Multivariate Gaussian Random Fields over Generalized Product Spaces involving the Hypertorus

The paper deals with multivariate Gaussian random fields defined over generalized product spaces that involve the hypertorus. The assumption of Gaussianity implies the finite dimensional distributions to be completely specified by the covariance functions, being in this case matrix valued mappings.

We start by considering the spectral representations that in turn allow for a characterization of such covariance functions. We then provide some methods for the construction of these matrix valued mappings. Finally, we consider strategies to evade radial symmetry (called isotropy in spatial statistics) and provide representation theorems for such a more general case.

Multivariate Kalman filtering for spatio-temporal processes

An increasing interest in models for multivariate spatio-temporal processes has been noted in the last years. Some of these models are very flexible and can capture both marginal and cross spatial associations amongst the components of the multivariate process. In order to contribute to the statistical analysis of these models, this paper deals with the estimation and prediction of multivariate spatio-temporal processes by using multivariate state-space models. In this context, a multivariate spatio-temporal process is represented through the well-known Wold decomposition. Such an approach allows for an easy implementation of the Kalman filter to estimate linear temporal processes exhibiting both short and long range dependencies, together with a spatial correlation structure. We illustrate, through simulation experiments, that our method offers a good balance between statistical efficiency and computational complexity. Finally, we apply the method for the analysis of a bivariate dataset on average daily temperatures and maximum daily solar radiations from 21 meteorological stations located in a portion of south-central Chile.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s00477-022-02266-3.

DNA methylation may mediate psychotropic drug-induced metabolic side effects: results from a 1-month observational study

Introduction

Metabolic side effects of psychotropic medications are a major drawback to patients’ effective treatment. Among the mechanisms underlying their development, DNA methylation may be involved.

Objectives

The aim of this study was to estimate DNA methylation changes occurring secondary to psychotropic treatment and evaluate associations between 1-month metabolic changes and baseline DNA methylation or 1-month DNA methylation changes, using an epigenome-wide approach.

Methods

Seventy-nine psychiatric patients recruited as part of PsyMetab study, who started a treatment with either an antipsychotic, a mood stabilizer or mirtazapine were selected. Epigenome-wide DNA methylation was measured using the Illumina Methylation EPIC BeadChip at baseline and after one month of treatment.

Results

A global methylation increase was observed after 1 month of treatment, which was more pronounced in patients whose weight remained stable (i.e., <2.5% weight increase). Epigenome-wide significant methylation changes were observed at 52 loci in the whole cohort and at one site, namely cg12209987, located in an intergenic region within an enhancer, specifically in patients who underwent important early weight gain (i.e., ≥5% weight increase) during the same period of treatment (p<5*10^-8). Multivariable analysis confirmed an association between an increase in methylation at this locus and weight gain in the whole cohort (p=0.004). Epigenome-wide association analyses failed to identify any significant link between other metabolic changes (e.g. glucose or lipid levels) and methylation data.

Conclusions

These findings give new insight into the mechanisms of psychotropic drug-induced weight gain. With improved understanding of the metabolic side effects, the use of precision medicine with epigenetics may become possible

Disclosure

No significant relationships.

P–794 Prevalence of positivity for SARS-CoV–2 RNA in follicular fluid in infertile patients

Study question

Is Sars-Cov–2 present in the follicular fluid of infertile patients?

Summary answer

In the experience of the Infertility and IVF Unit, University Of Bologna, Italy, RNA of SARS-Cov–2 was not detected in the follicular fluid.

What is known already

Data on the risk of virus presence in reproductive cells and transmissibility in IVF procedures are very limited. In literature only one study reports the detection of SARS-Cov–2 viral RNA in oocytes of PCR positive women. Research of RNA in follicular fluid could be a marker able to indicate whether to continue IVF treatments in the case of swab-positive patients.

Study design, size, duration

Prospective study performed at Infertility and IVF Unit, Sant’Orsola University Hospital, University of Bologna, Italy, from March 2020 to January 2021. 451 IVF cycles were performed on 902 patients. In addition 59 cycles of oocyte cryopreservation were also performed to fertility preservation in oncological patients. In all positive swab patients was analyzed the follicular fluid for RNA virus detection.

Participants/materials, setting, methods

961 patients underwent telephone triage before going to the IVF Center to identify subjects with suspected or confirmed infection. Body temperature was measured on all patients before entering the IVF Center.

All patients were subjected to real-time analysis (RT PCR) of pharyngeal swab samples 48 hours before transvaginal ultrasound-guided oocyte retrieval.

In case of positive swab, PCR was performed on follicular fluid.

Main results and the role of chance

In our population of infertile patients the incidence of SARS COV–2 infection positivity was 0.4% (4/961).

No IVF treatments were suspended. The oocytes of the 4 women with positive swab were cryopreserved using closed devices stored in a special dedicated cryogenic container. No viral RNA was detected in the follicular fluid.

Limitations, reasons for caution

there are no limitations to the study.

Wider implications of the findings: The absence of SARS-COV–2 RNA in the follicular fluid is a reassuring result in the storage and future use of oocytes.

Trial registration number

Not applicable

P–098 Use of Dimethylxanthine Theophylline in surgical retrieved sperms that do not recover motility after thawing

Study question

Can the use of Theophylline recover motility of frozen surgically retrieved sperms in case of absence of motility after thawing?

Summary answer

Theophylline allows to recover motility of thawed surgically retrieved sperms. The utilization of sperms with or without pharmacological activation gives comparable clinical outcomes.

What is known already

Testicular sperm motility is usually poor. A method is needed to detect viable sperm for ICSI when motility is totally absent after freezing/thawing. Hypo-osmotic swelling test, mechanical touch technique, laser-assisted immotile sperm selection, birefringence-polarization microscopy and exposure to pharmacological stimulation are techniques used for this purpose. Among pharmacological agents Dimethylxanthine Theophylline is a phosphodiesterase inibitor that improves sperm motility by promoting an increase in intracellular cyclic AMP levels. Few studies report that it is efficient for recovery of sperm motility in cases of thawed testicular and retrograde ejaculation samples improving reproductive outcomes.

Study design, size, duration

Retrospective analysis of sixty frozen surgical sperm cycles (45 patients) utilized from February 2018 to November 2020. After thawing, samples were divided in two Groups according to motility recovery. Group A: presence of motility, Group B: absence of motility. Group B was treated with Theophilline and motility was re-assessed after incubation. Activated sperms were utilized for ICSI when available. Sperm motility recovery, fertilization, pregnancy rate/transfer, implantation and miscarriage rate were evaluated in both Groups.

Participants/materials, setting, methods

Surgical specimens were treated and concentrated in SpermRinse™ Medium (Vitrolife) and then cryopreservated in nitrogen vapor in TEST Yolk Buffer (Irvine Scientific). After thawing, only samples with no motility recovery were treated with a brief incubation in Theophylline (GM501 SpermMobil, Gynemed) and washed in Polyvinylpyrrolidone (ICSITM Vitrolife) before injection. ICSI was performed in all cases approximately 4–5 hours after sperm thawing. After fertilization check, transfer was scheduled in day 2.

Main results and the role of chance

Women’s age Group A (34,39±2,29 M±SD) and group B (35,87±4,34 M±SD) and men’s age Group A (37,31±5,12 M±SD) and group B (40,89±8.15 M±SD) were not significantly different (P= .328 and P=.218) respectively.

Group A: 13/60 cycles (21.7%) (9 patients). Pre freezing and post thawing total motility percentage were 34.0±19.0 (M±SD) and 13.5±15.6 (M±SD) respectively (39.8% recovery). Group B: 47/60 cycles (78.3%) (36 patients). Pre freezing total motility percentage was 5.3±8.5 (M±SD) and no motility was recovered post thawing (0%). After treatment with Theophylline total motility was 1.8±1.8 (M±SD) (33.5% recovery). Motile sperms were utilized in all cases except from two in the Group B.

Number of injected oocytes was 2.8±1.1 (M±SD) in Group A and 4.3±3.1 (M±SD) in Group B (P=.004) respectively.

Fertilisation rate (63.1% and 45.4%, P=.066), Number of embryos transferred (1.8±0.7 M±SD and 1.6±0.7 M±SD, P=.271), Pregnancy rate/Transfer (54.5% and 37.1%, P=.502), Implantation rate (30.0% and 27.8%, P=.919) and Miscarriage rate (33.3% and 30.7%, P=.675) were not statistically significant between Group A and B respectively.

In the two cases of group B injected with immotile sperm, fertilization rate was 0% (0/3) and 50% (2/4).

Limitations, reasons for caution

A larger study is needed to investigate the recovery of sperms motility (and/or their activation) and clinical outcomes, in particular referring to the origin of sampling (epididymal aspirate and testicular tissue) and type of azoospermia (obstructive and non-obstructive).

Wider implications of the findings: Theophylline is an effective tool for sperm motility recovery after thawing allowing to inject viable sperm and facilitating laboratory handling.

Trial registration number

Not applicable

P–486 Psychological determinants of the decision to attend couples infertility counselling

Study question

May specific psychological variables related to the experience of infertility have a predicting effect over the decision of accepting counselling?

Summary answer

Specific infertility related sources of sufferance including low levels of infertility self-efficacy and poor quality of life significantly predict the request for professional help.

What is known already

Available data on the access to infertility counselling services suggest that only 10–34% of patients who are offered such opportunity actually pursue it. Qualitative studies pointed out that this might be due to a lack of information about available support and to negative attitudes toward counselling. It seems also that women and men who accept counselling have worse levels of psychological distress. However, there is a lack of quantitative studies on the topic and among those available none used measures that are specific to the experience of infertility itself

Study design, size, duration

The data presented herein are part of a larger data collection promoted by the Italian Ministry of Health on the psychological impact of assisted reproduction. The present study is a cross-sectional research and involves a sample of 184 patients, composed by 92 women waiting for infertility treatment and their partners, enrolled between October 2019 and October 2020 at the Infertility and IVF Unit of the S. Orsola University Hospital in Bologna, Italy.

Participants/materials, setting, methods

Participants were voluntarily enrolled in the study at their first medical consult. They were informed about the possibility to attend free couples infertility counselling sessions and asked to fill in the following questionnaires: Infertility Self-Efficacy Scale (ISE); Fertility Quality of Life (FERTIQoL); Dyadic Adjustment Scale (DAS). To attend infertility counselling a shared agreement between partners was requested. Couples who agreed to the study but not to counselling sessions were provided only with questionnaires.

Main results and the role of chance

The 34.8% (n = 32 couples) of the sample accepted to receive counselling sessions. The two groups (counselling vs no-counselling) were comparable in all socio-demographic variables, aside for education, with higher education levels in the counselling group.

Overall, the counselling group reported greater psychological sufferance than the no-counselling group, with lower scores at the ISE, FERTIQoL, and DAS questionnaires.

Regarding which factors predicted the decision to attend counselling sessions, logistic regression analysis showed that: for the female partner’s dimensions low scores at the ISE and at the Emotional subscale of the FertiQoL were predictive of accepting counselling (when scores increased the odds of being in the counselling group would decrease by 46% and 8% respectively); for the male’s partner dimensions, predictive factors were low scores on the Social subscale and high scores on the Relational subscale of the FertiQoL (when scores increased the odds of being in the counselling group would decrease by 8% and increase by 10% respectively).

In conclusion, impairments in self-efficacy, emotional well-being and social life may drive a greater need for help, but a close relationship with the partner may be also necessary to predispose men to accept couples infertility counselling.

Limitations, reasons for caution

Data were collected from a well enough homogeneous sample which may have helped in better enhancing the specificity of infertile couples’ needs. However, the small sample size and the fact that data were collected from a sole Italian clinic may impact the representativity of our results.

Wider implications of the findings: Findings provide important information for clinical interventions with infertile couples. Patients accepting counselling might be having a worse adjustment to the experience of infertility. Besides, women and men may be affected in different ways. Men’s closeness to the partner might be a favourable factor and should be further studied.

Trial registration number

The study was approved by the Ethical Committee of the S. Orsola Hospital, University of Bologna (CE: 273/2018/Sper/AOUBO) and funded by the Italian Ministry of Health (J33C17000560001)

Lamb's problem on random mass density fields with fractal and Hurst effects

This paper reports on a generalization of Lamb's problem to a linear elastic, infinite half-space with random fields (RFs) of mass density, subject to a normal line load. Both, uncorrelated and correlated (with fractal and Hurst characteristics) RFs without any weak noise restrictions, are proposed. Cellular automata (CA) is used to simulate the wave propagation. CA is a local computational method which, for rectangular discretization of spatial domain, is equivalent to applying the finite difference method to the governing equations of classical elasticity. We first evaluate the response of CA to an uncorrelated mass density field, more commonly known as white-noise, of varying coarseness as compared to CA's node density. We then evaluate the response of CA to multiscale mass density RFs of Cauchy and Dagum type; these fields are unique in that they are able to model and decouple the field's fractal dimension and Hurst parameter. We focus on stochastic imperfection sensitivity; we determine to what extent the fractal or the Hurst parameter is a significant factor in altering the solution to the planar stochastic Lamb's problem by evaluating the coefficient of variation of the response when compared with the coefficient of variation of the RF.