Identification of Structural Proteins of Rhizobium meliloti Temperate Phage 16-3

The structural proteins of Rhizobium meliloti temperate phage 16-3 have been analysed by means of polyacrylamide gel electrophoresis, isoelectric focusing and agarose gel electrophoresis. Five major and five minor proteins were identified and characterized with respect to their size, isoelectric point and their distribution between the head and tail of the phage particle. The synthesis of structural proteins was studied by one- and two-dimensional gel electrophoresis

A média hatása a kisiskolás gyermekek viselkedésére

A 21. században már nélkülözhetetlenné nőtték ki magukat a különböző médiaeszközök, azok megtalálhatók szinte minden gyermek környezetében. Írásunkban a médiahasználat és a média veszélyeinek áttekintése után saját feltárásunk eredményét mutatjuk be. Kutatásunkban azt vizsgáltuk, hogy a 3−4. osztályos gyermekek milyen média eszközöket használnak, mennyi időt töltenek egy adott eszközzel, illetve ezt kivel együtt teszik. Kutattuk azt is, hogy mindez milyen hatást gyakorol a gyermekek viselkedésére, tanulmányi teljesítésére, valamint azt, hogy van-e összefüggés az agresszív viselkedés és a médiahasználat között

A média hatása a kisiskolás gyermekek viselkedésére

A 21. században már nélkülözhetetlenné nőtték ki magukat a különböző médiaeszközök, azok megtalálhatók szinte minden gyermek környezetében. Írásunkban a médiahasználat és a média veszélyeinek áttekintése után saját feltárásunk eredményét mutatjuk be. Kutatásunkban azt vizsgáltuk, hogy a 3−4. osztályos gyermekek milyen média eszközöket használnak, mennyi időt töltenek egy adott eszközzel, illetve ezt kivel együtt teszik. Kutattuk azt is, hogy mindez milyen hatást gyakorol a gyermekek viselkedésére, tanulmányi teljesítésére, valamint azt, hogy van-e összefüggés az agresszív viselkedés és a médiahasználat között

Excision efficiency is not strongly coupled to transgenic rate: cell type dependent transposition efficiency of Sleeping Beauty and piggyBac DNA transposons

The Sleeping Beauty (SB) and piggyBac (PB) DNA transposons represent an emerging new gene delivery technology, potentially suitable for human gene therapy applications. Previous studies pointed to important differences between these transposon systems, depending on the cell types examined and the methodologies applied. However, efficiencies cannot always be compared because of differences in applications. In addition, “overproduction inhibition,” a phenomenon believed to be a characteristic of DNA transposons, can remarkably reduce the overall transgenic rate, emphasizing the importance of transposase dose applied. Therefore, because of lack of comprehensive analysis, researchers are forced to optimize the technology for their own “in-house” platforms. In this study, we investigated the transposition of several SB (SB11, SB32, SB100X) and PB (mPB and hyPB) variants in various cell types at three levels: comparing the excision efficiency of the reaction by real-time PCR, testing the overall transgenic rate by detecting cells with stable integrations, and determining the average copy number when using different transposon systems and conditions. We concluded that high excision activity is not always followed by a higher transgenic rate, as exemplified by the hyperactive transposases, indicating that the excision and the integration steps of transposition are not strongly coupled as previously thought. In general, all levels of transposition show remarkable differences depending on the transposase used and cell lines examined, being the least efficient in human embryonic stem cells (hESCs). In spite of the comparably low activity in those special cell types, the hyperactive SB100X and hyPB systems could be used in hESCs with similar transgenic efficiency and with reasonably low (2–3) transgene copy numbers, indicating their potential applicability for gene therapy purposes in the future

Functional characterization of the ABCG2 5' non-coding exon variants: Stem cell specificity, translation efficiency and the influence of drug selection.

ABCG2 is a multidrug transporter with wide substrate specificity, and is believed to protect several cell types from various xenobiotics and endobiotics. This "guardian" function is important in numerous cell types and tissue barriers but becomes disadvantageous by being responsible for the multidrug resistance phenotype in certain tumor cells. ABCG2 regulation at the protein level has already been extensively studied, however, regulation at the mRNA level, especially the functional role of the various 5' untranslated exon variants (5' UTRs) has been elusive. In the present work, we describe a comprehensive characterization of four ABCG2 mRNA variants with different exon 1 sequences, investigate drug inducibility, stem cell specificity, mRNA stability, and translation efficiency. Although certain variants (E1B and E1C) are considered as "constitutive" mRNA isoforms, we show that chemotoxic drugs significantly alter the expression pattern of distinct ABCG2 mRNA isoforms. When examining human embryonic stem cell lines, we provide evidence that variant E1A has an expression pattern coupled to undifferentiated stem cell stage, as its transcript level is regulated parallel to mRNAs of Oct4 and Nanog pluripotency marker genes. When characterizing the four exon 1 variants we found no significant differences in terms of mRNA stabilities and half-lives of the isoforms. In contrast, variant E1U showed markedly lower translation efficiency both at the total protein level or regarding the functional presence in the plasma membrane. Taken together, these results indicate that the different 5' UTR variants play an important role in cell type specific regulation and fine tuning of ABCG2 expression

Nitro-oxidative response to internalized multi-walled carbon nanotubes in Brassica napus and Solanum lycopersicum

In addition to their beneficial effects on plant physiology, multi-walled carbon nanotubes (MWCNTs) are harmful to plants in elevated concentrations. This study compared the effects of two doses of MWCNT (10 and 80 mg/L) in Brassica napus and Solanum lycopersicum seedlings focusing on nitro-oxidative processes. The presence of MWCNTs was detectable in the root and hypocotyl of both species. Additionally, transmission electron microscopy analysis revealed that MWCNTs are heavily transformed within the root cells forming large aggregates. The uptake of MWCNTs negatively affected root viability and root cell proliferation of both species, but more intense toxicity was observed in S. lycopersicum compared to B. napus. The presence of MWCNT triggered more intense protein carbonylation in the relative sensitive S. lycopersicum, where increased hydrogen peroxide levels were observed. Moreover, MWCNT exposure increased the level of physiological protein tyrosine nitration which was more intense in S. lycopersicum where notable peroxynitrite accumulation occurred. These suggest for the first time that MWCNT triggers secondary nitro-oxidative stress which contributes to its toxicity. Moreover, the results indicate that the extent of the nitro-oxidative processes is associated with the extent of MWCNT toxicity