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Biomedical subjects

V Machán

Publications and source records attributed to V Machán.

13 recordsLinked to original sources
PubMed1984

99mTc-labelled compounds prepared with molybdenum III as reducing agent.

The experiment of labelling DTPA, HEDSPA and gluconate revealed that it is also possible to make successful use of Mo(III) to reduce pertechnetate in solution of pH 5.5. 99mTc after i.v. administration of [99mTc]Mo-DTPA is quickly removed from the organism without any more remarkable cumulation being manifested in any one of the organs; after administration of [99mTc]Mo-HEDSPA it is cumulated in bones (42% in 1 h). During gluconate labelling two types of technetium complexes are formed depending upon the duration of pertechnetate reduction. Complex I is formed during 1-3 min reduction, giving, in biological experiments, 20% of applied 99mTc activity within 2 h in kidneys. Complex II, which is formed after 45 min reduction, loses its affinity towards kidneys, being cumulated in bones (12% in 2 h).

Animals↗
PubMed1981

99mTc-labelled compounds prepared with sodium dithionite as reducing agent.

The paper deals with the applications of Na2S2O4 as reducing agent in the preparation of 99mTc-labelled compounds. The reduction of pertechnetate can advantageously be carried out in neutral solutions of pH 7. Using this procedure, DTPA, HEDSPA, MDP, gluconate, citrate and trypsin were successfully labelled. In HEDSPA and MDP labelling, a high as cumulation of 99mTc in rat bones (50%) was obtained. In gluconate labelling, under various reaction temperatures, two types of complexes were prepared. Complex I shows a 99mTc biodistribution which is comparable with the kidney diagnosticum 99mTc-Sn-gluconate (24% of 99mTc in kidneys). Complex II, on the other hand, exhibited a reduced affinity of 99mTc to kidneys (2.2%) which, however, increases in bone to 15.4%. The experimental results indicated that Tc(V) is bound in Complex I. In technetium complexing no "mixed complex" is formed technetium being complexed directly by chelate-forming groups on the labelled compound.

Animals↗
PubMed1978

Age-dependent variations in the intensity of isoprenaline-induced myocardial lesions in rats.

Isoprenaline dosed 50 mg/kg was injected intraperitoneally into rats aged 42 days, 3 months, and 18 months. At intervals of 12, 18, 24, 48 hours and 5 days the degree of myocardial lesion was checked by the technetium-labeled oxytetracycline [99mTc-Sn-oxytetracycline] method. Three hours after its i. v. injection the myocardial radioactivity was measured in a control group and in the group treated with isoprenaline. Markedly higher radioactivity was found in animals given isoprenaline than in the controls. Besides, the degree of myocardial lesion considerably varied in dependence on the animals' age, being lowest in the 42-days-old and highest in the 18-months-old rats. In all age groups a biphasic alteration was observed, consisting of a phase of rapid decrease in radioactivity up to 24 hours, and a phase of slow decrease from the 24th hour till the 5th day after injection of isoprenaline. The authors consider the method using technetium-labeled oxytetracycline convenient for assessing the degree of myocardial lesion.

Age Factors↗