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Biomedical subjects

G C Roberts

Publications and source records attributed to G C Roberts.

220 records · Page 13Linked to original sources
PubMed1967

Effects of adrenaline on human blood platelets.

1. Adrenaline at concentrations too low to cause aggregation of human platelets potentiates the aggregation by adenosine diphosphate. Noradrenaline has the same effect but is less active than adrenaline; isopropylnoradrenaline is inactive or inhibitory.2. The potentiation of adenosine diphosphate by catecholamines is blocked by the adrenergic alpha-receptor antagonists phentolamine and dihydroergotamine but not by 2-halogenoethylamines or by adrenergic beta-receptor antagonists.3. Both the first and second phases of adenosine diphosphate aggregation are potentiated by catecholamines but the second phase more than the first.4. The release from the platelets of adenine nucleotides which is associated with the second phase of aggregation is also increased by adrenaline.

Adenine Nucleotides↗
PubMedDate not supplied

Crystallization and preliminary X-ray diffraction studies of human cytochrome P450 reductase.

The two functional domains of a cloned human fibroblast NADPH-cytochrome P450 reductase have been expressed in Escherichia coli and purified on the milligram scale for crystallization studies. One domain contains the cofactor FMN-binding site and the other contains the binding sites for cofactor FAD and substrate NADPH. Crystals of both domains have been obtained by the microbatch method. The crystals of the FMN domain belong to the monoclinic space group P21, with unit cell dimensions of a = 39.3 A, b = 51.5 A, c = 47.8 A, and beta = 105.7 degrees and have one molecule in the asymmetric unit. Diffraction data up to 2.3 A were collected with a merging residual on intensity of 9.3%. The crystals of the FAD/NADPH domain belong to the ortho-rhombic space group P212121 with unit cell dimensions of a = 55.9 A, b = 58.6 A, c = 131.1 A and have one molecule in the asymmetric unit. Diffraction data up to 2.6 A were collected with a merging residual on intensity of 8.0%.

Amino Acid Sequence↗
PubMedDate not supplied

Computerized selection of donors for inclusion in red cell antibody panels.

This study evaluated various algorithms for the generation of a red cell antibody identification panel by computer. The algorithms depended on schemes that optimized Fisher's exact p value for each specificity in the panel rather than using predetermined formulations of desired phenotypic combinations. Panels produced by these computer-driven algorithms offered the distinction of a greater number of antibody specificities than manually created panels. They were also evaluated by a group of technologists to be more useful for general serologic work than panels created manually. Although the panels were created from a database of only 252 donors, an objective numeric evaluation showed that the panels were more useful than commercial panels. The computer approach used in this study may offer means of efficiently creating panels for general use as well as creating panels for resolution of particular serologic problems. They may also facilitate and encourage the construction of panels from small donor databases.

Blood Donors↗