The role of the lymphatic system in the development of experimental ornithosis in mice after intranasal and intraplantar infection,in relation to the use of lymphotropic antibiotics

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   Введенный мышам в нос в количестве 1000 LD₅₀ вирус орнитоза мы раньше всего находили в легких, а именно через 24 часа после инфекции; позднее, через 48 час. после инфекции,—и в лимфатических узлах средостения у мышей. В крови и в шейных лимфатических узлах мы в течение 48 час. после заражения вируса не находили. После такого же способа введения вируса в количестве около 200 000 LD₅₀ мы нашли вирус опять-таки в легких—уже через 6 час. после заражения. Через более долгие промежутки времени он распространялся потом во все исследовавшиеся нами органы (кровь, шейные и паховые лимфатические узлы, селезенка и мозг). При этом наиболее значительное размножение вируса наблюдалось в легких и сопровождалось тяжелыми патологическими изменениями, которые с 6-го дня после заражения приводили к гибели животных.     

Antimicrobial resistance ofEnterococcus spp. isolates from raw beef and meat products

E. faecalis (67%) and E. faecium (13.7%) were most frequently isolated among enterococci that contaminate cooled and frozen processed meat, follow-up heat-treated meat products and unheated fermented dry salami. Most isolates of both species were resistant to cephalothin (95 and 83 %) and clindamycin (77 and 67%, respectively). Furthermore, E. faecalis and E. faecium isolates were resistant to erythromycin (44 and 72%), tetracycline (34.5 and 17.4%), and streptomycin (13.3 and 4.3%, respectively). Only a few of the isolates were resistant to ampicillin, ampicillin-sulbactam, chloramphenicol, and vancomycin while all isolates were susceptible to gentamicin, penicillin, and teicoplanin. During the production of heat-treated meat products, numbers of resistant isolates increased in spite of the decreasing enterococcal contamination of the samples. An opposite situation was found in the production of fermented dry salami.     

Temporal changes in genetic diversity of common bean (Phaseolus vulgaris L.) accessions cultivated between 1800 and 2000

Fourteen microsatellite markers were used to describe genetic diversity in a sample of 128 common bean (Phaseolus vulgaris L.) accessions cultivated within the territory of Slovenia and its nearby regions between 1800 and 2000. The accessions were grouped into three periods: period I comprising accessions from the beginning of the 19th century, while the other two periods included accessions from the middle (period II) and the end of the 20th century (period III). Seven control accessions of known Mesoamerican and Andean origin were also included in the study. A total of 130 alleles were generated. Allelic richness, in terms of number of alleles per locus, was 6.07 for period I, 6.71 for period II, and 6.07 for period III. In the UPGMA dendrogram, all studied accessions were intermixed in three main clusters, indicating that the diversity in the time periods overlapped. Two clusters consisted of accessions of Andean and Mesoamerican origin, while the third represents additional variation, which existed in this area already 200 years ago. The analysis of molecular variance showed that a great part of genetic diversity has been preserved till today, confirming the results of cluster analysis. The calculation of number of alleles per locus revealed no significant quantitative change in genetic diversity over the last 200 years of common bean cultivation. However, the calculation of genetic distances indicated slight qualitative shifts in genetic diversity of common bean germplasm over time, while the calculations of allelic frequency variation and polymorphic information content revealed recent decline of some alleles’ frequencies. These findings should stress the need for establishing an appropriate strategy of genetic resources management. The text was submitted by the authors in English.     

Survival and colonisation potential of photoautotrophic microorganisms within a glacierised catchment on Svalbard, High Arctic

The survival and colonisation potential of photoautotrophic microbes (cyanobacteria and microalgae) were investigated in three terrestrial environments within a glacierised catchment on Svalbard: old vegetation-covered soil, recently deglaciated barren soil and subglacial sediments. One-year reciprocal transplant incubations of photoautotrophic microbial communities from the three soil/sediment environments were conducted in order to reveal the autochthonous or allochthonous origin of the present photoautotrophs. The abundance and taxonomic composition of photoautotrophic microbes and their changes over time and between soil/sediment types and physico-chemical characteristics of the soils/sediments were determined. The recovery time of a photoautotrophic community by import of cells was between several months in subglacial and vegetated soils and up to 27 years in proglacial soils. No active growth was recorded in subglacial sediments, whilst positive growth, and so the potential for autochthonous recovery, was found in proglacial and vegetated soils. The most suitable environment for the survival of transplanted microbes was provided in proglacial soil. We show here that the new proglacial substrata can be successfully colonised by photoautotrophic microbes, and that input of allochthonous cells may, in some cases, exceed in situ microbial growth. Whilst the subglacial environment is rather a conduit for photoautotrophic microbes than a place of growth and production, the supply of viable photoautotrophs in it is relatively high and may serve as a significant resource of nutrients for subglacial microbial communities.     

Novel amidino substituted 2-phenylbenzothiazoles: Synthesis,antitumor evaluation in vitro and acute toxicity testing in vivo

The efficient synthesis of new bis-substituted nitro-amidino, amino-amidino (10a, 10b–13a, 13b) and previously prepared diamidino 2-phenyl-benzothiazoles (9a, 9b) is described. The compounds 11a and 11b were prepared by recently developed methodology of the key precursors in zwitterionic form 8a and 8b with 4-nitrobenzoylchloride in a very good yield (70%). All compounds except diamidino-substituted 2-phenylbenzothiazole 9a show exceptionally prominent tumor cell-growth inhibitory activity and cytotoxicity, whereby the special selectivity of amino-amidine 2-phenylbenzothiazole 12a towards MCF-7 and H 460 cells makes this compound a prospective lead compound that should be further evaluated in animal models. All in vivo tested compounds (12a, 12b, 13a and 13b) are absorbed from mice gastrointestinal system. LD₅₀ are between 67.33 and 696.2 mg/kg body weight (OECD/EPA toxicity categories 2–3).     

Identifying hybridizing taxa within the <Emphasis Type="Italic">Daphnia longispina</Emphasis> species complex: a comparison of genetic methods and phenotypic approaches

Daphnia galeata Sars, D. longispina O. F. Müller and D. cucullata Sars (Crustacea: Cladocera) are closely related species which often produce interspecific hybrids in natural populations. Several marker systems are available for taxon determination in this hybridizing complex, but their performance and reliability has not been systematically assessed. We compared results from identifications by three molecular methods. More than 1,200 individuals from 10 localities in the Czech Republic were identified as parental species or hybrids by allozyme electrophoresis and the analysis of the restriction fragment length polymorphism of the internal transcribed spacer (ITS-RFLP); over 440 of them were additionally analyzed and identified by 12 microsatellite loci. Identification by microsatellite markers corresponded well with allozyme analyses. However, consistent discrepancies between ITS-RFLP and other markers were observed in two out of 10 studied localities. Although some marker discrepancies may have been caused by occasional recent introgression, consistent deviations between ITS-RFLP and other markers suggest a long-term maintenance of introgressed alleles. These results warn against its use as a sole identification method in field studies. Additionally, we quantitatively evaluated the discriminatory power of geometric morphometric (elliptic Fourier) analysis of body shapes based on photos of over 1,300 individuals pre-classified by allozyme markers. Furthermore, a randomly selected subset of 240 individuals was independently determined from photos by several experts. Despite a tendency for morphological divergence among parental Daphnia species, some taxa (especially D. galeata, D. longispina, and their hybrids) substantially overlapped in their body shapes. This was reflected in different determination success for particular species and hybrids in discriminant analysis based on shape data as well as from photographs.     

Oligomerization of adenosin‐5′‐O‐ylmethylphosphonate,an isopolar AMP analogue: Evaluation of the route to short oligoadenylates

In an attempt to prepare a library of short oligoadenylate analogues featuring both the enzyme‐stable internucleotide linkage and the 5′‐O‐methylphosphonate moiety and thus obtain a pool of potential RNase L agonists/antagonists, we studied the spontaneous polycondensation of the adenosin‐5′‐O‐ylmethylphosphonic acid (p_cA), an isopolar AMP analogue, and its imidazolide derivatives employing N,N′‐dicyclohexylcarbodiimide under nonaqueous conditions and uranyl ions under aqueous conditions, respectively. The RP LC–MS analyses of the reaction mixtures per se, and those obtained after the periodate treatment, along with analyses and separations by capillary zone electrophoresis, allowed us to characterize major linear and cyclic oligoadenylates obtained. The structure of selected compounds was supported, after their isolation, by NMR spectroscopy. Ab initio calculation of the model structures simulating the AMP‐imidazolide and p_cA‐imidazolide offered the explanation why the latter compound exerted, in contrast to AMP‐imidazolide, a very low stability in aqueous solutions. © 2009 Wiley Periodicals, Inc. Biopolymers 93: 277–289, 2010. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com     

Co-occurring graminoid and forb species do not differ in their root morphological response to soil heterogeneity

We measured the proliferation of roots into experimental nutrient patches in a grassland community, distinguishing roots of graminoids and forbs. Biomass, length, and specific length were estimated for roots of each of the two functional groups, collected from patches differing in nutrient concentration, and established at four different times during a season. The ratio of graminoid and forb roots was compared with the graminoid-forb ratio in the above-ground biomass. Plant roots proliferated more intensively into patches with higher nutrient concentration, but the roots of the two functional groups had a similar ability to target richer patches. Relative proportion of graminoids was higher below-ground than above-ground and changed during the season, being lowest after mowing. Specific root length was higher for graminoid species, but did not respond to nutrient concentration in patches for either functional group. This is the first study to provide comparative information about root morphological response for graminoids and forbs, measured in a real, semi-natural plant community. The study shows no significant overall difference in the ability of these two functional types to place roots into nutrient-rich patches, but indicates other important differences among the two functional groups.     

DNA ploidy levels and intraspecific DNA content variability in Romanian fescues (Festuca, Poaceae) measured in fresh and herbarium material

DNA ploidy level estimates are presented for 11 species and two natural hybrids ofFestuca sampled from 39 locations in Romania. Altogether 48 living samples (22 of them also as one-year-old herbarium specimens) and additional 65 one-year-old herbarium specimens were analyzed using flow cytometry with DAPI staining. The following DNA ploidy levels were assessed:F. callieri (4x),F. ovina (2x),F. pallens (2x),F. polesica (2x),F. pseudodalmatica (2x, 4x, 5x),F. pseudovaginata (2x),F. pseudovina (2x),F. pseudovina ×F. rupicola (4x),F. rupicola (6x),F. vaginata (2x),F. vaginata ×F. valesiaca (2x),F. valesiaca (2x) andF. xanthina (2x).Festuca pseudovaginata is reported for the flora of Romania for the first time. Measurements of one-year-old herbarium specimens produced significantly smaller sample/standard ratios (P<0.001) and higher coefficients of variance (P < 0.001) when compared with fresh plant samples. Several species exhibited marked intraspecific nuclear DNA content variability, documented by non-overlapping double-peaks or bimodal peaks in simultaneous measurements. A maximum difference of about 9.2% in relative DNA contents was observed inF. pallens, 5.5% inF. polesica, 4.2% inF. vaginata, and 3.8% inF. rupicola. DiploidF. xanhina (Festuca sect.Eskia) had 1.39–1.58 times higher monoploid relative DNA content in relation to the species of sectionFestuca.