The nature of the germinal mass (gonad) in trematode parthenites (Trematoda)

Dynamics of reproduction of the Notocotylus imbricatus (Notocotylidae), Echinostom caproni (Echinostomatidae), Sphaeridiotrema globulus and Psilotrema tuberculata (Psilostomatidae) rediae was examined. Forming of germinal mass in trematodes is considered and discussed on the base of literary and original data.     

Effect of lysozyme on the growth of murine lymphoma and antineoplastic activity of cyclophosphamide]

It was shown that hen egg-white lysozyme (LM) in the dose 100 mg/kg under the daily intragastral use slightly inhibited tumor grown or did not influence significantly upon it and did not change antitumor activity of cyclophosphamide. When used at mice C57Bl/6J with the transplanted ascitic or solid T-cell lymphoma EL4 (syngeneic system). On model of the same tumors in ascitic form at mice-hybrids (C57Bl/6J x DBA2)F1 (semisingeneic system) LM significantly potentiates antitumor activity of cyclophosphamide, though it had no effect on the rate of tumor growth. Potentiation of the effect of cyclophosphamide revealed itself in more slow development of ascite, increased mean life-span and the overall survival, appearance of completely cured animals. Our clinic-laboratory studies have revealed a sharp deficit of endogenic lysozyme in the blood serum of leukemic patients and extremely low lysozyme content in lavage liquid, from leukemic patients, with pneumonia. These data suggest that LM can be useful as a food additive in the complex treatment of oncological patients for enhancing antineoplastic chemotherapy efficacy.     

Development of mother sporocysts of Echinostoma caproni (Trematoda: Echinostomatidae)

New data on the migration and development of Echinostoma caproni mother sporocysts in two mollusk species of the genus Biomphalaria are obtained. It is confirmed, that the formation of primary and second generative cells takes place only as a result of undifferentiated cells' proliferation and following differentiation of some of them. These processes in miracidium, as well as in the parasitic stage of mother sporocyst, take place in a special organ, germinal mass, which occupies caudal position in both cases. The supposition of the role of germinal mass as the universal centre of multiplication and development of generative elements in all generations of Echinostoma caproni parthenites is confirmed. It is established, that mother sporocysts do not relize their reproductive potential completely, and the degree of its realization depends on the conditions arising in the host organism.     

Characterization of 13 newly isolated strains of anaerobic, cellulolytic, thermophilic bacteria

Characteristics of 13 newly isolated thermophilic, anaerobic, and cellulolytic strains were compared with previously described strains of Clostridium thermocellum: ATCC 27405 and JW20 (ATCC 31549). Colony morphology, antibiotic sensitivity, fermentation end-products, and cellulose degradation were documented. All 13 strains were sensitive to erythromycin (5 μg/ml) and chloramphenicol (25 μg/ml), and all strains but one were sensitive to kanamycin (20 μg/ml). Polymerase chain reaction (PCR) amplification using primers based on gene sequences from C. thermocellum ATCC 27405 was successful for all 13 strains in the case of the hydrogenase gene and 11 strains in the case of phosphotransacetylase/acetate kinase genes. Ten strains amplified a product of the expected size with primers developed to be specific for C. thermocellum 16SrRNA primers. Two of the 13 strains did not amplify any product with the PCR primers designed for the phosphotransacetylase/acetate kinase and 16SrRNA primers. A MboI-like GATC- recognizing restriction activity was present in all of the five strains examined. The results of this study have several positive implications with respect to future development of a transformation system for cellulolytic thermophiles. Journal of Industrial Microbiology & Biotechnology (2001) 27, 275–280. Received 12 September 2000/ Accepted in revised form 20 November 2000     

Conditions for Ethanol Production during Bioconversion of Cellulose-Containing Raw Material

Several natural associations composed of thermophilic anaerobic bacteria capable of utilizing various cellulose materials at 60 ± 2°C and pH 6.0–7.0 were isolated from the sludge of Kamchatka geothermal springs. The rate of ethanol production (up to 1.7 g/l per day) and the concentration of ethanol in the medium (up to 1.2%), as well as the fermentation period (10–15 days), were determined under anaerobic conditions in the presence of cellulose, coniferous sawdust, newsprint, or paper pulp as a carbon source. Microorganisms were found that inhibited the production of ethanol. The initial pH value was found to influence both the ethanol production rate and ethanol/acetate ratio. A pH decrease from 7.0 to 5.0 led to a 6.7-fold increase in ethanol production and caused a 23.8-fold increase in the ethanol/acetate ratio.     

Two approaches to the use of benzo[c][1,2]oxaboroles as active fragments for synthetic transformation of clarithromycin*

Clarithromycin (active against Gram positive infections) and 1-hydroxy-1,3-dihydrobenzo[c][1,2]oxaborole derivatives (effective for Gram negative microbes) are the ligands of bacterial RNA. The antimicrobial activities of these benzoxaboroles linked with clarithromycin at 9 or 4″ position were compared. Two synthetic pathways for these conjugates were elaborated. First pathway explored the substitution of the C-9 carbonyl group of macrolactone’s cycle via oxime linker, the second direction used the modification of the 4″-O-group of cladinose via the formation of carbamates of benzoxaboroles. 4″-O-(3-S-(1-Hydroxy-1,3-dihydro-benzo[c][1,2]oxaborole)-methyl-carbamoyl-clarithromycin showed twofold decrease in MICs for S. epidermidis and S. pneumoniae than clarithromycin. 4″-O-Modified clarithromycin demonstrated an efficacy against Gram positive strains only. Compounds with C-9 substitution were more active than 4″-O-substituted antibiotics for susceptible strains E. coli tolC and did not exceed the activity of initial antibiotics.     

Activity of embryonic mink genome during diapause (cytogenetic analysis): nucleolar and extranucleolar rna synthesis

The nucleolar and extranucleolar RNA synthesis was studied in the mink blastocysts at different stages of embryonic diapause and during the periimplantation period using cytoradioautography. The data obtained suggest a differential and stage specific activity of the embryonic mRNA and rRNA synthesis during the period of delayed implantation.     

Conformational properties of neuromedin NmU-8 and its modified analogs

The comparative study of the spatial organization and conformational properties of NmU-8 neuropeptide and its modified analogs with available experimental data has been carried out. The effect of amino acids point mutation on conformational states of native neuropeptide has been discussed. The low-energy conformations responsible for neuropeptide contractile activity was revealed.