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Biomedical subjects

E Chiotellis

Publications and source records attributed to E Chiotellis.

7 recordsLinked to original sources
PubMed1992

Synthesis, radiochemistry and biological evaluation of technetium-99m complexes with 1,8-diamine-3,6-dithiaoctane (DDO) ligands.

The synthesis, radiochemical analysis and biological characteristics of some 1,8-diamine-3,6-dithiaoctane derivatives labelled with Tc-99m are reported. Analysis by HPLC shows that most of the 99mTc-chelates are multicomponent. Furthermore, almost all 99mTc-complexes isolated by HPLC are lipophilic and stable in vitro. The biodistributions of the most lipophilic of these complexes were evaluated in mice. The N-morpholinylethyl and N,N'-bisalicylyl derivatives of 1,8-diamine-3,6-dithiaoctane yielded 99mTc-complexes which exhibit considerable uptake and retention in organs of interest, such as the heart and the brain.

Animals↗
PubMed1988

Comparative evaluation of 99mTc-labeled aminothiols as possible brain perfusion imaging agents.

Several new 99mTc aminodithiols were prepared and evaluated comparatively in experimental animals. The ligands were diamine, triamine or tetramine dithiols. Substituents were either attached on one of the nitrogens or introduced in between the two nitrogens of diamino dithiol (DADT) backbone. 99mTc-derivatives prepared by coupling DADT to secondary amines via ethylene group showed in mice high initial brain uptake and significant retention in brain tissue. These preparations were mixtures of more than one 99mTc-complex differing in brain uptake and clearance from the brain. The highest brain retention (brain to blood ratio 2.53, 15 min p.i.) was achieved with the 99mTc-complex prepared by coupling DADT with ethylene pyrrolidine. Lengthening the chain between the nitrogens of DADT moiety by introducing methyl or amino alkyl groups resulted in 99mTc-complexes with poor brain accumulation.

Animals↗
PubMed1979

Absorbed dose estimation of some 99mTc-hepatobiliary agents.

The absorbed dose estimates of several organs after administration in humans of six new hepatobiliary agents (five 99mTc-Pyridoxal amino acid complexes and the 99mTc-HIDA) are presented in comparison with 131I-Rose-Bengal. The results indicated that the radiation doses absorbed by the total body and gonads as well as by the critical organ (upper part of the large intestine) are significantly lower than those of Rose Bengal. Therefore, the new 99mTc-agents can be safely applied to humans.

Adult↗
PubMed1978

99MTc-HIDA, a gallbladder imaging agent: experimental aspects.

The molecule N-(2,6-dimethyl-phenyl-carbamoyl-methyl)-iminodiacetic acid (HIDA), capable of chelating reduced 99mTc, was synthesized, characterized, labeled with 99mTc, and studied in experimental animals. The results indicated that the new 99mTc-radiopharmaceutical is rapidly cleared from the blood to the liver, then rapidly removed to the gallbladder and excreted into the duodenum through the common bile duct. A comparative kinetic study of 99mTc-HIDA and 131I-Rose Bengal performed in rabbits demonstrated that both radiopharmaceuticals had a similar blood clearance rate, but cleared at a different rate from liver to gallbladder. 99mTc-HIDA showed a faster accumulation in the gallbladder than 131I-Rose Bengal. These findings, combined with the advantage of the low acute toxicity of HIDA, were promising enough to encourage a further evaluation and clinical investigation of this new Tc-99m hepatobiliary agent.

Animals↗