Exposure of Porcine Oocytes to Methylparaben During In Vitro Maturation Alters the Expression of Genes Involved in Cumulus Cell Expansion and Steroidogenesis, Decreasing Hyaluronic Acid and Progesterone Synthesis.

Parabens are widely used because of their antimicrobial properties in drugs, cosmetics, and food; however, it has been reported that methylparaben may adversely influence female reproduction. Methylparaben decreases oocyte in vitro maturation at a maturation inhibition concentration 50 of 780.31 μM but also decreases oocyte viability at a lethal concentration 50 of 2028.

In vitro exposure of porcine spermatozoa to methylparaben, and propylparaben, alone or in combination adversely affects sperm quality.

Parabens (PBs) are widely used in the cosmetic, pharmaceutical, and food industries as preservatives of products. Because of its great use, humans and other organisms are highly exposed daily. However, little is known about the effect of PBs on male infertility.

Comparison of DNA damage in granulosa cells of women undergoing controlled ovarian stimulation in in vitro fertilization protocols with the recombinant human follicle-stimulating hormones Corneumon, Gonal-F, Pergoveris and Puregon: a randomized trial.

Purpose: To compare the DNA damage in granulosa cells (GCs) of women undergoing ovarian-stimulated cycles with four widely used recombinant human follicle-stimulating hormones (rhFSH) in in vitro fertilization (IVF) protocols (Corneumon, Gonal-F, Pergoveris and Puregon).

Methods: A randomized trial was carried out at a Mexican hospital. GCs were isolated from 18 women with infertility undergoing assisted reproductive techniques (ART).

Chronic stress decreases fertility parameters in female rats.

Multiple effects of stress on health have been reported; however, reproductive alterations in oocytes and cumulus cells have not been fully described. In females, chronic stress has been shown to produce alterations in the estrous cycle, to decrease oocyte maturation, and to increase the percentage of abnormal oocytes. The aim of this study was to evaluate whether the oocytes from chronically stressed female rats could recover and mature by providing them with all the necessary culture conditions, as well as to evaluate the functionality of the GAP junctions, and the viability and DNA integrity of the cumulus cells, which are crucial for the complete maturation and development of the oocyte.

Reproductive disruption in adult female and male rats prenatally exposed to mesquite pod extract or daidzein.

Phytoestrogens are considered to be endocrine disruptors, since they can alter the endocrine system, thus disturbing many reproductive events. The intake of diets containing a high content of phytoestrogens has increased worldwide in human populations and in domestic animals. Phytoestrogens in maternal blood can pass through the placenta to the fetus in high amounts and can have long-term organizational effects.

Physiological role of reactive oxygen species in testis and epididymal spermatozoa.

The reactive oxygen species (ROS) play an important role in various aspects of male reproductive function, for spermatozoa to acquire the ability to fertilize. However, the increase in ROS generation, both due to internal and external factors, can induce oxidative stress, causing alterations in the structure and function of phospholipids and proteins. In the nucleus, ROS attack DNA, causing its fragmentation and activation of apoptosis, thus altering gene and protein expression.

The need for regulation in the practice of human assisted reproduction in Mexico. An overview of the regulations in the rest of the world.

Background: The emergence of assisted reproductive technology (ART) in humans has been an important tool for the treatment of infertility. The number of treatments performed in Latin America has been increasing, and Mexico is the third country with the most assisted reproduction cycles performed in the region. However, Mexico lacks a national regulation for assisted reproduction.

DNA damage in cumulus cells generated after the vitrification of in vitro matured porcine oocytes and its impact on fertilization and embryo development.

Background: The evaluation of the DNA damage generated in cumulus cells after mature cumulus-oocyte complexes vitrification can be considered as an indicator of oocyte quality since these cells play important roles in oocyte developmental competence. Therefore, the aim of this study was to determine if matured cumulus-oocyte complexes exposure to cryoprotectants (CPAs) or vitrification affects oocytes and cumulus cells viability, but also if DNA damage is generated in cumulus cells, affecting fertilization and embryo development.

Results: The DNA damage in cumulus cells was measured using the alkaline comet assay and expressed as Comet Tail Length (CTL) and Olive Tail Moment (OTM).

Chronic Stress Detrimentally Affects In Vivo Maturation in Rat Oocytes and Oocyte Viability at All Phases of the Estrous Cycle.

Background: Stress has been considered as one of the causes of decreased reproductive function in women. However, direct evidence of the effect of chronic stress on oocytes depending on estrous cycle phases is limited.

Objective: The present study aimed to evaluate the impact of chronic stress on the viability, integrity, and maturation of rat oocytes depending on estrous cycle phases, specifically proestrus, estrus, and diestrus.

Effects of Porcine Immature Oocyte Vitrification on Actin Microfilament Distribution and Chromatin Integrity During Early Embryo Development .

Vitrification is mainly used to cryopreserve female gametes. This technique allows maintaining cell viability, functionality, and developmental potential at low temperatures into liquid nitrogen at -196°C. For this, the addition of cryoprotectant agents, which are substances that provide cell protection during cooling and warming, is required.

(-75 G>A and 83 C>T) and (2488 C>T) polymorphisms and their association with myocardial infarction, lipids and apolipoproteins in patients with type 2 diabetes mellitus.

Introduction: The increased risk of myocardial infarction (MI) in type 2 diabetes mellitus (T2DM) is well documented. Polymorphisms in and genes allow us to identify new genetic markers in the Mexican population with T2DM and MI.

Material And Methods: We studied 135 patients with DMT2 and MI (DI); another 85 non-infarcted diabetic individuals with DMT2 but without previous ischemic events (NID) and 242 healthy subjects (HS).

Effect of porcine immature oocyte vitrification on oocyte-cumulus cell gap junctional intercellular communication.

Vitrification may severely affect cumulus cells and oocyte morphology and viability, limiting their maturation and developmental potential. The aim of this study was to evaluate the gap junction intercellular communication (GJIC) integrity after the vitrification of porcine immature cumulus-oocyte complexes (COCs). Fresh COCs were randomly distributed in three groups: untreated (control), toxicity (cryoprotectants exposure), and vitrification, then subjected to in vitro maturation (IVM).

Effect of perfluorohexane sulfonate on pig oocyte maturation, gap-junctional intercellular communication, mitochondrial membrane potential and DNA damage in cumulus cells in vitro.

Perfluorohexane sulfonate (PFHxS) is one of the most abundant perfluorinated compounds in the environment. Exposure to this compound has been correlated to a decrease in human fertility, although the molecular and cellular mechanisms underlying this correlation have not been described. The adverse reproductive effects of PFHxS could be based on alterations in oocyte maturation, the process rendering oocytes competent for fertilization.

Neuroendocrine disruption is associated to infertility in chronically stressed female rats.

Infertility is a growing worldwide public health problem, and stress is a main factor exerting detrimental effects on female reproduction. However, knowledge regarding the neuroendocrine changes caused by chronic stress in females is limited. Therefore, this study assessed the effects of stress on hormones that control female reproduction during the proestrus and diestrus stages of the estrous cycle, as well as its effects on fertility.

Effects of methylparaben on in vitro maturation of porcine oocytes.

Parabens (PBs) are compounds widely used in industry for food and personal care products as antimicrobials and preservatives. Their indiscriminate use has resulted in their detection in different ecosystems so that humans and other organisms are highly exposed. Methylparaben (MePB), compared with other PBs, is mostly detected in food, personal care and baby care products.

Mechanical test study in composites using digital holographic interferometry and optical coherence tomography simultaneously.

A dual optical configuration to inspect the internal and external mechanical response of a composite specimen is presented. The inspection simultaneously uses two equally aligned optical techniques, digital holographic interferometry and Fourier domain optical coherence tomography, to retrieve surface and internal data, respectively. The sample under study is a composite specimen of poly-methyl-methacrylate reinforced with metallic particles.

An efficiency comparison of different in vitro fertilization methods: IVF, ICSI, and PICSI for embryo development to the blastocyst stage from vitrified porcine immature oocytes.

Background: Most studies carried out to evaluate recovery and development after porcine oocyte vitrification, reported better rates when cryopreserved in embryonic development stages or zygotes, but not in immature oocytes. For this reason, many studies are performed to improve immature oocyte vitrification protocols testing the use of different cryoprotectant concentrations, cooling devices, incubation times; but only a few of them have evaluated which fertilization procedure enhances blastocyst rates in vitrified oocytes. Therefore, this study was aimed to evaluate: 1) if the sperm selection with hyaluronic acid (HA) or polyvinylpyrrolidone (PVP) before injection could play a key role in increasing fertilization and blastocyst formation and 2) the embryo developmental ability and blastocyst production of porcine immature oocytes retrieved after vitrification-warming and co-cultured with granulosa cells during IVM, using different fertilization techniques: in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI) and conventional ICSI with hyaluronic acid (HA) sperm selection, known as physiological intracytoplasmic sperm injection (PICSI) and.

Gradual decrease in spermatogenesis caused by chronic stress.

Chronic stress induces decreased sperm motility, viability and concentration in stressed males. Also, stress modifies oxidative status and causes apoptosis in testes, as well as a decrease in the epithelial area of seminiferous tubules. However, there are no studies that analyze the alterations caused by stress in testicular cells.

Pronuclear formation by ICSI using chemically activated ovine oocytes and zona pellucida bound sperm.

Background: In order to improve ICSI, appropiate sperm selection and oocyte activation is necessary. The objective of the present study was to determine the efficiency of fertilization using ICSI with chemically activated ovine oocytes and sperm selected by swim up (SU) or swim up + zona pellucida (SU + ZP) binding.

Results: Experiment 1, 4-20 replicates with total 821 matured oocytes were chemically activated with ethanol, calcium ionophore or ionomycin, to determine oocyte activation (precense of one PN).

Porcine embryo production following in vitro fertilization and intracytoplasmic sperm injection from vitrified immature oocytes matured with a granulosa cell co-culture system.

This study was designed to evaluate the capacity of vitrified-warmed porcine immature oocytes to mature and to be fertilized using in vitro fertilization or intracytoplasmic sperm injection, and to determine the subsequent embryo development. Immature oocytes were vitrified using ethylene glycol and dimethylsulphoxide as cryoprotectants and the Cryolock method. After warming oocytes were cultured 44 h for maturation.

Co-culture with granulosa cells improve the in vitro maturation ability of porcine immature oocytes vitrified with cryolock.

This study was designed to evaluate the efficiency of two oocyte vitrification-warming procedures using two different devices: Superfine Open Pulled Straws (SOPS) and Cryolock, as well as the effect of the co-culture of vitrified immature oocytes with fresh granulosa cells to improve in vitro maturation (IVM). Immature oocytes were vitrified with two procedures: A) Oocytes were exposed to an increasing concentration of ethylene glycol (EG) from 4% to 35% with 0.5 M trehalose.