P-556 Younger maternal age as a factor associated with embryonic mosaicism. Analysis of 3222 blastocyst by Next Generation Sequencing

Study question

Is there an association between healthy younger women under 30 years old and blastocyst mosaicism rate evaluated by NGS analysis?

Summary answer

Embryo mosaicism is independent to younger maternal age. However, morphological embryo quality is associated with embryo mosaicism.

What is known already

Embryo aneuploidy rate is strongly associated with maternal age, increasing in women older than 36y. On the contrary, the aneuploidy rate remains lower in women between 22 to 35y. However, the mosaicism rate in younger women seems to be slightly higher compared to older women. Although, there is still controversy on the relationship with maternal age and others factors.

Study design, size, duration

This retrospective study include 786 oocytes donation cycles were performed from 2016 to 2020. These IVF cycles generated 3222 blastocyst that were analyzed with PGT-A(NGS. Veryseq-Illumina). Mosaic embryos were call when variation was between 20-80%. Mosaic embryos were also sub-classify as a whole or segmental chromosome mosaicism. Mosaic embryos were according to the impact level as a: high Mosaic level (>50%) and low mosaic level (≤50%). Data was classified by donor age: group-1(18-22y)(n = 288) and group-2(23-30y)(n = 498).

Participants/materials, setting, methods

All donors had a normal ovarian reserve and without any pathological or chromosome translocation. Donors had conventional oocyte stimulation with antagonist protocol trigger with agonist GnRH. Embryos were cultured with Lifeglobal media family under 7% CO2 and 5%O2.

A multilevel model was made and associations between variables by logistic regression were adjusted according to paternal age, morphological blastocyst quality, fertilization method, biopsy operator, day of embryo biopsy, number of chromosomes impacted per embryo and sperm quality.

Main results and the role of chance

Oocyte donation cycles generated 3222 blastocyst that were analyzed by NGS. The euploidy rate was 60.4% (n = 723) and 58.6% (n = 1186). Aneuploidy rate was 22.6% (n = 271) and 26.2% (n = 531) (p = 0.04). Mosaicism rate was 17% (n = 204) and 15.1% (n = 309) in group 1 and 2 respectively (p = 0.4)

Mosaic embryos were also further studied and classified according to the impact level. Interestingly, a vast majority of mosaic embryos have low mosaicism level (86.1%) compared to high mosaic level (13.9%) (p < 0.001).

The multilevel model shows that embryo quality correlated with embryo mosaicism where good quality embryos have a lower mosaicism rate compared to fair and poor quality blastocyst.

Finally, the chromosomes 21, 22 and 14 were the most frequent chromosome affect in whole chromosome mosaicism while the chromosomes 1, 2 and 5 were affected by segmental chromosome mosaicism and it was independent of maternal age.

Limitations, reasons for caution

The analysis was limited only for healthy women under 30 year old and it should not be extrapolate to patients with other pathologies.

Wider implications of the findings

The present study revealed that embryo mosaicism remains at similar percentage in younger healthy women. The mosaic embryos generated from young women have a lower chromosome impact, which according to other studies has a good implantation potential.

Trial registration number

N.A

Access improvement to aircraft passengers' hand luggage

BACKGROUND

Efficient use of space and passenger comfort in aircraft interiors are major issues. There is not much research available about the flying experience regarding passengers' personal belongings.

OBJECTIVE

The objective of this study is to explore concepts within the current aircraft seats which improve the passenger experience related to their personal belongings like wallets, mobile phones and laptops.

METHODS

Through on-site observations, interviews and online questionnaires, data regarding the number of personal belongings taken into the airplane and opinions about access to hand luggage were gathered. These data were used to develop different concepts to optimize the aircraft interior, which were evaluated by passengers.

RESULTS

Almost every passenger carries a phone (88%), wallet (94%), travel documents (98%) and keys (76%) with them and they like to have these stored close by. Passengers rate the concept that provides integrated storage in the tray table of the aircraft seat the best.

CONCLUSIONS

Extra storage possibility in the table-tray seems a promising solution according to the passengers.

Identification of Enterobacter bacteria as saxitoxin producers in cattle's rumen and surface water from Venezuelan Savannahs

We have previously shown that a paralytic toxin able to block sodium channels in nerve is associated with a cattle disease known as bovine paraplegic syndrome (BPS) [Toxicon. 31 (1993) 1581]. We have now identified this as saxitoxin (STX) using HPLC by either the methods of [Toxicon. 31 (1993) 1581], or [Toxicon. 25 (1987) 1105]. In recent experiments we were able to collect and cultivate facultative anaerobic bacteria growing on rumen, grass and ponds of corrals with high incidence of BPS; the cultured bacteria produce compounds indistinguishable from STX under both HPLC procedures described above. Two species of the Enterobacter genus (E. asburiae and E. cloacae) and a strain of Klebsiella pneumoniae, were identified using standard biochemical criteria as well as gas chromatography of bacterial lipids. All these bacteria produced STX in aerobic cultures.

[Non-invasive fungal sinusitis: allergic fungal sinusitis and sinusal mycetomas]

We review non-invasive fungal sinusitis (FS) cases treated at our Unit following the recent SF classification, based on physiopathology, treatment and prognosis. We report 7 FS cases treated during 2 years and followed a minimum of 24 months. They are two allergic FS, one of them related to an allergic bronchopulmonary aspergillosis, and five mycetomas, two of them without a sinusal foreign body, sphenoidal and maxillary respectively, and three caused by a maxillary foreign body. All were treated by endoscopic sinus surgery (ESS). The two allergic cases were also treated with systemic corticoids in the postoperative period. We review the clinical presentation of the different types of non-invasive FS, the importance of endoscopy and imaging techniques in their management, the usefulness of ESS, the common association of FS to foreign bodies, and their prognosis.

Periodic explosions by positive feedback in a rising foam column

An aqueous foam rising adiabatically in a column suffers a drop in temperature. Under appropriate conditions, such a column periodically explodes. We here trace this explosion to the tight thermal coupling between the foam and its enclosing glass column. When the surface surfactant concentration is unbuffered by micelles, a positive feedback exists between the flow of heat from the walls into the foam and the thermal conductivity of the foam itself. In our highly expanded foam, heat is conducted through the foam cells' interior primarily by the heat-pipe effect. Such an effect is retarded by a dense layer of surfactant molecules. Heat absorption causes cell expansion, which, in a foam unbuffered by micelles, causes a reduction in surface concentration of surfactant molecules and, hence, in an increase in thermal conductivity. This interpretation of our observed periodic explosions is in agreement with all of our observations.