PubMed Health⌕ Search

Biomedical subjects

S Vilcek

Publications and source records attributed to S Vilcek.

69 records · Page 4Linked to original sources

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↗

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↗

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↗

Application of genetic methods to study the relationship between classical swine fever outbreaks.

Eleven viruses isolated between 1993 and 1997 from outbreaks of classical swine fever in the neighbouring countries of Slovakia, The Czech Republic and Austria were compared after partial sequencing of the NS5B and E2 genes. Viruses collected from South-Central and West Slovakia were indistinguishable during a period of four years, even when associated with outbreaks of variable severity. Outbreaks that occurred in the Czech Republic in 1996 involved two types of virus, one of which was related to the Slovakian outbreaks, and the other to Austrian outbreaks. The results show that the molecular-genetic approach can reveal epizootiological relationships between outbreaks that would not otherwise be apparent. Furthermore, the relative genetic stability of the classical swine fever virus in the field, means that quite small sequence differences can have epizootiological significance.

Animals↗