Konstantinos Dafopoulos

Prof. Konstantinos Dafopoulos

orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

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

Representative Publications

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1 January 2010 in Reproductive Biology and Endocrinology
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George AnifandisGeorge Anifandis
George Anifandis
KDKonstantinos Dafopoulos
Konstantinos Dafopoulos
CMChristina I. Messini
Christina I. Messini
NCNektarios Chalvatzas
Nektarios Chalvatzas
NLNikolaos Liakos
Nikolaos Liakos
IMIoannis Messinis
Ioannis Messinis
The aim of the present study was to measure serum and follicular fluid 25-OH vitamin D and glucose levels in women who underwent IVF-ET treatment and to further investigate whether the circulating 25-OH vitamin D and glucose levels correlate with IVF success. This prospective observational study included 101 consecutive women who underwent 101 IVF-ICSI ovarian stimulation cycles and were allocated to one of the three groups according to their follicular fluid 25-OH vitamin D concentrations. Group A (n = 31) with less than 20 ng/ml, group B (n = 49) with vitamin levels between 20.1 and 30 ng/ml and group C (n = 21) with more than 30 ng/ml vitamin concentration. Follicular fluid vitamin levels significantly correlated with the quality of embryos in total (r = -0.27, p = 0.027), while the quality of embryos of group C were of lower quality as compared to those of groups A and B (p = 0.009). Follicular fluid glucose levels were lower in women of group C as compared to the respective levels of groups A and B (p = 0.003). Clinical pregnancy rate demonstrated in 14.5% in women of group C and 32.3% and 32.7% in groups A and B, respectively (p = 0.047). The data suggests that excess serum and follicular fluid vitamin levels in combination with decreased follicular fluid glucose levels have a detrimental impact on the IVF outcome.

George AnifandisGeorge Anifandis
George Anifandis
KKKaterina Katsanaki
Katerina Katsanaki
GLGeorgia Lagodonti
Georgia Lagodonti
CMChristina I. Messini
Christina I. Messini
Mara SimopoulouMara Simopoulou
Mara Simopoulou
ADAlexandros Daponte
Alexandros Daponte
Glyphosate is the active ingredient of Roundup®, which is one of the most popular herbicides worldwide. Although many studies have focused on the reproductive toxicity of glyphosate or glyphosate-based herbicides, the majority of them have concluded that the effect of the specific herbicide is negligible, while only a few studies indicate the male reproductive toxicity of glyphosate alone. The aim of the present study was to investigate the effect of 0.36 mg/L glyphosate on sperm motility and sperm DNA fragmentation (SDF). Thirty healthy men volunteered to undergo semen analysis for the purpose of the study. Sperm motility was calculated according to WHO 2010 guidelines at collection time (zero time) and 1 h post-treatment with glyphosate. Sperm DNA fragmentation was evaluated with Halosperm® G2 kit for both the control and glyphosate-treated sperm samples. Sperm progressive motility of glyphosate-treated samples was significantly reduced after 1 h post-treatment in comparison to the respective controls, in contrast to the SDF of glyphosate-treated samples, which was comparable to the respective controls. Conclusively, under these in vitro conditions, at high concentrations that greatly exceed environmental exposures, glyphosate exerts toxic effects on sperm progressive motility but not on sperm DNA integrity, meaning that the toxic effect is limited only to motility, at least in the first hour.

1 May 2015 in Best Practice & Research Clinical Obstetrics & Gynaecology
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Journal Article
Closed access
IMIoannis Messinis
Ioannis Messinis
CMChristina I. Messini
Christina I. Messini
George AnifandisGeorge Anifandis
George Anifandis
KDKonstantinos Dafopoulos
Konstantinos Dafopoulos

21 December 2017 in Toxics
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GAGeorgios S Amiridis
Georgios S Amiridis
GAGeorgios S Amiridis
Georgios S Amiridis
KDKonstantinos Dafopoulos
Konstantinos Dafopoulos
ADAlexandros Daponte
Alexandros Daponte
EDEleni Dovolou
Eleni Dovolou
Anna-Maria G. PsarraAnna-Maria G. Psarra
Anna-Maria G. Psarra
Toxicants, such as herbicides, have been hypothesized to affect sperm parameters. The most common method of exposure to herbicides is through spraying or diet. The aim of the present study was to investigate the effect of direct exposure of sperm to 1 mg/L of the herbicide Roundup on sperm motility and mitochondrial integrity. Sperm samples from 66 healthy men who were seeking semen analysis were investigated after written informed consent was taken. Semen analysis was performed according to the World Health Organization guidelines (WHO, 2010). Mitochondrial integrity was assessed through mitochondrial staining using a mitochondria-specific dye, which is exclusively incorporated into functionally active mitochondria. A quantity of 1 mg/L of Roundup was found to exert a deleterious effect on sperm’s progressive motility, after 1 h of incubation (mean difference between treated and control samples = 11.2%) in comparison with the effect after three hours of incubation (mean difference = 6.33%, p < 0.05), while the relative incorporation of the mitochondrial dye in mitochondria of the mid-piece region of Roundup-treated spermatozoa was significantly reduced compared to relative controls at the first hour of incubation, indicating mitochondrial dysfunction by Roundup. Our results indicate that the direct exposure of semen samples to the active constituent of the herbicide Roundup at the relatively low concentration of 1 mg/L has adverse effects on sperm motility, and this may be related to the observed reduction in mitochondrial staining.

Verified
Journal Article
Open access
PDF file
George AnifandisGeorge Anifandis
George Anifandis
CMChristina I. Messini
Christina I. Messini
KDKonstantinos Dafopoulos
Konstantinos Dafopoulos
SSSotirios Sotiriou
Sotirios Sotiriou
IMIoannis Messinis
Ioannis Messinis
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.

Varvara MouchtouriVarvara Mouchtouri
Varvara Mouchtouri
Dimitrios PapagiannisDimitrios Papagiannis
Dimitrios Papagiannis
AKAntonios Katsioulis
Antonios Katsioulis
George RachiotisGeorge Rachiotis
George Rachiotis
KDKonstantinos Dafopoulos
Konstantinos Dafopoulos
Christos HadjichristodoulouChristos Hadjichristodoulou
Christos Hadjichristodoulou
A survey among 573 pregnant women in Greece was conducted through self-completion of a questionnaire in July 2016. Traveling abroad the last six months was declared by 10.5% and 13.0% of pregnant women and their male sex partners, respectively, while 77.4% (441/570) had heard about Zika virus disease (ZVD). A lack of knowledge about sexual transmission of ZVD was identified in 63.3% of pregnant women, and 24.1% of responders did not know the risks to the fetus and baby. Approximately 73% of responders believed that the mosquito bites can affect their fetus and baby and 18% did not take measures to prevent mosquito bites routinely. Multivariable logistic regression models showed that traveling abroad the last six months by pregnant women correlated with correctly answering the question about the transmission of ZVD through bites of infected mosquitoes (Odds Ratio, OR = 10.47, 95% CI = 1.11–98.41). Traveling abroad with a male sex partner over the last six months correlated (OR = 2.05, 95% CI = 0.99–4.23) with responding correctly to the four key questions about the transmission of ZVD through mosquito bites, the risk of microcephaly, and the risks of traveling to the affected countries. A score of ≥5 for the nine responses given to questions of knowledge and attitudes was associated with a Bachelor of Science degree (OR = 1.54, 95% CI = 1.09–2.18), antenatal care at a public hospital (OR = 2.26, 95% CI = 1.28–3.98), being a civil servant as occupation (OR = 1.96, 95% CI = 1.10–3.48), and having gotten information about ZVD from the public health sector (OR = 2.04, 95% CI = 1.05–3.98). In conclusion, we found considerable knowledge gaps related to ZVD among Greek pregnant women. These study results are useful in targeting pregnant women for the prevention of potential Zika virus infections.