Meiotic outcome in two carriers of Y autosome reciprocal translocations: selective elimination of certain segregants

BACKGROUND: Reciprocal Y autosome translocations are rare but frequently associated with male infertility. We report on the meiotic outcome in embryos fathered by two males with the karyotypes 46,X,t(Y;4)(q12;p15.32) and 46,X,t(Y;16)(q12;q13). The two couples underwent preimplantation genetic diagnosis (PGD) enabling determination of the segregation types that were compatible with fertilization and preimplantation embryo development. Both PGD and follow up analysis were carried out via fluorescence in situ hybridization (FISH) or array comparative genomic hybridization (aCGH) allowing the meiotic segregation types to be determined in a total of 27 embryos. RESULTS: Interestingly, it was seen that the number of female embryos resulting from alternate segregation with the chromosome combination of X and the autosome from the carrier gamete differed from the corresponding balanced males with derivative Y and the derivative autosome by a ratio of 7:1 in each case (P = 0.003) while from the adjacent-1 mode of segregation, the unbalanced male embryos with the combination of der Y and the autosome were seen in all embryos from couple A and in couple B with the exception of one embryo only that had the other chromosome combination of X and derivative autosome (P = 0.011). In both cases the deficit groups have in common the der autosome chromosome that includes the segment Yq12 to qter. CONCLUSION: The most likely explanation may be that this chromosome is associated with the X chromosome at PAR2 (pseudoautosomal region 2) in the sex-body leading to inactivation of genes on the autosomal segment that are required for the meiotic process and that this has led to degeneration of this class of spermatocytes during meiosis

Meiotic and mitotic behaviour of a ring/deleted chromosome 22 in human embryos determined by preimplantation genetic diagnosis for a maternal carrier

<p>Abstract</p> <p>Background</p> <p>Ring chromosomes are normally associated with developmental anomalies and are rarely inherited. An exception to this rule is provided by deletion/ring cases. We were provided with a unique opportunity to investigate the meiotic segregation at oogenesis in a woman who is a carrier of a deleted/ring 22 chromosome. The couple requested preimplantation genetic diagnosis (PGD) following the birth of a son with a mosaic karyotype.</p> <p>The couple underwent two cycles of PGD. Studies were performed on lymphocytes, single embryonic cells removed from 3 day-old embryos and un-transferred embryos. Analysis was carried out using fluorescence in situ hybridisation (FISH) with specific probe sets in two rounds of hybridization.</p> <p>Results</p> <p>In total, 12 embryos were biopsied, and follow up information was obtained for 10 embryos. No embryos were completely normal or balanced for chromosome 22 by day 5. There was only one embryo diagnosed as balanced of 12 biopsied but that accumulated postzygotic errors by day 5. Three oocytes apparently had a balanced chromosome 22 complement but all had the deleted and the ring 22 and not the intact chromosome 22. After fertilisation all the embryos accumulated postzygotic errors for chromosome 22.</p> <p>Conclusion</p> <p>The study of the preimplantation embryos in this case provided a rare and significant chance to study and understand the phenomena associated with this unusual type of anomaly during meiosis and in the earliest stages of development. It is the first reported PGD attempt for a ring chromosome abnormality.</p

Integrating imaging-based classification and transcriptomics for quality assessment of human oocytes according to their reproductive efficiency

PURPOSE: Utilising non-invasive imaging parameters to assess human oocyte fertilisation, development and implantation; and their influence on transcriptomic profiles. METHODS: A ranking tool was designed using imaging data from 957 metaphase II stage oocytes retrieved from 102 patients undergoing ART. Hoffman modulation contrast microscopy was conducted with an Olympus IX53 microscope. Images were acquired prior to ICSI and processed using ImageJ for optical density and grey-level co-occurrence matrices texture analysis. Single-cell RNA sequencing of twenty-three mature oocytes classified according to their competence was performed. RESULT(S): Overall fertilisation, blastulation and implantation rates were 73.0%, 62.6% and 50.8%, respectively. Three different algorithms were produced using binary logistic regression methods based on "optimal" quartiles, resulting in an accuracy of prediction of 76.6%, 67% and 80.7% for fertilisation, blastulation and implantation. Optical density, gradient, inverse difference moment (homogeneity) and entropy (structural complexity) were the parameters with highest predictive properties. The ranking tool showed high sensitivity (68.9-90.8%) but with limited specificity (26.5-62.5%) for outcome prediction. Furthermore, five differentially expressed genes were identified when comparing "good" versus "poor" competent oocytes. CONCLUSION(S): Imaging properties can be used as a tool to assess differences in the ooplasm and predict laboratory and clinical outcomes. Transcriptomic analysis suggested that oocytes with lower competence may have compromised cell cycle either by non-reparable DNA damage or insufficient ooplasmic maturation. Further development of algorithms based on image parameters is encouraged, with an increased balanced cohort and validated prospectively in multicentric studies

Reproductive outcomes from ten years of elective oocyte cryopreservation

Research question: To assess the relationship between the number of oocytes retrieved during elective oocyte cryopreservation (EOC) cycles with various clinical, biochemical, and radiological markers, including age, body mass index (BMI), baseline anti-Müllerian hormone (AMH), antral follicle count (AFC), Oestradiol level (E2) and total number of follicles ≥ 12 mm on the day of trigger. To also report the reproductive outcomes from women who underwent EOC. Methods: A retrospective cohort of 373 women embarking on EOC and autologous oocyte thaw cycles between 2008 and 2018 from a single London clinic in the United Kingdom. Results: 483 stimulation cycles were undertaken amongst 373 women. The median (range) age at cryopreservation was 38 (26–47) years old. The median numbers of oocytes retrieved per cycle was 8 (0–37) and the median total oocytes cryopreserved per woman was 8 (0–45). BMI, E2 level and number of follicles ≥ 12 mm at trigger were all significant predictors of oocyte yield. Multivariate analysis confirmed there was no significant relationship between AFC or AMH, whilst on univariate analysis statistical significance was proven. Thirty six women returned to use their cryopreserved oocytes, of which there were 41 autologous oocyte thaw cycles undertaken. There were 12 successful livebirths achieved by 11 women. The overall livebirth rate was 26.8% per cycle. No livebirths were achieved in women who underwent EOC ≥ 40 years old, and 82% of all livebirths were achieved in women who had done so between 36 and 39 years old. Conclusion: Clinical, biochemical and radiological markers can predict oocyte yield in EOC cycles. Reproductive outcomes are more favourable when cryopreservation is performed before the age of 36, with lower success rates of livebirth observed in women aged 40 years and above

Early Psychosis Intervention-Spreading Evidence-based Treatment (EPI-SET) : Protocol for an effectiveness-implementation study of a structured model of care for psychosis in youth and emerging adults

Introduction While early psychosis intervention (EPI) has proliferated in recent years amid evidence of its effectiveness, programmes often struggle to deliver consistent, recovery-based care. NAVIGATE is a manualised model of EPI with demonstrated effectiveness consisting of four components: individualised medication management, individual resiliency training, supported employment and education and family education. We aim to implement NAVIGATE in geographically diverse EPI programmes in Ontario, Canada, evaluating implementation and its effect on fidelity to the EPI model, as well as individual-level outcomes (patient/family member-reported and interviewer-rated), system-level outcomes (captured in provincial administrative databases) and engagement of participants with lived experience. Methods and analysis This is a multisite, non-randomised pragmatic hybrid effectiveness-implementation type III mixed methods study coordinated at the Centre for Addiction and Mental Health (CAMH) in Toronto. Implementation is supported by the Provincial System Support Program, a CAMH-based programme with provincial offices across Ontario, and Extension of Community Healthcare Outcomes Ontario Mental Health at CAMH and the University of Toronto. The primary outcome is fidelity to the EPI model as measured using the First Episode Psychosis Services-Fidelity Scale. Four hundred participants in the EPI programmes will be recruited and followed using both individual-level assessments and health administrative data for 2 years following NAVIGATE initiation. People with lived experience will be engaged in all aspects of the project, including through youth and family advisory committees. Ethics and dissemination Research ethics board approval has been obtained from CAMH and institutions overseeing the local EPI programmes. Study findings will be reported in scientific journal articles and shared with key stakeholders including youth, family members, programme staff and policymakers. Trial registration number NCT03919760; Pre-results

Immunofluorescence staining of spindles, chromosomes, and kinetochores in human oocytes

Understanding how human oocytes execute chromosome segregation is of paramount importance as errors in this process account for the overwhelming majority of human aneuploidies and increase exponentially with advancing female age. The spindle is the cellular apparatus responsible for separating chromosomes at anaphase. For accurate chromosome segregation, spindle microtubules must establish appropriately configured attachments to chromosomes via kinetochores. With regard to understanding the mechanistic basis for human aneuploidies therefore, it will be important to explore the molecular underpinnings of spindle structure and the interaction of its microtubules with chromosomes in human oocytes. Here we describe a technique for simultaneously immunolabelling chromosomes, spindle microtubules and kinetochores in human oocytes

Next Generation Sequencing Detects Premeiotic Errors in Human Oocytes

Autosomal aneuploidy is the leading cause of embryonic and foetal death in humans. This arises mainly from errors in meiosis I or II of oogenesis. A largely ignored source of error stems from germinal mosaicism, which leads to premeiotic aneuploidy. Molecular cytogenetic studies employing metaphase fluorescence in situ hybridization and comparative genomic hybridisation suggest that premeiotic aneuploidy may affect 10&ndash;20% of oocytes overall. Such studies have been criticised on technical grounds. We report here an independent study carried out on unmanipulated oocytes that have been analysed using next generation sequencing (NGS). This study confirms that the incidence of premeiotic aneuploidy in an unselected series of oocytes exceeds 10%. A total of 140 oocytes donated by 42 women gave conclusive results; of these, 124 (88.5%) were euploid. Sixteen out of 140 (11.4%) provided evidence of premeiotic aneuploidy. Of the 140, 112 oocytes were immature (germinal vesicle or metaphase I), of which 10 were aneuploid (8.93%); the remaining 28 were intact metaphase II - first polar body complexes, and six of these were aneuploid (21.4%). Of the 16 aneuploid cells, half contained simple errors (one or two abnormal chromosomes) and half contained complex errors. We conclude that germinal mosaicism leading to premeiotic aneuploidy is a consistent finding affecting at least 10% of unselected oocytes from women undergoing egg collection for a variety of reasons. The importance of premeiotic aneuploidy lies in the fact that, for individual oocytes, it greatly increases the risk of an aneuploid mature oocyte irrespective of maternal age. As such, this may account for some cases of aneuploid conceptions in very young women

Accuracy of drilling guides for transfer from three-dimensional CT-based planning to placement of zygoma implants in human cadavers

The accuracy of surgical drilling guides was assessed for placement of zygoma implants. Six zygoma fixtures of length 45 mm (Nobel Biocare, Göteborg, Sweden) were placed in three formalin-fixed human cadavers using surgical drilling guides. The fabrication of these custom-made drilling guides was based on three-dimensional computerized tomography (3D-CT) data for the maxillary-zygomatic complex. The installation of the implants was simulated preoperatively using an adopted 3D-CT planning system. In addition, anatomical measurements of the zygomatic bone were performed on the 3D images. The preoperative CT images were then matched with postoperative ones in order to assess the deviation between the planned and installed implants. The angle between the planned and actually placed implants was < 3° in four out of six cases. The largest deviation found at the exit point of one of the six implants was 2.7 mm. The present study showed that the use of surgical drilling guides should be encouraged for zygoma implant placement because of the lengths of the implants involved and the anatomical intricacies of the region.SCOPUS: ar.jFLWINinfo:eu-repo/semantics/publishe