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Biomedical subjects

S Osman

Publications and source records attributed to S Osman.

80 records · Page 5Linked to original sources
PubMed1983

Lung transit of 111Indium-labelled granulocytes. Relationship to labelling techniques.

The early in vivo distribution of 111Indium-labelled granulocytes, recorded by dynamic imaging using a gamma camara and computer, varied according to the separation and labelling technique. Following i.v. bolus injection, 4 kinetic patterns could be identified: (A) rapid transit through the pulmonary vasculature, (B) delayed transit through the lung with clearance by about 30 min, (C) complete retention by the lung, for up to 10 min, followed by slow release over a period of 1 to 2 h, (D) delayed transit through the lung with a similar time course to (B) but with subsequent heavy liver uptake. Granulocytes labelled with 111In-tropolonate and maintained in plasma throughout the labelling procedure, whether injected as a 'pure' (separated by plasma-enriched density gradient centrifugation) or 'crude' (separated by differential centrifugation) preparation, displayed type A kinetics, thought to most closely represent the normal behaviour of granulocytes. 'Crude' cells labelled in saline with 111In-acetylacetonate displayed type B kinetics. 'Pure' cells isolated on Percoll-saline and labelled in saline with 111In-acetylacetonate displayed type C kinetics, thought to represent granulocyte 'stimulation' and/or damage, or type D kinetics, thought to represent severe damage. The importance is stressed of labelling granulocytes for kinetic studies with a technique that results in minimal alteration of cell behaviour.

Cell Movement↗
PubMed1983

Imaging of inflammation with indium-111 tropolonate labeled leukocytes.

Indium-111 tropolonate has recently been introduced as a new cell-labeling agent. It has the interesting property of labeling cells in plasma with high efficiency, and may therefore promote an improvement in viability of labeled cells. This paper describes our initial experience with In-111 tropolonate as a leukocyte label for abscess imaging. Pure populations of separated granulocytes, as well as crude leukocyte preparations, have been labeled. Of 101 studies performed, 51 were positive (no false positives) and 50 negatives, of which only two were false negatives. Localization in sites of inflammation was prominent and rapid. Of 36 positive studies, 27 were already positive at 40 min following injection and an additional nine at 3 hr. Of the other 15 positive studies, 11 were scanned for the first time at 3 hr, when they were positive. Granulocytes labeled with this agent in plasma showed minimal sequestration in lungs and liver, interpreted as indicating improved viability in comparison with cells displaying prolonged lung sequestration.

Abdomen↗
PubMed1981

Cell labelling and cell damage with indium-111 acetylacetone-an alternative to indium 111 oxine.

The labelling of HeLa S3 cells with 111In acetylacetone (111In-acac) was studied together with cell damage, measured by the reduction in colony-forming ability of labelled cells. Using 2 X 10(5) cells/ml in Hepes saline buffer at pH 7.6 incubated with 7.4-185 kBq (0.2-5.0 microCi)/ml 111In-acac, containing 0.19% acetylacetone for 15 minutes at room temperature, 60-80% 111In was bound to the cells. The cell binding was linear with activity and resulted in an exponential reduction in colony forming ability and a D0 of 26 kBq (0.7 microCi)/2 X 10(5) cells. Radiation was shown to be the major cause of cell damage. It is concluded that 111In-acac is preferable to 111In oxine because it is soluble in physiological buffers, which eliminates the use of ethanol; it is quick and easy to prepare; and compared with previous results using HeLa S3 cells labelled with 111In oxine, 111In-acac gives much more reproducible results and is no more toxic. Clinically 111In-acac was shown to give similar results to 111In oxine.

Cell Survival↗
PubMed1979

Cell damage resulting from the labeling of rat lymphocytes and HeLa S3 cells with In-111 oxine.

Rat thoracic-duct lymphocytes and HeLa S3 cells were labeled in vitro with different amounts of indium-111 oxine. The labeled rat lymphocytes were tested for their ability to recirculate normally in syngeneic rats; the labeled HeLa S3 cells for their ability to divide to form colonies in tissue culture. Both cell types behaved normally by these criteria when labeled with small amounts of indium-111 oxine but at higher doses were obviously damaged. Evidence was obtained for the HeLa S3 cells that this damage was primarily radiation-induced. These findings may impose limitations on the use of In-111 oxine as a cell label for clinical purposes.

Animals↗