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R May

Publications and source records attributed to R May.

At least 19 recordsLinked to original sources
PubMed1992

Domain structure of the human immunodeficiency virus reverse transcriptase.

The spatial arrangement of subunits p51 and p66 of the HIV-1 reverse transcriptase and the position of the RNase H containing domain, p15, have been determined by means of neutron small-angle scattering. The reverse transcriptase (p66/p51) is a flat molecule, which can be approximated by an ellipsoid with the half axes of 5.2 nm, 4.8 nm and 1.4 nm. The two subunits p51 and p66 having a centre-to-centre distance of 3.3 +/- 0.3 nm are attached at their flat sides, slightly shifted sideways. The p15 domain is located at the long axis of the ellipsoidal reverse transcriptase having a distance of 5.0 +/- 0.5 nm to the centre of the p51d domain, which is part of the p66 subunit, and a distance of 5.3 +/- 1.2 nm to the centre of the neighbouring p51s subunit.

Chromatography, Affinity↗
PubMed1992

Structural dynamics of translating ribosomes.

We describe three groups of small angle neutron scattering (SANS) experiments with translating ribosomes: 1) regular protonated (normal abundance hydrogen) particles; 2) two isotopic hybrid particles which are reconstituted from one protonated and the other deuterated subunit; 3) four isotypic hybrid particles differing from each other by the extent of protein and RNA deuteration. Using the SANS contrast variation method the radii of gyration of protein and RNA components in both ribosomal subunits as well as the intersubunit distance in the pre- and post-translocation states were determined. The results obtained suggest the following model of the ribosome as a dynamic machine. The ribosome oscillates between two major conformers differing in geometrical dimensions. The 'active' (pulsating) part of the ribosome is the 30S subunit. We believe that the movement of its 'head' relative to the passive 50S subunit is the main mechanical act of translocation. The radius of gyration of the 30S subunit and the intersubunit distance change upon the movement. This is corroborated by neutron scattering data.

Bacterial Proteins↗
PubMed1979

Varicose veins.

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Arteries↗
PubMed1979

Thrombosis after phlebography?

In contrast to the report by Albrechtsson, we have never seen clinically manifest thrombosis in more than 20,000 phlebographies; only small, clinically insignificant thrombi in a very few cases. The reason is because we have used only 40 cm3 of a 45% contrast medium in connection with heparin precaution. However, there is the possibility that the deep venous valves are damaged. Therefore Amipaque is important for the phlebography. Our test, 20 cm3 45% conventional contrast medium injected directly into varicose veins, always gives a venous thrombosis of about 20 cm. The same amount of Amipaque has never shown a reaction.

Diatrizoate↗
PubMed1978

[Venous surgery: varicose veins (author's transl)].

INDICATION: varicose veins of the long saphenous vein and short saphenous vein. CONTRAINDICATION: locally developed varicose veins and all forms of edema. When there is doubt, venography and tracing of the lymphatic vessels should be performed. Preservation of the lymphatic channels: incision in the groin higher than usual. Note the seven variations of the junction of the short saphenous vein. In case of damaged deep veins, operative treatment only if venous pressure curve shows improvement after compression of the superficial varicose veins.

Blood Pressure Determination↗