O-259 Free and extracellular vesicle-associated microRNAs from endometrial fluid as non-invasive diagnostic biomarkers of implantative endometrium

Study question

Is it possible to use free and extracellular vesicle-associated microRNAs from endometrial fluid as non-invasive biomarkers for implantative endometrium?

Summary answer

It is feasible to use free and extracellular vesicle-associated miRNAs as non-invasive tools for the detection of an implantative endometrium.

What is known already

MicroRNAs (miRNAs) and extracellular vesicles (EVs) from endometrial fluid (EF) have been described as mediators of embryo-endometrial crosstalk. Therefore, the miRNA analysis of EF could provide a non-invasive technique for recognizing an implantative endometrium and consequently improve implantation rates.

Study design, size, duration

A cohort of 162 women who assisted the human reproduction unit from January 2018 to February 2021. Of them, 72 participated in the setup and samples were collected before starting any fertility treatment in natural cycles. For the discovery of the predicted models (n = 30) and validation (n = 60), the EF was obtained from women undergoing frozen embryo transfer on day 5 and the sample was collected immediately before embryo transfer.

Participants/materials, setting, methods

We compared five different methodologies, two of which consisted of direct RNA extraction while the other three had EV enrichment prior to RNA extraction. A smallRNA-seq was performed to determine the most efficient method and to find a predictive model to differentiate between implantation and non-implantation endometrium. The models were confirmed by qPCR in two set of samples, discovery and validation cohorts with a different implantation outcome.

Main results and the role of chance

Our results showed that EV-enrichment protocols permit detection of a higher number of miRNAs. In addition, we obtained two predictive models based on three miRNAs that allow us to differentiate between an implantative and non-implantative endometrium. Results for model 1 in discovery cohort were: AUC=0.93; p-value = 0.003 and in validation cohort were: AUC= 0.69; p-value = 0.019. Results for model 2 in discovery cohort were: AUC=0.92; p-value = 0.0002 and in validation cohort were: AUC= 0.78; p-value= 0.0002.

Limitations, reasons for caution

One limitation to consider is the inherent variability of both the women involved in the trial and the embryos transferred. In our study, we have previously selected embryos based on morphology but we lacked genetic and molecular studies, a good complement that will certainly improve our test’s accuracy.

Wider implications of the findings

This study introduces new protocols to analyze miRNAs from very small volumes of EF, which could be implemented in clinical practice for the assessment of the endometrial status using miRNA-based non-invasive tools. Our results suggest that with model-2 it is possible to identify a non-implantative endometrium with 0.6-sensitivity and 0.93-specificity.

Trial registration number

not applicable

Concentration compared with total urinary excretion of 11,17-DOA in cynomolgus monkey urine

Strees sensitive molecules exhibit great variation in concentration in the circulation and it may often be advantageous to quantify these in urine or feces rather than in serum or plasma. We advocate that all urine-or feces-should be collected, and that excretion of stress sensitive molecules should be expressed as amounts excreted per time unit per kg body-weight, rather than being expressed as concentrations in samples. Urine and feces excretion varies significantly within and between animals over time, which may render simple concentration measures of molecules of little biological relevance.

Stress in cynomolgus monkeys (Macaca fascicularis) subjected to long-distance transport and simulated transport housing conditions

The stress associated with transportation of non-human primates used in scientific research is an important but almost unexplored part of laboratory animal husbandry. The procedures and routines concerning transport are not only important for the animals' physical health but also for their mental health as well. The transport stress in cynomolgus monkeys (Macaca fascicularis) was studied in two experiments. In Experiment 1, 25 adult female cynomolgus monkeys were divided into five groups of five animals each that received different diets during the transport phase of the experiment. All animals were transported in conventional single animal transport cages with no visual or tactile contact with conspecifics. The animals were transported by lorry for 24 h at ambient temperatures ranging between 20 degrees C and 35 degrees C. Urine produced before, during and after transport was collected and analysed for cortisol by enzyme-linked immunosorbent assay (ELISA). All monkeys exhibited a significant increase in cortisol excretion per time unit during the transport and on the first day following transport.Although anecdotal reports concerning diet during transport, including the provision of fruits and/or a tranquiliser, was thought likely to influence stress responses, these were not corrobated by the present study. In Experiment 2, behavioural data were collected from 18 cynomolgus macaques before and after transfer from group cages to either single or pair housing, and also before and after a simulated transport, in which the animals were housed in transport cages. The single housed monkeys were confined to single transport cages and the pair housed monkeys were kept in their pairs in double size cages. Both pair housed and singly housed monkeys showed clear behavioural signs of stress soon after their transfer out of their group cages.However, stress-associated behaviours were more prevalent in singly housed animals than in pair housed animals, and these behaviours persisted for a longer time after the simulated transport housing event than in the pair housed monkeys. Our data confirm that the transport of cynomolgus monkeys is stressful and suggest that it would be beneficial for the cynomolgus monkeys to be housed and transported in compatible pairs from the time they leave their group cages at the source country breeding facility until they arrive at their final laboratory destination in the country of use.

Impact of chronic catheterization and automated blood sampling (Accusampler) on serum corticosterone and fecal immunoreactive corticosterone metabolites and immunoglobulin A in male rats

Jugular catheters were inserted in nine male rats under general isofluorane anesthesia and the catheters were connected to a commercially available computerized blood sampling device (Accusampler). Blood samples (150 microl) were collected every 4 h during the first 24 h after surgery and every 12 h during the following 72 h until 94 h after surgery, when the animals were killed. All fecal pellets were collected at blood sampling. Serum corticosterone and fecal concentrations of immunoreactive corticosterone metabolites and immunoglobulin A (IgA) were quantified by ELISAs. In blood, high corticosterone concentrations (>200 ng/ml) were recorded in the first samples obtained after surgery, but the concentrations decreased steadily during the day and became cyclical, showing a diurnal variation with high levels during evenings and low levels in the mornings. The automatic blood sampling itself did not result in recordable increases in serum corticosterone concentrations. The time delay between the presence of elevated corticosterone levels in blood and in feces was approximately 12 h. Fecal immunoreactive corticosterone metabolite levels remained elevated during the 94 h study period after surgery. The fecal concentrations of IgA showed substantial between-animal variation and decreased non-significantly after the surgery. Like serum corticosterone, fecal IgA showed a diurnal variation in amounts excreted, in this case with high values in the morning and low values in the evening. The concentrations of fecal corticosterone and IgA were negatively correlated in samples obtained before surgery but no correlation existed after surgery. This indicates that fecal immunoreactive corticosterone metabolites, but not IgA, constitute a good marker of acute stress. For immunoreactive corticosterone metabolites as well as for IgA, the concentration in feces correlated well with total excretion, making single fecal samplings usable as a measure of total secretion.

Thermodynamic Properties of Isomeric Butanols with 2-Bromobutane

Excess volumes and excess enthalpies for mixtures of isomeric butanols with 2-bromobutane were determined at the temperatures of 298.15 K and 313.15 K. Excess volumes are positive over the whole composition range except for the mixture 1-butanol with 2-bromobutane at 298.15 K in which

Calorimetric Behaviour of Primary Bromobutanes with Isomeric Butanols

Excess enthalpies for mixtures of 1-bromobutane or 1-bromo-2-methylpropane with isomeric butanols were determined at the temperatures of 298.15 and 313.15 K. All the systems show positive excess enthalpies. Predictions with the modified UNIFAC method were also obtained.

[Serum theophylline levels after oral administration in a group of asthmatic children]

Serum levels of theophylline were determined in 54 asthmatics children aged 3,92 +/- 2,45 years, who were taken oral theophylline at doses of 4,99 +/- 0,45 mg. The serum levels at 0 hours (9,22 +/- 4,90 mcg/ml) and at 2 hours (15,22 +/- 5,5 mcg/ml) showed a great variation, although they were taken similar doses. Two hours after ingestion, 34 patients showed levels between 10-20 mcg/ml in 10 children were less than 10 mcg/ml, and another 10 shown serum levels over 20 mcg/ml without symptoms. There was a good correlation between levels at 0 and 2 hours (p less than 0,002). These data may support the utility of doses employed. It is advisable knowing the individual response to theophylline for managing episodes of asthma in children, that can be made by only one determination 2 hours after ingestion.