Selenium levels in patients with autoimmune thyroiditis and controls in lower Austria.

Autoimmune thyroiditis (AIT) is one of the most common autoimmune diseases; genetic as well as environmental factors contribute to its pathogenesis. The thyroid is the organ with the highest selenium content per unit weight. Selenium status appears to have an impact on the development of thyroid pathologies. We investigated a possible difference of selenium serum levels as a marker of nutritional selenium supply between patients with AIT in central Lower Austria and a matched group of healthy persons living in the same region. Selenium serum levels in the patients with AIT were 98.0 ± 15.6 µg/l. A significant difference to the matched group of normal persons, whose selenium serum levels were 103.2 ± 12.4 µg/l, could not be detected by the t-test (p>0.05). We considered the serum selenium levels to be indicators of selenium supply (by alimentation). A serum level of 120-160 µg/l of selenium represents the normal range. According to this, most patients and control persons showed mild to moderate selenium deficiency (80-120 µg/l selenium). Although our data present slightly higher selenium levels in normal persons than in patients with AIT, this weak and statistically insignificant trend is not sufficient to support the conclusion of a link between inadequate selenium supply and autoimmune thyroid disease.

Synthesis and biological evaluation of gallium polyaminothiols (PAT).

Two polyaminothiol ligands, one hexadentate, N,N',N"-tris[2-methyl(2-propanethiol)]-1,4,7-triazacyclononane (TACN), and another potentially heptadentate, tris[2-methyl(2-propanethiol)]aminoethylamine (TMAE), were synthesized and characterized using spectroscopic and analytical methods. Both ligands were labeled with gallium-67 at pH 3.0-3.5 in high yields. The resulting gallium chelates were lipophilic. The biodistribution studies for both the chelates showed hepatic uptake and biliary clearance. The total % ID activity for [67Ga]TACN in liver and intestine at 5 min was 33.86 increasing gradually to 61.4% at 30 min. The chelates were in vivo stable to plasma-transferrin transchelation as confirmed by scintigraphic images obtained by [67Ga]TACN in rats and by plasma incubation of the chelates. These results indicate that Ga-TACN is a potentially useful tracer for hepatobiliary imaging using PET. No brain uptake was found.