Size structures and comparative phenology of syntopic populations of <Emphasis Type="Italic">Hirudo verbana</Emphasis> and <Emphasis Type="Italic">Hirudo medicinalis</Emphasis> in eastern Ukraine

Ranges of different species of medicinal leeches (Hirudo spp.) are nearly mutually exclusive with very few areas of overlapping. This biogeographical pattern suggests different ecological requirements for the two species. However, two habitats in Hungary and Ukraine where populations of H. verbana and H. medicinalis coexist were found. The aim of this research was to reveal differences in size structures and phenologies between the two species in a steppe pond with two populations. The study was conducted from March to September in 2009 and 2010 in Horila Dolyna, Kharkiv Region. Leeches were collected several times during the season, weighed and released. The abundance of H. verbana was always higher. The Mann-Whitney U-test and the Wilcoxon test were applied. Significant differences between sequential samples within the species were found. The large weight classes of H. verbana emerged by the end of summer and caused a higher variance in contrast to H. medicinalis. This suggests the higher growth rate and the more r-strategic biology of H. verbana in comparison with the largely K-strategic H. medicinalis.     

The new iminothiadiazole derivative VP1.14 ameliorates hippocampal damage after an excitotoxic injury

J. Neurochem. (2012) 122, 1193-1202. ABSTRACT: Increased levels of glutamate causing excitotoxic damage accompany many neurological disorders. A well-characterized model of excitotoxic damage involves administration of kainic acid (KA), which causes limbic seizure activity and subsequent neuronal death, particularly in the CA1 and CA3 areas of the hippocampus. Inhibition of the enzyme glycogen synthase kinase-3 (GSK-3) and cAMP levels might play an important role in neuroprotection. As intracellular cAMP levels depend, in part, on the activity of the phosphodiesterase enzymes (PDEs), these enzymes have recently emerged as potential therapeutic targets for the treatment of several diseases. In previous works, we have shown a potent anti-inflammatory and neuroprotective effect of GSK-3 inhibition in a model of excitotoxicity, as well as a reduction of nigrostriatal dopaminergic neuronal cell death after phosphodiesterase 7 inhibition, which leads to an increase in cAMP levels. This study was undertaken to determine whether simultaneous inhibition of GSK-3 and PDE-7 by a novel 5-imino-1,2,4-thiadiazole compound, named VP1.14, could prevent the massive neuronal loss in the hippocampus evoked by intrahippocampal injection of KA. Here, we show that rats treated with VP1.14 showed a reduced inflammatory response after KA injection, and exhibited a significant reduction in pyramidal cell loss in the CA1 and CA3 areas of the hippocampus. Studies with hippocampal HT22 cells in vitro also showed a clear neuroprotective effect of VP1.14 and an anti-inflammatory effect shown by a decrease in the nitrite liberation and in the expression of pro-inflammatory cytokines by primary cultures of astrocytes treated with lipopolysaccharide.     

Characterization of lytic Pseudomonas aeruginosa bacteriophages via biological properties and genomic sequences

Pseudomonas aeruginosa is an important cause of infections, especially in patients with immunodeficiency or diabetes. Antibiotics are effective in preventing morbidity and mortality from Pseudomonas infection, but because of spreading multidrug-resistant bacterial strains, bacteriophages are being explored as an alternative therapy. Two newly purified broad host range Pseudomonas phages, named vB_Pae-Kakheti25 and vB_Pae-TbilisiM32, were characterized as candidates for use in phage therapy. Morphology, host range, growth properties, thermal stability, serology, genomic sequence, and virion composition are reported. When phages are used as bactericides, they are used in mixtures to overcome the development of resistance in the targeted bacterial population. These two phages are representative of diverse siphoviral and podoviral phage families, respectively, and hence have unrelated mechanisms of infection and no cross-antigenicity. Composing bactericidal phage mixtures with members of different phage families may decrease the incidence of developing resistance through a common mechanism.     

Genetic and geographic origin of domesticated peanut as evidenced by 5S rDNA and chloroplast DNA sequences

The history of the cultivated peanut involves natural evolution and human domestication. Despite the economic importance of peanuts and the many studies carried out on their cytology and genetic variability, current knowledge on the origin of the cultigen is still very limited compared with other major crops. In this context, we analyzed the polymorphisms of some non-coding cpDNA regions and the non-transcribed spacer of the nuclear 5S rDNA of the six botanical varieties of the two subspecies of the cultigen, of the wild tetraploid A. monticola, and of the nine diploid species so far proposed as the most probable relatives of the peanut, to gain more insight into the genetic and geographic origin of this legume crop. The analysis showed complete homology in the sequences of all the peanut and A. monticola samples. These results strongly suggest that the six botanical varieties of the cultigen have a single genetic origin and that A. monticola should be regarded as the immediate tetraploid ancestor from which A. hypogaea has arisen upon domestication. Here we provide results from the first sequence-based analysis in which the maternal (A. duranensis) and paternal (A. ipa?nsis) wild diploid species of the AABB tetraploids of Arachis were unequivocally identified. Not only that, but the combination of cpDNA and NTS 5S rDNA identified the population of A. duranensis from Río Seco, Salta, Argentina, and the only known population of A. ipa?nsis from Villa Montes, Tarija, Bolivia, as those to which the genome donors of the peanut could have belonged.     

Soil Bacterial Consortia and Previous Exposure Enhance the Biodegradation of Sulfonamides from Pig Manure

Persistence or degradation of synthetic antibiotics in soil is crucial in assessing their environmental risks. Microbial catabolic activity in a sandy loamy soil with pig manure using 12C- and 14C-labelled sulfamethazine (SMZ) respirometry showed that SMZ was not readily degradable. But after 100 days, degradation in sulfadiazine-exposed manure was 9.2%, far greater than soil and organic manure (0.5% and 0.11%, respectively, p < 0.05). Abiotic degradation was not detected suggesting microbial catabolism as main degradation mechanism. Terminal restriction fragment length polymorphism showed biodiversity increases within 1 day of SMZ spiking and especially after 200 days, although some species plummeted. A clone library from the treatment with highest degradation showed that most bacteria belonged to α, β and γ classes of Proteobacteria, Firmicutes, Bacteroidetes and Acidobacteria. Proteobacteria (α, β and γ), Firmicutes and Bacteroidetes which were the most abundant classes on day 1 also decreased most following prolonged exposure. From the matrix showing the highest degradation rate, 17 SMZ-resistant isolates biodegraded low levels of 14C-labelled SMZ when each species was incubated separately (0.2-1.5%) but biodegradation was enhanced when the four isolates with the highest biodegradation were incubated in a consortium (Bacillus licheniformis, Pseudomonas putida, Alcaligenes sp. and Aquamicrobium defluvium as per 16S rRNA gene sequencing), removing up to 7.8% of SMZ after 20 days. One of these species (B. licheniformis) was a known livestock and occasional human pathogen. Despite an environmental role of these species in sulfonamide bioremediation, the possibility of horizontal transfer of pathogenicity and resistance genes should caution against an indiscriminate use of these species as sulfonamide degraders.     

Low-dosage inhibition of Dll4 signaling promotes wound healing by inducing functional neo-angiogenesis

Recent findings regarding Dll4 function in physiological and pathological conditions indicate that this Notch ligand may constitute an important therapeutic target. Dll4 appears to be a major anti-angiogenic agent, occupying a central role in various angiogenic pathways. The first trials of anti-Dll4 therapy in mice demonstrated a paradoxical effect, as it reduced tumor perfusion and growth despite leading to an increase in vascular density. This is seen as the result of insufficient maturation of the newly formed vasculature causing a circulatory defect and increased tumor hypoxia. As Dll4 function is known to be closely dependent on expression levels, we envisioned that the therapeutic anti-Dll4 dosage could be modulated to result in the increase of adequately functional blood vessels. This would be useful in conditions where vascular function is a limiting factor for recovery, like wound healing and tissue hypoxia, especially in diabetic patients. Our experimental results in mice confirmed this possibility, revealing that low dosage inhibition of Dll4/Notch signaling causes improved vascular function and accelerated wound healing.