Publications by authors named "Dimitra Christopikou"

The field of preimplantation genetic testing (PGT) is evolving fast, and best practice advice is essential for regulation and standardisation of diagnostic testing. The previous ESHRE guidelines on best practice for PGD, published in 2005 and 2011, are considered outdated, and the development of new papers outlining recommendations for good practice in PGT was necessary. The current paper provides recommendations on the technical aspects of PGT for chromosomal structural rearrangements (PGT-SR) and PGT for aneuploidies (PGT-A) and covers recommendations on array-based comparative genomic hybridisation (aCGH) and next-generation sequencing (NGS) for PGT-SR and PGT-A and on fluorescence in situ hybridisation (FISH) and single nucleotide polymorphism (SNP) array for PGT-SR, including laboratory issues, work practice controls, pre-examination validation, preclinical work-up, risk assessment and limitations.

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Purpose: Artificial oocyte activation using calcium ionophores and enhancement of embryonic developmental potential by the granulocyte-macrophage colony-stimulating factor (GM-CSF) have already been reported. In this study, we evaluated the synergistic effect of these two methods on aged human unfertilized oocytes after intracytoplasmic sperm injection (ICSI). Then, we cultured the resulting embryos to the blastocyst stage and screened them for chromosomal abnormalities, to assess the safety of this protocol.

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Study Question: How accurate is array comparative genomic hybridization (array CGH) analysis of the first polar body (PB1) and second polar body (PB2) in predicting aneuploidies of maternal meiotic origin in the cleavage stage embryos of women of advanced maternal age?

Summary Answer: Almost all of the aneuploidies detected in cleavage stage embryos were associated with copy number changes in the polar bodies (93%) and all but one (98.5%) were predicted to be aneuploid. A minority of copy number changes (17%), mainly in PB1, did not result in the predicted changes in the embryo, but many of these were small copy number changes, which are likely to be artefacts.

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Organisation of chromosome territories in interphase nuclei has been studied in many systems and positional alterations have been associated with disease phenotypes (e.g. laminopathies, cancer) in somatic cells.

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Background: The association between infertility and sperm disomy is well documented. Results vary but most report that men with severely compromised semen parameters have a significantly elevated proportion of disomic sperm. The relationship between individual semen parameters and segregation of specific chromosome pairs is however less well reported as is the variation of disomy levels in individual men.

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