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result(s) for
"Anifandis, George"
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An Update on Physiopathological Roles of Akt in the ReprodAKTive Mammalian Ovary
by
Antonouli, Sevastiani
,
Cecconi, Sandra
,
Giaccari, Carlo
in
1-Phosphatidylinositol 3-kinase
,
AKT protein
,
Apoptosis
2024
The phosphoinositide 3-kinase (PI3K)/Akt pathway is a key signaling cascade responsible for the regulation of cell survival, proliferation, and metabolism in the ovarian microenvironment. The optimal finetuning of this pathway is essential for physiological processes concerning oogenesis, folliculogenesis, oocyte maturation, and embryo development. The dysregulation of PI3K/Akt can impair molecular and structural mechanisms that will lead to follicle atresia, or the inability of embryos to reach later stages of development. Due to its pivotal role in the control of cell proliferation, apoptosis, and survival mechanisms, the dysregulation of this molecular pathway can trigger the onset of pathological conditions. Among these, we will focus on diseases that can harm female fertility, such as polycystic ovary syndrome and premature ovarian failure, or women’s general health, such as ovarian cancer. In this review, we report the functions of the PI3K/Akt pathway in both its physiological and pathological roles, and we address the existing application of inhibitors and activators for the balancing of the molecular cascade in ovarian pathological environments.
Journal Article
The Influence of Sexually Transmitted Bacteria and Human Papillomavirus on Sperm Parameters: Data from a Preliminary Study
2026
Background and Objectives: The microbiome plays a pivotal role in male infertility, with distinct microbial species exerting both beneficial and deleterious effects on reproductive function. Sexually transmitted bacteria and several viruses, including human papillomavirus (HPV), have been identified in semen. This cross-sectional study aimed to examine the prevalence of single and co-infections of sexually transmitted bacteria (STB)—such as Chlamydia trachomatis, Mycoplasma spp., and Ureaplasma spp.—with various HPV subtypes in Greek male partners of infertile couples and to evaluate their potential impact on sperm parameters. In addition, the possible effect of cryopreservation on the maintenance of these pathogens was assessed. Materials and Methods: Eighty-two semen samples were initially collected from 82 individuals undergoing routine sperm analysis. In total, 80/82 (97.6%) participants proceeded to further analysis, as 2/82 (2.4%) were excluded due to poor DNA quality. Results: A total of 18/80 (22.5%) sperm samples tested positive for STB, with Ureaplasma spp. representing the most frequently detected pathogen. Co-infection of Ureaplasma spp. and Mycoplasma hominis was observed in 4/80 (5%) samples. Twelve samples (12/80, 15%) were positive for HPV, including low-risk (LR) and high-risk (HR) types, and HPV 16 was the predominant HR genotype. Notably, a co-infection of STB and HPV was not found in our specimens. STB-positive samples demonstrated significantly higher sperm concentration and improved progressive motility compared with STB-negative samples. HPV-positive samples exhibited lower sperm volume and concentration and increased non-progressive motility compared with HPV-negative samples. Following three months of cryopreservation, LR HPV and STB were no longer detectable, whereas HR HPV types remained detectable. Conclusions: These preliminary findings are interesting, as they could be useful for routine screening of HPV and STB in sperm samples preserved in sperm banks and highlight the need for future research.
Journal Article
A comprehensive review and update on human fertility cryopreservation methods and tools
by
Antonouli, Sevastiani
,
Messini, Christina
,
Rajender, Singh
in
Cryopreservation
,
embryo
,
Embryos
2023
The broad conceptualization of fertility preservation and restoration has become already a major concern in the modern western world since a large number of individuals often face it in the everyday life. Driven by different health conditions and/or social reasons, a variety of patients currently rely on routinely and non-routinely applied assisted reproductive technologies, and mostly on the possibility to cryopreserve gametes and/or gonadal tissues for expanding their reproductive lifespan. This review embraces the data present in human-focused literature regarding the up-to-date methodologies and tools contemporarily applied in IVF laboratories' clinical setting of the oocyte, sperm, and embryo cryopreservation and explores the latest news and issues related to the optimization of methods used in ovarian and testicular tissue cryopreservation.
Journal Article
Molecular and Cellular Mechanisms of Sperm-Oocyte Interactions Opinions Relative to in Vitro Fertilization (IVF)
by
Sotiriou, Sotiris
,
Messinis, Ioannis
,
Messini, Christina
in
ADAM Proteins - metabolism
,
Egg Proteins - metabolism
,
Female
2014
One of the biggest prerequisites for pregnancy is the fertilization step, where a human haploid spermatozoon interacts and penetrates one haploid oocyte in order to produce the diploid zygote. Although fertilization is defined by the presence of two pronuclei and the extraction of the second polar body the process itself requires preparation of both gametes for fertilization to take place at a specific time. These preparations include a number of consecutive biochemical and molecular events with the help of specific molecules and with the consequential interaction between the two gametes. These events take place at three different levels and in a precise order, where the moving spermatozoon penetrates (a) the outer vestments of the oocyte, known as the cumulus cell layer; (b) the zona pellucida (ZP); where exocytosis of the acrosome contents take place and (c) direct interaction of the spermatozoon with the plasma membrane of the oocyte, which involves a firm adhesion of the head of the spermatozoon with the oocyte plasma membrane that culminates with the fusion of both sperm and oocyte membranes (Part I). After the above interactions, a cascade of molecular signal transductions is initiated which results in oocyte activation. Soon after the entry of the first spermatozoon into the oocyte and oocyte activation, the oocyte’s coat (the ZP) and the oocyte’s plasma membrane seem to change quickly in order to initiate a fast block to a second spermatozoon (Part II). Sometimes, two spermatozoa fuse with one oocyte, an incidence of 1%–2%, resulting in polyploid fetuses that account for up to 10%–20% of spontaneously aborted human conceptuses. The present review aims to focus on the first part of the human sperm and oocyte interactions, emphasizing the latest molecular and cellular mechanisms controlling this process.
Journal Article
Evaluation of Sperm DNA Fragmentation Using Two Different Methods: TUNEL via Fluorescence Microscopy, and Flow Cytometry
by
Fleva, Alexandra
,
Chatzimeletiou, Katerina
,
Anifandis, George
in
Analysis
,
Chromatin
,
Correlation analysis
2023
Background and Objectives: Sperm DNA fragmentation refers to any break in one or both of the strands of DNA in the head of a sperm. The most widely used methodologies for assessing sperm DNA fragmentation are the sperm chromatin structure assay (SCSA), the sperm chromatin dispersion assay (SCD), the single-cell gel electrophoresis assay (SCGE–comet), and the terminal-deoxynucleotidyl-transferase (TdT)-mediated dUTP nick end labelling (TUNEL) assay. The aim of this study was to compare the efficiency and sensitivity of the analysis of sperm DNA fragmentation using TUNEL via fluorescence microscopy, and flow cytometry. Materials and Methods: Semen samples were collected and analyzed for standard characteristics using light microscopy, and for sperm DNA fragmentation using both TUNEL via fluorescence microscopy, and flow cytometry. Results: There were no significant differences in the values of the sperm DNA fragmentation index (DFI) obtained when the analysis was performed using TUNEL or flow cytometry (p = 0.543). Spearman’s correlation analysis revealed a significant negative correlation between sperm motility (%) and sperm DNA fragmentation (p < 0.01), as well as between sperm concentration and sperm DNA fragmentation (p < 0.05). The Mann–Whitney U test showed no significant difference in the DFI among couples with repeated implantation failure (RIF) and miscarriages (p = 0.352). Conclusions: Both methods (TUNEL via fluorescence microscopy, and flow cytometry) have a high efficiency and sensitivity in accurately detecting sperm DNA fragmentation, and can be effectively used to assess male fertility.
Journal Article
Oncofertility and Fertility Preservation for Women with Gynecological Malignancies: Where Do We Stand Today?
by
Antonouli, Sevastiani
,
Daponte, Nikoletta
,
Messini, Christina
in
Cancer
,
Cancer patients
,
Cancer therapies
2024
Oncofertility is a growing medical and research field that includes two main areas: oncology and reproductive medicine. Nowadays, the percentage of patients surviving cancer has exponentially increased, leading to the need for intervention for fertility preservation in both men and women. Specifically, gynecological malignancies in women pose an additional layer of complexity due to the reproductive organs being affected. In the present review, we report fertility preservation options with a cancer- and stage-specific focus. We explore the drawbacks and the necessity for planning fertility preservation applications during emergency statuses (i.e., the COVID-19 pandemic) and comment on the importance of repro-counseling for multifaceted patients during their oncological and reproductive journey.
Journal Article
Human Papilloma Virus (HPV) and Fertilization: A Mini Review
by
Koukoulis, George
,
Zacharis, Konstantinos
,
Messini, Christina I.
in
assisted reproductive technology
,
cryopreservation
,
fertility
2018
Human papilloma virus (HPV) is one of the most prevalent viral sexually transmitted diseases. The ability of HPV to induce malignancy in the anogenital tract and stomato-pharyngeal cavity is well documented. Moreover, HPV infection may also affect reproductive health and fertility. Although, the impact of HPV on female fertility has not been thoroughly studied it has been found also to have an impact on semen parameters. Relative information can be obtained from studies investigating the relationship between HPV and pregnancy success. Furthermore, there is an ongoing debate whether HPV alters the efficacy of assisted reproductive technologies. An association between HPV and assisted reproductive technologies (ART) programs has been reported. Nevertheless, due to conflicting data and the small number of existing studies further research is required. It remains to be clarified whether HPV detection and genotyping could be included in the diagnostic procedures in couples undergoing in vitro fertilization (IVF)/intrauterine insemination (IUI) treatments. Vaccination of both genders against HPV can reduce the prevalence of HPV infection and eliminate its implications on human fertility. The aim of the present mini-review is to reiterate the association between HPV and human fertility through a systematic literature review.
Journal Article
Prolactin Response to a Submaximal Dose of Ghrelin in Different Phases of the Normal Menstrual Cycle
by
Messini, Christina I.
,
Anifandis, George
,
Messinis, Ioannis E.
in
Adult
,
Catheters
,
Estradiol
2024
Background and Objectives: A similar secretory pattern of prolactin (PRL) and growth hormone (GH) during the menstrual cycle has been reported in response to a high dose of ghrelin in adult healthy women. The present study aimed to assess the pattern of PRL and GH secretions in response to a submaximal dose of ghrelin during different menstrual phases in adult healthy women. Materials and Methods: Eight female subjects with normal cyclicity were enrolled. These subjects were either in the early follicular (EF), late follicular (LF), or mid-luteal (ML) phase of their cycles. Each subject received an IV dose of normal saline (2 mL each time) during the first cycle after enrollment, followed by an IV dose of ghrelin (0.30 μg/kg bw) in the second cycle. The blood samples were collected before and after the IV dosage at −15, 0, 15, 30, 45, 60, 75, 90 and 120 min, where 0 min denotes the time of IV dosage. Results: All the enrolled subjects experienced ovulatory cycles as assessed by increased serum progesterone levels. Serum estradiol levels were significantly higher in the LF than in the EF (p < 0.001) and ML phases (p < 0.01); these levels were also significantly higher in the ML than in the EF phase (p < 0.01). The administration of saline did not affect serum GH or PRL levels. Following the administration of ghrelin, plasma ghrelin levels and serum GH levels increased significantly (p < 0.001). The response amplitude of GH was similar in the three stages of cycle 2. In contrast to GH, the ghrelin injection induced a significant increase in serum PRL levels only in the LF phase (p < 0.05). Conclusions: These results show, for the first time, a different pattern of PRL and GH in response to a submaximal dose of ghrelin during the normal menstrual cycle. It is suggested that the ghrelin threshold for pituitary lactotrophs is higher than for somatotrophs and that, unlike GH, ghrelin-stimulated PRL secretion can be influenced by ovarian steroids.
Journal Article
Insights into the Role of Telomeres in Human Embryological Parameters. Opinions Regarding IVF
by
Chatzimeletiou, Katerina
,
Thodou, Eleni
,
Samara, Maria
in
Aging
,
assisted reproduction
,
biomarkers
2021
Telomeres promote genome integrity by protecting chromosome ends from the activation of the DNA damage response and protecting chromosomes from the loss of coding sequences due to the end replication problem. Telomere length (TL) is progressively shortened as age progresses, thus resulting in cellular senescence. Therefore, TL is in strong adverse linear correlation with aging. Mounting evidence supports the notion that telomeres and male/female infertility are in a close relationship, posing the biology of telomeres as a hot topic in the era of human-assisted reproduction. Specifically, the length of sperm telomeres is gradually increasing as men get older, while the telomere length of the oocytes seems not to follow similar patterns with that of sperm. Nonetheless, the telomere length of the embryos during the cleavage stages seems to have a paternal origin, but the telomere length can be further extended by telomerase activity during the blastocyst stage. The latter has been proposed as a new molecular biomarker with strong predictive value regarding male infertility. As far as the role of telomeres in assisted reproduction, the data is limited but the length of telomeres in both gametes seems to be affected mainly by the cause of infertility rather than the assisted reproductive therapy (ART) procedure itself. The present review aims to shed more light into the role of telomeres in human embryological parameters, including gametes and embryos and also presents opinions regarding the association between telomeres and in vitro fertilization (IVF).
Journal Article
Effects of Different Drug Therapies and COVID-19 mRNA Vaccination on Semen Quality in a Man with Ankylosing Spondylitis: A Case Report
by
Fleva, Alexandra
,
Chatzimeletiou, Katerina
,
Kolibianakis, Efstratios
in
ankylosing spondylitis
,
Arthritis
,
Case Report
2022
Background and Objectives: Ankylosing spondylitis (AS) is a condition that affects 0.1% to 0.5% of the adult population. The aim of this case report was to investigate the possible effects of the drugs taken for treatment of AS as well as mRNA vaccination for COVID-19 on semen quality by performing a highly detailed analysis. Materials and Methods: Sperm characteristics were examined by light microscopy, DNA fragmentation (DFI) was analysed by flow cytometry and morphology was evaluated by transmission electron microscopy (TEM). Results: Semen analysis under therapy with (1) celecoxib and sulphasalazine showed: concentration 47 million/mL, 53% progressive motility, 7% normal morphology and 9.6% DFI, (2) Golimumab and before mRNA Vaccination showed: concentration 108 million/mL, 82% progressive motility, 1% normal morphology and 7.6% DFI, and (3) Golimumab and after 3 doses of mRNA Vaccination showed: concentration 142 million/mL, 85% progressive motility, 1% normal morphology and 6.8% DFI. TEM revealed head, neck and tail abnormalities, as well as the presence of cells with incomplete spermiogenesis white cells and phagocytes in the sample under therapy with celecoxib and sulphasalazine. Golimumab treatment lead to an increased incidence of elongated heads but in general reduced inflammation as no white cells were evident in TEM. Conclusion: The anti-inflamatory drugs celecoxib and sulphasalazine had no adverse effect on sperm quality as all parameters were within normal limits and the patient achieved under that treatment 2 pregnancies following natural conception that lead to the birth of a healthy boy and girl respectively. Anti-TNFa treatment with Golimumab exerted a negative effect on morphology but not on concentration, motility and DFI. After 3 doses of mRNA Vaccination, sperm concentration increased while motility, morphology and DFI remained similar to the values before vaccination suggesting no negative effect of the mRNA vaccine for COVID-19 on sperm quality.
Journal Article