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Journal of Applied Genetics Jun 2024Expression of the telomerase reverse-transcriptase (TERT) gene and activity of telomerase have been reported in the somatic tissues and gonads in fish irrespective of...
Expression of the telomerase reverse-transcriptase (TERT) gene and activity of telomerase have been reported in the somatic tissues and gonads in fish irrespective of their age and size. Nevertheless, little is known about TERT expression in the fish eggs. In the current study, the presence of the TERT transcripts was confirmed in the rainbow trout ovulated eggs before and after activation with nonirradiated and UV-irradiated (gynogenesis) sperm. Eggs originating from eight females had high and comparable quality expressed by similar hatching rates. However, survival of the gynogenetic larvae that hatched from eggs activated with UV-irradiated sperm and further exposed to the high hydrostatic pressure (HHP) shock for duplication of the maternal chromosomes varied between females from 2.1 ± 0.4 to 40.5 ± 2.2%. Increased level of TERT transcripts was observed in eggs originating from two females, and gametes from only one of them showed improved competence for gynogenesis (27.3 ± 1.9%). In turn, eggs from the female that exhibited the highest survival after gynogenetic activation were characterized by the lowest expression of the TERT gene. Telomerase in rainbow trout eggs may compensate erosion of the telomeres during early embryonic development; however, its upregulation does not assure better development after gynogenetic activation.
PubMed: 38922511
DOI: 10.1007/s13353-024-00887-8 -
Veterinary Sciences Jun 2024The allogeneic follicular fosterage (AFF) technique transfers cumulus-oocyte complexes (COCs) from pubertal female animals to the dominant follicles of adult female... (Review)
Review
The allogeneic follicular fosterage (AFF) technique transfers cumulus-oocyte complexes (COCs) from pubertal female animals to the dominant follicles of adult female animals for further development, allowing the COCs to further develop in a completely in vivo environment. This article reviews the history of AFF and JIVET and their effects on oocyte and embryo development as well as freezing resistance. Improving the efficiency and reproducibility of AFF technology is crucial to its clinical application. This article discusses factors that affect the success rate of AFF, including differences in specific technical procedures and differences between pubertal and adult follicles. Designing standardized procedures and details to improve the synchronization of donor COCs and recipient follicle maturity and reducing the damage to COCs caused by follicular aspiration may be the direction for improving the success rate of AFF in the future.
PubMed: 38922023
DOI: 10.3390/vetsci11060276 -
Annals of the Academy of Medicine,... Jan 2024Female fecundity decreases significantly after the age of 32, and rapidly so after age 37. There is no treatment to prevent this decline. Furthermore, globally, women... (Review)
Review
INTRODUCTION
Female fecundity decreases significantly after the age of 32, and rapidly so after age 37. There is no treatment to prevent this decline. Furthermore, globally, women are getting married later and the age at which they have their first child is increasing. As of July 2023, elective egg freezing (EEF) or oocyte cryopreservation (OC) for age-related fertility decline, commenced in Singapore. With medical advancements in OC, EEF is no longer considered experimental. The aim of this review is to examine the existing literature around EEF with regard to reproductive outcomes and its safety, to better guide clinicians in counselling young single women.
METHOD
Published studies were examined to increase understanding on optimal age for EEF, ideal number of oocytes for a live birth, recommended OC protocols, cryopreservation techniques affecting thaw survival or fertilisation, oocyte storage and pregnancy risks.
RESULTS
Models predict that EEF should be performed at age <37 years and to achieve a 70% chance of live birth, women would need 14, 15 and 26 mature oocytes at ages 30-34, 35-37 and >38 years, respec-tively. An antagonist stimulation protocol with an agonist trigger would minimise ovarian hyper-stimulation syndrome and duration of stimulation without affecting outcomes. Oocyte vitrification in comparison to slow freezing increases thaw survival, fertilisation and clinical pregnancy rates. No increased risks exist for the woman, future pregnancy or child when compared with conventional IVF.
CONCLUSION
EEF is a viable option for single women desiring fertility preservation. Financial costs are significant, but returns are worthwhile if oocytes are utilised.
Topics: Humans; Cryopreservation; Female; Oocytes; Pregnancy; Fertility Preservation; Adult; Pregnancy Rate; Singapore; Vitrification; Live Birth; Ovulation Induction; Age Factors
PubMed: 38920213
DOI: 10.47102/annals-acadmedsg.2023226 -
Annals of the Academy of Medicine,... Dec 2023Two decades after the Rotterdam 2003 consensus workshop, there have been considerable advances in elucidating the pathophysiology and epidemiology of polycystic ovary... (Review)
Review
INTRODUCTION
Two decades after the Rotterdam 2003 consensus workshop, there have been considerable advances in elucidating the pathophysiology and epidemiology of polycystic ovary syndrome (PCOS). This has prompted the re-examination of the features that characterise this common condition. Current definitions have led to great heterogeneity in the prevalence of PCOS and have contributed to inconsistent treatment protocols and assessment of therapeutic outcomes. Diagnosis is further complicated by the lack of universal agreement on threshold cut-offs for ovarian dysfunction and ethnic differences in hirsutism; both of which are key features in the definitions that are commonly used currently. These challenges often result in dissatisfaction with medical care among PCOS patients and their physicians.
METHOD
Our factor analysis mathematically identified anti-Mullerian hormone (AMH), associated polycystic ovarian morphology (PCOM) and serum testosterone as the only significant cluster associated with menstrual cycle length variability.
RESULTS AND CONCLUSION
As such, we propose a simplified criteria wherein the presence of at least 2 of the 3 features below would be sufficient to define PCOS: (1) chronic oligo-ovulation or anovulation as indicated by oligomenorrhea (cycle lengths >35 days) or amenorrhea; (2) PCOM: raised AMH ≥37.0 pmol/L instead of transvaginal ultrasound assessment of ovaries; and (3) Androgen excess, or raised serum androgens above the laboratory reference for women. Further studies are required to examine whether the proposed criteria would reduce diagnostic confusion and improve care and outcomes, especially among patients of East Asian ethnicities.
Topics: Humans; Polycystic Ovary Syndrome; Female; Testosterone; Phenotype; Anti-Mullerian Hormone; Asian People; Hirsutism; Oligomenorrhea; Anovulation; Factor Analysis, Statistical; Amenorrhea; Menstrual Cycle; Ovary; East Asian People
PubMed: 38920160
DOI: 10.47102/annals-acadmedsg.202369 -
Frontiers in Endocrinology 2024As the incidence of endometrial cancer (EC) and atypical endometrial hyperplasia (AEH) has been increasing, and has shown young trend. It is crucial to study the... (Review)
Review
As the incidence of endometrial cancer (EC) and atypical endometrial hyperplasia (AEH) has been increasing, and has shown young trend. It is crucial to study the fertility-preserving treatment of endometrial lesions and fertility-promoting protocols. Age, obesity, and irregular ovulation are not only high-risk factors for endometrial lesions but also key factors affecting female fertility. Assisted reproductive technology (ART) can significantly improve pregnancy outcomes in patients with AEH and EC after conservative treatment. Based on the existing studies, this article reviews the progress of research on pregnancy outcomes of ART and its influencing factors in such patients. It helps physicians in providing optimal fertility guidance.
Topics: Humans; Female; Endometrial Neoplasms; Reproductive Techniques, Assisted; Endometrial Hyperplasia; Pregnancy; Conservative Treatment; Fertility Preservation; Pregnancy Outcome; Infertility, Female
PubMed: 38919483
DOI: 10.3389/fendo.2024.1377396 -
Frontiers in Nutrition 2024Excessive calorie intake poses a significant threat to female fertility, leading to hormonal imbalances and reproductive challenges. Overconsumption of unhealthy fats...
INTRODUCTION
Excessive calorie intake poses a significant threat to female fertility, leading to hormonal imbalances and reproductive challenges. Overconsumption of unhealthy fats exacerbates ovarian dysfunction, with an overproduction of reactive oxygen species causing oxidative stress, impairing ovarian follicle development and leading to irregular ovulation and premature ovarian failure. Interest in biological matrices with high antioxidant properties to combat diet-related oxidative stress has grown, as they contain various bioactive factors crucial for neutralizing free radicals potentially preventing female reproductive health. This systematic review evaluates the female reproductive impact of biological matrices in mitigating oxidative damages induced by over calory habits and, in particular, high fat diets.
METHODS
A comparative approach among mammalian models was utilized to interpret literature available data. This approach specifically investigates the antioxidant mechanisms of biological matrices on early and late ovarian folliculogenesis, under physiological and hormone-induced female reproductive cycle. Adhering to the PRISMA 2020 guidelines, only English-language publications from peer-reviewed international indexes were considered.
RESULTS
The analysis of 121 publications meeting the inclusion criteria facilitated the identification of crucial components of biological matrices. These components, including carbocyclic sugars, phytonutrients, organosulfur compounds, and vitamins, were evaluated for their impact on ovarian follicle resilience, oocyte quality, and reproductive lifespan. The detrimental effects of oxidative stress on female fertility, particularly exacerbated by high saturated fat diets, are well-documented. studies across mammalian preclinical models have underscored the potential of antioxidants derived from biological matrices to mitigate diet-induced conditions. These antioxidants enhance steroidogenesis and ovarian follicle development, thereby improving oocyte quality. Additionally, discussions within these publications emphasized the clinical significance of these biological matrices, translating research findings into practical applications for female health.
CONCLUSION
Further research is essential to fully exploit the potential of these matrices in enhancing female reproduction and mitigating the effects of diets rich in fatty acids. This requires intensified studies and comprehensive collection of data before clinical trials. The promotion of ovarian resilience offers promising avenues for enhancing understanding and advancing female reproductive health world-wide.
PubMed: 38915855
DOI: 10.3389/fnut.2024.1415455 -
BioRxiv : the Preprint Server For... Jun 2024Inactivating mutations in the melanocortin 4 receptor ( ) gene cause monogenic obesity. Interestingly, female patients also display various degrees of reproductive...
Inactivating mutations in the melanocortin 4 receptor ( ) gene cause monogenic obesity. Interestingly, female patients also display various degrees of reproductive disorders, in line with the subfertile phenotype of MC4RKO female mice. However, the cellular mechanisms by which MC4R regulates reproduction are unknown. Kiss1 neurons directly stimulate gonadotropin-releasing hormone (GnRH) release through two distinct populations; the Kiss1 neurons, controlling GnRH pulses, and the sexually dimorphic Kiss1 neurons controlling the preovulatory LH surge. Here, we show that expressed in Kiss1 neurons is required for fertility in females. , deletion of from Kiss1 neurons in female mice replicates the reproductive impairments of MC4RKO mice without inducing obesity. Conversely, reinsertion of in Kiss1 neurons of MC4R null mice restores estrous cyclicity and LH pulsatility without reducing their obese phenotype. , we dissect the specific action of MC4R on Kiss1 vs Kiss1 neurons and show that MC4R activation excites Kiss1 neurons through direct synaptic actions. In contrast, Kiss1 neurons are normally inhibited by MC4R activation except under elevated estradiol levels, thus facilitating the activation of Kiss1 neurons to induce the LH surge driving ovulation in females. Our findings demonstrate that POMC neurons acting through MC4R, directly regulate reproductive function in females by stimulating the "pulse generator" activity of Kiss1 neurons and restricting the activation of Kiss1 neurons to the time of the estradiol-dependent LH surge, and thus unveil a novel pathway of the metabolic regulation of fertility by the melanocortin system.
PubMed: 38915534
DOI: 10.1101/2024.02.18.580873 -
Scientific Reports Jun 2024Despite the proven superiority of various luteal phase support protocols (LPS) over placebo in view of improved pregnancy rates in fresh cycles of IVF (in vitro... (Meta-Analysis)
Meta-Analysis Comparative Study
Despite the proven superiority of various luteal phase support protocols (LPS) over placebo in view of improved pregnancy rates in fresh cycles of IVF (in vitro fertilization) and ICSI (intracytoplasmic sperm injection) cycles, there is ongoing controversy over specific LPS protocol selection, dosage, and duration. The aim of the present study was to identify the optimal LPS under six core aspects of ART success, clinical pregnancy, live birth as primary outcomes and biochemical pregnancy, miscarriage, multiple pregnancy, ovarian hyperstimulation syndrome (OHSS) events as secondary outcomes. Twelve databases, namely Embase (OVID), MEDLINE (R) (OVID), GlobalHealth (Archive), GlobalHealth, Health and Psychosocial Instruments, Maternity & Infant Care Database (MIDIRS), APA PsycTests, ClinicalTrials.gov, HMIC Health Management Information Consortium, CENTRAL, Web of Science, Scopus and two prospective registers, MedRxiv, Research Square were searched from inception to Aug.1st, 2023, (PROSPERO Registration: CRD42022358986). Only Randomised Controlled Trials (RCTs) were included. Bayesian network meta-analysis (NMA) model was employed for outcome analysis, presenting fixed effects, odds ratios (ORs) with 95% credibility intervals (CrIs). Vaginal Progesterone (VP) was considered the reference LPS given its' clinical relevance. Seventy-six RCTs, comparing 22 interventions, and including 26,536 participants were included in the present NMA. Overall CiNeMa risk of bias was deemed moderate, and network inconsistency per outcome was deemed low (Multiple pregnancy χ: 0.11, OHSS χ: 0.26), moderate (Clinical Pregnancy: χ: 7.02, Live birth χ: 10.95, Biochemical pregnancy: χ: 6.60, Miscarriage: χ: 11.305). Combinatorial regimens, with subcutaneous GnRH-a (SCGnRH-a) on a vaginal progesterone base and oral oestrogen (OE) appeared to overall improve clinical pregnancy events; VP + OE + SCGnRH-a [OR 1.57 (95% CrI 1.11 to 2.22)], VP + SCGnRH-a [OR 1.28 (95% CrI 1.05 to 1.55)] as well as live pregnancy events, VP + OE + SCGnRH-a [OR 8.81 (95% CrI 2.35 to 39.1)], VP + SCGnRH-a [OR 1.76 (95% CrI 1.45 to 2.15)]. Equally, the progesterone free LPS, intramuscular human chorionic gonadotrophin, [OR 9.67 (95% CrI 2.34, 73.2)] was also found to increase live birth events, however was also associated with an increased probability of ovarian hyperstimulation, [OR 1.64 (95% CrI 0.75, 3.71)]. The combination of intramuscular and vaginal progesterone was associated with higher multiple pregnancy events, [OR 7.09 (95% CrI 2.49, 31.)]. Of all LPS protocols, VP + SC GnRH-a was found to significantly reduce miscarriage events, OR 0.54 (95% CrI 0.37 to 0.80). Subgroup analysis according to ovarian stimulation (OS) protocol revealed that the optimal LPS across both long and short OS, taking into account increase in live birth and reduction in miscarriage as well as OHSS events, was VP + SCGnRH-a, with an OR 2.89 [95% CrI 1.08, 2.96] and OR 2.84 [95% CrI 1.35, 6.26] respectively. Overall, NMA data suggest that combinatorial treatments, with the addition of SCGnRH-a on a VP base result in improved clinical pregnancy and live birth events in both GnRH-agonist and antagonist ovarian stimulation protocols.
Topics: Humans; Female; Sperm Injections, Intracytoplasmic; Pregnancy; Network Meta-Analysis; Fertilization in Vitro; Luteal Phase; Pregnancy Rate; Progesterone; Live Birth; Bayes Theorem; Ovulation Induction; Randomized Controlled Trials as Topic; Ovarian Hyperstimulation Syndrome; Abortion, Spontaneous
PubMed: 38914570
DOI: 10.1038/s41598-024-64804-z -
Theriogenology Jun 2024This study aimed to evaluate the effects of different doses of equine chorionic gonadotropin (eCG; 200 and 300 IU) administered at the end of a fixed-time artificial...
This study aimed to evaluate the effects of different doses of equine chorionic gonadotropin (eCG; 200 and 300 IU) administered at the end of a fixed-time artificial insemination (FTAI) treatment protocol on ovulation, pregnancy, and twin rates in Bos taurus beef heifers. In addition, pregnancy losses in heifers with singleton and twin pregnancies were determined. A total of 2382 Angus heifers treated with a 6-day estradiol/progesterone-based protocol for FTAI (J-Synch protocol) were randomly allocated to two experimental groups to receive 200 or 300 IU of eCG administered intramuscularly at the time of intravaginal progesterone device removal; FTAI was performed from 60 to 72 h after device removal. The pregnancy rate did not differ (P = 0.89) between the 200 and 300 IU eCG groups. The number of corpus luteum induced by both eCG doses was determined by ultrasonographic examination 14 days after insemination and those treated with 300 IU of eCG had a greater double ovulation rate (P < 0.05). In addition, 300 IU eCG treated heifers had a higher twinning rate on day 30 of gestation (P < 0.05) and parturition (P < 0.05). Pregnancy losses from 30 days of gestation to calving did not differ between heifers treated with 200 and 300 IU of eCG (P = 0.70). However, regardless of the experimental group, heifers bearing twins had greater pregnancy losses than heifers with singletons (P < 0.05). In conclusion, reducing the dose of eCG from 300 to 200 IU under FTAI treatment protocol decreases double ovulation and twinning rates, maintaining a similar pregnancy rate in heifers. Nulliparous cows carrying two fetuses suffer greater pregnancy losses than cows with singletons.
PubMed: 38914033
DOI: 10.1016/j.theriogenology.2024.06.015 -
Marine Biotechnology (New York, N.Y.) Jun 2024Naturally, the ovaries of many farmed fish can only develop to stage IV (mainly including stage IV oocytes, known as full-grown postvitellogenic oocytes). Therefore,...
Naturally, the ovaries of many farmed fish can only develop to stage IV (mainly including stage IV oocytes, known as full-grown postvitellogenic oocytes). Therefore, spawn-inducing hormone injections are used to promote ovary development and oocyte maturation, facilitating reproduction in the aquaculture industry. The study of spawn-inducing hormones and their underlying neuroendocrine mechanisms has been a recent focus in fish reproductive biology. However, the intra-ovarian regulatory mechanisms of ovary development and oocyte maturation after hormone injection require further investigation. In this study, we explored the histological and transcriptomic map of the ovary of Hemibarbus labeo after hormone injection to reveal changes in the ovary. The gonad index significantly increased after hormone injection for 5.5 h, after which no significant change was observed. Histological analysis showed that the nuclei had moved to one side of the oocytes at 5.5 h after hormone injection. Moreover, the volume of the oocytes increased and their yolk membranes thickened. Oocytes then underwent their first meiotic division at 5.5-11 h after hormone injection. Subsequently, the follicular membrane was ruptured, and ovulation was completed at 11-16.5 h after hormone injection. In addition, we identified 3189 differentially expressed genes (DEGs) on comparing the transcriptomes at different time points after hormone injection. These DEGs were significantly enriched in the GO terms of nervous system process, molecular transducer activity, and extracellular region, and the KEGG pathways of TNF signaling and cytokine-cytokine receptor interaction; these may play important roles in ovary development and oocyte maturation. Within these pathways, genes such as apoe, creb3, jun, junb, il11, and il8 may play important roles in steroid hormone synthesis and ovulation. Conclusively, our results show detailed sequential dynamics of oocyte development and provide new insights into the intra-ovarian regulatory mechanisms of ovarian development and oocyte maturation in H. labeo. These findings may be important for research on improving egg quality and reproduction in aquaculture.
PubMed: 38913221
DOI: 10.1007/s10126-024-10335-7