Biomechanical characteristics of the ovarian cortex in POI patients and functional outcomes after drug-free IVA.

PURPOSE: There is increasing evidence that the ovarian extracellular matrix (ECM) plays a critical role in follicle development. The rigidity of the cortical ECM limits expansion of the follicle and consequently oocyte maturation, maintaining the follicle in its quiescent state. Quiescent primordial, primary, and secondary follicles still exist in primary ovarian insufficiency (POI) patients, and techniques as in vitro activation (IVA) and drug-free IVA have recently been developed aiming to activate these follicles based on the Hippo signaling disruption that is essential in mechanotransduction. In this context, we analyze the effect of drug-free IVA in POI patients, comparing the relationship between possible resumption ovarian function and biomechanical properties of ovarian tissue. METHODS: Nineteen POI patients according to ESHRE criteria who underwent drug-free IVA by laparoscopy between January 2018 and December 2019 and were followed up for a year after the intervention. A sample of ovarian cortex taken during the intervention was analyzed by atomic force microscopy (AFM) in order to quantitatively measure tissue stiffness (Young's elastic modulus, E) at the micrometer scale. Functional outcomes after drug-free were analyzed. RESULTS: Resumption of ovarian function was observed in 10 patients (52.6%) and two of them became pregnant with live births. There were no differences in clinical characteristics (age and duration of amenorrhea) and basal hormone parameters (FSH and AMH) depending on whether or not there was activation after surgery. However, ovarian cortex stiffness was significantly greater in patients with ovarian activity after drug-free IVA: median E = 5519 Pa (2260-11,296) vs 1501 (999-3474); p-value < 0.001. CONCLUSIONS: Biomechanical properties of ovarian cortex in POI patients have a great variability, and higher ovarian tissue stiffness entails a more favorable status when drug-free IVA is applied in their treatment. This status is probably related to an ovary with more residual follicles, which would explain a greater possibility of ovarian follicular reactivations after treatment.

Pregnancy after drug-free in vitro activation of follicles and fresh tissue autotransplantation in primary ovarian insufficiency patient: a case report and literature review.

BACKGROUND: The aim of this report was to describe a case of pregnancy after drug-free in vitro activation (IVA) of follicles and fresh tissue autotransplantation in primary ovarian insufficiency (POI) patient and to review the pertinent literature. METHODS: We present a case in wich a 32 - years old patient with POI became pregnant after IVA without tissue culture and with ovarian tissue transplantation. We also reviewed the literature using Pubmed database. CASE PRESENTATION: Pretreatment with estradiol/progesterone stopped the day before surgery. The removal of the ovarian cortex and autotransplantation were performed by laparoscopy in the same surgical act. Ovarian fragments were transplanted in contralateral ovary and peritoneal pocket near to the ovary. Immediately after surgery GnRH agonist together HMG injections started, leading the growth of 3 preovulatory follicles and the retrieval of two mature eggs. After IVF two embryos were transferred and singleton pregnancy was established and currently she is 25 weeks pregnant. RESULTS: A total of 51 patients with POI in whom an in vitro activation of ovarian tissue was performed, were collected from the revieew of the literature. In 29.4% of them, follicular development was obtained and in 4 of them a pregnancy. In all of them, a combined technique (fragmentation and activation) was performed in two laparoscopies. No case has been reported successfully after drug-free in vitro activation. CONCLUSIONS: This is the first report about a case with pregnancy after drug-free in vitro activation of follicles and fresh tissue autotransplantation in POI patient.

Oscillatory flow in a y-shaped bifurcation.

Fluid particle trajectories in oscillatory flow in Y-branched tubes of equal radii were quantitatively analyzed for an oscillatory number square root 2pi/Tv.ro of the order of unity and qualitatively for an oscillatory number of the order of 25. Radial distribution of trajectories and secondary motions are described. This work is an attempt to know some of the features of oscillatory flow present in blood and air motion with similar boundary conditions.

Oscillatory flow in a y-shaped bifurcation.

Fluid particle trajectories in oscillatory flow in Y-branched tubes of equal radii were quantitatively analyzed for an oscillatory number square root 2pi/Tv.ro of the order of unity and qualitatively for an oscillatory number of the order of 25. Radial distribution of trajectories and secondary motions are described. This work is an attempt to know some of the features of oscillatory flow present in blood and air motion with similar boundary conditions.

Oscillatory flow in a y-shaped bifurcation

Fluid particle trajectories in oscillatory flow in Y-branched tubes of equal radii were quantitatively analyzed for an oscillatory number square root 2pi/Tv.ro of the order of unity and qualitatively for an oscillatory number of the order of 25. Radial distribution of trajectories and secondary motions are described. This work is an attempt to know some of the features of oscillatory flow present in blood and air motion with similar boundary conditions.