The effect of a suspension of brain cells from mice of varying age on the growth of tumors, transplanted under the capsule

Antitumour activity of cerebral cells at different stages of ontogenesis (embryonic, new-born, adult) has been studied. Researches have been carried out at killer-activity patterns in vitro with target-cells and tumour transplantation under mice kidney's capsule in vivo. It has been established that mice cerebral cells' suspension can decrease the tumour transplants' growth under kidney's capsule. Antiproliferative activity of embryonic and new-born mice cerebral cells was much higher than adult one. The kidney and liver new-born mice cells had no antiproliferative activity at all.     

Certain biophysical properties of Ukrain

Ukrain was found to be relatively resistant in vitro to mean intensity radiation over the whole UV range. Of the seven peaks in the absorption spectrum of Ukraine those at 210 and 230 nm are conspicuous in the spectrum of the plasma of colorectal patients injected the previous day with this drug.     

Conformations of DNA duplexes containing 8-oxoguanine

As a step towards elucidating the mechanisms of mutagenesis induced by irradiation and oxidation, we study the incorporation of 8-oxoguanine (OG) into duplex DNA. Molecular modelling is used to reveal changes in DNA conformational parameters due to mispairs within the sequences d(A5XA5).d(T5YT5) and d(G5XG5).d(C5YC5) where one of the bases of the bases of the central X:Y pair is OG and the other A,T,G or C. The G:C to OG:C replacements in DNA duplexes produce only minor conformational changes, similar to normal base sequence effects. The calculations suggest that both OG(syn):G and OG(syn):A mispairs can also be introduced without drastic distortion of sugar-phosphate backbone. The distortions produced by OG-containing mispairs are also found to be sequence dependent. Overall these calculations suggest that the G-->OG conversion could be an important factor in the irradiative or oxidative damage of DNA.     

The comparative characteristics of preparations of Yersinia pestis capsular antigen F1 obtained from producer strains with different lipopolysaccharide structures

The main protective antigen of the causative agent of plague is capsular antigen F1. The preparations of this antigen isolated from Y.pestis strain EV are characterized by a high content of polysaccharide chains of endotoxins. This can be avoided by using R-variants of bacteria as producers. In this work the comparative study of the preparations of antigen F1 obtained from Y.pestis strain EV, Escherichia coli producer strain HB101 pFS1 with the complete structure of LPS and Salmonella minnesota producer strain Re595 pFS1 with maximally reduced LPS has been made. As revealed in this study, the physico-chemical properties of these preparations (the isoelectric point, electrophoretic mobility, the molecular weight of subunits) are identical. The preparation of antigen F1 obtained from S.minnesota has been found to give the highest yield and to have the lowest content of polysaccharide admixtures. This preparation has proved to possess the maximal protective potency, which may be linked with the adjuvant and immunogenic activity of microadmixtures of glycolipid Re, contained in F1.