Publications by authors named "Korfiatis N"

Background: Cabazitaxel is an effective treatment in metastatic castration-resistant prostate cancer (mCRPC) patients previously exposed to docetaxel and novel hormonal treatments. Understanding the molecular biology of mCRPC disease and taking into account the several approved treatment options, biomarkers are needed to guide decision making including cabazitaxel treatment.

Methods: Cababone was a phase II translational study that attempted to identify predictors of cabazitaxel efficacy.

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This paper presents learning analytics data for measuring the impact of study satisfaction on students' academic self-efficacy and performance. For this purpose, a specially designed questionnaire was developed and distributed across 124 undergraduate students. Preliminary analysis using descriptive statistics for items and confirmatory factor analysis is provided.

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This study addresses diabetes physicians' information seeking behavioural paths (digital, conventional, interpersonal) which lead to information needs satisfaction and the barriers encountered in this process. The study was based on empirical evidence from a survey of 159 physicians. Theoretical analysis was informed by Wilson's model of information seeking behaviour.

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In this comparative study, reproductive parameters and semen characteristics of cloned bulls (n = 3) derived from somatic cell nuclear transfer (SCNT) were compared to their original cell donor Holstein-Friesian (n = 2) bulls from the same enterprise to assess the differences in reproductive potential between a donor bull and its clones. The parameters evaluated included motility of fresh, frozen-thawed and Percoll-treated frozen-thawed spermatozoa, as well as in vitro fertilization (IVF) ability, embryo quality, birth and survival of calves following IVF and embryo transfer with frozen-thawed semen. With fresh semen, spermatozoa from one cloned bull had lower motility than its donor.

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The efficiency of generating cloned animals following somatic cell nuclear transfer appears to have reached a plateau, despite ongoing research to improve developmental outcomes. A major limitation appears in the restricted nature of the adult/donor cell to de-differentiate to form a totipotent nucleus. Serial nuclear transfer, a modified cloning technique, has increased the developmental competence of amphibian, murine and porcine cloned embryos.

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The aim of the present study was to compare the in vitro and in vivo developmental competence of hand-made cloning (HMC) embryos with the conventional nuclear transfer (NT) method using five somatic cell lines and in vitro-fertilised (IVF; control) embryos. Modifications to the HMC procedure included fusion efficiency optimisation, effect of cytoplasmic volume and cloned embryo aggregation. The developmental competence of blastocysts from each of the treatment groups and cell lines used was assessed following transfer to 345 recipients.

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Adenosine triphosphate (ATP) plays an important role during fertilisation of the mammalian oocyte through its ability to alter the frequency and duration of calcium oscillations. It has also been shown that higher ATP levels correlate with increased developmental competence in bovine and human oocytes. During somatic cell nuclear transfer (NT), the incoming nucleus is remodelled extensively, undoubtedly using a variety of ATP-dependent enzymes.

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The hand-made cloning (HMC) technique describes a simplified nuclear transfer process without the need for micromanipulators. The technique involves manual bisection of zona-free oocytes, selection of cytoplasts by Hoechst staining and fusion of a single somatic cell and two cytoplasts. In this proof-of-principle experiment, the objective was to examine the developmental competence of HMC embryos following embryo transfer.

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While the expression and epigenetic differences of imprinted genes have been extensively characterized in the mouse and human, little is known about imprinted genes in livestock species. In the current study, eight genes that are imprinted in the human or mouse were investigated in preimplantation bovine embryos. Amplified cDNA was created from three single metaphase II (MII) oocytes or embryos throughout preimplantation development.

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Histological staining and counting of blastocyst inner cell mass (ICM) and trophectoderm (TE) cells differentially with chromatin-specific dyes is a more accurate indicator of cultured blastocyst quality and normality than total cell number assessment. The aim of this study was to test the effectiveness of a simplified method of chemically-defined differential blastocyst staining. The TE of cultured mouse and bovine blastocysts of different developmental stages was stained when blastocysts were treated with a permeabilizing solution containing the ionic detergent Triton X-100 and the fluorochrome propidium iodide.

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We have examined the reprogramming ability of donor fibroblast nuclei in various phases of the cell cycle, upon transfer to cytoplasts, using a bovine nuclear transfer (NT) model. Bovine fetal fibroblasts were cultured in reduced serum and conditioned medium to induce quiescence (G0) and treated with nocodazole to induce M phase arrest. Unsynchronized actively dividing cells (control) were mainly in G1.

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The efficiency of animal production using cloning technology is still relatively low and research to determine a more efficient nuclear transfer procedure is ongoing. One approach which may be informative in assessing the viability of nuclear transfer embryos is the analysis of embryonic gene expression. Using RT-PCR techniques we have previously detected the aberrant expression of FGF4, FGFr2 and IL6 in a significant proportion of bovine granulosa cell-derived nuclear transfer embryos, which correlated with a limited developmental potential in vivo.

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