Fixation in Form-Acetic allows hyaluronic acid detection in mouse ovaries

Lay summary To visualise tissues to determine the presence of disease or simply to understand anatomy, it is important to preserve fresh tissue. Fixatives are chemical solutions that preserve tissues to enable microscopic evaluation. However, some fixatives introduce artefact such as shrinkage of cells. Recently, a new fixative, Form-Acetic, was developed that is superior for preserving the structure of ovary tissue and allows investigation of ovary composition. One component of the ovary is hyaluronic acid (HA), which plays a crucial role in normal ovary function and fertility. Importantly, HA is sensitive to different fixative solutions. Therefore, it is meaningful to verify whether Form-Acetic is suitable for detecting HA. In this study, adult mouse ovaries were fixed in Form-Acetic and HA was detected. All HA-containing structures in the ovary were clearly distinguished which proves that the novel fixative allows the detection of HA.

Onset of normal cycles in postpartum anovulatory dairy cattle treated with kisspeptin

The efficacy of a long-acting synthetic derivative of kisspeptin (Kp) to initiate normal estrous cycles was tested in 24 mixed-aged, Holstein-Friesian cows that were 18 to 25 d postpartum on day of treatment (D0). Groups of eight received saline (Sal) vehicle by intramuscular injection at 0800 and 1600 h (Sal-Sal), Kp at 800 h and vehicle at 1600 h (Kp-Sal) or Kp on both occasions (Kp-Kp). The Kp dose was 15 nmol per 60 kg body weight. The cows ovaries were examined daily by ultrasonography between D-4 and D14. Blood samples were collected from a tail vessel 0, 2, 4, 8, 10 and 12 h relative to the time of first injection for LH and FSH assay. Additional samples were collected daily from D-4 until D14 and D19, 22, 26 and 29 for progesterone assay. An LH surge-like response were observed in cows treated with Kp at 0800 h. Ovulation was consistently induced by Kp within 48 h when there was a dominant follicle of at least 10 mm in diameter on the ovaries (8/14), but in no cases (6/14) during a new wave of ovarian follicular development consisting of follicles <10 mm diameter. The subsequent ovulatory cycle was of normal length in most cases, as compared with short 8 to 12 d cycles observed in spontaneously ovulating cows. We conclude that Kp treatment can induce ovulation in postpartum dairy cows, with ensuing estrous cycles of normal length, if administered when a mature dominant follicle is present on the ovaries.

Q fever and early pregnancy failure: a Scottish case control study

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Retrospective cohort study on preparation regimens for frozen embryo transfer

Objective: To examine the pregnancy outcomes from frozen embryo transfer (FET) cycles using different endometrial preparation regimens, compared to ovulation induction with letrozole (letrozole OI). Design: Retrospective cohort study. Setting: Fertility centre in Sydney, Australia. Patient(s): 6060 frozen embryo transfer cycles. Interventions: Cycles were stratified into one of four ways to achieve endometrial preparation. These were either a natural, letrozole OI, OI with follicle stimulating hormone (FSH OI) or a programmed cycle. Main Outcome Measure(s): The primary outcome was live birth rate per embryo transfer (LBR). Secondary outcomes included clinical pregnancy and biochemical pregnancy rates, adverse events including miscarriage, ectopic pregnancy, stillbirth, neonatal death and multiple births. Ovarian stimulation parameters were also analysed including time taken to reach the luteal phase and the number of blood or urine tests required for monitoring of the cycle. Results: The LBR following letrozole OI cycles was higher when compared to natural cycles (OR 1.27 (1.07 – 1.49)) and programmed cycles (OR 2.36 (1.67 – 3.34)). There was no significant difference between letrozole OI and FSH OI LBR (OR 0.99 (0.76 – 1.28)). An improved LBR with letrozole OI compared to natural cycles was maintained when only women with a normal length cycle were considered (OR 1.44 (1.10 – 1.89)). There was a significant reduction in miscarriage rates when letrozole OI was compared to programmed cycles (OR 0.46 (0.26 – 0.83)). Conclusion(s): The use of letrozole OI for endometrial preparation in an FET cycle may be associated with higher LBR and lower miscarriage rate, compared to using a programmed cycle.

Nonhormonal therapy for endometriosis based on energy metabolism regulation

Objectives: Ovarian function suppression is the current pharmacotherapy of endometriosis with limited benefit and adverse effects. New therapeutic strategies other than hormonal therapy are developed based on the molecular mechanisms involved in the hypoxic and oxidative stress environments and metabolism unique to endometriosis. Methods: A literature search was performed between January 2000 and March 2021 in the PubMed database using a combination of specific terms. Results: Endometriosis-associated metabolic changes have been organized into four hallmarks: (1) glucose uptake, (2) aerobic glycolysis, (3) lactate production and accumulation, and (4) metabolic conversion from mitochondrial oxidative phosphorylation (OXPHOS) to aerobic glycolysis. Endometriotic cells favor glycolytic metabolism over mitochondrial OXPHOS to produce essential energy for cell survival. Hypoxia, a common feature of the endometriosis environment, is a key player in this metabolic conversion, which may lead to glucose transporter overexpression, pyruvate dehydrogenase kinase 1 (PDK1) and lactate dehydrogenase kinase A (LDHA) activation, and pyruvate dehydrogenase complex inactivation. Evading mitochondrial OXPHOS mitigates excessive generation of reactive oxygen species (ROS) that may trigger cell death. Therefore, the coinactivation of LDHA and PDK1 can induce the accumulation of mitochondrial ROS by converting energy metabolism to mitochondrial OXPHOS, causing endometriotic cell death. Conclusion: Metabolic pattern reconstruction in endometriotic lesions is a critical factor in cell survival and disease progression. One therapeutic strategy that may avoid hormone manipulation is focused on mitigating metabolic changes that have been detected in cells/tissues from women with endometriosis.

Can antioxidants protect against chemotherapy in rat spermatogonial stem cell line?

LAY ABSTRACT: Boys administered chemotherapy to treat childhood cancer are at risk of damage to their healthy testicular tissue, which can lead to infertility in adulthood. Researchers are therefore investigating treatments to protect the testis during cancer treatment. Here, cells originating from the testicles of rats were cultured for four days and exposed to chemotherapy drugs with or without antioxidants for the final two days. Antioxidants can reduce cellular damage by inactivating toxic compounds. Here, the antioxidants melatonin or n-acetylcysteine were tested against chemotherapy agents’ cisplatin, doxorubicin, or vincristine. Cultures were repeated four times, with cell survival measured at the end of culture. The antioxidants themselves were not damaging to the cells and partially protected against cisplatin, although not against doxorubicin. Surprisingly, n-acetylcysteine was found to enhance the damage induced by vincristine. The results suggest that using antioxidants to try to protect the testis could have either beneficial or harmful effects when given alongside different chemotherapy drugs: this is important, considering that patients are often treated with multiple drugs which could react differently to protectants.

Is there a valid ethical objection to the clinical use of in vitro-derived gametes?

Advancements in the field of in vitro gametogenesis (IVG) have led to the induction of viable germ cells from stem cells in the mouse, and considerable progress has been made towards achieving the same ends using human cells. While this has the potential to revolutionise reproductive therapies, ethical issues have been raised. This essay outlines the importance of distinguishing between safety concerns and ethical objections when considering whether IVG ought to be permitted for use in human reproduction. The strongest ethical objections against reproductive IVG posed in the literature are then put forth and argued against. Four objections are discussed: the argument that it is ethically suspect due to its facilitation of new kinds of parenthood; the argument that it could supposedly encourage embryo farming, selective breeding and designer baby creation; the slippery slope argument; and the argument from natural law. It is concluded that even the strongest of these arguments does not represent a valid ethical objection to the use of IVG in human reproduction. For this reason, it is proposed that IVG ought to be used in the clinic once safety issues have been overcome.

Highly sensitive in vitro bioassay for Luteinizing Hormone and Chorionic Gonadotropin

IIn previous studies, we had shown the synergistic effect of 10-5 M forskolin (FSK) on the detection threshold of the cyclic AMP response to Luteinizing Hormones (LH) and Chorionic Gonadotropins (CG) from various species in the mouse Leydig Tumor cell (mLTC) cell line. Indepedently, we had started to study the effect of 10-12 – 10-6 M OXT also on the cyclic AMP response to LH and CG preparations on these same cells and found an amplifying effect on the luminescence response caused by gonadotropins. The aim was then to explore the effects of 10-12 – 10-6 M OXT on the gonadotropin-induced cAMP response, in the presence or absence of 10 µM FSK to optimize the assay down to a sensitivity compatible with the detection of the circulating concentrations of these hormones in various species. Finally the optimization relies on three independent phenomena: 1/ the inhibition of nucleotide phosphodiesterase by IBMX to avoid cAMP degradation, 2/ the strong synergy of 10 µM forskolin with low concentrations of LH or CG during the 1-hour luminescence measurement and, 3/ the stimulatory effect of 10-8M oxytocin on the amplitude of transfected cAMP-sensitive luciferase response. By doing this, the detectable concentrations are at the 1-10 pg/well (pM range) for the LHs and CGs from various species. The bioactivities of circulating LHs and CGs in blood or urine are therefore expected to be measurable in 10µL-plasma samples from mammalian species and maybe others.

After egg collection, can we predict the chance of embryos for day 5 transfer or freezing?

Lay summary Even partway through an IVF cycle, at the point when a woman’s eggs have been collected, it is hard to provide reliable answers to the common question of ‘Am I likely to have a good embryo to transfer?’ Sometimes, it only takes one good egg to be successful. However, doctors and patients are acutely aware that low egg numbers, older age and having conditions such as endometriosis can stack the odds against success. We have developed a model to try and answer this question for those patients who wish for more information to help guide their expectations after egg collection. A new tool is presented to predict whether a woman having IVF treatment will have a good enough embryo either to transfer on day 5 or freeze. It was built using information from all 2015 to 2016 UK cycles and predicts using age, number of eggs collected and cause of subfertility.

The role of mitophagy during oocyte aging in human, mouse and Drosophila; implications for oocyte quality and mitochondrial disease

There is a worldwide trend for women to have their first pregnancy later in life. However, as oocyte quality declines with maternal aging, this trend leads to an increase in subfertility. The cellular mechanisms underlying this decline in oocyte competence are poorly understood. Oocyte mitochondria are the subcellular organelles that supply the energy that drives early embryogenesis, and thus their quality is critical for successful conception. Mitochondria contain their own DNA (mtDNA) and mutations in mtDNA cause mitochondrial diseases with severe symptoms, such as neurodegeneration and heart disease. Since mitochondrial function declines in tissues as humans age accompanied by an accumulation of mtDNA mutations, mtDNA is implicated as a cause of declining oocyte quality in older mothers. While this mutation load could be caused by declining accuracy of the mitochondrial replisome, age-related decline in mitochondrial quality control likely contributes however knowledge is lacking. Mitophagy, a cellular process which specifically targets and recycles damaged mitochondria, may be involved, but studies are scarce. And although assisted reproductive technologies (ART) can help older mothers, how these techniques affect the mechanisms that regulate mitochondrial and oocyte quality have not been studied. With the long-term goal of understanding the molecular mechanisms that control mitochondrial quality in the oocyte, model systems including Drosophila and mouse as well as human oocytes have been used. In this review we explore the contribution of mitophagy to oocyte quality and the need for further systematic investigation in oocytes during maternal aging using different systems.