Athanasios Zikopoulos

Dr. Athanasios Zikopoulos


Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Verified
Journal Article
Open access
PDF file
Aris KaltsasAris Kaltsas
Aris Kaltsas
AZAthanasios Zikopoulos
Athanasios Zikopoulos
Fotios DimitriadisFotios Dimitriadis
Fotios Dimitriadis
DSDanja Sheshi
Danja Sheshi
MPMagdalena Politis
Magdalena Politis
ATHANASIOS ZACHARIOUATHANASIOS ZACHARIOU
ATHANASIOS ZACHARIOU
Erectile dysfunction (ED) is a prevalent condition affecting men’s sexual health, with oxidative stress (OS) having recently been identified as a significant contributing causative factor. This narrative review aims to elucidate the role of OS in the pathophysiology of ED, focusing on impact, mechanisms, and potential therapeutic interventions. Key findings indicate that OS disrupts endothelial function and nitric oxide (NO) signaling, crucial for erectile function. Various sources of reactive oxygen species (ROS) and their detrimental effects on penile tissue are discussed, including aging, diabetes mellitus, hypertension, hyperlipidemia, smoking, obesity, alcohol consumption, psychological stress, hyperhomocysteinemia, chronic kidney disease, and sickle cell disease. Major sources of ROS, such as NADPH oxidase, xanthine oxidase, uncoupled endothelial NO synthase (eNOS), and mitochondrial electron transport, are identified. NO is scavenged by these ROS, leading to endothelial dysfunction characterized by reduced NO availability, impaired vasodilation, increased vascular tone, and inflammation. This ultimately results in ED due to decreased blood flow to penile tissue and the inability to achieve or maintain an erection. Furthermore, ROS impact the transmission of nitrergic neurotransmitters by causing the death of nitrergic neurons and reducing the signaling of neuronal NO synthase (nNOS), exacerbating ED. Therapeutic approaches targeting OS, including antioxidants and lifestyle modifications, show promise in ameliorating ED symptoms. The review underscores the need for further research to develop effective treatments, emphasizing the interplay between OS and vascular health in ED. Integrating pharmacological and non-pharmacological strategies could enhance clinical outcomes for ED patients, advocating for OS management in ED treatment protocols to improve patient quality of life.

Verified
Journal Article
Open access
PDF file
Aris KaltsasAris Kaltsas
Aris Kaltsas
AZAthanasios Zikopoulos
Athanasios Zikopoulos
DVDionysios N Vrachnis
Dionysios N Vrachnis
CSCharikleia Skentou
Charikleia Skentou
Evangelos N. SymeonidisEvangelos N. Symeonidis
Evangelos N. Symeonidis
ATHANASIOS ZACHARIOUATHANASIOS ZACHARIOU
ATHANASIOS ZACHARIOU
As global demographics shift toward increasing paternal age, the realm of assisted reproductive technologies (ARTs), particularly in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), faces new challenges and opportunities. This study provides a comprehensive exploration of the implications of advanced paternal age on ART outcomes. Background research highlights the social, cultural, and economic factors driving men toward later fatherhood, with a focus on the impact of delayed paternity on reproductive outcomes. Methods involve a thorough review of existing literature, centering on changes in testicular function, semen quality, and genetic and epigenetic shifts associated with advancing age. Study results point to intricate associations between the father’s age and ART outcomes, with older age being linked to diminished semen quality, potential genetic risks, and varied impacts on embryo quality, implantation rates, and birth outcomes. The conclusions drawn from the current study suggest that while advanced paternal age presents certain risks and challenges, understanding and mitigating these through strategies such as sperm cryopreservation, lifestyle modifications, and preimplantation genetic testing can optimize ART outcomes. Future research directions are identified to further comprehend the epigenetic mechanisms and long-term effects of the older father on offspring health. This study underscores the need for a comprehensive approach in navigating the intricacies of delayed fatherhood within the context of ART, aiming for the best possible outcomes for couples and their children.

25 November 2024 in Biomedicines
Verified
Journal Article
Open access
PDF file
Aris KaltsasAris Kaltsas
Aris Kaltsas
SSSofoklis Stavros
Sofoklis Stavros
ZKZisis Kratiras
Zisis Kratiras
AZAthanasios Zikopoulos
Athanasios Zikopoulos
NMNIKOLAOS MACHAIRIOTIS
NIKOLAOS MACHAIRIOTIS
ATHANASIOS ZACHARIOUATHANASIOS ZACHARIOU
ATHANASIOS ZACHARIOU
Background/Objectives: Non-obstructive azoospermia (NOA) is a severe form of male infertility characterized by the absence of sperm in the ejaculate due to impaired spermatogenesis. Testicular sperm extraction (TESE) combined with intracytoplasmic sperm injection is the primary treatment, but success rates are unpredictable, causing significant emotional and financial burdens. Traditional clinical and hormonal predictors have shown inconsistent reliability. This review aims to evaluate current and emerging non-invasive preoperative predictors of successful sperm retrieval in men with NOA, highlighting promising biomarkers and their potential clinical applications. Methods: A comprehensive literature review was conducted, examining studies on clinical and hormonal factors, imaging techniques, molecular biology biomarkers, and genetic testing related to TESE outcomes in NOA patients. The potential role of artificial intelligence and machine learning in enhancing predictive models was also explored. Results: Traditional predictors such as patient age, body mass index, infertility duration, testicular volume, and serum hormone levels (follicle-stimulating hormone, luteinizing hormone, inhibin B) have limited predictive value for TESE success. Emerging non-invasive biomarkers—including anti-Müllerian hormone levels, inhibin B to anti-Müllerian hormone ratio, specific microRNAs, long non-coding RNAs, circular RNAs, and germ-cell-specific proteins like TEX101—show promise in predicting successful sperm retrieval. Advanced imaging techniques like high-frequency ultrasound and functional magnetic resonance imaging offer potential but require further validation. Integrating molecular biomarkers with artificial intelligence and machine learning algorithms may enhance predictive accuracy. Conclusions: Predicting TESE outcomes in men with NOA remains challenging using conventional clinical and hormonal parameters. Emerging non-invasive biomarkers offer significant potential to improve predictive models but require validation through large-scale studies. Incorporating artificial intelligence and machine learning could further refine predictive accuracy, aiding clinical decision-making and improving patient counseling and treatment strategies in NOA.

4 December 2024 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
Aris KaltsasAris Kaltsas
Aris Kaltsas
AZAthanasios Zikopoulos
Athanasios Zikopoulos
EMEleftheria Markou
Eleftheria Markou
ATHANASIOS ZACHARIOUATHANASIOS ZACHARIOU
ATHANASIOS ZACHARIOU
MSMarios Stavropoulos
Marios Stavropoulos
MCMichael Chrisofos
Michael Chrisofos
Background/Objectives: Varicoceles are a common contributor to male infertility, significantly impacting male-factor infertility cases. Traditional diagnostic methods often lack the sensitivity to detect the molecular and cellular disruptions caused by varicoceles, limiting the development of effective, personalized treatments. This narrative review aims to explore the advancements in proteomics and metabolomics as innovative, non-invasive diagnostic tools for varicocele-associated male infertility and their potential in guiding personalized therapeutic strategies. Methods: A comprehensive literature search was conducted using databases such as PubMed, Scopus, and Web of Science up to October 2024. Studies focusing on the application of proteomic and metabolomic analyses in varicocele-associated male infertility were selected. The findings were critically analyzed to synthesize current knowledge and identify future research directions. Results: Proteomic analyses revealed differentially expressed proteins in the sperm and seminal plasma of varicocele patients, revealing disruptions in pathways related to oxidative stress, mitochondrial dysfunction, apoptosis, and energy metabolism. Key proteins such as heat shock proteins, mitochondrial enzymes, and apoptotic regulators were notably altered. Metabolomic profiling uncovered specific metabolites in seminal plasma—such as decreased levels of lysine, valine, and fructose—that correlate with impaired sperm function and fertility potential. The integration of proteomic and metabolomic data provides a comprehensive molecular fingerprint of varicocele-induced infertility, facilitating the identification of novel biomarkers for early diagnosis and the development of personalized therapeutic interventions. Conclusions: Advances in proteomics and metabolomics have significantly enhanced our understanding of the molecular mechanisms underlying varicocele-associated male infertility. These “omics” technologies hold great promise for improving diagnostic accuracy and personalizing treatment, ultimately leading to better outcomes for affected men. Future large-scale clinical trials and validations are essential to confirm these biomarkers and facilitate their integration into routine clinical practice.

22 November 2024 in Medicina
Verified
Journal Article
Open access
PDF file
Aris KaltsasAris Kaltsas
Aris Kaltsas
AZAthanasios Zikopoulos
Athanasios Zikopoulos
VKVladimir Kojovic
Vladimir Kojovic
Fotios DimitriadisFotios Dimitriadis
Fotios Dimitriadis
NSNikolaos Sofikitis
Nikolaos Sofikitis
ATHANASIOS ZACHARIOUATHANASIOS ZACHARIOU
ATHANASIOS ZACHARIOU
Background and Objectives: Recurrent pregnancy loss (RPL) affects numerous couples worldwide and has traditionally been attributed mainly to maternal factors. However, recent evidence highlights significant paternal influences on pregnancy viability and outcomes. This review aims to comprehensively examine male contributions to pregnancy loss, focusing on underlying mechanisms, novel biomarkers, and integrated strategies for improved reproductive success. Materials and Methods: A comprehensive narrative review was conducted by searching databases including PubMed and Embase for the literature published from January 2004 to October 2024. Studies focusing on paternal influences in RPL—encompassing oxidative stress, genetic and epigenetic mechanisms, health conditions, lifestyle factors, environmental exposures, and advancements in sperm proteomics—were included. Inclusion criteria were peer-reviewed articles in English that directly addressed paternal factors in RPL; studies not meeting these criteria were excluded. Results: The review identified that paternal factors such as advanced age, metabolic and cardiovascular health issues, chronic diseases, lifestyle habits (e.g., smoking, alcohol consumption, poor diet), and environmental exposures significantly affect sperm integrity through mechanisms like oxidative stress, DNA fragmentation, and epigenetic alterations. Advanced paternal age and poor health conditions are associated with increased risks of miscarriage and adverse pregnancy outcomes. Novel sperm proteomic biomarkers have been identified, offering potential for enhanced diagnostics and personalized interventions. Integrated approaches involving multidisciplinary assessments, preventive strategies, and genetic counseling are essential for effectively addressing RPL. Conclusions: Integrating paternal factors into clinical evaluations is crucial for effectively addressing recurrent pregnancy loss. Recognizing and modifying paternal risk factors through lifestyle changes, medical interventions, and environmental management can improve pregnancy outcomes. The findings underscore the need for incorporating paternal assessments into standard care and highlight the importance of future research focusing on standardizing diagnostic protocols, expanding studies on paternal contributions, and integrating proteomic biomarkers into clinical practice to facilitate personalized treatment strategies.

4 July 2024 in Biomedicines
Verified
Journal Article
Open access
PDF file
Aris KaltsasAris Kaltsas
Aris Kaltsas
MSMarios Stavropoulos
Marios Stavropoulos
Evangelos N. SymeonidisEvangelos N. Symeonidis
Evangelos N. Symeonidis
ZKZisis Kratiras
Zisis Kratiras
ATHANASIOS ZACHARIOUATHANASIOS ZACHARIOU
ATHANASIOS ZACHARIOU
MCMichael Chrisofos
Michael Chrisofos
Endometriosis is a debilitating gynecological condition commonly seen in individuals designated female at birth; however, there has been limited research focused on its prevalence and impact among transgender men. This narrative review aims to fill a critical knowledge gap by exploring the epidemiology, clinical manifestations, management strategies, and quality-of-life implications of endometriosis among transgender individuals who identify as male. Specifically, this study seeks to estimate the prevalence rates and describe the symptoms experienced by transgender men undergoing testosterone therapy. Additionally, it addresses the diagnostic challenges posed by hormonal treatments and the lack of culturally competent healthcare services for this population. Recent molecular studies indicate that hormonal imbalances, such as increased estrogen synthesis and progesterone resistance, are significant factors in the persistence of endometriosis symptoms despite testosterone therapy. Moreover, evidence suggests that testosterone therapy may not always suppress endometrial activity completely, contributing to the persistence of symptoms in some individuals. Endometriosis in transgender men requires personalized approaches that consider both testosterone therapy and its interactions with endometriosis, as well as fertility preservation and the psychosocial aspects of treatment. This review emphasizes the necessity of taking an inclusive approach in both research and clinical practice to improve healthcare outcomes for this underserved population. The results demonstrate how continued research, education, and healthcare services tailored specifically to transgender men are necessary to better understand and treat endometriosis, thus improving both their overall health and quality of life.