[Further improvement of the methods for the arrest of nasal bleeding].

Gauze tamponade of the nasal cavity is one of the most popular and convenient methods for the arrest of nasal bleeding. We used a polyvinyl pyrrolidone (PVP) powder that prevents local fibrinolysis by virtue of its sorption properties. PVP placed on the tampons and insufflated into the nasal cavity after their removal was shown to significantly decrease manifestations of reactive oedema and frequency of recurrent bleeding. These effects are attributable to the modifying action of PVP on fibrin thrombus and amplification of erythrocyte aggregation. On the one hand, fibrin thrombi formed close to the source of bleeding become harder due to the thickening of fibrin filaments; on the other hand, increased permeability of the fibrin network facilitates unobstructed penetration of fibrinolytic factors into the nasal cavity where they are sorbed and inactivated by PVP molecules. The hemostatic effect of PVP is promoted by enhanced erythrocyte aggregation.

Effective properties of suspensions/emulsions, porous and composite materials.

A new method (a version of a mean field method) is suggested to calculate effective properties of suspensions/emulsions, porous and dispersed materials. The aim is to demonstrate a wide range of applicability of the new method. To show the idea of the new method the dependence of the effective diffusion coefficient in the porous medium on the porosity is deduced. Based on the same method the following dependences are deduced: the effective viscosity of suspensions and emulsions as functions of volume fraction of suspended particles or droplets, elastic modules of rubber/polymer sheets with cracks and elastic modules of composite materials on the volume fraction of inclusions in the case of an arbitrary number of different types of inclusions. In all cases the calculated dependences are compared with available experimental data and published theoretical models.

[Effect of plasmid pIJ350 on genetic stability of antibiotic production by Streptomyces bambergiensis]. / Vliianie plazmidy pIJ350 na geneticheskuiu stabil'nost' priznaka antibiotikoobrazovaniia u Streptomyces bambergiensis.

It was shown that S. bambergiensis S800 was genetically instable with respect to the property of the antibiotic production (Ant) while in strain S712 of S. bambergiensis this property was stable. Transformation of S. bambergiensis protoplasts with pIJ350 plasmid DNA and analysis of the transformants screening revealed induction of the Ant instability in both the strains. In case of plasmids pVG101 and pIJ943 this effect was not shown. Analysis of the S800 (pIJ350) transformant screening revealed five groups of mutants differing in the antibiotic production level and the presence of pIJ350 plasmid. Restriction analysis of the total DNA of the mutants showed that there were large deletions in the genome of two of them. Retransformation of the mutants with pIJ350 plasmid DNA showed that in all the cases induction of the instability was lacking. The behaviour of the spontaneous mutants Ant- of strain S800 with respect to pIJ350 plasmid was analogous to that of the mutants Ant- from the transformant S800 (pIJ350) screening. A hypothetic model for the determinant incompatibility with pIJ350 plasmid genetically linked to the Ant property in the genome of S. bambergiensis and unstable in strain S800 was proposed.

[Relation of bacitracin synthesis and manganese content in Bacillus licheniformis: antibiotic production in colonies forming on media with high levels of Mn2+]. / Vzaimozavisimost' mezhdu sintezom batsitratsina i soderzhaniem margantsa u Bacillus licheniformis: Antibiotikoobrazovanie u kolonii, sformirovannykh na srede s vysokim urovnem Mn2+.

Population of B. licheniformis is not homogeneous with respect to its sensitivity to Mn2+. Active bacitracin producing cultures with high and low sensitivity to exogenic manganese are described. In media containing high sublethal concentrations of Mn2+ there were detected two types of bacitracin-producing colonies i.e. light and dark differing likely in the mechanisms of their cell protection from the metal excess. Since bacitracin production did not always correlate with sensitivity to Mn2+ at the level of the colony formation the use of Mn2+ as a selective factor for isolating inactive strains of B. licheniformis is of low efficiency.

[Transformation of Streptomyces bambergiensis S712 by plasmid DNA]. / Transformatsiia protoplastov Streptomyces bambergiensis S712 plazmidnoi DNK.

Optimal conditions for protoplast formation in the moenomycin-producing strain S712 of S. bambergiensis were developed. The protoplasts of this strain were transformed with DNA of plasmids pVG101 and pIJ350. The plasmids isolated from the transformants and designated as pVG101SB and pIJ350SB respectively were used for transformation of the initial culture protoplasts. No significant increase in the transformation efficiency was observed. Studies with the plasmid retransformation from S. bambergiensis S712 to S. lividans 66 and vice verse were conducted. Limitation of the plasmid replication during the retransformation in these strains was not detected. Partial restriction analysis of plasmids pVG101 and pVG101SB as well as pIJ350 and pIJ350SB showed that the used restriction enzymes had the same effect on the respective plasmids. Genetic stability of the plasmids in S. bambergiensis S712 was studied. It is concluded that plasmids pVG101 and pIJ350 can be used as vector molecules for this strain.

[Analysis of the patient contingent at a specialized pediatric clinic]. / Analiz kontingenta bol'nykh detskoi spetsializirovannoi kliniki.

Clinico-syndromologic, cytogenetic and biochemical screening embraced 330 patients of a specialized pediatric clinic. Of all cases of diseases 78.8% were either fully or partially accounted for by hereditary factors: 54% chromosome-related syndromes, 5.2% monogenic syndromes, 3.6% nonclassified combinations of developmental anomalies 16% isolated congenital defects of development. Others (21.2%) displayed the organic CNS defects, embryo- and fetopathies due to environmental impacts. The study resulted in diagnosis changes in 6.7% of the cases and identification of 14 hereditary syndromes. The prevalence of hereditary pathology in the morbidity structure of this contingent strongly suggests the necessity of medical genetic consultation in their families.

[Isolation and characteristics of a plasmid from the thermotolerant strain of Bacillus licheniformis]. / Vydelenie i kharakteristika plazmidy iz termotolerantnogo shtamma Bacillus licheniformis.

A 8.3 kb cryptic plasmid was isolated from the thermotolerant strain of Bacillus licheniformis 28KA and designated pLT83. The replicative (rep) region was localized on the plasmid map. The pLT83 plasmid labelled in vitro with an antibiotic resistance determinant is able to replicate in B. subtilis cells. The pLT83 plasmid replicates stably in B. licheniformis strain at higher temperatures (37-60 degrees C) than in B. subtilis cells (37-50 degrees C). The plasmid and its derivatives may be used as vectors for gene cloning in B. subtilis and B. licheniformis cells.

[Fusion of Bacillus subtilis and Bacillus licheniformis protoplasts. The mapping of the mutations leading to the supersynthesis of riboflavin in interspecies hybrids]. / Sliianie protoplastov Bacillus subtilis i Bacillus licheniformis. Kartirovanie mutatsii, privodiashchikh k sverkhsintezu riboflavina u mezhvidovykh gibridov.

As a result of fusion of the protoplasts of B. subtilis and B. licheniformis the majority of the prototrophic hybrids, as well as the auxotrophs with the Thi-Hom-phenotype or the Thi-phenotype acquired capacity for over-production of riboflavin lacking in the initial parent strains. When grown on the minimal Spizizen medium with aeration at 37 degrees C the auxotrophic recombinants accumulated 10-60 micrograms/ml of riboflavin for 2 days, while the prototrophic recombinants accumulated up to 90 micrograms/ml of riboflavin. The respective figures for their cultivation in the sucrose fermentation medium were 100-330 and 600 micrograms/ml. For mapping 3 random variants of them with different phenotypes, i.e. SL-7 (prototroph), SL-15 Thi-and SL-52 Thi-Hom-were used. Localization of the mutation on the chromosome of B. subtilis was based on transformation experiments with three marker crossing, where hybrid strains SL-7, S1-15 and SL-52 were used as the DNA donor and strain lys-rib-of B. subtilis was used as the recipient. The analysis showed that the required mutation designated as R1 was localized on the chromosome of B. subtilis in the regulatory region rib0 of the riboflavin operon.

[Fusion of Bacillus subtilis and Bacillus licheniformis protoplasts. Interspecies recombination resulting from protoplast fusion]. / Sliianie protoplastov Bacillus subtilis i Bacillus licheniformis. Mezhvidovaia rekombinatsiia v rezul'tate sliianiia protoplastov.

Recombinants between B. subtilis and B. licheniformis were prepared by fusion of the bacterial protoplasts. Genetically marked strains SB25 trp C hisH and 168 ade-met-leu- of B. subtilis and 1001 ura-thr- and 1001 met- of B. licheniformis were used as the parent strains. The recombinants were selected with the indirect method followed by analysis of their nutrient requirements and cultural and morphological features. All the hybrids acquired the specific properties of B. subtilis. Apparently, their formation was based on the whole chromosome of B. subtilis and recombination of separate fragments of B. licheniformis with it. Hybrids with prototrophic properties with respect to one, two or three markers of the initial strains were detected independent of the genotype of the B. subtilis parent strains. Moreover, the protoplast fusion resulted in formation of hybrids which were prototrophic with respect to the amino acid markers of B. subtilis and deficient with respect to homoserine and thiamine or only thiamine, whereas the initial strains were not auxotrophic with respect to homoserine and thiamine. Thi-Hom- and a number of the prototrophic recombinants were characterized by the capacity for increased synthesis of riboflavin lacking in the initial cultures. Homologous and heterologous transformation appeared to be possible in the recombinants of the Thi-Hom- phenotype, while transformation of the initial strain SB25 by the intergenocytic markers was possible in reciprocal crossings. It is concluded that contrary to transformation of isolated DNA, protoplast fusion may result in formation of interspecies recombinants of B. subtilis and B. licheniformis with respect to different operones of amino acid synthesis.

[Use of the protoplast fusion method in the selection of Streptomyces griseus--the producer of the streptothricin antibiotic grisin]. / Ispol'zovanie metoda sliianiia protoplastov v selektsii Streptomyces griseua--produtsenta streptotritsinovogo antibiotika grizina.

An effective method for protoplast fusion in S. griseus producing grisin was developed. The method requires the use of polyethylene glycol with a molecular weight of 1000. It was demonstrated that protoplasts formed most effectively in this organism, when the mycelium of the streptomycete previously treated with ultrasound in the process of its growth was used for the treatment with lysozyme. The efficacy of protoplast regeneration in the strains with the use of the modified hypertonic medium R2MD was 25-75 per cent. The possibility of using the protoplast fusion method for constructing phage resistant strains producing kormogrisin was shown.

[Transformation of Bacillus licheniformis by plasmid DNA]. / Transformatsiia Bacillus licheniformis plazmidnoi DNK.

A system for obtaining regenerating protoplasts of highly active Bacillus licheniformis 1001 strain was developed. Transformation of protoplasts by pUB110 and pminiKC plasmids (constructed from plasmids pUB110 and pC194) leading to the expression of kanamycine resistance, was demonstrated. It is supposed that in Bac licheniformis, the pminiKC plasmid is integrated into cellular chromosome, in contrast to pUB110 and parental Bac subtilis (pminiKC) strain. Still, the integrated plasmid seems to be not completely under control of the host chromosome. As a result of such integration, the plasmid conversion takes place, resulting in alteration of cytokinesis (filament formation) and sporulation, but not interfering with the ability to produce antibiotic bacitracin.

[Eremothecium ashbyii mutants resistant to 8-azaguanine. III. Nucleotide pyrophosphorylase activity of mutants with a varying degree of 8-azaguanine resistance]. / Mutanty Eremothecium ashbyii, ustoichivye k 8-azaguaninu. Soobshchenie III. Nukleotidpirofosforilaznaia aktivnost' mutantov s razlichnoi stepen'iu ustoichivosti k 8-azaguaninu.

Eremothecium ashbyii mutants resistant to low and high concentrations of 8-azaguanine (AZG), have been obtained. In low resistant mutants (10(-4) M AZG) isolated by one step selection, the activity of GMP- and AMP-pyrophosphorylases was decreased, as compared with the initial sensitive strain. The stepwise increase of the mutants resistance to AZG resulted in increasing of resistance to 8-azaadenine and decreasing of the activity of GMP-pyrophosphorylase, while this did not affect the level of AMP-pyrophosphorylase. Characteristics of the cross-resistance of mutant to purine analogues and the level of nucleotide-pyrophosphorylases activity were discussed in the light of their possible influence on riboflavin biosynthesis.

[Bacillus subtilis mutants resistant to roseoflavin]. / Mutanty Bacillus subtilis, ustoichivye k rozeoflavinu.

Bacillus subtilis mutants resistant to 100 mkg/ml of roseoflavin/8-dimethylamino (nor) riboflavin/have been shown to excrete 0.5 to 20 mkg/ml riboflavin and small amounts of FMN and FAD into the culture medium. The rosR mutations are localized in the operator region of riboflavin operon. The combination of rosR and ribC mutations (the latter being mutation in the regulator gene) leads to hyperproduction of riboflavin.

[Effect of auxotrophic mutations on the bacitracin production level in Bacillus licheniformis]. / Vliianie auksotgrofnykh mutatsii na uroven' produktsii batsitratsina u Bacillus licheniformis.

The bacitracin production levels in some auxotrophic mutants of a highly active strain 1001 and strain ATCC 10716 were studied. It was shown that auxotrophic mutations in the genomes of the above strains resulted in decreasing of bacitracin production. In double auxotrophic mutants the synthesis of bacitracin was sometimes at the level of the initial strain. It was found that various amino acids and bases added to the cultivation medium in concentrations of 1 to 10 mg/ml either increased or decreased the production of bacitracin. It is suggested that some amino acids may play the decisive role in the control of the bacitracin synthesis.

[Effect of bacitracin and other drugs on the synthesis of the antibiotic itself (bacitracin) by a Bacillus licheniformis culture]. / Vliianie batsitratsina i drugikh lekarstvennykh veshchestv na sintez sobstvennogo antibiotika (batsitratsina) kul'turoi Bacillus licheniformis.

The type and level of resistance of Bac. licheniformis 1001 to the antibiotic produced by it, i. e. bacitracin and the effect of bacitracin and some other drugs on the culture variation with respect to the feature of the antibiotic production were studied. It was found that strain 1001 possessed an inducible resistance to its own antibiotic. In addition, a cross inducible resistance to bacitracin and penicillin was observed. The mutations of the resistance to bacitracin, as well as streptomycin, rifampicin and sulfaethidole had no effect on bacitracin production by strain 1001.

[Changes in the level of bacitracin synthesis in autolysin-resistant strains of Bacillus licheniformis]. / Izmenenie urovnia sinteza batsitratsina u autolizinustoichivykh shtamm Bacillus licheniformis.

Production of bacitracin by Bac. licheniformis 1001 and its spontaneous autolysin resistant variants was studied. It was found that the antibiotic activity of some variants was 1.5--2 times higher than that of the initial strain. No differences in the activity of serine exoprotease in the initial strain and resistant variants were observed. The latter variants lost their resistance to autolysis in 2--3 subcultures on solid and liquid nutrient media. their antibiotic activity in these cases decreased to the control level. The study indicates that there is a phenomenologic relation between the autolytic and antibiotic activities of Bac. licheniformis. The nature of the relation is not known yet. Possibly, it is due to changes in the specific metabolic steps connected with regulation of bacitracin synthesis.

[Biosynthesis of the antibiotic, grizin, by prototrophic revertants of Streptomyces griseus biochemical mutants]. / Biosintez antibiotika grizina prototrofnymi revertantami biokhimicheskikh mutantov Streptomyces griseus.

Spontaneous and nitrosomethylbiuret-induced prototrophic revertants of various biochemical mutants of Str. griseus producing grisin, a streptothricin antibiotic, were isolated. The antibiotic production level of the revertants was studied. It was found that most of the prototrophic revertants synthesized much higher amounts of grisin than the initial biochemical mutants. It was also shown that a number of the prototrophic revertants of the methionine- and arginine-dependent mutants synthesized 20-23% higher amounts of grisin as compared to the control.

[Action of grisin on the variability of an Acinomyces griseus culture and the use of the same antibiotic as a selection agent in the selection of active variants]. / Deistvie grizina na izmenchivost' kul'tury Actinomyces griseus i ispol'zovanie dannogo antibiotika v kachestve selektivnogo agenta pri otbore aktivnykh variantov.

The effect of grisin on survival and variation of Actinomyces griseus producin grisin was studied. The efficiency of various concentrations of grisin on induction of variation according to the feature of the antibiotic production was compared. A possibility of increasing the productivity of strain. VNIIGenetics-115 by the use of the mutations of resistance to grisin is shown.