Endre Sulyok

Background/Objectives: Dynamic remodeling of the zona pellucida (ZP) is a fundamental biochemical and structural process during human preimplantation development; however, its quantitative characterization and clinical relevance remain incompletely defined. The objective of this study was to evaluate dynamic ZP thinning as a functional marker of embryo developmental competence and to examine its relationship with follicular fluid (FF) biomarkers and clinical pregnancy. Methods: This prospective observational study included 47 IVF cycles performed at a single center, yielding 64 transferred blastocysts with complete time-lapse data. ZP thickness was measured from fertilization to 120 h post-fertilization using time-lapse imaging. Two quantitative parameters were derived: the relative thinning ratio (Δrel) and the linear thinning rate (slope). FF concentrations of growth differentiation factor 9 (GDF-9), hyaluronic acid (HA), and syndecan-4 (Syn4) were quantified by ELISA. Embryo-level associations with spontaneous blastocyst hatching were assessed using logistic regression and multivariate analyses, while patient-level models evaluated predictors of clinical pregnancy. Results: Embryos that underwent spontaneous hatching exhibited significantly greater Δrel than non-hatching embryos (p < 0.001). Δrel remained the strongest predictor of hatching in multivariable models (AUC = 0.91). Among FF biomarkers, only GDF-9 showed a positive association with spontaneous hatching. At the patient level, higher Δrel values of transferred embryos were associated with clinical pregnancy (OR 3.65, p = 0.009), whereas FF biomarkers and assisted hatching showed no significant association. Conclusions: Dynamic ZP thinning quantified by Δrel represents a promising indicator of embryo developmental competence. The concordance between embryo-level hatching behavior and patient-level clinical pregnancy suggests potential clinical relevance of ZP dynamics as an integrative embryological marker, warranting validation in larger cohorts.

This preliminary study was designed to determine follicular fluid (FF) vanin-1 levels, to assess their relation to serum vanin-1 and to reveal their potential to predict the outcome of in vitro fertilization (IVF). Eighteen unselected, consecutive women undergoing IVF were included. Serum and pooled FF samples were obtained simultaneously during routine IVF procedures. Vanin-1 levels were measured by using commercially available ELISA kits. As most of the values were below 0.6 ng/mL, the data are given as optical density. It was found that vanin-1 can be detected in FF and that it is not significantly related to its maternal serum levels (p = 0.06). FF vanin-1 levels proved to be higher in non-pregnant as compared to pregnant women (p < 0.04). There are significant positive relationships between the FF to serum vanin-1 ratio and body mass index (BMI, p < 0.02), anti-Müllerian hormone (AMH, p < 0.02) and baseline serum estradiol (p < 0.01). Moreover, the FF/serum vanin-1 ratio tended to increase with cumulative FSH dose, but this increase did not reach statistical significance (p = 0.064). It may be concluded that FF vanin-1 may serve as a biomarker to predict IVF outcome. To confirm this contention, further studies are to be performed.

Background. Cardiovascular (CV) diseases are the most common causes of morbidity and mortality in hemodialysis (HD) patients. We studied the effect of high visit-to-visit ultrafiltration (UF) variability on CV abnormalities in HD patients. Methods. Twenty-nine consecutive patients (age: 65.6 ± 10.4 years) were recruited. Samples for routine lab tests were drawn pre-HD for syndecan-1 (SDC-1) and endothelin-1 (ET-1) measurements pre-, mid- and post-HD. Applanation tonometry was performed pre-, mid- and post-HD. Visit-to-visit ultrafiltration volume variability (UVSD) was calculated as the standard deviation of the UF volume/dialysis session in the preceding 12 months. Echocardiography was performed post-HD. Results. Patients were divided into two groups based on the median of UVSD (500 mL). The average UF volume/HD was not different between the groups. Blood pressure (BP) values were similar. Pre-HD cfPWV (10.75 m/s) was lower in the high UVSD group (14.1 m/s, p = 0.03). In the high UVSD group, post-HD cfPWV (13.9 m/s) was higher than the pre-HD cfPWV (p < 0.05). Pre-HD ET-1 was lower in the high UVSD group (8.6 ± 3.9 vs. 10.8 ± 2.7 pg/mL, p < 0.05). Left ventricular end-diastolic diameter (LVEDD) and left ventricular mass index (LVMI) were higher in the high UVSD group (55.7 ± 7.3 vs. 51.0 ± 5.4 mm and 449.9 ± 180.5 vs. 350.3 ± 85.9 g/m², p < 0.005, respectively). Left ventricular ejection fraction (LVEF) was lower in the high UVSD group (53.5 vs. 60, p < 0.05). Conclusions. High UVSD was associated with increased left ventricular hypertrophy and dysfunction and decreased LVEF compared to low visit-to-visit UV variability despite similar UF volumes temporarily compensated by more elastic arteries. The observed abnormalities may increase CV risk.

Thrombocytes play an essential role in hemostasis and thrombosis. Moreover, the controlled activation of thrombocytes is required in reproduction and fertility. The platelet-activating factor and the controlled activation of platelets have important roles in folliculogenesis, ovulation, placental development, implantation and embryo development. Activated platelets accumulate in the follicular vessels surrounding the follicle and, due to its released soluble molecules (factors, mediators, chemokines, cytokines, neurotransmitters), locally increase oocyte maturation and hormone secretion. Furthermore, activated platelets are involved in the pathogenesis of ovarian hyperstimulation syndrome (OHSS) and preeclampsia. Low-dose aspirin can prevent OHSS during ovulation induction, while intrauterine or intraovarian administration of platelet-rich plasma (PRP) increases the endometrium thickness and receptivity as well as oocyte maturation. Activated thrombocytes rapidly release the contents of intracellular granules and have multiple adhesion molecules and receptors on their surface. Considering the numerous homeostatic endocrine functions of thrombocytes, it is reasonable to suppose a platelet-associated regulatory system (PARS) in reproduction. Although we are far from a complete understanding of the regulatory processes, the results of PARS research and the therapeutic application of aspirin and PRP during in vitro fertilization are promising.

Background: Chronic hemodialysis (HD) patients have a very high cardiovascular risk. Acute vascular changes during dialysis mediated by factors of the endothelium may have a crucial role in this. The aim of this article is to study the acute vascular changes during HD. Methods: In 29 consecutive chronic HD patients (age: 65.6 ± 10.4 years), their pre-, mid-, and post-HD plasma syndecan-1 (SDC-1) and endothelin-1 (ET-1) levels were measured. Applanation tonometry was performed before HD. Results: Their SDC-1 levels increased during HD (p = 0.004). Males had higher ET-1 levels. The patients were divided into two groups based on their pre-HD pulse wave velocity (PWV): PWV ≥ 12 m/s and PWV < 12 m/s. The pre-HD and mid-HD SDC-1 levels were higher in the group with a PWV ≥ 12 m/s (10.174 ± 2.568 vs. 7.928 ± 1.794 ng/mL, p = 0.013, and 10.319 ± 3.482 vs. 8.248 ± 1.793 ng/mL, p = 0.044, respectively). The post-HD ET-1 levels were higher in the patient group with a PWV ≥ 12 m/s (10.88 ± 3.00 vs. 8.05 ± 3.48 pg/l, p = 0.027). Patients with a PWV ≥ 12 m/s had higher pre-HD peripheral and aortic systolic blood pressures (p < 0.05). The total cholesterol correlated with the SDC-1 decrease during HD (r = 0.539; p = 0.008). The pre-, mid-, and post-HD SDC-1 correlated with ultrafiltration (r = 0.432, p = 0.019; r = 0.377, p = 0.044; and r = 0.401, p = 0.012, respectively). Conclusion: SDC-1 and ET-1 contribute to the vascular changes observed during HD, and they have correlations with some cardiovascular risk factors.

Chronic hemodialysis (HD) patients have very high cardiovascular risk. Acute vascular changes during dialysis mediated by factors of the endothelium may have a crucial role in this. Aim: To study acute vascular changes during HD. In 29 consecutive chronic HD patients (age: 65.6±10.4 years) pre-, mid-, and post-HD plasma syndecan-1 (SDC-1) and endothelin-1 (ET-1) levels were measured. Applanation tonometry was performed before HD. SDC-1 levels increased during HD (p=0.004). Males had higher ET-1 levels. Patients were divided into 2 groups based on pulse wave velocity (PWV): PWV≥12 m/s and PWV<12 m/s. Pre-HD and mid-HD SDC-1 levels were higher in the group with PWV≥12 m/s (10.174±2.568 vs. 7.928±1.794 ng/ml, p=0.013, and 10.319±3.482 vs. 8.248±1.793 ng/ml, p=0.044, respectively). Post-HD ET-1 levels were higher in the patient group having PWV≥12 m/s (10.88±3.00 vs. 8.05±3.48 pg/l, p=0.027). Patients having PWV≥12 m/s had higher pre-HD peripheral and aortic systolic blood pressure (p<0.05). Total cholesterol correlated with the SDC-1 decrease during HD (r=0.539; p=0.008). Pre-, mid-, and post-HD SDC-1 correlated with the ultrafiltration (r=0.432, p=0.019; r=0.377, p=0.044; and r=0.401, p=0.012, respectively). SDC-1 and ET-1 contribute to vascular changes observed during HD, and they have correlations with some cardiovascular risk factors.

Based on epidemiological observations Barker et al. put forward the hypothesis/concept that an adverse intrauterine environment (involving an insufficient nutrient supply, chronic hypoxia, stress, and toxic substances) is an important risk factor for the development of chronic diseases later in life. The fetus responds to the unfavorable environment with adaptive reactions, which ensure survival in the short run, but at the expense of initiating pathological processes leading to adult diseases. In this review, the major mechanisms (including telomere dysfunction, epigenetic modifications, and cardiovascular–renal–endocrine–metabolic reactions) will be outlined, with a particular emphasis on the role of oxidative stress in the fetal origin of adult diseases.

This study aimed to evaluate the interrelationship between telomere length, telomerase activity and oxidative DNA damage in patients undergoing in vitro fertilization (IVF). This single-center, observational clinical study comprised 102 unselected, consecutive patients with various infertility diagnoses. Granulosa cells (GCs) and follicular fluid (FF) were analyzed simultaneously for telomere functions and for the marker of oxidative DNA damage, 8-hydroxy-2-deoxyguanosine (8-OHdG). An Absolute Human Telomere Lengths Quantification qPCR Assay kit and Telomerase Activity Quantification qPCR Assay kit (Nucleotestbio, Budapest, Hungary), as well as an 8-OHdG ELISA kit (Abbexa Ltd., Cambridge, United Kingdom) were used for analyses. Similar telomere lengths were found in GCs and FF, however telomerase activity was markedly depressed, while 8-OHdG levels were markedly elevated in FF compared with those in GCs (p < 0.01). Telomere lengths were independent of telomerase activity both in GCs and FF. However, GC 8-OHdG was inversely related to telomerase activity in GCs and FF (p < 0.05). Importantly, 8-OHdG levels both in GCs and FF had significant negative impact on the number of the retrieved and MII oocytes (p < 0.01), whereas FF 8-OHdG was negatively related further to the number of fertilized oocytes and blastocysts (p < 0.01). In conclusion, we could not confirm the direct association of telomere function and reproductive potential. However, oxidative DNA damage, as mainly reflected by 8-OHdG, adversely affected early markers of IVF outcome and clinical pregnancies.

Based on current findings, the presence of oxidative stress has a significant impact on the quality of gametes and embryos when performing assisted reproductive techniques (ART). Unfortunately, in vitro manipulation of these cells exposes them to a higher level of reactive oxygen species (ROS). The primary goal of this review is to provide a comprehensive overview of the development of oxidative stress in female and male reproductive systems, as well as in the case of the pre-implantation embryo and its environment. This review also focuses on the origins of ROS and the mechanisms of oxidative stress-induced damage during ART procedures. A well-known but underestimated hazard, light exposure-related photo-oxidation, is particularly concerning. The effect of oxidative stress on ART outcomes, as well as the various strategies for preventing it, are also discussed. We emphasize the role and significance of antioxidants and light protection including forms, functions, and mechanisms in the development of gametes and embryos in vivo and in vitro.

Accumulating evidence are available on the involvement of l-arginine-nitric oxide (NO) system in complex biological processes and numerous clinical conditions. Particular attention was made to reveal the association of l-arginine and methylarginines to outcome measures of women undergoing in vitro fertilization (IVF). This review attempts to summarize the expression and function of the essential elements of this system with particular reference to the different stages of female reproduction. A literature search was performed on the PubMed and Google Scholar systems. Publications were selected for evaluation according to the results presented in the The regulatory role of NO during the period of folliculogenesis, oocyte maturation, fertilization, embryogenesis, implantation, placentation, pregnancy, and delivery was surveyed. The major aspects of cellular l-arginine uptake via cationic amino acid transporters (CATs), arginine catabolism by nitric oxide synthases (NOSs) to NO and l-citrulline and by arginase to ornithine, and polyamines are presented. The importance of NOS inhibition by methylated arginines and the redox-sensitive elements of the process of NO generation are also shown. The l-arginine-NO system plays a crucial role in all stages of female reproduction. Insufficiently low or excessively high rates of NO generation may have adverse influences on IVF outcome.