[Population polymorphism of silver-stained nucleolar organizer chromosome regions in man]. / Populiatsionnyi polimorfizm okrashivaiushchiksia serebrom iadryshkoobrazuiushchikh raionov khromosom u cheloveka.

Activity of nucleolar organizer regions (NORs) of acrocentric chromosomes determined by Ag-staining was comparatively studied in 40 individuals of Bulgarian and 40 individuals of Russian populations. Chromosome 21 was found to be significantly more often stained in both populations. The other NORs did not differ significantly in staining from the means. No differences were noted between individual NORs, in respect of the intensity of Ag-staining in both populations, except chromosome 15 which showed markedly decreased staining capacity in Russians. The data obtained are compared with those published in literature concerning four other populations.

[Plasma renin and erythropoietic activity following a decrease in extracellular volume]. / Reninovaia i éritropoéticheskaia aktivnost' plazmy posle umen'sheniia ékstratselliuliarnogo ob'ema

A reduction of the extracellular volume of the peritoneal dialysis in rats induced modifications in plasma renin activity, plasma erythropoietic activity, and in renin activity in the renal cortex. A significant increase in the renin and erythropoietic activity was revealed in the experimental animals. It is assumed that renin and erythropoietin could be regarded as two links of the same broad control system, responsible for optimum tissue oxygen supply.