The intelligentsia informed habitus in social distance strategies of Polish migrants in the UK

Antagonism and conflict within newly resident UK Polish migrants has been typically related to labour market competition. Without denying the relevance of this argument, we argue that explanations of antagonism within the Polish community should also take into account the role of a Polish intelligentsia habitus. This habitus provides a repertoire of available discursive strategies used for interpreting antagonistic and “risk” situations both in Poland and among Poles abroad. It is argued that not only can this intelligentsia habitus critically legitimize intergroup inequalities in status and symbolic power but also may impact on the patterns of a migrant’s integration, linkage to social networks, access to different capital resources, and interactions with the indigenous population.     

Isolation, cloning and characterisation of motifs containing (GA/TC)n repeats isolated from vetch, Vicia bithynica

Microsatellites are widely distributed in plant genomes and comprise unstable regions that undergo mutational changes at rates much greater than that observed for non-repetitive sequences. They demonstrate intrinsic genetic instability, manifested as frequent length changes due to insertions or deletions of repeat units. Detailed analysis of 1600 clones containing genomic sequences of Vicia bithynica revealed the presence of microsatellite repeats in its genome. Based on the screening of a partial DNA library of plasmids, 13 clones harbouring (GA/TC)n tracts of various lengths of repeated motif were identified for further analysis of their internal sequence organization. Sequence analyses revealed the precise length, number of repeats, interruptions within tracts, as well as sequence composition flanking the repeat motifs. Representative plasmids containing different lengths of (GA/TC)n embedded in their original flanking sequence were used to investigate the genetic stability of the repeats. In the study presented herein, we employed a well characterised and tractable bacterial genetic system. Recultivations of Escherichia coli harbouring plasmids containing (GA/TC)n inserts demonstrated that the genetic instability of (GA/TC)n microsatellites depends highly on their length (number of repeats). These observations are in agreement with similar studies performed on repetitive sequences from humans and other organisms.     

Statistical distribution of amino acid sequences: a proof of Darwinian evolution

MOTIVATION: The article presents results of the listing of the quantity of amino acids, dipeptides and tripeptides for all proteins available in the UNIPROT-TREMBL database and the listing for selected species and enzymes. UNIPROT-TREMBL contains protein sequences associated with computationally generated annotations and large-scale functional characterization. Due to the distinct metabolic pathways of amino acid syntheses and their physicochemical properties, the quantities of subpeptides in proteins vary. We have proved that the distribution of amino acids, dipeptides and tripeptides is statistical which confirms that the evolutionary biodiversity development model is subject to the theory of independent events. It seems interesting that certain short peptide combinations occur relatively rarely or even not at all. First, it confirms the Darwinian theory of evolution and second, it opens up opportunities for designing pharmaceuticals among rarely represented short peptide combinations. Furthermore, an innovative approach to the mass analysis of bioinformatic data is presented. CONTACT: eitner@amu.edu.pl SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.     

Methods of embryo scoring in in vitro fertilization

It has been 25 years since the introduction of in vitro fertilization (IVF) for treatment of infertility. During this time very dynamic advances have taken place in all aspects of assisted reproductive technology (ART). The rapid improvement in embryological methods, especially these related to preimplantation embryo evaluation are of great importance. This article is a review of embryo classification systems utilized in ART programs. The most widely used scoring systems of zygotes and embryos (including blastocysts) are described. Additionally, the advantages of advanced embryo classifications in relation to ART success rates are presented.     

Deletion of the glutamate carboxypeptidase II gene in mice reveals a second enzyme activity that hydrolyzes N-acetylaspartylglutamate

Glutamate carboxypeptidase II (GCPII, EC 3.14.17.21) is a membrane-bound enzyme found on the extracellular face ofglia. The gene for this enzyme is designated FOLH1 in humans and Folh1 in mice. This enzyme has been proposed to be responsible for inactivation of the neurotransmitter N-acetylaspartylglutamate (NAAG) following synaptic release. Mice harboring a disruption of the gene for GCPII/Folh1 were generated by inserting into the genome a targeting cassette in which the intron-exon boundary sequences of exons 1 and 2 were removed and stop codons were inserted in exons 1 and 2. Messenger RNA for GCPII was not detected by northern blotting or RT-PCR analysis of RNA from the brains of -/- mutant mice nor was GCPII protein detected on western blots of this tissue. These GCPII null mutant mice developed normally to adulthood and exhibited a normal range of neurologic responses and behaviors including mating, open field activity and retention of position in rotorod tests. No significant differences were observed among responses of wild type, heterozygous mutant and homozygous mutant mice on tail flick and hot plate latency tests. Glutamate, NAAG and mRNA for metabotropic glutamate receptor type 3 levels were not significantly altered in response to the deletion of glutamate carboxypeptidase II. A novel membrane-bound NAAG peptidase activity was discovered in brain, spinal cord and kidney of the GCPII knock out mice. The kinetic values for brain NAAG peptidase activity in the wild type and GCPII nullmutant were Vmax = 45 and 3 pmol/mg/min and Km = 2650 nm and 2494 nm, respectively. With the exception of magnesium and copper, this novel peptidase activity had a similar requirement for metal ions as GCPII. Two potent inhibitors of GCPII, 4,4'-phosphinicobis-(butane-1,3 dicarboxilic acid) (FN6) and 2-(phosphonomethyl)pentanedioic acid (2-PMPA) inhibited the residual activity. The IC50 value for 2-PMPA was about 1 nm for wild-type brain membrane NAAG peptidase activity consistent with its activity against cloned ratand human GCPII, and 88 nm for the activity in brain membranes of the null mutants.     

Measuring protein conformational changes by FRET/LRET

Fluorescence resonance energy transfer (FRET) provides a unique means of measuring interatomic distances in biological molecules in real time. Recent advances have been made in the application of this technique to studies of conformational changes in proteins. New ways of introducing fluorescence probes into proteins, newly developed fluorescence probes, and progress in the technologies for fluorescence signal detection have greatly expanded the range of applications of FRET. In particular, studies of conformational changes in proteins at a single molecule level and in the native in vivo context of a living cell are now possible.     

Evaluation of mouse preimplantation embryos exposed to oxidative stress cultured with insulin-like growth factor I and II, epidermal growth factor, insulin, transferrin and selenium

Blastocyst culture requires strictly defined culture media to sustain its viability and quality. Although blastocyst media are commercially available, they do not meet all the needs and research focused on blastocyst-promoting agents is on the way. The aims of the study were to evaluate the significance of insulin-like growth factors I (IGF-I) and II (IGF-II); epidermal growth factor (EGF) and a mixture of insulin, transferrin and selenium (ITS) on the development of embryos exposed to oxidative stress. C3B6F1 mice were stimulated with 5 IU of pregnant mare serum gonadotropin following by administration of 5 IU of equine chorionic gonadotropin and mating with DBA males. The mice were killed 40 h after eCG injection by cervical dislocation and then the 2 cell embryos were flushed out from the fallopian tubes. To evaluate whether the growth factors may compensate the unfavorable--oxidative milieu created by hydrogen peroxide (H2O2), the embryos were transferred to 1/ control medium, 2/ control medium+0.1 mM (H2O2) or 3/ control medium+H2O2 enriched with 10(-7) g/ml of IGF-I, IGF-II, EGF or a mixture of insulin (5x10(-6) g/ml), transferrin (5 x10(-6) g/ml) and selenium (5x10(-9) g/ml; ITS). Embryos were evaluated 96-144 hours following eCG injection. In the study the dynamics of embryo development and blastocyst cell numbers (including inner cell mass) were assessed. The morphological evaluation comprised viability and apoptosis (TUNEL). In oxidative stress setting, IGF-I, IGF-II, EGF and ITS minimized the negative influence of H2O2, and embryos developed faster than in control conditions. Blastocysts cultured with hydrogen peroxide and growth factors or ITS displayed normal morphology and had more cells--also within the inner cell mass--than those treated only with H2O2. The positive TUNEL reactions were sporadically observed in embryos cultured with hydrogen peroxide supplemented with growth factors. IGF-I, IGF-II, EGF and ITS have a positive effect on pre-implantation embryo development in detrimental culture conditions of oxidative stress.