P–546 Exome sequencing and preimplantation genetic testing for unexplained recurrent fetal malformations

Study question

Could patient suffering unexplained recurrent fetal malformations be benefit of PGT-M by exome sequencing mutations identification?

Summary answer

Patients suffering unexplained recurrent fetal malformations could be benefit of the use of exome sequencing in combination to PGT-M to have a healthy live birth.

What is known already

Fetal malformations account for approximately 3% of live births and causes include: chromosomal abnormalities, exposure to toxic substances or teratogens and infections. Recently, studies have shown that several monogenic diseases are linked to fetal abnormalities. However, because of the large number of potential genes, genetic testing is challenging. Exome sequencing is widely used to detect genetic mutations and has emerged as a useful tool for finding the genetic cause of fetal abnormalities. The aim of this study was to show how exome sequencing in patients suffering unexplained recurrent fetal malformations in combination to PGT-M could lead to successful healthy newborn.

Study design, size, duration

Case report of a non-consanguineous couple with unexplained, recurrent fetal malformations. Couple were recruited during clinical consultation for unexplained recurrent fetal malformations at a private reproductive medicine clinic. The couple had two malformed fetus with the same congenital abnormalities: hydrocephalus, cerebellar vermis agenesis, cerebellar hypoplasia and enlarged cisterna magna. Patients signed written informed consent regarding to exome testing. For fetal sample, informed consent was obtained from parents.

Participants/materials, setting, methods

Sample of the affected fetus were provided. Parental genomic DNA was extracted from peripheral blood. Exome sequencing was performed using TrusightOne (Illumina®). FASTAQ data were processed through BWA and GATK algorithm. VCF files were analysed using Variant Interpreter software. After genetic counselling, PGT-M was performed using linkage polymorphic markers analysis and mutation sequencing. Embryo biopsy was carried at blastocyst stage. Embryos were vitrified and one healthy embryo was thaw and transfer in a subsequent cycle.

Main results and the role of chance

An homozygous novel pathogenic mutation c.641 C>T (p.Ala214Val) in FVLCR2 gene was found. The parents were heterozygous carriers revealing that the detected variant follow an autosomal recessive pattern. The FLVCR2 (14q24.3) gene encodes a transmembrane protein that belongs to the major facilitator superfamily of secondary carriers that transport small solutes in response to chemiosmosis ion gradients, such as calcium. Mutations in this gene are related to fetal central nervous system defects. This disorder is diagnosed prenatally and is lethal. PGT-M was recommended during genetic counselling. After control ovarian stimulation 14 oocytes were retrieved and finally 4 embryos were suitable for embryo biopsy at blastocyst stage. One embryo was diagnosed as healthy, two affected and one heterozygous carrier. The healthy embryo was thaw and transferred and a healthy male baby was born.

Limitations, reasons for caution

Exome sequencing has technical limitations: only covers mutations in coding regions and does not cover noncoding regions of the genome. It also cannot reliably detect copy-number variants at single gene level.

Wider implications of the findings: This study offers strong evidence of exome-sequencing as a new diagnostic strategy and powerful tool discovering the underlying etiology of recurrent fetal malformations and identifying new genes important for human development. Using this strategy in combination with PGT-M, clinicians can help couples with recurrent fetal malformations to have healthy newborns.

Trial registration number

Not applicable

P–550 Clinical outcomes of mosaic embryos are similar between young and older women

Study question

Are there differences in the clinical outcomes of mosaic embryos depending on the female age?

Summary answer

Clinical outcomes of mosaic embryo transfers are similar regardless female age.

What is known already

Chromosomal abnormalities are common in embryos analyzed in preimplantation genetic testing for aneuploidy (PGT-A) cycles. Mosaicism (the presence of two or more chromosomally distinct cell lines) is a usual event in embryos derived from IVF cycles.

Several studies show that mosaic embryos have reduced potential to reach term, compared to euploid embryos. The factors affecting the implantation potential and development of mosaic embryos are controversial. Recently, Victor et al. (2019) argued that mosaic blastocysts generated at younger ages show better outcomes compared to older ages. The aim of this study was to test this hypothesis in our centre.

Study design, size, duration

A total of 136 mosaic embryos from patients undergoing PGT-A cycles from May 2014 to October 2020 were retrospectively analyzed in this study. The blastocyst trophoectoderm biopsies of day 5 and 6 were analysed by aCGH (n = 47, 30.1%) and NGS (n = 109, 69.9%). An embryo was considered mosaic when the percentage of aneuploid cells were 25–50% in aCGH and 20–50% in NGS. Only single embryo transfer cycles were included in the analysis.

Participants/materials, setting, methods

Embryo analysis were performed using Agilent SurePrint G3 8x60K CGH microarrays or Veriseq NGS (Illumina), with previous whole genome amplification. We evaluated if clinical results of mosaic embryos transfers in IVF cycles were correlated with female age. The main outcome measures were β-hCG, implantation rate and ongoing pregnancy rate. β-hCG was measured in blood 14 days after the embryo transfer and was considered positive when it was >2 mUI/ml.The statistical analysis was performed with SPSSv20.0.

Main results and the role of chance

A total of 136 mosaic embryos were included in this study. Overall, we evaluated factors affecting embryo mosaicism implantation potential. Neither the percentage of mosaicism nor the segmental mosaicism were related to mosaic embryo implantation, pregnancy and ongoing pregnancy rates.

To evaluate the impact of female age in clinical outcomes, we established two different groups depending on whether mosaic blastocysts were generated from oocytes retrieved at young maternal ages (≤35 years; n = 62) or at older ages (>35years; n = 74).

No differences were found between groups. Nonetheless, to reduce bias, embryo quality, percentage of mosaicism, segmental mosaicism and whether the transferred embryo was frozen or fresh were included as confounding factors.

The rate of positive β-hCG was similar between groups: 45.2% in ≤ 35y group vs 54.1% in > 35y (p = 0.476). The implantation rate was also similar: 30.6% vs 39.2%% (p = 0.855), respectively. Furthermore, the ongoing pregnancy rate was higher in the >35y group (35.1%), compared to the ≤35y group (19.4%) without reaching statistically significant differences (p = 0.245).

Limitations, reasons for caution

The sample size is a limitation. aCGH test and a different definition for mosaic embryo in terms of percentage of abnormal cells was employed in this study compared to Victor et. al. (2019) study. Larger prospective studies should evaluate the impact of maternal age in the outcome of mosaic embryos.

Wider implications of the findings: Our results challenge that female age is associated with clinical outcomes after the transfer of mosaic embryos. Comparable results were obtained in young and older women. Therefore, in the absence of euploid embryos, mosaic embryos might be considered for transfer and similar outcomes are expected regardless of the maternal age.

Trial registration number

Not applicable

P–540 A feasible diagnostic approach for the cryptic subtelomeric traslocations in early recurrent miscarriage patients by preimplantation genetic testing (PGT)

Study question

Could cryptic subtelomeric traslocations in early recurrent miscarriage patients be diagnosed by preimplantation genetic testing?

Summary answer

PGT is a powerful tool to detect subtelomeric cryptic traslocations identifying the cause of early recurrent miscarriage and allowing subsequent genetic counselling. What is known already: Chromosome translocations are frequently associated with birth defects, spontaneous early pregnancy losses and infertility. However, submicroscopic traslocations (so-called cryptic traslocations) are too small to be detected by conventional karyotyping.. Due to balanced status, high resolution molecular techniques as arrayCGH are not able to detect it. Thus, cryptic traslocations detection is challenging. PGT is able to detect CNVs at higher resolution than routine karyotyping. Therefore, the recurrent diagnosis of CNV at embryo level could suggest a subchromosomal parental traslocation. The aim of this study is to investigate the feasibility of using PGT as an indicator of parental balanced cryptic traslocations.

Study design, size, duration

We included three couples who underwent PGT for unexplained repeated pregnancy loss (RPL) in our clinic from February 2020 to November 2020. Common established causes of RPL (uterine anomalies, antiphospholipid syndrome, immunological, hormonal and metabolic disorders) were previously rouled-out. Even couple karyotypes were normal. Twenty-three embryos from those couples were biopsied at blastocyst and analysed for CNVs detection using low coverage whole genome NGS.

Participants/materials, setting, methods

PGT by NGS was performed by Veriseq-NGS (Illumina), with previous whole genome amplification. Fluorescence in situ hybridization (FISH) using parental blood samples were performed to validate the origin of subchromosomal number variation. Commercially available subtelomeric specific probes were selected according to the CNV identified and the procedures were performed according to the manufacturer’s protocols.

Main results and the role of chance

Overall, CNVs of terminal duplication and deletion that imply unbalanced traslocation derivatives were detected in the 43.5% of biopsied embryos. For couple 1, 4 out of 5 embryos (80%) carried deletion of telomeric region on chromosomes 5 and 21. Three out of 6 biopsed embyos (50%) were diagnosed with subchromosomal copy variants at telomeric region on chromosomes 6 and 16 for couple 2. In the case of couple 3, three out of 12 embryos (25%) were carriers of CNV at subtelomeric region on chromosomes 2 and 6. The size of CNVs detected ranges from 8Mb to 20Mb. Accurate diagnosis with the parental study was made by FISH. The combination of probes to detect the structural chromosome alteration were: Tel5qter-LSI21q, Tel6pter-CEP16 and Tel6pter-CEP6 for each couple respectively. The FISH studies reveal that CNVs were inherited from one parent carrying the balanced cryptic traslocation. Ultimately, the abnormal karyotype from the carrier parent were 46,XY,t(5;21)(q33.2;q21.2) for couple 1, 46,XY,t(6;16)(p22.3;q22.1) for couple 2 and 46,XY,t(2;6)(p25.1;p24.2) for couple 3. Finally, each couple performed a cryotransfer of a single normal balanced embryo. Two pregnancies are ongoing.

Limitations, reasons for caution

The main limitation of this approach is the NGS- PGT resolution. CNVs smaller than 5Mb could not be detected.

Wider implications of the findings: This study shows the value of PGT for unexplained RPL, followed by parental FISH to better characterize CNVs and identify couples in whom one partner carries a cryptic translocation. Accurate diagnosis of parental chromosome translocation can achieve with FISH only, but FISH would not be performed unless PGT showed CNVs.

Trial registration number

Not applicable

O-143 Characterization of vaginal and endometrial microbiome in patients with chronic endometritis (CE)

Study question

Could vaginal and endometrial microbiome by sequencing 16S rRNA be comparable to classic diagnostic methods or immunohistochemistry CD138 for diagnosis of chronic endometritis?

Summary answer

A characteristic endometrial and vaginal microbiome is present in patients with chronic endometritis. An abnormal vaginal microbiome correlates with the presence of chronic endometritis.

What is known already

Chronic endometritis is a disease characterized by persistent inflammation of the endometrial lining. Currently, histopathological evaluation by immunohistochemistry CD138 marker is most common diagnostic method for CE. Microbiome analysis based on subunit 16S rRNA sequencing is a fast tool that can enable the identification of pathogenic microorganisms associated with CE. The main bacteria at vaginal and endometrial level belong to genus Lactobacillus, producers of lactic acid that allows maintaining acidic pH of vagina and acts as barrier against pathogens. Investigations on the effect of an abnormal endometrial and vaginal microbiome could improve assisted reproductive technologies.

Study design, size, duration

This is a observational pilot study (60 patients and 120 samples). The study population consists of patients attending to our fertility clinic for frozen euploid embryo transfer (FET) from May 2017 to May 2019. Preimplantation Genetic Testing of aneuploidy (PGT-A) was performed at blastocyst stage using Veriseq (Illumina). The inclusion criteria to be meet by patients were: age between 18 and 50 years, own or donated oocytes and use of ICSI.

Participants/materials, setting, methods

Cohort study with sixty patients undergoing assisted reproductive treatment (TRA) with their own or donated gametes and PGT-A Vaginal and endometrial samples were taken in the cycle prior to embryo transfer. The vaginal and endometrial microbiome was analyzed by mass sequencing of the V3V4 region of 16S rRNA. Bioinformatics analysis was performed using QIIME2 and MicrobiomeAnalyst packages. Alpha, beta diversity and taxonomic characterization were compared with positive and negative CD138 groups for chronic endometritis (CE).

Main results and the role of chance

Different bacterial communities were detected when vaginal and endometrial samples were analyzed in patients with and without endometritis diagnosed with CD138 immunohistochemistry. In patients with endometritis, a higher alpha diversity index tendency was found in vaginal samples (p = 0.15 for the Shannon index) and significant differences in endometrial samples (p = 0.01 for the Shannon index). In the beta diversity analysis, no significant differences were observed between the groups established as per the diagnosis of endometritis. Vaginal and endometrial samples from women with endometritis showed a microbiome pattern not dominated by Lactobacillus spp. Relative abundance analysis identified the genera Ralstonia and Gardnerella in endometrial sample, and the genera Streptoccoccus and Ureaplasma in vaginal sample of patients diagnosed with CD138 for endometritis. Comparing endometrial and vaginal samples CD138 positive diagnosed for endometritis, alpha diversity (p = 0.06 for the Shannon index and p = 0.08 for the Simpson index) and beta diversity (p < 0.001) showed significant differences. Relative abundance identified the genera Lactobacillus (p = 3.76E-4), Ralstonia (p = 8.19E-4), Delftia (p = 0.004) and Anaerobacillus (p = 0.004) in these sample groups.

Limitations, reasons for caution

The main limitation of this study is the small sample size. Larger studies including a higher number of samples are needed to confirm the different microbiome pattern observed at the vaginal and endometrial levels in correlation with chronic endometritis. The microbiome pattern has not been analyzed after treatment of CE.

Wider implications of the findings

Our findings suggest the existence of a characteristic vaginal and endometrial microbiota in patients with chronic endometritis. Different genera and species were identified in patients with and without endometritis depending on whether the sample was endometrial or vaginal. An abnormal vaginal microbiome appears to be strongly correlated with chronic endometritis.

Trial registration number

Not Applicable

High rate of hypomorphic variants as the cause of inherited ataxia and related diseases: study of a cohort of 366 families

PURPOSE

Diagnosis of inherited ataxia and related diseases represents a real challenge given the tremendous heterogeneity and clinical overlap of the various causes. We evaluated the efficacy of molecular diagnosis of these diseases by sequencing a large cohort of undiagnosed families.

METHODS

We analyzed 366 unrelated consecutive patients with undiagnosed ataxia or related disorders by clinical exome-capture sequencing. In silico analysis was performed with an in-house pipeline that combines variant ranking and copy-number variant (CNV) searches. Variants were interpreted according to American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines.

RESULTS

We established the molecular diagnosis in 46% of the cases. We identified 35 mildly affected patients with causative variants in genes that are classically associated with severe presentations. These cases were explained by the occurrence of hypomorphic variants, but also rarely suspected mechanisms such as C-terminal truncations and translation reinitiation.

CONCLUSION

A significant fraction of the clinical heterogeneity and phenotypic overlap is explained by hypomorphic variants that are difficult to identify and not readily predicted. The hypomorphic C-terminal truncation and translation reinitiation mechanisms that we identified may only apply to few genes, as it relies on specific domain organization and alterations. We identified PEX10 and FASTKD2 as candidates for translation reinitiation accounting for mild disease presentation.

Characterization of the vaginal and endometrial microbiome in patients with chronic endometritis

OBJECTIVE

To compare the endometrial and vaginal microbiome of women with and without chronic endometritis.

STUDY DESIGN

A cohort study with 60 patients undergoing assisted reproductive treatment with their own or donated gametes was undertaken. Vaginal and endometrial samples were taken in the cycle prior to embryo transfer. The endometrial and vaginal microbiome was analysed by mass sequencing of the V3V4 region of 16S rRNA gene. Bioinformatics analysis was performed using QIIME2 and MicrobiomeAnalyst packages. Alpha diversity, beta diversity and taxonomic characterization were compared between samples that tested positive and negative for chronic endometritis on CD138 immunohistochemistry.

RESULTS

Different bacterial communities were detected when vaginal and endometrial samples were analysed in patients with and without endometritis diagnosed using CD138 immunohistochemistry. In patients with endometritis, a higher alpha-diversity index was found in vaginal samples (p = 0.15 for the Shannon index) and significant differences were found in endometrial samples (p = 0.01 for the Shannon index). In the beta-diversity analysis, no significant differences were observed between the groups with and without endometritis. Vaginal and endometrial samples from women with endometritis showed a microbiome pattern that was not dominated by Lactobacillus spp. Relative abundance analysis identified Ralstonia and Gardnerella spp. in endometrial samples, and Streptoccoccus and Ureaplasma spp. in vaginal samples of patients diagnosed with chronic endometritis on CD138 immunohistochemistry. When comparing endometrial and vaginal samples diagnosed with endometritis on CD138 immunohistochemistry, both alpha diversity (p = 0.06 for the Shannon index and p = 0.08 for the Simpson index) and beta diversity (p < 0.001) showed significant differences. Lactobacillus spp. (p = 3.76E-4), Ralstonia spp. (p = 8.19E-4), Delftia spp. (p = 0.004) and Anaerobacillus spp. (p = 0.004) were identified in these sample groups.

CONCLUSION

These results demonstrate the existence of a characteristic vaginal and endometrial microbiota in patients with chronic endometritis. Different genera and species were identified in patients with and without chronic endometritis depending on whether the sample was endometrial or vaginal. There is a clear relationship between changes in the vaginal microbiome and chronic endometritis. The microbiota is a continuum throughout the female reproductive tract, so study of the vaginal microbiota could be useful for the diagnosis of diseases of the upper reproductive tract, such as chronic endometritis.

AB0878-HPR EFFECT OF AQUATIC PHYSIOTHERAPY ON PAIN AND QUALITY OF LIFE IN ELDERLY WOMEN WITH FIBROMYALGIA

Background:

Fibromyalgia is defined as a chronic non-articular rheumatic disease, characterized by generalized, diffuse bilateral pain and the presence of tender points in specific anatomical regions. Its symptoms are characterized by a very varied picture and the etiology is considered multifactorial. Today, with difficult treatment, fibromyalgia has been a major challenge for healthcare professionals. Aquatic physiotherapy is currently one of the most commonly used forms of intervention in the management of fibromyalgia, and for this reason it has been used in interdisciplinary rehabilitation programs to promote health.

Objectives:

To evaluate the effects of aquatic physiotherapy on pain and quality of life in patients with fibromyalgia.

Methods:

This is an interventional, quasi-experimental study carried out at the Physiotherapy School Clinic of Universidade Cesumar in the city of Maringá, PR, Brazil. The study was approved by the Human Research Ethics Committee of Unicesumar under opinion No. 1,025,567. Participated in the study, elderly women aged 60 years, with clinical diagnosis of fibromyalgia. To assess the quality of life, the Medical Outcomes Study 36 - Item Short-Form Health Survey (SF-36) instrument was used and to verify the intensity of the pain, the Visual Analogue Scale was used. The aquatic physiotherapy intervention protocol was to perform 10 Watsu sessions, performed twice a week, lasting 40 minutes each. To perform the Watsu method, the following steps of the technique were followed: before starting, opening, delivering the water, dancing the breath in the water, breathing balance and to finish releasing the spine. For data analysis, the Shapiro-Wilk test was initially applied to verify the normality of the variables under study. As the data presented a normal distribution, mean, standard deviation, minimum and maximum were used to characterize the results. To compare the initial and final variables, the dependent student t test was used. The significance adopted was p <0.05.

Results:

The study included 17 elderly women with a mean age of 67.5 ± 4.7 years. When comparing the evaluation and the reassessment, a statistically significant improvement was evidenced in the domains of quality of life: functional capacity (p=0.00445), limitation due to physical aspects (p=0.01347), pain (p=0.00861), vitality (p=0.00044), limitation due to emotional aspects (p=0.02019), mental health (p=0.00748). The domains that did not show statistical increase were the general health status (p=0.30663) and the social aspects (p=0.05037). The pain, on the other hand, was statistically less after the intervention (p=0.00059).

Conclusion:

Aquatic physical therapy provided benefits in reducing pain and improving the quality of life of elderly women with fibromyalgia. It is important to encourage individuals with fibromyalgia to perform non-pharmacological interventions, such as aquatic physiotherapy, to promote their health and quality of life.

References:

[1]Oliveira DV, Ferreira AAM, Oliveira DCD, Leme DEDC, Antunes MD, Nascimento Júnior JRAD. Association of the practice of physical activity and of health status on the quality of life of women with fibromyalgia. Journal of Physical Education. 2019;30(1): e3027. https://doi.org/10.4025/jphyseduc.v30i1.3027.

[2]Antunes MD, Vertuan MP. Miquilin A, Leme DEC, Morales RC, Oliveira DV. Efeitos do Watsu na qualidade de vida e quadro doloroso de idosas com fibromialgia. ConScientiae Saúde. 2016;15(4), 636-641. https://doi.org/10.5585/conssaude.v15n4.6756.

[3]Antunes M, Ferreira A, Oliveira D, Júnior JN, Bertolini S, Marques AP. There is association between the level of physical activity and quality of life of women with fibromyalgia?. Annals of rheumatic diseases. 2019;78(2)650-1. http://dx.doi.org/10.1136/annrheumdis-2019-eular.2835.

Acknowledgements:

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001.

Disclosure of Interests:

None declared

Seroconversion and Abundance of IgG Antibodies against S1-RBD of SARS-CoV-2 and Neutralizing Activity in the Chilean Population

COVID-19 is a pandemic caused by SARS-CoV-2. In Chile, half a million people have been infected and more than 16,000 have died from COVID-19. As part of the clinical trial NCT04384588, we quantified IgG against S1-RBD of SARS-CoV-2 (anti-RBD) in recovered people in Santiago and evaluated their suitability as COVID-19 convalescent plasma donors. ELISA and a luminescent SARS-CoV-2 pseudotype were used for IgG and neutralizing antibody quantification. 72.9% of the convalescent population (468 of 639) showed seroconversion (5-55 μg/mL anti-RBD IgG) and were suitable candidates for plasma donation. Analysis by gender, age, and days after symptom offset did not show significant differences. Neutralizing activity correlated with an increased concentration of anti-RBD IgG (p < 0.0001) and showed a high variability between donors. We confirmed that the majority of the Chilean patients have developed anti-SARS-CoV-2 antibodies. The quantification of anti-RBD IgG in convalescent plasma donors is necessary to increase the detection of neutralizing antibodies.

Milk and meat fatty acids from sheep fed a plantain-chicory mixture or a grass-based permanent sward

Plantain and chicory are interesting forage species since they present good nutritional quality and are more resistant to drought than many temperate grasses. The fatty acid (FA) profile in milk and meat is related to a growing concern for the consumption of healthy foods, that is, with a lower content of saturated FA, higher polyunsaturated FA (PUFA) and a favourable n-6 : n-3 FAs ratio. Our objective was to evaluate the FA content in ewe's milk and lamb's meat fed a plantain-chicory mixture (PCH) or a grass-based permanent sward (GBS) dominated by perennial ryegrass. Eighteen Austral ewes in mid-lactation were allocated to PCH and GBS treatments. Milk samples were obtained during September (spring). Thirty weaned lambs were finished on both treatments from November to December (7 weeks), slaughtered and their meat sampled. Fat from milk and meat samples was extracted and stored until analysed by gas chromatography. Milk fat from GBS was higher than from PCH (P < 0.05) in C18:0 (11 385 v. 5874 mg/100 g FA), 9c-18:1 (15 750 v. 8565 mg/100 g FA), 11 t-18:1 (4576 v. 2703 mg/100 g FA) and 9c,11 t-18:2 (1405 v. 921 mg/100 g FA) and lower in 18:2n-6 (827 v. 1529 mg/100 g FA) and 18:3n-3 (943 v. 1318 mg/100 g FA) FA. Total mono-unsaturated FA was higher in GBS than PCH (P < 0.05). Meat fat from PCH swards presented a higher (P < 0.05) content than GBS for 18:2n-6 (46.8 v. 28.2 mg/100 g FA), linolenic (24.6 v. 14.2 mg/100 g FA), polyunsaturated FA (119.7 v. 73.4 mg/100 g FA), n-6 (65.9 v. 40.8 mg/100 g FA) and n-3 (53.8 v. 32.5 mg/100 g FA), respectively. No effect of treatment (P > 0.05) was detected for 9c-18:1 (283.9 v. 205.8 mg/100 g FA), 11 t-18:1 (26.2 v. 19.3 mg/100 g FA) and 9c,11 t-18:2 (10.1 v. 7.6 mg/100 g FA), for PCH and GBS. These results suggest that grazing a PCH mixture results in a higher concentration of PUFA in ewes' milk and in lambs' fat, as compared to a GBS sward.

Chiral asymmetry detected in a 2D array of permalloy square nanomagnets using circularly polarized x-ray resonant magnetic scattering

The sensitivity of circularly polarized x-ray resonant magnetic scattering (CXRMS) to chiral asymmetry has been demonstrated. The study was performed on a 2D array of Permalloy (Py) square nanomagnets of 700 nm lateral size arranged in a chess pattern, in a square lattice of 1000 nm lattice parameter. Previous x-ray magnetic circular dichroism photoemission electron microscopy (XMCD-PEEM) images on this sample showed the formation of vortices at remanence and a preference in their chiral state. The magnetic hysteresis loops of the array along the diagonal axis of the squares indicate a non-negligible and anisotropic interaction between vortices. The intensity of the magnetic scattering using circularly polarized light along one of the diagonal axes of the square magnets becomes asymmetric in intensity in the direction transversal to the incident plane at fields where the vortex states are formed. The asymmetry sign is inverted when the direction of the applied magnetic field is inverted. The result is the expected in the presence of an unbalanced chiral distribution. The effect is observed by CXRMS due to the interference between the charge scattering and the magnetic scattering.

RAS Mutation Decreases Overall Survival After Optimal Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy of Colorectal Peritoneal Metastasis: A Modification Proposal of the Peritoneal Surface Disease Severity Score

BACKGROUND

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are currently the most accepted treatment for peritoneal metastases from colorectal cancer. Restrictive selection criteria are essential to obtain the best survival benefits for this complex procedure. The most widespread score for patient selection, the peritoneal surface disease severity score (PSDSS), does not include current biological factors that are known to influence on prognosis. We investigated the impact of including RAS mutational status in the selection criteria for these patients.

METHODS

We studied the risk factors for survival by multivariate analysis using a prospective database of consecutive patients with carcinomatosis from colorectal origin treated by CRS and HIPEC in our unit from 2009 to 2017. The risk factors obtained were validated in a multicentre, international cohort, including a total of 520 patients from 15 different reference units.

RESULTS

A total of 77 patients were selected for local análisis. Only RAS mutational status (HR: 2.024; p = 0.045) and PSDSS stage (HR: 2.90; p = 0.009) were shown to be independent factors for overall survival. Early PSDSS stages I and II associated to RAS mutations impaired their overall survival with no significant differences with PSDSS stage III overall survival (p > 0.05). These results were supported by the international multicentre validation.

CONCLUSIONS

By including RAS mutational status, we propose an updated RAS-PSDSS score that outperforms PSDSS alone providing a quick and feasible preoperative assessment of the expected overall survival for patients with carcinomatosis from colorectal origin undergone to CRS + HIPEC.

Comprehensive mitochondrial DNA analysis and IVF outcome

STUDY QUESTION

Do mitochondrial DNA (mtDNA) copy number and heteroplasmy in human embryos affect the ongoing pregnancy rate?

SUMMARY ANSWER

Our study suggests that mtDNA copy number above a specific threshold is associated with the ongoing pregnancy rate.

WHAT IS KNOWN ALREADY

Mitochondria play a vital role in cell function. Recently, there has been increasing research on mtDNA as a biomarker of embryo implantation. Although reports showed that high levels of mtDNA in the blastocyst are associated with low implantation potential, other publications were unable to confirm this. Confounding factors may influence the mtDNA copy number in euploid embryos. On the other hand it has been speculated that both mtDNA heteroplasmy and copy number contribute to mitochondrial function. Next generation sequencing (NGS) allows us to study in depth mtDNA heteroplasmy and copy number simultaneously.

STUDY DESIGN, SIZE, DURATION

A prospective non-selection study was performed. We included 159 blastocyst biopsies from 142 couples who attended our clinic for preimplantation genetic testing for aneuploidies (PGT-A), from January 2017 to December 2017. All embryos were biopsied on Day 5 or Day 6. The aneuploid testing was performed by NGS. All blastocysts were diagnosed as euploid non-mosaic and were transferred. The mtDNA analysis was performed once the embryo diagnosis was known.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Sequencing reads mapping to the mtDNA genome were extracted from indexed bam files to identify copy number and heteroplasmy. The relative measure of mtDNA copy number was calculated by dividing the mtDNA reads by the nuclear DNA value to normalize for technical variants and the number of cells collected at the biopsy. All the results were subjected to a mathematical correction factor according to the embryo genome. Heteroplasmy was assigned by MitoSeek.

MAIN RESULTS AND THE ROLE OF CHANCE

The mean average copy number and SD of mtDNA per genome was 0.0016 ± 0.0012. Regarding heteroplasmy, 40 embryos were heteroplasmy carriers (26.32%). MtDNA variants were detected in coding and non-coding regions and the highest number of variants in an embryo was eight. With respect to IVF outcome for mtDNA copy number analysis, we set a threshold of 0.003 for the following analysis. The vast majority of the embryos were below the threshold (142/159, 89.31%) and 17 embryos were classified as having higher mtDNA levels. We showed a reduction in ongoing pregnancy rate associated with elevated mtDNA copy number (42.96% versus 17.65%, P < 0.05). This result was independent of maternal age and day of the biopsy: these factors were included as confounding factors because mtDNA copy number was negatively correlated with female age (25 –30 y: 0.0017 ± 0.0011, 30 –35 y: 0.0012 ± 0.0007, 35 –40 y: 0.0016 ± 0.0009, over 40 y: 0.0024 + 0.0017, P < 0.05). Embryos biopsied on Day 5 were more likely to have higher quantities of mtDNA compared with those biopsied on Day 6 (0.0017 versus 0.0009, P < 0.001). According to IVF outcome and heteroplasmy, a lower ongoing pregnancy rate was reported for embryos that carried more than two variants. However, this did not reach statistical significance when we compared embryos with a number of variants lower or higher than two (39.15 versus 20.0, P = 0.188). Finally, a clear positive association between the mtDNA variants and copy number was reported when we compare embryos with or without heteroplasmy (0.0013 ± 0.0009 versus 0.0025 ± 0.0014, P < 0.001) and among different numbers of variants (0:0.0013 ± 0.0009, 1–2:0.0023 ± 0.0012, >2:0.0043 ± 0.0014, P < 0.05).

LIMITATIONS, REASONS FOR CAUTION

A limitation may be the size of the sample and the high-throughput sequencing technology that might not have detected heteroplasmy levels below 2% which requires high sequence depth A clinical randomized trial comparing the clinical outcome after the transfer of embryos selected according to mtDNA levels or only by morphological evaluation will be necessary. More research into the impact of mtDNA heteroplasmy and copy number on IVF outcome is needed.

WIDER IMPLICATIONS OF THE FINDINGS

Our results demonstrate that embryos with elevated mtDNA copy number have a lower chance of producing an ongoing pregnancy. MtDNA copy number is higher in older women and is dependent upon the number of cell divisions that preceded biopsy. Moreover, our data suggest that mitochondrial activity could be a balance between functional capacity and relative mtDNA copy number.

STUDY FUNDING/COMPETING INTEREST(S)

There are no conflicts of interest or sources of funding to declare.

Trial registration number

Not applicable.

Systematic review of the mesopancreas: concept and clinical implications

BACKGROUND

In 2007, Gockel et al. coined the term mesopancreas (MP). In the next 10 years, a limited number of publications about MP have been published, but little is known about the oncological benefit of MP resection. We performed a systematic review of the literature on MP.

METHODS

An electronic search was performed in PubMed, EMBASE, Cochrane, Latindex, Scielo, and Koreamed databases until 15 June 2017 to identify all published articles dealing with the subject of MP. Some language restriction was done (Chinese and Rumanian).

RESULTS

The search yielded 51 articles; 28 articles were selected as relevant. All were retrospective studies focused more on describing technical variants, feasibility and safety than on the cancer results. The R0 rate in patients with MP resection ranged between 57 and 96.7%. In all the articles with a control group, the R0 rate was higher in the MP excision group. Survival data were explicitly stated only in five series.

CONCLUSION

MP is a difficult-to-excise retropancreatic area. In theory, it is agreed that MP excision raises the rate of R0 resections, which in turn reflected in an improvement in the oncological results; however, at present there are no randomized studies to prove this. Achieving a worldwide consensus on its concept, landmarks, excision technique and oncological results is essential.

Charge-Transfer Processes in Warm Dense Matter: Selective Spectral Filtering for Laser-Accelerated Ion Beams

We investigate, both experimentally and theoretically, how the spectral distribution of laser accelerated carbon ions can be filtered by charge exchange processes in a double foil target setup. Carbon ions at multiple charge states with an initially wide kinetic energy spectrum, from 0.1 to 18 MeV, were detected with a remarkably narrow spectral bandwidth after they had passed through an ultrathin and partially ionized foil. With our theoretical calculations, we demonstrate that this process is a consequence of the evolution of the carbon ion charge states in the second foil. We calculated the resulting spectral distribution separately for each ion species by solving the rate equations for electron loss and capture processes within a collisional radiative model. We determine how the efficiency of charge transfer processes can be manipulated by controlling the ionization degree of the transfer matter.

Psychological impact of multigene cancer panel testing in patients with a clinical suspicion of hereditary cancer across Spain

OBJECTIVE

Patients' psychological reactions to multigene cancer panel testing might differ compared with the single-gene testing reactions because of the complexity and uncertainty associated with the different possible results. Understanding patients' preferences and psychological impact of multigene panel testing is important to adapt the genetic counselling model.

METHODS

One hundred eighty-seven unrelated patients with clinical suspicion of hereditary cancer undergoing a 25-gene panel test completed questionnaires after pretest genetic counselling and at 1 week, 3 months, and 12 months after results to elicit their preferences regarding results disclosure and to measure their cancer worry and testing-specific distress and uncertainty.

RESULTS

A pathogenic variant was identified in 38 patients (34 high penetrance and 4 moderate penetrance variants), and 54 patients had at least one variant of uncertain significance. Overall, cancer panel testing was not associated with an increase in cancer worry after results disclosure (P value = .87). Twelve months after results, carriers of a moderate penetrance variant had higher distress and uncertainty scores compared with carriers of high penetrance variants. Cancer worry prior to genetic testing predicted genetic testing specific distress after results, especially at long term (P value <.001). Most of the patients reported the wish to know all genetic results.

CONCLUSIONS

Our results suggest that patients can psychologically cope with cancer panel testing, but distress and uncertainty observed in carriers of moderate penetrance cancer variants in this cohort warrant further research.