Publications by authors named "Jennie Risopatron"

Purpose: Ferroptosis is a type of iron-dependent regulated cell death characterized by increased bioavailability of redox-active iron, loss of GPX4 antioxidant capacity, and oxidation of polyunsaturated fatty acid-containing phospholipids mediated by reactive oxygen species (ROS). The aim of this study was to evaluate the effect of oxidative stress induced by arachidonic acid (AA) on ferroptotic cell death in human spermatozoa.

Materials And Methods: Spermatozoa from normozoospermic donors were exposed to AA (5, 25, and 50 µM) for 1 hour at 37 ℃, including an untreated control.

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In recent decades, there has been a growing interest in optimizing the protocols intended to sperm cryopreservation in domestic animals. These protocols include initial cooling, freezing, and thawing. While different attempts have been devised to improve sperm cryopreservation, the efficiency of this reproductive biotechnology is still far from being optimal.

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Fish are ectotherms and many have an external reproductive mode. An environmental factor which triggers fish reproductive activity in fish is water temperature. However, climate change is causing increasingly frequent events in which the water temperature varies rapidly; as a result, both in hatchery and in natural conditions, fish sperm are exposed to varying environmental temperatures during their journey toward the egg.

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The chorion fulfills important functions in fish embryos, including protecting the embryo during development. The characterization of the protein profile of this envelope could be used as a bioindicator in the evaluation of the quality of embryonic development. The object of this work was to validate a standardized protocol for protein extraction from chorion of embryos at 280 accumulated thermal units (ATU) by comparing and combining existing methods.

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The regulation of sperm motility is controlled by several variables, including mainly ion concentrations. In fish, Ca concentrations play an important role in the regulation of sperm motility, and several reports highlight the importance of certain Ca channels in the regulation of this cell function. CatSper is a calcium channel scarcely studied in fish.

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Valproic acid (VPA) is a drug used to treat epilepsy, bipolar disorders and headaches. As a secondary effect, this antiepileptic drug can cause a decrease in androgens and gonadotropins, and dose-dependent testicular defects, such as reduction of testicular weights, sperm motility and degeneration of the seminiferous tubules. In offspring exposed to VPA, its effects have not been evaluated, so the study aimed to determine the morphological effects of the use of VPA along testicular development in mice.

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Valproic acid (VPA) is a teratogenic antiepileptic, causing alterations in oxidative stress in prenatal development, being altered the development of the male reproductive system. The purpose of this study was to determine the protective effect of vitamin E (VE) on the testicular development in embryos, foetuses and pubertal mice exposed to VPA, VPA+VE and only VE. Sixty pregnant adult female mice were used, to which they were administered 600 mg/kg of VPA (VPA groups), 600 mg/kg of VPA and 200 IU of VE (VPA+VE groups), 200 IU VE (VE groups) and 0.

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The addition of antioxidants to the cryopreservation medium has been shown to exert a positive effect on the quality of frozen-thawed sperm in different species. The objective of the present study was to evaluate the effects of supplementing the freezing medium with butylhydroxytoluene (BHT) and melatonin (MEL) in frozen-thawed pig spermatozoa. With this purpose, six ejaculates coming from six separate boars were cryopreserved in traditional freezing medium (i.

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In swine, the use of frozen-thawed boar sperm for artificial insemination remains a suboptimal reproductive technology. Among the negative effects of cryopreservation on sperm cells, it is worth highlighting that cryopreservation causes irreversible alterations in motility and components of the sperm membrane as a result of dramatic changes in temperature (cooling/freezing curve) and osmolality. In addition, freeze-thawing may induce oxidative stress and increase the generation of reactive oxygen species (ROS) and nitrogen reactive species (RNS).

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Saccharides have bioprotective properties, with a high capacity to preserve biological proteins and membranes during sperm cryopreservation. The aim of this study was to evaluate how replacing the lactose of cryopreservation media by sucrose (SUC) or trehalose (TRE) at concentrations of 0.2 M (SUC-1 and TRE-1) and 0.

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Background: The sperm vitrification developed by this group is based on the ultrarapid freezing of a vitrification solution composed of a non-permeable cryoprotectant (saccharides and protein), in which previously selected spermatozoa are resuspended, free of seminal plasma, and then plunged directly into liquid nitrogen. Compared to traditional sperm freezing, vitrification does not cause chemical or physical damage to the intracellular structures and reduces the damage to the plasma membrane because no ice crystals form, thus preserving motility and DNA integrity.

Objectives: This manuscript is a review of the vitrification methodology developed by the authors' research group, including studies showing the application in human reproduction therapy.

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Short-term storage of semen is a necessary key procedure in fish; it allows maximizing the use of gametes. Nevertheless, sperm quality decreases during storage has been associated with oxidative stress damage due to an increase in reactive oxygen species (ROS) during storage. This study was designed to optimize a short-term storage protocol for Coho salmon (Oncorhynchus kisutch) spermatozoa, evaluating the effect of extender dilution and the addition of butyl-hydroxytoluene (BHT) antioxidant on sperm function parameters.

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The aim of this study was to evaluate effects of selection using the Percoll density gradient method on motility, mitochondrial membrane potential (ΔΨMit) and fertility in a subpopulation of testicular spermatozoa obtained from Atlantic salmon (Salmo salar). Samples were divided into three groups: Control (C), T1 (45/90 % Percoll®) and T2 (45/60 % Percoll®). Sperm motility was evaluated using CASA (Computer-Assisted Sperm Analysis), ΔΨMit using flow cytometry, and fertility evaluating whether cleavage of fertilised eggs had occurred after 16 h of incubation at 10 °C.

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Among all the Ca channels, CatSper channels have been one of the most studied in sperm of different species due to their demonstrated role in the fertilization process. In fish sperm, the calcium channel plays a key role in sperm activation. However, the functionality of the CatSper channels has not been studied in any of the fish species.

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Sperm motility in fish with external fertilization is critical for reproductive efficiency in aquaculture, especially in salmonids. Gamete preservation techniques, such as cryopreservation, however, reduce sperm motility and fertilizing capacity. Very few studies have addressed cryodamage from energetic and cell signalling approaches.

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The semen cryopreservation processes are associated with state of oxidative stress induced by high levels of reactive oxygen species (ROS), causing damage to functional spermatozoa. Whereby, antioxidants have been utilized to scavenge or neutralize the elevated levels of ROS. The aim of at the present study was to evaluate the effect of adding BHT to the freezing extenders on post-thaw characteristics of domestic cat spermatozoa.

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In this study, the morphology and ultrastructure of Eleginops maclovinus spermatozoa were characterized through scanning and electron microscopy. Findings revealed that E. maclovinus spermatozoa can be differentiated into three major parts: a spherical head without acrosome (typical for externally fertilizing teleost), a midpiece containing 2-5 spherical mitochondria, and a long flagellum.

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SummaryThere is no information about the characteristics of early cleavage in the Patagonian blennie (Eleginops maclovinus), which can be used as a diagnostic tool for embryo quality. The purpose of this investigation, therefore, was to characterize the first blastomeres of E. maclovinus morphologically.

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In this study, the morphology and ultrastructure of Genypterus blacodes spermatozoa were characterized through scanning and transmission electron microscopy. Findings revealed that the G. blacodes spermatozoa can be differentiated into three major parts: a spherical head without an acrosome (typical for externally fertilizing fish), a short mid-piece, and a long flagellum.

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Patagonian blenny (E. maclovinus) is a marine species recently placed in captivity and which are potentially farmable. Understanding and improving its sperm capacity to withstand short-term storage conditions is a key element of initiating an artificial propagation program for this species.

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Sperm cryopreservation allows for a long-term storage of genetic. However, changes due to factors as cold shock, osmotic and oxidative stress cause reduction in viability and fertilising ability of frozen/thawed spermatozoa. Therefore, evaluation of cryoinjury of cat spermatozoa is a key factor in achieving better cryopreservation results.

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Oxidative and nitrosative stress are common problems when handling gametes in vitro. In vitro development in mammalian embryos is highly affected by culture conditions, especially by reactive oxygen species (ROS) and reactive nitrogen species (RNS), because their absence or overproduction causes embryo arrest and changes in gene expression. Melatonin in gamete co-incubation during in vitro fertilization (IVF) has deleterious or positive effects, depending on the concentration used in the culture medium, demonstrating the delicate balance between antioxidant and pro-oxidant activity.

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Some reports have linked intracytoplasmic sperm injection (ICSI) with chromosomal abnormalities, low developmental potential and altered gene expression in embryos. ICSI has also been linked with obesity, early aging and increased incidence of tumors in offspring. Other reports have demonstrated that some of these complications disappeared within a few weeks of life or even showed a lack of such associations.

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High levels of reactive oxygen species (ROS), which may be related to reduced semen quality, are detected during semen cryopreservation in some species. The objectives of this study were to measure the oxidative stress during ram semen cryopreservation and to evaluate the effect of adding 2 antioxidant mimics of superoxide dismutase (Tempo and Tempol) during the cooling process on sperm motility, viability, acrosomal integrity, capacitation status, ROS levels, and lipid peroxidation in frozen and/or thawed ram spermatozoa. Measuring of ROS levels during the cooling process at 35, 25, 15, and 5 °C and after freezing and/or thawing showed a directly proportional increase (P < 0.

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The main objective was to study the effects, on sperm function, of the addition of two superoxide dismutase (SOD) analogues (Tempo and Tempol) to alpaca semen extender for cryopreservation. Twelve alpaca semen samples were collected using an artificial vagina and then diluted at a 1:3 ratio in an extender based on skim milk, egg yolk, and fructose. Each semen sample was divided into three equal parts to form the following groups: control, Tempo (1 mM), and Tempol (1 mM).

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