Comparative screening for thyroid disorders in old age in areas of iodine deficiency, long-term iodine prophylaxis and abundant iodine intake.

Objective: To investigate the effect of varying amounts of iodine intake on the prevalence of thyroid dysfunction, autoimmunity and goitre in old age.

Design: The first screening study where elderly subjects with varying amounts of iodine supply but from the same geographical and ethnographical region (Carpathian basin) were compared, and all hormone measurements and ultrasonography were performed by the same laboratory or person.

Patients: Nursing home residents were screened for thyroid disorders from: (A) an iodine-deficient area, Northern Hungary (n = 119; median age 81 years; median iodine excretion (MIE) 0.

Is an amphiphilic region responsible for the haemolytic activity of Bacillus thuringiensis toxin?

The amino acid sequence of the 27 kDa protein responsible for the haemolytic activity of Bacillus thuringiensis subsp. israelensis toxin has been analysed by secondary structure prediction, helical wheel/net diagrams and molecular mechanics calculations. We found that segment 116-126 presumably forms a strongly amphiphilic alpha-helix.

Identification of a fluorescent dye-containing peptide of glyceraldehyde-3-phosphate dehydrogenase.

The NAD-induced local conformational changes in the fluorescent dye-binding region of muscle glyceraldehyde-3-phosphate dehydrogenase were studied (Ovádi et al., 1982). We have isolated a dominant peptide containing the fluorescent dye from the tryptic digest of labelled dehydrogenase, and identified this labelled amino acid residue.

Identification of an intramolecular cross-link in troponin C after cross-linking the troponin complex with 1,3-difluoro-4,6-dinitrobenzene.

The troponin complex isolated from rabbit skeletal muscle was cross-linked with 1,3-difluoro-4,6-dinitrobenzene, subjected to tryptic hydrolysis, and the labelled peptides were separated. One peptide was purified to homogeneity; it proved to be peptide Gly(89)-Arg(100) of troponin C on the basis of amino acid composition and N-terminal analysis. The absorption spectrum of this peptide between 300 and 500 nm was very similar to that of 1-(S-cysteinyl)-5-(N epsilon-lysyl)-2,4-dinitrobenzene, which could only be due to cross-link formation between Lys-90 and Cys-98.