Development of integrative vectors for Actinomycetes--producers of antibiotics]

The integrative vectors pSU 475 and pSU 476 with variable numbers of copies per genome were developed for antibiotic producing actinomycetes. For this, the amplifying sequence AUD-Sr 1 of Streptomyces rimosus and the BamHIB fragment of the eSA 1 genetic element from Streptomyces antibioticus were used. The eSA 1 fragment was an element required for integration of a vector to the actinomycete chromosomes since it was homologous with the chromosomal DNAs of S. lividans, S. erythraeus and S. antibioticus. At the first stage the AUD-Sr 1 sequence within the actinomycete plastid pSU 23 was cloned by the vector pUC 19 to E coli. In that experiment the 12.4-kb plasmid pSU 449 was isolated. At the second stage the BamHIB-fragment of the eSA 1 element was incorporated into the resultant hybrid plasmid pSU 449. The 16.5-kb hybrid plasmids pSU 475 and pSU 476 were isolated. In these plasmids the BamHIB fragment of eSA 1 was present in two orientations. The developed vectors were useful in cloning DNA to S. lividans and S. erythraeus.     

Synthetic medium for cultivating Bacillus thuringiensis

Bacillus thuringiensis subsp. galleriae 69/6 was cultivated in a synthetic medium containing 5 amino acids and nicotinic acid. The dynamics of the culture growth and amino acid assimilation were studied in this medium and in a medium containing yeast extract. The phase of spore germination increased, the yield decreased and the maximal growth rate became higher when the culture grew in the synthetic medium. The percentage of thermoresistant spores was slightly lower in the synthetic medium comparing to the medium with yeast extract.     

Myeloinhibitory effect of the action of some antitumor antibiotics and its comparative assessment]

General toxic and myeloinhibitory effects of some antitumor antibiotics, such as rubomycin, olivomycin, bruneomycin and karminomycin administered intraperitoneally in a single LD50 to mice were studied. It was found that the general toxicity of bruneomycin and karminomycin was almost the same and 5 to 8 times higher than that of rubomycin and olivomycin. The use of the above antibiotics resulted in definite shifts in the blood systems of healthy mice. The most significant suppression of hemopoesis accompanied by a pronounced depression of the number of the myelocariocytes was observed after the use of olivomycin. The effect of karminomycin was characterized by suppression of erythro-, myelo- and lymphopoesis and depression of the number of the granulocytes and lymphocytes of the blood. Bruneomycin and rubomycin had a short-time myeloinhibitory effect. The erythroid cords of the bone marrow proved to be most sensitive to the inhibitory effect of the antibiotics. However, inhibition of the erythropoesis accompanied by deep reticulocytopenia did not induce the respective depression of the erythrocyte number. The lymphoid cords was in the 2nd place by its sensitivity to the antibiotics and the myeloid and megocariocytal cords were in the 3rd and the 4th places respectively. Complete reduction of hemopoesis in the animals was observed by the 10th day of the drugs use.     

Synthetic medium for the biosynthesis of gentamicin]

A synthetic medium for biosynthesis of gentamicin was developed. It includes maltose, gelatine, potassium phosphate, ammonium sulphate, cobalt chloride, sodium chloride, magnesium sulphate and zinc sulphate. The dynamics of the biochemical changes in the above medium was studied.     

Electrochemical interactions between some beta-lactam antibiotics and aminoglycoside antibiotics

Complexation reactions between the two aminoglycosides tobramycin and gentamycin and the two beta-lactam antibiotics carbenicillin and ticarcillin were studied conductimetrically, in aqueous solution. Carbenicillin and gentamycin form a 21 adduct in which about 75% of the antibiotics are bound. Likewise, carbenicillin and tobramycin form a 21 adduct binding about 67% of its components. Tobramycin and ticarcillin also interact, but weakly, binding about 12% of the adduct components. Only a trace of adduct formation was observed between cephalothin and gentamycin and between cephalothin and tobramycin. Cephalothin did not interact with carbenicillin. It appears that the adsorption behavior of the aminoglycosides differs considerably from that of the beta-lactams.     

A comparative study of flavonoids in some members of the Papaveraceae

The leaf flavonoids of the family Papaveraceae were studied.     

Glutamate transporter: an unexpected target for some antibiotics

Molecular pain is a relatively new and rapidly expanding research field that represents an advanced step from conventional pain research. Molecular pain research addresses physiological and pathological pain at the cellular, subcellular and molecular levels. These studies integrate pain research with molecular biology, genomics, proteomics, modern electrophysiology and neurobiology. The field of molecular pain research has been rapidly expanding in the recent years, and has great promise for the identification of highly specific and effective targets for the treatment of intractable pain. Although several existing journals publish articles on classical pain research, none are specifically dedicated to molecular pain research. Therefore, a new journal focused on molecular pain research is needed. Molecular Pain, an Open Access, peer-reviewed, online journal, will provide a forum for molecular pain scientists to communicate their research findings in a targeted manner to others in this important and growing field.