Identification of B‐cell epitopes of Borrelia burgdorferi outer surface protein C by screening a phage‐displayed gene fragment library

Outer surface protein C (OspC) of Borrelia stimulates remarkable immune responses during early infection and is therefore currently considered a leading diagnostic and vaccine candidate. The sensitivity and specificity of serological tests based on whole protein OspC for diagnosis of Lyme disease are still unsatisfactory. Minimal B‐cell epitopes are key in the development of reliable immunodiagnostic tools. Using OspC fragments displayed on phage particles (phage library) and anti‐OspC antibodies isolated from sera of naturally infected patients, six OspC epitopes capable of distinguishing between LD patient and healthy control sera were identified. Three of these epitopes are located at the N‐terminus (OspC E1 aa19–27, OspC E2 aa38–53, OspC E3 aa62–66) and three at the C‐terminal end (OspC E4 aa155–163, OspC E5 aa184–190 and OspC E6 aa201–207). OspC E1, E4 and E6 were highly conserved among LD related Borreliae. To our knowledge, epitopes OspC E2, E3 and E5 were identified for the first time in this study. Minimal B‐cell epitopes may provide fundamental data for the development of multi‐epitope‐based diagnostic tools for Lyme disease.     

Contribution to the biology of germination of four species ofChenopodium album agg. under different condition

The study investigated various factors stimulating germination of seeds of four species ofChenopodium album agg.—C. album L. s. str.,C. ficifolium Sm.,C. strictum Roth,C. suecicum J. Murr. These factors were: storage in wet and cold, alternating temperature, nitrates mainly in combination with light and, to a lesser degree, the duration of chilling. Germination was inhibited by darkness, which was most marked with seeds ofC. strictum. The effect of alternating temperature was better on the germination ofC. ficifolium andC. suecicum than on that ofC. album andC. strictum. We also discussed several differences in specific reactions of the individual species to the factors under consideration.     

The ecology of germination and reproduction of less frequent and vanishing species of the Czechoslovak flora II.Pulsatilla slavica Reuss

The conditions of embryo development, of germination and sprouting in the speciesPulsatilla slavica (north Carpathian endemite) were ascertained. By studies of germination ecology ofPulsatilla slavica it was found that the development of the underdeveloped embryo and germination set in at about 10 °C to about 30 °C. Of the temperatures examined, the temperature of about 25 °C, and alternating ones, the temperature of 10/30 °C appeared to be the optima. At the temperature of 25 °C, the rate of loss of germination capacity was ascertained partly in fully ripe achenes, partly in achenes collected in the stage of wax-ripeness. After 39 weeks of room storage, 62.6% of fully ripe achenes and 32.6% of achenes collected in the stage of waxripeness germinated. The achenes sown after full ripeness in the middle of June sprouted in the middle of July, those sown at the beginning of October sprouted during the first decade of May, and those sown at the beginning of April sprouted during the, third decade of May-Pulsatilla slavica reproduces spontaneously only in the generative way, but it can also be propagated vegetatively by root cuttings.     

Decoding of Baby Calls: Can Adult Humans Identify the Eliciting Situation from Emotional Vocalizations of Preverbal Infants?

Preverbal infants often vocalize in emotionally loaded situations, yet the communicative potential of these vocalizations is not well understood. The aim of our study was to assess how accurately adult listeners extract information about the eliciting situation from infant preverbal vocalizations. Vocalizations of 19 infants aged 5-10 months were recorded in 3 negative (Pain, Isolation, Demand for Food) and 3 positive (Play, Reunion, After Feeding) situations. The recordings were later rated by 333 adult listeners on the scales of emotional valence and intensity. Subsequently, the listeners assigned the eliciting situations in a forced choice task. Listeners were almost perfectly able to discriminate whether a recording came from a negative or a positive situation. Their discrimination may have been based on perceived valence as they consistently assigned higher valence when listening to positive, and lower valence when listening to negative, recordings. Ability to identify the particular situation within the negative or positive realm was substantially weaker, with only three of the six situations being discriminated above chance. The best discriminated situation, Play, was associated with high perceived intensity. The weak qualitative discrimination of negative situations seemed to be based on graded perception of negative recordings, from the most intense and unpleasant (assigned to Pain) to the least intense and least unpleasant (assigned to Demand for Food). Parenthood and younger age, but not gender of listeners, had weak positive effects on the accuracy of judgments. Our results indicate that adults almost flawlessly distinguish positive and negative infant sounds, but are rather inaccurate regarding identification of the specific needs of the infant and may normally employ other sensory channels to gain this information.     

The plant Pontin and Reptin homologues,RuvBL1 and RuvBL2a,colocalize with TERT and TRB proteins in vivo,and participate in telomerase biogenesis

Telomerase maturation and recruitment to telomeres is regulated by several telomerase‐ and telomere‐associated proteins. Among a number of proteins, human Pontin and Reptin play critical roles in telomerase biogenesis. Here we characterized plant orthologues of Pontin and Reptin, RuvBL1 and RuvBL2a, respectively, and show association of Arabidopsis thaliana RuvBL1 (AtRuvBL1) with the catalytic subunit of telomerase (AtTERT) in the nucleolus in vivo. In contrast to mammals, interactions between AtTERT and AtRuvBL proteins in A. thaliana are not direct and they are rather mediated by one of the Arabidopsis thaliana Telomere Repeat Binding (AtTRB) proteins. We further show that plant orthologue of dyskerin, named AtCBF5, is indirectly associated with AtTRB proteins but not with the AtRuvBL proteins in the plant nucleus/nucleolus, and interacts with the Protection of telomere 1 (AtPOT1a) in the nucleolus or cytoplasmic foci. Our genome‐wide phylogenetic analyses identify orthologues in RuvBL protein family within the plant kingdom. Dysfunction of AtRuvBL genes in heterozygous T‐DNA insertion A. thaliana mutants results in reduced telomerase activity and indicate the involvement of AtRuvBL in plant telomerase biogenesis.     

The contribution of tellurite resistance genes to the fitness of Escherichia coli uropathogenic strains

The presence of tellurite resistance gene operons has been reported in several human pathogens despite the fact that tellurium, as well as its soluble salts, are both rare in nature and are no longer in use as antimicrobial agents. We have introduced the cloned terWZA-F genes from an uropathogenic Escherichia coli isolate into another clinical E. coli isolate that was shown to be ter-gene free. The presence of the introduced genes increased the level of potassium tellurite resistance, as well as the level of resistance to oxidative stress mediated by hydrogen peroxide; and prolonged the ability of particular strains to survive in macrophages. We therefore propose that the contribution of tellurite resistance genes to oxidative stress resistance in bacteria is at least one reason for their presence in the genomes of a broad range of pathogenic microorganisms.