An equilibrium needs to be established by the cellular and acellular components of the ovarian follicle if developmental competence is to be acquired by the oocyte. Both cumulus cells (CCs) and follicular fluid (FF) are critical determinants for oocyte quality. Understanding how CCs and FF influence oocyte quality in the presence of deleterious systemic or pelvic conditions may impact clinical decisions in the course of managing infertility. Given that the functional integrities of FF and CCs are susceptible to concurrent pathological conditions, it is important to understand how pathophysiological factors influence natural fertility and the outcomes of pregnancy arising from the use of assisted reproduction technologies (ARTs). Accordingly, this review discusses the roles of CCs and FF in ensuring oocyte competence and present new insights on pathological conditions that may interfere with oocyte quality by altering the intrafollicular environment.
This study evaluated the potential protective effect of the antioxidants, l-carnitine (LC) and N-acetyl-cysteine (NAC), in preventing meiotic oocyte damage induced by follicular fluid (FF) from infertile women with mild endometriosis (ME). We performed an experimental study. The FF samples were obtained from 22 infertile women undergoing stimulated cycles for intracytoplasmic sperm injection (11 with ME and 11 without endometriosis). Immature bovine oocytes were submitted to in vitro maturation (IVM) divided into 9 groups: no-FF (No-FF); with FF from control (CFF) or ME (EFF) groups; and with LC (C + LC and E + LC), NAC (C + NAC and E + NAC), or both antioxidants (C + 2Ao and E + 2Ao). After IVM, oocytes were immunostained for visualization of microtubules and chromatin by confocal microscopy. The percentage of meiotically normal metaphase II (MII) oocytes was significantly lower in the EFF group (51.35%) compared to No-FF (86.36%) and CFF (83.52%) groups. The E + NAC (62.22%), E + LC (80.61%), and E + 2Ao (61.40%) groups showed higher percentage of normal MII than EFF group. The E + LC group showed higher percentage of normal MII than E + NAC and E + 2Ao groups and a similar percentage to No-FF and CFF groups. Therefore, FF from infertile women with ME causes meiotic abnormalities in bovine oocytes, and, for the first time, we demonstrated that the use of NAC and LC prevents these damages. Our findings elucidate part of the pathogenic mechanisms involved in infertility associated with ME and open perspectives for further studies investigating whether the use of LC could improve the natural fertility and/or the results of in vitro fertilization of women with ME.
Although we observed a small improvement (∼5%) in live birth/ongoing pregnancy and clinical pregnancy rates (PRs), the evidence is of very low quality and the best interpretation is that we are still very uncertain about differences in this comparison. The clinical equipoise remains and more large well-conducted randomized controlled trials are needed. They should use the same incubators in both groups and the embryologists should be blinded at least when evaluating laboratory outcomes.
Objective: Preeclampsia is a specific disorder of human pregnancy that is associated with hyperuricemia and higher levels of pro-inflammatory cytokines. Adenosine deaminase (ADA) is an enzyme present in all human tissues, and is considered an indicator of cellular inflammation. In the present study we assess whether adenosine deaminase (ADA) activity is altered in women with preeclampsia (PE) and contributes to elevated levels of uric acid and pro-inflammatory cytokine production. Study design: The population studied consisted of 60 women with PE, 30 normotensive pregnant women (NT) and 20 non-pregnant women (NP). Uric acid concentration and ADA activity were determined in the serum. Peripheral blood mononuclear cells (PBMCs) were isolated and evaluated for intracellular nuclear transcription factor kappa B (NF-jB) levels and for endogenous tumor necrosis factor-a (TNF-a) and interleukin-1b (IL-1b) production. The data were evaluated with parametric or non-parametric tests with significance set at P < 0.05. Results: ADA levels were higher in the PE group compared with the NT and NP groups (P < 0.001). A positive correlation between ADA and uric acid levels was identified in women with PE (P < 0.001). Endogenous production of IL-1b and TNF-a, as well as intracellular NF-jB levels, were higher in PBMCs from the PE group than from NT and NP women (P < 0.01) and correlated with the ADA concentration in preeclamptic women (P < 0.01). Conclusion: An elevation in ADA activity in women with PE may contribute to their increased levels of uric acid and pro-inflammatory immune activity.
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