[A synthetic medium containing growth factors for the cultivation of producer cell lines]. / Sinteticheskaia sreda, soderzhashchaia faktory rosta, dlia kul'tivirovaniia nekotorykh linii kletok-produtsentov.

A synthetic medium with low serum contents has been composed. As basic substitutes for serum a mixture containing a fibroblast growth factor, insulin, albumin and fibronectin is proposed. It allows to carry out a long-term cultivation of RH-PA cells, which are producers of a plasminogen activator, both in static conditions and on microcarriers. The suitability of the suggested medium for cultivation of other biotechnologically important cell lines (SPEV, NIH 3T3, Vero, CHO) is demonstrated.

[The stimulation of crystalline lens regeneration in adult tritons]. / Stimuliatsiia regeneratsii khrustalika u vzroslykh tritonov.

The lens removal from the newt eye stimulates regeneration of the latter from the dorsal iris cells. We have undertaken an attempt to stimulate lens regeneration from teh ventral iris pigmented cells by growth factors: basic and acidic forms of the fibroblast growth factor and the epidermal growth factor. In the presence of the growth factors, the mitotic activity of the ventral iris cells increased 1.5-to 3-fold on the 30th (18) and 70th (58) days after the operation (implantation). Depigmentation of the pupal margin and separation of the ventral iris sheets was observed on the 70th day in teh same animals, what was considered as stage III of lens regeneration. No such stimulation of proliferation was observed in the dorsal iris, but by the 70th day additional lenses have been found to form from the dorsal iris cells.

[Thrombolytic effect of urokinase upon various methods of administration into the body]. / Tromboliticheskoe deistvie urokinazy pri raznykh sposobakh ee vvedeniia v organizm.

A preparation of urokinase, obtained from human kidney cell culture, was administered into rats at a single dose of 5,000-10,000 U/200 g of body mass in a variety of ways using intravenous, intraperitoneal and subcutaneous inoculations. After intraperitoneal and subcutaneous administrations an increase of fibrinolytic activity in blood was more long-term although less distinct; the phase of reactive hypercoagulation was only slightly detected within 24 hrs after these procedures. Thrombin-produced provocation of thrombosis led to a lesser ratio of death in these animals as compared with the animals group administered intravenously. However, thrombolytic effect of similar doses of urokinase was the highest in intravenous administration. The fibrinolytic activity correlated well with content of the antigen (enzyme) in blood but not with the antiplasmin content in all the procedures used.

[Heparin-bound growth factors produced by the established RH-PA cell line]. / Geparinsviazyvaemye faktory rosta, produtsiruemye perevivaemoi liniei kletok RH-PA.

Two types of heparin-bound growth factors (HBGF) are isolated from serum-free culture media of RH-PA cells, which are effective producers of urokinase type plasminogen activator, and from a lysate of these cells. According to affinity to heparin, molecular weight and cells proliferation stimulation, these HBGF are similar to basic and acidic fibroblast growth factors. It is shown that the obtained preparations, produced by RH-PA cells at 2 pg/ml concentration and more, exert mitogenic effect towards RH-PA and NIH 3T3 cells. This effect is additive to the bovine serum factors. It is established that urokinase at the 0.5-25 micrograms/ml concentration also exerts mitogenic effect. The addition of HBGF in concentration of more than 0.05 micrograms/ml significantly stimulates urokinase production. It is suggested that both the factors--HBGF and urokinase--may be elements of the common mechanism of autocrine regulation of the RH-PA cell line proliferation and urokinase production.

Two-step modification of aspartate aminotransferase with 1,5-difluoro-2,4-dinitrobenzene. Cross-link localization.

At pH 7, the apoenzyme of carboxymethylated and acylated aspartate aminotransferase reacts selectively with 1,5-difluoro-2,4-dinitrobenzene to form a single intramolecular covalent bond with the epsilon-amino group of the functional lysine residue located within the active centre. On shifting the pH to 9, the second fluorine atom of the bifunctional reagent is substituted with the sterically adjacent side groups of cysteine and tyrosine residues. The modified apoenzyme was subjected to partial proteolysis with pronase, and the digest was used to obtain and isolate the labeled products and to localize amino acid residues involved in the reaction. The established structures of several peptides containing Cys-2,4-dinitrobenzene-Lys and Tyr-2,4-dinitrobenzene-Lys allowed the identification of the amino acid residues involved in the reaction with the bifunctional reagent as Lys 258, Cys 390 and probably Tyr-70. The residues of Cys and Tyr are thus located at a distance of approximately 5 A (the length of the dinitrophenylene bridge) from the lysine residue forming an aldimine bond with pyridoxal 5'-phosphate in the active site.

[Quantitative dansyl micromethod of amino acid analysis. Study of peptide maps of ribonuclease tryptic hydrolysate]. / Kolichestvennyi dansil'nyi mikrometod analiza aminokislot. issledovanie peptidnykh kart tripticheskogo gidrolizata ribonukleazy.

Some variants of the quantitative dansyl method in combination with thin-layer chromatography on polyamide plates have been compared, and principles of its optimization have been demonstrated. Sensitivity of the method is about 10(-11) mole, the error does not exceed 10%. Data are given on the analysis by the dansyl method of peptides of the tryptic hydrolysate of bovine pancreatic ribonuclease after their separation by peptide mapping procedure.

[Secondary structure of nuclear precursors of the informational RNA (pre-mRNA)]. / Izuchenie vtorichnoi struktury iadernykh predshestvennikov informatsionnoi RNK (pro-mRNK).

The secondary structure of pre-mRNA species from mouse Ehrlich ascites carcinoma cells extracted with phenol at the temperatures either 55-65 degrees C or 65-85 degrees C was investigated. A fraction of the double helical regions of pre-mRNA was estimated by two methods: a) by recording of melting curves; b) by measuring fluorescence lifetimes of acridine orange dye adsorbed on the nucleic acid. This fraction was about 64-68%. Further lowering of ionic strength down to 0.024 results in 10-15% decrease in the fraction of double regions. Both lowering of ionic strength and increase of the temperature up to 50-55 degrees C results in despiralisation of pre-mRNA regions which contain more than 70% of AU-nucleotide pairs. Only regions containing mainly GC-nucleotide pairs remain double-stranded under heating to temperatures above 50 degrees C. These facts were established on the basis of studies of acriflavin dye complexes with pre-mRNA.