Search PubMed⌕ Search

Biomedical subjects

I Robertson

Publications and source records attributed to I Robertson.

At least 127 records · Page 7Linked to original sources

Standard for human thrombin.

Ten laboratories took part in an international study of the proposed standard for human thrombin. A freeze-dried preparation (coded 70/157) was shown, using clotting time tests, to be suitable to serve as a standard for the assay of human and bovine thrombin preparations. The study shows that assay variation within laboratories was much less than between laboratories. The preparation was stable, having a negligible estimated loss of potency after ten years under the recommended storage conditions (--20 degrees C in the dark). Each ampoule of the standard was assigned a potency of 100 units of thrombin activity, and one unit was defined as the activity contained in 0.0853 mg of the freeze-dried preparation. It was agreed by the participants in the study and by the International Committee on Thrombosis and Haemostasis (Vienna, 1973) that the thrombin preparation coded 70/157 is suitable to serve as an international standard for human thrombin.

Animals↗

Keratoconus and the Ehlers-Danlos syndrome: a new aspect of keratoconus.

Hypermobility of the joints is a frequent finding in patients who have keratoconus. Twenty-two of 44 patients (50%) presenting in 1973 were found to have hypermobility of joints (mainly Ehlers-Danlos syndrome II or mitis type). The significance of this finding is discussed in relation to biochemical defects recently found in corneas with keratoconus. The hypothesis is presented that keratoconus is often a part of a generalized heritable disorder of connective tissue due to a biochemical defect causing a weakness in its structure.

Adolescent↗

Measurement of calcium in sections of a human skeleton using a reactor spectrum-in vivo activation analysis technique.

Factors influencing the precision of measuring changes in the calcium content of sections of bone, including vertebrae, using reactor neutrons for partial body in vivo activation analysis have been examined and quantified. These factors include (a) the choice of incidient neutron spectrum, (b) the uniformity of activation with depth in the body, (c) reproducibility, (d) interfering reactions, (e) sensitivity and (f) dosimetry. It is concluded that an overall precision of 2.8%-3.2% (coefficient of variation) can be attained with a neutron dose of 50 mrad or 3-4% with a dose as low as 20 mrad.

Activation Analysis↗

A high sensitivity dual-detector shadow-shield whole-body counter with an 'invariant' response for total body in vivo neutron activation analysis.

The development of a dual-detector shadow-shield whole-body counting system of high sensitivity is described. The sensitivity and performance of the counter are analysed, with specific references to total body in vivo neutron activation analysis, and shown to be at least comparable with those of many conventional shielded-room counters.

Activation Analysis↗