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Dive into the research topics where Theodora Papamitsou is active.

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Featured researches published by Theodora Papamitsou.


Medical Science Monitor | 2011

Testosterone-induced hypertrophy, fibrosis and apoptosis of cardiac cells – an ultrastructural and immunohistochemical study

Theodora Papamitsou; Dimitris Barlagiannis; Vasileios Papaliagkas; Eleni Kotanidou; Maria Dermentzopoulou-Theodoridou

Summary Background Androgen abuse is an increasing problem amongst professional and amateur athletes. Moreover, testosterone, apart from its widely accepted indications, is used for a variety of other indications such as aging and ischemia. Its actions are mainly attributed to a specific genomic mechanism through the androgen receptor, but emerging evidence reveals non-genomic effects as well. The use of androgens has been linked with several adverse effects. The purpose of this study was to examine the effects of testosterone on the morphology and the ultrastructure of the myocardium and to investigate the possible role of apoptosis. Material/Methods We used 12 adult male Wistar rats, separated into 2 groups. Group A consisted of 6 rats that were administered high doses of testosterone enanthate, while group B consisted of 6 male Wistar rats that received placebo (normal saline) intramuscularly. After the last day of treatment, all rats were anesthetized and sacrificed, and the hearts were removed and processed for optical and electron microscopy and immunohistochemical detection of caspase-3, an apoptosis marker. Results We found significant myocardial hypertrophy along with abundant ultrastructural alterations. The immunohistochemical staining of the myocardial cells for caspase-3 was positive in group A (experimental group), which is interpreted as an activation of apoptosis by testosterone treatment. Conclusions Testosterone abuse has serious adverse effects, including myocardial hypertrophy, myocardial fibrosis and activation of apoptosis. These findings need to be taken into account whenever androgens are prescribed to improve performance or as hormone therapy.


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.


American Journal of Drug and Alcohol Abuse | 2010

Evaluation of prooxidant-antioxidant balance in chronic heroin users in a single assay: an identification criterion for antioxidant supplementation.

Leda Kovatsi; Samuel Njau; Kakia Nikolaou; Konstantina Topouridou; Theodora Papamitsou; George Koliakos

Background: Opiate abuse has been linked to oxidative stress, through the separate evaluation of oxidants and antioxidants. Objectives: To determine prooxidant–antioxidant balance (PAB) in chronic heroin users in a single assay, easily applied in a clinical setting. Specifically, to examine whether PAB values correlate with the duration of abuse or with the presence of anti-HCV antibodies. Methods: Sixty-four chronic heroin users - 34 cases and 30 controls - participated in this study. PAB was determined by an Enzyme-linked immunosorbent assay (ELISA) method, developed by members of the study group. Results: In heroin users, oxidative balance was disrupted in favor of prooxidants. There was no correlation of PAB values with the duration of abuse or with the presence of anti-Hepatitis C virus (HCV) antibodies. Conclusions: Chronic heroin users can benefit from an antioxidant therapy, and the method currently presented can be used as an identification criterion.


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.


Journal of Biological Research-thessaloniki | 2017

Sudden infant death syndrome due to long QT syndrome: a brief review of the genetic substrate and prevalence

Nikolaos S. Ioakeimidis; Theodora Papamitsou; Soultana Meditskou; Zafiroula Iakovidou-Kritsi

The pathophysiological mechanisms which lead to sudden infant death syndrome (SIDS) are not completely understood. Cardiac channelopathies are a well-established causative factor with long QT syndrome (LQTS) being the most frequent one, accounting for approximately 12% of SIDS cases. The genetic substrate of the above arrhythmogenic syndrome has been thoroughly described but only specific gene mutations or polymorphisms have been identified as SIDS causative. The review will focus on the prevalence of LQTS-induced SIDS or near-SIDS cases and the mutations held responsible. A literature search was performed in PubMed and Scopus electronic databases. Search terms used were: long QT syndrome, channelopathies, QT prolongation, cardiac ion channels. The above-mentioned search terms were always combined with the term: sudden infant death syndrome. Study types considered eligible were: case–control, family pedigree analysis, case reports. The prevalence of LQTS-induced SIDS according to six broad genetic studies ranges from 3.9 to 20.6%, with an average of 12%. Since LQTS can be effectively managed, LQTS-related SIDS cases could be prevented, provided that a screening method is efficient enough to detect all the affected infants.


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 Surgery | 2014

Immediate and delayed surgical repair of duodenal defects in rats with small intestinal submucosa patch.

Dimosthenis Miliaras; Spyridon Miliaras; Soultana Meditskou; Theodora Papamitsou

UNLABELLED Duodenal injuries, though rare, carry high rates of morbidity and mortality. The aim of the study was to evaluate the healing of the duodenal wall with the use of a Small Intestinal Submucosa (SIS) patch. MATERIAL AND METHODS We studied 40 Wistar-Albino rats divided into two groups. In group A, we created a small defect in the duodenal wall, which was immediately covered with a SIS patch. In group B, the SIS patch was sutured over the defect after 6-8 hours, in order to induce peritonitis. The animals of both groups were sacrificed after 2, 6, 12 and 16 weeks respectively. In addition, we studied the immunohistochemical expression of TGF-β, which is a major constituent of SIS, and plays a central role in the healing process. RESULTS Histology showed progressive development of the layers of the duodenal wall over the patch as early as the 2nd week in some of the animals of group A. Mucosa developed later on in the animals of group B, presumably due to the more intense inflammation elicited by peritonitis. Expression of TGF-β was initially more pronounced in the epithelial cells of the regenerating mucosa of animals of group A, but it was maintained in higher levels in the animals of group B, which showed delayed mucosa degeneration. CONCLUSIONS SIS appears to be both efficient and safe for the management of duodenal trauma. TGF-β seems to play an important role in the healing process, inducing regeneration of the stroma, and controlling epithelial growth.


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


World Journal of Gastroenterology | 2010

AMACR is associated with advanced pathologic risk factors in sporadic colorectal adenomas

Sotiris Lakis; Theodora Papamitsou; Constantina Panagiotopoulou; Rodoula Kotakidou; Vassiliki Kotoula


Hippokratia | 2010

Breast tumor developed in a pregnant rat after treatment with the teratogen Cycloheximide.

Emmanouil-Nikoloussi En; Nikoloussis E; Maria-Eleni Manthou; Goula OCh; Likartsis Ch; Theodora Papamitsou; Frangou H; Massouridou S; Lazaridis Ch; Manthos A

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Dive into the Theodora Papamitsou's collaboration.

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Antonia Sioga

Aristotle University of Thessaloniki

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Ioannis Makaronidis

Aristotle University of Thessaloniki

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Paraskevi Papaioannidou

Aristotle University of Thessaloniki

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Soultana Meditskou

Aristotle University of Thessaloniki

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Dimosthenis Miliaras

Aristotle University of Thessaloniki

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Ioannis Kyriakidis

Aristotle University of Thessaloniki

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Anastasios Manthos

Aristotle University of Thessaloniki

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Athanasia Alvanou

Aristotle University of Thessaloniki

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Chrysanthi Simou

Aristotle University of Thessaloniki

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Dimitris Barlagiannis

Aristotle University of Thessaloniki

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