Association of serum selenium with thyroxin in severely iodine-deficient young children from the Amhara region of Ethiopia.

BACKGROUND/OBJECTIVES: Selenium (Se) as part of glutathione peroxidase and iodothyronine deiodinase enzymes influences thyroid metabolism. This study investigated the association of serum Se levels with thyroid metabolism of severely iodine-deficient young children from the Amhara region of Ethiopia. SUBJECTS/METHODS: In a cross-sectional study, Se, thyroid-stimulating hormone, total thyroxin, total triiodothyronine and thyroglobulin in serum of children (N=628) 54-60 months of age from the Amhara region, Ethiopia, were analyzed. In addition, iodine in urine and household salt was analyzed, and the presence of goiter was assessed. RESULTS: The median serum Se concentration was 61.4 µg/l (10.7-290.9 µg/l). Selenium deficiency (serum Se <70 µg/l) was detected in 57.8% (N=349) of the children. The median urinary iodine concentration (UIC) was 9.8 µg/l. The majority (86.6%, N=449) of children had UIC below the recommended value (100 µg/l). In addition, 59.8% (N=310) of children were severely iodine deficient (UIC<20 µg/l). Only 12.7% of salt samples had iodine. Goiter was present in 44.6% (N=280) of the children. Selenium-deficient children had higher serum thyroxin (T4) than children with normal serum Se concentration (P<0.001). CONCLUSIONS: Serum Se was negatively associated with T4 level in young children from the Amhara region of Ethiopia and may endanger the effectiveness of the salt iodization program.

Developments in industrially important thermostable enzymes: a review.

Cellular components of thermophilic organisms (enzymes, proteins and nucleic acids) are also thermostable. Apart from high temperature they are also known to withstand denaturants of extremely acidic and alkaline conditions. Thermostable enzymes are highly specific and thus have considerable potential for many industrial applications. The use of such enzymes in maximising reactions accomplished in the food and paper industry, detergents, drugs, toxic wastes removal and drilling for oil is being studied extensively. The enzymes can be produced from the thermophiles through either optimised fermentation of the microorganisms or cloning of fast-growing mesophiles by recombinant DNA technology. In this review, the source microorganisms and properties of thermostable starch hydrolysing amylases, xylanases, cellulases, chitinases, proteases, lipases and DNA polymerases are discussed. The industrial needs for such specific thermostable enzyme and improvements required to maximize their application in the future are also suggested.