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Relationship between genome and epigenome--challenges and requirements for future research.
Get PDFUnderstanding the links between genetic, epigenetic and non-genetic factors throughout the lifespan and across generations and their role in disease susceptibility and disease progression offer entirely new avenues and solutions to major problems in our society. To overcome the numerous challenges, we have come up with nine major conclusions to set the vision for future policies and research agendas at the European level
Mechanizmy wirulencji paciorkowców beta-hemolizujących
Get PDFPaciorkowce to grupa gram dodatnich bakterii, o wysokim stopniu zróżnicowania. Przy podziale zwykle bierze się pod uwagę rodzaj hemolizy oraz typ występującego na ich powierzchni grupowego wielocukru (lub określonych kwasów lipotejchojowych) oznaczanego jako grupa A, B, C, itd., niemalże do końca alfabetu. Do klasyfikacji paciorkowców często stosuje się również podział na grupy filogenetyczne (ang. divisions). Wyróżniane są: grupa ropotwórcza (ang. pyogenic), grupa anginosus, zwana również „milleri”, grupa mitis/oralis, grupa salivarius i grupa bovis. Paciorkowce beta-hemolizujące wchodzą w skład grupy ropotwórczej i częściowo grupy anginosus, natomiast pozostałe grupy określane są często zbiorczo jako paciorkowce zieleniące (viridans) ze względu na występowanie niepełnej hemolizy typu alfa.
Wśród paciorkowców wyróżnia się szereg patogennych gatunków powodujących choroby u ludzi i zwierząt, a u co najmniej kilku gatunków zaobserwowano poszerzenie zakresu gospodarza – od zwierząt – do ludzi. W ciągu ostatnich czterech dekad badań nad paciorkowcami chorobotwórczymi, zidentyfikowano cały szereg czynników wirulencji odpowiedzialnych za ich niezwykłą plastyczność i dynamikę powodowanych infekcji
Spectroscopic characterisation of dimeric oxidation products of phytosterols.
Get PDFSterol dimers are the main oxidation products formed during sterols degradation at elevated temperatures. An investigation was carried out to decipher the structure of dimers differing in polarity, formed during β-sitosterol thermo-oxidation. The oxidation products were fractionated using silica gel into non-polar (NP), mid-polar (MP) and polar fractions (P). Oligomers were further separated by size-exclusion chromatography (SEC). Tentative chemical structures of non-polar, mid-polar and polar dimers were identified using Ag(+)/CIS-MS and APCI-MS procedures after on-line RP-HPLC separation. Further structures were verified by NMR and FT-IR spectroscopies
Complex formation of fenchone with alpha-cyclodextrin: NMR titrations
Get PDF13C NMR titration studies of inclusion complexes of bicyclic terpenoid, fenchone enantiomers with acyclodextrin
revealed their 1:2 guest–host stoichiometry. Sequential binding constants were determined indicating a strong binding cooperativity of two a-cyclodextrin to fenchone. The overall association constants were used to calculate the Gibbs free energies of diastereomeric complex formation, which might be used as a measure of chiral
recognition of fenchone by a-cyclodextrin. These results
were compared with corresponding data derived for camphor,
which is an isomeric bicyclic terpenoid
DNA vaccines against influenza.
Get PDFGenetic vaccine technology has been considerably developed within the last two decades. This cost effective and promising strategy can be applied for therapy of cancers and for curing allergy, chronic and infectious diseases, such as a seasonal and pandemic influenza. Despite numerous advantages, several limitations of this technology reduce its performance and can retard its commercial exploitation in humans and its veterinary applications. Inefficient delivery of the DNA vaccine into cells of immunized individuals results in low intracellular supply of suitable expression cassettes encoding an antigen, in its low expression level and, in turn, in reduced immune responses against the antigen. Improvement of DNA delivery into the host cells might significantly increase effectiveness of the DNA vaccine. A vast array of innovative methods and various experimental strategies have been applied in order to enhance the effectiveness of DNA vaccines. They include various strategies improving DNA delivery as well as expression and immunogenic potential of the proteins encoded by the DNA vaccines. Researchers focusing on DNA vaccines against influenza have applied many of these strategies. Recent examples of the most successful modern approaches are discussed in this review
DNA probe modified with 3-iron bis(dicarbollide) for electrochemical determination of DNA sequence of Avian Influenza Virus H5N1.
Get PDFIn this work, we report on oligonucleotide probes bearing metallacarborane [3-iron bis(dicarbollide)] redox label, deposited on gold electrode for electrochemical determination of DNA sequence derived from Avian Influenza Virus (AIV), type H5N1. The oligonucleotide probes containing 5'-terminal NH2 group were covalently attached to the electrode, via NHS/EDC coupling to 3-mercaptopropionic acid SAM, previously deposited on the surface of gold. The changes in redox activity of Fe(III) centre of the metallacarborane complex before and after hybridization process was used as analytical signal. The signals generated upon hybridization with targets such as complementary or non-complementary 20-mer ssDNA or various PCR products consisting of 180-190 bp (dsDNA) were recorded by Osteryoung square-wave voltammetry (OSWV). The developed system was very sensitive towards targets containing sequence complementary to the probe with the detection limit estimated as 0.03 fM (S/N=3.0) and 0.08 fM (S/N=3.0) for 20-mer ssDNA and for dsDNA (PCR product), respectively. The non-complementary targets generated very weak responses. Furthermore, the proposed genosensor was suitable for discrimination of PCR products with different location of the complementarity region
Effect of salt stress on prenol lipids in the leaves of Tilia ‘Euchlora’
Get PDFSoil contamination caused by the NaCl used to de-ice slippery roads in winter is now recognized
as one of the major causes of nutrient disorders and death in urban trees. It is believed that polyisoprenoids
may have a specific role in the adaptation of plants to adverse conditions and habitats; it is further believed
that in the cell, they may exhibit a protective effect in response to biotic and abiotic stress. The aim of this
study was to evaluate the effect of salt stress on the content of prenol lipids in the leaves of Crimean linden
(Tilia ‘Euchlora’). The Cl content in the slightly damaged (“healthy”) leaves averaged 0.96%, while that
in the heavily damaged (“sick”) leaves averaged 2.02%. The leaves of control trees contained on average
0.57% Cl. The Na contents in the healthy and damaged leaves were 208 mg/kg and 1038 mg/kg, respectively,
and the Na content in the control areas was 63 mg/kg. A mixture of polyprenols consisting of four
compounds, prenol-9, prenol-10, prenol-11 and prenol-12, was identified in the leaves of Crimean linden.
This mixture was dominated by prenol-10 (2.16–6.90 mg/g). The polyprenol content was highest in the
leaves of “healthy” trees (approximately 13.31 mg/g), was lower in the case of “sick” trees (approximately
9.18 mg/g), and was the lowest in the control trees (mean 4.71 mg/g). No changes were observed in the
composition of the mixture of polyprenols under these conditions. The results suggest that polyprenols
may affect the accumulation of Cl in leaves. This phenomenon is evidenced by the high content of prenols
in the leaves of trees considered “healthy” but growing under conditions of increased soil salinity and the
lower content of prenols in the leaves of the “sick” and control trees. It is advisable to further investigate
the role of prenol lipids in the leaves of trees subjected to salt stress.
BACZEWSKA A., DMUCHOWSKI W., JÓŹWIAK A., GOZDOWSKI D., BRĄGOSZEWSKA P., DĄBROWSKI P., ŚWIEŻEWSKA E
Human Annexins A1, A2, and A8 as Potential Molecular Targets for Ni(II) Ions
No full textNickel is harmful for humans, but molecular mechanisms of its toxicity are far from being fully elucidated. One of such mechanisms may be associated with the Ni(II)-dependent peptide bond hydrolysis, which occurs before Ser/Thr in Ser/Thr-Xaa-His sequences. Human annexins A1, A2, and A8, proteins modulating the immune system, contain several such sequences. To test if these proteins are potential molecular targets for nickel toxicity we characterized the binding of Ni(II) ions and hydrolysis of peptides Ac-KALTGHLEE-am (A1-1), Ac-TKYSKHDMN-am (A1-2), and Ac-GVGTRHKAL-am (A1-3), from annexin A1, Ac-KMSTVHEIL-am (A2-1) and Ac-SALSGHLET-am (A2-2), from annexin A2, and Ac-VKSSSHFNP-am (A8-1), from annexin A8, using UV-vis and circular dichroism (CD) spectroscopies, potentiometry, isothermal titration calorimetry, high-performance liquid chromatography (HPLC), and electrospray ionization mass spectrometry (ESI-MS). We found that at physiological conditions (pH 7.4 and 37 °C) peptides A1-2, A1-3, A8-1, and to some extent A2-2 bind Ni(II) ions sufficiently strongly in 4N complexes and are hydrolyzed at sufficiently high rates to justify the notion that these annexins can undergo nickel hydrolysis in vivo. These results are discussed in the context of specific biochemical interactions of respective proteins. Our results also expand the knowledge about Ni(II) binding to histidine peptides by determination of thermodynamic parameters of this process and spectroscopic characterization of 3N complexes. Altogether, our results indicate that human annexins A1, A2, and A8 are potential molecular targets for nickel toxicity and help design appropriate cellular studies
MobC of conjugative RA3 plasmid from IncU group autoregulates the expression of bicistronic mobC-nic operon and stimulates conjugative transfer
Get PDFThe IncU conjugative transfer module represents highly efficient promiscuous system widespread among conjugative plasmids of different incompatibility groups. Despite its frequent occurrence the mechanisms of relaxosome formation/action are far from understood. Here we analyzed the putative transfer auxiliary protein MobC of the conjugative plasmid RA3 from the IncU incompatibility group.
MobC is a protein of 176 amino acids encoded in the bicistronic operon mobC-nic adjacent to oriT. MobC is homologous to prokaryotic transcription factors of the ribbon-helix-helix (RHH) superfamily. Conserved LxxugxNlNQiaxxLn motif clusters MobC with the clade of conjugative transfer auxilliary proteins of MobP relaxases. MobC forms dimers and tetramers in solution and autoregulates the expression of mobCp by binding to an imperfect palindromic sequence (OM) located between putative -35 and -10 motifs of the promoter. Medium-copy number test plasmid containing the oriT-mobCp region is mobilized with a high frequency by the RA3 conjugative system. The mutations introduced into OM that abolished MobC binding in vitro decreased 2-3 fold the frequency of mobilization of the test plasmids. The deletion of OM within the RA3 conjugative module had no effect on transfer if the mobC-nic operon was expressed from the heterologous promoter. If only nic was expressed from the heterologous promoter (no mobC) the conjugative transfer frequency of such plasmid was 1000-fold lower.
The MobC is an auxiliary transfer protein of dual function. It autoregulates the expression of mobC-nic operon while its presence significantly stimulates transfer efficiency