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Dive into the research topics where Antonia Sioga is active.

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Featured researches published by Antonia Sioga.


Histology and Histopathology | 2014

Immunohistochemical study of immunological markers: HLAG, CD16, CD25, CD56 and CD68 in placenta tissues in recurrent pregnancy loss.

Theodora Papamitsou; Alexandros Toskas; Kyriaki Papadopoulou; Antonia Sioga; Sotirios Lakis; Maria Chatzistamatiou; Zinon Economou; Adriopoulou L

INTRODUCTION Recurrent pregnancy loss (RPL) of unknown etiology is correlated with immunological alterations during pregnancy. Normally, changes in leukocyte subpopulations and HLA expression take place in pregnant uterus in order to tolerate the semi-allogenic embryo. OBJECTIVE Our research tries to enlighten the immunological changes that take place in the uterus of women with recurrent abortions of unknown etiology during first trimester of pregnancy. MATERIALS AND METHODS The miscarriage group was obtained from 25 women who miscarried between the ages of 35 to 42 years and controls consisted of 25 healthy women between the ages of 27 to 39 years, who had electively terminated their pregnancies during the first trimester of pregnancy. The abortion was processed and specimens taken were studied using immunohistochemical methods. Specimens were taken from decidua basalis and decidua parietalis. Monoclonal antibodies were used against HLAG (Human Leukocyte Antigen G), CD68( Cluster of Differentiation 68), CD56, CD16 and CD25. The results were statistically analysed with Mann-Whitney test. RESULTS HLA-G expression in decidua basalis from miscarriage group was found to be decreased. CD25+ cell expression was found to be invariable in deciduas from both groups. CD16+ cell and CD68 + cell expression was found to be increased in deciduas from the miscarriage group. CD56+ cell expression was found to be increased in decidua parietalis from miscarriage group. Conclusion : Several differences in the immunological profile of deciduas from RPL group were observed. Changes in feto-protective HLA-G expression and a possible implication of macrophages and NK cells were found.


Medical Hypotheses | 2013

Is copper chelation an effective anti-angiogenic strategy for cancer treatment?

Vasilis Antoniades; Antonia Sioga; Eva-Maria Dietrich; S. Meditskou; L. Ekonomou; Konstantinos Antoniades

Angiogenesis and the acquisition of an angiogenic phenotype is important for cancer cell proliferation. Copper in an essential trace element that participates in many enzymatic complexes like the cytochrome c, superoxide dismutase and lysyl oxidase and it is involved in processes, like embryogenesis, growth, angiogenesis and carcinogenesis. In particular, its involvement in carcinogenesis was described for the first time in oral submucous fibrosis, where fibroblasts produce large amounts of collagen in the presence of copper. Coppers action in carcinogenesis is two-fold: (1) it participates in reactions with an increased redox potential that result in the production of oxidative products and oxidative stress. Through this mechanism, copper may cause DNA mutations in the nucleus and mitochondria or alterations to membrane phospholipids, (2) it participates in angiogenesis even in the absence of angiogenic molecules, as it was reported for the first time in rabbit cornea models with copolymer pellets charged with PGE1. Copper chelation regimens like penicillamine and tetrathiomolybdate are being described in the literature as having anti-angiogenic, anti-fibrotic and anti-inflammatory actions. Animal models of brain cancer that evaluated the anti-angiogenic properties of copper, have proven evidence of the reduction of tumors microvascular supply, tumor volume and vascular permeability after plasma copper levels reduction. Interestingly, plasma copper levels reduction was shown to suppress micrometastases generation in mice models of breast cancer. We hypothesize that copper chelation therapy: increases oxidative stress in cancer cells to a level that does not allow survival because of the reduction of anti-oxidative enzymes production. It may also result in inhibition of angiogenesis and of the initiation of the angiogenic switch, because copper normally enhances endothelial cell migration and proliferation, improves binding of growth factors to endothelial cells and enhances the expression of angiogenic molecules. Copper chelation may also reduce extracellular matrix degradation and cancer spread, through reduction of MMP-9 production and probably of other collagenases and may inhibit propagation of micrometastases. However, copper chelation therapy may enhance angiogenesis through reduction of thrombospondin-1, that results into an increase in VEGF-VEGFR2 complexes and a high level of active MMP-9. These hypotheses help in understanding of the anti-angiogenic action of copper chelation therapies and of the complex network of interactions between copper and other molecules involved in angiogenesis. It may also stimulate further research regarding differences in copper metabolism, the effects of anti-copper regimens on organs, the development of resistance, and their possible angiogenic action through thrombospondin expression reduction.


Fertility and Sterility | 2011

Semen analysis by electron and fluorescence microscopy in a case of partial hydatidiform mole reveals a high incidence of abnormal morphology, diploidy, and tetraploidy.

Katerina Chatzimeletiou; Antonia Sioga; Louisa Oikonomou; Sophia Charalampidou; Persa Kantartzi; Vasiliki Zournatzi; Dimitrios Panidis; Dimitrios G. Goulis; Ioannis Papadimas; Basil C. Tarlatzis

OBJECTIVE To perform a highly detailed semen analysis in a man whose wife had a partial mole. DESIGN Case report. SETTING Gynecology departments of two university hospitals and a laboratory of histology/embryology. PATIENT(S) A 32-year-old man whose wife had a partial mole. INTERVENTION(S) Sperm characteristics were examined by light microscopy, morphology was analysed by electron microscopy (TEM), DNA fragmentation was evaluated by TUNEL using fluorescence microscopy, and chromosomal abnormalities were assessed by fluorescence in situ hybridization using probes for chromosomes 13, 15, 16, 18, 21, 22, X, and Y. MAIN OUTCOME MEASURE(S) Sperm count, motility, morphology, DNA fragmentation, and incidence of diploidy, tetraploidy, and aneuploidy. RESULT(S) Sperm concentration was 61 million/mL, with 31% progressive motility and 4% normal morphology. TEM revealed a high incidence of head, neck, and tail abnormalities as well as the presence of phagocytes. DNA fragmentation was within normal limits (11.6%). Aneuploidy levels were low for all chromosomes tested. However, there was a high level of diploidy, with XY, XX, and YY constitution. Tetraploid sperm (XXYY) were also noted. CONCLUSION(S) Semen analysis revealed a high incidence of abnormal morphology and increased diploidy. It may be important to perform FISH testing, to verify increased diploidy in sperm, in men whose wives have had partial moles. These couples could be informed of the option to have preimplantation genetic diagnosis as a means to distinguish between diploid and triploid embryos arising from fertilization of a haploid egg by diploid sperm.


Anatomy research international | 2012

Meniscofibular Ligament: Morphology and Functional Significance of a Relatively Unknown Anatomical Structure

Konstantinos Natsis; George Paraskevas; Nikolaos Anastasopoulos; Theodora Papamitsou; Antonia Sioga

Purpose. A relatively unknown ligamentous structure of the posterolateral corner of the knee joint, the so-called meniscofibular ligament (MFL), was investigated as regards its macroscopic morphology, its histological features, and its reaction to knee movements. Material and Methods. MFL was exposed on 21 fresh-frozen unpaired knee joints. Its microscopic morphology was examined utilizing for comparison the fibular collateral and the popliteofibular ligament. Results. MFL was encountered in 100% of the specimens as a thin striplike fibrous band extending between the lower border of the lateral meniscus and the head of the fibula. MFL was tense during knee extension and external rotation of the tibia, whereas its histological features were similar to those of fibular collateral and popliteofibular ligament. Discussion. Its precise histological nature is studied as well as its tension alterations during knee movements. The potential functional significance of the MFL with respect to its role in avoidance of lateral meniscus and lateral coronary ligament tears is discussed. Conclusions. MFL presumably provides an additional protection to the lateral meniscus during the last stages of knee extension, as well as to the lateral coronary ligament reducing the possibility of a potential rupture.


Clinical and Experimental Gastroenterology | 2010

The role of somatostatin in 67 consecutive pancreatectomies: a randomized clinical trial.

Anastasios Katsourakis; Louiza Oikonomou; Efthimios Chatzitheoklitos; Georgios Noussios; Michail S Pitiakoudis; Aleksandros Polychronidis; Konstantinos E Simopoulos; Antonia Sioga

Background: Somatostatin has been found to be effective in the prevention of postoperative complications in pancreatic surgery. It can inhibit the pancreatic secretions that, quite often, are responsible for complications during the postoperative period. Methods: We randomized 67 patients in 2 groups. In the study group (n = 35), somatostatin was administered 30 minutes prior to surgery as well as intraoperatively and postoperatively. No medication was given to the control group (n = 32). Biopsies were taken and processed for electron microscopy and ultrastructural morphometric analysis. Results: Administration of somatostatin reduced the exocrine granule number, and the patients suffered from fewer postoperative complications. Conclusions: Somatostatin reduces granule number and size of pancreatic cells, which can partially explain the prophylactic effect of the drug on early complications of pancreatic surgery, and which is confirmed by the clinical findings.


Zygote | 2017

Effects of vitrification on blastomere viability and cytoskeletal integrity in mouse embryos.

Zenon Oikonomou; Katerina Chatzimeletiou; Antonia Sioga; Louisa Oikonomou; Basil C. Tarlatzis; Efstratios M. Kolibianakis

Vitrification is widely used to cryopreserve supernumerary embryos following in vitro fertilization (IVF). The mouse model was used to investigate the effects of vitrification on blastomere viability, using viability markers, and on the cytoskeleton, by analysing spindle/chromosome configurations, using confocal scanning microscopy. Ninety cleavage and morula stage dimethyl sulphoxide (DMSO)/EG vitrified mouse embryos were either processed immediately following warming for viability assessment by labelling with the fluorescent markers carboxyfluorescein-diacetate succinimidylester (CFSE) and propidium iodide (PI) or were cultured to the blastocyst stage and immunostained with α-tubulin antibody to visualize microtubules and DAPI or PI to visualize DNA. Sixty-five fresh embryos were also used as the control. Vitrified embryos showed high survival rates following warming, but they had a higher incidence of damaged blastomeres compared with fresh embryos. Most mitotic spindles examined in all groups were normal, but multivariable analysis revealed that the proportion of abnormal spindles was significantly higher in vitrified/warmed embryos (P < 0.05). This study is the first to examine the immediate effects of vitrification on blastomere viability, using fluorescent markers and shows that although vitrification results in a higher incidence of damaged blastomeres, vitrified embryos may compensate for this limited number of damaged/abnormal cells, as development to the blastocyst stage was not compromised.


Histology and Histopathology | 2016

Expression of peroxisome proliferator activation receptors (PPARs) and TNFα in placenta tissues in unexplained recurrent pregnancy loss: an immunohistochemical study.

Theodora Papamitsou; Alexandros Toskas; Kyriaki Papadopoulou; Zinon Economou; Antonia Sioga

INTRODUCTION PPAR expression in placenta tissues regulates proinflammatory cytokine production and preserves the quiescence of the uterus during pregnancy. PPAR-γ regulates inflammatory response during gestation while PPAR-δ and TNFα play a central role at implantation, decidualization and placentation. However, their expression levels affect normal pregnancy and may cause gestational complications and miscarriage. The aim of this report is to investigate the relationship of these molecules with unexplained recurrent miscarriage. MATERIALS-METHODS The miscarriage group was obtained from 12 women, between the ages of 35 to 42 years, who miscarried during the 1st trimester of gestation and controls consisted of 12 healthy women, between the ages of 27 to 39 years, who had electively terminated their pregnancies, during the 1st trimester of gestation. The abortion material was processed and specimens taken were studied using immunohisto-chemical methods. Specimens were taken from decidua basalis and decidua parietalis. Monoclonal antibodies were used against PPAR-γ (Peroxisome Proliferator Activation Receptor γ), PPAR-δ and TNFα (Tumor Necrosis Factor alpha). The results were statistically analyzed with Mann-Whitney test. RESULTS Our research identified PPAR-γ expression in decidua basalis and decidua parietalis from control group and decidua basalis from miscarriage group. PPAR-δ expression was also identified in both deciduas from both groups. Statistically, no significant change in PPAR-γ and PPAR-δ expression was observed between recurrent miscarriage group and controls. On the contrary, a statistically significant upregulation of TNFα was identified in both deciduas between miscarriage group and controls (p<0.05). CONCLUSIONS Our evidence did not support a possible role of PPARs expression in recurrent pregnancy loss. However, a potential involvement of TNFα in the syndrome was reported. Further research should be performed due to insufficient bibliographic data.


Polish journal of pathology : official journal of the Polish Society of Pathologists | 2013

The immunohistochemical expression of CD24 and CD171 adhesion molecules in borderline ovarian tumors

Alexandra Moulla; Dimosthenis Miliaras; Antonia Sioga; Aikaterini Kaidoglou; Louisa Economou


Histology and Histopathology | 2011

Low expression of progesterone receptor A in intermediate trophoblast of miscarriages.

Theodora Papamitsou; Maria Chatzistamatiou; Danai Grammatikopoulou; Kyriaki Papadopoulou; Sotirios Lakis; Zinon Economou; Chrisi Papadopoulou; Antonia Sioga


Histology and Histopathology | 2007

Histological evaluation of colonic anastomotic healing, during perioperative Capecitabine administration. Experimental study in rats

Harilaos D. Konstantinidis; Antonia Sioga; Louise Economou; K.D. Mpallas; Charalampos I. Demertzidis; Theano T. Pissanidou

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Dive into the Antonia Sioga's collaboration.

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Theodora Papamitsou

Aristotle University of Thessaloniki

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Basil C. Tarlatzis

Aristotle University of Thessaloniki

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Katerina Chatzimeletiou

Aristotle University of Thessaloniki

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Louise Economou

Aristotle University of Thessaloniki

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Dimitrios G. Goulis

Aristotle University of Thessaloniki

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Harilaos D. Konstantinidis

Aristotle University of Thessaloniki

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Konstantinos Natsis

Aristotle University of Thessaloniki

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Nikolaos Anastasopoulos

Aristotle University of Thessaloniki

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Alexandros Karagiannidis

Aristotle University of Thessaloniki

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Antonis Kalpatsanidis

Aristotle University of Thessaloniki

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