[Human thyroid gland DNA methylase in nodular and diffuse goiter].

The heterogeneity and some properties of DNA-methylases isolated from nonmalignant human thyroid formations--nodular and diffuse goiters--have been studied. Isoelectrofocusing of methylase preparations produced 6-7 distinct activity peaks distinguished by pI, activity towards Ca2+ and Mg2+, sensitivity towards dithiothreitol and capacity to methylase cytosine into mono-, di- and tripyrimidine blocks in vitro. The degree of DNA methylation in vivo depended on the origin of of the goiter.

[Experimental substantiation of maximum allowable concentration of phosphoric acid in the water of reservoirs].

It has been found out on the basis of experimental studies, that the threshold concentration of phosphorous acid is 85.7 mg/l according to the influence on organoleptic water properties, I mg/l--according to the influence on the sanitary regimen of water reservoirs. The preparation is of low toxicity when administered perorally to laboratory animals, cumulation degree is medium.