The work was aimed at studying the ability of Aspergillus and Penicillium species to isolate phosphomonoesterases (PMEases) in the cultural broth in the course of submerged cultivation in a complex nutrient medium. The cultures produced both acid and alkaline PMEases, but acid PMEase was produced at a much greater rate than alkaline PMEase. The activity of acid and alkaline PMEases decreased in most cases when the cultural broth and cell-free extracts were incubated with urea. The activity of exocellular acid PMEases was inhibited by the cell-free extracts of most cultures. The inhibition of PMEases from different sources is manifested in the studied cultures of Aspergillus and Penicillium in a different manner.

The influence of certain L-amino acids and their mixtures on the synthesis of exoprotease from Bacillus thuringiensis was studied. Physiological experiments showed that the mixture of 20 amino acids added to the artificial medium repressed the synthesis of exoprotease. Among the compounds studied there are both the compounds which stimulate the synthesis of exoprotease (glutamic and aspartic acids, glycine), and the compounds which repress the synthesis of the enzyme (proline, tryptophane, tyrosine, asparagine, serine, cystein). None of the amino acids caused a change in the exoprotease activity. It has been assumed that the repression of the protease synthesis in the presence of the amino acids is accomplished by ammonium ions, which are formed when using the amino acids of Bac. thuringiensis. The glutamine synthetase activity of cells was determined during the growth of Bac. thuringiensis both on a medium containing triptone and after the addition of certain amino acids to the cell suspension. The correlation between the influence of different amino acids on the synthesis of exoprotease and the glutamine synthetase activity was demonstrated.

The effect of various nitrogen sources on cellulase biosynthesis by the mutant strain Trichoderma viride 44 was examined. This strain may utilized nitrogen in the nitrate, ammonium of organic form. When cultivating this strain, it appears advantageous to add to the nutrient medium yeast and yeast lyzates as well as their mixture with ammonium sulfate. Cellulase reached its maximum activity of 20.2, 21.5 and 23.2 mu/ml when grown on the medium containing ammonium phosphate, peptone and brewing yeast plus ammonium sulfate, respectively. It is useful to apply nitrogen in its organic forms in small quantities and in combination with mineral forms. The nitrogen presence in the medium is necessary only at the exponential stage of fungal growth. The lack of nitrogen in the stationary stage characterized by the maximum cellulase formation does not inhibit an increase in the enzyme activity.

The chromosomes stained by trypsin G-banding technique were studied in five Djungarian hamster cell sublines, resistant to different concentrations of methotrexate. In all cells of two independent sublines, approximately 13 times more resistant to the drug, an additional material on the distal part of the short arm of chromosome 3 was revealed. The size and banding pattern of this new material were different in two sublines and in individual cells of each subline. In cells, which were 25-fold resistant to methotrexate, the additional material was found both in the short arm of chromosome 3 and in the long arm of chromosome 4. In some cells the additional material in chromosome 4 contained the long homogeneously staining regions (HSRs). In a subline which was 100-fold resistant to methotrexate, all cells had the chromosome 4 bearing the long HSR. The further increase in the level of drug resistance (300-fold) was accompanied by the increase in the size of HSRs in chromosome 4, the appearance of the second HSR in the short arm of chromosome 3 and emergence of small chromatin bodies. In cells with trisomy 4 and a low level of colchicine-resistance, methotrexate-resistance arises more frequently than in colchicine-sensitive cells bearing two chromosomes 4, or in cells possessing the high level of colchicine-resistance and trisomy of the short arm of chromosome 4 only. The similarities and differences of karyotypic alterations accompanying the development of colchicine- and methotrexate-resistance in Djungarian hamster cells, are discussed.

Bacillus thuringiensis was shown to grow better in media with albumin, gelatin and casein than in a chemically defined medium; proteins did not induce the synthesis of exoprotease. Two maxima were found in the enzyme synthesis: the first one at the exponential phase of the cultural growth, and the second one during spore formation by the culture. The synthesis at the exponential growth phase was susceptible to nitrogen metabolite repression while the synthesis of exoprotease at the stationary phase of growth was not repressed in the presence of high concentrations of ammonium ions in the medium.

Fragments specific for the amplified regions in DNA of Djungarian hamster colchicine-resistant cells were studied after restriction endonuclease digestion. We used three different methods of detection of these fragments: a) comparison of the wild type and resistant cell DNA electroforegramms stained by ethidium bromide; b) blotting of DNA from sensitive and resistant variants onto nitrocellulose filters and their hybridization with nick-translated DNA from resistant cells, in the presence of the excess of unlabelled DNA from the wild type cells (competitive hybridization); c) investigation of autonomously replicating DNA from sensitive and colchicine-resistant sublines. The highest resolution was found using the third method. However, the competitive hybridization is evidently a more universal approach to restriction analysis of DNA amplified sequences, because it gives quite high resolution and may be used for studying both autonomously and non-autonomously replicating sequences.

A study has been made of the effect of ethanol and CCl4 on hormonal induction of tyrosine aminotransferase in mouse liver. Both the hepatotropic poisons administered for a long time lose the induction effect and considerably reduce the same effect exerted by hydrocortisone. Microscopic study has revealed fatty dystrophy of the liver cells and even the formation of the areas of necrosis as a result of administering CCl4. The liver tissue stroma has been shown to develop reactive inflammation.

The influence of some agents on gene amplification in Djungarian hamster and mouse cells was studied. The tumor promotor 12-O-tetradecanoylphorbol-13-acetate (TPA), the epidermal growth factor (EGF), insulin, and 5-bromodeoxyuridine (BUdR) increase the incidence of colchicine-resistance, connected with amplification of the genes, which probably encode the polypeptide p22. The highest frequency of gene amplification was observed after the pretreatment of cells with TPA, which enhanced the number of colchicine-resistant colonies 44-200-fold. Mitostatic agents colchicine and colcemid increased the number of methotrexate-resistant cells, 2.0-6.5 times. These cells usually arise as the result of amplification of dihydrofolate reductase genes. Dexamethasone and ethidium bromide did not change the portion of cells resistant to colchicine. Ethylmethane sulfonate (EMS) decreased the number of colchicine-resistant cells. The cells of two Djungarian hamster colchicine-resistant clones obtained after treatment with TPA did not differ from those of spontaneously derived colchicine-resistant clones. Both have similar survival patterns in the medium with different colchicine concentrations, unstable inheritance of the drug resistance, the additional chromosome 4 and small chromatin bodies-the structures containing the amplified genes. Possible mechanisms of the induction of gene amplification by the agents used are discussed.

DNA-mediated transfer of colchicine-resistance from Djungarian hamster DM5/7 cell line, 750-fold resistant to the drug, was studied. The resistance to colchicine of DM5/7 cells is due to amplification of the genes, possibly coding for the polypeptide p22. Both high-molecular weight DNA (presumably, chromosomal DNA) and low-molecular weight DNA (presumably, extrachromosomal DNA) effectively transferred the colchicine-resistance to Djungarian hamster and mouse cells. DNA of sensitive to colchicine but resistant to ouabain mouse cells CAK-143OuaR was not capable to transfer colchicine-resistance, but effectively transferred ouabain-resistance connected with a mutation in Na+/K+-dependent ATP-ase locus. The differences in genetic transformation with amplified p22 genes and mutant Na+/K+-dependent ATP-ase genes were revealed. All cells of 3 colchicine-resistant transformants of DM-15 cells and all 10 spontaneously derived resistant clones contain the additional chromosome 4. The role of trisomy 4 in the development of colchicine-resistance in DM-15 cells is discussed.

Using immunofluorescent technique, a soluble antigen--hydrocortisone induced isoenzyme of tyrosineaminotransferase--was localized in sections of the intact rat liver. Tyrosineaminotransferase was not detected in all the hepatocytes. 5 hours following hydrocortisone to rats, the intensity of specific fluorescence that characterizes trosineaminotransferase activity in hepatocytes, was found to increase, and clearly outlined zones of entire fluorescence were seen in the liver sections. The data obtained are discussed in terms of hormonal induction mechanisms.

Three nearhexaploid sublines were obtained from hypotriploid mouse L cells by means of colcemid treatment. When cultivated on solid substratum, all of them did not differ from the parental line either in doubling time or in cloning efficiency. The ability of polyploid cell variants to be initiated for proliferation in a semi-solid medium was equal to that of hypotriploid cells, while the average diameter of colonies formed by hexaploid cells in methyl cellulose turned out to be significantly smaller than the size of colonies of parental cells. The inhibition of growth in the semi-solid medium may reflect partial normalization of the transformed phenotype of polyploid L cells.

Aspergillus terreus was found to have two functionally different cellobiases. One of them is excreted into the surrounding medium and is a part of the cellulase complex. The second one is an endocellular (or periplasmic) enzyme. It is distinguished by its stability, the time of mRNA operation, the sorption of cell debris; moreover, its activity does not depend on changes in the parameters of the medium when the incubation mixture is replaced and the surface is treated with 0.5 M NaCl. The synthesis of all components in the cellulase complex of A. terreus is coordinated. The time it takes the mRNAs for cellulases to function does not exceed 2 h. A close correlation exists between the synthesis and secretion of polysaccharases (endoglucanases and exoglucosidases) in A. terreus. Cellobiase is adsorbed by the fungal cell wall owing to charge interactions; its desorption depends on the ionic strength and the pH of the medium.

The effect of phenobarbital (PB, 2 and 80 mg/kg, 3 intraperitoneal injections) on the rate of chromosomal aberrations in the bone marrow cells of rats induced by a single intraperitoneal injection of cyclophosphamide (CP) in a dose of 25 mg/kg was studied. Activity of mixed function oxygenase (MFO) was evaluated from the content of cytochrome P450, b5 and activity of aniline hydroxylase. The rate of the cells with chromosomal aberrations in the bone marrow after combined action of PB and CP did not depend on the PB dose and was significantly higher as compared with CP action alone. After injection of 2 mg/kg, PB activity of MFO did not differ from that in control and increased 2 times after 80 mg/kg. Combined action of PB and CP did not induce any significant changes in activity of MFO compared with PB alone.

One-hour ischemia followed by rat liver reoxygenation brings about the accumulation of endogenous products of lipid peroxidation (LPO) and deterioration of the monooxygenase system (the drop of cytochrome P-450 content, amidopyrine N-demethylase and NADP X H cytochrome reductase activity). Application of the antioxidant ionol inhibited LPO and protected the monooxygenase system from reoxygenation but not from ischemic injuries. Phenobarbital alone and combined with ionol did not protect the monooxygenase system from ischemic and reoxygenation injuries but provided the retention of high absolute indicators of the system. Ionol and its combination with phenobarbital also increased the survival of rats with ischemized liver.

The functions of rat hepatic and renal lysosomes were explored during severe mechanical trauma caused by soft tissue compression in the presence of acetylcholinesterase induction by multiple acetylcholine administration. The increase of the trauma severity entailed the accumulation of non-hydrolyzed acetylcholine, thereby producing an injurious action on lysosomal membranes. Varying intensity of the changes in the activity of lysosomal hydrolases under study is likely to be related to the structural features of hepatic and renal lysosomes.

Regularities of the effect of a biostimulator produced by years-like fungi on accumulation of CoA, biotin and levorin in a developing culture of S. levoris were studied. It was shown that addition of the biostimulator to the fermentation medium resulted in increased accumulation of CoA and biotin in the mycelium of the levorin-producing culture within the first 48 hours of the growth and in their more intensive consumption at the final stages of the fermentation process. The rate of the levorin synthesis in the medium with the biostimulator markedly exceeded that in the control.

The natural transcription polarity of proximal and distal elements of the rplJL-rpoBC operon is increased when translation is inhibited in Escherichia coli cells. It is shown that transcription uncoupling to translation terminates within EcoRI-2,6 fragment of the operon which contains the transcription attenuator. We suggest that transcription attenuation in the rplJL-rpoBC operon is regulated by the coupling of transcription to translation of the intergenic fragment which overlaps the attenuator sequence.