white light allowed a partial restoration of the synthesis of the enzyme (photoreactivation). Ultraviolet irradiation of these same cells also inhibited their ability to incorporate labeled uridine and labeled amino acids. Subsequent illumination with white light gave a partial restoration of the ability of the cells to incorporate uridine while a similar post-ultraviolet-irradiation treatment failed to restore the amino acid incorporation. The system in tobacco known to repair ultraviolet-damaged viral RNA thus does not seem to repair ultraviolet damage to the protein-synthesizing system of the cell. The photoreactivation of nitrate reductase production is best explained by the action of a DNA photorepairing system.

Amino Acids↗
PubMed1969

Proterozoic eucaryotes from eastern california.

Both procaryotic and eucaryotic nannofossils occur in chert from the upper Beck Spring Dolomite (Pahrump Group) in northeastern San Bernardino County, California. These fossils include the oldest reasonably certain records to date of chlorophycean and chrysophycean algae, and hence of the eucaryotic or mitosing cell. Associated with these are cyanophycean procaryotes of still more ancient affinities. Indirect radiometric evidence implies an age of 1.2 to 1.4 aeons (1.2 to 1.4 x 10(9) years) for the enclosing rocks. Associated stromatolites are consistent with such an age assignment.

Journal Article↗