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Dive into the research topics where Alexandra Kalogeraki is active.

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Featured researches published by Alexandra Kalogeraki.


Toxicology | 2013

Histopathological lesions, oxidative stress and genotoxic effects in liver and kidneys following long term exposure of rabbits to diazinon and propoxur.

Christina Tsitsimpikou; Manolis Tzatzarakis; Persefoni Fragkiadaki; Leda Kovatsi; Polychronis Stivaktakis; Alexandra Kalogeraki; Demetrios Kouretas; Aristidis M. Tsatsakis

PURPOSE The aim of the present study was to investigate the effects of diazinon and propoxur on liver and kidneys, following long term exposure of rabbits. METHODS Ten New Zealand white female rabbits were used. The animals were divided into 5 groups, consisting of 2 animals each. Diazinon (groups 1 and 2) and propoxur (groups 3 and 4) were administered at 2 different doses, and group 5 served as the control group. Histopathological lesions in the liver and kidneys, oxidative stress and oxidative DNA damage were evaluated. RESULTS Both pesticides induced focal inflammation and fibrosis in the liver and kidneys. The low dose of propoxur induced a significant increase in total antioxidant capacity (TAC), with no difference in reduced glutathione (GSH), while the high dose of propoxur induced an increase in GSH with no change in TAC. For diazinon-exposed animals, the opposite findings were observed. Both diazinon and propoxur induced a statistically significant oxidative DNA damage in the liver and kidneys and a subsequent increase in telomerase activity in these tissues, possibly as a counteracting mechanism. Furthermore, systemic inflammation, as depicted by the dose-dependent increase in telomerase activity in peripheral blood mononuclear cells (PBMCs), was observed in propoxur treated animals. CONCLUSIONS Histopathological lesions, oxidative stress and genotoxic effects were induced in liver and kidneys following long term exposure of rabbits to diazinon and propoxur.


Iubmb Life | 2013

Syndecan‐2 is a key regulator of transforming growth factor beta 2/smad2‐mediated adhesion in fibrosarcoma cells

Maria Mytilinaiou; Artan Bano; Dragana Nikitovic; Aikaterini Berdiaki; Kallirroi Voudouri; Alexandra Kalogeraki; Nikos K. Karamanos

Fibrosarcoma is a rare malignant tumor originating from fibroblasts. Transforming growth factor beta 2 (TGFβ2) has been established to regulate processes correlated to fibrosarcoma tumorigenesis. In this study, we investigated the possible participation of syndecan‐2 (SDC‐2), a cell membrane heparan sulfate (HS) proteoglycan on these TGFβ2 functions. Our results demonstrate that the inhibition of SDC‐2 expression by short interfering RNA (siSDC2) abolished TGFβ2‐dependent HT1080 cell adhesion (P ≤ 0.01). In parallel, the downregulation of SDC‐2 significantly inhibited TGFβ2‐induced Smad2 phosphorylation (P ≤ 0.01). The immunoflourescence signal of TGF receptor III as well as its protein expression was decreased in SDC‐2‐deficient cells. The enhancement of adhesion molecules integrin β1 (P ≤ 0.01) and focal adhesion kinase expression, induced by TGFβ2 treatment (P ≤ 0.001), was markedly inhibited in SDC‐2‐defficient cells (P ≤ 0.01). Conclusively, the obtained data suggest that SDC‐2 modulates TGFβ2 transcriptional regulation via Smad signaling to facilitate fibrosarcoma cell adhesion.


Reproductive Biomedicine Online | 2012

History of endometriosis may adversely affect the outcome in menopausal recipients of sibling oocytes.

Yannis Prapas; Maria Goudakou; Ioannis Matalliotakis; Alexandra Kalogeraki; Charikleia Matalliotaki; Yannis Panagiotidis; Konstantinos Ravanos; Nikos Prapas

Due to the known adverse effect of endometriosis on gamete quality, it has always been difficult to demonstrate a direct effect of endometriosis on implantation. In order to eliminate these confounding effects, this prospective comparative study studied a population of menopausal recipients with and without endometriosis sharing sibling oocytes coming from the same donor. The aim was to understand the impact of endometriosis on implantation, pregnancy and live birth rates in menopausal recipients. A total of 240 menopausal recipients of donated sibling oocytes, were divided in two groups. Group I consisted of 120 recipients diagnosed with endometriosis and group II consisted of 120 controls. The implantation and pregnancy rates were significantly lower in the endometriosis group compared with the control group (23.81% versus 31.48%, P=0.019; 45.00% versus 58.33%, P=0.039, respectively). In oocyte donation cycles, a recipients history of endometriosis might have a negative impact on implantation, pregnancy and live birth rates, even in menopausal women. Infertility in endometriosis may be due to poor oocyte quality or embryos with decreased ability to implant due to impaired fertilization. There are no conclusive data on the impact of endometriosis on implantation. The already-known adverse effect of endometriosis on gamete quality makes it more difficult to demonstrate a direct effect of endometriosis on implantation. In order to eliminate these confounding effects we studied a population of menopausal recipients with and without endometriosis sharing sibling oocytes coming from the same oocyte donor. The oocyte donation model was used in an attempt to understand whether the endometrium, the oocytes or both are affected by endometriosis. The aim of the present study was to understand the impact of endometriosis on implantation, pregnancy and live birth rates in menopausal recipients. A total of 240 menopausal recipients of donated sibling oocytes were divided into two groups. Group I consisted of 120 recipients diagnosed with endometriosis and group II consisted of 120 controls. The pregnancy and implantation rates were significantly lower in the endometriosis group compared to the control group (45.00% versus 58.33%, P=0.039) and (23.81% versus 31.48%, P=0.019) respectively. In oocyte donation cycles, a recipients history of endometriosis might have a negative impact on implantation, pregnancy and live birth rates, even in menopausal women.


Toxicology | 2013

Relationship between the paraoxonase 1 (PON1) M55L and Q192R polymorphisms and lymphohaematopoietic cancers in a Greek agricultural population

Michalis Koureas; Efthimios Dardiotis; Pavlina Almpanidou; Alexandra Kalogeraki; Despoina Kyriakou; Georgios M. Hadjigeorgiou; Christos Hadjichristodoulou

The aim of this study was to investigate the association between Paraoxonase 1 (PON1) gene polymorphisms (M55L and Q192R) and lymphohaematopoietic cancers (LHC) in an agricultural region of Greece. A hospital-based case-control study was conducted. A structured questionnaire including information on demographics, residence, occupation, agricultural practices, pesticide exposure, family history, smoking, alcohol consumption and medical history, was used. Genotyping of 316 cases of LHC and 351 healthy controls by using standard laboratory methods was performed. To control for confounders, Binary and Multinomial Logistic Regression analyses were used. Possession of QQ genotype or presence of the Q allele were associated with increased risk of developing LHC (OR 1.94, 95% CI 1.42-2.66 and OR 1.72, 95% CI 1.33-2.23 respectively). The QQ genotype in the recessive model was independently associated with LHC (OR 1.92, 95% CI 1.40-2.65), leukaemia (OR 1.99, 95% CI 1.13-3.49), lymphoma (OR 2.17, 95% CI 1.21-3.90) and plasmacell disease (OR 1.92, 95% CI 1.40-2.65) even after controlling for age, sex, pesticide exposure, smoking and family history (cancers, LHC and immunological disorders) as confounders. Possession of QQ genotype was found to have a stronger association with LHC in the high and medium pesticide exposed groups(OR 2.15, 95% CI 1.35-3.40, P-value 0.001 and OR 2.25, 95% CI 1.21-4.19, P-value 0.010 respectively), compared with the Low/No exposed group where the association was not statistically significant (OR 1.51, 95% CI 0.76-3.00, P-value 0.224). We found no association between M55L polymorphism and LHC. PON1 polymorphisms may influence the risk for LHC in our agricultural area. The results encourage further investigation on the PON1 polymorphisms and their importance on the individuals susceptibility especially when exposure to pesticides occurs.


Reproductive Biomedicine Online | 2012

Cryptic sperm defects may be the cause for total fertilization failure in oocyte donor cycles.

Maria Goudakou; Alexandra Kalogeraki; Ioannis Matalliotakis; Yannis Panagiotidis; Giuseppe Gullo; Yannis Prapas

In conventional IVF cycles with total fertilization failure, rescue intracytoplasmic sperm injection (ICSI) performed 24h after insemination has yielded poor results. However, when ICSI is used, total fertilization failure is a rare event. The aim of the present study is to investigate the degree of sperm contribution to fertilization failures using the egg-sharing model in oocyte donor cycles. The study included only the oocyte donor cycles of sibling oocytes with total fertilization failure in at least one of the matched recipients. Oocytes from 49 oocyte donor cycles were equally shared among 98 recipients undergoing conventional IVF. Due to total fertilization failure in half of the recipients, rescue ICSI was carried out. Compared with the conventional IVF only group, the rescue ICSI group had a lower pregnancy rate (30.61% versus 71.43%), clinical pregnancy rate (28.57% versus 67.35%) and ongoing pregnancy rate (28.57% versus 63.27%) (all P<0.01). Cryptic sperm defects in apparently normal spermatozoa may be the cause of total fertilization failure, indicating the need for simple routine tests to detect them.


Diagnostic Cytopathology | 2013

A brief chronicle of cytology: from Janssen to Papanicolaou and beyond.

Aristides Diamantis; Apostolos Beloukas; Alexandra Kalogeraki; Emmanouil Magiorkinis

The aim of our study was to outline and present the major hallmarks in the history of clinical cytology. For this purpose, an extensive research in modern literature and the PubMed database was undertaken. Furthermore, we studied original papers and books of the pioneers in cytopathology. The development of the first microscope by Hans and Sacharias Janssen is a hallmark in biological sciences, since the study of microcosmos was made feasible. From the discovery of single cells by Robert Hooke and the cell theory by Schleiden and Schwann till the establishment of exfoliative cytology by George Papanicolaou and the invention of fine‐needle aspiration biopsy technique by Martin and Ellis, there is a three‐century continuum of important discoveries and research. Today, flow cytometry and the introduction of molecular techniques have revolutionized medicine and are expected to change the face of cytology in the near future. Diagn. Cytopathol. 2013.


Acta Cytologica | 2003

E-cadherin Expression on Fine Needle Aspiration Biopsies of Breast Invasive Ductal Carcinomas and Its Relationship to Clinicopathologic Factors

Alexandra Kalogeraki; Francesco Garbagnati; Mario Santinami; Odyseas Zoras

OBJECTIVE To evaluate E-cadherin expression on fine needle aspiration biopsies (FNAB) of breast ductal invasive carcinomas and to correlate that expression with the grade of the tumors, axillary lymph node status, primary tumor size, menopausal status, estrogen-progesterone receptors and Bcl-2 expression. STUDY DESIGN One hundred female patients ranging in age from 25 to 82 underwent FNAB under ultrasound guidance and were diagnosed as having breast carcinomas. Biopsy was done with 22-gauge Chiba needles under local anesthesia. All FNAB specimens were stained using Papanicolaou and Giemsa stain, diagnosed cytologically as ductal invasive breast carcinomas and confirmed histologically postoperatively. E-cadherin (L-CAM), monoclonal mouse IgG1, primary antibodies ER (clone 1D5), PGR (clone PGR) and Bcl-2 monoclonal antibody (clone 124) were used. Immunostaining was performed using the alkaline phosphatase method. RESULTS The expression (transmembrane) of E-cadherin was found in 66 (66%) cases. Decreased expression of E-cadherin statistically correlated (P < .005) (chi 2 test) with high grade (grade 3) tumors (26.6%), axillary lymph node metastasis (42.2%) (according to the TNM classification), premenopausal status (43.1%), negative estrogen-progesterone receptors (49.1% and 41%, respectively) and negative Bcl-2 expression (32.2%). No relationship was found between E-cadherin expression and primary tumor size. CONCLUSION E-cadherin evaluation on FNAB specimens can be helpful in preoperatively predicting tumor cell differentiation and invasiveness, defining a population of patients with breast ductal carcinomas and a possible poor outcome, and should be taken into consideration in management of the disease.


Cancer | 2002

DNA fragmentation and cell proliferation correlated with tumor grade in patients with hepatocellular carcinoma

Alexandra Kalogeraki; Francesco Garbagnati; Mario Santinami; Odysseas Zoras

DNA fragmentation and cell proliferation in patients with hepatocellular carcinoma (HCC) have not been well described on fine‐needle aspiration biopsies (FNABs). To investigate the contribution of apoptosis, a major mechanism of cell death, to the growth of HCC, the authors analyzed both apoptosis and cell proliferation in patients with HCC.


Toxicology Letters | 2017

The immunotoxicological pattern of subchronic and chronic benzene exposure in rats

A. V. Karaulov; Irina V. Mikhaylova; Alexander I. Smolyagin; Viktor M. Boev; Alexandra Kalogeraki; Aristides M. Tsatsakis; Ayse Basak Engin

Exposure to benzene and its inevitable metabolites can result in deleterious effects on human health, including lymphocytopenia, hematotoxicity and cancer. However, the duration of exposure might alter the effects including immune consequences. The aim of this study was to determine whether benzene could modulate lymphocyte proliferation induced by the T cell mitogen concanavalin A, in rats, at different exposure durations. 386 Wistar rats were assigned into control and treatment groups which were subdivided into groups for 45, 90 and 135days for 0,6mL/kg of drinking water mixed benzene treatment. The percentage of CD3+, CD4+, CD8+ spleen lymphocytes was defined using the flow cytometer. Interleukin (IL)-4, IL-6, IL-10 and interferon-gamma, in supernatants of splenocyte cultures stimulated with Concanavalin A, were assessed by enzyme-linked immunosorbent assay (ELISA) technique. The decrease in the total lymphocyte and T cell counts were associated with increased benzene exposure duration. Th2-type cytokine, IL-4 significantly increased, whereas IL-6, CD4+T cells, CD4+/CD8+ ratio and CD3+ T cells decreased. Despite the positive correlation between benzene toxicity and indicated increased immune responses, 45-day exposure to benzene appeared to be the most sensitive time point for evaluating benzene cytotoxicity.


Romanian Journal of Internal Medicine | 2016

EUS - Fine- Needle Aspiration Biopsy (FNAB) in the Diagnosis of Pancreatic Adenocarcinoma: A Review.

Alexandra Kalogeraki; Georgios Z. Papadakis; Dimitrios Tamiolakis; Iliana Karvela-Kalogeraki; Mihailos Karvelas-Kalogerakis; John Segredakis; Michael Papadakis; Eleni Moustou; Galateia Datseri; Maria Tzardi

Solid masses of the pancreas represent a variety of benign and malignant neoplasms of the exocrine and endocrine tissues of the pancreas. A tissue diagnosis is often required to direct therapy in the face of uncertain diagnosis or if the patient is not a surgical candidate either due to advanced disease or comorbidities. Endoscopic ultrasound (EUS) is a relatively new technology that employs endoscopy and high-frequency ultrasound (US). EUS involves imaging of the pancreatic head and the uncinate from the duodenum and imaging of the body and tail from the stomach. It has been shown to be a highly sensitive method for the detection of pancreatic masses. It is superior to extracorporeal US and computed tomographic (CT) scans, especially when the pancreatic tumor is smaller than 2-3 cm. Although EUS is highly sensitive in detecting pancreatic solid masses, its ability to differentiate between inflammatory masses and malignant disease is limited. Endoscopic retrograde cholangiopancreatography (ERCP) brushing, CT-guided biopsies, and transabdominal ultrasound (US) have been the standard nonsurgical methods for obtaining a tissue diagnosis of pancreatic lesions, but a substantial false-negative rate has been reported. Transabdominal US-guided fine-needle aspiration biopsy (US-FNAB) has been used for tissue diagnosis in patients with suspected pancreatic carcinoma. It has been shown to be highly specific, with no false-positive diagnoses. With the advent of curvilinear echoendoscopes, transgastric and transduodenal EUS-FNAB of the pancreas have become a reality EUS with FNAB has revolutionized the ability to diagnose and stage cancers of the gastrointestinal tract and assess the pancreas. Gastrointestinal cancers can be looked at with EUS and their depth of penetration into the intestinal wall can be determined. Any suspicious appearing lymph nodes can be biopsied using EUS/FNAB. The pancreas is another organ that is well visualized with EUS. Abnormalities such as tumors and cysts of the pancreas can be carefully evaluated using EUS and then biopsied with FNAB. There are many new applications of EUS using FNAB. Researchers are looking to deliver chemotherapeutics into small pancreatic cancers and cysts. Nerve blocks using EUS/FNAB to inject numbing medicines into the celiac ganglia, a major nerve cluster, are now routinely performed in patients with pain due to pancreatic cancer. The aim of this study is to perform a review of the literature regarding the usefulness of EUS/FNAB in the diagnosis of pancreatic adenocarcinoma.

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