THE CONTRIBUTION OF SHORT-TERM MEMORY, WORKING MEMORY AND DEMOGRAPHIC CHARACTERISTICS TO THE LINGUISTIC ACHIEVEMENT OF GREEK MIDDLE SCHOOL-AGE CHILDREN: IMPLICATIONS FOR NATIVE LANGUAGE DEVELOPMENT

The present study delved into the involvement of Greek-speaking middle primary school children’s mnemonic recourses and demographic features in their performance in language tests. One hundred and seventy-six students aged 8.50-12.05 (mean age = 10.11 years) participated. The native language of the sample differed from English, in which most investigations have been conducted. Children’s verbal short-term memory (STM) and working memory (WM) capacity were assessed with a simple verbal retention measure (straight digit recall) and a task requiring parallel storage and processing of verbal information (backward digit recall), respectively. Pupils’ vocabulary knowledge was estimated through an assignment of expressive vocabulary. Children were also administered a reading fluency and a reading comprehension task. Pearson’s r and Spearman’s rho correlation coefficients showed that students’ verbal STM and WM significantly correlated with their reading fluency and text comprehension, accordingly. In addition, by employing simple linear regression analysis, increase in participants’ age was found to predict their extended reading fluency, while one-way Analysis of Variance (ANOVA) of independent samples revealed that vocabulary knowledge varied, being subject to pupils’ school grade. Lastly, independent samples t-test demonstrated no substantial difference in reading fluency between the two genders of children. Current findings are discussed in relation to participants’ age growth, their cumulating linguistic experience and the historical properties of the Greek language, indicating the need for further research that takes into account the unique and multifaceted nature of readers’ profile and outlining a few connotations for literacy instruction.  Article visualizations

A Human Recombinant Autoantibody-Based Immunotoxin Specific for the Fetal Acetylcholine Receptor Inhibits Rhabdomyosarcoma Growth In Vitro and in a Murine Transplantation Model

Rhabdomyosarcoma (RMS) is the most common malignant soft tissue tumor in children and is highly resistant to all forms of treatment currently available once metastasis or relapse has commenced. As it has recently been determined that the acetylcholine receptor (AChR) γ-subunit, which defines the fetal AChR (fAChR) isoform, is almost exclusively expressed in RMS post partum, we recombinantly fused a single chain variable fragment (scFv) derived from a fully human anti-fAChR Fab-fragment to Pseudomonas exotoxin A to generate an anti-fAChR immunotoxin (scFv35-ETA). While scFv35-ETA had no damaging effect on fAChR-negative control cell lines, it killed human embryonic and alveolar RMS cell lines in vitro and delayed RMS development in a murine transplantation model. These results indicate that scFv35-ETA may be a valuable new therapeutic tool as well as a relevant step towards the development of a fully human immunotoxin directed against RMS. Moreover, as approximately 20% of metastatic malignant melanomas (MMs) display rhabdoid features including the expression of fAChR, the immunotoxin we developed may also prove to be of significant use in the treatment of these more common and most often fatal neoplasms

A Novel Immunological Assay for Hepcidin Quantification in Human Serum

Contains fulltext : 81054.pdf (publisher's version ) (Open Access)BACKGROUND: Hepcidin is a 25-aminoacid cysteine-rich iron regulating peptide. Increased hepcidin concentrations lead to iron sequestration in macrophages, contributing to the pathogenesis of anaemia of chronic disease whereas decreased hepcidin is observed in iron deficiency and primary iron overload diseases such as hereditary hemochromatosis. Hepcidin quantification in human blood or urine may provide further insights for the pathogenesis of disorders of iron homeostasis and might prove a valuable tool for clinicians for the differential diagnosis of anaemia. This study describes a specific and non-operator demanding immunoassay for hepcidin quantification in human sera. METHODS AND FINDINGS: An ELISA assay was developed for measuring hepcidin serum concentration using a recombinant hepcidin25-His peptide and a polyclonal antibody against this peptide, which was able to identify native hepcidin. The ELISA assay had a detection range of 10-1500 microg/L and a detection limit of 5.4 microg/L. The intra- and interassay coefficients of variance ranged from 8-15% and 5-16%, respectively. Mean linearity and recovery were 101% and 107%, respectively. Mean hepcidin levels were significantly lower in 7 patients with juvenile hemochromatosis (12.8 microg/L) and 10 patients with iron deficiency anemia (15.7 microg/L) and higher in 7 patients with Hodgkin lymphoma (116.7 microg/L) compared to 32 age-matched healthy controls (42.7 microg/L). CONCLUSIONS: We describe a new simple ELISA assay for measuring hepcidin in human serum with sufficient accuracy and reproducibility

Connection between Telomerase Activity in PBMC and Markers of Inflammation and Endothelial Dysfunction in Patients with Metabolic Syndrome

Metabolic syndrome (MS) is a constellation of metabolic derangements associated with vascular endothelial dysfunction and oxidative stress and is widely regarded as an inflammatory condition, accompanied by an increased risk for cardiovascular disease. The present study tried to investigate the implications of telomerase activity with inflammation and impaired endothelial function in patients with metabolic syndrome. Telomerase activity in circulating peripheral blood mononuclear cells (PBMC), TNF-α, IL-6 and ADMA were monitored in 39 patients with MS and 20 age and sex-matched healthy volunteers. Telomerase activity in PBMC, TNF-α, IL-6 and ADMA were all significantly elevated in patients with MS compared to healthy volunteers. PBMC telomerase was negatively correlated with HDL and positively correlated with ADMA, while no association between TNF-α and IL-6 was observed. IL-6 was increasing with increasing systolic pressure both in the patients with MS and in the healthy volunteers, while smoking and diabetes were positively correlated with IL-6 only in the patients' group. In conclusion, in patients with MS characterised by a strong dyslipidemic profile and low diabetes prevalence, significant telomerase activity was detected in circulating PBMC, along with elevated markers of inflammation and endothelial dysfunction. These findings suggest a prolonged activity of inflammatory cells in the studied state of this metabolic disorder that could represent a contributory pathway in the pathogenesis of atherosclerosis

The glycosylated IgII Extracellular domain of EMMPRIN is implicated in the induction of MMP-2

EMMPRIN is a widely expressed transmembrane glycoprotein that plays important roles in many physiological and pathological processes, such as tumor invasion and metastasis. It stimulates the production of matrix metalloproteinase (MMPs) by tumor-associated fibroblasts. In the present study, our aim was to (a) to investigate if the IgII loop domain of the extracellular domain (ECD) of EMMPRIN contributes to the MMP production by fibroblasts and (b) to evaluate the significance of glycosylation in this process. For this purpose, we expressed the ECD, IgI, or IgII domains of EMMPRIN, in their glycosylated and non-glycosylated forms, in the heterologous expression systems of P. pastoris and E. coli, respectively. Dermal fibroblasts were treated with purified recombinant domains and proteins from cell extracts and supernatants were analyzed by Western blot and zymography assays. Fibroblasts treated with ECD-, IgI-, and IgII-glycosylated domains of EMMPRIN significantly stimulated the gelatinolytic activity of MMP-2, compared to untreated fibroblasts, whereas no significant effect was observed after treatment with the non-glycosylated ECD, IgI, and IgII domains. Western blot analysis from cell extracts and supernatants revealed that only the glycosylated forms were able to stimulate MMP-2 production and secretion, respectively. Quantitative PCR revealed that this effect was not attributed to transcriptional alterations. This study showed that N-glycosylation was a prerequisite for efficient MMP-2 production, with the IgII loop domain contributing significantly to this process. Perturbation of the function of IgII-EMMPRIN loop could have potential therapeutic value in the inhibition of MMP-2-dependent cancer cell invasion and metastasis. © 2013 Springer Science+Business Media New York

Isolation of a GABA receptor from bovine brain using a benzodiazepine affinity column

AbstractBenzodiazepine receptor solubilized from bovine cortical membranes was bound to a new benzodiazepine affinity column, the synthesis of which is described. Bio-specific elution with the benzodiazepine compound chlorazepate resulted in the elution of fractions highly enriched in specific binding for the GABA receptor agonist muscimol. Specific activity for [3H]muscimol binding was >1.3 nmol/mg protein. It is shown that [3H]flunitrazepam binding activity can be recovered by removal of chlorazepate from the purified fraction. These results strongly support a model which suggests that the 2 binding sites reside on the same physical entity